Alternative model of the Antonov problem

Astrophysical systems will never be in a real Thermodynamic equilibrium: they undergo an evaporation process due to the fact that the gravity is not able to confine the particles. Ordinarily, this difficulty is overcome by enclosing the system in a rigid container which avoids the evaporation. We proposed an energetic prescription which is able to confine the particles, leading in this way to an alternative version of the Antonov isothermal model which unifies the well-known isothermal and polytropic profiles. Besides of the main features of the isothermal sphere model: the existence of the gravitational collapse and the energetic region with a negative specific heat, this alternative model has the advantage that the system size naturally appears as a consequence of the particles evaporation.Comment: RevTex4, 9 pages, 10 figures, Version Submitted to PR

Capturing architects’ designerly ways of knowing about users: Exploring an ethnographic research approach

Transferring knowledge about diverse users’ experiences from research into architectural design practice is not straightforward. Effective knowledge transfer requires taking into account architects’ design practice. This paper explores a research approach to gain insight into architects’ designerly ways of knowing about users. It discusses why an ethnographic research approach offers a means to study a culture of practice such as architectural design practice. A fieldwork account from a pilot study in an architecture firm provides insight into the experiential issues architects deal with. It illustrates how fieldwork techniques can be applied to map the socio-material aspects (e.g., different stakeholders and design materials) that mediate knowledge about users. Exploiting these aspects of architectural design practice is expected to open new ways of thinking about informing architects about users’ experiences. For instance, there lies an opportunity in engaging architects’ creative representational skills, which challenges architects’ and researchers’ roles in knowledge transfer

Populating architectural design: Introducing scenario-based design in residential care projects

Copyright: © 2019 van der Linden, Dong, & Heylighen. Despite the very aim of designing living environments for people, the perspectives of the end users are underrepresented in architectural design processes. Architects are expected to address the challenges of a diverse and ageing society but, due to increasingly complex design processes, they often have limited access to the perspectives of those they are designing for. This study aims to bring people’s spatial experience to the foreground in architects’ design processes, by turning to techniques developed by related design disciplines. More precisely, it analyses the potential of scenario-based design, a family of techniques for exploring user experience in design, which architects are largely unfamiliar with. Based on elements like personas, scenarios, and user journeys, a scenario-based design approach tailored to architectural design’s particularities was developed. Test workshops were conducted in two architecture firms involved in designing residential care projects, and findings were discussed with an expert panel. Findings illustrate how these workshops offered architects insight into user profiles and themes, facilitated exploring and diversifying potential futures during design development, and supported communication with team members and the client. Additional opportunities and challenges are identified, which can advance the development of an integrated approach to support architects in designing human-centred environments.Flanders Innovation and Entrepreneurship; PhD Fellowship of the Research Foundation–Flanders (FWO)

Model Systems to Study the Mechanism of Vascular Aging

Cardiovascular diseases are the leading cause of death globally. Within cardiovascular aging, arterial aging holds significant importance, as it involves structural and functional alterations in arteries that contribute substantially to the overall decline in cardiovascular health during the aging process. As arteries age, their ability to respond to stress and injury diminishes, while their luminal diameter increases. Moreover, they experience intimal and medial thickening, endothelial dysfunction, loss of vascular smooth muscle cells, cellular senescence, extracellular matrix remodeling, and deposition of collagen and calcium. This aging process also leads to overall arterial stiffening and cellular remodeling. The process of genomic instability plays a vital role in accelerating vascular aging. Progeria syndromes, rare genetic disorders causing premature aging, exemplify the impact of genomic instability. Throughout life, our DNA faces constant challenges from environmental radiation, chemicals, and endogenous metabolic products, leading to DNA damage and genome instability as we age. The accumulation of unrepaired damages over time manifests as an aging phenotype. To study vascular aging, various models are available, ranging from in vivo mouse studies to cell culture options, and there are also microfluidic in vitro model systems known as vessels-on-a-chip. Together, these models offer valuable insights into the aging process of blood vessels.</p

Ideal kink instability of a magnetic loop equilibrium

The force-free coronal loop model by Titov & D\'emoulin (1999} is found to be unstable with respect to the ideal kink mode, which suggests this instability as a mechanism for the initiation of flares. The long-wavelength ($m=1$) mode grows for average twists \Phi\ga3.5\pi (at a loop aspect ratio of $\approx$ 5). The threshold of instability increases with increasing major loop radius, primarily because the aspect ratio then also increases. Numerically obtained equilibria at subcritical twist are very close to the approximate analytical equilibrium; they do not show indications of sigmoidal shape. The growth of kink perturbations is eventually slowed down by the surrounding potential field, which varies only slowly with radius in the model. With this field a global eruption is not obtained in the ideal MHD limit. Kink perturbations with a rising loop apex lead to the formation of a vertical current sheet below the apex, which does not occur in the cylindrical approximation.Comment: Astron. Astrophys. Lett., accepte

Geïntegreerde bestrijding van trips en weekhuidmijten

Omdat meer kennis over natuurlijke bestrijders in zomerbloemen gewenst is, hebben de projectpartners een vijftal bijeenkomsten gehouden. Voor deze bijeenkomsten zijn de telers van zomerbloemen uitgenodigd. De bijeenkomsten werden begeleid door LTO Groeiservice, FytoConsult en DLV Plant. Naast de bijeenkomsten is onderzoek gedaan in Delphinium en Alchemilla naar de aanwezigheid en vestiging van roofmijten. In Delphinium komen weekhuidmijten voor en in Alchemilla komt trips voor als plaag. Spint kan eveneens in deze gewassen optreden. In beide gewassen werden drie soorten roofmijten geïntroduceerd: Neoseiulus alpinus, Neoseiulus reductus en Amblyseisus montdorensis. In Delphinium werden tijdens de waarnemingen geen weekhuidmijten gevonden en in Alchemilla was trips schaars. Neoseiulus reductus werd goed terug gevonden in Delphinium, in tegenstelling tot de andere soorten roofmijten. In Alchemilla werden alle drie de soorten roofmijten terug gevonden. Voorlopig lijkt Neoseiulus alpinus in het voordeel in Alchemilla, gevolgd door Neoseiulus reductus. Om hieromtrent duidelijkheid te krijgen en ook om een effect aan te tonen van de roofmijten op de plagen zijn meer waarnemingen noodzakelijk

A Case Study Exploring Side-Channel Attacks On Pet Wearables

IoT has long since come to the pet industry resulting in a proliferation of data-intensive devices including tracking anything from activity, health, to location. The resulting ‘Internet of Pets’ is generating large volumes of animal data which, due to the close link between the digital profile of companion animals held as pets (e.g., cats and dogs) and their caregivers holds significant security and privacy implications. In this case study we explore the vulnerability of such pet wearables to side-channel attacks, describing our implementation of an electromagnetic attack on a now discontinued dog activity tracker. We show how we were able to successfully exfiltrate data from the device during the Base64 encoding process and discuss what implications this holds for the security of these devices, given the lack of protection that animal data is afforded under extant existing data protection policy and legislation