bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of donor characteristics, technique of harvesting and in vitro processing on culturing of human marrow stroma cells for tissue engineered growth of bone
Authors: Bertram Helge , Mayer Hubert , Schliephake Henning
Published: September 2005

Abstract: The aim of this study was to assess the effect of donor characteristics and the technique of harvesting and in vitro processing on the efficacy of culturing of human mesenchymal stem cells (hMSCs) for tissue engineered growth of bone. Cultures of hMSCs were derived from iliac crest bone marrow aspirates (21 donors, age 11–76) and from cancellous bone grafting material (32 donors, age 13–84). Age had no significant effect on the ability to isolate and culture hMSCs, although the failure rate was 55.6% in donors beyond the age of 60, while it varied between 14.3% and 22.2% in donors under 60 years of age. Male and female donors had comparable failure rates (27.3% and 28.6%, respectively). Culturing of hMSCs was successful in 90.4% of marrow aspirates from 21 donors and in 62.5% of cancellous bone specimens from 35 donors. This difference was statistically significant (P=0.023). Regression analysis confirmed that at simultaneous testing of the three variables, only the source of cells significantly affected the result (P=0.043). Morphological evaluation of the unfractionated primary population showed a change in cell shape of the adherent cells from a triangular into thin spindle‐shaped elongated form, which remains until confluence. When the cultures were exposed to osteoinductive medium, various morphotypes expressing different levels of alkaline phosphatase and secreting different amounts of mineral were evident. Morphology of marrow stroma cells (MSCs) from marrow aspirates was not different from MSCs derived from cancellous bone specimens. Expression of osteogenic markers in MSCs as shown by PCR as well, did not differ between the two sources. It is concluded that marrow aspirates and cancellous bone specimens produce comparable populations of MSCs. However, bone marrow aspirates from donors under the age of 60 years rather than cancellous bone chips are favourable for isolation and expansion of hMSCs for tissue engineered growth of bone.
Root repair after injury from mini‐screw
Authors: Asscherickx Karlien , Vannet Bart Vande , Wehrbein Heiner , Sabzevar Mehran Moradi
Published: September 2005

Abstract: Mini‐implants and mini‐screws are commonly used in orthodontics to provide extra anchorage. One potential insertion site is between the roots in the alveolar process, which results in a risk of damaging the roots of neighbouring teeth. In an animal‐experimental study, 20 mini‐screws (bracket screw bone anchors, BSBAs) were inserted into the mandible of five beagle dogs. Each dog received two BSBAs in each lower quadrant, between the roots of the second and third, and third and fourth premolars. Sequential point labelling was performed every 6 weeks with vital stains, and apical X‐rays were taken every 6 weeks. Radiographic examination demonstrated damage at three roots because of insertion of the BSBAs. Histological examination at these three roots demonstrated an almost complete repair of the periodontal structure (e.g. cementum, periodontal ligament and bone) in a period of 12 weeks, following removal of the screws.
Detection of N‐nitrosomelatonin and other N‐nitrosotryptophan derivatives by transnitrosation of APF and DAF‐2
Authors: Kirsch Michael , de Groot Herbert
Published: September 2005

Abstract:  S‐nitrosothiols can be analyzed with some simple detection procedures and this fact strongly accelerated the understanding of the biological impact of S‐nitrosothiols. Unfortunately, such simple analytic methods are presently missing for low molecular weight N‐nitrosotryptophan derivatives like N‐nitrosomelatonin (NOMela). Here we demonstrate that commercially available primary aromatic amines, i.e. aminophenylfluorescein (APF) and 4,5‐diaminofluorescin (DAF‐2), can be used for a quantitative determination of NOMela. Under optimized conditions (e.g. pH 11) of the assays, the lifetime of N‐nitrosotryptophan derivatives is largely prolonged and the reactivity of S‐nitrosothiols with aromatic amines can be safely ignored. The influence of reactive nitrogen oxide species like N2O3 is additionally limited at the alkaline pH and may be further decreased by working under hypoxic conditions. As a result of these optimal conditions, the APF assay has a detection limit for NOMela of about 25 nm but this assay fails to detect protein‐bound N‐nitrosotryptophan residues. The DAF‐2 assay, however, might be used for a qualitative analysis of such residues. Due to the high efficacy of the APF assay it is safely demonstrated that in regard to peroxynitrite, N2O3 is about 50‐fold more effective in nitrosating melatonin at physiological pH.
Sorting of Major Cargo Glycoproteins into Clathrin‐Coated Vesicles
Authors: Harasaki Kouki , Lubben Nienke B. , Harbour Michael , Taylor Marcus J. , Robinson Margaret S.
Published: September 2005

The AP‐1 and AP‐2 complexes are the most abundant adaptors in clathrin‐coated vesicles (CCVs), but clathrin‐mediated trafficking can still occur in the absence of any detectable AP‐1 or AP‐2. To find out whether adaptor abundance reflects cargo abundance, we used lectin pulldowns to identify the major membrane glycoproteins in CCVs from human placenta and rat liver. Both preparations contained three prominent high molecular‐weight proteins: the cation‐independent mannose 6‐phosphate receptor (CIMPR), carboxypeptidase D (CPD) and low‐density lipoprotein receptor‐related protein 1 (LRP1). To investigate how these proteins are sorted, we constructed and stably transfected CD8 chimeras into HeLa cells. CD8‐CIMPR localized mainly to early/tubular endosomes, CD8‐CPD to the trans Golgi network and CD8‐LRP1 to late/multivesicular endosomes. All three constructs redistributed to the plasma membrane when clathrin was depleted by siRNA. CD8‐CIMPR was also strongly affected by AP‐2 depletion. CD8‐CPD was moderately affected by AP‐2 depletion but strongly affected by depleting AP‐1 and AP‐2 together. CD8‐LRP1 was only slightly affected by AP‐2 depletion; however, mutating an NPXY motif in the LRP1 tail caused it to become AP‐2 dependent. These results indicate that all three proteins have AP‐dependent sorting signals, which may help to explain the relative abundance of AP complexes in CCVs. However, the relatively low abundance of cargo proteins in CCV preparations suggests either that some of the APs may be empty or that the preparations may be dominated by empty coats.
Lymphozytische Infiltration durch die Einnahme von Tamsulosin (Alna®)
Authors: Diesler Sandra , Hirche Frank , Krieg Thomas , Hunzelmann Nicolas
Published: September 2005

Wir berichten über einen 69‐jährigen Patienten, bei dem es nach der p. o. Einnahme von Tamsulosin (Alna®) zur Manifestation von rötlich‐lividen Plaques im Bereich des Rückens, Rima ani, Ellenbogen bds. sowie Fingergelenke kam. Die Hauteffloreszenzen bildeten sich reproduzierbar nach dem Absetzen von Tamsulosin zurück. Die histologische Begutachtung einer Probebiopsie aus einem UVA‐exponierten Areal im Bereich des Rückens ergab die Diagnose einer lymphozytischen Infiltration. Typ‐I‐ und Typ‐IV‐Sensibilisierungen gegen Tamsulosin konnten im Prick‐ und Epikutantest nicht festgestellt werden. Nach unserem Wissen ist dies der erste Fall, bei dem es nach der Einnahme von Tamsulosin zu einer Medikamentenunverträglichkeit unter dem histologischen und klinischen Bild einer lymphozytische Infiltration gekommen ist. Seit Absetzen von Tamsulosin ist der Patient beschwerdefrei.
Oxcarbazepin‐induziertes lokalisiertes Ödem am Penis
Authors: Rallis Efstathios , Theodoridis Athanasios , Moussatou Vasiliki , Papadakis Pavlos , Verros Constantinos
Published: September 2005

Oxcarbazepin ist ein Carbamazepin‐Analog mit antikonvulsiver und schmerzstillender Wirkung. Wir berichten über einen Patienten, bei dem ein lokalisiertes Penisödem durch Oxcarbazepin induziert wurde. Der kausale Zusammenhang wurde durch eine Expositionstestung bestätigt. Umschriebene Ödeme wurden bisher noch nicht als Nebenwirkung dieser Substanz beschrieben.
KTP‐Laser‐Koagulation bei Xanthelasma palpebrarum
Authors: Berger Claudia , Kopera Daisy
Published: September 2005

Hintergrund: Xanthelasma palpebrarum repräsentiert gutartige Fetteinlagerungen an den Augenlidern. Die Pathogenese dieser gelblichen Plaques ist nicht hinlänglich geklärt. Ein Zusammenhang mit Hyperlipidämie, Diabetes mellitus und Schilddrüsenfunktionsstörungen wird diskutiert. Ihre Behandlung wird meist mehr aus ästhetischen als aus medizinischen Gründen angestrebt. Es wurde über verschiedenste mehr oder weniger invasive Behandlungsalternativen zur Reduktion der Xanthelasmen berichtet. Neuere, minimal invasive Techniken sollten ein geringes Risiko von Nebenwirkungen wie Narbenbildung und postläsioneller Hyperpigmentierung aufweisen.

Patienten und Methoden: Wir beschreiben erstmals den Einsatz eines KTP‐Lasers (532 nm) zur Reduktion von Xanthelasma palpebrarum bei 14 PatientInnen an 33 Lidern.

Ergebnisse: Die Mehrzahl der PatientInnen (71 %) tolerierte die KTP‐Laser‐Therapie ohne Lokalanästhesie. Nach ein bis drei Behandlungsdurchgängen konnte in 85,7 % eine aus ästhetischer Sicht respektable Reduktion der Xanthelasmen erzielt werden. Unerwünschte Nebeneffekte traten nicht auf.

Schlussfolgerung: KTP‐Laser‐Behandlung ist eine wenig invasive, sichere und effektive Behandlungsoption zur Reduktion von Xanthelasma palpebrarum ohne unerwünschte Nebeneffekte.
Single nucleotide polymorphisms in four functionally related immune response genes in the horse: CD14,TLR4, Cɛ, andFcɛ R1 alpha
Authors: Vychodilova‐Krenkova L. , Matiasovic J. , Horin P.
Published: September 2005

The objective of this study was to identify single nucleotide polymorphisms (SNPs) within four functionally related immune response genes in the horse, and to develop genotyping techniques that could be useful for future genomic studies of horse infectious and allergic diseases. The genes analysed were: the lipopolysaccharide (LPS) receptor gene CD14, the toll‐like receptor 4 gene TLR4, the gene Cɛ encoding the IgE heavy chain molecule and the gene FcɛR1 alpha coding for the alpha subunit of the IgE receptor molecule. Horse‐specific primers amplifying selected gene regions were designed and SNPs were searched by selective resequencing and/or by PCR‐SSCP (polymerase chain reaction‐sequence specific conformational polymorphism) or PCR‐RFLP (PCR‐restriction fragment length polymorphism). Gene expression was analysed by RT‐PCR (reverse transcriptase‐PCR) of all four genes examined. For CD14, the cDNA sequence was determined and a novel sequence of the 5′UTR region was identified. The protein‐coding sequence was identical to that previously deposited in GenBank. 5′UTR, intronic and both synonymous and non‐synonymous exonic SNPs were identified. Three SNPs were found in the CD14 gene, four in the TLR4 gene; two SNPs were identified in the Cɛ gene, and one SNP was found in the FcɛR1 alpha gene. PCR‐RFLP was developed for genotyping eight of the SNPs identified. The RT‐PCR assay showed that all the SNPs reported here are parts of expressed genes. The results showed that important immunity‐related genes in horses are polymorphic and that even non‐synonymous SNPs with potential functional impact may occur. The methods developed for genotyping and haplotyping the SNPs identified represent, along with markers described previously, a potentially useful tool for genomic analysis of the function and role of these genes in immunity and in mechanisms of disease.
Frequencies of the common promoter polymorphisms in cytokine genes in a Polish population
Authors: Kurzawski M. , Pawlik A. , Czerny B. , Domański L. , Różański J. , Droździk M.
Published: September 2005

Common polymorphisms in cytokine genes, widely distributed in many populations, may affect gene transcription, leading to individual variations in cytokine levels. Some of those polymorphisms were associated with the risk of graft rejection or autoimmune and parasitic diseases development as well as treatment outcome. In the current study the frequencies of promoter polymorphisms in genes encoding interleukin‐2 (−330 G/C), interleukin‐4 (−590 C/T), interleukin‐6 (−174 G/C), interleukin‐10 (−1082 G/A, −592 C/A) and TNFα (−307 G/A) have been studied in a sample of 205 unrelated healthy Polish subjects of Caucasian origin. The frequencies of the determined cytokine alleles were as follows: interleukin‐2 (−330 G/C): T −64.9%, G −35.1%; interleukin‐4 (−590 C/T): C −79.8%, T −20.2%; interleukin‐6 (−174 G/C): G −53.4%, C −46.6%; interleukin‐10 (−1082 G/A, −819 G/T, −592 C/A): GCC −44.1%, ACC −32.0, ATA −23.9%; TNFα (−307 G/A): G −85.1%, A −14.9%. We also compared our results with other populations studied to date, describing some significant differences.
Reliability of HLA‐Cw data collected in unrelated bone marrow registry and their usefulness for preliminary donor selection
Authors: Nowak J. , Mika‐Witkowska R. , Zajko M. , Lopacz P.
Published: September 2005

In the present study, we addressed the question of how often HLA‐DRB1‐matched donors can be found by further typing of AB‐matched donors and whether Cw preselection can be helpful. Sixty‐eight patients and 174 donors were enrolled in the study. In all donors, confirmatory DNA Cw typing was performed to check reliability of registry Cw data. Among the 129 Cw serologically typed donors, 11 (8.5%) were not confirmed by DNA typing and for 77 (60%) at least one Cw blank antigen was genetically confirmed. In healthy controls, haplotype frequency higher than 1% has been found for 21 (55%) out of 38 Cw‐DRB1 haplotypes observed. A subtotal delta made up 67% of subtotal haplotype frequency fraction of 21 haplotypes confirming strong linkage disequilibrium of Cw‐DRB1 loci. After Cw preselection 12 (15.4%) out of 78 donors were matched in both DRB1. On the other hand, only two (2.1%) out of 96 AB‐matched donors with unknown or incompatible Cw were matched in both DRB1 at low‐resolution level (OR = 8.55; P = 0.0060; 95%CI 1.85–39.5). We found at least one DRB1‐matched donor for 12 (26.1%) out of 46 patients with Cw‐matched donors for which 1–5 (median = 1) of Cw‐preselected donors were chosen for further typing. Cw preselection of HLA AB‐matched donors for further DRB1 typing may improve the efficacy of stem cell donor search process.
Cochlear function in mice with only one copy of the prestin gene
Authors: Cheatham M. A. , Zheng J. , Huynh K. H. , Du G. G. , Gao J. , Zuo J. , Navarrete E. , Dallos P.
Published: September 2005

Targeted deletion of the prestin gene reduces cochlear sensitivity and eliminates both frequency selectivity and outer hair cell (OHC) somatic electromotility. In addition, it has been reported by Liberman and colleagues that F2 generation heterozygotes exhibit a 6 dB reduction in sensitivity, as well as a decrease in protein and electromotility. Considering that the active process is non‐linear, a halving of somatic electromotility would be expected to produce a much larger change in sensitivity. We therefore re‐evaluated comparisons between heterozygotes and wildtype mice using both in vivo and in vitro electrophysiology, as well as molecular biology. Data reported here for F3–F5 generation mice indicate that compound action potential thresholds and tuning curves, as well as the cochlear microphonic, are similar in heterozygotes and wildtype controls. Measurements of non‐linear capacitance in isolated OHCs demonstrate that charge density, as well as the voltage dependence and sensitivity of motor function, is indistinguishable in the two genotypes, as is somatic electromotility. In addition, both immunocytochemistry and western blot analysis in young adult mice suggest that prestin protein in heterozygotes is near normal. In contrast, prestin mRNA is always less than in wildtype mice at all ages tested. Results from F3–F5 generation mice suggest that one copy of the prestin gene is capable of compensating for the deleted copy and that heterozygous mice do not suffer peripheral hearing impairment.
Localization of myosin II and V isoforms in cultured rat sympathetic neurones and their potential involvement in presynaptic function
Authors: Takagishi Yoshiko , Futaki Sugiko , Itoh Kanako , Espreafico Enilza M. , Murakami Noriko , Murata Yoshiharu , Mochida Sumiko
Published: September 2005

While vesicle transport is one of the principal functions of myosin motors in neurones, the role played by specific myosin subtypes in discrete vesicle trafficking is poorly understood. We conducted electrophysiological and morphological experiments to determine whether myosin isoforms II and V might be involved in the transport of small synaptic vesicles in presynaptic nerve terminals of a model cholinergic synapse. Electron microscopy revealed the presence of normal synaptic architecture and synaptic vesicle density in presynaptic terminals of cultured superior cervical ganglion neurones (SCGNs) from myosin Va null rats (dilute‐opisthotonus, dop). Similarly, electrophysiological analyses of synaptic transmission and synaptic vesicle cycling at paired SCGN synapses failed to uncover any significant differences in synaptic development and function between normal and dop rats. Immunocytochemistry and in situ localization of green fluorescent protein (GFP)‐fusion proteins in wild‐type synapses revealed that myosins IIB and Va were distributed throughout the cell soma and processes of SCGNs, while myosins IIA and Vb were not detected in SCGNs. Myosin Va was conspicuously absent in presynaptic nerve terminals, but myosin IIB alone was found to be expressed. Furthermore, synaptic transmission was inhibited by introduction of myosin IIB heavy chain fragments into presynaptic terminals of SCGNs. Together these results suggest that only myosin IIB isoform participates in vesicle trafficking in presynaptic nerve terminals of cultured SCGNs.
Tryptophan scanning mutagenesis of the HERG K+ channel: the S4 domain is loosely packed and likely to be lipid exposed
Authors: Subbiah Rajesh N. , Kondo Mari , Campbell Terence J. , Vandenberg Jamie I.
Published: September 2005

Inherited mutations or drug‐induced block of voltage‐gated ion channels, including the human ether‐à‐go‐go‐related gene (HERG) K+ channel, are significant causes of malignant arrhythmias and sudden death. The fourth transmembrane domain (S4) of these channels contains multiple positive charges that move across the membrane electric field in response to changes in transmembrane voltage. In HERG K+ channels, the movement of the S4 domain across the transmembrane electric field is particularly slow. To examine the basis of the slow movement of the HERG S4 domain and specifically to probe the relationship between the S4 domain with the lipid bilayer and rest of the channel protein, we individually mutated each of the S4 amino acids in HERG (L524–L539) to tryptophan, and characterized the activation and deactivation properties of the mutant channels in Xenopus oocytes, using two‐electrode voltage‐clamp methods. Tryptophan has a large bulky hydrophobic sidechain and so should be tolerated at positions that interact with lipid, but not at positions involved in close protein–protein interactions. Significantly, we found that all S4 tryptophan mutants were functional. These data indicate that the S4 domain is loosely packed within the rest of the voltage sensor domain and is likely to be lipid exposed. Further, we identified residues K525, R528 and K538 as being the most important for slow activation of the channels.
A shot-noise experiment with computer control and data acquisition
Authors: Kraftmakher Yaakov
Published: September 2005

A shot-noise experiment for the determination of the electron charge is described. The experiment uses common data-acquisition hardware and analysis software, in addition to a standard ac voltmeter.
Visualizing infrared phenomena with a webcam
Authors: Gross N. A. , Hersek M. , Bansil A.
Published: September 2005

The concept of light (electromagnetic radiation) outside of the visible spectrum is an abstract concept for students in an introductory science class. When students are presented with demonstrations or experiments meant to explore this portion of the spectrum, the equipment involved often hides the phenomena. A simple modification to a standard, inexpensive web camera (webcam) can take advantage of the sensitivity of the charged-coupled-device (CCD) to the infrared (IR) portion of the spectrum, allowing students to visualize many IR phenomena. This note reports how such a modified webcam can be used in lecture demonstrations and laboratory activities to study infrared phenomena including an IR light emitting diode (LED), the IR component of different light sources, IR spectroscopy, and blackbody radiation. As a final example, the modified camera can be employed to view the charcoal under-drawing of a “painting” created for this paper and used in our classroom demonstrations.
The Concept of Temperature in Magnetism
Authors: Bloembergen N.
Published: September 2005

This is an English translation of a paper which appeared in Nederlands Tydschrift voor Natuurkunde, [38, 198 (1972)] in honor of H. B. G. Casimir.
Experiments in Molecular Physics with an Acoustic Interferometer
Authors: Rossing Thomas D.
Published: September 2005

An acoustic interferometer provides an inexpensive means for making precise studies of the kinetics of gas molecules. Two experiments are described: (1) Measurement of the vibrational relaxation time of gas molecules and (2) determination of intermolecular (van der Waals) forces in molecules.
“Broader Curricular Issues” in Physics: Technology, History, Science, Society
Authors: Hartmann-Hoddeson Lillian
Published: September 2005

A dilemma now faces many physics teachers: how to meet the demand, made both on humanistic and practical grounds, for courses which extend the physics curriculum beyond physics by relating it to human affairs. Can physics teachers qualify to teach such courses? What should they teach? This article describes the dilemma and presents one such experimental course, “Science and Technology in Society,” offered in the physics department at Rutgers.
Experiment in Fourier Analysis
Authors: Lonc W. P.
Published: September 2005

Utilizing only commonly available components and instruments, construction and performance details are given for a system capable of extracting the sinusoidal components of a 10 kHz square wave and a 10 kHz half-wave rectified sine wave to at least the seventh harmonic with an amplitude accuracy of at least 10%.
Sufficient Conditions for Construction of the Character System of a Finite Group
Authors: Rudin Robert A.
Published: September 2005

Necessary and sufficient conditions for the construction of the character table of a finite group from its multiplication table are discussed. It is pointed out that the technique most commonly used to evaluate the characters is inadequate. A rigorous method is described and its utility is discussed.
A Student's Gyrocompass
Authors: Knudsen A. W.
Published: September 2005

A land or survey-type gyrocompass, usable and under-standable by undergraduate students, is described. A motor-driven gyro with nominally horizontal spin-axis is suspended, in a special way, by a fine metallic band. The gyro executes slow harmonic azimuthal oscillations of easily calculable period. Being symmetrical with respect to the plane of the local meridian, these oscillations allow an accurate determination of true or gyroscopic north. Using simple accessory items, the student may sight the north star to obtain the astronomic north. This may be accurately compared with the gyro north. Agreement of the two north determinations to within 0.1° has been obtained.
The Quantum Electrostatic Electron
Authors: Carver J. R.
Published: September 2005

The one-electron contributions to the charge-fluctuation and electrostatic self-energy densities are calculated in the rest frame of the electron according to conventional quantum electrodynamics and related to some earlier work by Weisskopf. The one-electron portion of the current-fluctuation density is evaluated and indicated to be the quantum-electrodynamic counterpart to the “zitterbewegung” of the quantum mechanics of the relativistic electron.
Introduction to Field Operators in Quantum Mechanics
Authors: Robertson Baldwin
Published: September 2005

The equivalence of the field operator formulation of quantum mechanics and ordinary wave mechanics is proved in an efficient and elementary way. The discussion proceeds algebraically from the (anti-) commutation relations, which the field operators are defined to satisfy. Although the paper is introductory and presumes only a knowledge of elementary wave mechanics, it is intended to cover all of the essential elements of the subject in a rigorous way.
The Physical Scientist in an Interdisciplinary Course
Authors: Laws Priscilla W.
Published: September 2005

A broadly interdisciplinary course in environmental studies which includes perspectives from the social and natural sciences as well as the humanities is described. An attempt is made to define the ways in which a physical scientist can contribute to such an enterprise.
Independent Study Unit on Accelerated Reference Frames
Authors: Poultney S. K.
Published: September 2005

After studying circular motion and Galilean reference frames in mechanics, the general science student is introduced to accelerated reference frames in a study unit and allowed to choose a topic to pursue during the laboratory period of that unit. The student makes contact with topics ranging from the large scale wind patterns on the earth to direct-reading automobile accelerometers to artificial gravity on space stations to general relativity. A list of topics, suggested areas of investigation in each topic, and a small, complete set of references are given along with a perspective on the topics.
Student Laboratory Demonstration of the Josephson Effects with Clarke Slugs
Authors: Manikopoulos Constantine N. , Hannah Eric C.
Published: September 2005

We describe a simple inexpensive laboratory for undergraduate students wherein the students construct and test Clarke slugs. Displaying the I-V relationship for the slug on an oscilloscope, the student observes the dc and ac Josephson effects, self-induced steps, measures the Bessel function dependence of the ac effect with power, determines the flux quanta by magnetically modulating a double-junction Clarke slug, and ascertains e/h to ±O.4%. The experiment requires only a helium storage dewar and a Gunn oscillator as a microwave source in addition to readily available laboratory equipment. Detailed sections on slug preparation and trouble-shooting are included.
Astrology in Introductory Astronomy Courses for Nonscience Specialists
Authors: Zeilik Michael
Published: September 2005

Students exhibit immense interest in astrology but introductory astronomy courses commonly ignore the topic. This paper reports on a horoscope-casting exercise which capitalizes on the student's fascination to promote a discussion on astrology and its relationship to astronomy and science in general.
On the Radial Momentum Operator
Authors: Liboff Richard L. , Nebenzahl Isaiah , Fleischmann Hans H.
Published: September 2005

The validity of the radial momentum operator as an observable equivalent is investigated. In addition to the fundamental mathematical prescription, purely physical arguments are presented which demonstrate its inadmissibility. This remains in spite of its correct commutator relationship with the radial coordinate. In the course of presenting these arguments, the condition r1/2Ψ(r)←0, r←0, is derived to be a necessary condition that Ψ be an acceptable wave function.
Use of the Laplace Transform Method to Solve the One-Dimensional Periodic-Potential Problem
Authors: Santana Paulo Henrique A. , Rosato Abel
Published: September 2005

The one-dimensional periodic-potential problem is solved using the Laplace transform method. This method allows an easy generalization of the Kronig-Penney model so that it is applied to solve far more complex one-dimensional periodic structure.
General, Interactive Computer Program for the Solution of the Schrödinger Equation
Authors: Griffin Donald C. , McGhie James B.
Published: September 2005

Numerical solutions of the Schrödinger equation for a wide variety of one-dimensional problems, as well as three-dimensional spherically symmetric problems, can be obtained by students with a small computer and a general, interactive computer program. The program is described and a typical student-computer interaction is presented. As an application, solutions to the Thomas-Fermi-Dirac central field approximation for 4f electrons at the onset of the first rare-earth series of elements are discussed.
Birefringence Experiments for the Introductory Physics Course
Authors: Cloud Stanley D.
Published: September 2005

An experimental approach to birefringence has been developed for the introductory physics course. The experiments enable students to explore quantitatively the relationship between birefringence (or retardation) and the colors transmitted through birefringent material between crossed polarizers. An expression for transmitted intensity is derived, and two experiments are described, one using a grating spectrometer and the other a scanning spectrophotometer.
Description of Nonlinear Optics on an Atomic Scale
Authors: Haueisen D. C.
Published: September 2005

An examination is made of charge motion on an atomic scale in response to an applied electric field at optical frequencies to demonstrate the physical origin of nonlinear optical effects. In particular, second harmonic generation in a crystal of zinc blende structure is considered, and the zero and nonzero components of the nonlinear susceptibility tensor are obtained. Also, an estimate of the magnitude of the nonlinear susceptibility is made.
On the Negative-Energy Wave Functions for the Coulomb Field
Authors: Goodisman Jerry
Published: September 2005

In the textbook treatment of the power-series solution for the negative-energy Coulomb-field wave functions, it is usually stated that the series beginning with r−l−1 leads to a wave function diverging for r→0. This is generally not true, as we show by working out the power series explicitly.
Use of Observers in Physics Sections
Authors: Casper Karl J.
Published: September 2005

Many basic aspects of the teaching of physics can be improved through the use of relatively unskilled observers without prior training in physics. In this article, the selection of these observers and their roles within the classroom and in interaction with the instructor are described.
Magnetic Repulsion: An Introductory Experiment
Authors: Romer Alfred
Published: September 2005

To measure the repulsion between two bar magnets gives students direct experience of action at a distance and of an inverse square force. This can be done using a balance assembled from standard laboratory components. The results are analyzed by assuming an interaction between two fixed poles located near the ends of the magnets, the force between them varying inversely with the square of the distance. The theory can be extended to cover all the interactions of the two pairs of poles. Calculations from the extended theory show that within the useful range of the experiment there are no induction effects and the poles do remain fixed. Although these theories are inconsistent with the usual presentation of electromagnetic forces arising from the interactions of charges, the experiment is useful as an illustration of model-building in physics.
Copernicus and His Prescient Revolution
Authors: Raman V. V.
Published: September 2005

A remarkable feature in the life and work of Copernicus is that one can detect in them patterns and modes which were to characterize the future course of the scientific enterprise. It seems as though it was not simply a new era in science that Copernicus inaugurated; unknowingly, he also gave some indications of the nature of science and of the scientific mind in the centuries to follow.
A unified model for the long and high jump
Authors: Helene O. , Yamashita M. T.
Published: September 2005

A simple model based on the maximum energy that an athlete can produce in a small time interval is used to describe the high and long jump. Conservation of angular momentum is used to explain why an athlete should run horizontally to perform a vertical jump. Our results agree with world records.
Subaru Telescope Observations of Deep Impact
Authors: Sugita S. , Ootsubo T. , Kadono T. , Honda M. , Sako S. , Miyata T. , Sakon I. , Yamashita T. , Kawakita H. , Fujiwara H. , Fujiyoshi T. , Takato N. , Fuse T. , Watanabe J. , Furusho R. , Hasegawa S. , Kasuga T. , Sekiguchi T. , Kinoshita D. , Meech K. J. , Wooden D. H. , Ip W. H. , A'Hearn M. F.
Published: September 2005

The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (â¼10
6
kilograms) of dust and formed two wings approximately Â±45Â° from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.
Toll-Like Receptor 3 Is Induced by and Mediates Antiviral Activity against Rhinovirus Infection of Human Bronchial Epithelial Cells
Authors: Hewson Christopher A. , Jardine Alice , Edwards Michael R. , Laza-Stanca Vasile , Johnston Sebastian L.
Published: September 2005

Rhinoviruses (RV) are the major cause of the common cold and acute exacerbations of asthma and chronic obstructive pulmonary disease. Toll-like receptors (TLRs) are a conserved family of receptors that recognize and respond to a variety of pathogen-associated molecular patterns. TLR3 recognizes double-stranded RNA, an important intermediate of many viral life cycles (including RV). The importance of TLR3 in host responses to virus infection is not known. Using BEAS-2B (a human bronchial epithelial cell-line), we demonstrated that RV replication increased the expression of TLR3 mRNA and TLR3 protein on the cell surface. We observed that blocking TLR3 led to a decrease in interleukin-6, CXCL8, and CCL5 in response to poly(IC) but an increase following RV infection. Finally, we demonstrated that TLR3 mediated the antiviral response. This study demonstrates an important functional requirement for TLR3 in the host response against live virus infection and indicates that poly(IC) is not always a good model for studying the biology of live virus infection.
Virion Envelope Content, Infectivity, and Neutralization Sensitivity of Simian Immunodeficiency Virus
Authors: Yuste Eloísa , Johnson Welkin , Pavlakis George N. , Desrosiers Ronald C.
Published: September 2005

A truncating E767stop mutation was introduced into the envelope glycoprotein of simian immunodeficiency virus (SIV) strain SIV239-M5 (moderately sensitive to antibody-mediated neutralization and lacking five sites for N-linked carbohydrate attachment) and strain SIV316 (very sensitive to neutralization, with eight amino acid changes from the neutralization-resistant parental molecular clone, SIV239). The truncating mutation increased Env content in virions, increased infectivity, and decreased sensitivity to antibody-mediated neutralization in both strains. However, the magnitude of the effect on infectivity and neutralization sensitivity differed considerably between the two strains. In the context of strain SIV239-M5, truncation increased Env content in virions approximately 10-fold and infectivity in a reporter cell assay 24-fold. The truncated SIV239-M5 was only slightly more resistant to neutralization by polyclonal monkey sera and by monoclonal antibodies than SIV239-M5 with a full-length envelope glycoprotein. In the context of strain SIV316, truncation increased infectivity a dramatic 480-fold, while envelope content in virions was increased only about 14-fold. This dramatic increase in infectivity cannot be simply explained by the increase in envelope content and is likely due to an increase in inherent infectivity, i.e., infectivity per spike, that results from truncation. The truncated SIV316 was extremely resistant to antibody-mediated neutralization. In fact, it was not neutralized by any of the antibodies tested. When increasing amounts of SIV316 envelope glycoprotein (full length) were provided intransto SIV316, infectivity was increased and sensitivity to neutralization was decreased, but to nowhere near the degree that was obtained when truncated SIV316 envelope glycoprotein was used. Truncated forms of SIV239 and SIV239-M5 required higher levels of soluble CD4 for inhibition of infection than their nontruncated forms; truncated SIV316 did not. Our results suggest that envelope content in SIV virions, infectivity, and resistance to antibody-mediated neutralization can be increased not only by truncation of the cytoplasmic domain but also by provision of excess envelope intrans. The striking increase in infectivity that results from truncation in the context of SIV316 appears to be due principally to an increase in inherent infectivity per spike.
Simian Immunodeficiency Virus Infection in Free-Ranging Sooty Mangabeys (
Cercocebus atys atys
) from the Taï Forest, Côte d'Ivoire: Implications for the Origin of Epidemic Human Immunodeficiency Virus Type 2
Authors: Santiago Mario L. , Range Friederike , Keele Brandon F. , Li Yingying , Bailes Elizabeth , Bibollet-Ruche Frederic , Fruteau Cecile , Noë Ronald , Peeters Martine , Brookfield John F. Y. , Shaw George M. , Sharp Paul M. , Hahn Beatrice H.
Published: September 2005

Simian immunodeficiency virus of sooty mangabeys (SIVsmm) is recognized as the progenitor of human immunodeficiency virus type 2 (HIV-2) and has been transmitted to humans on multiple occasions, yet the epidemiology and genetic diversity of SIVsmm infection in wild-living populations remain largely unknown. Here, we report the first molecular epidemiological survey of SIVsmm in a community of ∼120 free-ranging sooty mangabeys in the Taï Forest, Côte d'Ivoire. Fecal samples (
n
= 39) were collected from 35 habituated animals (27 females and 8 males) and tested for SIVsmm virion RNA (vRNA). Viral
gag
(800 bp) and/or
env
(490 bp) sequences were amplified from 11 different individuals (eight females and three males). Based on the sensitivity of fecal vRNA detection and the numbers of samples analyzed, the prevalence of SIVsmm infection was estimated to be 59% (95% confidence interval, 0.35 to 0.88). Behavioral data collected from this community indicated that SIVsmm infection occurred preferentially in high-ranking females. Phylogenetic analysis of
gag
and
env
sequences revealed an extraordinary degree of genetic diversity, including evidence for frequent recombination events in both the recent and distant past. Some sooty mangabeys harbored near-identical viruses (<2% interstrain distance), indicating epidemiologically linked infections. These transmissions were identified by microsatellite analyses to involve both related (mother/daughter) and unrelated individuals, thus providing evidence for vertical and horizontal transmission in the wild. Finally, evolutionary tree analyses revealed significant clustering of the Taï SIVsmm strains with five of the eight recognized groups of HIV-2, including the epidemic groups A and B, thus pointing to a likely geographic origin of these human infections in the eastern part of the sooty mangabey range.
Characterization of the Infectious Salmon Anemia Virus Fusion Protein
Authors: Aspehaug Vidar , Mikalsen Aase B. , Snow Michael , Biering Eirik , Villoing Stéphane
Published: September 2005

Infectious salmon anemia virus (ISAV) is an orthomyxovirus causing serious disease in Atlantic salmon (
Salmo salar
L.). This study presents the characterization of the ISAV 50-kDa glycoprotein encoded by segment 5, here termed the viral membrane fusion protein (F). This is the first description of a separate orthomyxovirus F protein, and to our knowledge, the first pH-dependent separate viral F protein described. The ISAV F protein is synthesized as a precursor protein, F
0
, that is proteolytically cleaved to F
1
and F
2
, which are held together by disulfide bridges. The cleaved protein is in a metastable, fusion-activated state that can be triggered by low pH, high temperature, or a high concentration of urea. Cell-cell fusion can be initiated by treatment with trypsin and low pH of ISAV-infected cells and of transfected cells expressing F, although the coexpression of ISAV HE significantly improves fusion. Fusion is initiated at pH 5.4 to 5.6, and the fusion process is coincident with the trimerization of the F protein, or most likely a stabilization of the trimer, suggesting that it represents the formation of the fusogenic structure. Exposure to trypsin and a low pH prior to infection inactivated the virus, demonstrating the nonreversibility of this conformational change. Sequence analyses identified a potential coiled coil and a fusion peptide. Size estimates of F
1
and F
2
and the localization of the putative fusion peptide and theoretical trypsin cleavage sites suggest that the proteolytic cleavage site is after residue K
276
in the protein sequence.
Risk of lymphatic or haematopoietic cancer mortality with occupational exposure to animals or the public
Authors: Svec M A , Ward M H , Dosemeci M , Checkoway H , De Roos A J
Published: September 2005

Background:Occupational exposure to animals or the public could result in exposure to infectious agents, which may play a role in the aetiology of lymphohaematopoietic (LH) cancers.

Aims:To conduct a population based, case-control study of death certificate data from 1984 to 1998 in 24 US states in order to evaluate the risk of mortality from LH neoplasms associated with occupational exposure to animals or the public.

Methods:Cases were selected as those with an underlying cause of death of non-Hodgkin’s lymphoma (NHL, n = 72 589), Hodgkin’s disease (HD, n = 5479), multiple myeloma (n = 35 857), or leukaemia (n = 68 598); 912 615 controls were randomly selected from all remaining deaths, frequency matched on age, sex, race, and geographic region.

Results:Occupational exposure to animals was associated with modest increased risks of mortality from all four LH cancers; these associations varied by region. Occupational exposure to the public was associated with only negligible increased risk with LH cancer outcomes. Occupations involving animal exposure were predominantly agricultural, and the risks associated with employment in the livestock industry exceeded the corresponding risks associated with the crop industry for all outcomes except HD.

Conclusions:Increased risks of NHL, HD, multiple myeloma, and leukaemia were associated with occupations that involved animal exposure. Regional differences in risk imply that the risks may be associated with exposure to specific livestock or farming practices. However, these associations may be confounded by other farming related exposures, such as pesticides. Because the use of death certificates to classify occupation may result in misclassification during aetiologically relevant time periods, these hypotheses should be further explored in studies with detailed information on lifetime occupation.
Bayesian nonparametric analysis of stockrecruitment relationships
Authors: Munch Stephan B , Kottas Athanasios , Mangel Marc
Published: September 2005

The relationship between current abundance and future recruitment to the stock is fundamental to managing fish populations. However, many different recruitment models are plausible and the data are insufficient to distinguish among them. Although nonparametric methods may be used to circumvent this problem, these are devoid of biological underpinnings. Here, we present a Bayesian nonparametric approach that allows straightforward incorporation of prior biological information and use it to estimate several fishery reference points. We applied this method to artificial data sets generated from a variety of parametric models and compare the results with the fit of Ricker and BevertonHolt models. We found that the Bayesian nonparametric method fit the data nearly as well as the true parametric model and always performed better than incorrect parametric alternatives. The estimated reference points agree closely with true values calculated for the underlying parametric model. Finally, we apply the method to empirical data for lingcod (Ophiodon elongatus) and several salmonids. Since this method is capable of reproducing the behavior of any of the parametric models and provides flexible, data-driven estimates of stockrecruitment relationships, it should be of great value in fisheries applications where the true functional relationship is always unknown.
Potential benefits of a conservation hatchery program for supplementing Oregon coast coho salmon (Oncorhynchus kisutch) populations: a stochastic model investigation
Authors: Oosterhout Gretchen R , Huntington Charles W , Nickelson Thomas E , Lawson Peter W
Published: September 2005

This study developed a stochastic life cycle model to simulate idealized supplementation strategies to investigate the following question: under what circumstances could hatchery fish stocking contribute to the recovery of Oregon coast coho salmon (Oncorhynchus kisutch)? Simulations were used to find a solution space, defined by the attributes of wild and hatchery-bred salmon, their offspring, and their environments, where hatchery fish could supplement natural production without further depressing it until natural or human factors restricting production were relieved. These simulations suggest that short-duration, tightly controlled, low-intensity conservation hatchery programs designed to minimize genetic and ecological risks may yield minor short-term increases in adult coho salmon abundance while posing significant ecological and genetic risks. No solution space was found that indicated clear long-term benefits from such a supplementation program. Of all the management actions modeled, habitat restoration offered by far the largest and only permanent gains in coho salmon abundance while posing no genetic or ecological risk to the fish. The modeled benefits of habitat restoration were significant regardless of assumptions made about the fitness of hatchery fish and their offspring.
Impacts of water depth, sediment pigment concentration, and benthic macrofaunal biomass on sediment oxygen demand in the western Arctic Ocean
Authors: Clough Lisa M , Renaud Paul E , Ambrose Jr. William G
Published: September 2005

We investigated the impacts of water depth, sediment pigment concentration, and benthic macrofaunal biomass on sediment oxygen demand (SOD) during three cruises to the western Arctic Ocean. SOD values were similar to those of most studies from the Arctic and ranged from a high of 20.68 mmol O2·m2·day1 at a shallow shelf station to a low of 0.29 mmol O2·m2·day1 at the deepest basin station (3648 m). SOD was significantly greater at shallow sites (<500 m; mean = 7.39 mmol O2·m2·day1; standard deviation (SD) = ±5.38) than at deep sites (>500 m; mean = 1.39 mmol O2·m2·day1; SD = ±0.96). As hypothesized, SOD was negatively correlated with water depth and positively correlated with both surface-sediment pigment concentration and macrofaunal biomass, with macrofaunal biomass explaining approximately 74% of the variability in SOD. We propose that higher macrofauna-normalized respiration rates (i.e., SOD divided by macrofaunal biomass) in deep water indicate that microbialmeiofaunal respiration predominates in deep versus shallow water. Finally, deeper stations associated with Barrow Canyon had SODs, benthic macrofaunal biomass, and surface-sediment pigment concentrations that were similar to those of shallower shelf locations, suggesting down-canyon transport of organic material.