Modelling water transport and phosphorus eutrophication in an interconnected lake system : a scenario study

The water in the south-western Frisian lake district is highly eutrophicated. Summer chlorophyll-a concentrations often exceed 150 μg.l -1, while total phosphorus (TP) concentrations are mostly above 0.2 mg.l -1. Therefore, a research project was started in 1984 to study the origin and dynamics of phosphorus (P) in the area. The nutrient P was chosen because reducing TP concentrations was believed to result in favourable conditions for restoration of the aquatic ecosystem. The objective of the study was to model the TP dynamics and to use the model for the simulation of management reduction scenarios. In order to achieve this objective, three problems had to be solved. Firstly, information about the water transport, especially in the boundary canals, was poor. This problem was solved by the application of a wind driven water transport model using water levels in the boundary canals. Secondly, the lack of large-scale information about the TP loads from the surrounding polders was solved by an intensive monitoring program. Thirdly, knowledge about the distribution of TP in sediments and about TP exchange processes between water and sediments had to be assessed. The simulations with the dynamic TP mass balance model resulted in TP balances during three periods, showing that there were two main sources in the area: from the surrounding polders and from Lake IJssel. Moreover, management simulation scenarios showed that 75% TP concentration reductions in the external loads would be necessary to achieve the 0. 15 mg.l -1TP concentration standard and incidentally the 0.07 mg.l -1. target concentration

A Reduction-Preserving Completion for Proving Confluence of Non-Terminating Term Rewriting Systems

We give a method to prove confluence of term rewriting systems that contain non-terminating rewrite rules such as commutativity and associativity. Usually, confluence of term rewriting systems containing such rules is proved by treating them as equational term rewriting systems and considering E-critical pairs and/or termination modulo E. In contrast, our method is based solely on usual critical pairs and it also (partially) works even if the system is not terminating modulo E. We first present confluence criteria for term rewriting systems whose rewrite rules can be partitioned into a terminating part and a possibly non-terminating part. We then give a reduction-preserving completion procedure so that the applicability of the criteria is enhanced. In contrast to the well-known Knuth-Bendix completion procedure which preserves the equivalence relation of the system, our completion procedure preserves the reduction relation of the system, by which confluence of the original system is inferred from that of the completed system

Zeven Limburgse gemeenten stoppen met het gebruik van gif

In Limburg is de laatste decennia veel succes geboekt met het verbeteren van de waterkwaliteit. Dit is met name te danken aan een gestructureerde aanpak bij de sanering van de puntbronnen. Uit waterkwaliteitsonderzoek blijkt dat de meeste oppervlaktewateren echter (nog) niet voldoen aan de normen. Probleemstoffen in oppervlaktewater zijn onder andere chemische onkruidbestrijdingsmiddelen. Met name het gebruik van chemische middelen door de gemeenten leidt tot hoge concentraties in oppervlaktewater, omdat bij regenval de middelen direct of via de riolering afspoelen naar het oppervlaktewater. Om een impuls te geven aan het omschakelen naar een gifvrij beheer van de openbare ruimte in Limburg, hebben het Zuiveringschap Limburg, Provincie Limburg, Rijkswaterstaat directie Limburg en de gemeenten Echt-Susteren, Heerlen, Helden, Horst aan de Maas, Maastricht, Roermond, Roerdalen en Venlo gezamenlijk het initiatief genomen om de omschakeling naar gifvrije onkruidbestrijding door gemeenten nadrukkelijk onder de aandacht brengen. Dit resulteerde in 2001 in het project 'Gifvrije onkruidbestrijding Limburg'. Het vormt één van de speerpuntprojecten van het 'Gemeenschappelijk actieprogramma diffuse bronnen Limburg'. Het project is inmiddels afgerond. In dit artikel staan de belangrijkste succesfactoren, valkuilen en conclusies op een ri

Idiopathic multifocal choroiditis and punctate inner choroidopathy: an evaluation in pregnancy

Purpose: To evaluate the clinical course of idiopathic multifocal choroiditis (MFC) and punctate inner choroidopathy (PIC) and the efficacy and safety of treatment options during pregnancy. Methods: Patients with MFC or PIC and a pregnancy in 2011–2019 from two academic centres were enrolled. For the most recent pregnancy, data on best-corrected visual acuity (BCVA) before and after pregnancy, relapse rate in pregnancy and postpartum period and obstetric, maternal and neonatal outcomes were collected. Treatment regimens consisted of a wait-and-see regime and an immunosuppressive treatment regime with systemic corticosteroids and/or azathioprine, both combined with intravitreal antivascular endothelial growth factor injections when indicated. Results: Sixteen women (26 affected eyes) were included. Median Snellen BCVA was 20/19 before pregnancy and 20/18 after delivery. In seven pregnancies a wait-and-see regime and in nine pregnancies an immunosuppressive treatment regime was carried out. Fourteen intravitreal anti-VEGF injections were given in six pregnancies. The relapse rate during pregnancy was 44% and in the postpartum period 31%. Maternal/obstetrical and fetal complications occurred in 31% and 13% of the pregnancies, respectively. Fifteen healthy children were born and one pregnancy ended in a stillbirth in a patient with a complicated obstetrical history. One patient treated with azathioprine developed intrahepatic cholestasis of pregnancy (ICP). Conclusions: Among women with MFC and PIC BCVA remained stable during pregnancy despite a relapse rate of 44% in pregnancy. No major maternal, obstetric and fetal complications occurred in pregnant patients treated with systemic corticosteroids, azathioprine or intravitreal anti-VEGF injections, though one patient developed ICP while treated with azathioprine

Hot Spots and Turbulent Initial Conditions of Quark-Gluon Plasmas in Nuclear Collisions

As a result of multiple mini-jet production, initial conditions of the QCD plasma formed in ultrarelativistic nuclear collisions may be inhomogeneous, with large fluctuations of the local energy density (hot spots), and turbulent, with a chaotic initial transverse velocity field. Assuming rapid local thermalization, the evolution of such plasmas is computed using longitudinal boost-invariant 3+1-dimensional hydrodynamics. We compare the evolution in case that the speed of sound in the plasma is constant to one resulting from an equation of state involving a strong first order transition, with a minimum of the velocity of sound as a function of energy density. We find that azimuthally asymmetric fluctuations and correlations of the transverse energy flow can develop in both cases due to the initial inhomogeneities. Hot spots also enhance significantly high-transverse momenta direct photon yields. In the case with a phase transition, the hadronization surface evolves into an unusual foam-like structure. Also in that case, we find that hadronization is considerably delayed relative to the ideal gas case, just as previous studies have found for homogeneous initial conditions. The time-delay signature of a rapid cross-over transition region in the QCD equation of state (as observable via meson interferometry) is thus found to be remarkably robust to uncertainties in the initial conditions in heavy-ion reactions.Comment: 28 pages, LaTeX, 20 figures, available as uucompressed file (including LaTeX-file) ftp://nt1.phys.columbia.edu/pub/turb/turb2.uu (username: ftp, password: complete email address

Association of Risk Variants in the <i>CFH </i>Gene With Elevated Levels of Coagulation and Complement Factors in Idiopathic Multifocal Choroiditis

Importance: Idiopathic multifocal choroiditis (MFC) is poorly understood, thereby hindering optimal treatment and monitoring of patients. Objective: To identify the genes and pathways associated with idiopathic MFC. Design, Setting, and Participants: This was a case-control genome-wide association study (GWAS) and protein study of blood plasma samples conducted from March 2006 to February 2022. This was a multicenter study involving 6 Dutch universities. Participants were grouped into 2 cohorts: cohort 1 consisted of Dutch patients with idiopathic MFC and controls, and cohort 2 consisted of patients with MFC and controls. Plasma samples from patients with idiopathic MFC who had not received treatment were subjected to targeted proteomics. Idiopathic MFC was diagnosed according to the Standardization of Uveitis Nomenclature (SUN) Working Group guidelines for punctate inner choroidopathy and multifocal choroiditis with panuveitis. Data were analyzed from July 2021 to October 2022. Main outcomes and measures: Genetic variants associated with idiopathic MFC and risk variants associated with plasma protein concentrations in patients. Results: This study included a total of 4437 participants in cohort 1 (170 [3.8%] Dutch patients with idiopathic MFC and 4267 [96.2%] controls; mean [SD] age, 55 [18] years; 2443 female [55%]) and 1344 participants in cohort 2 (52 [3.9%] patients with MFC and 1292 [96.1%] controls; 737 male [55%]). The primary GWAS association mapped to the CFH gene with genome-wide significance (lead variant the A allele of rs7535263; odds ratio [OR], 0.52; 95% CI, 0.41-0.64; P = 9.3 × 10-9). There was no genome-wide significant association with classical human leukocyte antigen (HLA) alleles (lead classical allele, HLA-A*31:01; P = .002). The association with rs7535263 showed consistent direction of effect in an independent cohort of 52 cases and 1292 control samples (combined meta-analysis OR, 0.58; 95% CI, 0.38-0.77; P = 3.0 × 10-8). In proteomic analysis of 87 patients, the risk allele G of rs7535263 in the CFH gene was strongly associated with increased plasma concentrations of factor H-related (FHR) proteins (eg, FHR-2, likelihood ratio test, adjusted P = 1.1 × 10-3) and proteins involved in platelet activation and the complement cascade. Conclusions and relevance: Results suggest that CFH gene variants increase systemic concentrations of key factors of the complement and coagulation cascades, thereby conferring susceptibility to idiopathic MFC. These findings suggest that the complement and coagulation pathways may be key targets for the treatment of idiopathic MFC.</p

HPF1-dependent histone ADP-ribosylation triggers chromatin relaxation to promote the recruitment of repair factors at sites of DNA damage

Poly(ADP-ribose) polymerase 1 (PARP1) activity is regulated by its co-factor histone poly(ADP-ribosylation) factor 1 (HPF1). The complex formed by HPF1 and PARP1 catalyzes ADP-ribosylation of serine residues of proteins near DNA breaks, mainly PARP1 and histones. However, the effect of HPF1 on DNA repair regulated by PARP1 remains unclear. Here, we show that HPF1 controls prolonged histone ADP-ribosylation in the vicinity of the DNA breaks by regulating both the number and length of ADP-ribose chains. Furthermore, we demonstrate that HPF1-dependent histone ADP-ribosylation triggers the rapid unfolding of chromatin, facilitating access to DNA at sites of damage. This process promotes the assembly of both the homologous recombination and non-homologous end joining repair machineries. Altogether, our data highlight the key roles played by the PARP1/HPF1 complex in regulating ADP-ribosylation signaling as well as the conformation of damaged chromatin at early stages of the DNA damage response.Smith, Zentout et al. investigate the role of HPF1 in DNA repair using live-cell imaging methods and find that HPF1-dependent histone ADP-ribosylation drives early process in DNA repair, including chromatin relaxation and repair factor recruitment.Genome Instability and Cance

Scientific Objectives of Einstein Telescope

The advanced interferometer network will herald a new era in observational astronomy. There is a very strong science case to go beyond the advanced detector network and build detectors that operate in a frequency range from 1 Hz-10 kHz, with sensitivity a factor ten better in amplitude. Such detectors will be able to probe a range of topics in nuclear physics, astronomy, cosmology and fundamental physics, providing insights into many unsolved problems in these areas.Comment: 18 pages, 4 figures, Plenary talk given at Amaldi Meeting, July 201

Test of CPT Symmetry and Quantum Mechanics with Experimental data from CPLEAR

We use fits to recent published CPLEAR data on neutral kaon decays to $\pi^+\pi^-$ and $\pi e\nu$ to constrain the CPT--violation parameters appearing in a formulation of the neutral kaon system as an open quantum-mechanical system. The obtained upper limits of the CPT--violation parameters are approaching the range suggested by certain ideas concerning quantum gravity.Comment: 9 pages of uuencoded postscript (includes 3 figures

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)

We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 ${\rm fb}^{-1}$ recorded at the $\Upsilon(4S)$ resonance and 3.9 ${\rm fb}^{-1}$ off-resonance. One of the neutral B mesons, which are produced in pairs at the $\Upsilon(4S)$, is fully reconstructed in the CP decay modes $J/\psi K^0_S$, $\psi(2S) K^0_S$, $\chi_{c1} K^0_S$, $J/\psi K^{*0}$ ($K^{*0}\to K^0_S\pi^0$) and $J/\psi K^0_L$, or in flavor-eigenstate modes involving $D^{(*)}\pi/\rho/a_1$ and $J/\psi K^{*0}$ ($K^{*0}\to K^+\pi^-$). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample finds $\Delta m_d = 0.516\pm 0.016 {\rm (stat)} \pm 0.010 {\rm (syst)} {\rm ps}^{-1}$. The value of the asymmetry amplitude $\sin2\beta$ is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged $B^0$ decays in the CP-eigenstate modes. We find $\sin2\beta=0.59\pm 0.14 {\rm (stat)} \pm 0.05 {\rm (syst)}$, demonstrating that CP violation exists in the neutral B meson system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review