2,780 research outputs found
A Bijection between Atomic Partitions and Unsplitable Partitions
In the study of the algebra of symmetric functions in
noncommutative variables, Bergeron and Zabrocki found a free generating set
consisting of power sum symmetric functions indexed by atomic partitions. On
the other hand, Bergeron, Reutenauer, Rosas, and Zabrocki studied another free
generating set of consisting of monomial symmetric functions
indexed by unsplitable partitions. Can and Sagan raised the question of finding
a bijection between atomic partitions and unsplitable partitions. In this
paper, we provide such a bijection.Comment: 6 page
FeedBreath: Designing Complementary Treatment Wearable Biofeedback System for Teenagers with anxiety disorder
Seed physiological performance of soybeans with altered saturated fatty acid contents
Soybean (Glycine max (L.) Merr.) seeds with elevated or reduced percentages of palmitate and elevated percentages of stearate were compared with seeds of typical composition in tests for germination, seedling growth rate and leachate conductivity. In general, seeds with altered compositions did well in these physiological tests, but their vigour tended to be negatively correlated with the percentages of stearate and palmitate in various lipid classes
Stable Isotope-Resolved Metabolomics Shows Metabolic Resistance to Anti-Cancer Selenite in 3D Spheroids Versus 2D Cell Cultures
Conventional two-dimensional (2D) cell cultures are grown on rigid plastic substrates with unrealistic concentration gradients of O2, nutrients, and treatment agents. More importantly, 2D cultures lack cellâcell and cellâextracellular matrix (ECM) interactions, which are critical for regulating cell behavior and functions. There are several three-dimensional (3D) cell culture systems such as Matrigel, hydrogels, micropatterned plates, and hanging drop that overcome these drawbacks but they suffer from technical challenges including long spheroid formation times, difficult handling for high throughput assays, and/or matrix contamination for metabolic studies. Magnetic 3D bioprinting (M3DB) can circumvent these issues by utilizing nanoparticles that enable spheroid formation and growth via magnetizing cells. M3DB spheroids have been shown to emulate tissue and tumor microenvironments while exhibiting higher resistance to toxic agents than their 2D counterparts. It is, however, unclear if and how such 3D systems impact cellular metabolic networks, which may determine altered toxic responses in cells. We employed a Stable Isotope-Resolved Metabolomics (SIRM) approach with 13C6-glucose as tracer to map central metabolic networks both in 2D cells and M3DB spheroids formed from lung (A549) and pancreatic (PANC1) adenocarcinoma cells without or with an anti-cancer agent (sodium selenite). We found that the extent of 13C-label incorporation into metabolites of glycolysis, the Krebs cycle, the pentose phosphate pathway, and purine/pyrimidine nucleotide synthesis was largely comparable between 2D and M3DB culture systems for both cell lines. The exceptions were the reduced capacity for de novo synthesis of pyrimidine and sugar nucleotides in M3DB than 2D cultures of A549 and PANC1 cells as well as the presence of gluconeogenic activity in M3DB spheroids of PANC1 cells but not in the 2D counterpart. More strikingly, selenite induced much less perturbation of these pathways in the spheroids relative to the 2D counterparts in both cell lines, which is consistent with the corresponding lesser effects on morphology and growth. Thus, the increased resistance of cancer cell spheroids to selenite may be linked to the reduced capacity of selenite to perturb these metabolic pathways necessary for growth and survival
Geographic variation in poststroke depression among veterans with acute stroke
This study compared patterns of poststroke depression (PSD) detection among veterans with acute stroke in eight U.S. geographic regions. Department of Veterans Affairs (VA)
medical and pharmacy data as well as Medicare data were used. International Classification of Diseases-9th Revision depression codes and antidepressant medication dispensing were applied to define patientsâ PSD status 12 months poststroke. Logistic regression models were fit to compare VA PSD diagnosis and overall PSD detection between the regions. The use of VA medical data alone may underestimate the rate of
PSD. Geographic variation in PSD detection depended on the data used. If VA medical data alone were used, we found no significant variation. If VA medical data were used along with Medicare and VA pharmacy data, we observed a significant variation in overall PSD detection across the regions after adjusting for potential risk factors. VA clinicians and policy makers need to consider enrolleesâ use of services outside the system when conducting program evaluation. Future research on PSD among veteran patients should use VA medical data in combination with Medicare and VA pharmacy data to obtain a comprehensive understanding of patientsâ PSD
Is there evidence of changes in tropical Atlantic variability modes under AMO phases in the observational record?
The Atlantic multidecadal oscillation (AMO) is the leading mode of Atlantic sea surface temperature (SST) variability at multidecadal time scales. Previous studies have shown that the AMO could modulate El NiñoâSouthern Oscillation (ENSO) variance. However, the role played by the AMO in the tropical Atlantic variability (TAV) is still uncertain. Here, it is demonstrated that during negative AMO phases, associated with a shallower thermocline, the eastern equatorial Atlantic SST variability is enhanced by more than 150% in boreal summer. Consequently, the interannual TAV modes are modified. During negative AMO, the Atlantic Niño displays larger amplitude and a westward extension and it is preceded by a simultaneous weakening of both subtropical highs in winter and spring. In contrast, a meridional seesaw SLP pattern evolving into a zonal gradient leads the Atlantic Niño during positive AMO. The north tropical Atlantic (NTA) mode is related to a Scandinavian blocking pattern during winter and spring in negative AMO, while under positive AMO it is part of the SST tripole associated with the North Atlantic Oscillation. Interestingly, the emergence of an overlooked variability mode, here called the horseshoe (HS) pattern on account of its shape, is favored during negative AMO. This anomalous warm (cool) HS surrounding an eastern equatorial cooling (warming) is remotely forced by an ENSO phenomenon. During negative AMO, the tropicalâextratropical teleconnections are enhanced and the Walker circulation is altered. This, together with the increased equatorial SST variability, could promote the ENSO impacts on TAV. The results herein give a step forward in the better understanding of TAV, which is essential to improving its modeling, impacts, and predictability
Two-photon Lithography for 3D Magnetic Nanostructure Fabrication
Ferromagnetic materials have been utilised as recording media within data
storage devices for many decades. Confinement of the material to a two
dimensional plane is a significant bottleneck in achieving ultra-high recording
densities and this has led to the proposition of three dimensional (3D)
racetrack memories that utilise domain wall propagation along nanowires.
However, the fabrication of 3D magnetic nanostructures of complex geometry is
highly challenging and not easily achievable with standard lithography
techniques. Here, by using a combination of two-photon lithography and
electrochemical deposition, we show a new approach to construct 3D magnetic
nanostructures of complex geometry. The magnetic properties are found to be
intimately related to the 3D geometry of the structure and magnetic imaging
experiments provide evidence of domain wall pinning at a 3D nanostructured
junction
Evidence for the immobile bipolaron formation in the paramagnetic state of the magnetoresistive manganites
Recent research suggests that the charge carriers in the paramagnetic state
of the magnetoresistive manganites are small polarons. Here we report studies
of the oxygen-isotope effects on the intrinsic resistivity and thermoelectric
power in several ferromagnetic manganites. The precise measurements of these
isotope effects allow us to make a quantitative data analysis. Our results do
not support a simple small-polaron model, but rather provide compelling
evidence for the presence of small immobile bipolarons, i.e., pairs of small
polarons. Since the bipolarons in the manganites are immobile, the present
result alone appears not to give a positive support to the bipolaronic
superconductivity theory for the copper-based perovskites.Comment: 6 pages, 5 figures, monor correction
Composition and geochronology of the deep-seated xenoliths from the southeastern margin of the North China Craton.
Transcriptomic Analyses of Inner Ear Sensory Epithelia in Zebrafish
Analysis of gene expression has the potential to assist in the understanding of multiple cellular processes including proliferation, cell-fate specification, senesence, and activity in both healthy and disease states. Zebrafish model has been increasingly used to understand the process of hearing and the development of the vertebrate auditory system. Within the zebrafish inner ear, there are three otolith organs, each containing a sensory macula of hair cells. The saccular macula is primarily involved in hearing, the utricular macula is primarily involved in balance and the function of the lagenar macula is not completely understood. The goal of this study is to understand the transcriptional differences in the sensory macula associated with different otolith organs with the intention of understanding the genetic mechanisms responsible for the distinct role each organ plays in sensory perception. The sensory maculae of the saccule, utricle, and lagena were dissected out of adult Et(krt4:GFP)
zebrafish expressing green fluorescent protein in hair cells for transcriptional analysis. The total RNAs of the maculae were isolated and analyzed by RNA GeneChip microarray. Several of the differentially expressed genes are known to be involved in deafness, otolith development and balance. Gene expression among these otolith organs was very well conserved with less than 10% of genes showing differential expression. Data from this study will help to elucidate which genes are involved in hearing and balance. Furthermore, the findings of this study will assist in the development of the zebrafish model for human hearing and balance disorders. Anat Rec, 303:527-543, 2020. © 2019 American Association for Anatomy
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