Modelling water temperature in TOXSWA

A reasonably accurate estimate of the water temperature is necessary for a good description of the degradation of plant protection products in water which is used in the surface water model TOXSWA. Based on a consideration of basic physical processes that describe the influence of weather on the energy balance of natural water bodies, we propose to extend TOXSWA with a 1D bulk approach to estimate water temperature. Evaluation of such a system confirmed that it is physically realistic and yet simple, with limited data requirements. It is expected to perform reasonably well in most conditions, and fits well into the present structure of the TOXSWA model. In particular the estimation of degradation rates in shallow and turbid water will benefit from introducing the proposed system

Emissions of N2O from fertilized and grazed grassland on organic soil in relation to groundwater level

Intensively managed grasslands on organic soils are a major source of nitrous oxide (N2O) emissions. The Intergovernmental Panel on Climate Change (IPCC) therefore has set the default emission factor at 8 kg N–N2O ha-1 year-1 for cultivation and management of organic soils. Also, the Dutch national reporting methodology for greenhouse gases uses a relatively high calculated emission factor of 4.7 kg N–N2O ha-1 year-1. In addition to cultivation, the IPCC methodology and the Dutch national methodology account for N2O emissions from N inputs through fertilizer applications and animal urine and faeces deposition to estimate annual N2O emissions from cultivated and managed organic soils. However, neither approach accounts for other soil parameters that might control N2O emissions such as groundwater level. In this paper we report on the relations between N2O emissions, N inputs and groundwater level dynamics for a fertilized and grazed grassland on drained peat soil. We measured N2O emissions from fields with different target groundwater levels of 40 cm (‘wet’) and 55 cm (‘dry’) below soil surface in the years 1992, 1993, 2002, 2006 and 2007. Average emissions equalled 29.5 kg N2O–N ha-1 year-1 and 11.6 kg N–N2O ha-1 year-1 for the dry and wet conditions, respectively. Especially under dry conditions, measured N2O emissions exceeded current official estimates using the IPCC methodology and the Dutch national reporting methodology. The N2O–N emissions equalled 8.2 and 3.2% of the total N inputs through fertilizers, manure and cattle droppings for the dry and wet field, respectively and were strongly related to average groundwater level (R 2 = 0.74). We argue that this relation should be explored for other sites and could be used to derive accurate emission data for fertilized and grazed grasslands on organic soil

Live imaging of DORNRÖSCHEN and DORNRÖSCHEN-LIKE promoter activity reveals dynamic changes in cell identity at the microcallus surface of Arabidopsis embryonic suspensions

Key message Transgenic DRN::erGFP and DRNL::erGFP reporters access the window from explanting Arabidopsis embryos to callus formation and provide evidence for the acquisition of shoot meristem cell fates at the microcalli surface. Abstract The DORNRÖSCHEN (DRN) and DORNRÖSCHEN-LIKE (DRNL) genes encode AP2-type transcription factors, which are activated shortly after fertilisation in the zygotic Arabidopsis embryo. We have monitored established transgenic DRN::erGFP and DRNL::erGFP reporter lines using live imaging, for expression in embryonic suspension cultures and our data show that transgenic fluorophore markers are suitable to resolve dynamic changes of cellular identity at the surface of microcalli and enable fluorescence-activated cell sorting. Although DRN::erGFP and DRNL::erGFP are both activated in surface cells, their promoter activity marks different cell identities based on real-time PCR experiments and whole transcriptome microarray data. These transcriptome analyses provide no evidence for the maintenance of embryogenic identity under callus-inducing high-auxin tissue culture conditions but are compatible with the acquisition of shoot meristem cell fates at the surface of suspension calli

Lockin to Weak Ferromagnetism in TbNi2B2C and ErNi2B2C

This article describes a model in which ferromagnetism necessarily accompanies a spin-density-wave lockin transition in the borocarbide structure provided the commensurate phase wave vector satisfies Q = (m/n)a* with m even and n odd. The results account for the magnetic properties of TbNi2B2C, and are also possibly relevant also for those of ErNi2B2C.Comment: 4 page

Wideband 0.5-50 GHz double-ridged guide horn antenna using coaxial-to-ridge waveguide launcher

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request.Ever-increasing bandwidth requirements from various industries drive the need for the ever-increasing bandwidth of antennas used for testing. Broadband Double-Ridged Guide Horn (DRGH) antennas are used extensively in antenna measurement and ElectroMagnetic Compatibility/Interference (EMC/I) testing. The current state-of-the-art broadband DRGH antennas reported in the literature for use in measurement applications cover bandwidth ratios as large as 36:1 (0.5–18 GHz). This paper presents the design and realisation of a DRGH antenna with a 100:1 bandwidth ratio (0.5–50 GHz). To achieve such a wide bandwidth, the ridge gap, width and feed were optimised, and a novel coaxial-to-ridge waveguide launcher section based on a typical Vivaldi antenna was developed. Backward radiation was reduced using an absorber-filled cavity. A prototype DRGH antenna was manufactured using additive manufacturing, also referred to as 3D printing. Simulated and measured results obtained in an anechoic chamber are presented.Saab Grintek Defence.https://ietresearch.onlinelibrary.wiley.com/journal/17518733hj2024Electrical, Electronic and Computer EngineeringSDG-09: Industry, innovation and infrastructur

Alendroninezuur effectiever dan alfacalcidol voor preventie van osteoporose bij patiënten met een reumatische ziekte die starten met glucocorticoïdtherapie

OBJECTIVE: To compare the effects of alendronate and alfacalcidol in the prevention ofglucocorticoid-related osteoporosis in patients with a rheumatic disease. DESIGN: Randomised, double-blind, double-placebo clinical trial (www. clinicaltrials.gov; number: NCT00138983). METHODS: A total of 201 patients with rheumatic disease who were starting glucocorticoid treatment at a daily dose that was equivalent to at least 7.5 mg of prednisone were randomised to alendronate (10 mg) and a placebo capsule ofalfacalcidol daily (n = 100) or alfacalcidol (1 microg) and a placebo tablet ofalendronate daily (n = 101) for 18 months. Primary outcome was change in lumbar spine bone mineral density at 18 months. The main secondary outcome was the incidence of morphometrically confirmed vertebral deformities. RESULTS: Overall, 163 patients completed the study. The bone mineral density of the lumbar spine increased by 2.1% (95% CI: 1.1-3.1) in the alendronate group and decreased by 1.9% (95% CI: -3.I--0.7) in the alfacalcidol group. At 18 months the mean difference in change in bone mineral density between the two groups was 4.0% (95% CI: 2.4-5-5). Three patients in the alendronate group had a new vertebral deformity, compared with 8 patients in the alfacalcidol group, including 5 symptomatic vertebral fractures in 3 patients; the hazard ratio was 0.4 (95% CI: 0.1-1.4). CONCLUSION: Alendronate was more effective than alfacalcidol in preventing glucocorticoid-induced bone loss during this 18-month trial in patients with rheumatic diseases who were starting glucocorticoid treatment

Influence of applying different units of measurement on reporting antimicrobial consumption data for pig farms

Background: Antimicrobial use in livestock is one of the factors contributing to selection and spread of resistant microorganisms in the environment. National ve

Elliptically shaped quad-ridge horn antennas as feed for a reflector

Quad-ridge horn antennas of various geometries are considered as possible candidates for a wideband reflector antenna feed. It is demonstrated that shaping the sidewalls of the ridge horns significantly improves the radiation characteristics of the horns. The conical quad-ridge horn with an elliptically shaped sidewall shows the most promise as a wideband reflector antenna feed. The radiation patterns are rotationally symmetric, and the 10-dB beamwidth is reasonably constant over a wide frequency range.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?reload=true&punumber=772

Quad-ridge horn antenna with elliptically shaped sidewalls

We present a quad-ridge horn antenna as a feed for a reflector antenna for use in radio astronomy applications. The antenna uses elliptically shaped sidewalls to limit the variation of beamwidth over a wide frequency range and to obtain greater radiation pattern rotational symmetry. The antenna is dual-polarized and matched over more than a 4:1 bandwidth. A design procedure is presented and a prototype designed according to this procedure is shown. Measured and simulated results of the prototype agree with each other well. The antenna is analyzed with a prime focus reflector to determine the range of efficiencies that can be expected.National Research Foundationhttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=8hb2014ai201