This study compared the indirect water-deprivation test with direct detection of plasma copeptin, a precursor of arginine vasopressin, in patients with hypotonic polyuria. Direct measurement of ...hypertonic saline–stimulated plasma copeptin had higher diagnostic accuracy.
FREYA (Fission Reaction Event Yield Algorithm) is a fission event generator which models complete fission events. As such, it automatically includes fluctuations as well as correlations between ...observables, resulting from conservation of energy and momentum. The purpose of this paper is to present the main differences between FREYA versions 1.0 and 2.0.2 : additional fissionable isotopes, angular momentum conservation, Giant Dipole Resonance form factor for the statistical emission of photons, improved treatment of fission photon emission using RIPL database, and dependence on the incident neutron direction. FREYA 2.0.2 has been integrated into the LLNL Fission Library 2.0.2, which has itself been integrated into MCNP6.2, TRIPOLI-4.10, and can be called from Geant4.10.
Program title:FREYA 2.0.2
Program Files doi: ” http://dx.doi.org/10.17632/2mssy7r3gt.1”
Licensing provisions: BSD 3-clause
Programming language: Fortran 90, C++
Journal Reference of previous version: J. M Verbeke, J. Randrup, R. Vogt, “Fission Reaction Yield Algorithm FREYA for Event-by-Event Simulation of Fission,” Comp. Phys. Comm. 191, pp. 178–202; doi:10.1016/j.cpc.2015.02.002 (2015).
Does the new version supersede the previous version? Yes.
Reasons for the new version: New physics and more fissionable isotopes.
Summary of revisions: Additional fissionable isotopes, angular momentum conservation, Giant Dipole Resonance form factor for the statistical emission of photons, improved treatment of fission photon emission using RIPL database, and dependence on the incident neutron direction.
Nature of problem: Modeling of fission events.
Solution method: Simulation of complete fission events, production of secondary fission fragments, fission neutrons and photons.
Restrictions: Restricted to spontaneous fission of 238U, 238Pu, 240Pu, 242Pu, 244Cm, 252Cf; neutron-induced fission of 233U, 235U, 238U, 239Pu, 241Pu, for incident neutron energies less than 20 MeV.
In recent years, the
J/
ψ signal in heavy-ion collisions at the CERN SPS has attracted much attention as a potential quark–gluon plasma signature. This review discusses the prediction of
J/
ψ ...suppression and the systematics of this signature as a function of the transverse energy of the collision and the transverse momentum of the
J/
ψ. Since
J/
ψ suppression was already present in hadron–nucleus interactions, hadronic models of absorption by nucleons and scattering with comoving secondaries soon emerged. After a discussion of
J/
ψ and other related production data in
pp,
pA
, and
AB interactions, hadronic suppression models are introduced and compared with the CERN SPS data. Plasma model predictions are also given for CERN SPS collisions as well as for the future RHIC and LHC heavy-ion colliders.
Turbulence characteristics in the urban boundary layer of a mid-latitude European city are investigated using a quadrant analysis of more than 12 years of eddy-covariance measurements at 39 m above ...street level. To describe the ongoing turbulent-exchange processes, particularly the properties of ejection and sweep events, presented here are the transfer efficiency and the similarity of momentum, heat, CO
2
and H
2
O fluxes. In addition, an event-detection algorithm is applied to derive information on the importance of organized structures for the turbulent exchange, finding that momentum and heat fluxes are primarily controlled by atmospheric stability, whereas CO
2
and H
2
O fluxes are more affected by the presence of active sources of the corresponding scalars (e.g. traffic for CO
2
fluxes). The transfer efficiencies of momentum and heat can thus be modelled accurately, but the prediction for CO
2
and H
2
O fluxes fails because of scalar dissimilarity. Generally, ejections are more important under buoyancy-driven unstable conditions and responsible for large structures, and sweeps are more characteristic of stable cases and smaller structures. The quadrant statistics enable the identification of scales between a hole-size factor of 10 and 20 where turbulent exchange is especially efficient and almost solely takes place by ejection–sweep cycles. This information is used to apply an event-detection algorithm, which quantifies flux fractions of such reoccurring structures to be around 0.5–0.8, with the time fraction being usually around 0.1.
Aquatic ecosystems are subject to multiple interacting stressors that obscure regulatory mechanisms and reduce the effectiveness of management strategies. Here we estimate the unique and interactive ...effects of continental climate systems, regional meteorology, river hydrology, and internal lake characteristics on patterns of landscape-scale water quality in six productive lakes within a 52 000 km
2
catchment. We quantify variation in mean summer and monthly algal abundance, surface bloom intensity, water clarity, and density of potentially toxic cyanobacteria during 16 years on the Canadian Prairies. Internal lake characteristics best predicted overall water quality change, while climate systems, regional weather, and river hydrology characterized indirect pathways that influenced physicochemical environments. Scenario analysis of future environmental change predicted that atmospheric warming (3–5 °C) will have the strongest effect on water quality in these productive lakes, but unexpectedly predicted that even severe industrial water extraction (1% of inflow) will have negligible effects on transparency or algal abundance. Instead, nutrient management represents the only practical means to sustain water quality, although atmospheric and lake warming may override re-oligotrophication of eutrophied sites in future decades.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
1. Plant growth is a fundamental ecological process, integrating across scales from physiology to community dynamics and ecosystem properties. Recent improvements in plant growth modelling ...have allowed deeper understanding and more accurate predictions for a wide range of ecological issues, including competition among plants, plant–herbivore interactions and ecosystem functioning.
2. One challenge in modelling plant growth is that, for a variety of reasons, relative growth rate (RGR) almost universally decreases with increasing size, although traditional calculations assume that RGR is constant. Nonlinear growth models are flexible enough to account for varying growth rates.
3. We demonstrate a variety of nonlinear models that are appropriate for modelling plant growth and, for each, show how to calculate function‐derived growth rates, which allow unbiased comparisons among species at a common time or size. We show how to propagate uncertainty in estimated parameters to express uncertainty in growth rates. Fitting nonlinear models can be challenging, so we present extensive worked examples and practical recommendations, all implemented in R.
4. The use of nonlinear models coupled with function‐derived growth rates can facilitate the testing of novel hypotheses in population and community ecology. For example, the use of such techniques has allowed better understanding of the components of RGR, the costs of rapid growth and the linkage between host and parasite growth rates. We hope this contribution will demystify nonlinear modelling and persuade more ecologists to use these techniques.
Aim/hypothesis
Glucocorticoid hormones (GCs) are widely used to treat a variety of inflammatory and immune diseases. However, their long-term administration is associated with adverse metabolic ...effects, including glucose intolerance and diabetes. Our objective was to elucidate the mechanisms by which GCs affect beta cell survival with a specific emphasis on the role of the thioredoxin-interacting protein (TXNIP) in beta cell apoptosis.
Methods
Human and mouse islets, together with MIN6 beta cells, were exposed to dexamethasone (Dex) and apoptosis was assessed by measuring the percentage of sub-G1 cells, the appearance of cleaved caspase-3 or by using a TUNEL assay. Dex-upregulated expression of
Txnip
mRNA was analysed by real-time PCR, and GC-modulated production and modification of proteins were determined by western blotting.
Results
We provide evidence that TXNIP, a negative regulator of the antioxidant thioredoxin (TRX), is strongly induced in beta cells by GCs and that its induction is dependent on p38 mitogen-activated protein kinase (MAPK) activation. TXNIP downregulation by RNA interference, overexpression of the radical scavenger TRX1 or elevation of intracellular cAMP levels attenuated the Dex-mediated apoptosis. Dex-induced
Txnip
expression and beta cell apoptosis are mediated by the glucocorticoid receptor (GR), as the GR antagonist RU486 fully abolishes these effects.
Conclusions/interpretation
Altogether, our data suggest TXNIP as a novel mediator of GC-induced apoptosis in beta cells and further contribute to our understanding of beta cell death pathways.
Incidence rates of de novo aneurysm formation and recurrence after clip ligation remain controversial. In this meta-analysis, the authors provide data on pooled annual incidence rates and the ...association of patient characteristics with time to formation of de novo aneurysms and time to recurrence after clipping.
A search of the literature up to June 15, 2016, on PubMed and a systematic review were performed. The association of age, aneurysm rupture status, aneurysm multiplicity, and anatomical location with time to recurrence or formation of de novo aneurysm was estimated using multivariable Cox proportional-hazards models. Kaplan-Meier estimates (event-free survival curves) are shown. Pooled annualized incidence rates of recurrent and de novo aneurysms were estimated using Poisson regression. Proportions of aneurysms and average follow-up times are displayed as bubble plots with LOESS smoothers weighted for study size.
Of the 7606 articles screened, 92 were included in the study. Case reports on 101 patients with recurrent aneurysms and 132 patients with de novo aneurysms were analyzed. Long-term follow-up studies on de novo aneurysm formation included 13,723 patients with 101,378 patient-years of follow-up; studies on aneurysm recurrence included 5922 patients with 31,055 patient-years of follow-up. Mean time to recurrence was 12.9 ± 6.6 years (mean ± standard deviation), and mean time to de novo formation was 9.3 ± 6.1 years. No association with sex, aneurysm location, and initial rupture could be shown. De novo aneurysms occurred later in patients with multiplicity of aneurysms at diagnosis (HR 0.63, p = 0.03) and in patients with increasing age (HR per 10 yrs 0.88, p = 0.06). Pooled annualized incidence rates were 0.35% for de novo aneurysms and 0.13% for recurrent aneurysms.
Despite low reported annual incidence rates, the cumulative risk of 9.6%-22% for aneurysm recurrence or de novo formation 20 years after clip ligation warrants lifelong follow-up. Screening at 5, 10, and 20 years would detect 30.8% (95% CI 23.3%-37.6%), 64.2% (95% CI 55.9%-70.9%), and 95.9% (95% CI 90.9%-97.9%) of de novo aneurysms. Screening for recurrent aneurysms at 10, 15, and 20 years would detect 36.6% (95% CI 26.5%-45.4%), 65.3% (95% CI 54.7%-73.5%), and 95.1% (95% CI 85.8%-96.6%) of lesions.
The total charm cross section Vogt, R.
The European physical journal. ST, Special topics,
03/2008, Letnik:
155, Številka:
1
Journal Article
Recenzirano
Odprti dostop
.
We assess the theoretical uncertainties on the total charm cross section. We discuss the importance of the quark mass, the scale choice and the parton densities on the estimate of the uncertainty. ...We conclude that due to the small charm quark mass, which amplifies the effect of varying the other parameters in the calculation, the uncertainty on the total charm cross section is difficult to quantify.
Femtosecond transient absorption experiments and density functional calculations are presented for 2-methyl-1-nitronaphthalene, 2-nitronaphthalene, and 1-nitronaphthalene in cyclohexane and ...acetonitrile solutions. Excitation of 2-methyl-1-nitronaphthalene at 340 nm populates the Franck–Condon singlet state, which bifurcates into two barrierless decay channels with sub-200-fs lifetimes. The primary decay channel connects the Franck–Condon singlet excited state with a receiver triplet state, whereas the second, minor channel involves conformational relaxation to populate an intramolecular charge-transfer state, as previously reported for 1-nitronaphthalene ( J. Chem. Phys. 2009, 113, 224518 ). Conversely, the experimental and computational data for 2-nitronaphthalene shows that almost the entire Franck–Condon singlet excited-state population intersystem crosses to the triplet state in less than 200 fs due to a sizable energy barrier of ca. 5 kcal/mol that must be surmounted to access the intramolecular charge-transfer state. Our results lend support to the idea that the probability of population transfer to the triplet manifold in these nitronaphthalene derivatives is controlled not only by the small energy gap between the Franck–Condon singlet excited state and the receiver triplet state but also by the region of configuration space sampled in the singlet excited-state potential energy surface at the time of excitation. It is proposed that the ultrafast intersystem crossing dynamics in these nitronaphthalene molecules most likely occurs between nonequilibrated excited states in the strongly nonadiabatic regime.
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