bluuebunny/crossref_metadata_2025 huggingface dataset:
Canning—an approach to the physics laboratory
Authors: Dowling John
Published: March 2005

This paper is a reexamination of the concept of a canned computer lab. The canned computer lab uses a stored computer program to perform calculations, analyze data, determine errors, and to ask questions after a student performs a lab. Primary use of the canned lab is for computer−disadvantaged institutions with no on−line facilities. The educational and software advantages and disadvantages of this approach are discussed. Conclusions and anti−conclusions reached after over two years use of canned labs are given. An appendix gives a sample output for the ballistic pendulum lab.
A simple model of electron drift velocity
Authors: Zane L. I.
Published: March 2005

Some elementary texts treat the derivation of the electron drift velocity in a very cavalier fashion. We show that by using simple ideas of probability theory the desired result can be obtained without invoking suspicious steps.
Phonograph cartridges as displacement transducers
Authors: Fishman F. J.
Published: March 2005

The utility of inexpensive, piezoelectric−type phonograph cartridges in the undergraduate laboratory is pointed out. Typical voltage sensitivities of 7×104 V/m and charge sensitivities of 2×10−5 C/m, along with leakage resistance of the order of 1011 ω and are reported, and corresponding implications for compatible electrical circuitry discussed. Two experiments using these cartridges in a ’’Physics of Music’’ laboratory are described.
Definition of instantaneous frequency and frequency measurability
Authors: Gupta Madhu Sudan
Published: March 2005

It is pointed out that the definitions of instantaneous and Fourier frequencies of a signal are noncausal and their measurement requires physically unrealizable systems. Some additional definitions of frequency are given that are causal.
Why −i∇ is the momentum
Authors: Jordan Thomas F.
Published: March 2005

The operators −i∇, the translation generators, are related to mass and velocity by a simple argument that determines the form of the Hamiltonian, in terms of the translation generators, along with the Galilei generators, for a nonrelativistic particle. For a relativistic particle, a similar discussion is given for the analogous problem of determining the position operators for an irreducible unitary representation of the Poincaré group, at least well enough to identify the velocity operators and thus identify the momentum.
Optical activity demonstration
Authors: Freier George , Eaton B. G.
Published: March 2005

This article describes in general terms a hall demonstration of optical activity using Karo syrup. This particular demonstration is used as an eye-catcher to lure students into stopping and also looking at the other demonstrations. [The apparatus described in this article was second prize winner in the College Demonstration category of the 1975 AAPT Apparatus Competition—Editor]
Coupled-cavity interferometer for the optics laboratory
Authors: Peterson R. W.
Published: March 2005

A flexible coupled-cavity interferometer for student use has been constructed. A helium–neon laser serves as a source of radiation and as a phase-sensitive detector of optical path changes. A phonograph turntable allows the convenient magnetic mounting of various reflecting components at varying linear velocities. Methods of calibration and possible laboratory measurements of transient events are discussed. [The apparatus described in this article was first prize winner in the College Intructional Laboratory category of the 1975 AAPT Apparatus Competition—Editor]
Demonstrations using a Fabry–Perot. I. Multiple-slit interference
Authors: Roychoudhuri Chandrasekhar
Published: March 2005

A method is described by which a multiple-slit interference pattern can be demonstrated quite easily with the help of an inexpensive Fabry–Perot etalon and a low-power laser beam. The separation between the ’’slits’’ can be adjusted continuously. The experiment brings forth the similarity between a grating and a Fabry–Perot as a fringe-sharpening device. A simple derivation of the analytical expression for such fringes is presented.
Demonstrations using a Fabry–Perot. II. Laser modes display
Authors: Roychoudhuri Chandrasekhar , Noble Robert H.
Published: March 2005

A Fabry–Perot etalon is used to display both the longitudinal and the transverse modes present in a laser beam. Analysis and experimentations show that plates no better than λ/20 flatness and spacers in the range between 4 and 10 cm are satisfactory for helium–neon lasers.
Analysis of a thermal conductivity of gas experiment
Authors: Benenson R. E. , Dubin R. R.
Published: March 2005

The data from a projects laboratory experiment are analyzed to give values of the coefficient of thermal conductivity λ. Experiments using simplified apparatus were carried out on the temperature and pressure dependence. Thermal conductivity of gas measurements are discussed for the case of large gradients in coaxial cylinder apparatus, a technique used in recent research. The various sources of error common to such measurements are assessed, including convection according to recent treatments.
Tensor description of physical properties of crystals
Authors: Gaylord T. K.
Published: March 2005

The use of tensors for describing the physical properties of crystals is not particularly widespread in undergraduate curricula. Tensor concepts, however, are unavoidable in describing the properties of anisotropic media, of which crystals are a very important example. This paper describes suggested introductory material on tensors for use in an undergraduate materials science course. Special emphasis has been placed on communicating the basic tensor concepts through the use of examples. Mathematical manipulations have intentionally been minimized.
Second-order phase transitions: Models and analogies
Authors: Guyon Etienne
Published: March 2005

We present models of second-order phase transitions, using elementary equipment, which reproduce the static behavior above a mean field phase transition and the thermodynamic slowing down on each side of it. The model is compared to continuum physics examples involving side effects in liquid crystals (Freedericksz transition) and in superconductors (proximity effect).
Resourse Letter TLA−2: Technology, literature, and the arts, contemporary
Authors: Davenport William H.
Published: March 2005

Prepared at the request of the AAPT Editorial Board for Resource Letters. This is a supplement to one of a series of Resource Letters on different topics intended to guide college physicists, astronomers, and other scientists to some of the literature and other teaching aids that may help improve course contents in specified fields. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter or supplement on some of the main subjects of interest. Comments on these materials as well as suggestions for future topics will be welcomed. Please send such communications to Professor Arthur R. Quinton, Editor, Resource Letter Board, Department of Physics and Astronomy, University of Massachusetts, Amherst, Massachusetts 01002.

Reprints: When ordering, request Resource Letter TLA−2, enclose 50 cents per copy (not in stamps) together with a stamped and self−addressed envelope to Arnold A. Strassenburg, Executive Officer, American Association of Physics Teachers, Drawer AW, Stony Brook, New York 11790.
A convincing demonstration of the Rutherford csc4 (θ/2) law
Authors: Ramage J. C. , McKeown J. , Ledingham K. W. D.
Published: March 2005

The object of this paper is to show that the angular dependence of the Rutherford scattering of alpha particles from foils is by no means an easy problem, but if sufficient care is taken, it provides a very satisfactory experiment for an advanced undergraduate teaching laboratory. Moreover, if the alpha particle energy is simultaneously investigated as the angle is changed, then the energy of the recoiling raget nucleus and the alpha particle energy loss through thin foils can also be measured.
Supra-Canonical
26
Al/
27
Al and the Residence Time of CAIs in the Solar Protoplanetary Disk
Authors: Young Edward D. , Simon Justin I. , Galy Albert , Russell Sara S. , Tonui Eric , Lovera Oscar
Published: March 2005

The canonical initial
26
Al/
27
Al ratio of 4.5 × 10
-5
has been a fiducial marker for the beginning of the solar system. Laser ablation and whole-rock multiple-collector inductively coupled plasma-source mass spectrometry magnesium isotope analyses of calcium- and aluminum-rich inclusions (CAIs) from CV3 meteorites demonstrate that some CAIs had initial
26
Al/
27
Al values at least 25% greater than canonical and that the canonical initial
26
Al/
27
Al cannot mark the beginning of solar system formation. Using rates of Mg diffusion in minerals, we find that the canonical initial
26
Al/
27
Al is instead the culmination of thousands of brief high-temperature events incurred by CAIs during a 10
5
-year residence time in the solar protoplanetary disk.
Activation of a Phytopathogenic Bacterial Effector Protein by a Eukaryotic Cyclophilin
Authors: Coaker Gitta , Falick Arnold , Staskawicz Brian
Published: March 2005

Innate immunity in higher plants invokes a sophisticated surveillance system capable of recognizing bacterial effector proteins. In
Arabidopsis
, resistance to infection by strains of
Pseudomonas syringae
expressing the effector AvrRpt2 requires the plant resistance protein RPS2. AvrRpt2 was identified as a putative cysteine protease that results in the elimination of the
Arabidopsis
protein RIN4. RIN4 cleavage serves as a signal to activate RPS2-mediated resistance. AvrRpt2 is delivered into the plant cell, where it is activated by a eukaryotic factor that we identify as cyclophilin. This activation of AvrRpt2 is necessary for protease activity. Active AvrRpt2 can then directly cleave RIN4.
Bactericidal Activity of Colicin V Is Mediated by an Inner Membrane Protein, SdaC, of
Escherichia coli
Authors: Gérard Fabien , Pradel Nathalie , Wu Long-Fei
Published: March 2005

Colicin V (ColV) is a peptide antibiotic that kills sensitive cells by disrupting their membrane potential once it gains access to the inner membrane from the periplasmic face. Recently, we constructed a translocation suicide probe, RR-ColV, that is translocated into the periplasm via the TAT pathway and thus kills the host cells. In this study, we obtained an RR-ColV-resistant mutant by using random Tn
10
transposition mutagenesis. Sequencing analysis revealed that the mutant carried a Tn
10
insertion in the
sdaC
(also called
dcrA
) gene, which is involved in serine uptake and is required for C1 phage adsorption. ColV activity was detected both in the cytoplasm and in the periplasm of this mutant, indicating that RR-ColV was translocated into the periplasm but failed to interact with the inner membrane. The
sdaC
::Tn
10
mutant was resistant only to ColV and remained sensitive to colicins Ia, E3, and A. Most importantly, the
sdaC
::Tn
10
mutant was killed when ColV was anchored to the periplasmic face of the inner membrane by fusion to EtpM, a type II integral membrane protein. Taken together, these results suggest that the SdaC/DcrA protein serves as a specific inner membrane receptor for ColV.
Nosocomial Outbreak Caused by
Salmonella enterica
Serotype Livingstone Producing CTX-M-27 Extended-Spectrum β-Lactamase in a Neonatal Unit in Sousse, Tunisia
Authors: Bouallègue-Godet Olfa , Salem Youssef Ben , Fabre Laëtitia , Demartin Marie , Grimont Patrick A. D. , Mzoughi Ridha , Weill François-Xavier
Published: March 2005

In this study, we report an outbreak of
Salmonella enterica
serotype Livingstone resistant to extended-spectrum cephalosporins that occurred in a neonatal ward of the maternity department of Farhat Hached Hospital, Sousse, Tunisia, in 2002. A total of 16 isolates were recovered from 16 babies hospitalized in the ward during the period 1 to 16 July. All these babies developed diarrhea, and three of them developed septicemia. All the isolates demonstrated resistance to ceftriaxone and ceftazidime due to the production of an extended-spectrum β-lactamase (ESBL). The isolates were also resistant to aminoglycosides (kanamycin, tobramycin, netilmicin, gentamicin, and amikacin) and sulfamethoxazole-trimethoprim. DNA profiles were determined by pulsed-field gel electrophoresis using the XbaI and SpeI endonucleases and by ribotyping with PstI digestion. They yielded the same patterns, showing that the outbreak was caused by a single clone. The ESBL was identified as CTX-M-27 by sequencing of PCR products and by isoelectric focusing. The ESBL resistance was transferred by a 40-kb conjugative plasmid. The mobile insertion sequence IS
Ecp1
was found to be located upstream of
bla
CTX-M-27
in the same position as that known for a
bla
CTX-M-14
sequence. A new gene named
dfrA21
, encoding resistance to trimethoprim and carried by a 90-kb plasmid, was characterized. The
dfrA21
gene was inserted as a single resistance cassette in a class I integron. The babies were treated with colistin, and all except two recovered. The outbreak came to an end when appropriate actions were taken: patient isolation, hand washing, and disinfection of the ward.
Establishment of a Universal Size Standard Strain for Use with the PulseNet Standardized Pulsed-Field Gel Electrophoresis Protocols: Converting the National Databases to the New Size Standard
Authors: Hunter Susan B. , Vauterin Paul , Lambert-Fair Mary Ann , Van Duyne M. Susan , Kubota Kristy , Graves Lewis , Wrigley Donna , Barrett Timothy , Ribot Efrain
Published: March 2005

The PulseNet National Database, established by the Centers for Disease Control and Prevention in 1996, consists of pulsed-field gel electrophoresis (PFGE) patterns obtained from isolates of food-borne pathogens (currently
Escherichia coli
O157:H7,
Salmonella
,
Shigella
, and
Listeria
) and textual information about the isolates. Electronic images and accompanying text are submitted from over 60 U.S. public health and food regulatory agency laboratories. The PFGE patterns are generated according to highly standardized PFGE protocols. Normalization and accurate comparison of gel images require the use of a well-characterized size standard in at least three lanes of each gel. Originally, a well-characterized strain of each organism was chosen as the reference standard for that particular database. The increasing number of databases, difficulty in identifying an organism-specific standard for each database, the increased range of band sizes generated by the use of additional restriction endonucleases, and the maintenance of many different organism-specific strains encouraged us to search for a more versatile and universal DNA size marker. A
Salmonella
serotype Braenderup strain (H9812) was chosen as the universal size standard. This strain was subjected to rigorous testing in our laboratories to ensure that it met the desired criteria, including coverage of a wide range of DNA fragment sizes, even distribution of bands, and stability of the PFGE pattern. The strategy used to convert and compare data generated by the new and old reference standards is described.
Identification of
Mycobacterium
Species by
secA1
Sequences
Authors: Zelazny Adrian M. , Calhoun Leslie B. , Li Li , Shea Yvonne R. , Fischer Steven H.
Published: March 2005

We describe a novel molecular method for the differentiation and identification of 29 mycobacterial species. The target is the
secA1
gene that codes for the essential protein SecA1, a key component of the major pathway of protein secretion across the cytoplasmic membrane. A 700-bp region of the
secA1
gene was amplified and sequenced from 47 American Type Culture Collection strains of 29
Mycobacterium
species as well as from 59 clinical isolates. Sequence variability in the amplified segment of the
secA1
gene allowed the differentiation of all species except for the members of the
Mycobacterium tuberculosis
(MTB) complex, which had identical sequences. A range of 83.3 to 100% interspecies similarity was observed. All species could also be differentiated by their amino acid sequences as deduced from the sequenced region of the
secA1
gene, with the exception of the MTB complex. Partial sequences of
secA1
from clinical isolates belonging to nine frequently isolated species of mycobacteria revealed a very high intraspecies similarity at the DNA level (typically >99%; range, 96.0 to 100%); all clinical isolates were correctly identified. Comparison of the deduced 233-amino-acid sequences among clinical isolates of the same species showed between 99.6 and 100% similarity. To our knowledge, this is the first time a secretion-related gene has been used for the identification of the species within a bacterial genus.
Extended-Spectrum β-Lactamase-Producing Shiga Toxin Gene (
stx
1
)-Positive
Escherichia coli
O26:H11: a New Concern
Authors: Ishii Yoshikazu , Kimura Soichiro , Alba Jimena , Shiroto Katsuaki , Otsuka Masanobu , Hashizume Naotaka , Tamura Kazumichi , Yamaguchi Keizo
Published: March 2005

Escherichia coli
strain TUM2139 was isolated from a stool sample from a 9-year-old girl on 16 June 2004. This strain was categorized as Shiga toxin-producing
Escherichia coli
(STEC) because the Shiga-like toxin gene
stx
1
was detected by immunochromatography and PCR assay. The strain was highly resistant to cefotaxime (256 μg/ml) and was also resistant to cefepime, cefpodoxime, ceftriaxone, and aztreonam. In the presence of 4 μg of clavulanic acid per ml, the MIC of cefotaxime decreased to ≤0.12 μg/ml, indicating that this strain was an extended-spectrum β-lactamase (ESBL) producer. Cefotaxime resistance was transferred to
E. coli
C600 by conjugation at a frequency of 3.0 × 10
−6
. A PCR assay was performed with primer sets specific for TEM-type and SHV-type ESBLs and for the CTX-M-2 (Toho-1), CTX-M-3, and CTX-M-9 groups of ESBLs. A specific signal was observed with the primer set specific for the CTX-M-9 group of β-lactamases. This β-lactamase was confirmed to be the ESBL CTX-M-18 by DNA sequencing. This is the first report of an ESBL-producing STEC isolate.
Molecular Epidemiology of Norovirus Infections in Stockholm, Sweden, during the Years 2000 to 2003: Association of the GGIIb Genetic Cluster with Infection in Children
Authors: Lindell Annika Tiveljung , Grillner Lena , Svensson Lennart , Wirgart Benita Zweygberg
Published: March 2005

The incidence of norovirus-associated gastroenteritis and the molecular epidemiology of norovirus strains were studied during three seasons (2000-2001, 2001-2002, and 2002-2003) among patients of all ages, mainly from the Stockholm region in Sweden. A total of 3,252 fecal samples were analyzed by reverse transcription-PCR. The incidences of norovirus infection among adults were 23, 26, and 30% during the three seasons studied and 18, 11, and 15% among children 0 to 15 years of age. During the first season, all norovirus strains detected by PCR were typed either by reverse line blot hybridization or nucleotide sequence analysis. During the two successive seasons, a total of 60 norovirus-positive strains from the beginning, peak, and end of the seasons were selected for nucleotide sequence analysis. We identified two dominant norovirus variants over the seasons: a new norovirus variant, recently described as the GGIIb genetic cluster, dominated among children during the first season, and during the following two seasons, a GGII-4 variant dominated. Our data suggest that norovirus infections are common, not only among adults, but also among children, and that some strains may predominantly affect children.
Detection and Identification of
Ehrlichia
spp. in Ticks Collected in Tunisia and Morocco
Authors: Sarih M'Hammed , M'Ghirbi Youmna , Bouattour Ali , Gern Lise , Baranton Guy , Postic Danièle
Published: March 2005

A broad-range 16S rRNA gene PCR assay followed by partial sequencing of the 16S rRNA gene was used for the detection of members of the family
Anaplasmataceae
in ticks in North Africa. A total of 418 questing
Ixodes ricinus
ticks collected in Tunisia and Morocco, as well as 188
Rhipicephalus
ticks from dogs and 52
Hyalomma
ticks from bovines in Tunisia, were included in this study. Of 324 adult
I. ricinus
ticks, 16.3% were positive for
Ehrlichia
spp., whereas only 3.4 and 2.8% of nymphs and larvae, respectively, were positive. A large heterogeneity was observed in the nucleotide sequences. Partial sequences identical to that of the agent of human granulocytic ehrlichiosis (HGE) were detected in
I. ricinus
and
Hyalomma detritum
, whereas partial sequences identical to that of
Anaplasma platys
were detected in
Rhipicephalus sanguineus
. However, variants of
Anaplasma
, provisionally designated
Anaplasma-
like, were predominant in the
I. ricinus
tick population in Maghreb. Otherwise, two variants of the genus
Ehrlichia
were detected in
I. ricinus
and
H. detritum
. Surprisingly, a variant of
Wolbachia pipientis
was evidenced from
I. ricinus
in Morocco. These results emphasized the potential risk of tick bites for human and animal populations in North Africa.
Typing of
Saccharomyces cerevisiae
Clinical Strains by Using Microsatellite Sequence Polymorphism
Authors: Malgoire J. Y. , Bertout S. , Renaud F. , Bastide J. M. , Mallié M.
Published: March 2005

It seems that
S. cerevisiae
, which was thought for about 30 years to be a nonpathogenic yeast, should now be considered an opportunistic pathogen. In this study, we estimated the discrimination ability of the microsatellite sequence amplification technique within a sample of clinical and reference
S. cerevisiae
strains and
S. boulardii
reference strains.
Detection of Human Metapneumovirus Antigens in Nasopharyngeal Secretions by an Immunofluorescent-Antibody Test
Authors: Ebihara Takashi , Endo Rika , Ma Xiaoming , Ishiguro Nobuhisa , Kikuta Hideaki
Published: March 2005

Human metapneumovirus (hMPV) is a recently discovered pathogen associated with respiratory tract infections, primarily in young children, immunocompromised individuals, and elderly individuals. Reverse transcription-PCR (RT-PCR) has been reported to be a more sensitive method for the diagnosis of hMPV infections than virus isolation by culture and serological study. However, there has been no report on rapid methods, such as an immunofluorescent-antibody test or an enzyme-linked immunosorbent assay, for the detection of hMPV antigens in nasopharyngeal secretions. In this study, we compared an indirect immunofluorescent-antibody test (IFA) with a monoclonal antibody with RT-PCR for detection of hMPV in nasal secretions from 48 hospitalized children with respiratory tract infections. Fifteen of the 48 children were positive for hMPV by RT-PCR. IFA results were positive for 11 of the 15 RT-PCR-positive children (sensitivity, 73.3%) and 1 of the 33 RT-PCR-negative children (specificity, 97.0%). Although the sensitivity of IFA is lower than that of RT-PCR, IFA is a rapid and useful test for the diagnosis of hMPV infections in children.
Vi Antigen Expression in
Salmonella enterica
Serovar Typhi Clinical Isolates from Pakistan
Authors: Wain John , House Deborah , Zafar Afia , Baker Stephen , Nair Satheesh , Kidgell Claire , Bhutta Zulfiqar , Dougan Gordon , Hasan Rumina
Published: March 2005

The accurate identification of
Salmonella enterica
subsp.
enterica
serovar Typhi variants that fail to express the capsular polysaccharide, Vi, is an important and much discussed issue for medical microbiology. We have tested a multiplex PCR method which shows the presence or absence of the genetic locus required for Vi expression. Of 2,222
Salmonella
serovar Typhi clinical isolates collected from patients' blood over a 4-year period in a region of Pakistan where typhoid is endemic, 12 tested negative for Vi expression by serological agglutination. However, only 1 of these 12 was Vi negative by the multiplex PCR method. This result was confirmed by immunofluorescence, the most sensitive method for Vi characterization in
Salmonella
serovar Typhi. The multiplex PCR described therefore represents a simple and accurate method for surveillance for Vi-negative variants of
Salmonella
serovar Typhi in Pakistan. Testing of clinical isolates of
Salmonella
serovar Typhi, before subculture, from other regions where Vi-negative
Salmonella
serovar Typhi has been described should be carried out so that the impact of vaccination with purified Vi antigen on the levels of Vi-negative
Salmonella
serovar Typhi in bacterial populations can be assessed.
Comparative Typing of
Campylobacter jejuni
by Heat-Stable Serotyping and PCR-Based Restriction Fragment Length Polymorphism Analysis
Authors: Nakari Ulla-Maija , Laaksonen Katja , Korkeila Maija , Siitonen Anja
Published: March 2005

Campylobacter
jejuni
has become the most common bacterial cause of human
gastroenteritis worldwide. Rapid, discriminatory typing methods are
required to identify potential clusters of infections. The major
disadvantage of the well-evaluated and widely used Penner heat-stable
serotyping method is the high level of nontypeability. The correlation
of the types determined by the Penner heat-stable serotyping method and
PCR-based restriction fragment length polymorphism (RFLP) analysis of
the lipooligosaccharide (LOS) biosynthesis genes of
C. jejuni
was studied with 149
C. jejuni
strains. Of these strains, 79
were patient strains belonging to 25 Penner serotypes, 60 were
nontypeable patient strains, and 10 were reference strains. A 9.6-kb
DNA fragment of the LOS gene cluster was amplified and digested with
the restriction enzymes HhaI and DdeI. Altogether, 39
different RFLP types (including 30 HhaI profiles and 32 DdeI profiles)
were identified. Type Hh1Dd1 was the most common type, with 36%
of the strains and strains of 12 serotypes being of this type. A high
level of discrimination was obtained, and a correlation between the
Penner serotypes and the PCR-RFLP types could be seen. Also, variation
in the LOS biosynthesis genes within a single Penner serotype was
found. Although the PCR-RFLP method may not be sufficient to compensate
for Penner serotyping, it can give valuable information about
nontypeable strains and further characterize strains of common
serotypes.
Epidemiologic Import of Tuberculosis Cases Whose Isolates Have Similar but Not Identical IS
6110
Restriction Fragment Length Polymorphism Patterns
Authors: Cave M. D. , Yang Z. H. , Stefanova R. , Fomukong N. , Ijaz K. , Bates J. , Eisenach K. D.
Published: March 2005

Isolates of
Mycobacterium tuberculosis
from patients with epidemiologic links frequently demonstrate identical IS
6110
restriction fragment length polymorphism (RFLP) patterns (i.e., RFLP clustering) because they are infected with the same strain. Uncertainty arises with isolates that differ from one another by a few IS
6110
hybridizing bands. During the period from 1 January 1996 to 31 December 1999, isolates from 585 tuberculosis (TB) cases were analyzed by RFLP, representing 98.2% of the 596 culture-positive TB cases reported in Arkansas during the study period. Of the 585 cases for which RFLP was available, 419 (71.6%) had an RFLP pattern with more than five copies of IS
6110
. Of the total 74 clusters, 48 comprised isolates with more than five copies of IS
6110
and included 164 cases. Sixty-nine isolates with more than five copies of IS
6110
comprising 16 clusters and 60 unique isolates were found to be similar to at least 1 other isolate (differing from it by one or two hybridizing bands). Among the 129 cases whose isolates were similar to other clustered or unique isolates, 16 cases were discovered with epidemiologic links: 14 (15.2%) were among the 92 cases with IS
6110
RFLP patterns similar to those in clusters, and 2 (5.2%) were among the 37 unique cases that were similar to another unique case. The isolates from the epidemiologically linked patients shared common spoligotypes; all except one case shared common polymorphic GC-rich sequence (PGRS) patterns. Of the 129 patients whose isolates differed from another by one or two hybridizing IS
6110
bands, 101 (78.3%) shared common spoligotypes and 87 (67.4%) shared common PGRS RFLP patterns.
Identification of
Streptococcus canis
Isolated from Milk of Dairy Cows with Subclinical Mastitis
Authors: Hassan Abdulwahed Ahmed , Akineden Ömer , Usleber Ewald
Published: March 2005

Streptococcus canis
was isolated from 31 milk samples from 11 cows in a dairy herd (with 49 lactating cows) affected by subclinical mastitis in north Rhine-Westphalia, Germany. Thirty-one isolates from the infected udder quarters were further characterized for their phenotypic and molecular properties. Most isolates (83.9%) produced α-galactosidase, and all were negative for β-
d
-glucuronidase. Amplification of the 16S rRNA gene by the PCR method and digestion with the restriction enzymes RsaI, MspI, and AvaII yielded species-specific patterns. Additional identification by species-specific amplification of the 16S rRNA gene, the 16S-23S rRNA gene intergenic spacer region, the CAMP factor-encoding gene
cfg
, and the internal fragments of the
sodA
gene was consistent with
S. canis
. Macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis showed that the
S. canis
isolates originated from a single clone or were very closely related.
Comparison of Easy-Flow Copan Liquid Stuart's and Starplex Swab Transport Systems for Recovery of Fastidious Aerobic Bacteria
Authors: Drake Cheryl , Barenfanger Joan , Lawhorn Jerry , Verhulst Steven
Published: March 2005

Because samples are frequently submitted on swabs from distant sites, viability of the organism must be maintained. We compared two transport systems, a new Copan Liquid Stuart's swab with an Easy-Flow swab applicator and the Starplex Liquid Stuart's swab. The purpose of the study was to assess the release and/or recovery of organisms from the Copan system compared to that from Starplex. Triplicate swabs were seeded with 3 dilutions of
Neisseria gonorrhoeae
,
Neisseria meningitidis
,
Haemophilus influenzae
, and
Streptococcus pneumoniae
. Although the amount of the initial inoculum was the same for both transport systems, recovery by the roll-plate method at time zero was consistently increased with the Copan system (31 to 87% higher). This is the most important finding in this study. With
N. gonorrhoeae
, subsequent recoveries were similar for Copan and Starplex but poor for both systems. With
N. meningitidis
and
Haemophilus
, higher levels of recovery were clearly obtained with Copan (
P
< 0.05 to
P
< 0.001). With
Streptococcus
, subsequent recoveries for Copan and Starplex were mixed. In conclusion, Copan generally demonstrated better recovery of organisms compared to Starplex even (and especially) at time zero.
Human Cytomegalovirus Reactivation during Lactation and Mother-to-Child Transmission in Preterm Infants
Authors: Meier Johannes , Lienicke Uta , Tschirch Edda , Krüger Detlev H. , Wauer Roland R. , Prösch Susanna
Published: March 2005

In a clinical trial, the incidence of cytomegalovirus reactivation in breastfeeding mothers and transmission to their preterm infants were studied. Breast milk from 73 mothers as well as urine and tracheal and pharyngeal aspirates from their 89 infants were screened weekly for human cytomegalovirus (HCMV) DNA during the first 2 months after delivery. Of the 73 mothers, 48 (66%) were positive for HCMV DNA in the lactating breast. HCMV reactivation could be confirmed for 19 of 20 (95%) immunoglobulin G-positive mothers. Of the eight immunoglobulin G-negative mothers one was positive for HCMV DNA in breast milk. In only 2 out of 13 seropositive mothers with HCMV DNA in breast milk could viral DNA be detected in the peripheral blood. HCMV mother-to-child transmission was concluded for 20 of the 48 (42%) mothers positive for DNA or 7 of 19 (37%) seropositive for HCMV and positive for HCMV DNA in breast milk and one of one mother seronegative for HCMV but positive for HCMV DNA in breast milk. One mother transmitted the virus to her twins. In addition, one infant acquired postnatal HCMV infection despite the mother's being negative for HCMV DNA in breast milk; altogether, we found 22 infants with HCMV infection. In 13 of these 22 infants, virus infection occurred definitively postnatally; two of them developed severe symptomatic HCMV infection. HCMV-infected infants demonstrated higher incidences of amniotic infection, respiratory distress syndrome, bronchopulmonary dysplasia, and retinopathia praenatalis than noninfected infants, however, the differences were not statistically significant. In summary, our study confirmed a very high incidence of HCMV reactivation in mothers during lactation and a significant risk of transmission to preterm infants with the possibility of severe disease in these babies.
Effect of Clarithromycin Treatment on
Chlamydia pneumoniae
in Vascular Tissue of Patients with Coronary Artery Disease: a Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Berg Hans F. , Maraha Boulos , van der Zee Anneke , Gielis Siska K. , Roholl Paul J. M. , Scheffer Gert-Jan , Peeters Marcel F. , Kluytmans Jan A. J. W.
Published: March 2005

Several small clinical trials have indicated that antibiotic treatment of
Chlamydia pneumoniae
infection is associated with a better outcome in patients with coronary artery disease (CAD). It has not been demonstrated whether antibiotic treatment eradicates
C. pneumoniae
from vascular tissue. The aim of the present study was to assess the effect of clarithromycin on the presence of
C. pneumoniae
in the vascular tissue of patients with CAD. Patients who had CAD and who were waiting for coronary artery bypass graft surgery were enrolled in a randomized, double-blind, placebo-controlled trial. Patients were treated with clarithromycin at 500 mg or placebo once daily from the day of inclusion in the study until surgery. Several vascular tissue specimens were obtained during surgery. The presence of
C. pneumoniae
in vascular tissue specimens was examined by immunohistochemical staining (IHC) and two PCR assays.
Chlamydia
immunoglobulin G (IgG) titers were determined by an enzyme-linked immunosorbent assay at the time of inclusion in the study and 8 weeks after surgery. A total of 76 patients were included, and 180 vascular tissue specimens were obtained (80 specimens from the group treated with clarithromycin and 100 specimens from the group treated with placebo). Thirty-five patients received clarithromycin (mean duration, 27 days; standard deviation [SD], 12.2 days), and 41 patients received placebo (mean duration, 27 days; SD, 13.9 days). IHC detected the
C. pneumoniae
major outer membrane protein antigen in 73.8% of the specimens from the group treated with clarithromycin and 77.0% of the specimens from the group treated with placebo (
P
was not significant).
Chlamydia
lipopolysaccharide antigen was found in only one specimen from the group that received placebo.
C. pneumoniae
DNA was not detected in any specimen. Baseline
Chlamydia
-specific IgG titers were equally distributed in both groups and were not significantly different after treatment. There was no indication of an active
C. pneumoniae
infection in vascular tissue.
Chlamydia
-specific IgG titers remained unchanged throughout the study in both the antibiotic- and the placebo-treated patients.
Genomic Relatedness of the New Matlab Variants of
Vibrio cholerae
O1 to the Classical and El Tor Biotypes as Determined by Pulsed-Field Gel Electrophoresis
Authors: Safa Ashrafus , Bhuiyan Nurul Amin , Alam Munirul , Sack David A. , Nair G. Balakrish
Published: March 2005

The genomes of the recently described Matlab variants of
Vibrio cholerae
O1 that are hybrids between classical and El Tor biotypes were compared with those of El Tor and classical biotypes by the use of pulsed-field gel electrophoresis. Dendrograms constructed using the unweighted-pair group method using average linkages generated from NotI restriction patterns of whole-chromosomal DNA grouped these strains into two major clusters that were found to be similar but not identical to those of either of the biotypes. Strains that clustered with the classical biotype appear to have been derived from the classical strains, which are thought to be extinct.
Comparison of COBAS AMPLICOR
Neisseria gonorrhoeae
PCR, Including Confirmation with
N. gonorrhoeae-
Specific 16S rRNA PCR, with Traditional Culture
Authors: Luijt Dirk S. , Bos Petra A. J. , van Zwet Anton A. , van Voorst Vader Pieter C. , Schirm Jurjen
Published: March 2005

A total of 3,023 clinical specimens were tested for
Neisseria gonorrhoeae
by using COBAS AMPLICOR (CA) PCR and confirmation of positives by
N. gonorrhoeae
-specific 16S rRNA PCR. The sensitivity of CA plus 16S rRNA PCR was 98.8%, compared to 68.2% for culture. Confirmation of CA positives increased the positive predictive value from 54.8 to 96.6%.
Fatal Peritonitis Caused by
Pasteurella multocida
Capsular Type F in Calves
Authors: Catry Boudewijn , Chiers Koen , Schwarz Stefan , Kehrenberg Corinna , Decostere Annemie , de Kruif Aart
Published: March 2005

A fatal case of atypical septicemia of pasteurellosis in veal calves is described. The causative organism was identified as a multiresistant
Pasteurella multocida
capsular type F isolate. The outbreak was characterized by fibrinous peritonitis and mortality, which are hitherto unreported features of
P. multocida
capsular type F infections.
Airway Colonization by
Acrophialophora fusispora
in Patients with Cystic Fibrosis
Authors: Cimon Bernard , Challier Svetlana , Béguin Hugues , Carrère Jacqueline , Chabasse Dominique , Bouchara Jean-Philippe
Published: March 2005

Acrophialophora fusispora
is a thermotolerant soil fungus which is very unusual in clinical samples. Here we report four cases of transient or chronic airway colonization by
A. fusispora
in patients with cystic fibrosis (CF). However, the prevalence of this fungus in CF patients may be underestimated due to the currently poor knowledge of this fungus in most of the medical mycology laboratories. In addition, its clinical importance regarding CF remains to be evaluated.
A woman who couldn’t speak: report of methotrexate neurotoxicity
Authors: Szawarski P , Chapman C S
Published: March 2005

The association between methotrexate therapy and idiosyncratic neurological complications is well recognised in children. This case illustrates the importance of considering the diagnosis of methotrexate toxicity in an adult patient with behavioural and speech disturbances, who received it by intrathecal route only and in whom the only indicator was an abnormal electroencephalographic study
Adult intussusception: case reports and review of literature
Authors: Yalamarthi S , Smith R C
Published: March 2005

Adult intussusception occurs infrequently and differs from childhood intussusception in its presentation, aetiology, and treatment. Diagnosis can be delayed because of its longstanding, intermittent, and non-specific symptoms and most cases are diagnosed at emergency laparotomy. With more frequent use of computed tomography in the evaluation of patients with abdominal pain, the condition can be diagnosed more reliably. Treatment entails simple bowel resection in most cases. Reduction of the intussusception before resection is controversial, but there is a shift against this, especially in colonic cases. Surgical treatment can be difficult in gastroduodenal and coloanal intussusceptions, sometimes requiring innovative techniques. This paper presents the diagnosis and management of four cases of adult intussusception, followed by review of the literature.
Isolated conjunctival lymphoma metastasis from previous low grade non-Hodgkin’s lymphoma
Authors: Cackett P , Bower M , Stebbing J
Published: March 2005

Ocular involvement of systemic non-Hodgkin’s lymphoma is rare. This report describes the unusual occurrence of a biopsy confirmed low grade lymphoma recurring in the conjunctiva, three years after initial diagnosis of systemic disease. The tumour was surgically resected and the patient remains disease free four years later. After the diagnosis of lymphoma, long term follow up is advised as recurrences in unusual sites can occur.
OPTIMAL VERSION SEQUENCING IN FAULT-TOLERANT PROGRAMS
Authors: LEVITIN GREGORY
Published: March 2005

This paper considers software systems consisting of fault-tolerant components. These components are built from functionally equivalent but independently developed versions characterized by different reliability and execution times. Because of resource constraints, the number of versions that can run simultaneously is limited. The expected system execution time and its reliability (defined as probability of obtaining the correct output within a specified time) strictly depends on the sequence of versions execution. Different sequences can provide either maximal system reliability or minimal expected execution time. An optimization procedure is suggested for finding such sequences. The procedure is based on an algorithm for determining system execution time distribution that uses the moment generating function approach and on the genetic algorithm. Both N-version programming and the recovery block scheme are considered within a universal model. An illustrated example is presented.
AN ASSIGNMENT-BASED LOCAL SEARCH METHOD FOR SOLVING VEHICLE ROUTING PROBLEMS
Authors: ZENG L. , ONG H. L. , NG K. M.
Published: March 2005

In this paper, we propose an assignment-based local search method for solving vehicle routing problems. This method is a multi-route improvement algorithm that can operate on several routes at a time. To evaluate the performance of the proposed method, extensive computational experiments on the proposed method applied to a set of benchmark problems are carried out. The results show that the proposed method, when coupled with metaheuristics such as simulated annealing, is comparable with other efficient heuristic methods proposed in the literature.
A VISUALIZABLE REPRESENTATION OF THE ELEMENTARY PARTICLES
Authors: AVRIN J. S.
Published: March 2005

Rudimentary knots are invoked to generate a representation of the elementary particles, a model that endows the particles with visualizable structure. The model correlates with the basic tenets, taxonomy, and interactions of the Standard Model, but goes beyond it in a number of important ways, the most significant being that all particles (hadrons and leptons, fermions and bosons) and interactions share a common topology. Among other consequences of the modeling are the topological basis for isospin invariance and its connection to electric charge, the necessary identity of electron and proton charge magnitudes, and the existence of precisely three generations on the particle family tree. The salient feature of the model is that the elementary particles are viewed not as discrete, point-like objects in a vacuum but rather as sustainable, membrane-like distortions embodying curvature and torsion in and of an otherwise featureless continuum and that their manifest physical attributes correlate with the distortion. There are additional connections to the theories of fiber bundles, superstrings and instantons and, historically, to the work of Kelvin in the mid-nineteenth century and Cartan in the 1920s among others.
BERGE'S KNOTS IN THE FIBER SURFACES OF GENUS ONE, LENS SPACE AND FRAMED LINKS
Authors: YAMADA YUICHI
Published: March 2005

In 1990, John Berge described several families of knots in the three-dimensional sphere which have non-trivial Dehn surgeries yielding lens spaces. We study a subfamily of them from the view point of resolution of singularity of complex curves and surfaces, Kirby calculus in topology of four-dimensional manifolds and A'Campo's divide knot theory.
CALCULATION OF DIHEDRAL QUANDLE COCYCLE INVARIANTS OF TWIST SPUN 2-BRIDGE KNOTS
Authors: IWAKIRI MASAHIDE
Published: March 2005

Carter, Jelsovsky, Kamada, Langford and Saito introduced the quandle cocycle invariants of 2-knots, and calculated the cocycle invariant of a 2-twist-spun trefoil knot associated with a 3-cocycle of the dihedral quandle of order 3. Asami and Satoh calculated the cocycle invariants of twist-spun torus knots τrT(m,n) associated with 3-cocycles of some dihedral quandles. They used tangle diagrams of the torus knots. In this paper, we calculate the cocycle invariants of twist-spun 2-bridge knots τrS(α,β) by a similar method.
COPPER IODIDE THIN FILMS AS A p-TYPE ELECTRICAL CONDUCTIVITY IN DYE-SENSITIZED p-CuI|Dye|n-TiO2 HETEROJUNCTION SOLID STATE SOLAR CELLS
Authors: RUSOP M. , SOGA T. , JIMBO T. , UMENO M.
Published: March 2005

The transparent semiconducting copper iodide ( CuI ) films were deposited by pulsed laser deposition (PLD) and their structural and optoelectrical properties in the power output of TiO 2| Dye | CuI cells are reported. These CuI films exhibited optical transmittance of over 80% in the wavelength range from 400 to 900 nm and a minimum resistivity of about 2 KΩ-cm. An efficient charge generation is observed through the illumination of the TiO 2 layer of the fabricated p - CuI | Dye | n - TiO 2 cells. The cells performances have been given in the current–voltage (I–V) working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm 2, 25°C). The maximum short circuit photo current density (J sc ) of about 12.2 mA/cm 2 and open circuit photo voltage (V oc ) of about 480 mV were obtained for the TiO 2| Dye | CuI cells with good reproducibility. The fill factor ( FF ) and power conversion efficiency (η) were about 47.8% and 2.8%, respectively.
COMPUTATION OF LOCAL VOLATILITIES FROM REGULARIZED DUPIRE EQUATIONS
Authors: HANKE MARTIN , RÖSLER ELISABETH
Published: March 2005

We propose a new method to calibrate the local volatility function of an asset from observed option prices of the underlying. Our method is initialized with a preprocessing step in which the given data are smoothened using cubic splines before they are differentiated numerically. In a second step the Dupire equation is rewritten as a linear equation for a rational expression of the local volatility. This equation is solved with Tikhonov regularization, using some discrete gradient approximation as penalty term. We show that this procedure yields local volatilities which appear to be qualitatively correct.
OPTIMAL INVESTMENT STRATEGY VIA INTERVAL ARITHMETIC
Authors: STRADI BENITO , HAVEN EMMANUEL
Published: March 2005

This paper studies the optimal replacement policy of an item that experiences stochastic geometric growth in maintenance costs. The model integrates corporate taxes, tax credits, depreciation, and salvage value. We extend this traditional application to cover the cost of replacement with the payout from two bonds. The two-bond portfolio is passively immunized. The intersections between the continuation and replacement boundaries are computed using the Interval-Newton Generalized-Bisection (IN/GB) method. We allow small fluctuations of the replacement boundary. With these fluctuations, multiple intersections of the two boundaries are determined. The IN/GB method finds all these intersections without the need for initial guesses of the problem variables. This is a major computational improvement over traditional single-root finding implementations that require multiple initial guesses and provide no guarantees of existence or uniqueness. We demonstrate that without fluctuations one would expect to find a single optimal replacement time. However with fluctuations, there are several intersections of the continuation and replacement boundaries and the bond weight fractions may change by more than 200% between intersection points. These large changes in portfolio wealth allocation highlight the fragility of the idealized solution in the realm of fluctuations in replacement costs.
TRENDS IN CHINESE URBAN ENVIRONMENTAL MANAGEMENT
Authors: JU MEITING , SHI LINGLING , CHEN XIAOHUA
Published: March 2005

The course of urban environmental management (UEM) development in China is reviewed and analysed in this paper. The current situation that exists in the field of urban environmental management is also analysed from the aspects of the legislation, environmental policies, economic incentives and market mechanisms, technical instruments and environmental education and public participation. Further, this paper highlights the problems in China's UEM and puts forward some suggestions according to the existing characteristics of UEM in China.