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Suciu I, Pamies D, Peruzzo R, Wirtz PH, Smirnova L, Pallocca G, Hauck C, Cronin MTD, Hengstler JG, Brunner T, Hartung T, Amelio I, Leist M. G × E interactions as a basis for toxicological uncertainty. Arch Toxicol 2023; 97:2035-2049. [PMID: 37258688 PMCID: PMC10256652 DOI: 10.1007/s00204-023-03500-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/17/2023] [Indexed: 06/02/2023]
Abstract
To transfer toxicological findings from model systems, e.g. animals, to humans, standardized safety factors are applied to account for intra-species and inter-species variabilities. An alternative approach would be to measure and model the actual compound-specific uncertainties. This biological concept assumes that all observed toxicities depend not only on the exposure situation (environment = E), but also on the genetic (G) background of the model (G × E). As a quantitative discipline, toxicology needs to move beyond merely qualitative G × E concepts. Research programs are required that determine the major biological variabilities affecting toxicity and categorize their relative weights and contributions. In a complementary approach, detailed case studies need to explore the role of genetic backgrounds in the adverse effects of defined chemicals. In addition, current understanding of the selection and propagation of adverse outcome pathways (AOP) in different biological environments is very limited. To improve understanding, a particular focus is required on modulatory and counter-regulatory steps. For quantitative approaches to address uncertainties, the concept of "genetic" influence needs a more precise definition. What is usually meant by this term in the context of G × E are the protein functions encoded by the genes. Besides the gene sequence, the regulation of the gene expression and function should also be accounted for. The widened concept of past and present "gene expression" influences is summarized here as Ge. Also, the concept of "environment" needs some re-consideration in situations where exposure timing (Et) is pivotal: prolonged or repeated exposure to the insult (chemical, physical, life style) affects Ge. This implies that it changes the model system. The interaction of Ge with Et might be denoted as Ge × Et. We provide here general explanations and specific examples for this concept and show how it could be applied in the context of New Approach Methodologies (NAM).
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Affiliation(s)
- Ilinca Suciu
- In Vitro Toxicology and Biomedicine, Department Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Constance, Germany
| | - David Pamies
- Department of Biological Sciences, University of Lausanne, 1005, Lausanne, Switzerland
| | - Roberta Peruzzo
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
| | - Petra H Wirtz
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, 78457, Constance, Germany
- Biological Work and Health Psychology, Department of Psychology, University of Konstanz, 78457, Constance, Germany
| | - Lena Smirnova
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | | | - Christof Hauck
- Department of Cell Biology, University of Konstanz, 78457, Constance, Germany
| | - Mark T D Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, 44139, Dortmund, Germany
| | - Thomas Brunner
- Biochemical Pharmacology, Department of Biology, University of Konstanz, 78457, Constance, Germany
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, 21205, USA
- CAAT Europe, University of Konstanz, 78457, Constance, Germany
| | - Ivano Amelio
- Division for Systems Toxicology, Department of Biology, University of Konstanz, 78457, Constance, Germany
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Constance, Germany.
- CAAT Europe, University of Konstanz, 78457, Constance, Germany.
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Pillai RR, Riedel J, Schwarzkopf L. The role of ecdysis in repair of an attachment system: A case study using geckos. J Exp Biol 2023; 226:309498. [PMID: 37042266 PMCID: PMC10184769 DOI: 10.1242/jeb.245286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/31/2023] [Indexed: 04/13/2023]
Abstract
Skin provides functions such as protection and prevention of water loss. In some taxa the outer surface of skin has been modified to form structures that enable attachment to various surfaces. Constant interaction with surfaces is likely to cause damage to these attachment systems and reduce function. It seems logical that when skin is shed via ecdysis, its effectiveness may increase, through repair of damage or other rejuvenating mechanisms. We address two questions using three diplodactylid geckos as model species: (i) does repeated mechanical damage affect clinging ability in geckos to the point that they cannot support their own body weight? (ii) Does use without induced damage reduce effectiveness of the attachment system, and if so, does ecdysis restore clinging ability? We found that repeated damage reduced clinging ability in all three species, although at different rates. Additionally, use reduced clinging ability over time when no apparent damage was incurred. Clinging ability increased after ecdysis in all three species, both when damage was specially induced, and when it was not. After use without induced damage, the increase in clinging ability after ecdysis was statistically significant in two of three species. Our findings show that use decreases clinging ability, and mechanical damage also effects geckos' capacity to exert shear forces consistently. Thus, ecdysis improves clinging ability, in both scenarios where damage is induced, and more generally. In addition to the physiological functions provided by skin, our study highlights an important function of ecdysis in a speciose vertebrate group.
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Affiliation(s)
- Rishab R Pillai
- College of Science and Engineering, James Cook University, Townsville, Australia
| | - Jendrian Riedel
- Evolutionary Biology, Bielefeld University, Bielefeld, Germany
- Herpetology Section, Zoological Research Museum Alexander Koenig (ZFMK) - Leibniz Institute for the Analysis of Biodiversity Change (LIB), Bonn, Germany
| | - Lin Schwarzkopf
- College of Science and Engineering, James Cook University, Townsville, Australia
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Mesa-Lavista M, Álvarez-Pérez J, Tejeda-Piusseaut E, Lamas-Fernández F. Safety-factor dataset for high embankments determined with different analytical methods. Data Brief 2021; 38:107315. [PMID: 34485645 PMCID: PMC8403731 DOI: 10.1016/j.dib.2021.107315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/07/2021] [Accepted: 08/19/2021] [Indexed: 11/27/2022] Open
Abstract
Slope-stability analysis is one of the parameters in the design of road embankments that the designer must consider in order to ensure stable and safe construction. The technical standards recommend slopes to heights of 12 m, depending on the soil types and the topography. In the present work, the limit equilibrium methods (Fellenius, Bishop, Janbu, Morgensten-Price) and the finite element method are used to determine the safety factor of road embankments for different slopes flanking the road. Five embankment heights were simulated: 6 m, 12 m, 18 m, 24 m, and 30 m. The dataset compiled can be used for modeling embankments.
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Affiliation(s)
- Milena Mesa-Lavista
- Universidad Autónoma de Nuevo León (UANL), Facultad de Ingeniería Civil (FIC), Departamento de Estructuras, Ave. Universidad, s/n CP. 66455, San Nicolás de los Garza, Nuevo León, Mexico
| | - José Álvarez-Pérez
- Universidad Autónoma de Nuevo León (UANL), Facultad de Ingeniería Civil (FIC), Departamento de Estructuras, Ave. Universidad, s/n CP. 66455, San Nicolás de los Garza, Nuevo León, Mexico
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Yang J, Li Y, Shi X, Shen M, Shi K, Shen L, Yang C. Design and analysis of three-dimensional printing of a porous titanium scaffold. BMC Musculoskelet Disord 2021; 22:654. [PMID: 34340671 PMCID: PMC8330076 DOI: 10.1186/s12891-021-04520-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/12/2021] [Indexed: 11/16/2022] Open
Abstract
Objective Mechanic strength, pore morphology and size are key factors for the three-dimensional (3D) printing of porous titanium scaffolds, therefore, developing optimal structure for the 3D printed titanium scaffold to fill bone defects in knee joints is instructive and important. Methods Structural models of titanium scaffolds with fifteen different pore unit were designed with 3D printing computer software; five different scaffold shapes were designed: imitation diamond-60°, imitation diamond-90°, imitation diamond-120°, regular tetrahedron and regular hexahedron. Each structural shape was evaluated with three pore sizes (400, 600 and 800 μm), and fifteen types of cylindrical models (size: 20 mm; height: 20 mm). Autodesk Inventor software was used to determine the strength and safety of the models by simulating simple strength acting on the knee joints. We analyzed the data and found suitable models for the design of 3D printing of porous titanium scaffolds. Results Fifteen different types of pore unit structural models were evaluated under positive pressure and lateral pressure; the compressive strength reduced when the pore size increased. Under torsional pressure, the strengths of the imitation diamond structure were similar when the pore size increased, and the strengths of the regular tetrahedron and regular hexahedron structures reduced when the pore size increased. In each case, the compressive strength of the regular hexahedron structure was highest, that of the regular tetrahedron was second highest, and that of the imitation diamond structure was relatively low. Fifteen types of cylindrical models under a set force were evaluated, and the sequence of comprehensive compressive strength, from strong to weak was: regular hexahedron > regular tetrahedron > imitation diamond-120° > imitation diamond-90° > imitation diamond-60°. The compressive strength of cylinder models was higher when the pore size was smaller. Conclusion The pore size and pore morphology were important factors influencing the compressive strength. The strength of each structure reduced when the pore size (400, 600 and 800 μm) increased. The models of regular hexahedron, regular tetrahedron and imitation diamond-120°appeared to meet the conditions of large pore sizes and high compressive strength.
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Affiliation(s)
- Jiajie Yang
- Nantong Haimen People's Hospital, 1201 Beijing Road, Haimen District, Nantong City, 226100, Jiangsu Province, China
| | - Yaqiang Li
- Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 145 Shandong Zhong Lu, Shanghai, 200001, China
| | - Xiaojian Shi
- Nantong Haimen People's Hospital, 1201 Beijing Road, Haimen District, Nantong City, 226100, Jiangsu Province, China
| | - Meihua Shen
- Nantong Haimen People's Hospital, 1201 Beijing Road, Haimen District, Nantong City, 226100, Jiangsu Province, China
| | - Kaibing Shi
- Nantong Haimen People's Hospital, 1201 Beijing Road, Haimen District, Nantong City, 226100, Jiangsu Province, China
| | - Lingjie Shen
- Nantong Haimen People's Hospital, 1201 Beijing Road, Haimen District, Nantong City, 226100, Jiangsu Province, China
| | - Chunxi Yang
- Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 145 Shandong Zhong Lu, Shanghai, 200001, China.
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Abstract
While electrical stimulation with pulses of milli- or microsecond duration is possible without electroporation, stimulation with nanosecond pulses typically entails electroporation, and nanosecond pulses can even cause electroporation without stimulation. A recently proposed explanation for this intriguing finding is that stimulation requires not only that a threshold membrane potential is reached, but also that it is sustained for a certain time tmin, while electroporation occurs almost immediately after a higher threshold potential is reached. Here we analytically derive stimulation and electroporation thresholds for membranes that satisfy these assumptions. We analyze the safety factor, i.e. the ratio between electroporation and stimulation threshold and its dependence on pulse duration, membrane charging time constant, and tmin. We find that the safety factor is sharply reduced if both the pulse duration and the membrane charging time constant are below tmin. We discuss different approaches to get models with varying tmin that could be used to experimentally test this theory and cardiac applications.
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Affiliation(s)
- Christian W Zemlin
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Campus Box 8234, 660 S Euclid Ave, St. Louis, MO 63110, USA.
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Daegling DJ, Bhramdat HD, Toro-Ibacache V. Efficacy of shear strain gradients as an osteogenic stimulus. J Theor Biol 2021; 524:110730. [PMID: 33894230 DOI: 10.1016/j.jtbi.2021.110730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/06/2021] [Accepted: 04/15/2021] [Indexed: 11/18/2022]
Abstract
The question of which mechanical variables are responsible for inducing osteogenic activity is unresolved despite extensive experimental and theoretical investigation. Candidate variables include strain magnitude, loading frequency, the interaction of magnitude and frequency (strain rate), and strain gradients. An additional challenge is discerning the coordination of periosteal and endosteal expansion during growth, and whether this coordination (or lack thereof) is fully dependent or partially independent of the local mechanical environment. In this study, under the assumption that calculated stresses correspond to relative strain magnitudes, we specify alternative growth algorithms of bone cross-sectional size and geometry to explore skeletal growth under alternative scenarios of osteogenic activity that are tracking 1) an attractor stress, 2) local stress magnitude or 3) steepness of stress gradients. These developmental simulations are initiated from two initial geometries (symmetrical and asymmetrical ellipses) under a time-varying torsional load whose magnitude is proportional to body size growth in a model primate. In addition, we model endosteal expansion under three conditions hypothesized in the literature, in which endosteal expansion is 1) independent of the mechanical milieu, 2) completely dependent on the mechanical milieu, and 3) a "hybrid" model in which intrinsic biological (independent) growth is operative early but gives way to mechanically-sensitive (dependent) growth at later ages. Three variables were recorded over each growth simulation: the safety factor (ratio of yield stress to actual stress), an efficiency ratio (invested bone area per unit of stress), and proximity to an isostress condition (an optimal design criterion in which stress is invariant throughout the structure). The attractor stress algorithm produces the most "adapted" bones in terms of mechanical competence and economy of material. Localized osteogenic activity that is guided in direct proportion to stress magnitude produces competent bones but with variable adult geometries depending on conditions of endosteal expansion. Stress gradients also produce functional but relatively inefficient bones, with widely variable safety factors during growth and heterogeneous stress fields. If, in fact, the osteocyte network monitors strain gradients to generate osteogenic signals, the resulting morphology is competent but falls well short of an optimal mechanical solution.
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Affiliation(s)
- David J Daegling
- Department of Anthropology, University of Florida, Gainesville, FL 32611-7305, USA.
| | - Henna D Bhramdat
- Department of Anthropology, University of Florida, Gainesville, FL 32611-7305, USA
| | - Viviana Toro-Ibacache
- Craniofacial Translational Research Lab|Center of Quantitative Analysis in Dental Anthropology, Facultad de Odontología Universidad de Chile, Olivos 943, Independencia, Región Metropolitana, Chile
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Gu Q, Huang Z, Li S, Zeng W, Wu Y, Zhao K. An approach for water-inrush risk assessment of deep coal seam mining: a case study in Xinlongzhuang coal mine. Environ Sci Pollut Res Int 2020; 27:43163-43176. [PMID: 32729037 DOI: 10.1007/s11356-020-10225-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
Most coal mines in China are opting for deep mining due to the rapid reduction of shallow coal reserves, which increases the risk of water-inrush accidents. Given the limitation of water-inrush coefficient method in evaluating the risk of water inrush from the coal seam floor, we analyzed the permeability resistance of the floor under different lithology combinations, and structural conditions of the lower group coal in Yanzhou mining area, based on the in situ pressure permeability test data. Our comprehensive analysis of the influencing factors of water inrush from the coal seam floor reveals key indices for evaluating the water inrush from the coal seam floor and also recommend values for average water-resistance strength of the different lithology, and structure of the lower coal seam floor of Xinglongzhuang coal mine. Besides, we establish a model based on the water-resistance conditions, and two adjacent lower coal working faces minefields of Xinglongzhuang coal mine in Yanzhou are used for the evaluation. Comparative analysis of water-inrush coefficient method and impermeability resistance condition to evaluate the applicability of safety conditions of coal mining under pressure are also performed. Our results show that the impermeability strength is a better measurement for the water-resistance capacity of the floor. These findings may guide the prevention and control of water disasters in coal mining under pressure in the lower formation of the minefield.
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Affiliation(s)
- Qixiong Gu
- School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China
| | - Zhen Huang
- School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China.
| | - Shijie Li
- School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China
| | - Wei Zeng
- School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China
| | - Yun Wu
- School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China
| | - Kui Zhao
- School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China
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Willie BM, Zimmermann EA, Vitienes I, Main RP, Komarova SV. Bone adaptation: Safety factors and load predictability in shaping skeletal form. Bone 2020; 131:115114. [PMID: 31648080 DOI: 10.1016/j.bone.2019.115114] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/06/2019] [Accepted: 10/17/2019] [Indexed: 02/09/2023]
Abstract
Much is known about skeletal adaptation in relation to the mechanical functions that bones serve. This includes how bone adapts to mechanical loading during an individual's lifetime as well as over evolutionary time. Although controlled loading in animal models allows us to observe short-term bone adaptation (epigenetic mechanobiology), examining an assemblage of extant vertebrate bones or a group of fossils' bony structures can reveal the combined effects of long-term trends in loading history and the effects of natural selection. In this survey we examine adaptations that take place over both time scales and highlight a few of the extraordinary insights first published by John Currey. First, we provide a historical perspective on bone adaptation control mechanisms, followed by a discussion of safety factors in bone. We then summarize examples of structural- and material-level adaptations and mechanotransduction, and analyze the relationship between these structural- and material-level adaptations observed in situations where loading modes are either predictable or unpredictable. We argue that load predictability is a major consideration for bone adaptation broadly across an evolutionary timescale, but that its importance can also be seen during ontogenetic growth trajectories, which are subject to natural selection as well. Furthermore, we suggest that bones with highly predictable load patterns demonstrate more precise design with lower safety factors, while bones that experience less predictable loads or those that are less capable of repair and adaptation are designed with a higher safety factor. Finally, exposure to rare loading events with high potential costs of failure leads to design of structures with very high safety factor compared to everyday loading experience. Understanding bone adaptations at the structural and material levels, which take place over an individual's lifetime or over evolutionary time has numerous applications in translational and clinical research to understand and treat musculoskeletal diseases, as well as to permit the furthering of human extraterrestrial exploration in environments with altered gravity.
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Affiliation(s)
- Bettina M Willie
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada.
| | - Elizabeth A Zimmermann
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Isabela Vitienes
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Russell P Main
- Department of Basic Medical Sciences and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Svetlana V Komarova
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Faculty of Dentistry, McGill University, Montreal, Canada
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9
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Reinhardt K, Voigt D, Gorb SN. Evidence for a sexually selected function of the attachment system in bedbugs Cimex lectularius (Heteroptera, Cimicidae). J Exp Biol 2019; 222:jeb.206136. [PMID: 31053647 DOI: 10.1242/jeb.206136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/29/2019] [Indexed: 11/20/2022]
Abstract
Attachment to surfaces is a major aspect of an animal's interaction with the environment. Consequently, shaping of the attachment system in relation to weight load and substrate is considered to have occurred mainly by natural selection. However, sexual selection may also be important because many animals attach to their partner during mating. The two hypotheses generate opposing predictions in species where males are smaller than females. Natural selection predicts that attachment ability will scale positively with load, and hence body size, and so will be larger in females than males. Sexual selection predicts attachment forces in males will be larger than those in females, despite the males' smaller size because males benefit from uninterrupted copulation by stronger attachment to the female. We tested these predictions in the common bedbug Cimex lectularius, a species in which both sexes, as well as nymphs, regularly carry large loads: blood meals of up to 3 times their body weight. By measuring attachment forces to smooth surfaces and analysing in situ fixed copulating pairs and the morphology of attachment devices, we show that: (i) males generate twice the attachment force of females, despite weighing 15% less; (ii) males adhere to females during copulation using hairy tibial adhesive pads; (iii) there are more setae, and more setae per unit area, in the pads of males than in those of females but there is no difference in the shape of the tarsal setae; and (iv) there is an absence of hairy tibial attachment pads and a low attachment force in nymphs. These results are consistent with a sexually selected function of attachment in bedbugs. Controlling sperm transfer and mate guarding by attaching to females during copulation may also shape the evolution of male attachment structures in other species. More generally, we hypothesise the existence of an arms race in terms of male attachment structures and female counterparts to impede attachment, which may result in a similar evolutionary diversification to male genitalia.
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Affiliation(s)
- Klaus Reinhardt
- Applied Zoology, Faculty of Biology, Technische Universität Dresden, D-01062 Dresden, Germany .,Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Dagmar Voigt
- Institute for Botany, Faculty of Biology, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, D-24098 Kiel, Germany
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Dettrick D, Costelloe J, Arora M, Yuen S. A comparison of measured and predicted diffusion coefficients applied to sand and silt sized acid mine drainage materials. J Environ Manage 2019; 231:1106-1116. [PMID: 30602235 DOI: 10.1016/j.jenvman.2018.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/23/2018] [Accepted: 08/02/2018] [Indexed: 06/09/2023]
Abstract
Determining the rate at which Acid Mine Drainage (AMD) sulfide oxidation occurs in mining waste products is a central requirement for safe and sustainable long term design of storages, including tails storage facilities, ore stockpiles and waste rock dumps. Inappropriate design can result in AMD acidification, mobilisation of heavy metals and pollution of ground and surface waters. The use of soil gas (oxygen) transport modelling to model AMD based sulfide oxidation and potential acidity loads is widespread, but diffusion coefficients used for modelling are based on existing diffusion coefficient models derived for natural and agricultural soils. Mining wastes are often well sorted due to mineral processing, and differences in soil structure and porosity can impact on diffusion coefficient behaviour compared to natural soils. This study compares a variety of approaches to estimate the diffusion coefficient and compare these results to measured values for comparison and analysis. A diffusion column apparatus is used to compare diffusion coefficient models from the literature with test results from the laboratory in several mining derived AMD materials. The results of the comparison indicate that laboratory testing of diffusion provides more accurate estimation of soil gas diffusion coefficients in mine materials. The use of diffusion coefficient safety factor approaches are explored as possible alternatives, if measurement of mine material matrix soil gas diffusion coefficient is not possible.
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Affiliation(s)
- D Dettrick
- University of Melbourne, Department of Infrastructure Engineering, 3010, Victoria, Australia; Earth Systems, 14 Church St, Hawthorn, 3122, Victoria, Australia.
| | - J Costelloe
- University of Melbourne, Department of Infrastructure Engineering, 3010, Victoria, Australia
| | - M Arora
- University of Melbourne, Department of Infrastructure Engineering, 3010, Victoria, Australia
| | - S Yuen
- University of Melbourne, Department of Infrastructure Engineering, 3010, Victoria, Australia
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11
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Voigt D, Gorb S. Functional morphology of tarsal adhesive pads and attachment ability in ticks Ixodes ricinus (Arachnida, Acari, Ixodidae). ACTA ACUST UNITED AC 2018; 220:1984-1996. [PMID: 28566356 DOI: 10.1242/jeb.152942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/16/2017] [Indexed: 11/20/2022]
Abstract
The presence of well-developed, elastic claws on ticks and widely pilose hosts led us to hypothesise that ticks are mostly adapted to attachment and locomotion on rough, strongly corrugated and hairy, felt-like substrates. However, by using a combination of morphological and experimental approaches, we visualised the ultrastructure of attachment devices of Ixodes ricinus and showed that this species adheres more strongly to smooth surfaces than to rough ones. Between paired, elongated, curved, elastic claws, I. ricinus bears a large, flexible, foldable adhesive pad, which represents an adaptation to adhesion on smooth surfaces. Accordingly, ticks attached strongest to glass and to surface profiles similar to those of the human skin, generating safety factors (attachment force relative to body weight) up to 534 (females). Considerably lower attachment force was found on silicone substrates and as a result of thanatosis after jolting.
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Affiliation(s)
- Dagmar Voigt
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel D-24098, Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel D-24098, Germany
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12
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Voigt D, Takanashi T, Tsuchihara K, Yazaki K, Kuroda K, Tsubaki R, Hosoda N. Strongest grip on the rod: tarsal morphology and attachment of Japanese pine sawyer beetles. Zoological Lett 2017; 3:16. [PMID: 28904812 PMCID: PMC5591571 DOI: 10.1186/s40851-017-0076-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 08/23/2017] [Indexed: 05/28/2023]
Affiliation(s)
- Dagmar Voigt
- Surface & Adhesion Science Group, Research Center for Structural Materials (RCSM), National Institute for Materials Science (NIMS), 1-1, Namiki, Tsukuba, Ibaraki, 305-0044 Japan
- Institute for Botany, Technische Universitaet Dresden, D-01062 Dresden, Germany
| | - Takuma Takanashi
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687 Japan
| | - Kazuko Tsuchihara
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687 Japan
- Department of Information Science, Tohoku Gakuin University, Sendai, Miyagi 981-3193 Japan
| | - Kenichi Yazaki
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687 Japan
| | - Katsushi Kuroda
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687 Japan
| | - Remi Tsubaki
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687 Japan
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa Japan
| | - Naoe Hosoda
- Surface & Adhesion Science Group, Research Center for Structural Materials (RCSM), National Institute for Materials Science (NIMS), 1-1, Namiki, Tsukuba, Ibaraki, 305-0044 Japan
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Yu QZ, Ding LY, Zhou C, Luo HB. Analysis of factors influencing safety management for metro construction in China. Accid Anal Prev 2014; 68:131-138. [PMID: 23932091 DOI: 10.1016/j.aap.2013.07.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
With the rapid development of urbanization in China, the number and size of metro construction projects are increasing quickly. At the same time, and increasing number of accidents in metro construction make it a disturbing focus of social attention. In order to improve safety management in metro construction, an investigation of the participants' perspectives on safety factors in China metro construction has been conducted to identify the key safety factors, and their ranking consistency among the main participants, including clients, consultants, designers, contractors and supervisors. The result of factor analysis indicates that there are five key factors which influence the safety of metro construction including safety attitude, construction site safety, government supervision, market restrictions and task unpredictability. In addition, ANOVA and Spearman rank correlation coefficients were performed to test the consistency of the means rating and the ranking of safety factors. The results indicated that the main participants have significant disagreement about the importance of safety factors on more than half of the items. Suggestions and recommendations on practical countermeasures to improve metro construction safety management in China are proposed.
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Affiliation(s)
- Q Z Yu
- School of Civil Engineering & Mechanics, Huazhong University of Science & Technology, Wuhan, China; Institute of Construction Management, Huazhong University of Science & Technology, Wuhan, China
| | - L Y Ding
- School of Civil Engineering & Mechanics, Huazhong University of Science & Technology, Wuhan, China; Institute of Construction Management, Huazhong University of Science & Technology, Wuhan, China
| | - C Zhou
- School of Civil Engineering & Mechanics, Huazhong University of Science & Technology, Wuhan, China; Institute of Construction Management, Huazhong University of Science & Technology, Wuhan, China.
| | - H B Luo
- School of Civil Engineering & Mechanics, Huazhong University of Science & Technology, Wuhan, China; Institute of Construction Management, Huazhong University of Science & Technology, Wuhan, China
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