72 research outputs found
Improving Accessibility of Elevation Control in an Immersive Virtual Environment
No full textDespite the advances made in Virtual Reality (VR) technology, the design of VR experiences lacks sufficient focus on accessibility and inclusion as the primary requirements. These are especially important for STEM education, where engaging in experiential activities is essential. This study was conducted to investigate accessibility considerations in the design and development of Immersive VR (IVR) learning spaces for wheelchair users. The specific research question is: How can we make a VR system easier to interact with for wheelchair users needing vertical movement? A user study with thirty (30) participants in three groups was conducted: Group A (the control group, non-wheelchair users) who used natural body movement to interact with the environment, Group B (verification group, non-wheelchair users) who used software controls for accessibility, and Group C (wheelchair users) who used the same software accessibility feature. The results indicate that the accessibility feature enabled wheelchair users to complete the tasks requiring raising or lowering of the body, with almost similar levels of completion rate and accuracy. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ChemE/Materials for Energy Conversion and Storag
Designing a reliable-sustainable supply chain network: adaptive m-objective ε-constraint method
No full textIn the current era emphasizing sustainability and circularity, supply chain network design is a critical challenge for making reliable decisions. The optimization of facility location-allocation inventory problems (FLAIPs) holds the key to achieving dependable product delivery with reduced costs and carbon emissions. Despite the importance of these challenges, a substantial research gap exists regarding economic, reliability, and sustainability criteria for FLAIPs. This paper aims to fill this gap by introducing a multi-objective mixed-integer linear programming model, focusing on configuring a reliable sustainable supply chain network. The model addresses three key objectives: minimizing costs, minimizing emissions, and maximizing reliability. A notable contribution of this research lies in elaborating on five levels of a supply chain network catering to the delivery of multiple products across various periods. Another novelty is the simultaneous incorporation of economic, environmental, and reliability objectives in the network design—a facet rarely addressed in prior research. Results highlight that varying demand levels for each facility lead to altered trade-offs between objectives, empowering practitioners to make diverse decisions in facility location allocation. The proposed mathematical model undergoes validation through numerical examples and sensitivity analysis of parameters. The paper concludes by presenting theoretical and managerial implications, contributing valuable insights to the field of sustainable supply chains.Rivers, Ports, Waterways and Dredging Engineerin
Cortical bone architecture of hominid intermediate phalanges reveals functional signals of locomotion and manipulation
No full textDATA AVAILABILITY STATEMENT :
Copies of all scans are curated by the relevant curatorial institutions that are responsible for the original specimens and access can be requested through each institution. The authors confirm that the data supporting the findings of this study are available from the corresponding author upon reasonable request.OBJECTIVES :
Reconstruction of fossil hominin manual behaviors often relies on comparative analyses of extant hominid hands to understand the relationship between hand use and skeletal morphology. In this context, the intermediate phalanges remain understudied. Thus, here we investigate cortical bone morphology of the intermediate phalanges of extant hominids and compare it to the cortical structure of the proximal phalanges, to investigate the relationship between cortical bone structure and inferred loading during manual behaviors.
MATERIALS AND METHODS :
Using micro-CT data, we analyze cortical bone structure of the intermediate phalangeal shaft of digits 2–5 in Pongo pygmaeus (n = 6 individuals), Gorilla gorilla (n = 22), Pan spp. (n = 23), and Homo sapiens (n = 23). The R package morphomap is used to study cortical bone distribution, cortical thickness and cross-sectional properties within and across taxa.
RESULTS :
Non-human great apes generally have thick cortical bone on the palmar shaft, with Pongo only having thick cortex on the peaks of the flexor sheath ridges, while African apes have thick cortex along the entire flexor sheath ridge and proximal to the trochlea. Humans are distinct in having thicker dorsal shaft cortex as well as thick cortex at the disto-palmar region of the shaft.
DISCUSSION :
Variation in cortical bone distribution and properties of the intermediate phalanges is consistent with differences in locomotor and manipulative behaviors in extant great apes. Comparisons between the intermediate and proximal phalanges reveals similar patterns of cortical bone distribution within each taxon but with potentially greater load experienced by the proximal phalanges, even in knuckle-walking African apes. This study provides a comparative context for the reconstruction of habitual hand use in fossil hominins and hominids.H2020 European Research Council;
HORIZON EUROPE Marie Sklodowska-Curie Actions.http://wileyonlinelibrary.com/journal/ajpahj2024AnatomySDG-03:Good heatlh and well-bein
Cortical bone architecture of hominid intermediate phalanges reveals functional signals of locomotion and manipulation
No full textObjectives: Reconstruction of fossil hominin manual behaviors often relies on comparative analyses of extant hominid hands to understand the relationship between hand use and skeletal morphology. In this context, the intermediate phalanges remain understudied. Thus, here we investigate cortical bone morphology of the intermediate phalanges of extant hominids and compare it to the cortical structure of the proximal phalanges, to investigate the relationship between cortical bone structure and inferred loading during manual behaviors.
Materials and Methods: Using micro‐CT data, we analyze cortical bone structure of the intermediate phalangeal shaft of digits 2–5 in Pongo pygmaeus (n = 6 individuals), Gorilla gorilla (n = 22), Pan spp. (n = 23), and Homo sapiens (n = 23). The R package morphomap is used to study cortical bone distribution, cortical thickness and cross‐sectional properties within and across taxa.
Results: Non‐human great apes generally have thick cortical bone on the palmar shaft, with Pongo only having thick cortex on the peaks of the flexor sheath ridges, while African apes have thick cortex along the entire flexor sheath ridge and proximal to the trochlea. Humans are distinct in having thicker dorsal shaft cortex as well as thick cortex at the disto‐palmar region of the shaft.
Discussion: Variation in cortical bone distribution and properties of the intermediate phalanges is consistent with differences in locomotor and manipulative behaviors in extant great apes. Comparisons between the intermediate and proximal phalanges reveals similar patterns of cortical bone distribution within each taxon but with potentially greater load experienced by the proximal phalanges, even in knuckle‐walking African apes. This study provides a comparative context for the reconstruction of habitual hand use in fossil hominins and hominids
Cortical bone distribution of the proximal phalanges in great apes: implications for reconstructing manual behaviours
No full textPrimate fingers are typically in direct contact with the environment during both locomotion and manipulation, and aspects of external phalangeal morphology are known to reflect differences in hand use. Since bone is a living tissue that can adapt in response to loading through life, the internal bone architecture of the manual phalanges should also reflect differences in manual behaviours. Here, we use the R package Morphomap to analyse high‐resolution microCT scans of hominid proximal phalanges of digits 2–5 to determine whether cortical bone structure reflects variation in manual behaviours between bipedal (Homo), knuckle‐walking (Gorilla, Pan) and suspensory (Pongo) taxa. We test the hypothesis that relative cortical bone distribution patterns and cross‐sectional geometric properties will differ both among extant great apes and across the four digits due to locomotor and postural differences. Results indicate that cortical bone structure reflects the varied hand postures employed by each taxon. The phalangeal cortices of Pongo are significantly thinner and have weaker cross‐sectional properties relative to the African apes, yet thick cortical bone under their flexor sheath ridges corresponds with predicted loading during flexed finger grips. Knuckle‐walking African apes have even thicker cortical bone under the flexor sheath ridges, as well as in the region proximal to the trochlea, but Pan also has thicker diaphyseal cortices than Gorilla. Humans display a distinct pattern of distodorsal thickening, as well as relatively thin cortices, which may reflect the lack of phalangeal curvature combined with frequent use of flexed fingered hand grips during manipulation. Within each taxon, digits 2–5 have a similar cortical distribution in Pongo, Gorilla and, unexpectedly, Homo, which suggest similar loading of all fingers during habitual locomotion or hand use. In Pan, however, cortical thickness differs between the fingers, potentially reflecting differential loading during knuckle‐walking. Inter‐ and intra‐generic variation in phalangeal cortical bone structure reflects differences in manual behaviours, offering a comparative framework for reconstructing hand use in fossil hominins
Cortical bone asymmetry in La Ferrassie Neandertals and modern human thumbs revealsoccupational stress patterns
No full textInternational audienceThe transformation of our environment is facilitated by the use of our hands. This interaction, guided by muscularcoordination, was crucial during the Paleolithic period for the creation of the first lithic tools, which transformed homininstrategies for resource exploitation. Bones, as living tissues, have the ability to adapt their shape in response to different physicalconstraints [1]. In this context, the internal structure of metacarpals offers valuable insights into hominin behavioural patternsand can help reconstruct their evolutionary history. In this study, we aim to test the hypothesis that Neanderthal firstmetacarpals exhibit bilateral asymmetry—an idea supported by archaeological evidence associated with these individuals [2].We also investigate whether the structure of cortical bone reflects signatures of precise manipulation, a skill essential for lithictool production.Using microCT data, we analysed the right and left first metacarpals (MC1) of the La Ferrassie Neanderthals 1 and 2 (42–47 ka), as well as of modern Homo sapiens, to identify bilateral asymmetry and activity-related markers in cortical bonearchitecture. Our modern human sample includes individuals with well-documented biological profiles and occupationalhistories [3,4], providing a comparative framework for interpreting the Neanderthal data.Using the morphomap package in R [5], we examined the effects of bilateral asymmetry on average cortical bone thicknessand the polar moment of inertia (J). Different patterns of bilateral asymmetry were observed along various parts of the diaphysiswhen analyzing average cortical thickness across occupational groups. We found pronounced right-side dominance in the areacorresponding to the insertion of the opponens pollicis muscle in individuals engaged in fine, precise manual tasks. In contrast,those involved in forceful precision tasks exhibited right-side dominance at the opponens pollicis insertion site and left-sidedominance at the abductor pollicis insertion site. Individuals performing heavy manual labour displayed high variability. Whenassessing J, men engaged in precision work had a more mechanically resistant in the right MC1, whereas male heavy labourersshowed greater resistance in the left MC1. Women exhibited similar bilateral asymmetry patterns, except for J in the proximaldiaphysis: women with specialized occupations had a more resistant right MC1, while those with unspecialized tasks had amore resistant left MC1.Finally, we observed sexual dimorphism between LF1 (male) and LF2 (female), with LF1 exhibiting greater corticalthickness and rigidity. Each individual also showed different directional asymmetry: right-side bias in LF1 and left-side bias inLF2. LF1 followed a pattern similar to that of precision workers, while LF2 resembled the pattern of heavy manual labourers,suggesting that the thumbs of these two Neanderthals were subjected to different mechanical stresses. This study lays thefoundation for future research into the relationship between functional constraints and bilateral asymmetry in hand bones
Cortical bone asymmetry in La Ferrassie Neandertals and modern human thumbs revealsoccupational stress patterns
No full textInternational audienceThe transformation of our environment is facilitated by the use of our hands. This interaction, guided by muscularcoordination, was crucial during the Paleolithic period for the creation of the first lithic tools, which transformed homininstrategies for resource exploitation. Bones, as living tissues, have the ability to adapt their shape in response to different physicalconstraints [1]. In this context, the internal structure of metacarpals offers valuable insights into hominin behavioural patternsand can help reconstruct their evolutionary history. In this study, we aim to test the hypothesis that Neanderthal firstmetacarpals exhibit bilateral asymmetry—an idea supported by archaeological evidence associated with these individuals [2].We also investigate whether the structure of cortical bone reflects signatures of precise manipulation, a skill essential for lithictool production.Using microCT data, we analysed the right and left first metacarpals (MC1) of the La Ferrassie Neanderthals 1 and 2 (42–47 ka), as well as of modern Homo sapiens, to identify bilateral asymmetry and activity-related markers in cortical bonearchitecture. Our modern human sample includes individuals with well-documented biological profiles and occupationalhistories [3,4], providing a comparative framework for interpreting the Neanderthal data.Using the morphomap package in R [5], we examined the effects of bilateral asymmetry on average cortical bone thicknessand the polar moment of inertia (J). Different patterns of bilateral asymmetry were observed along various parts of the diaphysiswhen analyzing average cortical thickness across occupational groups. We found pronounced right-side dominance in the areacorresponding to the insertion of the opponens pollicis muscle in individuals engaged in fine, precise manual tasks. In contrast,those involved in forceful precision tasks exhibited right-side dominance at the opponens pollicis insertion site and left-sidedominance at the abductor pollicis insertion site. Individuals performing heavy manual labour displayed high variability. Whenassessing J, men engaged in precision work had a more mechanically resistant in the right MC1, whereas male heavy labourersshowed greater resistance in the left MC1. Women exhibited similar bilateral asymmetry patterns, except for J in the proximaldiaphysis: women with specialized occupations had a more resistant right MC1, while those with unspecialized tasks had amore resistant left MC1.Finally, we observed sexual dimorphism between LF1 (male) and LF2 (female), with LF1 exhibiting greater corticalthickness and rigidity. Each individual also showed different directional asymmetry: right-side bias in LF1 and left-side bias inLF2. LF1 followed a pattern similar to that of precision workers, while LF2 resembled the pattern of heavy manual labourers,suggesting that the thumbs of these two Neanderthals were subjected to different mechanical stresses. This study lays thefoundation for future research into the relationship between functional constraints and bilateral asymmetry in hand bones
Cortical bone asymmetry in La Ferrassie Neandertals and modern human thumbs revealsoccupational stress patterns
No full textInternational audienceThe transformation of our environment is facilitated by the use of our hands. This interaction, guided by muscularcoordination, was crucial during the Paleolithic period for the creation of the first lithic tools, which transformed homininstrategies for resource exploitation. Bones, as living tissues, have the ability to adapt their shape in response to different physicalconstraints [1]. In this context, the internal structure of metacarpals offers valuable insights into hominin behavioural patternsand can help reconstruct their evolutionary history. In this study, we aim to test the hypothesis that Neanderthal firstmetacarpals exhibit bilateral asymmetry—an idea supported by archaeological evidence associated with these individuals [2].We also investigate whether the structure of cortical bone reflects signatures of precise manipulation, a skill essential for lithictool production.Using microCT data, we analysed the right and left first metacarpals (MC1) of the La Ferrassie Neanderthals 1 and 2 (42–47 ka), as well as of modern Homo sapiens, to identify bilateral asymmetry and activity-related markers in cortical bonearchitecture. Our modern human sample includes individuals with well-documented biological profiles and occupationalhistories [3,4], providing a comparative framework for interpreting the Neanderthal data.Using the morphomap package in R [5], we examined the effects of bilateral asymmetry on average cortical bone thicknessand the polar moment of inertia (J). Different patterns of bilateral asymmetry were observed along various parts of the diaphysiswhen analyzing average cortical thickness across occupational groups. We found pronounced right-side dominance in the areacorresponding to the insertion of the opponens pollicis muscle in individuals engaged in fine, precise manual tasks. In contrast,those involved in forceful precision tasks exhibited right-side dominance at the opponens pollicis insertion site and left-sidedominance at the abductor pollicis insertion site. Individuals performing heavy manual labour displayed high variability. Whenassessing J, men engaged in precision work had a more mechanically resistant in the right MC1, whereas male heavy labourersshowed greater resistance in the left MC1. Women exhibited similar bilateral asymmetry patterns, except for J in the proximaldiaphysis: women with specialized occupations had a more resistant right MC1, while those with unspecialized tasks had amore resistant left MC1.Finally, we observed sexual dimorphism between LF1 (male) and LF2 (female), with LF1 exhibiting greater corticalthickness and rigidity. Each individual also showed different directional asymmetry: right-side bias in LF1 and left-side bias inLF2. LF1 followed a pattern similar to that of precision workers, while LF2 resembled the pattern of heavy manual labourers,suggesting that the thumbs of these two Neanderthals were subjected to different mechanical stresses. This study lays thefoundation for future research into the relationship between functional constraints and bilateral asymmetry in hand bones
Mechanical loading of primate fingers on vertical rock surfaces
No full textMechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arboreal primates by dissipating forces and economising the recruitment of muscles during climbing. The recent discovery of extremely curved phalanges in a hominin, Homo naledi, is puzzling, for it suggests life in an arboreal milieu, or, alternatively, habitual climbing on vertical rock surfaces. The importance of climbing rock walls is attested by several populations of baboons, one of which uses a 7-m vertical surface to enter and exit Dronkvlei Cave, De Hoop Nature Reserve, South Africa. This rock surface is an attractive model for estimating the probability of extreme mechanical loading on the phalanges of rock-climbing primates. Here we use three-dimensional photogrammetry to show that 82–91% of the climbable surface would generate high forces on the flexor tendon pulley system and severely load the phalanges of baboons and H. naledi. If such proportions are representative of vertical rock surfaces elsewhere, it may be sufficient to induce stress-mitigating curvature in the phalanges of primates
Designed electrochemical sensor based on metallocene modified conducting polymer composite for effective determination of tramadol in real samples
No full textA novel composite for the electrochemical sensing of tramadol (Tr) was developed by the inclusion of metallocene mediator between two layers of conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer, in presence of sodium dodecyl sulfate (SDS); (P/mediator/P…SDS). Three charge transfer mediators were evaluated: ferrocene carboxylic acid (FC1), ferrocene (FC2) and cobaltocene (CC) for Tr electrocatalytic oxidation. FC1-charge mediator showed relatively higher current response that was assisted by the electronic conduction of the polymer film. Moreover, SDS presented a great impact, resulting in the enhancement of the preconcentration/accumulation of Tr ions at the interface leading to faster electron transfer. In addition, the practical application of the proposed FC1 composite for the determination of Tr in real urine and serum samples was successfully achieved with adequate recovery results. Very low detection limits of 18.6 nM and 16 nM in the linear dynamic ranges of 7 M to 300 M and 5 M to 280 M, respectively, were obtained at the proposed sensor. Furthermore, the simultaneous determination of of Tr with common interfering species; paracetamol (PAPA), morphine (MO), dopamine (DA), ascorbic acid (AA) and uric acid (UA) proved excellent with good resolution and large potential peaks separation. The excellent characteristics of the proposed composite such as high reproducibility, good sensitivity, selectivity, anti-interference ability and good stability enhanced its application for determination of other narcotics drugs.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
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