bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalyst‐functionalized nanomaterials
Authors: Lu Yi , Liu Juewen 
Published: November 2008

AbstractWith rapid development in both nanotechnology and biotechnology, it is now possible to combine these two exciting fields to modulate the physical properties of nanomaterials with the molecular recognition and catalytic functional properties of biomolecules. Such research efforts have resulted in a larger number of sensors that can detect a broad range of analytes ranging from metal ions, small molecules, and nucleic acids down to proteins. These sensors will find important applications in nanomedicine. In this article, the design of sensors with four classes of nanomaterials (metallic, semiconductor, magnetic, and carbon nanotube nanoparticles) is reviewed. Metallic nanoparticles possess distance‐dependent optical properties and are useful for designing colorimetric sensors. Semiconductor nanoparticles or quantum dots (QDs) appear to be superior alternatives to traditional organic fluorophores in many aspects, such as broad excitation range, narrow emission peaks, and high photo stability. QD sensors based on either energy transfer or charge transfer are summarized. Furthermore, magnetic nanoparticles are shown to be useful as smart magnetic resonance imaging (MRI) contrast agents. Finally, some carbon nanotubes show near‐IR emission properties, and thus, are potentially useful for in vivo sensing. Sensors based on either tuning the emission intensity or wavelength are discussed. Copyright © 2008 John Wiley & Sons, Inc.This article is categorized under:

Diagnostic Tools > In Vitro Nanoparticle-Based Sensing
Coerced sexual debut and lifetime abortion attempts among women in Rakai, Uganda
Authors: Polis Chelsea B. , Lutalo Tom , Wawer Maria , Serwadda David , Kigozi Godfrey , Nalugoda Fred , Kiwanuka Noah , Gray Ronald 
Published: November 2008

AbstractObjectiveTo assess whether reported coercion at sexual debut is associated with a greater lifetime risk of attempting an abortion among women in Rakai, Uganda.MethodsAnalysis of data from sexually experienced, ever‐pregnant women in a longitudinal, population‐based, open cohort study in 56 rural communities in Rakai, Uganda (n = 4784). For univariate analysis, the t test was used for continuous variables and the Pearson χ2 or Fisher exact tests for categorical variables. Multivariate logistic regression was used to control for potential confounding.ResultsTwenty percent of women reported coercion at sexual debut. Compared with women who reported consensual sexual debut, the adjusted odds ratio (OR) of subsequent abortion attempts among coerced women was 1.57 (95% CI, 1.11–2.20).ConclusionThere is a need to protect women from sexual coercion, implement policies for prevention of violence, and provide comprehensive reproductive health care, including prevention of unwanted pregnancy and unsafe abortions.
Normal Motor Nerve Conduction Studies Using Surface Electrode Recording from the Supraspinatus, Infraspinatus, Deltoid, and Biceps
Authors: Buschbacher Ralph Michael , Weir Susan Karolyi , Bentley John Greg , Cottrell Erika 
Published: November 2008

ObjectiveProximal peripheral nerve conduction studies can provide useful information to the clinician. The difficulty of measuring the length of the proximal nerve as well as a frequent inability to stimulate at 2 points along the nerve adds a challenge to the use of electrodiagnosis for this purpose. The purpose of this article is to present normal values for the suprascapular, axillary, and musculocutaneous nerves using surface electrodes while accounting for side‐to‐side variability.DesignProspective, observational study.SettingPatients were evaluated in outpatient, private practices affiliated with tertiary care systems in the United States and Malaysia.ParticipantsOne hundred volunteers were recruited and completed bilateral testing. Exclusion criteria included age younger than 18 years; previous shoulder surgery/atrophy; symptoms of numbness, tingling, or abnormal sensations in the upper extremity; peripheral neuropathy; or presence of a cardiac pacemaker.MethodsNerve conduction studies to bilateral supraspinatus, infraspinatus, deltoid, and biceps brachii muscles were performed with documented technique. Distal latency, amplitude, and area were recorded. Side‐to‐side comparisons were made. A mixed linear model was fit to the independent variables of gender, race, body mass index, height, and age with each recorded value.Main Outcome MeasurementsDistal latency, amplitude, area, and side‐to‐side variability of nerve conduction studies of the suprascapular, axillary, and musculocutaneous nerves with correlation to significant independent variables.ResultsData are presented showing normal distal latency, amplitude, and area values subcategorized by clinically significant variables, as well as acceptable side‐to‐side variability. Increased height correlated with increased distal latency in all the nerves tested. Amplitudes were larger in the infraspinatus recordings from women, while the amplitudes from the biceps and deltoid were greater in men. A larger body mass index was associated with a smaller amplitude in the deltoid in men. No correlations were seen with age or race.ConclusionNormative values for distal latency, amplitude, duration, and area were developed for proximal nerve conductions to the axillary, musculocutaneous, and suprascapular nerves. Simple surface electrode placement allows for easy reproduction of the authors' techniques. This is a useful standard to facilitate evaluation of these proximal peripheral nerves.
THE CULTURAL LOGIC OF HIERARCHY IN THE TARASCAN STATE
Authors: Haskell David L. 
Published: November 2008

AbstractThis paper seeks to broaden our understanding of the Tarascan state by analyzing the cultural logic of hierarchy as revealed in theRelación de Michoacán. Following the insights of Dumont (1980) and Sahlins (1985), it is proposed that the historical narrative contained within that document is concerned with legitimizing the rule of the Tarascan royal dynasty through a conception of hierarchy based on the logic of encompassment. This analysis interprets the characters of the narrative as instantiations of “elementary categories,” and the interactions between these characters serve to define and ultimately transform those categories. The most important transformation is the encompassing of the “Islander” category by the “Chichimec” category. It is through this encompassment that the royal dynasty symbolized a socio-cosmic totality and therefore possessed legitimate authority. Furthermore, I outline a model of elite interaction and the development of the Tarascan state in which the royal dynasty sought to monopolize foreign trade goods, thus materially constructing its own identity as a possessor of legitimate authority and, therefore, as Chichimecs, according to one connotation of that term. At the same time, a class of status markers was created that could be shared with the lesser nobility, conferring legitimacy on them while preserving the wealth and identity of the royal dynasty.
A new biodegradable nanocomposite based on polyhedral oligomeric silsesquioxane nanocages: cytocompatibility and investigation into electrohydrodynamic jet fabrication techniques for tissue‐engineered scaffolds
Authors: Raghunath Joanne , Zhang Hongbo , Edirisinghe Mohan J. , Darbyshire Arnold , Butler Peter E. , Seifalian Alexander M. 
Published: November 2008

Our group has developed a non‐biodegradable nanocomposite based on POSS (polyhedral oligomeric silsesquioxane) nanocages with PCU [poly(carbonate urethane)] and previous studies have shown good cell‐compatibility and antithrombogenic properties. The latest biodegradable formulation is a POSS‐modified poly(hexanolactone/carbonate)urethane/urea containing 80% hexanolactone (caprolactone) with the tradename UCL‐NanoBio™. The direct effect of the polymer on cells was investigated by seeding stem cells on to circular discs of the polymer in 24‐well plates; these discs were prepared mainly by electrohydrodynamic jetting. To assess the indirect effect of the polymer, various concentrations of the polymer powder were added to CCM (cell culture medium) and left on a shaker for 10 days. The precipitate was then removed and the CCM was used for culturing the cells seeded on to 24‐well plates. Cell viability and growth at 48 and 96 h were assessed using Alamar Blue™ and lactate dehydrogenase, and morphology was studied by scanning electron microscopy. Cells were shown to adhere well to the polymer, with cell metabolism being comparable with that found on TCP (tissue‐culture plastic). Indirect assessment demonstrated some decrease in cell viability with high concentrations of polymer, but showed no difference in cell death between polymer concentrations. The viability of cells seeded on to the polymer was comparable with that of those seeded on to TCP. Cell viability was comparable on both electrosprayed and electrospun scaffolds, but infiltration into the scaffold was much more evident on the electrospun scaffolds. It can be concluded that this new nanocomposite can support the growth and viability of stem cells and that scaffolds of this polymer nanocomposite fabricated by electrohydrodynamic jetting routes have potential use for tissue engineering in the future.
Toxoplasma gondiiinfection blocks the development of allergic airway inflammation in BALB/c mice
Authors: Fenoy I , Giovannoni M , Batalla E , Martin V , Frank F M , Piazzon I , Goldman A 
Published: November 2008

SummaryThere is a link between increased allergy and a reduction of some infections in western countries. Epidemiological data also show that respiratory allergy is less frequent in people exposed to orofaecal and foodborne microbes such as Toxoplasma gondii. Infection with T. gondii induces a strong cell-mediated immunity with a highly polarized T helper type 1 (Th1) response in early stages of infection. Using a well-known murine model of allergic lung inflammation, we sought to investigate whether T. gondii infection could modulate the susceptibility to develop respiratory allergies. Both acute and chronic infection with T. gondii before allergic sensitization resulted in a diminished allergic inflammation, as shown by a decrease in bronchoalveolar lavage (BAL) eosinophilia, mononuclear and eosinophil cell infiltration around airways and vessels and goblet cell hyperplasia. Low allergen-specific immunoglobulin (Ig)E and IgG1 and high levels of allergen-specific IgG2a serum antibodies were detected. A decreased interleukin (IL)-4 and IL-5 production by lymph node cells was observed, while no antigen-specific interferon-γ increase was detected. Higher levels of the regulatory cytokine IL-10 were found in BAL from infected mice. These results show that both acute and chronic parasite infection substantially blocked development of airway inflammation in adult BALB/c mice. Our results support the hypothesis that T. gondii infection contributes to protection against allergy in humans.
Diverse T‐cell differentiation potentials of human fetal thymus, fetal liver, cord blood and adult bone marrow CD34 cells on lentiviral Delta‐like‐1‐modified mouse stromal cells
Authors: Patel Ekta , Wang Bei , Lien Lily , Wang Yichen , Yang Li‐Jun , Moreb Jan S. , Chang Lung‐Ji 
Published: November 2008

SummaryHuman haematopoietic progenitor/stem cells (HPCs) differentiate into functional T cells in the thymus through a series of checkpoints. A convenient in vitro system will greatly facilitate the understanding of T‐cell development and future engineering of therapeutic T cells. In this report, we established a lentiviral vector‐engineered stromal cell line (LSC) expressing the key lymphopoiesis regulator Notch ligand, Delta‐like 1 (DL1), as feeder cells (LSC‐mDL1) supplemented with Flt3 ligand (fms‐like tyrosine kinase 3, Flt3L or FL) and interleukin‐7 for the development of T cells from CD34+ HPCs. We demonstrated T‐cell development from human HPCs with various origins including fetal thymus (FT), fetal liver (FL), cord blood (CB) and adult bone marrow (BM). The CD34+ HPCs from FT, FL and adult BM expanded more than 100‐fold before reaching the β‐selection and CD4/CD8 double‐positive T‐cell stage. The CB HPCs, on the other hand, expanded more than 1000‐fold before β‐selection. Furthermore, the time required to reach β‐selection differed for the various HPCs, 7 days for FT, 14 days for FL and CB, and 35 days for adult BM. Nevertheless, all of the T cells developed in vitro were stalled at the double‐positive or immature single‐positive stage with the exception that some CB‐derived T cells arrived at a positive selection stage. Consequently, the LSC‐mDL1 culture system illustrated diverse T‐cell development potentials of pre‐ and post‐natal and adult human BM HPCs. However, further modification of this in vitro T‐cell development system is necessary to attain fully functional T cells.
T‐cell receptor binding affinities and kinetics: impact on T‐cell activity and specificity
Authors: Stone Jennifer D. , Chervin Adam S. , Kranz David M. 
Published: November 2008

SummaryThe interaction between the T‐cell receptor (TCR) and its peptide–major histocompatibility complex (pepMHC) ligand plays a critical role in determining the activity and specificity of the T cell. The binding properties associated with these interactions have now been studied in many systems, providing a framework for a mechanistic understanding of the initial events that govern T‐cell function. There have been various other reviews that have described the structural and biochemical features of TCR : pepMHC interactions. Here we provide an overview of four areas that directly impact our understanding of T‐cell function, as viewed from the perspective of the TCR : pepMHC interaction: (1) relationships between T‐cell activity and TCR : pepMHC binding parameters, (2) TCR affinity, avidity and clustering, (3) influence of coreceptors on pepMHC binding by TCRs and T‐cell activity, and (4) impact of TCR binding affinity on antigenic peptide specificity.
A discussion of different types of glacial refugia used in mountain biogeography and phylogeography
Authors: Holderegger Rolf , Thiel‐Egenter Conny 
Published: November 2008

AbstractWith the recent rise of phylogeography, the biogeography of mountain species (species with their current main distribution above timber line), especially their glacial history, has attracted renewed interest. In particular, the question of where mountain species survived the ice ages has been approached in many phylogeographical studies. The terminology of glacial refugia of mountain species is often confusing, contradictory or counter‐intuitive. Our aim is to clarify and simplify this terminology. First, we offer a general definition of the term glacial refugium for mountain species. Then, we discuss three main types of glacial refugia of mountain species, i.e. nunatak, peripheral and lowland refugia. We believe that the discrimination of these three types of glacial refugia is sufficient to describe the glacial survival of (most) mountain species. Finally, we argue that the terms in situ survival and ex situ survival and the term periglacial refugium should only be used to describe specific cases of glacial history. No simple classification system can adequately describe every kind of glacial refugium, but we propose that authors should focus on providing comprehensive descriptions of particular refugial situations instead of introducing new terminology.
Population genetics of Galápagos land iguana (genus Conolophus) remnant populations
Authors: TZIKA ATHANASIA C. , ROSA SABRINA F. P. , FABIANI ANNA , SNELL HOWARD L. , SNELL HEIDI M. , MARQUEZ CRUZ , TAPIA WASHINGTON , RASSMANN KORNELIA , GENTILE GABRIELE , MILINKOVITCH MICHEL C. 
Published: November 2008

AbstractThe Galápagos land iguanas (genus Conolophus) have faced significant anthropogenic disturbances since the 17th century, leading to severe reduction of some populations and the extinction of others. Conservation activities, including the repatriation of captive‐bred animals to depleted areas, have been ongoing since the late 1970s, but genetic information has not been extensively incorporated. Here we use nine species‐specific microsatellite loci of 703 land iguanas from the six islands where the species occur today to characterize the genetic diversity within, and the levels of genetic differentiation among, current populations as well as test previous hypotheses about accidental translocations associated with early conservation efforts. Our analyses indicate that (i) five populations of iguanas represent distinct conservation units (one of them being the recently discovered rosada form) and could warrant species status, (ii) some individuals from North Seymour previously assumed to be from the natural Baltra population appear related to both Isabela and Santa Cruz populations, and (iii) the five different management units exhibit considerably different levels of intrapopulation genetic diversity, with the Plaza Sur and Santa Fe populations particularly low. Although the initial captive breeding programmes, coupled with intensive efforts to eradicate introduced species, saved several land iguana populations from extinction, our molecular results provide objective data for improving continuing in situ species survival plans and population management for this spectacular and emblematic reptile.
The roles of allopatric divergence and natural selection in quantitative trait variation across a secondary contact zone in the lizard Anolis roquet
Authors: JOHANSSON HELENA , SURGET‐GROBA YANN , THORPE ROGER S. 
Published: November 2008

AbstractPopulations of the Caribbean lizard, Anolis roquet, are thought to have experienced long periods of allopatry before recent secondary contact. To elucidate the effects of past allopatry on population divergence in A. roquet, we surveyed parallel transects across a secondary contact zone in northeastern Martinique. We used diagnostic molecular mitochondrial DNA markers to test fine‐scale association of mitochondrial DNA lineage and geological region, multivariate statistical techniques to explore quantitative trait pattern, and cline fitting techniques to model trait variation across the zone of secondary contact. We found that lineages were strongly associated with geological regions along both transects, but quantitative trait patterns were remarkably different. Patterns of morphological and mitochondrial DNA variation were consistent with a strong barrier to gene flow on the coast, whereas there were no indications of barriers to gene flow in the transitional forest. Hence, the coastal populations behaved as would be predicted by an allopatric model of divergence in this complex, while those in the transitional forest did not, despite the close proximity of the transects and their shared geological history. Patterns of geographical variation in this species complex, together with environmental data, suggest that on balance, selection regimes on either side of the secondary contact zone in the transitional forest may be more convergent, while those either side of the secondary contact zone on the coast are more divergent. Hence, the evolutionary consequences of allopatry may be strongly influenced by local natural selection regimes.
Revealing the hidden complexities of mtDNA inheritance
Authors: WHITE DANIEL JAMES , WOLFF JONCI NIKOLAI , PIERSON MELANIE , GEMMELL NEIL JOHN 
Published: November 2008

AbstractMitochondrial DNA (mtDNA) is a pivotal tool in molecular ecology, evolutionary and population genetics. The power of mtDNA analyses derives from a relatively high mutation rate and the apparent simplicity of mitochondrial inheritance (maternal, without recombination), which has simplified modelling population history compared to the analysis of nuclear DNA. However, in biology things are seldom simple, and advances in DNA sequencing and polymorphism detection technology have documented a growing list of exceptions to the central tenets of mitochondrial inheritance, with paternal leakage, heteroplasmy and recombination now all documented in multiple systems. The presence of paternal leakage, recombination and heteroplasmy can have substantial impact on analyses based on mtDNA, affecting phylogenetic and population genetic analyses, estimates of the coalescent and the myriad of other parameters that are dependent on such estimates. Here, we review our understanding of mtDNA inheritance, discuss how recent findings mean that established ideas may need to be re‐evaluated, and we assess the implications of these new‐found complications for molecular ecologists who have relied for decades on the assumption of a simpler mode of inheritance. We show how it is possible to account for recombination and heteroplasmy in evolutionary and population analyses, but that accurate estimates of the frequencies of biparental inheritance and recombination are needed. We also suggest how nonclonal inheritance of mtDNA could be exploited, to increase the ways in which mtDNA can be used in analyses.
Drastic post‐LGM expansion and lack of historical genetic structure of a subtropical fig‐pollinating wasp (Ceratosolensp. 1) ofFicus septicain Taiwan
Authors: LIN RONG‐CHIEN , YEUNG CAROL K‐L. , LI SHOU‐HSIEN 
Published: November 2008

AbstractThe climatic oscillations of the last glacial period have had profound influences on the demography and levels of genetic diversity of extant species. Molecular evidence of glacial effects on temperate species has been well documented, whereas little is known regarding that on subtropical species. Here we present analyses based on partial sequences of the mitochondrial cytochromecoxidase subunit I (COI) gene (1052 bp) and genotypes at 15 microsatellite loci to investigate the historical demography, population structure and ongoing gene flow of an undescribed fig‐pollinating wasp (Ceratosolensp. 1) ofFicus septicain subtropical Taiwan. Reconstructed historical demography based on the coalescent tree ofCOIsequences suggests thatC. sp. 1 has undergone a drastic population expansion which was tightly coupled with climatic changes since the last glacial maximum (LGM). The magnitude of the population size change was approximately 500‐fold, indicating that the population of this wasp and its host was likely highly compressed during the last glacial period. The lack of significant population differentiation (FST < 0.02, for all pairwiseFSTvalues) may be due to rapid postglacial expansion facilitated by long‐distance dispersal, although a low frequency of first‐generation migrants was detected. Our results clearly demonstrate how recent climatic changes since the LGM and dispersal ability have jointly shaped the genetic composition of a subtropical fig‐pollinating wasp.