175 GHz, 400-fs-pulse harmonically mode-locked surface emitting semiconductor laser

We report a harmonically mode-locked vertical external cavity surface emitting laser (VECSEL) producing 400 fs pulses at a repetition frequency of 175 GHz with an average output power of 300 mW. Harmonic mode-locking was established using a 300 µm thick intracavity single crystal diamond heat spreader in thermal contact with the front surface of the gain sample using liquid capillary bonding. The repetition frequency was set by the diamond microcavity and stable harmonic mode locking was achieved when the laser cavity length was tuned so that the laser operated on the 117th harmonic of the fundamental cavity. When an etalon placed intracavity next to the gain sample, but not in thermal contact was used pulse groups were observed. These contained 300 fs pulses with a spacing of 5.9 ps. We conclude that to achieve stable harmonic mode locking at repetition frequencies in the 100s of GHz range in a VECSEL there is a threshold pulse energy above which harmonic mode locking is achieved and below which groups of pulses are observed

Iodinated contrast media and cerebral hemorrhage after intravenous thrombolysis

<p>Background and Purpose: Iodinated contrast is increasingly used in CT perfusion or angiographic examinations in acute stroke. Increased risk of intracranial hemorrhage (ICH) complicating microcatheter contrast injections has recently been reported in the second Interventional Management of Stroke (IMS 2) trial with contrast toxicity potentially contributory.</p> <p>Methods: We reviewed clinical and radiological data on all patients treated with intravenous alteplase at a single center between May 2003 and November 2008.</p> <p>Results: Of 312 patients treated with intravenous alteplase, 69 (22.1%) received intravenous iodinated contrast in volumes between 50 and 150 mL. Incidence of symptomatic ICH defined as per European Cooperative Acute Stroke Study 2 was 16 of 312 (5.1%; 95% CI, 2.7% to 7.6%); among patients not given contrast, it was 12 of 243 (4.9%; 2.2% to 7.7%) compared with 4 of 69 (5.8%; 0.3% to 11.3%) in those given contrast. Incidence of symptomatic ICH defined as per Safe Implementation of Thrombolysis in Stroke-MOnitoring Study (SITS-MOST) criteria was 12 of 312 (3.9%; 1.7% to 6%), 9 of 243 (3.7%; 1.3% to 6%) among those not given contrast, and 3 of 69 (4.4%; 95% CI, -0.5% to 9.2%) among those given contrast. Patients with symptomatic ICH were older, had higher pretreatment National Institutes of Health Stroke Scale, and blood glucose than those without symptomatic ICH. In logistic regression analysis, pretreatment blood glucose was the only significant predictor of symptomatic ICH by either definition (OR, 1.23; 95% CI, 1.03 to 1.48 per mmol/L increment; P=0.024). Contrast administration or dose was not associated with symptomatic ICH.</p> <p>Conclusions: Intravenous iodinated contrast in doses typically required for CT angiography and perfusion imaging was not associated with symptomatic intracranial hemorrhage in patients treated with alteplase.</p&gt

Saturated gain spectrum of VECSELs determined by transient measurement of lasing onset

We describe time-resolved measurements of the evolution of the spectrum of radiation emitted by an optically-pumped continuous-wave InGaAs-GaAs quantum well laser, recorded as lasing builds up from noise to steady state. We extract a fitting parameter corresponding to the gain dispersion of the parabolic spectrum equal to ?79 ± 30 fs2 and ?36 ± 6 fs2 for a resonant and anti-resonant structure, respectively. Furthermore the recorded evolution of the spectrum allows for the calculation of an effective FWHM gain bandwidth for each structure, of 11 nm and 18 nm, respectively

Ecology and Management Potential for Purple Loosestrife (Lythrum salicaria)

Purple loosestrife (Lythrum salicaria), an exotic wetland plant from Eurasia, has become widespread in the northeast and northcentral regions of the U.S. and Canada. When it becomes established in a wetland, it crowds out most native plant species, and can form dense stands either in standing water or on moist soil. This results in decreased plant diversity and the loss of food and cover species valuable to wildlife. Some attempted control methods, such as controlled burning and water-level manipulation have proven to be unsuccessful. Other control measures, including mechanical cutting, replacement, and cattail competition, have shown encouraging, but inconclusive, results. This study was therefore initiated to further explore the possibility of controlling purple loosestrife through competition with cattails (Typha angustifolia) in mixed stands. A competitive edge was given to Typha by cutting Lythrum and selectively fertilizing Typha. First-year results of the study showed a significant decrease in Lythrum biomass as a result of cutting treatments. Cutting did not significantly reduce resprouting Lythrum stems, as Lythrum resprouted in greater numbers than Typha, but Typha sprouts grew faster and increased in biomass more quickly than Lythrum sprouts. With carbohydrate replenishment to the roots reduced, it is expected that Lythrum biomass will be reduced in subsequent years. The stress caused by cutting, and increased shade by the Typha canopy, may help to control purple loosestrife spread

Churchmanship and personality among clergymen in the church in Wales : are Anglo-Catholic priests more feminine?

The aim of the present study is to develop and test a new measure of Anglo-Catholic orientation capable of assessing the extent of the continuing influence of the Anglican-Catholic movement among Anglican clergy and useful for testing theories regarding the association between Anglo-Catholic orientation and personality. Data provided by a sample of 232 clergymen serving in the Church in Wales support the internal consistency reliability of the 21-item Francis-Littler Anglo-Catholic Orientation Scale, and, in terms of the Eysenckian dimensional model of personality, demonstrate that Anglo-Catholic orientation is associated with higher levels of psychological femininity as assessed by the neuroticism scale, but not as assessed by the psychoticism scale

Génération d'impulsions ultrabrèves de haute puissance et a haut taux de répétition par amplification fibrée en régime auto-similaire ou d'auto-modulation de phase

Nous démontrons l’amplification d’impulsions pico- et femto-secondes par un dispositif fibré à un taux de répétition de 1 GHz obtenu par utilisation d’un VECSEL passivement mode-locké. Deux régimes non-linéaires d’amplification sont alors clairement mis en évidence, l’un dominé par l’auto-modulation de phase et l’autre par une évolution autosimilaire. Ce dernier régime conduit après recompression temporelle à des impulsions en limite de Fourier avec une durée temporelle inférieure à 150 fs

Molecular cloning and characterization of human endothelial nitric oxide synthase

AbstractThe constitutive calcium/calmodulin-dependent nitric oxide (NO) synthase expressed in vascular endothelium shares common biochemical and pharmacologic properties with neuronal NO synthase. However, recent cloning and molecular characterization of NO synthase from bovine endothelial cells indicated the existence of a family of constitutive NO synthases. Accordingly, we undertook molecular cloning and sequence analysis of human endothelial NO synthase. Complementary DNA clones predict a protein of 1,203 amino acids sharing 94% identity with the bovine endothelial protein, but only 60% identity with the rat brain NO synthase isoform. Northern blot analysis with an endothelial-derived cDNA identified a 4.6–4.8 kb mRNA transcript in HUVEC and in situ hybridization localized transcripts to vascular endothelium but not neuronal tissue