Reduced evolutionary rate in reemerged Ebola virus transmission chains

On 29 June 2015, Liberia’s respite from Ebola virus disease (EVD) was interrupted for the second time by a renewed outbreak (“flare-up”) of seven confirmed cases. We demonstrate that, similar to the March 2015 flare-up associated with sexual transmission, this new flare-up was a reemergence of a Liberian transmission chain originating from a persistently infected source rather than a reintroduction from a reservoir or a neighboring country with active transmission. Although distinct, Ebola virus (EBOV) genomes from both flare-ups exhibit significantly low genetic divergence, indicating a reduced rate of EBOV evolution during persistent infection. Using this rate of change as a signature, we identified two additional EVD clusters that possibly arose from persistently infected sources. These findings highlight the risk of EVD flare-ups even after an outbreak is declared over

Differentiating Questions from Statements: The Role of Intonation

The most salient cues to yes/no questions and statements are rising and falling terminal pitch contours. Because young children readily differentiate rising from falling pitch contours, the presumption is that they can discern speakers’ questioning or declarative intentions from intonation alone. This thesis examined developmental changes in the use of intonation to identify questions and statements. In the first of three studies, participants from 5 years of age judged naturally produced utterances and low-pass filtered versions as questions or statements. Children correctly identified utterance type above chance levels and achieved adult accuracy levels at 9 years of age, highlighting younger children’s confusion about the links between intonation contours and pragmatic intentions. In the second study, participants from 8 years of age judged utterances with graded manipulations of terminal contours as questions or statements. Children’s question/statement judgments shifted more gradually than those of adults, reflecting greater uncertainty, but the location of the category shift was comparable across age. Adults' discrimination of utterance pairs was best for the pair that crossed the category shift, implying categorical perception of the intonation contours. In the final study, participants from 7 years of age judged the statement or question status of child- and adult-directed utterances in a gating task with words added incrementally. After limited exposure to the speaker’s voice, adults and children from 9 years of age correctly identified questions and statements from the initial word, demonstrating for the first time that English-speaking adults and children perceive pre-terminal cues to these utterance types. Identification was more accurate for child-directed than for adult-directed utterances, indicating that the former speech register exaggerates the distinctions between question and statements. Collectively, the findings reveal a protracted course of development for the questioning and declarative intentions signalled by intonation patterns and, more generally, for the pragmatic functions of intonation.Ph.D

Music Processing in Deaf Adults with Cochlear Implants

Cochlear implants (CIs) provide coarse representations of pitch, which are adequate for speech but not for music. Despite increasing interest in music processing by CI users, the available information is fragmentary. The present experiment attempted to fill this void by conducting a comprehensive assessment of music processing in adult CI users. CI users (n =6) and normally hearing (NH) controls (n = 12) were tested on several tasks involving melody and rhythm perception, recognition of familiar music, and emotion of recognition in speech and music. CI performance was substantially poorer than NH performance and at chance levels on pitch processing tasks. Performance was highly variable, however, with one individual achieving NH performance levels on some tasks, probably because of low-frequency residual hearing in his unimplanted ear. Future research with a larger sample of CI users can shed light on factors associated with good and poor music processing in this population.MAS

Water-Resources Investigations Report 83-4238

From introduction: This documentation is designed to provide the user with the basic philosophy and structure of PRMS, instructions for application of established models designed as cataloged procedures, and instructions for interaction with the PRMS library to permit user additions or modifications of model components. The components and subroutines described in this document are those available at the time of publication. However, the library is dynamic and will be enhanced and updated through time. This manual will be updated to reflect major additions and changes through manual inserts or republications

Deliberating debate's digital futures

The article focuses on the need to create a system that facilitates collective discussion and decision making on the issue of information technology integration with debates. The process of integrating technology via collective discussion is exemplified by citing how the Amish community responds to innovations in digital communciation technology. This paper looks at the technical issues surrounding the implementation of the Digital Debate Archive (DDA), an online database that houses data pertaining to debate tournaments, and suggests ways to promote effective decision making regarding its usage

Children's and adults' perception of questions and statements from terminal fundamental frequency contours

The present study compared children's and adults' identification and discrimination of declarative questions and statements on the basis of terminal cues alone. Children (8-11 years, n = 41) and adults (n = 21) judged utterances as statements or questions from sentences with natural statement and question endings and with manipulated endings that featured intermediate fundamental frequency (F0) values. The same adults and a different sample of children (n = 22) were also tested on their discrimination of the utterances. Children's judgments shifted more gradually across categories than those of adults, but their category boundaries were comparable. In the discrimination task, adults found cross-boundary comparisons more salient than within-boundary comparisons. Adults' performance on the identification and discrimination tasks is consistent with but not definitive regarding categorical perception of statements and questions. Children, by contrast, discriminated the cross-boundary comparisons no better than other comparisons. The findings indicate age-related sharpening in the perception of statements and questions based on terminal F0 cues and the gradual emergence of distinct perceptual categories.Research reported in this article was supported by grants from the Natural Sciences and Engineering Research Council of Canada to S.E.T. and E.G.S

Structural Properties of Recycled Plastic/Sawdust Lumber Decking Planks

Plastic lumber is being used to replace wooden lumber in some construction applications, especially in outdoor applications where the plastic lumber is presumed to weather better than the wood. However, the structural properties of the plastic lumber are not well understood, and the use of plastic lumber in structural applications is not authorized in the common building codes. In this research effort, standard 2×6 plastic lumber planks were tested for many different structural properties. The plastic lumber tested was a blend of recycled plastic and sawdust. The tests were conducted at −23.3°C to simulate winter conditions, and at 40.6°C to simulate summer conditions. In all cases the high temperature strength and stiffness was lower than at low temperature, so the high temperature values would determine the allowable strength and stiffness for design. The high temperature modulus of the plastic lumber was 5.79, 1.03, and 1.12 GPa in compression, flexure and tension respectively. High temperature strength values were 16.8, 12.0, and 1.45 MPa in compression, flexure and tension respectively. The high temperature shear strength of the plastic lumber was 5.31 MPa. Strength tests were also performed for nail and screw connections typically used with lumber, and the pull-out and lateral load were comparable to wooden lumber. The plastic lumber performed well under sustained load tests at high temperature. Slip resistance tests were performed, and it was found that the plastic lumber is more slippery than wooden lumber, but probably does not represent a safety hazard. The conclusion was that the plastic lumber is a good structural material, but it is not appropriate to simply substitute plastic lumber for wooden lumber pieces of the same dimension in structural applications. Plastic lumber structures must be designed using the structural properties of the plastic lumber

Structural Properties of Recycled HDPE Plastic Lumber Decking Planks

Plastic lumber is being used to replace wooden lumber in some construction applications, especially in outdoor applications where the plastic lumber is presumed to weather better than the wood. However, the structural properties of the plastic lumber are not well understood, and the use of plastic lumber in structural applications is not authorized in the common building codes. Contractors who use plastic lumber in structural applications such as outdoor decks are in most cases violating the building codes. In this research effort, standard 1 6 tongue-in-grove plastic lumber planks were tested for many different structural properties. The tests were conducted at -23.3°C to simulate winter conditions, and at 40.6°C to simulate summer conditions. In all cases the high temperature strength and stiffness was lower than at low temperature, so the high temperature values would determine the allowable strength and stiffness for design. The conclusion was that the plastic lumber is a good structural material, but that it is not appropriate to simply substitute plastic lumber for wooden lumber pieces of the same size in structural applications. The plastic lumber is not as strong and stiff as the wooden lumber, and so larger sizes must be used to obtain the same strength and stiffness. Because of the much lower modulus, compression members made from plastic lumber may need to be of much larger size to resist buckling