Birth rate of planktonic rotifers in relation to food concentration in a shallow, eutrophic lake in western Canada

1979 ◽  
Vol 57 (6) ◽  
pp. 1206-1214 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Birth Rate ◽  
Environmental Parameters ◽  
Eutrophic Lake ◽  
Food Concentration ◽  
Western Canada ◽  
Birth Rates ◽  
Keratella Cochlearis ◽  
Shallow Eutrophic Lake ◽  
Keratella Quadrata ◽  
Planktonic Rotifers

Population dynamics and birth rates of Keratella quadrata, Keratella cochlearis, Keratella earlinae, Pompholyx sulcata, and Brachionus angularis were studied in a shallow eutrophic lake of western Canada during 1975–1976. The Keratella species were collected throughout the year with maximum population densities in spring and fall. Pompholyx sulcata and B. angularis were common only during summer months.An extensive correlation analysis involving 'lagged' variables was performed to ascertain relations between birth rates and environmental parameters (temperature and food). Birth rates of all five species were positively correlated with temperature. Concentrations of certain phytoplankton (Rhabdomonas, Rhodomonas, Chlamydomonas, and Ankistrodesmus) were positively correlated with Keratella birth rates. Birth rates of K. cochlearis and P. sulcata were positively correlated with concentration of bacteria. Correlations involving 'lagged' variables were often different from those using 'simultaneous' variables.

Specific status of Keratella cochlearis (Gosse) and K. earlinae Ahlstrom (Rotifera: Brachionidae): morphological and ecological considerations

1979 ◽  
Vol 57 (9) ◽  
pp. 1719-1722 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Vertical Distribution ◽  
Birth Rate ◽  
Recent Literature ◽  
Eutrophic Lake ◽  
Seasonal Abundance ◽  
Western Canada ◽  
Keratella Cochlearis ◽  
Stable Species ◽  
Shallow Eutrophic Lake ◽  
Two Populations

Keratella cochlearis and K. earlinae were found to coexist in a shallow eutrophic lake in western Canada. Differences between the two populations were found with respect to size, shape, seasonal abundance, birth rate, and vertical distribution. Results suggest that the two populations represent stable species and not ecophenotypes as suggested by recent literature.

Epidemiology of Twin Births in Southeast China: 1993–2005

2013 ◽  
Vol 16 (2) ◽  
pp. 608-613 ◽  
Author(s):  
Xinrong Lu ◽  
Jun Zhang ◽  
Yinghui Liu ◽  
Ting Wang ◽  
Yanyu Lu ◽  
...  
Keyword(s):  
Urban Areas ◽  
Birth Rate ◽  
Perinatal Care ◽  
Care Program ◽  
Developed Countries ◽  
Population Based ◽  
Fertility Treatment ◽  
Birth Rates ◽  
Southeast China ◽  
Twin Birth

Recently, there has been a significant increase in the rate of multiple births in most developed countries. However, few population-based studies have been conducted in China regarding the epidemiology of twin births in recent years. We performed a descriptive analysis of twin births from 1993 to 2005 using data from a population-based perinatal care program in southeast China. The twin birth rate in southeast China was 0.65%, and the twin birth rates from 1993 to 2005 fluctuated between 0.60% and 0.70%. During the three periods of 1993–1996, 1997–2000, and 2001–2005, the twin birth rate increased from 0.57% to 0.71% in urban areas (p = .005) and from 0.59% to 0.68% in mothers who had an education level of high school or higher (p = .046). After 2000, the twin birth rate of primiparae 30 years of age and older significantly increased from 0.72% to greater than 1.20%. We concluded that the twin birth rates in southeast China from 1993 to 2005 stayed constant in the overall population but increased in certain subgroups of women, presumably due to increased use of fertility treatment and the development of assisted reproductive technology.

Testing aluminum addition as a tool for lake restoration in shallow, eutrophic Lake Sønderby, Denmark

Hydrobiologia ◽  
2003 ◽  
Vol 506-509 (1-3) ◽  
pp. 781-787 ◽  
Author(s):  
Kasper Reitzel ◽  
Jonas Hansen ◽  
Henning S. Jensen ◽  
Frede Ø. Andersen ◽  
Kjeld S. Hansen
Keyword(s):  
Lake Restoration ◽  
Eutrophic Lake ◽  
Aluminum Addition ◽  
Shallow Eutrophic Lake

scholarly journals Validity of pre and post-term birth rates based on the date of last menstrual period compared to early obstetric ultrasonography

2015 ◽  
Vol 31 (4) ◽  
pp. 885-890 ◽  
Author(s):  
Maria Nilza Lima Medeiros ◽  
Nádia Carenina Nunes Cavalcante ◽  
Fabrício José Alencar Mesquita ◽  
Rosângela Lucena Fernandes Batista ◽  
Vanda Maria Ferreira Simões ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Birth Rate ◽  
Menstrual Period ◽  
Last Menstrual Period ◽  
Birth Rates ◽  
Term Birth ◽  
Preterm Birth Rate ◽  
Obstetric Ultrasonography

The aim of this study was to assess the validity of the last menstrual period (LMP) estimate in determining pre and post-term birth rates, in a prenatal cohort from two Brazilian cities, São Luís and Ribeirão Preto. Pregnant women with a single fetus and less than 20 weeks' gestation by obstetric ultrasonography who received prenatal care in 2010 and 2011 were included. The LMP was obtained on two occasions (at 22-25 weeks gestation and after birth). The sensitivity of LMP obtained prenatally to estimate the preterm birth rate was 65.6% in São Luís and 78.7% in Ribeirão Preto and the positive predictive value was 57.3% in São Luís and 73.3% in Ribeirão Preto. LMP errors in identifying preterm birth were lower in the more developed city, Ribeirão Preto. The sensitivity and positive predictive value of LMP for the estimate of the post-term birth rate was very low and tended to overestimate it. LMP can be used with some errors to identify the preterm birth rate when obstetric ultrasonography is not available, but is not suitable for predicting post-term birth.

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