Modulation of human corticospinal excitability by paired associative stimulation in patients with amyotrophic lateral sclerosis and effects of Riluzole

BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that causes an impairment in both the upper and lower motor neurons. The recent description of numerous non-motor signs points to an involvement of the neocortex networks that is more complex than was previously believed. Paired associative stimulation (PAS), a combination of transcranial magnetic stimulation (TMS) and peripheral nerve stimulation, can enhance motor output in the contralateral hand through an NMDA-mediated sensorimotor mechanism. OBJECTIVE To describe the effects of PAS on ALS patients before and after Riluzole intake compared with healthy subjects. METHODS PAS was used to detect differences between 24 newly-diagnosed ALS patients and 25 age-matched healthy controls. MEP amplitude from the abductor pollicis brevis was considered before PAS, immediately after (T0) and after 10 (T10), 20 (T20), 30 (T30) and 60 (T60) minutes. Statistical significance was calculated using RM-ANOVA. RESULTS In healthy controls, PAS significantly increased MEP amplitude at T10, T20 and T30 (p < 0.05). In ALS patients, a significant increase in MEP amplitude was also observed after 60 min (p < 0.05), thus demonstrating NMDA-mediated enhanced facilitatory plasticity. After two weeks of riluzole intake, no MEP amplitude increase was evident after PAS at any time point. In three monomelic-onset ALS patients, sensorimotor facilitation was evident only in the hemisphere corresponding to the affected side and appeared in the opposite hemisphere when the patients manifested contralateral symptoms. CONCLUSIONS PAS may be considered a useful tool when investigating NMDA-mediated neocortical networks in ALS patients and the modulation of such networks after anti-glutamatergic drug intake

Phase-Insensitive Scattering of Terahertz Radiation

The nonlinear interaction between Near-Infrared (NIR) and Terahertz pulses is principally investigated as a means for the detection of radiation in the hardly accessible THz spectral region. Most studies have targeted second-order nonlinear processes, given their higher efficiencies, and only a limited number have addressed third-order nonlinear interactions, mainly investigating four-wave mixing in air for broadband THz detection. We have studied the nonlinear interaction between THz and NIR pulses in solid-state media (specifically diamond), and we show how the former can be frequency-shifted up to UV frequencies by the scattering from the nonlinear polarisation induced by the latter. Such UV emission differs from the well-known electric-field-induced second harmonic (EFISH) one, as it is generated via a phase-insensitive scattering, rather than a sum- or difference-frequency four-wave-mixing process

Association between serum Mg2+ concentrations and cardiovascular organ damage in a cohort of adult subjects

Magnesium (Mg2+) levels are associated with insulin resistance, hypertension, atherosclerosis, and type 2 diabetes (T2DM). We evaluated the clinical utility of physiological Mg2+ in assessing subclinical cardiovascular organ damage including increased carotid artery intima-media thickness (c-IMT) and left ventricular mass index (LVMI) in a cohort of well-characterized adult non-diabetic individuals. Age-and gender-adjusted correlations between Mg2+ and metabolic parameters showed that Mg2+ circulating levels were correlated negatively with body mass index (BMI), fasting glucose, and 2h-oral glucose tolerance test (OGTT) glucose. Similarly, Mg2+ levels were significantly and negatively related to c-IMT and LVMI. A multivariate regression analysis revealed that age (β = 0.440; p &lt; 0.0001), BMI (β = 0.225; p &lt; 0.0001), and Mg2+ concentration (β = −0.122; p &lt; 0.01) were independently associated with c-IMT. Age (β = 0.244; p = 0.012), Mg2+ (β = −0.177; p = 0.019), and diastolic blood pressure (β = 0.184; p = 0.038) were significantly associated with LVMI in women, while age (β = 0.211; p = 0.019), Mg2+ (β = −0.171; p = 0.038) and the homeostasis model assessment index of insulin resistance (HOMA-IR) (β = −0.211; p = 0.041) were the sole variables associated with LVMI in men. In conclusion, our data support the hypothesis that the assessment of Mg2+ as part of the initial work-up might help unravel the presence of subclinical organ damage in subjects at increased risk of cardiovascular complications

Prehospital ambulance 12-lead electrocardiograms reduce door to needle time for thrombolysis in the emergency room

Digitalitzat per Artypla

Reply to Comment on: Hawking radiation from ultrashort laser pulse filaments

A comment by R. Schutzhold et al. raises possible concerns and questions regarding recent measurements of analogue Hawking radiation. We briefly reply to the opinions expressed in the comment and sustain that the origin of the radiation may be understood in terms of Hawking emission

Comprehensive Family Hygiene Promotion in Peri-Urban Cape Town: Reduction of Respiratory Illness in Children Under Five

Background: Examination with Cone Beam CT (CBCT) is common for localizing maxillary canines with eruption disturbance. The benefits and costs of these examinations are unclear. Objectives: To measure: 1. the proportion of orthodontists' treatment decisions that were different based on intraoral and panoramic radiography (M1) compared with CBCT and panoramic radiography (M2); and 2. the costs of producing different treatment plans, regarding patients with maxillary canines with eruption disturbance. Subjects and methods: Orthodontists participated in a web-based survey and were randomly assigned to denote treatment decisions and the level of confidence in this decision for four patient cases presented with M1 or M2 at two occasions for the same patient case. Results: One hundred and twelve orthodontists made 445 assessments based on M1 and M2, respectively. Twenty-four per cent of the treatment decisions were different depending on which method the raters had access to, whereof one case differed significantly from all other cases. The mean total cost per examination was €99.84 using M1 and €134.37 using M2, resulting in an incremental cost per examination of €34.53 for M2. Limitations: Benefits in terms of number of different treatment decisions must be considered as an intermediate outcome for the effectiveness of a diagnostic method and should be interpreted with caution. Conclusions: For the patient cases presented in this study, most treatment decisions were the same irrespective of radiological method. Accordingly, this study does not support routine use of CBCT regarding patients with maxillary canine with eruption disturbance

Representative elementary volumes for evaluating effective seismic properties of heterogeneous poroelastic media

Understanding and quantifying seismic energy dissipation in fluid-saturated porous rocks is of considerable interest because it offers the perspective of extracting information with regard to the elastic and hydraulic rock properties. An important, if not dominant, attenuation mechanism prevailing in the seismic frequency band is wave-induced fluid pressure diffusion in response to the contrasts in elastic stiffness in the mesoscopic-scale range. An effective way to estimate seismic velocity dispersion and attenuation related to this phenomenon is through the application of numerical upscaling procedures to synthetic rock samples of interest. However, the estimated seismic properties are meaningful only if the underlying sample volume is at least of the size of a representative elementary volume (REV). In the given context, the definition of an REV and the corresponding implications for the estimation of the effective seismic properties remain largely unexplored. To alleviate this problem, we have studied the characteristics of REVs for a set of idealized rock samples sharing high levels of velocity dispersion and attenuation. For periodically heterogeneous poroelastic media, the REV size was driven by boundary condition effects. Our results determined that boundary condition effects were absent for layered media and negligible in the presence of patchy saturation. Conversely, strong boundary condition effects arose in the presence of a periodic distribution of finite-length fractures, thus leading to large REV sizes. The results thus point to the importance of carefully determining the REV sizes of heterogeneous porous rocks for computing effective seismic properties, especially in the presence of strong dry frame stiffness contrasts. </jats:p

Detectability of large-scale counter-rotating stellar disks in galaxies with integral-field spectroscopy

In recent years integral-field spectroscopic surveys have revealed that the presence of kinematically decoupled stellar components is not a rare phenomenon in nearby galaxies. However, complete statistics are still lacking because they depend on the detection limit of these objects. We investigate the kinematic signatures of two large-scale counter-rotating stellar disks in mock integral-field spectroscopic data to address their detection limits as a function of the galaxy properties and instrumental setup. We built a set of mock data of two large-scale counter-rotating stellar disks as if they were observed with the Multi-Unit Spectroscopic Explorer (MUSE). We accounted for different photometric, kinematic, and stellar population properties of the two counter-rotating components as a function of galaxy inclination. We extracted the stellar kinematics in the wavelength region of the calcium triplet absorption lines by adopting a Gauss-Hermite (GH) parameterization of the line-of-sight velocity distribution (LOSVD). We confirm that the strongest signature of the presence of two counter-rotating stellar disks is the symmetric double peak in the velocity dispersion map, already known as the $2\sigma$ feature. The size, shape, and slope of the 2$\sigma$ peak strongly depend on the velocity separation and relative light contribution of the two counter-rotating stellar disks. When the $2\sigma$ peak is difficult to detect due to the low signal-to-noise ratio of the data, the large-scale structure in the $h_3$ map can be used as a diagnostic for strong and weak counter-rotation. The counter-rotating kinematic signatures become fainter at lower viewing angles as an effect of the smaller projected velocity separation between the two counter-rotating components. We confirm that the observed frequency of $2\sigma$ galaxies represents only a lower limit of the stellar counter-rotation phenomenon.Comment: Accepted for publication in Astronomy & Astrophysics. 17 pages, 11 figures, 2 table

RegExpBlasting (REB), a Regular Expression Blasting algorithm based on multiply aligned sequences

Background: One of the most frequent uses of bioinformatics tools concerns functional characterization of a newly produced nucleotide sequence (a query sequence) by applying Blast or FASTA against a set of sequences (the subject sequences). However, in some specific contexts, it is useful to compare the query sequence against a cluster such as a MultiAlignment (MA). We present here the RegExpBlasting (REB) algorithm, which compares an unclassified sequence with a dataset of patterns defined by application of Regular Expression rules to a given-as-input MA datasets. The REB algorithm workflow consists in i. the definition of a dataset of multialignments ii. the association of each MA to a pattern, defined by application of regular expression rules; iii. automatic characterization of a submitted biosequence according to the function of the sequences described by the pattern best matching the query sequence. Results: An application of this algorithm is used in the "characterize your sequence" tool available in the PPNEMA resource. PPNEMA is a resource of Ribosomal Cistron sequences from various species, grouped according to nematode genera. It allows the retrieval of plant nematode multialigned sequences or the classification of new nematode rDNA sequences by applying REB. The same algorithm also supports automatic updating of the PPNEMA database. The present paper gives examples of the use of REB within PPNEMA. Conclusion: The use of REB in PPNEMA updating, the PPNEMA "characterize your sequence" option clearly demonstrates the power of the method. Using REB can also rapidly solve any other bioinformatics problem, where the addition of a new sequence to a pre-existing cluster is required. The statistical tests carried out here show the powerful flexibility of the method