bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Diversity, Determined on the Basis of
katG463
and
gyrA95
Polymorphisms, Spoligotyping, and IS
6110
Typing, of
Mycobacterium tuberculosis
Complex Isolates from Italy
Authors: Lari Nicoletta , Rindi Laura , Sola Christophe , Bonanni Daniela , Rastogi Nalin , Tortoli Enrico , Garzelli Carlo
Published: April 2005

Mycobacterium tuberculosis
complex isolates (
n
= 248) collected during a 1-year period in Tuscany, Italy, were genotyped for the
katG463
and
gyrA95
polymorphisms and by standard spacer oligonucleotide typing (spoligotyping) and IS
6110
restriction fragment length polymorphism (RFLP) assays. Most of the isolates (
n
= 212; 85.5%) belonged to genotypic groups 2 and 3, which included most isolates from Italian-born patients. The remaining isolates were genotypic group 1 organisms, which were prevalent among foreign-born patients (29 of 36; 80.6%). Spoligotype analysis detected 116 unique patterns and 34 clusters including 166 isolates. The combination of spoligotyping and IS
6110
RFLP analyses yielded 28 distinct clusters including 65 identical isolates (26.2%)—22 clusters with 2 isolates, 4 clusters with 3 isolates, 1 cluster with 4 isolates, and 1 cluster with 5 isolates—thus proving a low transmission rate in the community. Predominant spoligotypes representing 50% of clustered isolates were found in six clusters that included widespread type ST53 (clade T1) with 29 isolates (11.7% of total isolates); types ST50 and ST47 (Haarlem family) with 18 isolates (7.3%) and 8 isolates (3.2%), respectively; type ST42 (Latino-American and Mediterranean clade) with 13 isolates (5.2%); new type ST1737 (named “Tuscany”) with 8 isolates (3.2%); and type ST1 (W-Beijing family) with 7 isolates (2.8%). Other spoligotype families, such as the
Mycobacterium africanum
, East African-Indian (EAI2/Manila), and central Asia 1 (CAS1/Delhi) families (all including organisms of genotypic group 1) and the Cameroun family (genotypic group 2), were detected especially among immigrant patients. The occurrence of genotypes originally found in distant geographic areas with a high prevalence of tuberculosis may represent a hallmark for changes in the dynamics of transmission of tuberculosis in the region in the near future.
Efficient Discrimination within aCorynebacterium diphtheriaeEpidemic Clonal Group by a Novel Macroarray-Based Method
Authors: Mokrousov Igor , Narvskaya Olga , Limeschenko Elena , Vyazovaya Anna
Published: April 2005

A large diphtheria epidemic in the 1990s in Russia and neighboring countries was caused by a clonal group of closely relatedCorynebacterium diphtheriaestrains (ribotypes Sankt-Peterburg and Rossija). In the recently published complete genome sequence ofC. diphtheriaestrain NCTC13129, representative of the epidemic clone (A. M. Cerdeño-Tarraga et al., Nucleic Acids Res. 31:6516-6523, 2003), we identified in silico two direct repeat (DR) loci 39 kb downstream and 180 kb upstream of theoriCregion, consisting of minisatellite (27- to 36-bp) alternating DRs and variable spacers. We designated these loci DRA and DRB, respectively. A reverse-hybridization macroarray-based method has been developed to study polymorphism (the presence or absence of 21 different spacers) in the larger DRB locus. We name it spoligotyping (spacer oligonucleotide typing), analogously to a similar method ofMycobacterium tuberculosisgenotyping. The method was evaluated with 154 clinical strains of theC. diphtheriaeepidemic clone from the St. Petersburg area in Russia from 1997 to 2002. By comparison with the international ribotype database (Institut Pasteur, Paris, France), these strains were previously identified as belonging to ribotypes Sankt-Peterburg (n= 79) and Rossija (n= 75). The 154 strains were subdivided into 34 spoligotypes: 14 unique strains and 20 types shared by 2 to 46 strains; the Hunter Gaston discriminatory index (HGDI) was 0.85. DRB locus-based spoligotyping allows fast and efficient discrimination within theC. diphtheriaeepidemic clonal group and is applicable to both epidemiological investigations and phylogenetic reconstruction. The results are easy to interpret and can be presented and stored in a user-friendly digital database (Excel file), allowing rapid type determination of new strains.
Phenotypic and Genetic Characterization of Clinical Isolates of CDC Coryneform Group A-3: Proposal of a New Species of
Cellulomonas
,
Cellulomonas denverensis
sp. nov
Authors: Brown June M. , Frazier Rodrick P. , Morey Roger E. , Steigerwalt Arnold G. , Pellegrini Gerald J. , Daneshvar Maryam I. , Hollis Dannie G. , McNeil Michael M.
Published: April 2005

CDC coryneform group A-3 bacteria are rare human pathogens. In this study, six group A-3 isolates (two from blood, one from cerebrospinal fluid, and one each from homograft valve, lip wound, and pilonidal cyst) were compared to the type strains of phenotypically related organisms,
Cellulomonas fimi
,
Cellulomonas hominis
,
Oerskovia turbata
, and
Sanguibacter suarezii
, and characterized by phenotypic, chemotaxonomic, and genotypic studies. DNA-DNA reassociation analysis identified two genomic groups, and phylogenetic analysis of the 16S rRNA gene sequence identified the taxonomic positions of these groups to genus level. Two groups were defined, and both were more closely related to
Cellulomonas
species: one group of three strains, for which we propose the new species
Cellulomonas denverensis
sp. nov., with the type strain W6929 (ATCC BAA-788
T
or DSM 15764
T
), was related to
C. hominis
ATCC 51964
T
(98.5% 16S rRNA gene sequence similarity), and the second group of three strains was related to
C. hominis
ATCC 51964
T
(99.8 to 99.9% 16S rRNA gene sequence similarity). The definition of this new
Cellulomonas
species and the confirmation of three strains as
C. hominis
serve to further clarify the complex taxonomy of CDC coryneform group A-3 bacteria and will assist in our understanding of the epidemiology and clinical significance of these microorganisms.
Evaluation of Broth Microdilution Antifungal Susceptibility Testing Conditions for
Trichophyton rubrum
Authors: Santos D. A. , Hamdan J. S.
Published: April 2005

Fifty clinical isolates of
Trichophyton rubrum
were selected to test with ketoconazole, fluconazole, itraconazole, griseofulvin, and terbinafine by following the National Committee for Clinical Laboratory Standards susceptibility testing guidelines for filamentous fungi (M38-A). In addition, other susceptibility testing conditions were evaluated: (i) three medium formulations including RPMI 1640 (standard medium), McVeigh & Morton (MVM), and Sabouraud dextrose broth (SDB); (ii) two incubation temperatures (28 and 35°C); and (iii) three incubation periods (4, 7, and 10 days). The strains
Candida parapsilosis
(ATCC 22019),
Candida krusei
(ATCC 6258),
T. rubrum
(ATCC 40051), and
Trichophyton mentagrophytes
(ATCC 40004) were included as quality controls. All isolates produced clearly detectable growth only after 7 days of incubation. MICs were significantly independent of the incubation temperature (28 or 35°C) (
P
< 0.05). Different incubation periods resulted in MICs which were consistently different for each medium when azoles and griseofulvin were tested (
P
< 0.05). MICs obtained from different media at the same incubation time for the same isolate were significantly different when azoles and griseofulvin were tested (
P
< 0.05). MICs were consistently higher (usually 1 to 2 dilutions) with RPMI than with MVM or SDB (
P
< 0.05). When terbinafine was tested, no parameter had any influence on MICs (
P
< 0.05). RPMI standard medium appears to be a suitable testing medium for determining the MICs for
T. rubrum
. MICs obtained at different incubation times need to be correlated with clinical outcome to demonstrate which time has better reliability.
Detection of Human Metapneumovirus in Clinical Samples by Immunofluorescence Staining of Shell Vial Centrifugation Cultures Prepared from Three Different Cell Lines
Authors: Landry Marie L. , Ferguson David , Cohen Sandra , Peret Teresa C. T. , Erdman Dean D.
Published: April 2005

Monoclonal antibody MAb-8 was evaluated for detection of human metapneumovirus (HMPV) in shell vial centrifugation cultures (SVCC). Detection of HMPV was similar in A549, HEp-2, and LLC-MK2 SVCC, and MAb-8 staining was optimal on day 2 postinoculation. Availability of SVCC for HMPV will be of significant benefit to clinical laboratories.
Identity and Prevalence of Multilocus Sequence Typing-Defined Clones of Group A Streptococci within a Hospital Setting
Authors: McGregor Karen F. , Spratt Brian G.
Published: April 2005

Between July and October 2003, 121 clinical isolates of group A streptococci (GAS) were collected from a London hospital and characterized by multilocus sequence typing (MLST) to determine the identity and prevalence of clones circulating within this setting. A total of 39 sequence types (ST), of which 20 were represented by a single isolate, were identified. The eight most prevalent clones among the 121 GAS were ST117/emm81(16%), ST39/emm4(9%), ST62/emm87(7%), ST28/emm1(6%), ST36/emm12(6%), ST46/emm22(5%), ST334/emm82(5%), and ST101/emm89(4%). Compared to those in the MLST database (http://spyogenes.mlst.net), 12 (31%) of the 39 STs had not been previously identified, although 7 of these differed from recognized STs at only a single locus, suggesting they were closely related to previously recognized strains. Resistance to erythromycin and tetracycline was seen in 7 and 20% of isolates, respectively, with four isolates resistant to both agents. GAS strains with higher (>80)emmtypes accounted for 45% of GAS isolates collected during this study. Continuing GAS surveillance, using easily comparable methods, is important for detecting changes in the character of disease-causing isolates.
REGULAR AND PERIODIC TACHYON KINKS
Authors: BAZEIA D. , MENEZES R. , RAMOS J. G.
Published: April 2005

We search for regular tachyon kinks in an extended model, which includes the tachyon action recently proposed to describe the tachyon field. The extended model that we propose adds a new contribution to the tachyon action, which allows one to obtain stable tachyon kinks of regular profile, which may appropriately lead to the singular kink found by Sen sometime ago. Also, under specific conditions we may find periodic array of kink–antikink configurations.
CASIMIR EFFECT FOR SCALAR FIELDS WITH ROBIN BOUNDARY CONDITIONS IN SCHWARZSCHILD BACKGROUND
Authors: SETARE M. R.
Published: April 2005

The stress–tensor of a massless scalar field satisfying Robin boundary conditions on two one-dimensional wall in two-dimensional Schwarzschild background is calculated. We show that vacuum expectation value of stress–tensor can be obtained explicitly by Casimir effect, trace anomaly and Hawking radiation.
MIRROR SYMMETRY OF CALABI–YAU SUPERMANIFOLDS
Authors: AHN CHANGHYUN
Published: April 2005

We study super Landau–Ginzburg mirrors of the weighted projective superspace WCP3|2 which is a Calabi–Yau supermanifold and appeared in hep-th/0312171 in the topological B-model. One of them is an elliptic fibration over the complex plane whose coordinate is given in terms of two bosonic and two fermionic variables as well as Kähler parameter of WCP3|2. The other is some patch of a degree-3 Calabi–Yau hypersurface in CP2 fibered by the complex plane whose coordinate depends on both the above four variables and Kähler parameter but its dependence behaves quite differently.
A WAVELET-BASED BLIND DECONVOLUTION ALGORITHM FOR ULTRASONIC IMAGE PROCESSING
Authors: XU QINZHEN , WAN SUIREN , PEI WENJIANG , YANG LUXI , HE ZHENYA
Published: April 2005

The low resolution of ultrasonic images is mainly caused by the convolution between the reflect function of the measured tissues and the system impulse response. In this paper, the system impulse response is first estimated on the envelope ultrasonic image data using higher-order spectra. Subsequently, wavelet-based deconvolution is implemented. The algorithm proposed in this paper removes the coupling problem between the tissue signals and the impulse response, which has been a puzzle in homomorphic deconvolution. It also preserves spatial components of ultrasonic images much better compared to Fourier domain deconvolution. The resulting images behave clearer in velamen boundary and tissue layers, and the texture information also appears more detailed. The deconvolved images achieve good resolution gains in both axial and lateral directions.
INDUCTORLESS REALIZATION OF NONAUTONOMOUS MLC CHAOTIC CIRCUIT USING CURRENT-FEEDBACK OPERATIONAL AMPLIFIERS
Authors: ÇAM UǦUR , KILIÇ RECAİ
Published: April 2005

An inductorless realization of nonautonomous (Murali–Lakshmanan–Chua) MLC chaotic circuit is proposed. The main purpose of this study is to improve the performance of nonautonomous MLC chaotic circuit using only CFOAs. CFOA-based topology used in this realization enables to simulate floating inductance. This modification provides to the designer wideband chaotic signals for secure communication systems. In addition to this major improvement, a CFOA-based nonlinear resistor was used in the new realization of nonautonomous MLC chaotic circuit. The usage of CFOA-based inductance simulator and nonlinear resistor in the circuit structure reduces the component count and provides isolated outputs. The performance of the proposed inductorless nonautonomous chaotic circuit is demonstrated with both PSpice simulations and experimental results.
A NEURAL-BASED PAGE SEGMENTATION SYSTEM
Authors: ALGINAHI Y. , FEKRI D. , SID-AHMED M. A.
Published: April 2005

Page segmentation is necessary for optical character recognition and very useful in document image manipulation. This paper describes two classification methods, a modified linear adaptive method and a proposed neural network system that classifies an image into text, halftone image (photos, dark images, etc.), and graphics (graphs, tables, flowcharts, etc.). The blocks were segmented using the Run Length Smearing Algorithm. The smearing process was done automatically by fixing the threshold values for smearing. Features are extracted from the segmented blocks for classification into text, graphics, and halftone images. The second method uses a multi-layer perceptron neural network for classification. Two parameters, a shape factor, f1, and an angle from the rectangular block segments, were fed into the neural network system giving us three classes: text, halftone images, and graphics. Experiments on 30 mixed-content document images show that the method works well on a wide variety of layouts in document images.
CONSCEP: A CONFIGURABLE SoC EMULATION PLATFORM FOR C-BASED FAST PROTOTYPING
Authors: YANG WOOSEUNG , KYUNG CHONG-MIN
Published: April 2005

FPGA-based emulation, which is now widely used in the design and verification of System-on-a-Chip (SoC), is applicable only when the RTL design for the whole system is available, thus resulting in a long design turn-around time. In this paper, we present a new design flow based on a C-to-hardware IMPLEmentation tool (CIMPLE) and a CONfigurable SoC Emulation Platform (CONSCEP) that emulates the on-chip bus system prior to the RTL design of each SoC component. With the emulation environment set up in the early stage of the design process, the design and verification task of each functional block in the SoC can be performed not only faster, but also more complete as a more complete set of test vectors can be applied before the integration. CONSCEP consists of (1) configurable bus components for the given on-chip bus standard and (2) a set of transactors to link the HDL models of the pre-verified IP blocks with the C models for the behavioral blocks to be designed, or software blocks. CIMPLE translates the C model for a hardware module to a SystemC code, which can be synthesized and directly attached to the CONSCEP as an IP. CIMPLE allows global variables, nested function calls, and simple pointer access, which significantly reduces the code migration. The proposed design flow is demonstrated using a JPEG encoder/decoder system and successfully applied to a commercial MPEG4 video codec chip.
OXIDATIVE ADDITION OF C–X BOND IN HCCX (X = H, CH3, ANDSiH3) TO RHODIUM(I) COMPLEX AND SUBSEQUENT 1,3-MIGRATION OF X: A DFT LEVEL STUDY
Authors: SURESH CHERUMUTTATHU H. , KOGA NOBUAKI
Published: April 2005

Oxidative addition of the C – X bond in HCCX ( X = H , CH 3, SiH 3) to RhCl ( PH 3)2, as well as the subsequent 1,3-migration of the substituent X from Rh to the β carbon of the ethynyl group leading to vinylidine-Rh complex, is studied using the localized molecular orbital (LMO) analysis at the density functional theory level. The highest Δ G ‡ values of 20.2, 16.3, and 18.5 kcal/mol are obtained respectively for the endothermic C–H bond oxidative additions of HCCH , HCCCH 3, and HCCSiH 3, which correspond to the slippage of the η2 alkyne complex RhCl (η2- HCCX )( PH 3)2. The 1,3-hydrogen migration, a one step process from Rh(H)(CCX)(Cl) ( PH 3)2 proceeds via a three center transition state involving H ⋯( CC ) interactions with Δ G ‡ values of 18.7, 16.3, and 18.1 kcal/mol for X = H , CH 3, and SiH 3, respectively. The overall nature of the reaction profiles and the LMO features suggest nearly identical behavior for all the C – H bond oxidative additions as well as the 1,3-hydrogen migrations. However, the energy profiles and LMO features of the C – CH 3 and the C – SiH 3 oxidative additions as well as the 1,3-shift of methyl and silyl groups show significant differences. The C – CH 3 oxidative addition is highly endothermic (21.7 kcal/mol) and thermodynamically disfavored as it require a Δ G ‡ of 42.2 kcal/mol. On the other hand, the C – SiH 3 oxidative addition is the least endothermic (6.4 kcal/mol) and it requires a moderate Δ G ‡ of 19.6 kcal/mol. Further, the 1,3-SiH 3 migration is the most favored reaction among all the reactions studied here as it proceed with a Δ G ‡ of 13.3 kcal/mol. The small Δ G ‡ for C – SiH 3 oxidative addition and the 1,3-SiH 3 migration are well explained based on the hypervalent character of silicon atom in the corresponding transition states as evidenced from their geometric and LMO features.
SOLVENT EFFECTS OF KINETICS OF [1,5] H-SHIFT IN CYCLOPENTADIENE AND ITS DERIVATIVES
Authors: PARASUK VUDHICHAI , UNARUNOTAI SAKULSUK
Published: April 2005

Geometries of reactants, products (in the case of fluoro derivatives), and transition states in gas and solution phases of [1,5] H-shift of cyclopentadiene and 2-fluorocyclo-pentadiene were optimized using B3LYP/6-31++G(d,p) . The solvent effects were included using the Polarizable Continuum Model (PCM). Four solvent systems i.e. chloroform, dichloromethane, diethylether, and methanol, were considered. For cyclopentadiene, single point MP2/6-31++G(d,p) were also carried out. For cyclopentadiene and 2-fluorocyclopentadiene, using B3LYP/6-31++G(d,p) activation free energies of 25.47 and 28.74 kcal/mol respectively were yielded for the reaction in vacuum. In solutions, calculated activation energies for the reaction are slightly decreased with the reduction of around 0.5–3 kcal/mol depending on solvent. Good correlation between the solvent polarity and activation energies was also observed. Thus, the [1.5] H-shift in cyclopentadiene and its derivatives could be enhanced in polar solvents.
NONADIABATIC TRANSITION AND CHEMICAL DYNAMICS: MULTI-DIMENSIONAL TUNNELING THEORY AND APPLICATIONS OF THE ZHU–NAKAMURA THEORY
Authors: NAKAMURA HIROKI
Published: April 2005

Tunneling and nonadiabatic transition are the most important quantum mechanical effects in chemical dynamics. They are important not only for understanding the dynamics properly, but also for controlling molecular functions. The Zhu–Nakamura (ZN) theory can be combined with the quasi-classical trajectory method and with the IVR(Initial Value Representation)-type semiclassical theory to deal with large chemical systems. Laser control of molecular processes and control of molecular functions can also be realized by properly controlling nonadiabatic transitions. Furthermore, we have recently formulated an accurate theory for evaluating tunneling splitting and tunneling decay rate in multi-dimensional systems and also developed an efficient method to find caustics in multi-dimensional space. These methods combined with the ZN theory are expected to clarify various large scale chemical dynamics. This is a short review article on our recent activities mentioned above.
SEMICLASSICAL FROZEN GAUSSIAN PROPAGATION METHOD FOR ELECTRONICALLY NONADIABATIC CHEMICAL DYNAMICS: MØLLER OPERATOR FORMULATION AND INCORPORATION OF THE ZHU-NAKAMURA THEORY
Authors: KONDORSKIY ALEXEY , NAKAMURA HIROKI
Published: April 2005

The title theory is developed by combining the Herman–Kluk semiclassical theory for adiabatic propagation on single potential energy surface and the Zhu–Nakamura theory for nonadiabatic transition. A fairly simple expression for the propagator based on classical trajectories is derived using the Møller operator formulation of scattering theory. The theory takes into account almost all quantum effects that occur during nonadiabatic transition, especially at low energies and is expected to be applicable to general chemical dynamics of high dimensions. Application to a two-dimensional model system shows that the theory works well for the propagation duration of several molecular vibrational periods and wide wave packet energy range.
SEMICLASSICAL FORMULATION OF OPTIMAL CONTROL THEORY
Authors: KONDORSKIY ALEXEY , NAKAMURA HIROKI
Published: April 2005

In the present paper, semiclassical formulation of optimal control theory is made by combining the conjugate gradient search method with new approximate semiclassical expressions for correlation function. Two expressions for correlation function are derived. The simpler one requires calculations of coordinates and momenta of classical trajectories only. The second one requires extra calculation of common semiclassical quantities; as a result additional quantum effects can be taken into account. The efficiency of the method is demonstrated by controlling nuclear wave packet motion in a two-dimensional model system.
A COMPUTATIONAL GRID SYSTEM FOR QUANTUM CHEMICAL CALCULATIONS TESTED IN A MODELING OF THE GE(001) SURFACE
Authors: KWAK JAESIK , LEE YOON SUP
Published: April 2005

A computational Grid system with the simple architecture was constructed based on Globus and the concept of web application for the quantum chemical calculation. The computational Grid provides interfaces to a web-based input module and several molecular orbital calculation packages. Some aspects of the cluster modeling of the Ge (001) surface were tested on the constructed Grid. A number of conditions and parameters of the cluster model can be easily varied on the Grid, enabling concurrent testing of multiple choices of the model possible. These models were benchmarked on the Grid system. After that, the potential energy surface of the acetylene molecule moving over the model Ge (001) surface was scanned, in an effort to understand the adsorption reaction. Each point of the potential energy surface was calculated on the distributed node of the Grid system. These results demonstrate that the concept of high throughput computing can be successfully adapted to computational chemistry with a computational Grid. The result of modeling for the Ge surface itself is also described and could be of some interest.
A NEW SCALE OF ELECTRONEGATIVITY BASED ON ABSOLUTE RADII OF ATOMS
Authors: GHOSH DULAL C.
Published: April 2005

A new scale of electronegativity is designed on the basis of the environment independent absolute radii of atoms. In this scale, the electronegativity is an intrinsic free-atom property and the basis of assumption is quantum mechanically viable. The qualitative relation between the size and electronegativity is relied upon and a quantitative general formula of evaluation of electronegativity in terms of the absolute radii of atoms is suggested as χ = a × (1/R)+ b, where χ is electronegativity and R is absolute radius of atoms, a and b are two constants determined by least square fitting for each period of elements separately. A number known as electronegativity is computed for each 103 elements of periodic table through the above formula and the unit assigned to χ is energy. The new scale of electronegativity is found to observe the simple rules that all the scales of electronegativity must obey. The evaluated scale reproduces the silicon rule where the electronegativities of the eight elements of metalloid group are very close to each other and the electronegativity of silicon atom is smallest of the group. A striking feature of the new scale is that the electronegativity of N atom is greater than that of Cl atom. The characteristic properties of chalcogens and transition metal atoms have been nicely correlated in terms of the computed values of χ of such elements. The evaluated electronegativities of the elements beautifully exhibit the periodic behaviour of periods and groups of the Periodic Table. The revealed internal consistencies suggest that the present effort of introducing a scale of electronegativity based on absolute radius of atoms is largely successful.
A DENSITY FUNCTIONAL STUDY OF THE STRUCTURE OF SILANE COUPLING AGENT 3–AMINOPROPYLTRIETHOXYSILANE
Authors: MA N. L. , WU P.
Published: April 2005

Using density functional theory, we predicted the solution structure of the hydrolyzed 3–aminopropyltriethoxysilane (h–APS), which is a silane coupling agent commonly used in many industrial applications. We have located five stable minima on the potential energy surface of h–APS in which four of them are "neutral", and the remaining one is zwitterionic (dipolar) in nature. Our calculations suggested that the stability of the most stable form of h–APS in water (denoted as II_N) arose from strong intramolecular OH ⋯ N hydrogen bond. The least stable form is the zwitterionic form (I_ZW), which is estimated to be over 90 kJ mol -1 less stable than II_N. The factors governing the relative stabilities of different forms are discussed.
Assessing Immigrant Assimilation: New Empirical and Theoretical Challenges
Authors: Waters Mary C. , Jiménez Tomás R.
Published: April 2005

This review examines research on the assimilation of immigrant groups. We review research on four primary benchmarks of assimilation: socioeconomic status, spatial concentration, language assimilation, and intermarriage. The existing literature shows that today's immigrants are largely assimilating into American society along each of these dimensions. This review also considers directions for future research on the assimilation of immigrant groups in new southern and midwestern gateways and how sociologists measure immigrant assimilation. We document the changing geography of immigrant settlement and review the emerging body of research in this area. We argue that examining immigrant assimilation in these new immigrant gateways is crucial for the development of theories about immigrant assimilation. We also argue that we are likely to see a protracted period of immigrant replenishment that may change the nature of assimilation. Studying this change requires sociologists to use both birth cohort and generation as temporal markers of assimilation.
Emerging Theories of Care Work
Authors: England Paula
Published: April 2005

Care work is done in the home as well as in markets for pay. Five theoretical frameworks have been developed to conceptualize care work; the frameworks sometimes offer competing answers to the same questions, and other times address distinct questions. The “devaluation” perspective argues that care work is badly rewarded because care is associated with women, and often women of color. The “public good” framework points out that care work provides benefits far beyond those to the direct recipient and suggests that the low pay of care work is a special case of the failure of markets to reward public goods. The “prisoner of love” framework argues that the intrinsic caring motives of care workers allow employers to more easily get away with paying care workers less. Instead of seeing the emotional satisfactions of giving care as its own reward, the “commodification of emotion” framework focuses on emotional harm to workers when they have to sell services that use an intimate part of themselves. The “love and money” framework argues against dichotomous views in which markets are seen as antithetical to true care.
The abts and sulp families of anion transporters from Caenorhabditis elegans
Authors: Sherman Teresa , Chernova Marina N. , Clark Jeffrey S. , Jiang Lianwei , Alper Seth L. , Nehrke Keith
Published: April 2005

The slc4 and slc26 gene families encode two distinct groups of gene products that transport HCO3− and other anions in mammalian cells. The SLC4 and SLC26 proteins are important contributors to transepithelial movement of fluids and electrolytes and to cellular pH and volume regulation. Herein we describe the cDNA cloning from the nematode Caenorhabditis elegans of four anion bicarbonate transporter ( abts) homologs of slc4 cDNA and eight sulfate permease ( sulp) homologs of slc26 cDNA. Analysis of transgenic nematode strains carrying promoter::GFP fusions suggests relatively restricted expression patterns for many of these genes. At least three genes are expressed primarily in the intestine, three are expressed primarily in the excretory cell, and one is expressed in both of these polarized cell types. One of the genes is also expressed exclusively in the myoepithelium-like cells of the pharynx. Many of the sulp gene products localize to the basolateral membrane rather than to the apical membrane. Several ABTS and SULP proteins exhibited anion transport function in Xenopus oocytes. The strongest Cl− transporter among these also mediated Cl−/HCO3− exchange. These findings encourage exploitation of the genetic strengths of the nematode model system in the study of the physiological roles of anion transport by the proteins of these two highly conserved gene families.
RhoA-Rho kinase pathway mediates thrombin- and U-46619-induced phosphorylation of a myosin phosphatase inhibitor, CPI-17, in vascular smooth muscle cells
Authors: Pang Huan , Guo Zhenheng , Su Wen , Xie Zhongwen , Eto Masumi , Gong Ming C.
Published: April 2005

Protein kinase C-potentiated phosphatase inhibitor of 17 kDa (CPI-17) mediates some agonist-induced smooth muscle contraction by suppressing the myosin phosphatase in a phosphorylation-dependent manner. The physiologically relevant kinases that phosphorylate CPI-17 remain to be identified. Several previous studies have shown that some agonist-induced CPI-17 phosphorylation in smooth muscle tissues was attenuated by the Rho kinase (ROCK) inhibitor Y-27632, suggesting that ROCK is involved in agonist-induced CPI-17 phosphorylation. However, Y-27632 has recently been found to inhibit protein kinase C (PKC)-δ, a well-recognized CPI-17 kinase. Thus the role of ROCK in agonist-induced CPI-17 phosphorylation remains uncertain. The present study was designed to address this important issue. We selectively activated the RhoA pathway using inducible adenovirus-mediated expression of a constitutively active mutant RhoA (V14RhoA) in primary cultured rabbit aortic vascular smooth muscle cells (VSMCs). V14RhoA caused expression level-dependent CPI-17 phosphorylation at Thr38 as well as myosin phosphatase phosphorylation at Thr853. Importantly, we have shown that V14RhoA-induced CPI-17 phosphorylation was not affected by the PKC inhibitor GF109203X but was abolished by Y-27632, suggesting that ROCK but not PKC was involved. Furthermore, we have shown that the contractile agonists thrombin and U-46619 induced CPI-17 phosphorylation in VSMCs. Similarly to V14RhoA-induced CPI-17 phosphorylation, thrombin-induced CPI-17 phosphorylation was not affected by inhibition of PKC with GF109203X, but it was blocked by inhibition of RhoA with adenovirus-mediated expression of exoenzyme C3 as well as by Y-27632. Taken together, our present data provide the first clear evidence indicating that ROCK is responsible for thrombin- and U-46619-induced CPI-17 phosphorylation in primary cultured VSMCs.
PSGL-1 derived from human neutrophils is a high-efficiency ligand for endothelium-expressed E-selectin under flow
Authors: Zou Xiaoyan , Shinde Patil Vivek R. , Dagia Nilesh M. , Smith Lee A. , Wargo Maureen J. , Interliggi Kimberly A. , Lloyd Christopher M. , Tees David F. J. , Walcheck Bruce , Lawrence Michael B. , Goetz Douglas J.
Published: April 2005

P-selectin glycoprotein ligand-1 (PSGL-1) has been proposed as an important tethering ligand for E-selectin and is expressed at a modest level on human leukocytes. Sialyl Lewis x (sLex)-like glycans bind to E-selectin and are expressed at a relatively high level on circulating leukocytes. It is unclear whether PSGL-1 has unique biochemical attributes that contribute to its role as an E-selectin ligand. To probe this issue, we conjugated microspheres with either sLex or PSGL-1 purified from myeloid cells (neutrophils and HL-60) and compared their adhesion to endothelial expressed E-selectin under defined shear conditions. We found that both sLex and PSGL-1 microspheres adhere to 4 h of IL-1β-activated human umbilical vein endothelial cells predominantly through E-selectin. Analysis of the adhesion revealed that the rate of initial tethering of the PSGL-1 microspheres to E-selectin was significantly greater than the rate of initial tethering of the sLex microspheres despite the fact that the sLex microspheres tested had higher ligand densities than the PSGL-1 microspheres. We also found that pretreatment of the PSGL-1 or sLex microspheres with HECA-452 had no significant effect on initial tethering to E-selectin. These results support the hypotheses that 1) PSGL-1 is a high-efficiency tethering ligand for E-selectin, 2) ligand biochemistry can significantly influence initial tethering to E-selectin, and 3) PSGL-1 tethering to E-selectin can occur via non-HECA-452 reactive epitopes.
Regulation of elastin gene transcription by proteasome dysfunction
Authors: Kuang Ping-Ping , Goldstein Ronald H.
Published: April 2005

Elastin, a major extracellular matrix protein and the core component of elastic fiber, is essential to maintain lung structural integrity and normal physiological function. We previously found that the downregulation of elastin gene transcription by IL-1β is mediated via activation of NF-κB and CCAAT/enhancer binding protein (C/EBP)β, both targets of the ubiquitin-proteasome pathway. To further investigate the molecular mechanisms that underlie the control of elastin gene expression, we disrupted the ubiquitin-proteasome pathway with specific proteasome inhibitors. We found that specific proteasome inhibitors decreased the steady-state level of elastin mRNA in a dose-responsive manner. Run-on assay and promoter reporter study indicated that the proteasome inhibitor MG-132 repressed the rate of elastin transcription. MG-132 did not affect mRNA levels of NF-κB and C/EBPβ, or the nuclear presence of NF-κB, but markedly increased C/EBPβ isoforms, including liver-enriched transcriptional activating protein and liver-enriched transcriptional inhibitory protein. Addition of cycloheximide blocked these increases and the downregulation of elastin mRNA by MG-132. The MG-132-induced downregulation of elastin transcription was dependent on C/EBPβ expression as assessed with small interfering RNA. These results indicate that the ubiquitin-proteasome pathway plays an essential role in maintaining elastin gene expression in lung fibroblasts. Disruption of this pathway results in the downregulation of tropoelastin transcription via posttranscriptionally induced C/EBPβ isoforms.
Effects of pancreatic polypeptide on pancreas-projecting rat dorsal motor nucleus of the vagus neurons
Authors: Browning Kirsteen N. , Coleman F. Holly , Travagli R. Alberto
Published: April 2005

We investigated the pre- and postsynaptic effects of pancreatic polypeptide (PP) on identified pancreas-projecting neurons of the rat dorsal motor nucleus of the vagus in thin brain stem slices. Perfusion with PP induced a TTX- and apamin-sensitive, concentration-dependent outward (22% of neurons) or inward current (21% of neurons) that was accompanied by a decrease in input resistance; PP was also found to affect the amplitude of the action potential afterhyperpolarization. The remaining 57% of neurons were unaffected. PP induced a concentration-dependent inhibition in amplitude of excitatory ( n = 22 of 30 neurons) and inhibitory ( n = 13 of 17 neurons) postsynaptic currents evoked by electrical stimulation of the adjacent nucleus of the solitary tract, with an estimated EC50 of 30 nM for both. The inhibition was accompanied by an alteration in the paired pulse ratio, suggesting a presynaptic site of action. PP also decreased the frequency, but not amplitude, of spontaneous excitatory ( n = 6 of 11 neurons) and inhibitory currents ( n = 7 of 9 neurons). In five neurons, chemical stimulation of the area postrema (AP) induced a TTX-sensitive inward ( n = 3) or biphasic (outward and inward) current ( n = 2). Superfusion with PP reversibly reduced the amplitude of these chemically stimulated currents. Regardless of the PP-induced effect, the vast majority of responsive neurons had a multipolar somata morphology with dendrites projecting to areas other than the fourth ventricle or the central canal. These results suggest that pancreas-projecting rat dorsal motor nucleus of the vagus neurons are heterogeneous with respect to their response to PP, which may underlie functional differences in the vagal modulation of pancreatic functions.
Anti-inflammatory effect of fibrate protects from cisplatin-induced ARF
Authors: Li Shenyang , Gokden Neriman , Okusa Mark D. , Bhatt Renu , Portilla Didier
Published: April 2005

Recently, we demonstrated that peroxisome proliferator-activated receptor-α (PPARα) ligand ameliorates cisplatin-induced acute renal failure (ARF) by preventing inhibition of substrate oxidation, and also by preventing apoptosis and necrosis of the proximal tubule (Li S, Bhatt R, Megyesi J, Gokden N, Shah SV, and Portilla D. Am J Physiol Renal Physiol 287: F990–F998, 2004). In the following studies, we examined the protective effect of PPARα ligand on cisplatin-induced inflammatory responses during ARF. Mice subjected to a single intraperitoneal injection of cisplatin developed ARF at day 3. Cisplatin increased mRNA and protein expression of TNF-α, RANTES, and also upregulated endothelial adhesion molecules ICAM-1/VCAM-1 and chemokine receptors CCR1/CCR5. Cisplatin also led to neutrophil infiltration in the corticomedullary region. Pretreatment of wild-type mice with WY-14,643, a fibrate class of PPARα ligands, before cisplatin significantly suppressed cisplatin-induced upregulation of cytokine/chemokine expression, prevented neutrophil accumulation, and ameliorated renal dysfunction. In contrast, treatment with PPARα ligand before cisplatin did not prevent cytokine/chemokine production, neutrophil accumulation, and did not protect kidney function in PPARα null mice. In addition, we observed that cisplatin-induced NF-κB binding activity in nuclear extracts from wild-type mice was markedly reduced by treatment with PPARα ligand. These results demonstrate that PPARα exerts an anti-inflammatory effect in kidney tissue by a mechanism that includes inhibition of NF-κB DNA binding activity, and this effect results in inhibition of neutrophil infiltration, cytokine/chemokine release, and amelioration of cisplatin-induced ARF.
Regulation of the renal thiazide-sensitive Na-Cl cotransporter, blood pressure, and natriuresis in obese Zucker rats treated with rosiglitazone
Authors: Khan Osman , Riazi Shahla , Hu Xinqun , Song Jian , Wade James B. , Ecelbarger Carolyn A.
Published: April 2005

Previously, we showed an increase in protein abundance of the renal thiazide-sensitive Na-Cl cotransporter (NCC) in young, prediabetic, obese Zucker rats relative to lean age mates (Bickel CA, Verbalis JF, Knepper MA, and Ecelbarger CA. Am J Physiol Renal Physiol 281: F639–F648, 2001). To test whether this increase correlated with increased thiazide sensitivity (NCC activity) and blood pressure, and could be modified by insulin-sensitizing agents, we treated lean and obese Zucker rats (9 wk old) with either a control diet or this diet supplemented with 3 mg/kg body wt rosiglitazone (RGZ), a peroxisomal proliferator-activated receptor subtype γ agonist and potent insulin-sensitizing agent, for 12 wk ( n = 9/group). The rise in blood pressure, measured continuously by radiotelemetry, was significantly blunted in the RGZ-treated obese rats. Similarly, blood glucose and urinary albumin were markedly decreased in these rats. RGZ-treated rats whether lean or obese excreted a NaCl load faster but excreted less sodium in response to hydrochlorothiazide, applied as a novel in vivo measure of NCC activity. Obese rats had increased renal protein abundance and urinary excretion of NCC; however, this was not significantly reduced by RGZ (densitometry in cortex homogenate − %lean control): 100 ± 9, 93 ± 4, 124 ± 9, and 141 ± 14 for lean control, lean RGZ, obese control, and obese RGZ, respectively. Subcellular localization, as evaluated by confocal microscopy and immunoblotting following differential centrifugation, of NCC was not different between rat groups. Overall, RGZ reduced blood pressure and thiazide sensitivity; however, the mechanism(s) did not seem to involve a decrease in NCC protein abundance or cellular location. Decreased NCC activity may have contributed to the maintenance of normotension in RGZ-treated obese rats.
Na+-K+-ATPase properties in rat heart and skeletal muscle 3 mo after coronary artery ligation
Authors: Barr D. J. , Green H. J. , Lounsbury D. S. , Rush J. W. E. , Ouyang J.
Published: April 2005

This study was designed to determine whether chronic heart failure (CHF) results in changes in Na+-K+-ATPase properties in heart and skeletal muscles of different fiber-type composition. Adult rats were randomly assigned to a control (Con; n = 8) or CHF ( n = 8) group. CHF was induced by ligation of the left main coronary artery. Examination of Na+-K+-ATPase activity (means ± SE) 12 wk after the ligation measured, using the 3- O-methylfluorescein phosphatase assay (3- O-MFPase), indicated higher ( P < 0.05) levels in soleus (Sol) (250 ± 13 vs. 179 ± 18 nmol·mg protein−1·h−1) and lower ( P < 0.05) levels in diaphragm (Dia) (200 ± 12 vs. 272 ± 27 nmol·mg protein−1·h−1) and left ventricle (LV) (760 ± 62 vs. 992 ± 16 nmol·mg protein−1·h−1) in CHF compared with Con, respectively. Na+-K+-ATPase protein content, measured by the [3H]ouabain binding technique, was higher ( P < 0.05) in white gastrocnemius (WG) (166 ± 12 vs. 135 ± 7.6 pmol/g wet wt) and lower ( P < 0.05) in Sol (193 ± 20 vs. 260 ± 8.6 pmol/g wet wt) and LV (159 ± 10 vs. 221 ± 10 pmol/g wet wt) in CHF compared with Con, respectively. Isoform content in CHF, measured by Western blot techniques, showed both increases (WG; P < 0.05) and decreases (Sol; P < 0.05) in α1. For α2, only increases [red gastrocnemius (RG), Sol, and Dia; P < 0.05] occurred. The β2-isoform was decreased (LV, Sol, RG, and WG; P < 0.05) in CHF, whereas the β1 was both increased (WG and Dia; P < 0.05) and decreased (Sol and LV; P < 0.05). For β3, decreases ( P < 0.05) in RG were observed in CHF, whereas no differences were found in Sol and WG between CHF and Con. It is concluded that CHF results in alterations in Na+-K+-ATPase that are muscle specific and property specific. Although decreases in Na+-K+-ATPase content would appear to explain the lower 3- O-MFPase in the LV, such does not appear to be the case in skeletal muscles where a dissociation between these properties was observed.
Stimulation of Melatonin Receptors Decreases Calcium Levels in Xenopus Tectal Cells by Activating GABAC Receptors
Authors: Prada Claudia , Udin Susan B. , Wiechmann Allan F. , Zhdanova Irina V.
Published: April 2005

To investigate the physiological effects of melatonin receptors in the Xenopus tectum, we have used the fluorescent indicator Fluo-4 AM to monitor calcium dynamics of cells in tectal slices. Bath application of KCl elicited fluorescence increases that were reduced by melatonin. This effect was stronger at the end of the light period than at the end of the dark period. Melatonin increased γ-aminobutyric acid-C (GABAC)–receptor activity, as demonstrated by the ability of the GABAC-receptor antagonists, picrotoxin and TPMPA, to abolish the effects of melatonin. In contrast, neither the GABAA-receptor antagonist bicuculline nor the GABAB-receptor antagonist CGP 35348 diminished the effects of melatonin. RT-PCR analyses revealed expression of the 3 known melatonin receptors, MT1 (Mel1a), MT2 (Mel1b), and Mel1c. Because the effect of melatonin on tectal calcium increases was antagonized by an MT2-selective antagonist, 4-P-PDOT, we performed Western blot analyses with an antibody to the MT2 receptor; the data indicate that the MT2 receptor is expressed primarily as a dimeric complex and is glycosylated. The receptor is present in higher amounts at the end of the light period than at the end of the dark period, in a pattern complementary to the changes in melatonin levels, which are higher during the night than during the day. These results imply that melatonin, acting by MT2 receptors, modulates GABAC receptor activity in the optic tectum and that this effect is influenced by the light–dark cycle.
Lack of Serum Oligoclonal Antibody Responses to Chlamydophila pneumoniae in Multiple Sclerosis
Authors: Chapman M.D. , Hartley J.C. , Furrows S.J. , Ridgeway G.L. , Thompson E.J. , Church A.J. , Candler P.M. , Giovannoni G.
Published: April 2005

Chlamydophila pneumoniae has been proposed as an aetiological agent in MS via a mechanism involving molecular mimicry. We undertook to investigate whether the presence of CSF oligoclonal IgG OCB or oligoclonal bands correlated with serum IgG raised against C. pneumoniae. Paired serum and CSF of 19 MS patients and 27 control patients with other neurological diseases were studied by IEF and Western blotting. Only 1 of 19 MS patients had serum antibodies against C. pneumoniae compared with 2 of the 26 control patients. This was not significant, leading us to conclude that this study does not support the theory of an association between C. pneumoniae and MS.
Sayyids of Hadhramaut in Early Modern India
Authors: Khalidi Omar
Published: April 2005

Ethnic Arab communities in medieval India originate mainly from the Arabian Peninsula and the Persian Gulf. Among these Arabs, the ones that gained widespread fame within India and abroad were the Sayyids of Hadhramaut, descendants of Prophet Muhammad, through his daughter Fatima. Many of these Hadhrami Sayyids achieved rapid upward social mobility in India through their ascribed status as the Prophet's descendants, as exemplars of good Muslims, and as preachers and teachers of Islam in a non-Muslim environment. However, migration to India at the dawn of the modern era heralded changes in their traditional status and occupation. The sources of this article are primary works in Arabic, Persian and, Urdu, supplemented with interviews and field observations.