Camera a miroir giratoire muni d'une optique interchangeable

A rotating mirror camera constructed from simple components is described, which can be adapted to the dimensions of the process to be filmed by interchanging the optical equipment in front of the rotating mirror. Frequeney range; 20,000-300,000 i/s., image scale between 1 : 10 and 5 : 1.On decrit ici une camera a miroir giratoire, construite a partir d'e1ements simples, et susceptible de s'adapter a l'ordre de grandeur du phenomene a photographier; il suffit de changer la partie de l' optique placee devant le miroir giratoire. Domaine de frequences; de 20000 a 300000 i/s; echelle de reproduction situee entre 1 : 10 et 5 : 1

Characterization of a Biosynthetic Pathway Yielding Anticancer Natural Products from a Marine Bacterium

Natural products are bioactive secondary metabolites produced by living organisms and are prevalently utilized as pharmaceutical drugs. Marine adapted organisms are a promising source of new natural products possessing unique chemical structures and biological activities. By studying the biosynthetic pathways employed by living organisms to produce natural products, insights into new strategies to generate molecules to combat disease and overcome drug resistance may be gained. This thesis study aimed to uncover the biosynthetic pathway employed by a marine actinomycete, Nocardiopsis sp. CMB-M0232, to catalyze the assembly of the nocardioazines. These molecules are a group of 2,5-diketopiperazine natural products that feature structurally unique functional groups. Nocardioazine A, the hypothesized end product of the nocardioazine biosynthetic pathway, exhibits anticancer activity. Bioinformatics analyses revealed three biosynthetic gene clusters from Nocardiopsis encoding proteins with hypothesized roles in nocardioazine A biosynthesis. Two cyclodipeptide synthases (CDPSs), NozA and NcdA, were biochemically characterized in vivo and in vitro to reveal that both are substrate specific enzymes that utilize tryptophan-charged tRNA substrates to catalyze assembly of cyclo(L-Trp-L-Trp), a proposed precursor of nocardioazines. Fidelity is uncommon amongst characterized CDPSs, making NozA and NcdA important CDPS family additions. This study also aimed to characterize NozD and NozE, two cytochrome P450 homologs with predicted roles as diketopiperazine-tailoring enzymes. Heterologous expression of these enzymes in Streptomyces strains was not able to confirm the functions of NozD and NozE but set the stage for future studies to optimize conditions for probing their roles in nocardioazine A biosynthesis. The results gathered from this study, along with future work to better understand the engineering of unique functional groups from Nocardiopsis may provide opportunities to produce new bioactive molecules

Dual-gated bilayer graphene hot electron bolometer

Detection of infrared light is central to diverse applications in security, medicine, astronomy, materials science, and biology. Often different materials and detection mechanisms are employed to optimize performance in different spectral ranges. Graphene is a unique material with strong, nearly frequency-independent light-matter interaction from far infrared to ultraviolet, with potential for broadband photonics applications. Moreover, graphene's small electron-phonon coupling suggests that hot-electron effects may be exploited at relatively high temperatures for fast and highly sensitive detectors in which light energy heats only the small-specific-heat electronic system. Here we demonstrate such a hot-electron bolometer using bilayer graphene that is dual-gated to create a tunable bandgap and electron-temperature-dependent conductivity. The measured large electron-phonon heat resistance is in good agreement with theoretical estimates in magnitude and temperature dependence, and enables our graphene bolometer operating at a temperature of 5 K to have a low noise equivalent power (33 fW/Hz1/2). We employ a pump-probe technique to directly measure the intrinsic speed of our device, >1 GHz at 10 K.Comment: 5 figure

Effects of place attachment on home return travel: a spatial perspective

Recent studies on place-mobility relationships suggest an increasing possibility that people can have multiple place attachments at varied spatial scales. Yet our understanding of how place attachment in different spatial scales affects mobility remains limited. This study investigates home return visits by Chinese diaspora tourists from North America who have made multiple trips to China. A total of 27 in-depth interviews with repeat home return travellers was conducted. Four different types of return movements were identified: local; dispersed; local & dispersed; and second-migration locale focused. A relationship was found between the participants’ sense of place, place identity and home return travel. The findings suggest that home return travel is more complex than previously thought. More focused sense of place and strong personal connection to ancestral homes may lead to more localized return, while a more generic sense of place (i.e. to ‘China’) and collective personal identity would result in a more dispersed travel pattern. Family migration history and strong attachment to family’s first migration destination also leads to focused return to the place. The study highlights the fact that place and place attachment are deeply personal and can evolve over time and space

Cochlear implant programming: a global survey on the state of the art

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe