bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing transferability of ecological models: an underappreciated aspect of statistical validation
Authors: Wenger Seth J. , Olden Julian D.
Published: January 2012

1. Ecologists have long sought to distinguish relationships that are general from those that are idiosyncratic to a narrow range of conditions. Conventional methods of model validation and selection assess in‐ or out‐of‐sample prediction accuracy but do not assess model generality or transferability, which can lead to overestimates of performance when predicting in other locations, time periods or data sets.

2. We propose an intuitive method for evaluating transferability based on techniques currently in use in the area of species distribution modelling. The method involves cross‐validation in which data are assigned non‐randomly to groups that are spatially, temporally or otherwise distinct, thus using heterogeneity in the data set as a surrogate for heterogeneity among data sets.

3. We illustrate the method by applying it to distribution modelling of brook trout (Salvelinus fontinalisMitchill) and brown trout (Salmo truttaLinnaeus) in western United States. We show that machine‐learning techniques such as random forests and artificial neural networks can produce models with excellent in‐sample performance but poor transferability, unless complexity is constrained. In our example, traditional linear models have greater transferability.

4. We recommend the use of a transferability assessment whenever there is interest in making inferences beyond the data set used for model fitting. Such an assessment can be used both for validation and for model selection and provides important information beyond what can be learned from conventional validation and selection techniques.
Cascade multivariate regression tree: a novel approach for modelling nested explanatory sets
Authors: Ouellette Marie‐Hélène , Legendre Pierre , Borcard Daniel
Published: January 2012

1. Ecological data analysis frequently calls for the assessment of the relationship between species composition and a set of explanatory variables of interest. The assessment may have to be pursued while taking into account the influence of another set of explanatory variables. The hypothetical nature and structure of the influence of an explanatory set on the effect of a distinct explanatory set guides the proper choice of modelling methodology for a combined explanatory assessment.

2. Here, we describe a framework where the relationship between the response data and a main set of explanatory variables is not linear. It may, for example, take the form of abrupt changes in the response following thresholds of the explanatory variables, or any other nonlinearizable relationship. The influence of a second set of explanatory variables is determined a posteriori, after the influence of the main explanatory set has been taken into account. This is useful when one of the sets is thought to have an effect that varies as a function of the other.

3. To achieve this type of assessment, we propose a cascade of multivariate regression trees (CMRT). We decompose the total dispersion of a response matrix between two explanatory data sets in a nested manner. By handling each leaf (group) resulting from the first‐level multivariate regression tree (MRT) analysis as separate independent data sets in following analyses, we can separate the explanatory power of the first partition from those of the subordinate partitions computed using a second explanatory set. A preliminary biological hypothesis will guide the choice of which set of explanatory variables should be used to compute the main partition. The method could be extended to more than two explanatory data sets whose effects on the response data are hierarchical.

4. Cascade of multivariate regression trees allows the users to impose a nested structure to their causal hypotheses in MRT analysis. To illustrate this new procedure, we use the well‐known and readily available Doubs fish and oribatid mite data sets and provide the necessary R functions in a package available on CRAN (http://cran.r‐project.org).
Practice other than playing games apparently has only a modest role in the development of chess expertise
Authors: Howard Robert W.
Published: January 2012

Evidence that chess expertise rests on practice alone mostly comes from studies using a correlational retrospective recall paradigm, which confounds amount of study with number of games played and possible innate talent. Researchers also often use latest performance rating and include participants who play and study little. Study 1 partially replicated such studies with improvements such as use of peak rating and a large, skilled sample. Number of internationally‐rated games played was the strongest predictor of peak rating. Total study hours was a significant but weaker predictor. Study 2 controlled for sampling confounds by including only very well‐practiced players who had played at least 350 internationally‐rated games. Total study hours did not predict rating at 350 games. Study 3 found that the subjective phenomenon of reaching a performance ceiling and undertaking specific practice to get beyond it does occur but does not distinguish between stronger and weaker players. Study 4 found that many players play relatively few internationally‐rated games mostly because of other commitments, such as work and education. Extensive study may go along with great interest in and persistence at chess but apparently lacks a major causative role in chess performance level.
Manipulation of Thermal Emission by Use of Micro and Nanoscale Structures
Authors: Hasman Erez , Kleiner Vladimir , Dahan Nir , Gorodetski Yuri , Frischwasser Kobi , Balin Igal
Published: January 2012

In high temperature and vacuum applications, for which heat transfer is predominantly by radiation, the material’s surface texture is of substantial importance. Several micro and nanostructures designs have been proposed to enhance a material’s emissivity and its radiative coherence. Control of thermal emission is of crucial concern in the design of infrared sources, in electronic chip coolants, in high-efficiency photovoltaic cells, and in solar energy conversion. In this review paper, we present microscale and nanoscale structures supporting surface waves for obtaining polarization manipulation of thermal emission, extraordinary coherent thermal radiation, bandgap in the spectral emission, spin symmetry breaking of coupled thermal antenna array, and a broadband infrared absorption.
Near-field light focusing by a slit array in a planar metal film with nonuniform slit dielectric material
Authors: David Wellems L. , Huang Danhong
Published: January 2012

We study the interference of evanescent electromagnetic waves generated from multi-slits in a metal film and demonstrate the anomalous bending of light at infrared frequencies due to negative refraction. We also calculate the diffraction of an incident plane electromagnetic waves by a metallic film with an arbitrary linear array of slits, slit separation, and slit dielectric material. In contrast to a double-convex shaped quartz lens, we show that a planar metallic film with a one-dimensional slit array can also focus polarized light in the near-field region when either the slit width or the slit dielectric material becomes spatially nonuniform.
Resource Letter AFHEP-1: Accelerators for the Future of High-Energy Physics
Authors: Barletta William A.
Published: January 2012

This Resource Letter provides a guide to literature concerning the development of accelerators for the future of high-energy physics. Research articles, books, and Internet resources are cited for the following topics: motivation for future accelerators, present accelerators for high-energy physics, possible future machine, and laboratory and collaboration websites.
On Klein tunneling in graphene
Authors: Robinson T. R.
Published: January 2012

The essential features of Klein tunneling of massless fermions in graphene may be treated in one dimension without the need for Dirac spinors. Two dimensions needs a spinor treatment and is investigated numerically, which lets us compare tunneling through smooth potential barriers with that through idealized step potentials.
Student understanding of energy: Difficulties related to systems
Authors: Lindsey Beth A. , Heron Paula R. L. , Shaffer Peter S.
Published: January 2012

Choosing a system of interest and identifying the interactions of the system with its environment are crucial steps in applying the relation between work and energy. Responses to problems that we administered in introductory calculus-based physics courses show that many students fail to recognize the implications of a particular choice of system. In some cases, students do not believe that particular groupings of objects can even be considered to be a system. Some errors are more prevalent in situations involving gravitational potential energy than elastic potential energy. The difficulties are manifested in both qualitative and quantitative reasoning.
Undergraduate experiment in superconductor point-contact spectroscopy with a Nb/Au junction
Authors: Janson Lucas , Klein Matthew , Lewis Heather , Lucas Andrew , Marantan Andrew , Luna Katherine
Published: January 2012

We describe an experiment in superconductivity suitable for an advanced undergraduate laboratory. Point-contact spectroscopy is performed by measuring the differential conductance between an electrochemically etched gold tip and a 100-nm thick superconducting niobium film with a transition temperature Tc ≈ 7 K. By fitting the results to Blonder–Tinkham–Klapwijk theory using a finite lifetime of quasiparticles, we obtain a superconducting gap energy Δ ≈ 1.53 meV, a lower bound to the Fermi velocity vF ≥ 3.1 × 107 cm/s, and a BCS coherence length ξ ≈ 43 nm for niobium. These results are in good agreement with previous measurements.
Meissner effect, diamagnetism, and classical physics—a review
Authors: Essén Hanno , Fiolhais Miguel C. N.
Published: January 2012

We review the literature on what classical physics says about the Meissner effect and the London equations. We discuss the relevance of the Bohr-van Leeuwen theorem for the perfect diamagnetism of superconductors and conclude that the theorem is based on invalid assumptions. We also point out results in the literature that show how magnetic flux expulsion from a sample cooled to superconductivity can be understood as an approach to the magnetostatic energy minimum. These results have been published several times but many textbooks on magnetism still claim that there is no classical diamagnetism, and virtually all books on superconductivity repeat Meissner’s 1933 statement that flux expulsion has no classical explanation.
Charge and Energy Stored in a Capacitor
Authors: Kraftmakher Yaakov
Published: January 2012

Using a data-acquisition system, the charge and energy stored in a capacitor are measured and displayed during the charging/discharging process. The experiment is usable as a laboratory work and/or a lecture demonstration.
Measuring the Effects of Lift and Drag on Projectile Motion
Authors: Cross Rod
Published: January 2012

The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces.1 The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms−1 (89.5 mph), it experiences a drag force of about 1.5 N. The gravitational force on the ball 1.42 N. Nevertheless, the trajectory of a baseball pitched without spin is not strongly affected by the drag force. Because the ball is relatively heavy and the flight distance is relatively small (about 60 ft), the drag force reduces the ball speed by only about 10% by the time it reaches the batter. As a result, the time taken for the ball to reach the batter is only about 5% longer than in a vacuum, and the actual trajectory is also very similar.2
Collisions with Springs: A Useful Context for the Study of Analytical Dynamics
Authors: Twomey Patrick , O'Sullivan Colm , O'Riordan John , Fahy Stephen
Published: January 2012

A recent paper1 in this journal describes an experimental demonstration of the conservation of total momentum before, during, and after an elastic collision between two bodies. The experiment also appears to show that total kinetic energy is conserved in the process, including during the collision. There is a danger that this may give rise to some misconception given that, in any collision that takes place over a finite time, some kinetic energy must transfer to potential energy—albeit temporarily in the case of an elastic collision. Indeed, when a collision is observed in the c.m. frame, all kinetic energy is lost momentarily. The sequence of simple experiments described below, which can be performed using standard equipment available in undergraduate laboratories, was developed so that undergraduate students could study a collision process in some detail. It was designed to enable students to gain insight into a range of important ideas in elementary analytical dynamics, including conservation of momentum, energy transfer in inelastic collisions, and coefficient of restitution. An extension of the experiment also gives insight into wave propagation in elastic media.
How Einstein Discovered E=mc2
Authors: Hecht Eugene
Published: January 2012

This paper traces Einstein's discovery of “the equivalence of mass [m] and energy [E0].” He came to that splendid insight in 1905 while employed by the Bern Patent Office, at which time he was not an especially ardent reader of physics journals. How then did the young savant, working outside of academia in semi-isolation, realize that these two seemingly disparate concepts were actually “identical”? Until now little attention has been given to exploring the physics that guided his thinking in this remarkable endeavor. That work culminated (1907) in the equation E0=mc2, where E0 is “rest energy” and m is “invariant mass.” Despite claims to the contrary, Einstein did not write this equation, or its ambiguous variant,1 E=mc2, in 1905. Furthermore, we will propose a compelling reason for his otherwise inexplicable caution. This paper is meant to help clarify the contemporary literature in the service of an informed pedagogy.
Discovery Garden — Physics and Architecture Meet Outside to Talk
Authors: Tabor-Morris Anne , Briles Timothy , Froriep Kathleen , McGuire Catherine
Published: January 2012

The purpose of Georgian Court University's “Discovery Garden” is to create an experience of the physical sciences for students, both science and non-science majors, in a place of serenity: an outdoor garden. Why a garden? Consider that the traditional laboratory experience for students is one of stark rooms ventilated with noisy hoods and endemic with lab coats and safety glasses, an alien environment that can be a source of anxiety for some students studying science, while the idea of a garden excites the imagination and conjures peace. The garden also serves as a reminder that ideas learned in the classroom apply to the everyday world. In addition, the garden is a model of informal learning, which can be especially interesting for pre-service teachers. Outlined here are some general suggestions for the design of a science garden, applicability of educational philosophy to full-body experiences, and activities suggested for students and future teachers in such a garden, as well as a mini-tour of our garden.
Millikan's Oil-Drop Experiment: A Centennial Setup Revisited in Virtual World
Authors: Gagnon Michel
Published: January 2012

Early in the last century, Robert Millikan developed a precise method of determining the electric charge carried by oil droplets.1–3 Using a microscope and a small incandescent lamp, he observed the fall of charged droplets under the influence of an electric field inside a small observation chamber. In so doing, Millikan demonstrated the existence of a fundamental unit of electric charge, and established its quantization. Now renowned as one of the most famous experiments of 20th-century physics, Millikan's oil-drop experiment has been reproduced with more or less success in most, if not all, high school and university physics classes. This has encouraged many improvements of the apparatus, now making this experiment much more accurate and easier to realize for advanced students. However, the required apparatus remains rather expensive, and for introductory college or high school students the experiment is still quite difficult to conduct. As an alternative to the traditional setup, a realistic computer-based simulator to replicate the Millikan oil-drop experiment has been developed. Using this software, students are able to undertake a complete experiment, obtain an accurate set of results, and thus gain a better understanding of the original experiment and its historical importance.
Modeling Physical Systems Using Vensim PLE Systems Dynamics Software
Authors: Widmark Stephen
Published: January 2012

Many physical systems are described by time-dependent differential equations or systems of such equations. This makes it difficult for students in an introductory physics class to solve many real-world problems since these students typically have little or no experience with this kind of mathematics. In my high school physics classes, I address this problem by having my students use a variety of software solutions to model physical systems described by differential equations. These include spreadsheets, applets, software my students themselves create, and systems dynamics software.1 For the latter, cost is often the main issue in choosing a solution for use in a public school and so I researched no-cost software. I found Sphinx SD,2OptiSim,3 Systems Dynamics,4 Simile (Trial Edition),5 and Vensim PLE.6 In evaluating each of these solutions, I looked for the fewest restrictions in the license for educational use, ease of use by students, power, and versatility. In my opinion, Vensim PLE best fulfills these criteria.7
Electrochemical preparation of poly(vinylferrocenium)perchlorate-polyaniline composite-modified platinium electrode in methylene chloride
Authors: Kavanoz Muammer , Şen Mine , Pekmez Nuran Özçiçek
Published: January 2012

A new surface based on poly(vinylferrocenium)perchlorate-polyaniline (PVF+ClO4–-PANI) composite-modified platinum electrode was prepared electrochemically to combine the electrocatalytic properties of an intrinsically conducting polymer and a redox polymer. The composite film was synthesized as a bilayer from individual polymerization solutions. Furthermore, PVF+ClO4– and PANI polymers were simultaneously deposited as a mixture from a methylene chloride solution containing PVF polymer and aniline monomer on Pt electrode. When PVF+ClO4– and PANI were codeposited by cycling the potential between 0.20 and 1.80 V vs Ag|AgCl, these polymers were encapsulated within each other. The encapsulation of PVF+ClO4– inside the growing PANI polymer provided the retainment of PVF+ClO4– on the electrode surface even if it was in dedoped form (PVF). This composite film was characterized by cyclic voltammetry, FTIR, SEM and conductivity measurements. The response of the composite film to catechol and hydroquinone was investigated by chronocoulometry in aqueous medium. It was found that the increase in charge consumption for catechol and hydroquinone was observed up to 7.5 and 5.0 times, respectively, when compared to that of PANI film. This might be due to the presence of PVF+ClO4– in the composite film, which played an important role in accelerating the electron transfer.
Voltammetric determination of flutamide and its metabolite 4-nitro-3-trifluoromethylaniline at a hanging mercury drop minielectrode
Authors: Pecková Karolina , Průchová Markéta , Moreira Josino C. , Barek Jiří , Fischer Jan , Vyskočil Vlastimil
Published: January 2012

Optimum conditions were found for direct current and differential pulse voltammetric determination of anticancer drug Flutamide and its main metabolite 4-nitro-3-trifluoromethylaniline on a hanging mercury drop minielectrode in mixed Britton–Robinson buffer (pH 12.0)–methanol (9:1) or 0.01MNaOH–methanol (9:1) media with limit of quantitation ca. 10–7mol l–1. It was proved that the newly developed method is applicable for the determination of Flutamide in pharmaceutical formulations and for the determination of both Flutamide and 4-nitro-3-trifluoromethylaniline in urine either directly with limit of quantitation ca. 10–5mol l–1or after solid phase extraction with limit of quantitation in the 10–7mol l–1concentration range. The sufficient peak potential difference of the two substances suggests the possibility of the analysis of their mixtures.
Studies on Formation and Decomposition of the Layered Cobaltite LixNayCoO2
Authors: Semenova A. S. , Samigullina R. F. , Shalaeva E. V. , Kourov N. I. , Kellerman D. G.
Published: January 2012

Lithium-sodium cobaltite LixNayCoO2(x≈y≈0.5) with ordered layered structure is promising thermoelectric material. Here we report the peculiarities of this phase formation and decomposition processes studied by TG/DTA, XRD, SEM, and TEM methods. Significant weight loss resulting from oxygen liberation and endothermic effect atT≈1000°C are the main features of the LixNayCoO2formation. Decomposition of the ordered phase is accompanied by exothermic effect at≈940°C and the weight increase. Electron microscopic study shows that the lithium-sodium cobaltite decomposes into LiCoO2and γ-Na0.7CoO2. Lattices of the initial phase and formed ones demonstrate mutual orientation.
Multiple, Unilateral Lisch Nodules in the Absence of Other Manifestations of Neurofibromatosis Type 1
Authors: Adams E. G. , Stewart K. M. A. , Borges O. A. , Darling T.
Published: January 2012

Lisch nodules associated with Neurofibromatosis Type 1 (NF1) are usually multiple and bilateral in nature. Here, we report a 21-year-old healthy, Caucasian female who was diagnosed with multiple, unilateral Lisch nodules during routine eye examination. A thorough history and physical examination revealed no other signs of NF1. We diagnosed the rare occurrence of numerous, unilateral Lisch nodules in the absence of additional features of NF1 in our patient and provide a discussion concerning the differential diagnosis of Lisch nodules as well as the potential genetic explanation of this finding.
Comparison between Satellite Water Vapour Observations and Atmospheric Models’ Predictions of the Upper Tropospheric Thermal Radiation
Authors: Dim J. R. , Nakajima T. Y. , Takamura T. , Kikuchi N.
Published: January 2012

Atmospheric profiles (temperature, pressure, and humidity) are commonly used parameters for aerosols and cloud properties retrievals. In preparation of the launch of the Global Change Observation Mission-Climate/Second-Generation GLobal Imager (GCOM-C/SGLI) satellite, an evaluation study on the sensitivity of atmospheric models to variations of atmospheric conditions is conducted. In this evaluation, clear sky and above low clouds water vapour radiances of the upper troposphere obtained from satellite observations and those simulated by atmospheric models are compared. The models studied are the Nonhydrostatic ICosahedral Atmospheric Model (NICAM) and the National Center for Environmental Protection/Department Of Energy (NCEP/DOE). The satellite observations are from the Terra/Moderate Resolution Imaging Spectroradiometer (Terra/MODIS) satellite. The simulations performed are obtained through a forward radiative transfer calculation procedure. The resulting radiances are transformed into the upper tropospheric brightness temperature (UTBT) and relative humidity (UTRH). The discrepancies between the simulated data and the observations are analyzed. These analyses show that both the NICAM and the NCEP/DOE simulated UTBT and UTRH have comparable distribution patterns. However the simulations’ differences with the observations are generally lower with the NCEP/DOE than with the NICAM. The NCEP/DOE model outputs very often overestimate the UTBT and therefore present a drier upper troposphere. The impact of the lower troposphere instability (dry convection) on the upper tropospheric moisture and the consequences on the models’ results are evaluated through a thunderstorm and moisture predictor (the K-stability index). The results obtained show a positive relation between the instability and the root mean square error (RMSE: observation versus models). The study of the impact of convective clouds shows that the area covered by these clouds increases with the humidity of the upper troposphere in clear sky and above low clouds, and at the same time, the error between the observations and the models also increases. The impact of the above low clouds heat distribution on the models is studied through the relation between the low clouds cover and their effective emissivity. The models’ error appears to be high at midrange effective emissivity clouds.
Environmental Influences on South African Fish Catch: South Coast Transition
Authors: Jury Mark R.
Published: January 2012

This study considers environmental factors influencing aggregate fish catch in the South Coast transition of South Africa. The environmental forcing is studied via (i) seasonal analysis of SeaWifs chlorophyll and related variables, (ii) composite analysis of atmospheric and oceanographic reanalysis data, (iii) statistical analysis of annual FAO fish catch with climatic indices, and (iv) analysis of depth-latitude hydrographic sections over the shelf (33–36S, 22–26E). In years of higher fish catch there is a northward shift of the subtropical anticyclones and upwelling that is partially related to Pacific El Nino. Westerly troughs skirt the Agulhas Bank creating onshore Ekman transport. Higher sea surface height inshore, and cooler sea temperatures and lower salinity offshore induce a gradient that weakens the Agulhas Current. These environmental conditions favour the southeastward migration of juvenile fish from west to south coast. A multivariate model of aggregate fish stocks, using four environmental variables: salinity and zonal currents in the Agulhas Current, sea temperature in the Agulhas source region, and geopotential height over the Cape, accounts for 53% of variance at 0-1 year lead. Freshening of the boundary current is a factor influencing aggregate fish catch in the South Coast transition.
The Plasma Membrane Potential and the Organization of the Actin Cytoskeleton of Epithelial Cells
Authors: Chifflet Silvia , Hernández Julio A.
Published: January 2012

The establishment and maintenance of the polarized epithelial phenotype require a characteristic organization of the cytoskeletal components. There are many cellular effectors involved in the regulation of the cytoskeleton of epithelial cells. Recently, modifications in the plasma membrane potential (PMP) have been suggested to participate in the modulation of the cytoskeletal organization of epithelia. Here, we review evidence showing that changes in the PMP of diverse epithelial cells promote characteristic modifications in the cytoskeletal organization, with a focus on the actin cytoskeleton. The molecular paths mediating these effects may include voltage-sensitive integral membrane proteins and/or peripheral proteins sensitive to surface potentials. The voltage dependence of the cytoskeletal organization seems to have implications in several physiological processes, including epithelial wound healing and apoptosis.
On Extremal Self-Dual Ternary Codes of Length 48
Authors: Nebe Gabriele
Published: January 2012

All extremal ternary self-dual codes of length 48 that have some automorphism of prime order are equivalent to one of the two known codes, the Pless code or the extended quadratic residue code.
Electromechanical and Dynamic Characterization of In-House-Fabricated Amplified Piezo Actuator
Authors: Panda P. K. , Sahoo B. , Raja S. , M. P. Vijaya Kumar , Shankar V.
Published: January 2012

A diamond-shaped amplified piezo actuator (APA) fabricated using six multilayered piezo stacks with maximum displacement of 173 μm at 175 V and the amplification factor of 4.3. The dynamic characterization of the actuator was carried out at different frequencies (100 Hz–1 kHz) and at different AC voltages (20 V–40 V). The actuator response over this frequency range was found neat, without attenuation of the signal. Numerical modeling of multilayered stack actuator was carried out using empirical equations, and the electromechanical analysis was carried out using ABAQUS software. The block force of the APA was 81 N, calculated by electromechanical analysis. This is similar to that calculated by dynamic characterization method.
480 MHz 10‐tap Clock Generator Using Edge‐Combiner DLL for USB 2.0 Applications
Authors: Kawamoto Takashi , Ueda Kazuhiro , Noto Takayuki
Published: January 2012

A clock generator with an edge‐combiner DLL (ECDLL) has been developed for USB 2.0 applications. The clock generator generates 480 MHz 10‐tap output signals from a 12 MHz reference signal and consists of three DLLs to shrink the design area so that it is smaller than a conventional one based on a PLL. Each DLL is applied to our proposed shot pulse reset technique to prevent from a harmonic lock and is applied to a voltage‐controlled delay line (VCDL) with a trimming function to operate against any process voltage temperature (PVT) variations. A 90 nm CMOS process was used to fabricate our proposed clock generator. The 480 MHz 10‐tap output signals satisfy the USB 2.0 specifications. A power consumption is less than 1.3 mW and a locking time is less than 3.5 μs, which are far less than a conventional one, 10.0 μs. The design area is 200 × 225 μm, which is half that of the conventional one.
Influence of Synthesis pH on Textural Properties of Carbon Xerogels as Supports for Pt/CXs Catalysts for Direct Methanol Fuel Cells
Authors: Alegre C. , Gálvez M. E. , Sebastián D. , Moliner R. , Lázaro M. J.
Published: January 2012

Carbon xerogels (CXs) have been prepared by polycondensation of resorcinol and formaldehyde. Two synthesis pHs were studied in order to evaluate its influence on the electrochemical behaviour of Pt catalysts supported on previous carbon xerogels, synthesized by conventional impregnation method. Catalysts were also synthesized over a commercial carbon black (Vulcan-XC-72R) for comparison purposes. Characterization techniques included nitrogen physisorption, scanning electron microscopy, and X-ray diffraction. Catalysts electrochemical activity towards the oxidation of carbon monoxide and methanol was studied by cyclic voltammetry and chronoamperometry to establish the effect of the carbon support on the catalysts performance. Commercial Pt/C catalyst (E-TEK) was analyzed for comparison purposes. It was observed that the more developed and mesopore-enriched porous structure of the carbon xerogel synthesized at a higher initial pH resulted in an optimal utilization of the active phase and in an enhanced and promising catalytic activity in the electrooxidation of methanol, in comparison with commercial catalysts.
Clinical Features and Polysomnographic Findings in Greek Male Patients with Obstructive Sleep Apnea Syndrome: Differences Regarding the Age
Authors: George Efremidis , Katerina Varela , Maria Spyropoulou , Lambros Beroukas , Konstantina Nikoloutsou , Dimitrios Georgopoulos
Published: January 2012

Background-Aim. Although sleep disturbance is a common complaint among patients of all ages, research suggests that older adults are particularly vulnerable. The aim of this retrospective study was to elucidate the influence of age on clinical characteristics and polysomnographic findings of obstructive sleep apnea syndrome (OSAS) between elderly and younger male patients in a Greek population.Methods. 697 male patients with OSAS were examined from December 2001 to August 2011. All subjects underwent an attended overnight polysomnography (PSG). They were divided into two groups: young and middle-aged (<65 years old) and elderly (≥65 years old). We evaluated the severity of OSAS, based on apnea-hypopnea index (AHI), and the duration of apnea-hypopnea events, the duration of hypoxemia during total sleep time (TST) and during REM and NREM sleep, and the oxygen saturation in REM and in NREM sleep.Results. PSG studies showed that elderly group had significant higher duration of apnea-hypopnea events, longer hypoxemia in TST and in NREM sleep, as well as lower oxygen saturation in REM and NREM sleep than the younger group. Otherwise, significant correlation between BMI and neck circumference with AHI was observed in both groups.Conclusions. The higher percentages of hypoxemia during sleep and longer duration of apnea-hypopnea events that were observed in the elderly group might be explained by increased propensity for pharyngeal collapse and increased deposition of parapharyngeal fat, which are associated with aging. Another factor that could explain these findings might be a decreased partial arterial pressure of oxygen (PaO2) due to age-related changes in the respiratory system.
Optimal Conditions for Continuous Immobilization of Pseudozyma hubeiensis (Strain HB85A) Lipase by Adsorption in a Packed-Bed Reactor by Response Surface Methodology
Authors: Bussamara Roberta , Dall'Agnol Luciane , Schrank Augusto , Fernandes Kátia Flávia , Vainstein Marilene Henning
Published: January 2012

This study aimed to develop an optimal continuous process for lipase immobilization in a bed reactor in order to investigate the possibility of large-scale production. An extracellular lipase of Pseudozyma hubeiensis (strain HB85A) was immobilized by adsorption onto a polystyrene-divinylbenzene support. Furthermore, response surface methodology (RSM) was employed to optimize enzyme immobilization and evaluate the optimum temperature and pH for free and immobilized enzyme. The optimal immobilization conditions observed were 150 min incubation time, pH 4.76, and an enzyme/support ratio of 1282 U/g support. Optimal activity temperature for free and immobilized enzyme was found to be 68°C and 52°C, respectively. Optimal activity pH for free and immobilized lipase was pH 4.6 and 6.0, respectively. Lipase immobilization resulted in improved enzyme stability in the presence of nonionic detergents, at high temperatures, at acidic and neutral pH, and at high concentrations of organic solvents such as 2-propanol, methanol, and acetone.
Is Collective Efficacy Age Graded? The Development and Evaluation of a New Measure of Collective Efficacy for Older Adults
Authors: Galinsky Adena M. , Cagney Kathleen A. , Browning Christopher R.
Published: January 2012

Objectives. Community processes are key determinants of older adults’ ability to age in place, but existing scales measuring these constructs may not provide accurate, unbiased measurements among older adults because they were designed with the concerns of child-rearing respondents in mind. This study examines the properties of a new theory-based measure of collective efficacy (CE) that accounts for the perspectives of older residents.Methods. Data come from the population-based Chicago Neighborhood Organization, Aging and Health study (N = 1,151), which surveyed adults aged 65 to 95. Using descriptive statistics, correlations, and factor analysis, we explored the acceptability, reliability, and validity of the new measure.Results. Principal component analysis indicated that the new scale measures a single latent factor. It had good internal consistency reliability, was highly correlated with the original scale, and was similarly associated with neighborhood exchange and disorder, self-rated health, mobility, and loneliness. The new scale also showed less age-differentiated nonresponse compared to the original scale.Discussion. The older adult CE scale has reliability and validity equivalent to that of the existing measure but benefits from a more developed theoretical grounding and reduced likelihood of age-related differential nonresponse.
Structure, Expression, and Function of ICAM-5
Authors: Yang Heping
Published: January 2012

Cell adhesion is of utmost importance in normal development and cellular functions. ICAM-5 (intercellular adhesion molecule-5, telencephalin, TLN) is a member of the ICAM family of adhesion proteins. As a novel cell adhesion molecule, ICAM-5 shares many structural similarities with the other members of IgSF, especially the ICAM subgroup; however, ICAM-5 has several unique properties compared to the other ICAMs. With its nine extracellular Ig domains, ICAM-5 is the largest member of ICAM subgroup identified so far. Therefore, it is much more complex than the other ICAMs. The expression of ICAM-5 is confined to the telencephalic neurons of the central nervous system whereas all the other ICAM members are expressed mostly by cells in the immune and blood systems. The developmental appearance of ICAM-5 parallels the time of dendritic elongation and branching, and synapse formation in the telencephalon. As a somatodendrite-specific adhesion molecule, ICAM-5 not only participates in immune-nervous system interactions, it could also participate in neuronal activity, Dendrites’ targeting signals, and cognition. It would not be surprising if future investigations reveal more binding partners and other related functions of ICAM-5.
Medicinal Plants Used by Various Tribes of Bangladesh for Treatment of Malaria
Authors: Rahmatullah Mohammed , Hossan Shahadat , Khatun Afsana , Seraj Syeda , Jahan Rownak
Published: January 2012

It has been estimated that 300–500 million malaria infections occur on an annual basis and causes fatality to millions of human beings. Most of the drugs used for treatment of malaria have developed drug-resistant parasites or have serious side effects. Plant kingdom has throughout the centuries proved to be efficient source of efficacious malarial drugs like quinine and artemisinin. Since these drugs have already developed or in the process of developing drug resistance, it is important to continuously search the plant kingdom for more effective antimalarial drugs. In this aspect, the medicinal practices of indigenous communities can play a major role in identification of antimalarial plants. Bangladesh has a number of indigenous communities or tribes, who because of their living within or in close proximity to mosquito-infested forest regions, have high incidences of malaria. Over the centuries, the tribal medicinal practitioners have treated malaria with various plant-based formulations. The objective of the present study was to conduct an ethnomedicinal survey among various tribes of Bangladesh to identify the plants that they use for treatment of the disease. Surveys were conducted among seven tribes, namely, Bawm, Chak, Chakma, Garo, Marma, Murong, and Tripura, who inhabit the southeastern or northcentral forested regions of Bangladesh. Interviews conducted with the various tribal medicinal practitioners indicated that a total of eleven plants distributed into 10 families were used for treatment of malaria and accompanying symptoms like fever, anemia, ache, vomiting, and chills. Leaves constituted 35.7% of total uses followed by roots at 21.4%. Other plant parts used for treatment included barks, seeds, fruits, and flowers. A review of the published scientific literature showed that a number of plants used by the tribal medicinal practitioners have been scientifically validated in their uses. Taken together, the plants merit further scientific research towards possible discovery of novel compounds that can be used to successfully treat malaria with less undesirable sideeffects.
Two Case Reports of Familial Chylomicronemia Syndrome
Authors: Chen Yan-Hui , Ke Zhong-Ling , Wang Yan-Xia , Wang Yong , Zheng Yong-Zhi
Published: January 2012

Familial chylomicronemia is a rare autosomal recessive disorder which is also called Hyperlipoproteinemia type I. Here we report two cases with this rare disorder that were admitted to our hospital in recent years.
Digital Mapping of Soil Drainage Classes Using Multitemporal RADARSAT-1 and ASTER Images and Soil Survey Data
Authors: Niang Mohamed Abou , Nolin Michel , Bernier Monique , Perron Isabelle
Published: January 2012

Discriminant analysis classification (DAC) and decision tree classifiers (DTC) were used for digital mapping of soil drainage in the Bras-d’Henri watershed (QC, Canada) using earth observation data (RADARSAT-1 and ASTER) and soil survey dataset. Firstly, a forward stepwise selection was applied to each land use type identified by ASTER image in order to derive an optimal subset of soil drainage class predictors. The classification models were then applied to these subsets for each land use and merged to obtain a digital soil drainage map for the whole watershed. The DTC method provided better classification accuracies (29 to 92%) than the DAC method (33 to 79%) according to the land use type. A similarity measure (S) was used to compare the best digital soil drainage map (DTC) to the conventional soil drainage map. Medium to high similarities (0.6≤S<0.9) were observed for 83% (187 km2) of the study area while 3% of the study area showed very good agreement (S≥0.9). Few soil polygons showed very weak similarities (S<0.3). This study demonstrates the efficiency of combining radar and optical remote sensing data with a representative soil dataset for producing digital maps of soil drainage.
Robust Model Predictive Control Using Linear Matrix Inequalities for the Treatment of Asymmetric Output Constraints
Authors: Cavalca Mariana Santos Matos , Galvão Roberto Kawakami Harrop , Yoneyama Takashi
Published: January 2012

One of the main advantages of predictive control approaches is the capability of dealing explicitly with constraints on the manipulated and output variables. However, if the predictive control formulation does not consider model uncertainties, then the constraint satisfaction may be compromised. A solution for this inconvenience is to use robust model predictive control (RMPC) strategies based on linear matrix inequalities (LMIs). However, LMI-based RMPC formulations typically consider only symmetric constraints. This paper proposes a method based on pseudoreferences to treat asymmetric output constraints in integrating SISO systems. Such technique guarantees robust constraint satisfaction and convergence of the state to the desired equilibrium point. A case study using numerical simulation indicates that satisfactory results can be achieved.
Acute Muscle Trauma due to Overexercise in an Otherwise Healthy Patient with Cystic Fibrosis
Authors: Neubauer Henning , Wirth Clemens , Ruf Katharina , Hebestreit Helge , Beer Meinrad
Published: January 2012

Cystic fibrosis (CF) is one of the most common inherited diseases and is caused by mutations in the CFTR gene. Although the pulmonary and gastrointestinal manifestations of the disease remain in the focus of treatment, recent studies have shown expression of the CFTR gene product in skeletal muscle cells and observed altered intramuscular Ca2+release dynamics in CFTR-deficient animal models. Physical exercise is beneficial for maintaining fitness and well-being in CF patients and constitutes one aspect of modern multimodal treatment, which has considerably increased life span and reduced morbidity. We report on a case of acute muscle trauma resulting from excessive dumbbell exercise in a young adult with cystic fibrosis and describe clinical, laboratory and imaging characteristics of acute exercise-induced muscle injury.
Complex Etiology Underlies Risk and Survival in Head and Neck Cancer Human Papillomavirus, Tobacco, and Alcohol: A Case for Multifactor Disease
Authors: Smith Elaine M. , Rubenstein Linda M. , Haugen Thomas H. , Pawlita Michael , Turek Lubomir P.
Published: January 2012

Findings are inconsistent about whether tobacco, alcohol, and human papillomavirus (HPV) are two independent HNC risk factor groups that distinguish an infection-associated cancer from a tobacco/alcohol-associated HNC. We found that cancer in the oral cavity risk was greater in HPV-E6/E7 seropositive/heavy tobacco users (adjusted OR = 3.5) than in HPV-seronegative/heavy tobacco users (adjusted OR = 1.4); and HPV-seropositive/heavy alcohol users (adjusted OR = 9.8) had greater risk than HPV-seronegative/heavy alcohol users (adjusted OR = 3.1). In contrast, the risk of oropharyngeal cancer was greater in the HPV-seronegative/heavy tobacco (adjusted OR = 11.0) than in HPV-seropositive/heavy tobacco (adjusted OR = 4.7) users and greater in HPV-seronegative/heavy alcohol users (adjusted OR = 24.3) compared to HPV-seropositive/heavy alcohol users (adjusted OR = 8.5). Disease-specific and recurrence-free adjusted survival were significantly worse in oropharyngeal HPV-seronegative cases with no survival differences by HPV status seen in oral cavity cases. The association between tobacco/alcohol, HPV, and tumor site is complex. There appear to be distinct tumor site differences in the combined exposure risks, suggesting that different molecular pathways are involved.
Gender Differences in Modifying Lumbopelvic Motion during Hip Medial Rotation in People with Low Back Pain
Authors: Hoffman Shannon L. , Johnson Molly B. , Zou Dequan , Van Dillen Linda R.
Published: January 2012

Reducing increased or early lumbopelvic motion during trunk or limb movements may be an important component of low back pain treatment. The ability to reduce lumbopelvic motion may be influenced by gender. The purpose of the current study was to examine the effect of gender on the ability of people with low back pain to reduce lumbopelvic motion during hip medial rotation following physical therapy treatment. Lumbopelvic rotation and hip rotation before the start of lumbopelvic rotation were assessed pre- and posttreatment for 16 females and 15 males. Both men and women decreased lumbopelvic rotation and completed more hip rotation before the start of lumbopelvic rotation post-treatment compared to pre-treatment. Men demonstrated greater lumbopelvic rotation and completed less hip rotation before the start of lumbopelvic rotation than women both pre-andpost-treatment. Both men and women reduced lumbopelvic motion relative to their starting values, but, overall, men still demonstrated greater and earlier lumbopelvic motion. These results may have important implications for understanding differences in the evaluation and treatment of men and women with low back pain.
Some New Refined General Boas-Type Inequalities
Authors: Čižmešija A. , Pečarić J. , Pokaz D.
Published: January 2012

We state and prove a new refined Boas-type inequality in a setting with a topological space and generalσ-finite and finite Borel measures. As a consequence of the result obtained, we derive a new class of Hardy- and Pólya-Knopp-type inequalities related to balls inℝnand prove that constant factors involved in their right-hand sides are the best possible.
Heme Induction with Delta-Aminolevulinic Acid Stimulates an Increase in Water and Electrolyte Excretion
Authors: Quadri Syed , Jackson Debra W. , Prathipati Priyanka , Dean Courtney , Jackson Keith E.
Published: January 2012

Purpose. Studies were performed to examine hemodynamic and renal function before and after acute induction of the endogenous CO system with delta-aminolevulinic acid (DALA), which drives HO activity.Methods.In vivostudies were conducted on Inactin-anesthetized male Sprague Dawley rats (250–300 g) either with or without chronic pretreatment with L-NAME (50 mg/Kg, q12 hours x4d).Results. DALA (80 μmol/Kg, IV bolus) administration acutely increased endogenous CO production and HO-1 protein. In untreated and L-NAME-pretreated rats, DALA did not alter BP, GFR, or RBF but increased UF,UNaV, andUKV(untreated: Δ108.8 ± 0.28%, 172.1 ± 18.4%, and 165.2 ± 45.9%; pretreated: Δ109.4 ± 0.29%, 187.3 ± 26.9%, and 197.2 ± 45.7%). Acute administration of biliverdin (20 mg/kg, IV) and bilirubin (30 mg/kg, IV) to similarly treated animals did not alter UF,UNaV, andUKV.Conclusion. These results demonstrate that heme oxygenase induction increases urine and electrolyte excretion and suggest a direct tubular action of endogenous carbon monoxide.