The formation and evolution of the Society of Nuclear Medicine

The Society of Nuclear Medicine was created and constructed by persons from many branches of medicine and the physical sciences, but it originated mostly in the mind of a chemist-physicist-engineer named Norman "Jeff" Holter. Because most medical organizations seemed to care little about the use of radioactive materials for medical purposes, Holter believed a new organization was necessary for their promotion. From its origin in 1954 as the Pacific Northwest Society of Nuclear Medicine, The Society of Nuclear Medicine became a national, multidisciplinary organization in 1956. Rapidly gathering strength with an expanding membership, it employed an administrator in 1959. With this administrator and a dedicated volunteer editor, publication of the Journal of Nuclear Medicine began. Over the next several years the Society evolved into an active force in the development of the application of radioactivity to medical applications. It generated significant internal initiatives and participated in the generation of several important external institutions. The Society of Nuclear Medicine developed a tradition of annual meetings with strong educational programs for all members. By nurturing and embracing the Technologist Section, the Society became a robust and representative organization for all who serve nuclear medicine. From these beginnings came the vigorous Society of Nuclear Medicine of today. Jeff Holter (1914-1983) would be justifiably proud.     

GOST 34.10—A brief overview of Russia's DSA

GOST 34.10 is Russia's DSA. Like its US counterpart, GOST is an ElGamal-like signature scheme used in Schnorr mode. It is similar to NIST DSA in many aspects. In this paper we will overview GOST 34.10 and discuss the three main differences between the two algorithms, (i) GOST's principal design criterion does not seem to be computational efficiency: the algorithm is 1.6 times slower than the DSA and produces 512-bit signatures. This is mainly due to the usage of the modulus q which is at least 254 bits long. During verification, modular inverses are computed by exponentiation (while the Extended Euclidian algorithm is roughly 100 times faster for this parameter size) and the generation of the public parameters is much more complicated than in the DSA. This choice of the parameters makes GOST 34.10 very secure. (ii) GOST signers do not have to generate modular inverses as the basic signature equation is s = xr + mk (mod q) instead of (mod q). (iii) GOST's hash function (the Russian equivalent of the SHA) is the standard GOST 34.11 which uses the block cipher GOST 28147 (partially classified) as a building block. The hash function will be briefly described. Copyright     

Range mode and range median queries in constant time and sub-quadratic space

Given a list of n items and a function defined over sub-lists, we study the space required for computing the function for arbitrary sub-lists in constant time.For the function mode we improve the previously known space bound O(n²/logn) to O(n²loglogn/log²n) words.For median the space bound is improved to O(n²loglog²n/log²n) words from O(n²⋅log(k)n/logn), where k is an arbitrary constant and log(k) is the iterated logarithm.     

Prioritizing agile benefits and limitations in relation to practice usage

In recent years, there has been significant shift from rigid development (RD) toward agile. However, it has also been spotted that agile methodologies are hardly ever followed in their pure form. Hybrid processes as combinations of RD and agile practices emerge. In addition, agile adoption has been reported to result in both benefits and limitations. This exploratory study (a) identifies development models based on RD and agile practice usage by practitioners; (b) identifies agile practice adoption scenarios based on eliciting practice usage over time; (c) prioritizes agile benefits and limitations in relation to (a) and (b). Practitioners provided answers through a questionnaire. The development models are determined using hierarchical cluster analysis. The use of practices over time is captured through an interactive board with practices and time indication sliders. This study uses the extended hierarchical voting analysis framework to investigate benefit and limitation prioritization. Four types of development models and six adoption scenarios have been identified. Overall, 45 practitioners participated in the prioritization study. A common benefit among all models and adoption patterns is knowledge and learning, while high requirements on professional skills were perceived as the main limitation. Furthermore, significant variances in terms of benefits and limitations have been observed between models and adoption patterns. The most significant internal benefit categories from adopting agile are knowledge and learning, employee satisfaction, social skill development, and feedback and confidence. Professional skill-specific demands, scalability, and lack of suitability for specific product domains are the main limitations of agile practice usage. Having a balanced agile process allows to achieve a high number of benefits. With respect to adoption, a big bang transition from RD to agile leads to poor quality in comparison with the alternatives.     

Nonlinear robust state feedback control system design for nonlinear uncertain systems

This paper presents a systematic approach to the design of a nonlinear robust dynamic state feedback controller for nonlinear uncertain systems using copies of the plant nonlinearities. The technique is based on the use of integral quadratic constraints and minimax linear quadratic regulator control, and uses a structured uncertainty representation. The approach combines a linear state feedback guaranteed cost controller and copies of the plant nonlinearities to form a robust nonlinear controller with a novel control architecture. A nonlinear state feedback controller is designed for a synchronous machine using the proposed method. The design provides improved stability and transient response in the presence of uncertainty and nonlinearity in the system and also provides a guaranteed bound on the cost function. An automatic voltage regulator to track reference terminal voltage is also provided by a state feedback equivalent robust nonlinear proportional integral controller. Copyright © 2016 John Wiley & Sons, Ltd.     

Stability analysis and state feedback stabilization of pendulum-like systems with multiple nonlinearities

This paper addresses the Lagrange stability analysis problem and the state feedback Lagrange stabilization problem for pendulum-like systems with multiple nonlinearities. An existing method for analysing the Lagrange stability of pendulum-like systems with a single nonlinearity is generalized to pendulum-like systems with multiple nonlinearities. Also, a non-degeneracy condition of the existing Lagrange stability criterion is removed and a strict frequency-domain inequality is used instead. To study the state feedback Lagrange stabilization problem, this paper develops an extended strict bounded real lemma for linear systems which are not stable but stabilizable. A sufficient condition for state feedback Lagrange stabilization is proposed in terms of an algebraic Riccati equation with a sign indefinite solution.     

Interaction between radiation and drug damage in mammalian cells. II. The effect of actinomycin-D on the repair of the sublethal radiation damage in plateau phase cells

The effect of actinomycin-D (AMD) on radiation damage repair was studied in plateau phase V79 Chinese hamster cells. Sublethal radiation damage repair, as demonstrated by survival fluctuations following two x-ray exposures separted by time, was observed in our plateau phase cells. Plateau phase cells exposed to 0.01-0.04 mug/ml AMD (a nontoxic regimen to 8 hours) between x-ray exposures were less able to repair sublethal damage. If plateau phase cells were plated at low dilutions into fresh medium (conditions for resuming exponential growth) immediately after the first x-ray dose, and exposed to 0.01--0.04 mug/ml AMD until the second dose, inhibition of sublethal damage repair and additional cell killing were observed particularly at 0.04 mug/ml AMD. It is suggested that radiation-drug damage interactions should be studied in plateau phase cells and in cells resuming exponential growth after plateau phase (possibly analogous to "recruitment"), as well as in exponential phase cultures.     

Effects of hypothalamic temperature changes on the sweat rate in Macaca mulatta

The concept of cardiac reconditioning centers for the prevention and rehabilitation of coronary patients has been tremendously successful in Germany over the past 20 years. At least 40 such centers are located throughout the country. Physicians, nurses, and physical therapists work closely together in the various facets of the rehabilitation process. The financial backing for these facilities is primarily through governmental and regional insurance companies, whose officials are apparently convinced that in the long run supporting preventive measures is financially sound. Objective data supporting their convictions come from studies such as that of Brusis, who showed that such as that of 1,500 employees was diminished by nearly 70 percent during a two-year period after cardiac reconditioning, as compared to a similar time period before the rehabilitation experience. Subjective benefits, which are extremely difficult to quantitate in meaningful terms, were nonetheless expressed by nearly all the patients with whom I conversed. Perhaps they have experienced the same feelings that Mark Twain did when he observed that "all frets and worries and chafings sank to sleep in the presence of the benignant serenity of the Alps; the Great Spirit of the Mountains breathed his own peace upon their hurt minds and sore hearts and healed them."