bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linguistically mediated tool use and exchange by chimpanzees (Pan troglodytes)
Authors: Savage-Rumbaugh E. Sue , Rumbaugh Duane M. , Boysen Sally 
Published: February 2010

AbstractTwo chimpanzees have demonstrated the ability to learn to use graphic symbols to ask one another for tools needed to obtain food. The chimps readily attended to and complied with one another's requests by selecting the appropriate tool from six distinct alternatives. They then shared the food obtained by this means and readily reversed the roles of tool requester and tool provider. Their joint accuracy was 92%, even when human experimenters were absent from the room. When they were prevented from using the graphic system (by deactivation of their keyboards), joint accuracy dropped to 10%, even though the animals could still see and hear one another and could gesture or vocalize freely. The acquisition of tool names revealed that words are at first closely and concretely linked to function, and hence that the traditional object-naming paradigm alone is a comparatively difficult starting point for the chimpanzee.This work has demonstrated that two chimpanzees have been able to comprehend the symbolic and communicative function of the symbols they use. The results raise questions concerning chimpanzee research employing other kinds of symbolic communication systems. Apparently there is little evidence, apart from anecdote or uncontrolled tests, demonstrating that either Washoe or Sarah (chimps in other investigator's projects) has fully comprehended the symbolic nature and the communicative potential of their respective gestural and graphic token symbol systems.
Drift of large tabular icebergs in response to atmospheric surface pressure gradients, an observational study
Authors: Turnbull Ian D. 
Published: February 2010

AbstractWhile ocean current and winds certainly play a major role in guiding the trajectories of free-floating icebergs, the direct effect of atmospheric surface pressure gradients can also have an important influence on the trajectories of large icebergs whose horizontal dimensions are sufficiently great to span synoptic systems. This effect is examined as a way of understanding why icebergs B15A, B15J, B15K, and C16 became “trapped” in a limited region immediately north of Ross Island for a period of several years, without being grounded. This limited region is otherwise flushed annually by summer surface winds and currents; thus the delay of the northward drift of the large icebergs (particularly B15A and B15J) defied expectation. The best explanation for this unexpected iceberg behaviour is that the large volcanic massifs on Ross Island create a quasi-permanent surface pressure anomaly patterned as a dipole, with high pressure in the area upwind of the island (an area appropriately called Windless Bight), and low pressure in the downwind area of the iceberg parking lot. The surface pressure regime experienced by two icebergs B15A and B15K is estimated using Automatic Weather Station observations and Global Positioning System receivers deployed on their surfaces to explain why they remained trapped. Breakdown of the atmospheric pressure gradients allowed them to eventually escape from the region to the north-west.
WDM and Directed Star Arboricity
Authors: AMINI OMID , HAVET FRÉDÉRIC , HUC FLORIAN , THOMASSÉ STÉPHAN 
Published: February 2010

A digraph is m-labelled if every arc is labelled by an integer in {1, . . ., m}. Motivated by wavelength assignment for multicasts in optical networks, we introduce and study n-fibre colourings of labelled digraphs. These are colourings of the arcs of D such that at each vertex v, and for each colour α, in(v, α) + out(v, α) ≤ n with in(v, α) the number of arcs coloured α entering v and out(v, α) the number of labels l such that there is at least one arc of label l leaving v and coloured with α. The problem is to find the minimum number of colours λn(D) such that the m-labelled digraph D has an n-fibre colouring. In the particular case when D is 1-labelled, λ1(D) is called the directed star arboricity of D, and is denoted by dst(D). We first show that dst(D) ≤ 2Δ−(D)+1, and conjecture that if Δ−(D) ≥ 2, then dst(D) ≤ 2Δ−(D). We also prove that for a subcubic digraph D, then dst(D) ≤ 3, and that if Δ+(D), Δ−(D) ≤ 2, then dst(D) ≤ 4. Finally, we study λn(m, k) = max{λn(D) | D is m-labelled and Δ−(D) ≤ k}. We show that if m ≥ n, then $\ds \bigl\lceil\frac{m}{n}\bigl\lceil \frac{k}{n}\bigr\rceil + \frac{k}{n} \bigr\rceil\leq \lambda_n(m, k) \leq\bigl\lceil\frac{m}{n}\bigl\lceil \frac{k}{n}\bigr\rceil + \frac{k}{n} \bigr\rceil + C \frac{m^2\log k}{n}$ for some constant C. We conjecture that the lower bound should be the correct value of λn(m, k).
A SELF-REGULAR NEWTON BASED ALGORITHM FOR LINEAR OPTIMIZATION
Authors: SALAHI M. 
Published: February 2010

AbstractIn this paper, using the framework of self-regularity, we propose a hybrid adaptive algorithm for the linear optimization problem. If the current iterates are far from a central path, the algorithm employs a self-regular search direction, otherwise the classical Newton search direction is employed. This feature of the algorithm allows us to prove a worst case iteration bound. Our result matches the best iteration bound obtained by the pure self-regular approach and improves on the worst case iteration bound of the classical algorithm.
Charles Ives at ‘Christo's Gates’
Authors: VON GLAHN DENISE 
Published: February 2010

AbstractThroughout its 150-year history New York City's Central Park has inspired writers, painters, poets, and musicians. In 1906 Charles Ives was moved by its rich soundscape to compose his orchestral pieceCentral Park in the Dark; nearly one hundred years later, in 2005, the artists Christo and Jeanne-Claude unfurled 7500 saffron-coloured cloth panels for a sixteen-day installation at the park. Although separated by a century, these artworks appear similarly preoccupied with the construction, manipulation, and perception of nature and place, honouring and celebrating the park as a naturalistic setting, while also acknowledging it as a fabricated entity, shaped by human interactions, and as an ongoing cultural project. The present article suggests parallels between Ives's construction of the park in sound, and ‘Christo's Gates’, as the installation became known – parallels that suggest the continuing resonance of Ives's musical contemplation, as well as the issues that occupied its composer as the Gilded Age gave way to the progressive era.
A Composite Approach to Ives's ‘Cage’
Authors: MURPHY SCOTT 
Published: February 2010

AbstractLarry Starr's analysis of Charles Ives's ‘The Cage’, in his bookA Union of Diversities, contrasts with most readings of the song in that he focuses on how the points of congruence between the highly dissimilar vocal and piano parts form a ‘powerful unity’. However, he provides no specific analytical method for examining this unity more closely. This study offers one such method for ‘The Cage’, revealing a path within a virtual, bounded space that correlates with some of the syntactic and semantic aspects of the song's text. These syntactic correlations also hold true in a similar passage in Ives's song ‘Majority’.
The Establishment of the Virtual Performance Space in Rock
Authors: MOORE ALLAN F. , DOCKWRAY RUTH 
Published: February 2010

AbstractAnalysis of the spatial elements of popular music recordings can be made by way of the ‘sound-box’, a concept that acknowledges the way sound sources are perceived to exist in four dimensions: laterality, register, prominence, and temporal continuity. By late 1972 producers working across a range of styles and in different geographical locations had adopted a normative positioning of sound sources across these dimensions. In 1965 no such norm existed. This article contextualizes the notion of the sound-box within academic discourse on popular music and explores the methodology employed by a research project that addressed the gradual coming-into-existence of the norm, which the project defined as thediagonal mix. A taxonomy of types of mix is offered, and a chronology of the adoption of the diagonal mix in rock is presented.
Theoretical studies on the pK~a~ values of perfluoroalkyl carboxylic acids
Authors: Rayne Sierra , Forest Kaya 
Published: February 2010

AbstractComputational studies were conducted using the major levels of semiempirical, ab initio, density functional theory (DFT), and the CBS-Q//B3 method and various solvation models on a homologous series of straight chain perfluoroalkyl carboxylic acids (PFCAs) ranging in chain length from C~1~ (trifluoroacetic acid) to C~9~ (n-perfluorodecanoic acid) as well as the monomethyl branched C~7~ (n-perfluorooctanoic acid; n-PFOA) isomers. Regardless of perfluoroalkyl chain length and theoretical method employed, application of a computational thermodynamic cycle indicated no significant change in the estimated aqueous monomeric pK~a~ values between C~1~ and C~9~, all having a relatively constant pK~a~ of about 0 that is in agreement with earlier predictions and recent experimental evidence. Perfluoroalkyl chain helicity does not appear to result in increased monomeric PFCA pK~a~ values at chain lengths greater than 5. Increasing chain length does not substantially influence the structural or electronic character of the carboxylic acid head group. A MMFF94 conformational search yielded 2915 separate low- through high-energy conformers of n-PFOA. Ranking of these structures gave the 94 lowest MMFF94 energy conformations that were subjected to DFT investigations. Application of a thermodynamic cycle approach, coupled with aqueous and gas phase DFT calculations on the molecular and anionic forms for each of the conformers, gave conformationally averaged pK~a~ values for n-PFOA equal to the global minimum helical conformer pK~a~. The conformational populations under study occupy about 100 percent of the global n-PFOA conformational space, indicating no higher energy/low acidity conformations remain unexamined that could influence the predicted composite aqueous monomeric pK~a~ of zero for this compound.
Modeling Three-Dimensional Spatial Regulation of Bacterial Cell Division (Dissertation)
Authors: Arjunan Satya 
Published: February 2010

AbstractMany important cellular processes are regulated by reaction-diffusion (RD) of molecules that takes place both in the cytoplasm and on the membrane. To model and analyze such multicompartmental processes, we developed a lattice-based Monte Carlo method, Spatiocyte that supports RD in volume and surface compartments at single molecule resolution. Stochasticity in RD and the excluded volume effect brought by intracellular molecular crowding, both of which can significantly affect RD and thus, cellular processes, are also supported. We verified the method by comparing simulation results of diffusion, irreversible and reversible reactions with the predicted analytical and best available numerical solutions. Moreover, to directly compare the localization patterns of molecules in fluorescence microscopy images with simulation, we devised a visualization method that mimics the microphotography process by showing the trajectory of simulated molecules averaged according to the camera exposure time. In the rod-shaped bacterium Escherichia coli, the division site is suppressed at the cell poles by periodic pole-to-pole oscillations of the Min proteins (MinC, MinD and MinE) arising from carefully orchestrated RD in both cytoplasm and membrane compartments. Using Spatiocyte we could model and reproduce the in vivo MinDE localization dynamics by accounting for the previously reported properties of MinE. Our results suggest that the MinE ring, which is essential in preventing polar septation, is largely composed of MinE that is transiently attached to the membrane independently after recruited by MinD. Overall, Spatiocyte allows simulation and visualization of complex spatial and reaction-diffusion mediated cellular processes in volumes and surfaces. As we showed, it can potentially provide mechanistic insights otherwise difficult to obtain experimentally.
Progression through early drinking milestones in an adolescent treatment sample
Authors: Jackson Kristina M. 
Published: February 2010

ABSTRACTAims  Research using nationally representative and community samples demonstrates a robust association between early onset of drinking and increased likelihood of numerous adverse outcomes. However, little is known about the subsequent drinking that occurs early in the drinking career. The present study dissects the transition from any alcohol use to treatment entry by taking a fine‐grained approach to examining the attainment and progression of drinking events in a sample of adolescents in substance use treatment.Design/Setting  Data were taken from the Drug Abuse Treatment Outcome Study for Adolescents (DATOS‐A), a multi‐site, community‐based study of adolescents entering treatment.Participants  Respondents included 3331 youth aged 12–18 years (mean = 15.75) admitted to treatment in 1993–95 (74% male, 52% white, 24% African American, 20% Hispanic).Measurements  Age of attainment was obtained for five drinking‐related milestones, including first drink of alcohol, first time drunk, first monthly drinking, first drank five or more drinks/day on a weekly basis and first drank five or more drinks/day on a daily basis.Findings  Most milestones were attained at a very early age, and average progression through adjacent drinking events was relatively swift, Movement through early drinking milestones was accelerated in girls and white youth. Youth who reported their first drink at an early age (age 10 or younger) showed slower progression, suggesting the existence of distinct processes underlying early use and drinking transitions within an individual.Conclusions  This study provides data relevant to understanding drinking progression/natural history in a large clinical sample, especially for differences by gender and ethnicity. The findings have implications for the identification of intermediate stages that might benefit from selected intervention programs.
Gender differences in genetic and environmental influences on gambling: results from a sample of twins from the National Longitudinal Study of Adolescent Health
Authors: Beaver Kevin M. , Hoffman Taylor , Shields Ryan T. , Vaughn Michael G. , DeLisi Matt , Wright John Paul 
Published: February 2010

ABSTRACTAims  To examine the extent to which genetic factors and shared and non‐shared environmental factors are implicated in the development of gambling behaviors and to examine whether there are gender differences in the genetic and environmental contributors to gambling behaviors.Design  A genetically informative analysis was performed by using DeFries–Fulker (DF) analysis.Setting  Analysis of secondary data drawn from the National Longitudinal Study of Adolescent Health (Add Health).Participants  A total of 324 monozygotic (MZ) twins and 278 same‐sex dizygotic (DZ) twins were included in the analysis. Of these twins, there were 150 male MZ twins, 144 male DZ twins, 174 female MZ twins and 134 female DZ twins.Measurements  Gambling behavior was measured through eight self‐reported questions that tapped a range of items designed to measure problems related to gambling. Self‐reported measures of self‐control and delinquent involvement were also included to examine the degree to which these factors covaried with gambling behavior.Findings  The results of the DF analysis indicated that when male and female twin pairs were analyzed simultaneously, genetic factors explained approximately 70% of the variance in gambling and non‐shared environmental factors explained the remaining variance. When gender‐specific models were calculated, substantial gender differences emerged. For males, genetic factors explained approximately 85% of the variance in gambling, with the non‐shared environment accounting for the remaining variance. For females, genetic factors explained none of the variance in gambling behaviors, while the shared environment explained 45% of the variance and the non‐shared environment explained 55% of the variance.Conclusions  Analysis of twins from the Add Health data suggests that there are significant gender differences in the genetic and environmental underpinnings to gambling behaviors.
Trends in and predictors of second‐hand smoke exposure indexed by cotinine in children in England from 1996 to 2006
Authors: Sims Michelle , Tomkins Susannah , Judge Ken , Taylor Gordon , Jarvis Martin J , Gilmore Anna 
Published: February 2010

ABSTRACTAims To explore trends in and predictors of second‐hand smoke (SHS) exposure in children. To identify whether inequalities in SHS exposure are changing over time.Design Repeated cross‐sectional study with data from eight annual surveys conducted over an 11‐year period from 1996 to 2006.Setting England.Participants Nationally representative samples of children aged 4–15 years living in private households.Measurements Saliva cotinine (4–15‐year‐olds), current smoking status (8–15‐year‐olds), smoking status of parents and carers, smoking in the home, socio‐demographic variables.Findings The most important predictors of SHS exposure were modifiable factors—whether people smoke in the house on most days, whether the parents smoke and whether the children are looked after by carers who smoke. Children from more deprived households were more exposed and this remained the case even after parental smoking status has been controlled for. Exposure over time has fallen markedly among children (59% decline over 11 years in geometric mean cotinine), with the most marked decline observed in the period immediately preceding smoke‐free legislation. Declines in exposure have generally been greater in children most exposed at the outset. For example, in children whose parents both smoke, median cotinine declined annually by 0.115 ng/ml compared with 0.019 ng/ml where neither parent smokes (P < 0.05).Conclusions In the 11 years leading up to smoke‐free legislation in England, the overall level of SHS exposure in children as well as absolute inequalities in exposure have been declining. Further efforts to encourage parents and carers to quit and to avoid smoking in the home would benefit child health.
Missing data assumptions and methods in a smoking cessation study
Authors: Barnes Sunni A. , Larsen Michael D. , Schroeder Darrell , Hanson Andrew , Decker Paul A. 
Published: February 2010

ABSTRACTAim  A sizable percentage of subjects do not respond to follow‐up attempts in smoking cessation studies. The usual procedure in the smoking cessation literature is to assume that non‐respondents have resumed smoking. This study used data from a study with a high follow‐up rate to assess the degree of bias that may be caused by different methods of imputing missing data.Design and methods  Based on a large data set with very little missing follow‐up information at 12 months, a simulation study was undertaken to compare and contrast missing data imputation methods (assuming smoking, propensity score matching and optimal matching) under various assumptions as to how the missing data arose (randomly generated missing values, increased non‐response from smokers and a hybrid of the two).Findings  Missing data imputation methods all resulted in some degree of bias which increased with the amount of missing data.Conclusion  None of the missing data imputation methods currently available can compensate for bias when there are substantial amounts of missing data.
Impact of injecting drug use on mortality in Danish HIV‐infected patients: a nation‐wide population‐based cohort study
Authors: Larsen Mette V. , Omland Lars H. , Gerstoft Jan , Larsen Carsten S. , Jensen Janne , Obel Niels , Kronborg Gitte 
Published: February 2010

ABSTRACTObjectives  To estimate the impact of injecting drug use (IDU) on mortality in HIV‐infected patients in the highly active antiretroviral therapy (HAART) era.Design  Population‐based, nation‐wide prospective cohort study in Denmark (the Danish HIV Cohort Study).Methods  A total of 4578 HIV‐infected patients were followed from 1 January 1997 or date of HIV diagnosis. We calculated mortality rates stratified on IDU. One‐, 5‐ and 10‐year survival probabilities were estimated by Kaplan–Meier methods, and Cox regression analyses were used to estimate mortality rate ratios (MRR).Results  Of the patients, 484 (10.6%) were categorized as IDUs and 4094 (89.4%) as non‐IDUs. IDUs were more likely to be women, Caucasian, hepatitis C virus (HCV) co‐infected and younger at baseline; 753 patients died during observation (206 IDUs and 547 non‐IDUs). The estimated 10‐year survival probabilities were 53.2% [95% confidence interval (CI): 48.1–58.3] in the IDU group and 82.1% (95% CI: 80.7–83.6) in the non‐IDU group. IDU as route of HIV infection more than tripled the mortality in HIV‐infected patients (MRR: 3.2; 95% CI: 2.7–3.8). Adjusting for potential confounders did not change this estimate substantially. The risk of HIV‐related death was not increased in IDUs compared to non‐IDUs (MRR 1.1; 95% CI 0.7–1.7).Conclusions  Although Denmark's health care system is tax paid and antiretroviral therapy is provided free of charge, HIV‐infected IDUs still suffer from substantially increased mortality in the HAART era. The increased risk of death seems to be non‐HIV‐related and is due probably to the well‐known risk factors associated with intravenous drug abuse.
Proposed diagnostic criteria for internet addiction
Authors: Tao Ran , Huang Xiuqin , Wang Jinan , Zhang Huimin , Zhang Ying , Li Mengchen 
Published: February 2010

ABSTRACTObjective  The objective of this study was to develop diagnostic criteria for internet addiction disorder (IAD) and to evaluate the validity of our proposed diagnostic criteria for discriminating non‐dependent from dependent internet use in the general population.Methods  This study was conducted in three stages: the developmental stage (110 subjects in the survey group; 408 subjects in the training group), where items of the proposed diagnostic criteria were developed and tested; the validation stage (n = 405), where the proposed criteria were evaluated for criterion‐related validity; and the clinical stage (n = 150), where the criteria and the global clinical impression of IAD were evaluated by more than one psychiatrist to determine inter‐rater reliability.Results  The proposed internet addiction diagnostic criteria consisted of symptom criterion (seven clinical symptoms of IAD), clinically significant impairment criterion (functional and psychosocial impairments), course criterion (duration of addiction lasting at least 3 months, with at least 6 hours of non‐essential internet usage per day) and exclusion criterion (exclusion of dependency attributed to psychotic disorders). A diagnostic score of 2 + 1, where the first two symptoms (preoccupation and withdrawal symptoms) and at least one of the five other symptoms (tolerance, lack of control, continued excessive use despite knowledge of negative effects/affects, loss of interests excluding internet, and use of the internet to escape or relieve a dysphoric mood) was established. Inter‐rater reliability was 98%.Conclusion  Our findings suggest that the proposed diagnostic criteria may be useful for the standardization of diagnostic criteria for IAD.