588 research outputs found
Effects of Sustainable Diets containing Fish-Trim Waste, on Growth Performance of Juvenile Sablefish (Anopoploma fimbria)
A feeding trial was conducted to investigate the use of alternative fish feeds produced from fish-trim waste in high plant protein diets for juvenile sablefish (Anopoploma fimbria). Fish meal in the control diet (CD) was replaced in the experimental diets by low molecular weight hydrolysate (LMWH) protein derived from Pacific whiting (Merluccius productus) processing waste, or by Atlantic salmon (Salmo salar) processing trim (ST), which was incorporated into the feed with an experimental heated ball mill. The feeding trial was conducted in an indoor recirculating seawater system and each feed was randomly assigned to triplicate groups of 50 fish (average initial body weight of 57.5 g). The results showed that compared to the control diet, the diets containing LMWH or ST significantly increased feed consumption and fish weight gain. The ST group showed a significantly higher weight gain than the LMWH group. The ST feed, but not the LMWH feed, had a significantly lower feed conversion ratio than the CD feed. The ST feed increased lipid retention efficiency and lipid content in whole body tissue. These results demonstrate that salmon fish trim waste and enzyme hydrolyzed whiting trim in high plant protein diets can increase the performance in sablefish
Collisions of Deformed Nuclei: A Path to the Far Side of the Superheavy Island
A detailed understanding of complete fusion cross sections in heavy-ion
collisions requires a consideration of the effects of the deformation of the
projectile and target. Our aim here is to show that deformation and orientation
of the colliding nuclei have a very significant effect on the fusion-barrier
height and on the compactness of the touching configuration. To facilitate
discussions of fusion configurations of deformed nuclei, we develop a
classification scheme and introduce a notation convention for these
configurations. We discuss particular deformations and orientations that lead
to compact touching configurations and to fusion-barrier heights that
correspond to fairly low excitation energies of the compound systems. Such
configurations should be the most favorable for producing superheavy elements.
We analyse a few projectile-target combinations whose deformations allow
favorable entrance-channel configurations and whose proton and neutron numbers
lead to compound systems in a part of the superheavy region where alpha
half-lives are calculated to be observable, that is, longer than 1 microsecond.Comment: 15 pages. LaTeX with iopconf.sty style file. Submitted to Nuclear
Physics A. 25 figures not included here. PostScript version with figures
available at http://t2.lanl.gov/pub/publications/publications.html or at
ftp://t2.lanl.gov/pub/publications/cd
Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.
Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years
Discrete computation using a perturbed heteroclinic network
Copyright © 2005 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physics Letters A, Vol 347, Issues 4-6, 2005, DOI: 10.1016/j.physleta.2005.08.013Transient synchronization into clusters appears in many biological and physical
systems and seems to be important for computation within neural systems. In this
paper we show how one can robustly and effectively perform practical computations
using small perturbations to a very simple globally coupled network of oscillators.
Computations are performed by exploiting the spatio-temporal dynamics of a robust
attracting heteroclinic network (also referred to as `winnerless competition' dynamics)
to describe the states and transitions between them. We use different cluster
synchronization states to encode states and use this to design a simple multi-base
counter. The simulations indicate that this gives a robust computational system
exploiting the natural dynamics of the system
Ion antiport accelerates photosynthetic acclimation in fluctuating light environments
Many photosynthetic organisms globally, including crops, forests and algae, must grow in environments where the availability of light energy fluctuates dramatically. How photosynthesis maintains high efficiency despite such fluctuations in its energy source remains poorly understood. Here we show that Arabidopsis thaliana K+ efflux antiporter (KEA3) is critical for high photosynthetic efficiency under fluctuating light. On a shift from dark to low light, or high to low light, kea3 mutants show prolonged dissipation of absorbed light energy as heat. KEA3 localizes to the thylakoid membrane, and allows proton efflux from the thylakoid lumen by proton/potassium antiport. KEA3’s activity accelerates the downregulation of pH-dependent energy dissipation after transitions to low light, leading to faster recovery of high photosystem II quantum efficiency and increased CO2 assimilation. Our results reveal a mechanism that increases the efficiency of photosynthesis under fluctuating light. [EN]This project was funded by the Carnegie Institution for Science, by ERDF-cofinanced grants from the Ministry of Economy and Competitiveness (BIO2012-33655) and Junta de Andalucia (CVI-7558) to K.V., the Natural Sciences and Engineering Research Council of Canada (NSERC) PGS-D3 scholarship to L.P. and Deutsche Forschungsgemeinschaft grants (JA 665/10-1 and GRK 1525 to P.J.; AR 808/1-1 to U.A.).Peer reviewe
Arabidopsis CSP41 proteins form multimeric complexes that bind and stabilize distinct plastid transcripts
The spinach CSP41 protein has been shown to bind and cleave chloroplast RNA in vitro. Arabidopsis thaliana, like other photosynthetic eukaryotes, encodes two copies of this protein. Several functions have been described for CSP41 proteins in Arabidopsis, including roles in chloroplast rRNA metabolism and transcription. CSP41a and CSP41b interact physically, but it is not clear whether they have distinct functions. It is shown here that CSP41b, but not CSP41a, is an essential and major component of a specific subset of RNA-binding complexes that form in the dark and disassemble in the light. RNA immunoprecipitation and hybridization to gene chips (RIP-chip) experiments indicated that CSP41 complexes can contain chloroplast mRNAs coding for photosynthetic proteins and rRNAs (16S and 23S), but no tRNAs or mRNAs for ribosomal proteins. Leaves of plants lacking CSP41b showed decreased steady-state levels of CSP41 target RNAs, as well as decreased plastid transcription and translation rates. Representative target RNAs were less stable when incubated with broken chloroplasts devoid of CSP41 complexes, indicating that CSP41 proteins can stabilize target RNAs. Therefore, it is proposed that (i) CSP41 complexes may serve to stabilize non-translated target mRNAs and precursor rRNAs during the night when the translational machinery is less active in a manner responsive to the redox state of the chloroplast, and (ii) that the defects in translation and transcription in CSP41 protein-less mutants are secondary effects of the decreased transcript stability
A Linkage-Based Genome Assembly for the Mosquito Aedes albopictus and Identification of Chromosomal Regions Affecting Diapause
The Asian tiger mosquito, Aedes albopictus, is an invasive vector mosquito of substantial public health concern. The large genome size (similar to 1.19-1.28 Gb by cytofluorometric estimates), comprised of similar to 68% repetitive DNA sequences, has made it difficult to produce a high-quality genome assembly for this species. We constructed a high-density linkage map for Ae. albopictus based on 111,328 informative SNPs obtained by RNAseq. We then performed a linkage-map anchored reassembly of AalbF2, the genome assembly produced by Palatini et al. (2020). Our reassembled genome sequence, AalbF3, represents several improvements relative to AalbF2. First, the size of the AalbF3 assembly is 1.45 Gb, almost half the size of AalbF2. Furthermore, relative to AalbF2, AalbF3 contains a higher proportion of complete and single-copy BUSCO genes (84.3%) and a higher proportion of aligned RNAseq reads that map concordantly to a single location of the genome (46%). We demonstrate the utility of AalbF3 by using it as a reference for a bulk-segregant-based comparative genomics analysis that identifies chromosomal regions with clusters of candidate SNPs putatively associated with photoperiodic diapause, a crucial ecological adaptation underpinning the rapid range expansion and climatic adaptation of A. albopictus.Peer reviewe
Deconstructing the myth of Pasewalk: Why Adolf Hitler’s psychiatric treatment at the end of World War I bears no relevance
Background Even more than 70 years after the end of WW II, questions regarding the personality of dictator Adolf Hitler (1889-1945) remain unresolved. Among them, there is a focus on the problem of his state of mental health, in particular on the possible relevance of the medical treatment he received for a war injury at the military hospital of the small German town of Pasewalk in the last days of WW I. Some authors have come to postulate a profound change of his personality due either to a psychic trauma suffered or a hypnotic therapy he supposedly underwent for curing a hysterical blindness. Objectives The assumptions about Hitler’s war injury which rely on only two significant sources shall be assessed for their validity. Methods Existing historical sources and inferred hypotheses will be discussed in the light of alternative interpretations. Results The mentioned suppositions reveal their highly arbitrary character: neither a hysterical blindness of Hitler’s nor a hypnotic treatment at Pasewalk military hospital can be substantiated. Discussion Given the fact that Hitler’s medical sheet is most likely irrevocably lost, the authors plea for the acceptance of the limitations of historical research, even more so since the occurrences in Pasewalk lack any deeper importance for a historic assessment of Hitler’s personality
On designing heteroclinic networks from graphs
Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Physica D: Nonlinear Phenomena. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physica D: Nonlinear Phenomena Vol. 265 (2013), DOI: 10.1016/j.physd.2013.09.006Robust heteroclinic networks are invariant sets that can appear as attractors in symmetrically coupled or otherwise constrained dynamical systems. These networks may have a very complicated structure that is poorly understood and determined to a large extent by the constraints and dimension of the system. As these networks are of great interest as dynamical models of biological and cognitive processes, it is useful to understand how particular graphs can be realised as robust heteroclinic networks that are attracting. This paper presents two methods of realizing arbitrarily complex directed graphs as robust heteroclinic networks for flows generated by ODEs---we say the ODEs {\em realise} the graphs as heteroclinic networks between equilibria that represent the vertices. Suppose we have a directed graph on vertices with edges. The "simplex realisation" embeds the graph as an invariant set of a flow on an -simplex. This method realises the graph as long as it is one- and two-cycle free. The "cylinder realisation" embeds a graph as an invariant set of a flow on a -dimensional space. This method realises the graph as long as it is one-cycle free. In both cases we find the graph as an invariant set within an attractor, and discuss some illustrative examples, including the influence of noise and parameters on the dynamics. In particular we show that the resulting heteroclinic network may or may not display "memory" of the vertices visited.Mathematical Biosciences Institute (MBI), OhioRoyal SocietyUniversity of Aucklan
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