Quantitative ultraviolet measurements on wetted thin-layer chromatography plates using a charge-coupled device camera

This paper presents the first study of the UV imaging of spots on thin-layer chromatographic plates whilst still wet with solvent. Imaging of spots of benzophenone during and after development was carried out using a charge-coupled device camera. Limits of detection were found to be 5 ng on a wetted plate and 3 ng for a dry plate and the relationship between peak area and sample loading was found to be linear in the low nanograrn range over an order of magnitude for both wet and dry modes with r(2) values > 0.99. It was found that UV measurements on wet glass-backed plates suffer from low sensitivity; however, the use of aluminium-backed plates gave increased sensitivity. The apparent absorption coefficient (epsilon(app)) of 10AU m(2) g(-1) at 254 nm is consistent with reflection of the light from the aluminium surface with a double pass through the sorbent layer, and suggests that use of aluminium-backed plates should enable monitoring of separations by UV absorbance during TLC development. (c) 2008 Elsevier B.V. All rights reserved

Geometric Aspects of D-branes and T-duality

We explore the differential geometry of T-duality and D-branes. Because D-branes and RR-fields are properly described via K-theory, we discuss the (differential) K-theoretic generalization of T-duality and its application to the coupling of D-branes to RR-fields. This leads to a puzzle involving the transformation of the A-roof genera in the coupling.Comment: 26 pages, JHEP format, uses dcpic.sty; v2: references added, v3: minor change

Theory of Multiphonon Excitation in Heavy-Ion Collisions

We study the effects of channel coupling in the excitation dynamics of giant resonances in relativistic heavy ions collisions. For this purpose, we use a semiclassical approximation to the Coupled-Channels problem and separate the Coulomb and the nuclear parts of the coupling into their main multipole components. In order to assess the importance of multi-step processes, we neglect the resonance widths and solve the set of coupled equations exactly. Finite widths are then considered. In this case, we handle the coupling of the ground state with the dominant Giant Dipole Resonance exactly and study the excitation of the remaining resonances within the Coupled-Channels Born Approximation. A comparison with recent experimental data is made.Comment: 29 pages, 7 Postscript figures available upon reques

Spectropolarimetry of the Deep Impact target comet 9P/Tempel 1 with HiVIS

High resolution spectropolarimetry of the Deep Impact target, comet 9P/ Tempel 1, was performed during the impact event on July 4th, 2005 with the HiVIS Spectropolarimeter and the AEOS 3.67m telescope on Haleakala, Maui. We observed atypical polarization spectra that changed significantly in the few hours after the impact. The polarization of scattered light as a function of wavelength is very sensitive to the size and composition (complex refractive index) of the scattering particles as well as the scattering geometry. As opposed to most observations of cometary dust, which show an increase in the linear polarization with the wavelength (at least in the visible domain and for phase angles greater than about 30%, a red polarization spectrum) observations of 9P/Tempel 1 at a phase angle of 41 degrees beginning 8 minutes after impact and centered at 6:30UT showed a polarization of 4% at 650 nm falling to 3% at 950 nm. The next observation, centered an hour later showed a polarization of 7% at 650 nm falling to 2% at 950nm. This corresponds to a spectropolarimetric gradient, or slope, of -0.9% per 1000 Angstroms 40 minutes after impact, decreasing to a slope of -2.3% per 1000 Angstroms an hour and a half after impact. This is an atypical blue polarization slope, which became more blue 1 hour after impact. The polarization values of 4% and 7% at 650nm are typical for comets at this scattering angle, whereas the low polarization of 2% and 3% at 950nm is not. We compare observations of comet 9P/Tempel 1 to that of a typical comet, C/2004 Machholz, at a phase angle of 30 degrees which showed a typical red slope, rising from 2% at 650nm to 3% at 950nm in two different observations (+1.0 and +0.9% per 1000 Angstroms).Comment: Icarus Deep Impact special issue, accepted Aug 28 200

An evaluation of peptone products and fish meal on nursery pig performance

A total of 360 nursery pigs (PIC C327 × 1050, initially 11.8 lb and 21 d of age) were used in a 35-d study to evaluate the effects of select menhaden fish meal (SMFM), PEP2+ (also known as Ferm O Tide), Peptone 50, and PEP-NS on nursery pig performance. PEP2+, Peptone 50, and PEP-NS are all porcine intestinal mucosa products, but differ based on the carriers with which they are co-dried. PEP2+ is co-dried with enzymatically processed vegetable proteins. Peptone 50 is co-dried with a vegetable protein, while PEP-NS uses by-products from corn wet-milling. Phase 1 diets were fed in pellet form from d 0 to 8. Phase 2 diets were fed in meal form from d 8 to 21. A common corn-soybean meal diet was fed from d 21 to 35. There were 6 dietary treatments: (1) a negative control diet containing 2.5% spray-dried animal plasma (SDAP) in Phase 1 followed by no specialty protein sources in Phase 2; (2) a diet containing 5% SDAP in Phase 1 and 3% SMFM in Phase 2; (3) a blend of 5% SDAP and 3% SMFM during Phase 1 and 6% SMFM during Phase 2; (4) a blend of 5% SDAP and 3% PEP2+ during Phase 1 and 6% PEP2 during Phase 2; (5) a blend of 5% SDAP and 3% PEP 50 during Phase 1 and 6% PEP50 during Phase 2, and (6) a blend of 5% SDAP and 3% PEP-NS during Phase 1 and 6% PEP-NS during Phase 2. During Phase 1, there were no differences in F/G among pigs fed any of the dietary treatments. During Phase 2 (d 8 to 21), pigs fed 6% PEP2+ had greater (P < 0.05) ADG compared to those fed the negative control diet, 3% or 6% fish meal, with pigs fed PEP50 and PEP NS intermediate. Furthermore, pigs fed 6% PEP2+ had the greatest improvement (P < 0.02) in F/G compared to pigs fed all other experimental diets. Overall, pigs fed diets containing PEP2+ had increased (P < 0.03) ADG and ADFI compared to pigs fed the negative control diet. Pigs fed 3% PEP2+ during Phase 1 and 6% PEP2+ during Phase 2 had greater (P < 0.05) ADFI compared to those fed 3% SMFM during Phase 1 and 6% SMFM during Phase 2. In conclusion, PEP2+, Peptone 50, and PEP-NS can be used as specialty protein sources to replace select menhaden fish meal in Phase 2 nursery pig diets. In addition pigs fed PEP2+ had greater ADG than those fed fish meal

Quasi Stable Black Holes at the Large Hadron Collider

We adress the production of black holes at LHC and their time evolution in space times with compactified space like extra dimensions. It is shown that black holes with life times of hundred fm/c can be produced at LHC. The possibility of quasi-stable remnants is discussed.Comment: 4 pages, 3 figures, typos removed, omitted factors included, accepted for publicatio

Kinect vs. low-cost inertial sensing for gesture recognition

In this paper, we investigate efficient recognition of human gestures / movements from multimedia and multimodal data, including the Microsoft Kinect and translational and rotational acceleration and velocity from wearable inertial sensors. We firstly present a system that automatically classifies a large range of activities (17 different gestures) using a random forest decision tree. Our system can achieve near real time recognition by appropriately selecting the sensors that led to the greatest contributing factor for a particular task. Features extracted from multimodal sensor data were used to train and evaluate a customized classifier. This novel technique is capable of successfully classifying various gestures with up to 91 % overall accuracy on a publicly available data set. Secondly we investigate a wide range of different motion capture modalities and compare their results in terms of gesture recognition accuracy using our proposed approach. We conclude that gesture recognition can be effectively performed by considering an approach that overcomes many of the limitations associated with the Kinect and potentially paves the way for low-cost gesture recognition in unconstrained environments

Targeting Conservation Investments in Heterogeneous Landscapes: A distance function approach and application to watershed management

To achieve a given level of an environmental amenity at least cost, decision-makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to supplying an environmental amenity are often known, the way in which these attributes interact to produce the amenity is often unknown. Given the difficulty in converting multiple attributes into a unidimensional physical measure of an environmental amenity (e.g., habitat quality), analyses in the academic literature tend to use a single biophysical attribute as a proxy for the environmental amenity (e.g., species richness). A narrow focus on a single attribute, however, fails to consider the full range of biophysical attributes that are critical to the supply of an environmental amenity. Drawing on the production efficiency literature, we introduce an alternative conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds across a spatially heterogeneous landscape. An approach based on distance functions has the advantage of not requiring a parametric specification of the amenity function (or cost function), but rather only requiring that the decision-maker identify important biophysical and economic attributes. We apply the distance-function approach empirically to an increasingly common, but little studied, conservation initiative: conservation contracting for water quality objectives. The contract portfolios derived from the distance-function application have many desirable properties, including intuitive appeal, robust performance across plausible parametric amenity measures, and the generation of ranking measures that can be easily used by field practitioners in complex decision-making environments that cannot be completely modeled. Working Paper # 2002-01

Shear Viscosity to Entropy Density Ratio in Six Derivative Gravity

We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\alpha'$) and six derivative (with coefficient $\alpha'^2$) terms in bulk action. In general, there can be three possible four derivative terms and ten possible six derivative terms in the Lagrangian. Among them two four derivative and eight six derivative terms are ambiguous, i.e., these terms can be removed from the action by suitable field redefinitions. Rest are unambiguous. According to the AdS/CFT correspondence all the unambiguous coefficients (coefficients of unambiguous terms) can be fixed in terms of field theory parameters. Therefore, any measurable quantities of boundary theory, for example shear viscosity to entropy density ratio, when calculated holographically can be expressed in terms of unambiguous coefficients in the bulk theory (or equivalently in terms of boundary parameters). We calculate $\eta/s$ for generic six derivative gravity and find that apparently it depends on few ambiguous coefficients at order $\alpha'^2$. We calculate six derivative corrections to central charges $a$ and $c$ and express $\eta/s$ in terms of these central charges and unambiguous coefficients in the bulk theory.Comment: 29 pages, no figure, V2, results and typos correcte

Uniqueness Theorem for Generalized Maxwell Electric and Magnetic Black Holes in Higher Dimensions

Based on the conformal energy theorem we prove the uniqueness theorem for static higher dimensional electrically and magnetically charged black holes being the solution of Einstein (n-2)-gauge forms equations of motion. Black hole spacetime contains an asymptotically flat spacelike hypersurface with compact interior and non-degenerate components of the event horizon.Comment: 7 pages, RevTex, to be published in Phys.Rev.D1