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

Collateral benefits of Internet use: explaining the diverse outcomes of engaging with the Internet

This article examines the extent to which economic, cultural, social, and personal types of engagement with the Internet result in a variety of economic, cultural, social, and personal outcomes. Data from a representative survey of the Dutch population are analyzed to test whether engagement with a certain type of activity is related to “collateral” benefits in different domains of activities, independent from the socioeconomic or sociocultural characteristics of the person. The results show that what people do online and the skills they have affect outcomes in other domains and that this is independent of the characteristics of the person. This means that policy and interventions could potentially overcome digital inequalities in outcomes through skills training and providing opportunities to engage online in a broad variety of ways. A semiologic rather than an economistic approach is more likely to be effective in thinking about and tackling digital inequalities

Tangible outcomes of Internet use: from digital skills to tangible outcomes project report

In the past decade, digital divide discussions have moved from discussions of use or non-use, to a more nuanced recognition of different types and levels of access, motivation, skills and Internet use in a discourse that centres around digital inclusion and inequality. However, there remain challenges in measurement and conceptualisation. In 2014, the authors of this report started a project with the main objective to develop theoretically informed measures that can be used to explain how people use the Internet and what the benefits might be. A first report (van Deursen, Helsper & Eynon, 2014) looked at how to measure digital skills, an area in which a good amount of research has been done, although good measures with a solid theoretical grounding are scarce. In the current report, the authors move towards a research area that is very underdeveloped: the tangible outcomes that Internet use might result in. Most research in this area focuses on measuring engagement or different uses of the Internet and then assumes that activities performed online result in the corresponding outcomes. An unequal distribution of these types of engagement in turn is assumed to reinforce existing levels of social inequality. In this report, the framework used to design measures of engagement and related outcomes starts from the premise that outcomes of Internet use can be mapped onto different types of offline resources. It argues that a clear separation needs to be made between undertaking different kinds of activities in the digital sphere (i.e. digital resource fields) and the tangible outcomes in different spheres of everyday life (i.e. offline resource fields) that result from this engagement. &nbsp

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

Українська шляхта між польським та українським етносами

Appearance and existence of the Ukrainian gentry relates to the traditions of Polish political culture, so during the whole period of its life it was between the Ukrainian and the Polish ethnic groups. Polanisation of the Ukrainian gentry begins at the date when some of the Ukrainian territories become a part of Poland and strengthens after Cossack revolution in the middle and at the end of the 16th century. Especially this process becomes effective at the beginning of the 18th century when a great part of gentry from other Polish lands migrates to Pravoberezhia (right-banked Ukraine). Nevertheless, having captured upper class and partially middle class of the Ukrainian gentry, polanisation mainly influenced consciousness and less religion of the lower class of the Ukrainian gentry. As for ethnoculture and language local gentry was mostly Ukrainian and it assimilated numerous Polish gentlemen-immigrants

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

BIM : a methodology to transform business processes into software systems

This manuscript proposes a guiding methodology to obtain a software system that supports the execution of the business processes existing within an organization. The methodology promotes the usage of business process reference models and intends to reduce the implementation time of the software systems. The methodology assumes four distinct phases and several abstraction levels and is applicable both when developing systems from scratch or in re-engineering contexts. The methodology embodies a special phase to handle the diversity of the business processes of an organization. By tailoring process reference models and by considering the characteristics of a specific organization, a proper set of business processes is derived for that organization. Then, we can obtain a suitable information system and implement its automatable parts in a software solution that can run on top of open source software frameworks. We also present four new supporting concepts to the methodology, and a summarized execution of it

Reduced Life- and Healthspan in Mice Carrying a Mono-Allelic BubR1 MVA Mutation

Mosaic Variegated Aneuploidy (MVA) syndrome is a rare autosomal recessive disorder characterized by inaccurate chromosome segregation and high rates of near-diploid aneuploidy. Children with MVA syndrome die at an early age, are cancer prone, and have progeroid features like facial dysmorphisms, short stature, and cataracts. The majority of MVA cases are linked to mutations in BUBR1, a mitotic checkpoint gene required for proper chromosome segregation. Affected patients either have bi-allelic BUBR1 mutations, with one allele harboring a missense mutation and the other a nonsense mutation, or mono-allelic BUBR1 mutations combined with allelic variants that yield low amounts of wild-type BubR1 protein. Parents of MVA patients that carry single allele mutations have mild mitotic defects, but whether they are at risk for any of the pathologies associated with MVA syndrome is unknown. To address this, we engineered a mouse model for the nonsense mutation 2211insGTTA (referred to as GTTA) found in MVA patients with bi-allelic BUBR1 mutations. Here we report that both the median and maximum lifespans of the resulting BubR1(+/GTTA) mice are significantly reduced. Furthermore, BubR1(+/GTTA) mice develop several aging-related phenotypes at an accelerated rate, including cataract formation, lordokyphosis, skeletal muscle wasting, impaired exercise ability, and fat loss. BubR1(+/GTTA) mice develop mild aneuploidies and show enhanced growth of carcinogen-induced tumors. Collectively, these data demonstrate that the BUBR1 GTTA mutation compromises longevity and healthspan, raising the interesting possibility that mono-allelic changes in BUBR1 might contribute to differences in aging rates in the general population

Heavy quasiparticles in the ferromagnetic superconductor ZrZn2

We report a study of the de Haas-van Alphen effect in the normal state of the ferromagnetic superconductor ZrZn2. Our results are generally consistent with an LMTO band structure calculation which predicts four exchange-split Fermi surface sheets. Quasiparticle effective masses are enhanced by a factor of about 4.9 implying a strong coupling to magnetic excitations or phonons. Our measurements provide insight in to the mechanism for superconductivity and unusual thermodynamic properties of ZrZn2.Comment: 5 pages, 2 figures (one color