Results 1  10
of
16,285
Asymptotic equivalence for nonparametric regression
 Math. Methods Statist
"... Abstract. We consider a nonparametric model En, generated by independent observations Xi, i = 1,..., n, with densities p(x, θi), i = 1,..., n, the parameters of which θi = f(i/n) ∈ Θ are driven by the values of an unknown function f: [0, 1] → Θ in a smoothness class. The main result of the paper i ..."
Abstract

Cited by 22 (0 self)
 Add to MetaCart
is that, under regularity assumptions, this model can be approximated, in the sense of the Le Cam deficiency pseudodistance, by a nonparametric Gaussian shift model Yi = Γ(f(i/n)) + εi, where ε1,..., εn are i.i.d. standard normal r.v.’s, the function Γ(θ) : Θ → R satisfies Γ′(θ) = √I(θ) and I
Studies of transformation of Escherichia coli with plasmids
 J. Mol. Biol
, 1983
"... Factors that affect he probability of genetic transformation f Escherichia coli by plasmids have been evaluated. A set of conditions is described under which about one in every 400 plasmid molecules produces a transformed cell. These conditions include cell growth in medium containing elevated level ..."
Abstract

Cited by 1609 (1 self)
 Add to MetaCart
Factors that affect he probability of genetic transformation f Escherichia coli by plasmids have been evaluated. A set of conditions is described under which about one in every 400 plasmid molecules produces a transformed cell. These conditions include cell growth in medium containing elevated levels of Mg 2+. and incubation of the cells at 0 ~ in a solution of Mn 2+, ("a 2+, Rb + or K +, dimethyl sulfoxide, dithiothreitol, and hexamine cobalt (III). Transibrmation efficiency declines linearly with increasing plasmid size. Relaxed and supercoiled plasmids transfol'm with similar probabilities. Nontransforming DNAs compete consistent with mass. No significant variation is observed between competing DNAs of difi~rent source, complexity, length or form. Competition with both transforming and nontransforming plasmids indicates that each cell is capable of taking up many DNA molecules, and that the establishment of a transformation event is neither helped nor hindered significantly by the presence of multiple plasmids. 1. Introduct ion Both gramposit ive and gramnegative bacteria can take up and stably establish
Entrepreneurship: Productive, Unproductive, and Destructive
 Journal of Political Economy
, 1990
"... The basic hypothesis is that, while the total supply of entrepreneurs varies anlong societies, the productive contribution of the society's entrepreneurial activities varies much more because of their allocation between productive activities such as innovation and largely unproductive activitie ..."
Abstract

Cited by 599 (2 self)
 Add to MetaCart
The basic hypothesis is that, while the total supply of entrepreneurs varies anlong societies, the productive contribution of the society's entrepreneurial activities varies much more because of their allocation between productive activities such as innovation and largely unproductive activities such as rent seeking or organized crime. This allocation is heavily influenced by the relative payoffs society offers to such activities. This implies that policy can influence the allocation of entrepreneurship more effectively than it can influence its supply. Historical evidence from ancient Rome. early China, and the Middle Ages and Renaissance in Europe is used to investigate the hypotheses. It is often assumed that an economy of private enterprise has an automatic bias towards innovation, but this is not so. It has a bias only towards profit. [HOBSBAWM 1969, p. 401 When conjectures are offered to explain historic slowdowns or great leaps in economic growth, there is the group of usual suspects that is I am very grateful for the generous support of the research underlying this paper
The embryonic cell lineage of the nematode Caenorhabditis elegans
 Dev. Biol
, 1983
"... The number of nongonadal nuclei in the freeliving soil nematode Caenorhabditis elegans increases from about 550 in the newly hatched larva to about 810 in the mature hermaphrodite and to about 970 in the mature male. The pattern of cell divisions which leads to this increase is essentially invarian ..."
Abstract

Cited by 503 (16 self)
 Add to MetaCart
The number of nongonadal nuclei in the freeliving soil nematode Caenorhabditis elegans increases from about 550 in the newly hatched larva to about 810 in the mature hermaphrodite and to about 970 in the mature male. The pattern of cell divisions which leads to this increase is essentially invariant among individuals; rigidly determined cell lineages generate a fixed number of progeny cells of strictly specified fates. These lineages range in length from one to eight sequential divisions and lead to significant developmental changes in the neuronal, muscular, hypodermal, and digestive systems. Frequently, several blast cells follow the same asymmetric program of divisions; lineally equivalent progeny of such cells generally differentiate into functionally equivalent cells. We have determined these cell lineages by direct observation of the divisions, migrations, and deaths of individual cells in living nematodes. Many of the cell lineages are involved in sexual maturation. At hatching, the hermaphrodite and male are almost identical morphologically; by the adult stage, gross anatomical differences are obvious. Some of these sexual differences arise from blast cells whose division patterns are initially identical in the male and in the hermaphrodite but later diverge. In the hermaphrodite, these cells produce structures used in egglaying and mating, whereas, in the male, they produce morphologically different structures which function before and during copulation. In addition, development of the male involves a number of lineages derived from cells which do not divide in the hermaphrodite. Similar postembryonic developmental events occur in other nematode species.
Convex Analysis
, 1970
"... In this book we aim to present, in a unified framework, a broad spectrum of mathematical theory that has grown in connection with the study of problems of optimization, equilibrium, control, and stability of linear and nonlinear systems. The title Variational Analysis reflects this breadth. For a lo ..."
Abstract

Cited by 5350 (67 self)
 Add to MetaCart
In this book we aim to present, in a unified framework, a broad spectrum of mathematical theory that has grown in connection with the study of problems of optimization, equilibrium, control, and stability of linear and nonlinear systems. The title Variational Analysis reflects this breadth. For a long time, ‘variational ’ problems have been identified mostly with the ‘calculus of variations’. In that venerable subject, built around the minimization of integral functionals, constraints were relatively simple and much of the focus was on infinitedimensional function spaces. A major theme was the exploration of variations around a point, within the bounds imposed by the constraints, in order to help characterize solutions and portray them in terms of ‘variational principles’. Notions of perturbation, approximation and even generalized differentiability were extensively investigated. Variational theory progressed also to the study of socalled stationary points, critical points, and other indications of singularity that a point might have relative to its neighbors, especially in association with existence theorems for differential equations.
Semantic database modeling: Survey, applications, and research issues
 ACM Computing Surveys
, 1987
"... Most common database management systems represent information in a simple recordbased format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representi ..."
Abstract

Cited by 261 (3 self)
 Add to MetaCart
Most common database management systems represent information in a simple recordbased format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representing structurally complex interrelations among data typically arising in commercial applications. In general terms, semantic modeling complements work on knowledge representation (in artificial intelligence) and on the new generation of database models based on the objectoriented paradigm of programming languages. This paper presents an indepth discussion of semantic data modeling. It reviews the philosophical motivations of semantic models, including the need for highlevel modeling abstractions and the reduction of semantic overloading of data type constructors. It then provides a tutorial introduction to the primary components of semantic models, which are the explicit representation of objects, attributes of and relationships among objects, type constructors for building complex types, ISA relationships, and derived schema components. Next, a survey of the prominent semantic models in the literature is presented. Further, since a broad area of research has developed around semantic modeling, a number of related topics based on these models are discussed, including data languages, graphical interfaces, theoretical investigations, and physical implementation strategies.
Representations of Rigid Solids: Theory, Methods, and Systems
 ACM Computing Surveys
, 1980
"... Computerbased ystems for modehng the geometry ofrigid solid objects are becoming increasingly important inmechanical nd civil engineering, architecture, computer graphics, computer vision, and other fields that deal with spatial phenomena. At the heart of such systems are symbol structures (represe ..."
Abstract

Cited by 254 (2 self)
 Add to MetaCart
Computerbased ystems for modehng the geometry ofrigid solid objects are becoming increasingly important inmechanical nd civil engineering, architecture, computer graphics, computer vision, and other fields that deal with spatial phenomena. At the heart of such systems are symbol structures (representations) designating "abstract solids" (subsets of Euclidean space) that model physical solids. Representations arethe sources of data for procedures which compute useful properties ofobjects. The variety and uses of systems embodying representations f olids are growing rapidly, but so are the difficulties in assessing current designs, pecifying the characteristics that future systems should exhibit, and designing systems t9 meet such specifications. This paper esolves many of these difficulties by providing a coherent view, based on sound theoretical principles, of what is presently known about he representation of solids. The paper is divided into three parts. The first introduces a simple mathematical framework for characterizing certain important aspects of representations, for example, their semantic (geometric) ntegrity. The second part uses the framework to describe and compare all of the major knownschemes fo ~ representing solids. The third part briefly surveys extant geometric modeling systems and then applies the concepts developed in the paper to the highlevel design of a multiple*representation geometric modeling system which exhibits alevel of reliability and versatility supermr to that of systems currently used in industrial computeraided design and manufacturing.
Results 1  10
of
16,285