bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical analysis of acoustic wave propagation in layered carbon nanofiber reinforced polymer composites
Authors: Sun Li , Yu Yong , Song Gangbing , Gou Jihua
Published: August 2008

Polymer composites reinforced by carbon nanofibers (CNFs) in the form of paper sheet show significant vibration and acoustic damping improvement when compared to pure matrix materials. Without looking into the microscopic energy dissipation mechanisms, this paper analyzes the wave propagation in the composites from a macroscopic point of view. The CNF nanocomposites in this study were treated as stacking of alternating layers of pure polymer and CNF reinforced polymer. Analyses of acoustic wave propagation focused on revealing the effects of acoustic impedance discontinuity at the interfaces of the layered structure. Plane wave transmission coefficient has been calculated as a function of the number of the layer repeats and thickness at different wave frequencies. Oscillations in the transmission coefficient have been observed when the acoustic wavelength is on the same order of the bilayer thickness, indicating the possibility of designing the nanocomposite structure to optimize noise reduction characteristics. The numerical analysis converges with effective media theory when acoustic wavelength is much larger than the layer thickness.
Magnetic behavior of graphene absorbed with N, O, and F atoms: A first-principles study
Authors: Wu M. , Liu En-Zuo , Jiang J. Z.
Published: August 2008

Stable configurations, electronic structures, and magnetic behaviors for N, O, and F absorptions on graphene have been investigated by first-principles calculations. It is found that F atom is located just above the C atom, while both O and N atoms are located above the carbon-carbon bond. Strong interactions between absorbers and C atoms exist. N adatom has an unsaturated electron and its electrons are polarized, inducing 0.84 μB magnetic moment per N atom for graphene, while both F and O adatoms do not have polarized electrons, which results in no net magnetic moment. Possible mechanisms were discussed for different magnetic behaviors of graphene absorbed with N, O, and F atoms. We find that the p-type doping of graphene by N atom can result in strongly spin-polarized impurity states, which may lead to a possible pathway to high temperature magnetic order in graphene.
Factorial microarray analysis of zebrafish retinal development
Authors: Leung Yuk Fai , Ma Ping , Link Brian A. , Dowling John E.
Published: August 2008

In a zebrafish recessive mutantyoung(yng), retinal cells are specified to distinct cell classes, but they fail to morphologically differentiate. A null mutation in abrahma-related gene 1(brg1) is responsible for this phenotype. To identify retina-specific Brg1-regulated genes that control cellular differentiation, we conducted a factorial microarray analysis. Gene expression profiles were compared from wild-type andyngretinas and stage-matched whole embryos at 36 and 52 hours postfertilization (hpf). From our analysis, three categories of genes were identified: (i) Brg1-regulated retinal differentiation genes (731 probesets), (ii) retina-specific genes independent of Brg1 regulation (3,038 probesets), and (iii) Brg1-regulated genes outside the retina (107 probesets). Biological significance was confirmed by further analysis of components of the Cdk5 signaling pathway and Irx transcription factor family, representing genes identified in category 1. This study highlights the utility of factorial microarray analysis to efficiently identify relevant regulatory pathways influenced by both specific gene products and normal developmental events.
A semiparametric test to detect associations between quantitative traits and candidate genes in structured populations
Authors: Li Meijuan , Reilly Cavan , Hanson Timothy
Published: August 2008

Motivation: Although population-based association mapping may be subject to the bias caused by population stratification, alternative methods that are robust to population stratification such as family-based linkage analysis have lower mapping resolution. Recently, various statistical methods robust to population stratification were proposed for association studies, using unrelated individuals to identify associations between candidate genes and traits of interest. The association between a candidate gene and a quantitative trait is often evaluated via a regression model with inferred population structure variables as covariates, where the residual distribution is customarily assumed to be from a symmetric and unimodal parametric family, such as a Gaussian, although this may be inappropriate for the analysis of many real-life datasets.

Results: In this article, we proposed a new structured association (SA) test. Our method corrects for continuous population stratification by first deriving population structure and kinship matrices through a set of random genetic markers and then modeling the relationship between trait values, genotypic scores at a candidate marker and genetic background variables through a semiparametric model, where the error distribution is modeled as a mixture of Polya trees centered around a normal family of distributions. We compared our model to the existing SA tests in terms of model fit, type I error rate, power, precision and accuracy by application to a real dataset as well as simulated datasets.

Contact:  meijuanl@biostat.umn.edu
Supervised principal component analysis for gene set enrichment of microarray data with continuous or survival outcomes
Authors: Chen Xi , Wang Lily , Smith Jonathan D. , Zhang Bing
Published: August 2008

Motivation: Gene set analysis allows formal testing of subtle but coordinated changes in a group of genes, such as those defined by Gene Ontology (GO) or KEGG Pathway databases. We propose a new method for gene set analysis that is based on principal component analysis (PCA) of genes expression values in the gene set. PCA is an effective method for reducing high dimensionality and capture variations in gene expression values. However, one limitation with PCA is that the latent variable identified by the first PC may be unrelated to outcome.

Results: In the proposed supervised PCA (SPCA) model for gene set analysis, the PCs are estimated from a selected subset of genes that are associated with outcome. As outcome information is used in the gene selection step, this method is supervised, thus called the Supervised PCA model. Because of the gene selection step, test statistic in SPCA model can no longer be approximated well using t-distribution. We propose a two-component mixture distribution based on Gumbel exteme value distributions to account for the gene selection step. We show the proposed method compares favorably to currently available gene set analysis methods using simulated and real microarray data.

Software: The R code for the analysis used in this article are available upon request, we are currently working on implementing the proposed method in an R package.

Contact:  chenx3@ccf.org.
Melvin Calvin. 8 April 1911 — 8 January 1997
Authors: Seaborg Glenn T. , Benson Andrew A.
Published: August 2008

Melvin Calvin died in Berkeley on 8 January 1997, at the age of 85, from a heart attack following years of declining health. He was widely known for his mental intensity, skill in asking questions, and impressive presentation of his research and ideas.

During the period1946–57 Calvin directed laboratories utilizing carbon–14 and other radio–isotopes in the University of California's Radiation Laboratory, founded by Ernest Orlando Lawrence. Among his achievements was the delineation of the path of carbon in photo synthesis, for which he was awarded a Nobel Prize in 1961. He was elected to the National Academy of Sciences in 1954. Among his many honours were the Priestley Medal of the American Chemical Society in 1978, the US National Medal of Science in 1989, and the Davy Medal of the Royal Society in1964.
Sir Harry Raymond Pitt. 3 June 1914 — 8 October 2005
Authors: Bingham N. H. , Hayman W. K.
Published: August 2008

Sir Harry Pitt worked (as H. R. Pitt) with Norbert Wiener in 1938 on Wiener's general Tauberian theory. Mathematically, he is best known for Pitt's form of Wiener's Tauberian theorem, and as the author of the first (1958) monograph on Tauberian theory. He is otherwise best known for having been Vice–Chancellor of Reading University from 1964 to 1978.
Sir James Woodham Menter. 22 August 1921 — 18 July 2006
Authors: Hirsch Peter , Pashley D. W.
Published: August 2008

Jim Menter was a man of many parts: he excelled as a scientist, industrialist and academic administrator. He was well read and hadwide ranging interests in the Arts—in the words of one of his colleagues at Queen Mary College, he was a true Renaissanceman.

His most important scientific contributions were the first direct observations of crystal lattices by transmission electron microscopy and the first observation of an edge dislocation within such a lattice. The work was published in the
Proceedings of the Royal Society
in 1956 (11)*. This paper had a profound impact on electron microscopy of crystals and, by virtue of the direct observation of dislocations, made an important contribution to the general acceptance of the dislocation theory of crystal plasticity.
ETHICS COMMITTEES IN WESTERN AND CENTRAL AFRICA: CONCRETE FOUNDATIONS
Authors: EFFA PIERRE , MASSOUGBODJI ACHILLE , NTOUMI FRANCINE , HIRSCH FRANÇOIS , DEBOIS HENRI , VICARI MARISSA , DERME ASSETOU , NDEMANGA‐KAMOUNE JACQUES , NGUEMBO JOSEPH , IMPOUMA BENIDO , AKUÉ JEAN‐PAUL , EHOUMAN ARMAND , DIEYE ALIOUNE , KILAMA WEN
Published: August 2008

The involvement of developing countries in international clinical trials is necessary for the development of appropriate medicines for local populations. However, the absence of appropriate structures for ethical review represents a barrier for certain countries. Currently there is very little information available on existing structures dedicated to ethics in western and central Africa. This article briefly describes historical milestones in the development of networks dedicated to capacity building in ethical review in these regions and outlines the major conclusions of two workshops on this issue, which were held in September and October 2002 in Libreville, Gabon, and Paris, France. The workshops were the culmination of collaboration between the African Malaria Network Trust (AMANET) and the Pan African Bioethics Initiative (PABIN). They produced an update on ethics organizations with regard to mission, function, activities, members, and contact people, in eight countries within the regions discussed. As a result of the commitment of mandated delegates, a further prominent outcome followed these workshops: the creation of national structures, where none existed before, dedicated to the ethical review of clinical trials.
Is ACCTRAN better than DELTRAN?
Authors: Agnarsson Ingi , Miller Jeremy A.
Published: August 2008

When parsimony ancestral character reconstruction is ambiguous, it is often resolved in favour of the more complex character state. Hence, secondary loss (secondary “absence”) of a complex feature is favoured over parallel gains of that feature as this preserves the stronger hypothesis of homology. We believe that such asymmetry in character state complexity is important information for understanding character evolution in general. However, we here point out an inappropriate link that is commonly made between this approach and the accelerated transformation (ACCTRAN) algorithm. In ACCTRAN, changes are assigned along branches of a phylogenetic tree as close to the root as possible. This has been taken to imply that ACCTRAN will minimize hypotheses of parallel origins of complex traits and thus that ACCTRAN is philosophically better justified than the alternatives, such as delayed transformation (DELTRAN), where changes are assigned along branches as close to the tips as possible. We provide simple examples to show that such views are mistaken and that neither ACCTRAN nor DELTRAN consistently minimize parallel gain of complex traits. We therefore do not see theoretical grounds for favouring the popular ACCTRAN algorithm.

© The Willi Hennig Society 2008.
Adiponectin is an indicator of insulin resistance in non‐obese prepubertal children born large for gestational age (LGA) and is affected by birth weight
Authors: Darendeliler Feyza , Poyrazoglu Sukran , Sancakli Ozlem , Bas Firdevs , Gokcay Gulbin , Aki Semih , Eskiyurt Nurten
Published: August 2008

Background and objective  Being born as large for gestational age (LGA) has an increased risk of developing insulin resistance. Hypoadiponectinaemia is associated with insulin resistance. The aim of this study was to evaluate adiponectin levels and insulin resistance in association with body composition in LGA born non‐obese children at prepubertal ages.

Patients and methods  Thirty‐five (17 female and 18 male) LGA born non‐obese children (mean age 4·8 ± 0·3 years) were evaluated with respect to glucose, insulin, IGFBP‐1, leptin, adiponectin levels and body composition by DEXA. Their data were compared to that of non‐obese 49 (20 female, 29 male) appropriate for gestational age (AGA) children (mean age 3·8 ± 0·1 year).

Results  LGA children, who had similar body mass index standard deviation scores (BMI SDS) as AGA children, had significantly higher insulin (P = 0·043) and statistically borderline significant homeostasis model assessment‐insulin resistance (HOMA‐IR) levels (P = 0·054) than those of AGA children. Adiponectin levels were significantly lower in LGA than AGA children (P = 0·004) even after controlling for age, sex and BMI (P = 0·016). IGFBP‐1, leptin levels and body composition did not show a difference. When the LGA group was divided into subgroups according to birth weight, the analysis revealed that after controlling for BMI, being an LGA and having a higher birth weight in the upper half were associated with lower adiponectin levels (estimated marginal means of logarithmic adiponectin levels 2·6 ± 0·2 vs. 2·1 ± 0·2 µg/ml, P = 0·042).

Conclusion  LGA children have higher insulin and lower adiponectin levels than AGA children in spite of similar BMI. Adiponectin is a better indicator of insulin resistance in LGA children at prepubertal ages and is affected by birth weight.
Secretion of interferon‐γ by human macrophages demonstrated at the single‐cell level after costimulation with interleukin (IL)‐12 plus IL‐18
Authors: Darwich Laila , Coma Gemma , Peña Ruth , Bellido Rocio , Blanco Ester J. J. , Este José A. , Borras Francesc E. , Clotet Bonaventura , Ruiz Lidia , Rosell Antoni , Andreo Felipe , Parkhouse R. Michael E. , Bofill Margarita
Published: August 2008

The interferon (IFN)‐γ component of the immune response plays an essential role in combating infectious and non‐infectious diseases. Induction of IFN‐γ secretion by human T and natural killer (NK) cells through synergistic costimulation with interleukin (IL)‐12 and IL‐18 in the adaptive immune responses against pathogens is well established, but induction of similar activity in macrophages is still controversial, with doubts largely focusing on contamination of macrophages with NK or T cells in the relevant experiments. The possible contribution of macrophages to the IFN response is, however, an important factor relevant to the pathogenesis of many diseases. To resolve this issue, we analysed the production of IFN‐γ at the single‐cell level by immunohistochemistry and by enzyme‐linked immunosorbent spot (ELISPOT) analysis and unequivocally demonstrated that human macrophages derived from monocytes in vitro through stimulation with a combination of IL‐12 and IL‐18 or with macrophage colony‐stimulating factor (M‐CSF) were able to produce IFN‐γ when further stimulated with a combination of IL‐12 and IL‐18. In addition, naturally activated alveolar macrophages immediately secreted IFN‐γ upon treatment with IL‐12 and IL‐18. Therefore, human macrophages in addition to lymphoid cells contribute to the IFN‐γ response, providing another link between the innate and acquired immune responses.
Evaluation of a community‐based intervention to enhance breast cancer screening practices in Brazil
Authors: Thuler Luiz Claudio Santos , Freitas Hilda Guimaraes
Published: August 2008

Objectives  The primary aim of this study was to evaluate a programme called ‘Touch of Life’ (Toque de Vida in Portuguese) proposed to increase breast cancer screening awareness and provide free clinical breast examination (CBE) for asymptomatic women 40–69 years of age.

Method  Evaluation of the intervention used a before‐and‐after quasi‐experimental design without control groups. A total of 11 762 women, living in three cities in the State of Mato Grosso do Sul, Brazil, were submitted to breast cancer screening by CBE. The evaluation indicators were participation rate, abnormal call rate, cancer detection rate and rate of advanced‐stage breast cancers.

Results  Mean age was 42.6 years. Most women belonged to the 40–69‐year age group (56.7%) and had less than 8 years of formal education (60.9%). Mean age at menarche was 12.9 years (±1.7). The proportions of parous and nulliparous women were 85.1% and 14.8% respectively. Mean age of first pregnancy was 19.8 years (±4.4). Less than one‐third (29.3%) of the women had a history of abortion or miscarriage. History of breastfeeding was reported by 79.3% of the women, and 14.4% had used hormone replacement therapy at some time. For women between 40 and 49 years of age, the participation rate was 74.9%. The abnormal call rate for CBE was 10.7%. The main abnormalities found were breast lumps in 630 women (5.4%), thickening in 332 (2.8%) and other suspicious lesions in 316 (2.7%). The breast cancer detection rate was 1.3 per thousand, and only 20.0% of women were diagnosed with advanced‐stage disease (stages III and IV).

Conclusions  The intervention was effective in detecting new cases of breast cancer. A community‐wide screening approach based on CBE may be effective to enhance breast cancer detection in vulnerable populations, especially in areas where mammography screening is not available.
Automatic seamless mosaicing of microscopic images: enhancing appearance with colour degradation compensation and wavelet‐based blending
Authors: HSU W.‐Y. , POON W.‐F. PAUL , SUN Y.‐N.
Published: August 2008

In order to observe the fine details of biomedical specimens, various kinds of high‐magnification microscopes are used. However, they suffer from a limited field of view when visualizing highly magnified specimens. Image mosaicing techniques are necessary to integrate two or more partially overlapping images into one and make the whole specimen visible. In this study, we propose a new system that automatically creates panoramic images by mosaicing all the microscopic images acquired from a specimen. Not only does it effectively compensate for the congenital narrowness in microscopic views, but it also results in the mosaiced image containing as little distortion with respect to the originals as possible. The system consists of four main steps: (1) feature point extraction using multiscale wavelet analysis, (2) image matching based on feature points or by projection profile alignment, (3) colour difference adjustment and optical degradation compensation with a Gaussian‐like model and (4) wavelet‐based image blending. In addition to providing a precise alignment, the proposed system also takes into account the colour deviations and degradation in image mosaicing. The visible seam lines are eliminated after image blending. The experimental results show that the system performs well on differently stained image sequences and is effective on acquired images with large colour variations and degradation. It is expected to be a practical tool for microscopic image mosaicing.
Reverse genetics screen identifies six proteins important for malaria development in the mosquito
Authors: Ecker Andrea , Bushell Ellen S. C. , Tewari Rita , Sinden Robert E.
Published: August 2008

Transmission from the vertebrate host to the mosquito vector represents a major population bottleneck in the malaria life cycle that can successfully be targeted by intervention strategies. However, to date only about 25 parasite proteins expressed during this critical phase have been functionally analysed by gene disruption. We describe the first systematic, larger scale generation and phenotypic analysis of Plasmodium berghei knockout (KO) lines, characterizing 20 genes encoding putatively secreted proteins expressed by the ookinete, the parasite stage responsible for invasion of the mosquito midgut. Of 12 KO lines that were generated, six showed significant reductions in parasite numbers during development in the mosquito, resulting in a block in transmission of five KOs. While expression data, time point of essential function and mutant phenotype correlate well in three KOs defective in midgut invasion, in three KOs that fail at sporulation, maternal inheritance of the mutant phenotype suggests that essential function occurs during ookinete formation and thus precedes morphological abnormalities by several days.
Assays with lower detection limits: implications for epidemiological investigations
Authors: Whitcomb Brian W. , Schisterman Enrique F.
Published: August 2008

Epidemiological investigations of health effects related to chronic low‐level exposures or other circumstances often face the difficult task of dealing with levels of biomarkers that are hard to detect and/or quantify. In these cases instrumentation may not adequately measure biomarker levels. Reasons include a failure of instruments to detect levels below a certain value or, alternatively, interference by error or ‘noise’. Current laboratory practice determines a ‘limit of detection (LOD)’, or some other detection threshold, as a function of the distribution of instrument ‘noise’. Although measurements are produced above and below this threshold in many circumstances, rather than numerical data, all points observed below this threshold may be reported as ‘not detected’. The focus of this process of determination of the LOD is instrument noise and avoiding false positives. Moreover, uncertainty is assumed to apply only to the lowest values, which are treated differently from above‐threshold values, thereby potentially creating a false dichotomy.

In this paper we discuss the application of thresholds to measurement of biomarkers and illustrate how conventional approaches, though appropriate for certain settings, may fail epidemiological investigations. Rather than automated procedures that subject observed data to a standard threshold, the authors advocate investigators to seek information on the measurement process and request all observed data from laboratories (including the data below the threshold) to determine appropriate treatment of those data.
PREVALENCE AND CORRELATES OF ANAEMIA IN ESSENTIAL HYPERTENSION
Authors: Paul Biju , Wilfred Neeta C , Woodman Richard , DePasquale Carmine
Published: August 2008

Anaemia is an independent predictor of mortality in pro‐atherosclerotic conditions with impaired endothelial function, such as diabetes and chronic kidney disease. However, the prevalence of anaemia in hypertension, a condition characterized by endothelial dysfunction, is unclear.

Haemoglobin concentration, renal function and echocardiographic parameters of 187 consecutive patients (M : F 83 : 104; mean (±SD) age 58 ± 15 years) who underwent ambulatory blood pressure monitoring between 2005 and 2006 were assessed in a tertiary level university hospital.

The prevalence of normocytic anaemia in our cohort of hypertensive patients was 16% and was higher in patients with uncontrolled hypertension (20%) than among those with well‐controlled hypertension (4%; P = 0.03). Red cell indices (mean corpuscular volume, mean cell haemoglobin and mean cell haemoglobin concentration) did not differ between the groups. However, the haemoglobin concentration was progressively lower between patients with well‐controlled hypertension and uncontrolled hypertension (P = 0.007). Haematological parameters did not correlate to echocardiographic indices of left ventricular size and function.

Normocytic anaemia was highly prevalent in hypertensive patients. Poor blood pressure control was associated with lower haemoglobin concentration. This may indicate a higher cardiovascular risk in uncontrolled hypertension, as in other pro‐atherosclerotic conditions. Additional studies are needed to evaluate the effect of anaemia on morbidity and mortality in hypertensive patients.
POTENTIAL ROLE OF NITRIC OXIDE IN CONTRACTION‐STIMULATED GLUCOSE UPTAKE AND MITOCHONDRIAL BIOGENESIS IN SKELETAL MUSCLE
Authors: McConell Glenn K , Wadley Glenn D
Published: August 2008

The present review discusses the potential role of nitric oxide (NO) in the: (i) regulation of skeletal muscle glucose uptake during exercise; and (ii) activation of mitochondrial biogenesis after exercise.

We have shown in humans that local infusion of an NO synthase inhibitor during exercise attenuates increases in skeletal muscle glucose uptake without affecting blood flow. Recent studies from our laboratory in rodents support these findings in humans, although rodent studies from other laboratories have yielded conflicting results.

There is clear evidence that NO increases mitochondrial biogenesis in non‐contracting cells and that NO influences basal skeletal muscle mitochondrial biogenesis. However, there have been few studies examining the potential role of NO in the activation of mitochondrial biogenesis following an acute bout of exercise or in response to exercise training. Early indications are that NO is not involved in regulating the increase in mitochondrial biogenesis that occurs in response to exercise.

Exercise is considered the best prevention and treatment option for diabetes, but unfortunately many people with diabetes do not or cannot exercise regularly. Alternative therapies are therefore critical to effectively manage diabetes. If skeletal muscle NO is found to play an important role in regulating glucose uptake and/or mitochondrial biogenesis, pharmaceutical agents designed to mimic these effects of exercise may improve glycaemic control.
Anisotropy of magnetic susceptibility and petrofabric studies in the Garhwal synform, Outer Lesser Himalaya: Evidence of pop‐up klippen
Authors: Devrani Upasana , Dubey Ashok K.
Published: August 2008

Abstract Geological field, petrographic, and anisotropy of magnetic susceptibility studies help in understanding the evolutionary history of the Garhwal synform that lies in the western Outer Lesser Himalaya. Orientations of the magnetic susceptibility axes reveal large variations at short distances as a result of superimposed deformation, and predominant stress conditions favorable for normal faulting. Rocks forming the outer limbs of the Garhwal Synform are metamorphosed up to the lower greenschist facies. The metamorphic grade increases to chlorite zone in the inner limb and the core is characterized by chlorite–biotite to garnet zones. The different grades of metamorphism are separated by thrusts and the structure is described as a pop‐up klippen.
Sediment sequences and paleosols in the Kyichu Valley, southern Tibet (China), indicating Late Quaternary environmental changes
Authors: Kaiser Knut , Lai Zhongping , Schneider Birgit , Schoch Werner H. , Shen Xuhui , Miehe Georg , Brückner Helmut
Published: August 2008

Abstract  The Tibetan Plateau is highly sensitive to environmental changes and affects the settings of a far larger territory in Central Asia and beyond. Thus, knowledge on past environmental changes in that area is essential. Even though the Kyichu (Lhasa River) Valley and its tributaries is an easily accessible area, the Late Quaternary landscape evolution of southern Tibet is in general scarcely known. Therefore, 12 sedimentary sections in the middle and lower catchment were subjected to multidisciplinary analyses (sedimentology, paleopedology, AMS 14C and luminescence dating, and charcoal determination) aiming at results on regional paleoenvironmental changes. At the altitude studied (3600–4000 m above sealevel), no glacial relics could be detected, indicating that the valley positions have been unglaciated since the Last Interglacial. The lack of fluvial–lacustrine structures above the floodplain is due to the aggradational character of this tectonically (sub‐)active valley, which caused an alluvial burying of older valley bottoms. During the Late Pleistocene the mouth area of the Kyichu was occupied by a lake which was part of a larger dam‐lake in the superordinate Yarlung Zhangbo Valley. On the valley flanks, loesses were predominantly deposited before the Last Glacial Maximum (LGM), whereas eolian sands were predominantly deposited around and after the LGM. Paleosols of Last Interglacial, Last Glacial and Holocene ages regularly occur at terrestrial sites representing temperate to cool and humid to semiarid conditions during soil formation. Ages of colluvial sediments indicate that the widespread barren valley slopes were primarily formed by Late Pleistocene erosion followed by a secondary Holocene erosion phase. Charcoal spectra indicate a Late Holocene change from a forest environment to a pastoral environment with sparse grasses, herbs and dwarf shrubs. It is assumed that the Late Holocene environmental changes, such as loss of forests/woodlands and erosion, have at least been reinforced by humans, enhancing a regional climatic aridification and cooling trend.
Acute oxygen therapy does not improve cognitive and driving performance in hypoxaemic COPD
Authors: PRETTO Jeffrey J. , MCDONALD Christine F.
Published: August 2008

Background and objective:  Cognitive and neuropsychological function may be adversely affected by low blood oxygen levels and this has been previously demonstrated in hypoxaemic COPD. The aim of this study was to assess whether supplemental oxygen therapy while driving a motor vehicle is justified in hypoxaemic COPD. We therefore used computer‐based driving simulation to investigate whether acute intranasal oxygen therapy improves the cognitive and driving performance of such patients.

Methods:  Thirty hypoxaemic COPD subjects with a current driving licence performed a 20‐min computer‐based driving simulation task and a 10‐min psychomotor vigilance task (PVT) at baseline, and while breathing intranasal oxygen or intranasal air in a randomized, double‐blind, cross‐over protocol.

Results:  The mean (SD) age of the subjects was 72 years (8) and their mean driving experience was 50 years (10). Mean FEV1 was 41% (18) of predicted and PaO2 was 50.5 mm Hg (4.7) on air and 70.7 mm Hg (9.1) on oxygen. There were no statistically significant differences in any measure of driving performance or in reaction time measurements while breathing oxygen compared with air.

Conclusions:  Acute oxygen therapy does not improve simulated driving performance or neurocognitive function as assessed by PVT in patients with hypoxaemic COPD. These data do not support the recommendation that oxygen should be used by this patient group while driving.
Knowledge Conveyed in Gesture Is Not Tied to the Hands
Authors: Gather Philip , Alibali Martha Wagner , Goldin‐Meadow Susan
Published: August 2008

Children frequently gesture when they explain what they know, and their gestures sometimes convey different information than their speech does. In this study, we investigate whether children's gestures convey knowledge that the children themselves can recognize in another context. We asked fourth‐grade children to explain their solutions to a set of math problems and identified the solution procedures each child conveyed only in gesture (and not in speech) during the explanations. We then examined whether those procedures could be accessed by the same child on a rating task that did not involve gesture at all. Children rated solutions derived from procedures they conveyed uniquely in gesture higher than solutions derived from procedures they did not convey at all. Thus, gesture is indeed a vehicle through which children express their knowledge. The knowledge children express uniquely in gesture is accessible on other tasks, and in this sense, is not tied to the hands.
Extended Early Childhood Intervention and School Achievement: Age Thirteen Findings from the Chicago Longitudinal Study
Authors: Reynolds Arthur J. , Temple Judy A.
Published: August 2008

We evaluated the effects of participation in an extended program of compensatory education for 559 low‐income, inner‐city African American children up to seventh grade. The intervention is the federal and state‐funded Chicago Child‐Parent Center and Expansion Program, which began in 1967. Groups included 426 children who participated in the program from preschool to grades 2 or 3 and 133 children whose participation ceased in kindergarten. After taking into account initial differences in achievement at kindergarten entry and at the end of kindergarten, and after taking into account sample selection bias, program participation for 2 or 3 years after preschool and kindergarten was associated with significantly higher reading achievement up to seventh grade and with lower rates of cumulative grade retention and special education placement (4 to 5 years postprogram). Children participating in the follow‐on program for 3 years had significantly higher reading achievement in seventh grade and a lower rate of grade retention than 3 year participants. Only 3 year participants had significantly higher math achievement than the comparison group. Study findings provide rare longitudinal evidence of the beneficial effects of a large‐scale community‐based program of extended early childhood intervention.
Parent‐Adolescent Congruency in Reports of Adolescent Sexual Behavior and in Communications about Sexual Behavior
Authors: Jaccard James , Dittus Patricia J. , Gordon Vivian V.
Published: August 2008

Agreement between mothers' and adolescents' reports of communication about sex, satisfaction with the parent‐child relationship, maternal disapproval of adolescent sexual activity, and adolescent sexual behavior was investigated in a sample of 745 African American adolescents (ages 14–17) and their mothers. Congruence between the 2 sets of reports tended to be low. Adolescent perceptions and reports were found to be more predictive of adolescent sexual behavior than maternal reports. Mothers tended to underestimate the sexual activity of their teens and teens tended to underestimate their mothers' level of disapproval of their engaging in sexual activity. Reasons for these misperceptions were explored.
Hypnosis and Human Development: Interpersonal Influence of Intrapersonal Processes
Authors: Vandenberg Brian
Published: August 2008

This article revisits the too‐long‐forgotten relation between hypnosis and development, illuminating common processes underlying both, and using research on one to provide insights into the other. Hypnosis is defined within a communicatons framework, and essential features of hypnosis are identified in the communicative exchanges of the first months of life. This forces a reconsideration of our understanding of the ontogenesis of hypnosis. Hypnosis, in turn, offers important insights into development. Four key features of hypnosis are identified and their developmental implications examined.
Intention and Knowledge in Preschoolers' Conception of Pretend
Authors: Joseph Robert M.
Published: August 2008

Experiments 1 and 2 investigated 3‐ and 4‐year‐olds' understanding of the intended nature of pretend behaviors by testing their ability to distinguish between involuntary behaviors and the same behaviors emitted intentionally through acts of pretend. Four‐year‐olds' high rate of passing showed that (1) they understood intention as a mental cause of action and (2) they construed pretend behaviors mentalistically. Experiment 3 used the same contrastive procedure to examine Lillard's contention that 4‐year‐olds do not understand the knowledge conditions and hence the mental representational component of pretend actions. Whereas nearly all of the 5‐year‐olds understood that an agent who did not know of a specific animal could not be pretending to be that animal, 4‐year‐olds systematically associated ignorance with pretend. On the basis of the combined findings of the present experiments, and other research showing a mentalistic understanding of pretense by the age of 3 or 4, it was concluded that the specific reasoning requirements of Lillard's tasks resulted in an underestimation of children's appreciation of the mental features of pretend.
Rejection Sensitivity and Children's Interpersonal Difficulties
Authors: Downey Geraldine , Lebolt Amy , Rincón Claudia , Freitas Antonio L.
Published: August 2008

Some children respond to social rejection in ways that undermine their relationships, whereas others respond with more equanimity. This article reports 3 studies that test the proposition that rejection sensitivity—the disposition to defensively (i.e., anxiously or angrily) expect, readily perceive, and overreact to social rejection—helps explain individual differences in response to social rejection. Data were from urban, minority (primarily Hispanic and African American) fifth to seventh graders. Study 1 describes the development of a measure of rejection sensitivity for children. Study 2 provides experimental evidence that children who angrily expected rejection showed heightened distress following an ambiguously intentioned rejection by a peer. Study 3 shows that rejection sensitive children behaved more aggressively and experienced increased interpersonal difficulties and declines in academic functioning over time.
Response Decision Processes in Relational and Overt Aggression
Authors: Crick Nicki R. , Werner Nicole E.
Published: August 2008

Response decision processes of relationally and overtly aggressive children were assessed for both boys and girls. A hypothetical‐situation instrument, adapted from past research, was used to assess children's evaluations of relationally aggressive and overtly aggressive responses to both relational and instrumental conflict situations for third‐ through sixth‐grade children (n= 1,166). Findings revealed that both overtly aggressive boys and overtly aggressive girls evaluated overtly aggressive responses to instrumental conflict situations in relatively positive ways. Further, overtly aggressive girls, but not boys, evaluated overtly aggressive responses to relational conflict situations in relatively positive ways. Additionally, relationally aggressive boys evaluated relationally aggressive responses to instrumental conflict situations in relatively positive ways. Gender differences were also obtained. Boys evaluated overt aggression more positively, whereas girls evaluated relational aggression more positively. Implications of these findings for the role of gender, situation type, response type, and aggression type for our understanding of children's social information processing are discussed.
Fear and Anger Regulation in Infancy: Effects on the Temporal Dynamics of Affective Expression
Authors: Buss Kristin A. , Goldsmith H. Hill
Published: August 2008

Emotion regulation has been conceptualized as the extrinsic and intrinsic processes responsible for monitoring, facilitating, and inhibiting heightened levels of positive and negative affect. Regulation of distress is related to the use of certain behavioral strategies. Our study examined whether putative regulatory behaviors widely assumed to be conceptually associated with these strategies are actually empirically associated with the changes in fearful and angry distress in 6‐, 12‐, and 18‐month‐old infants. Our key finding was that the use of some putative regulatory behaviors (e.g., distraction and approach) reduced the observable intensity of anger but were less effective in reducing the intensity of fear. The results suggest (1) caution in assuming that postulated regulatory behaviors actually have general distress‐reducing effects and (2) the likelihood that “distress” is too global a construct for research on emotion regulation.
Models for Dependent Extremes Using Stable Mixtures
Authors: FOUGÈRES ANNE‐LAURE , NOLAN JOHN P. , ROOTZÉN HOLGER
Published: August 2008

Abstract. This paper unifies and extends results on a class of multivariate extreme value (EV) models studied by Hougaard, Crowder and Tawn. In these models, both unconditional and conditional distributions are themselves EV distributions, and all lower‐dimensional marginals and maxima belong to the class. One interpretation of the models is as size mixtures of EV distributions, where the mixing is by positive stable distributions. A second interpretation is as exponential‐stable location mixtures (for Gumbel) or as power‐stable scale mixtures (for non‐Gumbel EV distributions). A third interpretation is through a peaks over thresholds model with a positive stable intensity. The mixing variables are used as a modelling tool and for better understanding and model checking. We study EV analogues of components of variance models, and new time series, spatial and continuous parameter models for extreme values. The results are applied to data from a pitting corrosion investigation.
BROADBAND PROVISION AND FIRM LOCATION IN OHIO: AN EXPLORATORY SPATIAL ANALYSIS
Authors: MACK ELIZABETH A. , GRUBESIC TONY H.
Published: August 2008

Information and communication technologies (ICTs) are often cited as an important factor in firm location decisions. This is especially true for firms engaged in information intensive activities and those that have a strong need for advanced services such as broadband. Despite the suggested importance of these technologies, quantitative work evaluating the link between firm location and broadband provision is sparse and existing knowledge remains largely theoretical and speculative. However, theoretical evaluations of the impact of ICTs on firm location do provide a foundation for quantitative analyses of this relationship and may be grouped into three schools of thought: the deconcentration school, the concentration school, and the heterogeneous effects school. The predictions made by these three schools of thought will be analysed in an exploratory context to better understand the relationship between firm location and ICTs, with a focus on broadband service provision. A combination of basic spatial statistical analytical tools and geographic information systems (GIS) will be used in an exploratory spatial data analysis framework to evaluate the relationship between firm location and broadband provision trends from 1999 to 2004 in the state of Ohio. Results suggest that changes in broadband provision have no relationship with changes in firm location. However, a disaggregated, firm level analysis of this relationship does provide statistically significant results for a subset of industrial sectors. Firm size is also found to impact the correlation between firm presence and broadband provision. These results suggest that firm size and industry are perhaps critical components in determining the relative importance of ICTs, such as broadband, in firm location decisions.
Critical Whiteness Theories and the Evangelical “Race Problem”: Extending Emerson and Smith'sDivided by Faith
Authors: TRANBY ERIC , HARTMANN DOUGLAS
Published: August 2008

In their 2000 book,Divided by Faith,Michael Emerson and Christian Smith use the case of evangelical Christians to demonstrate how uncompromising individualist ideals get in the way of clear thinking and decisive action about racial inequalities in contemporary American society. We use insights developed from whiteness studies and critical race theory to sharpen and further extend this analysis. More specifically, we suggest: (1) that anti‐black stereotypes may be subtler, more pervasive, and more functionally necessary than Emerson and Smith assume; and (2) that the individualistic ideals Emerson and Smith focus on are not race neutral but, instead, are part of a taken‐for‐granted and vigorously defended majority white culture and identity. These points are developed through a theoretical reconstruction of Emerson and Smith's argument and a reevaluation of their methodological approach and data. Finally, we present data from a recent national survey of race and religion in American life that provide preliminary quantitative support for our revisionist claims.
Think before you eat: photographic food diaries as intervention tools to change dietary decision making and attitudes
Authors: Zepeda Lydia , Deal David
Published: August 2008

This paper examines the use of photographic and written food diaries as interventions to raise awareness of and change dietary habits. Weinstein's precaution adoption theory and Guagnano, Stern and Dietz's Attitude Behaviour Context theory provide the theoretical basis to explain why nutrition knowledge does not result in healthy eating behaviour and why an intervention may be necessary to change attitudes and behaviours. A pilot study using written and photographic food diaries was conducted with 43 participants. Qualitative analysis of participant interviews revealed that photographic food diaries can alter attitudes and behaviours associated with food choices, and they are more likely to do so than written diaries because they serve as an intervention at the point when decisions regarding what to eat are being made.
Bridges to learning: international student mobilities, education agencies and inter‐personal networks
Authors: COLLINS FRANCIS LEO
Published: August 2008

International education is a fundamentally transnational project. It relies on the movement of individuals or knowledge across national borders, disturbs the centrality of the nation‐state in educational reproduction, and is facilitated by economic and social networks that act as bridges between countries of origin and education. In this article, I address this latter point through reference to research conducted with South Korean international students in Auckland, New Zealand. In particular, I discuss the emergence of transnational social and economic activities that are facilitating the movement of international students from South Korea to Auckland — activities that might usefully be understood as forming ‘bridges to learning’. These include the activities of education agencies, immigrant entrepreneurs and the interpersonal relationships with which many students engage in the negotiation of their transnational lives. In a broader sense I illustrate how the emerging mobilities of international students cannot be viewed as independent of other phenomena but must be seen as embedded within transnational processes that take place at different geographic and social scales.
Moving images: world cities, connections and projects in Sydney's TV production industry
Authors: MOULD OLI
Published: August 2008

World city research concerned with connectivity has tended to focus on advanced producer service firms and on selected North American and European cities; the prevailing methodology has been quantitative. In this article I answer the call to ‘go beyond counting’ by bringing together a project‐based enquiry — on a TV mini‐seriesMary Bryant— with a more conventional assessment of network connectivity. The inclusion of a practice‐centred approach to this case study adds the performative data to the network, highlighting the actions and processes of those involved in maintaining the city networks. Furthermore, I demonstrate how this method of analysis is more suited to the study of project‐based cultural industries and highlight the role of Sydney in the global television industry — a city hitherto under‐explored in world city literature.