Vital Statistics, Biomass, and Seasonal Production of an Unexploited Walleye (Stizostedion vitreum vitreum) Population in West Blue Lake, Manitoba

1972 ◽  
Vol 29 (7) ◽  
pp. 1043-1052 ◽  
Author(s):  
J. R. M. Kelso ◽  
F. J. Ward
Keyword(s):  
Loss Rate ◽  
Total Population ◽  
Growing Season ◽  
Vital Statistics ◽  
Fish Growth ◽  
Initial Population ◽  
Stizostedion Vitreum ◽  
Daily Mortality ◽  
Blue Lake ◽  
New Recruits

The population of walleye, Stizostedion vitreum vitreum, (25 cm and greater) in West Blue Lake, Man., in May 1969 decreased from 1090 to 819 in May 1970. During summer and fall, the initial population was supplemented by new recruits, age II+, reaching a maximum of 3451 in September 1969. The total population in May 1970 was 2037. Mean daily mortality for all ages was small for the year, 0.0045, but loss rate was greatest in fall and winter. Growth in length was greatest for age II+ followed by older fish. Growth in weight was similar for ages III–V and lowest for age II+. Mean biomass, approximately 800 kg, was similar in May 1969 and May 1970. Production, 340 kg, coincided with the growing season (June to October) and was greatest from June to September. Greatest contribution to walleye production and biomass was made by age II+ fish. During winter and spring, zero or negative production occurred.

A systematic method for estimating the populations of Greek and Roman settlements

2017 ◽  
Vol 30 ◽  
pp. 301-324 ◽  
Author(s):  
J. W. Hanson ◽  
S. G. Ortman
Keyword(s):  
Economic History ◽  
Urban Population ◽  
Total Population ◽  
Vital Statistics ◽  
Systematic Method ◽  
Roman World ◽  
Greco Roman ◽  
History Of ◽  
Urbanization Rate

The last few years have seen a growing interest in the urbanism of the Greek and Roman world. This has led to a consensus of sorts about some of its vital statistics, such as the sizes of the populations of the most important settlements and the size of the overall urban population, the urbanization rate (i.e., the share of individuals that lived in urban, rather than rural, contexts), and the total population. A good example comes from W. Scheidel in the Cambridge economic history of the Greco-Roman world. According to him, it is likely that c.1.5 million people lived in the 5 largest cities of the Greco-Roman world by the 2nd c. A.D. These included Rome, which is usually agreed to have had a population of about 1 million; Alexandria, which might have had c.500,000; Antioch, which could have had at least 150,000; and Carthage and Ephesus (Scheidel does not give explicit figures for those).

Estimation of the parameters of a branching process from migrating binomial observations

1998 ◽  
Vol 30 (4) ◽  
pp. 948-967 ◽  
Author(s):  
C. Jacob ◽  
J. Peccoud
Keyword(s):  
Confidence Interval ◽  
Asymptotic Behaviour ◽  
Population Size ◽  
Branching Process ◽  
Total Population ◽  
Initial Population ◽  
Asymptotic Confidence Interval ◽  
Total Population Size ◽  
Initial Population Size ◽  
Watson Process

This paper considers a branching process generated by an offspring distribution F with mean m < ∞ and variance σ2 < ∞ and such that, at each generation n, there is an observed δ-migration, according to a binomial law Bpvn*Nnbef which depends on the total population size Nnbef. The δ-migration is defined as an emigration, an immigration or a null migration, depending on the value of δ, which is assumed constant throughout the different generations. The process with δ-migration is a generation-dependent Galton-Watson process, whereas the observed process is not in general a martingale. Under the assumption that the process with δ-migration is supercritical, we generalize for the observed migrating process the results relative to the Galton-Watson supercritical case that concern the asymptotic behaviour of the process and the estimation of m and σ2, as n → ∞. Moreover, an asymptotic confidence interval of the initial population size is given.

scholarly journals A Model of the Effect of Pseudothecia on Genetic Recombination and Epidemic Development in Populations of Mycosphaerella graminicola

2001 ◽  
Vol 91 (3) ◽  
pp. 240-248 ◽  
Author(s):  
L. Eriksen ◽  
M. W. Shaw ◽  
H. Østergård
Keyword(s):  
Genetic Recombination ◽  
Growing Season ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Considerable Proportion ◽  
Initial Population ◽  
Sexual Recombination ◽  
Epidemic Development ◽  
Rain Splash

It is generally agreed that ascospores are the origin of primary infections for the disease septoria tritici blotch of wheat caused by the fungus Mycosphaerella graminicola (anamorph Septoria tritici). The epidemic during the growing season was previously ascribed to the asexual pycni-diospores dispersed over short distances by rain splash, but recent observations suggest that the airborne ascospores also may play a role. As a consequence, the composition of the pathogen population over the growing season may change through genetic recombination. In an attempt to resolve the relative importance of the two spore types to the epidemic over the growing season, a model simulating disease caused by both types of spores was constructed and analyzed. The conclusion from the analysis of this model is that sexual recombination will affect the genetic composition of the population during a growing season. A considerable proportion of spores released at the end of the growing season may be sexual descendants of the initial population. However, ascospores are unlikely to affect the severity of the epidemic during the growing season. This is due to the much longer latent period for pseudothecia compared with pycnidia, resulting in ascospores being produced too late to influence the epidemic.

Diel Movement of Walleye, Stizostedion vitreum vitreum, in West Blue Lake, Manitoba, as Determined by Ultrasonic Tracking

1976 ◽  
Vol 33 (9) ◽  
pp. 2070-2072 ◽  
Author(s):  
J. R. M. Kelso
Keyword(s):  
High Activity ◽  
Body Length ◽  
Stizostedion Vitreum ◽  
Natural Activity ◽  
Blue Lake ◽  
Diel Movement ◽  
Ultrasonic Tracking ◽  
Sloping Bottom ◽  
Ultrasonic Transmitters

Eight walleye (Stizostedion vitreum vitreum) between 2 and 5 yr of age were equipped with ultrasonic transmitters, released, and followed for periods up to 24 h. During the study period, September 24–October 2, 1975, West Blue Lake was thermally stratified. Movement was limited to the homothermous epilimnion, above 10 m, and to the region of steeply sloping bottom of about 5–10 m which was usually within 100 m of shore. Midbasin crossings of the lake were infrequent. Transmitter attachment caused temporary high activity after which a more normal rhythm was apparent with peaks of activity at dusk and dawn. The majority, 86%, of observed swimming speeds were under 1 body length s−1. Since much localized activity, too restricted to measure, was apparent, these observations must be regarded as only approximations of natural activity.

Some Methods for Estimating Exploited Populations

1966 ◽  
Vol 23 (10) ◽  
pp. 1553-1574 ◽  
Author(s):  
K. Radway Allen
Keyword(s):  
Fishing Effort ◽  
Recruitment Rate ◽  
Initial Population ◽  
Natural Mortality ◽  
Age Composition ◽  
Natural Reproduction ◽  
Final Estimate ◽  
The Mean ◽  
Reproduction Method ◽  
New Recruits

Three methods of estimating population and one of estimating recruitment are described which are suitable for use where data are available on annual age composition, the numbers caught, and the effort expended in taking a known part of the catch.The recruitment rate is estimated, as the proportion of new recruits in the recruited population, from age composition data year by year without regard to the sizes of the parent populations, and from the approximate fishing mortality rate.The "q" population method estimates q, the coefficient of catchability, by comparing the rate of disappearance of a fixed group of year-classes with the rate of accumulation of fishing effort, using the rate of disappearance with age in a similar, unexploited population to eliminate the effects of natural mortality. The annual populations are then estimated from q and the catch per unit effort.The natural mortality and reproduction method is basically a modification of the DeLury method with an allowance for natural reproduction and recruitment. It obtains a series of estimates of the base year population by considering each of the periods beginning in this year and ending in each successive subsequent year, the final estimate being the mean of this series.The expected catch method takes as unknowns the initial population and the value of q, estimates the expected catches in each year, and compares them with the actual catches. It determines the values of the initial population and q which minimize the sum of the squares of the differences.Examples are worked out in full for all methods.

Applications of a Bioenergetics Model to Yellow Perch (Perca flavescens) and Walleye (Stizostedion vitreum vitreum)

1977 ◽  
Vol 34 (10) ◽  
pp. 1922-1935 ◽  
Author(s):  
James F. Kitchell ◽  
Donald J. Stewart ◽  
David Weininger
Keyword(s):  
Food Quality ◽  
Yellow Perch ◽  
Growth Parameters ◽  
Perca Flavescens ◽  
Activity Level ◽  
Fish Growth ◽  
Sensitivity Analyses ◽  
Stizostedion Vitreum ◽  
Bioenergetics Model ◽  
Ration Level

A simple energy budget equation is developed to yield a bioenergetics model designed to simulate fish growth. Parameters for the model are estimated from the literature for application to yellow perch (Perca flavescens) and walleye (Stizostedion vitreum vitreum). Simulations are presented that demonstrate model output as functions of body size, activity level, ration level, food quality, and environmental temperature. Sensitivity analyses identify the importance of food consumption, activity, and excretion as biological processes represented in the parameters. On the basis of temperature conditions in selected lakes and specified feeding levels, simulations are presented to quantify the importance of year-to-year variation of temperature in determining growth. In heterothermal systems, temperature selection by percids can have a significant effect on growth. For walleye on fixed rations, annual growth can vary from zero to twofold increments due entirely to differences in summer temperatures. Variations in food quality have lesser effects. Key words: Perca, Stizostedion, bioenergetics model, growth, sensitivity, simulations

scholarly journals Widowed persons in Serbia: Change in number and general demographic characteristics (1980-2016)

Stanovnistvo ◽  
2018 ◽  
Vol 56 (1) ◽  
pp. 83-108
Author(s):  
Goran Penev ◽  
Biljana Stankovic
Keyword(s):  
Psychological Health ◽  
Total Population ◽  
Population Group ◽  
The Elderly ◽  
Vital Statistics ◽  
Significant Finding ◽  
Policy Makers ◽  
Continuous Increase ◽  
Educational Structure ◽  
Demographic Indicators

Widowed persons represent a vulnerable population group, especially because the loss of a spouse is usually a part of old people?s experience. In old age, people are typically faced with multiple constraints, related to health, financial resources, family and other social relationships. Changes that accompany the death of spouse and widowhood are generally long-term and largely negative for many widowed persons. With advanced population ageing, the share of the widowed in the total population is increasing, and this is also true for Serbia. With a crude widowhood rate of 11.7% in 2011, Serbia is at the very top of the list of European countries and has the highest widowhood rate of men (5.2%). However, widowhood primarily affects women, and 78% of the widowed in Serbia are widows. This paper analyses the widowhood in Serbia from 1980 to 2016. The main objective is to describe the trends and characteristics of widowed persons in this period. This article is primarily based on the analysis of previously unpublished census results and vital statistics data. In Serbia, in the period of 1981-2011, there was a continuous increase in the number of widowed persons and in 2011 it was 37.5% higher than 30 years before. Furthermore, the share of the widowed in the total population increased significantly (from 8.5% to 11.7%). Widowhood is considerably more present among women and the elderly. More than four fifths of the widowed are older than 60 years, and the values of all used demographic indicators of widowhood are three or four times higher in women. The authors mention the noticeable decrease in remarriage among widowed persons and a major decrease in the nuptiality rate of the widowed, especially among widowers. The observed educational structure of the widowed shows a higher percentage of persons with a lower educational level. Another significant finding was that the widowed represent half of the total number of people who live alone in one-person households. Among them, more than four fifths are 65 years old or older, and a full half are older than 75. The authors concluded that further quantitative and qualitative studies of demographic, but also social, psychological, health and other aspects of the widowed in Serbia are needed. Additionally, these results can represent the analytical basis for policy makers to identify needs and define different measures and actions directed towards the elderly, among which widowed persons, and especially widowers, are particularly vulnerable categories.

Annual Summary of Vital Statistics—1986

PEDIATRICS ◽  
1987 ◽  
Vol 80 (6) ◽  
pp. 817-827
Author(s):  
Myron E. Wegman
Keyword(s):  
Death Rate ◽  
Birth Rate ◽  
Total Population ◽  
Vital Statistics ◽  
Mortality Data ◽  
Health Statistics ◽  
State Information ◽  
The Us ◽  
Final Data ◽  
International Data

Data from this article, as in previous reports,1 are drawn principally from Monthly Vital Statistics Report, published by the National Center for Health Statistics (NCHS).2-6 The international data come from the Demographic Yearbook7 and the quarterly Population and Vital Statistics Report,8 both published by the Statistical Office of the United Nations, which has also been kind enough to provide directly more recent data. Except for mortality data by cause and age, which are based on a 10% sample, all the US data for 1986 are estimates by place of occurrence, based upon a count of certificates received in state offices between two dates, 1 month apart, regardless of when the event occurred. Experience has shown that for the country as a whole the estimates, with few exceptions, are close to the subsequent final figures. There are considerable variations in some states, however, particularly in comparing provisional figures by place of occurrence and final data by place of residence. State information should be interpreted cautiously. Careful attention should be paid to the denominator when studying rates presented in this article. For overall rates, like the birth rate or death rate, the standard denominator is 1,000 total population. In instances where more refined analysis is possible, the denominator may be 100,000 and the character of the population specified. The particular denominator is indicated in the table or in the context.

The primary productivity of submerged macrophytes in West Blue Lake, Manitoba

1977 ◽  
Vol 55 (2) ◽  
pp. 118-127 ◽  
Author(s):  
R. J. R. Love ◽  
G. G. C. Robinson
Keyword(s):  
Primary Productivity ◽  
Depth Distribution ◽  
Submerged Macrophytes ◽  
Growing Season ◽  
Phytoplankton Production ◽  
Seasonal Trends ◽  
Chara Vulgaris ◽  
Blue Lake ◽  
Random Samples ◽  
Myriophyllum Alterniflorum

The productivity of Potamogeton Richardsonii, P. pectinatus, Myriophyllum alterniflorum, Megalodonta Beckii, and Chara vulgaris in West Blue Lake, Manitoba, is reported. Measurements of changes in biomass and assimilation of 14CO2 in random and non-random samples throughout the growing season of 1973 were used. Changes in biomass of P. Richardsonii, M. alterniflorum, M. Beckii, and C. vulgaris determined from random samples compared favourably with those determined from non-random samples. This was not the case for P. pectinatus because of its restricted occurrence. Similarly, measurements of 14CO2 assimilation in random samples of P. Richardsonii, M. alterniflorum, and M. Beckii compared well with non-random samples. Productivity values derived from 14CO2 uptake were far in excess of those attained from biomass changes. Seasonal trends of production and the depth distribution of production are discussed, and macrophyte production is compared with phytoplankton production.

Trumpetcreeper (Campsis radicans) Control in Double-Crop Glyphosate-Resistant Soybean with Glyphosate and Conventional Herbicide Systems

2004 ◽  
Vol 18 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Kevin W. Bradley ◽  
Edward S. Hagood ◽  
Paul H. Davis
Keyword(s):  
Untreated Control ◽  
Production Systems ◽  
Growing Season ◽  
Field Trials ◽  
Initial Population ◽  
Stem Density ◽  
Soybean Production ◽  
Herbicide Treatments

Field trials were conducted in Virginia to evaluate trumpetcreeper control with glyphosate and conventional herbicide systems in double-crop glyphosate-resistant soybean. When compared with the untreated control, none of the conventional herbicide systems evaluated in these trials provided any reductions in the trumpetcreeper stem density at 1 yr after treatment (YAT). Glyphosate systems generally provided much higher levels of trumpetcreeper stem reduction than conventional herbicide systems. By 1 YAT, densities of trumpetcreeper that received conventional herbicide treatments ranged from 97 to 141% of the initial population, whereas densities of trumpetcreeper that received preemergence (PRE) followed by postemergence (POST) or POST-only applications of the isopropylamine (IPA) or diammonium (DIA) salts of glyphosate ranged from 30 to 66% of the initial population. However, PRE applications of the IPA or DIA salts of glyphosate generally provided lower levels of trumpetcreeper stem reduction than PRE followed by POST or POST-only applications. These results indicate that glyphosate applications made later in the growing season will provide greater trumpetcreeper stem reductions than those made at or close to soybean planting in double-crop soybean production systems. Glyphosate systems did not provide higher soybean yields than the untreated control that contained trumpetcreeper only when densities averaged 6 trumpetcreeper stems/m2in 2000, but 12 of the 16 glyphosate-containing treatments provided higher soybean yields than the untreated control that contained trumpetcreeper only when densities averaged 13 stems/m2in 2001.

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