Midbrain adaptation may set the stage for the perception of musical beat

The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain preprocessing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat

Correlation between different PBL assessment components and the final mark for MB ChB III at a rural South African university

Background. Problem-based learning (PBL) is now an accepted component of many medical school programmes worldwide. Our university also follows the PBL ‘SPICES’ model for MB ChB III. The assessment modalities used are the modified essay questions (MEQ), objective structured practical examination (OSPE), individualised process assessment (IPA) and tutorial continuous assessment (TUT). This study was done to compare the students’ performances in individual assessment components with the final mark to determine the correlation between these parameters. Materials and methods. The study was retrospective, descriptive and analytical, based on the integrated marks of all the MB ChB III students at Walter Sisulu University (WSU) in 2007. Assessment marks were stratified according to blocks and different types of assessment (MEQ, TUT, OSPE, IPA). Regression analysis was used to compute and scrutinise these vis-à-vis their correspondence with the final marks for each block. Results. Three hundred and seventy-nine block assessment marks of 96 students from 4 blocks of MB ChB III were analysed and the correlation between the assessment components and final mark were compared. Regression analysis showed good correlation when analysing the assessment modality versus the final mark for the MEQs (r=0.93, 0.93, 0.94, 0.96), followed by OSPEs (r=0.71, 0.70, 0.76, 0.77) and IPAs (r=0.62, 0.51, 0.68, 0.77). However, correlation was not significant with the TUT. Conclusion. There was good correlation between the students’ performance in the majority of assessment modalities and the final mark in the different blocks of the MB ChB III examination. There may be a need to make tutorial assessment methods more objective, partly by additional tutor training

LASER in periodontal treatment: is it an effective treatment or science fiction?

There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application

Extraordinary absorption of sound in porous lamella-crystals

We present the design of a structured material supporting complete absorption of sound with a broadband response and functional for any direction of incident radiation. The structure which is fabricated out of porous lamellas is arranged into a low-density crystal and backed by a reflecting support. Experimental measurements show that strong all-angle sound absorption with almost zero reflectance takes place for a frequency range exceeding two octaves. We demonstrate that lowering the crystal filling fraction increases the wave interaction time and is responsible for the enhancement of intrinsic material dissipation, making the system more absorptive with less material.The work was supported by the Spanish Ministry of Science and Innovation and European Union FEDER through project FIS2011-29734-C02-01. J.C. gratefully acknowledges financial support from the Danish Council for Independent Research and a Sapere Aude grant (12-134776). V. R. G. gratefully acknowledges financial support from the ''Contratos Post-Doctorales Campus Excelencia Internacional'' UPV CEI-01-11.Christensen, J.; Romero García, V.; Picó Vila, R.; Cebrecos Ruiz, A.; Garcia De Abajo, FJ.; Mortensen, NA.; Willatzen, M.... (2014). Extraordinary absorption of sound in porous lamella-crystals. Scientific Reports. 4(4674). https://doi.org/10.1038/srep04674S44674Mei, J. et al. Dark acoustic metamaterials as super absorbers for low-frequency sound. Nat. Commun. 3, 756 (2012).Leroy, V., Strybulevych, A., Scanlon, M. G. & Page, J. Transmission of ultrasound through a single layer of bubbles. Eur. Phys. J. E 29, 123 (2009).Leroy, V., Bretagne, A., Fink, M. H. W., Tabeling, P. & Tourin, A. Design and characterization of bubble phononic crystals. Appl. Phys. Lett. 95, 171904 (2009).Thomas, E. L. Applied physics: Bubbly but quiet. Nature 462, 990 (2009).Romero-García, V., Sánchez-Pérez, J. V. & Garcia-Raffi, L. M. Tunable wideband bandstop acoustic filter based on two-dimensional multiphysical phenomena periodic systems. J. Appl. Phys. 110, 014904 (2011).Garcia-Chocano, V. M., Cabrera, S. & Sanchez-Dehesa, J. Broadband sound absorption by lattices of microperforated cylindrical shells. Appl. Phys. Lett. 101, 184101 (2012).Kushwaha, M. S., Halevi, P., Dobrzynski, L. & Djafari-Rouhani, B. Acoustic band structure of periodic elastic composites. Phys. Rev. Lett. 71, 2022 (1993).Vasseur, J. O. et al. Experimental and Theoretical Evidence for the Existence of Absolute Acoustic Band Gaps in Two-Dimensional Solid Phononic Crystals. Phys. Rev. Lett. 86, 3012 (2001).Liu, Z. et al. Locally Resonant Sonic Materials. Science 289, 1734 (2000).Christensen, J., Martin-Moreno, L. & Garcia-Vidal, F. J. All-angle blockage of sound by an acoustic double-fishnet metamaterial. Appl. Phys. Lett. 97, 134106 (2010).Botten, L. C., Craig, M. S., McPhedran, R. C., Adams, J. L. & Andrewartha, J. R. The finitely conducting lamellar diffraction grating. Optica Acta 28, 1087 (1981).McPhedran, R. C., Botten, L. C., Craif, M. S., Neviere, M. & Maystre, D. Lossy lamellar gratings in the quasistatic limit. Optica Acta 29, 289 (1982).Kravets, V. G., Schedin, F. & Grigorenko, A. N. Plasmonic blackbody: Almost complete absorption of light in nanostructured metallic coatings. Phys. Rev. B 78, 205405 (2008).Sondergaard, T. et al. Plasmonic black gold by adiabatic nanofocusing and absorption of light in ultra-sharp convex grooves. Nat. Commun. 3, 969 (2012).Clapham, P. B. & Hurtley, M. C. Reduction of Lens Reflexion by the Moth Eye Principle. Nature Vol. 244, 281 (1973).Garcia-Vidal, F. J., Pitarke, J. M. & Pendry, J. B. Effective Medium Theory of the Optical Properties of Aligned Carbon Nanotubes. Phys. Rev. Lett. 78, 4289 (1997).Yang, Z., Ci, L., Bur, J. A., Lin, S. & Ajayan, P. M. Experimental Observation of an Extremely Dark Material Made By a Low-Density Nanotube Array. Nano Lett. 8, 446 (2008).Garcia-Vidal, F. J. Metamaterials: Towards the dark side. Nat. Photonics 2, 215 (2008).Mizunoa, K. et al. A black body absorber from vertically aligned single-walled carbon nanotubes. Proc. Natl. Acad. Sci. USA 106, 6044 (2009).Lidorkis, E. & Ferrari, A. C. Photonics with Multiwall Carbon Nanotube Arrays. ACS Nano 3, 1238 (2009).Beenakker, C. W. J. & Brouwer, P. W. Distribution of the reflection eigenvalues of a weakly absorbing chaotic cavity. Physica E 9, 463 (2001).Lafarge, D., Lemarinier, P., Allard, J. F. & Tarnow, V. Dynamic compressibility of air in porous structures at audible frequencies. J. Acoust. Soc. Am. 102, 1995 (1997), With the macroscopic parameters: ϕ = 0.94, α∞ = 1, σ = 20000 Nm−4s and Λ = Λ′ = 0.41 μm.García de Abajo, F. J. Colloquium: Light scattering by particle and hole arrays. Rev. Mod. Phys. 79, 1267–1290 (2007)

Review of low-cost sensors for indoor air quality: Features and applications

Humans spend the majority of their time indoors, where they are potentially exposed to hazardous pollutants. Within this context, over the past few years, there has been an upsurge of low-cost sensors (LCS) for the measurement of indoor air pollutants, motivated both by recent technological advances and by increased awareness of indoor air quality (IAQ) and its potential negative health impacts. Although not meeting the performance requirements for reference regulatory-equivalent monitoring indoors, LCS can provide informative measurements, offering an opportunity for high-resolution monitoring, emission source identification, exposure mitigation and managing IAQ and energy efficiency, among others. This article discusses the strengths and limitations that LCS offer for applications in the field of IAQ monitoring; it provides an overview of existing sensor technologies and gives recommendations for different indoor applications, considering their performance in the complex indoor environment and discussing future trends

Metabonomics and Intensive Care

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901

Hardy's inequality for functions vanishing on a part of the boundary

We develop a geometric framework for Hardy's inequality on a bounded domain when the functions do vanish only on a closed portion of the boundary.Comment: 26 pages, 2 figures, includes several improvements in Sections 6-8 allowing to relax the assumptions in the main results. Final version published at http://link.springer.com/article/10.1007%2Fs11118-015-9463-

Effects of butyl toluidine blue photosensitizer on antimicrobial photodynamic therapy for experimental periodontitis treatment in rats.

AIM: This study evaluated three concentrations of butyl toluidine blue (BuTB) for antimicrobial photodynamic therapy (aPDT) in experimental periodontitis (EP) in rats. MATERIAL AND METHODS: EP was ligature-induced at the first mandibular molar in 105 rats. Ligature was removed after 7 days and animals were distributed into the following treatments: SRP, scaling and root planing (SRP) plus saline solution; BuTB-0.1, SRP plus BuTB at 0.1 mg/mL; aPDT-0.1, SRP plus BuTB at 0.1 mg/mL and InGaAlP diode laser (DL) irradiation; BuTB-0.5, SRP plus BuTB at 0.5 mg/mL; aPDT-0.5, SRP plus BuTB at 0.5 mg/mL and DL irradiation; BuTB-2.0, SRP plus BuTB at 2 mg/mL; aPDT-2.0, SRP plus BuTB at 2 mg/mL and DL irradiation. Five animals from each group were submitted to euthanasia at 7, 15 and 30 days post-treatment. The furcation area was submitted to histological, histometric and immunohistochemical (TGF-ß1, OCN and TRAP) analyses. RESULTS: aPDT-0.5 group presented a better tissue remodeling in all periods, resolution of the inflammatory response and bone neoformation areas at 30 days. aPDT-0.5 also resulted in higher immunolabeling patterns of TGF-ß1 at all periods (p < 0.05) and of OCN at 30 days (p < 0.05). CONCLUSION: aPDT-0.5 showed the best benefits for inflammatory response and periodontal repair process

Antimicrobial photodynamic therapy compared to systemic antibiotic therapy in non-surgical treatment of periodontitis: Systematic review and meta-analysis.

BACKGROUND: Periodontitis is one of the most prevalent inflammatory diseases in humans. It is associated with the presence of bacteria and is mediated by the host's immune response This study represents a systematic review and meta-analysis trying to answer the following question: "What is the effect of antimicrobial photodynamic therapy (aPDT) as an adjunct to scaling and root planing (SRP) compared to systemic antibiotic therapy with amoxicillin plus metronidazole (AMX+MTZ) on the non-surgical treatment of periodontitis?". METHODS: Clinical studies comparing aPDT with systemic use of AMX+MTZ were searched until January of 2020 using the databases: PubMed, MEDLINE, SCOPUS, EMBASE, Cochrane Central, Web of Science and Scielo, as well manual searches in related journals. Periodontal clinical parameters such as probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were statistically analyzed. RESULTS: Five randomized clinical studies (RCTs) were included within the eligibility criteria, and served as a basis for qualitative and quantitative analyzes. All the studies reported an improvement in the clinical parameters with both therapies, although in a direct comparison, our analyzes did not find statistical differences that indicate the superiority of one supporting treatment in relation to the other. CONCLUSION: Although the limited number of RCTs and the great heterogeneity between them, it can conclude that aPDT presents similar clinical results compared to antibiotic therapy with AMX+MTZ as adjuvants in the non-surgical treatment of periodontitis

A new XRD method to quantify plate and lath martensites of hardened medium-carbon steel

This paper introduces a new technique to separately measure the volume fraction and tetragonal ratio of co-existing lath and plate martensites in ultrahigh strength steel, and to calculate their different carbon contents. First of all, the two martensites are assumed to have body centre tetragonal lattice structures of different tetragonal ratios. X-ray diffraction is then applied to obtain the overlapping (200) diffraction peak, which is subsequently separated as four sub-peaks using a self-made multiple Gaussian peak-fitting method to allow the measurement of the individual lattice parameters c and a. Finally a modified equation is applied to calculate the carbon contents from the obtained tetragonal ratios. The new technique is then applied to investigate the effect of subsequent tempering on the decarbonisation of the as-quenched martensites. Keywords: Gaussian peak-fitting, martensite carbon content, martensite tetragonal ratio, medium-carbon steels, Xray diffractio