Main Injector synchronous timing system

The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumen-tation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to com-plete a full turn of the ring by 61 nanoseconds (or more than 3 RF buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Tim-ing System corrects for this phase slip as well as signal propagation time changes due to tem-perature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the RF clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design, and expected performance of the Synchronous Timing System

Monitoring grondgebondenheid melkveehouderij: 2015-2017

Toen de Algemene Maatregel van Bestuur Grondgebonden melkveehouderij op 1 januari 2016 van kracht werd, verkeerde de Nederlandse melkveehouderij in een expansiefase. Naar aanleiding van de groeiende mestproductie kondigde de overheid in juli 2015 de invoering van fosfaatrechten voor de melkveehouderij aan. Voordat dit stelsel per januari 2018 daadwerkelijk werd ingevoerd, zijn in 2017 via het fosfaatreductieplan ingrijpende maatregelen getroffen om de melkveehouderij onder het nationale sectorplafond van de fosfaatproductie te brengen. De genoemde ontwikkelingen hebben hun weerslag gehad op de grondgebondenheid van de melkveehouderij in de periode 2015-2017

Verkenning potentiële bijdrage pacht natuurgrasland aan natuurinclusieve landbouw : Een modelmatige bedrijfseconomische analyse

In the context of the development towards nature-inclusive agriculture, the relationship between the costs and benefits of management of natural areas by Staatsbosbeheer (national forest service) in conjunction with nature-inclusive measures on individual farmland areas was investigated. The analysis was completed for two representative dairy farms and a sample farm for suckler cows. The analysis reveals that, when the proportion of nature-inclusive agriculture increases, it becomes economically attractive for beef farmers to lease a larger area of natural grassland in order to compensate for the decrease of individual roughage production as a result of the nature-inclusive agricultural measures. Additionally, the factors of success or failure in the management of a profitable business were outlined in a qualitative analysis. Interviews support the insights gained from the model analysis in that the lease costs, the agricultural utility value, and the absent need for investment play an important role from a business economy standpoint in the optimum size of leased natural grassland in conjunction with nature-inclusive agriculture

Late-Onset Stargardt Disease Due to Mild, Deep-Intronic ABCA4 Alleles

PURPOSE. To investigate the role of two deep-intronic ABCA4 variants, that showed a mild splice defect in vitro and can occur on the same allele as the low penetrant c.5603A>T, in Stargardt disease (STGD1). METHODS. Ophthalmic data were assessed of 18 STGD1 patients who harbored c.769-784C>T or c.4253+43G>A in combination with a severe ABCA4 variant. Subjects carrying c.[769784C>T; 5603A>T] were clinically compared with a STGD1 cohort previously published carrying c.5603A>T noncomplex. We calculated the penetrances of the intronic variants using ABCA4 allele frequency data of the general population and investigated the effect of c.769-784C>T on splicing in photoreceptor progenitor cells (PPCs). RESULTS. Mostly, late-onset, foveal-sparing STGD1 was observed among subjects harboring c.769-784C>T or c.4253+43G>A (median age of onset, 54.5 and 52.0 years, respectively). However, ages of onset, phenotypes in fundo, and visual acuity courses varied widely. No significant clinical differences were observed between the c.[769-784C>T; 5603A>T] cohort and the c.4253+43G>A or the c.5603A>T cohort. The penetrances of c.769-784C>T (20.5%-39.6%) and c.4253+43G>A (35.8%-43.1%) were reduced, when not considering the effect of yet unidentified or known factors in cis, such as c.5603A>T (identified in 7/7 probands with c.769-784C>T; 1/8 probands with c.4253+43G>A). Variant c.769-784C>T resulted in a pseudo-exon insertion in 15% of the total mRNA (i.e., similar to 30% of the c.769-784C>T allele alone). CONCLUSIONS. Two mild intronic ABCA4 variants could further explain missing heritability in late-onset STGD1, distinguishing it from AMD. The observed clinical variability and calculated reduced penetrance urge research into modifiers within and outside of the ABCA4 gene

The common ABCA4 variant p.Asn1868ile shows nonpenetrance and variable expression of stargardt disease when present in trans with severe variants

PURPOSE. To assess the occurrence and the disease expression of the common p.Asn1868Ile variant in patients with Stargardt disease (STGD1) harboring known, monoallelic causal ABCA4 variants. METHODS. The coding and noncoding regions of ABCA4 were sequenced in 67 and 63 STGD1 probands respectively, harboring monoallelic ABCA4 variants. In case p.Asn1868Ile was detected, segregation analysis was performed whenever possible. Probands and affected siblings harboring p.Asn1868Ile without additional variants in cis were clinically evaluated retrospe