Article
Engineering, Mechanical
Alexandre Kawano, Antonino Morassi, Ramon Zaera
Summary: In this paper, a constructive procedure is proposed to determine the radial pretension in an axially-symmetric orb-web based on one eigenfrequency and its corresponding vibration mode. The method can be applied to both axisymmetric modes and non-axisymmetric modes, and regularization technique and filtering process are proposed to improve the reconstruction of the pretension field.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Review
Acoustics
Ramon Zaera, Oscar Serrano, Jose Fernandez-Saez, Antonino Morassi
Summary: Orb web spiders locate prey impacts in the web through sensitive sensors on their legs, even with limited information, allowing for accurate prey localization.
JOURNAL OF VIBRATION AND CONTROL
(2022)
Article
Engineering, Mechanical
Alexandre Kawano, Antonino Morassi, Ramon Zaera
Summary: Spiders use their orb-web as a sensor to capture prey and detect the impact position, transmitting vibratory information to their legs. Recent studies have made progress in formulating the catching problem as an inverse problem and using a membrane model for the orb-web. Relaxing the rigid support condition at the boundary of the web helps approach the reality of non-rigid substrates, leading to a reconstruction algorithm for load support identification.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Ecology
Marina Choppin, Miriam Schall, Barbara Feldmeyer, Susanne Foitzik
Summary: Aging is accompanied by various molecular processes and nutrient-sensing signalling pathways play a critical role in the aging process. Protein-rich diets can affect longevity and fecundity in different directions. In this study, we investigated the effect of protein to carbohydrate ratio in the diet on the survival and fecundity of fertile ant workers. The results showed that a protein-rich diet reduced worker survival without promoting reproduction, suggesting a negative impact on the overall fitness of fertile workers.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Multidisciplinary Sciences
Vinicius F. Dal Poggetto, Federico Bosia, Gabriele Greco, Nicola M. Pugno
Summary: This study introduces a numerical model based on nonlinear stress-strain constitutive relations for spider silk to investigate how the spider orb web allows spiders to detect and localize prey impacts. The results indicate that the orb web center's relative transverse displacements, produced by local resonance mechanisms, are used for precise localization, while nonlinear stress stiffening effects improve prey sensing. Additionally, it is shown that a large number of radial threads may not be necessary for prey localization.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Entomology
Lucas J. Kirschman, Lindsey Dewey, Andre Gregory
Summary: Trade-offs between immune function and reproductive effort were investigated in female wolf spiders, revealing that reproductive effort did not impact immune function in spiders carrying young. Individual differences in resource acquisition may explain the lack of relationship between reproductive effort and immune response in spiders carrying young. Maintaining resources for immune responses across reproductive stages could increase fitness in female wolf spiders, reducing kin competition among spiderlings.
PHYSIOLOGICAL ENTOMOLOGY
(2022)
Article
Entomology
Guang-Yun Li, Zhi-Qiang Zhang
Summary: This study focused on the aging patterns of two-spotted spider mites and found significant lifespan extension effects in females under dietary restriction and delayed mating, while the opposite was observed in males. Path analysis revealed no clear trade-offs between mite survival and reproduction traits. The additive effects of dietary restriction and delayed mating in extending the lifespan of female spider mites were confirmed, showing that diet restriction is a robust anti-aging intervention, and later onset of reproduction can prolong adult lifespan in females.
Article
Biology
Yong Zhi Foo, Malgorzata Lagisz, Rose E. O'Dea, Shinichi Nakagawa
Summary: Finding the balance between survival and reproduction is a central problem in life-history theory. The terminal investment hypothesis predicts that individuals facing a survival threat will increase immediate reproductive investment to maximize fitness. However, research on this hypothesis has yielded mixed results. In this study, a meta-analysis was conducted to examine reproductive investment in multicellular animals after an immune challenge. The results provided some support for the hypotheses, showing stronger terminal investment responses in older individuals with lower residual reproductive values, as well as an increase in variance, particularly in longer-living species.
Article
Mathematics, Applied
Alexandre Kawano, Antonino Morassi, Ramon Zaera
Summary: Researchers have developed the structure of small in-plane vibratory response of an axially symmetric orb-web supported at the boundary, demonstrating that knowledge of the in-plane dynamic response inside an annulus centered at the origin allows for the unique determination of the in-plane distributed load simulating the prey's impact.
SIAM JOURNAL ON APPLIED MATHEMATICS
(2021)
Article
Mathematics, Applied
Alexandre Kawano, Antonino Morassi, Ramos Zaera
Summary: In this paper, we study the problem of locating a prey in a spider orb-web by measuring its dynamic response after an impact. A reconstruction algorithm for the impact region is proposed based on discrete dynamic measurements. The results show that the sensitivity of the reconstruction to errors on the data is significant when the observation time is close to the theoretical minimum.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Ecology
Elisabeth G. Chapman, Jill G. Pilkington, Josephine M. Pemberton
Summary: Life history trade-offs are common and place constraints on the timing of reproduction events. However, studies on male mammals' lifetime breeding success are scarce due to sex-biased dispersal and genetic paternity requirements. We investigated early life reproduction in male Soay sheep and found that individuals born in years with low-density population had higher early breeding success. Singleton individuals were more successful than twins. Successful breeding at 7 months increased survival chances for the first winter. There was no association between early breeding success and later breeding success for individuals that survived their first winter. We believe that individual quality variations mask the costs of early reproduction in this population.
ECOLOGY AND EVOLUTION
(2023)
Article
Ecology
Cristhiana Ropke, Tiago H. S. Pires, Jansen Zuanon, Carlos E. C. Freitas, Marina C. Hernandes, Flavia Souza, Sidineia Amadio
Summary: Understanding the factors that regulate temporal changes in population size is crucial in ecology for maintaining species interactions, ecosystem stability, and biodiversity conservation. This study examined the population stability of 70 Amazonian floodplain fish species in relation to life-history traits and fishing pressure, finding significant relationships with certain life-history traits but not with fishing pressure. The findings stress the importance of life-history traits in controlling population size variation and can inform fisheries and conservation management strategies.
FRESHWATER BIOLOGY
(2021)
Article
Environmental Sciences
Xupeng Chi, Fang Zhang, Song Sun
Summary: Understanding the life history strategy of organisms is crucial for predicting population dynamics. In the case of scyphozoan jellyfish, we found that their asexual reproduction rate decreases over time but can be counteracted by longer culture durations. This study highlights the importance of sexual reproduction in renewing the asexual reproduction ability of a population and emphasizes the need to consider the asexual age of organisms in studying population dynamics.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Mathilde L. Tissier, Patrick Bergeron, Dany Garant, Sandrine Zahn, Francois Criscuolo, Denis Reale
Summary: Understanding the role of telomeres in life-history strategies is important in biology. In this study, the telomere length in wild Eastern chipmunks was examined and it was found that telomeres elongate with age and do not limit lifespan in this species. Furthermore, the findings suggest that telomere length is associated with life-history strategies in a sex-specific way.
Article
Ecology
Doreen Cabrera, Blaine D. Griffen
Summary: Complex life histories often involve trade-offs between different traits. This study examines the growth patterns of invasive male northern crayfish and finds evidence of a trade-off between body and chelae size growth. The crayfish undergo cyclic dimorphism, with different growth increments observed during different morphological transitions. The results support the idea that cyclic dimorphism is an adaptive strategy for optimizing energy allocation during reproduction in crayfish with complex life histories.
ECOLOGY AND EVOLUTION
(2023)