bluuebunny/crossref_metadata_2025 huggingface dataset:
GENETIC STUDY: BclI glucocorticoid receptor polymorphism and smoking in the general population
Authors: Siiskonen Satu J. , Visser Loes E. , Tiemeier Henning , Hofman Albert , Lamberts Steven W.J. , Uitterlinden André G. , Stricker Bruno H.Ch.
Published: April 2009

We studied the hypothesis that the BclI polymorphism of the glucocorticoid receptor gene is associated with an increased probability of being a (heavy) smoker and a decreased ability to quit smoking. The study cohort consisted of all subjects in the Rotterdam Study, a Dutch population‐based cohort of people aged 55 years and older, for whom BclI genotyping and smoking status at baseline were available. In prospective analyses, the smoking status was reassessed during three additional examination rounds. Logistic regression analysis was used to study the association between BclI polymorphism and being a smoker or a heavy smoker at baseline. Furthermore, the relationship between BclI polymorphism and incident smoking cessation was tested with Cox proportional hazards analysis within those who smoked at baseline. In total, 6358 subjects were included in the study. The presence of a G‐allele was not associated with current smoking at baseline [odds ratio (OR) = 0.96, 95%confidence interval (CI): 0.85–1.09] or with the incidence of smoking cessation during follow‐up [hazard ratio (HR) = 0.98, 95%CI: 0.80–1.19]. Within current smokers, having a G‐allele was not significantly associated with the risk of being a heavy smoker when measured by pack‐years smoked (OR = 1.07, 95%CI: 0.85–1.35) or daily consumption of tobacco (OR = 1.10, 95%CI: 0.88–1.37). We were not able to replicate the earlier findings indicating that the proportion of current smokers is lower among carriers of the CC‐genotype of the BclI glucocorticoid receptor. Furthermore, the BclI glucocorticoid receptor polymorphism did not predict the incidence of smoking cessation in the general elderly population.
GENETIC STUDY: Heritability and a genome‐wide linkage analysis of a Type II/B cluster construct for cannabis dependence in an American Indian community
Authors: Ehlers Cindy L. , Gilder David A. , Gizer Ian R. , Wilhelmsen Kirk C.
Published: April 2009

Subtyping of substance dependence disorders holds promise for a number of important research areas including phenotyping for genetic studies, characterizing clinical course, and matching treatment and prevention strategies. This study sought to investigate whether a dichotomous construct similar to Babor's Types A/B and Cloninger's Types I/II for alcohol dependence can be identified for cannabis dependence in a Native American sample. In addition, heritability of this construct and its behavior in a genetic linkage analyses were evaluated. Information on cannabis use and dependence symptoms and other psychiatric disorders was obtained using the Semi‐Structured Assessment for the Genetics of Alcoholism from a community sample of 606 American Indians. Hierarchical average linkage and K means cluster analysis was used, and a three‐cluster solution was found to generate the best separation of variables. Ninety‐one per cent of cannabis‐dependent participants fell into one of the two subtypes: Type A/I cluster (n = 114, 56%) and Type B/II cluster (n = 70, 35%). Heritability (estimated using Sequential Oligogenic Linkage Analysis Routines) was only significant for the Type B/II cluster (h2 = 0.44, SE = 0.18, P < 0.01). Evidence for linkage was found for the Type B/II cluster (versus no diagnosis) on chromosome 16 [at 139 centimorgans (cM), Log of the Odds (LOD) score = 4.4], and on chromosome 19 (at 74 cM, LOD score = 6.4). Regions of interest for this phenotype (LOD > 1.5) were also located on chromosomes 14, 21, 22. These findings suggest that a Type B/II cannabis dependence phenotype can be identified in this population and that it is in part heritable and linked to areas of the genome identified previously for drug dependence phenotypes in this population as well as in other studies.
A novel microdeletion at chromosome 2q31.1‐31.2 in a three‐generation family presenting duplication of great toes with clinodactyly
Authors: Tsai L‐P , Liao H‐M , Chen Y‐J , Fang J‐S , Chen C‐H
Published: April 2009

HOXD gene cluster maps to chromosome 2q31 and plays a key role in embryonic limb morphogenesis. Mutations of the HOXD13 and HOXD10 genes have been found to be associated with digital and limb malformations. In addition, dysregulation of HOXD gene cluster has been proposed to account for the limb abnormalities in patients with chromosome 2q rearrangements. In this report, we investigated a three‐generation family presenting clinical phenotypes of duplication of great toes, tapering fingers, and clinodactyly of the fifth finger in both hands, which were transmitted in a dominant fashion in this family. We identified and validated an interstitial microdeletion of ∼3.4 Mb at chromosome 2q31.1‐31.2 by array‐based comparative genomic hybridization, fluorescence in situ hybridization, and real‐time quantitative polymerase chain reaction that cosegregates with the clinical phenotypes in this family. The microdeletion removes 30 labeled genes including the entire HOXD gene cluster, suggesting that the digital abnormalities of this family may be attributed to the haploinsufficiency of the HOXD gene cluster. The delineation of the microdeletion region may contribute to the genotype–phenotype correlation study in patients with genomic rearrangements of the long arm of chromosome 2 and helps to understand the pathogenesis of haploinsufficiency of the HOXD gene cluster.
Importance of gene–environment interactions in the etiology of selected birth defects
Authors: Zhu H , Kartiko S , Finnell RH
Published: April 2009

It is generally understood that both genetic and environmental factors contribute to the highly complex etiology of structural birth defects, including neural tube defects, oral clefts and congenital heart defects, by disrupting highly regulated embryonic developmental processes. The intrauterine environment of the developing embryo/fetus is determined by maternal factors such as health/disease status, lifestyle, medication, exposure to environmental teratogens, as well as the maternal genotype. Certain genetic characteristics of the embryo/fetus also predispose it to developmental abnormalities. Epidemiologic and animal studies conducted over the last few decades have suggested that the interplay between genes and environmental factors underlies the etiological heterogeneity of these defects. It is now widely believed that the study of gene–environment interactions will lead to better understanding of the biological mechanisms and pathological processes that contribute to the development of complex birth defects. It is only through such an understanding that more efficient measures will be developed to prevent these severe, costly and often deadly defects. In this review, we attempt to summarize the complex clinical and experimental literature on current hypotheses of interactions between several select environmental factors and those genetic pathways in which they are most likely to have significant modifying effects. These include maternal folate nutritional status, maternal diabetes/obesity‐related conditions, and maternal exposure to selected medications and environmental contaminants. Our goal is to highlight the potential gene–environment interactions affecting early embryogenesis that deserve comprehensive study.
Four novel SPG3A/atlastin mutations identified in autosomal dominant hereditary spastic paraplegia kindreds with intra‐familial variability in age of onset and complex phenotype
Authors: Smith BN , Bevan S , Vance C , Renwick P , Wilkinson P , Proukakis C , Squitieri F , Berardelli A , Warner TT , Reid E , Shaw CE
Published: April 2009

Mutation of the atlastin gene (SPG3A) is responsible for ∼10% of autosomal dominant hereditary spastic paraplegia (AD‐HSP) cases. The goal of this study was to identify novel disease causing atlastin mutations. Atlastin nucleotide variations were detected by direct sequencing of all 14 exons in 70 autosomal dominant (AD), 16 single sibship and 14 sporadic spastic paraplegia patients. Six mis‐sense mutations (four of which were novel) were identified in six unrelated AD‐HSP kindreds in exons 4, 7 and 8 of the atlastin gene. One kindred with a novel mutation showed variability in clinical phenotype and age of onset. Mutations are predicted to decrease GTPase activity, cause morphological abnormalities of the endoplasmic reticulum and prevent maturation of the Golgi complex resulting in impaired vesicle trafficking. Our study significantly adds to the spectrum of mutations and clinical phenotype of SPG3A. We advocate that all spastin mutation negative AD‐HSP kindreds should be screened for pathogenic atlastin mutations regardless of age of onset or phenotypic complexity.
An X‐linked microcephaly syndrome caused by disruptions of CASK implicates the CASK‐TBR1‐RELN pathway in human brain development
Authors: Bailey Kathleen A. , Aldinger Kimbery A.
Published: April 2009

Mutations of CASK cause an X‐linked brain malformation phenotype with microcephaly and hypoplasia of the brainstem and cerebellum. Najm J et al.. (2008) Nature Genetics 40: 1065–1067.
Routine chest X‐ray is not required after a low‐risk central venous cannulation
Authors: PIKWER A. , BÅÅTH L. , PERSTOFT I. , DAVIDSON B. , ÅKESON J.
Published: April 2009

Background: Knowledge of the radiographic catheter tip position after central venous cannulation is normally not required for short‐term catheter use. Detection of a possible iatrogenic pneumothorax may nevertheless justify routine post‐procedure chest X‐ray. Our aim was to design a clinical decision rule to select patients for radiographic evaluation after central venous cannulation.

Methods: A total of 2230 catheterizations performed using external jugular, internal jugular or subclavian venous approaches during a 4‐year period were included consecutively. Information on patient data and corresponding procedures was recorded prospectively. A post‐procedure chest X‐ray was obtained after each cannulation.

Results: Thirteen cases (0.58%) of cannulation‐associated pneumothorax were identified. The risk of pneumothorax after a technically difficult (1.8%) or subclavian (1.6%) cannulation was significantly higher than after cannulation not considered as difficult (0.37%) or performed using other routes (0.33%). Clinical signs of pneumothorax within 8 h of cannulation were found in all seven patients with pneumothorax requiring specific treatment. A new clinical decision rule for radiographic evaluation after central venous cannulation based on the results of the present study shows that 48% of the post‐procedure chest X‐rays performed in our patients were clinically redundant.

Conclusion: Clinical symptoms were reported in all patients with pneumothorax requiring specific treatment. Approximately half of the post‐procedure chest X‐ray controls could be avoided using the proposed clinical decision rule to select patients for radiographic evaluation after central venous cannulation. A large prospective multi‐centre study should be carried out to further evaluate this decision rule.
Accessing genotype by environment interaction using within‐ and across‐country test‐day random regression sire models
Authors: Hammami H. , Rekik B. , Soyeurt H. , Bastin C. , Bay E. , Stoll J. , Gengler N.
Published: April 2009

First‐lactation test‐day (TD) milk records of Luxembourg and Tunisian Holsteins were analysed for evidence of genotype by environment interaction (G × E). The joint data included 730 810 TD records of 87 734 cows and 231 common sires. Random regression TD sire models with fourth‐order Legendre polynomials were used to estimate genetic parameters via within‐ and across‐country analyses. Daily heritability estimates of milk yield from within‐country analysis were between 0.11 and 0.32, and 0.03 and 0.13 in Luxembourg and Tunisia, respectively. Heritability estimates for 305‐day milk yield and persistency (defined as the breeding value for milk yield on DIM 280 minus the breeding value on DIM 80) were lower for Tunisian Holsteins compared with the Luxembourg population. Specifically, heritability for 305‐day milk yield was 0.16 for within‐ and 0.11 for across‐country analyses for Tunisian Holsteins and 0.38 for within‐ and 0.40 for across‐country analyses for Luxembourg Holsteins. Heritability for apparent persistency was 0.02 for both within‐ and across‐country analyses for Tunisian Holsteins and 0.08 for within‐ and 0.09 for across‐country analyses for Luxembourg Holsteins. Genetic correlations between the two countries were 0.50 for 305‐day milk yield and 0.43 for apparent persistency. Moreover, rank correlations between the estimated breeding values of common sires for 305‐day milk yield and persistency, estimated separately in each country, were low. Low genetic correlations are evidence for G × E for milk yield production while low rank correlations suggest different rankings of sires in both environments. Results from this study indicate that milk production of daughters of the same sires depends greatly on the production environment and that importing high merit semen for limited input systems might not be an effective strategy to improve milk production.
Genealogical analyses in open populations: the case of three Arab‐derived Spanish horse breeds
Authors: Cervantes I. , Gutiérrez J.P. , Molina A. , Goyache F. , Valera M.
Published: April 2009

This research assesses the genetic composition of three Arab‐derived Spanish horse breeds as an example to highlight the major shortcomings related to genealogical analyses in open populations and to propose approaches useful to deal with this task. The studbooks of three Spanish Arab (SA)‐derived horse breeds, Spanish Anglo‐Arab (dAA), Hispano‐Arab (dHA) and Spanish Sport Horse (dSSH) and those of their parental breeds SA, Spanish Purebred (SPB) and Thoroughbred (TB), totalling 211 754 individuals, were available. The genealogies of the dAA, dHA and dSSH were analysed not only using the corresponding studbook (breed exclusive dataset) but also including the genealogies of the founders from parental breeds (completed dataset). Coancestry analyses revealed that the present SA‐derived populations share more genes with the Arab than with the other parental breeds. Effective population size was computed by accounting for migration rates to obtain an equivalent closed‐population effective size (eqNe) of 39.2 for the dAA, 56.3 for dHA and 114.1 for dSSH. The essayed methodologies were useful for characterising populations involving migration. The consequences of the management of the analysed breeds are discussed. The results emphasize the need to include the complete genealogies of the individuals to attain reliable genealogical parameters.
Petrochemistry of sandstones from Neoproterozoic basins of the Bastar craton, Central Indian Shield: Implications for paleoweathering, provenance and tectonic history
Authors: Wani Hamidullah , Mondal Mohammad E. A.
Published: April 2009

Petrographic analysis and chemical analysis of major and trace elements including rare earth elements of the Neoproterozoic sandstones from the Chandarpur Group and the Tiratgarh Formation have been carried out to determine their provenance, tectonic setting and weathering conditions. All sandstone samples are highly enriched in quartz but very poor in feldspar and lithic fragments. Petrographically and geochemically these sandstones are classified as subarkose, sublitharenite and arenite. The Chemical Index of Alteration (CIA mean 68) and Th/U ratios (mean 4.2) for these sandstones suggest their moderate weathering nature. Generally, all sandstone samples are strongly depleted in major elements (except SiO2), trace elements (except Zr) and REE in comparison with Post Archean Australian Shale (PAAS) and Upper Continental Crust (UCC). Their mineralogy and mean of elemental ratios suitable for determination of provenance and tectonic setting, e.g. Al2O3/SiO2(0.02), K2O/Na2O (10), Eu/Eu* (0.67), (La/Lu)n (10.4), La/Sc (3), Th/Sc (1.2), La/Co (0.22), Th/Co (0.08), and Cr/Th (7.2), support a felsic source and a passive margin tectonic setting for these sandstones. Also these key elemental ratios do not show much variation over a range of SiO2. Thus we attest their significance in determining source rock characteristics of quartz rich sandstones. Chondrite‐normalized REE patterns with LREE enrichment and a strong negative Eu anomaly are also attributed to felsic source rock characteristics for these sandstones. The source rocks identified are granite and gneiss of the Bastar craton. Minor amounts may have been derived from older supracrustals of the Bastar craton. However, the major element data of the Paleoproterozoic Sakoli schists when compared with those of the Neoproterozoic sandstones indicate that the schists were derived from a mafic source and deposited in an active continental margin tectonic setting. There is, however, little difference in CIA values between the Paleoproterozoic Sakoli schists and Neoproterozoic sandstones, indicating prevailing of similar (moderate‐intense) weathering conditions throughout the Proterozoic in the Bastar craton. Our study also suggests a change in the provenance and tectonic setting of deposition of sediments from dominantly a mafic source and an active continental margin in the Paleoproterozoic to dominantly granite and gneiss (felsic source) and a passive continental margin in the Neoproterozoic in the Bastar craton.
Style of fluid flow and deformation in and around an ancient out‐of‐sequence thrust: An example from the Nobeoka Tectonic Line in the Shimanto accretionary complex, Southwest Japan
Authors: Mukoyoshi Hideki , Hirono Tetsuro , Hara Hidetoshi , Sekine Kotaro , Tsuchiya Noriyoshi , Sakaguchi Arito , Soh Wonn
Published: April 2009

To understand the characteristics of deformation of an out‐of‐sequence thrust (OST) and the style of fluid flow along it, we investigated the Nobeoka Tectonic Line, which has been interpreted as a deep OST (7–9 km), in the Shimanto accretionary complex, Southwest Japan. The shear zone in the footwall differs significantly in the along‐strike direction not only in thickness, which varied from 100 to 300 m, but also in lithology and mineral vein development. These variations might reflect primarily differences in lithology; that is, the sandstone‐dominant shear zone with a large amount of mineral veins precipitated in microcracks is relatively thick, whereas the shale‐dominant shear zone with a small amount of veins and with textures indicating highly pressurized pore fluid, is thinner. By comparison with characteristics of a shallow OST (3–5 km), we conclude that the shallow OST has experienced repeated brittle failure with rapid slip and focused fluid flow whereas the deep OST has experienced both brittle and ductile deformation, followed by fluid flow of various styles, depending on the lithology.
Sex among Asian men and women: The Global Better Sex Survey in Asia
Authors: Tan Hui Meng , Marumo Ken , Yang Dae‐yul , Hwang Thomas I‐sheng , Ong Moh‐Lim
Published: April 2009

Objectives:  To explore by a pooled subanalysis of the Global Better Sex Survey sexual aspirations and unmet needs of men and women from Hong Kong, Indonesia, Japan, Malaysia, Singapore, South Korea, Taiwan, and Thailand.

Methods:  To qualify, respondents must have had sexual intercourse at least once in the past 12 months. Women must have had heterosexual intercourse. Data were weighted by population size between countries.

Results:  Of 3538 Asian respondents (1776 men and 1762 women), 52% were aged <40 years, 40% were aged 40–59 years, and 8% were aged ≥60 years. The majority were married or in a relationship. Men and women reported having sexual intercourse 5.1 and 4.0 times monthly, respectively. Attraction to partner, foreplay, intercourse, and achieving orgasm were important to most men and women. Two thirds were less than very satisfied with their sex life, and 36% of men were interested in improving sex. For a good sexual experience, the man's ability to get and maintain an erection and erection hardness were important to the majority of Asian men and women. Few respondents reported using a prescription erectile dysfunction medication, but many showed interest in using these medications to improve their sex lives. A comparison between individual countries suggests that attitudes about sex differ from country to country, and between men and women in each country.

Conclusions:  Sex is very important to Asian men and women, but many of them are not fully satisfied with their sex lives and want to improve them.
Prevalence and risk factors of female urinary incontinence in eastern Turkey
Authors: Onur Rahmi , Deveci Suleyman Erhan , Rahman Suheyla , Sevindik Feyza , Acik Yasemin
Published: April 2009

Objectives:  To evaluate the prevalence of urinary incontinence (UI) and determine risk factors for its development in women living in eastern Turkey.

Methods:  A cross‐sectional study was conducted on 2275 women aged between 17 and 80 years. A questionnaire examining demographic characteristics, parity and pelvic organ prolapse was given. Presence and types of incontinence were examined using a validated form of the Turkish version of the urogenital distress inventory questionnaire‐short form (UDI‐6).

Results:  A total of 1054 (46.3%) women reported involuntary loss of urine. Stress UI was present in 46% of women, whereas urge UI was detected in 43% of them. Mean age of patients with and without UI were 44.57 + 11.04 and 35.04 + 9.51, respectively. Age, total number of pregnancies and number of deliveries were shown to be significantly different in patients with and without any type of UI. Multiple logistic regression analysis of the factors revealed that age, total delivery number, pelvic organ prolapse and difficult labor were significantly associated with the presence of UI.

Conclusions:  This is the first study examining the prevalence of UI in women living in eastern Turkey. By using a validated questionnaire, several risk factors for the development of UI were determined. Pelvic organ prolapse and increased number of births were found to be two most significant ones.
Antagonism of serotonergic 5‐HT2A/2Creceptors: mutual improvement of sleep, cognition and mood?
Authors: Landolt H.‐P. , Wehrle R.
Published: April 2009

Serotonin [5‐hydroxytryptamine (5‐HT)] and 5‐HT receptors are involved in sleep and in waking functions such as cognition and mood. Animal and human studies support a particular role for the 5‐HT2Areceptor in sleep, which has led to renewed interest in this receptor subtype as a target for the development of novel pharmacological agents to treat insomnia. Focusing primarily on findings in healthy human volunteers, a review of the available data suggests that antagonistic interaction with 5‐HT2Areceptors (and possibly also 5‐HT2Creceptors) prolongs the duration of slow wave sleep and enhances low‐frequency (< 7 Hz) activity in the sleep electroencephalogram (EEG), a widely accepted marker of sleep intensity. Despite certain differences, the changes in sleep and the sleep EEG appear to be remarkably similar to those of physiologically more intense sleep after sleep deprivation. It is currently unclear whether these changes in sleep are associated with improved vigilance, cognition and mood during wakefulness. While drug‐induced interaction with sleep must be interpreted cautiously, too few studies are available to provide a clear answer to this question. Moreover, functional relationships between sleep and waking functions may differ between healthy controls and patients with sleep disorders. A multimodal approach investigating subjective and objective aspects of sleep and wakefulness provides a promising research avenue for shedding light on the complex relationships among 5‐HT2A/2Creceptor‐mediated effects on sleep, the sleep EEG, cognition and mood in health and various diseases associated with disturbed sleep and waking functions.
Consequences of sleep deprivation on neurotransmitter receptor expression and function
Authors: Longordo Fabio , Kopp Caroline , Lüthi Anita
Published: April 2009

Several pieces of evidence suggest that sleep deprivation causes marked alterations in neurotransmitter receptor function in diverse neuronal cell types. To date, this has been studied mainly in wake‐ and sleep‐promoting areas of the brain and in the hippocampus, which is implicated in learning and memory. This article reviews findings linking sleep deprivation to modifications in neurotransmitter receptor function, including changes in receptor subunit expression, ligand affinity and signal transduction mechanisms. We focus on studies using sleep deprivation procedures that control for side‐effects such as stress. We classify the changes with respect to their functional consequences on the activity of wake‐promoting and/or sleep‐promoting systems. We suggest that elucidation of how sleep deprivation affects neurotransmitter receptor function will provide functional insight into the detrimental effects of sleep loss.
Functional and structural brain alterations in insomnia: implications for pathophysiology
Authors: Riemann D. , Kloepfer C. , Berger M.
Published: April 2009

Insomnia is defined as the complaint of not being able to fall asleep or to maintain sleep, and/or nonrestorative sleep, accompanied by impaired daytime functioning on a social, emotional or professional level. Insomnia per se is a very frequent complaint and can be caused by environmental, medical, mental or psychosocial factors or the intake of drugs. Primary insomnia is an insomnia subtype characterized by the absence of a causative medical or psychiatric factor. From a pathophysiological point of view, persistent hyperarousal on autonomous, emotional, cognitive or neurobiological levels is thought to be the decisive factor for the development and persistence of chronic primary insomnia. This view is supported by studies confirming that patients with primary insomnia display heightened levels of fast frequencies of the sleep EEG, show increased production of cortisol and interleukin‐6, and demonstrate increased metabolism in several brain areas during sleep (as measured by positron emission tomography). Furthermore, primary insomnia is coupled with cognitive deficits during waking and with impairments of nocturnal memory consolidation. Just recently, reductions in hippocampal volume size have been reported in patients suffering from primary insomnia. In the light of neurobiological theories of sleep–wake regulation, primary insomnia may be conceptualised as the final common pathway of the interaction of a genetic vulnerability to an imbalance between arousing and sleep‐inducing brain centres (which is triggered by psychosocial and/or medical stressors) with perpetuating mechanisms such as maladaptive behaviours, learned sleep‐preventing associations and cognitive factors.
Circadian clock genes and sleep homeostasis
Authors: Franken P. , Dijk D.‐J.
Published: April 2009

Circadian and sleep‐homeostatic processes both contribute to sleep timing and sleep structure. Elimination of circadian rhythms through lesions of the suprachiasmatic nuclei (SCN), the master circadian pacemaker, leads to fragmentation of wakefulness and sleep but does not eliminate the homeostatic response to sleep loss as indexed by the increase in EEG delta power. In humans, EEG delta power declines during sleep episodes nearly independently of circadian phase. Such observations have contributed to the prevailing notion that circadian and homeostatic processes are separate but recent data imply that this segregation may not extend to the molecular level. Here we summarize the criteria and evidence for a role for clock genes in sleep homeostasis. Studies in mice with targeted disruption for core circadian clock genes have revealed alterations in circadian rhythmicity as well as changes in sleep duration, sleep structure and EEG delta power. Clock‐gene expression in brain areas outside the SCN, in particular the cerebral cortex, depends to a large extent on prior sleep–wake history. Evidence for effects of clock genes on sleep homeostasis has also been obtained in Drosophila and humans, pointing to a phylogenetically preserved pathway. These findings suggest that, while within the SCN clock genes are utilized to set internal time‐of‐day, in the forebrain the same feedback circuitry may be utilized to track time spent awake and asleep. The mechanisms by which clock‐gene expression is coupled to the sleep–wake distribution could be through cellular energy charge whereby clock genes act as energy sensors. The data underscore the interrelationships between energy metabolism, circadian rhythmicity, and sleep regulation.
Astrocytes and oligodendrocytes can be generated from NG2+ progenitors after acute brain injury: intracellular localization of oligodendrocyte transcription factor 2 is associated with their fate choice
Authors: Zhao Jing‐Wei , Raha‐Chowdhury Ruma , Fawcett James W. , Watts Colin
Published: April 2009

Brain injury induces gliosis and scar formation; its principal cell types are mainly astrocytes and some oligodendrocytes. The origin of the astrocytes and oligodendrocytes in the scar remains unclear together with the underlying mechanism of their fate choice. We examined the response of oligodendrocyte transcription factor (Olig)2+ glial progenitors to acute brain injury. Both focal cortical (mechanical or excitotoxic) and systemic (kainic acid‐induced seizure or lipopolysaccharide‐induced inflammation) injury caused cytoplasmic translocation of Olig2 (Olig2TL) exclusively in affected brain regions as early as 2 h after injury in two‐thirds of Olig2+ cells. Many of the proliferating Olig2+ cells reacting to injury co‐expressed chondroitin sulphate proteoglycan neuron/glia antigen 2 (NG2). Using 5‐bromodeoxyuridine (BrdU) tracing protocols, proliferating Olig2TLGFAP+BrdU+ cells were observed from 2 days post‐lesion (dpl). Immature oligodendrocytes were also seen from 2 dpl and all of them retained Olig2 in the nucleus (Olig2Nuc). From 5 dpl Olig2TLNG2+GFAP+ cells were observed in the wound and some of them were proliferative. From 5 dpl NG2+RIP+ cells were also seen, all of which were Olig2Nuc and some of which were also BrdU+. Our results suggest that, in response to brain injury, NG2+ progenitors may generate a subpopulation of astrocytes in addition to oligodendrocytes and their fate choice was associated with Olig2TL or Olig2Nuc. However, the NG2+GFAP+ phenotype was only seen within a limited time window (5–8 dpl) when up to 20% of glial fibrillary acidic protein (GFAP) cells co‐expressed NG2. We also observed Olig2TLGFAP+ cells that appeared after injury and before the NG2+GFAP+ phenotype. This suggests that not all astrocytes are derived from an NG2+ population.
Corticosterone and dehydroepiandrosterone in songbird plasma and brain: effects of season and acute stress
Authors: Newman Amy E. M. , Soma Kiran K.
Published: April 2009

Prolonged increases in plasma glucocorticoids can exacerbate neurodegeneration. In rats, these neurodegenerative effects can be reduced by dehydroepiandrosterone (DHEA), an androgen precursor with anti‐glucocorticoid actions. In song sparrows, season and acute restraint stress affect circulating levels of corticosterone and DHEA, and the effects of stress differ in plasma collected from the brachial and jugular veins. Jugular plasma is an indirect index of the neural steroidal milieu. Here, we directly measured corticosterone and DHEA in several brain regions and jugular plasma, and examined the effects of season and acute restraint stress (30 min) (n = 571 samples). Corticosterone levels were up to 10× lower in brain than in jugular plasma. In contrast, DHEA levels were up to 5× higher in brain than in jugular plasma and were highest in the hippocampus. Corticosterone and DHEA concentrations were strongly seasonally regulated in plasma but, surprisingly, not seasonally regulated in brain. Acute stress increased corticosterone levels in plasma and brain, except during the molt, when stress unexpectedly decreased corticosterone levels in the hippocampus. Acute stress increased DHEA levels in plasma during the molt but had no effects on DHEA levels in brain. This is the first study to measure (i) corticosterone or DHEA levels in the brain of adult songbirds and (ii) seasonal changes in corticosterone or DHEA levels in the brain of any species. These results highlight several critical differences between systemic and local steroid concentrations and the difficulty of using circulating steroid levels to infer local steroid levels within the brain.
Sleep function: current questions and new approaches
Authors: Vassalli Anne , Dijk Derk‐Jan
Published: April 2009

The mammalian brain oscillates through three distinct global activity states: wakefulness, non‐rapid eye movement (NREM) sleep and REM sleep. The regulation and function of these ‘vigilance’ or ‘behavioural’ states can be investigated over a broad range of temporal and spatial scales and at different levels of functional organization, i.e. from gene expression to memory, in single neurons, cortical columns or the whole brain and organism. We summarize some basic questions that have arisen from recent approaches in the quest for the functions of sleep. Whereas traditionally sleep was viewed to be regulated through top‐down control mechanisms, recent approaches have emphasized that sleep is emerging locally and regulated in a use‐dependent (homeostatic) manner. Traditional markers of sleep homeostasis, such as the electroencephalogram slow‐wave activity, have been linked to changes in connectivity and plasticity in local neuronal networks. Thus waking experience‐induced local network changes may be sensed by the sleep homeostatic process and used to mediate sleep‐dependent events, benefiting network stabilization and memory consolidation. Although many questions remain unanswered, the available data suggest that sleep function will best be understood by an analysis which integrates sleep’s many functional levels with its local homeostatic regulation.
Possible role of reactive chlorine in microbial antagonism and organic matter chlorination in terrestrial environments
Authors: Bengtson Per , Bastviken David , De Boer Wietse , Öberg Gunilla
Published: April 2009

Several studies have demonstrated that extensive formation of organically bound chlorine occurs both in soil and in decaying plant material. Previous studies suggest that enzymatic formation of reactive chlorine outside cells is a major source. However, the ecological role of microbial‐induced extracellular chlorination processes remains unclear. In the present paper, we assess whether or not the literature supports the hypothesis that extracellular chlorination is involved in direct antagonism against competitors for the same resources. Our review shows that it is by no means rare that biotic processes create conditions that render biocidal concentrations of reactive chlorine compounds, which suggest that extracellular production of reactive chlorine may have an important role in antagonistic microbial interactions. To test the validity, we searched the UniprotPK database for microorganisms that are known to produce haloperoxidases. It appeared that many of the identified haloperoxidases from terrestrial environments are originating from organisms that are associated with living plants or decomposing plant material. The results of the in silico screening were supported by various field and laboratory studies on natural chlorination. Hence, the ability to produce reactive chlorine seems to be especially common in environments that are known for antibiotic‐mediated competition for resources (interference competition). Yet, the ability to produce haloperoxidases is also recorded, for example, for plant endosymbionts and parasites, and there is little or no empirical evidence that suggests that these organisms are antagonistic.
Use of topical negative pressure in assisted abdominal closure does not lead to high incidence of enteric fistulae
Authors: Shaikh I. A. , Ballard‐Wilson A. , Yalamarthi S. , Amin A. I.
Published: April 2009

Aim  Reports suggested an increase in enterocutaneous fistulae with topical negative pressure (TNP) use in the open abdomen. The purpose of this study was to establish if our experience raises similar concerns.

Method  This is a 5‐year prospective analysis, from January 2004 to December 2008, of 42 patients who developed deep wound dehiscence or their abdomen was left open at laparotomy requiring ‘TNP’ to assist in their management. The decision to use TNP was taken if it was felt unwise or not feasible to close the abdomen.

Results  There were 22 men; the median age was 68 (range 21–88) years. Twenty of 42 patients had peritonitis, 5/42 had oedematous bowel, 5/42 ischaemic gut, one had a large abdominal wall defect following debridement due to methicillin–resistant staphyloccus (MRSA) infection, 11/42 developed deep wound dehiscence. In 30/42, VAC® abdominal dressing system and TNP were applied. In 12/42, VAC® GranuFoam® and TNP were used, of these five patients required a mesh to control the oedematous bowel. Four of 42 patients died. A total of 34 patients had anastomotic lines, 2/42 developed enteric fistulae, and both survived.

Conclusion  This study does not support the reports suggesting a higher fistulae rate with TNP. In our opinion, its use in the open abdomen is safe.
Can the tropical conservatism hypothesis explain temperate species richness patterns? An inverse latitudinal biodiversity gradient in the New World snake tribe Lampropeltini
Authors: Pyron R. Alexander , Burbrink Frank T.
Published: April 2009

Aim  A latitudinal gradient in species richness, defined as a decrease in biodiversity away from the equator, is one of the oldest known patterns in ecology and evolutionary biology. However, there are also many known cases of increasing poleward diversity, forming inverse latitudinal biodiversity gradients. As only three processes (speciation, extinction and dispersal) can directly affect species richness in areas, similar factors may be responsible for both classical (high tropical diversity) and inverse (high temperate diversity) gradients. Thus, a modified explanation for differential species richness which accounts for both patterns would be preferable to one which only explains high tropical biodiversity.

Location  The New World.

Methods  We test several proposed ecological, temporal, evolutionary and spatial explanations for latitudinal diversity gradients in the New World snake tribe Lampropeltini, which exhibits its highest biodiversity in temperate regions.

Results  We find that an extratropical peak in species richness is not explained by latitudinal variation in diversification rate, the mid‐domain effect, or Rapoport's rule. Rather, earlier colonization and longer duration in the temperate zones allowing more time for speciation to increase biodiversity, phylogenetic niche conservatism limiting tropical dispersal and the expansion of the temperate zones in the Tertiary better explain inverse diversity gradients in this group.

Main conclusions  Our conclusions are the inverse of the predictions made by the tropical conservatism hypothesis to explain higher biodiversity near the equator. Therefore, we suggest that the processes invoked are not intrinsic to the tropics but are dependent on historical biogeography to determine the distribution of species richness, which we refer to as the ‘biogeographical conservatism hypothesis’.
Shrinking baseline: the growth in juvenile fisheries, with the Hong Kong grouper fishery as a case study
Authors: To Allen W L , De Mitcheson Yvonne Sadovy
Published: April 2009

Historic and current information on the grouper fishery from Hong Kong and adjacent waters reveals significant changes in species composition and fish sizes over the past 50 years in this important Asian centre for seafood consumption. Once dominant, large groupers are now rare and small species and sizes prevail in the present‐day fishery. Juveniles comprise over 80% of marketed fish by number among the most commonly retailed groupers, and reproductive‐sized fish are absent among larger species. Current fishery practices and the lack of management in Hong Kong and adjacent waters pose a significant threat to large species with limited geographic distribution such as Epinephelus akaara and Epinephelus bruneus, both now listed as threatened by the IUCN. The heavy reliance on juveniles, not only for groupers, but for an increasing diversity of desired fishes within Asia, potentially reduces stock spawning potential. The ‘shrinking baseline’ in terms of a progressive reduction in fish sizes being marketed in the region can seriously undermine fishery sustainability and recoverability of depleted fish stocks. Fishing pressure on groupers and other valuable food fishes within the Asia‐Pacific is intensifying, the declining long‐term trend of grouper landings in Hong Kong and the increasing focus on juveniles for immediate sale or for mariculture ‘grow‐out’ signal a worrying direction for regional fisheries. Moreover, the common appearance of small groupers for sale will influence public perception regarding what are ‘normal‐sized’ fish. Management attention is needed if these fisheries are to remain viable.
Possible functions of the octavolateralis system in fish schooling
Authors: Larsson Matz
Published: April 2009

The development of the octavolateralis system in fish ancestors created the phenomenon of sensory reafference associated with the fish’s own locomotion. Particularly in fish species living and moving in groups, there is a potential to produce complex pressure waves and other water movements interfering with the octavolateralis perception of critical environmental signals. The hypothesis presented is that the development of the octavolateralis system may have initiated, or been a factor in, the evolutionary development of synchronized group locomotion, eventually leading to schooling behaviour. Theoretical models suggest that schooling may be related to a reduction in masking of environmental signals, as well as to survival mechanisms, e.g. confusion of the lateral line and electro‐sensory systems of predators by overlapping pressure waves and overlapping electrical fields. The combined effects of reduced masking and predator confusion may help explain why schooling became an evolutionary success. Including pressure waves and other water movements in the model of join, stay or leave decisions might shed some light on fish shoal assortment. A model encompassing the complex effects of synchronized group locomotion on octavolateralis and electro‐sensory perception of both prey and predator fish might increase the understanding of schooling behaviour.
You Want to Know the Truth? Then Don't Mimic!
Authors: Stel Mariëlle , van Dijk Eric , Olivier Einav
Published: April 2009

Mimicry facilitates the ability to understand what other people are feeling. The present research investigated whether this is also true when the expressions that are being mimicked do not reflect the other person's true emotions. In interactions, targets either lied or told the truth, while observers mimicked or did not mimic the targets' facial and behavioral movements. Detection of deception was measured directly by observers' judgments of the extent to which they thought the targets were telling the truth and indirectly by observers' assessment of targets' emotions. The results demonstrated that nonmimickers were more accurate than mimickers in their estimations of targets' truthfulness and of targets' experienced emotions. The results contradict the view that mimicry facilitates the understanding of people's felt emotions. In the case of deceptive messages, mimicry hinders this emotional understanding.
Lost in the Sauce
Authors: Sayette Michael A. , Reichle Erik D. , Schooler Jonathan W.
Published: April 2009

Alcohol consumption alters consciousness in ways that make drinking both alluring and hazardous. Recent advances in the study of consciousness using a mind-wandering paradigm permit a rigorous examination of the effects of alcohol on experiential consciousness and metaconsciousness. Fifty-four male social drinkers consumed alcohol (0.82 g/kg) or a placebo beverage and then performed a mind-wandering reading task. This task indexed both self-caught and probe-caught zone-outs to distinguish between mind wandering inside and outside of awareness. Compared with participants who drank the placebo, those who drank alcohol were significantly more likely to report that they were zoning out when probed. After this increase in mind wandering was accounted for, alcohol also lowered the probability of catching oneself zoning out. The results suggest that alcohol increases mind wandering while simultaneously reducing the likelihood of noticing one's mind wandering. Findings are discussed with regard to theories of alcohol and theories of consciousness.
Optimal Social Insurance with Linear Income Taxation*
Authors: Bovenberg Lans , Birch Sørensen Peter
Published: April 2009

We study optimal social insurance aimed at insuring disability risk in the presence of linear income taxation. Optimal disability insurance benefits rise with previous earnings. Optimal insurance is incomplete even though disability risks are exogenous and verifiable so that moral hazard in disability insurance is absent. Imperfect insurance is optimal because it encourages workers to insure themselves against disability by working and saving more, thereby alleviating the distortionary impact of the redistributive income tax on labor supply and savings.
Neoclassical versus Frontier Production Models? Testing for the Skewness of Regression Residuals*
Authors: Kuosmanen Timo , Fosgerau Mogens
Published: April 2009

The empirical literature on production and cost functions is divided into two strands. The neoclassical approach concentrates on model parameters, while the frontier approach decomposes the disturbance term to a symmetric noise term and a positively skewed inefficiency term. We propose a theoretical justification for the skewness of the inefficiency term, arguing that this skewness is the key testable hypothesis of the frontier approach. We propose to test the regression residuals for skewness in order to distinguish the two competing approaches. Our test builds directly upon the asymmetry of regression residuals and does not require any prior distributional assumptions.
Incorporating Judgement in Fan Charts
Authors: Österholm Pär
Published: April 2009

Within a decision‐making group, such as a central bank's monetary‐policy committee, group members often hold differing views about the future of key economic variables. Such differences of opinion can be thought of as reflecting differing sets of judgement. This paper suggests modelling each agent's judgement as one scenario in a macroeconomic model. Each judgement set has a specific dynamic impact on the system and, accordingly, a particular predictive density—or fan chart—associated with it. A weighted linear combination of the predictive densities yields a final predictive density that reflects the uncertainty perceived by the agents generating the forecast.