Search results for "Vertebra"
showing 10 items of 1220 documents
Disentangling conditional effects of multiple regime shifts on Atlantic cod productivity
2020
AbstractRegime shifts are increasingly prevalent in the ecological literature. However, definitions vary, and many detection methods are subjective. Here, we employ an operationally objective means of identifying regime shifts, using a Bayesian online change-point detection algorithm able to simultaneously identify shifts in the mean and(or) variance of time series data. We detected multiple regime shifts in long-term (59-154 years) patterns of coastal Norwegian Atlantic cod (>70% decline) and putative drivers of cod productivity: North Atlantic Oscillation (NAO); sea-surface temperature; zooplankton abundance; fishing mortality (F). The consequences of an environmental or climate-relate…
The Peculiarities of Gonad Transformation in Teleosts
1983
In teleosts the problem of sex determination and sex differentiation is more puzzling than in other vertebrates. It is not known whether the intriguing variety in the conditions of sex results from the position of these fishes within the vertebrate pedigree. They represent the final products of actinopterygian evolution toward the end of the age of reptiles, that is late in the Jurassic era. However, with that evolutionary fact in mind it is more plausible that teleosts deviate in many ways from the pattern that we are used to attribute to vertebrates in general. The following features of sex differentiation are striking examples of teleost peculiarity: (1) In both sexes there is no morphol…
Comparison of sampling methods and habitat types for detecting impacts on lake littoral macroinvertebrate assemblages along a gradient of human distu…
2010
We explored environmental variables structuring littoral macroinvertebrate communities in a large lake basin along a gradient of nutrient enrichment. Furthermore, we evaluated sensitivity and cost-effi ciency of different sampling schemes (i.e. combinations of three habitat types and a number of standard sampling methods) to detect changes in macroinvertebrate communities along this anthropogenic disturbance gradient. Partial canonical ordination analysis showed that habitat characteristics accounted for a major part (56 % uniquely) of the explained variation in the species composition of invertebrate communities. When different mesohabitats were examined separately, assemblage variation of…
Tutela della Diversità degli ambienti aridi della Sicilia
2010
Sequence of the new Drosophila melanogaster small heat-shock-related gene, lethal(2) essential for life [l(2)efl], at locus 59F4,5.
1995
Abstract In this study, we report the molecular cloning of a novel Drosophila melanogaster small heat-shock (HS)-homologous gene, l(2)efl, identified on the right arm of the second chromosome at locus 59F4,5. We describe the temporal expression of l(2)efl in the wild-type and present its structure. The deduced amino-acid sequence of the Efl protein shows significant homology to all known small HS proteins identified in Drosophila and vertebrates, and to mammalian α-crystallin.
Surgical Highways to the Craniovertebral Junction: Is It Time for a Reappraisal?
2019
Background: The craniovertebral junction (CVJ) can be affected by a variety of congenital or acquired anomalies. Because of its complexity, a careful evaluation of bones and ligamentous structures in all three planes is required. This can be achieved by studying the CVJ in terms of several anatomical and radiological lines that have been visualized to facilitate understanding of its surgical anatomy. In this study we aimed to review the state-of-the art craniometric CVJ lines and approaches. Methods: In December 2016 a PubMed search was performed, including the search terms ‘CVJ surgical approach/line’, ‘cervical approach’, ‘craniometric measurement’, ‘CVJ anatomy’ and ‘ventral/dorsal/far-l…
Novel approach to study the perception of animacy in dogs.
2017
Humans tend to perceive inanimate objects as animate based on simple motion cues. So far this perceptual bias has been studied mostly in humans by utilizing two-dimensional video and interactive displays. Considering its importance for survival, the perception of animacy is probably also widespread among animals, however two-dimensional displays are not necessarily the best approach to study the phenomenon in non-human species. Here we applied a novel method to study whether dogs recognize a dependent (chasing-like) movement pattern performed by inanimate agents in live demonstration. We found that dogs showed more interest toward the agents that demonstrated the chasing-like motion, compar…
Reservoir computing model of prefrontal cortex creates novel combinations of previous navigation sequences from hippocampal place-cell replay with sp…
2019
As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites. Such spatial navigation capacity involves the replay of hippocampal place-cells during awake states, generating small sequences of spatially related place-cell activity that we call “snippets”. These snippets occur primarily during sharp-wave-ripples (SWRs). Here we focus on the role of such replay events, as the animal is learning a traveling salesperson task (TSP) across multiple trials. We hypothesize that snippet replay generates synthetic data that can substantially expand and restructure the experience available and make learni…
Influences of Relatedness, Food Deprivation, and Sex on Adult Behaviors in the Group-living Insect Forficula auricularia
2014
The evolution of group living is generally associated with the emergence of social behaviors that ensure fitness benefits to group members. However, the expression of these behaviors may depend on group composition, which can vary over time with respect to sex, starvation status, and relatedness. Here, we investigated (1) whether adults of the group-living European earwig, Forficula auricularia, show cooperative behaviors toward conspecifics and (2) whether sex, food availability, and relatedness shape the nature and frequency of these behaviors. We conducted a full-factorial experiment using 108 unisexual pairs of adults, in which we manipulated these three factors and video-recorded the e…