Congruent aero-tactile stimuli bias perception of voicing continua.

Multimodal integration is the formation of a coherent percept from different sensory inputs such as vision, audition, and somatosensation. Most research on multimodal integration in speech perception has focused on audio-visual integration. In recent years, audio-tactile integration has also been investigated, and it has been established that puffs of air applied to the skin and timed with listening tasks shift the perception of voicing by naive listeners. The current study has replicated and extended these findings by testing the effect of air puffs on gradations of voice onset time along a continuum rather than the voiced and voiceless endpoints of the original work. Three continua were tested: bilabial ("pa/ba"), velar ("ka/ga"), and a vowel continuum ("head/hid") used as a control. The presence of air puffs was found to significantly increase the likelihood of choosing voiceless responses for the two VOT continua but had no effect on choices for the vowel continuum. Analysis of response times revealed that the presence of air puffs lengthened responses for intermediate (ambiguous) stimuli and shortened them for endpoint (non-ambiguous) stimuli. The slowest response times were observed for the intermediate steps for all three continua, but for the bilabial continuum this effect interacted with the presence of air puffs: responses were slower in the presence of air puffs, and faster in their absence. This suggests that during integration auditory and aero-tactile inputs are weighted differently by the perceptual system, with the latter exerting greater influence in those cases where the auditory cues for voicing are ambiguous.

Development of a proficiency testing program for molecular diagnosis of influenza viruses.

BACKGROUND: The Molecular Virology Proficiency Testing Program at the Wadsworth Center began the assembly and distribution of influenza virus panels to US public health labs (PHLs) in 2008. The program was created to assist PHLs in assessing their performance and in meeting CLIA regulations for mandated proficiency testing (PT). OBJECTIVES: To design and distribute proficiency testing panels containing influenza A virus subtypes H1N1 and H3N2, and influenza B; when H1N1pdm09 emerged it also was incorporated into the panels. A secondary objective was to determine the best matrix for long term storage of the molecular PT samples. STUDY DESIGN: Viruses were quantitated using TCID(50) and quantitative real-time RT-PCR. Reference laboratories were enlisted to verify viral identity in the panels and to help determine viral titers to be used in the PT panels sent to PHLs. RESULTS AND CONCLUSIONS: Of the 29 laboratories that participated the first year, 27 were able to correctly identify all of the virus types in the panel. Fifty-one PHLs participated in the program the second year when pandemic H1N1 was added, and 45 were able to correctly detect, type and subtype all of the viruses in the panel. In the program's third year, 60 laboratories participated; 58 correctly detected and subtyped all of the viruses in the panel. Annual surveys of assay techniques showed that the PHLs had shifted their extraction methods and PCR-thermocycler instrumentation to meet FDA-approved methods. The degradation study revealed that frozen viral stocks were stable for at least 30months, thus allowing ample time to prepare and pre-test panels.

Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918.

The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized.