A fluorometric method for the estimation of tryptophan

The various colorimetric methods now employed for the estimation of tryptophan are not specific for tryptophan but give colored products with many compounds containing the indole nucleus, including indole itself. In order to facilitate studies of the enzymatic synthesis of tryptophan from indole and serine by extracts of Neurospora (1), a search for a rapid, quantitative method for the estimation of tryptophan in the presence of indole was undertaken. Tauber (2) reported that tryptophan gives a green fluorescence when treated with 70 to 72 per cent perchloric acid at room temperature. Modification of this procedure has led to a method for the rapid estimation of tryptophan, without preliminary extraction of indole, in hydrolyzed or unhydrolyzed tryptophan-containing materials

Determining dust temperatures and masses in the Herschel era: The importance of observations longward of 200 micron

Context. The properties of the dust grains (e.g., temperature and mass) can be derived from fitting far-IR SEDs (≥100 μm). Only with SPIRE on Herschel has it been possible to get high spatial resolution at 200 to 500 μm that is beyond the peak (~160 μm) of dust emission in most galaxies. Aims. We investigate the differences in the fitted dust temperatures and masses determined using only 200 μm data (new SPIRE observations) to determine how important having >200 μm data is for deriving these dust properties. Methods. We fit the 100 to 350 μm observations of the Large Magellanic Cloud (LMC) point-by-point with a model that consists of a single temperature and fixed emissivity law. The data used are existing observations at 100 and 160 μm (from IRAS and Spitzer) and new SPIRE observations of 1/4 of the LMC observed for the HERITAGE key project as part of the Herschel science demonstration phase. Results. The dust temperatures and masses computed using only 100 and 160 μm data can differ by up to 10% and 36%, respectively, from those that also include the SPIRE 250 & 350 μm data. We find that an emissivity law proportional to λ^(−1.5) minimizes the 100–350 μm fractional residuals. We find that the emission at 500 μm is ~10% higher than expected from extrapolating the fits made at shorter wavelengths. We find the fractional 500 μm excess is weakly anti-correlated with MIPS 24 μm flux and the total gas surface density. This argues against a flux calibration error as the origin of the 500 μm excess. Our results do not allow us to distinguish between a systematic variation in the wavelength dependent emissivity law or a population of very cold dust only detectable at λ ≥ 500 μm for the origin of the 500 μm excess

Losing the War Against Dirty Money: Rethinking Global Standards on Preventing Money Laundering and Terrorism Financing

Following a brief overview in Part I.A of the overall system to prevent money laundering, Part I.B describes the role of the private sector, which is to identify customers, create a profile of their legitimate activities, keep detailed records of clients and their transactions, monitor their transactions to see if they conform to their profile, examine further any unusual transactions, and report to the government any suspicious transactions. Part I.C continues the description of the preventive measures system by describing the government\u27s role, which is to assist the private sector in identifying suspicious transactions, ensure compliance with the preventive measures requirements, and analyze suspicious transaction reports to determine those that should be investigated. Parts I.D and I.E examine the effectiveness of this system. Part I.D discusses successes and failures in the private sector\u27s role. Borrowing from theory concerning the effectiveness of private sector unfunded mandates, this Part reviews why many aspects of the system are failing, focusing on the subjectivity of the mandate, the disincentives to comply, and the lack of comprehensive data on client identification and transactions. It notes that the system includes an inherent contradiction: the public sector is tasked with informing the private sector how best to detect launderers and terrorists, but to do so could act as a road map on how to avoid detection should such information fall into the wrong hands. Part I.D discusses how financial institutions do not and cannot use scientifically tested statistical means to determine if a particular client or set of transactions is more likely than others to indicate criminal activity. Part I.D then turns to a discussion of a few issues regarding the impact the system has but that are not related to effectiveness, followed by a summary and analysis of how flaws might be addressed. Part I.E continues by discussing the successes and failures in the public sector\u27s role. It reviews why the system is failing, focusing on the lack of assistance to the private sector in and the lack of necessary data on client identification and transactions. It also discusses how financial intelligence units, like financial institutions, do not and cannot use scientifically tested statistical means to determine probabilities of criminal activity. Part I concludes with a summary and analysis tying both private and public roles together. Part II then turns to a review of certain current techniques for selecting income tax returns for audit. After an overview of the system, Part II first discusses the limited role of the private sector in providing tax administrators with information, comparing this to the far greater role the private sector plays in implementing preventive measures. Next, this Part turns to consider how tax administrators, particularly the U.S. Internal Revenue Service, select taxpayers for audit, comparing this to the role of both the private and public sectors in implementing preventive measures. It focuses on how some tax administrations use scientifically tested statistical means to determine probabilities of tax evasion. Part II then suggests how flaws in both private and public roles of implementing money laundering and terrorism financing preventive measures might be theoretically addressed by borrowing from the experience of tax administration. Part II concludes with a short summary and analysis that relates these conclusions to the preventive measures system. Referring to the analyses in Parts I and II, Part III suggests changes to the current preventive measures standard. It suggests that financial intelligence units should be uniquely tasked with analyzing and selecting clients and transactions for further investigation for money laundering and terrorism financing. The private sector\u27s role should be restricted to identifying customers, creating an initial profile of their legitimate activities, and reporting such information and all client transactions to financial intelligence units

Common-Resolution Convolution Kernels for Space- and Ground-Based Telescopes

Multi-wavelength study of extended astronomical objects requires combining images from instruments with differing point spread functions (PSFs). We describe the construction of convolution kernels that allow one to generate (multi-wavelength) images with a common PSF, thus preserving the colors of the astronomical sources. We generate convolution kernels for the cameras of the Spitzer Space Telescope, Herschel Space Observatory, Galaxy Evolution Explorer (GALEX), Wide-field Infrared Survey Explorer (WISE), ground-based optical telescopes (Moffat functions and sum of Gaussians), and Gaussian PSFs. These kernels allow the study of the Spectral Energy Distribution (SED) of extended objects, preserving the characteristic SED in each pixel. The convolution kernels and the IDL packages used to construct and use them are made publicly available

Electron yields from spacecraft materials

Photoyields and secondary electron emission (SEE) characteristics were determined under UHV conditions for a group of insulating materials used in spacecraft applications. The SEE studies were carried out with a pulsed primary beam while photoyields were obtained with a chopped photon beam from a Kr resonance source with major emission at 123.6 nm. This provides a photon flux close to that of the Lyman alpha in the space environment. Yields per incident photon are obtained relative to those from a freshly evaporated and air oxidized Al surface. Results are presented for Kapton, FEP Teflon, the borosilicate glass covering of a shuttle tile, and spacesuit outer fabric