3,528 research outputs found

    Cephalopod Brains: An Overview of Current Knowledge to Facilitate Comparison With Vertebrates.

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    Cephalopod and vertebrate neural-systems are often highlighted as a traditional example of convergent evolution. Their large brains, relative to body size, and complexity of sensory-motor systems and behavioral repertoires offer opportunities for comparative analysis. Despite various attempts, questions on how cephalopod 'brains' evolved and to what extent it is possible to identify a vertebrate-equivalence, assuming it exists, remain unanswered. Here, we summarize recent molecular, anatomical and developmental data to explore certain features in the neural organization of cephalopods and vertebrates to investigate to what extent an evolutionary convergence is likely. Furthermore, and based on whole body and brain axes as defined in early-stage embryos using the expression patterns of homeodomain-containing transcription factors and axonal tractography, we describe a critical analysis of cephalopod neural systems showing similarities to the cerebral cortex, thalamus, basal ganglia, midbrain, cerebellum, hypothalamus, brain stem, and spinal cord of vertebrates. Our overall aim is to promote and facilitate further, hypothesis-driven, studies of cephalopod neural systems evolution

    A Synthetic Loop Replacement Peptide That Blocks Canonical NFâ κB Signaling

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    Aberrant canonical NFâ κB signaling is implicated in diseases from autoimmune disorders to cancer. A major therapeutic challenge is the need for selective inhibition of the canonical pathway without impacting the many nonâ canonical NFâ κB functions. Here we show that a selective peptideâ based inhibitor of canonical NFâ κB signaling, in which a hydrogen bond in the NBD peptide is synthetically replaced by a nonâ labile bond, shows an about 10â fold increased potency relative to the original inhibitor. Not only is this molecule, NBD2, a powerful tool for dissection of canonical NFâ κB signaling in disease models and healthy tissues, the success of the synthetic loop replacement suggests that the general strategy could be useful for discovering modulators of the many proteinâ protein interactions mediated by such structures.A peptideâ based inhibitor of canonical NFâ κB signaling, in which a hydrogen bond in the NBD peptide is synthetically replaced by a nonâ labile bond, shows an about 10â fold increased potency relative to the original inhibitor. The success of the synthetic replacement of a peptide loop suggests that the general strategy could be broadly useful for discovering modulators of many proteinâ protein interactions mediated by such structures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135096/1/anie201607990.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135096/2/anie201607990-sup-0001-misc_information.pd

    Algebras in Higher Dimensional Statistical Mechanics - the Exceptional Partition (MEAN Field) Algebras

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    We determine the structure of the partition algebra Pn(Q)P_n(Q) (a generalized Temperley-Lieb algebra) for specific values of Q \in \C, focusing on the quotient which gives rise to the partition function of nn site QQ-state Potts models (in the continuous QQ formulation) in arbitrarily high lattice dimensions (the mean field case). The algebra is non-semi-simple iff QQ is a non-negative integer less than nn. We determine the dimension of the key irreducible representation in every specialization.Comment: 4 page

    A Construction of Solutions to Reflection Equations for Interaction-Round-a-Face Models

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    We present a procedure in which known solutions to reflection equations for interaction-round-a-face lattice models are used to construct new solutions. The procedure is particularly well-suited to models which have a known fusion hierarchy and which are based on graphs containing a node of valency 11. Among such models are the Andrews-Baxter-Forrester models, for which we construct reflection equation solutions for fixed and free boundary conditions.Comment: 9 pages, LaTe

    Beluga whale (Delphinapterus leucas) acoustic foraging behavior and applications for long term monitoring

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    This paper is not subject to U.S. copyright. The definitive version was published in Castellote, M., Mooney, A., Andrews, R., Deruiter, S., Lee, W.-J., Ferguson, M., & Wade, P. Beluga whale (Delphinapterus leucas) acoustic foraging behavior and applications for long term monitoring. Plos One, 16(11), (2021): e0260485, https://doi.org/10.1371/journal.pone.0260485.Cook Inlet, Alaska, is home to an endangered and declining population of 279 belugas (Delphinapterus leucas). Recovery efforts highlight a paucity of basic ecological knowledge, impeding the correct assessment of threats and the development of recovery actions. In particular, information on diet and foraging habitat is very limited for this population. Passive acoustic monitoring has proven to be an efficient approach to monitor beluga distribution and seasonal occurrence. Identifying acoustic foraging behavior could help address the current gap in information on diet and foraging habitat. To address this conservation challenge, eight belugas from a comparative, healthy population in Bristol Bay, Alaska, were instrumented with a multi-sensor tag (DTAG), a satellite tag, and a stomach temperature transmitter in August 2014 and May 2016. DTAG deployments provided 129.6 hours of data including foraging and social behavioral states. A total of 68 echolocation click trains ending in terminal buzzes were identified during successful prey chasing and capture, as well as during social interactions. Of these, 37 click trains were successfully processed to measure inter-click intervals (ICI) and ICI trend in their buzzing section. Terminal buzzes with short ICI (minimum ICI <8.98 ms) and consistently decreasing ICI trend (ICI increment range <1.49 ms) were exclusively associated with feeding behavior. This dual metric was applied to acoustic data from one acoustic mooring within the Cook Inlet beluga critical habitat as an example of the application of detecting feeding in long-term passive acoustic monitoring data. This approach allowed description of the relationship between beluga presence, feeding occurrence, and the timing of spawning runs by different species of anadromous fish. Results reflected a clear preference for the Susitna River delta during eulachon (Thaleichthys pacificus), Chinook (Oncorhynchus tshawytscha), pink (Oncorhynchus gorbuscha), and coho (Oncorhynchus kisutch) salmon spawning run periods, with increased feeding occurrence at the peak of the Chinook and pink salmon runs.Project funding was provided by Georgia Aquarium, the Marine Mammal Laboratory of the Alaska Fisheries Science Center (MML/AFSC). Tagging was funded by the NOAA Fisheries Office of Science and Technology’s Ocean Acoustics Program. DTAG data analysis was funded by the U.S. Marine Mammal Commission grant #16-239. Funding for collecting and analyzing Cook Inlet beluga acoustic data in Susitna Delta was provided by the National Marine Fisheries Service Section 6 Office to the Alaska Department of Fish and Game. This publication is partially funded by the Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CICOES), University of Washington, under NOAA Cooperative Agreement NA15OAR4320063, Contribution No. 2021-1145

    Dinosaur tracks from the Kilmaluag Formation (Bathonian, Middle Jurassic) of Score Bay, Isle of Skye, Scotland, UK

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    Tracks of a juvenile theropod dinosaur with footprint lengths of between 2 and 9 cm as well as adults of the same ichnospecies with footprints of about 15–25 cm in length were found in the Bathonian (Middle Jurassic) Kilmaluag Formation of Score Bay, northwestern Trotternish Peninsula, Isle of Skye, Scotland, UK. Two footprint sizes occur together on the same bedding plane in the central portion of Score Bay, both in situ and on loose blocks. Another horizon containing footprints above this was also identified. The footprints from the lowest horizon were produced in a desiccated silty mud that was covered with sand. A close association of both adults and juveniles with similar travel direction indicated by the footprints may suggest post-hatching care in theropod dinosaurs. Other footprints, produced on a rippled sandy substrate, have been found on the slightly higher bedding plane at this locality. Loose blocks found 130 m to the northeast in the central part of Score Bay have not been correlated with any in situ sediments, but were preserved in a similar manner to those from the higher bedding plane. These tracks represent the youngest dinosaur remains yet found in Scotland

    teigen: An R Package for Model-Based Clustering and Classification via the Multivariate t Distribution

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    The teigen R package is introduced and utilized for model-based clustering and classification. The tEIGEN family of mixtures of multivariate t distributions is formed via an eigen-decomposition of the component covariance matrices and subsequent componentwise constraints. The teigen package implements all previously published tEIGEN family members as well as eight additional models: four multivariate and four univariate. The resulting family of 32 mixture models is implemented in both serial and parallel, with useful dedicated functions. Methodology and examples that illustrate teigen's functionality are presented

    Hamiltonians for the Quantum Hall Effect on Spaces with Non-Constant Metrics

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    The problem of studying the quantum Hall effect on manifolds with nonconstant metric is addressed. The Hamiltonian on a space with hyperbolic metric is determined, and the spectrum and eigenfunctions are calculated in closed form. The hyperbolic disk is also considered and some other applications of this approach are discussed as well.Comment: 16 page
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