2,803 research outputs found
Perceptual implications of different Ambisonics-based methods for binaural reverberation
Reverberation is essential for the realistic auralisation of enclosed spaces. However, it can be computationally expensive to render with high fidelity and, in practice, simplified models are typically used to lower costs while preserving perceived quality. Ambisonics-based methods may be employed to this purpose as they allow us to render a reverberant sound field more efficiently by limiting its spatial resolution. The present study explores the perceptual impact of two simplifications of Ambisonics-based binaural reverberation that aim to improve efficiency. First, a “hybrid Ambisonics” approach is proposed in which the direct sound path is generated by convolution with a spatially dense head related impulse response set, separately from reverberation. Second, the reverberant virtual loudspeaker method (RVL) is presented as a computationally efficient approach to dynamically render binaural reverberation for multiple sources with the potential limitation of inaccurately simulating listener's head rotations. Numerical and perceptual evaluations suggest that the perceived quality of hybrid Ambisonics auralisations of two measured rooms ceased to improve beyond the third order, which is a lower threshold than what was found by previous studies in which the direct sound path was not processed separately. Additionally, RVL is shown to produce auralisations with comparable perceived quality to Ambisonics renderings
A systematic review of the safety of lisdexamfetamine dimesylate
BACKGROUND: Here we review the safety and tolerability profile of lisdexamfetamine dimesylate (LDX), the first long-acting prodrug stimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD). METHODS: A PubMed search was conducted for English-language articles published up to 16 September 2013 using the following search terms: (lisdexamfetamine OR lisdexamphetamine OR SPD489 OR Vyvanse OR Venvanse OR NRP104 NOT review [publication type]). RESULTS: In short-term, parallel-group, placebo-controlled, phase III trials, treatment-emergent adverse events (TEAEs) in children, adolescents, and adults receiving LDX were typical for those reported for stimulants in general. Decreased appetite was reported by 25-39 % of patients and insomnia by 11-19 %. The most frequently reported TEAEs in long-term studies were similar to those reported in the short-term trials. Most TEAEs were mild or moderate in severity. Literature relating to four specific safety concerns associated with stimulant medications was evaluated in detail in patients receiving LDX. Gains in weight, height, and body mass index were smaller in children and adolescents receiving LDX than in placebo controls or untreated norms. Insomnia was a frequently reported TEAE in patients with ADHD of all ages receiving LDX, although the available data indicated no overall worsening of sleep quality in adults. Post-marketing survey data suggest that the rate of non-medical use of LDX was lower than that for short-acting stimulants and lower than or equivalent to long-acting stimulant formulations. Small mean increases were seen in blood pressure and pulse rate in patients receiving LDX. CONCLUSIONS: The safety and tolerability profile of LDX in individuals with ADHD is similar to that of other stimulants
Growth factor-enriched autologous plasma improves wound healing after surgical debridement in odontogenic necrotizing fasciitis: a case report
<p>Abstract</p> <p>Background</p> <p>Odontogenic necrotizing fasciitis of the neck is a fulminant infection of odontogenic origin that quickly spreads along the fascial planes and results in necrosis of the affected tissues. It is usually polymicrobial, occurs frequently in immunocompromised patients, and has a high mortality rate.</p> <p>Case presentation</p> <p>A 69-year old Mexican male had a pain in the maxillar right-canine region and a swelling of the submental and submandibular regions. Our examination revealed local pain, tachycardia, hyperthermia (39°C), and the swelling of bilateral submental and submandibular regions, which also were erythematous, hyperthermic, crepitant, and with a positive Godet sign. Mobility and third-degree caries were seen in the right mandibular canine. Bacteriological cultures isolated <it>streptococcus pyogenes </it>and <it>staphylococcus aureus</it>. The histopathological diagnosis was odontogenic necrotizing fasciitis of the submental and submandibular regions. The initial treatment was surgical debridement and the administration of antibiotics. After cultures were negative, the surgical wound was treated with a growth factor-enriched autologous plasma eight times every third day until complete healing occurred.</p> <p>Conclusions</p> <p>The treatment with a growth factor-enriched autologous plasma caused a rapid healing of an extensive surgical wound in a patient with odontogenic necrotizing fasciitis. The benefits were rapid tissue regeneration, an aesthetic and a functional scar, and the avoidance of further surgery and possible complications.</p
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Abstract:
Hepatitis E virus (HEV), which causes acute hepatitis, can progress to chronicity in immunosuppressed patients. Transfusion transmission has been reported, being asymptomatic carriers a virus reservoir and a potential threat to transfusion safety. In Argentina, HEV is not tested in blood banks and its control is a matter of debate. Our objective was to determine HEV serological and molecular prevalence in blood donors from Córdoba.
Five hundred and forty-seven plasma samples from blood donors (229 women, 318 men; median age: 35 years), obtained between February and May 2016 (n = 147), 2019 (n = 200), and 2020 (n = 200) were analyzed. IgG and IgM anti-HEV detection were performed by ELISA, and RNA detection was carried out by real-time RT-PCR and nested-PCR. Statistical analyzes were performed using R3.6.3 (statistical significance of p <0.05).
The global prevalence of anti-HEV IgG was 3.7% (19/547), being similar in all years: 2.05% in 2016 (3/147), 3.50% in 2019 (7/200) and 4.50% in 2020 (9/200) (p=0,47). A greater trend in HEV seroprevalence was observed in men than in women (4.72 vs 1.75%, p=0.06), and an increase with age (p=0,07), without statistical significance. Two positive samples for anti-HEV IgG were also IgM positive (2/19, 10.53%). RNA-HEV was detected in 1/547 (0.18%) samples, which corresponded to a 37-year-old male donor, without liver signs or symptoms or serological evidence of infection.
The resulted seroprevalences were similar to those previously described in the general population, reporting the first molecular finding in blood donors from Argentina. The local molecular prevalence is within the range described (0.012% to 0.6%) in blood donors from other non-endemic countries, in which immunocompetent RNA-HEV positive donors without serological evidence of infection were identified, highlighting: 1) the existence of the potential risk of transfusion transmission, particularly important for immunosuppressed patients; 2) the detection of HEV-RNA as the best option for screening in blood banks, although this would imply a high cost (thus pooling could be an appropriate option for HEV screening); and 3) the importance of continue HEV hemovigilance.Resumen:
El virus de hepatitis E (HEV), causante de hepatitis aguda, puede progresar a hepatitis crónica en inmunosuprimidos. Se ha reportado transmisión por vía transfusional, siendo los portadores asintomáticos reservorios del virus y una potencial amenaza para la seguridad transfusional. En Argentina, el HEV no es testeado en bancos de sangre y su control es un tema de debate. Nuestro objetivo fue determinar la prevalencia serológica y molecular para HEV en donantes de sangre de Córdoba.
Se estudiaron 547 muestras de plasma de donantes de sangre (229 mujeres, 318 hombres; mediana edad: 35 años), obtenidas entre febrero y mayo de 2016 (n=147), 2019 (n=200) y 2020 (n=200). Se realizó detección de IgG e IgM anti-HEV por ELISA, y de RNA mediante RT-PCR en tiempo real y nested-PCR. Se realizaron análisis estadísticos utilizando R3.6.3 (significancias estadísticas: p <0.05).
La prevalencia global de IgG anti-HEV fue 3,47% (19/547) resultando similar en todos los años: 2,05% en 2016 (3/147), 3,50% en 2019 (7/200) y 4,50% en 2020 (9/200) (p=0,47). Se observó una tendencia mayor en hombres que en mujeres (4,72 vs 1,75%, p=0,06), y un aumento con la edad (p=0,07), sin significancia estadística. Dos muestras positivas para IgG anti-HEV resultaron IgM positivas (2/19, 10,53%). Se detectó RNA-HEV en 1/547 (0,18%) muestras, la cual correspondió a un donante masculino de 37 años, sin signos ni síntomas hepáticos ni evidencia serológica de infección.
Las seroprevalencias obtenidas fueron similares a las descriptas previamente en población general, reportando el primer hallazgo molecular en donantes de sangre de Argentina. La prevalencia molecular local se encuentra dentro del rango descripto (0,012% a 0,6%) en donantes de sangre de otros países no endémicos, en los que se identificaron donantes inmunocompetentes RNA-HEV positivos sin evidencia serológica de infección, destacando: 1) la existencia del potencial riesgo de transmisión transfusional, particularmente importante para inmunosuprimidos; 2) la detección de RNA-HEV como la mejor opción para el screening en bancos de sangre, aunque esto implicaría un elevado costo, por lo que el agrupamiento en pools podría ser una opción apropiada para el tamizaje de HEV; y 3) la importancia de continuar la hemovigilancia de HEV.
A Machine Learning Approach to Measure and Monitor Physical Activity in Children to Help Fight Overweight and Obesity
Physical Activity is important for maintaining healthy lifestyles. Recommendations for physical activity levels are issued by most governments as part of public health measures. As such, reliable measurement of physical activity for regulatory purposes is vital. This has lead research to explore standards for achieving this using wearable technology and artificial neural networks that produce classifications for specific physical activity events. Applied from a very early age, the ubiquitous capture of physical activity data using mobile and wearable technology may help us to understand how we can combat childhood obesity and the impact that this has in later life. A supervised machine learning approach is adopted in this paper that utilizes data obtained from accelerometer sensors worn by children in free-living environments. The paper presents a set of activities and features suitable for measuring physical activity and evaluates the use of a Multilayer Perceptron neural network to classify physical activities by activity type. A rigorous reproducible data science methodology is presented for subsequent use in physical activity research. Our results show that it was possible to obtain an overall accuracy of 96 % with 95 % for sensitivity, 99 % for specificity and a kappa value of 94 % when three and four feature combinations were used
The HY5-PIF regulatory module coordinates light and temperature control of photosynthetic gene transcription
The ability to interpret daily and seasonal alterations in light and temperature signals is essential for plant survival. This is particularly important during seedling establishment when the phytochrome photoreceptors activate photosynthetic pigment production for photoautotrophic growth. Phytochromes accomplish this partly through the suppression of phytochrome interacting factors (PIFs), negative regulators of chlorophyll and carotenoid biosynthesis. While the bZIP transcription factor long hypocotyl 5 (HY5), a potent PIF antagonist, promotes photosynthetic pigment accumulation in response to light. Here we demonstrate that by directly targeting a common promoter cis-element (G-box), HY5 and PIFs form a dynamic activation-suppression transcriptional module responsive to light and temperature cues. This antagonistic regulatory module provides a simple, direct mechanism through which environmental change can redirect transcriptional control of genes required for photosynthesis and photoprotection. In the regulation of photopigment biosynthesis genes, HY5 and PIFs do not operate alone, but with the circadian clock. However, sudden changes in light or temperature conditions can trigger changes in HY5 and PIFs abundance that adjust the expression of common target genes to optimise photosynthetic performance and growth
Extracellular volume with bolus-only technique in amyloidosis patients: Diagnostic accuracy, correlation with other clinical cardiac measures, and ability to track changes in amyloid load over time
BACKGROUND: Extracellular volume (ECV) by T1 mapping requires the contrast agent distribution to be at equilibrium. This can be achieved either definitively with a primed contrast infusion (infusion ECV), or sufficiently with a delay postbolus (bolus-only ECV). For large ECV, the bolus-only approach measures higher than the infusion ECV, causing some uncertainty in diseases such as amyloidosis. PURPOSE: To characterize the relationship between the bolus-only and current gold-standard infusion ECV in patients with amyloidosis. STUDY TYPE: Bolus-only and infusion ECV were prospectively measured. POPULATION: In all, 186 subjects with systemic amyloidosis attending our clinic and 23 subjects with systemic amyloidosis who were participating in an open-label, two-part, dose-escalation, phase 1 trial. FIELD STRENGTH: Avanto 1.5T, Siemens Medical Solutions, Erlangen, Germany. ASSESSMENT: Bolus-only and infusion ECV were measured in all subjects using shortened modified Look-Locker inversion recovery (ShMOLLI) T1 mapping sequence. STATISTICAL TESTS: Pearson correlation coefficient (r); Bland-Altman; receiver operating characteristic (ROC) curve analysis. Linear regression model with a fractional polynomial transformation. RESULTS: The difference between the bolus-only and infusion myocardial ECV increased as the average of the two measures increased, with the bolus-ECV measuring higher. For an average ECV of 0.4, the difference was 0.013. The 95% limits of agreement for the two methods, after adjustment for the bias, were ±0.056. However, cardiac diagnostic accuracy was comparable (bolus-only vs. infusion ECV area under the curve [AUC] = 0.839 vs. 0.836), as were correlations with other clinical cardiac measures, and, in the trial patients, the ability to track changes in the liver/spleen with therapy. DATA CONCLUSION: In amyloidosis, with large ECVs, the bolus-only technique reads higher than the infusion technique, but clinical performance by any measure is the same. Given the work-flow advantages, these data suggest that the bolus-only approach might be acceptable for amyloidosis, and might support its use as a surrogate endpoint in future clinical trials. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2017
Destabilization of the Dystrophin-Glycoprotein Complex without Functional Deficits in α-Dystrobrevin Null Muscle
α-Dystrobrevin is a component of the dystrophin-glycoprotein complex (DGC) and is thought to have both structural and signaling roles in skeletal muscle. Mice deficient for α-dystrobrevin (adbn−/−) exhibit extensive myofiber degeneration and neuromuscular junction abnormalities. However, the biochemical stability of the DGC and the functional performance of adbn−/− muscle have not been characterized. Here we show that the biochemical association between dystrophin and β-dystroglycan is compromised in adbn−/− skeletal muscle, suggesting that α-dystrobrevin plays a structural role in stabilizing the DGC. However, despite muscle cell death and DGC destabilization, costamere organization and physiological performance is normal in adbn−/− skeletal muscle. Our results demonstrate that myofiber degeneration alone does not cause functional deficits and suggests that more complex pathological factors contribute to the development of muscle weakness in muscular dystrophy
Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC
We present the first results of meson production in the K^+K^- decay channel
from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by
the PHENIX detector at RHIC. Precision resonance centroid and width values are
extracted as a function of collision centrality. No significant variation from
the PDG accepted values is observed. The transverse mass spectra are fitted
with a linear exponential function for which the derived inverse slope
parameter is seen to be constant as a function of centrality. These data are
also fitted by a hydrodynamic model with the result that the freeze-out
temperature and the expansion velocity values are consistent with the values
previously derived from fitting single hadron inclusive data. As a function of
transverse momentum the collisions scaled peripheral.to.central yield ratio RCP
for the is comparable to that of pions rather than that of protons. This result
lends support to theoretical models which distinguish between baryons and
mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
DRB1*03:01 Haplotypes: Differential Contribution to Multiple Sclerosis Risk and Specific Association with the Presence of Intrathecal IgM Bands
BACKGROUND: Multiple sclerosis (MS) is a multifactorial disease with a genetic basis. The strongest associations with the disease lie in the Human Leukocyte Antigen (HLA) region. However, except for the DRB1*15:01 allele, the main risk factor associated to MS so far, no consistent effect has been described for any other variant. One example is HLA-DRB1*03:01, with a heterogeneous effect across populations and studies. We postulate that those discrepancies could be due to differences in the diverse haplotypes bearing that allele. Thus, we aimed at studying the association of DRB1*03:01 with MS susceptibility considering this allele globally and stratified by haplotypes. We also evaluated the association with the presence of oligoclonal IgM bands against myelin lipids (OCMB) in cerebrospinal fluid. METHODS: Genotyping of HLA-B, -DRB1 and -DQA1 was performed in 1068 MS patients and 624 ethnically matched healthy controls. One hundred and thirty-nine MS patients were classified according to the presence (M+, 58 patients)/absence (M-, 81 patients) of OCMB. Comparisons between groups (MS patients vs. controls and M+ vs. M-) were performed with the chi-square test or the Fisher exact test. RESULTS: Association of DRB1*03:01 with MS susceptibility was observed but with different haplotypic contribution, being the ancestral haplotype (AH) 18.2 the one causing the highest risk. Comparisons between M+, M- and controls showed that the AH 18.2 was affecting only M+ individuals, conferring a risk similar to that caused by DRB1*15:01. CONCLUSIONS: The diverse DRB1*03:01-containing haplotypes contribute with different risk to MS susceptibility. The AH 18.2 causes the highest risk and affects only to individuals showing OCMB
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