Membranes, mitochondria and amoebae: shape models

Most real-world shapes and images are characterized by high variability- they are not rigid, like crystals, for example—but they are strongly structured. Therefore, a fundamental task in the understanding and analysis of such image ensembles is the construction of models that incorporate both variability and structure in a mathematically precise way. The global shape models introduced in Grenander's general pattern theory are intended to do this. In this paper, we describe the representation of two-dimensional mitochondria and membranes in electron microscope photographs, and three-dimensional amoebae in optical sectioning microscopy. There are three kinds of variability to all of these patterns, which these representations accommodate. The first is the variability in shape and viewing orientation. For this, the typical structure is represented via linear, circular and spherical templates, with the variability accomodated via the application of transformations applied to the templates. The transformations form groups: scale, rotation and translation. They are locally applied throughout the continuum and of high dimension. The second is the textural variability; the inside and outside of these basic shapes are subject to random variation, as well as sensor noise. For this, statistical sensor models and Markov random field texture models are used to connect the constituent structures of the shapes to the measured data. The third variability type is associated with the fact that each scene is made up of a variable number of shapes; this number is not assumed to be known a priori. Each scene has a variable number of parameters encoding the transformations of the templates appropriate for that scene. For this, a single posterior distribution is defined over the countable union of spaces representing models of varying numbers of shapes. Bayesian inference is performed via computation of the conditional expectation of the parametrically defined shapes under the posterior. These conditional mean estimates are generated using jump-diffusion processes. Results for membranes, mitochondria and amoebae are shown.     

Constituents’ economic interests and senator support for spending limitations

Peltzman [Peltzman, S., 1984. Constituent interest and congressional voting. Journal of Law and Economics 27, 181–210] argues that if constituents’ economic interests have well-defined “winners and losers” and are appropriately measured, then constituents’ economic interests, and not legislator ideology, are the most important determinates of legislator voting. We test Peltzman's theory by examining senatorial voting on three mandated spending limitation bills. We find, consistent with Peltzman's theory, that the ratio of federal spending in a senator's state to federal taxes paid by that state, and not a senator's personal ideology, matters on legislation where there are well-defined economic “winners and losers.” This is particularly important because unlike other constituents’ economic interest measures that only impact a fraction of the constituency, the ratio of federal spending to federal taxes in a state represents the economic interests of all the constituents in a state.     

在应对入世后我国农业面临的挑战中分析测试技术和科学仪器担负的重任

本文概叙了入世后中国农业面临的农产品品质 安全性及价格的三重冲击和应采取的应对措施 着重分析了农产品安全问题和食品安全保障体系的构建 论述了分析测试技术和科学仪器的七项重任     

A Non-parametric Frailty Model for Temporally Clustered Multivariate Failure Times

Abstract A model is introduced here for multivariate failure time data arising from heterogenous populations. In particular, we consider a situation in which the failure times of individual subjects are often temporally clustered, so that many failures occur during a relatively short age interval. The clustering is modelled by assuming that the subjects can be divided into ‘internally homogenous’ latent classes, each such class being then described by a time‐dependent frailty profile function. As an example, we reanalysed the dental caries data presented earlier in Härkänen et al. [Scand. J. Statist. 27 (2000) 577], as it turned out that our earlier model could not adequately describe the observed clustering.     

Physician-nurse migration to the United States: regional and health status origins in relation to legislation and policy

This article examines the origins of physicians and nurses who were admitted as permanent immigrants to the US from 1962-1979. Data are mainly from the Immigration and Naturalization Service. Countries used in the developmental analysis are only those whose population was estimated at 1 million or more as of mid-1979, encompassing 99% of the physicians and 97% of the nurses. Life expectancy at birth is the criterion used to differentiate origin countries by developmental dimension of health status. During the study period, health workers constituted about 30% of immigrants admitted to the US; of these, nurses and physicians constituted 72-82% throughout the study period. The period 1962-1979 has 4 distinct phases, marked by important legislative and/or policy changes; 1) 1962-1965, when the McCarran-Walter Act prevailed; 2) ending in 1968, the 2nd phase covers the transition mandated under the 1965 Immigration Act, which encouraged physician immigration; 3) the 3rd phase, 1969-1976, covers the transition to the 1976 Immigration and Nationality Act amendments; and 4) the 4th stage is 1977-1979. Results show that 1) under the McCarran-Walter Act, North America became the dominant physician source; 2) from 1966-1968, Asia attained dominance as the physician source and became even more predominant after 1968; 3) North America produced relatively few physicians in the early 1970s; 4) Europe produced substantially fewer physicians in the 1970s than in the 1960s; 5) South America, Africa, and Oceania were the lowest contributors of physicians; 6) during the McCarran-Walter years, North America and Europe produced almost 90% of nurses admitted into the US; 7) the 1965 Immigration Act and its aftermath resulted in Asia becoming the dominant source of nurses; 8) prior to the 1965 Immigration Act, Canada generated 20% of the aggregate number of physicians; 9) the Philippines surpassed Canada during the transition and India led after the transition; and 10) Canada supplied 30% of the nurses up through the transition, with the Philippines in the lead 1969-1979. Low health status countries were a relatively minor nurse source. Health status at the origin was a far less significant determinant of physician immigration than that of nurses. English language high and low health status country groups produced substantially more physician and nurse immigrants that their corresponding non-English language counterparts. The US attracted more physicians and nurses from less developed countries than more developed countries after 1968.     

General characteristics of the electronic data processing system for the national census of 1988

The author describes in detail the procedures used in transferring population census data from the individual questionnaires to machine-readable form and the interim controls employed in the Central Statistical Agency of Poland and its regional offices.     

The influence of income on family fertility in the light of the results of empirical studies

Based on data from the 1973-83 Polish Family Budget Survey, this study examines the influence of income as a source of maintenance and income as a determinant of childbearing on family parity. It is assumed that income influences parity as a source of maintenance and as an influence on lifestyle or reproductive behavior. As a source of maintenance, the influence will be positive. As a life-style factor, it could be positive or negative. The hypotheses are 1) that positive influences are characteristics of older couples with a lower educational level and living in villages and small towns and income is a source of maintenance, and 2) a negative influence on parity reflects younger couples with higher educational levels from larger cities and income is a life-style factor. Some examples of how the theory of income influences total fertility are given in addition to a further elaboration of the theory. Other concepts introduced, as related to childbearing, are the value of goods and services with unchanged preferences and an increase in income, with preferences changing with income increases, with income preferences for nonprocreational and for procreational needs, and income as a factor influencing procreational needs and behavior. Correlation analysis is conducted for 33 subpopulations based on duration of marriage, educational level of the household, and size of residence. The results indicate that, in years 1973, 1975, and 1978 when income and parity are significant, the sign is positive. In 1980, there was a decrease in the number of subpopulations with a significant relationship, and in 3 subpopulations the results were negative. The 13 positive subpopulations were similar to those in the 1970s. In 1983, income explained an even smaller amount of parity. The subpopulations with a postive relationship usually have longer marriage durations, which suggest income as a source of maintenance. Negative results were among subpopulations with shorter marriage durations, which suggests life-style factor effects of income.     

Mortality among three Puerto Rican populations: residents of Puerto Rico and migrants in New York City and in the balance of the United States, 1979-81

"This study attempts to explain similarities and differences in the mortality experience of three population groups: Puerto Ricans on the island commonwealth, Puerto Rican born persons in New York City and Puerto Rican born persons in the rest of mainland United States. Mortality is much higher among Puerto Ricans in New York City than among those residing elsewhere. Much of the difference is due to excess mortality caused by cirrhosis of the liver and homicide. Puerto Rican born persons living on the mainland but outside New York City generally have low mortality, even when compared with U.S. whites."     

Gambling and the Law®: Endless fields of dreams

This article examines the current trends of proliferation of commercial gaming, especially in the United States, in the context of the third wave of legalization of gambling that has been experienced since the founding of the nation. The author looks at the historic foundations of the spread of casino-style gambling, and notes the types of casino gaming that have led the way in the current expansion. He also points out why it is reasonable to expect that this wave too may come crashing down, as general acceptance of wide-spread casino gaming in America may indeed be short-lived.Gambling and the Law^® is a registered trademark of I. Nelson Rose.