In-flight measurements of energetic radiation from lightning and thunderclouds

In the certification procedure aircraft builders carry out so-called icing tests flights, where the zero degree Celsius altitude is deliberately sought and crossed in or under thunderstorms. Airbus also used these flights to test ILDAS, a system aimed to determine lightning severity and attachment points during flight from high speed data on the electric and magnetic field at the aircraft surface. We used this unique opportunity to enhance the ILDAS systems with two x-ray detectors coupled to high speed data recorders in an attempt to determine the x-rays produced by lightning in-situ, with synchronous determination of the lightning current distribution and electric field at the aircraft. Such data are of interest in a study of lightning physics. In addition, the data may provide clues to the x-ray dose for personnel and equipment during flights. The icing campaign ran in April 2014; in six flights we collected data of 61 lightning strikes on an Airbus test aircraft. In this communication we briefly describe ILDAS and present selected results on three strikes, two aircraft initiated and one intercepted. Most of the x-rays have been observed synchronous with initiating negative leader steps, and as bursts immediately preceding the current of the recoil process. Those processes include the return stroke. The bursts last one to four micro-second and attain x-ray energies up to 10 MeV. Intensity and spectral distribution of the x-rays and the association with the current distribution are discussed. ILDAS also continuously records x-rays at low resolution in time and amplitude.Comment: 28 pages, 9 figure

Mutation Testing as a Safety Net for Test Code Refactoring

Refactoring is an activity that improves the internal structure of the code without altering its external behavior. When performed on the production code, the tests can be used to verify that the external behavior of the production code is preserved. However, when the refactoring is performed on test code, there is no safety net that assures that the external behavior of the test code is preserved. In this paper, we propose to adopt mutation testing as a means to verify if the behavior of the test code is preserved after refactoring. Moreover, we also show how this approach can be used to identify the part of the test code which is improperly refactored

Fermi Surface Properties of Low Concentration Cex_{x}La1−x_{1-x}B6_{6}: dHvA

The de Haas-van Alphen effect is used to study angular dependent extremal areas of the Fermi Surfaces (FS) and effective masses of Ce$_{x}$La$_{1-x}$B$_{6}$ alloys for $x$ between 0 and 0.05. The FS of these alloys was previously observed to be spin polarized at low Ce concentration ($x$ = 0.05). This work gives the details of the initial development of the topology and spin polarization of the FS from that of unpolarized metallic LaB$_{6}$ to that of spin polarized heavy Fermion CeB$_{6}$ .Comment: 7 pages, 9 figures, submitted to PR

Improvement in left ventricular ejection fraction after pharmacological up-titration in new-onset heart failure with reduced ejection fraction

OBJECTIVE: Recent studies have reported suboptimal up-titration of heart failure (HF) therapies in patients with heart failure and a reduced ejection fraction (HFrEF). Here, we report on the achieved doses after nurse-led up-titration, reasons for not achieving the target dose, subsequent changes in left ventricular ejection fraction (LVEF), and mortality. METHODS: From 2012 to 2018, 378 HFrEF patients with a recent (< 3 months) diagnosis of HF were referred to a specialised HF-nurse led clinic for protocolised up-titration of guideline-directed medical therapy (GDMT). The achieved doses of GDMT at 9 months were recorded, as well as reasons for not achieving the optimal dose in all patients. Echocardiography was performed at baseline and after up-titration in 278 patients. RESULTS: Of 345 HFrEF patients with a follow-up visit after 9 months, 69% reached ≥ 50% of the recommended dose of renin-angiotensin-system (RAS) inhibitors, 73% reached ≥ 50% of the recommended dose of beta-blockers and 77% reached ≥ 50% of the recommended dose of mineralocorticoid receptor antagonists. The main reasons for not reaching the target dose were hypotension (RAS inhibitors and beta-blockers), bradycardia (beta-blockers) and renal dysfunction (RAS inhibitors). During a median follow-up of 9 months, mean LVEF increased from 27.6% at baseline to 38.8% at follow-up. Each 5% increase in LVEF was associated with an adjusted hazard ratio of 0.84 (0.75–0.94, p = 0.002) for mortality and 0.85 (0.78–0.94, p = 0.001) for the combined endpoint of mortality and/or HF hospitalisation after a mean follow-up of 3.3 years. CONCLUSIONS: This study shows that protocolised up-titration in a nurse-led HF clinic leads to high doses of GDMT and improvement of LVEF in patients with new-onset HFrEF. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s12471-021-01591-6) contains supplementary material, which is available to authorized users

Ferromagnetic Properties of ZrZn2_2

The low Curie temperature (T_C approx 28K) and small ordered moment (M_0 approx 0.17 mu_B f.u.^-1) of ZrZn2 make it one of the few examples of a weak itinerant ferromagnet. We report results of susceptibility, magnetization, resistivity and specific heat measurements made on high-quality single crystals of ZrZn2. From magnetization scaling in the vicinity of T_C (0.001<|T-T_C|/T_C<0.08), we obtain the critical exponents beta=0.52+/-0.05 and delta=3.20+/-0.08, and T_C=27.50+/-0.05K. Low-temperature magnetization measurements show that the easy axis is [111]. Resistivity measurements reveal an anomaly at T_C and a non-Fermi liquid temperature dependence rho(T)=rho_0+AT^n, where n=1.67+/-0.02, for 1<T<14K. The specific heat measurements show a mean-field-like anomaly at T_C. We compare our results to various theoretical models.Comment: submitted to PR

Telefonisch Interview Cognitieve Status (TICS): psychometrische aspecten

Het Telefonisch Interview Cognitieve Status (TICS) is een telefonisch screeningsinstrument voor dementie bij ouderen. Hoewel in buitenlands onderzoek de psychometrische kwaliteiten zijn beschreven, zijn deze voor de Nederlandse versie onbekend. In deze studie wordt de Nederlandse versie van de TICS gepresenteerd en worden de betrouwbaarheid en de validiteit beschreven bij 51 patiënten die afkomstig zijn van het Diagnostisch Onderzoekscentrum voor Psychogeriatrische patiënten (N=24) en de Geheugenpoli (N=27) van het Academisch Ziekenhuis Maastricht. De Pearson correlatie en de intraclass correlatie voor de test-hertestbetrouwbaarheid bedroegen respectievelijk 0,93 en 0,92. De Pearson correlatie en de intraclass correlatie voor de interbeoordelaarsbetrouwbaarheid bedroegen respectievelijk 0,91 en 0,90. De sensitiviteit en de specificiteit zijn onderzocht door de verschillende afkappunten op de TICS te vergelijken met het afkappunt 23/24 op de Mini Mental State Examination (MMSE) en de diagnose dementie volgens de DSM-IV. Bij het afkappunt 26/27 op de TICS bedroegen de sensitiviteit en de specificiteit in alle gevallen 0,80 of meer. Het percentage onder de ROC bedroeg 90% en 93% met de MMSE, respectievelijk de diagnose dementie als criterium. Conclusie: de TICS is acceptabel voor het screenen op dementie bij ouderen. De TICS kan vooral efficiënt of bruikbaar zijn in onderzoekssituaties waar een persoonlijk contact niet mogelijk is

Footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in patients with diabetes: a systematic review

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