bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing for evolutionary trade‐offs in a phylogenetic context: ecological diversification and evolution of locomotor performance in emydid turtles
Authors: STEPHENS P. R. , WIENS J. J. 
Published: November 2007

AbstractThe evolution of ecological trade‐offs is an important component of ecological specialization and adaptive radiation. However, the pattern that would show that evolutionary trade‐offs have occurred between traits among species has not been clearly defined. In this paper, we propose a phylogeny‐based definition of an evolutionary trade‐off, and apply it to an analysis of the evolution of trade‐offs in locomotor performance in emydid turtles. We quantified aquatic and terrestrial speed and endurance for up to 16 species, including aquatic, semi‐terrestrial and terrestrial emydids. Emydid phylogeny was reconstructed from morphological characters and nuclear and mitochondrial DNA sequences. Surprisingly, we find that there have been no trade‐offs in aquatic and terrestrial speed among species. Instead, specialization to aquatic and terrestrial habitats seems to have involved trade‐offs in speed and endurance. Given that trade‐offs between speed and endurance may be widespread, they may underlie specialization to different habitats in many other groups.
Response of a rocky intertidal ecosystem engineer and community dominant to climate change
Authors: Menge Bruce A. , Chan Francis , Lubchenco Jane 
Published: November 2007

AbstractTo evaluate how climate change might impact a competitively dominant ecological engineer, we analysed the growth response of the mussel Mytilus californianus to climate patterns [El Niño‐Southern Oscillation, Pacific Decadal Oscillation (PDO)]. Mussels grew faster during warmer climatic events. Growth was initially faster on a more productive cape compared to a less productive cape. Growth rates at the two capes merged in 2002, coincidentally with a several year‐long shift from warm to cool PDO conditions. To determine the mechanism underlying this response, we examined growth responses to intertidal sea and air temperatures, phytoplankton, sea level and tide height. Together, water temperature (32%) and food (12.5%) explained 44.5% of the variance in mussel growth; contributions of other factors were not significant. In turn, water temperature and food respond to climate‐driven variation in upwelling and other, unknown factors. Understanding responses of ecosystem engineers to climate change will require knowing direct thermal effects and indirect effects of factors altered by temperature change.
Occupational Choice of High Skilled Immigrants in the United States
Authors: Chiswick Barry R. , Taengnoi Sarinda 
Published: November 2007

ABSTRACTThis paper explores the impact of English language proficiency and country of origin on the occupational choice of high‐skilled immigrants in the United States. The findings reveal that high‐skilled immigrants with limited proficiency in English, or whose first language is linguistically distant from English, are more likely to be in occupations in which English communication skills are not very important, such as computer and engineering occupations. Interestingly, the degree of exposure to English prior to immigration is found to have little influence on selecting occupations in the United States. Nonetheless, the paper also shows that some immigrants with little exposure to English, and whose native language is highly distinct from English, are present in some “speaking‐intensive” occupations, in particular social services occupations. These occupations may not require workers to be fluent in English if they mostly provide services to immigrants from the same linguistic background. The study also raises questions as to how heavily US immigration policy influences the decisions of highly‐skilled migrants before they even leave their home countries.
An Examination of the Danish Immigrant‐Trade Link
Authors: White Roger 
Published: November 2007

ABSTRACTThis paper investigates the influence of immigrants on Danish imports and exports. As public and political debates concerning immigration policy are expected to continue, the findings presented here provide valuable information. Prior to 2002, Denmark's immigration policy was among the most liberal in Europe. However, concerns regarding terrorism, social services depletion, and detrimental labour market effects, all purported to stem from immigration, led the Danish government to severely tighten its policy. In examining Denmark, we explore the immigrant‐trade relationship in a small host country that is globally well‐integrated, open to trade, and proximate to both major trading partners and primary immigrant source nations. Further, as the share of the Danish population constituted by immigrants increased from 2.6 to 5.6 per cent between 1980 and 2000, Denmark presents an opportunity to consider immigrant‐trade links for an increasingly diverse population that was initially relatively homogenous.We consider a number of variations regarding home countries and trade values to estimate immigrant‐trade links using a Tobit specification. The findings presented here, when considered in relation to prior research, suggest that the presence and magnitude of immigrant‐trade links vary according to host country population homogeneity.
Native Arteriovenous Fistulas: Correlation of Intra‐Access Blood Flow with Characteristics of Stenoses Found During Diagnostic Angiography
Authors: Monroy‐Cuadros Mauricio , Salazar Anastasio , Yilmaz Serdar , McLaughlin Kevin 
Published: November 2007

AbstractSurveillance of the intra‐access blood flow (Qa) has improved identification of thrombosis risk (Qa ≤ 500 ml/minute), and these patients are referred for angiogram and angioplasty. The purpose of this study was to correlate the Qa with patient and stenotic lesion characteristics both before and after angioplasty in a retrospective cohort of 210 patients who were preselected on the basis of reduced Qa (369 ± 121 ml/minute). Angiograms revealed a total of 643 stenoses, and all patients had at least one significant stenosis (>50% luminal narrowing). There was no significant association between the preangioplasty Qa and the number, location, or length of stenoses, but there was a significant negative correlation between the degree of stenosis and the preangioplasty Qa. Five hundred eighty stenoses in 190 patients were treated with angioplasty; the postangioplasty Qa was 633 ± 208 ml/minute. Of the residual stenoses, all had less than 50% narrowing. There was no correlation between the postangioplasty Qa and the length or degree of stenoses, but there was a significant negative correlation between the postangioplasty Qa and the number of stenoses. We conclude that the primary determinant of reduced preangioplasty Qa is the degree of stenosis, when stenoses are over 50%, whereas the primary determinant of reduced postangioplasty Qa is the number of stenosis. For patients with two or more residual stenoses and failure to achieve Qa > 500 p;ml/minute postangioplasty, the alternative procedure is a prompt surgical revision in order to maintain the goal of access patency.
Cephalic Arch Stenosis
Authors: Kian Kaveh , Asif Arif 
Published: November 2007

AbstractThe Kidney Dialysis Outcomes Quality Initiative guidelines and the Fistula First Initiative for vascular access have had a measurable impact on the incidence and prevalence of the type of access used to deliver hemodialysis in the United States. There has been a yearly increase in the placement of arteriovenous fistulas and an exponential increase in endovascular treatment of failing and immature fistulas. Undoubtedly, the predominant cause of fistula malfunction is stenosis within the access system. The stenotic lesions can occur anywhere within the access system from the arteries to the outflow and central veins. One of the relatively common sites for stenosis in patients with brachiocephalic fistulas is the cephalic arch region. While access stenoses at many other sites have been successfully treated with percutaneous balloon angioplasty, the results of this approach in the management of cephalic arch stenosis (CAS) have been rather disappointing. This has been in part due to multiple factors including the resistant nature of the stenosis, the development of early restenosis, as well as poor patency and high vein rupture rates. This article discusses the anatomy, postulated etiology and percutaneous interventions for the treatment of CAS. In addition, the report highlights surgical alternatives to the management of stenosis in this segment of the cephalic vein.
Role of Surgical Intervention for Cephalic Arch Stenosis in the “Fistula First” Era
Authors: Kian Kaveh , Unger Stephen W. , Mishler Rick , Schon Donald , Lenz Oliver , Asif Arif 
Published: November 2007

AbstractCephalic arch stenosis (CAS) is a frequent cause of vascular access dysfunction in patients with brachiocephalic fistulae. While percutaneous balloon angioplasty has been used to treat CAS, the results of this approach have been poor due to multiple factors including resistant nature of the stenosis, development of early restenosis, as well as poor patency and high vein rupture rates. In this analysis, we report the results of an alternative approach to manage this problem. Thirteen patients with frequently recurring CAS were referred for surgical intervention. Angiographic images recorded during the prior percutaneous procedures were made available to the surgeons. The surgical procedure entailed transecting the healthy portion of the cephalic vein distal to the stenotic segment in the arch, transposing and anastomosing it to the upper basilic/axillary vein. Following surgical revision, development of access dysfunction was treated with percutaneous balloon angioplasty. Patency rates for angioplasty before and after the surgical revision were evaluated. Primary patency rates for angioplasty before the surgical revision were 23%, 8% and 0% at 3, 6, and 12 months, respectively. Following surgical revision, all patients needed angioplasty procedure. However, primary patency increased to 92%, 69%, and 39% at 3, 6, and 12 months, respectively (p = 0.0001). Secondary patency before the surgical revision at 3, 6, and 12 months was 100%, 39%, and 8%, respectively, compared with 92% at 3, 6, and 12 months postsurgical revision (p = 0.0003). The results of this study demonstrate that surgical transposition of the cephalic vein in frequently recurring CAS is a viable option and yields better patency rates for future angioplasty procedures.
The value of comparing health outcomes in cohort studies: An example of self‐rated health in seven studies including 79 653 participants
Authors: Anstey Kaarin J , Butterworth Peter , Windsor Tim D , Burns Richard , Sargent‐Cox Kerry , Von Sanden Chwee , Christensen Helen , Booth Heather , Simons Leon A , Byles Julie E , Gibson Richard , Luszcz Mary A , Shaw Jonathan E , Broe Gerald A , Browning Colette , Mitchell Paul , Cumming Robert G , Kendig Hal 
Published: November 2007

Objective:  To demonstrate the value of comparing data from multiple cohort studies using the example of self‐rated health (SRH). Methods:  Seven Australian cohort studies including comparable data on SRH were identified. Comparisons of the distributions of SRH were conducted, and logistic regression was used to evaluate age, sex and education effects within studies. A nationally representative survey was used as a statistical reference to determine how studies differed from the Australian population in frequencies of responses. Results:  Ratings of SRH declined with increasing age. Low education was associated with higher frequencies of fair/poor SRH even in young adulthood but there were no sex differences. Results for smaller studies did not necessarily differ from nationally representative studies. Conclusion:  Collaborative reanalysis of Australian cohort permits analysis of health outcomes from a large numbers of participants. Health outcomes and their sociodemographic determinants may be more comprehensively evaluated through such collaborative projects.
Structures, Components and Functions of Secretory Tissues in Houttuynia cordata
Authors: Ni Xi‐Lu , Peng Li , Liu Wen‐Zhe 
Published: November 2007

Abstract
Houttuynia cordata Thunb., traditionally used as a therapeutic plant in folk medicine, has shown antioxidant and anticancer activities. The species, as a core component of paleoherbs, is normally characterized based on the presence of different types of secretory tissue: oil cells, three types of secretory cells and glandular hairs. The aim of this work was to study the structural, componential, and the functional characteristics of the secretory tissues in both the floral and vegetative parts. The results indicate that oil cells and secretory cells are distributed in all organs of the plant, while glandular hairs are situated on the aerial stems and leaves. Both oil cells and glandular hairs initiate from the protoderm, but their developmental processes are different. Although three types of secretory cells initiate from different primary meristems, the developmental patterns of different secretory cells are the same. Also, although the origins of secretory cells are different from oil cells, their early developmental processes are the same. Histochemical results show that oil cells, secretory cells and glandular hairs produce flavonoids, phenolic compounds, tannins, lipids, aldehyde and ketone‐compounds. In addition, there are terpenoids and pectic‐like substances in oil cells, alkaloids in secretory cells of aerial stems, and terpenoids and alkaloids in glandular hairs. These compounds play very important roles in protecting plants from being eaten by herbivores (herbivory) and infected by microbial pathogens. The oil cell and secretory cell, as unicellular secretory tissues, are intermediates between the primitive surface glandular and secretory cavity and canal during the evolution of secretory structures.
An Arabidopsis thaliana ABC transporter that confers kanamycin resistance in transgenic plants does not endow resistance to Escherichia coli
Authors: Burris Kellie , Mentewab Ayalew , Ripp Steven , Stewart C. Neal 
Published: November 2007

SummaryConcerns have been raised about potential horizontal gene transfer (HGT) of antibiotic resistance markers (ARMs) from transgenic plants to bacteria of medical and environmental importance. All ARMs used in transgenic plants have been bacterial in origin, but it has been recently shown that an Arabidopsis thaliana ABC transporter, Atwbc19, confers kanamycin resistance when overexpressed in transgenic plants. Atwbc19 was evaluated for its ability to transfer kanamycin resistance to Escherichia coli, a kanamycin‐sensitive model bacterium, under simulated HGT, staged by subcloning Atwbc19 under the control of a bacterial promoter, genetically transforming to kanamycin‐sensitive bacteria, and assessing if resistance was conferred as compared with bacteria harbouring nptII, the standard kanamycin resistance gene used to produce transgenic plants. NptII provided much greater resistance than Atwbc19 and was significantly different from the no‐plasmid control at low concentrations. Atwbc19 was not significantly different from the no‐plasmid control at higher concentrations. Even though HGT risks are considered low with nptII, Atwbc19 should have even lower risks, as its encoded protein is possibly mistargeted in bacteria.
Prevalence and Phylogenetic Analysis of Cryptosporidium in Pigs in Eastern China
Authors: Chen F. , Huang K. 
Published: November 2007

SummaryFaecal samples from 1488 pigs were collected from six pig farms in Jiangsu province and Shanghai city, eastern China, stained by the modified acid‐fast staining technique (MAFS) and observed by light and phase contrast microscopy to identify Cryptosporidium oocysts. A total of 178 (12%) positive animals were detected. Three randomly selected MAFS‐positive samples from each farm were further analysed by reverse‐transcription polymerase chain reaction (RT‐PCR) using primers designed to amplify DNA fragments from the small subunit ribosomal RNA (SSU rRNA) gene. PCR products from two positive samples were sequenced. Phylogenetic analysis and a distances matrix generated from these sequences showed that the isolates belonged to the species C. parvum, and were most similar to the C. parvum‘mouse’ genotype. The identification of this C. parvum genotype in pigs has not been reported previously. These findings are discussed in the context of the epidemiology of Cryptosporidium on pig farms.
NS3 Peptide, a Novel Potent Hepatitis C Virus NS3 Helicase Inhibitor: Its Mechanism of Action and Antiviral Activity in the Replicon System
Authors: Gozdek Agnieszka , Zhukov Igor , Polkowska Agnieszka , Poznanski Jaroslaw , Stankiewicz-Drogon Anna , Pawlowicz Jerzy M. , Zagórski-Ostoja Wlodzimierz , Borowski Peter , Boguszewska-Chachulska Anna M. 
Published: November 2007

ABSTRACT

Hepatitis C virus (HCV) chronic infections represent one of the major and still unresolved health problems because of low efficiency and high cost of current therapy. Therefore, our studies centered on a viral protein, the NS3 helicase, whose activity is indispensable for replication of the viral RNA, and on its peptide inhibitor that corresponds to a highly conserved arginine-rich sequence of domain 2 of the helicase. The NS3 peptide (p14) was expressed in bacteria. Its 50% inhibitory activity in a fluorometric helicase assay corresponded to 725 nM, while the ATPase activity of NS3 was not affected. Nuclear magnetic resonance (NMR) studies of peptide-protein interactions using the relaxation filtering technique revealed that p14 binds directly to the full-length helicase and its separately expressed domain 1 but not to domain 2. Changes in the NMR chemical shift of backbone amide nuclei (
1
H and
15
N) of domain 1 or p14, measured during complex formation, were used to identify the principal amino acids of both domain 1 and the peptide engaged in their interaction. In the proposed interplay model, p14 contacts the clefts between domains 1 and 2, as well as between domains 1 and 3, preventing substrate binding. This interaction is strongly supported by cross-linking experiments, as well as by kinetic studies performed using a fluorometric assay. The antiviral activity of p14 was tested in a subgenomic HCV replicon assay that showed that the peptide at micromolar concentrations can reduce HCV RNA replication.
Implications of Rewiring Bacterial Quorum Sensing
Authors: Haseltine Eric L. , Arnold Frances H. 
Published: November 2007

ABSTRACT

Bacteria employ quorum sensing, a form of cell-cell communication, to sense changes in population density and regulate gene expression accordingly. This work investigated the rewiring of one quorum-sensing module, the
lux
circuit from the marine bacterium
Vibrio fischeri
. Steady-state experiments demonstrate that rewiring the network architecture of this module can yield graded, threshold, and bistable gene expression as predicted by a mathematical model. The experiments also show that the native
lux
operon is most consistent with a threshold, as opposed to a bistable, response. Each of the rewired networks yielded functional population sensors at biologically relevant conditions, suggesting that this operon is particularly robust. These findings (i) permit prediction of the behaviors of quorum-sensing operons in bacterial pathogens and (ii) facilitate forward engineering of synthetic gene circuits.
The Native Bacterioplankton Community in the Central Baltic Sea Is Influenced by Freshwater Bacterial Species
Authors: Riemann L. , Leitet C. , Pommier T. , Simu K. , Holmfeldt K. , Larsson U. , Hagström Å. 
Published: November 2007

ABSTRACT

The Baltic Sea is one of the largest brackish environments on Earth. Despite extensive knowledge about food web interactions and pelagic ecosystem functioning, information about the bacterial community composition in the Baltic Sea is scarce. We hypothesized that due to the eutrophic low-salinity environment and the long water residence time (>5 years), the bacterioplankton community from the Baltic proper shows a native “brackish” composition influenced by both freshwater and marine phylotypes. The bacterial community composition in surface water (3-m depth) was examined at a single station throughout a full year. Denaturing gradient gel electrophoresis (DGGE) showed that the community composition changed over the year. Further, it indicated that at the four extensive samplings (16S rRNA gene clone libraries and bacterial isolates from low- and high-nutrient agar plates and seawater cultures), different bacterial assemblages associated with different environmental conditions were present. Overall, the sequencing of 26 DGGE bands, 160 clones, 209 plate isolates, and 9 dilution culture isolates showed that the bacterial assemblage in surface waters of the central Baltic Sea was dominated by
Bacteroidetes
but exhibited a pronounced influence of typical freshwater phylogenetic groups within
Actinobacteria
,
Verrucomicrobia
, and
Betaproteobacteria
and a lack of typical marine taxa. This first comprehensive analysis of bacterial community composition in the central Baltic Sea points to the existence of an autochthonous estuarine community uniquely adapted to the environmental conditions prevailing in this brackish environment.
Colonization and Persistence of Antibiotic-Resistant
Enterobacteriaceae
Strains in Infants Nursed in Two Neonatal Intensive Care Units in East London, United Kingdom
Authors: Millar Michael , Philpott Alex , Wilks Mark , Whiley Angela , Warwick Simon , Hennessy Enid , Coen Pietro , Kempley Stephen , Stacey Fiona , Costeloe Kate 
Published: November 2007

ABSTRACT

Stool samples were collected from infants nursed in two neonatal intensive care units (NICUs) in East London, United Kingdom. The aim of the study was to determine the incidence of and risk factors for the carriage of multiresistant
Enterobacteriaceae
strains (MRE; resistant to three or more classes of antibiotic) and the extent of the persistence of resistant strains following discharge. Sixty-two (50%) of 124 infants had acquired MRE by 2 weeks of postnatal age, and 69 (56%) infants had acquired MRE by discharge. The proportions of infants at 2 weeks carrying strains that were resistant to antibiotics were the following: tetracycline, 79%; amoxicillin, 78%; cephalosporins, 31%; trimethoprim, 20%; piperacillin-tazobactam, 11%; chloramphenicol, 9%; and aminoglycoside, 4%. A gestational age of less than 26 weeks was a risk factor for colonization with MRE at discharge, but not at 2 weeks. Analysis within a NICU showed that exposure of an infant to a specific antibiotic in the NICU was not a risk factor for the carriage of a strain resistant to that antibiotic. Estimates of persistence from discharge to 6 months were the following: for tetracycline, 57% (95% confidence intervals [CI], 0.35 to 0.87); chloramphenicol, 49% (95% CI, 0.20 to 0.83); trimethoprim, 45% (95% CI, 0.22 to 0.74); piperacillin-tazobactam, 42% (95% CI, 0.20 to 0.71); and augmentin, 34% (95% CI, 0.11 to 0.66). Strains resistant to cephalosporins or aminoglycosides showed lower levels of persistence. Nine of 34 infants (26.5%) with
Escherichia coli
and 4 (7.1%) of 56 infants with
Klebsiella
spp. at discharge carried strains indistinguishable by randomly amplified polymorphic DNA and antibiotic susceptibility patterns at 6 months. MRE were found at high frequency in the infants during their stay in the NICU and persisted in a proportion of infants.