bluuebunny/crossref_metadata_2025 huggingface dataset:
On Compensation in Multidimensional Response Modeling
Authors: van der Linden Wim J.
Published: November 2011

The issue of compensation in multidimensional response modeling is addressed. We show that multidimensional response models are compensatory in their ability parameters if and only if they are monotone. In addition, a minimal set of assumptions is presented under which the MLEs of the ability parameters are also compensatory. In a recent series of articles, beginning with Hooker, Finkelman, and Schwartzman (2009) in this journal, the second type of compensation was presented as a paradoxical result for certain multidimensional response models, leading to occasional unfairness in maximum-likelihood test scoring. First, it is indicated that the compensation is not unique and holds generally for any multiparameter likelihood with monotone score functions. Second, we analyze why, in spite of its generality, the compensation may give the impression of a paradox or unfairness.
Risk Factors and Clinical Presentation of Cats with Feline Idiopathic Cystitis
Authors: Defauw Pieter AM , Van de Maele Isabel , Duchateau Luc , Polis Ingeborgh E , Saunders Jimmy H , Daminet Sylvie
Published: November 2011

Feline idiopathic cystitis (FIC) is the most common cause of feline lower urinary tract disease (FLUTD). This retrospective, case-controlled study evaluated possible risk factors associated with FIC and compared different clinical presentations in 64 cats with FIC. Several risk factors known to be involved in FLUTD were identified as playing a role in FIC. Of the stressful situations considered, most did not occur with increased frequency in cats with FIC compared to controls, except for a house move. The presence of pyuria, haematuria and an increased urine protein:creatinine ratio were significantly higher in obstructed males compared with non-obstructed males. An obstruction was significantly more likely in cats with struvite crystalluria compared with cats without struvite crystalluria. These findings suggest that urethral plugs might be an important cause or contributing factor of obstruction in FIC. Episodes of FIC seem to occur mainly in susceptible cats in combination with a deficient environment.
Unpacking the Black Box of Causality: Learning about Causal Mechanisms from Experimental and Observational Studies
Authors: IMAI KOSUKE , KEELE LUKE , TINGLEY DUSTIN , YAMAMOTO TEPPEI
Published: November 2011

Identifying causal mechanisms is a fundamental goal of social science. Researchers seek to study not only whether one variable affects another but also how such a causal relationship arises. Yet commonly used statistical methods for identifying causal mechanisms rely upon untestable assumptions and are often inappropriate even under those assumptions. Randomizing treatment and intermediate variables is also insufficient. Despite these difficulties, the study of causal mechanisms is too important to abandon. We make three contributions to improve research on causal mechanisms. First, we present a minimum set of assumptions required under standard designs of experimental and observational studies and develop a general algorithm for estimating causal mediation effects. Second, we provide a method for assessing the sensitivity of conclusions to potential violations of a key assumption. Third, we offer alternative research designs for identifying causal mechanisms under weaker assumptions. The proposed approach is illustrated using media framing experiments and incumbency advantage studies.
A seasonal survey of gastrointestinal parasites in captive wild impala antelope on a game facility south of Lusaka, Zambia
Authors: Nalubamba K.S. , Mudenda N.B. , Malamo M.R.
Published: November 2011

Faecal samples (n = 1947) from captive wild impala (Aepyceros melampus melampus) were examined over a period of 14 months to determine quantitative seasonal helminth egg excretion patterns and qualitative protozoan oocyst excretion patterns. Geometric mean monthly faecal egg counts (FECs) ranged from 20 to 575 and coprocultures revealed three parasite genera, namelyTrichostrongylus,HaemonchusandStrongyloides. Larvae of theTrichostrongylusspp. were most predominant from faecal cultures. No trematode eggs or lungworms were detected and eggs of the cestodeMoneziawere only seen in two samples during the entire study period. The nematode FECs showed a marked seasonal variation, being higher during the rainy season, moderate during the cool dry season and low during the hot dry season. The rainy season had significantly higher FECs than the dry season (P < 0.01). The percentage of helminth-egg positive faecal samples ranged from 90.6 to 100% in the rainy season and 72.4 to 85.6% in the dry season. Overall mean FECs in unpelleted faeces were significantly higher than in pelleted faeces (P < 0.01). However, the FECs were not significantly different among seasons in unpelleted faeces (P>0.05), but were significantly higher in pelleted faeces in the rainy season than the dry season (P < 0.05). Pellet size had a significant effect on FEC, with smaller pellets having higher FEC (P < 0.05).Strongyloideseggs and coccidia oocysts were only seen during the rainy season. This represents the first documentation of seasonal parasitic infestation in captive wild antelopes in Zambia. Treatment and control strategies for helminths in these captive wild impala are also suggested based on the findings from this study.
Drugs' rapid payoffs distort evaluation of their instrumental uses
Authors: Ainslie George
Published: November 2011

Science has needed a dispassionate valuation of psychoactive drugs, but a motivational analysis should be conducted with respect to long-term reward rather than reproductive fitness. Because of hyperbolic overvaluation of short-term rewards, an individual's valuation depends on the time she forms it and the times she will revisit it, sometimes making her best long-term interest lie in total abstinence.
Drug instrumentalization and evolution: Going even further
Authors: Lende Daniel H.
Published: November 2011

Müller & Schumann (M&S) deserve applause for their interdisciplinary examination of drug use, evolution, and learning. Further steps can deepen their evolutionary analysis: a focus on adaptive benefits, a distinction between approach and consummatory behaviors, an examination of how drugs can create adaptive lag through changing human niche construction, the importance of other neurobehavioral mechanisms in drug use besides instrumentalization, and the importance of sociocultural dynamics and neural plasticity in both human evolution and drug use.
Sacramental and spiritual use of hallucinogenic drugs
Authors: Móró Levente , Noreika Valdas
Published: November 2011

Arguably, the religious use of hallucinogenic drugs stems from a human search of metaphysical insight rather than from a direct need for cognitive, emotional, social, physical, or sexual improvement. Therefore, the sacramental and spiritual intake of hallucinogenic drugs goes so far beyond other biopsychosocial functions that it deserves its own category in the drug instrumentalization list.
CoRoT mission highlights
Authors: Deleuil Magali , Bordé Pascal , Moutou Claire ,   the CoRoT exoplanet science team
Published: November 2011

The CoRoT space telescope is detecting planets with the transit method for more than four years. Its tally includes hot jupiter planets with orbital periods up to 95 days but also the first Super-Earth, CoRoT-7b, whose density is similar to the Earth's one, as well as close-in brown dwarfs. We review the status of the CoRoT/Exoplanet program, including some elements of the multi step strategy of complementary observations. We then present some of the CoRoT exoplanetary systems and how they widen the range of properties of the close-in low mass population and contribute to our understanding of the properties of planets.
Formation of brown dwarfs and planets
Authors: Nordlund Åke
Published: November 2011

Brown dwarfs and massive planets have similar structures, and there is probably an overlap in mass between the most massive planets and the lowest mass brown dwarfs. This raises questions as to what extent the structures of the most massive planets and lowest mass brown dwarfs differ, and what similarities (or not) there might be between their formation mechanisms. Here I discuss these issues on the background of recent numerical simulations of star formation, new evidence from cosmochemistry about the conditions in the early solar system, and recently discovered mechanisms that can expedite planetesimal and possibly planet formation greatly.
The photometric follow-up observations for transiting exoplanet XO-2b
Authors: Gu Sheng-hong , Cameron Andrew Collier , Wang Xiao-bin , Fang Xiang-song , Cao Dong-tao , Zhang Li-yun
Published: November 2011

Four new transit light curves of XO-2b obtained in 2008 and 2009, are analyzed by using MCMC algorithm, and the system parameters are derived. The result demonstrates that the orbital period of the system obtained from new observations is almost the same as Burke et al.'s one (2007), which does not confirm the result of Fernandez et al. (2009).
Alien Earth: Glint observations of a remote planet
Authors: Barry Richard K. , Deming L. Drake
Published: November 2011

We give a preliminary report on a multi-wavelength study of specular reflections from the oceans and clouds of Earth. We use space-borne observations from a distance sufficient to ensure that light rays reflected from all parts of Earth are closely parallel, as they will be when studying exoplanets. We find that the glint properties of Earth in this far-field vantage point are surprising - in the sense that some of the brightest reflections are not from conventional ocean-glints, but appear to arise from cirrus cloud crystals. The Earth observations discussed here were acquired with the High Resolution Instrument (HRI) - a 0.3 m f/35 telescope on the Deep Impact (DI) spacecraft during the Extrasolar Planet Observation and Characterization (EPOCh) investigation.
Characterization of rocky exoplanets from their infrared phase curve
Authors: Maurin Anne-Sophie , Selsis Franck , Hersant Franck , Delbò Marco
Published: November 2011

During the last few years, observations have yielded an abundant population of short-period planets under 15 Earth masses. Among those, hot terrestrial exoplanets represent a key population to study the survival of dense atmospheres close to their parent star. Thermal emission from exoplanets orbiting low-mass stars will be observable with the next generation of infrared telescopes, in particular the JWST. In order to constrain planetary and atmospheric properties, we have developed models to simulate the variation of the infrared emission along the path of the orbit (IR phase curve) for both airless planets and planets with dense atmospheres. Here, we focus on airless planets and present preliminary results on the influence of orbital elements, planet rotation, surface properties and observation geometry. Then, using simulated noisy phase curves, we test the retrieval of planets' properties and identify the degeneracies.
Conditions for outward migration
Authors: Bitsch Bertram , Kley Willy
Published: November 2011

The migration of protoplanets in discs not only depends on the thermodynamics of the ambient disc but also on the orbital parameters of the embedded planet. In the fully radiative regime, planets can migrate outward if their orbital parameters fit in a very small range. We simulate planets in fully radiative discs (and isothermal discs - for reference) and determine the influence of the orbital parameters (a, e and i) and the planetary mass on the migration time scale and direction.
The 2:1 librating-circulating planetary configuration produced by a hybrid scenario
Authors: Ji Jianghui , Sun Zhao , Jin Sheng , Zhang Niu
Published: November 2011

Different migration scenario of two giant planets may play a major role in forming the diverse resonant planetary configurations. The studies on the HD 128311 and HD 73526 systems show that two gas giants are captured in a 2:1 resonance but not in apsidal corotation, because one of the resonant argument circulates over the dynamical evolution. Herein we explore potential scenarios to produce the 2:1 librating-circulating resonance configuration. In the simulations, we find that both colliding or scattering events at early stage of dynamical evolution can induce the configurations trapped into resonance. In this sense, the librating-circulating resonance configuration is more likely to form by a hybrid mechanism of scattering and collision.
The variation of biomarkers in the spectrum of Earthshine
Authors: Naud Marie-Eve , Lamontagne R. , Wesemael F.
Published: November 2011

We present preliminary results from a study of the variations of the optical spectrum of the Earthshine over a period of a year. Our goal is to follow, on several timescales, the spectral changes of the signature of various biomarkers that are potential indicators of habitability and/or biological activity, and of the Vegetation Red Edge, a feature around 700 nm due to photosynthetic organisms.
Long‐term increase in mesozooplankton biomass in the Sargasso Sea: Linkage to climate and implications for food web dynamics and biogeochemical cycling
Authors: Steinberg Deborah K. , Lomas Michael W. , Cope Joseph S.
Published: November 2011

Changes in zooplankton biomass and species composition over long time scales can have significant effects on biogeochemical cycling and transfer of energy to higher trophic levels. We analyzed size‐fractionated mesozooplankton biomass (>200μm) from biweekly to monthly day and night tows taken from 1994 to 2010 in the epipelagic zone at the Bermuda Atlantic Time series Study (BATS) site in the oligotrophic North Atlantic subtropical gyre. During this 17‐year period total mesozooplankton biomass increased 61% overall, although a few short‐term downturns occurred over the course of the time series. The overall increase was higher in the nighttime compared to daytime, resulting in an increase in calculated diel vertical migrator biomass. The largest seasonal increase in total biomass was in the late‐winter to spring (February–April). Associated with the larger increase in late‐winter/spring biomass was a shift in the timing of annual peak biomass during the latter half of the time series (from March/April to a distinct March peak for all size fractions combined, and April to March for the 2–5 mm size fractions). Zooplankton biomass was positively correlated with sea‐surface temperature, water column stratification, and primary production, and negatively correlated with mean temperature between 300 and 600 m. Significant correlations exist between multidecadal climate indices–the North Atlantic Oscillation plus three different Pacific Ocean climate indices, and BATS zooplankton biomass, indicating connections between patterns in climate forcing and ecosystem response. Resultant changes in biogeochemical cycling include an increase in the magnitude of both active carbon flux by diel vertical migration and passive carbon flux of fecal pellets as components of the export flux. The most likely mechanism driving the zooplankton biomass increase is bottom‐up control by smaller phytoplankton, which has also increased in biomass and production at BATS, translating up the microbial food web into mesozooplankton. Decreases in top‐down control or expansion of the range of tropical species northward as a result of warming may also play a role.
Use of paired simple and complex models to reduce predictive bias and quantify uncertainty
Authors: Doherty John , Christensen Steen
Published: November 2011

Modern environmental management and decision‐making is based on the use of increasingly complex numerical models. Such models have the advantage of allowing representation of complex processes and heterogeneous system property distributions inasmuch as these are understood at any particular study site. The latter are often represented stochastically, this reflecting knowledge of the character of system heterogeneity at the same time as it reflects a lack of knowledge of its spatial details. Unfortunately, however, complex models are often difficult to calibrate because of their long run times and sometimes questionable numerical stability. Analysis of predictive uncertainty is also a difficult undertaking when using models such as these. Such analysis must reflect a lack of knowledge of spatial hydraulic property details. At the same time, it must be subject to constraints on the spatial variability of these details born of the necessity for model outputs to replicate observations of historical system behavior. In contrast, the rapid run times and general numerical reliability of simple models often promulgates good calibration and ready implementation of sophisticated methods of calibration‐constrained uncertainty analysis. Unfortunately, however, many system and process details on which uncertainty may depend are, by design, omitted from simple models. This can lead to underestimation of the uncertainty associated with many predictions of management interest. The present paper proposes a methodology that attempts to overcome the problems associated with complex models on the one hand and simple models on the other hand, while allowing access to the benefits each of them offers. It provides a theoretical analysis of the simplification process from a subspace point of view, this yielding insights into the costs of model simplification, and into how some of these costs may be reduced. It then describes a methodology for paired model usage through which predictive bias of a simplified model can be detected and corrected, and postcalibration predictive uncertainty can be quantified. The methodology is demonstrated using a synthetic example based on groundwater modeling environments commonly encountered in northern Europe and North America.
Thermoelastic properties of ReB2 at high pressures and temperatures and comparison with Pt, Os, and Re
Authors: Kavner Abby , Armentrout Matthew M. , Rainey Emma S. G. , Xie Miao , Weaver Beth E. , Tolbert Sarah H. , Kaner Richard B.
Published: November 2011

We have measured the phase stability and thermoelastic equation of state of ultrahard rhenium diboride at pressures up to 30 GPa and temperatures up to 2500 K using a laser heated diamond anvil cell in conjunction with synchrotron X-ray diffraction. ReB2 is shown to be stable throughout this pressure and temperature region. The ratio of the c-axis to the a-axis provides a monitor of the annealing of plastic stresses during compression. We show that ReB2 has a small thermal anisotropy but a large mechanical anisotropy. Combining this new data set with previously existing results from a large volume press yields a thermoelastic equation of state with a Grüneisen parameter of 2.4 (0.08) and a q of 2.7. A comparison of ReB2 with other high electron density incompressible metals—Os, Re, and Pt—shows that ReB2 has the lowest thermal pressure and the highest bulk modulus.
Raman and photoluminescence characterization of focused ion beam patterned InGaN/GaN multi-quantum-wells nanopillar array
Authors: Wang X. H. , Ning J. Q. , Xu S. J. , Choi H. W.
Published: November 2011

High crystal quality GaN nanopillar arrays containing InGaN/GaN multi-quantum wells (MQWs) have been fabricated by focused ion beam followed by wet etch treatments to remove the ion damage. The first order Raman spectra reveal a well-built additional peak when the diameter of the nanopillars is less than 220 nm. This peak is also observed in the GaN pillars without MQW and is clearly assigned to the surface optical (SO) mode originating from the A1 phonon in wurtzite GaN. The frequency of this SO mode is found to be sensitive with the diameter and surface roughness of the nanopillars. Temperature-variable photoluminescence measurements show that a broadband emission in the as-grown sample split into the two well-resolved bands for nanopillars and the emission band at the higher energy side quickly thermally quenched.
Enhancement of thermal conductivity upon application of magnetic field to Fe3O4 nanofluids
Authors: Altan Cem L. , Elkatmis Alper , Yüksel Merve , Aslan Necdet , Bucak Seyda
Published: November 2011

Enhancement of thermal conductivity of fluids upon addition of nanoparticles has been previously observed. In this study, Fe3O4 magnetite particles were used and thermal conductivity enhancements both in water and in heptane with increasing volume fraction have been shown. Upon measuring thermal conductivity under externally applied magnetic field, it has been shown experimentally that thermal conductivity can be further increased even at low concentrations and low magnetic field strengths in both fluids. Theoretical calculations are presented to support the effect of magnetic field on the thermal conductivity enhancement. This enhancement is attributed to the thermomagnetic convection which due to a temperature gradient, results in a non-uniform magnetic body force resulting in more efficient thermal conductance.
Non-integrability of a class of Hamiltonian systems
Authors: Li Wenlei , Shi Shaoyun , Liu Bing
Published: November 2011

In this paper, using the Morales-Ramis theory, we will give some new non-integrability results for a class of famous Hamiltonian models.
Magnetic reconstruction at oxygen-deficient SrMnO3 (001) surface: A first-principle investigation
Authors: Hou Fang , Cai Tian-Yi , Ju Sheng , Shen Ming-Rong
Published: November 2011

Based on extensive first-principle density functional theory calculations, we have revealed the spin-flip process at the oxygen-deficient Mn-terminated SrMnO3 (001) surface. With the increase of oxygen vacancies, the occupancy of eg orbitals at surface and subsurface Mn ions gets increased and surface magnetic ordering changes from antiferromagnetic spin-flip to the ferromagnetic one, and further to antiferromagnetic one, and finally a G-type bulk-like antiferromagnetic ordering. Ferromagnetic interlayer coupling is found to develop only when eg orbitals are partially filled at both surface and subsurface Mn ions.
Clarification of enhanced ferromagnetism in Be-codoped InMnP fabricated using Mn/InP:Be bilayers grown by molecular beam epitaxy
Authors: Shon Yoon , Lee Sejoon , Taek Yoon Im , Jeon H. C. , Lee D. J. , Kang T. W. , Song J. D. , Yoon Chong S. , Kim D. Y. , Park C. S.
Published: November 2011

The p-type InMnP:Be epilayers were prepared by the sequential growth of Mn/InP:Be bilayers using molecular-beam-epitaxy and the subsequent in-situ annealing at 200–300 °C. In triple-axis x-ray diffraction patterns, the samples revealed a shoulder peak indicative of intrinsic InMnP. The ferromagnetic transition in InMnP:Be was observed to occur at the elevated temperature of ∼140 K, and the ferromagnetic spin-domains clearly appeared in magnetic force microscopy images. The improved ferromagnetic properties are attributed to the increased p–d hybridation due to high p-type conductivity of InMnP:Be (p ∼ 1020 cm−3). The results suggest that enhanced ferromagnetism can be effectively obtained from Be-codoped InMnP.
Nitrogen Metabolism in Sinorhizobium meliloti–Alfalfa Symbiosis: Dissecting the Role of GlnD and PII Proteins
Authors: Yurgel Svetlana N. , Rice Jennifer , Kahn Michael L.
Published: November 2011

To contribute nitrogen for plant growth and establish an effective symbiosis with alfalfa, Sinorhizobium meliloti Rm1021 needs normal operation of the GlnD protein, a bifunctional uridylyltransferase/uridylyl-cleavage enzyme that measures cellular nitrogen status and initiates a nitrogen stress response (NSR). However, the only two known targets of GlnD modification in Rm1021, the PII proteins GlnB and GlnK, are not necessary for effectiveness. We introduced a Tyr→Phe variant of GlnB, which cannot be uridylylated, into a glnBglnK background to approximate the expected state in a glnD-sm2 mutant, and this strain was effective. These results suggested that unmodified PII does not inhibit effectiveness. We also generated a glnBglnK-glnD triple mutant and used this and other mutants to dissect the role of these proteins in regulating the free-living NSR and nitrogen metabolism in symbiosis. The glnD-sm2 mutation was dominant to the glnBglnK mutations in symbiosis but recessive in some free-living phenotypes. The data show that the GlnD protein has a role in free-living growth and in symbiotic nitrogen exchange that does not depend on the PII proteins, suggesting that S. meliloti GlnD can communicate with the cell by alternate mechanisms.
First Report of Bacterial Streak of Fennel (Foeniculum vulgare) in California Caused by Pseudomonas syringae pv. apii
Authors: Jardini T. M. , Koike S. T. , Bull C. T.
Published: November 2011

A previously undescribed disease appeared on commercially grown fennel (Foeniculum vulgare) in Salinas (Monterey County), CA in March 2010. Initial symptoms consisted of small, dark brown-to-black lesions on leaves and stems. As disease progressed, lesions expanded in a linear fashion and eventually spread down the stems and into the bulbs. Once the disease reached the fennel bulbs, the plants were unmarketable. Eighteen, gram-negative, blue-fluorescing bacterial isolates were obtained on sucrose peptone agar from individual plants of two outbreaks from different fields in Salinas. The isolates were dome shaped on sucrose-amended media and produced necrotic lesions when injected into tobacco. Isolates were oxidase negative and did not rot potatoes or hydrolyze arginine. These reactions corresponded to Lelliot's group 1, which includes Pseudomonas syringae (2). The fennel isolates were identical to recently characterized isolates of P. syringae pv. apii from parsley grown in coastal California (1) and similar to the pathotype strain of P. syringae pv. apii according to DNA fragment banding patterns of amplicons generated from repetitive extragenic palindromic sequence (rep)-PCR using the BOXA1R primer. The isolates were distinct from the pathotype strain P. syringae pv. coriandricola. Like P. syringae pv. apii, the fennel isolates did not nucleate ice but did hydrolyze gelatine. Six isolates were tested for pathogenicity in each of two independent experiments with a total of six replications per isolate. Healthy, potted fennel plant stems of a proprietary cultivar were pierced once with insect display pins that had been dipped into bacterial colonies grown for 48 h on nutrient agar. Control stems were inoculated with sterile pins. Plants were incubated for 48 h at 100% relative humidity and then held in a greenhouse. After 4 to 6 days, inoculated fennel plants developed symptoms similar to those originally observed in the field. Bacteria isolated from surface-disinfested symptomatic tissue were fluorescent and identical to strains used to inoculate plants as evaluated by rep-PCR, thus fulfilling Koch's postulates. Control plants remained symptomless. To our knowledge, this is the first report of this pathogen causing a disease on fennel; the disease has been named bacterial streak. The disease occurred in three fields in 2010 and incidence was <1% in each case. Similar symptoms were also observed on fennel in the 2011 season in at least two fields. Previously, the host range of P. syringae pv. apii was reported to be restricted to celery. This research expands the natural host range of P. syringae pv. apii; thus, care should be taken in choosing Apiaceae crops for plantings subsequent to the occurrence of this pathogen.

References: (1) C. T. Bull et al. Phytopathology 101:847, 2011. (2) R. A. Lelliott. J. Appl. Bacteriol. 29:470, 1966.
Examining the cross-reactivity and neutralization mechanisms of a panel of mAbs against adeno-associated virus serotypes 1 and 5
Authors: Harbison Carole E. , Weichert Wendy S. , Gurda Brittney L. , Chiorini John A. , Agbandje-McKenna Mavis , Parrish Colin R.
Published: November 2011

Neutralizing antibodies play a central role in the prevention and clearance of viral infections, but can be detrimental to the use of viral capsids for gene delivery. Antibodies present a major hurdle for ongoing clinical trials using adeno-associated viruses (AAVs); however, relatively little is known about the antigenic epitopes of most AAV serotypes or the mechanism(s) of antibody-mediated neutralization. We developed panels of AAV mAbs by repeatedly immunizing mice with AAV serotype 1 (AAV1) capsids, or by sequentially immunizing with AAV1 followed by AAV5 capsids, in order to examine the efficiency and mechanisms of antibody-mediated neutralization. The antibodies were not cross-reactive between heterologous AAV serotypes except for a low level of recognition of AAV1 capsids by the AAV5 antibodies, probably due to the initial immunization with AAV1. The neutralization efficiency of different IgGs varied and Fab fragments derived from these antibodies were generally poorly neutralizing. The antibodies appeared to display various alternative mechanisms of neutralization, which included inhibition of receptor-binding and interference with a post-attachment step.
The evolutionary rate of citrus tristeza virus ranks among the rates of the slowest RNA viruses
Authors: Silva Gonçalo , Marques Natália , Nolasco Gustavo
Published: November 2011

Citrus tristeza virus (CTV) has been studied intensively at the molecular level. However, knowledge regarding the dynamics of its evolution is practically non-existent. In the past, diverse authors have referred to CTV as a highly variable virus, implying rapid evolution. Others have, in recent times, referred to CTV as an exceptionally slowly evolving virus. In this work, we used the capsid protein (CP) gene to estimate the rate of evolution. This was obtained from a large set of heterochronous CP gene sequences using a Bayesian coalescent approach. The best-fitting evolutionary and population models pointed to an evolutionary rate of 1.58×10−4 nt per site year−1 (95 % highest posterior density, 1.73×10−5–3.16×10−4 nt per site year−1). For an unbiased comparison with other plant and animal viruses, the evolutionary rate of synonymous substitutions was considered. In a series of 88 synonymous evolutionary rates, ranging from 5.2×10−6 to 6.2×10−2 nt per site year−1, CTV ranks in the 10th percentile, embedded among the slowest animal RNA viruses. At the time of citrus dissemination to Europe and the New World, the major clades that led to the current phylogenetic groups were already defined, which may explain the absence nowadays of geographical speciation.
Simulating hypoxia and modelling the airway
Authors: Farmery A. D.
Published: November 2011

Apnoea due to airway obstruction is an ever present concern in anaesthesia and critical care practice and results in rapid development of hypoxaemia that is not always remediable by manual bag‐mask ventilation. As it is often difficult or impossible to study experimentally (although some historical animal data exist), it is useful to model the kinetics of hypoxaemia following airway obstruction. Despite being a complex event, the consequences of airway obstruction can be predicted with reasonable fidelity using mathematical and computer modelling. Over the last 15 years, a number of high fidelity mathematical and computer models have been developed, that have thrown light on this important event.
An evidence‐based approach to airway management: is there a role for clinical practice guidelines?
Authors: Crosby E. T.
Published: November 2011

Complications arising out of airway management represent an important cause of anaesthesia‐associated morbidity and mortality. Anaesthetic practice itself can lead to preventable harm, a particular example being persistent attempts at direct laryngoscopy, that results in delay in employing alternative strategies (or devices) when intubation is difficult. When patients are injured, expert review is called upon and often concludes that airway management provided by the anaesthetists was substandard. Many training programmes do not offer their trainees structured or organised teaching in airway management and many trainees probably enter practice with limited skills to deal with difficult airways. The literature on the management of the difficult airway in anaesthesia practice (especially as it relates to new technology and salvage strategies) is expanding rapidly. New technologies and practised response algorithms may be helpful in the management of the difficult airway, reducing the potential for adverse patient outcomes. Specialist societies and national interest groups can play an important role by critically reviewing and then applying the evidence base to generate clinical practice guidelines. The recommendations contained in such guidelines should be based on the most current evidence and they should be reviewed regularly for their content and continued relevance.
Dissecting T‐cell activation with high‐resolution live‐cell microscopy
Authors: Illingworth Joseph J. , van der Merwe P. Anton
Published: November 2011

Results from live‐cell microscopy suggest that the behaviour of isolated components of the T‐cell activation machinery in vitro does not represent the reality inside cells. Understanding the cellular‐scale dynamics of microcluster migration can only be accomplished by in situ observation. Developments in ‘super‐resolution’ microscopy have permitted investigators to move beyond tracking the movements of individual molecules, allowing the recognition of protein islands and nanodomains present in quiescent and active T cells. Many high‐resolution techniques have their own susceptibilities to artefacts, so it is important to take a multifaceted approach to confirm results. A major challenge for the future will be to integrate all the new information into a coherent model of antigen recognition and T‐cell activation.
Associations between seasonal variations in day length (photoperiod), sleep timing, sleep quality and mood: a comparison between Ghana (5°) and Norway (69°)
Authors: FRIBORG ODDGEIR , BJORVATN BJØRN , AMPONSAH BENJAMIN , PALLESEN STÅLE
Published: November 2011

The hypothesis of whether day length (photoperiod) is an important zeitgeber (time‐giver) for keeping the circadian rhythm entrained to a 24‐hour cycle was examined, as was its association with sleep patterns and mood problems. Data were collected prospectively from a site with very large differences in daylight duration across seasons (Tromsø in Norway, 69°39′N) and a site with very small seasonal differences in daylight duration (Ghana in Accra, 5°32′N). Two hundred subjects were recruited from both sites in January. At the follow‐up in August, 180 and 150 subjects in Ghana and Norway participated, respectively. Use of a weekly sleep diary indicated low to moderately strong seasonal changes in rise‐ and bedtime, sleep efficiency and sleep onset latency only in the northern latitude. No seasonal changes in sleep duration or night awakenings were observed. The self‐report measures indicated moderate to strong seasonal differences in insomnia and fatigue, and weaker differences in depressed mood in Norway, but small to non‐existing seasonal differences in Ghana. Lack of daylight was related to phase‐delayed rise‐ and bedtimes, increased problems falling asleep, daytime fatigue and depressive mood. However, total sleep duration and sleep quality appeared unaffected.
Patient involvement in mental health care: one size does not fit all
Authors: Tambuyzer Else , Pieters Guido , Van Audenhove Chantal
Published: November 2011

Background Involvement of mental health‐care patients in the decision‐making processes is considered to be an ethical requirement. Health‐care systems worldwide are increasingly emphasizing the value of participatory approaches. There is, however, no consensus on the definition of patient involvement. The literature is particularly inconsistent and lacks clarity.

Objective The purpose of this article is to clarify the concept of patient involvement in mental health care (MHC), taking into account its multidimensional nature.

Search strategy We searched the literature in online databases from January 1998 until August 2010 using synonyms of ‘patient involvement’, combined with the terms ‘mental health(care)’.

Data synthesis Based on 45 different descriptions found in the literature, we constructed a definition of patient involvement and we drew up a model identifying its determinants and outcomes.

Results We propose a comprehensive model of patient involvement to be used in MHC. This model can serve as a guide for policy makers and field workers to shape policies to stimulate involvement.

Discussion and conclusions There are three main problems in the literature concerning patient involvement. First, there is a proliferation of conceptualizations of the topic, leading to conceptual vagueness. Furthermore, there is a lack of quantitative data, and some aspects of involvement remain underexposed, such as the involvement of specific target groups and practical ways to shape the involvement processes. Involvement processes should be tailored to the specific target group and context.
Long non‐coding RNAs in nuclear bodies
Authors: Ip Joanna Y. , Nakagawa Shinichi
Published: November 2011

High‐throughput analyses of mammalian transcriptomes have revealed that more than half of the transcripts produced by RNA polymerase II are non‐protein‐coding. One class of these non‐coding transcripts is the long non‐coding RNAs (lncRNAs), which are more than 200 nucleotides in length and are molecularly indistinguishable from other protein‐coding mRNAs. Although the molecular functions of these lncRNAs have long remained unknown, emerging evidence implicates the functional involvement of lncRNAs in the regulation of gene expression through the modification of chromatin, maintenance of subnuclear structures, transport of specific mRNAs, and control of pre‐mRNA splicing. Here, we discuss the functions of a distinct group of vertebrate‐specific lncRNAs, NEAT1/MENε/β/VINC, MALAT1/NEAT2, and Gomafu/RNCR2/MIAT, which accumulate abundantly within the nucleus as RNA components of specific nuclear bodies.
Pattern of moderate‐to‐severe symptoms of premenstrual syndrome in a selected hospital in China
Authors: Wang Yan‐hong , Lin Shou‐qing , Chen Rong , Benita Walton‐Moss
Published: November 2011

Aim:  Premenstrual syndrome (PMS) is a commonly encountered complaint among women. It may affect women's quality of life and reduce their occupational productivity. This study aims to describe the symptoms of moderate‐to‐severe PMS and to examine the onset, stability, and severity of PMS among Chinese women.

Methods:  A descriptive study included 142 women with self‐reported PMS, aged 18–45 years, who were recruited by the Outpatient Department of Gynecological Endocrinology, Peking Union Medical College Hospital. Premenstrual symptoms were retrospectively assessed by using screening questionnaires modified with the DSM‐IV. In total, 126 eligible subjects were asked to record their daily symptoms during two consecutive menstrual cycles by using a premenstrual syndrome diary (PMSD).

Results:  Of 126 eligible subjects, 67 filled in the PMSD for two cycles. The median of total scores of PMSD peaked on the day before menses and dropped after the beginning of the menses. Mood swings were the most common moderate‐to‐severe symptom prospectively reported by the subjects. The symptoms of PMS were relatively consistent across the two cycles.

Conclusions:  Women with moderate‐to‐severe PMS were vulnerable to psychological symptoms. Further studies are needed to understand the correlations between hormonal changes and the experience of symptoms related to the menstrual cycle.
Exploring the effects of using consumer culture as a unifying pedagogical framework on the ethical perceptions of MBA students
Authors: Burns David J.
Published: November 2011

Although ethics education within the business curriculum has been receiving attention, much is unknown about the effectiveness of such education, particularly when it is integrated into the curriculum. This study looks at selected short‐term effects produced by one form of integrated ethics instruction in an introductory marketing course in a graduate business MBA program in the United States. Specifically, students were introduced to an examination of consumer culture as a unifying framework to explore the ethics of decision making. As a consequence of taking the course, students are hypothesized to hold less favorable attitudes toward consumer culture (love of money, materialism, possession satisfaction index, prestige sensitivity) relative to the attitudes held at the start of the course. Interestingly, few attitudinal changes are observed. Where changes in attitudes are observed, the relationships are in the opposite direction to that hypothesized.
Impacts of space, local environment and habitat connectivity on macrophyte communities in conservation lakes
Authors: O’Hare Matthew T. , Gunn Iain D. M. , Chapman Daniel S. , Dudley Bernard J. , Purse Bethan V.
Published: November 2011

Aim  To assess the relative impacts of spatial, local environmental and habitat connectivity on the structure of aquatic macrophyte communities in lakes designated for their conservation value.

Location  Selected lakes of conservation importance all over Scotland, representing a wide variety of lake habitat types and associated macrophyte communities.

Methods  Local environmental variables and species occurrence were measured in the field. Spatial variables were generated using principal coordinates of neighbour matrices (PCNM) analysis. Connectivity between each lake and its neighbours was defined as either (i) all lakes within a radius of 5, 10, 25, 50, 75 or 100 km; (ii) all lakes in same river system; or (iii) all lakes in the same catchment and upstream of the lake. Using variance partitioning within canonical correspondence analysis, the relative impact of E = local environment, S = space and C = lake connectivity was compared on submerged (n = 119 lakes) and emergent (n = 96 lakes) macrophyte assemblages.

Results  Local environmental conditions, such as total phosphorus, alkalinity/conductivity and the presence of invasive species, as well as spatial gradients were key drivers of observed variation in macrophyte communities; e.g., for submerged macrophytes, a combination of local to moderate factors relating to water chemistry and broad‐scale gradients reflecting elevation and climate are important. Spatially structured environmental variables explained a large portion of observed variation.

Main conclusions  Our findings confirmed the need to manage local environmental pressures such as eutrophication, but suggested that the traditional catchment approach was insufficient. The spatial aggregation of environmental and connectivity factors indicated that a landscape scale approach should be used in lake management to augment the risk assessment to conservation species from the deterioration of suitable lake sites over broad biogeographic areas.
Field and action potential recordings in heart slices: correlation with established in vitro and in vivo models
Authors: Himmel Herbert M , Bussek Alexandra , Hoffmann Michael , Beckmann Rolf , Lohmann Horst , Schmidt Matthias , Wettwer Erich
Published: November 2011

BACKGROUND AND PURPOSE Action potential (AP) recordings in ex vivo heart preparations constitute an important component of the preclinical cardiac safety assessment according to the ICH S7B guideline. Most AP measurement models are sensitive, predictive and informative but suffer from a low throughput. Here, effects of selected anti‐arrhythmics (flecainide, quinidine, atenolol, sotalol, dofetilide, nifedipine, verapamil) on field/action potentials (FP/AP) of guinea pig and rabbit ventricular slices are presented and compared with data from established in vitro and in vivo models.

EXPERIMENTAL APPROACH Data from measurements of membrane currents (hERG, INa), AP/FP (guinea pig and rabbit ventricular slices), AP (rabbit Purkinje fibre), haemodynamic/ECG parameters (conscious, telemetered dog) were collected, compared and correlated to complementary published data (focused literature search).

KEY RESULTS The selected anti‐arrhythmics, flecainide, quinidine, atenolol, sotalol, dofetilide, nifedipine and verapamil, influenced the shape of AP/FP of guinea pig and rabbit ventricular slices in a manner similar to that observed for rabbit PF. The findings obtained from slice preparations are in line with measurements of membrane currents in vitro, papillary muscle AP in vitro and haemodynamic/ECG parameters from conscious dogs in vivo, and were also corroborated by published data.

CONCLUSION AND IMPLICATIONS FP and AP recordings from heart slices correlated well with established in vitro and in vivo models in terms of pharmacology and predictability. Heart slice preparations yield similar results as papillary muscle but offer enhanced throughput for mechanistic investigations and may substantially reduce the use of laboratory animals.
Maximizing tumour exposure to anti‐neuropilin‐1 antibody requires saturation of non‐tumour tissue antigenic sinks in mice
Authors: Bumbaca Daniela , Xiang Hong , Boswell C Andrew , Port Ruediger E , Stainton Shannon L , Mundo Eduardo E , Ulufatu Sheila , Bagri Anil , Theil Frank‐Peter , Fielder Paul J , Khawli Leslie A , Shen Ben‐Quan
Published: November 2011

BACKGROUND AND PURPOSE Neuropilin‐1 (NRP1) is a VEGF receptor that is widely expressed in normal tissues and is involved in tumour angiogenesis. MNRP1685A is a rodent and primate cross‐binding human monoclonal antibody against NRP1 that exhibits inhibition of tumour growth in NPR1‐expressing preclinical models. However, widespread NRP1 expression in normal tissues may affect MNRP1685A tumour uptake. The objective of this study was to assess MNRP1685A biodistribution in tumour‐bearing mice to understand the relationships between dose, non‐tumour tissue uptake and tumour uptake.

EXPERIMENTAL APPROACH Non‐tumour‐bearing mice were given unlabelled MNRP1685A at 10 mg·kg−1. Tumour‐bearing mice were given 111In‐labelled MNRP1685A along with increasing amounts of unlabelled antibody. Blood and tissues were collected from all animals to determine drug concentration (unlabelled) or radioactivity level (radiolabelled). Some animals were imaged using single photon emission computed tomography – X‐ray computed tomography.

KEY RESULTS MNRP1685A displayed faster serum clearance than pertuzumab, indicating that target binding affected MNRP1685A clearance. I.v. administration of 111In‐labelled MNRP1685A to tumour‐bearing mice yielded minimal radioactivity in the plasma and tumour, but high levels in the lungs and liver. Co‐administration of unlabelled MNRP1685A with the radiolabelled antibody was able to competitively block lungs and liver radioactivity uptake in a dose‐dependent manner while augmenting plasma and tumour radioactivity levels.

CONCLUSIONS AND IMPLICATIONS These results indicate that saturation of non‐tumour tissue uptake is required in order to achieve tumour uptake and acceptable exposure to antibody. Utilization of a rodent and primate cross‐binding antibody allows for translation of these results to clinical settings.