bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eight years of Legionnaires' disease transmission in travellers to a condominium complex in Las Vegas, Nevada
Authors: SILK B. J. , MOORE M. R. , BERGTHOLDT M. , GORWITZ R. J. , KOZAK N. A. , THA M. M. , BROWN E. W. , WINCHESTER J. L. , LABUS B. J. , ROWLEY P. , MIDDAUGH J. P. , FIELDS B. S. , HICKS L. A. 
Published: January 2012

SUMMARYTravel is a risk factor for Legionnaires' disease. In 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. We reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. Exposures were assessed by matched case-control analyses (2001) and case-series interviews (2008). We sampled potable water and other water sources. Isolates were compared using sequence-based typing. From 2001 to 2008, 35 cases were identified. Confirmed cases reported after the cluster in 2001–2002 were initially considered sporadic, but retrospective case-finding identified five additional cases. Cases were more likely than controls to stay in tower 2 of the condominium [matched odds ratio (mOR) 6·1, 95% confidence interval (CI) 1·6–22·9]; transmission was associated with showering duration (mOR 23·0, 95% CI 1·4–384). We characterized a clinical isolate as sequence type 35 (ST35) and detected ST35 in samples of tower 2's potable water in 2001, 2002, and 2008. This prolonged outbreak illustrates the importance of striving for permanent Legionella eradication from potable water.
EFL learner collaborative interaction in Second Life
Authors: Peterson Mark 
Published: January 2012

AbstractThis paper reports on the task-based interaction of English as a Foreign Language (EFL) learners in the 3D multiuser virtual environment (MUVE) Second Life. The discussion first explores research on the precursors of MUVEs, text-based 2D virtual worlds known as MOOs. This is followed by an examination of studies on the use of MUVEs in Computer Assisted Language Learning (CALL). The discussion then focuses on an investigation of the Second Life-based text chat of learners located at a university in Japan. Data analysis reveals that the environment, and tasks, elicited types of collaborative interaction hypothesized as beneficial in the sociocultural account of language development. Collaborative interaction identified in the data involved peer-scaffolding focusing on lexis, and correction. The data further showed that the participants actively maintained a supportive atmosphere through the provision of utterances designed to signal interest, and the extensive use of positive politeness. These factors facilitated social cohesion, intersubjectivity, and the consistent production of coherent target language output focused on the tasks. Participant feedback was broadly positive, and indicates that specific features of Second Life such as individual avatars, coupled to the computer-based nature of the interaction, appeared to enhance discourse management, engagement, and participation. The findings suggest that Second Life provides an arena for learner centered social interaction that offers valuable opportunities for target language practice, and the development of autonomy. Areas of potential for future research are identified.
Sweating the Vote: Heat and Abstention in the US House of Representatives
Authors: Cohen Alexander 
Published: January 2012

AbstractSeveral recent studies noted systematic links between weather conditions and voting turnout amid the mass public. This article extends this logic to the elite level by exploring the relationship between summer heat and abstentions in the US House of Representatives. In controlled multivariate regressions, heat is a significant predictor of abstentions across all votes held between 1991 and 2000. This finding provides new insight into legislative behavior as well as the motivation behind some abstentions, which could inform the understanding of the literature on legislative shirking.
Self-Organizing Tissue-Engineered Constructs in Collagen Hydrogels
Authors: Gourdie Robert G. , Myers Tereance A. , McFadden Alex , Li Yin-xiong , Potts Jay D. 
Published: January 2012

AbstractA novel self-organizing behavior of cellularized gels composed of collagen type 1 that may have utility for tissue engineering is described. Depending on the starting geometry of the tissue culture well, toroidal rings of cells or hollow spheroids were prompted to form autonomously when cells were seeded onto the top of gels and the gels released from attachment to the culture well 12 to 24 h after seeding. Cells within toroids assumed distinct patterns of alignment not seen in control gels in which cells had been mixed in. In control gels, cells formed complex three-dimensional arrangements and assumed relatively higher levels of heterogeneity in expression of the fibronectin splice variant ED-A—a marker of epithelial mesenchymal transformation. The tissue-like constructs resulting from this novel self-organizing behavior may have uses in wound healing and regenerative medicine, as well as building blocks for the iterative assembly of synthetic biological structures.
Snowpack variations since AD 1150 in the Andes of Chile and Argentina (30°–37°S) inferred from rainfall, tree‐ring and documentary records
Authors: Masiokas M. H. , Villalba R. , Christie D. A. , Betman E. , Luckman B. H. , Le Quesne C. , Prieto M. R. , Mauget S. 
Published: January 2012

The Andean snowpack is the main source of freshwater and arguably the single most important natural resource for the populated, semi‐arid regions of central Chile and central‐western Argentina. However, apart from recent analyses of instrumental snowpack data, very little is known about the long term variability of this key natural resource. Here we present two complementary, annually‐resolved reconstructions of winter snow accumulation in the southern Andes between 30°–37°S. The reconstructions cover the past 850 years and were developed using simple regression models based on snowpack proxies with different inherent limitations. Rainfall data from central Chile (very strongly correlated with snow accumulation values in the adjacent mountains) were used to extend a regional 1951–2010 snowpack record back to AD 1866. Subsequently, snow accumulation variations since AD 1150 were inferred from precipitation‐sensitive tree‐ring width series. The reconstructed snowpack values were validated with independent historical and instrumental information. An innovative time series analysis approach allowed the identification of the onset, duration and statistical significance of the main intra‐ to multi‐decadal patterns in the reconstructions and indicates that variations observed in the last 60 years are not particularly anomalous when assessed in a multi‐century context. In addition to providing new information on past variations for a highly relevant hydroclimatic variable in the southern Andes, the snowpack reconstructions can also be used to improve the understanding and modeling of related, larger‐scale atmospheric features such as ENSO and the PDO.
Informational Masking and Spatial Hearing in Listeners With and Without Unilateral Hearing Loss
Authors: Rothpletz Ann M. , Wightman Frederic L. , Kistler Doris J. 
Published: January 2012

Purpose
This study assessed selective listening for speech in individuals with and without unilateral hearing loss (UHL) and the potential relationship between spatial release from informational masking and localization ability in listeners with UHL.

Method
Twelve adults with UHL and 12 normal-hearing controls completed a series of monaural and binaural speech tasks that were designed to measure informational masking. They also completed a horizontal localization task.

Results
Monaural performance by participants with UHL was comparable to that of normal-hearing participants. Unlike the normal-hearing participants, the participants with UHL did not exhibit a true spatial release from informational masking. Rather, their performance could be predicted by head shadow effects. Performance among participants with UHL in the localization task was quite variable, with some showing near-normal abilities and others demonstrating no localization ability.

Conclusion
Individuals with UHL did not show deficits in all listening situations but were at a significant disadvantage when listening to speech in environments where normal-hearing listeners benefit from spatial separation between target and masker. This inability to capitalize on spatial cues for selective listening does not appear to be related to localization ability.
Cochlear Implant in the Second Year of Life: Lexical and Grammatical Outcomes
Authors: Caselli Maria Cristina , Rinaldi Pasquale , Varuzza Cristiana , Giuliani Anna , Burdo Sandro 
Published: January 2012

Purpose
The authors studied the effect of the cochlear implant (CI) on language comprehension and production in deaf children who had received a CI in the 2nd year of life.

Method

The authors evaluated lexical and morphosyntactic skills in comprehension and production in 17 Italian children who are deaf (
M
= 54 months of age) with a CI and in 2 control groups of children with normal hearing (NH; 1 matched for chronological age and the other whose chronological age corresponded to the duration of CI activation). The authors also compared children with unilateral CI to children with bilateral CI.

Results
Children with CI appeared to keep pace with NH children matched for time since CI activation in terms of language acquisition, and they were similar to same-age NH children in lexical production. However, children with CI showed difficulties in lexical comprehension when a task required phonological discrimination as well as in grammar comprehension and production. Children with bilateral CI showed better comprehension than did children with unilateral CI; the 2 groups were similar for production.

Conclusions
Activation of CI in the 2nd year of life may provide children who are deaf with a good opportunity to develop language skills, although some limitations in phonological and morphological skills are still present 3 years after auditory reafferentation.
Written Narrative Characteristics in Adults With Language Impairment
Authors: Suddarth Rachael , Plante Elena , Vance Rebecca 
Published: January 2012

Purpose
Adults with language-based disabilities are known to have deficits in oral language; however, less is known about their written language skills. Two studies were designed to characterize the writing of adults with language-based disabilities.

Method
In Study 1, 60 adults, 30 with language impairment and 30 with typical language, completed written narratives. Forty-one written language measures were analyzed. In Study 2, the measures that had the most potential for reliably indexing deficits were analyzed in an additional 77 adults.

Results
Three measures that showed significant between-group differences and had robust effect sizes in Study 1, total number of verbs, 1-part verbs, and errors, were applied to the samples in Study 2. A group difference for percentage of errors was replicated in the second sample. A discriminant analysis identified 75% of the adults with language impairment and 30% of the adults with typical language as having an impairment based on the percent of written errors.

Conclusions
The writing task revealed consistent group differences in written errors and is clinically applicable in describing a client’s writing. However, the number of written errors was not robust enough to identify whether an adult had a language impairment or not.
Asynchronous Vowel-Pair Identification Across the Adult Life Span for Monaural and Dichotic Presentations
Authors: Fogerty Daniel , Kewley-Port Diane , Humes Larry E. 
Published: January 2012

Purpose
Temporal order abilities decrease with age. Declining temporal processing abilities may influence the identification of rapid vowel sequences. Identification patterns for asynchronous vowel pairs were explored across the life span.

Method
Young, middle-aged, and older listeners completed temporal order tasks for pairs of 70-ms and 40-ms vowel stimuli. For a given vowel duration, naturally spoken vowels were equated for duration, intensity, and fundamental frequency. Listeners completed monaural and dichotic temporal order tasks that involved identifying the vowel pair in the correct order. The stimulus onset asynchrony that yielded 50% accuracy for identifying the vowel pair in the correct order was used to equate performance among listeners. Vowel identification response patterns were determined at this stimulus onset asynchrony threshold.

Results
Vowel identification patterns were largely consistent across age groups. Older listeners were influenced by the order of certain vowel pairs. Not all vowel pairs were identified equally well. Vowel dominance patterns were also observed, with /a/ being identified most accurately for the vowel pairs tested. Formant dynamics explained, in part, identification and confusion patterns.

Conclusion
Vowel identification accuracy patterns were reasonably similar across the life span, regardless of presentation mode, vowel duration, or effect of considerable stimulus exposure. Large effects of vowel order were observed, particularly for older listeners.
Evidence for the extraterrestrial origin of a natural quasicrystal
Authors: Bindi Luca , Eiler John M. , Guan Yunbin , Hollister Lincoln S. , MacPherson Glenn , Steinhardt Paul J. , Yao Nan 
Published: January 2012

We present evidence that a rock sample found in the Koryak Mountains in Russia and containing icosahedrite, an icosahedral quasicrystalline phase with composition Al
63
Cu
24
Fe
13
, is part of a meteorite, likely formed in the early solar system about 4.5 Gya. The quasicrystal grains are intergrown with diopside, forsterite, stishovite, and additional metallic phases [khatyrkite (CuAl
2
), cupalite (CuAl), and β-phase (AlCuFe)]. This assemblage, in turn, is enclosed in a white rind consisting of diopside, hedenbergite, spinel (MgAl
2
O
4
), nepheline, and forsterite. Particularly notable is a grain of stishovite (from the interior), a tetragonal polymorph of silica that only occurs at ultrahigh pressures (≥10 Gpa), that contains an inclusion of quasicrystal. An extraterrestrial origin is inferred from secondary ion mass spectrometry
18
O/
16
O and
17
O/
16
O measurements of the pyroxene and olivine intergrown with the metal that show them to have isotopic compositions unlike any terrestrial minerals and instead overlap those of anhydrous phases in carbonaceous chondrite meteorites. The spinel from the white rind has an isotopic composition suggesting that it was part of a calcium-aluminum-rich inclusion similar to those found in CV3 chondrites. The mechanism that produced this exotic assemblage is not yet understood. The assemblage (metallic copper-aluminum alloy) is extremely reduced, and the close association of aluminum (high temperature refractory lithophile) with copper (low temperature chalcophile) is unexpected. Nevertheless, our evidence indicates that quasicrystals can form naturally under astrophysical conditions and remain stable over cosmic timescales, giving unique insights on their existence in nature and stability.
Spiral chain O
4
form of dense oxygen
Authors: Zhu Li , Wang Ziwei , Wang Yanchao , Zou Guangtian , Mao Ho-kwang , Ma Yanming 
Published: January 2012

Oxygen is in many ways a unique element: It is the only known diatomic molecular magnet, and it exhibits an unusual O
8
cluster in its high-pressure solid phase. Pressure-induced molecular dissociation as one of the fundamental problems in physical sciences has been reported from theoretical or experimental studies of diatomic solids H
2
, N
2
, F
2
, Cl
2
, Br
2
, and I
2
but remains elusive for molecular oxygen. We report here the prediction of the dissociation of molecular oxygen into a polymeric spiral chain O
4
structure (space group
I
4
1
/
acd
,
θ
-O
4
) above 1.92-TPa pressure using the particle-swarm search method. The
θ
-O
4
phase has a similar structure as the high-pressure phase III of sulfur. The molecular bonding in the insulating
ε
-O
8
phase or the isostructural superconducting
ζ
-O
8
phase remains remarkably stable over a large pressure range of 0.008–1.92 TPa. The pressure-induced softening of a transverse acoustic phonon mode at the zone boundary
V
point of O
8
phase might be the ultimate driving force for the formation of
θ
-O
4
. Stabilization of
θ
-O
4
turns oxygen from a superconductor into an insulator by opening a wide band gap (approximately 5.9 eV) that originates from the
sp
3
-like hybridized orbitals of oxygen and the localization of valence electrons.
Evaluating bacterial gene-finding HMM structures as probabilistic logic programs
Authors: Mørk Søren , Holmes Ian 
Published: January 2012

Abstract
Motivation: Probabilistic logic programming offers a powerful way to describe and evaluate structured statistical models. To investigate the practicality of probabilistic logic programming for structure learning in bioinformatics, we undertook a simplified bacterial gene-finding benchmark in PRISM, a probabilistic dialect of Prolog.
Results: We evaluate Hidden Markov Model structures for bacterial protein-coding gene potential, including a simple null model structure, three structures based on existing bacterial gene finders and two novel model structures. We test standard versions as well as ADPH length modeling and three-state versions of the five model structures. The models are all represented as probabilistic logic programs and evaluated using the PRISM machine learning system in terms of statistical information criteria and gene-finding prediction accuracy, in two bacterial genomes. Neither of our implementations of the two currently most used model structures are best performing in terms of statistical information criteria or prediction performances, suggesting that better-fitting models might be achievable.
Availability: The source code of all PRISM models, data and additional scripts are freely available for download at: http://github.com/somork/codonhmm.
Contact: soer@ruc.dk
Supplementary information: Supplementary data are available at Bioinformatics online.
NtSCP1 from Tobacco Is an Extracellular Serine Carboxypeptidase III That Has an Impact on Cell Elongation
Authors: Bienert Manuela Désirée , Delannoy Mélanie , Navarre Catherine , Boutry Marc 
Published: January 2012

Abstract
The leaf extracellular space contains several peptidases, most of which are of unknown function. We isolated cDNAs for two extracellular serine carboxypeptidase III genes from tobacco (Nicotiana tabacum), NtSCP1 and NtSCP2, belonging to a phylogenetic clade not yet functionally characterized in plants. NtSCP1 and NtSCP2 are orthologs derived from the two ancestors of tobacco. Reverse transcription-polymerase chain reaction analysis showed that NtSCP1 and NtSCP2 are expressed in root, stem, leaf, and flower tissues. Expression analysis of the β-glucuronidase reporter gene fused to the NtSCP1 transcription promoter region confirmed this expression profile. Western blotting of NtSCP1 and expression of an NtSCP1-green fluorescent protein fusion protein showed that the protein is located in the extracellular space of tobacco leaves and culture cells. Purified His-tagged NtSCP1 had carboxypeptidase activity in vitro. Transgenic tobacco plants overexpressing NtSCP1 showed a reduced flower length due to a decrease in cell size. Etiolated seedlings of these transgenic plants had shorter hypocotyls. These data provide support for a role of an extracellular type III carboxypeptidase in the control of cell elongation.
It was the best of times, it was the worst of times: A psychophysiologist's view of cognitive aging
Authors: Fabiani Monica 
Published: January 2012

AbstractThis paper reviews research on age‐related changes in working memory and attention control. This work is interpreted within a framework labeled “GOLDEN aging” (growing of lifelong differences explains normal aging), which is based on the idea that normal aging (as opposed to pathological aging) represents maturational processes causing progressive shifts in the distributions of mental abilities over the lifespan. As such, brain phenomena observed in normal aging are already apparent, under appropriate conditions, in younger adults. Among the phenomena that can be interpreted according to the GOLDEN aging framework are reductions in working memory capacity, impairments of inhibitory processes, increases in frontal lobe activation, and lack of suppression of responses as a function of repetition.
Are phonological representations in bilinguals language specific? An ERP study on interlingual homophones
Authors: Carrasco‐Ortiz Haydee , Midgley Katherine J. , Frenck‐Mestre Cheryl 
Published: January 2012

AbstractEvent‐related potentials (ERPs) served to investigate whether phonological representations from both the first (L1) and second (L2) language of bilinguals are activated during silent reading of L2 words. French‐English late bilinguals and control monolingual English speakers read interlingual homophones (e.g., “knee” in English, which has substantial phonological overlap with the French word “nid,” meaning “nest”) and matched control words. Results showed a reduction in N400 amplitude in response to interlingual homophones in comparison to control words for bilinguals, but not for English monolinguals. The reduced N400 response to homophones in bilinguals suggests facilitation of word recognition. These results suggest parallel activation of both L1 and L2 phonological representations when reading silently in the L2. These findings point to a language nonspecific model for bilinguals at the phonological level of representation.
Finding the missing stimulus mismatch negativity (MMN): Emitted MMN to violations of an auditory gestalt
Authors: Salisbury Dean F. 
Published: January 2012

AbstractDeviations from repetitive auditory stimuli evoke a mismatch negativity (MMN). Counterintuitively, omissions of repetitive stimuli do not. Violations of patterns reflecting complex rules also evoke MMN. To detect a MMN to missing stimuli, we developed an auditory gestalt task using one stimulus. Groups of six pips (50 ms duration, 330 ms stimulus onset asynchrony [SOA], 400 trials), were presented with an intertrial interval (ITI) of 750 ms while subjects (n = 16) watched a silent video. Occasional deviant groups had missing 4th or 6th tones (50 trials each). Missing stimuli evoked a MMN (p < .05). The missing 4th (−0.8 µV, p <.01) and the missing 6th stimuli (−1.1 µV, p < .05) were more negative than standard 6th stimuli (0.3 µV). MMN can be elicited by a missing stimulus at long SOAs by violation of a gestalt grouping rule. Patterned stimuli appear more sensitive to omissions and ITI than homogenous streams.