The growth and composition of branching populations

1984 ◽  
Vol 16 (2) ◽  
pp. 221-259 ◽  
Author(s):  
Peter Jagers ◽  
Olle Nerman
Keyword(s):  
Exponential Growth ◽  
Probability Space ◽  
Point Processes ◽  
Age Distribution ◽  
Single Type ◽  
Survey Paper ◽  
Stable Age Distribution ◽  
Definition Of ◽  
Counting Yield ◽  
Strict Definition

A single-type general branching population develops by individuals reproducing according to i.i.d. point processes on R+, interpreted as the individuals' ages. Such a population can be measured or counted in many different ways: those born, those alive or in some sub-phase of life, for example. Special choices of reproduction point process and counting yield the classical Galton–Watson or Bellman–Harris process. This reasonably self-contained survey paper discusses the exponential growth of such populations, in the supercritical case, and the asymptotic stability of composition according to very general ways of counting. The outcome is a strict definition of a stable population in exponential growth, as a probability space, a margin of which is the well-known stable age distribution.

The growth and composition of branching populations

1984 ◽  
Vol 16 (02) ◽  
pp. 221-259 ◽  
Author(s):  
Peter Jagers ◽  
Olle Nerman
Keyword(s):  
Exponential Growth ◽  
Probability Space ◽  
Point Processes ◽  
Age Distribution ◽  
Single Type ◽  
Survey Paper ◽  
Stable Age Distribution ◽  
Definition Of ◽  
Counting Yield ◽  
Strict Definition

A single-type general branching population develops by individuals reproducing according to i.i.d. point processes on R +, interpreted as the individuals' ages. Such a population can be measured or counted in many different ways: those born, those alive or in some sub-phase of life, for example. Special choices of reproduction point process and counting yield the classical Galton–Watson or Bellman–Harris process. This reasonably self-contained survey paper discusses the exponential growth of such populations, in the supercritical case, and the asymptotic stability of composition according to very general ways of counting. The outcome is a strict definition of a stable population in exponential growth, as a probability space, a margin of which is the well-known stable age distribution.

Exponential growth of a branching process usually implies stable age distribution

1979 ◽  
Vol 16 (03) ◽  
pp. 651-656
Author(s):  
Bo Berndtsson ◽  
Peter Jagers
Keyword(s):  
Population Size ◽  
Exponential Function ◽  
Exponential Growth ◽  
Branching Process ◽  
Age Distribution ◽  
Length Distribution ◽  
Random Variables ◽  
Stable Age Distribution

Start a Bellman–Harris branching process from one or several ancestors, whose ages are identically distributed random variables. Assume that the life-length distribution decays more quickly than exponentially and that the distribution of ages at start does not give too much mass to high ages (in a sense to be made precise). Then, if the expected population size is an exponential function of time, the ages must follow the stable age distribution of the process.

Exponential growth of a branching process usually implies stable age distribution

1979 ◽  
Vol 16 (3) ◽  
pp. 651-656 ◽  
Author(s):  
Bo Berndtsson ◽  
Peter Jagers
Keyword(s):  
Population Size ◽  
Exponential Function ◽  
Exponential Growth ◽  
Branching Process ◽  
Age Distribution ◽  
Length Distribution ◽  
Random Variables ◽  
Stable Age Distribution

Start a Bellman–Harris branching process from one or several ancestors, whose ages are identically distributed random variables. Assume that the life-length distribution decays more quickly than exponentially and that the distribution of ages at start does not give too much mass to high ages (in a sense to be made precise). Then, if the expected population size is an exponential function of time, the ages must follow the stable age distribution of the process.

scholarly journals L2-BETTI NUMBERS OF DISCRETE MEASURED GROUPOIDS

2005 ◽  
Vol 15 (05n06) ◽  
pp. 1169-1188 ◽  
Author(s):  
ROMAN SAUER
Keyword(s):  
Probability Space ◽  
Betti Numbers ◽  
Free Action ◽  
Countable Group ◽  
Equivalence Relations ◽  
Dimension Theory ◽  
Discrete Groups ◽  
Type Ii ◽  
Orbit Equivalent ◽  
Definition Of

There are notions of L2-Betti numbers for discrete groups (Cheeger–Gromov, Lück), for type II1-factors (recent work of Connes-Shlyakhtenko) and for countable standard equivalence relations (Gaboriau). Whereas the first two are algebraically defined using Lück's dimension theory, Gaboriau's definition of the latter is inspired by the work of Cheeger and Gromov. In this work we give a definition of L2-Betti numbers of discrete measured groupoids that is based on Lück's dimension theory, thereby encompassing the cases of groups, equivalence relations and holonomy groupoids with an invariant measure for a complete transversal. We show that with our definition, like with Gaboriau's, the L2-Betti numbers [Formula: see text] of a countable group G coincide with the L2-Betti numbers [Formula: see text] of the orbit equivalence relation [Formula: see text] of a free action of G on a probability space. This yields a new proof of the fact the L2-Betti numbers of groups with orbit equivalent actions coincide.

scholarly journals Note on osmotic pressure

1914 ◽  
Vol 90 (615) ◽  
pp. 41-45
Keyword(s):  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Numerical Data ◽  
The Other ◽  
Present Moment ◽  
Capillary Surface ◽  
Pure Solvent ◽  
Definition Of ◽  
Complete Account ◽  
Strict Definition

The vapour pressure theory regards osmotic pressure as the pressure required to produce equilibrium between the pure solvent and the solution. Pressure applied to a solution increases its internal vapour pressure. If the compressed solution be on one aide of a semi-permeable partition and the pure solvent on the other, there is osmotic equilibrium when the com-pression of the solution brings its vapour pressure to equality with that of the solvent. So long ago as 1894 Ramsay* found that with a partition of palladium, permeable to hydrogen but not to nitrogen, the hydrogen pressures on each side tended to equality, notwithstanding the presence of nitrogen under pressure on one side, which it might have been supposed would have resisted tin- transpiration of the hydrogen. The bearing of this experiment on the problem of osmotic pressure was recognised by van’t Hoff, who observes that "it is very instructive as regards the means by which osmotic pressure is produced." But it was not till 1908 that the vapour pressure theory of osmotic pressure was developed on a finu foundation by Calendar. He demonstrated, by the method of the "vapour sieve" piston, the proposition that “any two solutions in equilibrium through any kind of membrane or capillary surface must have the same vapour pressures in respect of each of their constituents which is capable of diffusing through their surface of separation"—a generalisation of great importance for the theory of solutions. Findlay, in his admirable monograph, gives a very complete account of the contending theories of osmotic pressure, a review of which leaves no doubt that at the present moment the vapour pressure theory stands without a serious rival Some confusion of ideas still arises from the want of adherence to a strict definition of osmotic pressure to which numerical data from experimental measurements should he reduced. Tire following definitions appear to be tire outcome of tire vapour pressure theory :— Definition I.—The vapour pressure of a solution is the pressure of the vapour with which it is in equilibrium when under pressure of its own vapour only.

scholarly journals Contribution of Flow Cytometry to Acute Leukemia Classification in Tunisia

2000 ◽  
Vol 16 (3-4) ◽  
pp. 131-133 ◽  
Author(s):  
S. Feki ◽  
H. El Omri ◽  
M. A. Laatiri ◽  
S. Ennabli ◽  
K. Boukef ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Monoclonal Antibodies ◽  
Age Distribution ◽  
Tunisian Population ◽  
Acute Leukemias ◽  
Flow Cytometric Method ◽  
Technical Innovations ◽  
Definition Of ◽  
Sahel Region ◽  
Cluster Of Differentiation

The precision of immunological characterization of leukemias was improved by a certain number of technical innovations, particularly hybridoma production and standardization, resulting in monoclonal antibodies and definition of recognised cellular antigens (designated by CD: Cluster of Differentiation).The aim of this work was to determine the immunophenotyping profile of patients with leukemia, by means of a flow cytometric method: 66 blood samples coming from leukemic persons in the Sahel region were studied by flow cytometry, using about thirty monoclonal antibodies all marked with a fluorochrome, in one or two colour systems to assess their distribution according to type (lymphoid B or T / myeloid) and age, and to search for possible co-expressions of markers of different lineages.The marked preponderance of childhood B-ALL in our series is, at least partly, attributable to the age distribution of the Tunisian population. In agreement with studies from other countries, the majority of AML cases occurred among adults. A high proportion of AML cases in our series co-expressed markers of other lineages. Overall, accurate classification of acute leukemias was possible from a simple peripheral blood sample in 62 of 66 cases (93.9%).

The coincidence approach to stochastic point processes

1975 ◽  
Vol 7 (1) ◽  
pp. 83-122 ◽  
Author(s):  
Odile Macchi
Keyword(s):  
Poisson Process ◽  
Probability Space ◽  
Point Processes ◽  
Counting Process ◽  
Regular Point ◽  
General Point ◽  
Completely Regular ◽  
Photon Process ◽  
Stochastic Point Processes

The structure of the probability space associated with a general point process, when regarded as a counting process, is reviewed using the coincidence formalism. The rest of the paper is devoted to the class of regular point processes for which all coincidence probabilities admit densities. It is shown that their distribution is completely specified by the system of coincidence densities. The specification formalism is stressed for ‘completely’ regular point processes. A construction theorem gives a characterization of the system of coincidence densities of such a process. It permits the study of most models of point processes. New results on the photon process, a particular type of conditioned Poisson process, are derived. New examples are exhibited, including the Gauss-Poisson process and the ‘fermion’ process that is suitable whenever the points are repulsive.

scholarly journals STUDI LALAT PENGOROK DAUN LIRIOMYZA SPP. PADA PERTANAMAN BAWANG DAUN, DAN PARASITOID OPIUS CHROMATOMYIAE BELOKOBYLSKIJ & WHARTON (HYMENOPTERA: BRACONIDAE)

2009 ◽  
Vol 9 (1) ◽  
pp. 22-31
Author(s):  
Rusli Rustam ◽  
Aunu Rauf ◽  
Nina Maryana ◽  
Pudjianto Pudjianto ◽  
Dadang Dadang
Keyword(s):  
Age Distribution ◽  
Host Density ◽  
Field Studies ◽  
Reproductive Value ◽  
Laboratory Studies ◽  
Demographic Parameter ◽  
Liriomyza Huidobrensis ◽  
Stable Age Distribution ◽  
Net Reproduction ◽  
Density Results

Studies on Leafminer Liriomyza spp. in Green Onion Fields, and Parasitoid Opius chromatomyiae Belokobylskij & Wharton (Hymenoptera: Braconidae).  Field studies were conducted to determine population abundance of leafminers and their parasitoids in green onion fields in Puncak, West Java. In addition to that, laboratory studies were carried out to determine demographic parameter of Opius chromatomyiae as well as response of parasitoid to increasing host density. Results revealed that green onions were infested by two species of leafminers, Liriomyza huidobrensis and Liriomyza chinensis.  Leafminer flies emerged from Erwor leaves (54.5) were significantly higher than those of RP leaves (18.65) (P = 0.0005). However, number of  leafminer flies caught on sticky traps was not statistically different (P = 0.297).  Two species of parasitoid, Hemiptarsenus varicornis and O. chromatomyiae, were associated with leafminers in green onion fields. Higher number of parasitoids emerged from Erwor leaves (13.68) as compared to RP (6.90) (P =0.0007 ). However, level of parasitization were 24.36% on Erwor and 28.45% on RP, and was not significantly different (P = 0.387). Laboratory studies indicated that net reproduction (Ro) of O. chromatomyiae was 28.55, generation time (T) 15.96 days, intrinsic growth rate 0.21, and total of reproductive value 223.64.  The stable age distribution of parasitoid were 37.93% eggs, 24.92% larvae, 20.36% pupae and 16.78% adults.  The parasitoid showed functional response type II to increasing host density, with a = 0.08 and Th = 2.58.

scholarly journals Poor ovarian reserve and male infertility in a rural in vitro fertilization setup: a case report

2021 ◽  
Vol 10 (10) ◽  
pp. 4020
Author(s):  
Neha V. Harne ◽  
Vaibhav K. Nadkarni ◽  
Purnima Nadkarni ◽  
Jigna Garasia
Keyword(s):  
Semen Analysis ◽  
Oocyte Quality ◽  
Reproductive Age ◽  
Vitro Fertilization ◽  
Advanced Reproductive Age ◽  
Sperm Chromosomes ◽  
Definition Of ◽  
Poor Ovarian Reserve ◽  
Strict Definition

Female fertility begins to decline many years prior to the onset of menopause despite continued regular ovulatory cycles. Although there is no strict definition of advanced reproductive age in women, infertility becomes more pronounced after the age of 35. In the female, the number of oocytes decreases with age until the menopause. Oocyte quality also diminishes, due in part to increased aneuploidy because of factors such as changes in spindle integrity. Although older male age affects the likelihood of conception, abnormalities in sperm chromosomes and in some components of the semen analysis are less important than the frequency of intercourse. Age is as accurate as any other predictor of conception with assisted reproductive technology.

Hypnotic responding and self-deception

1997 ◽  
Vol 20 (1) ◽  
pp. 118-119 ◽  
Author(s):  
Irving Kirsch
Keyword(s):  
State Of Affairs ◽  
Definition Of ◽  
Strict Definition

As understood by neodissociation and sociocognitive theorists, hypnotic responses are instances of self-deception. Neodissociation theory matches the strict definition of Sackeim and Gur (1978) and sociocognitive theory matches Mele's looser definition. Recent data indicate that many hypnotized individuals deceive themselves into holding conflicting beliefs without dissociating, but others convince themselves that the suggested state of affairs is true without simultaneously holding a contrary belief.

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