Characterization of interstitial stem cells in hydra by cloning

A procedure has been developed for cloning interstitial stem cells from hydra. Clones are prepared by introducing small numbers of viable cells into aggregates of nitrogen mustard-inactivated host tissue. Clones derived from added stem cells are identified after 1–2 weeks of growth by staining with toluidine blue. The incidence of clones increases with increasing input of viable cells according to one-hit Poisson statistics, indicating that clones arise from single cells. After correction for cell losses in the procedure, about 1.2% of the input cells are found to form clones. This compares with estimates from in vivo experiments of about 4% stem cells in whole hydra [David, C. N., and Gierer, A. (1974). Cell cycle kinetics and development of Hydra attenuata. III. Nerve and nematocyte differentiation. J. Cell Sci. 16, 359–375.] Differentiation of nematocytes and nerve cells in clones was analyzed by labeling precursors with [3H]thymidine and scoring labeled nerves and nematocytes 2 days later. Nine clones examined in this way contained both differentiated nerve cells and nematocytes, demonstrating that the interstitial stem cell is multipotent. This result suggests that the observed localization of nerve and nematocyte differentiation in whole hydra probably occurs at the level of stemcell determination. The observation that differentiated cells occur very early in clone development suggests that a stem cell's decision to proliferate or differentiate is regulated by shortrange feedback signals which are already saturated in young clones

Debt Instruments and Eurosystem Eligible Assets — Some Developments from an Irish Perspective

Changing demands of market investors, combined with developments in risk management and have led to huge changes in the type and volume of debt instruments issued in recent years.

The Volcker Rule: A Legal Analysis

This report provides an introduction to the Volcker Rule, which is the regulatory regime imposed upon banking institutions and their affiliates under Section 619 of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (P.L. 111-203). The Volker Rule is designed to prohibit “banking entities” from engaging in all forms of “proprietary trading” (i.e., making investments for their own “trading accounts”)—activities that former Federal Reserve Chairman Paul A. Volcker often condemned as contrary to conventional banking practices and a potential risk to financial stability. The statutory language provides only general outlines of prohibited activities and exceptions. Through it, however, Congress has empowered five federal financial regulators with authority to conduct coordinated rulemakings to fill in the details and complete the difficult task of crafting regulations to identify prohibited activities, while continuing to permit activities considered essential to the safety and soundness of banking institutions or to the maintenance of strong capital markets. In December 2014, more than two years after enactment of the law, coordinated implementing regulations were issued by the Office of the Comptroller of the Currency (OCC), the Federal Deposit Insurance Corporation (FDIC), the Board of Governors of the Federal Reserve System (FRB), the Securities and Exchange Commission (SEC), and the Commodity Futures Trading Commission (CFTC). The Rule is premised on a two-pronged central core restricting activities by “banking entities”—a term that includes all FDIC-insured bank and thrift institutions; all bank, thrift, or financial holding companies; all foreign banking operations with certain types of presence in the United States; and all affiliates and subsidiaries of any of these entities. Specifically, the Rule broadly prohibits banking entities from engaging in “proprietary trading” and from making investments in or having relationships with hedge and similar “covered funds” that are exempt from registering with the CFTC as commodity pool operators or with the SEC under the Investment Advisors Act. The Rule couples its broad prohibitions with numerous exclusions and by designating myriad activities as permissible so long as various terms and conditions are met, unless they otherwise would involve or result in a material conflict of interest; a material exposure to high-risk assets or high-risk trading strategies; pose a threat to the safety and soundness of the banking entity; or pose a threat to the financial stability of the United States. The exceptions to the ban on proprietary trading include underwriting by securities underwriters; market-making “designed not to exceed the reasonably expected near term demands of clients”; trading in government securities; fiduciary activities; insurance company portfolio investments; and risk-mitigating hedging activities. The ban on investing in and owning “covered funds” exempts certain types of funds, under specified conditions, and permits de minimis investment in any such fund up to 3% of the outstanding ownership interests of the fund with an aggregate cap on the total ownership interest in “covered funds” of 3% of the banking entity’s core capital. To prevent evasion, the Rule has extensive requirements mandating comprehensive compliance programs that include ongoing management involvement, precise metrics measuring risk assessment, verification and documentation of any activities conducted under one of the Rule’s exceptions or exclusions, and recurring reports and assessments. Full compliance is required by July 21, 2015, subject to the possibility that further extensions may be provided by the regulators. In the case of investments involving “illiquid funds” subject to contractual provisions seriously impacting their marketability or sale, full divestiture might not be required until July 21, 2022

Intake Ground Vortex Prediction Methods

For an aircraft turbofan engine in ground operations or during the take-off run a ground vortex can occur which is ingested and could potentially adversely affect the engine performance and operation. The vortex characteristics depend on the ground clearance, intake flow capture ratio and the relative wind vector. It is a complex flow for which there is currently very little appropriate quantitative preliminary design information. These aspects are addressed in this work where a range of models are developed to provide a method for estimating the key metrics such as the formation boundary and the ground vortex size and strength. Three techniques are presented which utilize empirical, analytical and semi-empirical approaches. The empirical methods are primarily based on a large dataset of model-scale experiments which quantitatively measured the ground vortex characteristics for a wide range of configurations. These include the effects of intake ground clearance, approaching boundary layer thickness, intake Mach number and capture velocity ratio. Overall the models are able to predict some of the key measured behaviours such as the velocity ratio for maximum vortex strength. With increasing empiricism for key sub-elements of the model construction, an increasing level of agreement is found with the experimental results. Overall the three techniques provide a relatively quick and easy method in establishing the important vortex characteristics for a given headwind configuration which is of significant use from a practical engineering perspective

Searching for New Physics in the Three-Body Decays of the Higgs-like Particle

We show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay $h \to Z \ell \bar{\ell}$, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.Comment: 20 pages, 5 figures, matches version published in JHE