Numerical Changes and Population Regulation in Brook Trout Salvelinus fontinalis

1967 ◽  
Vol 24 (7) ◽  
pp. 1425-1459 ◽  
Author(s):  
James T. McFadden ◽  
Gaylord R. Alexander ◽  
David S. Shetter
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Brook Trout ◽  
Egg Production ◽  
Age Groups ◽  
Small Range ◽  
Age Group ◽  
Density Dependent ◽  
Group I ◽  
Range Of Values

A brook trout population in a stable stream environment was studied for 14 years. Population estimates were made each September, the catch of fish by anglers was recorded, and collections of fish were made to determine sex ratio, age at sexual maturity, and fecundity.The sex ratio was close to 1:1 for all age-groups. Some male trout were sexually mature at the end of the 1st year of life, most were mature at the end of the 2nd year, and all were mature at the end of the 3rd. No females were mature at the end of their 1st year, most were mature at the end of the 2nd, and all were mature at the end of the 3rd year of life. The regression of egg content on total length of female trout was determined.On the average 132,000 eggs were produced annually by the population in the study area, from which 4813 fish survived to the end of the 1st year; 1966 to the end of the 2nd; 356 to the 3rd; 29 to the 4th; and 0.6 to the end of the 5th year.The growth rate of the fish varied little during the period of study. Annual egg production varied between 80,000 and 212,000; the number of age-group 0 fish between 2809 and 6703; age-group I fish between 1589 and 2653; age-group II between 175 and 685; age-group III between 13 and 68; and age-group IV fish between 0 and 2.During the 14 years of observation, survival of adult fish tended to increase, leading to larger numbers of spawners. The larger egg complements which resulted tended to experience lower survival, thus largely preventing substantial increases in population size. Positive serial correlations exist in some of the series of estimates of numbers and of survival. No biological explanation is advanced for these serial correlations.Life tables and age-specific fecundity rates were calculated for 11 successive cohorts of brook trout. Net reproduction rates varied from 0.74 to 1.88, averaging 1.14. The lx components were about three times as variable as the mx components, indicating that changes in death rates rather than changes in birth rates have been the principal immediate cause of fluctuations in the population.The mx values were not related to population density in any way that would tend to regulate population size. Survival from the 12th to the 24th month of life was directly density-dependent. The pattern of survival from the 24th to the 36th month of life suggested an inverse density-dependent relationship.The number of 12-month-old progeny surviving varied from 2809 to 6703, and the parental egg complement varied from 80,000 to 212,000. The form of the relationship between these two variables could not be defined, partly because of the relatively small range of values of parental egg complement.Even though the form of the density-survival relationship was defined for several stages of the life history, no relationship between the size of a parental egg complement and the lifetime egg production of the progeny could be established, again partly because of the small range of values of the former variable.

Maturation and Fecundity of Brook Trout from Infertile Streams

1966 ◽  
Vol 23 (5) ◽  
pp. 623-649 ◽  
Author(s):  
Richard S. Wydoski ◽  
Edwin L. Cooper
Keyword(s):  
Brook Trout ◽  
Age Groups ◽  
Reproductive Rate ◽  
Seasonal Development ◽  
Age Group ◽  
Group Iii ◽  
Total Length ◽  
Group I ◽  
Reproductive Rates ◽  
Curvilinear Regression

The reproductive rate of brook trout populations from infertile Pennsylvania streams was determined. The standing crops for eight streams varied between 14 and 41 lb/acre. Trout in age-groups 0 through III were found to grow slowly with very few individuals reaching a total length of 6 inches.The seasonal development of ova was determined by measuring all ova larger than 0.2 mm from selected females. The maturing ova of most females of age-groups II and III increased in diameter from 0.9 mm in February to 1.0 mm in June, 1.75 mm in July, 2.5 mm in August, 3.0 mm in September, and 4.0 mm in October. Maturing females could be distinguished from immature females by late August or early September on the basis of ova diameters. The mean diameter of ripe ova from 67 females was 4.05 mm with a range between 3.37 and 5.01 mm for individual trout ranging from 4.6 to 8.6 inches total length.The relationship between the number of mature ova and the total length of the female for one population was described by a curvilinear regression (log Y = −0.5361 + 3.23 log X, where Y = number of eggs, and X = the total length of the fish) for brook trout between 3.6 inches (18 eggs) and 7.7 inches (213 eggs). Variation in this relationship existed among streams.Ova production was estimated as 9050 ova per acre for one population and 13,620 ova per acre for another. Age-group-I females contributed approximately 9% of this production; age-group-II females, 54%; and age-group-III females, 37%. An ecological life table was constructed for two populations comparing rates of survival, age-specific fecundity rates, and reproductive rates.

scholarly journals Assessment of intraocular pressure in chinchillas of different age groups using rebound tonometry

2016 ◽  
Vol 46 (8) ◽  
pp. 1466-1471 ◽  
Author(s):  
Flor Diana Yokoay Claros Chacaltana ◽  
João Antonio Tadeu Pigatto ◽  
Ione Terezinha Denardin
Keyword(s):  
Intraocular Pressure ◽  
Age Groups ◽  
Time Of Day ◽  
Age Group ◽  
Group Iii ◽  
Rebound Tonometer ◽  
Indirect Ophthalmoscopy ◽  
Group I ◽  
Schirmer Tear Test ◽  
The Mean

ABSTRACT: The aim of this research was to measure the intraocular pressure (IOP) of normal chinchilla eyes using the rebound tonometer. A further aim was to assess whether there were differences in the values of intraocular pressure in relation to animals age, gender and time of day. Thirty-six chinchillas were divided into three groups of 12 chinchillas each, by age: Group I (2-6-month-old), Group II (20 and 34 months) and Group III (37 and 135 months). Ophthalmic examination was performed previously by Schirmer tear test, slit lamp biomicroscopy, indirect ophthalmoscopy and fluorescein test in all chinchillas. Three measurements of intraocular pressure were assessed on the same day (7, 12 and 19h). Tonometry was performed on both eyes using the rebound tonometer after calibration in "p" mode. Statistical analysis was performed with SigmaPlot for Windows. The mean IOP for groups I, II and III were 2.47±0.581mmHg, 2.47±0.581mmHg and 2.51±0.531mmHg, respectively. No significant differences were reported between age and IOP and no significant differences were reported between the time of day and IOP. The IOP in chinchillas did not differ significantly between genders or ages of the animals, and did not change with time of day.

scholarly journals Ascitic Fluid Cytology Seen in a Tertiary Hospital in Nigeria

2020 ◽  
pp. 345-350
Author(s):  
CC Nwafor ◽  
K Obioha ◽  
TO Akhiwu
Keyword(s):  
Sex Ratio ◽  
Patient Care ◽  
Ascitic Fluid ◽  
Age Groups ◽  
Tertiary Hospital ◽  
Age Group ◽  
Malignant Cells ◽  
Female Ratio ◽  
Male To Female ◽  
Fluid Cytology

Ascites is a symptom that can originate due to diverse pathologies. A lot of investigations including ascitic fluid cytology (AFC) can be done on it to help determine its origin. The aim of this study, is to document the findings and highlight the importance of AFC in patient care in Uyo. All AFC reports and slides in the Department of Histopathology, University of Uyo were retrieved, reviewed and used for this study. The age ranged from 1.5 – 80 years with mean age, 41.79 (±17.23) years. About 71.8% of the ascitic fluid (AF) specimens were from patients between the 3rd and 6th decade. Females predominated in all age groups expect 10-19 year's group, with a male to female sex ratio of 1:2.4. Malignant cells were seen in 28.7% of all the samples, while 51.2% were negative for malignant cells. Malignant cells were seen in 4 (6.7%), 11 (18.3%) and 6 (10%) of the AFC performed due to various liver pathologies, ovarian malignancies and intra-abdominal malignancies respectively. Malignant cells were found more in females with a male to female ratio of 1: 3.6. Age group 40-49 years accounted for most of the malignant cases (26.6%). The pattern of AFC in Uyo is similar to the pattern in other parts of Nigeria

scholarly journals Recruitment dynamics of the Gulf of Riga herring stock: density-dependent and environmental effects

2010 ◽  
Vol 67 (9) ◽  
pp. 1914-1920 ◽  
Author(s):  
Tiit Raid ◽  
Georgs Kornilovs ◽  
Ain Lankov ◽  
Anne-Marin Nisumaa ◽  
Heli Shpilev ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Egg Production ◽  
Age Groups ◽  
Zooplankton Community ◽  
Density Dependent ◽  
Current Period ◽  
Open Sea ◽  
Gulf Of Riga ◽  
The Baltic ◽  
Peak Abundance

Abstract Raid, T., Kornilovs, G., Lankov, A., Nisumaa, A-M., Shpilev, H., and Järvik, A. 2010. Recruitment dynamics of the Gulf of Riga herring stock: density-dependent and environmental effects. – ICES Journal of Marine Science, 67: 1914–1920. The Gulf of Riga and open-sea stocks of the Baltic herring have displayed remarkably consistent inverse recruitment and stock development patterns since the 1970s: the open-sea stocks steadily declined, whereas the Gulf stock increased rapidly in the early 1990s, reaching a peak abundance in the early 2000s and exceeding the level of the 1970s by a factor of 2–3. The increase was accompanied by a decline in the mean weight-at-age and the condition factor. The estimated decline (by 30–40%) in the average annual consumption rate per individual and changes observed in the zooplankton community suggest that density-dependent effects may have increased since the 1970s. The current period of high stock sizes is also characterized by greater recruitment variability. Historical fecundity investigations have established that the average egg production per individual has decreased in all age groups by 20–50%, along with a decrease in mean weight and condition. Yet, the effect on recruitment has been low so far, because lower fecundity has been compensated by the greater abundance and population fecundity has been maintained at the original level. Recruitment appears to be more influenced by environmental conditions than by spawning-stock biomass.

scholarly journals A herd immunity to measles and rubella viruses in the population of the Republic of Serbia

2021 ◽  
Vol 11 (1) ◽  
pp. 171-176
Author(s):  
M. A. Bichurina ◽  
S. Filipovic-Vignjevic ◽  
A. Yu. Antipova ◽  
M. Bancevic ◽  
I. N. Lavrentieva
Keyword(s):  
Measles Virus ◽  
Herd Immunity ◽  
Age Groups ◽  
Age Group ◽  
Igg Antibodies ◽  
Mmr Vaccine ◽  
Igg Antibody ◽  
Group I ◽  
Study Results ◽  
The Republic

According to the WHO Strategic Plan, measles should be eradicated in 2020 in the five WHO Regions including European Region. However, large measles outbreaks are being periodically registered in diverse European countries. In the Republic of Serbia (SRB), 5,076 measles cases were detected in 2018, among which 15 cases were fatal.Aim of the study was to examine herd immunity to measles and rubella viruses in the population of the Republic of Serbia.Materials and methods. Blood serum samples obtained in 2018 and 2019 from conditionally healthy residents of the Republic of Serbia were tested for the presence of IgG antibodies to measles and rubella viruses in five age groups: I — children from 2 to 6 years old, II — children from 8 to 14 years old, III — 15 to 24 years old, IV — 25 to 49 years old and V — over 50 years old. A total of 1000 samples were obtained, 200 sera in each group. Enzygnost® Anti-Measles virus/IgG and Enzygnost® Anti-Rubella virus/IgG ELISA test systems (Siemens Healthcare Diagnostics Products GmbH, Germany) were used according to the manufacturer's instructions.Results. Overall, around 23.0% and 33.7% of the surveyed persons had no or low level of anti-measles IgG antibody (≥ 275.0 — ≤ 1000.0 IU/1). In age group I, 60% children contained no or “low” anti-measles antibodies titer (29.5% and 30.5%, respectively). In addition, low antibody titer level was mainly detected in individuals from age group II and III (p < 0.05). A third of children under 8—14 contained high IgG-antibodies titer against measles (> 3000.0 IU/l) that might serve as an evidence that such subjects recently recovered after measles. Similar results were obtained for IgG antibodies to rubella in the same age groups.Discussion. The study results evidence about altered routine immunization against measles and rubella in children aged 12—15 months (first vaccination) and those at age of 6—7 years (revaccination) with MMR vaccine. The data obtained correlate with official data on coverage with measles and rubella vaccines in the Republic of Serbia.

scholarly journals STUDI PERBANDINGAN DUA KELOMPOK UMUR TERHADAP MULA KERJA DAN MASA KERJA ANESTETIKA LOKALPADA KASUS PENCABUTAN GIGI MOLAR I ATAU MOLAR II ATAS

Biomedika ◽  
2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Mahmud Kholifa
Keyword(s):  
Age Groups ◽  
Experimental Studies ◽  
Age Group ◽  
Lidocaine Group ◽  
Maxillary Molars ◽  
Group I ◽  
Group 15 ◽  
Quasi Experimental ◽  
The Mean ◽  
The Difference

Effect of in ltration due to the action of anesthesiasubstance on terminal nerve  bers maxillary molars the anesthesia uid  ow through the bone viahavers channels.This study is a quasi-experimental studies (clinical trials), which aims to determine the difference of onset and durationLidocaine between age groups 15-24 years age group 25-34 years in the case of extraction a molar tooth I or II maxilla conducted on patients who came to the Polyclinic FKG UGM, Yogyakarta. The number of samples obtained was 34 samples divided into two groups, Group I were patients with 15-24 years of age or younger, group II is patients aged 25-34 years or older. The data obtained areonset and duration of the age group 15-24 years compared with onset and duration of Lidocaine in the age group 25-34 years. The data obtained were analyzed by t-test with signicance level (p <0.05). The results of this study indicate that there are no signi cant differences between the onsetLidocaine in the age group 15-24 years with onset on the Lidocaine group 25-34 years. There is also a non-signi cant difference between Lidocaineduration in the group aged 15 - 24 years with a duration of Lidocaine on the group 25-34 years at p <0.05. The mean - median onsetLidocaine in the age group 15-24 years was 60.3 seconds with a range between 22-95 seconds while the onset on the Lidocaine group 25-34 years was 55.5 seconds with a range between 14-111 seconds. The mean - average durationLidocaine in the age group 15-24 years was 162.59 minutes with a range between 120-195 minutes while the duration of Lidocaine on the group 25-34 years was 184.41 with a range between 120-330 minutes.

scholarly journals Sexual Dimorphism in Blood Pressure and Hypertension among Adult Parengi Porjas of Visakhapatnam, Andhra Pradesh, India

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
I. Arjun Rao ◽  
Adimoolam Chandrasekhar ◽  
Venugopal N. Pulamaghatta ◽  
Subal Das ◽  
Kaushik Bose
Keyword(s):  
Blood Pressure ◽  
Sex Difference ◽  
Andhra Pradesh ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Stage I ◽  
Age Group ◽  
Sectional Study ◽  
Cross Sectional ◽  
Group I

The present study investigated blood pressure levels as well as the prevalence of hypertension among adult Parengi Porja tribals of village Munchingput Mandalam, Visakhapatnam district, Andhra Pradesh, India. A cross-sectional study was used to collect data on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate. A total of 137 adults (100 males and 37 females) were measured and classified into three age groups, that is, Gr-I: 23 to 32 years, Gr-II: 33 to 42 years, and Gr-III: ≥ 43 years. Negative significant sex difference in SBP among age group I (t=-2.409; P<0.05) was observed. Positive significant sex difference in DBP among age group I (t=2.545; P<0.05) was also observed. Significant age group difference was noticed for SBP (F=4.332; P<0.01) among males. Based on SBP, the prevalence of prehypertension and stage I hypertension in males was 25.0% and 5.0%, respectively. Similarly, in females the prevalence of prehypertension and stage I hypertension based on SBP was 32.4% and 5.4%, respectively. On the basis of DBP, the prevalence of stage I hypertension in males was 5.0%. Similarly, in females, the prevalence of stage I hypertension based on DBP was 5.4%. Our results suggest that females of this ethnic group were more prone to have prehypertension and stage I hypertension than males.

scholarly journals Condition of Periodontal Tissues in Pregnant Women of Different Age Groups

2021 ◽  
Vol 6 (1) ◽  
pp. 244-248
Author(s):  
M. A. Pasichnyk ◽  
◽  
A. I. Furdychko ◽  
I. I. Gorban ◽  
I. R. Fedun ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Pregnant Women ◽  
Age Groups ◽  
Clinical Signs ◽  
Significant Risk ◽  
Age Group ◽  
Periodontal Tissue ◽  
Group Iii ◽  
Periodontal Tissues ◽  
Group I

There are numerous domestic and foreign studies of periodontal disease in pregnant women, but there are still a number of unresolved issues. The data about the development of periodontal tissue diseases in pregnant women in terms of age is not enough. The purpose of this work was to study the development of periodontal disease in pregnant women in different age groups. Material and methods. A survey of 83 women in the ІІ and ІІІ trimesters of pregnancy, aged 19-45 years, was divided into three groups according to age. Group I (34 people) included pregnant women aged 19-25 years, group II (29 people) had pregnant women aged 26-35 years, group III (20 people) comprised pregnant women aged 36-45 years. Periodontal and hygienic indices were determined to assess the clinical signs of periodontal disease (to assess the clinical signs of periodontal disease, periodontal and hygienic indices were determined (papillary-marginal-alveolar index, degree of bleeding gums, Schiller-Pisarev test, numerical value of Schiller-Pisarev test – Svrakov's number and simplified index of cavity hygiene). Results and discussion. The obtained results indicated a high level of periodontal disease in pregnant women. Periodontal disease was found in 74.7% of subjects. The study found a significant progression of periodontal tissue pathology in pregnant women over 26 years of age, indicating that women in this age group were at significant risk of periodontal disease. The obtained data indicated that the value of the bleeding index was the lowest in pregnant women with periodontal disease of group I, and the highest in women of group III. The value of the PMA index differed 1.3 times (p˂0.05) in pregnant women of groups I and II, 1.2 times (p˂0.05) in women of groups II and III, and 1.5 times (p˂0.05) in pregnant women of groups I and III. In addition, the likelihood of developing periodontal disease increased with age of women. Conclusion. The values of the Svrakov's number had a similar tendency to increase in age groups, as well as the results of the previously described indices. Hygiene in pregnant women of all ages who had periodontal disease was not very good. Thus, special attention should be paid to the timely diagnosis, treatment and prevention of periodontal disease in pregnant women, taking into account their age

scholarly journals Anthropometric Evaluation of Volume of Maxillary Sinus and Nasal Septum Patterns as an AID in Personal Identification Using CBCT-A Retrospective Study

2021 ◽  
pp. 318-331
Author(s):  
Rakhi Chandak ◽  
Manoj Chandak ◽  
Pranali Thakare ◽  
Ramhari Sathawane ◽  
Runal Bansod ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Maxillary Sinus ◽  
Nasal Septum ◽  
Age Groups ◽  
Personal Identification ◽  
Age Group ◽  
Oral Medicine ◽  
Maxillary Sinus Volume ◽  
Group I ◽  
The Right

Aims: To determine the reliability and accuracy of maxillary sinus volume and nasal septum patterns in personal identification in forensics using CBCT (cone beam computed tomography). Study Design: Retrospective Study Place and Duration of Study: Department of Oral Medicine and Radiology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital Nagpur, from September 2019-December 2019. Methodology: 110 CBCT scans of bilateral maxillary sinuses and nasal septum images were retrospectively obtained from the Oral Medicine and Radiology database (68 men and 42 females). The study was divided into two groups based on age. Group -I consists of 58 CBCT scans taken between the ages of 20 and 40, while Group -II consists of 52 CBCT scans taken between the ages of 41 and 80. The height, breadth, and depth of the maxillary sinus were measured linearly. The nasal septum was classed as simple deviation to the right or left, sigmoid type, reverse sigmoid type, and straight based on the septa's deviations. Each person's combined maxillary sinus and nasal septum pattern was documented. Results: The difference in maxillary sinus volume between two age groups was significant (P<0.5). In age group I, there was a substantial change in the left deviation pattern, and there was a significant change in the reverse sigmoid pattern in males and the straight nasal septum pattern in females. With whatever nasal septum configuration, there were no volumetric alterations(P>0.5). Conclusion: In future, further research will be needed with a larger number of images to compare in order to arrive at a definitive identification.

scholarly journals The sex ratio of pneumonia mortality

1944 ◽  
Vol 43 (5) ◽  
pp. 315-327
Author(s):  
W. J. Martin
Keyword(s):  
Sex Ratio ◽  
Age Groups ◽  
Heavy Drinking ◽  
Male Infant ◽  
Local Characteristic ◽  
Standardized Mortality Ratio ◽  
Age Group ◽  
Male Mortality ◽  
Heavy Drinkers ◽  
Mortality Ratio

The size of the mortality sex ratio from pneumonia depends upon several factors which exert varying pressure with age, since it was shown for the London boroughs that the relative male risk was not high or low throughout life but displayed considerable variations.In infancy social conditions have little effect upon the ratio, and there was no association with the degree of urbanization. In London the correlations with the indices of density became insignificant when the infant death-rate from pneumonia was kept constant. The male infant risk increases with the prevalence of the disease, and significant correlations were obtained when the indices of overcrowding were kept constant.In childhood the size of the mortality sex ratio is not related to urbanization. The conditions operating for a high male mortality in childhood varies from those in infancy, since, for the eighty-three county boroughs, there was no correlation between the two ratios.For the age group 15–65, in which the male pneumonia rate was twice that for females, there was a distinct association with degree of urbanization. In the London boroughs the mortality sex ratio was unrelated to social and economic conditions when the usual indices, the proportion of the population living more than two to a room, and the proportion of males in social class V were used. That environmental conditions had little effect on the ratio is also suggested by the experience of the mining communities which showed little difference in the mortality sex ratio between the county boroughs and urban districts. The rural mining areas were in agreement with the urban when allowance was made for the agricultural workers in these districts. In London there was a small significant correlation between the sex ratio and the pneumonia mortality sex ratio, indicating that the residential or industrial character of the borough was associated with the mortality ratio. Some support for this is given by the county boroughs where high ratios were found in the industrial towns and low ratios in the residential towns. Some occupations involve a direct risk of pneumonia, i.e. furnacemen, rollermen, etc., and others have a more indirect risk, e.g. inn-keepers, hotel-keepers, etc. Although the prognosis of pneumonia is affected by previous indulgence in alcohol, the effect of this factor can only be a matter of speculation. The mortality sex ratio from pneumonia in the three occupations in which a higher proportion of heavy drinkers are found than in the general population, inn-keepers, hotel-keepers, etc., barmen, etc., makers of alcoholic drinks, all of which have a high standardized mortality ratio from pneumonia, form an interesting progression. These values were 247, 394, and 1200, but the number of deaths among wives in the last two groups, 5 and 2, was so small that the ratios are really of no value. Yet there is, perhaps, an indication that as the opportunity for the wives to indulge in heavy drinking decreases with each class the mortality sex ratio from pneumonia increases. This factor of alcoholic indulgence probably operates in most occupations, and since the proportion of heavy drinkers is larger among men than among women, it would be necessary for only a small proportion of men to carry a heavy risk of pneumonia mortality to effect a large increase in the mortality sex ratio. It seems that the factors responsible for the relatively high male mortality from pneumonia, in this age group, were an occupational risk and the habits of the males.In old age, as with the young age groups, there was no association with degree of urbanization. The mortality sex ratios of the London boroughs showed evidence of a geographical distribution. This was apparently a local characteristic, since the ratio of the county boroughs did not show any tendency to vary geographically.

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