Characteristic matrices for linear periodic delay differential equations

Szalai et al. (SIAM J. on Sci. Comp. 28(4), 2006) gave a general construction for characteristic matrices for systems of linear delay-differential equations with periodic coefficients. First, we show that matrices constructed in this way can have a discrete set of poles in the complex plane, which may possibly obstruct their use when determining the stability of the linear system. Then we modify and generalize the original construction such that the poles get pushed into a small neighborhood of the origin of the complex plane.Comment: 17 pages, 1 figur

Trace formula for a dielectric microdisk with a point scatterer

Two-dimensional dielectric microcavities are of widespread use in microoptics applications. Recently, a trace formula has been established for dielectric cavities which relates their resonance spectrum to the periodic rays inside the cavity. In the present paper we extend this trace formula to a dielectric disk with a small scatterer. This system has been introduced for microlaser applications, because it has long-lived resonances with strongly directional far field. We show that its resonance spectrum contains signatures not only of periodic rays, but also of diffractive rays that occur in Keller's geometrical theory of diffraction. We compare our results with those for a closed cavity with Dirichlet boundary conditions.Comment: 39 pages, 18 figures, pdflate

«Tous chercheurs» et «Tous dignes», l’égalité dans la légalité :: un enseignement basé sur les pratiques pédagogiques de « La Maison des Enfants » de Buzet en Belgique est-il concevable dans le système scolaire bernois ? obéit-il aux exigences du Plan d’Études Romand (PER) ?

L’objectif principal de M. Pulver, directeur de l’instruction publique du canton de Berne, pour les prochaines années, est d’instaurer un dialogue pédagogique entre les écoles, et entre les écoles et la Direction de l’instruction publique, afin que celles-ci prennent conscience des moyens qu’elles ont à disposition afin de façonner leur environnement et leur enseignement. Il vaut la peine pour les écoles et le corps enseignant de considérer d’autres formes d’enseignement et de modèles scolaires. La législation scolaire laisse donc, d’une part de larges zones d’initiative à l’enseignant et incite d’autre part à des actions pédagogiques audacieuses. Une telle invitation a encouragé la recherche que j’ai entreprise afin d’envisager la mise en oeuvre, dans ma pratique professionnelle, des pratiques pédagogiques s’inspirant de l’Éducation Nouvelle. Je me suis alors posé cette question : un enseignement fondé sur la mise en recherche des enfants et une appropriation des connaissances passant par l’auto-socio- construction des savoirs et des compétences, de la personne et de la société, chère au mouvement d’Éducation Nouvelle dans lequel s’inscrit «La Maison des Enfants » à Buzet, est-il compatible avec le système scolaire actuel de Suisse romande et plus spécifiquement avec le Plan d’Études Romand (PER) et ses valeurs

Nepodnošljivost (intolerancija) laktoze i potrošnja mlijeka

The disaccharide lactose is one of the main components of milk. During the digestion, it is hydrolysed by the enzyme ß-galactosidase into glucose and galactose. With the exception of the Caucasian populations the lactase activity decreases in most people in the age of weaning. After the ingestion of large amounts of lactose, symptoms as bloating, flatulence, abdominal pain and diarrhea can occur due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance or lactose maldigestion. But also in Caucasian populations there are some people who suffer from it. In the past, such populations have used this phenomenon, after weaning, to discourage the consumption of milk. However, nowadays it is recognised that lactose maldigesters can tolerate one cup of milk or two cups of milk a day, when taken over the day with meals. They can also consume cheese that contains no or only small amounts of lactose. Studies performed during the last 15 years have shown that yogurt is very well tolerated by lactose maldigesters. This is attributed to the presence of living lactic acid bacteria in fermented dairy products and to the lactase present in these products.Disaharid laktoza predstavlja jedan od glavnih sastojaka mlijeka. Tijekom probave hidrolizira se djelovanjem enzima ß-galaktozidaze, u glukozu i galaktozu. Aktivnost laktaze smanjuje se kod većine rasa (s izuzetkom Kavkaske rase) i to nakon perioda dojenja. Unošenjem veće količine laktoze u organizam javljaju se različiti simptomi poput naduvenosti, vjetrova, boli u trbuhu, diareje i dr. Ova pojava naziva se intolerancija (nepodnošljivost) laktoze ili neprobavljivost laktoze, koja se može pojaviti čak i kod dijela Kavkaske rase. U povijesti se ova pojava koristila da bi se ljudi odbili od konzumiranja mlijeka. Međutim modema znanost je dokazala da ljudi koji ne podnose laktozu mogu konzumirati jednu do dvije šalice mlijeka dnevno bez značajnijih poteškoća. Ova grupa ljudi također može konzumirati sir koji sadržava malu količinu laktoze ili sir u kojem nema laktoze. Istraživanja tijekom 15 godina su pokazala da takova grupa ljudi vrlo dobro podnosi jogurt, što objašnjava prisutnošću živih bakterija mliječne kiseline i laktaze u fermentiranim mliječnim proizvodima

The Ursinus Weekly, July 13, 1942

Freshmen rally in extra frame to knot series • Deferment ratings further changed to favor students • Sixty city slickers attend barn dance in Freeland hayloft • Twelve-week summer term opens with enrollment of 137 students • Ursinus health program features touch football during third full week • College host to 135 at 5-day conference • Two Ursinus couples recently married; three pairs engaged • Men\u27s tennis tourney to begin this week • Collapsed editors cut Weekly to fit short summer term • First chapel service to be held Wednesday • Out-door vespers program on theme of rededicationhttps://digitalcommons.ursinus.edu/weekly/1789/thumbnail.jp

Semiclassical Theory of Quantum Chaotic Transport: Phase-Space Splitting, Coherent Backscattering and Weak Localization

We investigate transport properties of quantized chaotic systems in the short wavelength limit. We focus on non-coherent quantities such as the Drude conductance, its sample-to-sample fluctuations, shot-noise and the transmission spectrum, as well as coherent effects such as weak localization. We show how these properties are influenced by the emergence of the Ehrenfest time scale \tE. Expressed in an optimal phase-space basis, the scattering matrix acquires a block-diagonal form as \tE increases, reflecting the splitting of the system into two cavities in parallel, a classical deterministic cavity (with all transmission eigenvalues either 0 or 1) and a quantum mechanical stochastic cavity. This results in the suppression of the Fano factor for shot-noise and the deviation of sample-to-sample conductance fluctuations from their universal value. We further present a semiclassical theory for weak localization which captures non-ergodic phase-space structures and preserves the unitarity of the theory. Contrarily to our previous claim [Phys. Rev. Lett. 94, 116801 (2005)], we find that the leading off-diagonal contribution to the conductance leads to the exponential suppression of the coherent backscattering peak and of weak localization at finite \tE. This latter finding is substantiated by numerical magnetoconductance calculations.Comment: Typos in central eqns corrected (this paper supersedes cond-mat/0509186) 20page

Intrinsic disorder in the common N-terminus of human adenovirus 5 E1B-55K and its related E1BN proteins indicated by studies on E1B-93R

AbstractThe E1B transcription unit of human adenovirus encodes at least five different proteins generated by alternative splicing of a common E1B precursor mRNA. E1B-156R, -93R and -84R contain individual carboxy termini but share a common amino terminus. To acquire data on the structure of the amino terminus we performed biophysical analyses on E1B-93R. We show that E1B-93R is mostly unstructured and fulfills the criteria of an intrinsically disordered protein (IDP). The intrinsic disorder in the amino terminus of these proteins is evolutionary conserved in all seven human adenovirus species. As IDPs comprise a rapidly growing family of proteins which, despite their lack of a well defined structure, often fulfill essential regulatory functions, the observations described here might open up a new avenue for the understanding of the regulation and functions of E1B proteins, in particular the multifunctional E1B-55K oncoprotein

Effect of dietary alpine butter rich in conjugated linoleic acid on milk fat composition of lactating sows

Multiparous sows (n 17) were included in a controlled cross-over-study in order to investigate the influence of a natural source of conjugated linoleic acid (CLA) (alpine butter) on the milk fatty acid composition of lactating sows (as an animal model for lactating women) and on the growth performance of their progeny. The usual fat source of a standard lactation diet was replaced by either CLA-rich alpine butter or margarine (control diet). Compared with the margarine diet, feeding the alpine butter-supplemented diet increased (P0·05) affected. Growth performance of the progeny was similar for both dietary treatments. In summary, the findings show that adding alpine butter to the diet does not provoke a milk fat depression and does not alter the composition of total SFA, MUFA and PUFA in sow milk but increases its CLA concentratio

Designing Robust Hierarchically Textured Oleophobic Fabrics

Commercially available woven fabrics (e.g., nylon- or PET-based fabrics) possess inherently re-entrant textures in the form of cylindrical yarns and fibers. We analyze the liquid repellency of woven and nanotextured oleophobic fabrics using a nested model with n levels of hierarchy that is constructed from modular units of cylindrical and spherical building blocks. At each level of hierarchy, the density of the topographical features is captured using a dimensionless textural parameter D[subscript n][superscript *]. For a plain-woven mesh comprised of chemically treated fiber bundles (n = 2), the tight packing of individual fibers in each bundle (D[subscript 2][superscript *] ≈ 1) imposes a geometric constraint on the maximum oleophobicity that can be achieved solely by modifying the surface energy of the coating. For liquid droplets contacting such tightly bundled fabrics with modified surface energies, we show that this model predicts a lower bound on the equilibrium contact angle of θE ≈ 57° below which the Cassie–Baxter to Wenzel wetting transition occurs spontaneously, and this is validated experimentally. We demonstrate how the introduction of an additional higher order micro-/nanotexture onto the fibers (n = 3) is necessary to overcome this limit and create more robustly nonwetting fabrics. Finally, we show a simple experimental realization of the enhanced oleophobicity of fabrics by depositing spherical microbeads of poly(methyl methacrylate)/fluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) onto the fibers of a commercial woven nylon fabric.United States. Army Research Office (W911NF-13-D-0001