Introducing BITTSy: The Behavioral Infant & Toddler Testing System.

This manuscript introduces BITTSy, the Behavioral Infant & Toddler Testing System. This software system is capable of running the headturn preference procedure, preferential looking, conditioned headturn, and visual fixation/habituation procedures. It uses only commercial-off-theshelf (COTS) hardware to implement the procedures in an affordable and space-efficient setup. The software package, example protocols and data sets, and manual are freely available and downloadable from go.umd.edu/BITTSy, making this entire set of procedures available to resource-limited labs. Researchers can easily use BITTSy at multiple sites in a uniform manner, resulting in a standardized, powerful research tool that can enhance cross-site research collaborations.

Self-assembly of a space-tessellating structure in the binary system of hard tetrahedra and octahedra.

We report the formation of a binary crystal of hard polyhedra due solely to entropic forces. Although the alternating arrangement of octahedra and tetrahedra is a known space-tessellation, it had not previously been observed in self-assembly simulations. Both known one-component phases - the dodecagonal quasicrystal of tetrahedra and the densest-packing of octahedra in the Minkowski lattice - are found to coexist with the binary phase. Apart from an alternative, monoclinic packing of octahedra, no additional crystalline phases were observed.

Correction: Self-assembly of a space-tessellating structure in the binary system of hard tetrahedra and octahedra.

Correction for 'Self-assembly of a space-tessellating structure in the binary system of hard tetrahedra and octahedra' by A. T. Cadotte et al., Soft Matter, 2016, DOI: .

The perceptual consequences of within-talker variability in fricative production.

The effect of talker and token variability on speech perception has engendered a great deal of research. However, most of this research has compared listener performance in multiple-talker (or variable) situations to performance in single-talker conditions. It remains unclear to what extent listeners are affected by the degree of variability within a talker, rather than simply the existence of variability (being in a multitalker environment). The present study has two goals: First, the degree of variability among speakers in their /s/ and /S/ productions was measured. Even among a relatively small pool of talkers, there was a range of speech variability: some talkers had /s/ and /S/ categories that were quite distinct from one another in terms of frication centroid and skewness, while other speakers had categories that actually overlapped one another. The second goal was to examine whether this degree of variability within a talker influenced perception. Listeners were presented with natural /s/ and /S/ tokens for identification, under ideal listening conditions, and slower response times were found for speakers whose productions were more variable than for speakers with more internal consistency in their speech. This suggests that the degree of variability, not just the existence of it, may be the more critical factor in perception.

Perceptual normalization for speaking rate. II: Effects of signal discontinuities.

In a series of experiments, we examined how rate normalization in speech perception is influenced by segments that occur after the target. Perception of the syllable-initial target was influenced by the durations of both the adjacent vowel and the segment after the vowel, even when the identity of the talker was changed during the syllable. These results, together with earlier findings of a temporal window that follows a target phoneme within which segment duration influences perception of the target, help to resolve apparently conflicting results that have been reported previously. Overall, the results fit within a theoretical framework in which the rate at which events take place is extracted early in processing, prior to segregating voices, and the use of this information is obligatory in subsequent processing.

Protection of platelet glycoprotein IIb/IIIa receptor complex preserves platelet function during in vitro ventricular assisted circulation.

Platelet dysfunction probably contributes to bleeding associated with ventricular assist devices (VADs). Previous evidence suggests that VAD associated platelet dysfunction may be due to dysfunction of the platelet fibrinogen receptor. The purpose of this investigation was to test the hypothesis that selective protection of platelet fibrinogen receptor preserves platelet aggregating ability during in vitro ventricular assisted circulation. Eight in vitro nonpulsatile centrifugal VAD circuits were simulated for four days using 450 ml of fresh human whole blood. Temperature, activated clotting time, pH, PCO2, PO2, Ca2+, and glucose were maintained at physiologic values. Flow was maintained at a constant 2.0 L/min/m2. We examined whole blood platelet aggregation induced by ristocetin, collagen, and adenosine diphosphate (ADP). We added a highly specific reversible inhibitor (MK-383) of the glycoprotein (GP) IIb/IIIa receptor complex before start of circulation to the final four VAD experiments. ADP induced aggregation decreased within the first hour of circulation. Ristocetin and collagen induced aggregation decreased to negligible levels after 10 hours of circulation. With MK-383, ristocetin induced aggregation was preserved. Addition of MK-383 did not alter the decrease of ADP and collagen induced aggregation. These results suggest platelet aggregating ability is maintained with protection of the platelet fibrinogen receptor during in vitro ventricular assisted circulation.

Postmortem DNA diagnosis of factor V Leiden in a neonate with systemic thrombosis and probable antithrombin deficiency.

BACKGROUND: Spontaneous neonatal thrombosis due to heritable gene defects has been reported in the past. A recently discovered defect, the factor V Leiden mutation, is the most frequent inherited risk factor for venous thrombosis. CASE: Factor V Leiden was diagnosed postmortem in a neonate who died from complications of vena caval and aortic thrombosis. Investigation into the family history revealed that the father had a record of multiple thromboses, and blood testing demonstrated that the father had antithrombin deficiency and the mother was heterozygous for factor V Leiden. Although we were unable to demonstrate directly the presence of antithrombin deficiency in the infant, we propose that a combination of the two inherited disorders was likely the cause of fatal neonatal thrombosis. CONCLUSION: The present report highlights the importance of a complete prenatal genetic analysis, including factor V Leiden testing and antithrombin measurement in families with a history of thrombotic disorders.

How children reason about ability from report card grades: a developmental study.

Elementary school students were interviewed to see how they reason about ability in the context of report card grades. Eighty-four 2nd, 4th, and 6th graders were presented with hypothetical children's report card grades for performance and effort and were asked to compare the children's "smartness." Four age-related levels of reasoning about ability were identified, in accordance with findings from past research. However, 6th graders did not use the expected highest levels of reasoning, which involve covariation of performance and effort information; rather, their reasoning emphasized the efficacy of effort. Reasons for differences between the present and previous findings are discussed.

Lexical neighborhood effects in phonetic processing.

Previous research on spoken word recognition has demonstrated that identification of a phonetic segment is affected by the lexical status of the item in which the segment occurs. W. F. Ganong (1980) demonstrated that a category boundary shift occurs when the voiced end of 1 voice-onset time continuum is a word but the voiceless end of another series is a word; this is known as the "lexical effect." A series of studies was undertaken to examine how lexical neighborhood; in contrast to lexical status, might influence word perception. Pairs of nonword series were created in which the voiced end of 1 series had a higher frequency-weighted neighborhood density, whereas the reverse was true for the other series. Lexical neighborhood was found to affect word recognition in much the same way as lexical status.

The cocktail party effect in infants.

Most speech research with infants occurs in quiet laboratory rooms with no outside distractions. However, in the real world, speech directed to infants often occurs in the presence of other competing acoustic signals. To learn language, infants need to attend to their caregiver's speech even under less than ideal listening conditions. We examined 7.5-month-old infants' abilities to selectively attend to a female talker's voice when a male voice was talking simultaneously. In three experiments, infants heard a target voice repeating isolated words while a distractor voice spoke fluently at one of three different intensities. Subsequently, infants heard passages produced by the target voice containing either the familiar words or novel words. Infants listened longer to the familiar words when the target voice was 10 dB or 5 dB more intense than the distractor, but not when the two voices were equally intense. In a fourth experiment, the assignment of words and passages to the familiarization and testing phases was reversed so that the passages and distractors were presented simultaneously during familiarization, and the infants were tested on the familiar and unfamiliar isolated words. During familiarization, the passages were 10 dB more intense than the distractors. The results suggest that this may be at the limits of what infants at this age can do in separating two different streams of speech. In conclusion, infants have some capacity to extract information from speech even in the face of a competing acoustic voice.

Perceptual normalization for speaking rate: effects of temporal distance.

A series of studies was undertaken to examine how rate normalization in speech perception would be influenced by the similarity, duration, and phonotactics of phonemes that were adjacent or distal from the initial, target phoneme. The duration of the adjacent (following) phoneme always had an effect on perception of the initial target. Neither phonotactics nor acoustic similarity seemed to have any influence on this rate normalization effect. However, effects of the duration of the nonadjacent (distal) phoneme were only found when that phoneme was temporally close to the target. These results suggest that there is a temporal window over which rate normalization occurs. In most cases, only the adjacent phoneme or adjacent two phonemes will fall within this window and thus influence perception of a phoneme distinction.

Heparin contamination in coagulation testing and a protocol to avoid it and the risk of inappropriate FFP transfusion.

Artifactual heparin contamination of blood samples drawn for coagulation testing is an ongoing problem. A retrospective analysis of activated partial thromboplastin times (APTTs) greater than 45 seconds from patients on neither heparin nor Coumadin (Dupont, Wilmington, DE) therapy shows complete correction of the APTT to normal in 39% of such samples after treatment with heparinase. Recheck of samples with significantly prolonged APTTs after treatment with heparinase is proposed as the best method to avoid inappropriate transfusion of fresh frozen plasma.

Physical mapping of deletion breakpoints in patients with X-linked ichthyosis: evidence for clustering of distal and proximal breakpoints.

Previous studies have shown that approximately 80% of patients with X-linked ichthyosis have a total deletion of the steroid sulphatase (STS) locus which lies in Xp22.3-Xpter. We show by Southern analysis that a common core of sequences are absent in 78.6% of our cases, suggesting that the deletion breakpoints may be highly clustered. To characterize the region in more detail a long-range physical map of over 3 megabases (Mb) surrounding the STS locus was constructed using pulse-field gel electrophoresis. The map enabled the order of sequences tel-SI19-GMGXY3-[STS,GMGXY19]-GMGX9-[dic56 ,SIII2]-cen and the localization of the deletion breakpoints to be established. In ten cases the pulse-field evidence supports the clustering of breakpoints and indicates a deletion size of 2 Mb in most patients. Five CpG islands have been positioned around the STS locus and may be associated with other loci in the region involved in mental retardation and Kallman's syndrome. The map will be instrumental in an attempt to isolate and characterize the deletion breakpoints and to access other genes located in the region.

Children's use of multiple-counting skills: adaptation to task factors.

The purpose of the study was to determine conditions under which young children enumerate by counting in multiples. Thirty-eight kindergartners and first-graders enumerated dot displays and gave verbal reports of their strategies; additionally, they were given an independent assessment of multiple-counting skill. Dot displays varied according to overall numerosity, perceptual arrangement (random, clustered, rectangular), and numerosity of subgroupings. Children were relatively accurate at enumerating small-numerosity and nonrandom displays. They were relatively likely to report counting by multiples, rather than by ones, on small-numerosity and clustered displays. Contingent upon their skill level, children counted by multiple units (twos, threes, and fours) that corresponded to the numerosity of subgroupings (2, 3, and 4). Contrasting effects of different numerosities and perceptual arrangements are discussed in terms of contextual support for the use, and development, of numerical skills among young children.

Excessive blood loss and its relationship to clotting system changes during and after major surgery.

The massively hemorrhaging patient still remains one of the major problems that can be faced by the general surgeon. This article attempts to summarize the biophysiology of this process in an intuitively understandable manner that has direct clinical applications.

Long-term prediction of achievement and attitudes in mathematics and reading.

The purpose of the longitudinal study was to investigate the prediction of children's academic achievement on the basis of cognitive tasks given prior to kindergarten, and academic attitudes on the basis of teachers' and mothers' ratings of the children's general cognitive abilities and actual achievement. Subjects were tested initially before entering kindergarten; from 105 to 154 of the 255 kindergarten children were followed through grades 1, 2, 3, 5, and 10. A subset of cognitive tasks maintained a high relation to high school achievement scores, especially in reading. Tenth-grade self-concept of ability, expectancy for success, value of success, and perception of task difficulty showed effects of sex and academic content area, with boys generally being more favorable toward math and girls more favorable toward reading. Children's attitudes were related both to mothers' earlier ratings of their children's cognitive abilities and actual achievement scores; this was especially the case for girls. There was a negative relation between mothers' ratings and girls' attitudes toward mathematics. Sex differences in all measures throughout the 11-year period are reviewed.