1,117 research outputs found
Gender based prescriptions: evidence for altruism
This paper analyzes the way in which men and women are expected to behave differently in an experimental situation. To do so, we concentrate on a single topic: altruism. Since the dictator game provides the most suitable design for studying altruism and generosity in the lab setting, we use a modified version to study the beliefs involved in the game. Our results are substantial: men and women are expected to behave differently and both believe that women are more generous. These two premises affect their behavior.prescriptions, dictator game, beliefs, generosity, gender
Solar cycle variations of large frequency separations of acoustic modes: Implications for asteroseismology
We have studied solar cycle changes in the large frequency separations that
can be observed in Birmingham Solar Oscillations Network (BiSON) data. The
large frequency separation is often one of the first outputs from asteroseismic
studies because it can help constrain stellar properties like mass and radius.
We have used three methods for estimating the large separations: use of
individual p-mode frequencies, computation of the autocorrelation of
frequency-power spectra, and computation of the power spectrum of the power
spectrum. The values of the large separations obtained by the different methods
are offset from each other and have differing sensitivities to the realization
noise. A simple model was used to predict solar cycle variations in the large
separations, indicating that the variations are due to the well-known solar
cycle changes to mode frequency. However, this model is only valid over a
restricted frequency range. We discuss the implications of these results for
asteroseismology.Comment: 9 pages, 11 figures, accepted for publication in MNRAS, references
updated, corrections following proof
Anticancer Activities of Meroterpenoids Isolated from the Brown Alga Cystoseira usneoides against the Human Colon Cancer Cells HT-29
Colorectal cancer (CRC) is one of the most common types of cancers and a leading cause of cancer death worldwide. The current treatment for CRC mainly involves surgery, radiotherapy, and chemotherapy. However, due to the side effects and the emergence of drug resistance, the search for new anticancer agents, pharmacologically safe and effective, is needed. In the present study, we have investigated the anticancer effects of eight algal meroterpenoids (AMTs, 1-8) isolated from the brown seaweed Cystoseira usneoides and their underlying mechanisms of action using HT-29, a highly metastatic human colon cancer cell line. All the tested meroterpenoids inhibited the growth of HT-29 malignant cells and were less toxic towards non-cancer colon cells, with the AMTs 1 and 5 exhibiting selectivity indexes of 5.26 and 5.23, respectively. Treatment of HT-29 cells with the AMTs 1, 2, 3, 4, 5, and 7 induced cell cycle arrest in G2/M phase and, in some instances, apoptosis (compounds 2, 3, and 5). Compounds 1-8 also exhibited significant inhibitory effects on the migration and/or invasion of colon cancer cells. Mechanistic analysis demonstrated that the AMTs 1, 2, 5, 6, 7, and 8 reduced phosphorylation levels of extracellular signal-regulated kinase (ERK) and the AMTs 2, 3, 4, 5, 7, and 8 decreased phosphorylation of c-JUN N-terminal kinase (JNK). Moreover, the AMTs 1, 2, 3, 4, 7, and 8 inhibited phosphorylation levels of protein kinase B (AKT) in colon carcinoma cells. These results provide new insights into the mechanisms and functions of the meroterpenoids of C. usneoides, which exhibit an anticancer effect on HT-29 colon cancer cells by inducing cell cycle arrest and apoptosis via the downregulation of ERK/JNK/AKT signaling pathways
Quasi-Biennial variations in helioseismic frequencies: Can the source of the variation be localized?
We investigate the spherical harmonic degree (l) dependence of the "seismic"
quasi-biennial oscillation (QBO) observed in low-degree solar p-mode
frequencies, using Sun-as-a-star Birmingham Solar Oscillations Network (BiSON)
data. The amplitude of the seismic QBO is modulated by the 11-yr solar cycle,
with the amplitude of the signal being largest at solar maximum. The amplitude
of the signal is noticeably larger for the l=2 and 3 modes than for the l=0 and
1 modes. The seismic QBO shows some frequency dependence but this dependence is
not as strong as observed in the 11-yr solar cycle. These results are
consistent with the seismic QBO having its origins in shallow layers of the
interior (one possibility being the bottom of the shear layer extending 5per
cent below the solar surface). Under this scenario the magnetic flux
responsible for the seismic QBO is brought to the surface (where its influence
on the p modes is stronger) by buoyant flux from the 11-yr cycle, the strong
component of which is observed at predominantly low-latitudes. As the l=2 and 3
modes are much more sensitive to equatorial latitudes than the l=0 and 1 modes
the influence of the 11-yr cycle on the seismic QBO is more visible in l=2 and
3 mode frequencies. Our results imply that close to solar maximum the main
influence of the seismic QBO occurs at low latitudes (<45 degrees), which is
where the strong component of the 11-yr solar cycle resides. To isolate the
latitudinal dependence of the seismic QBO from the 11-yr solar cycle we must
consider epochs when the 11-yr solar cycle is weak. However, away from solar
maximum, the amplitude of the seismic QBO is weak making the latitudinal
dependence hard to constrain.Comment: 10 pages, 6 figures, accepted for publication in MNRA
Role of Nitrate Reductase in NO Production in Photosynthetic Eukaryotes
Nitric oxide is a gaseous secondary messenger that is critical for proper cell signaling and plant survival when exposed to stress. Nitric oxide (NO) synthesis in plants, under standard phototrophic oxygenic conditions, has long been a very controversial issue. A few algal strains contain NO synthase (NOS), which appears to be absent in all other algae and land plants. The experimental data have led to the hypothesis that molybdoenzyme nitrate reductase (NR) is the main enzyme responsible for NO production in most plants. Recently, NR was found to be a necessary partner in a dual system that also includes another molybdoenzyme, which was renamed NO-forming nitrite reductase (NOFNiR). This enzyme produces NO independently of the molybdenum center of NR and depends on the NR electron transport chain from NAD(P)H to heme. Under the circumstances in which NR is not present or active, the existence of another NO-forming system that is similar to the NOS system would account for NO production and NO effects. PII protein, which senses and integrates the signals of the CâN balance in the cell, likely has an important role in organizing cell responses. Here, we critically analyze these topics
Systematic identification of phenotypically enriched loci using a patient network of genomic disorders
Background
Network medicine is a promising new discipline that combines systems biology approaches and network science to understand the complexity of pathological phenotypes. Given the growing availability of personalized genomic and phenotypic profiles, network models offer a robust integrative framework for the analysis of "omics" data, allowing the characterization of the molecular aetiology of pathological processes underpinning genetic diseases.
Methods
Here we make use of patient genomic data to exploit different network-based analyses to study genetic and phenotypic relationships between individuals. For this method, we analyzed a dataset of structural variants and phenotypes for 6,564 patients from the DECIPHER database, which encompasses one of the most comprehensive collections of pathogenic Copy Number Variations (CNVs) and their associated ontology-controlled phenotypes. We developed a computational strategy that identifies clusters of patients in a synthetic patient network according to their genetic overlap and phenotype enrichments.
Results
Many of these clusters of patients represent new genotype-phenotype associations, suggesting the identification of newly discovered phenotypically enriched loci (indicative of potential novel syndromes) that are currently absent from reference genomic disorder databases such as ClinVar, OMIM or DECIPHER itself.
Conclusions
We provide a high-resolution map of pathogenic phenotypes associated with their respective significant genomic regions and a new powerful tool for diagnosis of currently uncharacterized mutations leading to deleterious phenotypes and syndromes
Effect of antimony content on electrical and structural properties of 0.98(K0.48Na0.52)0.95Li0.05Nb1âSb O3â0.02Ba0.5(Bi0.5Na0.5)0.5ZrO3 ceramics
Lead-free 0.98(K0.48Na0.52)0.95Li0.05Nb1âxSbxO3â0.02Ba0.5(Bi0.5Na0.5)0.5ZrO3 (KNLNSxâBBNZ)solid solution with 0.04 < x < 0.08 was prepared by traditional solid-state process. Sampleswere sintered using a conventional method at 1120 âŠC for 4h. The effect of Sb5+ content onthe phase structure, microstructure, ferroelectric, dielectric and piezoelectric properties ofthe KNLNSxâBBNZ ceramics was studied. The phase transition of the ceramic was determined by the temperature dependence of the dielectric properties, while the structuralproperties, like the phase coexistence, were studied by X-ray diffraction. It was found thatceramics in the composition range of 0.06 < x < 0.08 possess an orthorhombic (Amm2) andtetragonal (P4mm) phases coexistence. The best piezoelectric properties were obtained inthe ceramics with x = 0.07: d33 = 282 pC/N, âd31 = 103 pC/N, kp = 46%, Δr = 1820, tanı = 3% andTc = 271 âŠC. Furthermore, this composition exhibited a good thermal stability, up to 200 âŠC ond33 piezoelectric constant, indicating that this material have great potential for applicationfrom room temperature until this temperature limit
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