The intertidal gastropod Littorina saxatilis is a model system to study speciation and local adaptation. The repeated occurrence of distinct ecotypes showing different levels of genetic divergence ...makes L. saxatilis particularly suited to study different stages of the speciation continuum in the same lineage. A major finding is the presence of several large chromosomal inversions associated with the divergence of ecotypes and, specifically, the species offers a system to study the role of inversions in this divergence. The genome of L. saxatilis is 1.35 Gb and composed of 17 chromosomes. The first reference genome of the species was assembled using Illumina data, was highly fragmented (N50 of 44 kb), and was quite incomplete, with a BUSCO completeness of 80.1% on the Metazoan dataset. A linkage map of one full-sibling family enabled the placement of 587 Mbp of the genome into 17 linkage groups corresponding to the haploid number of chromosomes, but the fragmented nature of this reference genome limited the understanding of the interplay between divergent selection and gene flow during ecotype formation. Here, we present a newly generated reference genome that is highly contiguous, with a N50 of 67 Mb and 90.4% of the total assembly length placed in 17 super-scaffolds. It is also highly complete with a BUSCO completeness of 94.1% of the Metazoa dataset. This new reference will allow for investigations into the genomic regions implicated in ecotype formation as well as better characterization of the inversions and their role in speciation.
A drug library of 17200 compounds was screened to select small molecules that inhibit the secretion of amyloid β peptide (Aβ), the major component of Alzheimer disease senile plaques, from a human ...neuronal cell line. Twenty-nine hits were validated that decreased Aβ secretion by >40% at 10 μM, for a 0.17% hit rate. A lead hit was selected for further study based on its activity and low cytotoxicity, and it was found to inhibit Aβ secretion through activation of the α-secretase pathway. Twenty-four commercially available and 53 synthesized analogues were analyzed for activity. Selected analogues were evaluated for biological stability by incubation with hepatoma cells and for transcellular permeability using Caco-2 cell monolayers. The analogue with the best permeability was evaluated in 2-month old amyloid precursor protein transgenic mice and found to acutely reduce cerebral Aβ levels by 40% after a single iv administration.
Broere and Hattingh proved that the Kronecker product of two cycles is a circulant if and only if the cycle lengths are coprime. In this paper, we specify which of these Kronecker products are ...actually optimal circulants. Further, we present their salient characteristics based on their edge decompositions into Hamiltonian cycles. It turns out that certain products thus distinguished have the added property of being tight-optimal, so their average distances are the least among all circulants of the same order and size. A benefit of the present study is that the existing results on the Kronecker product of two cycles may be used to good effect while putting these circulants into practice. The areas of applications include parallel computers, distributed systems and VLSI.
The goal of the seventh industrial fluid properties simulation challenge was to test the ability of molecular simulation methods to predict the adsorption of organic adsorbates in zeolite materials. ...Zeolite adsorbents are used in a variety of applications due to their high surface area and abilities to adsorb or desorb sorbates depending upon the applied conditions. With increasing numbers of applications, the ability to predict the performance of zeolites for a wide range of adsorbates would be very valuable in pre-optimizing systems and reducing product development time. The seventh challenge focused, in particular, on the adsorption of perfluorohexane in BCR-704 Faujasite Zeolite. Entrants were challenged to predict the adsorption of perfluorohexane in the zeolite at 293K and at relative pressures of 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, and 0.8. The relative pressure is defined as that relative to the bulk saturation pressure predicted by the model at a given temperature (293K in this case). The predictions were judged by comparison to a benchmark set of experimentally determined values. Overall good agreement and consistency were found between the predictions of most entrants.
Patients with hematologic malignancies are less likely to receive specialist palliative care services than patients with solid tumors. Reasons for this difference are poorly understood.
This was a ...multisite, mixed-methods study to understand and contrast perceptions of palliative care among hematologic and solid tumor oncologists using surveys assessing referral practices and in-depth semistructured interviews exploring views of palliative care. We compared referral patterns using standard statistical methods. We analyzed qualitative interview data using constant comparative methods to explore reasons for observed differences.
Among 66 interviewees, 23 oncologists cared exclusively for patients with hematologic malignancies; 43 treated only patients with solid tumors. Seven (30%) of 23 hematologic oncologists reported never referring to palliative care; all solid tumor oncologists had previously referred. In qualitative analyses, most hematologic oncologists viewed palliative care as end-of-life care, whereas most solid tumor oncologists viewed palliative care as a subspecialty that could assist with complex patient cases. Solid tumor oncologists emphasized practical barriers to palliative care referral, such as appointment availability and reimbursement issues. Hematologic oncologists emphasized philosophic concerns about palliative care referrals, including different treatment goals, responsiveness to chemotherapy, and preference for controlling even palliative aspects of patient care.
Most hematologic oncologists view palliative care as end-of-life care, whereas solid tumor oncologists more often view palliative care as a subspecialty for comanaging patients with complex cases. Efforts to integrate palliative care into hematologic malignancy practices will require solutions that address unique barriers to palliative care referral experienced by hematologic malignancy specialists.
Amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) is a fatal neurodegenerative disorder, and continued innovation is needed for improved understanding and for developing therapeutics. ...We have created next-generation genomically humanized knockin mouse models, by replacing the mouse genomic region of Sod1, Tardbp (TDP-43), and Fus, with their human orthologs, preserving human protein biochemistry and splicing with exons and introns intact. We establish a new standard of large knockin allele quality control, demonstrating the utility of indirect capture for enrichment of a genomic region of interest followed by Oxford Nanopore sequencing. Extensive analysis shows that homozygous humanized animals only express human protein at endogenous levels. Characterization of humanized FUS animals showed that they are phenotypically normal throughout their lifespan. These humanized strains are vital for preclinical assessment of interventions and serve as templates for the addition of coding or non-coding human ALS/FTD mutations to dissect disease pathomechanisms, in a physiological context.
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•Replacement in mice of Sod1, Tardbp, and Fus with orthologous human genomic sequence•Thorough allele QC of knockin alleles using targeted long-read sequencing•Mice are viable, fertile, and provide refined tools for ALS/FTD research•Aging of hFUS mice reveals no overt phenotype and minimal transcriptomic disruption
Neurogenetics; Neuroscience; Model organism
White-light emitting ultra-small CdSe nanocrystals present exciting possibilities in the area of solid-state lighting technology. In this work, thirteen dissimilar polymers were examined as potential ...encapsulants for these single-sized nanocrystals. Films of the encased nanocrystals were characterized in terms of nanocrystal aggregation and changes to the nanocrystals' natural emission. The Hildebrand and Hansen solubility parameters of each encapsulant were found to be correlated to the quality of nanocrystal encapsulation achieved. Encapsulants with cyclosiloxane or bisphenol-A type epoxy structures caused extensive aggregation of the nanocrystals at low loading levels ( < 0.5% w/w) due to the solubility difference between the polymer structure and the nanocrystals' ligands. Of the encapsulants tested, the most robust, color stable, and homogenous encapsulation was obtained using a biphenylperfluorocyclobutyl polymer. In this polymer, nanocrystal loading levels up to 18% w/w were achieved. White-light emitting CdSe nanocrystals encapsulated in the biphenylperfluorocyclobutyl polymer were coated on various UV-LEDs creating a white light source with chromaticity coordinates of (0.32,0.322) and a high color-rendering index of 93.
Octonions as Clifford-like algebras Depies, Connor M.; Smith, Jonathan D.H.; Ashburn, Mitchell D.
Journal of algebra,
04/2024, Letnik:
644
Journal Article
Recenzirano
Odprti dostop
The associative Cayley-Dickson algebras over the field of real numbers are also Clifford algebras. The alternative but nonassociative real Cayley-Dickson algebras, notably the octonions and split ...octonions, share with Clifford algebras an involutary anti-automorphism and a set of mutually anticommutative generators. On the basis of these similarities, we introduce Kingdon algebras: alternative Clifford-like algebras over vector spaces equipped with a symmetric bilinear form. Over three-dimensional vector spaces, our construction quantizes an alternative non-associative analogue of the exterior algebra. The octonions and split octonions, along with other real generalized Cayley-Dickson algebras in Albert's sense, arise as Kingdon algebras. Our construction gives natural characterizations of the octonion and split octonion algebras by a universality property endowing them with a selected superalgebra structure.
Ecosystem responses to climate change will largely be driven by responses of the dominant species. However, if co-dominant species have traits that lead them to differential responses, then ...predicting how ecosystem structure and function will be altered is more challenging. We assessed differences in response to climate change factors for the two dominant C
4 grass species in tallgrass prairie,
Andropogon gerardii and
Sorghastrum nutans, by measuring changes in a suite of plant ecophysiological traits in response to experimentally elevated air temperatures and increased precipitation variability over two growing seasons. Maximum photosynthetic rates, stomatal conductance, water-use efficiency, chlorophyll fluorescence, and leaf water potential varied with leaf and canopy temperature as well as with volumetric soil water content (0–15
cm). Both species had similar responses to imposed changes in temperature and water availability, but when differences occurred, responses by
A. gerardii were more closely linked with changes in air temperature whereas
S. nutans was more sensitive to changes in water availability. Moreover,
S. nutans was more responsive overall than
A. gerardii to climate alterations. These results indicate both grass species are responsive to forecast changes in temperature and precipitation, but their differential sensitivity to temperature and water availability suggest that future population and community structure may vary based on the magnitude and scope of an altered climate.
The Clifford algebra of a direct sum of real quadratic spaces appears as the superalgebra tensor product of the Clifford algebras of the summands. The purpose of the current paper is to present a ...purely settheoretical version of the superalgebra tensor product which will be applicable equally to groups or to their non-associative analogues - quasigroups and loops. Our work is part of a project to make supersymmetry an effective tool for the study of combinatorial structures. Starting from group and quasigroup structures on four-element supersets, our superproduct unifies the construction of the eight-element quaternion and dihedral groups, further leading to a loop structure which hybridizes the two groups. All three of these loops share the same character table.
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