1,444 research outputs found
Technical quality assessment of an optoelectronic system for movement analysis
The Optoelectronic Systems (OS) are largely used in gait analysis to evaluate the motor performances of healthy subjects and patients. The accuracy of marker trajectories reconstruction depends on several aspects: the number of cameras, the dimension and position
of the calibration volume, and the chosen calibration procedure. In this paper we propose a methodology to evaluate the eects of the mentioned sources of error on the reconstruction of marker trajectories. The novel contribution of the present work consists in the dimension of the tested calibration volumes, which is comparable with the ones normally used in gait analysis; in addition, to simulate trajectories during clinical gait analysis, we provide non-default
paths for markers as inputs. Several calibration procedures are implemented and the same trial is processed with each calibration le, also considering dierent cameras congurations.
The RMSEs between the measured trajectories and the optimal ones are calculated for each comparison. To investigate the signicant dierences between the computed indices, an ANOVA analysis is implemented. The RMSE is sensible to the variations of the considered calibration volume and the camera congurations and it is always inferior to 43 mm
Domains of elliptic operators on sets in Wiener space
Let X be a separable Banach space endowed with a non-degenerate centered Gaussian measure μ. The associated Cameron-Martin space is denoted by H. Consider two sufficiently regular convex functions U: X → R and G: X →R We let ν = e-Uμ and ω = G-1(-∞, 0]. In this paper, we study the domain of the self-adjoint operator associated with the quadratic form {equation presented} and we give sharp embedding results for it. In particular, we obtain a characterization of the domain of the Ornstein-Uhlenbeck operator in Hilbert space with ω = X and on half-spaces, namely if U 0 and G is an affine function, then the domain of the operator defined via (0.1) is the space u {equation presented}, where ρ is the Feyel-de La Pradelle Hausdorff-Gauss surface measure
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Effect of voicing and articulation manner on aerosol particle emission during human speech.
Previously, we demonstrated a strong correlation between the amplitude of human speech and the emission rate of micron-scale expiratory aerosol particles, which are believed to play a role in respiratory disease transmission. To further those findings, here we systematically investigate the effect of different 'phones' (the basic sound units of speech) on the emission of particles from the human respiratory tract during speech. We measured the respiratory particle emission rates of 56 healthy human volunteers voicing specific phones, both in isolation and in the context of a standard spoken text. We found that certain phones are associated with significantly higher particle production; for example, the vowel /i/ ("need," "sea") produces more particles than /ɑ/ ("saw," "hot") or /u/ ("blue," "mood"), while disyllabic words including voiced plosive consonants (e.g., /d/, /b/, /g/) yield more particles than words with voiceless fricatives (e.g., /s/, /h/, /f/). These trends for discrete phones and words were corroborated by the time-resolved particle emission rates as volunteers read aloud from a standard text passage that incorporates a broad range of the phones present in spoken English. Our measurements showed that particle emission rates were positively correlated with the vowel content of a phrase; conversely, particle emission decreased during phrases with a high fraction of voiceless fricatives. Our particle emission data is broadly consistent with prior measurements of the egressive airflow rate associated with the vocalization of various phones that differ in voicing and articulation. These results suggest that airborne transmission of respiratory pathogens via speech aerosol particles could be modulated by specific phonetic characteristics of the language spoken by a given human population, along with other, more frequently considered epidemiological variables
Modulation of the lexical-semantic network by auditory semantic priming: An event-related functional MRI study
The current event-related fMRI study specifies the neuroanatomical correlates of semantic priming and differences in semantic relation types using an auditory primed lexical decision task (LDT). Word pairs consisted of different relation types, associations (key–chain), pure categorical relations (cow–dog), and unrelated words (table–window), as well as word–pseudoword (way–tinne) and pseudoword–pseudoword (ahurn–döva) pairs. The factor lexical status, i.e., the processing of words compared to pseudowords, was associated with activation in the middle temporal gyri and the left striatum. The factor relatedness, i.e., the contrast between unrelated and related target words, was associated with increased activation of the left inferior frontal gyrus, the deep frontal operculum bilaterally, and the middle frontal gyri. A direct contrast between the two semantic relation types indicated that the processing of purely categorical compared to associative information recruits the right precuneus, the isthmus gyrus cinguli, and the cuneus, suggesting more effortful processing of the former information type. The present data show that the factors lexical status, semantic relatedness, and type of semantic relation in a primed LDT modulate the hemodynamic response in cerebral areas that subserve auditory word recognition and subsequent lexical–semantic processing
The radio and IR counterparts of the ring nebula around HD211564
We report the detection of the radio and infrared counterparts of the ring
nebula around the WN3(h) star HD211564 (WR152), located to the southwest of the
HII region Sh2132. Using radio continuum data from the Canadian Galactic Plane
Survey, we identified the radio counterparts of the two concentric rings, of
about 9' and 16' in radius, related to the star. After applying a filling
factor f = 0.05-0.12, electron densities and ionized masses are in the range
10-16 cm^-3 and 450-700 Mo, respectively. The analysis of the HI gas emission
distribution allowed the identification of 5900 Mo of neutral atomic gas with
velocities between -52 and -43 km/s probably linked to the nebula. The region
of the nebula is almost free of molecular gas. Only four small clumps were
detected, with a total molecular mass of 790 Mo. About 310 Mo are related to a
small infrared shell-like source linked to the inner ring, which is also
detected in the MSX band A. An IRAS YSO candidate is detected in coincidence
with the shell-like IR source.
We suggest that the optical nebula and its neutral counterparts originated
from the stellar winds from the WR star and its massive progenitor, and are
evolving in the envelope of a slowly expanding shell centered at (l,b) = (102
30, -0 50), of about 31 pc in radius. The bubble's energy conversion efficiency
is in agreement with recent numerical analysis and with observational results.Comment: 11 pages, 7 figures, accepted in MNRA
Multifrequency study of the ring nebula SG13
We investigate the morphology and kinematics of the interstellar medium in
the environs of the open cluster Mrk50, which includes the Wolf-Rayet star
WR157 and a number of early B-type stars. The analysis was performed using
radio continuum images at 408 and 1420 MHz, and HI 21cm line data taken from
the Canadian Galactic Plane Survey, molecular observations of the 12CO (J=1-0)
line at 115 GHz from the Five College Radio Astronomy Observatory and available
mid and far IR observations obtained with the MSX and IRAS satellites,
respectively. This study allowed identification of the radio continuum and
molecular counterpart of the ring nebula SG13, while no neutral atomic
structure was found to be associated. The nebula is also detected in images in
the mid and far infrared, showing the existence of dust well mixed with the
ionized gas. We estimate the main physical parameters of the material linked to
the nebula. The interstellar gas distribution in the environs of Mrk50 is
compatible with a stellar wind bubble created by the mass loss from WR157. The
distribution of young stellar object (YSO) candidates in the region shows that
stellar formation activity may be present in the molecular shell that encircles
the ring nebula.Comment: Accepted for publication in MNRAS, 13 pages, 11 figure
[Accepted Manuscript] Field testing a draft version of the UNICEF/Washington Group Module on child functioning and disability. Background, methodology and preliminary findings from Cameroon and India
Background
Global child disability data are generally non-comparable, comprising different tools, methodologies and disability definitions. UNICEF and The Washington Group on Disability Statistics (WG) have developed a new tool on child functioning and disability to address this need.
Aims
The aim of this paper is to describe the development of the new module, and to present an independent field test of the draft module in two contrasting settings.
Methods
UNICEF and the WG developed a parent-reported survey module to identify children aged 2�17 years with functional difficulties in population-based surveys through: review of existing documentation, consultation with experts and cognitive testing. A field test of the draft module was undertaken in Cameroon and India within a population-based survey. Functional limitation in each of 14 domains was scored on a scale comprising �no difficulty�, �some difficulty�, �a lot of difficulty� and �cannot do�.
Results
In all, 1713 children in Cameroon and 1101 children in India were assessed. Sixty-four percent of children in Cameroon and 35% of children in India were reported to have at least some difficulty in one or more domain. The proportion reported to have either �a lot of difficulty� or �cannot do� was 9% in Cameroon and 4% in India. There were no significant differences in reported functional difficulties by sex but children aged 2�4 were reported to have fewer functional difficulties of any kind compared with older children in both countries.
Conclusion
Comparable estimates were generated between the two countries, providing an initial overview of the tool's outputs. The continued development of this standardised questionnaire for the collection of robust and reliable data on child disability is essential
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