Laryngeal somatosensory deficits in Parkinson’s disease: implications for speech respiratory and phonatory control

Parkinson’s disease (PD) is often associated with substantial impairment of speech respiratory and phonatory control. However, the degree to which these impairments are related to abnormal laryngeal sensory function is unknown. This study examined whether individuals with PD exhibited abnormal and more asymmetric laryngeal somatosensory function compared with healthy controls, and whether these deficits were associated with disease and voice severity. Nineteen PD participants were tested and compared with 18 healthy controls. Testing included endoscopic assessment of laryngeal somatosensory function, with aerodynamic and acoustic assessment of respiratory and phonatory control, and clinical ratings of voice and disease severity. PD participants exhibited significantly abnormal and asymmetric laryngeal somatosensory function compared with healthy controls. Sensory deficits were significantly associated with timing of phonatory onset, voice intensity, respiratory driving pressure, laryngeal resistance, lung volume expended per syllable, disease severity, and voice severity. These results suggest that respiratory and phonatory control are influenced by laryngeal somatosensory function, that speech-related deficits in PD are related to abnormal laryngeal somatosensory function, and that this function may degrade as a function of disease severity. Thus, PD may represent a model of airway sensorimotor disintegration, highlighting the important role of the basal ganglia and related neural networks in the integration of laryngeal sensory input for speech-related motor control

Sparse coding on the spot: Spontaneous retinal waves suffice for orientation selectivity

Ohshiro, Hussain, and Weliky (2011) recently showed that ferrets reared with exposure to flickering spot stimuli, in the absence of oriented visual experience, develop oriented receptive fields. They interpreted this as refutation of efficient coding models, which require oriented input in order to develop oriented receptive fields. Here we show that these data are compatible with the efficient coding hypothesis if the influence of spontaneous retinal waves is considered. We demonstrate that independent component analysis learns predominantly oriented receptive fields when trained on a mixture of spot stimuli and spontaneous retinal waves. Further, we show that the efficient coding hypothesis provides a compelling explanation for the contrast between the lack of receptive field changes seen in animals reared with spot stimuli and the significant cortical reorganisation observed in stripe-reared animals

Subthalamic nucleus deep brain stimulation changes speech respiratory and laryngeal control in Parkinson\u27s disease

Adequate respiratory and laryngeal motor control are essential for speech, but may be impaired in Parkinson\u27s disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on respiratory and laryngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of respiratory and laryngeal control, and whether these changes were correlated with limb function and stimulation parameters. Eighteen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when DBS was on, and again 1 h after DBS was turned off, and included aerodynamic measures during syllable production, and standard clinical ratings of limb function. We found that PD participants exhibited changes with DBS, consistent with increased respiratory driving pressure (n = 9) and increased vocal fold closure (n = 9). However, most participants exceeded a typical operating range for these respiratory and laryngeal control variables with DBS. Changes were uncorrelated with limb function, but showed some correlation with stimulation frequency and pulse width, suggesting that speech may benefit more from low-frequency stimulation and shorter pulse width. Therefore, high-frequency STN DBS may be less beneficial for speech-related respiratory and laryngeal control than for limb motor control. It is important to consider these distinctions and their underlying mechanisms when assessing the impact of STN DBS on PD

Subthalamic nucleus deep brain stimulation changes velopharyngeal control in Parkinson’s disease

Purpose—Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson’s disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal control, and whether these changes were correlated with limb function and stimulation settings. Methods—Seventeen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when STN DBS was on, and again 1 h after STN DBS was turned off, and included aerodynamic measures during syllable production, and standard neurological ratings of limb function. Results—We found that PD participants exhibited changes with STN DBS, primarily consistent with increased intraoral pressure (n = 7) and increased velopharyngeal closure (n = 5). These changes were modestly correlated with measures of limb function, and were correlated with stimulation frequency. Conclusion—Our findings suggest that STN DBS may change velopharyngeal control during syllable production in PD, with greater benefit associated with low frequency stimulation. However, DBS demonstrates a more subtle influence on speech-related velopharyngeal control than limb motor control. This distinction and its underlying mechanisms are important to consider when assessing the impact of STN DBS on PD

Subthalamic nucleus deep brain stimulation changes speech respiratory and laryngeal control in Parkinson's disease

Adequate respiratory and laryngeal motor control are essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on respiratory and laryngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of respiratory and laryngeal control, and whether these changes were correlated with limb function and stimulation parameters. Eighteen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when DBS was on, and again 1 h after DBS was turned off, and included aerodynamic measures during syllable production, and standard clinical ratings of limb function. We found that PD participants exhibited changes with DBS, consistent with increased respiratory driving pressure (n = 9) and increased vocal fold closure (n = 9). However, most participants exceeded a typical operating range for these respiratory and laryngeal control variables with DBS. Changes were uncorrelated with limb function, but showed some correlation with stimulation frequency and pulse width, suggesting that speech may benefit more from low-frequency stimulation and shorter pulse width. Therefore, high-frequency STN DBS may be less beneficial for speech-related respiratory and laryngeal control than for limb motor control. It is important to consider these distinctions and their underlying mechanisms when assessing the impact of STN DBS on PD

Bioaccessibility performance data for fifty-seven elements in guidance material BGS 102

BGS 102, a guidance material for bioaccessible arsenic (As) and lead (Pb), was produced during validation of the in vitro Unified Bioaccessibility Method (UBM). This paper reports a compilation of reproducible bioaccessible guidance values for fifty-five additional elements in BGS 102, providing guidance for analysts to broaden the scope of UBM analyses for a wider range of elements based on data collected over an average of 60 separate analytical batches per element. Data are presented in categories for both gastric (STOM) and gastrointestinal (STOM + INT) extraction phases, where reproducibility, measured as relative standard deviation (RSD) was; ≤ 10% RSD for 27 elements (Mg, Al, Si, P, Ca, Cr, Mn, Co, Ni, As, Rb, Sr, Y, Ba, La, Ce, Pr, Nd, Sm, Eu, Tb, Gd, Dy, Ho, Er, Tm, Yb); between 10 and 20% RSD for 10 elements (Li, K, V, Fe, Cu, Zn, Cd, Lu, Pb, U); and ≥ 20% RSD for 19 elements in the gastric phase (Be, B, S, Ti, Ga, Se, Zr, Nb, Mo, Ag, Sn, Sb, Cs, Hf, Ta, W, Tl, Bi, Th). Two elements (Mg, Rb) met the ≤ 10% RSD criteria in the UBM gastrointestinal extraction phase due to the alkaline conditions of this phase precipitating out the majority of determinands. Certain elements, including Na, K, Zn and Se, were found to be a significant component of the extraction fluids with proportionally higher concentrations compared to the guidance material. Bioaccessible fractions (%BAF) were also calculated, but were found to be a less reproducible format for confirming the accuracy of measurements. The low concentration of some elements of interest in BGS 102, such as antimony (Sb), justifies the preparation of an alternative certified reference material (CRM). This paper presents an opportunity to broaden the scope of the UBM method to address food security issues (e.g. Fe and Zn micronutrient deficiencies) and contributions to dietary intake from extraneous dust or soil through evidence of the analytical possibilities and current limitations requiring further investigation

Using Raman Spectroscopy to Improve Hyperpolarized Noble Gas Production for Clinical Lung Imaging Techniques

Spin-exchange optical pumping (SEOP) can be used to “hyperpolarize” 129Xe for human lung MRI. SEOP involves transfer of angular momentum from light to an alkali metal (Rb) vapor, and then onto 129Xe nuclear spins during collisions; collisions between excited Rb and N2 ensure that incident optical energy is nonradiatively converted into heat. However, because variables that govern SEOP are temperature-dependent, the excess heat can complicate efforts to maximize spin polarization—particularly at high laser fluxes and xenon densities. Ultra-low frequency Raman spectroscopy may be used to perform in situ gas temperature measurements to investigate the interplay of energy thermalization and SEOP dynamics. Experimental configurations include an “orthogonal” pump-and-probe design and a newer “inline” design (with source and detector on the same axis) that has provided a >20-fold improvement in SNR. The relationship between 129Xe polarization and the spatiotemporal distribution of N2 rotational temperatures has been investigated as a function of incident laser flux, exterior cell temperature, and gas composition. Significantly elevated gas temperatures have been observed—hundreds of degrees hotter than exterior cell surfaces—and variances with position and time can indicate underlying energy transport, convection, and Rb mass-transport processes that, if not controlled, can negatively impact 129Xe hyperpolarization

Lifetime measurement of the metastable 3d 2D5/2 state in the 40Ca+ ion using the shelving technique on a few-ion string

We present a measurement of the lifetime of the metastable 3d 2D5/2 state in the 40Ca+ ion, using the so-called shelving technique on a string of five Doppler laser-cooled ions in a linear Paul trap. A detailed account of the data analysis is given, and systematic effects due to unwanted excitation processes and collisions with background gas atoms are discussed and estimated. From a total of 6805 shelving events, we obtain a lifetime tau=1149+/-14(stat.)+/-4(sys.)ms, a result which is in agreement with the most recent measurements.Comment: 10 pages, 7 figures. Submitted for publicatio

A Herschel study of Planetary Nebulae

We present Herschel PACS and SPIRE images of the dust shells around the planetary nebulae NGC 650, NGC 6853, and NGC 6720, as well as images showing the dust temperature in their shells. The latter shows a rich structure, which indicates that internal extinction in the UV is important despite the highly evolved status of the nebulae.Comment: 2 pages, 1 figure, 2012, proceedings IAU Symposium 283 Planetary Nebulae: An Eye to the Futur

Melatonin as a treatment after traumatic brain injury: a systematic review and meta-analysis of the pre-clinical and clinical literature

Traumatic brain injury is common and yet effective treatments of the secondary brain injury are scarce. Melatonin is a potent, non-selective neuroprotective and anti-inflammatory agent that is showing promising results in neonatal brain injury. The aim of this study was to systematically evaluate the pre-clinical and clinical literature for the effectiveness of Melatonin to improve outcome after TBI. Using the systematic review protocol for animal intervention studies (SYRCLE) and Cochrane methodology for clinical studies, a search of English articles was performed. Eligible studies were identified and data was extracted. Quality assessment was performed using the SYRCLE risk of bias tool. Meta-analyses were performed using standardized mean differences (SMD). Seventeen studies (15 pre-clinical, 2 clinical) met inclusion criteria. There was heterogeneity in the studies, and all had moderate-to-low risk of bias. Meta-analysis of pre-clinical data revealed an overall positive effect on neurobehavioural outcome with SMD of 1.51 (95% CIs: 1.06-1.96). Melatonin treatment had a favorable effect on the neurological status, by a SMD of 1.35 (95% CI: 0.83-1.88) and cognition by a SMD of 1.16 (95% CIs: 0.4-1.92). Melatonin decreased the size of the contusion by a SMD of 2.22 (95% CI: 0.84-3.59) and cerebral oedema by SMD of 1.91 (95% CI: 1.08-2.74). Only two clinical studies were identified. They were of low quality, used for symptom management, and were of uncertain significance. In conclusion, there is evidence that Melatonin treatment after TBI significantly improves both behavioural outcomes and pathological outcomes, but significant research gaps exist especially in clinical populations