5,788 research outputs found
A gain-loss framework based on ensemble flow forecasts to switch the urban drainage-wastewater system management towards energy optimization during dry periods
Precipitation is the cause of major perturbation to the flow in urban
drainage and wastewater systems. Flow forecasts, generated by coupling
rainfall predictions with a hydrologic runoff model, can potentially be used
to optimize the operation of integrated urban drainage–wastewater systems
(IUDWSs) during both wet and dry weather periods. Numerical weather prediction
(NWP) models have significantly improved in recent years, having increased their
spatial and temporal resolution. Finer resolution NWP are suitable for urban-catchment-scale applications, providing longer lead time than radar
extrapolation. However, forecasts are inevitably uncertain, and fine
resolution is especially challenging for NWP. This uncertainty is commonly
addressed in meteorology with ensemble prediction systems (EPSs). Handling
uncertainty is challenging for decision makers and hence tools are necessary
to provide insight on ensemble forecast usage and to support the rationality
of decisions (i.e. forecasts are uncertain and therefore errors will be made;
decision makers need tools to justify their choices, demonstrating that these
choices are beneficial in the long run).
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This study presents an economic framework to support the decision-making
process by providing information on when acting on the forecast is
beneficial and how to handle the EPS. The relative economic value (REV)
approach associates economic values with the potential outcomes and determines
the preferential use of the EPS forecast. The envelope curve of the REV diagram
combines the results from each probability forecast to provide the highest
relative economic value for a given gain–loss ratio. This approach is
traditionally used at larger scales to assess mitigation measures for
adverse events (i.e. the actions are taken when events are forecast). The
specificity of this study is to optimize the energy consumption in IUDWS
during low-flow periods by exploiting the electrical smart grid market (i.e.
the actions are taken when no events are forecast). Furthermore, the results
demonstrate the benefit of NWP neighbourhood post-processing methods to
enhance the forecast skill and increase the range of beneficial uses
Sex-Specific Effect of Serum Lipids and Body Mass Index on Psychotic Symptoms, a Cross-Sectional Study of First-Episode Psychosis Patients
Background: Schizophrenia is a disorder with considerable heterogeneity in course and outcomes, which is in part related to the patients' sex. Studies report a link between serum lipids, body mass index (BMI), and therapeutic response. However, the role of sex in these relationships is poorly understood. In a cross-sectional sample of first-episode psychosis (FEP) patients, we investigated if the relationship between serum lipid levels (total cholesterol, HDL-C, LDL-C, and triglycerides), BMI, and symptoms differs between the sexes. Methods: We included 435 FEP patients (males: N = 283, 65%) from the ongoing Thematically Organized Psychosis (TOP) study. Data on clinical status, antipsychotics, lifestyle, serum lipid levels, and BMI were obtained. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS) were used to assess psychotic and depressive symptoms. General linear models were employed to examine the relationship between metabolic variables and symptomatology. Results: We observed a female-specific association between serum HDL-C levels and negative symptoms (B = −2.24, p = 0.03) and between triglycerides levels (B = 1.48, p = 0.04) and BMI (B = 0.27, p = 0.001) with depressive symptoms. When controlling for BMI, only the association between serum HDL-C levels and negative symptoms remained significant. Moreover, the HDL-C and BMI associations remained significant after controlling for demography, lifestyle, and illness-related factors. Conclusion: We found a relationship between metabolic factors and psychiatric symptoms in FEP patients that was sex-dependent.publishedVersio
Cosmological mass limits on neutrinos, axions, and other light particles
The small-scale power spectrum of the cosmological matter distribution
together with other cosmological data provides a sensitive measure of the hot
dark matter fraction, leading to restrictive neutrino mass limits. We extend
this argument to generic cases of low-mass thermal relics. We vary the cosmic
epoch of thermal decoupling, the radiation content of the universe, and the new
particle's spin degrees of freedom. Our treatment covers various scenarios of
active plus sterile neutrinos or axion-like particles. For three degenerate
massive neutrinos, we reproduce the well-known limit of m_nu < 0.34 eV. In a
3+1 scenario of 3 massless and 1 fully thermalized sterile neutrino we find
m_nu < 1.0 eV. Thermally produced QCD axions must obey m_a < 3.0 eV,
superseding limits from a direct telescope search, but leaving room for solar
eV-mass axions to be discovered by the CAST experiment.Comment: 15 pages, 6 figures, matches version in JCA
What it takes to measure a fundamental difference between dark matter and baryons: the halo velocity anisotropy
Numerous ongoing experiments aim at detecting WIMP dark matter particles from
the galactic halo directly through WIMP-nucleon interactions. Once such a
detection is established a confirmation of the galactic origin of the signal is
needed. This requires a direction-sensitive detector. We show that such a
detector can measure the velocity anisotropy beta of the galactic halo.
Cosmological N-body simulations predict the dark matter anisotropy to be
nonzero, beta~0.2. Baryonic matter has beta=0 and therefore a detection of a
nonzero beta would be strong proof of the fundamental difference between dark
and baryonic matter. We estimate the sensitivity for various detector
configurations using Monte Carlo methods and we show that the strongest signal
is found in the relatively few high recoil energy events. Measuring beta to the
precision of ~0.03 will require detecting more than 10^4 WIMP events with
nuclear recoil energies greater than 100 keV for a WIMP mass of 100 GeV and a
32S target. This number corresponds to ~10^6 events at all energies. We discuss
variations with respect to input parameters and we show that our method is
robust to the presence of backgrounds and discuss the possible improved
sensitivity for an energy-sensitive detector.Comment: 15 pages, 8 figures, accepted by JCAP. Matches accepted versio
Non-steroidal CYP17A1 Inhibitors: Discovery and Assessment.
CYP17A1 is an enzyme that plays a major role in steroidogenesis and is critically involved in the biosynthesis of steroid hormones. Therefore, it remains an attractive target in several serious hormone-dependent cancer diseases, such as prostate cancer and breast cancer. The medicinal chemistry community has been committed to the discovery and development of CYP17A1 inhibitors for many years, particularly for the treatment of castration-resistant prostate cancer. The current Perspective reflects upon the discovery and evaluation of non-steroidal CYP17A1 inhibitors from a medicinal chemistry angle. Emphasis is placed on the structural aspects of the target, key learnings from the presented chemotypes, and design guidelines for future inhibitors
Spatio-temporal patterns in a mechanical model for mesenchymal morphogenesis
We present an in-depth study of spatio-temporal patterns in a simplified version of a mechanical model for pattern formation in mesenchymal morphogenesis. We briefly motivate the derivation of the model and show how to choose realistic boundary conditions to make the system well-posed. We firstly consider one-dimensional patterns and carry out a nonlinear perturbation analysis for the case where the uniform steady state is linearly unstable to a single mode. In two-dimensions, we show that if the displacement field in the model is represented as a sum of orthogonal parts, then the model can be decomposed into two sub-models, only one of which is capable of generating pattern. We thus focus on this particular sub-model. We present a nonlinear analysis of spatio-temporal patterns exhibited by the sub-model on a square domain and discuss mode interaction. Our analysis shows that when a two-dimensional mode number admits two or more degenerate mode pairs, the solution of the full nonlinear system of partial differential equations is a mixed mode solution in which all the degenerate mode pairs are represented in a frequency locked oscillation
The last bastion? X-chromosome genotyping of Anopheles gambiae species-pair males from a hybrid zone reveals complex recombination within the major candidate ‘genomic island of speciation’
Speciation with gene flow may be aided by reduced recombination helping to build linkage between genes involved in the early stages of reproductive isolation. Reduced recombination on chromosome-X has been implicated in speciation within the Anopheles gambiae complex, species of which represent the major Afrotropical malaria vectors. The most recently diverged, morphologically-indistinguishable, species-pair, An. gambiae and An. coluzzii, ubiquitously display a ‘genomic island of divergence’ spanning over 4Mb from chromosome-X centromere, which represents a particularly promising candidate region for reproductive isolation genes, in addition to containing the diagnostic markers used to distinguish the species. Very low recombination makes the island intractable for experimental recombination studies, but an extreme hybrid zone in Guinea Bissau offers the opportunity for natural investigation of X-island recombination. SNP-analysis of chromosome-X hemizygous males revealed: (i) strong divergence in the X-island despite a lack of autosomal divergence; (ii) individuals with multiple-recombinant genotypes, including likely double crossovers and localized gene conversion; (iii) recombination-driven discontinuity both within and between the molecular species markers, suggesting that the utility of the diagnostics is undermined under high hybridization. The largely-, but incompletely-protected nature of the X-centromeric genomic island is consistent with a primary candidate area for accumulation of adaptive variants driving speciation with gene flow, whilst permitting some selective shuffling and removal of genetic variation
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