bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracellular loop C of NPC1L1 is important for binding to ezetimibe
Authors: Weinglass Adam B. , Kohler Martin , Schulte Uwe , Liu Jessica , Nketiah Emmanuel O. , Thomas Anu , Schmalhofer William , Williams Brande , Bildl Wolfgang , McMasters Daniel R. , Dai Kevin , Beers Lindsey , McCann Margaret E. , Kaczorowski Gregory J. , Garcia Maria L.
Published: August 2008

Niemann–Pick C1-like protein (NPC1L1) mediates the absorption of dietary cholesterol in the proximal region of the intestine, a process that is blocked by cholesterol absorption inhibitors (CAIs), including ezetimibe (EZE). Using a proteomic approach, we demonstrate that NPC1L1 is the protein to which EZE and its analogs bind. Next, we determined the site of interaction of EZE analogs with NPC1L1 by exploiting the different binding affinities of mouse and dog NPC1L1 for the radioligand analog of EZE, [
3
H]AS. Chimeric and mutational studies indicate that high-affinity binding of [
3
H]AS to dog NPC1L1 depends on molecular determinants present in a 61-aa region of a large extracellular domain (loop C), where Phe-532 and Met-543 appear to be key contributors. These data suggest that the [
3
H]AS-binding site resides in the intestinal lumen and are consistent with preclinical data demonstrating
in vivo
efficacy of a minimally bioavailable CAI. Furthermore, these determinants of [
3
H]AS binding lie immediately adjacent to a hotspot of human NPC1L1 polymorphisms correlated with hypoabsorption of cholesterol. These observations, taken together with the recently described binding of cholesterol to the N terminus (loop A) of the close NPC1L1 homologue, NPC1, may provide a molecular basis for understanding EZE inhibition of NPC1L1-mediated cholesterol absorption. Specifically, EZE binding to an extracellular site distinct from where cholesterol binds prevents conformational changes in NPC1L1 that are necessary for the translocation of cholesterol across the membrane.
Herpesvirus tegument protein activates NF-κB signaling through the TRAF6 adaptor protein
Authors: Liu XueQiao , Fitzgerald Katherine , Kurt-Jones Evelyn , Finberg Robert , Knipe David M.
Published: August 2008

Viruses remodel the host cell to optimize their replication both by delivery of virion proteins into the cell and by
de novo
expression of viral proteins. The HSV particle contains several proteins that function to prepare the host cell for viral replication, including the VP16 transcriptional activator protein and virion host shutoff protein. HSV infection activates NF-κB pathways through Toll-like receptor (TLR) 2 and non-TLR pathways, and NF-κB activity is required for efficient viral replication. In a screen of the HSV proteome, we observed that the HSV U
L
37 tegument protein activates NF-κB signaling in a TLR2-independent manner. Expression of U
L
37 in transfected cells leads to IκB degradation and activation of both reporter genes and the endogenous IL-8 gene. This activation requires TNF receptor–associated factor 6 (TRAF6), and U
L
37 contains a TRAF6-binding domain that is required for interaction with TRAF6 and activation of NF-κB. A mutant virus encoding U
L
37 with an altered TRAF6-binding site shows reduced NF-κB activation in the early phase of infection. Therefore, the HSV U
L
37 virion structural protein can activate NF-κB through TRAF6. Activation of NF-κB by a virion tegument protein that is delivered into the host cell cytoplasm during viral entry represents a mechanism for activation of this pathway by a virus.
Effects of colonization, luminescence, and autoinducer on host transcription during development of the squid-vibrio association
Authors: Chun Carlene K. , Troll Joshua V. , Koroleva Irina , Brown Bartley , Manzella Liliana , Snir Einat , Almabrazi Hakeem , Scheetz Todd E. , de Fatima Bonaldo Maria , Casavant Thomas L. , Soares M. Bento , Ruby Edward G. , McFall-Ngai Margaret J.
Published: August 2008

The light–organ symbiosis between the squidEuprymna scolopesand the luminous bacteriumVibrio fischerioffers the opportunity to decipher the hour-by-hour events that occur during the natural colonization of an animal's epithelial surface by its microbial partners. To determine the genetic basis of these events, a glass-slide microarray was used to characterize the light-organ transcriptome of juvenile squid in response to the initiation of symbiosis. Patterns of gene expression were compared between animals not exposed to the symbiont, exposed to the wild-type symbiont, or exposed to a mutant symbiont defective in either of two key characters of this association: bacterial luminescence or autoinducer (AI) production. Hundreds of genes were differentially regulated as a result of symbiosis initiation, and a hierarchy existed in the magnitude of the host's response to three symbiont features: bacterial presence > luminescence > AI production. Putative host receptors for bacterial surface molecules known to induce squid development are up-regulated by symbiont light production, suggesting that bioluminescence plays a key role in preparing the host for bacteria-induced development. Further, because the transcriptional response of tissues exposed to AI in the natural context (i.e., with the symbionts) differed from that to AI alone, the presence of the bacteria potentiates the role of quorum signals in symbiosis. Comparison of these microarray data with those from other symbioses, such as germ-free/conventionalized mice and zebrafish, revealed a set of shared genes that may represent a core set of ancient host responses conserved throughout animal evolution.
Electrophysiological evidence of illusory audiovisual speech percept in human infants
Authors: Kushnerenko Elena , Teinonen Tuomas , Volein Agnes , Csibra Gergely
Published: August 2008

How effortlessly and quickly infants acquire their native language remains one of the most intriguing questions of human development. Our study extends this question into the audiovisual domain, taking into consideration visual speech cues, which were recently shown to have more importance for young infants than previously anticipated [Weikum WM, Vouloumanos A, Navarra J, Soto-Faraco S, Sebastián-Gallés N, Werker JF (2007)
Science
316:1159]. A particularly interesting phenomenon of audiovisual speech perception is the McGurk effect [McGurk H, MacDonald J (1976)
Nature
264:746–748], an illusory speech percept resulting from integration of incongruent auditory and visual speech cues. For some phonemes, the human brain does not detect the mismatch between conflicting auditory and visual cues but automatically assimilates them into the closest legal phoneme, sometimes different from both auditory and visual ones. Measuring event-related brain potentials in 5-month-old infants, we demonstrate differential brain responses when conflicting auditory and visual speech cues can be integrated and when they cannot be fused into a single percept. This finding reveals a surprisingly early ability to perceive speech cross-modally and highlights the role of visual speech experience during early postnatal development in learning of the phonemes and phonotactics of the native language.
Alliances, Institutional Design, and the Determinants of Military Strategy
Authors: Wallace Geoffrey P.R.
Published: August 2008

This paper argues that the institutional design of alliances is a crucial but often neglected factor in the study of military strategy. Highly institutionalized alliances are found to be a strong determinant of a state's choice of strategy, while other forms of alliances turn out to have little impact. I posit that the level of institutionalization exhibits this effect because of the greater number of channels through which leading states can influence the strategies of their smaller allies and coordinate overall alliance strategy. By incorporating this externally driven process, the results also begin to call into question several previously cited factors affecting the choice of military strategy.
Bringing Cooperation Back In: A Dynamic Model of Interstate Interaction
Authors: Crescenzi Mark J.C. , Enterline Andrew J. , Long Stephen B.
Published: August 2008

In an earlier article (Crescenzi & Enterline, 2001), we developed a formal, dynamic model of the cooperative and conflictual dimensions central to interstate relationships. However, the empirical data employed as inputs into the original model informed only the model's conflictual dimension. Here, we operationalize the conflictual and cooperative dimensions of the model, with the latter derived by inputting information on joint participation in intergovernmental organizations (IGOs) for the period 1965—2000. Doing so enables us to trace the joint cooperative—conflictual temporal trajectories of interstate dyads, in addition to capturing the degree and dynamism of these relationships. We demonstrate the flexibility and practicality of the model-derived empirical indicators of interstate interaction with an analysis of dyadic interstate conflict. Our dynamic approach to studying interstate relationships promises to facilitate fruitful contributions to several research agendas in comparative politics and international relations.
Corrections to a sequence of papers in Nuclear Fusion
Authors: Otto Kardaun  , Knud Thomsen  , Alexander Chudnovskiy
Published: August 2008

Please see PDF file for details.
Comment on ‘network-constrained regularization and variable selection for analysis of genomic data’
Authors: Binder Harald , Schumacher Martin
Published: August 2008

Contact:  binderh@fdm.uni-freiburg.de

Supplementary information: Supplementary data are available at Bioinformatics online.
Crammer's Corner
Authors: Riley Ben
Published: August 2008

Each month, Crammer's Corner features information and practical advice to help you learn the core knowledge and skills described in the RCGP curriculum and prepare for the new MRCGP assessments.
Low Back Pain
Authors: Davies Richard
Published: August 2008

Acute lower back pain is defined as back pain between the costal margins and the inferior gluteal folds. It is a common and important problem in primary care. The lifetime prevalence for acute low back pain lasting less than 6 weeks is 58% and, in a survey in 1998, 40% of adults said that they had experienced an episode of back pain lasting longer than 24 hours last year. At 6 weeks, 90% of patients are symptom free Department for Work and Pensions. Chronic low back pain lasts over 3 months; if it persists over 12 months, the prognosis worsens significantly. With each new presentation, it is important to assess how the patient has been affected so far by the pain, work together to speed recovery, keep alert to possible serious or sinister causes of back pain, pick up those patients with nerve root pain and identify which patients would benefit from referral onto secondary care.
Osteoarthritis
Authors: Everitt Hazel
Published: August 2008

Osteoarthritis (OA) is the most common type of arthritis and a leading cause of locomotor disability. Over 4.4 million people in the United Kingdom have moderate to severe OA. It is a chronic disease that causes a significant burden to society and healthcare resources and its impact is likely to increase with an ageing population and rising levels of obesity.
A comparative analysis of two conserved motifs in bacterial poly(A) polymerase and CCA-adding enzyme
Authors: Just Andrea , Butter Falk , Trenkmann Michelle , Heitkam Tony , Mörl Mario , Betat Heike
Published: August 2008

Showing a high sequence similarity, the evolutionary closely related bacterial poly(A) polymerases (PAP) and CCA-adding enzymes catalyze quite different reactions—PAP adds poly(A) tails to RNA 3′-ends, while CCA-adding enzymes synthesize the sequence CCA at the 3′-terminus of tRNAs. Here, two highly conserved structural elements of the corresponding Escherichia coli enzymes were characterized. The first element is a set of amino acids that was identified in CCA-adding enzymes as a template region determining the enzymes’ specificity for CTP and ATP. The same element is also present in PAP, where it confers ATP specificity. The second investigated region corresponds to a flexible loop in CCA-adding enzymes and is involved in the incorporation of the terminal A-residue. Although, PAP seems to carry a similar flexible region, the functional relevance of this element in PAP is not known. The presented results show that the template region has an essential function in both enzymes, while the second element is surprisingly dispensable in PAP. The data support the idea that the bacterial PAP descends from CCA-adding enzymes and still carries some of the structural elements required for CCA-addition as an evolutionary relic and is now fixed in a conformation specific for A-addition.
The Bloom's syndrome helicase (BLM) interacts physically and functionally with p12, the smallest subunit of human DNA polymerase δ
Authors: Selak Nives , Bachrati Csanád Z. , Shevelev Igor , Dietschy Tobias , Loon Barbara van , Jacob Anette , Hübscher Ulrich , Hoheisel Joerg D. , Hickson Ian D. , Stagljar Igor
Published: August 2008

Bloom's syndrome (BS) is a cancer predisposition disorder caused by mutation of the BLM gene, encoding a member of the RecQ helicase family. Although the phenotype of BS cells is suggestive of a role for BLM in repair of stalled or damaged replication forks, thus far there has been no direct evidence that BLM associates with any of the three human replicative DNA polymerases. Here, we show that BLM interacts specifically in vitro and in vivo with p12, the smallest subunit of human POL δ (hPOL δ). The hPOL δ enzyme, as well as the isolated p12 subunit, stimulates the DNA helicase activity of BLM. Conversely, BLM stimulates hPOL δ strand displacement activity. Our results provide the first functional link between BLM and the replicative machinery in human cells, and suggest that BLM might be recruited to sites of disrupted replication through an interaction with hPOL δ. Finally, our data also define a novel role for the poorly characterized p12 subunit of hPOL δ.
Performance of climate envelope models in retrodicting recent changes in bird population size from observed climatic change
Authors: Green Rhys E , Collingham Yvonne C , Willis Stephen G , Gregory Richard D , Smith Ken W , Huntley Brian
Published: August 2008

Twenty-five-year population trends of 42 bird species rare as breeders in the UK were examined in relation to changes in climatic suitability simulated using climatic envelope models. The effects of a series of potential ‘nuisance’ variables were also assessed. A statistically significant positive correlation was found across species between population trend and climate suitability trend. The demonstration that climate envelope models are able to retrodict species' population trends provides a valuable validation of their use in studies of the potential impacts of future climatic changes.
The coincidence of climatic and species rarity: high risk to small-range species from climate change
Authors: Ohlemüller Ralf , Anderson Barbara J , Araújo Miguel B , Butchart Stuart H.M , Kudrna Otakar , Ridgely Robert S , Thomas Chris D
Published: August 2008

Why do areas with high numbers of small-range species occur where they do? We found that, for butterfly and plant species in Europe, and for bird species in the Western Hemisphere, such areas coincide with regions that have rare climates, and are higher and colder areas than surrounding regions. Species with small range sizes also tend to occur in climatically diverse regions, where species are likely to have been buffered from extinction in the past. We suggest that the centres of high small-range species richness we examined predominantly represent interglacial relict areas where cold-adapted species have been able to survive unusually warm periods in the last
ca
10 000 years. We show that the rare climates that occur in current centres of species rarity will shrink disproportionately under future climate change, potentially leading to high vulnerability for many of the species they contain.
Spatial analysis improves species distribution modelling during range expansion
Authors: De Marco Paulo , Diniz-Filho José Alexandre Felizola , Bini Luis Mauricio
Published: August 2008

Species distribution models (SDMs) assume equilibrium between species' distribution and the environment. However, this assumption can be violated under restricted dispersal and spatially autocorrelated environmental conditions. Here we used a model to simulate species' ranges expansion under two non-equilibrium scenarios, evaluating the performance of SDM coupled with spatial eigenvector mapping. The highest fit is for the models that include space, although the relative importance of spatial variables during the range expansion differs in the two scenarios. Incorporating space to the models was important only under colonization-lag non-equilibrium, under the expected scenario. Thus, mechanisms that generate range cohesion and determine species' distribution under climate changes can be captured by spatial modelling, with advantages compared with other techniques and in line with recent claims that SDMs have to account for more complex dynamic scenarios.
Climate and land use change impacts on plant distributions in Germany
Authors: Pompe Sven , Hanspach Jan , Badeck Franz , Klotz Stefan , Thuiller Wilfried , Kühn Ingolf
Published: August 2008

We present niche-based modelling to project the distribution of 845 European plant species for Germany using three different models and three scenarios of climate and land use changes up to 2080. Projected changes suggested large effects over the coming decades, with consequences for the German flora. Even under a moderate scenario (approx. +2.2°C), 15–19% (across models) of the species we studied could be lost locally—averaged from 2995 grid cells in Germany. Models projected strong spatially varying impacts on the species composition. In particular, the eastern and southwestern parts of Germany were affected by species loss. Scenarios were characterized by an increased number of species occupying small ranges, as evidenced by changes in range-size rarity scores. It is anticipated that species with small ranges will be especially vulnerable to future climate change and other ecological stresses.
Digit length may reveal unusual breeding behaviour in a seabird
Authors: Genovart Meritxell , Louzao Maite , Igual José M , Oro Daniel
Published: August 2008

The hormonal environment experienced during prenatal development may affect adult phenotype and behaviour. Digit lengths may provide an estimate of steroid levels encountered during embryonic development in humans and other vertebrates. Finger patterns in humans have been shown to reveal sexual orientation or cooperative behaviour. We explored individual breeding behaviour in a monogamous seabird, the Balearic shearwater
Puffinus mauretanicus
and unexpectedly detected some cooperative breeders. Furthermore, we show evidence of correlation between digit lengths and cooperative breeding in this species. Additionally, we suggest that the first digit could be a possible indicator of prenatal steroid levels. These results are the starting point for further tests of the hypothesis that first digit length is an indicator of prenatal hormone levels in other vertebrate species. Moreover, these results may offer practical use in wild populations to study the implications of the changes in prenatal environment for adult social behaviour.
Arabidopsis thaliana
and the Robin Hood parasite: a chivalrous oomycete that steals fitness from fecund hosts and benefits the poorest one?
Authors: Salvaudon Lucie , Héraudet Virginie , Shykoff Jacqui A
Published: August 2008

Are parasites always harmful to their hosts? By definition, indeed, but in a few cases and particular environments, hosts experience higher fitness in the presence than in the absence of their parasites. Symbiotic associations form a continuum of interactions, from deleterious to beneficial effects on hosts. In this paper, we investigate the outcome of parasite infection of
Arabidopsis thaliana
by its natural pathogen
Hyaloperonospora arabidopsis
. This system exhibits a wide range of parasite impact on host fitness with, surprisingly, deleterious effects on high fecundity hosts and, at the opposite extreme, seemingly beneficial effects on the least fecund one. This phenomenon might result from varying levels of tolerance among host lines and even overcompensation for parasite damage analogous to what can be observed in plant–herbivore systems.
Microfluidic single-cell analysis of intracellular compounds
Authors: Chao Tzu-Chiao , Ros Alexandra
Published: August 2008

Biological analyses traditionally probe cell ensembles in the range of 10
3
–10
6
cells, thereby completely averaging over relevant individual cell responses, such as differences in cell proliferation, responses to external stimuli or disease onset. In past years, this fact has been realized and increasing interest has evolved for single-cell analytical methods, which could give exciting new insights into genomics, proteomics, transcriptomics and systems biology. Microfluidic or lab-on-a-chip devices are the method of choice for single-cell analytical tools as they allow the integration of a variety of necessary process steps involved in single-cell analysis, such as selection, navigation, positioning or lysis of single cells as well as separation and detection of cellular analytes. Along with this advantageous integration, microfluidic devices confine single cells in compartments near their intrinsic volume, thus minimizing dilution effects and increasing detection sensitivity. This review overviews the developments and achievements of microfluidic single-cell analysis of intracellular compounds in the past few years, from proof-of-principle devices to applications demonstrating a high biological relevance.
Impacts of climate change on wheat in England and Wales
Authors: Semenov Mikhail A
Published: August 2008

The frequency and magnitude of extreme weather events are likely to increase with global warming. However, it is not clear how these events might affect agricultural crops and whether yield losses resulting from severe droughts or heat stress will increase in the future. The aim of this paper is to analyse changes in the magnitude and spatial patterns of two impact indices for wheat: the probability of heat stress around flowering and the severity of drought stress. To compute these indices, we used a wheat simulation model combined with high-resolution climate scenarios based on the output from the Hadley Centre regional climate model at 18 sites in England and Wales. Despite higher temperature and lower summer precipitation predicted in the UK for the 2050s, the impact of drought stress on simulated wheat yield is predicted to be smaller than that at present, because wheat will mature earlier in a warmer climate and avoid severe summer drought. However, the probability of heat stress around flowering that might result in considerable yield losses is predicted to increase significantly. Breeding strategies for the future climate might need to focus on wheat varieties tolerant to high temperature rather than to drought.
The structure of Taylor's constraint in three dimensions
Authors: Livermore Philip W , Ierley Glenn , Jackson Andrew
Published: August 2008

In a 1963 edition of
Proc. R. Soc. A
, J. B. Taylor (Taylor 1963
Proc. R. Soc. A
9
, 274–283) proved a necessary condition for dynamo action in a rapidly rotating electrically conducting fluid in which viscosity and inertia are negligible. He demonstrated that the azimuthal component of the Lorentz force must have zero average over any geostrophic contour (i.e. a fluid cylinder coaxial with the rotation axis). The resulting dynamical balance, termed a Taylor state, is believed to hold in the Earth's core, hence placing constraints on the class of permissible fields in the geodynamo. Such states have proven difficult to realize, apart from highly restricted examples. In particular, it has not yet been shown how to enforce the Taylor condition exactly in a general way, seeming to require an infinite number of constraints. In this work, we derive the analytic form for the averaged azimuthal component of the Lorentz force in three dimensions after expanding the magnetic field in a truncated spherical harmonic basis chosen to be regular at the origin. As the result is proportional to a polynomial of modest degree (simply related to the order of the spectral expansion), it can be made to vanish identically on every geostrophic contour by simply equating each of its coefficients to zero. We extend the discussion to allow for the presence of an inner core, which partitions the geostrophic contours into three distinct regions.
Learning by embryos and the ghost of predation future
Authors: Mathis Alicia , Ferrari Maud C.O , Windel Nathan , Messier François , Chivers Douglas P
Published: August 2008

Most research on the effects of exposure to stressful stimuli during embryonic development has focused on post-embryonic behaviour that appears to be abnormal or maladaptive. Here, we tested whether exposure to some stressful stimuli (predatory cues) can lead to post-embryonic behaviour that is adaptive. When eggs of ringed salamanders (
Ambystoma annulatum
) were exposed to chemical cues from predators, post-hatching larvae showed reduced activity and greater shelter-seeking behaviour; larvae that had been exposed to control cues did not show these behaviours. In addition, wood frog (
Rana sylvatica
)tadpoles learned to respond to chemical cues from unfamiliar predators with danger based on embryonic conditioning. Therefore, if embryonic experience is a good predictor of future risk, learning associated with exposure to negative stimuli during development may be adaptive.
The dynamics of memory: Context-dependent updating
Authors: Hupbach Almut , Hardt Oliver , Gomez Rebecca , Nadel Lynn
Published: August 2008

Understanding the dynamics of memory change is one of the current challenges facing cognitive neuroscience. Recent animal work on memory reconsolidation shows that memories can be altered long after acquisition. When reactivated, memories can be modified and require a restabilization (reconsolidation) process. We recently extended this finding to human episodic memory by showing that memory reactivation mediates the incorporation of new information into existing memory. Here we show that the spatial context plays a unique role for this type of memory updating: Being in the same spatial context during original and new learning is both necessary and sufficient for the incorporation of new information into existing episodic memories. Memories are automatically reactivated when subjects return to an original learning context, where updating by incorporating new contents can occur. However, when in a novel context, updating of existing memories does not occur, and a new episodic memory is created instead.
Reactivation-dependent amnesia in Pavlovian approach and instrumental transfer
Authors: Lee Jonathan L.C. , Everitt Barry J.
Published: August 2008

The theory of memory reconsolidation relates to the hypothesized restabilisation process that occurs following the reactivation of a memory through retrieval. Thus the demonstration of reactivation-dependent amnesia for a previously acquired memory is a prerequisite for showing that such a memory undergoes reconsolidation. Here we show that the appetitive Pavlovian representations that underlie Pavlovian approach and Pavlovian-instrumental transfer are destabilized following their retrieval. This reactivation-dependent amnesia demonstrates that the general motivational or incentive properties of appetitive conditioned stimuli, as well as their conditioned reinforcing properties, can be reduced by blocking memory reconsolidation.
Perirhinal cortex lesions produce retrograde amnesia for spatial information in rats: Consolidation or retrieval?
Authors: Ramos Juan M.J.
Published: August 2008

Several lines of evidence in humans and experimental animals suggest that the hippocampus is critical for the formation and retrieval of spatial memory. However, although the hippocampus is reciprocally connected to adjacent cortices within the medial temporal lobe and they, in turn, are connected to the neocortex, little is known regarding the function of these cortices in memory. Here, using a reference spatial memory task in the radial maze, we show that neurotoxic perirhinal cortex lesions produce a profound retrograde amnesia when learning–surgery intervals of 1 or 50 d are used (Experiment 1). With the aim of dissociating between consolidation and retrieval processes, we injected lidocaine either daily after training (Experiment 2) or before a retention test once the learning had been completed (Experiment 3). Results show that reversible perirhinal inactivation impairs retrieval but not consolidation. However, the same procedure followed in Experiment 2 disrupted consolidation when the lidocaine was injected into the dorsal hippocampus. The results of Experiment 4 rule out the possibility that the deficit in retrieval is due to a state-dependent effect. These findings demonstrate the differential contribution of various regions of the medial temporal lobe to memory, suggesting that the perirhinal cortex plays a key role in the retrieval of spatial information for a long period of time.
The Arabidopsis NFYA5 Transcription Factor Is Regulated Transcriptionally and Posttranscriptionally to Promote Drought Resistance
Authors: Li Wen-Xue , Oono Youko , Zhu Jianhua , He Xin-Jian , Wu Jian-Min , Iida Kei , Lu Xiao-Yan , Cui Xinping , Jin Hailing , Zhu Jian-Kang
Published: August 2008

Nuclear factor Y (NF-Y) is a ubiquitous transcription factor composed of three distinct subunits (NF-YA, NF-YB, and NF-YC). We found that the Arabidopsis thaliana NFYA5 transcript is strongly induced by drought stress in an abscisic acid (ABA)-dependent manner. Promoter:β-glucuronidase analyses showed that NFYA5 was highly expressed in vascular tissues and guard cells and that part of the induction by drought was transcriptional. NFYA5 contains a target site for miR169, which targets mRNAs for cleavage or translational repression. We found that miR169 was downregulated by drought stress through an ABA-dependent pathway. Analysis of the expression of miR169 precursors showed that miR169a and miR169c were substantially downregulated by drought stress. Coexpression of miR169 and NFYA5 suggested that miR169a was more efficient than miR169c at repressing the NFYA5 mRNA level. nfya5 knockout plants and plants overexpressing miR169a showed enhanced leaf water loss and were more sensitive to drought stress than wild-type plants. By contrast, transgenic Arabidopsis plants overexpressing NFYA5 displayed reduced leaf water loss and were more resistant to drought stress than the wild type. Microarray analysis indicated that NFYA5 is crucial for the expression of a number of drought stress–responsive genes. Thus, NFYA5 is important for drought resistance, and its induction by drought stress occurs at both the transcriptional and posttranscriptional levels.
Being Relaxed and Powerful: Children’s Lived Experiences of Coping with Stress
Authors: Kostenius Catrine , Öhrling Kerstin
Published: August 2008

Our aim was to describe and develop an understanding of children’s lived experiences of coping with stress. Twenty‐three Swedish children, ages 10–12, wrote open letters and were interviewed. The phenomenological analysis resulted in three main themes: (i) depending on oneself, others and the world around, (ii) choosing to be a doer and (iii) being in the here and now. We understood the children’s lived experiences of coping with stress as them being relaxed and powerful. The children chose to be active doers or inactive beings and their relationships, as well as their surroundings, helped or hindered their coping. Possible health promotion work is discussed.
Childhood, Agency and Youth Justice
Authors: Smith Roger
Published: August 2008

This article seeks to reframe debates in the sphere of youth justice in order to move away from narrow and one‐sided conceptualisations of young people who offend and appropriate forms of intervention with them. Whilst different positions have been adopted within the field of youth justice, largely around ‘justice’ or ‘welfare’ models of practice, the apparent polarisation of this conflict has obscured an underlying consensus, namely that the ‘problem’ is the child or young offender, and he/she needs either to be helped or coerced into becoming a conforming adult citizen. Largely absent from the field of youth justice have been other theoretical influences such as consideration of the nature of ‘agency’ and the construction of childhood. These alternative perspectives could offer us some insight into the limitations of historical debates in youth justice policy and practice, as will as pointing the way towards innovative and progressive alternative forms of practice. The strengths and shortcomings of contemporary developments, such as restorative interventions, will be discussed in this context, and the article will conclude that there is scope for developing positive, young person‐centred models of youth justice practice if we base these on a proper understanding of childhood and children’s agency.
Factors influencing duiker dung decay in north‐east Gabon: are dung beetles hiding duikers?
Authors: Van Vliet Nathalie , Nasi Robert , Lumaret Jean Pierre
Published: August 2008

We analysed seasonality of dung decay time and the influence of rainfall, leaf fall, beetle attack and moisture on dung decay. Our study was carried out at the Ipassa Reserve, north‐east Gabon. We compared the seasonality of dung decay with the seasonality of dung beetle abundance and guild structure. Dung beetle activity was the main factor influencing dung decay in our study site. Decay time was the highest during the main dry season (3.4 days) and the lowest during the short rainy season (0.7 days). Dung decay time was closely related to dung beetle abundance, especially to the abundance of nocturnal beetles. We discuss the implications of such results for duiker survey methods based on dung pellet counts in areas where decay time is extremely short or unknown.
Stability and compatibility of drug mixtures in an implantable infusion system
Authors: Bianchi F. , Ginggen A. , Tardy Y.
Published: August 2008

This study evaluated the stability and the compatibility of mixtures of morphine sulphate, bupivacaine, and clonidine hydrochloride and of hydromorphone, bupivacaine, and clonidine hydrochloride, when used in constant flow implantable pumps under simulated clinical use conditions. The pumps were filled with drug mixtures and incubated at 37 °C for a period of 90 days. Aliquots were sampled monthly from the reservoir and catheter outlet and the drug concentrations analysed using validated chromatography methods. Individual materials from the infusion system were immersed in the drug mixtures and stored at 37 °C for 60 weeks and evaluated for mechanical performance for compatibility testing. Both drug mixtures were found to be stable over 90 days in the pump at 37 °C. All device materials retained acceptable mechanical performance following exposure. These results demonstrate that both drug mixtures are stable when maintained at simulated body temperature in an implantable infusion system for 90 days.
A Bayesian approach to inverse modelling of stratigraphy, part 2: Validation tests
Authors: Charvin Karl , Hampson Gary J. , Gallagher Kerry , Labourdette Richard
Published: August 2008

A novel inverse modelling method is applied to the problem of constraining the environmental parameters (e.g. relative sea level, sediment supply) that control stratigraphic architecture. This technique links forward modelling of shallow‐marine wave/storm‐dominated stratigraphy to a combination of inverse methods formulated in a Bayesian framework. We present a number of examples in which relative sea‐level and sediment‐supply curves were inferred from synthetic vertical successions of grain size (e.g. wells) and synthetic thickness curves (e.g. seismically derived isopachs) extracted from a forward model simulation. These examples represent different scenarios that are designed to test the impact of data distribution, quantity and quality on the uncertainty of the inferred parameters. The inverse modelling approach successfully reproduces the gross stratigraphic architectures and relative sea level and sediment‐supply histories of the synthetic forward model simulation, within the constraints of the modelled data quality. The relative importance of the forcing parameters can be evaluated by their sensitivity and impact on the inverted data. Of equal importance, the inverse results allow complete characterisation of the uncertainties inherent to the stratigraphic modelling tool and to the data quality, quantity and distribution. The numerical scheme also successfully deals with the problem of non‐uniqueness of the solution of the inverse problem. These preliminary results suggest that the inverse method is a powerful tool in constraining stratigraphic architecture for hydrocarbon reservoir characterisation and modelling, and it may ultimately provide a process‐based geological complement to standard geostatistical tools.
Habitat associations of exploited fish species in the Lower Amazon river–floodplain system
Authors: MARTELO JOANA , LORENZEN KAI , CROSSA MARCELO , MCGRATH DAVID G.
Published: August 2008

1. Modification of floodplain morphology and land use is widely recognized as a major threat to fish communities of river–floodplain systems. We assess habitat associations of major exploited fish species in the Lower Amazon, where modifications are more extensive than in the Central or Upper Amazon.

2. Habitat was characterized in terms of physical environment, vegetation cover, distance from river and mean depth. Habitat associations of late juvenile and adult fish of the 14 major exploited species were established by comparing the distribution of the habitat sampled with the distribution of the habitat sampled weighed by a fish abundance index (catch per unit of effort).

3. Eight species showed significant habitat associations, generally being most abundant in floodplain lakes. Five of these eight species were associated with open water. Of the three exceptions, two preferred flooded forest lakes and another macrophyte‐dominated channels. The majority of those species with significant associations also preferred waters shallower than 7.25 m and relatively distant from the river mainstream.

4. While flooded forest is often assumed to be a key habitat for Amazon fish, only two of the main exploited species in the Lower Amazon had a significant association with this habitat. The majority of exploited species, including one that is associated with flooded forest in the central and upper Amazon, either showed no habitat associations or preferred open water lakes. The full range of pristine and modified floodplain habitats should be considered as important to fish conservation and fisheries productivity.
Composition and dispersal of riverine and lake phytoplankton communities in connected systems with different water retention times
Authors: BERGSTRÖM ANN‐KRISTIN , BIGLER CHRISTIAN , STENSDOTTER ULRIKA , LINDSTRÖM EVA S.
Published: August 2008

1. Lake phytoplankton community structure may be influenced by both internal factors (predation, competition, resource constraints) and external ones, such as dispersal of materials and cells between connected habitats. However, little is known about the importance of cell dispersal for phytoplankton community structure in lakes.

2. We investigated the abundance and dispersal of phytoplankton cells between connected rivers and lakes, and analysed whether similarities in phytoplankton community composition between rivers and lakes were primarily related to cell import rates or to characteristics of the local habitat. We focused on lakes along a gradient of theoretical water retention times (TWRT). Two data sets from Swedish lakes were used; a seasonal study of two connected boreal forest lakes, differing in TWRT, and a multi‐lake study of 13 lakes with a continuous range of TWRTs.

3. Phytoplankton cells were transported and dispersed in all investigated rivers. In the seasonal study, cell import rates and similarities in phytoplankton community composition between the lake and its inlet(s) were much higher in the lake with a shorter TWRT. Phytoplankton community structure in different habitats was associated with total organic carbon (TOC). This indicates that local habitat characteristics may be important in determining lake phytoplankton community composition, even in the presence of substantial cell import.

4. The multi‐lake study also showed a negative relationship between TWRT and similarities in phytoplankton community composition between inlets and lakes. Moreover, similarity in community structure was related to both cell import rates from inlet to lake and differences in habitat characteristics between inlet and lake. However, the variable most strongly correlated with community structure was TOC, indicating that species sorting rather than a mass effect was the most important mechanism underlying the correlation between community structure and retention time.

5. Overall, our data suggest that local habitat characteristics may play a key role in determining community similarity in this set of lakes covering a large range of habitat connectedness. Due to the strong co‐variations between cell dispersal and TOC, it was hard to unequivocally disentangle the different mechanisms; hence, there is a need for further studies of the role of dispersal for phytoplankton community structures.
Soluble CD38 significantly prolongs the lifespan of memory B‐cell responses
Authors: Liu Xue Q. , Hart Derek N. J. , MacPherson Gordon G. , Good Michael F. , Wykes Michelle N.
Published: August 2008

The development and maintenance of memory B cells (MBC) is dependent on germinal centres (GC) with follicular dendritic cell (FDC) networks. We have previously shown that FDC networks within GC of the spleen express a novel ligand for CD38 and that the administration of soluble CD38 induces an expansion of these cellular structures. We therefore used adoptive transfer studies to investigate whether the expansion of FDC networks with soluble CD38 affected the generation and maintenance of antigen‐specific MBC. These studies found that the administration of soluble CD38 significantly extended the period after which MBC could be activated and that the frequencies of these cells also were increased. In conclusion, soluble CD38 appears to significantly extend the lifespan of antibody memory by increasing the numbers of MBC.
Peering into large lectures: examining peer and expert mark agreement using peerScholar, an online peer assessment tool
Authors: Paré D.E. , Joordens S.
Published: August 2008

As class sizes increase, methods of assessments shift from costly traditional approaches (e.g. expert‐graded writing assignments) to more economic and logistically feasible methods (e.g. multiple‐choice testing, computer‐automated scoring, or peer assessment). While each method of assessment has its merits, it is peer assessment in particular, especially when made available online through a Web‐based interface (e.g. our peerScholar system), that has the potential to allow a reintegration of open‐ended writing assignments in any size class – and in a manner that is pedagogically superior to traditional approaches. Many benefits are associated with peer assessment, but it was the concerns that prompted two experimental studies (n = 120 in each) using peerScholar to examine mark agreement between and within groups of expert (graduate teaching assistants) and peer (undergraduate students) markers. Overall, using peerScholar accomplished the goal of returning writing into a large class, while producing grades similar in level and rank order as those provided by expert graders, especially when a grade accountability feature was used.
‘The devil lay upon her and held her down’ Hypnagogic hallucinations and sleep paralysis described by the Dutch physician Isbrand van Diemerbroeck (1609–1674) in 1664
Authors: KOMPANJE E. J. O.
Published: August 2008

Hypnagogic and hypnopompic hallucinations are visual, tactile, auditory or other sensory events, usually brief but sometimes prolonged, that occur at the transition from wakefulness to sleep (hypnagogic) or from sleep to wakefulness (hypnopompic). Hypnagogic and hypnopompic hallucinations are often associated with sleep paralysis. Sleep paralysis occurs immediately prior to falling asleep (hypnagogic paralysis) or upon waking (hypnopompic paralysis). In 1664, the Dutch physician Isbrand Van Diemerbroeck (1609–1674) published a collection of case histories. One history with the title ‘Of the Night‐Mare’ describes the nightly experiences of the 50‐year‐old woman. This case report is subject of this article. The experiences in this case could without doubt be diagnosed as sleep paralysis accompanied by hypnagogic hallucinations. This case from 1664 should be cited as the earliest detailed account of sleep paralysis associated with hypnagogic illusions and as the first observation that sleep paralysis and hypnagogic experiences occur more often in supine position of the body.
No effect of 8‐week time in bed restriction on glucose tolerance in older long sleepers
Authors: ZIELINSKI MARK R. , KLINE CHRISTOPHER E. , KRIPKE DANIEL F. , BOGAN RICHARD K. , YOUNGSTEDT SHAWN D.
Published: August 2008

The aim of this study was to investigate the effects of 8 weeks of moderate restriction of time in bed (TIB) on glucose tolerance and insulin sensitivity in healthy older self‐reported long sleepers. Forty‐two older adults (ages 50–70 years) who reported average sleep durations of ≥8.5 h per night were assessed. Following a 2‐week baseline, participants were randomly assigned to two 8‐week treatments: either (i) TIB restriction (n = 22), which involved following a fixed sleep schedule in which time in bed was reduced by 90 min compared with baseline; (ii) a control (n = 18), which involved following a fixed sleep schedule but no imposed change of TIB. Sleep was monitored continuously via wrist actigraphy recordings, supplemented with a daily diary. Glucose tolerance and insulin sensitivity were assessed before and following the treatments. Compared with the control treatment, TIB restriction resulted in a significantly greater reduction of nocturnal TIB (1.39 ± 0.40 h versus 0.14 ± 0.26 h), nocturnal total sleep time (TST) (1.03 ± 0.53 h versus 0.40 ± 0.42 h), and 24‐h TST (1.03 ± 0.53 h versus 0.33 ± 0.43 h) from baseline values. However, no significant effect of TIB restriction was found for glucose tolerance or insulin sensitivity. These results suggest that healthy older long sleepers can tolerate 8 weeks of moderate TIB restriction without impairments in glucose tolerance or insulin sensitivity.