The Role of the Gouy Phase in the Coherent Phase Control of the Photoionization and Photodissociation of Vinyl Chloride

We demonstrate theoretically and experimentally that the Gouy phase of a focused laser beam may be used to control the photo-induced reactions of a polyatomic molecule. Quantum mechanical interference between one- and three-photon excitation of vinyl chloride produces a small phase lag between the dissociation and ionization channels on the axis of the molecular beam. Away from the axis, the Gouy phase introduces a much larger phase lag that agrees quantitatively with theory without any adjustable parameters.Comment: 4 pages, 4 figure

Coherent instabilities in a semiconductor laser with fast gain recovery

We report the observation of a coherent multimode instability in quantum cascade lasers (QCLs), which is driven by the same fundamental mechanism of Rabi oscillations as the elusive Risken-Nummedal-Graham-Haken (RNGH) instability predicted 40 years ago for ring lasers. The threshold of the observed instability is significantly lower than in the original RNGH instability, which we attribute to saturable-absorption nonlinearity in the laser. Coherent effects, which cannot be reproduced by standard laser rate equations, can play therefore a key role in the multimode dynamics of QCLs, and in lasers with fast gain recovery in general.Comment: 5 pages, 4 figure

Controlled release of ethanehydroxy diphosphonate from polyurethane reservoirs to inhibit calcification of bovine pericardium used in bioprosthetic heart valves

Calcification (CALC) of bioprosthetic heart valves (BHVs) fabricated from either glutaraldehyde-pretreated bovine pericardial tissue or porcine aortic valves is the most frequent cause of clinical failure of these devices. Previous studies have demonstrated that calcification is inhibited by diphosphonate compounds released into the vicinity of bioprosthetic tissue implanted subcutaneously in rats. Controlled release of the anticalcification agent ethanehydroxy diphosphonate (EHDP), as a 1:1 mixture of Na2 EHDP and CaEHDP from cylindrical polyurethane (PU) reservoirs (o.d. = 0.36 cm i.d. = 0.33 cm, length = 4 cm) fabricated by solvent casting was assessed in vitro and in vivo. The diffusivity (D), determined independently using standard diffusion cells, for ionic EHDP diffusion across the PU membrane was 1.2 x 10 cm2/s. Volume influx of buffer into the reservoirs in vitro was observed experimentally to reach a maximum at 7.8 days (288 +/- 44 [mu]l) with a biexponential decline to 147 +/- 6 [mu]l at 70 days. The cumulative EHDP released in vitro after 70 days was 4.2 +/- 0.6% (4.8 +/- 0.7 mg) compared to 15.7 +/- 3.2% (18.1 +/- 3.7 mg) in vivo (subcutaneously in 3 week-old, male, CD rats) over 21 days. The release rate of EHDP from the reservoirs was not a zero-order process. Reservoir administration of EHDP effectively inhibited pericardial BHV-CALC in 21-day subdermal explants (Ca2+ = 4.5 +/- 1.4 [mu]g Ca2+/mg tissue; control, Ca2+ = 120 +/- 13 [mu]g Ca2+/mg tissue) without diphosphonate-related untoward effects at a dose of approx. 3 mg/kg per day.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28671/1/0000488.pd

The Paradox of Power in CSR: A Case Study on Implementation

Purpose Although current literature assumes positive outcomes for stakeholders resulting from an increase in power associated with CSR, this research suggests that this increase can lead to conflict within organizations, resulting in almost complete inactivity on CSR. Methods A single in-depth case study, focusing on power as an embedded concept. Results Empirical evidence is used to demonstrate how some actors use CSR to improve their own positions within an organization. Resource dependence theory is used to highlight why this may be a more significant concern for CSR. Conclusions Increasing power for CSR has the potential to offer actors associated with it increased personal power, and thus can attract opportunistic actors with little interest in realizing the benefits of CSR for the company and its stakeholders. Thus power can be an impediment to furthering CSR strategy and activities at the individual and organizational level

Host phenotype characteristics and MC1R in relation to early-onset basal cell carcinoma.

Basal cell carcinoma (BCC) incidence is increasing, particularly among adults under the age of 40 years. Pigment-related characteristics are associated with BCC in older populations, but epidemiologic studies among younger individuals and analyses of phenotype-genotype interactions are limited. We examined self-reported phenotypes and melanocortin 1 receptor gene (MC1R) variants in relation to early-onset BCC. BCC cases (n=377) and controls with benign skin conditions (n=390) under the age of 40 years were identified through Yale's Dermatopathology database. Factors most strongly associated with early-onset BCC were skin reaction to first summer sun for 1 hour (severe sunburn vs. tan odds ratio (OR)=12.27, 95% confidence interval (CI)=4.08-36.94) and skin color (very fair vs. olive OR=11.06, 95% CI=5.90-20.74). Individuals with two or more MC1R non-synonymous variants were 3.59 times (95% CI=2.37-5.43) more likely to have BCC than those without non-synonymous variants. All host characteristics and MC1R were more strongly associated with multiple BCC case status (37% of cases) than a single BCC case status. MC1R, number of moles, skin reaction to first summer sun for 1 hour, and hair and skin color were independently associated with BCC. BCC risk conferred by MC1R tended to be stronger among those with darker pigment phenotypes, traditionally considered to be at low risk of skin cancer

Marine microalgae as a potential source of single cell protein (SCP)

[Abstract] The marine microalgae Tetraselmis suecica, Isochrysis galbana, Dunaliella tertiolecta and Chlorella stigmatophora are good biological sources of single cell protein (SCP). Protein content accounts for 39.12%–54.20% of the dry matter, D. tertiolecta having the highest. Lysine values are between 3.67 and 4.52 g/100 g of protein, and thus are higher than those for freshwater species. The total nucleic acid content is less than 7% of the dry matter; this value is definitely lower than that for yeasts or bacteria, commonly used as SCP sources. Amino acid profiles of the four species are very similar and comparable to the FAO reference protein, buth with a low content of methionine and cystine and a high content of lysine. The MEAA indices are between 81 and 84.98, without significant differences among the four species. Marine microalgae can be used as a potential SCP source

Role of electromagnetically induced transparency in resonant four-wave-mixing schemes.

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