851 research outputs found
Effects of Age, Sex, and Body Position on Orofacial Muscle Tone in Healthy Adults
Purpose: Quantification of tissue stiffness may facilitate identification of abnormalities in orofacial muscle tone and thus contribute to differential diagnosis of dysarthria. Tissue stiffness is affected by muscle tone as well as age-related changes in muscle and connective tissue.
Method: The Myoton-3 measured tissue stiffness in 40 healthy adults, including equal numbers of men and women in each of two age groups: 18–40 years and 60+ years. Data were collected from relaxed muscles at the masseter, cheek, and lateral tongue surfaces in two positions: reclined on the side and seated with head tilted.
Results: Tissue stiffness differed across age, sex, and measurement site with multiple interaction effects. Overall, older subjects exhibited higher stiffness coefficients and oscillation frequency measures than younger subjects whereas sex differences varied by tissue site. Effects of body position were inconsistent across tissue site and measurement.
Conclusions: Although older subjects were expected to have lower muscle tone, age-related nonmuscular tissue changes may have contributed to yield a net effect of higher stiffness. These data raise several considerations for the development of accurate normative data and for future diagnostic applications of tissue stiffness assessment
Generalized motor programme and parameterization accuracy in apraxia of speech and conduction aphasia
The present study examined three aspects of motor programming (generalized motor programme (GMP) accuracy, temporal parameterization accuracy, and amplitude parameterization accuracy) in subjects with apraxia of speech (AOS) or conduction aphasia (CA) and normal speaking participants. Subjects were presented with a movement pattern on a monitor that they were required to produce with the jaw, after the target pattern had been removed from view. Analyses examined differences in relative (parameterization) and absolute (GMP) timing and amplitude between the target and actual movement. Examination of individual subject performance revealed inter- subject variability within the AOS group, with two of the four subjects demonstrating unimpaired GMP accuracy but poor parameterization accuracy, while the other two subjects exhibited the opposite pattern, impaired GMP accuracy but normal parameterization. No clear pattern of deficit was noted for the subjects with CA. Results are discussed with respect to motor control theories of AOS and CA
The Extratropical Transition of Tropical Cyclones. Part I: Cyclonic Evolution and Direct Impacts
Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review in 2003. Methods for diagnosing ET in reanalysis, observational, and model-forecast datasets are discussed. New climatologies for the eastern North Pacific and southwest Indian Oceans are presented alongside updates to western North Pacific and North Atlantic Ocean climatologies. Advances in understanding and, in some cases, modeling the direct impacts of ET-related wind, waves, and precipitation are noted. Improved understanding of structural evolution throughout the transformation stage of ET fostered in large part by novel aircraft observations collected in several recent ET events is highlighted. Predictive skill for operational and numerical model ET-related forecasts is discussed along with environmental factors influencing posttransition cyclone structure and evolution. Operational ET forecast and analysis practices and challenges are detailed. In particular, some challenges of effective hazard communication for the evolving threats posed by a tropical cyclone during and after transition are introduced. This review concludes with recommendations for future work to further improve understanding, forecasts, and hazard communication
Perceptual and instrumental assessments of orofacial muscle tone in dysarthric and normal speakers
Clinical assessment of orofacial muscle tone is of interest for differential diagnosis of the dysarthrias, but standardized procedures and normative data are lacking. In this study, perceptual ratings of tone were compared with instrumental measures of tissue stiffness for facial, lingual, and masticatory muscles in 70 individuals with dysarthria. Perceptual and instrumental tone data were discordant and failed to discriminate between five dysarthria types. These results raised concerns about the validity of Myoton-3 stiffness measures in the orofacial muscles. Therefore, a second study evaluated contracted and relaxed orofacial muscles in 10 neurotypical adults. Results for the cheek, masseter, and lateral tongue surface followed predictions, with significantly higher tissue stiffness during contraction. In contradiction, stiffness measures from the superior surface of the tongue were lower during contraction. Superior-to-inferior tongue thickness was notably increased during contraction. A third study revealed that tissue thickness up to ~10 mm significantly affected Myoton-3 measures. Altered tissue thickness due to neuromuscular conditions like spasticity and atrophy may have undermined the detection of group differences in the original sample of dysarthric speakers. These experiments underscore the challenges of assessing orofacial muscle tone and identify considerations for quantification of tone-related differences across dysarthria groups in future studies
Perceptual and instrumental assessments of orofacial muscle tone in dysarthric and normal speakers
Clinical assessment of orofacial muscle tone is of interest for differential diagnosis of the dysarthrias, but standardized procedures and normative data are lacking. In this study, perceptual ratings of tone were compared with instrumental measures of tissue stiffness for facial, lingual, and masticatory muscles in 70 individuals with dysarthria. Perceptual and instrumental tone data were discordant and failed to discriminate between five dysarthria types. These results raised concerns about the validity of Myoton-3 stiffness measures in the orofacial muscles. Therefore, a second study evaluated contracted and relaxed orofacial muscles in 10 neurotypical adults. Results for the cheek, masseter, and lateral tongue surface followed predictions, with significantly higher tissue stiffness during contraction. In contradiction, stiffness measures from the superior surface of the tongue were lower during contraction. Superior-to-inferior tongue thickness was notably increased during contraction. A third study revealed that tissue thickness up to ~10 mm significantly affected Myoton-3 measures. Altered tissue thickness due to neuromuscular conditions like spasticity and atrophy may have undermined the detection of group differences in the original sample of dysarthric speakers. These experiments underscore the challenges of assessing orofacial muscle tone and identify considerations for quantification of tone-related differences across dysarthria groups in future studies
Overcoming barriers to engaging socio-economically disadvantaged populations in CHD primary prevention: a qualitative study
<p><b>Background:</b> Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD).</p>
<p><b>Methods:</b> The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches.</p>
<p><b>Results:</b> Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention.</p>
<p><b>Conclusion:</b> Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.</p>
On the Necessity of Consciousness for Sophisticated Human Action
In this essay, we aim to counter and qualify the epiphenomenalist challenge proposed in this special issue on the grounds of empirical and theoretical arguments. The current body of scientific knowledge strongly indicates that conscious thought is a necessary condition for many human behaviors, and therefore, consciousness qualifies as a cause of those behaviors. We review illustrative experimental evidence for the causal power of conscious thought while also acknowledging its natural limitations. We argue that it is implausible that the metabolic costs inherent to conscious processes would have evolved in humans without any adaptive benefits. Moreover, we discuss the relevance of conscious thought to the issue of freedom. Many accounts hold conscious thought as necessary and conducive to naturalistic conceptions of personal freedom. Apart from these theories, we show that the conscious perception of freedom and the belief in free will provide sources of interesting findings, beneficial behavioral effects, and new avenues for research. We close by proposing our own challenge via outlining the gaps that have yet to be filled to establish hard evidence of an epiphenomenal model of consciousness. To be sure, we appreciate the epiphenomenalist challenge as it promotes critical thinking and inspires rigorous research. However, we see no merit in downplaying the causal significance of consciousness a priori. Instead, we believe it more worthwhile to focus on the complex interplay between conscious and other causal processes
Recommended from our members
Glucose inhibits cardiac muscle maturation through nucleotide biosynthesis.
The heart switches its energy substrate from glucose to fatty acids at birth, and maternal hyperglycemia is associated with congenital heart disease. However, little is known about how blood glucose impacts heart formation. Using a chemically defined human pluripotent stem-cell-derived cardiomyocyte differentiation system, we found that high glucose inhibits the maturation of cardiomyocytes at genetic, structural, metabolic, electrophysiological, and biomechanical levels by promoting nucleotide biosynthesis through the pentose phosphate pathway. Blood glucose level in embryos is stable in utero during normal pregnancy, but glucose uptake by fetal cardiac tissue is drastically reduced in late gestational stages. In a murine model of diabetic pregnancy, fetal hearts showed cardiomyopathy with increased mitotic activity and decreased maturity. These data suggest that high glucose suppresses cardiac maturation, providing a possible mechanistic basis for congenital heart disease in diabetic pregnancy
- …