bluuebunny/crossref_metadata_2025 huggingface dataset:
Soft materials with graphitic nanostructures
Authors: Aida Takuzo , Fukushima Takanori
Published: April 2007

This review article focuses on our recent studies on novel soft materials consisting of carbon nanotubes. Single-walled carbon nanotubes, when suspended in imidazolium ion-based ionic liquids and ground in an agate mortar, form physical gels (bucky gels), where heavily entangled bundles of carbon nanotubes are exfoliated to give highly dispersed, much finer bundles. By using bucky gels, the first printable actuators that operate in air for a long time without any external electrolyte are developed. Furthermore, the use of polymerizable ionic liquids as the gelling media results in the formation of electroconductive polymer/nanotube composites with enhanced mechanical properties. The article also highlights a new family of nanotubular graphite, via self-assembly of amphiphilic hexabenzocoronene (HBC) derivatives. The nanotubes consist of a graphitic wall composed of a great number of π-stacked HBC units and are electroconductive upon oxidation. The use of amphiphilic HBCs with functional groups results in the formation of nanotubes with various interesting properties.
Unconventional nanotubes self-assembled in alumina channels: morphology and surface potential of isolated nanostructures at surfaces
Authors: Palermo Vincenzo , Liscio Andrea , Talarico Anna Maria , Zhi Linjie , Müllen Klaus , Samorì Paolo
Published: April 2007

Synthetic nanographenes have been self-assembled from solution on the surface of nanometric channels of an alumina membrane template. By controlling the interplay between intermolecular and interfacial interactions, the molecules have been adsorbed either ‘face-on’ or ‘edge-on’ on the pore's surfaces, leading to the formation of columnar stacks in the latter case. Upon thermal treatment at high temperature, the molecular cross-linking of the columns has been triggered, transforming the delicate supramolecular arrangement into robust carbon nanotubes, with the graphitic planes at predetermined orientations with respect to the tube axis. Scanning force microscopy characterization of single nanotubes deposited from suspensions on mica showed that the nanotubes can self-assemble on flat surfaces adopting preferential alignments which reflect the threefold symmetry of the mica substrate. Kelvin probe force microscopy studies revealed that the nanotubes possess a surface potential much smaller than the work function of both graphite and conventional vacuum-processed nanotubes, providing evidence for their more confined electronic structure.
Energy migration in conjugated polymers: the role of molecular structure
Authors: Rose Aimee , Tovar John D , Yamaguchi Shigehiro , Nesterov Evgueni E , Zhu Zhengguo , Swager Timothy M
Published: April 2007

Conjugated polymers undergo facile exciton diffusion. Different molecular structures were examined to study the role of the excited state lifetimes and molecular conformations on energy transfer. There is a clear indication that extended fluorescence lifetimes give enhanced exciton diffusion as determined by fluorescence depolarization measurements. These results are consistent with a strong electronic coupling or Dexter-type energy transfer as the dominating mechanism. The control of polymer conformations in liquid crystal solvents was also examined and it was determined that more planar conformations gave enhanced energy transfer to emissive low band-gap endgroups.
Introduction. Modelling natural action selection
Authors: Prescott Tony J , Bryson Joanna J , Seth Anil K
Published: April 2007

Action selection is the task of resolving conflicts between competing behavioural alternatives. This theme issue is dedicated to advancing our understanding of the behavioural patterns and neural substrates supporting action selection in animals, including humans. The scope of problems investigated includes: (i) whether biological action selection is optimal (and, if so, what is optimized), (ii) the neural substrates for action selection in the vertebrate brain, (iii) the role of perceptual selection in decision-making, and (iv) the interaction of group and individual action selection. A second aim of this issue is to advance methodological practice with respect to modelling natural action section. A wide variety of computational modelling techniques are therefore employed ranging from formal mathematical approaches through to computational neuroscience, connectionism and agent-based modelling. The research described has broad implications for both natural and artificial sciences. One example, highlighted here, is its application to medical science where models of the neural substrates for action selection are contributing to the understanding of brain disorders such as Parkinson's disease, schizophrenia and attention deficit/hyperactivity disorder.
Do we expect natural selection to produce rational behaviour?
Authors: Houston Alasdair I , McNamara John M , Steer Mark D
Published: April 2007

We expect that natural selection should result in behavioural rules which perform well; however, animals (including humans) sometimes make bad decisions. Researchers account for these with a variety of explanations; we concentrate on two of them. One explanation is that the outcome is a side effect; what matters is how a rule performs (in terms of reproductive success). Several rules may perform well in the environment in which they have evolved, but their performance may differ in a ‘new’ environment (e.g. the laboratory). Some rules may perform very badly in this environment. We use the debate about whether animals follow the matching law rather than maximizing their gains as an illustration. Another possibility is that we were wrong about what is optimal. Here, the general idea is that the setting in which optimal decisions are investigated is too simple and may not include elements that add extra degrees of freedom to the situation.
The ecology of action selection: insights from artificial life
Authors: Seth Anil K
Published: April 2007

The problem of action selection has two components: what is selected and how is it selected? To understandwhatis selected, it is necessary to distinguish between behavioural and mechanistic levels of description. Animals do not choose between behavioursper se; rather, behaviour reflects interactions among brains, bodies and environments. To understand whatguidesselection, it is useful to take a normative perspective that evaluates behaviour in terms of a fitness metric. This perspective, rooted in behavioural ecology, can be especially useful for understanding apparently irrational choice behaviour. This paper describes a series of models that use artificial life (AL) techniques to address the above issues. We show that successful action selection can arise from the joint activity of parallel, loosely coupled sensorimotor processes. We define a class of AL models that help to bridge the ecological approaches of normative modelling and agent- or individual-based modelling (IBM). Finally, we show how an instance of apparently suboptimal decision making, the matching law, can be accounted for by adaptation to competitive foraging environments.
Compromise strategies for action selection
Authors: Crabbe Frederick L
Published: April 2007

Among the many properties suggested for action-selection mechanisms, a prominent one is the ability to select compromise actions, i.e. actions that are not the best to satisfy any active goal in isolation, but rather compromise between multiple goals. This paper briefly reviews the history of compromise behaviour and presents experimental analyses of it in an attempt to determine how much compromise behaviour aids an agent. It concludes that optimal compromise behaviour has a surprisingly small benefit over non-compromise behaviour in the experiments performed, and presents some reasons why this may be true and hypothesizes cases where compromise behaviour is truly useful. In particular, it hypothesizes that a crucial factor is the level at which an action is taken (low-level actions are specific, such as ‘move left leg’; high-level actions are vague, such as ‘forage for food’). This paper hypothesizes that compromise behaviour is more beneficial for high- than low-level actions.
Cortical mechanisms of action selection: the affordance competition hypothesis
Authors: Cisek Paul
Published: April 2007

At every moment, the natural world presents animals with two fundamental pragmatic problems: selection between actions that are currently possible and specification of the parameters or metrics of those actions. It is commonly suggested that the brain addresses these by first constructing representations of the world on which to build knowledge and make a decision, and then by computing and executing an action plan. However, neurophysiological data argue against this serial viewpoint. In contrast, it is proposed here that the brain processes sensory information to specify, in parallel, several potential actions that are currently available. These potential actions compete against each other for further processing, while information is collected to bias this competition until a single response is selected. The hypothesis suggests that the dorsal visual system specifies actions which compete against each other within the fronto-parietal cortex, while a variety of biasing influences are provided by prefrontal regions and the basal ganglia. A computational model is described, which illustrates how this competition may take place in the cerebral cortex. Simulations of the model capture qualitative features of neurophysiological data and reproduce various behavioural phenomena.
Towards an executive without a homunculus: computational models of the prefrontal cortex/basal ganglia system
Authors: Hazy Thomas E , Frank Michael J , O'Reilly Randall C
Published: April 2007

The prefrontal cortex (PFC) has long been thought to serve as an ‘executive’ that controls the selection of actions and cognitive functions more generally. However, the mechanistic basis of this executive function has not been clearly specified often amounting to a homunculus. This paper reviews recent attempts to deconstruct this homunculus by elucidating the precise computational and neural mechanisms underlying the executive functions of the PFC. The overall approach builds upon existing mechanistic models of the basal ganglia (BG) and frontal systems known to play a critical role in motor control and action selection, where the BG provide a ‘Go’ versus ‘NoGo’ modulation of frontal action representations. In our model, the BG modulate working memory representations in prefrontal areas to support more abstract executive functions. We have developed a computational model of this system that is capable of developing human-like performance on working memory and executive control tasks through trial-and-error learning. This learning is based on reinforcement learning mechanisms associated with the midbrain dopaminergic system and its activation via the BG and amygdala. Finally, we briefly describe various empirical tests of this framework.
Is there a brainstem substrate for action selection?
Authors: Humphries M.D , Gurney K , Prescott T.J
Published: April 2007

The search for the neural substrate of vertebrate action selection has focused on structures in the forebrain and midbrain, and particularly on the group of sub-cortical nuclei known as the basal ganglia. Yet, the behavioural repertoire of decerebrate and neonatal animals suggests the existence of a relatively self-contained neural substrate for action selection in the brainstem. We propose that the medial reticular formation (mRF) is the substrate's main component and review evidence showing that the mRF's inputs, outputs and intrinsic organization are consistent with the requirements of an action-selection system. The internal architecture of the mRF is composed of interconnected neuron clusters. We present an anatomical model which suggests that the mRF's intrinsic circuitry constitutes a small-world network and extend this result to show that it may have evolved to reduce axonal wiring. Potential configurations of action representation within the internal circuitry of the mRF are then assessed by computational modelling. We present new results demonstrating that each cluster's output is most likely to represent activation of a component action; thus, coactivation of a set of these clusters would lead to the coordinated behavioural response observed in the animal. Finally, we consider the potential integration of the basal ganglia and mRF substrates for selection and suggest that they may collectively form a layered/hierarchical control system.
Extending a biologically inspired model of choice: multi-alternatives, nonlinearity and value-based multidimensional choice
Authors: Bogacz Rafal , Usher Marius , Zhang Jiaxiang , McClelland James L
Published: April 2007

The leaky competing accumulator (LCA) is a biologically inspired model of choice. It describes the processes of leaky accumulation and competition observed in neuronal populations during choice tasks and it accounts for reaction time distributions observed in psychophysical experiments. This paper discusses recent analyses and extensions of the LCA model. First, it reviews the dynamics and examines the conditions that make the model achieve optimal performance. Second, it shows that nonlinearities of the type present in biological neurons improve performance when the number of choice alternatives increases. Third, the model is extended to value-based choice, where it is shown that nonlinearities in the value function explain risk aversion in risky choice and preference reversals in choice between alternatives characterized across multiple dimensions.
Hippocampal regulation of context-dependent neuronal activity in the lateral amygdala
Authors: Maren Stephen , Hobin Jennifer A.
Published: April 2007

Pavlovian fear conditioning is a robust and enduring form of emotional learning that provides an ideal model system for studying contextual regulation of memory retrieval. After extinction the expression of fear conditional responses (CRs) is context-specific: A conditional stimulus (CS) elicits greater conditional responding outside compared with inside the extinction context. Dorsal hippocampal inactivation with muscimol attenuates context-specific CR expression. We have previously shown that CS-elicited spike firing in the lateral nucleus of the amygdala is context-specific after extinction. The present study examines whether dorsal hippocampal inactivation with muscimol disrupts context-specific firing in the lateral amygdala. We conditioned rats to two separate auditory CSs and then extinguished each CS in separate and distinct contexts. Thereafter, single-unit activity and conditional freezing were tested to one CS in both extinction contexts after saline or muscimol infusion into the dorsal hippocampus. After saline infusion, rats froze more to the CS when it was presented outside of its extinction context, but froze equally in both contexts after muscimol infusion. In parallel with the behavior, lateral nucleus neurons exhibited context-dependent firing to extinguished CSs, and hippocampal inactivation disrupted this activity pattern. These data reveal a novel role for the hippocampus in regulating the context-specific firing of lateral amygdala neurons after fear memory extinction.
Combined treatment with green tea catechins and sodium nitrite selectively promotes rat forestomach carcinogenesis after initiation with N‐methyl‐N′‐ nitro‐N‐nitrosoguanidine
Authors: Kuroiwa Yuichi , Ishii Yuji , Umemura Takashi , Kanki Keita , Mitsumori Kunitoshi , Nishikawa Akiyoshi , Nakazawa Hiroyuki , Hirose Masao
Published: April 2007

Combined treatment with several phenolic antioxidants and sodium nitrite (NaNO2) has already shown to enhance rat forestomach carcinogenesis. In the present experiment, effects of green tea catechins (GTC) alone or in combination with NaNO2 on gastric carcinogenesis were investigated in a rat two‐stage carcinogenesis model. Groups of eight, 6‐week‐old F344 male rats were given 0.01%N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) in their drinking water and 5% NaCl in the diet for 10 weeks for glandular stomach initiation and a single intragastric administration of 100 mg/kg/bodyweight of MNNG at week 9 for forestomach initiation. From week 11, they received either drinking water containing 0.2% NaNO2 and a diet supplemented with 1% GTC in combination, each individual chemical alone or a basal diet until the end of week 42. In the forestomach, incidences and multiplicities of neoplastic lesions were clearly increased by the combined treatment, in spite of GTC alone suppressing the occurrence of papillomas. In a short‐term experiment with similar protocol without MNNG pretreatment, a significant increase of 8‐hydroxydeoxyguanosine (8‐OHdG) levels in forestomach DNA occurred 24 h after the combined treatment, concomitant with erosion and inflammatory cell infiltration. In an in vitro study, electron spin resonance demonstrated hydroxyl radical formation after incubation of epigallocatechin gallate or epicatechin gallate with the NO generator, NOC‐7. Thus, GTC alone showed a weak chemopreventive effect on forestomach carcinogenesis, but in the presence of NaNO2 it exerted a promotive effect which might involve hydroxyl‐radical‐associated oxidative DNA damage. However, no influence was exerted in the glandular stomach. (Cancer Sci 2007; 98: 949–957)
Telomere dysfunction and inactivation of the p16INK4a/Rb pathway in pyothorax‐associated lymphoma
Authors: Tresnasari Kristianti , Takakuwa Tetsuya , Ham Maria Francisca , Rahadiani Nur , Nakajima Hiroo , Aozasa Katsuyuki
Published: April 2007

Previous studies have indicated that genome instability is involved in the lymphomagenesis of pyothorax‐associated lymphoma (PAL), which develops in patients with a long‐standing history of pyothorax. One of the well‐known causes of genome instability is telomere dysfunction. In the present study, the condition of telomeres was analyzed in the cell lines and clinical samples from PAL. Telomere length (TL) in PAL cell lines was extremely short (<4.5 kbp). TL in tumor samples was broad in range, and shorter than that in the peripheral blood leukocytes from the matched patients. Three of five PAL cell lines showed frequent loss of telomere signals (telomere erosion); however, telomerase activity in PAL cell lines was similar to that in Burkitt lymphoma cell lines. Rb expression was detected in three PAL cell lines and four of 15 clinical samples, respectively. Rb protein expressed in three PAL cell lines was heavily phosphorylated, indicating that function of Rb protein was suppressed. p16INK4a expression was not detected in either cell lines or clinical samples. The promoter region in p16INK4a was heavily methylated in all cell lines as well as the clinical samples. Inactivation of the p16INK4a/Rb pathway may allow continuous cell division and critical telomere shortening, which induce genome instability, finally leading to malignant transformation. Taken together, telomere dysfunction and inactivation of the p16INK4a/Rb pathway might play a role for PAL development. (Cancer Sci 2007; 98: 978–984)
High familial risks for cerebral palsy implicate partial heritable aetiology
Authors: Hemminki Kari , Li Xinjun , Sundquist Kristina , Sundquist Jan
Published: April 2007

Cerebral palsy is the commonest cause of severe childhood disability, the aetiology of which is largely unknown. Data on familial aggregation of cerebral palsy are very limited. We defined familial risks for siblings who were hospitalised because of cerebral palsy in Sweden. A nationwide database for neurological diseases was constructed by linking the Multigeneration Register to the Hospital Discharge Register for the years 1987–2001. Standardised hospitalisation ratios (SHRs) were calculated for affected singletons and twins by comparing them with siblings who had no cerebral palsy. A total of 3997 patients were recorded with cerebral palsy. Familial cerebral palsy was uncommon, and it accounted for 1.6% of all cerebral palsy cases. However, for parents who had had one affected child the risk of recurrence in another child was considerably increased. Parents of one affected child had a 4.8‐fold risk of having a second affected child, and where the siblings were twins, the risk was 29‐fold. These familial risks were particularly high in some clinical subgroups: 17–25 in singletons and 37–155 in twins, including hemiplegia, diplegia and quadriplegia. The remarkably high familial risks are difficult to explain without some contribution of heritable factors. The lack of discordant pairs may suggest that heritable factors are disorder type‐specific. Affected concordant sibling pairs should be subjected to molecular studies aiming at identifying the susceptibility gene.
The Jerusalem Perinatal Study cohort, 1964–2005: methods and a review of the main results
Authors: Harlap Susan , Davies A. Michael , Deutsch Lisa , Calderon‐Margalit Ronit , Manor Orly , Paltiel Ora , Tiram Efrat , Yanetz Rivka , Perrin Mary C. , Terry Mary B. , Malaspina Dolores , Friedlander Yechiel
Published: April 2007

The Jerusalem Perinatal Study recorded information on population‐based cohorts of 92 408 live‐ and stillbirths in 1964–76, and their parents, with active surveillance of infant deaths and birth defects. Data on maternal conditions, obstetric complications and interventions during labour and delivery were recorded for 92% of the births. Subsets were surveyed with antenatal interviews in 1965–68 (n = 11 467), paediatric admissions to hospital (n = 17 782) and postpartum interviews in 1975–76 (n = 16 912). Data from some offspring were linked to records of a health examination at age 17. The offspring, mothers and fathers have been traced recently, their vital status assessed, and the data linked to Israel's Cancer Registry and Psychiatric Registry. This paper describes the different types of data available, their sources, and some potential biases. Characteristics of this unique population are shown. Findings from the study are reviewed and a list of references is provided. The cohorts provide a unique source of data for a wide variety of studies.
Male factor infertility: a twin study
Authors: Cloonan Yona K. , Holt Victoria L. , Goldberg Jack
Published: April 2007

There is a considerable body of literature on the causes of female infertility, but far less is known about male factor infertility. We conducted a classical twin study to estimate the genetic influence on 12‐month male factor infertility. The study used the Vietnam Era Twin (VET) Registry, which includes male twin pairs born between 1939 and 1957, and who served in the US military between 1965 and 1975. In 1987, a health survey was mailed to all twins and obtained a 74% response rate. The current analyses comprised 1795 complete pairs in which both twins were married only once. Proband‐wise concordance rates, tetrachoric correlations, and a bivariate probit model were used to calculate estimates of familial clustering and heritability for male factor infertility.

The proband concordance rate for male factor infertility was 38% [95% CI 32.8, 42.4] in monozygotic (MZ) pairs and 33% [95% CI 28.0, 38.6] in dizygotic (DZ) pairs. The tetrachoric correlations for male infertility were 0.15 in MZ and 0.04 in DZ pairs. This pattern provides evidence of familial clustering, although genetic influence was not evident (P = 0.21). The current study identified that 12‐month male factor infertility clustered within families. However, results suggest that factors unique to individual twins may play a more prominent role in male infertility than additive genetic effects or the common environment.
Maternal reproductive and demographic characteristics as risk factors for hypospadias
Authors: Carmichael Suzan L. , Shaw Gary M. , Laurent Cecile , Olney Richard S. , Lammer Edward J. ,   The National Birth Defects Prevention Study
Published: April 2007

This study examined the association of hypospadias risk with several maternal reproductive and demographic characteristics: age, parity, body mass index (BMI), nausea and vomiting of pregnancy (NVP), multiple pregnancy, fertility treatments and procedures, education and race‐ethnicity. The study included data on deliveries with estimated due dates from October 1997 to December 2000 that were part of the National Birth Defects Prevention Study, a multi‐state case–control study of many birth defects. The analysis included 502 cases with second or third degree hypospadias (i.e. the urethra opened at the penile shaft, scrotum or perineum) and 1286 male, liveborn, non‐malformed controls. Risks were estimated from a multivariable logistic regression model that included all exposures of interest.

Results indicated particularly elevated risks among births to women who were primiparae, aged ≥35 years and had a BMI of >26, compared with women who were multiparae, aged <30 years and had a BMI of ≤26 [adjusted OR 12.5, 95% CI 5.1, 30.8]. NVP at least once per day during the second or third month of pregnancy vs. no NVP was associated with slightly reduced risk [OR 0.8, 95% CI 0.6, 1.1]. Multiple birth, fertility treatments and college education were associated with increased risks, and Hispanic race‐ethnicity was associated with reduced risk. Although the potential contribution of underlying maternal endocrine parameters to the current findings are unknown, the results do provide clues regarding hypospadias aetiology that merit further investigation.
Maternal employment and breast‐feeding initiation: findings from the Millennium Cohort Study
Authors: Hawkins Summer S. , Griffiths Lucy J. , Dezateux Carol , Law Catherine ,   The Millennium Cohort Study Child Health Group
Published: April 2007

Maternal employment rates have increased rapidly in recent years and little is known about how this influences whether women start breast feeding. We examined data from the Millennium Cohort Study to determine whether a mother's employment status (full‐time, part‐time, self‐employed, on leave, not employed/student) and employment characteristics are related to breast‐feeding initiation. This analysis comprised 14 830 white mothers from Britain and Ireland (6917 employed) with singleton babies, born from 2000 to 2002. Information was obtained on infant feeding history and mother's employment when the cohort child was 9 months old.

We found that women employed full‐time were less likely to initiate breast feeding than mothers who were not employed/students, after adjustment for confounding factors [adjusted rate ratio (aRR) = 0.92; 95% confidence interval (CI) 0.89, 0.96]; however, there were no differences in breast‐feeding initiation between mothers employed part‐time, self‐employed, or on leave and mothers who were not employed/students. Among employed mothers, those who returned to work within 4 months postpartum were less likely to start breast feeding than women who returned at 5 or 6 months [aRR = 0.95; 95% CI 0.92, 0.99], and women who returned within the first 6 weeks were much less likely to start breast feeding [aRR = 0.85; 95% CI 0.77, 0.94]. Mothers returning for financial reasons were also less likely to initiate breast feeding [aRR = 0.96; 95% CI 0.93, 0.99] than those who returned for other reasons. Policies to increase breast feeding should address how both the time and circumstances of a mother's return to employment postpartum influence whether she decides to start breast feeding.
Does gravidity influence smoking behaviour in pregnancy? A comparison of multigravid and primigravid women
Authors: Morris Melanie , Maconochie Noreen , Doyle Pat
Published: April 2007

This study used the data from a retrospective cross‐sectional survey to describe the prevalence of smoking in pregnancy in a large UK sample, over more than 20 years of pregnancies. The main objective was to determine whether women in their second or subsequent pregnancy are more or less likely than primigravidae to change their smoking behaviour. The participants were 7506 ever‐pregnant women, from 7702 who answered the second stage of a survey of reproductive history in 2001–02, sent to 10 828 women, aged 18–55 years on the UK electoral register. These women gave detailed information on their last pregnancy. The main outcome measure was self‐reported cigarette consumption in the first trimester of pregnancy.

Nineteen per cent (1417/7506) of women in this sample smoked in the first trimester of the reported pregnancy. The data showed that there had been a decrease over the last 20 years in smoking prevalence, but this trend was not statistically significant after adjustment for confounding (Ptrend = 0.07). There was evidence that multigravidae were more likely to smoke in their pregnancies than were primigravidae (adjusted OR = 1.24, [95% CI 1.01, 1.53]), with a highly significant trend with increasing pregnancy order (Ptrend < 0.0001). Over time, women who reported smoking before pregnancy (n = 1926), showed a decreasing trend in continuing to smoke the same amount after recognising their pregnancies (Ptrend < 0.0001). After adjustment, multigravid smokers were almost 75% more likely than primigravid smokers to continue to smoke with no change in consumption (adjusted OR = 1.74, [95% CI 1.32, 2.28]), with a clear trend found with increasing pregnancy order (Ptrend = 0.001). In this UK population‐based study, multigravidae were more likely to smoke in pregnancy than women pregnant for the first time. If already a smoker, they were much less likely to cut down their smoking once they found out they were pregnant, regardless of age. This suggests that a great deal of the burden of morbidity associated with smoking in pregnancy is in the multigravid group.
Early and late phase asthmatic response in lower airways of cat‐allergic asthmatic patients – a comparison between experimental and environmental allergen challenge
Authors: Arvidsson M. B. , Löwhagen O. , Rak S.
Published: April 2007

Background:  Standardized experimental allergen challenges are usually adopted to investigate the effect of allergen exposure on the lower airways. Environmental (natural) allergen challenges are used less often, mainly because of difficulties in standardizing the method, safety reasons and costs. The aim of this study was to investigate the relationship between an experimental and an environmental bronchial challenge. For this reason a natural challenge model was developed.

Methods:  Sixty‐two patients with a history of cat allergen‐induced symptoms involving the lower airways, positive skin prick test, positive in vitro specific IgE to cat allergen and bronchial hyper‐responsiveness were included. All 62 patients underwent an experimental challenge in the laboratory followed by an environmental allergen challenge.

Results:  All 62 patients developed an early asthmatic response [≥20% fall in forced expiratory volume in 1 s (FEV1)] in the experimental challenge and 60% (37/62) during the environmental challenge. A late asthmatic response (≥15% fall in FEV1 within 3–24 h) was seen in 56% (35/62) of the patients after the experimental challenge. Following the environmental challenge 47% (29/62) of the patients developed a late response. Thirty‐four per cent (21/62) of the patients developed a late response in both challenge models and 31% (19/62) did not develop a late response in any model. Thus, there was consistency in 65% (40/62) of the patients in both challenge models.

Conclusion:  We found consistency in the pattern of response to inhaled allergen between the two challenge models and we believe that experimental bronchial challenge is likely to reflect the development of relevant inflammation in the lower airways after low‐dose allergen exposure in the environment.
Rupatadine in the treatment of chronic idiopathic urticaria: a double‐blind, randomized, placebo‐controlled multicentre study
Authors: Gimenez‐Arnau A. , Pujol R. M. , Ianosi S. , Kaszuba A. , Malbran A. , Poop G. , Donado E. , Perez I. , Izquierdo I. , Arnaiz E. ,   the Rupatadine Urticaria Study Group
Published: April 2007

Background: Chronic urticaria is one of the most common and disturbing cutaneous condition. The treatment of chronic idiopathic urticaria (CIU) is still a challenge. Antihistamines are recommended as first‐line treatment. Rupatadine is a new potent nonsedative anti‐H1.

Objective: To study rupatadine efficacy and safety for moderate to severe CIU treatment.

Methods: This randomized, double‐blind, placebo‐controlled, parallel‐group, multicentre, study was designed to assess primarily mean pruritus score (MPS) reduction with rupatadine, 10 and 20 mg, administered once daily for 4 weeks. Three hundred and thirty‐three patients with active episodes of moderate‐to‐severe CIU were included.

Results: A 57.5% (P < 0.005) and 63.3% (P = 0.0001) significative MPS reduction from baseline, was observed at week 4 with 10 and 20 mg rupatadine, respectively, compared with placebo (44.9%). Both doses of rupatadine were not significantly different at any time point, with respect to their effects on pruritus severity, number of wheals and total symptoms scores. Rupatadine 10 mg had an overall better adverse event profile.

Conclusion: Rupatadine 10 mg is a fast, long‐acting, efficacious and safe treatment option for the management of patients with moderate‐to‐severe CIU.
Isolation and characterization of native Cry j 3 from Japanese cedar (Cryptomeria japonica) pollen
Authors: Fujimura T. , Futamura N. , Midoro‐Horiuti T. , Togawa A. , Goldblum R. M. , Yasueda H. , Saito A. , Shinohara K. , Masuda K. , Kurata K. , Sakaguchi M.
Published: April 2007

Background:  Japanese cedar (Cryptomeria japonica) pollinosis is the most prevalent allergy in Japan. Recently, the Japanese cedar pollen allergen Cry j 3 was cloned as a homologue of Jun a 3, which is a major allergen from mountain cedar (Juniperus ashei) pollen. However, native Cry j 3 has not been isolated and there are no reports on its allergenic activity. The aims of this study were to isolate native Cry j 3 and assess its immunoglobulin E (IgE)‐binding capacity in patients with Japanese cedar pollinosis.

Methods:  Native Cry j 3 was purified from Japanese cedar pollen by multidimensional chromatography. We assessed the IgE‐binding capacity using sera from patients allergic to Japanese cedar pollen by immunoblot analysis and ELISA. Moreover, we assayed the capacity of Cry j 3 to induce histamine release from the patients’ leukocytes. We cloned cDNA corresponding to purified Cry j 3 from a cDNA library of Japanese cedar pollen.

Results:  We isolated native Cry j 3 as a 27‐kDa protein. The IgE‐binding frequency of Cry j 3 from the sera of patients allergic to Japanese cedar pollen was estimated as 27% (27/100) by ELISA. Cry j 3 induced the release of histamine from leukocytes. We cloned the cDNA and named it Cry j 3.8. Cry j 3.8 cDNA encoded 225 amino acids and had significant homology with thaumatin‐like proteins.

Conclusions:  Cry j 3 is a causative allergen in Japanese cedar pollinosis and may play crucial roles in the cross‐reactivity with oral allergy syndrome.
House dust (1–3)‐β‐d‐glucan and wheezing in infants
Authors: Iossifova Y. Y. , Reponen T. , Bernstein D. I. , Levin L. , Kalra H. , Campo P. , Villareal M. , Lockey J. , Hershey G. K. K. , LeMasters G.
Published: April 2007

Background:  (1–3)‐β‐d‐glucan is a fungal cell wall component, suspected to cause respiratory symptoms in adults. However, very little is known on the possible health effects of (1–3)‐β‐d‐glucan during infancy. We examined the association between (1–3)‐β‐d‐glucan exposure and the prevalence of allergen sensitization and wheezing during the first year of life in a birth cohort of 574 infants born to atopic parents. Endotoxin exposure was included as a possible confounder.

Methods:  (1–3)‐β‐d‐glucan and endotoxin exposures were measured in settled dust collected from infants’ primary activity rooms. The primary outcomes at approximately age one included parental reports of recurrent wheezing and allergen sensitization evaluated by skin prick testing to a panel of 15 aeroallergens as well as milk and egg white.

Results:  Exposure to high (1–3)‐β‐d‐glucan concentration (within fourth quartile) was associated with reduced likelihood of both recurrent wheezing [adjusted OR (aOR) = 0.39, 95% CI = 0.16–0.93] and recurrent wheezing combined with allergen sensitization (aOR = 0.13, 95% CI = 0.03–0.61). Similar trends were found between (1–3)‐β‐d‐glucan concentrations and allergen sensitization (aOR = 0.57, 95% CI = 0.30–1.10). In contrast, recurrent wheezing with or without allergen sensitization was positively associated with low (1–3)‐β‐d‐glucan exposure within the first quartile (aOR = 3.04, 95% CI = 1.25–7.38; aOR = 4.89, 95% CI = 1.02–23.57). There were no significant associations between endotoxin exposure and the studied health outcomes.

Conclusions:  This is the first study to report that indoor exposure to high levels of (1–3)‐β‐d‐glucan (concentration >60 μg/g) is associated with decreased risk for recurrent wheezing among infants born to atopic parents. This effect was more pronounced in the subgroup of allergen‐sensitized infants.
Airway expression of calcitonin gene‐related peptide in T‐cell peptide‐induced late asthmatic reactions in atopics
Authors: Kay A. B. , Ali F. R. , Heaney L. G. , Benyahia F. , Soh C. P. C. , Renz H. , Lee T. H. , Larché M.
Published: April 2007

Background:  The mechanisms of late asthmatic reactions provoked in atopic asthmatics by allergen‐derived T‐cell peptide epitopes remain unclear. Previous studies showed no changes in airway eosinophils or mast cell products after peptide challenge. In the present study our aim was to measure calcitonin gene‐related peptide (CGRP), neurokinin (NK)‐A, and substance P (SP) in bronchoalveolar lavage fluid and bronchial biopsies (BB) after inhalation of allergen‐derived T‐cell peptide epitopes since these neuropeptides (NP) had not previously been evaluated in this chronic asthma model.

Methods:  Bronchoscopy, with BB and bronchoalveolar lavage (BAL), was performed in 24 cat‐allergic subjects 6 h after inhalation of Fel d 1‐derived peptides. Neuropeptides were measured in BAL by enzyme‐linked immunosorbent assay and CGRP expression in the airways was assessed by immunohistochemistry and confocal microscopy.

Results:  Twelve subjects (termed ‘responders’) developed isolated late reactions. Calcitonin gene‐related peptide, but not NK‐A or SP, was significantly elevated in BAL in responders only. Biopsy studies showed that in virtually all responders peptide challenge induced marked increases in CGRP immunoreactivity in bronchial epithelial cells, infiltrating submucosal cells and in association with airway smooth muscle. Double immunostaining indicated that CGRP colocalized predominantly to CD3+/CD4+ and CD68+ submucosal inflammatory cells.

Conclusion:  Calcitonin gene‐related peptide, a potent vasodilator, is markedly up‐regulated in the airways of atopic asthmatics during late‐phase reactions provoked by inhalation of allergen‐derived T‐cell peptides.
Anaphylaxis during anaesthesia: diagnostic approach
Authors: Ebo D. G. , Fisher M. M. , Hagendorens M. M. , Bridts C. H. , Stevens W. J.
Published: April 2007

Correct management of anaphylaxis during anaesthesia requires a multidisciplinary approach with prompt recognition and treatment of the acute event by the attending anaesthesiologist, and subsequent determination of the responsible agent(s) with strict avoidance of subsequent administration of all incriminated and/or cross‐reacting compounds.

However, correct identification of the causative compound(s) and safe alternatives is not always straightforward and, too often, not done.

This review is not intended to discuss acute management of anaesthesia‐related anaphylaxis but summarizes the major causes of anaphylaxis during anaesthesia and the diagnostic approach of this rare but potentially life‐threatening complication. Apart from general principles about the diagnostic approach, history taking and importance of tryptase quantification, more specific confirmatory diagnostic procedures are organized on the basis of the major causes of perioperative anaphylactic reactions.
Creating the UK National Statistics 2001 Output Area Classification
Authors: Vickers Dan , Rees Phil
Published: April 2007

The paper describes the creation of the Office for National Statistics 2001 output area classification, which was created in collaboration with the authors. The classification places each 2001 census output area into one of seven clusters based on the socio-economic attributes of the residents of each area. The classification uses cluster analysis to reduce 41 census variables to a single socio-economic indicator. The classification was made available with a host of supporting and descriptive information as a National Statistic via National Statistics on line. The classification forms part of a suite of area classifications that were produced by the Office for National Statistics from 2001 census data. Classifications of local authorities, statistical wards and health areas are also available.
Methane‐flux‐dependent lateral faunal changes in a Late Cretaceous chemosymbiotic assemblage from the Nakagawa area of Hokkaido, Japan
Authors: JENKINS ROBERT G. , KAIM ANDRZEJ , HIKIDA YOSHINORI , TANABE KAZUSHIGE
Published: April 2007

A Late Cretaceous carbonate body (2 m in maximum diameter) surrounded by clastic rocks, recently discovered in the Nakagawa area (Hokkaido, Japan), is interpreted as a methane‐seep deposit, on the basis of negative carbon isotopic composition (as low as −43.5‰), variable sulphide sulphur isotopic composition, high carbonate content, and in situ fractures. It most likely formed owing to methane‐bearing pore‐water diffusion. We estimate that the concentration of methane decreased toward the margin of the carbonate body, and that only small carbonate concretions were precipitated at a certain distance from the methane‐seep centre. These spatial characteristics coincide well with the observed pattern of faunal distribution. The gastropod‐dominated association (indeterminate abyssochrysids and ataphrids and the acmaeid limpet Serradonta sp. are most common) co‐occurs with lucinid and thyasirid bivalves (Thyasira sp., Myrtea sp., and Miltha sp.), and was found within and just above the methane‐derived carbonate body. Acharax and Nucinella (solemyoid bivalves) are more typical of the peripheral part of the methane‐influenced sediments. We suggest that this pattern of faunal distribution reflects the decreasing concentration of methane and apparently also hydrogen sulphide when moving from the centre of discharge toward the periphery of the methane seep.
Distinct locomotive patterns of granulocytes, monocytes and lymphocytes in a stable concentration gradient of chemokines
Authors: BAE S. Y. , JUNG Y. J. , WOO S. Y. , PARK M. H. , SEOH J. Y. , RYU K. H.
Published: April 2007

The pattern of leukocyte locomotion can be changed in many pathological situations, but its accurate analysis is difficult because of technological limitation. In the present study, by using a newly developed time‐lapse videomicroscopic technique, we have analyzed the locomotive patterns of leukocytes in a stable concentration gradient of chemokines. Granulocytes, monocytes, and lymphocytes were purified from adult human peripheral blood. Locomotive behavior of the leukocytes was analyzed by an optical assay using a microchannel producing a stable concentration gradient of chemokines. Videomicroscopic analysis showed distinct locomotive patterns of granulocytes, monocytes, and lymphocytes. Granulocytes were intrinsically motile, vigorously moving in random direction without any chemokine stimulation. Upon stimulation with CXCL8/IL‐8, the speed of migration was increased from 13.3 ± 2.8 to 19.4 ± 2.5 μm/min (P = 0.002,n = 100) and they moved toward the chemokine, although many cells still wandered very much. Stimulation with CCL5/RANTES or CXCL12/SDF‐1αinduced similar changes in locomotive pattern. On the other hand, most lymphocytes did not polarize or move spontaneously without chemokine stimulation. Stimulation with CXCL12 induced directional migration in 37% of the lymphocytes at a speed of 9.6 ± 1.6 μm/min (n = 100). The movement pattern of monocytes was similar to that of granulocytes in that they tend to become polarized and move spontaneously, but they moved at a very slow speed ranging from 3.9 to 4.2 μm/min even with chemokine stimulation. The new optical assay may be useful for many diagnostic as well as basic studies.
A Symmetric Bipolar Nebula Around MWC 922
Authors: Tuthill P. G. , Lloyd J. P.
Published: April 2007

We report regular and symmetric structure around dust-enshrouded Be star MWC 922 obtained with infrared imaging. Biconical lobes that appear nearly square in aspect, forming this “Red Square” nebula, are crossed by a series of rungs that terminate in bright knots or “vortices,” and an equatorial dark band crossing the core delimits twin hyperbolic arcs. The intricate yet cleanly constructed forms that comprise the skeleton of the object argue for minimal perturbation from global turbulent or chaotic effects. We also report the presence of a linear comb structure, which may arise from optically projected shadows of a periodic feature in the inner regions, such as corrugations in the rim of a circumstellar disk. The sequence of nested polar rings draws comparison with the triple-ring system seen around the only naked-eye supernova in recent history: SN1987A.
Comment on "Wetland Sedimentation from Hurricanes Katrina and Rita"
Authors: Törnqvist Torbjörn E. , Paola Chris , Parker Gary , Liu Kam-biu , Mohrig David , Holbrook John M. , Twilley Robert R.
Published: April 2007

Turner
et al
. (Reports, 20 October 2006, p. 449) measured sedimentation from Hurricanes Katrina and Rita in coastal Louisiana and inferred that storm deposition overwhelms direct Mississippi River sediment input. However, their annualized hurricane deposition rate is overestimated, whereas riverine deposition is underestimated by at least an order of magnitude. Their numbers do not provide a credible basis for decisions about coastal restoration.
Structure of Fungal Fatty Acid Synthase and Implications for Iterative Substrate Shuttling
Authors: Jenni Simon , Leibundgut Marc , Boehringer Daniel , Frick Christian , Mikolásek Bohdan , Ban Nenad
Published: April 2007

We report crystal structures of the 2.6-megadalton α
6
β
6
heterododecameric fatty acid synthase from
Thermomyces lanuginosus
at 3.1 angstrom resolution. The α and β polypeptide chains form the six catalytic domains required for fatty acid synthesis and numerous expansion segments responsible for extensive intersubunit connections. Detailed views of all active sites provide insights into substrate specificities and catalytic mechanisms and reveal their unique characteristics, which are due to the integration into the multienzyme. The mode of acyl carrier protein attachment in the reaction chamber, together with the spatial distribution of active sites, suggests that iterative substrate shuttling is achieved by a relatively restricted circular motion of the carrier domain in the multifunctional enzyme.
Structural Basis for Substrate Delivery by Acyl Carrier Protein in the Yeast Fatty Acid Synthase
Authors: Leibundgut Marc , Jenni Simon , Frick Christian , Ban Nenad
Published: April 2007

In the multifunctional fungal fatty acid synthase (FAS), the acyl carrier protein (ACP) domain shuttles reaction intermediates covalently attached to its prosthetic phosphopantetheine group between the different enzymatic centers of the reaction cycle. Here, we report the structure of the
Saccharomyces cerevisiae
FAS determined at 3.1 angstrom resolution with its ACP stalled at the active site of ketoacyl synthase. The ACP contacts the base of the reaction chamber through conserved, charge-complementary surfaces, which optimally position the ACP toward the catalytic cleft of ketoacyl synthase. The conformation of the prosthetic group suggests a switchblade mechanism for acyl chain delivery to the active site of the enzyme.