Opposing and following responses in sensorimotor speech control : why responses go both ways

When talking, speakers continuously monitor and use the auditory feedback of their own voice to control and inform speech production processes. When speakers are provided with auditory feedback that is perturbed in real time, most of them compensate for this by opposing the feedback perturbation. But some speakers follow the perturbation. In the current study, we investigated whether the state of the speech production system at perturbation onset may determine what type of response (opposing or following) is given. The results suggest that whether a perturbation-related response is opposing or following depends on ongoing fluctuations of the production system: It initially responds by doing the opposite of what it was doing. This effect and the non-trivial proportion of following responses suggest that current production models are inadequate: They need to account for why responses to unexpected sensory feedback depend on the production-system’s state at the time of perturbation

Bed Particle Displacements and Morphological Development in a Wandering Gravel-Bed River

Bed particles were tracked using passive integrated transponder tags in a wandering reach of the San Juan River, British Columbia, Canada, to assess particle movement around three major bars in the river. In-channel topographic changes were monitored through repeat LiDAR surveys during this period and used in concert with the tracer data set to assess the relationship between particle displacements and changes in channel morphology, specifically, the development and re-working of bars. This has direct implications for virtual velocity and morphologic based estimates of bedload flux, which rely on accurate estimates of the variability and magnitude of particle path lengths over time. Tracers were deployed in the river at three separate locations in the Fall of 2015, 2016, 2017, and 2018, with recovery surveys conducted during the summer low-flow season the year after tracer deployment and multiple mobilizing events. Tracers exhibited path length distributions reflective of both morphologic controls and year to year differences related to the annual flow regime. Annual tracer transport was restricted primarily to less than one riffle-pool-bar unit, even during years with a greater number of peak floods and duration of competent flow. Tracer deposition and burial was focused along bar margins, particularly at or downstream of the bar apex, reflecting the downstream migration and lateral bar accretion observed on Digital Elevation Models of difference. This highlights the fundamental importance of bar development and re-working underpinning bedload transport processes in bar-dominated channels

Consistency influences altered auditory feedback processing

Previous research on the effect of perturbed auditory feedback in speech production has focused on two types of responses. In the short term, speakers generate compensatory motor commands in response to unexpected perturbations. In the longer term, speakers adapt feedforward motor programs in response to feedback perturbations, in order to avoid future errors. The current study investigated the relation between these two types of responses to altered auditory feedback. Specifically, it was hypothesized that consistency in previous feedback perturbations would influence whether speakers adapt their feedforward motor programs. In an altered auditory feedback paradigm, formant perturbations were applied either across all trials (the consistent condition) or only to some trials while the others remained unperturbed (the inconsistent condition). The results showed that speakers’ responses were affected by feedback consistency, with stronger speech changes in the consistent condition compared to the inconsistent condition. Current models of speech-motor control can explain this consistency effect. However, the data also suggest compensation and adaptation are distinct processes, which is not in line with all current models

A Cu2+ (S = 1/2) Kagom\'e Antiferromagnet: MgxCu4-x(OH)6Cl2

Spin-frustrated systems are one avenue for inducing macroscopic quantum states in materials. However, experimental realization of this goal has been difficult because of the lack of simple materials and, if available, the separation of the unusual magnetic properties arising from exotic magnetic states from behavior associated with chemical disorder, such as site mixing. Here we report the synthesis and magnetic properties of a new series of magnetically frustrated materials, MgxCu4-x(OH)6Cl2. Because of the substantially different ligand-field chemistry of Mg2+ and Cu2+, site disorder within the kagom\'e layers is minimized, as directly measured by X-ray diffraction. Our results reveal that many of the properties of these materials and related systems are not due to disorder of the magnetic lattice but rather reflect an unusual ground state.Comment: Accepted for publication in J. Am. Chem. Soc

Natural history of radiographic first metatarsophalangeal joint osteoarthritis: A nineteen‐year population‐based cohort study

Objective: To assess the long-term prevalence, natural history, progression and incidence of 73 radiographic first metatarsophalangeal joint (1st MTPJ) osteoarthritis (OA). Methods: A longitudinal, cohort design was used in which radiographic OA at the 1st MTPJ was 75 investigated in participants at year 6 (1995) and year 23 (2013-2015) from the Chingford 1000 76 Women study. Radiographic features of osteophytes (OPs) and/or joint space narrowing (JSN) at the 77 1st MTPJ were scored according to a validated foot atlas. Natural history was determined by the 78 change in prevalence, incidence, progression and worsening of OA in the 1st MTPJ. Results: Complete case matched foot radiographic data were available for 193 of the women 80 currently enrolled in the study, mean age: 75.7 years (SD: 5.2; range 69-90). At the level of the 1st 81 MTPJ, prevalence of OA at year 6 was 21.76% in the left and 24.35% in the right and at year 23 was 82 23.83% in the left and 32.64% in the right. Over the 19-year period, 13.5% of women developed 83 incident OA in the right 1st MTPJ and 8.3% in the left. Both progression and worsening of OA were 84 more evident for OPs and in the right 1st MTPJs. Conclusion: In this longest study of the natural history of radiographic 1st MTPJ OA to date, the 86 prevalence and incidence of 1st MTPJ OA increased over a 19-year period. Progression and/or 87 worsening of 1st MTPJ OA over time appears to be driven by OP development rather than JSN 88 suggestive of a biomechanical cause

The Tanzania Field Epidemiology and Laboratory Training Program: building and transforming the public health workforce

The Tanzania Field Epidemiology and Laboratory Training Program (TFELTP) was established in 2008 as a partnership among the Ministry of Health and Social Welfare (MOHSW), Muhimbili University of Health and Allied Sciences, National Institute for Medical Research, and local and international partners. TFELTP was established to strengthen the capacity of MOHSW to conduct public health surveillance and response, manage national disease control and prevention programs, and to enhance public health laboratory support for surveillance, diagnosis, treatment and disease monitoring. TFELTP is a 2-year full-time training program with approximately 25% time spent in class, and 75% in the field. TFELTP offers two tracks leading to an MSc degree in either Applied Epidemiology or, Epidemiology and Laboratory Management. Since 2008, the program has enrolled a total of 33 trainees (23 males, 10 females). Of these, 11 were enrolled in 2008 and 100% graduated in 2010. All 11 graduates of cohort 1 are currently employed in public health positions within the country. Demand for the program as measured by the number of applicants has grown from 28 in 2008 to 56 in 2011. While training the public health leaders of the country, TFELTP has also provided essential service to the country in responding to high-profile disease outbreaks, and evaluating and improving its public health surveillance systems and diseases control programs. TFELTP was involved in the country assessment of the revised International Health Regulations (IHR) core capabilities, development of the Tanzania IHR plan, and incorporation of IHR into the revised Tanzania Integrated Disease Surveillance and Response (IDSR) guidelines. TFELTP is training a competent core group of public health leaders for Tanzania, as well as providing much needed service to the MOHSW in the areas of routine surveillance, outbreak detection and response, and disease program management. However, the immediate challenges that the program must address include development of a full range of in-country teaching capacity for the program, as well as a career path for graduates

Genomic screening in family-based association testing

Due to the recent gains in the availability of single-nucleotide polymorphism data, genome-wide association testing has become feasible. It is hoped that this additional data may confirm the presence of disease susceptibility loci, and identify new genetic determinants of disease. However, the problem of multiple comparisons threatens to diminish any potential gains from this newly available data. To circumvent the multiple comparisons issue, we utilize a recently developed screening technique using family-based association testing. This screening methodology allows for the identification of the most promising single-nucleotide polymorphisms for testing without biasing the nominal significance level of our test statistic. We compare the results of our screening technique across univariate and multivariate family-based association tests. From our analyses, we observe that the screening technique, applied to different settings, is fairly consistent in identifying optimal markers for testing. One of the identified markers, TSC0047225, was significantly associated with both the ttth1 (p = 0.004) and ttth1-ttth4 (p = 0.004) phenotype(s). We find that both univariate- and multivariate-based screening techniques are powerful tools for detecting an association