Monitoring Proteolysis During Cheddar Cheese Ripening Using Two-Dimensional Gel Electrophoresis

A 2-D gel electrophoretic method, consisting of isoelectric focusing and alkaline urea-PAGE was used to monitor proteolysis during ripening (180d, 5°C and 8°C) of full- and reduced-fat Cheddar cheese. The method enabled quantifying changes in levels of peptides in cheese with good spot-resolution. Results can complement those from other analyses, especially those for determining low MW peptides. Notable effects were found for cheese composition and ripening temperature on gel pattern and on relative levels of selected proteolysis products. In both cheese varieties, most peptides reached a maximum during the first 3 ripening months and gradually disappeared as ripening advanced.     

The role of diffusion in determining the controlling creep mechanisms in Al-Zn solid-solutions: Part I

This is the first of a two part paper in which the role of diffusion in determining the rate controlling creep mechanisms in binary solid solutions is investigated. Part I deals with the appropriate diffusion coefficients for climb and glide controlled creep, while Part II involves a comparison of the climb and glide creep equations with experiment. The first part begins with a review of a number of diffusion coefficients that have been proposed for creep in binary solid solutions. We show that the diffusion coefficient for climb is while that for glide is . Two other diffusion coefficients that have been used in the literature are shown to be incorrect. To experimentally verify the theoretical diffusion coefficients, the creep behavior of Al-Zn alpha solid solutions was studied over a composition range of 0 to 60 at. pct Zn. Values of and the thermodynamic factor (1 +d lnγ _i/d lnX i) are taken from the literature and used to calculate D_cland D_glas a function of composition at 360 and 410°. It is found that the thermodynamic factor strongly affects the diffusion coefficientD _gl for glide-controlled creep. When these curves forD _cl andD _gl are compared with experimental creep data for the Al-Zn system,D _gl is found to explain the decrease in creep rate observed at the miscibility gap composition. Formerly Graduate Research Assistant     

Propagation dynamics of ultra-short high-power laser pulses in air: supercontinuum generation and transverse ring formation

Numerical and semi-analytical results of the propagation of high-power ultra-short near IR laser pulses propagating in ionizing air are presented.     

Book Notices

The variable gradient method was used to generate a Lyapunov function for the system of first-order differential equations describing the synchronous machine, and Fallside and Patel (1966) used this V-function to estimate the domain of stability of the system.

This particular problem, as mentioned by Barbashin (1961), was solved by Yanko-Trinitsky (1958). Trinitsky, according to Barbashin, used the ‘ separation of variables ’ method to generate his V-function, and in his analysis, he included second-order terms, which is more general than the problem solved by Fallside and Patel (1966).     

THE LIMITS AND POTENTIAL OF NONPROFIT ORGANIZATIONS IN PARTICIPATORY PLANNING: A CASE STUDY OF THE NEW YORK HIV PLANNING COUNCIL

ABSTRACT: In addition to providing a wide range of essential services in local communities, service‐providing nonprofit organizations play an important role in shaping de facto local social policy through their participation in community‐based planning processes that guide or determine the distribution of federal funding for health and social services. This social policy role has become increasingly important in the United States as the federal government continues to privatize health and human services through providing grant funds to states and cities that are ultimately used to support local nonprofit health and social service organizations. The important role of service‐providing nonprofits in shaping local social policy has been understudied, as most studies on nonprofits and policy‐making focus on citizen advocacy organizations and their lobbying and protest activities, primarily at the national level. This study uses the case of the New York HIV Planning Council to address this gap in the literature, highlighting the benefits and pitfalls of an urban community planning process dominated by service providers from local nonprofit social service organizations whose own organizations are affected by the planning group's decisions. Factors that contributed to nonprofit providers' dominance as well as factors that limited their self‐interested behavior are reviewed. The relationship between the HIV nonprofit service system and the AIDS social movement is explored in light of theory on new social movements to help explain why nonprofit providers were sometimes able to promote attentiveness to the general public good while also advocating for their more self‐interested organizational needs.     

Occurrence and Flavor Properties of Sinigrin Hydrolysis Products in Fresh Cabbage

Contrary to a published report, allyl isothiocyanate was confirmed as a major volatile sulfur compound along with 1-cyano-2,3-epithiopropane in dichloromethane extracts of freshly disrupted cabbage tissues resulting from thioglucosidase hydrolysis of allyl glucosinolate (sinigrin). Compared to authentic allyl isothiocyanate which had characteristic sharp, black mustard-like aroma notes, authentic 1-cyano-2,3-epithiopropane had weak, musty, sulfurous, and mustard-like aromas. Based on calculations of odor units (U_o) using data from the analysis of disrupted cabbage tissues, allyl isothiocyanate would contribute appreciably (to 245 U_o) while 1-cyano-2,3-epithiopropane would not likely contribute notably (<0.8 U_o) to fresh cabbage flavors.