2,269 research outputs found

    Optimal control-based methodology for active vibration control of pedestrian structures

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Civil structures such as floor systems with open-plan layouts or lightweight footbridges can be susceptible to excessive levels of vibrations caused by human activities. Active vibration control (AVC) via inertial-mass actuators has been shown to be a viable technique to mitigate vibrations, allowing structures to satisfy vibration serviceability limits. It is generally considered that the determination of the optimal placement of sensors and actuators together with the output feedback gains leads to a tradeoff between the regulation performance and the control effort. However, the "optimal" settings may not have the desired effect when implemented because simplifications assumed in the control scheme components may not be valid and/or the actuator/sensor limitations are not considered. This work proposes a design methodology for multi-input multi-output vibration control of pedestrian structures to simultaneously obtain the sensor/actuator placement and the control law. This novel methodology consists of minimising a performance index that includes all the significant practical issues involved when inertial-mass actuators and accelerometers are used to implement a direct velocity feedback in practice. Experimental results obtained on an in-service indoor walkway confirm the viability of the proposed methodology.The authors acknowledge the financial support provided by the Fundación Caja Madrid through the grant “II Convocatoria de Becas de Movilidad para profesores de las universidades públicas de Madrid durante el curso académico 2012/2013” and also the UK Engineering and Physical Sciences Research Council (EPSRC) though grant EP/J004081/2 entitled “Advanced Technologies for Mitigation of Human-Induced Vibration”

    Rugoscopy in human identification: a study in a sample of twins

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    Palatal rugae patterns can be useful for forensic identification purposes. However, some doubts persist in concerning the pattern singularity in twins. The purpose of this study was to assess palatal rugae pattern singularity in a sample of twins. To do this, the palatal rugae patterns of 19 pairs of monozygotic twins and 47 pairs of dizygotic twins were studied. Our results showed that in monozygotic twins, no statistical significant differences were found, either in the form or number of palatal rugae. However, in dizygotic twins, differences were found in the number or shape of all palatal rugae (except for the shape of the first two right ones), suggesting that the palatal rugae pattern can be useful for identification purposes of dizygotic, but not of monozygotic, twins.Generation XXI was funded by Programa Operacional de Saúde (Regional Department of Ministry of Health). It has support from the Portuguese Foundation for Science and Technology (FCT) and from the Calouste Gulbenkian Foundation.An individual grant to Braga S (SFRH/BD/120500/2016) by the Portuguese Foundation for Science and Technology (FCT) is gratefully acknowledged.This work was financed by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 – Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/MEC-MCI/29777/2017/POCI-01-0145-FEDER-029777

    A ansiedade, medo e stress nos Profissionais de Saude Oral durante o primeiro ano de pandemia por Covid-19

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    Objetivos: Caracterizar o impacto da atual pandemia de COVID-19 na ansiedade, medo e stress nos profissionais de saude oral. Metodos: Utilizou-se um questionario autoaplicado online que foi enviado, via email, para tres associacoes na area da Medicina Dentaria. As variaveis categoricas foram descritas atraves de frequencias absolutas e relativas. As variaveis continuas foram descritas utilizando a media e o desvio-padrao. Utilizou-se um modelo de regressao linear multipla para selecio-nar preditores da ansiedade avaliados no questionario. Resultados: Obteve-se uma taxa de participacao de 21,1%. A maioria dos participantes era do sexo feminino (67,2%). Atraves da escala GAD-7 apuramos que 18,3% dos profissionais apresentaram uma perturbacao de ansiedade moderada e grave. A maioria dos participan-tes (86,7%) referiu ter medo de infetar os familiares e amigos. Verificamos que ser do sexo feminino, o medo de infetar a familia e amigos, a possibilidade de a pandemia afetar nega-tivamente a profissao, a perda de rendimentos e as novas condicoes de trabalho eram pre-ditores estaticamente significativos para o aumento da ansiedade (p < 0,05). Pelo contrario, a medida que o numero de anos de pratica clinica aumenta, a ansiedade diminui significa-tivamente (p.0,006). Conclusoes: A pandemia de COVID-19 afetou negativamente os profissionais de saude oral. As medidas de prevencao e os protocolos de controlo de infecao devem ser rigorosamente cumpridos, para que haja diminuicao da transmissao do virus e, consequentemente, dimi-nua a ansiedade, o stress e o medo sentidos por estes profissionais. (Rev Port Estomatol Med Dent Cir Maxilofac. 2023;64(2):84-92) & COPY; 2023 Sociedade Portuguesa de Estomatologia e Medicina Dentaria. Publicado por SPEMD. Este e um artigo Open Access sob uma licenca CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Investigation of Biomarkers of Hepatic and Renal Toxicity in the Han Wistar Rat

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    The aim of this project was to identify urinary markers of hepatic and renal toxicity in the male Hanover-Wistar rat; acute and chronic injury models were developed by administration of CCl4. Nephrotoxicity was induced by administration of HCBD. In an acute dose study, CCl4-induced nephrotoxicity occurred above 2.0 mL/kg CCl4. To avoid kidney injury, 2.0 mL/kg CCl4 was chosen as the optimal dose. 1H NMR revealed many changes to the urinary metabolome following CCl4-induced liver injury including an increase in the resonances of taurine, creatine and formate and a decrease in hippurate and creatinine. Protein and gene expression markers were investigated in a HCBD-model of nephrotoxicity. Urinary α-GST, KIM-1 and albumin were the most sensitive biomarkers of proximal tubular injury. These markers could be used to detect unwanted kidney injury in future CCl4 hepatic studies. In a time course study, maximal liver injury from CCl4 was reached 24-48 hours post-dosing. Urinary metabolites followed the same trend and levels increased during the first 18-24 hours post-dosing. After 24 hours, there was a tendency for metabolites to return to control levels. A chronic model of CCl4-induced liver fibrosis was developed by dosing animals 3 times a week for 6 weeks to investigate the potential for reversibility and changes in urinary metabolites. After 6 weeks of CCl4-administration there was development of fibrous structures in the liver parenchyma followed by slight regeneration during the recovery period. Urinary metabolites that best reflected the development of fibrosis were creatinine, citrate and succinate. Taurine and hippurate may be useful for showing regenerative changes. In this project, we developed a good rat model of fibrosis which showed potential to reverse. 1H NMR analysis allowed characterisation of urinary metabolite changes in acute and chronic studies. Some of these metabolites have potential to be urinary markers for hepatic fibrosis

    Forensic age estimation using the eruption of the second permanent mandibular molar: determining age over 14 years-old

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    Little is known about the role of the second molar eruption in forensic age estimation; however, in countries where the legal age is 14-years-old, it can provide important information. This study aims to analyse whether the eruption stages of the second mandibular molar can be used for forensic age estimation purposes. The eruption stage of the second left mandibular molar was assessed and correlation between age and stage of eruption was evaluated using Spearman rank order correlation. A Chi-square test was used to assess the correlation between age equal or superior to 14 and stage C or D attainment. The level of significance was defined as p<0.05. Stage C and D attainment and age 14 were significantly related in both sexes (p<0.001). Still, stage 3 was attained by 37% and 44.4% of the males and females younger than 14 years, respectively; stage 4 was attained by 14.8% and 25.6% of the males and females younger than 14 years, respectively. Second molar emergence, particularly stage D, can be used as a dental age indicator. When stage D is attained, particularly in males, there is strong suggestion of age over 14 years. However, other markers should also be used

    A physically meaningful method for the comparison of potential energy functions

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    In the study of the conformational behavior of complex systems, such as proteins, several related statistical measures are commonly used to compare two different potential energy functions. Among them, the Pearson's correlation coefficient r has no units and allows only semi-quantitative statements to be made. Those that do have units of energy and whose value may be compared to a physically relevant scale, such as the root mean square deviation (RMSD), the mean error of the energies (ER), the standard deviation of the error (SDER) or the mean absolute error (AER), overestimate the distance between potentials. Moreover, their precise statistical meaning is far from clear. In this article, a new measure of the distance between potential energy functions is defined which overcomes the aforementioned difficulties. In addition, its precise physical meaning is discussed, the important issue of its additivity is investigated and some possible applications are proposed. Finally, two of these applications are illustrated with practical examples: the study of the van der Waals energy, as implemented in CHARMM, in the Trp-Cage protein (PDB code 1L2Y) and the comparison of different levels of the theory in the ab initio study of the Ramachandran map of the model peptide HCO-L-Ala-NH2.Comment: 30 pages, 7 figures, LaTeX, BibTeX. v2: A misspelling in the author's name has been corrected. v3: A new application of the method has been added at the end of section 9 and minor modifications have also been made in other sections. v4: Journal reference and minor corrections adde

    Use of Electroencephalography Brain-Computer Interface Systems as a Rehabilitative Approach for Upper Limb Function After a Stroke: A Systematic Review

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    Background: Brain-computer interface (BCI) systems have been suggested as a promising tool for neurorehabilitation. However, to date, there is a lack of homogeneous findings. Furthermore, no systematic reviews have analyzed the degree of validation of these interventions for upper limb (UL) motor rehabilitation poststroke. Objectives: The study aims were to compile all available studies that assess an UL intervention based on an electroencephalography (EEG) BCI system in stroke; to analyze the methodological quality of the studies retrieved; and to determine the effects of these interventions on the improvement of motor abilities. Type: This was a systematic review. Literature Survey: Searches were conducted in PubMed, PEDro, Embase, Cumulative Index to Nursing and Allied Health, Web of Science, and Cochrane Central Register of Controlled Trial from inception to September 30, 2015. Methodology: This systematic review compiles all available studies that assess UL intervention based on an EEG-BCI system in patients with stroke, analyzing their methodological quality using the Critical Review Form for Quantitative Studies, and determining the grade of recommendation of these interventions for improving motor abilities as established by the Oxford Centre for Evidence-based Medicine. The articles were selected according to the following criteria: studies evaluating an EEG-based BCI intervention; studies including patients with a stroke and hemiplegia, regardless of lesion origin or temporal evolution; interventions using an EEG-based BCI to restore functional abilities of the affected UL, regardless of the interface used or its combination with other therapies; and studies using validated tools to evaluate motor function. Synthesis: After the literature search, 13 articles were included in this review: 4 studies were randomized controlled trials; 1 study was a controlled study; 4 studies were case series studies; and 4 studies were case reports. The methodological quality of the included papers ranged from 6 to 15, and the level of evidence varied from 1b to 5. The articles included in this review involved a total of 141 stroke patients. Conclusions: This systematic review suggests that BCI interventions may be a promising rehabilitation approach in subjects with stroke. Level of Evidence: I

    Robust gap repair in the contractile ring ensures timely completion of cytokinesis.

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    Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure.This project has received funding from the European Research Council (grants 640553, 260892, and 338410), Fundo Europeu de Desenvolvimento Regional (FED ER) funds through the Operational Competitiveness Program (COM PETE), national funds through Fundação para a Ciência e a Tecnologia (FCT) under the project FCO MP-01-0124-FED ER-028255 (PTDC/BEX-BCM/0654/2012), Fundação Luso-Americana para o Desenvolvimento Life Science 2020, and the Louis-Jeantet Young Investigator Award to H. Maiato. A.X. Carvalho, R. Gassmann, and I.A. Telley have FCT Investigator positions funded by FCT and cofunded by the European Social Fund through Programa Operacional Temático Potencial Type 4.2 promotion of scientific employment. A.M. Silva holds an FCT fellowship (SFRH/BPD/95707/2013). D.S. Osório was cofunded by the Programa Operacional Regional do Norte under the Quadro de Downloaded from jcb.rupress.org on February 27, 2018 Laser microsurgery in the contractile ring • Silva et al. 799 Referência Estratégico Nacional through FED ER and by FCT grant NOR TE-07-0124-FED ER-000003 (Cell Homeostasis Tissue Organization and Organism Biology)

    Orofacial Injuries in Children and Adolescents (2009-2013): A 5-Year Study In Porto, Portugal

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    The aim of this study was to verify the prevalence of acts of aggression to the head, face and neck towards victims of Physical Violence against Children and Adolescents (PVCA) who were examined at the National Institute of Legal Medicine and Forensic Sciences Delegation North (INMLCF-DN) in Porto, Portugal. A study was carried out on 2,148 complaints of physical aggression against children and adolescents (0 to less than 18 years old) occurred between 2009 and 2013 and which were retrieved from information about violence held on INMLCF-DN data files. Continuous variables were described and the association between them was verified by Chi-square or Fischer’s Exact tests with 5% significance level. Within the 5-year timespan, 1,380 cases were identified with clinical relation with physical aggression. Most subjects evaluated were male adolescents and the most affected body region was the face, to which 747 injuries (24.7%) were recorded, with statistically significant association between sex and region (head and face). Victims in 15-17-year-old age group are more susceptible to violence than those in the 0-14-year-old age range. Dentists routinely examine the face, neck and skull, which make them the most appropriate health professionals to identify cases of aggression early.The authors thank the INMLCF-DN (Instituto Nacional de Medicina Legal e Ciências Forenses - Delegação do Norte, Portugal) for technical support and CAPES(Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil) for scholarship
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