bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of geographical and ecological factors on island beta diversity patterns
Authors: Fattorini Simone
Published: December 2009

Aim  To investigate the importance of various island characteristics in determining spatial patterns of variations in beta diversity for various animal groups.

Location  Analyses are presented for 10 animal groups living on the Aeolian Islands, a volcanic archipelago in the central Mediterranean, near Sicily.

Methods  Three hypotheses were formulated to explain patterns of beta diversity: the target‐area–distance effect, stepping stone dispersal and island age. Matrices of inter‐island dissimilarities were constructed under each hypothesis and correlated with matrices of faunal dissimilarities using Mantel tests. For the ‘target‐area–distance effect’ hypothesis, inter‐island dissimilarities were calculated using island sizes and distances to nearest mainland areas. For the ‘stepping stone dispersal’ hypothesis, inter‐island distances were measured. Finally, for the ‘island age’ hypothesis, inter‐island dissimilarities were calculated on the basis of the geological age of the islands. Cluster analysis was used to investigate inter‐island faunal relationships.

Results  Support for a target‐area–distance effect was found only for birds. For these highly mobile animals, inter‐island distances had no significant effects on beta diversity. Birds are known to colonize islands by crossing large sea barriers and thus they can easily reach the Aeolian Islands, which are close to source areas (notably Sicily). Inter‐island distances had a significant role in determining patterns of beta diversity in most invertebrates. For Mollusca, Opiliones, Chilopoda, Heteroptera, coprophagous Scarabaeoidea, and Tenebrionidae, even relatively short distances preclude invertebrates from colonizing an island regularly from the mainland, and most colonization probably results from inter‐island faunal exchanges. Island age was proved to be important only for orthopterans.

Main conclusions  The origin of most of the Aeolian invertebrate fauna is quite recent, and species appear to have established on the islands predominantly by stepping stone dispersal. Birds, which are highly mobile organisms, follow more direct mainland–island dynamics. As further studies on other islands become available, comparative analyses will confirm whether the factors influencing variations in beta diversity in this study and their relationships with species dispersal ability are consistent across scales and geographical context.
Maintaining gender sensitivity in the family practice: facilitators and barriers
Authors: Celik Halime , Lagro‐Janssen Toine , Klinge Ineke , Van Der Weijden Trudy , Widdershoven Guy
Published: December 2009

Objective  This study aims to identify the facilitators and barriers perceived by General Practitioners (GPs) to maintain a gender perspective in family practice.

Methods  Nine semi‐structured interviews were conducted among nine pairs of GPs. The data were analysed by means of deductive content analysis using theory‐based methods to generate facilitators and barriers to gender sensitivity.

Results  Gender sensitivity in family practice can be influenced by several factors which ultimately determine the extent to which a gender sensitive approach is satisfactorily practiced by GPs in the doctor–patient relationship. Gender awareness, repetition and reminders, motivation triggers and professional guidelines were found to facilitate gender sensitivity. On the other hand, lacking skills and routines, scepticism, heavy workload and the timing of implementation were found to be barriers to gender sensitivity.

Conclusion  While the potential effect of each factor affecting gender sensitivity in family practice has been elucidated, the effects of the interplay between these factors still need to be determined.
When guidelines need guidance: considerations and strategies for improving the adoption of chronic disease evidence by general practitioners
Authors: Kendall Elizabeth , Sunderland Naomi , Muenchberger Heidi , Armstrong Kylie
Published: December 2009

Objective  This paper provides a review of key issues affecting the uptake of clinical guidelines by general practitioners (GPs) in Australia and internationally. Attention is given to the barriers that affect guideline uptake, the quality of guidelines and the dissemination of guidelines to GPs in practice settings.

Method  A comprehensive cross‐disciplinary literature review of peer‐reviewed journals was conducted between January and April 2008. The literature review was undertaken by three independent researchers from diverse disciplinary backgrounds. The review focused on studies that explored the barriers and issues associated with the use of guidelines in general practice and suggestions for more effective use.

Results  Pathways for clinicians to evaluate and use guidelines are still not clear. The majority of contemporary literature promotes linear ‘uptake’ and ‘accessibility’ models for clinical guidelines that may not attend to more complex issues associated with GPs' ways of practising on a daily basis. There are also few clear guidelines for GPs on how to ‘adapt’ guidelines for local and individual patient circumstances.

Conclusions  Peak organizations such as General Practice Queensland in Australia can have a significant role in helping GPs to evaluate and use clinical guidelines. The suggested approach emphasizes the need for such peak bodies to promote respect for practitioner experience, interpretation and patient insight.
Promoting development and use of systematic reviews in a developing country
Authors: Yousefi‐Nooraie Reza , Rashidian Arash , Nedjat Saharnaz , Majdzadeh Reza , Mortaz‐Hedjri Soroush , Etemadi Arash , Salmasian Hojjat
Published: December 2009

Introduction  One major barrier to develop health systems is the limited capacity for conducting research and implementation of research findings. We assessed the views of researchers, decision makers and research policy makers on how the development and usage of evidence from systematic reviews can be promoted in a country with limited resources.

Methods  We surveyed 131 participants in six systematic review workshops for their views on important items influencing the production and usage of systematic reviews in a developing country. They were also asked to propose interventions to deal with potential barriers. We analysed the quantitative data using multidimensional scaling methods, and the qualitative data using content analysis approach.

Results  We identified seven clusters of items that contribute to the promotion of conducting and using systematic reviews. For each cluster a set of interventions are proposed that health care decision makers and research policy makers may use for promoting conduct and use of systematic reviews. The clusters are ‘importance for policy makers’, ‘access to international research’, ‘priority and support for systematic reviews’, ‘competency and willingness of researchers to conduct reviews’, ‘importance for end‐users’, ‘quality of local primary research’ and ‘visibility and access to local research’.

Discussion  The proposed interventions focus on national level initiatives for making the systematic reviews ‘wanted’ and improving the capacity to conduct research. Our findings emphasize the essential role of policy makers for promoting systematic reviews. They demonstrate that many barriers stem from the lower quality of and lack of access to primary research originating from developing countries.
Awareness, attitude and practice of evidence‐based medicine among primary health care doctors in Jordan
Authors: Al Omari Mousa , Khader Yousef , Jadallah Khaled , Dauod Ali Shakir , Al‐shdifat Amjad Ali Khalaf
Published: December 2009

Objectives  To assess the awareness, attitude and knowledge towards evidence‐based medicine (EBM) among primary health care doctors in Jordan and to identify the perceived barriers for practising EBM.

Methods  A simple random sample of 34 comprehensive primary health care centres was selected from a list of 64 centres in Jordan using random number table. A family doctor visited all selected centres and invited the available doctors to participate in the study. Participants were asked to fill the self‐administrated questionnaire that was designed to assess beliefs and attitude of doctors towards EBM.

Results  Of the total 220 clinicians approached, 202 (91.8%) completed the questionnaire. About 80.7% welcomed promotion of EBM and 91.1% agreed on that research findings are helpful in daily management of patients. About 85.1% stated that practising EBM improves patient care, 68.3% stated that EBM reduces health care costs, 74.8% stated that EBM improves quick knowledge update, 93.6% reported that the doctor–patient relationship is affected positively by practising EBM. About 60.9% reported that they know the concept of EBM and 56.1% reported that they ever used the EBM. Patient overload, limited resources and facilities, and the absence of an effective computer system were the most commonly reported barriers to the implementation of EBM.

Conclusions  In spite of the positive attitude towards EBM, this study demonstrated numerous personal, interpersonal and institutional barriers towards implementing EBM which necessitate prompt action to formulate a national plan to overcome such barriers.
How to teach evidence‐based medicine to teachers: reflections from a workshop experience
Authors: Murad Mchammad Hassan , Montori Victor M. , Kunz Regina , Letelier Luz M. , Keitz Sheri A. , Dans Antonio L. , Silva Suzana A. , Guyatt Gordon H.
Published: December 2009

Rationale, aims and objectives  To summarize 20‐year experience of conducting a workshop designed for educators who wish to improve their teaching skills of evidence based medicine (EBM). The goal is to provide tips for educators interested in replicating this educational model.

Methods  Qualitative description of factors associated with the success of the workshop.

Results  The factors considered by instructors to be most helpful are: the small group interactive design, role‐play and simulation of real world learning environments, a mentorship model and high educator to learner ratio.

Conclusions  Although this experience is observational and does not represent high quality evidence, certain attributes in the design of EBM workshops may lead to better dissemination of EBM concepts. Educators may consider empirically applying some of these attributes and testing their efficacy in comparative studies.
MR cholangiography in orthotopic liver transplantation: sensitivity and specificity in detecting biliary complications
Authors: Boraschi Piero , Donati Francescamaria , Gigoni Roberto , Volpi Alessia , Salemi Simonetta , Filipponi Franco , Falaschi Fabio
Published: December 2009

Boraschi P, Donati F, Gigoni R, Volpi A, Salemi S, Filipponi F, Falaschi F. MR cholangiography in orthotopic liver transplantation: sensitivity and specificity in detecting biliary complications. Clin Transplant 2010: 24: E82–E87. © 2009 John Wiley & Sons A/S.

Abstract:  Background:  To assess the diagnostic value of magnetic resonance cholangiography (MRC) when evaluating biliary complications in a large series of liver transplants.

Methods:  One hundred and twenty‐nine patients prospectively underwent magnetic resonance (MR) imaging and MR cholangiography at 1.5‐T device after orthotopic liver transplantation (OLT). After the preliminary acquisition of axial T1‐ and T2‐weighted images, MRC involved respiratory‐triggered, thin‐slab (2 mm), heavily T2‐weighted fast spin‐echo and breath‐hold, thick‐slab (10–50 mm), single‐shot T2‐weighted sequences. MR images were blindly evaluated by two experienced readers in conference to determine the biliary anatomy and the presence of complications, whose final diagnosis was based on endoscopic retrograde cholangiography, percutaneous trans‐hepatic cholangiography, and by integrating clinical follow‐up with ultrasound and/or MR findings.

Results:  Biliary complications were found in 60 patients (46.5%) and were represented by ischemic‐type biliary lesions (n = 21); anastomotic strictures (n = 13); non‐anastomotic strictures (n = 5); anastomotic strictures associated to lithiasis (n = 6); lithiasis (n = 6); papillary dysfunctions (n = 9). The sensitivity, specificity, positive predictive value, and negative predictive value of the reviewers for the detection of all types of biliary complications in patients with OLT were 98%, 94%, 94%, and 98%, respectively.

Conclusions:  MRC is a reliable technique for detecting post‐OLT biliary complications and should be recommended before planning therapeutic interventions.
Targeted integration and removal of transgenes in hybrid aspen (Populus tremula L. x P. tremuloides Michx.) using site‐specific recombination systems
Authors: Fladung M. , Becker D.
Published: December 2009

Two site‐specific recombination systems, Cre/lox and FLP/FRT, were tested for marker gene removal and targeted gene transfer in a model tree system. A hybrid aspen clone (Populus tremula × Populus tremuloides) was co‐transformed with plasmids containing either the FLP or the Cre recombinase, both under control of a heat‐inducible promoter (HSP, Gmhsp17.5‐E from soybean) flanked by the two recognition sites (FRT or lox). Molecular investigations of heat‐shock treated Cre or FLP transgenic lines indicate excision of inserts between the two recognition sites. Further, a site‐specific recombination at the FRT sites leading to targeted integration of a fragment could be demonstrated for the FLP/FRT system. Transgenic aspen carrying two constructs (each with different genes between the FRT sites) revealed (i) excision of both fragments between the FRT sites, and (ii) targeted integration of the fragment from the second construct exactly at the former position of the fragment in the first construct. These results indicate the usefulness of the two site‐specific recombination systems in the tree species Populus. Combining both site‐specific recombination systems, a strategy is suggested for targeted transgene transfer and removal of antibiotic marker genes.
Population structure and phenotypic variation of a spring barley world collection set up for association studies
Authors: Haseneyer G. , Stracke S. , Paul C. , Einfeldt C. , Broda A. , Piepho H.‐P. , Graner A. , Geiger H. H.
Published: December 2009

With 3 figures and 4 tables

Association mapping offers a tool to identify plant resources that carry important alleles for crop improvement and breeding. A necessary prerequisite for association mapping is a collection of genotypes representing a cross section of the examined germplasm. This study describes the genetic and phenotypic characterization of a collection of 224 spring barley (Hordeum vulgare L.) accessions sampled from the IPK gene bank. The analysis of the genetic structure of the collection was based on 45 EST‐derived simple sequence repeat (SSR) markers and it revealed two major subgroups, mainly comprising two‐rowed and six‐rowed barleys, respectively. The phenotypic data were based on field trials performed at three locations in Germany in 2004 and 2005. Significant genotypic variation and genotype × environment interaction were observed for all traits under study (thousand‐grain weight, crude protein content, starch content, plant height, and flowering time). For all analysed traits entry mean‐based heritability estimates exceeded 0.9. After appropriately correcting for population structure and geographic origin significant associations between SSR markers and all traits under study were detected.
The hypocretin–orexin system regulates cocaine self‐administration via actions on the mesolimbic dopamine system
Authors: España Rodrigo A. , Oleson Erik B. , Locke Jason L. , Brookshire Bethany R. , Roberts David C. S. , Jones Sara R.
Published: December 2009

Recent evidence suggests that the hypocretin–orexin system participates in the regulation of reinforcement processes. The current studies examined the extent to which hypocretin neurotransmission regulates behavioral and neurochemical responses to cocaine, and behavioral responses to food reinforcement. These studies used a combination of fixed ratio, discrete trials, progressive ratio and threshold self‐administration procedures to assess whether the hypocretin 1 receptor antagonist, SB‐334867, reduces cocaine self‐administration in rats. Progressive ratio sucrose self‐administration procedures were also used to assess the extent to which SB‐334867 reduces responding to a natural reinforcer in food‐restricted and food‐sated rats. Additionally, these studies used microdialysis and in vivo voltammetry in rats to examine whether SB‐334867 attenuates the effects of cocaine on dopamine signaling within the nucleus accumbens core. Furthermore, in vitro voltammetry was used to examine whether hypocretin knockout mice display attenuated dopamine responses to cocaine. Results indicate that when SB‐334867 was administered peripherally or within the ventral tegmental area, it reduced the motivation to self‐administer cocaine and attenuated cocaine‐induced enhancement of dopamine signaling. SB‐334867 also reduced the motivation to self‐administer sucrose in food‐sated but not food‐restricted rats. Finally, hypocretin knockout mice displayed altered baseline dopamine signaling and reduced dopamine responses to cocaine. Combined, these studies suggest that hypocretin neurotransmission participates in reinforcement processes, likely through modulation of the mesolimbic dopamine system. Additionally, the current observations suggest that the hypocretin system may provide a target for pharmacotherapies to treat cocaine addiction.
The Transformation of the Educational Semantic within a Changing Society: A Study of the Westernization of Modern Chinese Education1
Authors: WU MEIYAO
Published: December 2009

In the late 19th and early 20th centuries, the process of westernization of Chinese education – of the Chinese educational “system”– was marked by ongoing conflicts between traditional Chinese and modern western culture. This paper looks at the process by which, within the larger context of the “world‐society,” educational thought was constituted or reconstituted (regenerated) in modern China, thus taking on a more hybrid form. My analysis is guided by a Luhmannian approach which focuses on the distinction between the educational system and its environment, and on the changing concept of “education” throughout an important period in the history of modern China. I will try to analyze the historical description of the distinction between traditional Chinese and modern Western educational ideas.
Distinctions in descriptive and instrumental stakeholder theory: a challenge for empirical research
Authors: Egels‐Zandén Niklas , Sandberg Joakim
Published: December 2009

Stakeholder theory is one of the most influential theories in business ethics. It is perhaps not surprising that a theory as popular as stakeholder theory should be used in different ways, but when the disparity between different uses becomes too great, it is questionable whether all the ‘stakeholder research’ refers to the same underlying theory. This paper starts to clarify this definitional confusion by distinguishing between three different ways in which different lines of stakeholder research are connected with descriptive and instrumental stakeholder theory. First, a distinction is made between research connected with descriptive and with instrumental stakeholder theory as defined by Donaldson & Preston in the narrow or broad sense. Second, a distinction is made between research that interprets descriptive and instrumental stakeholder theories as either hypotheses or research areas. Third, a distinction is made between research that interprets Donaldson & Preston's central concept of ‘stakeholder management’ as either behaviour or rationale. Finally, the paper discusses the implications of these differences for empirical research into stakeholder theory.
A framework for comparing socially responsible investment markets: an analysis of the Dutch and Belgian retail markets
Authors: Benijts Tim
Published: December 2009

The increasing popularity of socially responsible investment among individual investors throughout Europe reveals the need for a framework that allows the comparison of socially responsible retail markets in different European countries. This article proposes such a framework, containing 16 different characteristics of socially responsible retail markets describing the size, institutionalization and nature of this market and correcting for differences in the size of countries and financial markets. When this framework was applied to the Dutch and Belgian socially responsible retail markets, differences were found with respect to the nature of both markets (specifically the use of non‐financial criteria, the asset allocation, the number of solidarity funds and investors' preferences for socially responsible savings products). Similarities were found with respect to the (absolute and relative) size and the degree of institutionalization of the socially responsible retail markets.
Revealing the dark side of traditional democracies in plurinational societies: the case of Catalonia and the Spanish ‘Estado de las Autonomías’
Authors: REQUEJO FERRAN
Published: December 2009

ABSTRACT. In this article, I will deal with some elements related to the analysis of theories of democracies and federalism in plurinational contexts. The paper highlights some flaws and shortcomings of traditional liberal democracies in these contexts and the challenge of establishing effective practices of a politics of recognition and constitutional accommodation of internal national pluralism (Section 1). Secondly, the paper analyses the case of Catalonia after the recent reform of its Statute of Autonomy (Constitutional Law) in 2006 and its relationship with the development of the Spanish Estado de las Autonomías. The Catalan case reveals some practical flaws and important difficulties in the political recognition and accommodation of internal national pluralism according to traditional decentralising patterns (Section 2). Finally, the article makes a number of concluding remarks relating the previously highlighted elements of the theory of democracy and federalism to the analysis of the Catalan case
Security threats, linguistic homogeneity, and the necessary conditions for political unification
Authors: GRIFFITHS RYAN D.
Published: December 2009

ABSTRACT.The proposition that security threats can drive states to pool their sovereignty has been around for some time. The existence of these threats, according to William Riker, is a necessary condition for political unification. A less common argument centers on linguistic homogeneity; it asserts that states must be sufficiently similar and speak the same language before they can successfully imagine a common state. This paper tests both hypotheses in a large‐Nanalysis that identifies all instances of voluntary political unification between 1816 and 2001. It takes the form of a falsification probe and examines whether any unification happened in the absence of either an external security threat or a common language. It finds that political unification has occurred in relatively tranquil settings, but that all unifying dyads have shared a common language. Security threats are not a necessary condition, but a common language may well be.
The marriage of state and nation in European constitutions
Authors: KISSANE BILL , SITTER NICK
Published: December 2009

ABSTRACT.This article maps out the role played by national identity in modern European constitutions. It does this by comparing its impact on constitutions across Gellner's time zones of European nationalism, and shows how the impact of nationalism has increased gradually over time, and is now strongest in Central and Eastern Europe. It concludes with a reflection on why this has been the case, and why constitutional politics have increasingly lent themselves to nationalist influences in the modern era.
The Qur’anists
Authors: Musa Aisha Y.
Published: December 2009

Stories relating the words and deeds of the Prophet Muhammad, known as Hadith in Arabic, have long been esteemed by the vast majority of Muslims as a source of law and guidance second only to the Qur'an in authority. In recent years, an increasingly vocal Muslim opposition to Hadith insists that the Qur'an alone should be the sole source of religious law and guidance in Islam. Rashad Khalifa, Kassim Ahmad, Edip Yuksel, and Ahmad Subhy Mansour are among the most important rejecters of the Hadith, whose arguments influence a wide variety of groups popularly labeled Ahl al‐Qur'an, Qur'niyyun or Qur'anists.
The Puzzle of Financial Reporting and Corporate Short‐Termism: A Universal Ownership Perspective
Authors: Drew Michael E.
Published: December 2009

This study considers the controversy surrounding financial reporting and corporate short‐termism as a puzzle. The question remains as to why corporate managers and investors persist in exhibiting behaviours that trade off long‐term value creation for meeting short‐term financial targets. Using inter‐temporal choice theory, the myopia characterising decision‐making is entirely rational, given the set of incentives faced. This study views the puzzle through the prism of universal owners (pension and superannuation funds), arguing that the investment policies or ‘mandates’ implemented by these financial behemoths is the source of the myopic behaviour. The paper explores a range of policies that universal owners may consider implementing to ensure that the payoffs to corporate managers and investors are optimised through the pursuit of long‐termism.
The Role of Short‐Termism in Financial Market Crises
Authors: Nesbitt John
Published: December 2009

The purpose of this paper is to examine the contribution short‐termist behaviours have had in various financial market crises. The early warning signs and drivers of short‐termism are investigated, as well as ways to mitigate short‐termist behaviour and consequences in the future. Short‐termism as defined for the purposes of this paper is the excessive focus on short‐term performance, earnings and other metrics at the expense of attention being given to the development of a long‐term strategy that promotes sustainable long‐term value creation.
Capital Markets Regulation: How Can Accounting Research Contribute?
Authors: Taylor Stephen
Published: December 2009

In examining the possible contribution that accounting research can play in ensuring effective and efficient regulation of securities markets, two principal opportunities stand out. First, the role of research in informing debate about proposed regulatory intervention (ex ante contribution to regulatory debate). Second, the ability of research to inform analysis as to the effectiveness of previously implemented regulatory changes (ex post contribution to regulatory debate). In the ex ante case, there is a natural tension between the way in which regulatory initiatives often arise quickly and the inevitable passage of time required to fully appreciate the degree to which underlying problems have been correctly characterised and can be framed in a manner suitable for addressing via rigorous analytical and empirical research. It is also impossible to empirically assess the effect of regulatory intervention that has not yet occurred. Finally, if data are simply not available, then research is limited to analytical analysis and prediction. In the ex post case, there is often a natural reluctance to subject regulatory intervention to mandatory analysis, and even when a statutory requirement exists for such analysis and review, the time horizon is often far too short for meaningful analysis. In both the ex ante and ex post cases, what is unavoidable is that regulation can only be legitimately informed by research that is sufficiently rigorous so as to have robust conclusions. Assessing research on these dimensions means that transparency is required so as to allow researchers to engage in meaningful debate about the validity of the conclusions. This inevitably means that research needs to be a partnership between regulatory agencies and academia, and that when research is used to justify regulatory interventions it must be publicly available and subject to robust debate.
In situ plasma diagnostics study of a commercial high-power hollow cathode magnetron deposition tool
Authors: Meng Liang , Raju Ramasamy , Flauta Randolph , Shin Hyungjoo , Ruzic David N. , Hayden Douglas B.
Published: December 2009

Using a newly designed and built plasma diagnostic system, the plasma parameters were investigated on a commercial 200mm high-power hollow cathode magnetron (HCM) physical vapor deposition tool using Ta target under argon plasma. A three dimensional (3D) scanning radio frequency (rf)-compensated Langmuir probe was constructed to measure the spatial distribution of the electron temperature (Te) and electron density (ne) in the substrate region of the HCM tool at various input powers (2–15kW) and pressures (10–70mTorr). The Te was in the range of 1–3eV, scaling with decreasing power and decreasing pressure. Meanwhile, ne was in the range of 4×1010–1×1012cm−3 scaling with increasing power and decreasing pressure. As metal deposits on the probe during the probe measurements, a self-cleaning plasma cup was designed and installed in the chamber to clean the tungsten probe tip. However, its effectiveness in recovering the measured plasma parameters was hindered by the metal layer deposited on the insulating probe tube which was accounted for the variation in the plasma measurements. Using a quartz crystal microbalance combined with electrostatic filters, the ionization fraction of the metal flux was measured at various input power of 2–16kW and pressure of 5–40mTorr. The metal ionization fraction reduced significantly with the increasing input power and decreasing gas pressure which were attributed to the corresponding variation in the ionization cross section and the residence time of the sputtered atoms in the plasma, respectively. Both the metal neutral and ion flux increased at higher power and lower pressure. The 3D measurements further showed that the ionization fraction decreased when moving up from the substrate to the cathode.
Molecular thin film chemical modifications under vacuum ultraviolet irradiation
Authors: Nghiem M.-P. , Tondu Th. , Roussel J.-F. , Faye D.
Published: December 2009

Spacecraft molecular contamination can be increased under vacuum ultraviolet irradiation because of contaminant sticking induced by photochemical reactions. Tridecan-2-one was experimentally studied as model contaminant. Thin films were irradiated by a deuterium lamp in order to investigate the quantitative formation of different volatility molecules. In this article, on the basis of a parametric irradiation study the authors highlight the formation of three populations of irradiation products. More volatile species come from photolysis that is showed to be strongly temperature dependent and fitted by an Arrhenius law (27 kJ/mol). Less volatile species are initially formed and eliminated afterward when photolysis stops. Nonvolatile species are continuously formed until saturation amount. With tridecan-2-one saturation occurred when 80% of the initial deposit was removed by photolysis and 20% stuck. Complementary gas chromatography coupled mass spectrometry results interpretation lead to a mechanism corresponding to primary molecular dissociation into free radicals followed by addition of radicals forming molecules of various volatility.
Acinetobacter baumannii
Increases Tolerance to Antibiotics in Response to Monovalent Cations
Authors: Hood M. Indriati , Jacobs Anna C. , Sayood Khalid , Dunman Paul M. , Skaar Eric P.
Published: December 2009

Acinetobacter baumannii
is well adapted to the hospital environment, where infections caused by this organism are associated with significant morbidity and mortality. Genetic determinants of antimicrobial resistance have been described extensively, yet the mechanisms by which
A. baumannii
regulates antibiotic resistance have not been defined. We sought to identify signals encountered within the hospital setting or human host that alter the resistance phenotype of
A. baumannii
. In this regard, we have identified NaCl as being an important signal that induces significant tolerance to aminoglycosides, carbapenems, quinolones, and colistin upon the culturing of
A. baumannii
cells in physiological NaCl concentrations. Proteomic analyses of
A. baumannii
culture supernatants revealed the release of outer membrane proteins in high NaCl, including two porins (CarO and a 33- to 36-kDa protein) whose loss or inactivation is associated with antibiotic resistance. To determine if NaCl affected expression at the transcriptional level, the transcriptional response to NaCl was determined by microarray analyses. These analyses highlighted 18 genes encoding putative efflux transporters that are significantly upregulated in response to NaCl. Consistent with this, the effect of NaCl on the tolerance to levofloxacin and amikacin was significantly reduced upon the treatment of
A. baumannii
with an efflux pump inhibitor. The effect of physiological concentrations of NaCl on colistin resistance was conserved in a panel of multidrug-resistant isolates of
A. baumannii
, underscoring the clinical significance of these observations. Taken together, these data demonstrate that
A. baumannii
sets in motion a global regulatory cascade in response to physiological NaCl concentrations, resulting in broad-spectrum tolerance to antibiotics.
Mechanism of Hepatitis C Virus RNA Polymerase Inhibition with Dihydroxypyrimidines
Authors: Powdrill Megan H. , Deval Jerome , Narjes Frank , De Francesco Raffaele , Götte Matthias
Published: December 2009

We studied the biochemical mechanisms associated with inhibition and resistance to a 4,5-dihydroxypyrimidine carboxylate that inhibits the hepatitis C virus (HCV) RNA-dependent RNA polymerase NS5B. On the basis of the structure of the pharmacophore, it has been suggested that these compounds may act as pyrophosphate (PP
i
) mimics. We monitored nucleotide incorporation events during the elongation phase and showed that the polymerase activity of wild-type NS5B was inhibited by the dihydroxypyrimidine at a 50% inhibitory concentration (IC
50
) of 0.73 μM. Enzymes with the G152E or P156L mutation, either of which confers resistance to this compound, showed four- to fivefold increases in IC
50
s. The inhibitor was competitive with respect to nucleotide incorporation. It was likewise effective at preventing the PP
i
-mediated excision of an incorporated chain terminator in a competitive fashion. In the absence of the dihydroxypyrimidine, the reaction was not significantly affected by the G152E or P156L mutation. These data suggest that the resistance associated with these two mutations is unlikely due to an altered interaction with the pyrophosphate-mimicking domain of the compound but, rather, is due to altered interactions with its specificity domain at a region distant from the active site. Together, our findings provide strong experimental evidence that supports the notion that the members of this class of compounds can act as PP
i
mimics that have the potential to mechanistically complement established nucleoside and nonnucleoside analogue inhibitors.
Probing the Antimalarial Mechanism of Artemisinin and OZ277 (Arterolane) with Nonperoxidic Isosteres and Nitroxyl Radicals
Authors: Fügi Matthias A. , Wittlin Sergio , Dong Yuxiang , Vennerstrom Jonathan L.
Published: December 2009

Peroxidic antimalarials such as the semisynthetic artemisinins are critically important in the treatment of drug-resistant malaria. Nevertheless, their peroxide bond-dependent mode of action is still not well understood. Using combination experiments with cultured
Plasmodium falciparum
cells, we investigated the interactions of the nitroxide radical spin trap, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), and four of its analogs with artemisinin and the ozonide drug development candidate OZ277. The antagonism observed for combinations of artemisinin or OZ277 with the TEMPO analogs supports the hypothesis that the formation of carbon-centered radicals is critical for the activity of these two antimalarial peroxides. The TEMPO analogs showed a trend toward greater antagonism with artemisinin than they did with OZ277, an observation that can be explained by the greater tendency of artemisinin-derived carbon-centered radicals to undergo internal self-quenching reactions, resulting in a lower proportion of radicals available for subsequent chemical reactions such as the alkylation of heme and parasite proteins. In a further mechanistic experiment, we tested both artemisinin and OZ277 in combination with their nonperoxidic analogs. The latter had no effect on the antimalarial activities of the former. These data indicate that the antimalarial properties of peroxides do not derive from reversible interactions with parasite targets.
AatA Is a Novel Autotransporter and Virulence Factor of Avian Pathogenic
Escherichia coli
Authors: Li Ganwu , Feng Yaping , Kariyawasam Subhashinie , Tivendale Kelly A. , Wannemuehler Yvonne , Zhou Fanghong , Logue Catherine M. , Miller Cathy L. , Nolan Lisa K.
Published: December 2009

Autotransporters (AT) are widespread in Gram-negative bacteria, and many of them are involved in virulence. An open reading frame (APECO1_O1CoBM96) encoding a novel AT was located in the pathogenicity island of avian pathogenic
Escherichia coli
(APEC) O1's virulence plasmid, pAPEC-O1-ColBM. This 3.5-kb APEC autotransporter gene (
aatA
) is predicted to encode a 123.7-kDa protein with a 25-amino-acid signal peptide, an 857-amino-acid passenger domain, and a 284-amino-acid β domain. The three-dimensional structure of AatA was also predicted by the threading method using the I-TASSER online server and then was refined using four-body contact potentials. Molecular analysis of AatA revealed that it is translocated to the cell surface, where it elicits antibody production in infected chickens. Gene prevalence analysis indicated that
aatA
is strongly associated with
E. coli
from avian sources but not with
E. coli
isolated from human hosts. Also, AatA was shown to enhance adhesion of APEC to chicken embryo fibroblast cells and to contribute to APEC virulence.
A Foreign Protein Incorporated on the Tip of T3 Pili in
Lactococcus lactis
Elicits Systemic and Mucosal Immunity
Authors: Quigley Bernard R. , Hatkoff Matthew , Thanassi David G. , Ouattara Mahamoudou , Eichenbaum Zehava , Scott June R.
Published: December 2009

The use of
Lactococcus lactis
to deliver a chosen antigen to the mucosal surface has been shown to elicit an immune response in mice and is a possible method of vaccination in humans. The recent discovery on Gram-positive bacteria of pili that are covalently attached to the bacterial surface and the elucidation of the residues linking the major and minor subunits of such pili suggests that the presentation of an antigen on the tip of pili external to the surface of
L. lactis
might constitute a successful vaccine strategy. As a proof of principle, we have fused a foreign protein (the
Escherichia coli
maltose-binding protein) to the C-terminal region of the native tip protein (Cpa) of the T3 pilus derived from
Streptococcus pyogenes
and expressed this fusion protein (MBP*) in
L. lactis
. We find that MBP* is incorporated into pili in this foreign host, as shown by Western blot analyses of cell wall proteins and by immunogold electron microscopy. Furthermore, since the MBP* on these pili retains its native biological activity, it appears to retain its native structure. Mucosal immunization of mice with this
L. lactis
strain expressing pilus-linked MBP* results in production of both a systemic and a mucosal response (IgG and IgA antibodies) against the MBP antigen. We suggest that this type of mucosal vaccine delivery system, which we term UPTOP (for unhindered presentation on tips of pili), may provide an inexpensive and stable alternative to current mechanisms of immunization for many serious human pathogens.
High horizontal stresses in Hudson Bay, Canada
Authors: Bell J. S. , Wu P.
Published: December 2009

Breakouts in four wells in Hudson Bay suggest that the Paleozoic section is currently subject to maximum horizontal compression about a northeast–southwest axis, with some local deflection in horizontal stress orientations related to faults. The Paleozoic section does not appear to be detached from the crystalline basement of the Canadian Shield, despite the presence of thick Silurian halite-rich intervals. The northeast–southwest compressional axis documented in the Hudson Bay Basin is compatible with stress orientations mat have been measured in other parts of cratonic North America. Leak-off tests from three wells imply that contemporary horizontal stress magnitudes above 1500 m depth exceed present-day overburden loads; comparable relative magnitudes have been measured elsewhere in central Canada. Finite-element modelling suggests mat this phenomenon is due to the effects of glacial loading, crustal rebound, and spreading of the Mid-Atlantic Ridge.
Style, controls, and timing of fold-and-thrust deformation of the Jago stock, northeastern Brooks Range, Alaska
Authors: Peapples Paige R. , Wallace Wesley K. , Hanks Catherine L. , Layer Paul W. , O'Sullivan Paul B.
Published: December 2009

Involvement of the Devonian Jago stock in Cenozoic fold-and-thrust deformation of the northeastern Brooks Range illustrates the influence of a relatively small, isolated crystalline body on the mechanical stratigraphy and subsequent deformational behavior of an otherwise layered sedimentary package. The small size of the stock allowed it and the structurally coupled overlying Mississippian Kekiktuk Conglomerate to deform nonpenetratively as a horse in a regional duplex, in contrast to the semiductile behavior of the nearby but much larger Okpilak batholith. Shear was localized in the upper part of the stock and the conglomerate due to partial detachment of the overlying Carboniferous Lisburne Group. North-vergent thrust-related folds formed in the mechanically layered Lisburne Group carbonates instead of the symmetrical, unfaulted detachment folds more typical of the region because an underlying regional detachment horizon in the Mississippian Kayak Shale is depositionally absent over the stock. Unusually competent contact-metamorphosed pre-Mississippian metasedimentary rocks were thrust over the stock and its cover because a ramp formed at the edge of the stock and cut upsection through the Lisburne Group due to the absence of Kayak Shale. A 40Ar/39Ar age of foliated white mica indicates thrusting of the stock by 61 Ma; fission-track ages indicate cooling at ~44 and ~28 Ma. These ages indicate a cooling history that implies ~11 km of unroofing since ~61 Ma, only ~1.5 km of which can be explained by the inferred duplex structure. The remaining ~9.5 km of unroofing is most likely due to subduplex structural thickening above a deep regional detachment.
Biostratigraphie et paléobiogéographie du Siluro-Dévonien de la zone de Meguma (Nouvelle-Écosse, Canada)
Authors: Bouyx E. , Blaise J. , Brice D. , Dégardin J. M. , Goujet D. , Gourvennec R. , Menn J. Le , Lardeux H. , Morzadec P. , Paris F.
Published: December 2009

Studies of fossils collected from the Nictaux–Torbrook and Bear River synclines (Nova Scotia) allow a reexamination of the Siluro-Devonian stratigraphy of the Meguma terrane. The location of this terrane relative to the main paleocontinents of the circumatlantic domain during this period is discussed. Wenlockian, Ludlovian, and Pridolian biostratigraphic horizons have been dated. The benthic fauna of the Torbrook Formation are assigned here to the Lochkovian, Pragian, and Lower Emsian. The Pridolian fauna shows northern European affinities. Thus, the Meguma terrane probably belonged to the North Atlantic domain, as for the Avalon terrane, and occupied a southern position in the "Euramerica" plate during this period. The Devonian fauna belongs to the "old world realm" and shows north Gondwanian and Rhenish affinities. As early as the Lochkovian, species known from both the Rhenish and north Gondwanian domains are recognized in Meguma, as well as others reported so far only from northwestern Africa, Iberian Peninsula, and (or) Armorican Massif. The presence of Rhenish fauna confirms the postulated location for the Meguma terrane during the Upper Silurian since this fauna is representative of southern Baltica marginal areas in Europe. On the other hand, the presence of north Gondwanian fauna implies close relationships with western European margin of Gondwana. The lack of a wide oceanic gap separating north Gondwana and Euramerica can explain the faunal exchanges during Lower Devonian times between western Europe and easternmost Appalachian province despite the presence of a physical barrier.
Large Explosions at Sea
Authors: Buchbinder Goetz G. R.
Published: December 2009

Two large unannounced events occurred at sea in aseismic areas in the Atlantic. Comparison of these with the announced event Chase III shows them to be explosions.Large explosions at sea may be recognized by the relatively small amplitude of long period surface waves with periods up to 10 s. Energy of longer periods is absent for events mb ≤ 5.5. The surface wave magnitudes for the events are at least 1.5 smaller at 10 s than those of underground explosions of equal mb, at 20 s they are at least 0.9 smaller. At longer periods the difference between body wave and surface wave magnitude is larger than 0.9 but larger explosions are needed to determine the separation. Underwater explosions on or near the continental shelf are very efficient in the generation of higher mode short period waves.
Tertiary Basalts of Baffin Island: Field Relations and Tectonic Setting
Authors: Clarke D. B. , Upton B. G. J.
Published: December 2009

This paper describes the field relations of Tertiary basalts which are preserved as small patches intermittently along the coast for 90 km northwest from Cape Dyer, Baffin Island. The flat-lying, subaerial lavas generally rest directly on the Precambrian basement but in some localities a thin sequence of terrestrial sediments intervenes between the basement and the volcanics. Where the sediments occur, the overlying volcanics tend to be divisible into a lower unit of subaqueous volcanic breccia and an upper sequence of subaerial flows. In age, stratigraphic position and magma-type, these volcanics strongly resemble those of the basalt province of west Greenland. A model is presented for the generation of both provinces in a single volcanic episode, related to the opening of Labrador Sea – Baffin Bay by continental drift.