bluuebunny/crossref_metadata_2025 huggingface dataset:
Osmotic Pressure in the Physics Course for Students of the Life Sciences
Authors: Hobbie Russell K.
Published: September 2005

Ideal gas models for equilibrium osmotic pressure and for nonequilibrium flow of solvent through an ideal semi-permeable membrane are presented. These models can easily be introduced in general physics courses for students of the life sciences. The models are justified in Appendices, which include a summary of the irreversible thermodynamics of flow through membranes. Some physiological examples are presented, including the Nernst equation and Gibbs-Donnan equilibrium.
Let There Be Light!
Authors: Onn David G. , Berg Richard A.
Published: September 2005

A new physics course devoted to phenomena of light and perception for nonscience majors is described. Content is related to student experience by reference to photography, atmospheric effects of light, Op Art, artist's techniques and palettes, optical illusions, color television, and other perception effects. The course features mixed teaching techniques within a preset schedule and includes a component of “hands-on” self-demonstrations and wide use of lecture demonstrations. Results of a professional course evaluation are presented, along with the curriculum and resource references. The success of the course is attested to by student re-enrollments in other physics courses.
The Poisson and Interval Distributions
Authors: Hinrichsen P. F.
Published: September 2005

A standard Geiger counter connected to a scalar and chart recorder is used to obtain data for the Poisson and interval distributions. By analysis of the same data for both distributions, the relation between them can be demonstrated, and many internal checks on the self-consistency of the data analysis can be performed. The appreciation of statistical uncertainties in nuclear counting is then applied to a test of the inverse square law for γ radiation over as large a range of distances as possible. Corrections for dead time and the limitations set by the background in nuclear measurements are demonstrated.
Resource Letter PE-1: Physics and the Environment
Authors: Shonle John I.
Published: September 2005

Prepared at the request of the AAPT Committee on Resource Letters. This is one of a series of Resource Letters on different topics intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and letters as well as suggestions for future topics will be welcomed. Please send such communications to Prof. Arthur Quinton, Chairman, Resource Letter Committee, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01002.
More Realistic Treatment of the Simple Pendulum without Difficult Mathematics
Authors: Miller B. J.
Published: September 2005

The damping phenomena in ordinary pendulums can be enhanced by using somewhat larger and less dense pendulum bobs than is usual. Convenient choices are shown to lead to damping behavior which definitely does not fit first power velocity damping, but gives a reasonable fit to square law velocity. A simple computer exercise is described which eventuates in a general law for amplitude decrease with square law damping. The same law is derived by analysis, but the computer approach requires much less mathematical background. Laboratory pendulums can be observed and their amplitude behavior satisfactorily compared to that predicted. A numerical measure of the damping force is thereby derived. The only measurements needed are measurements of successive pendulum amplitudes.
LCAO Molecular Orbitals in One Dimension
Authors: Lapidus I. Richard
Published: September 2005

A one-dimensional model with δ-function potentials is used to investigate the accuracy of approximations commonly used in the linear combination of atomic orbitals (LCAO) method for constructing molecular wavefunctions and determining molecular energies. Numerical evaluations of the errors are obtained for the one-dimensional analogue of butadiene.
Teaching Graduate Teaching Assistants to Teach
Authors: Muhlestein L. D. , DeFacio B.
Published: September 2005

A required course for graduate teaching assistants on improving the quality of instruction in the undergraduate laboratories is described. As a principal feature of the course, the graduate students improved existing laboratory experiments or developed new ones. Both self-evaluation and evaluation by faculty members were applied to the final products.
Resource Letter MPF-1: Mechanical Properties of Fluids
Authors: Stanley R. C.
Published: September 2005

Prepared at the request of the AAPT Committee on Resource Letters. This is one of a series of Resource Letters on different topics, intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and suggestions concerning the content and arrangement of letters as well as suggestions for future topics will be welcomed. Please send such communications to Professor Arthur Quinton, Chairman, Resource Letter Committee, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01002.

Notation: The letter E after an item indicates elementary level, useful principally for high school and introductory college use; the letter I indicates intermediate (junior, senior) level; and the letter A indicates advanced material principally suited for senior, graduate level. An asterisk (*) indicates items particularly recommended for introductory study.

Reprints: When ordering, request Resource Letter MPF-1, enclose 50 cents per copy (not in stamps) together with a stamped and self-addressed envelope, to Arnold A. Strassenberg, Executive Officer, American Association of Physics Teachers, Drawer AW, Stony Brook, New York 11790.
Fuel Economy of 1973 and 1974 Model Year Automobiles
Authors: Hodges Laurent
Published: September 2005

U. S. Environmental Protection Agency data on the fuel economy of 1973 and 1974 model year light-duty motor vehicles are summarized.
Albert Einstein and the Quantum Riddle
Authors: Landé Alfred
Published: September 2005

Einstein's “quantum riddle” is the almost forgotten problem of finding the ultimate reason for the quanta. It is solved here by deduction of quantum mechanics from three general postulates, those of symmetry, correspondence, and covariance, imposed on a general probabilistic connection between states. The derivation offers a systematic approach to the quantum mathematics and its teaching by trying to “comprehend the complexity and apparent disorder of Nature in the light of a supreme order” (Einstein).
Physics Instruction for Radiologic Technologists
Authors: Chaney Edward L. , Hendee William R. , Ibbott Geoffrey S. , Frank Mark N.
Published: September 2005

Traditionally, physics instruction in training programs for radiologic technologists has been inadequate for a number of reasons. Improvements are occurring, but slowly. To overcome difficulties inherent in traditional training techniques in Denver, the Denver Collaborative Training Program in Radiologie Technology was established in 1967. The Denver Program is a cooperative effort involving 18 metropolitan hospitals, the Community College of Denver, and the University of Colorado Medical Center. Physics instructors in the Denver Program are working together to identify a core of physics material essential to radiologie technologists, to prepare quality instructional materials in those areas of physics so identified, and to study innovative teaching techniques, including computer-assisted instruction and video tape presentations.
Training College Physics and Physical Science Teachers
Authors: Henderson R. B. , Neumann H. , Iona M. , Amme R. C.
Published: September 2005

The views of two-year and four-year colleges west of the Mississippi were surveyed on the need for and the best type of preservice training of future physics and physical science teachers, and job prospects in the next few years.
PSI Astronomy Unit: Astrology—The Space Age Science?
Authors: Zeilik Michael
Published: September 2005

This PSI unit may he used as a self-study guide or as part of a PSI or regular astronomy course to provide a simplified procedure for the casting of natal horoscopes.
Physics for Educationally Disadvantaged Students. II
Authors: Franklin Allan D. , Mohling Franz
Published: September 2005

We are reporting here on the second year of operation of a one-year introductory physics course for educationally disadvantaged students and on the performance of approximately 20 students who completed the course and continued on to a one-year modern physics course for nonmajors. Evaluation of student performance including comparison with other introductory physics students is given. Information on course enrollment, staffing, and format is included.
Advanced Undergraduate-Laboratory Experiment on Electron Spin Resonance in Single-Crystal Ruby
Authors: Collins Lee A. , Morrison Michael A. , Donoho Paul L.
Published: September 2005

An electron-spin-resonance experiment which has been successfully performed in the advanced undergraduate laboratory at Rice University is described. In this experiment, the ESR spectrum arising from Cr3+ ions in a single-crystal synthetic ruby is studied. Both the positions and the intensities of the observable resonance lines are measured, and the data are compared to the predictions of a theory based upon the use of a simple, effective-spin Hamiltonian for the Cr3+ ion. Although this experiment requires the use of apparatus not always available in undergraduate laboratories, it involves measurements on a quantum-mechanical system whose behavior, although far from trivial, is, nevertheless, simple enough that the correspondence between observable physical quantities and their theoretically predicted values can be convincingly demonstrated. Since the student who undertakes this experiment can carry out himself all the measurements and perform for himself all the calculations required for interpretation of the experimental results, the excellent agreement between the theory and the experiment is demonstrated for the student in a vivid fashion. The complete execution of the experiment, including the full theoretical analysis of the problem, is very helpful to the student in his attempt to grasp the significance of the many new quantum-mechanical quantities to which he is being exposed in his undergraduate studies.
Determination of Fourier Transforms on an Instructional Analog Computer
Authors: Anderson Owen T. , Greenwood Stephen R.
Published: September 2005

An analog computer program to find and display the Fourier transform of some real, even functions is described. The program has been used as the basis for an undergraduate project and as a lecture demonstration in a wave physics course. The program was run on an EAI TR-20 instructional analog computer and the resulting oscilloscope traces are shown for the Fourier transforms of a rectangular pulse, a Gaussian, a cosine wave, and a delayed narrow pulse.
Undergraduate Relativity Experiment
Authors: Higbie J.
Published: September 2005

The primary electrons in a γ-ray detector crystal are typically rather relativistic having kinetic energies of the order of their own rest mass. A technique is described which enables the student to observe the relativistic behavior of these electrons and compare his results with the classical and relativistic predictions. It is shown that it is possible to unambiguously determine the electron's momentum by knowing the Compton edge and photopeak energies of a γ-ray energy spectrum.
Shielding of the Magnetic Field of a Slowly Moving Point Charge by a Conducting Surface
Authors: Furry W. H.
Published: September 2005

In the region beyond a perfectly conducting surface, a stationary or slowly moving charge produces no electric field. For the magnetic field there is, in general, only partial shielding. Solutions for the magnetic field are obtained in the cases of a conducting plane surface and a conducting spherical surface.
Combined Physics Course for Future Elementary and Secondary School Teachers
Authors: McDermott Lillian C.
Published: September 2005

In order to improve the preparation of both future elementary school teachers to teach physical science and secondary school teachers to teach physics, a combined physics course which includes both groups of students has been developed. The course content, which emphasizes depth of understanding, is discussed in some detail. A description is given of the techniques used to encourage the development of the skills and attitudes necessary for teaching the new nationally developed, inquiry-oriented science curricula.
Kinematic Waves and Group Velocity: Applications to Natural and Man-Made Environment
Authors: Johnson J. N.
Published: September 2005

Determination of the group velocity for wave propagation in a dispersive medium is a problem addressed by almost every physics student at some time during a course in optics or electricity and magnetism. A simple derivation is given here for the group velocity of frequency-modulated waves in which the group velocity is equal to dω/dk, where ω is the angular frequency and k is the wave number. The mathematical description used to determine the group velocity is also shown to be applicable to kinematic waves in glacier flow as well as in traffic flow on crowded highways. These analogies thus provide physics students with examples of ways in which familiar ideas can be applied to new problems outside the conventional sphere of physics.
Tunneling between Two Moving Wells in the Adiabatic Approximation
Authors: Deutchman Philip A. , Koelsch David C.
Published: September 2005

A solution in the adiabatic approximation of the Born-Oppenheimer type to Schrödinger's time-dependent equation in one dimension for a model three-body system is presented. The model problem for this system is a particle of mass m interacting with two attractive square wells that are receding at constant relative speed. Graphs of the time development of the probability distribution for the tunneling particle are presented for various initial conditions. The series of graphical solutions is useful as a visual aid in understanding the time development of a simplified three-body problem and the results of the model problem are used as a basis for understanding a nuclear reaction leading to three bodies in the final state.
A Versatile Wave Phenomena Device for Use in Demonstrations and in the Laboratory
Authors: Kasper Joseph E. , Benedek Alfred F.
Published: September 2005

An electronic device is described which can be used for demonstrations and laboratory work in Fourier synthesis, Fourier analysis, phase and group speeds, beats and modulation, and Lissajous figures. The hardware required is inexpensive and simple. The system consists of a set of tuned feedback operational amplifiers and an operational amplifier in summing configuration, driven by a simple, readily available source which supplies a signal rich in the frequencies to which the amplifiers are tuned. The design for a power supply is included. The modes of use of the device are discussed. In each case alternative ways to deal with the same wave phenomenon are discussed to help the reader judge the value of the device.
Kinetic Energy, Size, and the Uncertainty Principle
Authors: Wolsky Alan M.
Published: September 2005

We give a careful but elementary derivation of the inequality 〈r·r〉〈T〉≥(9ħ2)/(8μ) and illustrate its use by applying the inequality to hydrogen, the deuteron, and the pion.
Medieval science, the Copernican revolution, and physics teaching
Authors: Uritam R. A.
Published: September 2005

We point out the need for a greater awareness among physicists of medieval physical science. We review briefly and give examples of notable achievements of that era in mechanics and in astronomy. In light of these, the essence of the role of the Scientific Revolution can be understood more clearly. It is argued that the view of science of fourteenth-century nominalism has greater affinity to today's theoretical physics than that of the Scientific Revolution. The role of medieval science in the teaching of physics is discussed.
Teaching Practices in Introductory Physics Courses
Authors: Whitaker Robert J. , Renner John W.
Published: September 2005

The teaching practices of 24 instructors of introductory physics were observed in six colleges and universities. These instructors were asked to indicate their objectives for the course and for the class period visited. The types and purposes of the questions that the instructors asked were determined from audiotape records of 45 class periods. We concluded that the instructors asked questions which on the average required minimum intellectual involvement of the students. We also noted that the instructor's emphasis in his teaching was directed primarily toward the content of physics and far less toward the processes of physics.
Frustration, Failure, and a “Meaningful” Lab Experience for Adult Nonscience Majors
Authors: Fryshman Bernard
Published: September 2005

Providing adult nonscience majors with an appreciation of experimental science involves a number of serious problems. An open-ended, research approach was used to try to overcome these difficulties. The actual experiment failed, but the resulting educational outcome of the attempt was surprisingly successful.
Relativistic Corrections to the Bohr Model of the Atom
Authors: Kraft David W.
Published: September 2005

A simple means for extending the Bohr model of the atom to include relativistic corrections is presented. The derivation, which assumes circular orbits and a stationary nucleus, is similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. Corrections, consistent with those of Sommerfeld, can thus be obtained to the radii and energy levels for circular orbits without recourse to the lengthy Sommerfeld procedure. The brevity of the derivation makes it suitable for inclusion in the standard first course in modern physics.
Heisenberg's Explosion Shower and the Froissart Bound
Authors: DeGrand Thomas A.
Published: September 2005

Heisenberg's old cosmic ray model, which predicts total cross sections rising like [log(s)]2, is reviewed and generalized. The model is suggested as a physical picture for understanding the Froissart bound.
Storage Oscilloscopes in the Modern Physics Laboratory
Authors: Huebner J. S. , Humphries J. T.
Published: September 2005

The use of storage oscilloscopes in several popular modern physics experiments is described. These oscilloscopes speed student's progress through rapid data collection and often make additional types of measurements possible. The use of storage oscilloscopes in lecture demonstrations is also briefly considered.
Quantum Measurements Are Reversible
Authors: Peres Asher
Published: September 2005

Traditionally, quantum measurements have been associated with irreversible transformations of pure states into mixtures. In this paper we show that this old hypothesis is redundant. A simple model is constructed in which the measuring process is described by a continuous unitary transformation of the state vector of the observed system and the apparatus. The final state is pure, but appears to be a mixture if we ignore the degrees of freedom of the apparatus. This property is most strikingly illustrated by reformulating the problem in the Heisenberg picture: The state vector is fixed, and the dynamical variables are changed by the measurement.
An Avenue of Undergraduate Involvement—Research
Authors: Anderson W. F. , Madjid A. H. , Pedulla J. , Martinez J. M.
Published: September 2005

Several hundred students with backgrounds ranging from liberal arts to physics have successfully participated in basic research in The Pennsylvania State University Thermionic Emission Laboratory for the past five years. The value of this involvement to the students and other participants, and the factors leading to the success of the program are described and discussed.
A Student's View of Undergraduate Involvement in Research
Authors: Breslin Lucy
Published: September 2005

Many courses in physics are being developed for non-science majors. If the course is a success it should leave the students with an inquiring mind about the topics covered in class and about the constant discoveries and revisions being added to the mass of physical knowledge. But what courses have been designed with allocations for this type of progress? What alternatives should be available to a student who would like more than just an introductory course in the field of physics? This article proposes a plan that involves undergraduates in research, including undergraduates not majoring in physics. This plan could be incorporated into most universities and many colleges. It has been used at The Pennsylvania State University, where it has been enthusiastically endorsed by both students and faculty.
A Remote-Position Analyzer with Electronic Output
Authors: Wood G. T.
Published: September 2005

A remote position measuring device with electrical coupling to a computer has been developed for use in the elementary-physics laboratory. Light from a moving object and a fixed-reference lamp is focused by a lens on a hollow, rotating drum with equally-spaced slits. The light passing through a slit is detected with a phototube. The time difference of amplified phototube signals from the object and reference-light sources is a measure of the position coordinate of the object at the time of the object signal. The model constructed has a precision of about 0.03 cm, better than a 3% differential linearity for a 40-cm field of view in the object plane and a sampling rate of 30  sec−1. The device can track more than one object simultaneously and has been successful in providing position samples for two colliding gliders on an air-track.
The Fundamental Length of Quantized Gravitation
Authors: Murphy George L.
Published: September 2005

The quantum-mechanical energy-time uncertainty relation and the expression for the effect of a gravitational field on the rate of a clock are used in a simple demonstration that a quantum theory of gravitation must place a limit on the smallness of space-time intervals which can be measured.
Classical Limit of Scattering in a 1/r2 Potential
Authors: Kayser Boris
Published: September 2005

The classical cross section for scattering by a 1/r2 potential is linear in the strength of the potential, while from the Born approximation to quantum mechanics one might expect it to be quadratic. To resolve this puzzle, we explicitly carry out the passage to the classical limit of the quantum-mechanical partial-wave series for this potential. In the process, we discover the conditions under which quantum scattering becomes classical; under these conditions the Born approximation is not applicable.
Measurements of Atmospheric Refraction
Authors: Pan Iao-Huei
Published: September 2005

The variation of atmospheric refraction between the zenith distances 65° and 90° has been observed using a simple achromatic camera. A new formula gives the angle of refraction more accurately at large zenith distances than the familiar tangent ξ formula. The techniques used for camera calibration are also presented.
C, P, T, and the Dirac Formalism
Authors: Hill Roger C.
Published: September 2005

A method of dealing with charge conjugation and other discrete symmetries for Dirac particles is presented using a manifestly covariant notation which is simple to work with and which can be used in any representation of the Dirac matrices not explicitly involving the usual “B” and “C” matrices presented in many textbooks. Its use is illustrated by its application to discrete symmetries of the Dirac equation, field operators, and transition-matrix elements, and in defining phase conventions for spinors. The linear-versus-antilinear nature of charge conjugation is also discussed.
Observations on the Bessel-Hagen Conservation Laws for Electromagnetic Fields
Authors: Plybon Benjamin F.
Published: September 2005

A derivation of the conservation laws for electromagnetic fields in vacuum which result from the invariance of Maxwell's equations under the conformal group is given. The arguments presented are easier to follow than those given by Bessel-Hagen in 1921, when the original investigation of these conservation laws was made. It is shown in this paper that four of the fifteen conservation laws can be derived from the remaining eleven. Only one of these eleven remains without physical interpretation. This particular conservation law is of some interest today in high-energy physics.
Electron Optics for Biologists: Physical Origins of Spherical Aberrations
Authors: Geissler Peter , Zadunaisky Jose
Published: September 2005

A new look at the physical origins of spherical aberrations in axially symmetric electrostatic lenses is offered with the hope of communicating to physics teachers what are the essentials of electron optics that are relevant to students of biology and medicine, who must think critically about the resolution of the electron microscope.
Laser Safety in the Laboratory
Authors: Weichel H. , Danne W. A. , Pedrotti L. S.
Published: September 2005

This paper deals with the subject of laser hazards, laser hazards control, and laser safety practices in the laboratory. Laser hazards, which fall into four categories (radiative, electrical, explosive, and toxic) are described in detail. Following this, the status of federal regulations which seek to define laser hazards control and safety standards is briefly reviewed. The paper concludes with a brief discussion of laser safety goggles and a list of suggestions of laser safety practices intended to assist those who are concerned or involved with the use of lasers in a laboratory environment.
A demonstration model of magnetic resonance
Authors: Sandhu H. S. , Peemoeller H.
Published: September 2005

A simple and inexpensive model to demonstrate the pulsed magnetic resonance phenomenon is described. It can be easily constructed in an undergraduate laboratory and can provide a direct demonstration of the precessional motion of a magnetic moment in a steady magnetic field. The decay of the signal induced by the precessing magnetic moment can be displayed on an oscilloscope. The model is quite suitable for demonstration in a classroom.
Determination of the Runge-Lenz Vector
Authors: Heintz W. H.
Published: September 2005

A procedure is demonstrated for determining the Runge-Lenz vector for the non-relativistic, classical Kepler problem. This vector constant of the motion enables one to determine the orbit of the particle in a simple way. It is also useful in finding the quantum mechanical solutions for this problem and for systematically studying the symmetry characteristics involved. This article, however, stresses only the classical aspects. The method used can, with appropriate modification, be applied to other problems.
Magnetic Moments of Two-Particle Systems
Authors: Urani John R. , Stillie Gordon D.
Published: September 2005

Magnetic moments of atomic, molecular and nuclear systems are common topics in physics courses at all levels. In modern physics and quantum mechanics an extremely important class of problems is that of two body systems where the orbital motion of the two particles is described by a spherical harmonic wave function. The magnetic moment operator in this case is more complicated than the single particle case where L = r × p and M = (q/2mc)L. The two particle problem is considered below in terms of the constituent angular momenta and an expression for the magnetic moment is found which is convenient to apply directly onto spherical harmonics.
Mathematics pre-requisites: A mastery approach
Authors: Larkin Jill H. , Brackett George C.
Published: September 2005

To ensure that every student entering a physics course can actually use the mathematics essential for the course, we have developed a math review unit in a mastery-learning format. To complete this unit, each student must demonstrate adequate mathematics skills by passing a test. This review unit has been used in both a lecture course and in “Keller plan” courses, and it has proved manageable with a class as large as 350 students.
Particle Diffraction by a Single Slit as Error Propagation
Authors: Purcell J. E.
Published: September 2005

An introductory approach to wave packet spreading is discussed which uses error propagation methods generally known to undergraduates. The specific example of particle diffraction by a single slit is used to illustrate the method. The corresponding quantum theory results are reviewed and sufficient conditions for the vanishing of a term linear in time are discussed.
TOWARDS MOBILITY SKELETONS
Authors: DU BOIS ANDRÉ RAUBER , TRINDER PHIL , LOIDL HANS-WOLFGANG
Published: September 2005

In mobile languages programmers control the placement of code or computations in open networks, e.g., a program can migrate between locations. Mobile computations are typically stateful and interact with the state at each location in the network. We propose mobility skeletons, a library of parameterisable functions that encapsulate common patterns of mobile computation. Mobility skeletons are analogous to, but very different from, algorithmic skeletons — parameterisable functions encapsulating common patterns of parallel computation. We have identified three common patterns of mobile computation, and implemented them as a library of higher-order functions in mobile Haskell. Each mobility skeleton is defined and illustrated with an example. We show how mobility skeletons can be composed and nested, and illustrate their use in a non-trivial case study: a distributed meeting planner. Mobility skeletons are extensible: there is a small set of mobility primitives, and medium-level abstractions such as remote evaluation can be defined using them. New mobility skeletons can be defined using the medium and low level abstractions.
Introduction of Non-Native Oysters: Ecosystem Effects and Restoration Implications
Authors: Ruesink Jennifer L. , Lenihan Hunter S. , Trimble Alan C. , Heiman Kimberly W. , Micheli Fiorenza , Byers James E. , Kay Matthew C.
Published: September 2005

▪ Abstract  Oysters have been introduced worldwide to 73 countries, but the ecological consequences of the introductions are not fully understood. Economically, introduced oysters compose a majority of oyster harvests in many areas. Oysters are ecosystem engineers that influence many ecological processes, such as maintenance of biodiversity, population and food web dynamics, and nutrient cycling. Consequently, both their loss, through interaction of overharvest, habitat degradation, disease, poor water quality, and detrimental species interactions, and their gain, through introductions, can cause complex changes in coastal ecosystems. Introductions can greatly enhance oyster population abundance and production, as well as populations of associated native species. However, introduced oysters are also vectors for non-native species, including disease-causing organisms. Thus, substantial population, community, and habitat changes have accompanied new oysters. In contrast, ecosystem-level consequences of oyster introductions, such as impacts on flow patterns, sediment and nutrient dynamics, and native bioengineering species, are not well understood. Ecological risk assessments for future introductions must emphasize probabilities of establishment, spread, and impacts on vulnerable species, communities, and ecosystem properties. Many characteristics of oysters lead to predictions that they would be successful, high-impact members of recipient ecosystems. This conclusion leaves open the discussion of whether such impacts are desirable in terms of restoration of coastal ecosystems, especially where restoration of native oysters is possible.
Comments on Classical Papers
Authors: Baldwin K. M.
Published: September 2005

This essay looks at the historical significance of one APS classic paper that is freely available online: Margaria R, Edwards HT, and Dill DB. The possible mechanisms of contracting and paying the oxygen debt and the role of lactic acid in muscular contraction. Am J Physiol 106: 689–715, 1933 ( http://ajplegacy.physiology.org/cgi/reprint/106/3/689 ).
FMD vs. pharmacological approaches for endothelial function
Authors: Tanaka Hirofumi
Published: September 2005

This letter is in response to the Point:Counterpoint series “Flow-mediated dilation does/does not reflect nitric oxide-mediated endothelial function” that appeared in the September issue (vol. 99: 1233–1238, 2005; doi:10.1152/japplphysiol.00601.2005; http://jap.physiology.org/content/vol99/issue3/2005 ).
Is there a threshold duration of vascular occlusion for hindlimb reactive hyperemia?
Authors: Rogers Jennifer , Sheriff Don D.
Published: September 2005

Relatively brief changes in perfusion pressure and flow through arterioles occur in a number of conditions, such as in the flying environment and during such common everyday activities such as bending forward at the waist. Also, brief periods of negative vertical acceleration (Gz) stress, which reduces perfusion in the lower body, has been shown to impair the regulation of arterial pressure during subsequent positive Gz stress. To examine the contribution that reactive hyperemia makes in these settings, studies on the hindlimb circulation of anesthetized rats ( n = 8) were carried out by imposing graded duration vascular occlusion (1, 2, 4, 10, and 30 s) to test the hypothesis that there is a threshold duration of reduction in perfusion that must be exceeded for reactive hyperemia to be triggered. Vascular conductance responses to 1 s of terminal aortic occlusion were no different before and after myogenic responses were blocked with nifedipine, indicating that 1 s of occlusion failed to elicit reactive hyperemia. Two seconds of occlusion elicited a small but significant elevation in hindlimb vascular conductance. The magnitude of the reactive hyperemia was graded in direct relation to the duration of occlusion for the 2-, 4-, and 10-s periods of occlusion and appeared to be approaching a plateau for the 30-s occlusion. Thus there is a threshold duration of terminal aortic occlusion (∼2 s) required to elicit reactive hyperemia in the hindlimbs of anesthetized rats, and the reactive hyperemia that results possesses a threat to the regulation of arterial pressure.
Shared genetic risk factors for obstructive sleep apnea and obesity
Authors: Patel Sanjay R.
Published: September 2005

Both obesity and obstructive sleep apnea (OSA) are complex disorders with multiple risk factors, which interact in a complicated fashion to determine the overall phenotype. In addition to environmental risk factors, each disorder has a strong genetic basis that is likely due to the summation of small to moderate effects from a large number of genetic loci. Obesity is a strong risk factor for sleep apnea, and there are some data to suggest sleep apnea may influence obesity. It is therefore not surprising that many susceptibility genes for obesity and OSA should be shared. Current research suggests that approximately half of the genetic variance in the apnea hypopnea index is shared with obesity phenotypes. Genetic polymorphisms that increase weight will also be risk factors for apnea. In addition, given the interrelated pathways regulating both weight and other intermediate phenotypes for sleep apnea such as ventilatory control, upper airway muscle function, and sleep characteristics, it is likely that there are genes with pleiotropic effects independently impacting obesity and OSA traits. Other genetic loci likely interact with obesity to influence development of OSA in a gene-by-environment type of effect. Conversely, environmental stressors such as intermittent hypoxia and sleep fragmentation produced by OSA may interact with obesity susceptibility genes to modulate the importance that these loci have on defining obesity-related traits.
Scientific considerations for physiological evaluations of elite athletes
Authors: Schumacher Yorck Olaf , Vogt Stefan , Roecker Kai , Schmid Andreas
Published: September 2005

This case describes the physiological maturation from ages 21 to 28 yr of the bicyclist who has now become the six-time consecutive Grand Champion of the Tour de France, at ages 27–32 yr. Maximal oxygen uptake (V̇o2max) in the trained state remained at ∼6 l/min, lean body weight remained at ∼70 kg, and maximal heart rate declined from 207 to 200 beats/min. Blood lactate threshold was typical of competitive cyclists in that it occurred at 76–85% V̇o2max, yet maximal blood lactate concentration was remarkably low in the trained state. It appears that an 8% improvement in muscular efficiency and thus power production when cycling at a given oxygen uptake (V̇o2) is the characteristic that improved most as this athlete matured from ages 21 to 28 yr. It is noteworthy that at age 25 yr, this champion developed advanced cancer, requiring surgeries and chemotherapy. During the months leading up to each of his Tour de France victories, he reduced body weight and body fat by 4–7 kg (i.e., ∼7%). Therefore, over the 7-yr period, an improvement in muscular efficiency and reduced body fat contributed equally to a remarkable 18% improvement in his steady-state power per kilogram body weight when cycling at a given V̇o2 (e.g., 5 l/min). It is hypothesized that the improved muscular efficiency probably reflects changes in muscle myosin type stimulated from years of training intensely for 3–6 h on most days.
Flow-mediated vasodilation is mediated by endothelium-derived nitric oxide
Authors: Creager Mark A.
Published: September 2005

This letter is in response to the Point:Counterpoint series “Flow-mediated dilation does/does not reflect nitric oxide-mediated endothelial function” that appeared in the September issue (vol. 99: 1233–1238, 2005; doi:10.1152/japplphysiol.00601.2005; http://jap.physiology.org/content/vol99/issue3/2005 ).
Mapping by Laser Photostimulation of Connections Between the Thalamic Reticular and Ventral Posterior Lateral Nuclei in the Rat
Authors: Lam Ying-Wan , Sherman S. Murray
Published: September 2005

We used laser scanning photostimulation through a focused UV laser of caged glutamate in an in vitro slice preparation through the rat’s somatosensory thalamus to study topography and connectivity between the thalamic reticular nucleus and ventral posterior lateral nucleus. This enabled us to focally stimulate the soma or dendrites of reticular neurons. We were thus able to confirm and extend previous observations based mainly on neuroanatomical pathway tracing techniques: the projections from the thalamic reticular nucleus to the ventral posterior lateral nucleus have precise topography. The reticular zone, which we refer to as a “footprint,” within which photostimulation evoked inhibitory postsynaptic currents (IPSCs) in relay cells, was relatively small and oval, with the long axis being parallel to the border between the thalamic reticular nucleus and ventral posterior lateral nucleus. These evoked IPSCs were large, and by using appropriate GABA antagonists, we were able to show both GABAA and GABAB components. This suggests that photostimulation strongly activated reticular neurons. Finally, we were able to activate a disynaptic relay cell-to-reticular-to- relay cell pathway by evoking IPSCs in relay cells from photostimulation of the region surrounding a recorded relay cell. This, too, suggests strong responses of relay cells, responses strong enough to evoke spiking in their postsynaptic reticular targets. The regions of photostimulation for these disynaptic responses were much larger than the above-mentioned reticular footprints, and this suggests that reticulothalamic axon arbors are less widespread than thalamoreticular arbors, that there is more convergence in thalamoreticular connections than in reticulothalamic connections, or both.
AMPA Receptors Are Modulated by Tachykinins in Rat Cerebellum Neurons
Authors: Pieri Massimo , Severini Cinzia , Amadoro Giuseppina , Carunchio Irene , Barbato Christian , Ciotti Maria Teresa , Zona Cristina
Published: September 2005

The peptides of the tachykinin family are widely distributed within the mammalian peripheral and central nervous systems and play a well-recognized role as neuromodulators, although their direct action on cerebellum granule cells have not yet been demonstrated. We have examined the effect of the best known members of the family, substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) on α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors from rat cerebellar granule cells in culture to assess the ability of these peptides to regulate the glutamatergic input. Both NKA and NKB, but not SP, produce a significant enhancement of ionic current through AMPA receptors activated by the agonist kainate in 53.5 and 46% of patched neurons, respectively. This effect was not observable in the presence of MEN 10,627 and Trp7βAla8, NKA and NKB competitive antagonist receptors, respectively, indicating that the current modulations were mediated by the respective receptors. NKB also produces a significant enhancement of ionic current through the AMPA receptors activated directly by its agonist AMPA and cyclothiazide, an allosteric modulator that selectively suppresses desensitization of AMPA receptors. The presence of NK3 receptors was demonstrated in these neurons by RT-PCR amplification of total RNA extracted from cerebellar granule cells, using NK3-specific primer pairs. Immunocytochemistry experiments, using a specific polyclonal antibody directed against NK3, also confirmed the presence of NK3 receptors and their co-localization with the GLUR2 AMPA subunit in about 54% of cerebellar granule neurons. This study adds the tachykinins to the list of neuromodulators capable of exerting a excitatory action on cerebellar granule cells.
Schatten′s theorems on functionally definedSchur algebras
Authors: Chaisuriya Pachara , Ong Sing-Cheong
Published: September 2005

For each triple of positive numbers p, q, r ≥ 1 and each
commutative C*‐algebra ℬ with identity 1 and the
set s(ℬ) of states on ℬ, the set 𝒮r(ℬ) of all matrices A = [ajk] over ℬ such that defines a bounded operator from ℓp to
ℓq for all ϕ ∈ s(ℬ) is shown to be a Banach
algebra under the Schur product operation, and the norm .
Schatten′s theorems about the dual of the compact
operators, the trace‐class operators, and the decomposition of the
dual of the algebra of all bounded operators on a Hilbert space
are extended to the 𝒮r(ℬ) setting.
A notion of functional completeness for first‐orderstructure
Authors: Temgoua Etienne R. Alomo , Tonga Marcel
Published: September 2005

Using ☆‐congruences and implications, Weaver (1993)
introduced the concepts of prevariety and quasivariety of
first‐order structures as generalizations of the corresponding
concepts for algebras. The notion of functional completeness on
algebras has been defined and characterized by Burris and
Sankappanavar (1981), Kaarli and Pixley (2001), Pixley (1996),
and Quackenbush (1981). We study the notion of functional
completeness with respect to ☆‐congruences. We extend some
results on functionally complete algebras to first‐order
structures A = (A; FA; RA) and
find conditions for these structures to have a compatible Pixley
function which is interpolated by term functions on suitable
subsets of the base set A.
On the periodic nature of some max‐typedifference equations
Authors: Elabbasy E. M. , El-Metwally H. , Elsayed E. M.
Published: September 2005

We study some qualitative behavior of solutions of some max‐type
difference equations with periodic coefficients. Some new results
of the periodicity character of solutions of that type of
difference equations will be established.
Linear algebra and differential geometry on abstract Hilbert space
Authors: Kryukov Alexey A.
Published: September 2005

Isomorphisms of separable Hilbert spaces are analogous to
isomorphisms of n‐dimensional vector spaces. However,
while n‐dimensional spaces in applications are always realized
as the Euclidean space Rn, Hilbert spaces admit various useful
realizations as spaces of functions. In the paper this simple
observation is used to construct a fruitful formalism of local
coordinates on Hilbert manifolds. Images of charts on manifolds in
the formalism are allowed to belong to arbitrary Hilbert spaces of
functions including spaces of generalized functions. Tensor
equations then describe families of functional equations on
various spaces of functions. The formalism itself and its
applications in linear algebra, differential equations, and
differential geometry are carefully analyzed.
Abelian subgroup separability of some one‐relator groups
Authors: Tieudjo D.
Published: September 2005

We prove that any group in the class of one‐relator groups given
by the presentation 〈a, b; [am, bn] = 1〉, where m
and n are integers greater than 1, is cyclic subgroup separable
(or πc). We establish some suitable properties of these
groups which enable us to prove that every finitely generated
abelian subgroup of any of such groups is finitely separable.
Three‐step iterations for mixed quasi variational‐like inequalities
Authors: Noor Muhammad Aslam
Published: September 2005

In this paper, we use the auxiliary principle technique in
conjunction with the Bregman function to suggest and analyze a
three‐step predictor‐corrector method for solving mixed quasi
variational‐like inequalities. We also study the convergence
criteria of this new method under some mild conditions. As special
cases, we obtain various new and known methods for solving
variational inequalities and related optimization problems.
On torsion‐free periodic rings
Authors: Khazal R. R. , Breaz S. , Călugăreanu G.
Published: September 2005

We characterize several large classes of periodic rings: periodic
rings with identity, finite‐rank torsion‐free periodic rings, and
rank‐two torsion‐free periodic rings.
An Orally Active Epoxide Hydrolase Inhibitor Lowers Blood Pressure and Provides Renal Protection in Salt-Sensitive Hypertension
Authors: Imig John D. , Zhao Xueying , Zaharis Constantine Z. , Olearczyk Jeffrey J. , Pollock David M. , Newman John W. , Kim In-Hae , Watanabe Takaho , Hammock Bruce D.
Published: September 2005

The present study tested the hypothesis that increasing epoxyeicosatrienoic acids by inhibition of soluble epoxide hydrolase (sEH) would lower blood pressure and ameliorate renal damage in salt-sensitive hypertension. Rats were infused with angiotensin and fed a normal-salt diet or an 8% NaCl diet for 14 days. The sEH inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), was given orally to angiotensin-infused animals during the 14-day period. Plasma AUDA metabolite levels were measured, and they averaged 10±2 ng/mL in normal-salt angiotensin hypertension and 19±3 ng/mL in high-salt angiotensin hypertension on day 14 in the animals administered the sEH inhibitor. Mean arterial blood pressure averaged 161±4 mm Hg in normal-salt and 172±5 mm Hg in the high-salt angiotensin hypertension groups on day 14. EH inhibitor treatment significantly lowered blood pressure to 140±5 mm Hg in the normal-salt angiotensin hypertension group and to 151±6 mm Hg in the high-salt angiotensin hypertension group on day 14. The lower arterial blood pressures in the AUDA-treated groups were associated with increased urinary epoxide-to-diol ratios. Urinary microalbumin levels were measured, and ED-1 staining was used to determine renal damage and macrophage infiltration in the groups. Two weeks of AUDA treatment decreased urinary microalbumin excretion in the normal-salt and high-salt angiotensin hypertension groups and macrophage number in the high-salt angiotensin hypertension group. These data demonstrate that sEH inhibition lowers blood pressure and ameliorates renal damage in angiotensin-dependent, salt-sensitive hypertension.