Root sprouting in American beech: production, survival, and the effect of parent tree vigor

1987 ◽  
Vol 17 (6) ◽  
pp. 539-544 ◽  
Author(s):  
Robert H. Jones ◽  
Dudley J. Raynal
Keyword(s):  
Life Table ◽  
Mortality Rates ◽  
Beech Bark Disease ◽  
Age Classes ◽  
American Beech ◽  
Parent Tree ◽  
Age Class ◽  
Per Capita ◽  
Individual Parent ◽  
Annual Mortality

Root sprout age-class distributions around American beech trees were measured to characterize production of sprouts under closed canopies. Annual mortality of root sprouts was estimated by static and cohort life table analyses. Sprouts around parent trees with and without beech bark disease were compared to test for effects of lowered parent vigor on sprout production and vigor. Age-class distributions were highly variable, indicating episodic production of sprouts. Trends in the data suggested that (i) for individual parent beech trees, the number of sprouts per age-class decreased exponentially as sprout age increased; and (ii) parent trees with larger diameters had more sprouts, more sprout age-classes, but greater variability in age-class distribution. Life table analyses indicated uniform per capita mortality rates for clumps of sprouts but decreasing mortality with age for individual sprouts within clumps. Low parent vigor, due in part to beech bark disease, was weakly correlated with reduced sprout production, but diseased trees maintained populations of older sprouts that differed little from sprouts associated with nondiseased trees.

Tsetse fly (Diptera: Glossinidae) population dynamics and the estimation of mortality rates from life-table data

1990 ◽  
Vol 80 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Brian G. Williams ◽  
Robert D. Dransfield ◽  
Robert Brightwell
Keyword(s):  
Life Table ◽  
Age Distribution ◽  
Glossina Pallidipes ◽  
Mortality Rates ◽  
Adult Mortality ◽  
Tsetse Fly ◽  
Age Class ◽  
Life Table Data ◽  
Stable Age Distribution ◽  
Table Data

AbstractThe estimation of tsetse fly mortality rates from life-table data is central to opulation dynamics studies and to the development of tsetse fly control programmes. For a population at equilibrium with a stable age distribution, the age-specific mortalities may be estimated directly from the number of individuals in each age class, but a correction must be applied when the population is growing or declining. Furthermore, if the mortality rates are changing with time, inaccuracies will be introduced into estimates of the mortality rates derived from the age structure of the population since the population will take time to reach a new stable age distribution. In this paper we use the Euler-Lotka equation, which relates the age-specific mortality and fecundity to the overall growth rate of the population, to study the loss rate of the tsetse fly Glossina pallidipes (Austen) as a function of pupal mortality, adult mortality and mortalities applied to each age class seperately. We then present a simulation model in order to quantity and to set limits on the precision of estimates of mortalities when the mortalities are themselves changing.

Age structure, mortality and breeding in a population of agile wallabies (Macropus agilis)

2008 ◽  
Vol 56 (6) ◽  
pp. 431 ◽  
Author(s):  
Simon C. Stirrat
Keyword(s):  
Sex Ratio ◽  
Age Structure ◽  
Mortality Rates ◽  
Adult Mortality ◽  
Study Data ◽  
Life Table Analysis ◽  
Wet Season ◽  
Age Classes ◽  
Table Analysis ◽  
Annual Mortality

Aspects of the demography of the agile wallaby (Macropus agilis) were investigated in an overabundant population in East Point Reserve, Darwin. The maximum wet-season population size was relatively stable for several years before, and during, this study. Data suggest that the population fluctuated in size seasonally. Life table analysis indicated that mortality of animals up to 18 months old (including pouch young and young-at-foot) was high compared with adult mortality rates. After 18 months of age, mortality rates of males increased throughout life whereas those of females declined slightly and were relatively stable in older age classes. Females reproduced throughout the year, but more large pouch young were observed in the wet season than at other times of the year. The sex ratio of the population was female-biased, probably a result of higher mortality of males in the dry season. Predation by dogs was documented but contributed a relatively small fraction of total annual mortality.

Chapter 4: The Graduation of Survivorship Data

1973 ◽  
Vol 27 ◽  
pp. 17-22
Author(s):  
Kenneth M. Weiss
Keyword(s):  
Life Table ◽  
Curve Fitting ◽  
Data Sets ◽  
Age Classes ◽  
Human Mortality ◽  
Age Class ◽  
Age Limits ◽  
Source Populations

The mortality between adjacent age classes can be estimated from the survivorship schedules derived in Chapter 3. The data, however, differ in each case in the number, size, and age limits of the age classes; therefore, it is not possible to derive strictly comparable information from the data sets. Further, it is not yet possible to define the internal mortality structure of each age class which must be known for the computation of many elements of the life table.If we assume, as is commonly done in demography, that human mortality patterns follow some function of age, then we can fit our 50 source populations to that function and assume that deviations from that fit are merely stochastic. This process of curve fitting is called graduation, and it is a powerful and useful smoothing operation for mortality or survivorship data.

A Successful Population Policy: Potentials and Constraints (Distinguishedl Lecture)

1993 ◽  
Vol 32 (4I) ◽  
pp. 411-431
Author(s):  
Hans-Rimbert Hemmer
Keyword(s):  
Developing Countries ◽  
Economic Development ◽  
Population Growth ◽  
Capita Income ◽  
Population Policy ◽  
Mortality Rates ◽  
Per Capita Income ◽  
Access To Health Services ◽  
Industrial Countries ◽  
Per Capita

The current rapid population growth in many developing countries is the result of an historical process in the course of which mortality rates have fallen significantly but birthrates have remained constant or fallen only slightly. Whereas, in industrial countries, the drop in mortality rates, triggered by improvements in nutrition and progress in medicine and hygiene, was a reaction to economic development, which ensured that despite the concomitant growth in population no economic difficulties arose (the gross national product (GNP) grew faster than the population so that per capita income (PCI) continued to rise), the drop in mortality rates to be observed in developing countries over the last 60 years has been the result of exogenous influences: to a large degree the developing countries have imported the advances made in industrial countries in the fields of medicine and hygiene. Thus, the drop in mortality rates has not been the product of economic development; rather, it has occurred in isolation from it, thereby leading to a rise in population unaccompanied by economic growth. Growth in GNP has not kept pace with population growth: as a result, per capita income in many developing countries has stagnated or fallen. Mortality rates in developing countries are still higher than those in industrial countries, but the gap is closing appreciably. Ultimately, this gap is not due to differences in medical or hygienic know-how but to economic bottlenecks (e.g. malnutrition, access to health services)

scholarly journals Health capabilities and the determinants of infant mortality in Brazil, 2004–2015: an innovative methodological framework

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alexandre Bugelli ◽  
Roxane Borgès Da Silva ◽  
Ladislau Dowbor ◽  
Claude Sicotte
Keyword(s):  
Infant Mortality ◽  
Educational Attainment ◽  
Health Professionals ◽  
Capita Income ◽  
Mortality Rates ◽  
Fertility Rate ◽  
Employment Rate ◽  
Infant Deaths ◽  
Bolsa Familia ◽  
Per Capita

Abstract Background Despite the implementation of a set of social and health policies, Brazil has experienced a slowdown in the decline of infant mortality, regional disparities and persistent high death levels, raising questions about the determinants of infant mortality after the implementation of these policies. The objective of this article is to propose a methodological approach aiming at identifying the determinants of infant mortality in Brazil after the implementation of those policies. Method A series of multilevel panel data with fixed effect nested within-clusters were conducted supported by the concept of health capabilities based on data from 26 Brazilian states between 2004 and 2015. The dependent variables were the neonatal, the infant and the under-five mortality rates. The independent variables were the employment rate, per capita income, Bolsa Família Program coverage, the fertility rate, educational attainment, the number of live births by prenatal visits, the number of health professionals per thousand inhabitants, and the access to water supply and sewage services. We also used different time lags of employment rate to identify the impact of employment on the infant mortality rates over time, and household income stratified by minimum wages to analyze their effects on these rates. Results The results showed that in addition to variables associated with infant mortality in previous studies, such as Bolsa Família Program, per capita income and fertility rate, other factors affect child mortality. Educational attainment, quality of prenatal care and access to health professionals are also elements impacting infant deaths. The results also identified an association between employment rate and different infant mortality rates, with employment impacting neonatal mortality up to 3 years and that a family income below 2 minimum wages increases the odds of infant deaths. Conclusion The results proved that the methodology proposed allowed the use of variables based on aggregated data that could hardly be used by other methodologies.

scholarly journals Mortality in Dementia from 1996 to 2015: A National Registry-Based Cohort Study

2021 ◽  
Vol 79 (1) ◽  
pp. 289-300
Author(s):  
Lærke Taudorf ◽  
Ane Nørgaard ◽  
Gunhild Waldemar ◽  
Thomas Munk Laursen
Keyword(s):  
Elderly People ◽  
Age Groups ◽  
Mortality Rates ◽  
Similar Rate ◽  
National Registry ◽  
Healthcare Data ◽  
Appropriate Care ◽  
People With Dementia ◽  
Rate Ratios ◽  
Annual Mortality

Background: It remains unclear whether the increased focus on improving healthcare and providing appropriate care for people with dementia has affected mortality. Objective: To assess survival and to conduct a time trend analysis of annual mortality rate ratios (MRR) of dementia based on healthcare data from an entire national population. Methods: We assessed survival and annual MRR in all residents of Denmark ≥65 years from 1996–2015 using longitudinal registry data on dementia status and demographics. For comparison, mortality and survival were calculated for acute ischemic heart disease (IHD) and cancer. Results: The population comprised 1,999,366 people (17,541,315 person years). There were 165,716 people (529,629 person years) registered with dementia, 131,321 of whom died. From 1996–2015, the age-adjusted MRR for dementia declined (women: 2.76 to 2.05; men: 3.10 to 1.99) at a similar rate to elderly people without dementia. The sex-, age-, and calendar-year-adjusted MRR was 2.91 (95%CI: 2.90–2.93) for people with dementia. MRR declined significantly more for acute IHD and cancer. In people with dementia, the five-year survival for most age-groups was at a similar level or lower as that for acute IHD and cancer. Conclusion: Although mortality rates declined over the 20-year period, MRR stayed higher for people with dementia, while the MRR gap, compared with elderly people without dementia, remained unchanged. For the comparison, during the same period, the MRR gap narrowed between people with and without acute IHD and cancer. Consequently, initiatives for improving health and decreasing mortality in dementia are still highly relevant.

Abstract P261: Intensive Systolic Blood Pressure Lowering Will Prevent Over 100,000 Deaths Annually

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Holly Kramer ◽  
Adam Bress ◽  
Srinivasan Beddhu ◽  
Paul Muntner ◽  
Richard S Cooper
Keyword(s):  
Blood Pressure ◽  
Mortality Rate ◽  
Systolic Blood Pressure ◽  
Mortality Rates ◽  
Mortality Data ◽  
Blood Pressure Lowering ◽  
Cvd Risk ◽  
Pressure Lowering ◽  
Annual Mortality ◽  
The U.S

Background: The Systolic Blood Pressure Intervention Trial (SPRINT) trial randomized 9,361 adults aged ≥50 years at high cardiovascular disease (CVD) risk without diabetes or stroke to intensive systolic blood pressure (SBP) lowering (≤120 mmHg) or standard SBP lowering (≤140 mmHg). After a median follow up of 3.26 years, all-cause mortality was 27% (95% CI 40%, 10%) lower with intensive SBP lowering. We estimated the potential number of prevented deaths with intensive SBP lowering in the U.S. population meeting SPRINT criteria. Methods: SPRINT eligibility criteria were applied to the National Health and Nutrition Examination Survey 1999-2006, a representative survey of the U.S. population, linked with the mortality data through December 2011. Eligibility included (1) age ≥50 years with (2) SBP 130-180 mmHg depending on number of antihypertensive classes being taken, and (3) presence of ≥1 CVD risk conditions (history of coronary heart disease, estimated glomerular filtration rate (eGFR) 20 to 59 ml/min/1.73 m 2 , 10-year Framingham risk score ≥15%, or age ≥75 years). Adults with diabetes, stroke history, >1 g/day proteinuria, heart failure, on dialysis, or eGFR<20 ml/min/1.73m 2 were excluded. Annual mortality rates for adults meeting SPRINT criteria were calculated using Kaplan-Meier methods and the expected reduction in mortality rates with intensive SBP lowering in SPRINT was used to determine the number of potential deaths prevented. Analyses accounted for the complex survey design. Results: An estimated 18.1 million U.S. adults met SPRINT criteria with 7.4 million taking blood pressure lowering medications. The mean age was 68.6 years and 83.2% and 7.4% were non-Hispanic white and non-Hispanic black, respectively. The annual mortality rate was 2.2% (95% CI 1.9%, 2.5%) and intensive SBP lowering was projected to prevent 107,453 deaths per year (95% CI 45,374 to 139,490). Among adults with SBP ≥145 mmHg, the annual mortality rate was 2.5% (95% CI 2.1%, 3.0%) and intensive SBP lowering was projected to prevent 60,908 deaths per year (95% CI 26, 455 to 76, 792). Conclusions: We project intensive SBP lowering could prevent over 100,000 deaths per year of intensive treatment.

scholarly journals Analysis of mortality from diarrheic diseases in under-five children in Brazilian cities with more than 150,000 inhabitants

2009 ◽  
Vol 25 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Juraci Vieira Sergio ◽  
Antônio Carlos Ponce de Leon
Keyword(s):  
Mortality Rate ◽  
Time Trends ◽  
Sharp Decrease ◽  
Mortality Rates ◽  
The North ◽  
Indicator Variables ◽  
Before And After ◽  
Geographic Regions ◽  
Annual Mortality ◽  
Children Under 5

This study analyzes mortality from infectious diarrheic diseases in children under 5 years of age in Brazilian municipalities with more than 150,000 inhabitants, excluding State capitals. The annual mortality rates by municipality from 1990 to 2000 were analyzed using a multilevel model, with years as first level units nested in municipalities as second level units. The dependent variable was the yearly mortality rate by municipality, on the log scale. Polynomial time trends and indicator variables to account for differences in geographic regions were used in the modeling. Time trends were centered on 1995, so they could be modeled differently before and after 1995. From 1990 to 1995 there was a sharp decrease in mortality rates by diarrheic diseases in most Brazilian municipalities, while from 1995 to 2000 the decrease was more heterogeneous. In 1995 the North and Northeast of Brazil had higher mortality rates than the Southeast, and the differences were statistically significant. Most importantly, the study concludes that there was an important difference in the pattern of mortality rate decreases over time, comparing the country's five geographic regions.

Mortality Estimation: Biased Results from Unbiased Ages

1984 ◽  
Vol 41 (12) ◽  
pp. 1843-1847 ◽  
Author(s):  
Jay Barlow
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Age Estimation ◽  
Age Determination ◽  
Mortality Rates ◽  
Age Classes ◽  
Estimation Errors ◽  
Mortality Estimation ◽  
Age Estimates

Estimates of mortality rates from age distributions are biased by imprecision in age estimation, even if age estimates are unbiased. I have derived a method for predicting the magnitude of this bias from information on the precision of age determination. Monte Carlo simulations show that bias can be accurately predicted. The commonly used Chapman–Robson mortality estimator is shown to be robust to imprecision in age determination if all age-classes are included. Errors are likely, however, if one or more age-classes are excluded or if other mortality estimators are used. Biases can be corrected if the distribution of age-estimation errors is known.

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