Demographic parameters at evolutionary equilibrium

1984 ◽  
Vol 62 (11) ◽  
pp. 2264-2271 ◽  
Author(s):  
Peter D. Taylor ◽  
George C. Williams
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Life Histories ◽  
Community Organization ◽  
Geometric Constraints ◽  
Physical Factors ◽  
Total Biomass ◽  
Age Cohort ◽  
Population Sizes ◽  
The Individual

We reason that natural selection acting under conditions imposed by physical factors (e.g., geometric constraints on growth rate) and community organization (e.g., persistent finite population sizes, equal total biomass of organisms in proportionately equal size ranges) should lead to certain life history features. The initial size of resource-capturing young should be the smallest that permits growth rate to exceed mortality rate so that the age cohort will start to increase in biomass. Production of such young must be an inefficient use of biomass because of metabolism, predation of embryos, the cost of males, and other losses. Mortality rate during juvenile growth should be a power function like growth rate, but always a bit lower so that the age cohort continues to increase and ultimately to compensate for the inefficiency of reproduction. In a constant environment, the individual should stop growing at the size of greatest expected excess of future reproductive resources over size, and thereafter devote all expendable resources to reproduction. Any given size range of animals, such as 1–2 mg or 1–2 kg, should consist of both mature and immature individuals in any community and should be devoting about a third of its investable resources to reproduction and the rest to growth. We use our equations to generate sample life histories. The simple form of our equations organizes these life tables into families of similar schedules with variable generation time.

scholarly journals Aplikasi teknologi bioflok (BFT) pada kultur ikan nila, Orechromis niloticus)

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Frandy Ombong ◽  
Indra R.N Salindeho
Keyword(s):  
Growth Rate ◽  
Nile Tilapia ◽  
Quality Parameters ◽  
Total Biomass ◽  
Daily Growth ◽  
Individual Fish ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Biofloc Technology ◽  
The Individual ◽  
Very High

This study was aimed to find out the growth rate of Nile Tilapia (Oreochromis niloticus) cultured with biofloc technology, and to understand the dynamic of several water quality parameters during culture period. This experiment was conducted in the Laboratory of Aquaculture Technology, FPIK, UNSRAT.  Several substances were added to stimulate the development of biofloc, which were: 0,3 mL of EM-4 containing probiotic-bacteria Lactobacillus casei dan Saccharomyces cerevisiae.; 15 mL of mollases;  0,5 g of  yeast commonly used to ferment soybean ; 12 g of dolomite.    60 seeds of  nile tilapia,  with an individual weight of 6 g, were stocked in each container.   Fish were fed at a dose of 3% of the total biomass/day at the first week, and the dose was decreased  down to 1% of the total biomass per day afterwards.  Fish were weighed at day-1, day-15 and day-30.   The change of water color and the density of the floc was consistently evaluated using imhoff-cone. The initial weight of the tested individual fish were 6,00 g. After 15 days, the weight was increased to 7,37g, and at the end of the experiment the individual fish weighed 11,47 g. Hence, the absolut growth of the tested fish was 5,47g,  the specific growth rate was 91% and the daily growth rate was 2,11%.    The density of flok reached 9,5 mL/L at the beginning of the second week, which was categorized as very high density.   The density of floc then was decreased to 4 mL/L.   The density of the floc was maintained around 5 mL/L during the experiment. The temperature of the medium was at the range of 26-300C.  The level of ammonia was 0,03mg/L and  the level of  nitrite fluctuated between 0,15-3mg/L, which is normal and safe for biofloc system.  The level of nitrate was 4-55 mg/L, which was quite high for biofloc system but not harmful for fish.   Keywords:  Biofloc, Nile-Tilapia, growth, floc-density

Graphical Estimation of Rates of Mortality and Growth

1970 ◽  
Vol 27 (1) ◽  
pp. 204-208 ◽  
Author(s):  
Roger H. Green
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Individual Growth ◽  
Individual Growth Rate ◽  
Population Mortality ◽  
The Individual ◽  
Average Size ◽  
Individual Size

A method is presented by which the individual growth rate and the population mortality rate can be estimated graphically in certain populations, given only knowledge of maximum individual size and of average size at two times of the year. The four graphs that are given may be used in several different ways, depending on the information available.

Territorial Distribution of Alcohol and Drug Addictions Mortality Concerning Regional Disparities in the Slovak Republic from Year 1996 to Year 2015

2020 ◽  
Keyword(s):  
Mortality Rate ◽  
Slovak Republic ◽  
Regional Disparities ◽  
Point Of View ◽  
Extreme Position ◽  
Data Set ◽  
Female Sex ◽  
Male Sex ◽  
The Individual ◽  
High Level

BACKGROUND: This paper deals with territorial distribution of the alcohol and drug addictions mortality at a level of the districts of the Slovak Republic. AIM: The aim of the paper is to explore the relations within the administrative territorial division of the Slovak Republic, that is, between the individual districts and hence, to reveal possibly hidden relation in alcohol and drug mortality. METHODS: The analysis is divided and executed into the two fragments – one belongs to the female sex, the other one belongs to the male sex. The standardised mortality rate is computed according to a sequence of the mathematical relations. The Euclidean distance is employed to compute the similarity within each pair of a whole data set. The cluster analysis examines is performed. The clusters are created by means of the mutual distances of the districts. The data is collected from the database of the Statistical Office of the Slovak Republic for all the districts of the Slovak Republic. The covered time span begins in the year 1996 and ends in the year 2015. RESULTS: The most substantial point is that the Slovak Republic possesses the regional disparities in a field of mortality expressed by the standardised mortality rate computed particularly for the diagnoses assigned to the alcohol and drug addictions at a considerably high level. However, the female sex and the male sex have the different outcome. The Bratislava III District keeps absolutely the most extreme position. It forms an own cluster for the both sexes too. The Topoľčany District bears a similar extreme position from a point of view of the male sex. All the Bratislava districts keep their mutual notable dissimilarity. Contrariwise, evaluation of a development of the regional disparities among the districts looks like notably heterogeneously. CONCLUSIONS: There are considerable regional discrepancies throughout the districts of the Slovak Republic. Hence, it is necessary to create a common platform how to proceed with the solution of this issue.

scholarly journals Robustness of life histories to environmental variability in complex versus simple life cycles

2021 ◽  
Author(s):  
Annie Jonsson
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Environmental Variability ◽  
Life Cycles ◽  
Relative Advantage ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Vital Rates ◽  
Habitat Separation ◽  
Simple Life

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

Movement, Growth and natural mortality rate of the Red Spot King Prawn, Penaeus longistylus Kubo, from the Great Barrier Reef Lagoon

1990 ◽  
Vol 41 (3) ◽  
pp. 399 ◽  
Author(s):  
MCL Dredge
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Great Barrier Reef ◽  
Annual Variation ◽  
Growth Parameters ◽  
Natural Mortality ◽  
Barrier Reef ◽  
Fishing Mortality ◽  
Nursery Areas ◽  
Reef Lagoon

Movement, growth and natural mortality rate of the red spot king prawn, Penaeus longistylus, occurring in waters of the Great Barrier Reef off Townsville, Queensland, were investigated in a series of tagging experiments. Adult P. longistylus did not migrate after leaving nursery areas. Their growth rate was slower than that of the conspecific species P. plebejus, and significant inter-annual variation in growth parameters was observed. The natural mortality rate, assessed by sequential tagging experiments that eliminated the possibility of confounding with the rate of fishing mortality, was estimated to be 0.072 (week-1).

scholarly journals THE DYNAMICS OF CHANGES IN STRUCTURE INDICES OF INFANT MORTALITY IN ST. PETERSBURG DURING 2005-2017 YEARS

2019 ◽  
Vol 21 (3) ◽  
pp. 157-160
Author(s):  
A. S. Simakhodsky ◽  
L. D. Sevostianova ◽  
U. V. Gorelik ◽  
N. P. Akincheva ◽  
U. V. Kolechko
Keyword(s):  
Mortality Rate ◽  
Infant Mortality ◽  
Infant Mortality Rate ◽  
High Tech ◽  
Structural Components ◽  
Long Period ◽  
The Russian Federation ◽  
Structure Indices ◽  
The Individual ◽  
The City

The review presents the literature data and, revealed by authors, the patterns of changes in the dynamics of the infant mortality rate and its structure over a long period (2005-2017) in St. Petersburg. This index is one of the lowest in the Russian Federation. There are analyzed changes in the individual components of the structure of the infant mortality rate, related both to objective and subjective factors. In the city of St. Petersburg there was shown a persistent decline in the infant mortality rate due to the implementation of federal and city programs, closely correlated with structural components. The authors believe the positive dynamics of structural components in St. Petersburg to indicate the organization of all types of specialized and high-tech medical care for newborns.

scholarly journals Development of Algae Guard Façade Paint with Statistical Modeling under Natural Phenomena

2018 ◽  
Author(s):  
Sheraz Ahmed Qureshi ◽  
Amir Shafeeq ◽  
Aamir Ijaz ◽  
Muhammad Moeen Butt
Keyword(s):  
Growth Rate ◽  
Paint Film ◽  
Effect Of Temperature ◽  
Natural Phenomena ◽  
Linear Effect ◽  
Positive Unit ◽  
Algae Growth ◽  
Temperature Variable ◽  
Explained Variation ◽  
The Individual

Algaecides are chemicals that cause serious health problems. Conventional paints contain algaecides to improve the algae resistance on the paint film. Present research has suggested an environmental friendly paint formulation that focuses on developing algae resistance without having algaecides. In this research, Algae growth on newly developed paint is modeled by incorporating dirt resistance of paint and natural phenomena including humidity, temperature and time respectively. The fitted Model revealed explained variation of 59.65% in the average algae growth, of which, Dirt Resistance, Humidity and temperature and some of their interactions play significant role in this variation. Model suggests that the proposed newly developed paint without algaecides is more resilient to algae growth and significantly decreased the average algae growth rate by 0.53% as compared to conventional paints. Keeping the effect of all other factors constant, if dirt resistance of paint (Dc value) increases by one percent, average algae growth decreases by 12.98%; when temperature increases by 1oC, average algae growth decreases by 22.4%; a positive unit change in the joint linear effect dirt resistance, temperature and humidity caused a decrease in average algae growth by 0.0031%. It was also observed that the individual effect of humidity variable was inversely related with average algae growth. However the combination of humidity and temperature, humidity and dirt resistance, humidity and time, and the quadratic effect of humidity were found to increase the average algae growth rate. The cubic effect of temperature variable by one degree centigrade resulted in decrease of average algae growth by 0.000907%.

scholarly journals N-terminal pro-brain natriuretic peptide and high-sensitivity troponin T exhibit additive prognostic value for the outcome of critically ill patients

2018 ◽  
Vol 9 (5) ◽  
pp. 496-503 ◽  
Author(s):  
Max Lenz ◽  
Konstantin A Krychtiuk ◽  
Georg Goliasch ◽  
Klaus Distelmaier ◽  
Johann Wojta ◽  
...  
Keyword(s):  
Intensive Care ◽  
Mortality Rate ◽  
Brain Natriuretic Peptide ◽  
Critically Ill ◽  
Natriuretic Peptide ◽  
Critically Ill Patients ◽  
Plasma Levels ◽  
Troponin T ◽  
High Sensitivity ◽  
The Individual

Background: Patients treated at medical intensive care units suffer from various pathologies and often present with elevated troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Both markers may reflect different forms of cardiac involvement in critical illness. Therefore, the aim of our study was to examine the synergistic prognostic potential of NT-proBNP and high-sensitivity TnT (hs)TnT in unselected critically ill patients. Methods: We included all consecutive patients admitted to our intensive care unit within one year, excluding those suffering from acute myocardial infarction or undergoing cardiac surgery and measured NT-proBNP and TnT plasma levels on the day of admission and 72 hours thereafter. Results: Of the included 148 patients, 52% were male, mean age was of 64.2 ± 16.8 years and 30-day mortality was 33.2%. Non-survivors showed significantly higher NT-proBNP and TnT plasma levels as compared with survivors ( p<0.01). An elevation of both markers exhibited an additive effect on mortality, as those with both NT-proBNP and TnT levels above the median had a 30-day mortality rate of 51.0%, while those with both markers below the median had a 16.7% mortality rate (hazard ratio 3.7). These findings were independent of demographic and clinical parameters ( p<0.05). Conclusions: Our findings regarding the individual predictive properties of NT-proBNP and TnT are in line with literature. However, we were able to highlight that they exhibit additive prognostic potential which exceeds their individual value. This might be attributed to a difference in underlying pathomechanisms and an assessment of synergistic risk factors.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

ICT, CoLs, CoPs, and Virtual Communities

2008 ◽  
pp. 71-77
Author(s):  
Antonio Cartelli
Keyword(s):  
Information And Communication Technologies ◽  
Virtual Communities ◽  
Community Organization ◽  
Communication Technologies ◽  
The Internet ◽  
Online Information ◽  
Information And Communication ◽  
The Individual ◽  
Knowledge Strategies ◽  
Different Levels

Every day, information and communication technologies (ICT) are extending their influence on knowing and transmitting knowledge. They act on humankind at different levels: the individual, the society, and the community/organization. The Internet more than other instruments in the past is changing human customs and knowledge strategies mostly due to the online information systems developed during last few years.

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