Platelet aggregation inhibiting and anticoagulant effects of oligoamines, XX: 4,4',4'-(1,3,5)-benzene-tris-sydnone imines

The synthesis of ten tris-sydnone imine derivatives, unknown up to now, is described. All compounds are alkyl or arylalkyl substituted in 3-position of the sydnone imine. The most powerful agent was the 3-propyl derivative 6c. It inhibits the aggregation of human platelets induced by collagen in a concentration of 1 mumol/L half maximally. Its N-ethoxycarbonyl derivative 7c, which was designed as a prodrug, showed only small antithrombotic effects in rats. The reason for this low degree of activity is discussed.     

A behavioral analysis of effective teaching.

Characterizes classroom instruction (CRI) from a behavior analytic perspective. It is argued that effective teaching strategies also serve managerial functions through the development of stimulus control and the management of behavioral choice. The stimulus control properties of CRI are discussed, and research concerning the effects of antecedent events on children's academic performance is reviewed. A theory for predicting choices in behavior, known as matching theory, is presented that evolved out of experimental operant research. The characteristics of CRI that make it particularly suited to matching theory analysis are identified, and research applying matching theory to children's classroom behavior is reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Property Owning and Democracy-Do the Twain Ever Meet?

Starting from the Conservative assertion that home ownership fosters politically active and virtuous citizens, this paper examines two lines of argument in housing theory; (a) Jim Kemeny's thesis that owner occupation is closely linked to increasing privatism, i.e. a growth in lifestyles centred around the home and privacy rather than the workplace or the public affairs in a society, and (b) Peter Saunders' thesis that home owners will organise and mobilise politically in defence of their property interests if and when various government agencies threaten to remove their tax subsidies. To test these propositions empirically, data on the effects of the rapid and comprehensive dismantling of tax privileges to Swedish home owners in the 1980s and early 1990s are confronted with data on political interest, participation and knowledge as well as civic trust and responsibility from the Swedish election surveys of 1979, 1985 and 1991. Contrary to Conservative beliefs, home owners do not stand out as 'democratic examples'; with the exception of political knowledge and party membership, they are no more 'civil' or 'democratic' than other citizens. There is also not much to support Kemeny's 'privatism' or Saunders' 'reaction-to-threat' theses. Although home owners in Sweden saw their tax privileges diminishing rapidly during the 1980s and early 1990s, they do not show the distinctive patterns of change in democratic orientation and spirit predicted by these two housing theorists. To allow for an even more conclusive test of Kemeny's 'privatism' thesis, however, one must overcome the mismatch of income definitions in housing statistics and election survey data.     

Remarks on the mean square tracking error

The purpose of this paper is to extend recent results of Ljung and Priouret to a more general class of regressors.     

Psychometric considerations in the dimensional analysis of subjective picture quality

A discussion of the factors involved in the subjective perception of television picture quality is presented. Much of the work in this field is cited, and it is concluded that future work needs to consider a broader range of variables than has been looked at so far.     

Eigenschaften,Anwendungsgebiete und physiko-chemische Untersuchungen von Polyethercarbonsäuren und ihren Salzen

Properties, Fields of Application and Physicochemical Research of Polyether Carbon Acids and their Salts There is a wide scope of application for polyether carbon acids as washing agents, detergents, body shampoos, emulsifiers for naphtha and as resources in the textile, printing, paper, plastic, metal and pharmaceutic industry because of the properties of these products, such as very good solubility even in aqueous inorganic salts solutions, indifference to hardness salts and hydrolysis, nontoxicity as well as a good soil-suspending power. A comprehensive compilation report of patents and scientific literature is presented in this paper. Relationships between the structure and the effect of selected polyether carboxylates are interpreted by own physicochemical research.     

A high-resolution burst-mode laser transmitter with fast and accurate level monitoring for 1.25 Gb/s upstream GPONs

An innovative burst-mode laser transmitter (BM-TX) is presented for gigabit-capable passive optical network (GPON) upstream transmission at 1.25 Gb/s. The laser bias and modulation current each can reach 80 mA with a resolution of 0.1 mA providing a total drive current up to 160 mA. Both currents are generated by 10-bit current steering digital-to-analog converters (DACs), the architecture of which is specially adapted to yield a monotonic current setting at settling times below 12.8 ns. Tests show that fast automatic power control (APC) can stabilize and track the launched optical power with a tolerance of less than 1 dB over a wide temperature range for outdoor operation. The APC only requires a straightforward calibration of the "0" and the "1" level at room temperature. Optical level monitoring on strings of four consecutive "0" bytes and two consecutive "1" bytes at 1.25 Gb/s is demonstrated. APC based on such short strings of data has not been shown before. The circuits have been designed in a 0.35 /spl mu/m SiGe BiCMOS process. Experimental results show that this dc-coupled BM-TX meets the specifications of the recently approved ITU-T Recommendation G.984.2 supporting an intelligent power leveling mechanism (PLM).     

The impact of CHP generation on CO2 emissions

The combined generation of heat and power (cogeneration) is praised by many as a technique for reducing the emissions of CO₂ in industrialized nations. This is generally true but not always. In this article we discuss the impact of some major variables on the CO₂ emission reduction capacity of cogeneration. Two sets of variables are predominant: the characteristics of the CHP process and the composition of the electricity generation sector. We highlight the interaction between the two sets of variables with the help of diagrams.     

Performance analysis of general tracking algorithms

A general family of tracking algorithms for linear regression models is studied. It includes the familiar least mean square gradient approach, recursive least squares, and Kalman filter based estimators. The exact expressions for the quality of the obtained estimates are complicated. Approximate, and easy-to-use, expressions for the covariance matrix of the parameter tracking error are developed. These are applicable over the whole time interval, including the transient, and the approximation error can be explicitly calculated