Nonlinear oscillatory mixing in the generalized Landau scenario

We present a set of phase-space portraits illustrating the extraordinary oscillatory possibilities of the dynamical systems through the so-called generalized Landau scenario. In its simplest form the scenario develops in N dimensions around a saddle-node pair of fixed points experiencing successive Hopf bifurcations up to exhausting their stable manifolds and generating N-1 different limit cycles. The oscillation modes associated with these cycles extend over a wide phase-space region by mixing ones within the others and by affecting both the transient trajectories and the periodic orbits themselves. A mathematical theory covering the mode-mixing mechanisms is lacking, and our aim is to provide an overview of their main qualitative features in order to stimulate research on it.Peer ReviewedPostprint (author's final draft

Nonlinear complexification of periodic orbits in the generalized Landau scenario

We have found a way for penetrating the space of the dynamical systems towards systems of arbitrary dimension exhibiting the nonlinear mixing of a large number of oscillation modes through which extraordinarily complex time evolutions may arise. The system design is based on assuring the occurrence of a number of Hopf bifurcations in a set of fixed points of a relatively generic system of ordinary differential equations, in which the main peculiarity is that the nonlinearities appear through functions of a linear combination of the system variables. The paper outlines the design procedure and presents a selection of numerical simulations with a variety of designed systems whose dynamical behaviors are really rich and full of unknown features. For concreteness, the presentation is focused to illustrating the oscillatory mixing effects on the periodic orbits, through which the harmonic oscillation born in a Hopf bifurcation becomes successively enriched with the intermittent incorporation of other oscillation modes of higher frequencies while the orbit remains periodic and without necessity of bifurcating instabilities. Even in the absence of a proper mathematical theory covering the nonlinear mixing mechanisms we find enough evidence to expect that the oscillatory scenario be truly scalable concerning the phase space dimension, the multiplicity of involved fixed points and the range of time scales, so that extremely complex but ordered dynamical behaviors could be sustained through it.Peer ReviewedPostprint (author's final draft

Double fitting of Maker fringes to characterize near-surface and bulk second-order nonlinearities in poled silica

An experimental analysis of the distribution and thickness of the bulk nonlinearity induced in poled silica is reported. The second-order susceptibility decreases exponentially from the anodic interface. Maker fringe patterns showing a double structure are interpreted in relation to the presence of two nonlinear profiles, one concentrated near the anodic surface and another extending into the bulk of the sample. The Maker fringe theory is properly generalized and a double fitting technique reproducing well the experimental results is used to characterize the induced nonlinearities. The dependence of the second-harmonic signal on the poling temperature is given, which is different from that of sol-gel silica

Coherent population trapping in two-electron three-level systems with aligned spins

The possibility of coherent population trapping in two electron states with aligned spins (ortho-system) is evidenced. From the analysis of a three-level atomic system containing two electrons, and driven by the two laser fields needed for coherent population trapping, a conceptually new kind of two-electron dark state appears. The properties of this trapping are studied and are physically interpreted in terms of a dark hole, instead of a dark two-electron state. This technique, among many other applications, offers the possibility of measuring, with subnatural resolution, some superposition-state matrix-elements of the electron-electron correlation that due to their time dependent nature are inaccesible by standard measuring procedures.Comment: 10 pages and 4 figure

Etiología y evolución a largo plazo de la hemoptisis amenazante en un hospital universitario

La hemoptisis amenaçant (HA) es una emergència de la qual la broncoscòpia i l'angiografia han millorat el pronòstic. L'objectiu d'aquest estudi va ser seguir la evolució d'aquests pacients a curt i llarg plaç. S'inclogueren els pacients ingressats per HA en un hospital de referència entre 1994 i 1996 als quals es realitzaren tècniques broncoscòpiques i angiografiques seguin la seva evolució als 5 anys. Les etiologies més freqüents varen ser les bronquiectasis i la tuberculosis. La broncoscòpia es mostra segura com a mesura de localització i terapèutica transitòria, la arteriografia va ser més definitiva a llarg plaç.La hemoptisis amenazante (HA) és una emergencia cuyo pronostico ha mejorado gracias a la broncoscòpia y la angiografia. El objectivo de este estudio fue seguir la evolución de estos pacientes a corto y largo plazo. Se incluyeron los pacientes ingresados por HA en un hospital de referencia entre 1994 y 1996 a los que se realizaron técnicas broncoscopicas y angiograficas siguiendo su evolución a los 5 años. Las etiologías más frecuentes fueron las bronquiectasias y la tuberculosis. La broncoscopia se mostró segura como medida de localización y terapéutica transitòria, la arteriografía se reveló más definitiva a largo plazo

Malignant asbestos‐related disease in a population exposed to asbestos

Abstract Objectives: The first asbestos fiber cement plant in Spain operated in Cerdanyola, in the Barcelona metropolitan area, between 1907 and 1997. We describe clinical and epidemiological characteristics of patients diagnosed with the malignant asbestosrelated disease (ARD) in the area of the plant between 2007 and 2016. Methods: A prospective, descriptive study was undertaken in the 12 municipalities of the county of Barcelona most proximate to the plant. We describe malignant ARD cases by time of diagnosis, source of exposure, periods of exposure and latency, and distribution by sex. Cumulative incidence and age‐standardized incidence rates (ASIR) are calculated. Results: Of 477 patients diagnosed with ARD between 2007 and 2016, 128 (26%) presented with asbestos‐associated malignancy. Pleural mesothelioma was noted in 105 patients (82.0%) with a linear trend Z‐score of −0.2 (NS) in men and 2.7 (P < .01) in women. The highest ASIRs for malignant ARD (6.1/100 000 residents/year; 95% confidence interval [CI], 2.2‐13.3) and pleural mesothelioma (4.8/100 000 residents/ year; 95% CI, 1.5‐11.6) occurred in municipalities closest to the focal point of contamination. The origin of malignant ARD was nonoccupational in 32.2% of men and 81.6% of women (P < .001). Conclusions: More than 20 years after the closure of the fiber cement plant, the grave consequences of exposure to asbestos remain. The detection of cases of pleural mesothelioma in men seems to have plateaued whereas in women an ascending trend continues, which principally has its origin in nonoccupational exposures

Experiència de pràctiques personalitzades i xerrades professionals en el màster interuniversitari en fotònica

S’ha posat en funcionament una doble estratègia innovadora orientada a potenciar competències transversals en el Màster en Fotònica. Per una banda, s’ha engegat una assignatura de pràctiques personalitzades, que permet ajustar les pràctiques disponibles als diferents perfils dels estudiants (segons la formació prèvia però també segons els seus interessos). Així, els estudiants poden triar entre cinc de les tretze sessions pràctiques de vuit hores cadascuna que s’oferten, seleccionant de entre la oferta disponible per part de tots els grups de recerca que donen suport al màster aquelles pràctiques que poden potenciar més el seu procés d’aprenentatge. Per una altra banda, s’ha reforçat el caràcter pràctic de la titulació potenciant l’esperit emprenedor dels estudiants mitjançant una sèrie de xerrades de persones actualment en l’àmbit empresarial de la Fotònica per acostar l’estudiant a aquest món. Les dues experiències han estat un èxit i tenen una valoració molt positiva per part de professors i estudiants, en un clar exemple de coordinació entre els interessos dels estudiants i el desenvolupament de competències transversals no “convencionals” en plans d’estudi anteriors al plantejament de Bolònia.Peer Reviewe

Pengaruh Model Pembelajaran Show Not Tell terhadap Keterampilan Menulis Teks Deskripsi Siswa Kelas VII SMP Negeri 3 Makassar

ABSTRAK Penelitian ini bertujuan (1) mendeskripsikan keterampilan menulis teks deskripsi sebelum menggunakan model pembelajaran show not tell siswa Kelas VII SMP Negeri 3 Makassar, (2) mendeskripsikan keterampilan menulis teks deskripsi sesudah menggunakan model pembelajaran show not tell siswa Kelas VII SMP Negeri 3 Makassar, (3) membuktikan pengaruh model pembelajaran show not tell terhadap keterampilan menulis teks deskripsi siswa Kelas VII SMP Negeri 3 Makassar. Penelitian ini adalah penelitian pre-eksperimen. Desain penelitian ini adalah one group pre-test and post-test design. Populasi pada penelitian ini adalah seluruh siswa SMP Negeri 3 Makassar. Sampel penelitian ini yaitu Kelas VII-4. Instrumen yang digunakan yaitu bentuk tugas. Data yang terkumpul dalam penelitian dianalisis menggunakan teknik analisis statistik deskriptif dan statistik inferensial uji regresi yang diolah dengan menggunakan program SPSS 20.0 for windows. Hasil penelitian menunjukkan bahwa keterampilan menulis teks deskripsi:(1) keterampilan menulis teks deskripsi siswa Kelas VII SMP Negeri 3 Makassar sebelum menggunakan model pembelajaran show not tell memperoleh nilai rata-rata 2.25 dengan kategori cukup terampil, (2) keterampilan menulis teks deskripsi siswa Kelas VII SMP Negeri 3 Makassar sesudah menggunakan model pembelajaran show not tell memperoleh nilai rata-rata 2.94 dengan kategori terampil, dan (3) model pembelajaran show not tell berpengaruh terhadap keterampilan menulis teks deskripsi pada siswa Kelas VII SMP Negeri 3 Makassar, dengan koefisien korelasi antara pre-test dan post-test adalah 0,559. Hasil terlihat bahwa nilai tersebut signifikan sebesar 0,000. Untuk menguji signifikansi koefisien korelasi adalah membandingkan nilai signifikansi yang diperoleh dengan harga α=0,05. Karena signifikansi 0,000 lebih kecil dari α=0,05 maka HI diterima. HI diterima apabila Sig. < = 0.05. Kesimpulan yang diperoleh adalah koefisien korelasi antara keterampilan menulis teks deskripsi sebelum menggunakan model pembelajaran show not tell dan keterampilan menulis teks deskripsi sesudah menggunakan model pembelajaran show not tell signifikan secara statistik. Kata Kunci : Pengaruh, show not tell, keterampilan menulis, teks deskripsi

Risk factors of mortality from all asbestos-related diseases: A competing risk analysis.

Background. The mortality from all malignant and nonmalignant asbestos-related diseases remains unknown. The authors assessed the incidence and risk factors for all asbestos-related deaths. Methods. The sample included 544 patients from an asbestos-exposed community in the area of Barcelona (Spain), between Jan 1, 1970, and Dec 31, 2006. Competing risk regression through a subdistribution hazard analysis was used to estimate risk factors for the outcomes. Results. Asbestos-related deaths were observed in 167 (30.7%) patients and 57.5% of these deaths were caused by some type of mesothelioma. The incidence rate after diagnosis was 3,600 per 100,000 person-years. In 7.5% of patients death was non-asbestos-related, while pleural and peritoneal mesothelioma were identified in 87 (16.0%) and 18 (3.3%) patients, respectively. Conclusions. Age, sex, household exposure, cumulative nonmalignant asbestos-related disease, and single malignant pathology were identified as risk factors for asbestos-related death. These findings suggest the need to develop a preventive approach to the community and to improve the clinical follow-up process of these patients

IDENTIFIKASI MISKONSEPSI SISWA DALAM MATA PELAJARAN FISIKA MELALUI TES PILIHAN GANDA DISERTAI WAWANCARA

IDENTIFIKASI MISKONSEPSI SISWA DALAM MATA PELAJARAN FISIKA MELALUI TES PILIHAN GANDA DISERTAI WAWANCAR