The analysis of data in studies of invertebrate reproduction. II. The analysis of oocyte size/frequency data, and comparison of different types of data

1983 ◽  
Vol 6 (5-6) ◽  
pp. 271-283 ◽  
Author(s):  
A. Grant ◽  
P. A. Tyler
Keyword(s):  
Frequency Data ◽  
Oocyte Size ◽  
Size Frequency ◽  
Different Types ◽  
Invertebrate Reproduction

scholarly journals Age analyses for size-frequency data

1987 ◽  
Vol 8 (2) ◽  
pp. 2_21-35
Author(s):  
Tatsuro AKAMINE
Keyword(s):  
Frequency Data ◽  
Size Frequency

Recruitment, growth, and mortality of a living articulate brachiopod, with implications for the interpretation of survivorship curves

Paleobiology ◽  
1977 ◽  
Vol 3 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Charles W. Thayer
Keyword(s):  
Population Structure ◽  
Mortality Rate ◽  
Direct Relationship ◽  
Frequency Data ◽  
Time And Space ◽  
Size Frequency ◽  
Morphologic Variation ◽  
Relationship Of

An intertidal sample of 118 to 155 Terebratalia transversa on Saltspring Island, B.C., was censused in 1974, 1975, and 1976. Growth in length was a maximum of 7.8 mm per year and declined with size (age). As in fossil articulates, mortality rate was independent of age (size). Recruitment was patchy in time and space, was multi-annual or continuous, and was concentrated near conspecific adults. There were as many as 800 individuals/m2. None moved or changed orientation. Morphologic variation of Terebratalia valves is not directly controlled by the intensity of waves or currents.Paleontological survivorship curves based on size-frequency data are subject to ambiguous interpretation because two critical assumptions (direct relationship of size and age, constant population structure) are difficult to justify.

Use of Size–Frequency Data to Estimate the Age Composition of Crayfish Populations

1991 ◽  
Vol 48 (12) ◽  
pp. 2324-2332 ◽  
Author(s):  
Robert France ◽  
John Holmes ◽  
Alejandro Lynch
Keyword(s):  
Frequency Data ◽  
Age Classes ◽  
Age Composition ◽  
Frequency Distributions ◽  
Limited Success ◽  
Size Frequency ◽  
Independent Analysis ◽  
Mean Size ◽  
The Mean ◽  
Rates Of Growth

Age-classes in crayfish populations can be determined from size–frequency data provided four tenets are adhered to: (1) only crayfish collected from areas of rock substrate are used; (2) trapping data are excluded; (3) species do not have longevities exceeding about 4 yr; and most importantly, (4) sample sizes are greater than about 200. Studies that have failed to follow these guidelines have met with limited success in dissecting mixed frequency distributions. Further, three validation procedures must be undertaken: (1) temporal replication within molting events to measure the precision of both data collection and size–frequency analysis; (2) corroboration with known-age crayfish from either field recaptures or laboratory molt increments; and (3) concordance with independent analysis of the mean size at onset of sexual maturity. When these checks support the size–frequency results, population age composition and analyses of rates of growth or mortality can be considered reliable.

Life history analysis of five dominant infaunal polychaete species from the continental slope off North Carolina

1993 ◽  
Vol 73 (1) ◽  
pp. 123-141 ◽  
Author(s):  
James A. Blake
Keyword(s):  
North Carolina ◽  
Life History ◽  
Continental Slope ◽  
Late Summer ◽  
Frequency Data ◽  
Size Frequency ◽  
History Analysis ◽  
Cape Hatteras ◽  
Lower Slope ◽  
Upper Slope

Observations were made on the reproduction and life history of five species of polychaetes collected from the continental slope off North Carolina, USA. Three species were studied at a 2000-m lower slope station off Cape Lookout (Aurospio dibranchiata, Microrbinia linea, and Pholoe anoculata) and the other two at a 600-m upper slope station off Cape Hatteras (Cossura longocirrata and Scalibregma inflatum). Aurospio dibranchiata, a surface feeding spionid, exhibited seasonally in egg diameter and size-frequency data, with the larger sizes occurring in late summer months. Pholoe anoculata, a small carnivorous scale worm, did not exhibit any evidence of seasonality in size-frequency data at the 2000-m station. Sexually mature specimens were absent from this population, but were present at shallower slope depths, indicating year-round recruitment into the lower slope from middle and upper slope populations.

scholarly journals Are rare hernias rarer: a ten-year observational study

2019 ◽  
Vol 6 (12) ◽  
pp. 4338
Author(s):  
Tanmay Pande ◽  
Arpan Yadav ◽  
B. K. Varghese ◽  
Anurakshat Gupta
Keyword(s):  
Inguinal Hernia ◽  
Adult Population ◽  
Tertiary Care ◽  
Perineal Hernia ◽  
Lumbar Hernia ◽  
Frequency Data ◽  
Common Reference ◽  
Different Types ◽  
The Right ◽  
Hernia Incidence

Background: Hernia is one of the most common ailments encountered in general surgery practice. The inguinal hernia constitutes majority of cases. The available literature describes umbilical, femoral, lumbar, perineal and many others rarer varieties. Our preliminary observations indicated a changing scenario. With a view to ascertain it, investigations were made to find out the incidence of hernia with frequency data of different types and demographic details of patients during last decade at tertiary care teaching hospital in Pune and then comparing it with the existing literature.Methods: Ten years data from October 2008 to October 2018 of all the adult population suffering from hernia reporting to this center was collected from the archives of hospital records maintained in OPD, wards and the department.Results: Inguinal hernia was the most common constituting 76.9% of the total cases. The right side was more affected than the left side with 51.0% cases being on right side. This was followed by umbilical hernia, 12.26% of the total cases. Males were more affected than the females except in incisional hernia. Only two cases of spigelian hernia had undergone repair over last one decade. There were no cases of femoral hernia, lumbar hernia and perineal hernia encountered during the last ten years in this center.Conclusions: The relative frequency of the incidence of different types of hernia was inguinal, umbilical, epigastric; incisional which have been in descending order. In the last decade at this centre which is in contrast with hernia incidence figures quoted in common reference books and the available literature. 

Gametogenic cycle and population structure of Nereis (Hediste) diversicolor and Nereis (Nereis) pelagica from north-east England

1981 ◽  
Vol 61 (1) ◽  
pp. 193-213 ◽  
Author(s):  
P. J. W. Olive ◽  
P. R. G. Garwood
Keyword(s):  
Population Structure ◽  
Frequency Data ◽  
Natural Conditions ◽  
Hediste Diversicolor ◽  
Gametogenic Cycle ◽  
North East ◽  
Size Frequency ◽  
Second Year ◽  
Biometrical Study

The development of the oocytes of Nereis (Hediste) diversicolor and Nereis (Nereis) pelagica takes up to 18 months from their first appearance in the coelom to maturity, and in the natural conditions experienced by the population studied in north-east England the females are in their second year before the oocytes begin to appear. The duration of spermatogenesis is less than that of oogenesis, taking up to 6 months for completion. This information permits a more rigorous interpretation of the size frequency data which have been obtained from a biometrical study of the jaws. In the populations of both species the majority of individuals seem to reach maturity when 3 years old.

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