bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribological properties of alkyl and hydroxyl groups on the imidazolium tetrafluoroborate ionic liquids
Authors: Song Yanxin , Xia Yanqiu , Liu Haiyan , Jia Zhengfeng
Published: November 2012

We present an investigation of effect of alkyl chain length and hydroxyl group functionalisation on the tribological properties of imidazolium tetrafluoroborate ionic liquids. Four kinds of hydroxyl‐functionalised ionic liquids with the alkyl chain of C1–C10 were synthesised, and the relationships between their structure and physicochemical properties such as viscosity, thermal stability and corrosion, before and after incorporation of a hydroxyl group, were measured. In particular, the studies on their lubrication properties as ionic liquid (IL) lubricants for steel–steel contacts, including the friction coefficient, the wear volume and so on, were particularly emphasised. Moreover, an in‐depth exploration about the function mechanism and failure mode of the ILs during the friction process were studied using the scanning electron microscope and X‐ray photoelectron spectroscope technologies, and a proposed interaction model between ILs and steel substrate was presented. Copyright © 2012 John Wiley & Sons, Ltd.
Dynamics of the Foehn Mechanism in the McMurdo Dry Valleys of Antarctica from Polar WRF
Authors: Steinhoff Daniel F. , Bromwich David H. , Monaghan Andrew
Published: November 2012

Foehn events over the McMurdo Dry Valleys (MDVs), the largest ice‐free region of Antarctica, promote glacial melt that supports biological activity in the lakes, streams, rocks and soils. Although MDVs foehn events are known to depend upon the synoptic‐scale circulation, the physical processes responsible for foehn events are unknown. A polar‐optimized version of the Weather Research and Forecasting model (Polar WRF) is used for a case study of a representative summer foehn event from 29 December 2006 to 1 January 2007 in order to identify and explain the MDVs foehn mechanism. Pressure differences across an elevated mountain gap upstream of the MDVs provide forcing for southerly flow into the western, upvalley entrance of the MDVs. Complex terrain over the elevated gap and the MDVs leads to mountain wave effects such as leeside acceleration, hydraulic jumps, wave breaking and critical layers. These mountain wave effects depend on the ambient (geostrophic) wind direction. Pressure‐driven channelling then brings the warm, dry foehn air downvalley to eastern MDV sites. Brief easterly intrusions of maritime air into the eastern MDVs during foehn events previously have been attributed to either a sea‐breeze effect in summer or local cold‐pooling effects in winter. In this particular case, the easterly intrusions result from blocking effects of nearby Ross Island and the adjacent Antarctic coast. Temperature variability during the summer foehn event, which is important for meltwater production and biological activity when it exceeds 0°C, primarily depends on the source airmass rather than differences in foehn dynamics.
Mischaracterising density dependence biases estimated effects of coloured covariates on population dynamics
Authors: Lindén Andreas , Fowler Mike S. , Jonzén Niclas
Published: November 2012

Environmental effects on population growth are often quantified by coupling environmental covariates with population time series, using statistical models that make particular assumptions about the shape of density dependence. We hypothesized that faulty assumptions about the shape of density dependence can bias estimated effect sizes of temporally autocorrelated covariates. We investigated the presence of bias using Monte Carlo simulations based on three common per capita growth functions with distinct density dependent forms (θ‐Ricker, Ricker and Gompertz), autocorrelated (coloured) ‘known’ environmental covariates and uncorrelated (white) ‘unknown’ noise. Faulty assumptions about the shape of density dependence, combined with overcompensatory intrinsic population dynamics, can lead to strongly biased estimated effects of coloured covariates, associated with lower confidence interval coverage. Effects of negatively autocorrelated (blue) environmental covariates are overestimated, while those of positively autocorrelated (red) covariates can be underestimated, generally to a lesser extent. Prewhitening the focal environmental covariate effectively reduces the bias, at the expense of the estimate precision. Fitting models with flexible shapes of density dependence can also reduce bias, but increases model complexity and potentially introduces other problems of parameter identifiability. Model selection is a good option if an appropriate model is included in the set of candidate models. Under the specific and identifiable circumstances with high risk of bias, we recommend prewhitening or careful modelling of the shape of density dependence.
Improved growth media and culture techniques for genetic analysis and assessment of biomass utilization by Caldicellulosiruptor bescii
Authors: Farkas Joel , Chung Daehwan , Cha Minseok , Copeland Jennifer , Grayeski Philip , Westpheling Janet
Published: November 2012

Methods for efficient growth and manipulation of relatively uncharacterized bacteria facilitate their study and are essential for genetic manipulation. We report new growth media and culture techniques for Caldicellulosiruptor bescii, the most thermophilic cellulolytic bacterium known. A low osmolarity defined growth medium (LOD) was developed that avoids problems associated with precipitates that form in previously reported media allowing the monitoring of culture density by optical density at 680 nm (OD680) and more efficient DNA transformation by electroporation. This is a defined minimal medium and does not support growth when a carbon source is omitted, making it suitable for selection of nutritional markers as well as the study of biomass utilization by C. bescii. A low osmolarity complex growth medium (LOC) was developed that dramatically improves growth and culture viability during storage, making it a better medium for routine growth and passaging of C. bescii. Both media contain significantly lower solute concentration than previously published media, allowing for flexibility in developing more specialized media types while avoiding the issues of growth inhibition and cell lysis due to osmotic stress. Plating on LOD medium solidified by agar results in ~1,000-fold greater plating efficiency than previously reported and allows the isolation of discrete colonies. These new media represent a significant advance for both genetic manipulation and the study of biomass utilization in C. bescii, and may be applied broadly across the Caldicellulosiruptor genus.
Effect of superthermal electrons on dust-acoustic shock waves in coupled dusty plasmas
Authors: PAKZAD HAMID REZA , TRIBECHE MOULOUD
Published: November 2012

Nonlinear dust-acoustic (DA) shock waves in coupled dusty plasmas with negative dust grains and kappa-distributed electrons are discussed. Using a generalized hydrodynamic model, the dispersion relation and the Korteweg–de Vries-Burger (KdVB) equation for low-frequency DA modes in a strongly coupled dusty plasma are derived. The dependence of shock waves on various plasma parameters is then explored. A solitonic profile may be converted into a shock structure when correlation among dust particles becomes stronger. The amplitude as well as the steepness of shock waves increases with increasing the value of the spectral index k.
The Bohm-sheath criterion in plasmas containing electrons and multiply charged ions
Authors: KHORAMABADI MANSOUR , GHOMI HAMID , SHUKLA P. K.
Published: November 2012

Using the multi-fluid model of plasmas, we have analytically obtained a generalized Bohm criterion in the plasma, including hot electrons and multiply charged ions, and have numerically examined its validity. The new Bohm-sheath criterion shows that increasing the charge number of positive ions and decreasing the charge number of negative ions would increase the minimum ion speed that is required for the Bohm criterion to satisfy.
The Moghia Menace, or the Watch Over Watchmen In British India
Authors: PILIAVSKY ANASTASIA
Published: November 2012

This paper contributes to the history of ‘criminal tribes’, policing and governance in British India. It focuses on one colonial experiment—the policing of Moghias, declared by British authorities to be ‘robbers by hereditary profession’—which was the immediate precursor of the first Criminal Tribes Act of 1871, but which so far altogether has passed under historians’ radar. I argue that at stake in the Moghia operations, as in most other colonial ‘criminal tribe’ initiatives, was neither the control of crime (as colonial officials claimed) nor the management of India's itinerant groups (as most historians argue), but the uprooting of the indigenous policing system. British presence on the subcontinent was punctuated with periodic panics over ‘extraordinary crime’, through which colonial authorities advanced their policing practices and propagated their way of governance. The leading crusader against this ‘crisis’ was the Thuggee and Dacoity Department, which was as instrumental in the ‘discovery’ of the ‘Moghia menace’ and ‘criminal tribes’ in the late nineteenth century as in the earlier suppression of the ‘cult of Thuggee’. As a policing initiative, the Moghia campaign failed consistently for more than two decades. Its failures, however, reveal that behind the façade-anxieties over ‘criminal castes’ and ‘crises of crime’ stood attempts at a systemic change of indigenous governance. The diplomatic slippages of the campaign also expose the fact that the indigenous rule by patronage persisted—and that the consolidation of the colonial state was far from complete—well into the late nineteenth century.
Geographical distribution and epidemiological features of Old WorldLeishmania infantumandLeishmania donovanifoci, based on the isoenzyme analysis of 2277 strains
Authors: PRATLONG FRANCINE , LAMI PATRICK , RAVEL CHRISTOPHE , BALARD YVES , DEREURE JACQUES , SERRES GHISLAINE , BAIDOURI FOUAD EL , DEDET JEAN-PIERRE
Published: November 2012

A series of 2277Leishmaniastrains from Old World visceral leishmaniasis foci, isolated between 1973 and 2008, were studied by isoenzyme analysis. The strains were obtained from humans, domestic and wild carnivores, rodents and phlebotomine sandflies, and came from 36 countries. In all, 60 different zymodemes were identified and clustered by a phenetic analysis into 3 different groups corresponding to the typically visceralizing speciesL. donovani(20 zymodemes, 169 strains),L. archibaldi(3 zymodemes, 46 strains) andL. infantum(37 zymodemes, 2,062 strains). The taxonomic position of these isoenzymatic groups is discussed in view of contradictory results obtained from recent molecular studies.
Arthur H. Ballet, 1924–2012
Authors: Trussler Simon
Published: November 2012

Tribute to the long-serving Advisory Editor of New Theatre Quarterly, who died on 30 January 2012.
ON MOMENT CONDITIONS FOR QUASI-MAXIMUM LIKELIHOOD ESTIMATION OF MULTIVARIATE ARCH MODELS
Authors: Avarucci Marco , Beutner Eric , Zaffaroni Paolo
Published: November 2012

This paper questions whether it is possible to derive consistency and asymptotic normality of the Gaussian quasi-maximum likelihood estimator (QMLE) for possibly the simplest multivariate GARCH model, namely, the multivariate ARCH(1) model of the Baba, Engle, Kraft, and Kroner form, under weak moment conditions similar to the univariate case. In contrast to the univariate specification, we show that the expectation of the log-likelihood function is unbounded, away from the true parameter value, if (and only if) the observable has unbounded second moment. Despite this nonstandard feature, consistency of the Gaussian QMLE is still warranted. The same moment condition proves to be necessary and sufficient for the stationarity of the score when evaluated at the true parameter value. This explains why high moment conditions, typically bounded sixth moment and above, have been used hitherto in the literature to establish the asymptotic normality of the QMLE in the multivariate framework.
Optimal number of samples to test for institutional respiratory infection outbreaks in Ontario
Authors: PECI A. , MARCHAND-AUSTIN A. , WINTER A-J. , GUBBAY J. B.
Published: November 2012

The objective of this study was to determine the optimal number of respiratory samples per outbreak to be tested for institutional respiratory outbreaks in Ontario. We reviewed respiratory samples tested for respiratory viruses by multiplex PCR as part of outbreak investigations. We documented outbreaks that were positive for any respiratory viruses and for influenza alone. At least one virus was detected in 1454 (85·2%) outbreaks. The ability to detect influenza or any respiratory virus increased as the number of samples tested increased. When analysed by chronological order of when samples were received at the laboratory, percent positivity of outbreaks testing positive for any respiratory virus including influenza increased with the number of samples tested up to the ninth sample, with minimal benefit beyond the fourth sample tested. Testing up to four respiratory samples per outbreak was sufficient to detect viral organisms and resulted in significant savings for outbreak investigations.
Complex visual hallucinations in a Parkinson patient: don't blame James if it's Charles's fault
Authors: Segers Kurt
Published: November 2012

A patient with a history of Parkinson's disease and severe bilateral peripheral vision loss due to vitreous hemorrhages had complex visual hallucinations that persisted for three days and appeared every morning on awakening. The persistent nature of these hallucinations, the patient's preserved insight, and the presence of severe visual impairment was suggestive for Charles Bonnet syndrome rather than Parkinson-related hallucinations. A treatment with carbamazepine was started and proved to be successful. Physicians treating Parkinson patients should be familiar with Charles Bonnet syndrome and consider it as a potential alternative etiology for visual hallucinations, especially when the patient has severely impaired vision and when the hallucinations are sustained during wakefulness.
MODELLING THE INTRODUCTION OF WOLBACHIA INTO AEDES AEGYPTI MOSQUITOES TO REDUCE DENGUE TRANSMISSION
Authors: NDII MEKSIANIS Z. , HICKSON ROSLYN I. , MERCER GEOFFRY N.
Published: November 2012

Infecting Aedes aegypti mosquitoes with the bacteria Wolbachia has been proposed as an innovative new strategy to reduce the transmission of dengue fever. Field trials are currently being undertaken in Queensland, Australia. However, few mathematical models have been developed to consider the persistence of Wolbachia-infected mosquitoes in the wild. This paper develops a mathematical model to determine the persistence of Wolbachia-infected mosquitoes by considering the competition between Wolbachia-infected and non-Wolbachia mosquitoes. The model has four steady states that are biologically feasible: all mosquitoes dying out, only non-Wolbachia mosquitoes surviving, and two steady states where non-Wolbachia and Wolbachia-infected mosquitoes coexist. The stability of the steady states is determined with respect to the key parameters in the mosquito life cycle. A global sensitivity analysis of the model is also conducted. The results show that the persistence of Wolbachia-infected mosquitoes is dominated by the reproductive rate, death rate, maturation rate and maternal transmission. For the parameter values where Wolbachia persists, it dominates the population, and hence the introduction of Wolbachia has great potential to reduce dengue transmission.
FROM CAUSAL MODELS TO COUNTERFACTUAL STRUCTURES
Authors: HALPERN JOSEPH Y.
Published: November 2012

Galles & Pearl (l998) claimed that “for recursive models, the causal model framework does not add any restrictions to counterfactuals, beyond those imposed by Lewis’s [possible-worlds] framework.” This claim is examined carefully, with the goal of clarifying the exact relationship between causal models and Lewis’s framework. Recursive models are shown to correspond precisely to a subclass of (possible-world) counterfactual structures. On the other hand, a slight generalization of recursive models, models where all equations have unique solutions, is shown to be incomparable in expressive power to counterfactual structures, despite the fact that the Galles and Pearl arguments should apply to them as well. The problem with the Galles and Pearl argument is identified: an axiom that they viewed as irrelevant, because it involved disjunction (which was not in their language), is not irrelevant at all.
Very low latitude (L = 1.08) whistlers
Authors: Singh Rajesh , Cohen Morris B , Maurya Ajeet K. , Veenadhari B. , Kumar Sushil , Pant P. , Said Ryan K. , Inan Umran S.
Published: November 2012

For decades, whistlers observed on the ground at mid and high latitudes have been used for diagnostics of Earth's plasmasphere. Whistlers have also been observed at low latitudes however, the propagation characteristics of low latitude whistlers are poorly understood thus they have not been used effectively as a diagnostic for the low latitude ionosphere. One key limitation with past studies has been lack of knowledge of the whistler source lightning location. Here we present the first cases of low latitude ground whistlers most likely linked with their causative lightning discharges in the conjugate zone. The Global Lightning Dataset 360 (GLD360) detected lightning discharges were found to be located close to the conjugate location of the recording stations, providing direct evidence of inter‐hemispheric propagation at the low latitudes. A total of 864 whistlers were observed at Allahabad, India (Geomag. lat. 16.05°N; Geomag. long. 155.34°E; L = 1.08) during the night of 26 January 2011. Using GLD360 network data, we show the occurrence of thunderstorm activity between 200 and 450 km from the conjugate point of Allahabad. We also report the distribution of peak currents of whistler‐producing lightning, which demonstrate a cutoff at 30 kA.
Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves
Authors: Zhu Hui , Su Zhenpeng , Xiao Fuliang , Zheng Huinan , Shen Chao , Wang Yuming , Wang Shui
Published: November 2012

Electromagnetic ion cyclotron (EMIC) waves have long been suggested to account for the rapid decay of ring current, which is usually described by the quasi‐linear theory. We demonstrate that the interactions between ring current protons and typical EMIC waves can be highly nonlinear. A dimensionless parameterRis derived to identify the nonlinear interaction region, and a test‐particle simulation is performed to analyze the motions of typical (kinetic energyEk = 50 keV) ring current protons in detail. Nonlinear phase bunching occurs widely in the region R ∼<1, whereas nonlinear phase trapping is confined in the region R∼ 1. The former produces the non‐stochastic pitch angle decrease, probably increasing the overall loss rate predicted by the quasi‐linear theory. In contrast, the latter causes the significant pitch angle increase, probably reducing the overall loss rate estimated from the quasi‐linear theory. These two nonlinear mechanisms lead to complex advection and diffusion processes, and an advection‐diffusion modeling is required to more accurately simulate the ring current decay induced by EMIC waves.
Modeling insights into deuterium excess as an indicator of water vapor source conditions
Authors: Lewis Sophie C. , LeGrande Allegra N. , Kelley Maxwell , Schmidt Gavin A.
Published: November 2012

Deuterium excess (d) is interpreted in conventional paleoclimate reconstructions as a tracer of oceanic source region conditions, such as temperature, where precipitation originates. Previous studies have adopted coisotopic approaches (using both δ18O and d) to estimate past changes in both site and oceanic source temperatures for ice core sites using empirical relationships derived from conceptual distillation models, particularly Mixed Cloud Isotopic Models (MCIMs). However, the relationship between d and oceanic surface conditions remains unclear in past contexts. We investigate this climate‐isotope relationship for sites in Greenland and Antarctica using multiple simulations of the water isotope‐enabled Goddard Institute for Space Studies ModelE‐R general circulation model and apply a novel suite of model vapor source distribution (VSD) tracers to assess d as a proxy for source temperature variability under a range of climatic conditions. Simulated average source temperatures determined by the VSDs are compared to synthetic source temperature estimates calculated using MCIM equations linking d to source region conditions. We show that although deuterium excess is generally a faithful tracer of source temperatures as estimated by the MCIM approach, large discrepancies in the isotope‐climate relationship occur around Greenland during the Last Glacial Maximum simulation, when precipitation seasonality and moisture source regions were notably different from the present. This identified sensitivity in d as a source temperature proxy suggests that quantitative climate reconstructions from deuterium excess should be treated with caution for some sites when boundary conditions are significantly different from the present day. Also, the exclusion of the influence of humidity and other evaporative source changes in MCIM regressions may be a limitation of quantifying source temperature fluctuations from deuterium excess in some instances.
Mismatch Negativity Responses in Children With a Diagnosis of Childhood Apraxia of Speech (CAS)
Authors: Froud Karen , Khamis-Dakwar Reem
Published: November 2012

Purpose

To evaluate whether a hypothesis suggesting that apraxia of speech results from phonological overspecification could be relevant for childhood apraxia of speech (CAS).

Method

High-density EEG was recorded from 5 children with CAS and 5 matched controls, ages 5–8 years, with and without CAS, as they listened to randomized sequences of CV syllables in two oddball paradigms: phonemic (/ba/, /pa/) and allophonic (/pa/, /p
h
a/).

Results

In the phonemic contrast condition, mismatch negativity (MMN) responses to oddball sounds were observed for the typically developing (comparison) group but not the CAS group, although a component similar to an immature mismatch response was apparent. The allophonic contrast did not elicit MMN responses in the comparison group, but in the CAS group, an MMN-like response was observed.

Conclusion

The authors propose that these preliminary findings are consistent with a view of CAS as a disorder that not only affects motor planning but also has a phonological component.
Synthesized Speech Intelligibility and Early Preschool-Age Children: Comparing Accuracy for Single-Word Repetition With Repeated Exposure
Authors: Pinkoski-Ball Carrie L. , Reichle Joe , Munson Benjamin
Published: November 2012

Purpose

This investigation examined the effect of repeated exposure to novel and repeated spoken words in typical environments on the intelligibility of 2 synthesized voices and human recorded speech in preschools.

Method

Eighteen preschoolers listened to and repeated single words presented in human-recorded speech, DECtalk Paul, and AT&T Voice Michael during 5 experimental sessions. Stimuli consisted of repeated and novel words presented in each speech output condition during each session. Sessions took place in the presence of typically occurring noise in classroom or home settings.

Results

There was a significant main effect for voice as participants accurately identified significantly more words in the human-recorded speech and AT&T Voice than in the DECtalk speech output condition. When averaged across speech output conditions, children increased their accuracy as they participated in additional sessions. There was a statistically significant interaction between session and voice. DECtalk had a slightly larger effect of session than did AT&T Voice and human-recorded speech.
Impact of Typical Aging and Parkinson’s Disease on the Relationship Among Breath Pausing, Syntax, and Punctuation
Authors: Huber Jessica E. , Darling Meghan , Francis Elaine J. , Zhang Dabao
Published: November 2012

Purpose

The present study examines the impact of typical aging and Parkinson’s disease (PD) on the relationship among breath pausing, syntax, and punctuation.

Method

Thirty young adults, 25 typically aging older adults, and 15 individuals with PD participated. Fifteen participants were age- and sex-matched to the individuals with PD. Participants read a passage aloud 2 times. Utterance length, location of breath pauses relative to punctuation and syntax, and number of disfluencies and mazes were measured.

Results

Older adults produced shorter utterances, a smaller percentage of breaths at major boundaries, and a greater percentage of breaths at minor boundaries than did young adults, but there was no significant difference between older adults and individuals with PD on these measures. Individuals with PD took a greater percentage of breaths at locations unrelated to a syntactic boundary than did control participants. Individuals with PD produced more mazes than did control participants. Breaths were significantly correlated with punctuation for all groups.

Conclusions

Changes in breath-pausing patterns in older adults are likely due to changes in respiratory physiology. However, in individuals with PD, such changes appear to result from a combination of changes to respiratory physiology and cognition.
Evaluation of the effect of hysteretic flow and root system on shallow landslide
Authors: Ma Kuo-Chen , Lin Yong-Jun , Maa Shyh-Yuan , Tan Yih-Chi
Published: November 2012

This paper analyses the mechanics of slope stability with regard to the hysteretic flow of unsaturated soil and the root system of the covering vegetation. The hysteresis of the soil water retention curves and root strength are important factors in the evaluation of unsaturated shear strength. Engineers should consider how the transportation of the soil water content and the plant root strength influence evaluation of surficial slope stability analysis. The integrated slope stability analysis considering the hysteretic flow and root strength were calculated on variations of the safety factor (SF) and in accordance with different infiltration profiles and several species of vegetation. The results show that it is possible to predict shallow landslide on unsaturated slopes covered by different vegetation types. Tree planting, in combination with mechanical reinforcement, on the slope’s toe was found to improve stability, in addition to having economic benefits. This process allows for the selection and comparison of combinations and densities of vegetation types, in order to find the optimum location for increased SF. This will quickly improve shallow slope stability before it is destroyed. A better understanding of the process mechanics, as provided by the model, is critical for a reliable and appropriate design for slope stabilisation.
Suppression in retrieval practice, part-set cueing, and negative priming memory: The hydrogen model
Authors: Radvansky Gabriel A. , Tamplin Andrea K.
Published: November 2012

A number of phenomena in memory have been explained using appeals to active suppression processes, including retrieval practice, part-set cueing, and the negative priming that is observed with associative interference. However, more formal attempts to capture such processes have been absent. This paper outlines the hydrogen model of memory retrieval, which aims to be a simple model with the modest goal of trying to explore what influence suppression would have on memory retrieval. This model contains a single activation component and a single suppression component in which suppression comes into play only after retrieval interference has been detected. This model was created to explore the plausibility and viability of ideas about the operation of suppression during memory retrieval. For hydrogen, the degree of suppression recruited is proportional to the amount of interference experienced. Overall, the pattern of human data was captured by the suppression model.
Flaming to Reduce Inocula of the Boxwood Blight Pathogen, Cylindrocladium pseudonaviculatum, in Field Soil
Authors: Dart Norman L. , Arrington Sarah M. , Weeda Sarah M.
Published: November 2012

Infested plant tissue can play a significant role in the epidemiology of boxwood blight in ornamental nursery systems. In an effort to reduce inoculum levels in an infested field in Carroll Co., Virginia, symptomatic plants were removed, collected into a pile, and destroyed by burning using a propane push flamer. The authors investigated whether soil flaming would be effective to reduce viable inocula of C. pseudonaviculatum in the upper layer of soil.

Accepted for publication 4 October 2012. Published 26 October 2012.
Modulation of the light-harvesting chlorophyll antenna size in
Chlamydomonas reinhardtii
by
TLA1
gene over-expression and RNA interference
Authors: Mitra Mautusi , Kirst Henning , Dewez David , Melis Anastasios
Published: November 2012

Truncated light-harvesting antenna 1
(
TLA1
) is a nuclear gene proposed to regulate the chlorophyll (Chl) antenna size in
Chlamydomonas reinhardtii
. The Chl antenna size of the photosystems and the chloroplast ultrastructure were manipulated upon
TLA1
gene over-expression and RNAi downregulation. The
TLA1
over-expressing lines possessed a larger chlorophyll antenna size for both photosystems and contained greater levels of Chl
b
per cell relative to the wild type. Conversely,
TLA1
RNAi transformants had a smaller Chl antenna size for both photosystems and lower levels of Chl
b
per cell. Western blot analyses of the
TLA1
over-expressing and RNAi transformants showed that modulation of
TLA1
gene expression was paralleled by modulation in the expression of light-harvesting protein, reaction centre D1 and D2, and VIPP1 genes. Transmission electron microscopy showed that modulation of
TLA1
gene expression impacts the organization of thylakoid membranes in the chloroplast. Over-expressing lines showed well-defined grana, whereas RNAi transformants possessed loosely held together and more stroma-exposed thylakoids. Cell fractionation suggested localization of the TLA1 protein in the inner chloroplast envelope and potentially in association with nascent thylakoid membranes, indicating a role in Chl antenna assembly and thylakoid membrane biogenesis. The results provide a mechanistic understanding of the Chl antenna size regulation by the
TLA1
gene.
The outcome of pregnancies in women with cystic fibrosis—single centre experience 1998–2011
Authors: Thorpe‐Beeston JG , Madge S , Gyi K , Hodson M , Bilton D
Published: November 2012

Objective

To describe the maternal and fetal outcomes of pregnancies in women with cystic fibrosis.

Design

Retrospective study.

Setting

Single obstetric hospital and adult cystic fibrosis centre.

Methods

Retrospective case‐note review of pregnant women with cystic fibrosis referred for antenatal care and delivery.

Main outcome measures

Maternal and fetal outcomes, mode of delivery, lung function and pregnancy complications.

Results

Forty‐eight pregnancies were studied in 41 women. There were two miscarriages, 44 singleton pregnancies and two sets of twins. All babies were liveborn and survived. The mean gestational age at delivery was 35.9 ± 3.3 weeks. There were no fetal abnormalities or terminations of pregnancy. The median birthweight centile was 31.9 (interquartile range 14.9–55.6). Twenty‐five (52.1%) of the women had pancreatic insufficiency and 17 (35.4%) required insulin. There was a positive correlation between booking predicted forced expiratory volume in 1 second (FEV1) and gestational age at delivery (P < 0.01). Women with FEV1 ≤60% were more likely to deliver earlier and by caesarean section compared with women with FEV1 >60% (35.0 ± 3.2 weeks versus 37.1 ± 3.0 weeks; P = 0.02 and 75.0% versus 25.0%; P = 0.01). Three of the seven women with an FEV1 <40% died within 18 months of delivery. Four of the eight women with FEV1 40–50% died between 2 and 8 years after delivery.

Conclusion

Pregnancy for women with cystic fibrosis is possible and results in favourable maternal and fetal outcomes, but the incidence of preterm delivery and caesarean section is increased. Women with pre‐existing poor lung function should be counselled antenatally to ensure that they understand the implications of their shortened life‐expectancy and parenthood.
Comparison between MICRO–CARD–FISH and 16S rRNA gene clone libraries to assess the active versus total bacterial community in the coastal Arctic
Authors: De Corte Daniele , Sintes Eva , Yokokawa Taichi , Herndl Gerhard J.
Published: November 2012

We collected surface‐ and deep‐water samples (maximum depth 300 m) during the spring–summer transition in the coastal Arctic along a transect in the Kongsfjorden (Ny‐Ålesund, Spitsbergen, Norway) to determine the structure of the active versus total marine bacterioplankton community using different approaches. Catalysed reporter deposition–fluorescence in situ hybridization combined with microautoradiography (MICRO–CARD–FISH) was used to determine the abundance and activity of different bacterial groups. The bacterial communities were dominated by members of Alphaproteobacteria followed by Bacteroidetes, whereas Gammaproteobacteria were present at low abundance but exhibited a high percentage of active cells taking up leucine. The clone libraries of 16S rRNA genes (16S rDNA) and 16S rRNA from two different depths were used to decipher the bacterial community structure. Independently of the type of clone libraries analysed (16S rDNA‐ or 16S rRNA‐based), four major and four minor taxonomic groups were detected. The bacterioplankton community was mainly dominated at both the DNA and the RNA levels by Alphaproteobacteria followed by Gammaproteobacteria. The Rhodobacteriaceae were the most abundant members of the Alphaproteobacteria in both DNA and RNA clone libraries, followed by the SAR11 clade, which was only detectable at the 16S rDNA level. Moreover, there was a general agreement between the results obtained with both techniques, although some specific phylogenetic groups, such as SAR11 and Roseobacter, deviated substantially from this relation. These discrepancies are most likely linked to different physiological states among members of the bacterioplankton community. Combined, MICRO–CARD–FISH and DNA and RNA clone libraries, however, allowed for accurately quantifying different bacterial groups and their activity as well as a detailed phylogenetic insight into the fractions of present versus metabolically active bacterial groups.
Chronic ketamine exposure induces permanent impairment of brain functions in adolescent cynomolgus monkeys
Authors: Sun Lin , Li Qi , Li Qing , Zhang Yuzhe , Liu Dexiang , Jiang Hong , Pan Fang , Yew David T.
Published: November 2012

Ketamine, a non‐competitive N‐methyl‐D‐aspartic acid receptor antagonist, has emerged as an increasingly popular drug among young drug abusers worldwide. Available evidence suggests that ketamine produces acute impairments of working, episodic and semantic memory along with psychotogenic and dissociative effects when a single dose is given to healthy volunteers. However, understanding of the possible chronic effects of ketamine on behavior, cognitive anomalies and neurochemical homeostasis is still incomplete. Although previous human studies demonstrate that ketamine could impair a range of cognitive skills, investigation using non‐human models would permit more precise exploration of the neurochemical mechanisms which may underlie the detrimental effects. The current study examined the abnormalities in behavior (move, walk, jump and climb) and apoptosis of the prefrontal cortex using terminal deoxynucleotidyl transferase‐mediated biotinylated dUTP nick end labeling (TUNEL) and apoptotic markers, including Bax, Bcl‐2 and caspase‐3 in adolescent male cynomolgus monkeys (Macaca fascicularis) after 1 or 6 months of sub‐anesthetic ketamine administration (1 mg/kg, i.v.). Results showed that ketamine decreased locomotor activity and increased cell death in the prefrontal cortex of monkeys with 6 months of ketamine treatment when compared with the control monkeys. Such decreases were not found in the 1‐month ketamine‐treated group. Our study suggested that ketamine administration of recreational dose in monkeys might produce permanent and irreversible deficits in brain functions due to neurotoxic effects, involving the activation of apoptotic pathways in the prefrontal cortex.
The Important but Underappreciated Transgastric Right Ventricular Inflow View for Transesophageal Echocardiographic Evaluation of Cardiac Implantable Device Infections
Authors: Allred Clint , Crandall Mark , Auseon Alex
Published: November 2012

Device infection is a potential complication of cardiovascular implantable electronic devices. We report a case of a 40‐year‐old man with nonischemic cardiomyopathy, status post biventricular implantable cardiac defilbrillator placement on continuous home dobutamine, who presented with methicillin‐resistant Staphylococcus aureus bacteremia. Transesophageal echocardiography showed a 2.4 cm vegetation near the right ventricular (RV) apex that was only seen in the transgastric RV inflow view. This case demonstrates an atypical distal location for a vegetation and illustrates the importance of obtaining multiple views, including the transgastric RV inflow view, when evaluating for device wire vegetations.
Nocebo as a potential confounding factor in clinical trials for Parkinson's disease treatment: a meta‐analysis
Authors: Stathis P. , Smpiliris M. , Konitsiotis S. , Mitsikostas D. D.
Published: November 2012

Background and purpose

Nocebo refers to adverse events (AEs) generated by patient's negative expectations that medical treatment will likely harm instead of heal and can be assessed in placebo‐controlled randomized controlled trials (RCTs). We examined AEs following placebo administration in RCTs for Parkinson's disease (PD).

Methods

After a systematic Medline search for RCTs for PD pharmacologic treatments published between 2000 and 2010, we assessed percentages of placebo‐treated patients reporting at least one AE or discontinuing due to placebo intolerance and searched for factors influencing nocebo's extent.

Results

Data were extracted from 41 RCTs fulfilling search criteria. Of 3544 placebo‐treated patients, 64.7% (95% CI: 53.6–74.4) reported at least one AE and 8.8% (95% CI: 6.8–11.5) discontinued placebo treatment due to intolerance. The number of AEs per 100 person‐months was 25.9 (95% CI: 16.8–39.8). Nocebo dropout rate was positively related to study population size and year of publication. Increased number of AEs per 100 person‐months was negatively correlated with the duration of treatment. AE rates, dropout rates, and AEs per 100 person‐months in placebo‐ and active drug‐treated patients were strongly correlated (r = 0.941, 0.695, and 0.824, respectively).

Conclusions

Our analysis indicates a significant dropout rate related to nocebo in trials for PD treatment. Adherence and efficacy may be adversely affected with additional implications for clinical practice.
Do increased summer precipitation and N deposition alter fine root dynamics in a Mojave Desert ecosystem?
Authors: Verburg Paul S. J. , Young Andrew C. , Stevenson Bryan A. , Glanzmann Isabelle , Arnone John A. , Marion Giles M. , Holmes Christopher , Nowak Robert S.
Published: November 2012

Climate change is expected to impact the amount and distribution of precipitation in the arid southwestern United States. In addition, nitrogen (N) deposition is increasing in these regions due to increased urbanization. Responses of belowground plant activity to increases in soil water content and N have shown inconsistent patterns between biomes. In arid lands, plant productivity is limited by water and N availability so it is expected that changes in these factors will affect fine root dynamics. The objectives of this study were to quantify the effects of increased summer precipitation and N deposition on fine root dynamics in a Mojave Desert ecosystem during a 2‐year field experiment using minirhizotron measurements. Root length density, production, and mortality were measured in field plots in the Mojave Desert receiving three 25 mm summer rain events and/or 40 kg N ha−1 yr−1. Increased summer precipitation and N additions did not have an overall significant effect on any of the measured root parameters. However, differences in winter precipitation resulting from interannual variability in rainfall appeared to affect root parameters with root production and turnover increasing following a wet winter most likely due to stimulation of annual grasses. In addition, roots were distributed more deeply in the soil following the wet winter. Root length density was initially higher under canopies compared to canopy interspaces, but converged toward the end of the study. In addition, roots tended to be distributed more deeply into the soil in canopy interspace areas. Results from this study indicated that increased summer precipitation and N deposition in response to climate change and urbanization are not likely to affect fine root dynamics in these Mojave Desert ecosystems, despite studies showing aboveground plant physiological responses to these environmental perturbations. However, changes in the amount and possibly distribution of winter precipitation may affect fine root dynamics.
Evasion of CO2 from streams – The dominant component of the carbon export through the aquatic conduit in a boreal landscape
Authors: Wallin Marcus B. , Grabs Thomas , Buffam Ishi , Laudon Hjalmar , Ågren Anneli , Öquist Mats G. , Bishop Kevin
Published: November 2012

Evasion of gaseous carbon (C) from streams is often poorly quantified in landscape C budgets. Even though the potential importance of the capillary network of streams as C conduits across the land–water–atmosphere interfaces is sometimes mentioned, low‐order streams are often left out of budget estimates due to being poorly characterized in terms of gas exchange and even areal surface coverage. We show that evasion of C is greater than all the total dissolved C (both organic and inorganic) exported downstream in the waters of a boreal landscape. In this study evasion of carbon dioxide (CO2) from running waters within a 67 km2 boreal catchment was studied. During a 4 year period (2006–2009) 13 streams were sampled on 104 different occasions for dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). From a locally determined model of gas exchange properties, we estimated the daily CO2 evasion with a high‐resolution (5 × 5 m) grid‐based stream evasion model comprising the entire ~100 km stream network. Despite the low areal coverage of stream surface, the evasion of CO2 from the stream network constituted 53% (5.0 (±1.8) g C m−2 yr−1) of the entire stream C flux (9.6 (±2.4) g C m−2 yr−1) (lateral as DIC, DOC, and vertical as CO2). In addition, 72% of the total CO2 loss took place already in the first‐ and second‐order streams. This study demonstrates the importance of including CO2 evasion from low‐order boreal streams into landscape C budgets as it more than doubled the magnitude of the aquatic conduit for C from this landscape. Neglecting this term will consequently result in an overestimation of the terrestrial C sink strength in the boreal landscape.
Contrasting effects of climate change in continental vs. oceanic environments on population persistence and microevolution of Atlantic salmon
Authors: Piou Cyril , Prévost Etienne
Published: November 2012

Facing climate change (CC), species are prone to multiple modifications in their environment that can lead to extinction, migration or adaptation. Identifying the role and interplay of different potential stressors becomes a key question. Anadromous fishes will be exposed to both river and oceanic habitat changes. For Atlantic salmon, the river water temperature, river flow and oceanic growth conditions appear as three main stressing factors. They could act on population dynamics or as selective forces on life‐history pathways. Using an individual‐based demo‐genetic model, we assessed the effects of these factors (1) to compare risks of extinction resulting from CC in river and ocean, and (2) to assess CC effects on life‐history pathways including the evolution of underlying genetic control of phenotypic plasticity. We focused on Atlantic salmon populations from Southern Europe for a time horizon of three decades. We showed that CC in river alone should not lead to extinction of Southern European salmon populations. In contrast, the reduced oceanic growth appeared as a significant threat for population persistence. An increase in river flow amplitude increased the risk of local extinction in synergy with the oceanic effects, but river temperature rise reduced this risk. In terms of life‐history modifications, the reduced oceanic growth increased the age of return of individuals through plastic and genetic responses. The river temperature rise increased the proportion of sexually mature parr, but the genetic evolution of the maturation threshold lowered the maturation rate of male parr. This was identified as a case of environmentally driven plastic response that masked an underlying evolutionary response of plasticity going in the opposite direction. We concluded that to counteract oceanic effects, river flow management represented the sole potential force to reduce the extinction probability of Atlantic salmon populations in Southern Europe, although this might not impede changes in migration life history.
Self‐transcendence and nurse–patient interaction in cognitively intact nursing home patients
Authors: Haugan Gørill , Rannestad Toril , Hanssen Brith , Espnes Geir A
Published: November 2012

Aims and objectives.  The aim of this study was to test whether nurse–patient interaction affects cognitively intact nursing home patients’ interpersonal and intrapersonal self‐transcendence, as well as testing the psychometric properties of the Nurse–Patient Interaction Scale (NPIS).

Background.  Self‐transcendence is considered a spiritual developmental process of maturity in adulthood, and a vital resource of well‐being at the end of life. The concept of self‐transcendence has previously been explored in various populations, yet the nurse–patient interactions’ potential influence on self‐transcendence in nursing home patients has not been published previously.

Design and methods.  A cross‐sectional design employing the Self‐Transcendence Scale and the NPIS was adopted. A sample of 202 cognitively well‐functioning nursing home patients in Norway was selected. The statistical analyses were carried out using lisrel 8.8 and structural equation modelling.

Results.  Structural equation modelling‐analysis indicates statistical significant effect of nurse–patient interaction on the patients’ self‐transcendence. Direct influence on the intrapersonal and indirect influence on the interpersonal self‐transcendence aspects was disclosed.

Conclusion.  Nurse–patient interaction significantly affected both interpersonal and intrapersonal self‐transcendence among cognitively intact nursing home patients. Hence, facilitating caring interventions can be significantly beneficial to older patients’ self‐transcendence and thereby well‐being, both emotional and physical.

Relevance to clinical practice.  Caring behaviour signifies the vital and ultimate qualitative nursing behaviour, which promotes self‐transcendence and thereby well‐being. These findings are important for clinical nursing that intends to increase patients’ well‐being.