scholarly journals Estimating the breeding population of an elephant seal colony from a single census

2020 ◽  
Author(s):  
Richard Condit ◽  
Sarah G. Allen ◽  
Daniel P. Costa ◽  
Sarah Codde ◽  
P. Dawn Goley ◽  
...  
Keyword(s):  
Population Size ◽  
Breeding Population ◽  
Elephant Seal ◽  
Annual Number ◽  
Correction Factors ◽  
Female Population ◽  
Calculated Correction ◽  
Point Reyes ◽  
Total Female ◽  
Departure Behavior

AbstractOur aim was to develop a method for estimating the annual number of female elephant seals pupping in a colony from a single count. This is difficult because breeding females are not synchronous so there is no time when the entire population is present. We applied models that describe arrival and departure behavior to account for those missed in any one count and calculated correction factors that yield total population from any single count throughout a season. At seven colonies in California for which we had multiple female counts per year, we found consistent timing in arrival and departure both within and between sites for as long as 50 years. This meant that the optimal correction factor, the date when the maximum number of females was onshore, was consistent. At Point Reyes, a female count on 27 or 28 Jan can be multiplied by 1.15 to yield the total female population; at Año Nuevo Island, the correction was 1.17 on 25-26 Jan; and at Año Nuevo Mainland, 1.13 on 28-30 Jan. Correction factors at Channel Island colonies and King Range were also 1.13. Across the colonies studied, the factor 1.15 multiplied by a female count between 26 and 30 Jan was close to optimal, and this provides a method for estimating the female population size at colonies not yet studied. Our method can produce population estimates with minimum expenditure of time and resources and will facilitate monitoring of the elephant seal population size over its entire range.

scholarly journals Change in medical practice over time? A register based study of regional trends in hysterectomy in Finland in 2001–2018

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tiina Vikstedt ◽  
Martti Arffman ◽  
Satu Heliövaara-Peippo ◽  
Kristiina Manderbacka ◽  
Eeva Reissell ◽  
...  
Keyword(s):  
Multilevel Models ◽  
Medical Decision ◽  
Hospital Discharges ◽  
Female Population ◽  
Medical Practices ◽  
Hospital District ◽  
Regional Trends ◽  
Region Of Residence ◽  
Total Female ◽  
Over Time

Abstract Background A persistent research finding in Finland and elsewhere has been variation in medical practices both between and within countries. Variation seems to exist especially if medical decision making involves discretion and the best treatment cannot be identified unambiguously. This is true for hysterectomy when performed for benign causes. The aim of the current study was to investigate regional trends in hysterectomy in Finland and the potential convergence of rates over time. Methods We used hospital discharge register data on hysterectomies performed, diagnoses, age, and region of residence to examine hospital discharges for women undergoing hysterectomy in 2001–2018 among total female population aged 25 years or older in Finland. We examined hysterectomy rates among biannual cohorts by indication, calculated age-standardised rates and used multilevel models to analyse potential convergence over time. Results Altogether 131,695 hysterectomies were performed in Finland 2001–2018. We found a decreasing trend, with the age-adjusted overall hysterectomy rate decreasing from 553/100,000 person years in 2001–2002 to 289/100,000 py in 2017–2018. Large but converging regional differences were found. The correlations between hospital district intercepts and slopes in time ranged from − 0.71 to − 0.97 (p < 0.001) suggesting diminishing variation. Conclusions Our findings demonstrate that change in hysterectomy practices and more uniformity across regions are achievable goals. Regional variation still exists suggesting differences in medical practices.

Abstract ID: 169 Monte Carlo calculated correction factors for a proton calorimeter in clinical proton beams

2017 ◽  
Vol 42 ◽  
pp. 35-36
Author(s):  
Francesco Romano ◽  
David Shipley ◽  
Lauren M. Petrie ◽  
Hugo Palmans
Keyword(s):  
Monte Carlo ◽  
Correction Factors ◽  
Proton Beams ◽  
Calculated Correction

A survey of 100 female senile admissions to a mental hospital

1962 ◽  
Vol 108 (457) ◽  
pp. 801-803 ◽  
Author(s):  
P. A. Morris
Keyword(s):  
Catchment Area ◽  
Mental Hospital ◽  
Admission Rate ◽  
Urban District ◽  
Female Population ◽  
Industrial Areas ◽  
Industrial Town ◽  
Total Female

An investigation was undertaken to determine the fate of 100 consecutive female admissions over 65 to a mental hospital. The patients were admitted to Kingsway Hospital, Derby, between October 1958 and December 1959 and were each followed up for a year or until death. These 100 patients formed 24% of the total female admissions for the period. The catchment area from which they came includes the County Borough of Derby (a heavy-industrial town) with a total of over-65 female population of 8,724; Shardlow Urban District (a rather rambling and mainly country area) with 5,633; and Long Eaton Urban District (a light-engineering town) with 1,934. Thus the total over-65 female population was 16,311. Working from these figures the expected admissions from these areas would be (in %): 53: 35: 12, whereas the actual figures were (in %): 62: 30: 8. This shows, as one would expect, a proportionately higher admission rate from the industrial areas.

Adult population dynamics and reproductive effort of the fishing spider Dolomedes triton (Araneae, Pisauridae) in central Alberta

1992 ◽  
Vol 70 (11) ◽  
pp. 2224-2233 ◽  
Author(s):  
Manfred Zimmermann ◽  
John R. Spence
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Adult Population ◽  
Adult Longevity ◽  
Male Population ◽  
Male Mortality ◽  
Mark Recapture ◽  
Female Population ◽  
Population Size Estimates ◽  
Dolomedes Triton

A combination of simple enumeration and more intensive Jolly–Seber and Manly–Parr mark–recapture estimation was required to give a complete picture of the population dynamics of adult Dolomedes triton on a small pond in central Alberta. The total number of spiders marked was 142 in 1986 and 210 in 1987, and annual adult emergence, using the population size estimates of the two mark–recapture methods, amounted to ca. 150 and 230 individuals in 1986 and 1987, respectively. The sex ratio was not different from 1:1 in 1986, but in 1987 more than twice as many males emerged than females. Males had significantly shorter observed residence times (life-spans) than females. Contrary to longevity estimates based on the survival probabilities given by the Jolly–Seber model, which were close to those based on enumeration, Manly–Parr survival estimates were strongly biased and even yielded impossible estimates of adult longevity. In both years the median date of male emergence preceded that of females by 5–10 days. Male population size decreased dramatically during the interval when the density of the female population increased, supporting the hypothesis that cannibalism by females is a major source of male mortality. Seventy and 55% of marked females produced egg sacs in 1986 and 1987, respectively. First egg sacs contained 472 ± 18.5 (SE) eggs. Four times as many nursery webs were found in 1986 as in 1987, suggesting that significant losses in female reproductive success occur during the period of egg sac care.

Invertebrate prey availability limits reproductive success but not breeding population size in suburban House Sparrows Passer domesticus

Ibis ◽  
2015 ◽  
Vol 157 (3) ◽  
pp. 601-613 ◽  
Author(s):  
Will J. Peach ◽  
John W. Mallord ◽  
Nancy Ockendon ◽  
Chris J. Orsman ◽  
William G. Haines
Keyword(s):  
Reproductive Success ◽  
Population Size ◽  
Prey Availability ◽  
Passer Domesticus ◽  
Breeding Population ◽  
House Sparrows ◽  
Invertebrate Prey

Population structure of the Sahiwal breed in Pakistan

1995 ◽  
Vol 60 (2) ◽  
pp. 163-168 ◽  
Author(s):  
A. Dahlin ◽  
U. N. Khan ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Effective Population Size ◽  
Breeding Population ◽  
Effective Population ◽  
Data Set ◽  
Inbreeding Coefficients ◽  
Sahiwal Cows ◽  
The Mean ◽  
Average Population Size

AbstractThe present study was undertaken to assist conservation and improvement schemes in the Sahiwal breed of cattle in Pakistan. A data set, consisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, the latter representing about 80% of all recorded Sahiwal cows in Pakistan born during a period covering about 20 years, was analysed with regard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsires were known, were 0·043 and 0·046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or grandparents in common. The mean additive relationship among the cows was 0·062, with within-herd averages ranging from 0·087 to 0·358. The average population size in a subdata set of recorded Sahiwal cattle from 1980 to 1984 was 1612, whereas the most likely estimate of the effective population size was about 30 animals for the same active breeding population. The study indicated the immediate need for an active conservation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.

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