bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmission spectroscopy of the sodium doublet in WASP-17b with the VLT
Authors: Wood Patricia L. , Maxted Pierre F. L.
Published: November 2011

The detection of sodium absorption during primary transit implies the presence of an atmosphere around an extrasolar planet. WASP-17b (Anderson et al. 2010a) is the least dense known planet, with a radius twice that of Jupiter. It orbits an F6-type star, and its low gravity gives its atmosphere a very large scale height. The sodium transit depth is expected to be 4.1 – 5.2 times deeper than for HD 209458b (Seager & Sasselov 2000). We obtained 24 spectra with the GIRAFFE spectrograph on the VLT, 8 during transit. We measured the flux in the sodium doublet at 5889.95 Å and 5895.92 Å using bandpasses 0.75, 1.5, 3.0 and 6.0 Å. We find a transit depth of 0.55±0.13% at 1.5 Å (4.3σ). WASP-17b therefore has an atmosphere which is depleted in sodium compared to predictions.
A methodology for evaluation of vertical dispersion and dry deposition of atmospheric aerosols
Authors: Kouznetsov Rostislav , Sofiev Mikhail
Published: November 2011

A new approach to treatment of vertical dispersion and dry deposition of atmospheric aerosols is suggested for primary application in mesoscale to global atmospheric transport models. The vertical exchange scheme extends the resistance analogy formulated earlier for gaseous species and fine aerosols. The approach is based on the exact solution of the steady‐state equation for aerosol flux within a finite layer. The flux is expressed as a linear function of concentrations at the layer boundaries and accounts for the vertical inhomogeneity of the diffusion coefficient and the regular vertical velocity. The new dry deposition scheme accounts for physical properties of the air flow, surface and depositing particles. The flow is given by the vertical profile of exchange coefficient and characteristic velocity at the surface. The deposition rate to smooth surfaces is obtained via solution of the budget equation for particle mass. The transition from smooth to rough flow regime is considered. Rough surfaces are characterized by two length scales: the aerodynamic roughness and the “collection scale”, introduced in this paper. The collection scale incorporates the effective size of collectors and a ratio of the airflow velocity at the top of the roughness elements to the friction velocity. The particles are described by their physical size, relaxation time and Brownian diffusivity. The scheme was developed basing exclusively on wind‐tunnel and numerical experiments available from the literature, and reproduces them well. The data of outdoor experiments have noticeably larger uncertainties, which allowed only general evaluation of their agreement with the predictions.
Flux distributions as robust diagnostics of stratosphere‐troposphere exchange
Authors: Orbe Clara , Holzer Mark , Polvani Lorenzo M.
Published: November 2011

We perform the first analysis of stratosphere‐troposphere exchange in terms of distributions that partition the one‐way flux across the thermal tropopause according to stratospheric residence time τ and the regions where air enters and exits the stratosphere. These distributions robustly quantify one‐way flux without being rendered ill defined by the short‐τ eddy‐diffusive singularity. Diagnostics are computed with an idealized circulation model with topography only in the Northern Hemisphere (NH) run under perpetual NH winter conditions. Suitable integrations of the flux distribution are used to determine the stratospheric mean residence time
and the mass fraction of the stratosphere in any given residence time interval. We find that the largest mass fraction is destined for isentropic cross‐tropopause transport, with one‐way fluxes that are sustained over a broad range of residence times. Air exiting the stratosphere in the winter hemisphere has significantly longer mean residence times than air exiting in the summer hemisphere because the winter hemisphere has a deeper circulation and stronger eddy diffusion. We also explore the sensitivity of the stratosphere‐troposphere exchange to changes in the circulation by increasing the amplitude of the topography. The resulting more vigorous residual mean circulation dominates over increased eddy diffusion, leading to decreased
except for air exiting at high NH latitudes, for which
increases. These findings underline that the flux distributions diagnose the integrated advective‐diffusive tropopause‐to‐tropopause transport and not merely advection by the residual mean circulation.
Methanogenic archaea are globally ubiquitous in aerated soils and become active under wet anoxic conditions
Authors: Angel Roey , Claus Peter , Conrad Ralf
Published: November 2011

The prototypical representatives of the Euryarchaeota—the methanogens—are oxygen sensitive and are thought to occur only in highly reduced, anoxic environments. However, we found methanogens of the genera Methanosarcina and Methanocella to be present in many types of upland soils (including dryland soils) sampled globally. These methanogens could be readily activated by incubating the soils as slurry under anoxic conditions, as seen by rapid methane production within a few weeks, without any additional carbon source. Analysis of the archaeal 16S ribosomal RNA gene community profile in the incubated samples through terminal restriction fragment length polymorphism and quantification through quantitative PCR indicated dominance of Methanosarcina, whose gene copy numbers also correlated with methane production rates. Analysis of the δ13C of the methane further supported this, as the dominant methanogenic pathway was in most cases aceticlastic, which Methanocella cannot perform. Sequences of the key methanogenic enzyme methyl coenzyme M reductase retrieved from the soil samples before incubation confirmed that Methanosarcina and Methanocella are the dominant methanogens, though some sequences of Methanobrevibacter and Methanobacterium were also detected. The global occurrence of only two active methanogenic archaea supports the hypothesis that these are autochthonous members of the upland soil biome and are well adapted to their environment.
Analysis and optimization approach for the doped amorphous layers of silicon heterojunction solar cells
Authors: Pysch Damian , Meinhard Christoph , Harder Nils-Peter , Hermle Martin , Glunz Stefan W.
Published: November 2011

Comparison of the open-circuit voltage (external voltage Voc,ext) determined by Suns-Voc measurements with the implied voltage Voc,impl determined by transient photoconductance decay lifetime measurements can yield a quick and easy analysis of silicon heterojunction (SHJ) solar cells, especially in regard to finding the optimum doping concentration of the emitter layer [or back surface field (BSF)]. A sufficiently high doping concentration of the emitter and BSF is mandatory to extract the internal Fermi-level splitting and thus the internal voltage, at the solar cell contacts. However increasing the concentration of doping gases during the deposition of doped amorphous silicon layers results in a reduction of the interface passivation quality and Voc,impl. The best trade off is realized when the ratio of Voc,ext to Voc,impl (external/internal Voc-ratio ζ) reaches a saturation value near 1 upon increasing the doping concentration. AFORS-HET (Automat FOR Simulation of HETerostructures) simulations resulted in the conclusion that the characteristics of the external/internal Voc-ratio are mainly determined by the active doping concentration (doping minus defect concentration).
Simulation of conformational preconditioning strategies for electrophoretic stretching of DNA in a microcontraction
Authors: Hsieh Chih-Chen , Lin Tsung-Hsien
Published: November 2011

We have used Brownian dynamics-finite element method to examine two conformational preconditioning approaches for improving DNA stretching in a microcontraction for the purpose of direct gene analysis. The newly proposed “pre-stretching” strategy is found to significantly improve the degree of DNA extension at the exit of the contraction. On the other hand, applying an oscillating extensional field to DNA yields no preconditioning effect. Detailed analysis of the evolution of DNA extension and conformation reveals that the success of our “pre-stretching” strategy relies on the “non-local” effect that cannot be predicted using simple kinematics analysis. In other words, accurate prediction can only be obtained using detailed simulations. Comparing to the existing preconditioning strategies, our “pre-stretching” method is easy to implement while still providing a very good performance. We hope that the insight gained from this study can be useful for future design of biomicrofluidic devices for DNA manipulation.
Equilibrium theory of cylindrical discharges with special application to helicons
Authors: Curreli Davide , Chen Francis F.
Published: November 2011

Radiofrequency discharges used in industry often have centrally peaked plasma density profiles n(r) although ionization is localized at the edge, even in the presence of a dc magnetic field. This can be explained with a simple cylindrical model in one dimension as long as the short-circuit effect at the endplates causes a Maxwellian electron distribution. Surprisingly, a universal profile can be obtained, which is self-similar for all discharges with uniform electron temperature Te and neutral density nn. When all collisions and ionizations are radially accounted for, the ion drift velocity toward the wall reaches the Bohm velocity at a radius which can be identified with the sheath edge, thus obviating a pre-sheath calculation. For non-uniform Te and nn, the profiles change slightly but are always peaked on axis. For helicon discharges, iteration with the HELIC code for antenna-wave coupling yields profiles consistent with both energy deposition and diffusion profiles. Calculated density is in absolute-value agreement with experiment.
Photovoltaic effect of CdS/Si nanoheterojunction array
Authors: He Chuan , Han Chang Bao , Xu Yu Rui , Li Xin Jian
Published: November 2011

Nanostructured materials have attracted much attention for enhancing the performance of solar cells due to their unique advantage of high light absorption. In this regard, here we propose a CdS/Si nanoheterojunction array, called CdS/Si-NPA, for harvesting the energy of sunlight. CdS/Si-NPA was obtained by depositing a continuous film of CdS onto silicon nanoporous pillar array (Si-NPA) via a chemical bath deposition (CBD) method and the average reflectance of CdS/Si-NPA was less than 7% in the wavelength range of 200–1000 nm. Under 1 sun air mass (AM) 1.5 G illumination, CdS/Si-NPA exhibits an obvious photovoltaic effect. These results indicate that CdS/Si-NPA has a strong broadband optical antireflection and might be a promising candidate for the assembly of high efficiency solar cells.
Terahertz temperature-dependent defect mode in a semiconductor-dielectric photonic crystal
Authors: Hung Hui-Chuan , Wu Chien-Jang , Chang Shoou-Jinn
Published: November 2011

In this work, terahertz (THz) temperature-dependent properties of defect mode in a defective semiconductor-dielectric photonic crystal (SDPC) are theoretically investigated based on the calculated transmittance spectrum. Two different defective PCs, the symmetric structure of (Si/SiO2)NInSb(SiO2/Si)N and the asymmetric one of (Si/SiO2)NInSb(Si/SiO2)N, will be considered. With a strongly temperature-dependent permittivity in defect layer InSb, the defect mode can be thermally tuned, that is, the defect frequency will be shifted to higher frequency as the temperature increases. With the inherent loss in InSb, the strength of defect mode will be strongly depressed at a higher temperature. We use the condition of impedance match to explain the presence of defect mode. The understanding of properties of defect mode could be of technical use in the terahertz optoelectronic applications.
Tailoring the Faraday effect by birefringence of two dimensional plasmonic nanorod array
Authors: Du G. X. , Saito S. , Takahashi M.
Published: November 2011

The ability to rotate the polarization of light propagating through a material by applying a magnetic field was discovered by Faraday. It is critically important for applications involving light modulation and sensors. Shaped plasmonic crystals function as miniature polarizers. This study investigates a gold nanorod array that can be used to significantly vary the Faraday effect originating from a dielectric material. The dependence of the Faraday effect on the polarizer angle exhibited well-defined characteristics. The birefringence of the nanorod array was characterized using a simplified setup for optical polarization tomography. The enhanced Faraday effect due to the plasmonic nanorods is promising for applications involving plasmonic circuits and refractometry.
Adaptive beam tracking and steering via electrowetting-controlled liquid prism
Authors: Cheng Jiangtao , Chen Chung-Lung
Published: November 2011

We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm × 10mm. With 1 wt. % KCl and 1 wt. % Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between −26° and 26° that can deflect and steer beam within the incidence angle of 0°–15°. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell.
Statistical aspects of on-farm experimentation
Authors: Piepho Hans-Peter , Richter Christel , Spilke Joachim , Hartung Karin , Kunick Arndt , Thöle Heinrich
Published: November 2011

This paper reviews options for the design and analysis of on-farm experiments. It covers both older approaches that have been popular since the Green Revolution, and more recent developments made possible by the availability of online monitoring systems as used in precision farming. The roles of randomisation as well as of geostatistical methods of analysis for these kinds of experiments are critically discussed. Two case studies are provided for illustration.
Follicle development in cryopreserved bitch ovarian tissue grafted to immunodeficient mouse
Authors: Commin L. , Buff S. , Rosset E. , Galet C. , Allard A. , Bruyere P. , Joly T. , Guérin P. , Neto V.
Published: November 2011

The present study evaluated: (1) in vivo follicular development in canine ovarian tissue after slow freezing and xenotransplantation; and (2) the use of erythropoietin (EPO) as an angiogenic factor to optimise the transplantation procedure. Frozen–thawed ovarian tissue from five bitches was grafted into severe combined immunodeficient (SCID) mice (n = 47) treated with or without EPO (500 IU kg–1, once daily for 3 days) (Groups A and B, respectively) and analysed after 0, 1, 8 or 16 weeks. Follicle grade, follicle density, follicle morphology and stromal cells density were assessed by histological analysis, whereas vascularisation of the graft was quantified by immunohistochemistry with anti-α-smooth muscle actin antibody. Despite a massive loss of follicles after grafting, secondary follicle density was higher at 8 and 16 weeks than at 1 week regardless of EPO treatment. EPO significantly improved early follicle morphology and stromal cell density after 8 weeks and blood vessel density at 16 weeks after transplantation (P < 0.05). Intact secondary follicles with more than three granulosa cells layers were observed 16 weeks after transplantation. The results suggest that canine ovarian tissue can be successfully preserved by our slow-freezing protocol because the tissue showed follicular growth after xenotransplantation. EPO treatment did not lessen the massive loss of follicles after transplantation.
Is anal sex a marker for sexual risk-taking? Results from a population-based study of young Croatian adults
Authors: Štulhofer Aleksandar , Baćak Valerio
Published: November 2011

Background There is evidence that anal sex is becoming increasingly popular among heterosexual women and men. Several studies carried out in especially vulnerable populations (e.g. sex workers and low-income youth) suggested that anal sex may indicate a more general propensity to sexual risk-taking. Methods: To assess whether this epidemiologically important finding holds in the case of young adults from the general population, we analysed data from a cross-sectional probability survey carried out in 2010 on 1005 Croatian women and men aged 18–25. Results: Anal intercourse was reported by 36.5% of 861 sexually experienced participants (42.7% of men and 29.8% of women). About one-third of them (34%) used a condom at most recent anal intercourse. The experience of anal sex was significantly associated (P < 0.001) with all four indicators of sexual risk-taking (condom use at most recent vaginal intercourse, number of sexual partners in the past year, concurrent sexual relationships and anonymous sex in the past year), as well as with negative attitudes and beliefs about condom use (P < 0.01). Sexual sensation-seeking mediated the relationship between anal sex and some of the sexual risk-taking behaviours. Conclusion: According to the findings, heterosexual anal sex is directly and indirectly associated with increased behavioural risks of acquiring HIV and other sexually transmissible infections (STI). Sex education and STI prevention programs should focus on the importance of using protection when practicing anal sex.
How likely are HIV-positive female sex workers in China to transmit HIV to others?
Authors: Lau Joseph T. F. , Gu Jing , Tsui Hiyi , Chen Hongyao , Wang Renfan , Hu Xianyou
Published: November 2011

Background Female sex workers (FSW) are highly marginalised and HIV-positive FSW are under a double stigma. No study has assessed the likelihood of secondary transmission via HIV-positive FSW in China. Methods: A total of 199 FSW who injected drugs were recruited by snowball sampling, and 158 non-injecting FSW were recruited from sex service establishments by convenience sampling in Dazhou, China. All participants were interviewed anonymously using a structured questionnaire. Results: If found to be HIV-positive, 11.7% of the participants would continue working as FSW, 24.6% would not care about transmitting HIV to others, 18.8% believed that they would eventually spread HIV to others and 9% would take revenge by spreading HIV to others. In multivariate models, factors associated with ≥1 of the four aforementioned perceptions (42.0%) included drug use (odds ratio (OR) = 1.82–3.26, P < 0.01), perceived discrimination towards people living with HIV and AIDS in China (OR = 2.03, P < 0.05) and perceived inaccessibility to medical treatments if diagnosed as HIV-positive (OR = 2.30, P < 0.01); the reverse was true for use of HIV-related services (OR = 0.53, P < 0.05) and suicidal intentions if found to be HIV-positive (OR = 0.42, P < 0.05). Conclusions: Improvement of the social, care and medical environment of HIV-positive FSW is likely to reduce secondary transmission via HIV-positive FSW. Special attention should be given to FSW who inject drugs.
Maintaining faith in agency under immutable constraints: Cognitive consequences of believing in negotiable fate
Authors: Au Evelyn W. M. , Chiu Chi‐yue , Chaturvedi Avinish , Mallorie LeeAnn , Viswanathan Madhu , Zhang Zhi‐Xue , Savani Krishna
Published: November 2011

Negotiable fate refers to the idea that one can negotiate with fate for control, and that people can exercise personal agency within the limits that fate has determined. Research on negotiable fate has found greater prevalence of related beliefs in Southeast Asia, East Asia, and Eastern Europe than in Western Europe and English‐speaking countries. The present research extends previous findings by exploring the cognitive consequences of the belief in negotiable fate. It was hypothesized that this belief enables individuals to maintain faith in the potency of their personal actions and to remain optimistic in their goal pursuits despite the immutable constraints. The belief in negotiable fate was predicted to (a) facilitate sense‐making of surprising outcomes; (b) increase persistence in goal pursuits despite early unfavorable outcomes; and (c) increase risky choices when individuals have confidence in their luck. Using multiple methods (e.g., crosscultural comparisons, culture priming, experimental induction of fate beliefs), we found supporting evidence for our hypotheses in three studies. Furthermore, as expected, the cognitive effects of negotiable fate are observed only in cultural contexts where the fate belief is relatively prevalent. Implications of these findings are discussed in relation to the intersubjective approach to understanding the influence of culture on cognitive processes (e.g., Chiu, Gelfand, Yamagishi, Shteynberg, & Wan, 2010), the sociocultural foundations that foster the development of a belief in negotiable fate, and an alternative perspective for understanding the nature of agency in contexts where constraints are severe. Future research avenues are also discussed.
FAT10 is a proteasomal degradation signal that is itself regulated by ubiquitination
Authors: Buchsbaum Samuel , Bercovich Beatrice , Ciechanover Aaron
Published: November 2011

FAT10 is a ubiquitin-like protein modifier that is induced in vertebrates following certain inflammatory stimuli. Its functions and the repertoire of its target substrates have remained elusive. In contrast to ubiquitin, its cellular abundance is tightly controlled by both transcriptional and posttranslational regulation, and it was reported to be rapidly degraded by the proteasome. Here we provide data to indicate that the degradation of FAT10 requires ubiquitination: degradation was inhibited in cells expressing a ubiquitin mutant that cannot be polymerized and in a mutant cell harboring a thermolabile ubiquitin-activating enzyme, E1. Of importance, FAT10 can serve as a degradation signal for otherwise stable proteins, and in this case, too, the targeting to the proteasome requires ubiquitination. Degradation of FAT10 is accelerated after induction of apoptosis, suggesting that it plays a role in prosurvival pathways.
Escapement of silver-phase European eels, Anguilla anguilla, determined from fishing activities in a Mediterranean lagoon (Or, France)
Authors: Charrier Fabien , Mazel Virgile , Caraguel Jean-Marie , Abdallah Yann , Le Gurun L. Laëtitia , Legault Antoine , Laffaille Pascal
Published: November 2011

Charrier, F., Mazel, V., Caraguel, J-M., Abdallah, Y., Le Gurun, L. L., Legault, A., and Laffaille, P. 2012. Escapement of silver-phase European eels, Anguilla anguilla, determined from fishing activities in a Mediterranean lagoon (Or, France). – ICES Journal of Marine Science, 69: 30–33. Escapement of silver eels from a Mediterranean lagoon was estimated by a capture–tagging–recapture and automated tag-reading study. The population of silver-phase eels in the lagoon was estimated to be 13.2 kg ha−1, with an escapement rate from the commercial fishery of 76.8%.
Predicting Take-All Severity in Second-Year Wheat Using Soil DNA Concentrations ofGaeumannomyces graminisvar.triticiDetermined with qPCR
Authors: Bithell Sean L. , McKay Alan , Butler Ruth C. , Herdina  , Ophel-Keller Kathy , Hartley Diana , Cromey Matthew G.
Published: November 2011

The lack of accurate detection of Gaeumannomyces graminis var. tritici inoculum in soil has hampered efforts to predict the risk of severe take-all for wheat growers. The current study used a molecular method to quantify soil G. graminis var. tritici concentrations in commercial wheat fields in New Zealand and to compare them with the proportion of crops surpassing the thresholds for visible and moderate to severe take-all over three growing seasons. The study evaluated a soil G. graminis var. tritici DNA-based take-all prediction system developed in Australia, with four take-all risk categories. These categories were found to be useful for predicting disease severity in second wheat but did not clearly separate risk between fields in medium- and high-risk categories. A sigmoidal relationship was identified between inoculum concentration and the proportion of fields exceeding the two disease thresholds. A logistic response curve was used to further examine this relationship and evaluate the boundaries between take-all risk categories. G. graminis var. tritici boundaries between medium- and high-risk categories were clustered near or within the upper plateau of the relationship. Alternative G. graminis var. tritici boundaries for a three-category system were identified that provided better separation of take-all risk between categories. This information could improve prediction of the risk of severe take-all.
Identification of a novel single-stranded, circular DNA virus from bovine stool
Authors: Kim Hye Kwon , Park Seong Jun , Nguyen Van Giap , Song Dae Sub , Moon Hyoung Joon , Kang Bo Kyu , Park Bong Kyun
Published: November 2011

We report the identification of a novel single-stranded, circular DNA virus isolated from bovine stool. The virus, named bovine stool-associated circular DNA virus (BoSCV), has a genome comprising 2600 bases of circular ssDNA, with two putative ORFs encoding replicase and capsid proteins, arranged inversely. The stem–loop structure was located between the 3′ ends of the two putative ORFs, as in chimpanzee stool-associated circular virus (ChimpSCV) and unlike other circular DNA viruses, including members of the familiesCircoviridae,NanoviridaeandGeminiviridae. BoSCV was also genetically similar to ChimpSCV, with approximately 30 % identity in the replicase and capsid proteins. A phylogenetic analysis based on the replicase protein showed that BoSCV and ChimpSCV are in the same clade. A field survey using BoSCV-specific PCRs targeting ORF1 detected BoSCV and BoSCV-like sequences in bovine and porcine stool samples. BoSCV appears to belong to a new genus of circular DNA viruses.
Evolution of gastro‐oesophageal reflux disease over 5 years under routine medical care – the ProGERD study
Authors: Malfertheiner P. , Nocon M. , Vieth M. , Stolte M. , Jaspersen D. , Koelz H. R. , Labenz J. , Leodolter A. , Lind T. , Richter K. , Willich S. N.
Published: November 2011

Aliment Pharmacol Ther 2012; 35: 154–164

Background  The evolution of gastro‐oesophageal reflux disease (GERD) under current management options remains uncertain.

Aim  To examine whether, depending on the initial presentation, non‐erosive (NERD) and erosive reflux disease (ERD) without Barrett’s oesophagus will progress to more severe disease under current routine care following the resolution of the initial condition.

Methods  Patients with the primary symptom of heartburn were included at baseline, and stratified into non‐erosive (NERD) and erosive reflux disease (ERD), LA grades A–D (Los Angeles classification). After a 2‐ to 8‐week course with esomeprazole therapy to achieve endoscopic healing in ERD and symptom relief in NERD, patients were treated routinely at the discretion of their physician. We report oesophagitis status and the presence of endoscopic and confirmed Barrett’s oesophagus after 5 years.

Results  A total of 6215 patients were enrolled in the study of whom 2721 patients completed the 5‐year follow‐up. Progression, regression and stability of GERD severity were followed from baseline to 5 years. Only a few patients with NERD and mild/moderate ERD progressed to severe forms of ERD and even Barrett’s oesophagus. Most patients remained stable or showed improvement in their oesophagitis; 5.9% of the NERD patients, 12.1% of LA grade A/B patients and 19.7% of LA grade C/D patients in whom no Barrett’s oesophagus was recorded at baseline progressed to endoscopic or confirmed Barrett’s oesophagus at 5 years.

Conclusion  Most GERD patients remain stable or improve over a 5‐year observation period under current routine clinical care.
Airway research: the current status and future directions
Authors: Isono S. , Greif R. , Mort T. C.
Published: November 2011

We highlight the areas we think important for future development of the subspeciality. The ultimate goal is to improve patient care and safety and to do this, we need to identify how and where episodes of harm arise. Simply continuing with current practice does not represent the best path towards our ultimate goal; objective evidence is needed to inform changes in practice.
Can we make airway management (even) safer? – lessons from national audit
Authors: Woodall N. , Frerk C. , Cook T. M.
Published: November 2011

The Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society (NAP4) has published an extensive report examining both current practices in the United Kingdom regarding airway management during anaesthesia and the complications of airway management during anaesthesia and in intensive care units and emergency departments. The report makes more than 160 recommendations designed to improve care of patients. These recommendations have implications for individuals, departments, organisations and potentially for national policy in terms of training, standards of practice and the need for guidelines. The report also indicates several specific areas where future research might be directed. This article focuses on the implementation phase of NAP4, emphasising the importance of taking the lessons derived from NAP4 and turning them into actions to improve the safety of airway care delivered to patients, wherever in hospital this takes place.
The history of anaesthetic equipment evaluation in the United Kingdom: lessons for developing future strategy
Authors: Wilkes A. R. , Pandit J. J. , O’Sullivan E.
Published: November 2011

Recent guidance published by the Association of Anaesthetists of Great Britain and Ireland encourages the purchase of equipment based on evidence of safety and performance. For many years, evidence of the safety and performance of anaesthetic equipment was published by various government departments and agencies. However, these schemes were gradually eroded over time such that many devices entered the market with little or no clinical evidence of their efficacy. This recently led to the Difficult Airway Society’s issuing guidance to its members on how best to select new airway devices; guidance that was based on the available evidence. This article provides a short history of the evaluation of anaesthetic equipment in the United Kingdom.
Supraglottic airways in difficult airway management: successes, failures, use and misuse
Authors: Timmermann A.
Published: November 2011

Supraglottic airway devices (SAD) play an important role in the management of patients with difficult airways. Unlike other alternatives to standard tracheal intubation, e.g. videolaryngoscopy or intubation stylets, they enable ventilation even in patients with difficult facemask ventilation and simultaneous use as a conduit for tracheal intubation. Insertion is usually atraumatic, their use is familiar from elective anaesthesia, and compared with tracheal intubation is easier to learn for users with limited experienced in airway management. Use of SADs during difficult airway management is widely recommended in many guidelines for the operating room and in the pre‐hospital setting. Despite numerous studies comparing different SADs in manikins, there are few randomised controlled trials comparing different SADs in patients with difficult airways. Therefore, most safety data come from extended use rather than high quality evidence and claims of efficacy and particularly safety must be interpreted cautiously.
Longitudinal relationship of early life immunomodulatory T cell phenotype and function to development of allergic sensitization in an urban cohort
Authors: McLoughlin R. M. , Calatroni A. , Visness C. M. , Wallace P. K. , Cruikshank W. W , Tuzova M. , Ly N. P. , Ruiz‐Perez B. , Kattan M. , Bloomberg G. R. , Lederman H. , Gern J. E. , Gold D. R.
Published: November 2011

Background

Immunomodulatory T cells are thought to influence development of allergy and asthma, but early life longitudinal data on their phenotype and function are lacking.

Objectives

As part of the Urban Environment and Childhood Asthma (URECA) study, we investigated the development of immunomodulatory T cell phenotype and function, and characterized their relation to allergic disease progression from birth through to 2 years of age.

Methods

Immunomodulatory T cell phenotype and function in cord blood mononuclear cells (CBMC) and peripheral blood mononuclear cells (PBMC) at 1 and 2 years of age were characterized by analysing CD25bright and FoxP3+ expression, proliferative responses and cytokine production. The relation of immunomodulatory T cell characteristics to allergic sensitization and disease at 1‐ and 2‐years of age was investigated.

Results

The proportion of CD4+CD25bright and CD4+CD25+FoxP3+ T cells (n = 114, 83, 82 at birth, 1‐ and 2‐years respectively) increased significantly, whereas there were no significant changes in the suppressive function of CD25+ T cells (n = 78, 71, 81 at birth, 1‐ and 2‐years respectively). Birth immunomodulatory T cell characteristics were not related to subsequent allergic sensitization or disease. However, increases in the numbers of CD4+CD25bright cells and their ability to suppress lymphoproliferative responses at 1 year of age were associated with reduced allergic sensitization at 1 (P = 0.03) and 2 (P = 0.02) years of age. Production of the anti‐inflammatory cytokine IL‐10 by CD25+ T cells appeared to mediate this protective suppressive function. In contrast, by 2 years of age, we observed the emergence of a positive association of CD4+CD25+FoxP3+ T cell numbers with allergic sensitization (P = 0.05) and eczema (P = 0.02).

Conclusions and clinical relevance

These findings suggest that the relationship between immunomodulatory T cell subsets, allergic sensitization and eczema is developmentally regulated. In the first year of life, CD4+CD25+ IL‐10 producing T cells are associated with a reduced incidence of allergic sensitization. Once allergic sensitization or eczema is established, CD4+CD25+FoxP3+ T‐reg cells expand to potentially counteract the allergic inflammatory response. Understanding the relationship between development of immunoregulatory T cells and early onset atopy could lead to new preventive strategies for allergic diseases.
Environmental variability and the ecological effects of spawning Pacific salmon on stream biofilm
Authors: RÜEGG JANINE , CHALONER DOMINIC T. , LEVI PETER S. , TANK JENNIFER L. , TIEGS SCOTT D. , LAMBERTI GARY A.
Published: November 2011

1. Variation in resource subsidies can create or reinforce heterogeneity in recipient ecosystems. Related activities of organisms delivering resource subsidies, such as ecosystem engineering by Pacific salmon spawners (Oncorhynchus spp.), also alter heterogeneity. We studied whether heterogeneity in stream environmental conditions and spawner abundances were reflected in the net ecological effects of salmon (i.e. enrichment by resource subsidies and disturbance by ecosystem engineering) on benthic biofilm.

2. We sampled seven Southeast Alaska streams over 3 years, both before and during the salmon run. In each stream and year, stream environmental characteristics and their influence on responses of benthic biofilm [mean and coefficient of variation of chlorophyll a (chl a), ash‐free dry mass (AFDM) and autotrophic index (AFDM:chl a)] to spawners were assessed.

3. Streams and periods before and during the salmon run were distinct based on their environmental characteristics. The responses of most biofilm metrics to spawners were stream‐ and year‐specific, suggesting that the ecological effect of spawners ranged from net enrichment to net disturbance depending on the stream or year studied. The environmental context, especially temperature, large wood, and sediment size, explained >50% of biofilm variability during the run, but <30% over the entire study, suggesting that salmon can alter environmental constraints.

4. Precision of biofilm estimates improved by increasing either the number of streams or the number of years sampled (i.e. spatial or temporal replication). However, combining data from different North Pacific Rim ecoregions inflated the confidence interval as compared with a single ecoregion, indicating the importance of regional environmental contexts for net salmon effects.

5. Our results suggest that biofilm responses to salmon can vary greatly, even within a single ecoregion, and that environmental conditions can modify net salmon effects. Consequently, generalisations about biofilm responses across the native range of salmon may be challenging.
Effects of livestock exclusion on in‐stream habitat and benthic invertebrate assemblages in montane streams
Authors: HERBST DAVID B. , BOGAN MICHAEL T. , ROLL SANDRA K. , SAFFORD HUGH D.
Published: November 2011

1. Stream and riparian ecosystems in arid montane areas, like the interior western United States, are often just narrow mesic strands, but support diverse and productive habitats. Meadows along many such streams have long been used for rangeland grazing, and, while impacts to riparian areas are relatively well known, the effect of livestock grazing on aquatic life in streams has received less attention.

2. Attempts to link grazing impacts to disturbance have been hindered by the lack of spatial and temporal replication. In this study, we compared channel features and benthic macroinvertebrate communities (i) between 16 stream reaches on two grazed allotments and between 22 reaches on two allotments where livestock had been completely removed for 4 years, (ii) before and after the 4‐year grazing respite at a subset of eight sites and (iii) inside and outside of small‐scale fenced grazing exclosures (eight pairings; 10+ year exclosures) in the meadows of the Golden Trout Wilderness, California (U.S.A.).

3. We evaluated grazing disturbance at the reach scale in terms of the effects of livestock trampling on per cent bank erosion and found that macroinvertebrate richness metrics were negatively correlated with bank erosion, while the percentage of tolerant taxa increased.

4. All macroinvertebrate richness metrics were significantly lower in grazed areas. Bank angle, temperature, fine sediment cover and erosion were higher in grazed areas, while riparian cover was lower. Regression models identified riparian cover, in‐stream substratum, bank conditions and bankfull width‐to‐depth ratios as the most important for explaining variability in macroinvertebrate richness metrics.

5. Small‐scale grazing exclosures showed no improvements for in‐stream communities and only moderate positive effects on riparian vegetation. In contrast, metrics of macroinvertebrate richness increased significantly after a 4‐year period of no grazing.

6. The success of grazing removal reported here suggests that short‐term removal of livestock at the larger, allotment meadow spatial scale is more effective than long‐term, but small‐scale, local riparian area fencing, and yields promising results in achieving stream channel, riparian and aquatic biological recovery.
The image of you: constructing nursing identities in YouTube
Authors: Kelly Jacinta , Fealy Gerard M. , Watson Roger
Published: November 2011

kelly j., fealy g.m. & watson r. (2011) The image of you: constructing nursing identities in YouTube. Journal of Advanced Nursing68(6), 1804–1813.

Aim.  This article is a report on a descriptive study of nursing identity as constructed in the Web 2.0 site YouTube.

Background.  Public images of the nurse carry stereotypes that rely on the taken for granted gender category of the nurse as woman. Nursing images represent a form of public discourse that has the capacity to construct nursing identity.

Methods.  Critical discourse analysis was used to describe, analyse and explain how nurse and nursing identity were constructed in a purposive sample of ten video clips accessed on 17 and 18 July 2010.

Results.  The ten most‐viewed videos depicting the nurse and nursing on YouTube offered narratives that constructed three distinct nursing identity types, namely nurse as ‘a skilled knower and doer’, nurse as ‘a sexual plaything’ and nurse as ‘a witless incompetent’ individual.

Conclusion.  Nursing identities recoverable from the texts of YouTube images propagate both favourable and derogatory nursing stereotypes. To mitigate the effects of unfavourable nursing stereotypes in such areas as interprofessional working and clinical decision‐making, nursing professional bodies need to act to protect the profession from unduly immoderate representations of the nurse and to support nurses in their efforts to maximize opportunities afforded by YouTube to promote a counter discourse.
Individual‐based modelling of moth dispersal to improve biosecurity incursion response
Authors: Guichard Sylvain , Kriticos Darren J. , Leriche Agathe , Kean John M. , Worner Susan P.
Published: November 2011

1. Some biosecurity systems aimed at reducing the impacts of invasive alien species that employ sentinel trapping systems to detect the presence of unwanted organisms. Once detected, the next challenge is to locate the source population of the invasive species. Tools that can direct search efforts towards the most likely sources of a trapped invasive alien species can improve the chance of rapidly delimiting and eradicating the local population and may help to identify the original introduction pathway. Ground‐based detection and delimitation surveys can be very expensive, and methods to focus search efforts to those areas most likely to contain the target organisms can make these efforts more effective and efficient.

2. An individual‐based semi‐mechanistic model was developed to simulate the spatio‐temporal dispersal patterns of an invasive moth. The model combines appetitive and pheromone anemotaxis behaviours in response to wind, temperature and pheromone conditions. The model was trained using data from a series of mark–release–recapture experiments on painted apple moth Teia anartoides.

3. The model was used to create hindcast simulations by reversing the time course of environmental conditions. The ability of the model to encompass the release location was evaluated using individual trap locations as starting points for the hindcast simulations.

4. The hindcast modelling generated a pattern of moth flights that successfully encompassed the origin from 86% of trap locations, representing 95% of the 1464 recaptures observed in the mark–release–recapture experiments.

5. Comparing the guided search area defined using the hindcast model with the area of a simple point‐diffusion search strategy revealed an optimized search strategy that combined searching a circle of 1 km radius around the trap followed by the area indicated by hindcast model predictions.

6. Synthesis and applications. Incorporating this novel moth dispersal model into biosecurity sentinel systems will allow incursion managers to direct search effort for the proximal source of the incursion towards those areas most likely to contain a local infestation. Such targeted effort should reduce the costs and time taken to detect the proximal source of an incursion.
Seasonal priority effects: implications for invasion and restoration in a semi‐arid system
Authors: Wainwright Claire E. , Wolkovich Elizabeth M. , Cleland Elsa E.
Published: November 2011

1. The timing of seasonal activity (i.e. phenology) may play an important role in plant invasions. In ecosystems characterized by seasonal rainfall, early‐active exotic species may pre‐empt resources and attain competitive dominance via a seasonal ‘priority advantage’. Exotic annual grasses in California are often active earlier than native species, potentially because they possess greater germination plasticity. While these problematic invaders may usually benefit from having early phenology, their flexible germination cues might be manipulated as a restoration strategy to germinate seeds far in advance of favourable growing conditions, leading to a ‘priority disadvantage’.

2. We manipulated the start of the growing season in an invaded California coastal sage scrub community characterized by a Mediterranean‐type climate to (i) identify whether early‐season phenology confers a performance advantage and (ii) test whether rainfall timing could be manipulated to favour native species. We compared the performance of seeded native and exotic focal species under ambient rainfall timing (winter rains) vs. with a pre‐growing season (late‐summer) watering event.

3. Under ambient rainfall timing, exotic annual grasses and forbs germinated earlier and reached higher levels of abundance than native species, consistent with a seasonal priority advantage. Many exotic annual grasses germinated with pre‐season watering, but none survived until the onset of natural rains. Observations suggest that early‐germinating seedlings suffered mortality via herbivory. The watering pulse thus depleted the exotic seedbank, fewer exotic individuals germinated with winter rains, and exotic species attained lower abundance than under the natural rainfall timing.

4. Native species, whether annual or perennial, did not germinate with the pre‐season watering pulse, suggesting they may have more constrained germination cues than the exotic species.

5. Synthesis and applications. Our results suggest that phenology is an important factor influencing invasion success, and that this could be manipulated to favour native species. Manipulation of the start of the growing season, for example through a pre‐growing season watering event, could be a successful restoration strategy for native species in some ecosystems.
Distinct microbial populations exist in the mucosa‐associated microbiota of sub‐groups of irritable bowel syndrome
Authors: Parkes G. C. , Rayment N. B. , Hudspith B. N. , Petrovska L. , Lomer M. C. , Brostoff J. , Whelan K. , Sanderson J. D.
Published: November 2011

Background  There is increasing evidence to support a role for the gastrointestinal microbiota in the etiology of irritable bowel syndrome (IBS). Given the evidence of an inflammatory component to IBS, the mucosa‐associated microbiota potentially play a key role in its pathogenesis. The objectives were to compare the mucosa‐associated microbiota between patients with diarrhea predominant IBS (IBS‐D), constipation predominant IBS (IBS‐C) and controls using fluorescent in situ hybridization and to correlate specific bacteria groups with individual IBS symptoms.

Methods  Forty‐seven patients with IBS (27 IBS‐D and 20 IBS‐C) and 26 healthy controls were recruited to the study. Snap‐frozen rectal biopsies were taken at colonoscopy and bacterial quantification performed by hybridizing frozen sections with bacterial‐group specific oligonucleotide probes.

Key Results  Patients with IBS had significantly greater numbers of total mucosa‐associated bacteria per mm of rectal epithelium than controls [median 218 (IQR – 209) vs 128 (121) P = 0.007], and this was chiefly comprised of bacteroides IBS [69 (67) vs 14 (41) P = 0.001] and Eubacterium rectale–Clostridium coccoides [52 (58) vs 25 (35) P = 0.03]. Analysis of IBS sub‐groups demonstrated that bifidobacteria were lower in the IBS‐D group than in the IBS‐C group and controls [24 (32) vs 54 (88) vs 32 (35) P = 0.011]. Finally, amongst patients with IBS, the maximum number of stools per day negatively correlated with the number of mucosa‐associated bifidobacteria (P < 0.001) and lactobacilli (P = 0.002).

Conclusions & Inferences  The mucosa‐associated microbiota in patients with IBS is significantly different from healthy controls with increases in bacteroides and clostridia and a reduction in bifidobacteria in patients with IBS‐D.