494 research outputs found
The seasonal relationship between intraseasonal tropical variability and ENSO in CMIP5
The El NiñoâSouthern Oscillation (ENSO) is tightly linked to the
intraseasonal tropical variability (ITV) that contributes to energise the
deterministic ocean dynamics during the development of El Niño. Here, the
relationship between ITV and ENSO is assessed based on models from the
Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5) taking into
account the so-called diversity of ENSO, that is, the existence of two types
of events (central Pacific versus eastern Pacific El Niño). As a first
step, the models' skill in simulating ENSO diversity is assessed. The
characteristics of the ITV are then documented revealing a large dispersion
within an ensemble of 16 models. A total of 11 models exhibit some skill in
simulating the key aspects of the ITV for ENSO: the total variance along the
Equator, the seasonal cycle and the characteristics of the propagation along
the Equator of the MaddenâJulian oscillation (MJO) and the convectively
coupled equatorial Rossby (ER) waves. Five models that account realistically
for both the two types of El Niño events and ITV characteristics are used
for the further analysis of seasonal ITVâŻââŻENSO relationship. The results
indicate a large dispersion among the models and an overall limited skill in
accounting for the observed seasonal ITVâŻââŻENSO relationship.
Implications of our results are discussed in light of recent studies on the
forcing mechanism of ENSO diversity
Baking quality of winter wheat (Triticum aestivum l.) is influenced by fractionation of nitrogen fertilization
Non-Peer ReviewedNitrogen (N) fertilization is one of the most common agronomic practice to increase wheat grain yield and protein content. However, the beneficial effects of nitrogen fertilization on grain yield and quality vary significantly [1]. The objective of the study was to understand the effect of total applied N and in fractions on the wheat grain protein composition and flour functionality under western European growth conditions. A field trial with five winter wheat (Triticum aestivum L.) cultivars, fertilized with 3 N-rates (suggested, -30% and +30%) applied in 3 or 4 fractions, were studied for grain yield and kernel characteristics, whole meal and flour composition and functionality. Flour quality was analyzed by baking tests and an elaborate screening of the bread quality. A significant interaction between total N and fractionation was observed for both yield and protein content whereas protein composition (gluten index, Farinograph water absorption and Alveograph P/L) was solely influenced by the fractionation of N application. Applying N in four fractions resulted in an overall 3.7% increase in loaf volume compared to three N-fractions. Principal component analysis illustrated the major contribution of starch related properties to end-product quality of bread, and a prominent genotype-effect which was observed throughout the stud
ACRIM-gap and total solar irradiance revisited: Is there a secular trend between 1986 and 1996?
A gap in the total solar irradiance (TSI) measurements between ACRIM-1 and
ACRIM-2 led to the ongoing debate on the presence or not of a secular trend
between the minima preceding cycles 22 (in 1986) and 23 (1996). It was recently
proposed to use the SATIRE model of solar irradiance variations to bridge this
gap. When doing this, it is important to use the appropriate SATIRE-based
reconstruction, which we do here, employing a reconstruction based on
magnetograms. The accuracy of this model on months to years timescales is
significantly higher than that of a model developed for long-term
reconstructions used by the ACRIM team for such an analysis. The constructed
`mixed' ACRIM - SATIRE composite shows no increase in the TSI from 1986 to
1996, in contrast to the ACRIM TSI composite.Comment: 4 figure
Covid-19 and tracing methodologies: A lesson for the future society
As the new coronavirus (SARS-CoV-2) surged across the globe, new technical solutions have supported policy makers and health authorities to plan and modulate containment measures. The introduction of these solutions provoked a large debate which has focused on risks for privacy and data protection. In this paper we offer an analysis of the available technical approaches and provide new arguments to move beyond the ongoing discussions. In particular, we argue that the past debate missed the opportunity to highlight the societal aspects of privacy and to stimulate a broader reflection on the actions needed to serve the good of society. With this paper, as well as providing an accessible review of the technical and legal aspects of the proposed solutions, we aim to offer new stimuli to reconsider contact tracing and its role in helping countries navigate the current pandemic
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Assessment of nutritional stress in famine burials using stable isotope analysis
YesObjectives: We compared ÎŽ15N and ÎŽ13C values from bone and dentine collagen profiles of individuals interred in famineârelated and attritional burials to evaluate whether individuals in medieval London who experienced nutritional stress exhibit enriched nitrogen in bone and tooth tissue. Dentine profiles were evaluated to identify patterns that may be indicative of famine during childhood and were compared with the age of enamel hypoplasia (EH) formation to assess whether isotopic patterns of undernutrition coincide with the timing of physiological stress.
Materials and Methods: ÎŽ15N and ÎŽ13C isotope ratios of bone collagen were obtained from individuals (n =â128) interred in attritional and famine burials from a medieval London cemetery (c. 1120â1539). Temporal sequences of ÎŽ15N and ÎŽ13C isotope profiles for incrementally forming dentine collagen were obtained from a subset of these individuals (n =â21).
Results: Results indicate that individuals from attritional graves exhibit significantly higher ÎŽ15N values but no significant differences were found between burial types for the sexes. Analyses of dentine profiles reveal that a lower proportion of famine burials exhibit stable dentine profiles and that several exhibit a pattern of opposing covariance between ÎŽ15N and ÎŽ13C. EH were also observed to have formed during or after the opposing covariance pattern for some individuals.
Conclusions: The results of this study may reflect differences in diet between burial types rather than nutritional stress. Though nutritional stress could not be definitively identified using bone and dentine collagen, the results from dentine analysis support previous observations of biochemical patterns associated with nutritional stress during childhood.Division of Behavioral and Cognitive Sciences. Grant Numbers: BCSâ1261682, BCSâ1540208. Office of the Vice President for Research, University of South Carolina. Grant Number: SPARC Fellowship Gran
Extracellular dsRNA induces a type I interferon response mediated via class A scavenger receptors in a novel Chinook salmon derived spleen cell line
The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.dci.2018.08.010 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Despite increased global interest in Chinook salmon aquaculture, little is known of their viral immune defenses. This study describes the establishment and characterization of a continuous cell line derived from Chinook salmon spleen, CHSS, and its use in innate immune studies. Optimal growth was seen at 14â18 °C when grown in Leibovitz's L-15 media with 20% fetal bovine serum. DNA analyses confirmed that CHSS was Chinook salmon and genetically different from the only other available Chinook salmon cell line, CHSE-214. Unlike CHSE-214, CHSS could bind extracellular dsRNA, resulting in the rapid and robust expression of antiviral genes. Receptor/ligand blocking assays confirmed that class A scavenger receptors (SR-A) facilitated dsRNA binding and subsequent gene expression. Although both cell lines expressed three SR-A genes: SCARA3, SCARA4, and SCARA5, only CHSS appeared to have functional cell-surface SR-As for dsRNA. Collectively, CHSS is an excellent cell model to study dsRNA-mediated innate immunity in Chinook salmon.Natural Sciences and Engineering Research Council of CanadaCanada Research Counci
Reconstructed and measured total solar irradiance: Is there a secular trend between 1978 and 2003?
Total solar irradiance reconstructed between 1978 and 2003 using solar
surface magnetic field distributions is compared with three composites of total
solar irradiance measurements. A good correspondence is found with the total
solar irradiance composite from PMOD/WRC, with no bias between the three
cycles. The agreement with the other composites (the ACRIM composite, mainly
based on the Active Cavity Radiometer Irradiance Monitors I, II & III, and the
IRMB composite from the Institut Royal Meteorologique Belgique) is
significantly poorer. In particular, a secular increase in the irradiance
exhibited by these composites is not present in the reconstructions. Hence any
secular trend in total solar irradiance between 1978 and 2003 is not due to
magnetic fields at the solar surface
A review of technological innovations leading to modern endovascular brain aneurysm treatment
Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment
Stellar jitter from variable gravitational redshift: implications for RV confirmation of habitable exoplanets
A variation of gravitational redshift, arising from stellar radius
fluctuations, will introduce astrophysical noise into radial velocity
measurements by shifting the centroid of the observed spectral lines. Shifting
the centroid does not necessarily introduce line asymmetries. This is
fundamentally different from other types of stellar jitter so far identified,
which do result from line asymmetries. Furthermore, only a very small change in
stellar radius, ~0.01%, is necessary to generate a gravitational redshift
variation large enough to mask or mimic an Earth-twin. We explore possible
mechanisms for stellar radius fluctuations in low-mass stars. Convective
inhibition due to varying magnetic field strengths and the Wilson depression of
starspots are both found to induce substantial gravitational redshift
variations. Finally, we investigate a possible method for monitoring/correcting
this newly identified potential source of jitter and comment on its impact for
future exoplanet searches.Comment: 6 pages, 1 figure, 1 tabl
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