34 research outputs found
Role of the Pelvis in the Mechanics and Energetics of Human Walking
No full textPeople vary widely in body shape and size, with considerable sex differences in body dimensions. The pelvis, in particular, shows the most pronounced sex-specific differences within the locomotor anatomy, with females typically having a wider pelvis relative to lower limb length than males. Two key characteristics of walking are stride length and its associated metabolic cost. Both pelvis width and lower limb length influence stride length, and the contribution of pelvic rotation in the transverse plane to stride length is termed the ‘pelvic step.’ Biomechanically, both pelvic rotation and pelvis width contribute to pelvic step; however, it is unclear how the pelvis contributes to the walking stride in individuals with different pelvis widths. While lower limb length has been positively linked to better walking economy, the limb functions in concert with pelvis motion rather than in isolation. The independent and combined effects of pelvis width and lower limb length on metabolic cost during walking remain poorly understood. Moreover, several clinical conditions are associated with increased pelvic rotation and elevated walking cost; thus, a better understanding of normal pelvis function in walking can enhance the clinical utility of gait analysis. Therefore, this dissertation investigates the role of pelvis width, both independently and relative to lower limb length, on walking mechanics and metabolic energy expenditure.
Musculoskeletal models are often used to analyze gait but are typically derived from male anatomy; therefore, we developed a female-specific musculoskeletal model to better reflect sex-specific pelvis morphology. Three-dimensional walking kinematics were captured using a motion capture system, and metabolic energy expenditure was measured using a portable metabolic system while 15 female and 15 male participants walked on a treadmill with embedded force platforms. We found that individuals with a relatively wider pelvis tend to rotate their pelvis more during walking, resulting in a greater pelvic step. However, relative pelvis width explained only a modest portion of the variance in pelvic step, with no significant sex differences observed. In contrast, pelvic rotation accounted for the largest variance in pelvic step, and its relationship with pelvic step was significantly stronger in females than in males. Despite this sex difference in the relationship, the average pelvic step amplitude did not differ significantly between sexes. Overall, differences in pelvis size and shape had a relatively small influence on gait kinematics with no meaningful sex differences.
We also found that in females, a shorter lower limb and a wider pelvis relative to limb length were associated with a lower metabolic cost of walking. In males, however, a longer lower limb and a narrower relative pelvis width were associated with lower cost. This suggests that pelvis and lower limb proportions influence metabolic cost differentially by sex. Still, as with pelvic step, relative pelvis width explained only a small to moderate portion of the variance in metabolic cost. The lowest walking costs observed among females (with shorter limbs and wider pelves) were similar to that among males (with longer limbs and narrower pelves), indicating that more than one body design can lead to economical walking. We conclude that relative pelvis width affects both pelvic step and metabolic energy consumption during walking, with some sex-specific differences. However, these effects were modest, likely reflecting the fact that pelvis morphology is only one of many factors influencing the way we walk and the associated metabolic cost.PhDMovement Science PhDUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/199364/1/sheeba_1.pd
Keyword Extraction Using Particle Swarm Optimization
No full textAbstractWithout formal structure data are those that have no prearranged form or structure and are full of textual data. Typical unstructured systems include emails, reports, telephone or messaging conversations, etc. The main goal of this work is to extract the keywords from a conversation using particle swarm optimization. Keywords are grouped together under their classification and then suggested to the user. In existing work, using diverse keyword extraction, to find topic modelling information, representation of the main topics of transcript and diverse keyword selection. It maximizes the coverage of topics that are automatically recognized in transcript of conversation fragment. Once a set of keywords is extracted, it is clustered according to their user queries and recommended to the user. At the end of result, a single implicit query cannot improve user's satisfaction with the recommended documents. So, swarm intelligence technique is to be applied, it will minimize redundancy in a short list of Keywords and provide accurate query result compared to greedy algorithm
Technological Singularity in Sujatha Ranganathan’s En Iniya Iyanthira and Meendum Jeeno
No full textThe research paper aims at exploring the narrative aesthetics of Tamil science fiction in which the author takes twenty-first-century politics in India within the context of technological singularity. The article presents the political situation and totalitarianism in the age of technological singularity. The research focuses on the social impacts of artificial intelligence’s ability to read, learn, think, and act against its pre-programmed mechanism. A robotic dog struggles to restore a democratic political system from autocracy. The dystopian fictions “En Iniya Iyanthira” and “Meendum Jeeno” written by Sujatha Ranganathan depict the cognitive power of super intelligence behind a woman’s political actions to protect the people of India from exploitation, and corruption to create a better future. The paper demonstrates what a world without individual freedom looks like under the digital surveillance system of a totalitarian regime. The paper raises the question of what happens when a robot develops its rationality and mimics human behaviour. In these fictions, humans attempt to destroy the robotic dog. The robotic dog reaches a standard where nothing can destroy it. The paper explores the ways the robotic dog gains the knowledge to understand and practice the concept of humanity. The paper concludes with the post-humanistic conflicts between a woman and a robotic dog in emotional, ethical, and political aspects
Mechanics, energetics and implementation of grounded running technique: a narrative review
No full textGrounded running predominantly differs from traditional aerial running by having alternating single and double stance with no flight phase. Approximately, 16% of runners in an open marathon and 33% of recreational runners in a 5 km running event adopted a grounded running technique. Grounded running typically occurs at a speed range of 2–3 m·s−1, is characterised by a larger duty factor, reduced vertical leg stiffness, lower vertical oscillation of the centre of mass (COM) and greater impact attenuation than aerial running. Grounded running typically induces an acute increase in metabolic cost, likely due to the larger duty factor. The increased duty factor may translate to a more stable locomotion. The reduced vertical oscillation of COM, attenuated impact shock, and potential for improved postural stability may make grounded running a preferred form of physical exercise in people new to running or with low loading capacities (eg, novice overweight/obese, elderly runners, rehabilitating athletes). Grounded running as a less impactful, but metabolically more challenging form, could benefit these runners to optimise their cardio-metabolic health, while at the same time minimise running-related injury risk. This review discusses the mechanical demands and energetics of grounded running along with recommendations and suggestions to implement this technique in practice
Molecular docking and spectroscopic investigations aided by density functional theory of Parkinson’s drug 2-(3,4-dihydroxyphenyl)ethylamine
No full textSurface modification of CZTS nanoparticles using reflux method for effective utilizing absorber material
No full textPerformance Analysis of Farrow Structure Based FBMC-OQAM System
No full textAbstractFarrow structure is used in the efficient implementation of high order filters. The number of unknown coefficients is much less in Farrow structure based implementation, in comparison with the direct form implementation of FIR filters. Some predefined multipliers can also be used in this method. Since they are known apriori they will not add much to the complexity of the system. It is seen that a relatively strong correlation exists among the adjacent impulse response coefficients of the frequency selective filters. This fact is exploited in the Farrow structure to reduce the number of multipliers required for the implementation of desired filter. And these Farrow coefficients are used for representing the polyphase components of the desired filter. This Farrow structure based prototype filter is used for implementing an FBMC-OQAM system. BER performance of Farrow structure based FBMC-OQAM system is studied and found comparable with that of existing FBMC-OQAM system
Performance Improvement of Multicarrier Systems Using Wavelet Filter Banks
No full textAbstractThe need for higher data rates with increased bandwidth efficiency has focussed the search for techniques which deliver better results than conventional Orthogonal Frequency Division Multiplexing (OFDM) system. A wavelet filter bank system is investigated as a multicarrier modulation system (MCM). Such a system is found to be flexible, efficient and has many advantages over the present OFDM systems. This paper deals with identifying the suitability of different wavelet families, which can be used to improve the performance parameters of existing systems. Different wavelets families Daubechies, Meyer and Battle-Lemarie, are used as filter coefficients for wavelet based OFDM system and it is found that Daubechies wavelet (Db4) based multicarrier system outperforms the other two
Immunogenicity of SARS-CoV-2 vaccines in patients with cancer
No full textTransmission of the SARS-CoV-2 virus and its corresponding disease (COVID-19) has been shown to impose a higher burden on cancer patients than on the general population. Approved vaccines for use include new technology mRNA vaccines such as BNT162b2 (Pfizer–BioNTech) and mRNA-1273 (Moderna), and nonreplicating viral vector vaccines such as Ad26.COV2.S (Johnson & Johnson) and AZD1222 (AstraZeneca). Impaired or delayed humoral and diminished T-cell responses are evident in patients with cancer, especially in patients with haematological cancers or those under active chemotherapy. Herein we review the current data on vaccine immunogenicity in cancer patients, including recommendations for current practice and future research
Strong wind events in the Antarctic
No full textWe use quality controlled in situ meteorological observations collected at Antarctic research stations over the last 60 years to carry out the first continent-wide investigation into the occurrence, variability, and trend in strong wind events (SWEs). Reanalysis/analysis fields are used to examine the synoptic background in which such events take place. SWEs are a feature of the extended winter season and involve a complex interaction between the downslope buoyancy forcing and the pressure gradient force from synoptic-scale cyclones. Around the coast of East Antarctica the significant majority of SWEs are associated with enhancement of the downslope katabatic flow by the broadscale synoptic circulation, involving a deepening of pressure off the coast and an increase of pressure inland. Orientation of the valleys in relation to the cyclone track is critical in enabling enhancement of the katabatic winds. Casey, Mawson, and Dumont d'Urville stations report the greatest number of winds of storm force and stronger. Interannual variability of SWE numbers is large. Trends in the number of winter strong wind reports are small. The greatest statistically significant increase in wind speed since the 1950s has been at Faraday/Vernadsky and Syowa stations. The largest wind speed increases since 1979 have been at Davis and Mawson stations. Comparison with high-resolution numerical simulations showed that the reanalysis/analysis fields are able to capture the large-scale synoptic features and the associated enhancement of the katabatic flow but underestimated the observed wind speed if it was strongly influenced by local topographical conditions
