New vibrational assignments in the Ā1 Au-[Xtilde] 1Σ+ g electronic transition of acetylene,C2H2: the v′1 frequency

New laser-induced fluorescence spectra of supersonic jet cooled acetylene (C₂H₂) in the wavelength region 230–205 nm have led to an improved understanding of the vibrational structure of the A ¹A_u state. Among the new bands observed are two weak perturbed bands at 46008 cm^?1 and 46116 cm^?1. Rotational analyses of these bands, together with the corresponding ‘hot’ bands arising from the ground state v4 fundamental, have shown that the upper states have asymmetric top K structure that is unaffected by a axis Coriolis coupling; this means that they do not involve overtones of the low frequency bending vibrations and therefore must be combinations of a_g vibrational normal modes. From their positions in the manifold, their vibrational assignments can only be 2² ₀3¹ ₀; and 1¹ ₀;3¹ ₀. These assignments lead to values of x ₂₂, x₁₃, and a revised value for the symmetric CH stretching frequency, ν₁ = 2880.5cm^?1; this revised value is 160cm^?1 lower than the previously accepted value, but consistent with new ab initio calculations that we performed at the EOM-CCSD level using a TZ2P (triple-zeta plus double polarization) basis set.     

Prioritization of high throughput screening data of compound mixtures using molecular similarity

This work addresses the problem of enriching high throughput screening (HTS) data of mixtures of five compounds/well without any redundancies and where no structural information of the drug target is available. Devising a mathematical model for mixtures of compounds is extremely difficult. Instead, we employed extended-connectivity fingerprints (ECFPs), which are a new class of fingerprints for molecular characterization. We calculated the Tanimoto similarity between all the compounds which appeared in the active mixtures and ranked them in order of decreasing similarity. This methodology enriched the data in three recent in-house HTS campaigns that were conducted in five compounds/well mixtures. The top 10% most similar compounds captured between 29% and 41% of the active compounds. Although this methodology is not particularly sensitive, considering the quality of the data (ca. 80% noise presumed to be inactive) and the simplicity of the method, we find it useful. It offers a true opportunity to quickly prioritize and enrich primary screening data from mixtures of compounds and therefore reduce the time and the high costs of the secondary screening.     

FISHERIES AND MARINE PROTECTED AREAS: A SPATIAL BIOECONOMIC ANALYSIS OF DISTRIBUTIONAL IMPACTS

Abstract Marine protected areas (MPAs), used increasingly as a tool for conservation of ocean and coastal environments, typically interact with fisheries. Indeed, implementation of an MPA in a coastal region will likely affect fishing communities along that coast but to differing degrees depending on their location relative to the MPA. The resulting creation of “winners” and “losers” has implications for the acceptance and long‐term viability of the MPA. This paper develops a spatially explicit bioeconomic simulation model to assess the distributional implications resulting from creation of a no‐take MPA. The key assumption is that this results in certain fishers being displaced from the MPA to new fishing locations, leading to decreased fishing time and increased costs. Is it possible for those being displaced to end up as “winners” in the fishery? Analysis of the model indicates that such an outcome can occur in certain circumstances, notably if the biological effects of the MPA produce (i) improved ecosystem health inside the MPA, such that fish stock carrying capacity increases; or (ii) to some extent, high fish stock migration rates between neighboring areas. The results indicate that in creating MPAs, careful attention to their design is needed in order to deal with corresponding distributional impacts on fishing communities.     

LONG-TERM EFFECTS OF A SINGLE DOSE OF ULTRAVIOLET-B ON ALBINO RABBIT CORNEA-I. in vivo ANALYSES

Both eyes of female albino rabbits (1.9 kg) were exposed to a single dose of UV-B (300 +/- 9 nm; 0.125 J/cm2 total dose) between 13.30 and 15.00 h. The average irradiance was 209 +/- 4 microW/cm2 delivered over 612 +/- 13 s. At various time periods thereafter (every 12 h for 3 days, 6, 7, 14, 28, 42, 56, 112, 224 and 336 days post-irradiation), the animals were subjected to a full slit lamp examination to evaluate the status of the cornea and the anterior segment along with optical or ultrasonic pachometry of central corneal thickness. The results were compared with studies on age-matched rabbits over the same time period. In response to the UV-B irradiation, the corneas showed a modest edema (20% increase in central corneal thickness) that peaked at 48 h. Nearly normal central corneal thickness returned in 6 days and followed by a secondary very slight swelling (less than 5%) that resolved by 14 days. The edema was accompanied by keratitis over the same period. Thereafter, both control and UV-B irradiated corneas progressively increased in thickness with age. Biomicroscopy also revealed the appearance of granular opacities in the corneal epithelium that peaked at 72-96 h and resolved over 28 days. In addition, very small microdot opacities of the corneal epithelium were present in the UV-B irradiated corneas that reached maximum at 72 h but persisted to some degree throughout the evaluation period. Biomicroscopy also revealed a progressive disruption of the homogeneous nature of the corneal stroma by the appearance of large 'bread crumb'-like opacities that started at 72 h and was still present at the end of the evaluation period. These results suggest that long-term evaluation of the cornea is important after acute UV-B exposure and indicate that acute exposure to UV-R can produce corneal changes resembling those reported following chronic exposure to UV-R-rich environments.     

The effect of H2O on the sulfation of Havelock limestone under oxy-fuel conditions in a thermogravimetric analyser

A gas mixture representing oxy-fuel combustion conditions was employed in a thermogravimetric analyser to determine the effect of water vapor and SO₂ concentration on limestone sulfation kinetics over the temperature range of 800 to 920 °C. Here, experiments used small samples of particles (4 mg), with small particle sizes (d_p < 38 µm) and large gas flow rates (120 mL/min@NTP) in order to minimize mass transfer interferences. The gas mixture contained 5000 ppm_v SO₂, 2% O₂, and the H₂O content was changed from 0% to 25% with the balance CO₂. When water vapor was added to the gas mixture at lower temperatures (800–870 °C), the limestone SO₂ capture efficiency increased. However, as the temperature became higher, the enhancement in total conversion values decreased. As expected, Havelock limestone at higher temperatures (890 °C, 920 °C, and 950 °C) experienced indirect sulfation and reacted at a faster rate than for lower temperatures (800–870 °C) for direct sulfation over the first five minutes of reaction time. However, the total conversion of Havelock limestone for direct sulfation was generally greater than for indirect sulfation.     

Enhanced optical nonlinearity based on silicon ring

The photoelectron spectrum of ethylene is studied using coupled cluster methods, including an existing ambiguity in what are reported to be its experimental vertical ionization potentals. Two complementary methods are used for generating the ionization potentials: δE CCSD(T) and IP-EOM-CCSD. The adiabatic IP of the neutral molecule in the ground state is well known and widely accepted to be 10.5122eV. The basis set extrapolated adiabatic IPS with zero-point corrections are 10.46 eV and 10.56 eV, respectively, but a vibronic coupling between the ground state cation and its first excited state can reduce these values by ～0.03 eV. From an exponential basis set extrapolation the vertical ionization potentials are predicted to be 10.8 eV (B_3u, 13.2eV (B_3g 15.0eV (A_g), 16.4eV (B_2u), and 19.6eV (B_1u) ±0.1 eV.     

A direct proof of a generalized harish-chandra isomorphism

A direct proof of a Harish-Chandra isomorphism recently established by Khoroshkin, Nazarov and Vinberg [10] involving Zhelobenko operators, is given. A key point is the computation of certain determinants analogous to those of Parthasarathy, Ranga Rao, Varadaragan [14]. This analysis avoids the passage to graded objects and the subsequent geometric arguments.