Towards a design process for computer-aided biomimetics

Computer-Aided Biomimetics (CAB) tools aim to support the integration of relevant biological knowledge into biomimetic problem-solving processes. Specific steps of biomimetic processes that require support include the identification, selection and abstraction of relevant biological analogies. Existing CAB tools usually aim to support these steps by describing biological systems in terms of functions, although engineering functions do not map naturally to biological functions. Consequentially, the resulting static, functional view provides an incomplete understanding of biological processes, which are dynamic, cyclic and self-organizing. This paper proposes an alternative approach that revolves around the concept of trade-offs. The aim is to include the biological context, such as environmental characteristics, that may provide information crucial to the transfer of biological information to an engineering application. The proposed design process is exemplified by an illustrative case study

Application of Deep Learning Models for Automated Identification of Parkinson’s Disease: A Review (2011–2021)

Parkinson’s disease (PD) is the second most common neurodegenerative disorder affecting over 6 million people globally. Although there are symptomatic treatments that can increase the survivability of the disease, there are no curative treatments. The prevalence of PD and disability-adjusted life years continue to increase steadily, leading to a growing burden on patients, their families, society and the economy. Dopaminergic medications can significantly slow down the progression of PD when applied during the early stages. However, these treatments often become less effective with the disease progression. Early diagnosis of PD is crucial for immediate interventions so that the patients can remain self-sufficient for the longest period of time possible. Unfortunately, diagnoses are often late, due to factors such as a global shortage of neurologists skilled in early PD diagnosis. Computer-aided diagnostic (CAD) tools, based on artificial intelligence methods, that can perform automated diagnosis of PD, are gaining attention from healthcare services. In this review, we have identified 63 studies published between January 2011 and July 2021, that proposed deep learning models for an automated diagnosis of PD, using various types of modalities like brain analysis (SPECT, PET, MRI and EEG), and motion symptoms (gait, handwriting, speech and EMG). From these studies, we identify the best performing deep learning model reported for each modality and highlight the current limitations that are hindering the adoption of such CAD tools in healthcare. Finally, we propose new directions to further the studies on deep learning in the automated detection of PD, in the hopes of improving the utility, applicability and impact of such tools to improve early detection of PD globally.</jats:p

Design optimization of consolidated granular-solid polymer prismatic beam using metamorphic development

AbstractTopologically optimized granular-solid structures from additive manufacturing processes have impending applications as lightweight load bearing structures. To facilitate application, a procedure for characterizing optimal structural performance is devised for the design optimization of ‘end-use’ functional structures. An approach capable of realizing this objective is presented and demonstrated for horizontal prismatic beams produced from Nylon-12 granular-solid polymer, by Selective Laser Sintering (SLS). It combines topology (or layout) optimization, calibration of material parameters, and finite element (FE) modelling. The metamorphic development (MD) method forms the basis of an adaptive growth and degeneration optimization by material distribution approach. Experimental measurements are used to calibrate a bimodulus constitutive Drucker–Prager (D–P) model. Simply-supported three-point bending (3PB) tests are used to assess the fidelity of optimized beams on the basis of numerically predicted performance

A new fatigue test procedure for die-casting tool materials

The objective of this research was to investigate a new test procedure for simulating the temperatures in die casting so that materials can be evaluated as tool materials for the high-pressure die casting of aluminium. Other procedures have been used for evaluating the thermal fatigue performance of tool materials, but these tests do not reproduce all the conditions found in production environments. A new test method has been established that enables the thermal fatigue resistance of materials to be identified. The test is robust, reliable, and versatile and has a large operating temperature range (25–1200°C), and the cycle times and dwell times are adjustable. The results have shown a similar number of cycles to induce the same level of fatigue cracking as in actual die-casting tools. The performance of different materials can be compared, and an approximate fatigue life for high-pressure die-casting tools can be determined

Stomatal closure is induced by hydraulic signals and maintained by ABA in drought-stressed grapevine

8noWater saving under drought stress is assured by stomatal closure driven by active (ABA-mediated) and/or passive (hydraulic-mediated) mechanisms. There is currently no comprehensive model nor any general consensus about the actual contribution and relative importance of each of the above factors in modulating stomatal closure in planta. In the present study, we assessed the contribution of passive (hydraulic) vs active (ABA mediated) mechanisms of stomatal closure in V. vinifera plants facing drought stress. Leaf gas exchange decreased progressively to zero during drought, and embolism-induced loss of hydraulic conductance in petioles peaked to ∼50% in correspondence with strong daily limitation of stomatal conductance. Foliar ABA significantly increased only after complete stomatal closure had already occurred. Rewatering plants after complete stomatal closure and after foliar ABA reached maximum values did not induced stomatal re-opening, despite embolism recovery and water potential rise. Our data suggest that in grapevine stomatal conductance is primarily regulated by passive hydraulic mechanisms. Foliar ABA apparently limits leaf gas exchange over long-term, also preventing recovery of stomatal aperture upon rewatering, suggesting the occurrence of a mechanism of long-term down-regulation of transpiration to favor embolism repair and preserve water under conditions of fluctuating water availability and repeated drought events.openopenTombesi, Sergio; Nardini, Andrea; Frioni, Tommaso; Soccolini, Marta; Zadra, Claudia; Farinelli, Daniela; Poni, Stefano; Palliotti, AlbertoTombesi, Sergio; Nardini, Andrea; Frioni, Tommaso; Soccolini, Marta; Zadra, Claudia; Farinelli, Daniela; Poni, Stefano; Palliotti, Albert

Sobrepeso e obesidade em escolares brasileiros de sete a nove anos: dados do projeto Esporte Brasil Overweight and obesity in seven to nine-year-old Brazilian students: data from the Brazilian Sports Project

OBJETIVO: Descrever a prevalência de sobrepeso e obesidade em escolares brasileiros de sete a nove anos e verificar a associação com as variáveis: sexo, idade e região geográfica. MÉTODOS: Estudo epidemiológico transversal conduzido em 2.913 escolares (1.478 do sexo masculino e 1.435 do feminino) com idade entre sete e nove anos. Como critério de diagnóstico de sobrepeso e obesidade foram utilizados os pontos de corte do índice de massa corpórea, propostos pela International Obesity Task Force. A comparação entre as proporções foi realizada mediante o teste qui-quadrado. As diferenças entre as proporções foram testadas por meio do teste de comparação entre duas proporções. RESULTADOS: A prevalência de sobrepeso e obesidade foi de 15,4 e 7,8% em meninos e meninas, respectivamente, com proporções similares entre sexo e idades. No sexo masculino, foi verificada associação do sobrepeso e obesidade apenas com região geográfica (p<0,001), com prevalências mais elevadas nas crianças da região Sul. No feminino, sobrepeso mais elevado foi observado nas crianças de sete anos da região Norte, enquanto a prevalência de obesidade foi maior nas crianças da região Sul. CONCLUSÕES: As crianças da região Sul apresentam maiores prevalências de sobrepeso e obesidade que aquelas das demais regiões do país. Os achados do presente estudo apontam uma tendência de aumento na prevalência de sobrepeso e obesidade na infância e corroboram os resultados encontrados em pesquisas mais abrangentes realizadas no Brasil.<br>OBJECTIVES: To describe the prevalence of overweight and obesity in Brazilian schoolchildren aged 7 to 9 years and determine its association with gender, age and geographic region. METHODS: This cross-sectional epidemiological study enrolled 2,913 students (1,478 boys and 1,435 girls) aged 7 to 9 years and was conducted between 2004 and 2005. The body mass index cutoff values proposed by the International Obesity Task Force were used as a diagnostic criterion for overweight and obesity. The chi-square test was used for comparison of proportions, and differences in prevalence rates were determined by testing for comparison between two proportions. RESULTS: The prevalence of overweight and obesity was 15.4% and 7.8% in boys and girls, respectively, with similar proportions in both genders and across all ages. In boys, overweight and obesity were only associated with geographic region (p<0.001), with a higher prevalence found in children from the South region. In girls, the prevalence of overweight was highest among those aged 7 years and those from the North region. In addition, an overall higher prevalence of obesity was observed among children from the South region. CONCLUSIONS: Schoolchildren from the South region of Brazil have a higher prevalence of overweight and obesity than those from other areas of the country. We conclude that overweight and obesity in childhood are on an upward trend, and our findings corroborate the results reported in other Brazilian studies