bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of weight status perception in contemporary Australian children and adolescents
Authors: Abbott Rebecca A , Lee Amanda J , Stubbs Christina O , Davies Peter SW
Published: April 2010

Aim:  To explore weight status perception and its relation to actual weight status in a contemporary cohort of 5‐ to 17‐year‐old children and adolescents.

Methods:  Body mass index (BMI), derived from height and weight measurements, and perception of weight status (‘too thin’, ‘about right’ and ‘too fat’) were evaluated in 3043 participants from the Healthy Kids Queensland Survey. In children less than 12 years of age, weight status perception was obtained from the parents, whereas the adolescents self‐reported their perceived weight status.

Results:  Compared with measured weight status by established BMI cut‐offs, just over 20% of parents underestimated their child's weight status and only 1% overestimated. Adolescent boys were more likely to underestimate their weight status compared with girls (26.4% vs. 10.2%, P < 0.05) whereas adolescent girls were more likely to overestimate than underestimate (11.8% vs. 3.4%, P < 0.05). Underestimation was greater by parents of overweight children compared with those of obese children, but still less than 50% of parents identified their obese child as ‘too fat’. There was greater recognition of overweight status in the adolescents, with 83% of those who were obese reporting they were ‘too fat’.

Conclusion:  Whilst there was a high degree of accuracy of weight status perception in those of healthy weight, there was considerable underestimation of weight status, particularly by parents of children who were overweight or obese. Strategies are required that enable parents to identify what a healthy weight looks like and help them understand when intervention is needed to prevent further weight gain as the child gets older.
Assembly history dictates ecosystem functioning: evidence from wood decomposer communities
Authors: Fukami Tadashi , Dickie Ian A. , Paula Wilkie J. , Paulus Barbara C. , Park Duckchul , Roberts Andrea , Buchanan Peter K. , Allen Robert B.
Published: April 2010

Ecology Letters (2010) 13: 675–684

Community assembly history is increasingly recognized as a fundamental determinant of community structure. However, little is known as to how assembly history may affect ecosystem functioning via its effect on community structure. Using wood‐decaying fungi as a model system, we provide experimental evidence that large differences in ecosystem functioning can be caused by small differences in species immigration history during community assembly. Direct manipulation of early immigration history resulted in three‐fold differences in fungal species richness and composition and, as a consequence, differences of the same magnitude in the rate of decomposition and carbon release from wood. These effects – which were attributable to the history‐dependent outcome of competitive and facilitative interactions – were significant across a range of nitrogen availabilities observed in natural forests. Our results highlight the importance of considering assembly history in explaining ecosystem functioning.
Decreasing resilience of kelp beds along a latitudinal temperature gradient: potential implications for a warmer future
Authors: Wernberg Thomas , Thomsen Mads S. , Tuya Fernando , Kendrick Gary A. , Staehr Peter A. , Toohey Benjamin D.
Published: April 2010

Ecology Letters (2010) 13: 685–694

Successful mitigation of negative effects of global warming will depend on understanding the link between physiological and ecological responses of key species. We show that while metabolic adjustment may assist Australasian kelp beds to persist and maintain abundance in warmer waters, it also reduces the physiological responsiveness of kelps to perturbation, and suppresses canopy recovery from disturbances by reducing the ecological performance of kelp recruits. This provides a warning not to rely solely on inventories of distribution and abundance to evaluate ecosystem function. The erosion of resilience is mediated by a shift in adult‐juvenile interactions from competitive under cool to facilitative under warm conditions, supporting the prediction that positive interactions may become increasingly important in a warmer future. Kelp beds may remain intact but with a lower threshold for where additional impacts (e.g., extreme storms or reduced water quality) will lead to persistent loss of habitat and ecological function.
Community‐level consequences of density dependence and habitat association in a subtropical broad‐leaved forest
Authors: Chen Lei , Mi Xiangcheng , Comita Liza S. , Zhang Liwen , Ren Haibao , Ma Keping
Published: April 2010

Ecology Letters (2010) 13: 695–704

How extraordinary numbers of species can coexist in hyper‐diverse communities remains unresolved. While numerous hypotheses have been proposed based on observational and theoretical investigations, little is known about which mechanisms are truly active in forest communities and less is known about their relative contributions to community assembly. In this study, generalized linear mixed models with crossed random effects were used to assess the relative contributions of density dependence and habitat association to community‐level diversity maintenance. Species habitat associations were classified based on soil nutrients, topography and species composition. Local neighbourhood effects were also addressed with spatially explicit models of seedling survival. The results shown here reveal that local‐ and community‐level seedling dynamics were consistent with density‐dependent predictions, although habitat association played a more important role in shaping short‐term seedling survival. We conclude that density dependence could promote species coexistence on the premise of habitat partitioning.
Detection of denitrification genes by in situ rolling circle amplification‐fluorescence in situ hybridization to link metabolic potential with identity inside bacterial cells
Authors: Hoshino Tatsuhiko , Schramm Andreas
Published: April 2010

A target‐primed in situ rolling circle amplification (in situ RCA) protocol was developed for detection of single‐copy genes inside bacterial cells and optimized with Pseudomonas stutzeri, targeting nitrite and nitrous oxide reductase genes (nirS and nosZ). Two padlock probes were designed per gene to target both DNA strands; the target DNA was cut by a restriction endonuclease close to the probe binding sites, which subsequently were made accessible by 5′‐3′ exonucleolysis. After hybridization, the padlock probe was circularized by ligation and served as template for in situ RCA, primed by the probe target site. Finally, the RCA product inside the cells was detected by standard fluorescence in situ hybridization (FISH). The optimized protocol showed high specificity and signal‐to‐noise ratio but low detection frequency (up to 15% for single‐copy genes and up to 43% for the multi‐copy 16S rRNA gene). Nevertheless, multiple genes (nirS and nosZ; nirS and the 16S rRNA gene) could be detected simultaneously in P. stutzeri. Environmental application of in situ RCA‐FISH was demonstrated on activated sludge by the differential detection of two types of nirS‐defined denitrifiers; one of them was identified as Candidatus Accumulibacter phosphatis by combining in situ RCA‐FISH with 16S rRNA‐targeted FISH. While not suitable for quantification because of its low detection frequency, in situ RCA‐FISH will allow to link metabolic potential with 16S rRNA (gene)‐based identification of single microbial cells.
Geographical and environmental gradients of lianas and vines in China
Authors: Hu Liang , Li Mingguang , Li Zhen
Published: April 2010

Aim  Climbing plants are characterized by long, wide vessel elements, which may be vulnerable to cold‐ or drought‐induced embolism. However, the difference in vulnerability between lianas (woody climbing plants) and vines (herbaceous climbing plants) has not yet been reported. Here we hypothesize that both lianas and vines are more sensitive to variations in water and temperature than are self‐supporting plants. Consequently, the proportions of lianas and vines in flora are expected to decline significantly along geographical and environmental gradients.

Location  China.

Methods  A unique dataset describing 82 floras in China was examined. The proportion of lianas in the flora (LPF) and the proportion of vines in the flora (VPF) were calculated independently. The proportion of the climbing plants in total spermatophyte flora (CPF) was also calculated. LPF and VPF were compared along latitudinal, mean annual rainfall (Rain), and mean January temperature (T1) gradients. Local linear regression analyses showed the changing tendencies of LPF and VPF. Prediction models of LPF using geographical and environmental factors were studied in some subranges.

Results  (1) LPF was highest in the tropics (13.8% on average), decreased linearly with increasing latitude within the latitude < 42 °N subrange, and reached < 1% north of 42 °N in China. VPF fluctuated slightly from tropical (4.7%), to subtropical (4.2%) to warm temperate (4.5%) regions, but declined significantly in temperate (3.2%) and dry (1.5%) zones in China. (2) LPF decreased significantly with decreasing rainfall, and decreased significantly with decreasing T1 in areas where T1 > −10 °C. In contrast, VPF tended to be constant in areas where T1 > −5 °C or Rain > 1000 mm, and declined under extreme water or temperature stresses. (3) Predictions of LPF using Rain and T1 in areas where T1 > −10 °C, and using latitude and altitude within the latitude < 42 °N subrange were both reliable. According to the geographical model for LPF and a constant VPF, tropical Asian forests would have a LPF as high as 25.4% and the highest CPF would be c. 30%.

Conclusions  We conclude that liana diversity is more sensitive to temperature and water availability than that of vines and other plants. Geographical and environmental gradients affected LPF but not VPF. Shorter life spans and underground nutrient storage may be effective strategies adopted by vines to avoid drought and cold stresses.
Deconstructing spatial patterns in species composition of ectoparasite communities: the relative contribution of host composition, environmental variables and geography
Authors: Krasnov Boris R. , Mouillot David , Shenbrot Georgy I. , Khokhlova Irina S. , Poulin Robert
Published: April 2010

Aim  We determined whether dissimilarity in species composition between parasite communities depends on geographic distance, environmental dissimilarity or host faunal dissimilarity, for different subsets of parasite species with different levels of host specificity.

Location  Communities of fleas parasitic on small mammals from 28 different regions of the Palaearctic.

Method  Dissimilarities in both parasite and host species composition were computed between each pair of regions using the Bray–Curtis index. Geographic distances between regions were also calculated, as were measures of environmental dissimilarity consisting of the pairwise Euclidean distances between regions derived from elevation, vegetation and climatic variables. The 136 flea species included in the dataset were divided into highly host‐specific species (using 1–2 host species per region, on average), moderately host‐specific species (2.2–4 hosts per region) and generalist species (>4 hosts per region). The relative influence of geographic distance, host faunal dissimilarity and environmental dissimilarity on dissimilarity of flea species composition among all regions was analysed for the entire set of flea species as well as for the three above subsets using multiple regressions on distance matrices.

Results  When including all flea species, dissimilarity in flea species composition was affected by all three independent variables, although the pure effect of dissimilarity in host species composition was the strongest. Results were different when the subsets of fleas differing in host specificity were treated separately. In particular, dissimilarity in species composition of highly host‐specific fleas increased solely with environmental dissimilarity, whereas dissimilarity for both moderately specific and non‐specific fleas increased with both geographic distance and dissimilarity in host species composition.

Main conclusions  Host specificity seems to dictate which of the three factors considered is most likely to affect the dissimilarity between flea communities. Counter‐intuitively, environmental dissimilarity played a key role in determining dissimilarity in species composition of highly host‐specific fleas, possibly because, although their presence in a region relies on the occurrence of particular host species, their abundance is itself mostly determined by climatic conditions. Our results show that deconstructing communities into subsets of species with different traits can make it easier to uncover the mechanisms shaping geographic patterns of diversity.
The frog filter: amphibian introduction bias driven by taxonomy, body size and biogeography
Authors: Tingley Reid , Romagosa Christina M. , Kraus Fred , Bickford David , Phillips Benjamin L. , Shine Richard
Published: April 2010

Aim  Invasive species often exhibit a highly non‐random suite of traits relative to non‐invasive taxa, and these biases reflect strong selection at a series of steps along the invasion pathway. Here we investigate traits that are favoured in the first of these steps: the introduction of species outside their native geographic range. We use the global introduction of amphibians as our case study.

Location  Global.

Methods  We examined whether taxonomy, body size and attributes of the native geographic range predict the likelihood of an introduction event in amphibians. We then determined whether these characteristics differed between amphibian species that have been introduced intentionally and those that have been introduced unintentionally (i.e. stowaways).

Results  Comparisons of introduced and non‐introduced amphibians reveal significant biases with respect to taxonomic position (c. 50% of all introduced species originate from only 5% of all families), and characteristics of the native geographic range (most introduced species originate from the Northern Hemisphere, occupy a wide geographic range and are sympatric with high densities of humans). Many of these biases presumably reflect the ease and likelihood of capturing and transporting such animals. Additionally, intentionally introduced species are of larger than average body size, occupy higher elevations in their native ranges, and are more likely to originate from the Northern Hemisphere than unintentionally introduced species.

Main conclusions  Introduced amphibian species are not a random subset of the global amphibian fauna with respect to taxonomic affiliation and biogeography, and this restricts our ability to make robust generalizations regarding the ecological determinants of introduction success. Nevertheless, many of our findings are similar to those revealed by previous analyses of vertebrate and invertebrate introductions. Thus, our study suggests that biases in the anthropogenic mechanisms involved in transporting species around the globe are surprisingly consistent across broadly divergent taxa.
One size does not fit all: no evidence for an optimal body size on islands
Authors: Raia Pasquale , Carotenuto Francesco , Meiri Shai
Published: April 2010

Aim Optimal body size theories predict that large clades have a single, optimal, body size that serves as an evolutionary attractor, with the full body size spectrum of a clade resulting from interspecific competition. Because interspecific competition is believed to be reduced on islands, such theories predict that insular animals should be closer to the optimal size than mainland animals. We test the resulting prediction that insular clade members should therefore have narrower body size ranges than their mainland relatives.

Location World‐wide.

Methods We used body sizes and a phylogenetic tree of 4004 mammal species, including more than 200 species that went extinct since the last ice age. We tested, in a phylogenetically explicit framework, whether insular taxa converge on an optimal size and whether insular clades have narrow size ranges.

Results We found no support for any of the predictions of the optimal size theory. No specific size serves as an evolutionary attractor. We did find consistent evidence that large (> 10 kg) mammals grow smaller on islands. Smaller species, however, show no consistent tendency to either dwarf or grow larger on islands. Size ranges of insular taxa are not narrower than expected by chance given the number of species in their clades, nor are they narrower than the size ranges of their mainland sister clades – despite insular clade members showing strong phylogenetic clustering.

Main conclusions The concept of a single optimal body size is not supported by the data that were thought most likely to show it. We reject the notion that inclusive clades evolve towards a body‐plan‐specific optimum.
What does species richness tell us about functional trait diversity? Predictions and evidence for responses of species and functional trait diversity to land‐use change
Authors: Mayfield M. M. , Bonser S. P. , Morgan J. W. , Aubin I. , McNamara S. , Vesk P. A.
Published: April 2010

In the conservation literature on land‐use change, it is often assumed that land‐use intensification drives species loss, driving a loss of functional trait diversity and ecosystem function. Modern research, however, does not support this cascade of loss for all natural systems. In this paper we explore the errors in this assumption and present a conceptual model taking a more mechanistic approach to the species–functional trait association in a context of land‐use change. We provide empirical support for our model's predictions demonstrating that the association of species and functional trait diversity follows various trajectories in response to land‐use change. The central premise of our model is that land‐use change impacts upon processes of community assembly, not species per se. From the model, it is clear that community context (i.e. type of disturbance, species pool size) will affect the response trajectory of the relationship between species and functional trait diversity in communities undergoing land‐use change. The maintenance of ecosystem function and of species diversity in the face of increasing land‐use change are complementary goals. The use of a more ecologically realistic model of responses of species and functional traits will improve our ability to make wise management decisions to achieve both aims in specific at‐risk systems.
Anthropogenic and climatic impacts on surface pollen assemblages along a precipitation gradient in north‐eastern China
Authors: Zhang Yun , Kong Zhaochen , Wang Guohong , Ni Jian
Published: April 2010

Aim  To understand the scenarios of ‘anthropogenic biomes’ that integrate human and ecological systems, we need to explore the impacts of climate and human disturbance on vegetation in the past and present. Interactions among surface pollen, modern vegetation and human activities along climate and land‐use gradients are tested to evaluate the natural and anthropogenic forces shaping the modern vegetation, and hence to aid the reconstruction of vegetation and climate in the past. This in turn will help with future predictions.

Location  The North‐east China Transect (NECT) in north‐eastern China.

Methods  We analysed 33 surface pollen samples and 213 quadrats across four vegetation zones along the moisture/land‐use gradients of the NECT. Detrended correspondence analysis (DCA) and redundancy analysis (RDA) of 52 pollen taxa and three environmental variables were used to distinguish anthropogenic and climatic factors that affect surface pollen assemblages along the NECT.

Results  The 33 surface samples are divided into four pollen zones (forest, meadow steppe, typical steppe and desert steppe) corresponding to major vegetation types in the NECT. Variations in pollen ratios of fern/herb (F/H), Artemisia/Chenopodiaceae (A/C) and arboreal pollen/non‐arboreal pollen (AP/NAP) represent the vegetation and precipitation gradient along the NECT. DCA and RDA analyses suggest that surface pollen assemblages are significantly influenced by the precipitation gradient. Changes in the abundance of Chenopodiaceae pollen are related to both human activities and precipitation.

Main conclusions  Surface pollen assemblages, fossil pollen records, archaeological evidence and historical documents in northern China show that a large increase of Chenopodiaceae pollen indicates human‐caused vegetation degradation in sandy habitats. The A/C ratio is a good indicator of climatic aridity, but should be used in conjunction with multiple proxies of human activities and climate change in the pollen‐based reconstruction of anthropogenic biomes.
Long‐term non‐equilibrium dynamics of insular floras: a 17‐year record
Authors: Morrison Lloyd W.
Published: April 2010

Aim  To document long‐term rates of immigration, extinction and turnover in insular floras and evaluate the relative impacts of recent hurricane activity and climate change.

Location  Three archipelagos of small islands, in the Exuma Cays, Andros and Abacos, Bahamas.

Methods  I surveyed the floras of 194 vegetated islands in three archipelagos over several multi‐year periods, spanning up to 17 years. Changes in abundance (foliar cover) of persistent populations were measured on a subset of 14 islands in the Exuma Cays over a 9‐year period.

Results  Rates of plant turnover were generally low compared with other organisms, but varied among archipelagos and time periods. Turnover rates were usually higher in the second decade of this study, and extinction rates were often dramatically higher than immigration rates in the second decade, resulting in overall decreases in species richness. Turnover did not differ significantly among island types based on generalized location and surrounding water depths, and extinctions were not more likely to occur on more exposed islands. The abundance (foliar cover) of populations that did not go extinct decreased steadily over the second decade of this study, indicating, along with higher extinction rates, a generalized decline in these insular floras.

Main conclusions  Although some islands may have been at or near a state of dynamic equilibrium in the first decade of this study, average species richness declined in all three archipelagos during the second decade, when extinctions greatly outnumbered immigrations. Four major hurricanes affected the study archipelagos in the second decade of this study, although the available evidence suggests that the hurricanes were not directly responsible for the declines. Indirect effects of hurricanes such as increased herbivory and possible decreased nutrient availability, along with a long‐term (25 years) increase in temperature and decline in rainfall are likely contributing factors.
Reactive Attachment Disorder Symptoms in Adults with Intellectual Disabilities
Authors: Minnis Helen , Fleming Gail , Cooper Sally‐Ann
Published: April 2010

Background  Studies with children suggest that reactive attachment disorder (RAD) is associated with pathogenic early care. Little is known about RAD in adults with intellectual disabilities, many of whom experience adversity and abuse in early life. We investigated whether RAD symptoms occur in this population, and explored whether hypothesized risk factors are associated with higher RAD symptom scores.

Method  Fifty adults with intellectual disabilities residing in long‐stay hospitals and their carers participated in a questionnaire survey of RAD symptoms, childhood experiences, and disabilities.

Results  Reactive attachment disorder symptoms were present in this sample, and symptom scores were independently associated with early childhood adversity, diminished with age, but were not associated with cognitive ability, gender, other disabilities, nor number of childhood years in institutional care.

Conclusions  As with children with RAD, it is possible that some maltreated adults with intellectual disabilities fail to develop stranger anxiety by the usual developmental age. Over decades, they may gradually learn.
Evaluating differences in linkage disequilibrium between populations
Authors: Hrafnkelsson Birgir , Helgason Agnar , Jonsson Gudbjorn F. , Gudbjartsson Daniel F. , Jonsson Thorlakur , Thorvaldsson Sverrir , Stefansson Hreinn , Steinthorsdottir Valgerdur , Vidarsdottir Nanna , Middleton Derek , Petersen Henning S. , Martinez Conrado , Snaedal Jon , Jonsson Palmi V. , Bjornsson Sigurbjorn , Gulcher Jeffrey R. , Stefansson Kari
Published: April 2010

We propose two methods to evaluate the statistical significance of differences in linkage disequilibrium (LD) between populations, where LD is measured by the standardised parameter D′. The first method is based on bootstrapping individuals within populations in order to test LD differences for each pair of loci. Using this approach we propose a solution to the problem of testing multiple locus‐pairs by means of a single test for the number of pairs that exhibit significant LD differences among populations. The second method provides the Bayesian posterior probability that one population has greater LD than the other for each locus pair. Both methods can handle genotypes with unknown phase, and are demonstrated using two data sets. For the purpose of demonstration, we apply the methods to two different sets of data from humans. First, we explore the issue of LD differences between reproductively isolated populations using a new data set of twelve Xq25 microsatellites, typed in four European populations. Second, we examine evidence for LD differences between Alzheimer cases and controls from the Icelandic population using 19 single nucleotide polymorphisms (SNPs) from a 97 kb region flanking the Apolipoprotein E (APOE) gene on chromosome 19.
Social Network Analysis of the Genetic Structure of Pacific Islanders
Authors: Terrell John Edward
Published: April 2010

Social network analysis (SNA) is a body of theory and a set of relatively new computer‐aided techniques used in the analysis and study of relational data. Recent studies of autosomal markers from over 40 human populations in the south‐western Pacific have further documented the remarkable degree of genetic diversity in this part of the world. I report additional analysis using SNA methods contributing new controlled observations on the structuring of genetic diversity among these islanders. These SNA mappings are then compared with model‐based network expectations derived from the geographic distances among the same populations. Previous studies found that genetic divergence among island Melanesian populations is organised by island, island size/topography, and position (coastal vs. inland), and that similarities observed correlate only weakly with an isolation‐by‐distance model. Using SNA methods, however, improves the resolution of among population comparison, and suggests that isolation by distance constrained by social networks together with position (coastal/inland) accounts for much of the population structuring observed. The multilocus data now available is also in accord with current thinking on the impact of major biogeographical transformations on prehistoric colonisation and post‐settlement human interaction in Oceania.
It's not what you know but who you know that's important: the influence of social networks on communities
Authors: Kemp Gillian
Published: April 2010

Since its conception in 1945, the UK National Health Service (NHS) has been the focus of extensive political rhetoric regarding the involvement of patients and the public in the provision of health‐care services both locally and nationally. However, achieving substantial user involvement within local communities has proven to be a complex task. The exploratory research presented in this paper investigates the influence of social networks within local communities and its relevance for user involvement. Four main findings emerged: interviewees have strong informal social networks; there is a strong sense of generalized reciprocity; diversity is limited within the social groupings; and there exists a lack of trust in governmental institutions. With regards to health issues, there is an overriding feeling that ‘things like that should be left to the people who know’. If user involvement is to be achieved at the level envisioned by the UK government, achieving a greater relevance for users is essential.
Internal and external barriers to eco‐conscious apparel acquisition
Authors: Connell Kim Y. Hiller
Published: April 2010

Apparel consumption is a contributing cause of environmental change, and environmental integrity requires the encouragement of eco‐conscious apparel acquisition. Unfortunately, among consumers, there is limited engagement in this behaviour. Therefore, the purpose of this study was to expand the knowledge base of eco‐conscious apparel consumption and question the limited participation by identifying barriers that constrain consumers. This study used a qualitative approach to collect and analyse data from 26 eco‐conscious consumers. Data collection for the study occurred through semi‐structured interviews. Results indicate that consumers find it difficult to engage in eco‐conscious apparel acquisition on a consistent basis because a number of barriers stand in the way. These barriers include knowledge and attitudes about environmentally preferable apparel, availability of environmentally preferable apparel, economic resources, retail environments and societal norms. Consequently, the implication is that strategies intending to encourage eco‐conscious apparel acquisition should include a focus on diminishing these barriers.
Globalization vs. localization: global food challenges and local solutions
Authors: Wilhelmina Quaye , Joost Jongerden , George Essegbey , Guido Ruivenkamp
Published: April 2010

The objective of this study was to examine the effect of global–local interactions on food production and consumption in Ghana, and identify possible local solutions. Primary data were collected using a combination of quantitative‐qualitative methods, which included focus group discussions and one‐on‐one interviews. Approximately 450 household heads were randomly selected and interviewed between August 2007 and August 2008 in Eastern, Central, Upper East and Northern Regions of Ghana. Findings revealed increasing consumption of foreign rice as opposed to decreasing consumption of local rice and other staples like millet, sorghum and yam because of global–local interactions. However, opportunities exist to re‐localize production‐consumption patterns through the use of ‘glocal foods’ like improved ‘koose and waakye’. Referencing the situation in Ghana, the study recommends improved production and processing practices backed with appropriate technologies that reflect changing consumption dynamics in order to take full advantage of opportunities created as a result of global–local interactions.
Mice lacking p35 display hyperactivity and paradoxical response to psychostimulants
Authors: Krapacher Favio Ariel , Mlewski Estela Cecilia , Ferreras Soledad , Pisano Victoria , Paolorossi Mariana , Hansen Cristian , Paglini Gabriela
Published: April 2010

J. Neurochem. (2010) 114, 203–214.

Cyclin‐dependent kinase 5/p35 kinase complex plays a critical role in dopaminergic neurotransmission. Dysregulation of dopamine (DA) signaling is associated with neurological and neuropsychiatric disorders. As cyclin‐dependent kinase 5 (Cdk5) requires association with p35 for its proper activation, we hypothesized that dysregulation of Cdk5 activity might have an effect on striatal‐mediated behavior. We used a mutant mouse, deficient in p35 protein (p35 KO), which displayed reduced Cdk5 activity. Throughout behavioral and biochemical characterization of naïve and psychostimulant‐treated mice, we demonstrated that only juvenile p35 KO mice displayed spontaneous hyperactivity, responded with a paradoxical hypolocomotor effect to psychostimulant drugs and exhibited deficit on proper behavioral inhibition. Strong immunolabeling for tyrosine‐hydroxylase and high striatal DA synthesis and contents with a low DA turnover, which were reverted by psychostimulants, were also found in mutant mice. Our results demonstrate that p35 deficiency is critically involved in the expression of a hyperactive behavioral phenotype with hyper‐functioning of the dopaminergic system, emphasizing the importance of proper Cdk5 kinase activity for normal motor and emotional features. Thus, p35 KO mice may be another useful animal model for understanding cellular and molecular events underlying attention deficit hyperactivity disorder‐like disorders.
Advances in Strain Gauge Measurement on Composite Materials
Authors: Ajovalasit A.
Published: April 2010

Abstract:  This article gives an overview on the application of strain gauge techniques to the analysis of the strains in composite materials. The orthotropic behaviour of the composite influences the performance of strain gauges that are calibrated for use on isotropic materials. The article considers therefore the typical topics of the strain gauge technology applied to composites with particular reference to the compensation of thermal output, the measurement of the coefficients of thermal expansion, the determination of the strain and stress state, the influence of the misalignment error, the reinforcement effect, the determination of the stress intensification factor, the analysis of residual stresses by the hole drilling method and the effect of transverse sensitivity on the measurement of strains along the fibres.
Tightening Tests and Friction Coefficients Definition in the Steering Shaft of Front Motorbike Suspension
Authors: Croccolo D. , Vincenzi N.
Published: April 2010

Abstract:  The steering shaft of front motorbike suspensions is, usually, tightened up the fork by means of a nut and a locknut. The aim of this study is to evaluate the actual relation between the bolt torque and the preloading force of the steering shaft by performing some tightening tests. The bolt torque is given by a torque wrench whereas the preloading force has been evaluated by means of a strain gauge located on the steering shaft. The steering shaft has a hollow section with an external thread so that the strain gauge has been applied on its internal surface. In relating the bolt torque to the bolt tension, the friction coefficients have been accurately calculated: the friction coefficient values increase notably after the first set of tightening tests mainly because of the spoiling of the contact surfaces.
REAL GROSS DOMESTIC INCOME, RELATIVE PRICES, AND ECONOMIC PERFORMANCE ACROSS THE OECD
Authors: Macdonald Ryan
Published: April 2010

This paper uses OECD data to examine changes in labor productivity, real gross domestic product (GDP) and real gross domestic income (GDI), economic aggregates, and relative economic growth over time. Real GDI combines changes in production (real GDP) with a trading gain derived from relative price changes. The paper considers two sources of trading gains: the terms of trade, and the real exchange rate. For OECD countries, the terms of trade is the more important price ratio, making a contribution to real income growth that is, on average, an order of magnitude larger than the real exchange rate. Over long time periods, the most important source of real income growth is changes in production. Over shorter time horizons, however, the trading gain can make noteworthy contributions. Changes in aggregates like real private consumption, or the relative economic performance of nations, are shown to be particularly dependent on the trading gain during the large swings in resource prices that occurred post‐2002.
Mixture Analysis of Age at Onset in Migraine Without Aura: Evidence for Three Subgroups
Authors: Asuni Carlo , Manchia Mirko , Deidda Arianna , Stochino Maria Erminia , Cherchi Alessandra , Del Zompo Maria
Published: April 2010

(Headache 2010;50:1313‐1319)

Objective. — To verify the presence of different age at onset (AAO) subgroups of patients in a sample of patients with migraine without aura (MWA) and compare clinical correlates among them.

Background.— MWA is a long‐lasting disease whose prognosis has not yet been fully investigated. Patients may present complete remission, partial clinical remission, persistence and progression (migraine attack frequency and disability may increase over time leading to chronic migraine). Limited evidence exists regarding the identification of risk factors or predictors which might influence migraine prognosis. AAO has been proven a useful tool in the investigation of the clinical, biological, and genetic characteristics able to influence the prognosis of a number of neuropsychiatric disorders. AAO distribution was studied using mixture analysis, a statistical approach that breaks down the empirical AAO distribution observed into a mixture of normal components.

Methods.— A sample of 334 outpatients affected by MWA, recruited in a clinical genetic study at our Headache Center from 2004 to 2008, was enrolled for this study. Diagnosis was made according to International Headache Society criteria 2004. AAO distribution in patients was studied using mixture analysis. Chi‐square test was used to compare clinical correlates among identified subgroups. Logistic regression was performed in order to correct for effect of possible confounders.

Results.— Mixture analysis broke up the observed distribution of AAO into 3 normal theoretical distributions. Informational criteria clearly showed a better 3‐component model rather than the 2‐component one. An early‐onset (≤7 years of age), an intermediate‐onset (≥8 and ≤22), and a late‐onset group (≥23) were identified. Comparison of clinical correlates among subgroups by means of chi‐square test showed a statistically significant result for migraine frequency (χ2 = 7.41, P = .02). Considering the frequency of migraine attacks as a main outcome, the regression model showed a higher AAO is associated with low frequency (odds ratio = 0.95; P = .02).

Conclusions.— The significant association between AAO and attack frequency found in our study supports the hypothesis that AAO could act as a predictor factor able to influence prognosis. AAO could represent a phenotype suitable for identifying MWA susceptibility genes.
On Model Testing in Financial Economics
Authors: Jarrow Robert A.
Published: April 2010

This paper discusses the two different contradicting philosophies for testing models in financial economics (asset pricing, corporate finance, and market‐microstructure) using linear regression. We synthesize these two contradicting approaches, document the errors that may occur in the existing estimation methodologies, and suggest a modified procedure that avoids these errors.
Stock Splits and Bond Yields: Isolating the Signaling Hypothesis
Authors: Michayluk David , Zhao Ruoyun
Published: April 2010

One explanation offered for stock splits is that the split signals positive information by reducing the stock price range in expectation of improved future prospects. Price declines also lead to changes in stock price dynamics, but related securities are not subject to these other changes and therefore can be used to provide a separate assessment of the markets’ interpretation of the split. We examine corporate bond issues around stock splits and find a significant decline in the bond yield spread following stock splits, supporting the signaling hypothesis. We also confirm improvements in forecasted and realized earnings subsequent to stock splits.
The Moving Average Ratio and Momentum
Authors: Park Seung‐Chan
Published: April 2010

I show the ratio of the short‐term moving average to the long‐term moving average (moving average ratio, MAR) has significant predictive power for future returns. The MAR combined with nearness to the 52‐week high explains most of the intermediate‐term momentum profits. This suggests that an anchoring bias, in which investors use moving averages or the 52‐week high as reference points for estimating fundamental values, is the primary source of momentum effects. Momentum caused by the anchoring bias do not disappear in the long‐run even when there are return reversals, confirming that intermediate‐term momentum and long‐term reversals are separate phenomena.
Importance of Detection of Segmental Wall Motion Abnormalities of Left Ventricle in Nontraumatic Subarachnoid Hemorrhage: A Prospective Study
Authors: Jyotsna Maddury , Prasad Vannemreddy , Indrani Garre , Trikamji Bhavesh Vasant
Published: April 2010

Object: To find out the incidence and importance of segmental wall motion abnormalities (SWMAs) of the left ventricle in noncoronary artery disease (CAD) and nontraumatic subarachnoid hemorrhage (SAH) patients. Methods: Nontraumatic SAH patients were evaluated with two‐dimensional echocardiogram in addition to detailed clinical and investigative data. In echocardiogram, LV was evaluated as a 16‐segment approach and its function was noted. Cerebral angiogram was performed in all the patients. Repeat echocardiograms were performed on day 10 and 6 weeks later. Results: In 56 nontraumatic SAH patients, the average age was 45.8 ± 9.1 years. Among them 16 were females. Clinical grade was 3–5 in 26 (46.43%) patients and 24 (42.86%) patients had aneurysms. Echocardiogram was normal in 33 patients and in 23 (41.07%) patients there were left ventricular (LV) abnormalities. LV SWMA was present in 15 patients (65.22%) and global hypokinesia in 8 patients (34.78 %). In the SWMA group, preservation of apical function relative to the base was observed in 13 patients. The repeat echocardiogram on day 10 in SWMA group showed normalization of LV abnormalities in 14 patients and one patient died due to rebleed. In global hypokinesia group, four patients recovered and four died. Significant associations were observed between SWMA and presence of aneurysm (P < 0.05) and LV function (P < 0.001), mortality correlated with LV function (P < 0.001) and clinical grade (P < 0.02). Conclusion: Transient SWMA can occur due to aneurysmal SAH itself and when associated with LV dysfunction, it had a higher mortality. (Echocardiography 2010;27:496‐500)
Complex Atrial Septal Defect: Percutaneous Repair Guided by Three‐Dimensional Echocardiography
Authors: Georgakis Alexander , Radtke Wolfgang A.K. , Lopez Christian , Fiss David , Moser Cathy , VanDecker William , O'Murchu Brian
Published: April 2010

Three‐dimensional transesophageal echocardiography (3D TEE) has been used to guide the percutaneous repair of simple atrial septal defects (ASDs). There has been limited experience in using this imaging modality to guide complex ASD repair. In this report, we describe how 3D TEE was used to guide the repair of a complex, multifenestrated ASD. In a single view, 3D TEE provides a superior anatomic definition when compared to the traditional two‐dimensional echocardiography. We believe that this emerging technology will play a critical role as the number and complexity of percutaneous techniques treating structural heart disease continue to rise. (Echocardiography 2010;27:590‐593)
The Accuracy of Echocardiographic Assessment of Left Ventricular Size in Children by the 5/6 Area × Length (Bullet) Method
Authors: Nielsen James C. , Lytrivi Irene D. , Ko H. Helen , Yau Jen , Bhatla Puneet , Parness Ira A. , Srivastava Shubhika
Published: April 2010

Introduction: Left ventricular end‐diastolic volume (LVEDV) calculation is important in decision making in children with congenital heart disease (CHD). This study examined the accuracy of LVEDV calculation by the formula: 5/6 × area × length (“bullet” method), by comparing echocardiographic (ECHO) LVEDV against cardiac magnetic resonance (CMR). Methods: ECHO and CMR data from 72 consecutive subjects with CHD ≤10 years of age were retrospectively reviewed. Exclusion criteria included: >3 months between examinations; unavailable or poor‐quality images. Subxiphoid short‐ and long‐axis echocardiographic images were analyzed. Bullet LVEDV was compared to CMR volumes. Results: Seventeen subjects (median age 5.5 years, range 1–10 years) comprised the study group. ECHO and CMR LVEDV showed an excellent correlation (r = 0.97) and a good agreement with a mean difference (limits of agreement) of −1.0 mL (−13.9 to 11.9 mL). Conclusions: Subxiphoid echocardiographic bullet method of measuring LVEDV shows a good agreement with CMR obtained LV size in young children. (Echocardiography 2010;27:691‐695)
The Pocket Echocardiograph: Validation and Feasibility
Authors: Culp Benjamin C. , Mock Jonathan D. , Chiles Christopher D. , Culp William C.
Published: April 2010

Background: A new, miniaturized ultrasound device, the pocket echocardiograph (PE), is highly portable and can be carried inside a lab‐coat pocket. Studies of this device are limited and have not examined the use by novice echocardiographers. We hypothesize that a novice echocardiographer can use PE to produce interpretable cardiac images, and that both novice and expert echocardiographers can use PE to accurately quantify ejection fraction. Methods: Unselected subjects (n = 40) in an echocardiography laboratory underwent blinded formal transthoracic echocardiography (TTE) and PE (Acuson P10, Siemens, Mountain View, CA, USA). A cardiology fellow with 2 months of echocardiography training acquired PE images. The fellow and an experienced echocardiographer interpreted the PE studies offline in a blinded fashion. To assess adequacy, studies were graded as technically adequate, limited, or inadequate. A visual estimation of ejection fraction was made. Comparisons were made to the formal reported TTE. Results: Subjects were heterogeneous, 43% male; age 64 ± 17 years, and ejection fraction 52.4%± 12.3%. All PE studies were interpretable, and the vast majority of PE and TTE images were considered technically adequate (77.5% and 85% respectively; P = 0.32). Ejection fraction showed a good correlation, bias, and limits of agreement for the fellow's interpretation (r = 0.78, −5.9%, ±16.6%) with stronger association for the experienced echocardiographer (r = 0.88, −0.8%, ±11.4%). Conclusion: Novice echocardiographers using the PE can produce adequate quality images. Both expert and novice echocardiographers can use PE to quantify ejection fraction over a broad range of patients. The device's low cost and portability may greatly expand the availability of bedside echocardiography for routine or urgent cardiovascular assessment. (Echocardiography 2010;27:759‐764)
In Situ High‐Temperature Diffraction Study of the Thermal Dissociation of Ti3AlC2 in Vacuum
Authors: Pang Wei‐Kong , Low It‐Meng , Sun Zheng‐Ming
Published: April 2010

In this paper, the effect of high‐temperature vacuum annealing on the dynamic phase stability and phase transition of Ti3AlC2 at up to 1550°C was studied using in situ neutron diffraction. The decomposition of Ti3AlC2 into TiCx at an elevated temperature was observed to occur through the continuous sublimation of Al and Ti species in a dynamic environment of high vacuum. The rate of decomposition decreased with increasing temperature, resulting in negative apparent activation energy (i.e., −71.9 kJ/mol). Depth profiling of vacuum‐annealed Ti3AlC2 by grazing‐synchrotron radiation diffraction has revealed a graded composition of TiCx at the near‐surface.