Sample records for fertility populations meanings

  1. Fertility and Population Policy


    Ouedraogo, Abdoulaye; Tosun, Mehmet S.; Yang, Jingjing


    There have been significant changes in both the fertility rates and fertility perception since 1970s. In this paper, we examine the relationship between government policies towards fertility and the fertility trends. Total fertility rate, defined as the number of children per woman, is used as the main fertility trend variable. We use panel data from the United Nations World Population Policies database, and the World Bank World Development Indicators for the period 1976 through 2013. We find...

  2. Global fertility and population trends. (United States)

    Bongaarts, John


    Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Too old to have children? Lessons from natural fertility populations. (United States)

    Eijkemans, Marinus J C; van Poppel, Frans; Habbema, Dik F; Smith, Ken R; Leridon, Henri; te Velde, Egbert R


    fertility. We selected six natural fertility populations comprising 58 051 eligible women. While these populations represent different historical time periods, the distribution of the ages at last birth is remarkably similar. The curve denoting the end of fertility indicates that years meaning that almost 98% were able to have at least one child thereafter. The cumulative curve for the end of fertility slowly increases from 4.5% at age 25 years, 7% at age 30 years, 12% at age 35 years and 20% at age 38 years. Thereafter, it rises rapidly to about 50% at age 41, almost 90% at age 45 years and approaching 100% at age 50 years. It may be argued that these historical fertility data do not apply to the present time; however, the age-dependent decline in fertility is similar to current populations and is consistent with the pattern seen in women treated by donor insemination. Furthermore, for reproductive ageing, we note that it is unlikely that such a conserved biological process with a high degree of heritability would have changed significantly within a century or two. We argue that the age-specific ALB curve can be used to counsel couples who envisage having children in the future. Our findings challenge the unsubstantiated pessimism regarding the possibility of natural conception after age 35 years. No external funding was either sought or obtained for this study. There are no conflicts of interest to be declared.

  4. [Fertility change in Mexico and the politics of population]. (United States)

    Zavala De Cosio, M E


    This introduction to a detailed study of fertility change in Mexico assesses the available fertility data and describes the sources used, traces the beginning and course of the demographic transition in Mexico, and describes the work. Mexico's demographic transition began around 1930 with the acceleration of mortality decline. The considerable time lag between the mortality decline and the beginning of the fertility decline resulted in a period of very rapid growth. Between 1955 and 1975, the growth rate exceeded 3% annually. The start of the fertility decline dated to about 1970, the time of a major reform of population policy and creation of institutions to reduce growth. But the fertility decline was not solely the result of population programs. An incipient fertility decline could be observed in the metropolitan and more educated population sectors beginning in the early 1960s. The onset of the mortality decline in the 1930s resulted from the sustained social and economic progress made possible after the conclusion of the Mexican Revolution. Between 1930 and 1980, the adult illiteracy rate declined from 61.2% to 17%, while life expectancy increased from 33 years to 63.2 years. In Mexico as in other Latin American countries, the mortality decline, which disturbed the traditional balance between high mortality and high fertility, was the force setting off the demographic transition and the necessary precursor to fertility decline. The first of two main sections of the book focuses on examination of fertility variations in Mexico since around 1900 using cross-sectional and longitudinal methods of analysis. The second part describes the origins, history, and institutions involved in Mexico's population policies and the demographic programs and their principal results. The influence of population policies in demographic change is assessed, especially in the case of fertility changes induced by family planning programs. Both the first and second parts sought to place

  5. Fertility by birth order of population in Serbia

    Directory of Open Access Journals (Sweden)

    Mihajlović Vojislav


    Full Text Available Based on fertility by birth order, it is possible to research the level of the reproductive norms in certain population. In the period after World War II there were big changes in the fertility by birth order in Central Serbia and Vojvodina and that is the consequence of the population's reproductive norms decrease in these areas. Therefore, in this article we will analyze the trends of fertility by birth order changes for population in Central Serbia and Vojvodina in the period from 1948 to 2012.

  6. [Fertility of the Yanomami population of Sierra Parima (Amazonas Federal Territory, Venezuela)]. (United States)

    Schkolnik, S


    This article presents information on the age structure and level of female fertility obtained on the basis of a sample of the Yanomami population (653 individuals) residing in the Venezuelan margin of Sierra Parima. The population observed is very young, over 50% are less than age 15, and the mean age is 18. The total fertility rate reaches 7.76 children/woman while the age distribution of rates show that fertility begins at a very early age and begins to decrease only after age 30. (author's modified)

  7. Wealth, fertility and adaptive behaviour in industrial populations (United States)


    The lack of association between wealth and fertility in contemporary industrialized populations has often been used to question the value of an evolutionary perspective on human behaviour. Here, we first present the history of this debate, and the evolutionary explanations for why wealth and fertility (the number of children) are decoupled in modern industrial settings. We suggest that the nature of the relationship between wealth and fertility remains an open question because of the multi-faceted nature of wealth, and because existing cross-sectional studies are ambiguous with respect to how material wealth and fertility are linked. A literature review of longitudinal studies on wealth and fertility shows that the majority of these report positive effects of wealth, although levels of fertility seem to fall below those that would maximize fitness. We emphasize that reproductive decision-making reflects a complex interplay between individual and societal factors that resists simple evolutionary interpretation, and highlight the role of economic insecurity in fertility decisions. We conclude by discussing whether the wealth–fertility relationship can inform us about the adaptiveness of modern fertility behaviour, and argue against simplistic claims regarding maladaptive behaviour in humans. PMID:27022080

  8. A hypothetical study of populations under constant mortality and fertility. (United States)

    Gupta, R B


    28 countries with different characteristics have been selected in order to observe the amount of time it takes for these different countries to reach stable age distributions. The individual populations by sex and age were projected for 150 years in 5-year intervals with the present constant mortality and fertility schedules by component method. Observations have been made by considering the following characteristics of population when it has acquired stability: age distribution; the rate of growth, birthrate, and mortality rate; the population change; the intrinsic rate of growth, birthrate and mortality rate; and approximate time taken to stabilize the population. The initial age distribution has a significant part in the amount of time it takes for a population to acquire stability, and its intrinsic rate of growth is mostly dependent upon the existing age distribution of that population. The time taken for a country's population to become stable depends upon the age distribution, fertility and mortality schedules at the beginning. It has been observed that countries having a higher intrinsic rate of growth take comparatively less time in acquiring stability than the countries having a lower intrinsic rate of growth. The mortality and fertility schedules of a country is another important phenomenon. The populations of the different countries at the point of stability were growing according to their rates of growth. No specific trend of population growth could be found among the groups of countries. Time taken for stabilizing the population is completely based upon age distributions, fertility and mortality schedules a particular country was having at the beginning. The range of time taken for different countries to acquire stability generally ranged from 100 to 135 years. Among the different countries the relationship for the time it takes to acquire stability has not been established. This is a hypothetical approach in order to obtain some idea as to how a

  9. Too old to have children? Lessons from natural fertility populations

    NARCIS (Netherlands)

    Eijkermans, M.J.C.; van Poppel, F.W.A.; Habbema, J.D.F.; Smith, K.R.; Leridon, H.; te Velde, E.R.


    study question: Is it possible to construct an age curve denoting the ages above which women are biologically too old to reproduce? summaryanswer:We constructed a curve based on the distribution of female age at last birth in natural fertility populations reflecting the ages above which women have

  10. Selection to improve spring fertility in a crossbred sheep population


    Al-Shorepy, Salih Abdu


    Reproductive and productive performance of a composite sheep population, containing 50% Dorset, 25% Rambouillet and 25% Finnsheep breeding and under selection for ability to lamb in the fall, was evaluated. Traits considered were spring fertility, faIl litter size, live weights at birth, weaning, and at about 90 and 120 d of age, and scrotal circumference at weaning and at about 90 and 120 d of age. Fertility was defined as 1 or 0 depending upon whether a ewe lambed or failed t...

  11. The effect of plant population and nitrogen fertilizer on

    Directory of Open Access Journals (Sweden)

    mohamad reza asgaripor


    Full Text Available Interest has increased towards hemp (Cannabis sativa L. fibre production due to renewed demand for natural fibre in the world. A Study was conducted in 2005 at Shirvan in Northern Khorasan province, Iran, to determine the effects of three plant populations (30, 90 and 150 plant per m2 and three rates of nitrogen application (50, 150 and 250 kg N per ha on final stand, stalk height, basal stalk diameter, total stalk yield as well as fibre content from stalk and fibre yield in male and female plants. A split plot experimental with three replications was used. The result indicated that due to enhanced competition for light at higher population on density and N2 level plant mortality was higher than other treatment Morphological characteristics were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained at 250 plant m-2 when 150 kg N ha-1 was used. Lowest plant density did not show self-thinning but reduced above ground dry matter. Shoot dry matter increased with increasing plant density and nitrogen supply. Apparently, fibre content was greater at medium density and lowest nitrogen fertilizer, however, fibre yield was greatest at highest plant population and nitrogen fertilizer. In terms of fibre yield, approximate 31.7% of the fibre was located in the bottom parts, 22.4% in the middle and only 9.9% in the top part of the stem. The results suggest that hemp can yield large quantities of useful fibre at Shirvan when planted in proper plant densities and suitable nitrogen fertilizer.

  12. Estimation of population mean under systematic sampling (United States)

    Noor-ul-amin, Muhammad; Javaid, Amjad


    In this study we propose a generalized ratio estimator under non-response for systematic random sampling. We also generate a class of estimators through special cases of generalized estimator using different combinations of coefficients of correlation, kurtosis and variation. The mean square errors and mathematical conditions are also derived to prove the efficiency of proposed estimators. Numerical illustration is included using three populations to support the results.

  13. Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population. (United States)

    Anderton, D L; Bean, L L


    Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral

  14. [Fertility in the Yanomami population, Sierra Parima (Amazonas Federal Territory, Venezuela)]. (United States)

    Scholnik, S


    This article presents information on the age structure and the level of female fertility obtained on the basis of a sample of the yanomami population (653 individuals) residing in the Venezuelan margin of Sierra Parima. Data was gathered through a survey which had the character of a retrospective demographic investigation, consisting of a series of questions about past events. The survey was conducted almost in its entirety by an American missionary who has resided in the area since 1972. The study took place from March 1981 to March 1982. To estimate the number of births per anum Mortara's method was used. This method consists of plotting on a graph the number of live births according to the mother's age and adjusting the resulting curve so that irregularities disappear. The population observed was very young, over 50% were less than 15 years old and the mean age was 18 years. The total fertility rate reach 7.76 children/woman while the age distribution of rates showed that fertility began at early ages and started to decrease only after age 30. The comparison of the obtained parity averages with existing records of fertility rates suggest that the information given for the year previous to the survey was the most accurate. The importance of maintaining reliable and continuous records of live births is stressed. Results are illustrated in tables and charts.

  15. Low-fertility rate, market economy, and population control in China. (United States)

    Wu, C; Mu, G


    This article discusses the increasingly market-oriented economy in China and the implications for family planning and population control. Modern China has experienced in a few decades a dramatic decline in fertility. Some new issues include whether faster population increase is harmless with a rapidly growing economy, and about whether a large population size offers greater opportunity to attract investment. China adopted its population policies against a specific historical context, and future policies will pertain to new issues. The baby boom of the mid-1970s led to population increase and the impossibility of limiting total population by 2000 to under 1.6 billion. China's huge population size has a significant adverse effect on the survival and development of the nation. Land and natural resources limit the nation's ability to accommodate greater numbers of people. 22% of land is hilly and habitable, but 78.9% is largely uninhabitable basins, mountains, and plateaus. 53% of lands are arid or semi-arid. 20.3% of China's population live under harsh natural conditions, and many are impoverished. 95% of China's population live in the eastern part of the country. Population pressure depletes resources and creates environmental problems. There is pressure on consumption of grain, and labor surpluses threaten modernization and create conflicts between egalitarianism and efficiency. Unemployment insurance and social security are not yet in place to cushion a shift to a competitive market system. Success in rural economic reform is tied to absorbing surplus rural labor. Family planning is critical to improving individual lives, a planned economy, and world responsibility. A market economy in China is likely to modernize attitudes toward reproduction and smooth the transition to a low, stable fertility, but government population control will still be needed. The unanswered question is through what means population will be controlled.

  16. Female fertility preservation in the pediatric and adolescent cancer patient population. (United States)

    Algarroba, Gabriela N; Sanfilippo, Joseph S; Valli-Pulaski, Hanna


    The 5-year survival rate for childhood cancer is over 80%, thereby increasing the number of young women facing infertility in the future because of the gonadotoxic effects of chemotherapy and radiation. The gonadotoxic effects of childhood cancer treatment vary by the radiation regimen and the chemotherapeutic drugs utilized. Although the American Society of Clinical Oncology guidelines recommend fertility preservation for all patients, there are several barriers and ethical considerations to fertility preservation in the pediatric and adolescent female population. Additionally, the fertility preservation methods for pre- and postpubertal females differ, with only experimental methods available for prepubertal females. We will review the risk of chemotherapy and radiation on female fertility, the approach to fertility preservation in the pediatric and adolescent female population, methods of fertility preservation for both pre- and postpubertal females, barriers to fertility preservation, cost, and psychological and ethical considerations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Ecological feedbacks can reduce population-level efficacy of wildlife fertility control (United States)

    Ransom, Jason I.; Powers, Jenny G.; Hobbs, N. Thompson; Baker, Dan L.


    1. Anthropogenic stress on natural systems, particularly the fragmentation of landscapes and the extirpation of predators from food webs, has intensified the need to regulate abundance of wildlife populations with management. Controlling population growth using fertility control has been considered for almost four decades, but nearly all research has focused on understanding effects of fertility control agents on individual animals. Questions about the efficacy of fertility control as a way to control populations remain largely unanswered. 2. Collateral consequences of contraception can produce unexpected changes in birth rates, survival, immigration and emigration that may reduce the effectiveness of regulating animal abundance. The magnitude and frequency of such effects vary with species-specific social and reproductive systems, as well as connectivity of populations. Developing models that incorporate static demographic parameters from populations not controlled by contraception may bias predictions of fertility control efficacy. 3. Many population-level studies demonstrate that changes in survival and immigration induced by fertility control can compensate for the reduction in births caused by contraception. The most successful cases of regulating populations using fertility control come from applications of contraceptives to small, closed populations of gregarious and easily accessed species. 4. Fertility control can result in artificial selection pressures on the population and may lead to long-term unintentional genetic consequences. The magnitude of such selection is dependent on individual heritability and behavioural traits, as well as environmental variation. 5. Synthesis and applications. Understanding species' life-history strategies, biology, behavioural ecology and ecological context is critical to developing realistic expectations of regulating populations using fertility control. Before time, effort and funding are invested in wildlife

  18. Population differences in self-fertility in the "self-incompatible" milkweed Asclepias exaltata (Asclepiadaceae). (United States)

    Lipow, S R; Broyles, S B; Wyatt, R


    Individual plants of Asclepias exaltata (Asclepiadaceae) typically express an unusual self-incompatibility system under single-gene control. Hand-pollinations performed in six natural populations detected occasional self-fertile plants. The frequency of self-fertile individuals ranged from 0 to 34.0% and differed significantly among populations. Self-fertility appears to be under genetic control, as the ability of most plants (80.0 %) to set fruit following self-pollinations was identical under natural and greenhouse conditions. Seed- and fruit-set, however, were significantly lower from self- vs. cross-pollinations. Allozyme analysis of the population with the highest frequency of self-fertility revealed that adult plants were not significantly inbred. Finally, fruit-set following within-population cross-pollinations did not differ from that following wide, between-population cross-pollinations.

  19. A modified procedure for estimating the population mean in two ...

    African Journals Online (AJOL)

    A modified procedure for estimating the population mean in two-occasion successive samplings. Housila Prasad Singh, Suryal Kant Pal. Abstract. This paper addresses the problem of estimating the current population mean in two occasion successive sampling. Utilizing the readily available information on two auxiliary ...

  20. Two Populations Mean-Field Monomer-Dimer Model (United States)

    Alberici, Diego; Mingione, Emanuele


    A two populations mean-field monomer-dimer model including both hard-core and attractive interactions between dimers is considered. The pressure density in the thermodynamic limit is proved to satisfy a variational principle. A detailed analysis is made in the limit of one population is much smaller than the other and a ferromagnetic mean-field phase transition is found.

  1. Fertility, Mortality and Age Composition Effects of Population Transition in China and India: 1950-2015


    Chaurasia, Aalok Ranjan


    "This paper compares the population transition in China and India during 1950-2015 by decomposing population growth into the growth attributed to the changes in fertility and mortality (intrinsic growth), and the growth attributed to the change in population age composition (momentum growth). The analysis reveals similarities and differences in the population transition path followed by the two countries and suggests that India lags behind China by about 30 years in terms of population transi...

  2. Exponential Nutrient Loading as a Means to Optimize Bareroot Nursery Fertility of Oak Species (United States)

    Zonda K. D. Birge; Douglass F. Jacobs; Francis K. Salifu


    Conventional fertilization in nursery culture of hardwoods may involve supply of equal fertilizer doses at regularly spaced intervals during the growing season, which may create a surplus of available nutrients in the beginning and a deficiency in nutrient availability by the end of the growing season. A method of fertilization termed “exponential nutrient loading” has...

  3. The impact of development and population policies on fertility in India. (United States)

    Jain, A K


    This article examines the impact of development and population policies on fertility decline and regional variations in India during the 1970s. Indicators of development at the household level include female literacy and education, infant mortality, and poverty; at the village level they include availability of such social services as schools, medical facilities, and transportation and communication facilities. Multiple regression analysis of data aggregated at the state level demonstrates that conditions conducive to fertility decline include high adult female literacy and low infant mortality as indicators of social development, and high contraceptive use and, to a lesser extent, high female age at marriage as proximate determinants of fertility. There are reasons to believe that India's national family planning program contributed to the decline in fertility observed since the 1960s. The pace of fertility decline in the future will depend upon the pace of infant mortality decline, enhancement in female education, and improvements in family planning programs.

  4. Use of fertility drugs and risk of ovarian cancer: Danish population based cohort study


    Jensen, Allan; Sharif, Heidi; Frederiksen, Kirsten; Kj?r, Susanne Kr?ger


    Objective To examine the effects of fertility drugs on overall risk of ovarian cancer using data from a large cohort of infertile women. Design Population based cohort study. Setting Danish hospitals and private fertility clinics. Participants 54?362 women with infertility problems referred to all Danish fertility clinics during 1963-98. The median age at first evaluation of infertility was 30 years (range 16-55 years), and the median age at the end of follow-up was 47 (range 18-81) years. In...

  5. Beyond the Mean: Sensitivities of the Variance of Population Growth. (United States)

    Trotter, Meredith V; Krishna-Kumar, Siddharth; Tuljapurkar, Shripad


    Populations in variable environments are described by both a mean growth rate and a variance of stochastic population growth. Increasing variance will increase the width of confidence bounds around estimates of population size, growth, probability of and time to quasi-extinction. However, traditional sensitivity analyses of stochastic matrix models only consider the sensitivity of the mean growth rate. We derive an exact method for calculating the sensitivity of the variance in population growth to changes in demographic parameters. Sensitivities of the variance also allow a new sensitivity calculation for the cumulative probability of quasi-extinction. We apply this new analysis tool to an empirical dataset on at-risk polar bears to demonstrate its utility in conservation biology We find that in many cases a change in life history parameters will increase both the mean and variance of population growth of polar bears. This counterintuitive behaviour of the variance complicates predictions about overall population impacts of management interventions. Sensitivity calculations for cumulative extinction risk factor in changes to both mean and variance, providing a highly useful quantitative tool for conservation management. The mean stochastic growth rate and its sensitivities do not fully describe the dynamics of population growth. The use of variance sensitivities gives a more complete understanding of population dynamics and facilitates the calculation of new sensitivities for extinction processes.

  6. Nigeria's Population Policy and Future Fertility Decline | Mba ...

    African Journals Online (AJOL)

    The government of the Federal Republic of Nigeria, Africa's most populous country, promulgated its first explicit population policy in 1988, in response to the soaring population growth rate that impedes developmental efforts. The policy document has stipulated a number of quantitative demographic targets. Paramount ...

  7. Fertility change in the American Indian and Alaska Native population, 1980-2010

    Directory of Open Access Journals (Sweden)

    Sarah Cannon


    Full Text Available Background: Since 1990, Vital Statistics reports show a dramatic decline in the total fertility rates (TFRs of American Indian and Alaska Native (AI/AN women in the United States. Objective: We study whether the decrease in TFRs is due to a real change in fertility for a stable population; a compositional change in who identifies as AI/AN; or a methodological issue stemming from differences in identifying race across the data systems used to calculate fertility rates. Methods: We use data from the decennial US Census to study change in AI/AN fertility from 1980-2010. Results: We find declining TFRs when fertility is calculated within a single data system. Additionally, although TFRs are relatively stable within the subgroups of married and unmarried AI/AN women, the proportion of AI/AN women who are married has declined across birth cohorts. Conclusions: The decrease in TFRs for AI/AN women is a real change in fertility patterns and is not due to differences in racial identification across data systems. Contribution: We update knowledge of AI/AN fertility to include the decline in TFRs between 1980 and 2010.

  8. Use of fertility drugs and risk of ovarian cancer: Danish Population Based Cohort Study

    DEFF Research Database (Denmark)

    Jensen, Allan; Sharif, Heidi; Frederiksen, Kirsten


    OBJECTIVE: To examine the effects of fertility drugs on overall risk of ovarian cancer using data from a large cohort of infertile women. DESIGN: Population based cohort study. SETTING: Danish hospitals and private fertility clinics. PARTICIPANTS: 54,362 women with infertility problems referred...... confounding factors. RESULTS: Analyses within cohort showed no overall increased risk of ovarian cancer after any use of gonadotrophins (rate ratio 0.83, 95% confidence interval 0.50 to 1.37), clomifene (1.14, 0.79 to 1.64), human chorionic gonadotrophin (0.89, 0.62 to 1.29), or gonadotrophin releasing...... hormone (0.80, 0.42 to 1.51). Furthermore, no associations were found between all four groups of fertility drugs and number of cycles of use, length of follow-up, or parity. CONCLUSION: No convincing association was found between use of fertility drugs and risk of ovarian cancer....

  9. Minimizing the dependency ratio in a population with below-replacement fertility through immigration (United States)

    Simon, C.; Belyakov, A.O.; Feichtinger, G.


    Many industrialized countries face fertility rates below replacement level, combined with declining mortality especially in older ages. Consequently, the populations of these countries have started to age. One important indicator of age structures is the dependency ratio which is the ratio of the nonworking age population to the working age population. In this work we find the age-specific immigration profile that minimizes the dependency ratio in a stationary population with below-replacement fertility. It is assumed that the number of immigrants per age is limited. We consider two alternative policies. In the first one, we fix the total number of people who annually immigrate to a country. In the second one, we prescribe the size of the receiving country’s population. For both cases we provide numerical results for the optimal immigration profile, for the resulting age structure of the population, as well as for the dependency ratio. PMID:22781918

  10. High coffee population density to improve fertility of an oxisol


    Pavan,Marcos Antonio; Chaves,Júlio César Dias; Siqueira,Rubens; Androcioli Filho,Armando; Colozzi Filho,Arnaldo; Balota,Elcio Liborio


    The objective of this work was to evaluate the effect of coffee (Coffea arabica L.) population densities on the chemical and microbiological properties of an Oxisol. The work was carried out on soil samples of 0-20 cm depth originated from an experimental site which had been used for coffee tree spacing studies during 15 years, in Paraná State, Brazil. Eight coffee tree populations were evaluated: 7143, 3571, 2381, 1786, 1429, 1190, 1020, and 893 trees/ha. Increasing plant population increase...

  11. Use of fertility drugs and risk of ovarian cancer: Danish Population Based Cohort Study. (United States)

    Jensen, Allan; Sharif, Heidi; Frederiksen, Kirsten; Kjaer, Susanne Krüger


    To examine the effects of fertility drugs on overall risk of ovarian cancer using data from a large cohort of infertile women. Population based cohort study. Danish hospitals and private fertility clinics. 54,362 women with infertility problems referred to all Danish fertility clinics during 1963-98. The median age at first evaluation of infertility was 30 years (range 16-55 years), and the median age at the end of follow-up was 47 (range 18-81) years. Included in the analysis were 156 women with invasive epithelial ovarian cancer (cases) and 1241 subcohort members identified in the cohort during follow-up in 2006. Effect of four groups of fertility drugs (gonadotrophins, clomifene citrate, human chorionic gonadotrophin, and gonadotrophin releasing hormone) on overall risk of ovarian cancer after adjustment for potential confounding factors. Analyses within cohort showed no overall increased risk of ovarian cancer after any use of gonadotrophins (rate ratio 0.83, 95% confidence interval 0.50 to 1.37), clomifene (1.14, 0.79 to 1.64), human chorionic gonadotrophin (0.89, 0.62 to 1.29), or gonadotrophin releasing hormone (0.80, 0.42 to 1.51). Furthermore, no associations were found between all four groups of fertility drugs and number of cycles of use, length of follow-up, or parity. No convincing association was found between use of fertility drugs and risk of ovarian cancer.

  12. Effect of plant population and N fertilizer on the growth and yield of ...

    African Journals Online (AJOL)

    Responses of bambara groundnut (Vigna subterranea (L.) Verdc) to 3 levels of fertilizer N (0, 50, and 100 kg N/ha) and seven plant populations (55555, 63492, 74074, 88888, 111111, 148148 and 222222 plants/ha) were studied under field conditions in Nsukka, Nigeria. The experimental design was a randomized ...

  13. Overlapping chromosomal regions for fertility traits and production traits in the Danish Holstein population

    DEFF Research Database (Denmark)

    Höglund, Johanna Karolina; Buitenhuis, A J; Guldbrandtsen, B


    , it is of interest to validate which of the subtraits are affected by the QTL. Phenotypic and marker data were collected from 34 grandsire families from the Danish Holstein population. First, the trait data for "fertility treatments" were separated into their underlying subtraits: uterine infections, antibiotics...

  14. Computer-assisted semen analysis parameters as predictors for fertility of men from the general population

    DEFF Research Database (Denmark)

    Larsen, L; Scheike, Thomas Harder; Jensen, Tina Kold


    The predictive value of sperm motility parameters obtained by computer-assisted semen analysis (CASA) was evaluated for the fertility of men from general population. In a prospective study with couples stopping use of contraception in order to try to conceive, CASA was performed on semen samples...

  15. Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study


    Souza, Maria de Lourdes de; Lynn, Fiona Ann; Johnston, Linda; Tavares, Eduardo Cardoso Teixeira; Brüggemann, Odaléa Maria; Botelho, Lúcio José


    ABSTRACT Objective: analyze trends in fertility rates and associations with perinatal outcomes for adolescents in Santa Catarina, Brazil. Methods: a population-based study covering 2006 to 2013 was carried out to evaluate associations between perinatal outcomes and age groups, using odds ratios, and Chi-squared tests. Results: differences in the fertility rate among female adolescents across regions and time period were observed, ranging from 40.9 to 72.0 per 1,000 in mothers aged 15-19 ye...

  16. Economic benefit of fertility control in wild horse populations (United States)

    Bartholow, J.


    I projected costs for several contraceptive treatments that could be used by the Bureau of Land Management (BLM) to manage 4 wild horse (Equus caballus) populations. Potential management alternatives included existing roundup and selective removal methods combined with contraceptives of different duration and effectiveness. I projected costs for a 20-year economic life using the WinEquus?? wild horse population model and state-by-state cost estimates reflecting BLM's operational expenses. Findings revealed that 1) currently available 2-year contraceptives in most situations are capable of reducing variable operating costs by 15%, 2) experimental 3-year contraceptives may be capable of reducing costs by 18%, and 3) combining contraceptives with modest changes to herd sex ratio (e.g., 55-60% M) could trim costs by 30%. Predicted savings can increase when contraception is applied in conjunction with a removal policy that targets horses aged 0-4 years instead of 0-5 years. However, reductions in herd size result in greater variation in annual operating expenses. Because the horse program's variable operating costs make up about half of the total program costs (which include other fixed costs), contraceptive application and management can only reduce total costs by 14%, saving about $6.1 million per year. None of the contraceptive options I examined eliminated the need for long-term holding facilities over the 20-year period simulated, but the number of horses held may be reduced by about 17% with contraceptive treatment. Cost estimates were most sensitive to the oldest age adoptable and per-day holding costs. The BLM will experience significant cost savings as carefully designed contraceptive programs become widespread in the wild horse herds it manages.

  17. The effect of organic fertilizers on population dynamics of sugar beet cyst nematode, Heterodera schachtii 1871

    Directory of Open Access Journals (Sweden)

    N. Helalat


    Full Text Available Effect of Organic Manure on Sugar Beet Cyst Nematode Population Densities of Heterodera schachtii Schmidt 1871 Introduction. Sugar beet cyst nematode (SBCN, Hederodera schachtii Schmidt. 1871, marked as one of the most damaging disease of sugar beet worldwide. It's also an important disease of sugar beet in Isfahan Province, and causing plenty of an irreversible damage. Thus, the nematode infested fields for cultivation in the province and the country is to be threatened. This nematode has a wide host range, over 218 plant species from 95 genera, belonging to 23 families, including field crops, ornamentals and weeds as hosts, which have been identified and introduced so far. The SBCN management's strategies are a long term crop rotation, use of catch crops, early planting and the use of nematicides. In general, the best method reported to control SBCN is a 3 to 7-year rotation with non-host plants. In addition, incorporation of farm manure into the soil had a positive effect in controlling potato golden cyst nematode. Testing on vermicomposting and non-organic fertilizers revealed that, free-living nematodes in the population index were highest in the vermicompost treatments than non-organic fertilizers. Materials and methods. The initial population of SBCN in the infested soil was determined, before the treatment of the selected field. Then, 200 g. of soil were selected, out of several samples collected from every plots, which was air dried and in the file system using Fenwick, the cysts were extracted. Eggs and the second larvae in the soil and end up in a 200 g. of soil were calculated accordingly. All the organic matters, including, poultry manure at 10, 20 and 40 t/ha compost fertilizer by municipality of Isfahan wastes, vermicompost, waste cabbage leaves and farm manure (cow manure were employed. Reproductive factors and the percent decrease and or increase in SBCN populations in each treatment were calculated relative to the initial

  18. Population ecology of feral horses in an era of fertility control management (United States)

    Ransom, J.I.


    Management of wildlife often requires intervention to regulate growth of populations that would otherwise become overabundant. Controlling fecundity using contraceptives has become an increasingly popular tool for attempting to manage locally overabundant wildlife species, but the population-level effects of such applications are largely unknown. Contraceptive treatments can produce unexpected feedbacks that act on births, survival, immigration, and emigration. Such feedbacks may considerably influence our ability to regulate populations using fertility control. I followed feral horses (Equus caballus) in three intensively managed populations to assess longitudinal treatment effects on demography. The transient contraceptive porcine zona pellucida (PZP) produced longer duration of infertility than intended. Repeated PZP vaccinations of females extended the duration of infertility far beyond the targeted management period, with time to first post-treatment parturition increasing 411days for every annual inoculation received. When these animals did conceive and give birth, parturition was later in the year and temporally asynchronous with forage abundance. An average of 30% (range=11–77%) of females were contracepted annually during the treatment period in all three populations and apparent annual population growth rate was 4–9% lower in the post-treatment years as compared to pretreatment years. Population growth was positive, however, and increased steadily every year that a management removal did not occur. The observed number of births was 33% fewer than the expected number of births, based on number of treated females, individual efficacy of treatment, and number of untreated females and their age-specific fecundity rates. Only half of this difference was explained by the apparent residual effect of treatment. Birth rate in the youngest untreated females (age 2–5 years old) was reduced in years when their conspecifics were treated, enhancing the effects of

  19. Age-Specific Mortality and Fertility Rates for Probabilistic Population Projections


    Ševčíková, Hana; Li, Nan; Kantorová, Vladimíra; Gerland, Patrick; Raftery, Adrian E.


    The United Nations released official probabilistic population projections (PPP) for all countries for the first time in July 2014. These were obtained by projecting the period total fertility rate (TFR) and life expectancy at birth ($e_0$) using Bayesian hierarchical models, yielding a large set of future trajectories of TFR and $e_0$ for all countries and future time periods to 2100, sampled from their joint predictive distribution. Each trajectory was then converted to age-specific mortalit...

  20. An Evaluation of the Pearsonian Type I Curve of Fertility for Aboriginal Populations in Canada, 1996 to 2001

    Directory of Open Access Journals (Sweden)

    Verma, Ravi B.P.


    Full Text Available EnglishIn 2005, Statistics Canada published new projections of the Aboriginal populations (NorthAmerican Indians, Métis, and Inuit in Canada, the provinces and territories from 2001 to2017. To derive the number of births in these projections, the age-specific fertility rates weresimulated by fitting the Pearsonian Type I curve using the projected fertility parameters: totalfertility rates, mean ages of fertility, and modal ages of fertility. For the base period 1996 to2001, the parameters were estimated from the age-specific fertility rates derived from the 2001Census, using the “own-children method.” This paper evaluates the goodness of fit betweenthe age-specific fertility rates developed by the Type I curve and the estimated age-specificfertility rates for Aboriginal identity groups for the period 1996 to 2001 for Canada and forhigh and low fertility regions. Tests of validity of the Type I curve indicate that this method isappropriate for estimating/projecting the number of births for the Aboriginal populations.Key Words: Aboriginal populations, North American Indians, Métis, Inuit, own-childrenmethod, Pearsonian type I curve.FrenchEn 2005, Statistique Canada publiait de nouvelles projections des populations autochtones(Indiens de l’Amérique du Nord, Métis et Inuit au Canada, les provinces et les territoires de2001 à 2017. Afin de calculer le nombre de naissances dans ces projections, les taux de féconditépar âge ont été simulés en ajustant la courbe de Type I de Pearson selon les paramètresde fécondité projetés: l’indice synthétique de fécondité, l’âge moyen à l’accouchement et l’âgemodal à l’accouchement. Pour la période de base de 1996 à 2001, ces paramètres ont étéestimés selon les taux de fécondité par âge générés par la méthode du « décompte des enfantsau foyer » avec les données des enfants âgés de 0 à 4 ans et les femmes dans le groupe d’âgede 15 à 49 ans provenant du

  1. Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes de Souza

    Full Text Available ABSTRACT Objective: analyze trends in fertility rates and associations with perinatal outcomes for adolescents in Santa Catarina, Brazil. Methods: a population-based study covering 2006 to 2013 was carried out to evaluate associations between perinatal outcomes and age groups, using odds ratios, and Chi-squared tests. Results: differences in the fertility rate among female adolescents across regions and time period were observed, ranging from 40.9 to 72.0 per 1,000 in mothers aged 15-19 years. Adolescents had fewer prenatal care appointments than mothers ≥20 years, and a higher proportion had no partner. Mothers aged 15-19 years were more likely to experience preterm birth (OR:1.1; CI:1.08-1.13; p<0.001, have an infant with low birthweight (OR:1.1; CI:1.10-1.15; p<0.001 and low Apgar score at 5 minutes (OR:1.4; CI:1.34-1.45; p<0.001 than mothers ≥20 years, with the odds for adverse outcomes greater for those aged 10-14 years. Conclusion: this study provides evidence of fertility rates among adolescents remaining higher in regions of social and economic deprivation. Adolescent mothers and their infants more likely to experience adverse perinatal outcomes. Nurses, public health practitioners, health and social care professionals and educators need to work collaboratively to better target strategies for adolescents at greater risk; to help reduce fertility rates and improve outcomes.

  2. Adaptation of a lead-tolerant population of Agrostis tenuis to low soil fertility

    Energy Technology Data Exchange (ETDEWEB)

    Jowett, D


    A population of Agrostis tenuis growing on lead ore grindings at Goginan was found to be tolerant of lead. The pasture populations responded to calcium and phosphate, whereas the lead mine population showed no response to calcium and a lesser response to phosphate. The lead mine population data was included. A considerable range of adaption to soil mineral levels has now been found in this species. It has populations tolerant of lead, copper, and nickel poisoning, and of low levels of calcium and phosphate. In lead mine habitats A tenuis is not replaced by A. canina as in more normal habitats. A tenuis is subject to the most extreme conditions of low fertility. 4 tables.

  3. Manipulation of the fertility of marsupials for conservation of endangered species and control of over-abundant populations. (United States)

    Mate, K E; Molinia, F C; Rodger, J C


    Marsupials present a dichotomy in population management; the numbers of many Australian marsupial species have declined due to loss of habitat, competition from introduced herbivores and predation by introduced carnivores, but other species have become locally overabundant in Australia or are introduced pests in New Zealand. The manipulation of reproduction offers the means to increase or decrease productivity; however, considerable fundamental research is required before reproductive technologies can be applied to marsupials. Marsupials differ from eutherian mammals in several aspects of their reproduction including sex differentiation, gamete function and endocrinology, as well as in the relative lengths of gestation and lactation. Although these differences present unique problems in the application of reproductive technologies to marsupials, they also present unique opportunities for marsupial-specific fertility control. This paper summarises the assisted breeding technologies currently being applied to marsupials including superovulation, artificial insemination, in vitro fertilization and gene banking; unique marsupial targets for contraceptive intervention including gamete production, sperm capacitation, gamete surface antigens and embryonic development; and some options for the delivery of contraceptive vaccines to marsupial populations.

  4. Low twinning rate and seasonal effects on twinning in a fertile population, the Hutterites (United States)

    Nonaka, K.; Miura, T.; Peter, K.


    This paper analyzes from the mid 18th century to 1987 the birth records of the “Dariusleut,” one of the three subgroups of the Hutterite population. The aim of this study is to describe several aspects of the twinning rate in a fertile population. The overall rate of twinning was 0.90%:103 twins among all 11492 maternities. The rate peaked at the 7th birth order and at the maternal age of 40 years and over. Until the mid 19th century when the Hutterites lived in Russia, the twinning rate was higher (1.5%), and it decreased during the migration period in the second half of the 19th century (0.7%). After the group had settled in the USA and Canada, the population maintained a twinning rate of 1.0% until 1965. After 1965 the rate decreased to 0.7%, partly due to a decline in fertility among women aged 30 years and over. There was a significant seasonal variation: the twinning rate decreased to 0.5% in May July compared to 1.2% for the other three seasons during the years up to 1965 ( P<0.01), while more recent mothers did not show such a seasonal variation. The incidence of twin births in this population seems to have been influenced by environmental factors, which would change their effect seasonally and secularly.

  5. Assessment of phosphorus fertility by means of isotopically exchangeable phosphorus and the fixing capacity of soils

    International Nuclear Information System (INIS)

    Gachon, L.


    Using over 400 soils representative of French pedological types, the absorption kinetics of phosphorus were studied on Italian rye-grass grown in pots until assimilable reserves had been exhausted. At the same time, Russell's E value (isotopically exchangeable P in vitro), Larsen's L value (isotopically exchangeable P in vivo) and the fixing capacity of the soils were measured. The study shows a very close correlation between the phosphorus removed by the first four cuttings and fertility indices combining E or L with the fixing capacity. The agricultural value of the two indices proposed, Isub(E) and Isub(L), is confirmed by the results of about forty one-year and multi-year field experiments. Norms for the interpretation of these indices are deduced; these are independent of the pedological type but need to be modified as a function of the type of crop and the cultural practice. (author)

  6. Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae). (United States)

    Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M


    The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m ), finite rate of increase (λ), net reproductive rate (R 0 ), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m , λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.

  7. Mean-field games with logistic population dynamics

    KAUST Repository

    Gomes, Diogo A.


    In its standard form, a mean-field game can be defined by coupled system of equations, a Hamilton-Jacobi equation for the value function of agents and a Fokker-Planck equation for the density of agents. Traditionally, the latter equation is adjoint to the linearization of the former. Since the Fokker-Planck equation models a population dynamic, we introduce natural features such as seeding and birth, and nonlinear death rates. In this paper we analyze a stationary meanfield game in one dimension, illustrating various techniques to obtain regularity of solutions in this class of systems. In particular we consider a logistic-type model for birth and death of the agents which is natural in problems where crowding affects the death rate of the agents. The introduction of these new terms requires a number of new ideas to obtain wellposedness. In a forthcoming publication we will address higher dimensional models. ©2013 IEEE.

  8. Mean-field games with logistic population dynamics

    KAUST Repository

    Gomes, Diogo A.; De Lima Ribeiro, Ricardo


    In its standard form, a mean-field game can be defined by coupled system of equations, a Hamilton-Jacobi equation for the value function of agents and a Fokker-Planck equation for the density of agents. Traditionally, the latter equation is adjoint to the linearization of the former. Since the Fokker-Planck equation models a population dynamic, we introduce natural features such as seeding and birth, and nonlinear death rates. In this paper we analyze a stationary meanfield game in one dimension, illustrating various techniques to obtain regularity of solutions in this class of systems. In particular we consider a logistic-type model for birth and death of the agents which is natural in problems where crowding affects the death rate of the agents. The introduction of these new terms requires a number of new ideas to obtain wellposedness. In a forthcoming publication we will address higher dimensional models. ©2013 IEEE.

  9. [Recent population policy measures in Belgium, especially with respect to fertility]. (United States)

    Bosman, E


    Policy measures affecting fertility, recently adopted in Belgium, are reviewed. The author notes that although responsibility for population matters has been delegated to the respective language groups, the responsibility for family law, divorce, abortion, social security, taxation, and labor policy remains a national responsibility. There are currently no measures in these areas adopted primarily for demographic reasons. Differences between the approaches taken by the French- and Dutch-speaking communities are noted. The author suggests that the French-speaking community has focused on problems relating to contraception and abortion, and the Dutch-speaking community has emphasized social welfare and family policy

  10. Recent fertility and mortality trends among aboriginal and nonaboriginal populations of central Siberia. (United States)

    Leonard, W R; Keenleyside, A; Ivakine, E


    We examine mortality and fertility patterns of aboriginal (primarily Evenki and Keto) and Russian (i.e., nonaboriginal) populations from the Baykit District of Central Siberia for the period 1982-1994. Mortality rates in the aboriginal population of Baykit are substantially greater than those observed in the Russians and are comparable to levels recently reported for other indigenous Siberian groups. Infant mortality rates average 48 per 1000 live births among Baykit aboriginals, three times greater than the Russians of the district (15 per 1000 births) and more than double the rates for Inuit and Indian populations of Canada. Similarly, crude death rates of the Baykit aboriginals are twice as high as those observed in either the Baykit Russians or the Canadian aboriginal populations (13 vs 6-7 deaths per 1000 individuals). Birth rates of the indigenous population of Baykit are higher than those of the Russians (33 vs. 15 births per 1000 individuals) but are comparable to those of Canadian aboriginal groups. Violence and accidents are the leading causes of adult male mortality in both ethnic groups, whereas circulatory diseases have emerged as the prime cause of death in women. The greater male mortality resulting from violence and accidents is a widely observed cross-cultural phenomenon. The emergence of circulatory diseases as a major mortality risk for women, however, appears to be linked to specific lifestyle changes associated with Soviet reorganization of indigenous Siberian societies. Marked declines in mortality and increases in fertility were observed in the Baykit aboriginal population during the mid to late 1980s with the government's implementation of anti-alcohol policies. The decline in mortality, however, was largely erased during the early 1990s, as the region became increasingly isolated and marginalized following the collapse of the Soviet Union. Demographic trends in the Baykit District suggest that because the indigenous groups have become more


    Directory of Open Access Journals (Sweden)

    Mostafa A.R. IBRAHIM


    Full Text Available Artificial insemination (AI in livestock is used to optimize reproduction efficiency. Compared to other semenpreservation methods, cryopreservation is an established industry used worldwide for performing AI. Adequateprotocols for semen collection and freezing and then for the use in the AI are set up for all the animal species. Insheep, AI with frozen-thawed semen resulted low fertility rate, which limits the practical application of thistechnique. Progressive sperm motility, sperm viability, sperm plasma membrane integrity and NAR weresignificantly (P < 0.05 higher for BIOX, MILK, and TEY extenders. Progressive motility increased significantly (p< 0.01 using licorice extract 10, 50 and 100 g/ml. Diluter type had a significant effect (p < 0.01 on sperm motility.The percentage of progressive motility in all extenders media containing LDL was also higher compared with 20%EY (control during dilution and equilibration stages. All extenders containing LDL reduced the percentages ofabnormalities after dilution as compared to control 20% egg yolk. The percentages of intact Acrosome in all otherextenders containing LDL were significantly higher than 20% egg yolk extender. The highest percentage of postthawprogressive motility was recorded in extender containing 20mm glutamine. After dilution and equilibration,supplementation of glutamine at concentration of 40 and 60mm caused a significant increase in plasma membraneintact compared with control and all other concentrations tested. No significant difference between the control andthe irradiated samples for viability However, the semen samples irradiated with 6.12 J/cm2 showed a slight increasein sperm progressive motility, viability, osmotic resistance, Acrosome and DNA integrity, respect to the semensamples irradiated at low energy doses and control semen samples. Cysteine effected on the ultra-structure of theram sperm cell within the freezing- thawing dynamics. The positive effect of Cysteine could

  12. Fertility variation in two populations of taurus cedar (cedrus libani rich.)

    International Nuclear Information System (INIS)

    Ozel, H.B.; Bilir, N.


    Fertility variation, measured as half-sib family coefficient, based on number of one, two and three years cones were investigated in plantation population (PP), and a natural population (NP) of Taurus Cedar (Cedrus libani Rich.) sampled from southern part of Turkey. Fertility variation was higher in PP than NP for one, two and three years. It was the highest in PP for one year cones (2.34), while it was lowest in NP for three years cones (1.73) as shown in Table 2. The effective number of parents were 21.8 (38.4% of census number) for one year cones, 25.7 (47.9% of census number) for two years cones and 29.8 (52.6% of census number) for three cones in PP. On the other hand the effective number of parents were 28.3 (43.4% of census number) for one year cones, 32.8 (51.6% of census number) for two years cones and 36.4 (58.9% of census number) for three years cones in NP. Diameter at breast height and tree crown area had positive and significant (p<0.05) effective on cone production, while effects of tree height and tree age were not significant (NS) on that (Table 3). There were also positive and significant (p<0.05) correlation between years in cone production. (author)

  13. Population and trends in the global mean temperature

    NARCIS (Netherlands)

    Tol, Richard S.J.


    The Fisher ideal index, developed to measure price inflation, is applied to define a population-weighted temperature trend. This method has the advantages that the trend is representative for the population distribution throughout the sample but without conflating the trend in the population

  14. Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study. (United States)

    Souza, Maria de Lourdes de; Lynn, Fiona Ann; Johnston, Linda; Tavares, Eduardo Cardoso Teixeira; Brüggemann, Odaléa Maria; Botelho, Lúcio José


    analyze trends in fertility rates and associations with perinatal outcomes for adolescents in Santa Catarina, Brazil. a population-based study covering 2006 to 2013 was carried out to evaluate associations between perinatal outcomes and age groups, using odds ratios, and Chi-squared tests. differences in the fertility rate among female adolescents across regions and time period were observed, ranging from 40.9 to 72.0 per 1,000 in mothers aged 15-19 years. Adolescents had fewer prenatal care appointments than mothers ≥20 years, and a higher proportion had no partner. Mothers aged 15-19 years were more likely to experience preterm birth (OR:1.1; CI:1.08-1.13; ppobreza social y económica. Madres adolescentes y sus bebés tienen mayor probabilidad de efectos perinatales adversos. Enfermeros, trabajadores de salud pública, profesionales de salud y asistencia social y educadores deben colaborar para mejor dirigir estrategias a adolescentes con riesgo superior; para fines de ayudar a reducir las tasas de fertilidad y mejorar los resultados.

  15. Consanguinity and its relationship to differential fertility and mortality in the Kotia: a tribal population of Andhra Pradesh, India. (United States)

    Yasim; Naidu, J M; Mascie-Taylor, C G


    Data on patterns of marriage, differential fertility and mortality were collected from 211 Kotia women residing in Visakhapatnam district of Andhra Pradesh, India. Consanguineous marriages made up just over a quarter of the total, and of these, father's sister's daughter (FSD) were more common than mother's brother's daughter (MBD). The mean inbreeding coefficient for the sample (F) was 0.0172. Women in consanguineous marriages had a lower mean number of total conceptions, live births and living offspring (net fertility) than women in non-consanguineous marriages. Significant heterogeneity was found in the means of living offspring for FSD, MBD and non-consanguineous couples, but not for conceptions and live births.

  16. Fertility preservation in the male pediatric population: factors influencing the decision of parents and children. (United States)

    Wyns, C; Collienne, C; Shenfield, F; Robert, A; Laurent, P; Roegiers, L; Brichard, B


    How can the decision process for fertility preservation (FP) in adolescents and prepubertal boys be improved based on patient and parent feelings about FP counseling? The content of information given to patients and parents and hope for future parenthood appeared to positively impact on the decision to preserve fertility in the pediatric population and, therefore, deserves special attention to improve FP care. A vast body of literature on adult cancer patients shows that reproductive capacity is a major quality-of-life issue. Patients also have a strong desire to be informed of available FP options with a view to future parenthood of their own genetic child, considering that parents were able to make an informed and voluntary decision for their prepubertal sons despite the heavy emotional burden at the time of diagnosis, there is so far very limited information on patient expectations regarding FP. A lack of awareness often equates to suboptimal care by oncologists and FP specialists, and poor access to FP, therefore improving knowledge and identifying the expectations of pediatric patients and their parents are crucial for optimizing multidisciplinary collaborative care pathways (MCCPs), including counseling and access to FP methods, in the youngest population. A questionnaire survey was posted to an eligible population between May 2005 and May 2013. A total of 348 prepubertal boys and adolescents aged 0-18 years, diagnosed with cancer in a university hospital setting, were eligible. Three different questionnaires for two age groups of children (parents were established based on information from focus groups. Questions were subsequently reviewed by the institutional ethics board before being sent. Of the 348 eligible patients, 44 died and 14 were lost to follow-up. Thus, 290 patients (77 aged 12-18 years and 213 aged questionnaire. In total, 120 questionnaires were recovered, 45.5% (n = 35/77) from adolescents and 39.9% (n = 85/213) from children. FP acceptance

  17. Nutrition, fertility and steady-state population dynamics in a pre-industrial community in Penrith, northern England. (United States)

    Scott, S; Duncan, C J


    The effect of nutrition on fertility and its contribution thereby to population dynamics are assessed in three social groups (elite, tradesmen and subsistence) in a marginal, pre-industrial population in northern England. This community was particularly susceptible to fluctuations in the price of grains, which formed their basic foodstuff. The subsistence class, who formed the largest part of the population, had low levels of fertility and small family sizes, but women from all social groups had a characteristic and marked subfecundity in the early part of their reproductive lives. The health and nutrition of the mother during pregnancy was the most important factor in determining fertility and neonatal mortality. Inadequate nutrition had many subtle effects on reproduction which interacted to produce a complex web of events. A population boom occurred during the second half of the 18th century; fertility did not change but there was a marked improvement in infant mortality and it is suggested that the steadily improving nutritional standards of the population, particularly during crucial periods in pregnancy (i.e. the last trimester), probably made the biggest contribution to the improvement in infant mortality and so was probably the major factor in triggering the boom.

  18. Impaired Fertility Associated with Subclinical Hypothyroidism and Thyroid Autoimmunity: The Danish General Suburban Population Study

    Directory of Open Access Journals (Sweden)

    Anne-Dorthe Feldthusen


    Full Text Available Introduction. The aim of this study was to estimate the significance of TSH, thyroid peroxidase antibody (TPOAb, and mild (subclinical hypothyroidism in women from The Danish General Suburban Population Study (GESUS on the number of children born, the number of pregnancies, and the number of spontaneous abortions. Methods. Retrospective cross sectional study of 11254 women participating in GESUS. Data included biochemical measurements and a self-administrated questionnaire. Results. 6.7% had mild (subclinical hypothyroidism and 9.4% prevalent hypothyroidism. In women with mild hypothyroidism TPOAb was significantly elevated and age at first child was older compared to controls. TSH and TPOAb were negatively linearly associated with the number of children born and the number of pregnancies in the full cohort in age-adjusted and multiadjusted models. TSH or TPOAb was not associated with spontaneous abortions. Mild (subclinical hypothyroidism was associated with a risk of not having children and a risk of not getting pregnant in age-adjusted and multiadjusted models. Prevalent hypothyroidism was not associated with the number of children born, the number of pregnancies, or spontaneous abortions. Conclusion. Impaired fertility is associated with TSH, TPOAb, and mild (subclinical hypothyroidism in a Danish population of women.

  19. Effects of in vitro fertilization and maternal characteristics on perinatal outcomes : a population-based study using siblings

    NARCIS (Netherlands)

    Seggers, Jorien; Pontesilli, Martina; Ravelli, Anita C. J.; Painter, Rebecca C.; Hadders-Algra, Mijna; Heineman, Maas Jan; Repping, Sjoerd; Mol, Ben Willem J.; Roseboom, Tessa J.; Ensing, Sabine

    Objective: To study birthweight in consecutively born sibling singletons conceived with and without in vitro fertilization (IVF) to disentangle the effects of maternal characteristics from those of the IVF treatment itself. Design: Population-based study. Setting: Not applicable. Patient(s):

  20. Knowledge about factors that influence fertility among Australians of reproductive age: a population-based survey. (United States)

    Hammarberg, Karin; Setter, Tracey; Norman, Robert J; Holden, Carol A; Michelmore, Janet; Johnson, Louise


    To explore knowledge about the effects on fertility of age, obesity, smoking, and timing of intercourse among Australians of reproductive age. Telephone survey of a representative sample of Australians. Not applicable. Australians aged 18 to 45 years who wish to have a child or another child now or in the future. None. Knowledge about the effect on fertility of age, obesity, smoking, and timing of intercourse. A total of 462 interviews were conducted. The majority of respondents underestimated, by about 10 years, the age at which male and female fertility starts to decline. Only one in four correctly identified that female fertility starts to decline before age 35, and one in three identified that male fertility starts to decline before age 45. Most (59%) were aware that female obesity and smoking affect fertility, but fewer recognized that male obesity (30%) and smoking (36%) also influence fertility. Almost 40% of respondents had inadequate knowledge of when in the menstrual cycle a woman is most likely to conceive. Considerable knowledge gaps about modifiable factors that affect fertility were identified. These are targeted in a national education campaign to promote awareness of factors that influence fertility. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Long Term Population, City Size and Climate Trends in the Fertile Crescent: A First Approximation. (United States)

    Lawrence, Dan; Philip, Graham; Hunt, Hannah; Snape-Kennedy, Lisa; Wilkinson, T J


    Over the last 8000 years the Fertile Crescent of the Near East has seen the emergence of urban agglomerations, small scale polities and large territorial empires, all of which had profound effects on settlement patterns. Computational approaches, including the use of remote sensing data, allow us to analyse these changes at unprecedented geographical and temporal scales. Here we employ these techniques to examine and compare long term trends in urbanisation, population and climate records. Maximum city size is used as a proxy for the intensity of urbanisation, whilst population trends are modelled from settlement densities in nine archaeological surveys conducted over the last 30 years across the region. These two measures are then compared with atmospheric moisture levels derived from multiple proxy analyses from two locations close to the study area, Soreq Cave in Israel and Lake Van in south-eastern Turkey, as well as wider literature. The earliest urban sites emerged during a period of relatively high atmospheric moisture levels and conform to a series of size thresholds. However, after the Early Bronze Age maximum urban size and population levels increase rapidly whilst atmospheric moisture declines. We argue that although the initial phase of urbanization may have been linked to climate conditions, we can see a definitive decoupling of climate and settlement patterns after 2000 BC. We relate this phenomenon to changes in socio-economic organisation and integration in large territorial empires. The complex relationships sustaining urban growth during this later period resulted in an increase in system fragility and ultimately impacted on the sustainability of cities in the long term.

  2. Conception by means of in vitro fertilization is not associated with maternal depressive symptoms during pregnancy or postpartum. (United States)

    Gambadauro, Pietro; Iliadis, Stavros; Bränn, Emma; Skalkidou, Alkistis


    To study whether conception by means of in vitro fertilization (IVF) is associated with maternal depressive symptoms during pregnancy or postpartum. Longitudinal observational study. University hospital. A total of 3,283 women with singleton pregnancies receiving antenatal care and delivering in Uppsala from 2010 to 2015. A web-based self-administered structured questionnaire including sociodemographic, clinical and pregnancy-related items, and the Edinburgh Postnatal Depression Scale (EPDS) was delivered at 17 and 32 gestational weeks and at 6 weeks and 6 months postpartum. Prevalence of significant depressive symptoms (EPDS ≥12) and EPDS scores. A total of 167 women (5%) had conceived via IVF and 3,116 (95%) had a spontaneous pregnancy. IVF mothers were more frequently ≥35 years of age (46.1% vs. 22.6%) and primiparous (71.7% vs. 49.9%) and had a higher cesarean delivery rate (22.4% vs. 14.2%). Demographic and clinical characteristics were otherwise similar between the two groups. Significant depressive symptoms were reported by 12.8%, 12.4%, 13.8%, and 11.9% of women at 17 and 32 gestational weeks and 6 weeks and 6 months postpartum, respectively. The prevalence of depressive symptoms and the EPDS scores during pregnancy and postpartum were similar between women conceiving spontaneously or through IVF. The mode of conception was not associated with significant depressive symptoms at any time point, even when adjusting for several possible confounders in multivariable logistic regression analysis. Despite the psychologic distress characterizing subfertility and its treatment, conception by means of IVF is not associated with maternal depressive symptoms during pregnancy or postpartum. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  3. Nano Fertilizers

    Directory of Open Access Journals (Sweden)

    Hatice DAĞHAN


    Full Text Available Agricultural land is decreasing day by day due to erosion, environmental pollution, unconscious irrigation and fertilization. On the other hand, it is necessary to increase agricultural production in order to meet the needs of the developing industry as well as the nutritional needs of the growing population. In the recent years, nano fertilizers have begun to be produced to obtain the highest amount and quality of production from the unit area. Previous research shows that nano fertilizers cause an increase in the use efficiency of plant nutrients, reduce soil toxicity, minimize the potential adverse effects of excessive chemical fertilizer use, and reduce fertilizer application frequency. Nano fertilizers are important in agriculture to increase crop yield and nutrient use efficiency, and to reduce excessive use ofchemical fertilizers. The most important properties of these fertilizers are that they contain one or more of macro and micronutrients, they can be applied frequently in small amounts and are environmentally friendly. However, when applied at high doses, they exhibit decreasing effects on plant growth and crop yields, similar to chemical fertilizers. In this review, the definition, importan ce, and classification of nano fertilizers, their application in plant production, advantages and disadvantages and the results obtained in this field were discussed.

  4. Measuring the Impact of Antiretroviral Therapy Roll-Out on Population Level Fertility in Three African Countries.

    Directory of Open Access Journals (Sweden)

    Milly Marston

    Full Text Available UNAIDS official estimates of national HIV prevalence are based on trends observed in antenatal clinic surveillance, after adjustment for the reduced fertility of HIV positive women. Uptake of ART may impact on the fertility of HIV positive women, implying a need to re-estimate the adjustment factors used in these calculations. We analyse the effect of antiretroviral therapy (ART provision on population-level fertility in Southern and East Africa, comparing trends in HIV infected women against the secular trends observed in uninfected women.We used fertility data from four community-based demographic and HIV surveillance sites: Kisesa (Tanzania, Masaka and Rakai (Uganda and uMkhanyakude (South Africa. All births to women aged 15-44 years old were included in the analysis, classified by mother's age and HIV status at time of birth, and ART availability in the community. Calendar time period of data availability relative to ART Introduction varied across the sites, from 5 years prior to ART roll-out, to 9 years after. Calendar time was classified according to ART availability, grouped into pre ART, ART introduction (available in at least one health facility serving study site and ART available (available in all designated health facilities serving study site. We used Poisson regression to calculate age adjusted fertility rate ratios over time by HIV status, and investigated the interaction between ART period and HIV status to ascertain whether trends over time were different for HIV positive and negative women.Age-adjusted fertility rates declined significantly over time for HIV negative women in all four studies. However HIV positives either had no change in fertility (Masaka, Rakai or experienced a significant increase over the same period (Kisesa, uMkhanyakude. HIV positive fertility was significantly lower than negative in both the pre ART period (age adjusted fertility rate ratio (FRR range 0.51 95%CI 0.42-0.61 to 0.73 95%CI 0.64-0.83 and when

  5. Cultural meanings of musculoskeletal diseases in Chile's Mapuche Population. (United States)

    Alarcon, Ana M; Vidal, Aldo; Castro, Marcela


    Eight out of 10 Mapuche indigenous women have a musculoskeletal disorder (MSD) and do not seek early medical aid. To study both the cultural meanings and implications of MSD from the Mapuche worldview. Ethnographic study carried out from 2008 to 2011 on indigenous reserves in southern Chile. Sixty-four Mapuches participated in comprehensive interviews, which were transcribed and analyzed by the research team. Five cultural domains: (a) foro kutran/bone disease is the general denomination of MSD; (b) Re-Rume Kutran/progressive and incurable course, refers to the course of the disease; (c) Kalül fücha mawiza/body is an old tree, describes internal manifestations such as worn bones, dry body, weak blood, and spiritual weakness; (d) witrür tripai foro/deformation is the external manifestation of MSD; and (e) Reñma ka lof kutran/family and community suffering refers to the impact of MSD. The explanation of MSD is consistent with the integrated body-nature-spirit worldview of the Mapuche. To provide cultural nursing health care so that patients receive prompt diagnosis and care.

  6. Father absence and reproduction-related outcomes in Malaysia, a transitional fertility population. (United States)

    Sheppard, Paula; Snopkowski, Kristin; Sear, Rebecca


    Father absence is consistently associated with children's reproductive outcomes in industrialized countries. It has been suggested that father absence acts as a cue to particular environmental conditions that influence life history strategies. Much less is known, however, about the effects of father absence on such outcomes in lower-income countries. Using data from the 1988 Malaysian Family Life Survey (n = 567), we tested the effect of father absence on daughters' age at menarche, first marriage, and first birth; parity progression rates; and desired completed family size in Malaysia, a country undergoing an economic and fertility transition. Father absence during later childhood (ages 8 to 15), although not during earlier childhood, was associated with earlier progressions to first marriage and first birth, after controlling for other confounders. Father absence does not affect age at menarche, desired family size, or progression from first to second birth. The patterns found in this transitional population partly mirror those in developed societies, where father absence accelerates reproductive events. There is, however, a notable contrast between the acceleration in menarche for father-absent girls consistently found in developed societies and the lack of any association in our findings. The mechanisms through which father absence affects reproduction may differ in different ecological contexts. In lower-income contexts, direct paternal investment or influence may be of more importance in determining reproductive behavior than whether fathers act as a cue to environmental conditions.

  7. Comparison of fertility indices in Iranian and non-Iranian populations under coverage of Ray's health houses, 1376

    Directory of Open Access Journals (Sweden)

    Sadeghi Pour Roudsari HR


    Full Text Available We studied fertility indices of Iranian and non-Iranian populations which were covered by 23 Rays health houses. This cross-sectional study aimed to prove the effect of increasing number of non-Iranian immigrants on health indices of the area covered by Tehran university of medical sciences and health services, consequently giving attention to specific health programs. The data collection method was census of permanent residents of the villages by means of vital horoscopes. 8494 of 27611 persons were non-Iranian. Dependency ratio and natural growth rate was 75%, 1.14% in Iranians and 98%, 1.74% in non-Iranians, respectively. Mortality in non-Iranians was 1.24 times more than Iranians. General fertility rate in Iranians was 60 and in non-Iranians was 110 live births in 1000 women of child bearing age. Total fertility rate in Iranians was 1.73 and in non-Iranians 3.27 neonates for each woman. Age-specific fertility rates were absolutely higher in non-Iranians. Gross eproductive rate was 0.87 in Iranians and 1.59 in non-Iranians. Mean number of girls born by a non-Iranian mother will be double times of an Iranian mother (P<0.01. Modern contraceptive methods coverage was 70% in Iranian couples and less than 40% in non-Iranian couples. 96.94% of Iranian deliveries and 70.9% of non-Iranian deliveries were safe (P<0.01.

  8. Population growth enhances the mean fixation time of neutral mutations and the persistence of neutral variation. (United States)

    Waxman, D


    A fundamental result of population genetics states that a new mutation, at an unlinked neutral locus in a randomly mating diploid population, has a mean time of fixation of ∼4N(e) generations, where N(e) is the effective population size. This result is based on an assumption of fixed population size, which does not universally hold in natural populations. Here, we analyze such neutral fixations in populations of changing size within the framework of the diffusion approximation. General expressions are derived for the mean and variance of the fixation time in changing populations. Some explicit results are given for two cases: (i) the effective population size undergoes a sudden change, representing a sudden population expansion or a sudden bottleneck; (ii) the effective population changes linearly for a limited period of time and then remains constant. Additionally, a lower bound for the mean time of fixation is obtained for an effective population size that increases with time, and this is applied to exponentially growing populations. The results obtained in this work show, among other things, that for populations that increase in size, the mean time of fixation can be enhanced, sometimes substantially so, over 4N(e,0) generations, where N(e,0) is the effective population size at the time the mutation arises. Such an enhancement is associated with (i) an increased probability of neutral polymorphism in a population and (ii) an enhanced persistence of high-frequency neutral variation, which is the variation most likely to be observed.

  9. Birth Order and Sibling Sex Ratio in a Population with High Fertility: Are Turkish Male to Female Transsexuals Different? (United States)

    Bozkurt, Ali; Bozkurt, Ozlem Hekim; Sonmez, Ipek


    Western studies have consistently found that androphilic (sexually attracted to men) male-to-female transsexuals have a later birth order and a relative excess of brothers compared with appropriate control participants. However, non-Western studies on birth order and sibling sex ratio in androphilic males (transsexual or non-transsexual) are rare. The objective of the study was to test the hypothesis that androphilic male-to-female transsexuals have a late birth order and a relative excess of brothers in a non-Western culture with a higher fertility rate. The participants were 60 androphilic male-to-female transsexuals and 61 male heterosexual controls. The transsexual participants had significantly more older brothers than the control participants, but the groups did not differ in their numbers of older sisters, younger brothers, or younger sisters. The foregoing pattern is usually referred to as the "fraternal birth order effect." Slater's and Berglin's Indexes both showed that the mean birth order of the control participants was very close to that expected from a random sample drawn from a demographically stable population whereas the mean birth order of the transsexual participants was later. A measure of sibship composition, brothers/all siblings, showed that the transsexual group had a higher proportion of male siblings compared with the control group. In conclusion, the present study found that Turkish androphilic male-to-female transsexuals show the same high fraternal birth order that has been found in comparable androphilic samples in Western Europe, North America, and the South Pacific, which suggests a common underlying biological causal mechanism.

  10. Changes in Fertility at the Population Level in the Era of ART in Rural Malawi. (United States)

    McLean, Estelle; Price, Alison; Chihana, Menard; Kayuni, Ndoliwe; Marston, Milly; Koole, Olivier; Zaba, Basia; Crampin, Amelia


    HIV reduces fertility through biological and social pathways, and antiretroviral treatment (ART) can ameliorate these effects. In northern Malawi, ART has been available since 2007 and lifelong ART is offered to all pregnant or breastfeeding HIV-positive women. Using data from the Karonga Health and Demographic Surveillance Site in Malawi from 2005 to 2014, we used total and age-specific fertility rates and Cox regression to assess associations between HIV and ART use and fertility. We also assessed temporal trends in in utero and breastfeeding HIV and ART exposure among live births. From 2005 to 2014, there were 13,583 live births during approximately 78,000 person years of follow-up of women aged 15-49 years. The total fertility rate in HIV-negative women decreased from 6.1 [95% confidence interval (CI): 5.5 to 6.8] in 2005-2006 to 5.1 (4.8-5.5) in 2011-2014. In HIV-positive women, the total fertility rate was more stable, although lower, at 4.4 (3.2-6.1) in 2011-2014. In 2011-2014, compared with HIV-negative women, the adjusted (age, marital status, and education) hazard ratio was 0.7 (95% CI: 0.6 to 0.9) and 0.8 (95% CI: 0.6 to 1.0) for women on ART for at least 9 months and not (yet) on ART, respectively. The crude fertility rate increased with duration on ART up to 3 years before declining. The proportion of HIV-exposed infants decreased, but the proportion of ART-exposed infants increased from 2.4% in 2007-2010 to 3.5% in 2011-2014. Fertility rates in HIV-positive women are stable in the context of generally decreasing fertility. Despite a decrease in HIV-exposed infants, there has been an increase in ART-exposed infants.

  11. Heritability and Fitness Correlates of Personality in the Ache, a Natural-Fertility Population in Paraguay (United States)

    Bailey, Drew H.; Walker, Robert S.; Blomquist, Gregory E.; Hill, Kim R.; Hurtado, A. Magdalena; Geary, David C.


    The current study assessed the heritability of personality in a traditional natural-fertility population, the Ache of eastern Paraguay. Self-reports (n = 110) and other-reports (n = 66) on the commonly used Big Five Personality Inventory (i.e., extraversion, agreeableness, conscientiousness, neuroticism, openness) were collected. Self-reports did not support the Five Factor Model developed with Western samples, and did not correlate with other-reports for three of the five measured personality factors. Heritability was assessed using factors that were consistent across self- and other-reports and factors assessed using other-reports that showed reliabilities similar to those found in Western samples. Analyses of these items in combination with a multi-generation pedigree (n = 2,132) revealed heritability estimates similar to those found in most Western samples, although we were not able to separately estimate the influence of the common environment on these traits. We also assessed relations between personality and reproductive success (RS), allowing for a test of several mechanisms that might be maintaining heritable variation in personality. Phenotypic analyses, based largely on other-reports, revealed that extraverted men had higher RS than other men, but no other dimensions of personality predicted RS in either sex. Mothers with more agreeable children had more children, and parents mated assortatively on personality. Of the evolutionary processes proposed to maintain variation in personality, assortative mating, selective neutrality, and temporal variation in selection pressures received the most support. However, the current study does not rule out other processes affecting the evolution and maintenance of individual differences in human personality. PMID:23527163

  12. Mortality Reduction, Fertility Decline, and Population Growth: Toward a More Relevant Assessment of the Relationships among Them. World Bank Staff Working Papers No. 686 and Population and Development Series No. 11. (United States)

    Gwatkin, Davidson

    One of a special series on population change and development, this paper focuses primarily on the programs and policies responsible for mortality or fertility change, rather than on the growth impact of a mortality or fertility change per se. The first portion of the document examines three models for assessing the population growth implications…

  13. Factors in the Achievement of Below-Replacement Fertility in Chiang Mai, Thailand. Papers of the East-West Population Institute, Number 96, March 1986. (United States)

    Pardthaisong, Tieng

    The study assesses the impact of family planning programs on the fertility of women in the Chiang Mai province of Thailand, where family planning programs were introduced early in 1963. The study documents and estimates the fertility trend of Chiang Mai's population from existing sources of data. A demographic survey, in which a random sample of…

  14. [Women with high fertility in Mexico: orientations for a population policy]. (United States)

    Lopez, E


    The characteristics and correlates of high fertility women in Mexico were assessed for different age and residential groups with data from the National Demographic Survey of 1982. This survey included information on rural, urban and metropolitan Mexican women aged 15-49 years who had ever been in union. Rural areas were defined as those with fewer than 20,000 inhabitants. Metropolitan areas were Guadalajara, Monterrey, and Mexico City. High fertility was defined for the purpose of this study as at least 2 live births for women 15-19, 3 for women 20-24, 4 for those 25-29, 5 for those 30-34, 6 for those 35-39, and 7 for those 40-49. According to this definition about 40% of Mexican women are high fertility, with proportions ranging from about 1/3 of those 20-29 to half of those 35-49 years old. High fertility is about twice as common in women 15-19 in rural areas as in urban and metropolitan areas of Mexico. 10% of rural women aged 20-24 already have 5 children, compared to less than 1% of metropolitan women and under 3% of women in other urban areas. By age 45-49, 31% of rural women, 20% of other urban women, and 15% of metropolitan women have 10 or more children. 13% in all areas have 2 or 3. Large proportions of rural women in all age groups are high fertility, with the difference especially marked at young ages. The data on contraceptive usage indicate that high fertility women are among the increasing numbers of Mexican women attempting to control their family size. 10% of high fertility women in rural areas are sterilized and another 10% use oral contraceptives. Injectables and traditional methods share 3rd place. IUDs are almost nonexistent in rural areas. In urban and metropolitan zones about 1/4 of high fertility women have been sterilized. About 10% use pills. Traditional methods and IUDs are in 3rd place for urban women while injectables occupy 3rd place for metropolitan women. Except among women 30-34, about 70% of sterilizations in rural areas are in

  15. The Effect of Organic Fertilizers and Flowering Plants on Sheet-Web and Wolf Spider Populations (Araneae: Lycosidae and Linyphiidae) and Its Importance for Pest Control. (United States)

    El-Nabawy, El-Said M; Tsuda, Katsuo; Sakamaki, Yositaka; Oda, Asahi; Ushijima, Yurie


    The main goal of this study was to identify the treatment that increases the populations of spiders, which are effective predators in agroecosystems. In 2013 and 2014 the experimental eggplant (Solanum melongena L.) field was two different treatments, organic fertilizers and chemical fertilizer treatment, and in 2014 we surrounded organic fertilizer plots with the flowering plants mealy cup sage (Salvia farinacea Benth.), spearmint (Mentha spicata L.), and basil (Ocimum basilicum L.). Analysis using repeated measures ANOVA revealed significant influences of fertilizer type on the numbers of linyphiid spiders and Collembola in 2013. In 2014, the numbers of Collembola, thrips, and lycosid and linyphiid spider were higher in organic fertilizer with flowering plants treatment comparing with the chemical fertilizer treatment. Moreover, the numbers of Henosepilachna vigintioctopunctata (F.) were significantly lower in the organic fertilizer with flowering plants treatment than in chemical fertilizers treatment. Finally, we expect that Thysanoptera and Collembola were important alternative prey for linyphiid and lycosid spiders and the use of organic fertilizer and flowering plants enhanced the density of these spiders, and may increase their effectiveness in suppressing the populations of H. vigintioctopunctata (F.). © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

  16. On low fertility from the aspect of the economic activity of female population: Possibilities and restrictions in encouragement of childbearing

    Directory of Open Access Journals (Sweden)

    Šobot Ankica


    Full Text Available Below replacement fertility was the outcome of changes in the education and socio-professional structure of women, as well as modifications in values and life aspirations. On the other hand, economic strengthening of women and encourage-ment of jobs which require greater dedication and more of their time are important aspects of achieving gender equality. These two circumstances gave rise to contemplations on the connection between economic activities of female population and the level of births in postindustrial societies. The aim of this article is to point out to the positive influence of female employment on the fertility level, as a capacity for encouraging births in Serbia. When observing the most developed European countries, it can be noticed that greater birth rates are noted in those countries in which there are greater economic activity and employment rates of female population. Furthermore, a series of researches and comparative analyses confirm the positive relation between female employment and fertility. The differences regarding of birth rates among European welfare states are seen as a result of the possibilities of female employment, reconciliation between work and parenthood and the division of gender roles within the family. The influence of economic activity on fertility levels is determined by an institutional framework of family support and gender equality (Engelhardt and Prskawetz, 2004, Neyer, 2006; Andersson and Scott, 2007; Rovny, A.E. 2011; Seeleib-Kaise and Toivonen, 2011. During the first decade of the 21st century, the birth rates in Serbia were by about 30% lower than in the countries which had the highest fertility within European frameworks. The traditional labor division in the household and parenthood produces conflicts between families and employment, recognized in the practices of everyday life (Blagojević, 1997; Blagojević-Hjuson, 2013 and standpoints on the relation between parenthood and employment

  17. Regression toward the mean – a detection method for unknown population mean based on Mee and Chua's algorithm

    Directory of Open Access Journals (Sweden)

    Lüdtke Rainer


    Full Text Available Abstract Background Regression to the mean (RTM occurs in situations of repeated measurements when extreme values are followed by measurements in the same subjects that are closer to the mean of the basic population. In uncontrolled studies such changes are likely to be interpreted as a real treatment effect. Methods Several statistical approaches have been developed to analyse such situations, including the algorithm of Mee and Chua which assumes a known population mean μ. We extend this approach to a situation where μ is unknown and suggest to vary it systematically over a range of reasonable values. Using differential calculus we provide formulas to estimate the range of μ where treatment effects are likely to occur when RTM is present. Results We successfully applied our method to three real world examples denoting situations when (a no treatment effect can be confirmed regardless which μ is true, (b when a treatment effect must be assumed independent from the true μ and (c in the appraisal of results of uncontrolled studies. Conclusion Our method can be used to separate the wheat from the chaff in situations, when one has to interpret the results of uncontrolled studies. In meta-analysis, health-technology reports or systematic reviews this approach may be helpful to clarify the evidence given from uncontrolled observational studies.

  18. Response of sesame to population densities and nitrogen fertilization on newly reclaimed sandy soils

    International Nuclear Information System (INIS)

    Noorka, I.R.; Hafiz, S.I.


    Two field experiments were conducted at the Experimental Farm of Faculty of Agriculture, Suez Canal University at Ismailia during 2008 and 2009 seasons to study the effect of nitrogen fertilization and planting density on growth , yield, its attributes as well as seed quality of new sesame variety (Taka 2 cv.). On newly reclaimed sandy soils of Ismailia Governorate, Egypt, experimental design in split plots form with four replications was used. Four levels of nitrogen fertilization 55, 105, 155 and 205 Kg/ha were arranged randomly in the main plots and three planting distances between hills (10, 15 and 20 cm, respectively) were distributed at random in the sub plots. Increasing N fertilizer level up to 205 Kg/ha significantly increased plant height, fruiting zone length, height of the first fruiting branch, number of branches and capsules/plant, 1000-seed weight, seed weight/plant, seed oil content (%) and seed and oil yields /ha. Decreasing planting distance from 20 to 15 and 10 cm consistently and significantly increased plant height, height of the first fruiting branch and seed and oil yields /ha. The reverse was true regarding the yield components. These results were expected, since experiment soil was newly reclaimed sandy soil and very poor in the nutrients and organic matter. (author)

  19. A population-based survey on family intentions and fertility awareness in women and men in the United Kingdom and Denmark

    DEFF Research Database (Denmark)

    Vassard, Ditte; Lallemant, Camille; Nyboe Andersen, Anders


    BACKGROUND: Across several European countries family formation is increasingly postponed. The aims of the study were to investigate the desire for family building and fertility awareness in the UK and Denmark. METHODS: A population-based internet survey was used among women (n = 1,000) and men (n...... starts to decline around 25-30 years. Men had significantly lower fertility awareness. Women who underestimated the impact of age on female fertility were significantly more likely to have a desire or attempted their first child at a higher age. CONCLUSION: Even though the majority were aware of the age......-related decrease in female fertility, most desired having children at an age when female fertility has declined. Women who were not sufficiently aware of the impact of advanced age were significantly more likely to have their first child at a higher age. There is a need for developing educational programs...

  20. Meaning (United States)

    Harteveld, Casper

    The second world to be considered concerns Meaning. In contrast to Reality and Play, this world relates to the people, disciplines, and domains that are focused on creating a certain value. For example, if this value is about providing students knowledge about physics, it involves teachers, the learning sciences, and the domains education and physics. This level goes into the aspects and criteria that designers need to take into account from this perspective. The first aspect seems obvious when we talk of “games with a serious purpose.” They have a purpose and this needs to be elaborated on, for example in terms of what “learning objectives” it attempts to achieve. The subsequent aspect is not about what is being pursued but how. To attain a value, designers have to think about a strategy that they employ. In my case this concerned looking at the learning paradigms that have come into existence in the past century and see what they have to tell us about learning. This way, their principles can be translated into a game environment. This translation involves making the strategy concrete. Or, in other words, operationalizing the plan. This is the third aspect. In this level, I will further specifically explain how I derived requirements from each of the learning paradigms, like reflection and exploration, and how they can possibly be related to games. The fourth and final aspect is the context in which the game is going to be used. It matters who uses the game and when, where, and how the game is going to be used. When designers have looked at these aspects, they have developed a “value proposal” and the worth of it may be judged by criteria, like motivation, relevance, and transfer. But before I get to this, I first go into how we human beings are meaning creators and what role assumptions, knowledge, and ambiguity have in this. I will illustrate this with some silly jokes about doctors and Mickey Mouse, and with an illusion.

  1. An alternative procedure for estimating the population mean in simple random sampling

    Directory of Open Access Journals (Sweden)

    Housila P. Singh


    Full Text Available This paper deals with the problem of estimating the finite population mean using auxiliary information in simple random sampling. Firstly we have suggested a correction to the mean squared error of the estimator proposed by Gupta and Shabbir [On improvement in estimating the population mean in simple random sampling. Jour. Appl. Statist. 35(5 (2008, pp. 559-566]. Later we have proposed a ratio type estimator and its properties are studied in simple random sampling. Numerically we have shown that the proposed class of estimators is more efficient than different known estimators including Gupta and Shabbir (2008 estimator.

  2. A population-based cohort study of the effect of Caesarean section on subsequent fertility. (United States)

    Gurol-Urganci, I; Cromwell, D A; Mahmood, T A; van der Meulen, J H; Templeton, A


    Is there an association between Caesarean section and subsequent fertility? There is no or only a slight effect of Caesarean section on future fertility. Previous studies have reported that delivery by a Caesarean section is associated with fewer subsequent pregnancies and longer inter-pregnancy intervals. The interpretation of these findings is difficult because of significant weaknesses in study designs and analytical methods, notably the potential effect of the indication for Caesarean section on subsequent delivery. Retrospective cohort study of 1 047 644 first births to low-risk women using routinely collected, national administrative data of deliveries in English maternity units between 1 April 2000 and 31 March 2012. Primiparous women aged 15-40 years who had a singleton, term, live birth in the English National Health Service were included. Women with high-risk pregnancies involving placenta praevia, pre-eclampsia, eclampsia (gestational or pre-existing), hypertension or diabetes were excluded from the main analysis. Kaplan-Meier analyses and Cox proportional hazard models were used to assess the effect of mode of delivery on time to subsequent birth, adjusted for age, ethnicity, socio-economic deprivation and year of index delivery. Among low-risk primiparous women, 224 024 (21.4%) were delivered by Caesarean section. The Kaplan-Meier estimate of the subsequent birth rate at 10 years for the cohort was 74.7%. Compared with vaginal delivery, subsequent birth rates were marginally lower after elective Caesarean for breech (adjusted hazard ratio, HR 0.96, 95% CI 0.94-0.98). Larger effects were observed after elective Caesarean for other indications (adjusted HR 0.81, 95% CI 0.78-0.83), and emergency Caesarean (adjusted HR 0.91, 95% CI 0.90-0.93). The effect was smallest for elective Caesarean for breech, and this was not statistically significant in women younger than 30 years of age (adjusted HR 0.98, 95% CI 0.96-1.01). We used birth cohorts from maternity

  3. A population-based survey on family intentions and fertility awareness in women and men in the United Kingdom and Denmark. (United States)

    Vassard, Ditte; Lallemant, Camille; Nyboe Andersen, Anders; Macklon, Nick; Schmidt, Lone


    Across several European countries family formation is increasingly postponed. The aims of the study were to investigate the desire for family building and fertility awareness in the UK and Denmark. A population-based internet survey was used among women (n = 1,000) and men (n = 237) from the UK (40%) and Denmark (60%). Data covered socio-demographics, family formation, and awareness of female age-related fertility. Data analysis used descriptive statistics and logistic regression analysis for studying associations between low fertility awareness and desired family formation. The majority of all participants desired two or three children. Two-thirds of the childless participants desired a first child at 30+ years, and one-fifth of the women and one-third of the men desired a last child at age 40. Overall, 83% of women and 73% of men were aware that female fertility starts to decline around 25-30 years. Men had significantly lower fertility awareness. Women who underestimated the impact of age on female fertility were significantly more likely to have a desire or attempted their first child at a higher age. Even though the majority were aware of the age-related decrease in female fertility, most desired having children at an age when female fertility has declined. Women who were not sufficiently aware of the impact of advanced age were significantly more likely to have their first child at a higher age. There is a need for developing educational programs for women and men in order to increase the population's knowledge of fertility and risk factors for infertility.

  4. The CFTR Met 470 allele is associated with lower birth rates in fertile men from a population isolate.

    Directory of Open Access Journals (Sweden)

    Gülüm Kosova


    Full Text Available Although little is known about the role of the cystic fibrosis transmembrane regulator (CFTR gene in reproductive physiology, numerous variants in this gene have been implicated in etiology of male infertility due to congenital bilateral absence of the vas deferens (CBAVD. Here, we studied the fertility effects of three CBAVD-associated CFTR polymorphisms, the (TGm and polyT repeat polymorphisms in intron 8 and Met470Val in exon 10, in healthy men of European descent. Homozygosity for the Met470 allele was associated with lower birth rates, defined as the number of births per year of marriage (P = 0.0029. The Met470Val locus explained 4.36% of the phenotypic variance in birth rate, and men homozygous for the Met470 allele had 0.56 fewer children on average compared to Val470 carrier men. The derived Val470 allele occurs at high frequencies in non-African populations (allele frequency = 0.51 in HapMap CEU, whereas it is very rare in African population (Fst = 0.43 between HapMap CEU and YRI. In addition, haplotypes bearing Val470 show a lack of genetic diversity and are thus longer than haplotypes bearing Met470 (measured by an integrated haplotype score [iHS] of -1.93 in HapMap CEU. The fraction of SNPs in the HapMap Phase2 data set with more extreme Fst and iHS measures is 0.003, consistent with a selective sweep outside of Africa. The fertility advantage conferred by Val470 relative to Met470 may provide a selective mechanism for these population genetic observations.

  5. Population Consultation: A Powerful Means to Ensure that Health Strategies are Oriented Towards Universal Health Coverage. (United States)

    Rohrer, Katja; Rajan, Dheepa; Schmets, Gerard


    We seek to highlight why population consultations need to be promoted more strongly as a powerful means to move health reforms towards Universal Health Coverage (UHC). However, despite this increasing recognition that the "population" is the key factor of successful health planning and high-quality service delivery, there has been very little systematic reflection and only limited (international) attention brought to the idea of specifically consulting the population to improve the quality and soundness of health policies and strategies and to strengthen the national health planning process and implementation. So far, research has done little to assess the significance of population consultations for the health sector and its importance for strategic planning and implementation processes; in addition, there has been insufficient evaluation of population consultations in the health sector or health-related areas. We drew on ongoing programmatic work of World Health Organization (WHO) offices worldwide, as most population consultations are not well-documented. In addition, we analyzed any existing documentation available on population consultations in health. We then elaborate on the potential benefits of bringing the population's voice into national health planning. We briefly mention the key methods used for population consultations, and we put forward recent country examples showing that population consultation is an effective way of assessing the population's needs and expectations, and should be more widely used in strategizing health. Giving the voice to the population is a means to strengthen accountability, to reinforce the commitment of policy makers, decision-makers and influencers (media, political parties, academics, etc.) to the health policy objectives of UHC, and, in the specific case of donor-dependent countries, to sensitize donors' engagement and alignment with national health strategies. The consequence of the current low international interest for

  6. Maternal use of fertility drugs and risk of cancer in children--a nationwide population-based cohort study in Denmark

    DEFF Research Database (Denmark)

    Hargreave, Marie; Jensen, Allan; Nielsen, Thor Schütt Svane


    Large population-based studies are needed to examine the effect of maternal use of fertility drugs on the risk of cancer in children, while taking into account the effect of the underlying infertility. A cohort of 123,322 children born in Denmark between 1964 and 2006 to 68,255 women who had been...... evaluated for infertility was established. We used a case-cohort design and calculated hazard ratios (HRs) for cancer in childhood (0-19 years) and in young adulthood (20-29 years) associated with maternal use of six groups of fertility drugs (clomiphene, gonadotropins [i.e., human menopausal gonadotropins...... and follicle-stimulating hormone], gonadotropin-releasing hormone analogs, human chorionic gonadotropins, progesterone and other fertility drugs). We found no statistically significant association between maternal use of fertility drugs and risk for overall cancer in childhood or young adulthood. However...

  7. Population hemoglobin mean and anemia prevalence in Papua New Guinea: new metrics for defining malaria endemicity?

    Directory of Open Access Journals (Sweden)

    Nicolas Senn

    Full Text Available BACKGROUND: The hypothesis is that hemoglobin-based metrics are useful tools for estimating malaria endemicity and for monitoring malaria control strategies. The aim of this study is to compare population hemoglobin mean and anemia prevalence to established indicators of malaria endemicity, including parasite rates, rates of enlarged spleens in children, and records of (presumptive malaria diagnosis among populations living with different levels of malaria transmission. METHODOLOGY/PRINCIPAL FINDINGS: Convenience sample, multisite cross-sectional household surveys conducted in Papua New Guinea. Correlations (r(2 between population Hb mean and anemia prevalence and altitude, parasite rate, and spleen rate were investigated in children ages 2 to 10 years, and in the general population; 21,664 individuals from 156 different communities were surveyed. Altitude ranged from 5 to 2120 meters. In young children, correlations between altitude and parasite rate, population Hb mean, anemia prevalence, and spleen rate were high (r(2: -0.77, 0.73, -0.81, and -0.68; p1500 m (p<0.001. CONCLUSIONS/SIGNIFICANCE: In PNG, where Plasmodium vivax accounts for an important part of all malaria infections, population hemoglobin mean and anemia prevalence correlate well with altitude, parasite, and spleen rates. Hb measurement is simple and affordable, and may be a useful new tool, alone or in association with other metrics, for estimating malaria endemicity and monitoring effectiveness of malaria control programs. Further prospective studies in areas with different malaria epidemiology and different factors contributing to the burden of anemia are warranted to investigate the usefulness of Hb metrics in monitoring malaria transmission intensity.

  8. Finding the Balance: Fertility Control for the Management of Fragmented Populations of a Threatened Rock-Wallaby Species. (United States)

    Willers, Nicole; Martin, Graeme B; Matson, Phill; Mawson, Peter R; Morris, Keith; Bencini, Roberta


    Populations of Australian marsupials can become overabundant, resulting in detrimental impacts on the environment. For example, the threatened black-flanked rock-wallaby ( Petrogale lateralis lateralis ) has previously been perceived as overabundant and thus 'unwanted' when they graze crops and cause habitat degradation. Hormonally-induced fertility control has been increasingly used to manage population size in other marsupials where alternative management options are not viable. We tested whether deslorelin, a superagonist of gonadotropin-releasing hormone (GnRH), would suppress reproduction in free-living adult female rock-wallabies without adversely impacting body condition. We trapped, synchronised reproduction and allocated female rock-wallabies to a placebo implant (control, n = 22), one (n = 22) or two (n = 20) subcutaneous implants of deslorelin. Females were then recaptured over the following 36 months to monitor reproduction, including Luteinising Hormone levels, and body condition. Following treatment, diapaused blastocysts reactivated in five females and the resulting young were carried through to weaning. No wallabies treated with deslorelin, conceivede a new young for at least 27 months. We did not observe adverse effects on body condition on treated females. We conclude that deslorelin implants are effective for the medium-term suppression of reproduction in female black-flanked rock-wallabies and for managing overabundant populations of some marsupials.

  9. Finding the Balance: Fertility Control for the Management of Fragmented Populations of a Threatened Rock-Wallaby Species

    Directory of Open Access Journals (Sweden)

    Nicole Willers


    Full Text Available Populations of Australian marsupials can become overabundant, resulting in detrimental impacts on the environment. For example, the threatened black-flanked rock-wallaby ( Petrogale lateralis lateralis has previously been perceived as overabundant and thus ‘unwanted’ when they graze crops and cause habitat degradation. Hormonally-induced fertility control has been increasingly used to manage population size in other marsupials where alternative management options are not viable. We tested whether deslorelin, a superagonist of gonadotropin-releasing hormone (GnRH, would suppress reproduction in free-living adult female rock-wallabies without adversely impacting body condition. We trapped, synchronised reproduction and allocated female rock-wallabies to a placebo implant (control, n = 22, one (n = 22 or two (n = 20 subcutaneous implants of deslorelin. Females were then recaptured over the following 36 months to monitor reproduction, including Luteinising Hormone levels, and body condition. Following treatment, diapaused blastocysts reactivated in five females and the resulting young were carried through to weaning. No wallabies treated with deslorelin, conceivede a new young for at least 27 months. We did not observe adverse effects on body condition on treated females. We conclude that deslorelin implants are effective for the medium-term suppression of reproduction in female black-flanked rock-wallabies and for managing overabundant populations of some marsupials.

  10. The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments. (United States)

    Rodríguez-Andrade, Osvaldo; Fuentes-Ramírez, Luis E; Morales-García, Yolanda E; Molina-Romero, Dalia; Bustillos-Cristales, María R; Martínez-Contreras, Rebeca D; Muñoz-Rojas, Jesús


    It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Influence of Plant Population and Nitrogen-Fertilizer at Various Levels on Growth and Growth Efficiency of Maize

    Directory of Open Access Journals (Sweden)

    M. I. Tajul


    Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.

  12. Scaling of the mean and variance of population dynamics under fluctuating regimes. (United States)

    Pertoldi, Cino; Faurby, S; Reed, D H; Knape, J; Björklund, M; Lundberg, P; Kaitala, V; Loeschcke, V; Bach, L A


    Theoretical ecologists have long sought to understand how the persistence of populations depends on the interactions between exogenous (biotic and abiotic) and endogenous (e.g., demographic and genetic) drivers of population dynamics. Recent work focuses on the autocorrelation structure of environmental perturbations and its effects on the persistence of populations. Accurate estimation of extinction times and especially determination of the mechanisms affecting extinction times is important for biodiversity conservation. Here we examine the interaction between environmental fluctuations and the scaling effect of the mean population size with its variance. We investigate how interactions between environmental and demographic stochasticity can affect the mean time to extinction, change optimal patch size dynamics, and how it can alter the often-assumed linear relationship between the census size and the effective population size. The importance of the correlation between environmental and demographic variation depends on the relative importance of the two types of variation. We found the correlation to be important when the two types of variation were approximately equal; however, the importance of the correlation diminishes as one source of variation dominates. The implications of these findings are discussed from a conservation and eco-evolutionary point of view.

  13. Public pensions and population ageing : An economic analysis of fertility, migration and social-security policy

    NARCIS (Netherlands)

    Leers, T.


    This thesis examines the relation between the changing demographic composition of the population and its economic, political and international consequences from an economic-theoretical point of view. The ample current interest in this subject needs little comment. In the OECD-countries, virtually no

  14. An assessment of mean-field mixed semiclassical approaches: Equilibrium populations and algorithm stability

    International Nuclear Information System (INIS)

    Bellonzi, Nicole; Jain, Amber; Subotnik, Joseph E.


    We study several recent mean-field semiclassical dynamics methods, focusing on the ability to recover detailed balance for long time (equilibrium) populations. We focus especially on Miller and Cotton’s [J. Phys. Chem. A 117, 7190 (2013)] suggestion to include both zero point electronic energy and windowing on top of Ehrenfest dynamics. We investigate three regimes: harmonic surfaces with weak electronic coupling, harmonic surfaces with strong electronic coupling, and anharmonic surfaces with weak electronic coupling. In most cases, recent additions to Ehrenfest dynamics are a strong improvement upon mean-field theory. However, for methods that include zero point electronic energy, we show that anharmonic potential energy surfaces often lead to numerical instabilities, as caused by negative populations and forces. We also show that, though the effect of negative forces can appear hidden in harmonic systems, the resulting equilibrium limits do remain dependent on any windowing and zero point energy parameters.

  15. Analysis of Fusarium populations in a soybean field under different fertilization management by real-time quantitative PCR and denaturing gradient gel electrophoresis (United States)

    The abundance and population structure of Fusarium spp. in field soils were assessed to determine the effect of different fertilization treatments on soil microbial community and potential role in disease management. The field was under soybean-wheat-corn rotation located in the black soil (Udic Mo...

  16. Estimating mean change in population salt intake using spot urine samples. (United States)

    Petersen, Kristina S; Wu, Jason H Y; Webster, Jacqui; Grimes, Carley; Woodward, Mark; Nowson, Caryl A; Neal, Bruce


    Spot urine samples are easier to collect than 24-h urine samples and have been used with estimating equations to derive the mean daily salt intake of a population. Whether equations using data from spot urine samples can also be used to estimate change in mean daily population salt intake over time is unknown. We compared estimates of change in mean daily population salt intake based upon 24-h urine collections with estimates derived using equations based on spot urine samples. Paired and unpaired 24-h urine samples and spot urine samples were collected from individuals in two Australian populations, in 2011 and 2014. Estimates of change in daily mean population salt intake between 2011 and 2014 were obtained directly from the 24-h urine samples and by applying established estimating equations (Kawasaki, Tanaka, Mage, Toft, INTERSALT) to the data from spot urine samples. Differences between 2011 and 2014 were calculated using mixed models. A total of 1000 participants provided a 24-h urine sample and a spot urine sample in 2011, and 1012 did so in 2014 (paired samples n = 870; unpaired samples n = 1142). The participants were community-dwelling individuals living in the State of Victoria or the town of Lithgow in the State of New South Wales, Australia, with a mean age of 55 years in 2011. The mean (95% confidence interval) difference in population salt intake between 2011 and 2014 determined from the 24-h urine samples was -0.48g/day (-0.74 to -0.21; P spot urine samples was -0.24 g/day (-0.42 to -0.06; P = 0.01) using the Tanaka equation, -0.42 g/day (-0.70 to -0.13; p = 0.004) using the Kawasaki equation, -0.51 g/day (-1.00 to -0.01; P = 0.046) using the Mage equation, -0.26 g/day (-0.42 to -0.10; P = 0.001) using the Toft equation, -0.20 g/day (-0.32 to -0.09; P = 0.001) using the INTERSALT equation and -0.27 g/day (-0.39 to -0.15; P  0.058). Separate analysis of the unpaired and paired data showed that detection of

  17. How does variance in fertility change over the demographic transition? (United States)

    Hruschka, Daniel J; Burger, Oskar


    Most work on the human fertility transition has focused on declines in mean fertility. However, understanding changes in the variance of reproductive outcomes can be equally important for evolutionary questions about the heritability of fertility, individual determinants of fertility and changing patterns of reproductive skew. Here, we document how variance in completed fertility among women (45-49 years) differs across 200 surveys in 72 low- to middle-income countries where fertility transitions are currently in progress at various stages. Nearly all (91%) of samples exhibit variance consistent with a Poisson process of fertility, which places systematic, and often severe, theoretical upper bounds on the proportion of variance that can be attributed to individual differences. In contrast to the pattern of total variance, these upper bounds increase from high- to mid-fertility samples, then decline again as samples move from mid to low fertility. Notably, the lowest fertility samples often deviate from a Poisson process. This suggests that as populations move to low fertility their reproduction shifts from a rate-based process to a focus on an ideal number of children. We discuss the implications of these findings for predicting completed fertility from individual-level variables. © 2016 The Author(s).

  18. Allometric scaling of population variance with mean body size is predicted from Taylor's law and density-mass allometry. (United States)

    Cohen, Joel E; Xu, Meng; Schuster, William S F


    Two widely tested empirical patterns in ecology are combined here to predict how the variation of population density relates to the average body size of organisms. Taylor's law (TL) asserts that the variance of the population density of a set of populations is a power-law function of the mean population density. Density-mass allometry (DMA) asserts that the mean population density of a set of populations is a power-law function of the mean individual body mass. Combined, DMA and TL predict that the variance of the population density is a power-law function of mean individual body mass. We call this relationship "variance-mass allometry" (VMA). We confirmed the theoretically predicted power-law form and the theoretically predicted parameters of VMA, using detailed data on individual oak trees (Quercus spp.) of Black Rock Forest, Cornwall, New York. These results connect the variability of population density to the mean body mass of individuals.

  19. A small population of hypothalamic neurons govern fertility: the critical role of VAX1 in GnRH neuron development and fertility maintenance. (United States)

    Hoffmann, Hanne M; Mellon, Pamela L


    Fertility depends on the correct maturation and function of approximately 800 gonadotropin-releasing hormone (GnRH) neurons in the brain. GnRH neurons are at the apex of the hypothalamic-pituitary-gonadal axis that regulates fertility. In adulthood, GnRH neurons are scattered throughout the anterior hypothalamic area and project to the median eminence, where GnRH is released into the portal vasculature to stimulate release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary. LH and FSH then regulate gonadal steroidogenesis and gametogenesis. Absence of GnRH neurons or inappropriate GnRH release leads to infertility. Despite the critical role of GnRH neurons in fertility, we still have a limited understanding of the genes responsible for proper GnRH neuron development and function in adulthood. GnRH neurons originate in the olfactory placode then migrate into the brain. Homeodomain transcription factors expressed within GnRH neurons or along their migratory path are candidate genes for inherited infertility. Using a combined in vitro and in vivo approach, we have identified Ventral Anterior Homeobox 1 ( Vax1 ) as a novel homeodomain transcription factor responsible for GnRH neuron maturation and fertility. GnRH neuron counts in Vax1 knock-out embryos revealed Vax1 to be required for the presence of GnRH-expressing cells at embryonic day 17.5 (E17.5), but not at E13.5. To localize the effects of Vax1 on fertility, we generated Vax1 flox mice and crossed them with Gnrh cre mice to specifically delete Vax1 within GnRH neurons. GnRH staining in Vax1 flox/flox :GnRH cre mice show a total absence of GnRH expression in the adult. We performed lineage tracing in Vax1 flox/flox :GnRH cre :RosaLacZ mice which proved GnRH neurons to be alive, but incapable of expressing GnRH. The absence of GnRH leads to delayed puberty, hypogonadism and complete infertility in both sexes. Finally, using the immortalized model GnRH neuron cell lines, GN11 and

  20. Mean-field dynamics of a population of stochastic map neurons (United States)

    Franović, Igor; Maslennikov, Oleg V.; Bačić, Iva; Nekorkin, Vladimir I.


    We analyze the emergent regimes and the stimulus-response relationship of a population of noisy map neurons by means of a mean-field model, derived within the framework of cumulant approach complemented by the Gaussian closure hypothesis. It is demonstrated that the mean-field model can qualitatively account for stability and bifurcations of the exact system, capturing all the generic forms of collective behavior, including macroscopic excitability, subthreshold oscillations, periodic or chaotic spiking, and chaotic bursting dynamics. Apart from qualitative analogies, we find a substantial quantitative agreement between the exact and the approximate system, as reflected in matching of the parameter domains admitting the different dynamical regimes, as well as the characteristic properties of the associated time series. The effective model is further shown to reproduce with sufficient accuracy the phase response curves of the exact system and the assembly's response to external stimulation of finite amplitude and duration.

  1. Effect of the efficiency of N by use of different forms of fertilizer application in ground, evaluated by means of the isotopic technique and the N absorbed by the cultivation

    International Nuclear Information System (INIS)

    Delgado, Rodolfo; Ramirez, Ricardo; Urquiaga, Segundo


    The determination of the efficiency in the use of nitrogen fertilizers, constitutes one of the important aspects that should be considered in the process of the appropriated element doses recommendation. The form of fertilizer placement is a very important aspect that affects the efficiency, and its evaluation is the main objective of the present work, by means of the Direct Method with the use of N 1 5, and the Indirect Method by means of the N-absorbed by fertilized plants and no fertilized ones. The study was carried out in a Fluventic Haplustoll soil, located in San Carlos, Cojedes State, where three forms of fertilizer placement were evaluated : 1) broadcasting application and incorporation with harrows pass (V/R); 2) broadcasting application and incorporation with disc harrows pass (V/B); 3) application band fertilizer (B); 4) without fertilization; parcels of 200 m2 were sown with corn (Zea mayz), and received an application equivalent to 120 Kg N/ha, in the form of urea. In each of the fertilized parcels, three microparcels of 2,56 m2 were settled down where the normal urea was substituted by enriched urea with N 1 5 to 3% exc. During the crop cycle, the contents N-mineral extracted with KCl(2M) were evaluated and finally the production of dry matter, grain, and the contents of N-total and N 1 5. It was found that the efficiency in the N-fertilizer recovery, by means of the Direct Method, fluctuated between 18.8 and 23,7%, although the grain production was high, fluctuating between 6541 and 6007 kg/ha, suggesting little use of N-fertilizer although a significant use or the soil N. On the other hand, one observes that the processes of mineralization/inmobilization are affected by the application of N, highlighting the importance of their knowledge to improve the efficiency of the use of N-fertilizer and the N coming from soils [es

  2. Composite population kernels in ytterbium-buffer collisions studied by means of laser-saturated absorption

    International Nuclear Information System (INIS)

    Zhu, X.


    We present a systematic study of composite population kernels for 174 Yb collisions with He, Ar, and Xe buffer gases, using laser-saturation spectroscopy. 174 Yb is chosen as the active species because of the simple structure of its 1 S 0 - 3 P 1 resonance transition (lambda = 556 nm). Elastic collisions are modeled by means of a composite collision kernel, an expression of which is explicitly derived based on arguments of a hard-sphere potential and two-category collisions. The corresponding coupled population-rate equations are solved by iteration to obtain an expression for the saturated-absorption line shape. This expression is fit to the data to obtain information about the composite kernel, along with reasonable values for other parameters. The results confirm that a composite kernel is more general and realistic than a single-component kernel, and the generality in principle and the practical necessity of the former are discussed

  3. Patients with endometriosis have aneuploidy rates equivalent to their age-matched peers in the in vitro fertilization population. (United States)

    Juneau, Caroline; Kraus, Emily; Werner, Marie; Franasiak, Jason; Morin, Scott; Patounakis, George; Molinaro, Thomas; de Ziegler, Dominique; Scott, Richard T


    To determine whether endometriosis ultimately results in an increased risk of embryonic aneuploidy. Retrospective cohort. Infertility clinic. Patients participating in an in vitro fertilization (IVF) cycle from 2009-2015 using preimplantation genetic screening (PGS) who had endometriosis identified by surgical diagnosis or by ultrasound findings consistent with a persistent space-occupying disease whose sonographic appearance was consistent with endometriosis. None. Rate of aneuploidy in endometriosis patients undergoing IVF compared to controls without endometriosis undergoing IVF. There were 305 patients with endometriosis who produced 1,880 blastocysts that met the criteria for inclusion in the endometriosis group. The mean age of the patients with endometriosis was 36.1 ± 3.9 years. When the aneuploidy rates in patients with endometriosis and aneuploidy rates in patients without endometriosis were stratified by Society for Assisted Reproductive Technology age groups and compared, there were no statistically significant differences in the rate of aneuploidy (odds ratio 0.85; 95% confidence interval, 0.84-0.85). Patients with endometriosis undergoing IVF have aneuploidy rates equivalent to their age-matched peers in IVF population who do not have endometriosis. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Fertility preservation in young patients with cancer

    Directory of Open Access Journals (Sweden)

    Virender Suhag


    Full Text Available Infertility can arise as a consequence of treatment of oncological conditions. The parallel and continued improvement in both the management of oncology and fertility cases in recent times has brought to the forefront the potential for fertility preservation in patients being treated for cancer. Many survivors will maintain their reproductive potential after the successful completion of treatment for cancer. However total body irradiation, radiation to the gonads, and certain high dose chemotherapy regimens can place women at risk for acute ovarian failure or premature menopause and men at risk for temporary or permanent azoospermia. Providing information about risk of infertility and possible interventions to maintain reproductive potential are critical for the adolescent and young adult population at the time of diagnosis. There are established means of preserving fertility before cancer treatment; specifically, sperm cryopreservation for men and in vitro fertilization and embryo cryopreservation for women. Several innovative techniques are being actively investigated, including oocyte and ovarian follicle cryopreservation, ovarian tissue transplantation, and in vitro follicle maturation, which may expand the number of fertility preservation choices for young cancer patients. Fertility preservation may also require some modification of cancer therapy; thus, patients' wishes regarding future fertility and available fertility preservation alternatives should be discussed before initiation of therapy.

  5. Physical Education as a means of health and working efficiency improvement of population

    Directory of Open Access Journals (Sweden)

    Khasanova Rezeda R.


    Full Text Available In this article historical and contemporary influence of physical education (PE and sport instances are shown in economic indices. The notion “health”, as well as the influence of physical education and sport at its level, is given. Health-detrimental behavior (malnutrition, physical inactivity, alcohol abuse and smoking can be the cause of chronic diseases and have a significant influence on health of citizens. Experimental data, which approve that bad working conditions and health-detrimental behavior can discourage productivity and extend the periods of temporary incapacity for work, are marked. In addition, there is an access to the majority of the adult population, which provides a perfect opportunity for healthy lifestyle campaign. Consequently, the campaigns aimed at health improvement of the employable population at their working places, have potentials for a wide population segment engagement, which cannot be accessible for other medical campaigns. Experimental data on increase in labour productivity and economic effectiveness improvement by means of physical education are given; the latter was applied to people at their work during the soviet period, when the large-scale research was made. The necessity of physical education integration in the productive process is proved, which will finally have a positive impact on the whole economy.

  6. Use of fertility drugs and risk of uterine cancer: results from a large Danish population-based cohort study

    DEFF Research Database (Denmark)

    Jensen, Allan; Sharif, Heidi; Kjaer, Susanne K


    and 1998. In a case-cohort study, rate ratios and 95% confidence intervals were used to assess the effects of 4 groups of fertility drugs on overall risk of uterine cancer after adjustment for potentially confounding factors. Through mid-2006, 83 uterine cancers were identified. Ever use of any fertility......Some epidemiologic studies have indicated that uterine cancer risk may be increased after use of fertility drugs. To further assess this association, the authors used data from a large cohort of 54,362 women diagnosed with infertility who were referred to Danish fertility clinics between 1965...... drug was not associated with uterine cancer risk (rate ratio (RR) = 1.10, 95% confidence interval (CI): 0.69, 1.76). However, ever use of gonadotropins (follicle-stimulating hormone and human menopausal gonadotropin) increased uterine cancer risk (RR = 2.21, 95% CI: 1.08, 4.50); the risk was primarily...

  7. Temporal trends in general and age-specific fertility rates among women with schizophrenia (1996-2009): a population-based study in Ontario, Canada. (United States)

    Vigod, Simone N; Seeman, Mary V; Ray, Joel G; Anderson, Geoffrey M; Dennis, Cindy Lee; Grigoriadis, Sophie; Gruneir, Andrea; Kurdyak, Paul A; Rochon, Paula A


    There is substantial evidence that women with schizophrenia in many parts of the world have fewer children than their peers. Our objective was to analyze recent trends in general and age-specific fertility rates among women with schizophrenia in Ontario, Canada. We conducted a repeated cross-sectional population-based study from 1996 to 2009 using population-based linked administrative databases for the entire province of Ontario. Women aged 15-49 years were classified into schizophrenia and non-schizophrenia groups in each successive 12-month period. Annual general and age-specific fertility rates were derived. The general fertility rate (GFR) among women with schizophrenia was 1.16 times higher in 2007-2009 than in 1996-1998 (95% confidence interval [CI] 1.04-1.31). The annual GFR ratio of women with vs. without schizophrenia was 0.41 (95% CI 0.36-0.47) in 2009, which was slightly higher than the same ratio in 1996 of 0.30 (95% CI 0.25-0.35). Annual age-specific fertility rates (ASFR) increased over time among women with schizophrenia aged 20-24, 25-29, 35-39 and 40-44 years, but the increase was not always statistically significant. Among women aged 20-24 years, the ASFR ratio in women with vs. without schizophrenia was not significant by the end of the study period (0.93, 95% CI 0.70-1.22). The general fertility rate among women with schizophrenia appears to have increased modestly over the past 13 years. Clinical care and health policy should consider new strategies that focus on the mental health of women with schizophrenia as new mothers, while optimizing healthy pregnancies and child rearing. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Estimation of Finite Population Mean in Multivariate Stratified Sampling under Cost Function Using Goal Programming

    Directory of Open Access Journals (Sweden)

    Atta Ullah


    Full Text Available In practical utilization of stratified random sampling scheme, the investigator meets a problem to select a sample that maximizes the precision of a finite population mean under cost constraint. An allocation of sample size becomes complicated when more than one characteristic is observed from each selected unit in a sample. In many real life situations, a linear cost function of a sample size nh is not a good approximation to actual cost of sample survey when traveling cost between selected units in a stratum is significant. In this paper, sample allocation problem in multivariate stratified random sampling with proposed cost function is formulated in integer nonlinear multiobjective mathematical programming. A solution procedure is proposed using extended lexicographic goal programming approach. A numerical example is presented to illustrate the computational details and to compare the efficiency of proposed compromise allocation.

  9. Determination of Mean Glycated Haemoglobin in Healthy Adults of a Local Population. (United States)

    Nida, Sumbal; Khan, Dilshad Ahmed; Ijaz, Aamir; Khan, Muhammad Qaiser Alam; Aleef, Hira; Abbasi, Maria


    To determine the mean hemoglobin HbA1C levels of disease-free adults in a local population and its optimum cutoff for the diagnosis of diabetes. Cross-sectional study. Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, from January to September 2015. Healthy subjects aged 18 years and above of either gender were recruited from local population. Pregnant ladies and individuals with known diabetes, chronic kidney disease, chronic liver disease, congestive cardiac failure, anemia, hemoglobinopathies, mental illness and individuals on glucocorticoid therapy were excluded. Fasting plasma glucose (FPG) or 2-hour plasma glucose (2-h PG) was analyzed using hexokinase methodology and glycated hemoglobin (Hb A1C) was also analyzed using turbidimetric inhibition immunoassay technique. Receiver operating characteristic (ROC) curves were plotted. Differences among the groups were tested by one-way ANOVA, and p <0.05 was considered statistically significant. Among 558 subjects, 88.8% (496) were normoglycaemic (NG), 5.7% (32) were with impaired glucose fasting (IFG), and 5.4% (30) were diagnosed with diabetes mellitus (DM). A1C was 5.00 ±0.44% in NG and 6.28 ±1.16% in diabetics. FPG in NG was 4.55 ±0.95 mmol/Land in diabetics was 8.28 ±1.78 mmol/L. The optimal HbA1C cutoff value for diagnosis of DM was at 6.05% (AUC 0.827 95% CI 0.732 to 0.923, p ≤0.05 with its sensitivity of 53.3% and specificity of 98.5%. However, HbA1C showed suboptimal sensitivity and specificity for prediabetes. The mean HbAIC and cutoff point for diabetes in the study population is 5.07 ±0.58% and 6.05%, respectively (AUC 0.827, 95% CI: 0.732 to 0.923, p<0.001) with 53.3% sensitivity and 98.5% specificity.

  10. Determination of Mean Glycated Haemoglobin in Healthy Adults of a Local Population

    International Nuclear Information System (INIS)

    Nida, S.; Ijaz, A.; Aleef, H.; Khan, D. A.; Khan, M. Q. A.; Abbasi, M.


    Objective: To determine the mean hemoglobin HbA1C levels of disease-free adults in a local population and its optimum cutoff for the diagnosis of diabetes. Study Design: Cross-sectional study. Place and Duration of Study: Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, from January to September 2015. Methodology: Healthy subjects aged 18 years and above of either gender were recruited from local population. Pregnant ladies and individuals with known diabetes, chronic kidney disease, chronic liver disease, congestive cardiac failure, anemia, hemoglobinopathies, mental illness and individuals on glucocorticoid therapy were excluded. Fasting plasma glucose (FPG) or 2-hour plasma glucose (2-h PG) was analyzed using hexokinase methodology and glycated hemoglobin (Hb A1C) was also analyzed using turbidimetric inhibition immunoassay technique. Receiver operating characteristic (ROC) curves were plotted. Differences among the groups were tested by one-way ANOVA, and p <0.05 was considered statistically significant. Results: Among 558 subjects, 88.8% (496) were normoglycaemic (NG), 5.7% (32) were with impaired glucose fasting (IFG), and 5.4% (30) were diagnosed with diabetes mellitus (DM). A1C was 5.00 0.44% in NG and 6.28 +-1.16% in diabetics. FPG in NG was 4.55 +-0.95 mmol/L and in diabetics was 8.28 1.78 mmol/L. The optimal HbA1C cutoff value for diagnosis of DM was at 6.05% (AUC 0.827 95% CI 0.732 to 0.923, p <=0.05 with its sensitivity of 53.3% and specificity of 98.5%. However, HbA1C showed suboptimal sensitivity and specificity for prediabetes. Conclusion: The mean HbAIC and cutoff point for diabetes in the study population is 5.07 +-0.58% and 6.05%, respectively (AUC 0.827, 95% CI: 0.732 to 0.923, p<0.001) with 53.3% sensitivity and 98.5% specificity. (author)

  11. Diverging patterns of fertility decline in Uruguay

    Directory of Open Access Journals (Sweden)

    Mathías Nathan


    Full Text Available Background: The total fertility rate (TFR in Uruguay fell from 2.5 to 1.9 children per woman between 1996 and 2011. However, no study to date has examined the decline of the TFR by observing changes in fertility patterns by birth order. Objective: The main aim of this study is to analyze recent changes in fertility level and timing of childbearing by birth order in Uruguay. Methods: We estimate unconditional and conditional age- and birth-order-specific fertility rates for 1996-2011 using data from vital statistics, population census, and national population estimates. Additionally, three period summary measures of birth-order-specific fertility quantum are calculated: TFR, PATFR and TFRp*. Timing changes by birth order are examined with MAB and TMAB, focusing on MAB1 and its standard deviation and comparing their evolutions in Uruguay with those of selected countries. Results: Fertility decline fits a parity-specific stopping model with a moderate increase in the mean ages of first, second, and third births. The distribution of conditional fertility rates for first and second births depicts an asymmetric bimodal shape linked to the increasing heterogeneity of the timing of childbearing. Compared to countries with similar fertility trends, heterogeneity in the age at first birth in Uruguay is remarkably high. Conclusions: Previous studies suggest that heterogeneity in first and second birth timing is related to structural social inequalities, as women from lower social strata have not significantly changed the age at which they bear a first child, whereas women of middle to high social strata have started to postpone it. The new evidence reinforces the idea that postponement transition in Uruguay cannot be studied without considering this consolidation of social status polarization in fertility timing.


    Directory of Open Access Journals (Sweden)

    Jambulingam Subramani


    Full Text Available The present paper deals with a modified ratio estimator for estimation of population mean of the study variable when the population median of the auxiliary variable is known. The bias and mean squared error of the proposed estimator are derived and are compared with that of existing modified ratio estimators for certain known populations. Further we have also derived the conditions for which the proposed estimator performs better than the existing modified ratio estimators. From the numerical study it is also observed that the proposed modified ratio estimator performs better than the existing modified ratio estimators for certain known populations.

  13. Fertility treatment and reproductive health of male offspring: a study of 1,925 young men from the general population

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Jørgensen, Niels; Asklund, Camilla


    motile sperm (-4.0%, 95% CI: -8.0, -0.1), and fewer morphologically normal spermatozoa (-2.0%, 95% CI: -4.1, 0.0). They also had a lower serum testosterone level and free androgen index (results not statistically significant). These findings should be viewed in light of the increasing use of fertility......Little is known the about the reproductive health of offspring after fertility treatment. In 2001-2005, the authors approached young Danish men attending a compulsory physical examination to determine their fitness for military service. A total of 1,925 men volunteered, delivered a semen sample...

  14. Socioeconomic status and fertility decline

    DEFF Research Database (Denmark)

    Dribe, Martin; Breschi, Marco; Gagnon, Alain


    America to analyse the relationship between socio-economic status and fertility during the fertility transition. Using comparable analytical models and class schemes for each population, we examined the changing socio-economic differences in marital fertility and related these to common theories...

  15. Evaluation of low red blood cell mean corpuscular volume in an apheresis donor population. (United States)

    Bryant, Barbara J; Hopkins, Julie A; Arceo, Sarah M; Leitman, Susan F


    Apheresis donors are routinely evaluated with a complete blood count (CBC). Low red blood cell mean corpuscular volume (MCV) values (or=12.5 g/dL) could be due to iron deficiency or hemoglobinopathy. The etiology of a low MCV in a healthy apheresis donor population was assessed. Predonation samples for CBC were obtained from 1162 consecutive apheresis donors. Donors with a MCV of less than 80 fL were evaluated by CBC, iron studies (ferritin, serum iron, transferrin, percentage of transferrin saturation), and hemoglobin (Hb) electrophoresis. Iron deficiency was defined as a ferritin value below the reference range. Beta chain Hb variants were determined by Hb electrophoresis. Alpha thalassemia trait was presumed if the red blood cell (RBC) count was elevated, no variant Hbs were detected, and the iron studies were within normal ranges. In a 19-month period, 33 of 1162 apheresis donors had low MCV values. Iron deficiency was present in 64%; 49% had isolated iron deficiency and 15% had iron deficiency plus hemoglobinopathy. Hemoglobinopathy without concomitant iron deficiency was found in the remaining 36%. Iron deficiency is present in the majority of apheresis donors with repeatedly low MCV values and Hb levels of 12.5 g/dL or more. Hemoglobinopathy is also commonly present but may not be easily recognized in the setting of iron deficiency. The MCV is a useful screening tool to detect iron deficiency and hemoglobinopathy. Low MCV values should be investigated to determine if iron replacement therapy is indicated.

  16. Effects of fertility education on knowledge, desires and anxiety among the reproductive-aged population: findings from a randomized controlled trial. (United States)

    Maeda, E; Nakamura, F; Kobayashi, Y; Boivin, J; Sugimori, H; Murata, K; Saito, H


    What are the effects of fertility education on knowledge, childbearing desires and anxiety? Providing fertility information contributed to greater knowledge, but increased anxiety. Past studies have found that exposure to educational material improved fertility awareness and changed desires toward childbearing and its timing. Existing educational websites with evidence-based medical information provided in a non-judgmental manner have received favorable responses from reproductive-aged men and women. This three-armed (one intervention and two control groups), randomized controlled trial was conducted using online social research panels (SRPs) in Japan in January 2015. A total of 1455 participants (726 men and 729 women) between 20 and 39 years of age who hoped to have (more) children in the future were block-randomized and exposed to one of three information brochures: fertility education (intervention group), intake of folic acid during pregnancy (control group 1) or governmental financial support for pregnancy and childbirth (control group 2). Fertility knowledge was measured with the Japanese version of the Cardiff Fertility Knowledge Scale (CFKS-J). Knowledge, child-number and child-timing desires, subjective anxiety (i.e. whether participants felt anxiety [primary outcome]), and scores on the State-Trait Anxiety Inventory were assessed immediately after exposure. Non-inferiority comparisons were performed on subjective anxiety with non-inferiority declared if the upper limit of the two-sided 95% confidence interval (CI) for risk difference did not exceed a margin of 0.15. This test for non-inferiority was only performed for subjective anxiety; all the other variables were tests of superiority. Posttest scores on the CFKS-J (mean, SD) were higher in the intervention group than that of the control groups: intervention versus Control 1 and versus Control 2: 52.8 (28.8) versus 40.9 (26.2) (Pfertility may limit the generalizability of these findings. In addition to

  17. Use of fertility drugs and risk of uterine cancer: results from a large Danish population-based cohort study. (United States)

    Jensen, Allan; Sharif, Heidi; Kjaer, Susanne K


    Some epidemiologic studies have indicated that uterine cancer risk may be increased after use of fertility drugs. To further assess this association, the authors used data from a large cohort of 54,362 women diagnosed with infertility who were referred to Danish fertility clinics between 1965 and 1998. In a case-cohort study, rate ratios and 95% confidence intervals were used to assess the effects of 4 groups of fertility drugs on overall risk of uterine cancer after adjustment for potentially confounding factors. Through mid-2006, 83 uterine cancers were identified. Ever use of any fertility drug was not associated with uterine cancer risk (rate ratio (RR) = 1.10, 95% confidence interval (CI): 0.69, 1.76). However, ever use of gonadotropins (follicle-stimulating hormone and human menopausal gonadotropin) increased uterine cancer risk (RR = 2.21, 95% CI: 1.08, 4.50); the risk was primarily observed after 10 years of follow-up. Furthermore, uterine cancer risk increased with number of cycles of use for clomiphene (for > or =6 cycles, RR = 1.96, 95% CI: 1.03, 3.72) and human chorionic gonadotropin (for > or =6 cycles, RR = 2.18, 95% CI: 1.16, 4.08) but not for other gonadotropins. Use of gonadotropin-releasing hormone analogs was not associated with risk. Gonadotropins, and possibly clomiphene and human chorionic gonadotropin, may increase the risk of uterine cancer, with higher doses and longer follow-up leading to greater risk.

  18. Knowledge, attitudes, and practices regarding conception and fertility: a population-based survey among reproductive-age United States women. (United States)

    Lundsberg, Lisbet S; Pal, Lubna; Gariepy, Aileen M; Xu, Xiao; Chu, Micheline C; Illuzzi, Jessica L


    To assess overall knowledge, attitudes, and practices related to conception and fertility among reproductive-age women in the United States. Online survey of a cross-sectional sample of 1,000 women. United States, March 2013. Women aged 18-40 years. None. Knowledge, attitudes, and practices regarding selected topics in reproductive health. Forty percent of women across all age groups expressed concerns about their ability to conceive. Yet one-third of women were unaware of adverse implications of sexually transmitted infections, obesity, or irregular menses for procreative success, and one-fifth were unaware of the effects of aging. Approximately 40% were unfamiliar with the ovulatory cycle. Overall, younger women (18-24 years) demonstrated less knowledge regarding conception, fertility, and ovulation, whereas older women tended to believe in common myths and misconceptions. Respondents in all age groups identified women's health care providers (75%) and Web sites (40%) as top sources of reproductive health-related information; however, engagement with providers on specific factors affecting fertility is sparse. Knowledge regarding ovulation, fertility, and conception is limited among this sample of reproductive-age US women. Future initiatives should prioritize improved provider engagement and accurate information dissemination in Web-based venues. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  19. Annual mean effective dose of Slovak population due to natural radioactivity of building materials

    International Nuclear Information System (INIS)

    Cabanekova, H.


    Natural radiation is the main source of exposure to humans. The basic raw materials, generally used in the construction industry, contain natural radionuclides which reflects their natural origin and the geological conditions at the site of production. In the last time, most building materials are manufactured from secondary raw materials with higher concentration of natural radionuclides. The estimation of the 226 Ra content as well as the 232 Th and 40 K concentration in building materials and products is essential for the evaluation of the external x-ray contribution to the exposure. The building materials with high value of 226 Ra coupled with pronounced porosity of the final products make them potential indoor Rn sources. It means that external exposure and part of inhalation dose from radon and its progeny inside of building is caused to the radiation from the primordial radionuclides pres ent in building materials and products and can increase the indoor natural radiation exposure. For keeping the population exposure as low as reasonably achievable is in the Slovak legislation the radioactive content of primordial radionuclides in building materials and products regulated and the maximum of specific activity is 370 of radium equivalent activity and 120 of 226 Ra. The Health ministry and Slovak metrological institute nominated the department of Radiation Hygiene of Slovak medical university to investigate regularly the content of natural radionuclides and also the radon emanation in samples of raw and secondary building materials and products used in Slovak building industry. In the framework of the screening of building materials and products there were analyzed over 3 000 samples. The natural radionuclides are assessed through their progeny photo peaks. The specific activity of nuclides is determined as weighted average of their photo peaks. The obtained results are corrected to the background distribution and to the self absorption in the

  20. Risk for borderline ovarian tumours after exposure to fertility drugs: results of a population-based cohort study. (United States)

    Bjørnholt, Sarah Marie; Kjaer, Susanne Krüger; Nielsen, Thor Schütt Svane; Jensen, Allan


    Do fertility drugs increase the risk for borderline ovarian tumours, overall and according to histological subtype? The use of any fertility drug did not increase the overall risk for borderline ovarian tumours, but an increased risk for serous borderline ovarian tumours was observed after the use of progesterone. Many epidemiological studies have addressed the connection between fertility drugs use and risk for ovarian cancer; most have found no strong association. Fewer studies have assessed the association between use of fertility drugs and risk for borderline ovarian tumours, and the results are inconsistent. A retrospective case-cohort study was designed with data from a cohort of 96 545 Danish women with fertility problems referred to all Danish fertility clinics in the period 1963-2006. All women were followed for first occurrence of a borderline ovarian tumour from the initial date of infertility evaluation until a date of migration, date of death or 31 December 2006, whichever occurred first. The median length of follow-up was 11.3 years. Included in the analyses were 142 women with borderline ovarian tumours (cases) and 1328 randomly selected sub-cohort members identified in the cohort during the follow-up through 2006. Cases were identified by linkage to the Danish Cancer Register and the Danish Register of Pathology by use of personal identification numbers. To obtain information on use of fertility drugs, hospital files and medical records of infertility-associated visits to all Danish fertility clinics were collected and supplemented with information from the Danish IVF register. We used case-cohort techniques to calculate rate ratios (RRs) and corresponding 95% confidence intervals (CIs) for borderline ovarian tumours, overall and according to histological subtype, associated with the use of any fertility drug or five specific groups of fertility drugs: clomiphene citrate, gonadotrophins (human menopausal gonadotrophins and follicle


    Directory of Open Access Journals (Sweden)

    DARIUSZ Piwczynski


    Full Text Available The research was carried out on 4,030 Polish Merino ewes born in the years 1991- 2001, kept in 15 flocks from the Pomorze and Kujawy region. Fertility of ewes in subsequent reproduction seasons was analysed with the use of multiple logistic regression. The research showed that there is a statistical influence of the flock, year of birth, age of dam, flock year interaction of birth on the ewes fertility. In order to estimate the genetic parameters, the Gibbs sampling method was applied, using the univariate animal models, both linear as well as threshold. Estimates of fertility depending on the model equalled 0.067 to 0.104, whereas the estimates of repeatability equalled respectively: 0.076 and 0.139. The obtained genetic parameters were then used to estimate the breeding values of the animals in terms of controlled trait (Best Linear Unbiased Prediction method using linear and threshold models. The obtained animal breeding values rankings in respect of the same trait with the use of linear and threshold models were strongly correlated with each other (rs = 0.972. Negative genetic trends of fertility (0.01-0.08% per year were found.

  2. Correlations in fertility across generations: can low fertility persist? (United States)

    Kolk, Martin; Cownden, Daniel; Enquist, Magnus


    Correlations in family size across generations could have a major influence on human population size in the future. Empirical studies have shown that the associations between the fertility of parents and the fertility of children are substantial and growing over time. Despite their potential long-term consequences, intergenerational fertility correlations have largely been ignored by researchers. We present a model of the fertility transition as a cultural process acting on new lifestyles associated with fertility. Differences in parental and social influences on the acquisition of these lifestyles result in intergenerational correlations in fertility. We show different scenarios for future population size based on models that disregard intergenerational correlations in fertility, models with fertility correlations and a single lifestyle, and models with fertility correlations and multiple lifestyles. We show that intergenerational fertility correlations will result in an increase in fertility over time. However, present low-fertility levels may persist if the rapid introduction of new cultural lifestyles continues into the future. PMID:24478294

  3. Comparison between a sire model and an animal model for genetic evaluation of fertility traits in Danish Holstein population

    DEFF Research Database (Denmark)

    Sun, C; Madsen, P; Nielsen, U S


    Comparisons between a sire model, a sire-dam model, and an animal model were carried out to evaluate the ability of the models to predict breeding values of fertility traits, based on data including 471,742 records from the first lactation of Danish Holstein cows, covering insemination years from...... the results suggest that the animal model, rather than the sire model, should be used for genetic evaluation of fertility traits......Comparisons between a sire model, a sire-dam model, and an animal model were carried out to evaluate the ability of the models to predict breeding values of fertility traits, based on data including 471,742 records from the first lactation of Danish Holstein cows, covering insemination years from...... 1995 to 2004. The traits in the analysis were days from calving to first insemination, calving interval, days open, days from first to last insemination, number of inseminations per conception, and nonreturn rate within 56 d after first service. The correlations between sire estimated breeding value...

  4. Maternal use of fertility drugs and risk of cancer in children--a nationwide population-based cohort study in Denmark. (United States)

    Hargreave, Marie; Jensen, Allan; Nielsen, Thor Schütt Svane; Colov, Emilie Palmgren; Andersen, Klaus Kaae; Pinborg, Anja; Kjaer, Susanne Krüger


    Large population-based studies are needed to examine the effect of maternal use of fertility drugs on the risk of cancer in children, while taking into account the effect of the underlying infertility. A cohort of 123,322 children born in Denmark between 1964 and 2006 to 68,255 women who had been evaluated for infertility was established. We used a case-cohort design and calculated hazard ratios (HRs) for cancer in childhood (0-19 years) and in young adulthood (20-29 years) associated with maternal use of six groups of fertility drugs (clomiphene, gonadotropins [i.e., human menopausal gonadotropins and follicle-stimulating hormone], gonadotropin-releasing hormone analogs, human chorionic gonadotropins, progesterone and other fertility drugs). We found no statistically significant association between maternal use of fertility drugs and risk for overall cancer in childhood or young adulthood. However, with regard to specific cancers in childhood, our results showed that maternal use of progesterone before childbirth markedly increased the risks of their offspring for acute lymphocytic leukemia (any use: HR, 4.95; 95% CI, 1.69-14.54; ≥ three cycles of use: HR, 9.96; 95% CI, 2.63-37.77) and for sympathetic nervous system tumors (any use: HR, 5.79; 95% CI, 1.23-27.24; ≥ three cycles of use: HR, 8.51; 95% CI, 1.72-42.19). These findings show that maternal use of progesterone may increase the risk for specific cancers in the offspring. Additional large epidemiological studies are urgently needed to confirm our finding. © 2014 UICC.

  5. Device for the determination of concentrations of fissile and/or fertile materials by means of x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Von Baeckmann, A.; Neuber, J.


    In analyzing fissile and/or fertile materials in the thorium, uranium, neptunium, plutonium, americium and curium group, time and accuracy are significant factors. An automated system for rapidly analyzing these materials includes: sample preparation device in which aliquots of sample are weighed and mixed with known amounts of solution; x-ray fluorescence spectrometer; and, a central control system for controlling the operation and analyzing the data. (auth)

  6. 'Just because a doctor says something, doesn't mean that [it] will happen': self-perception as having a Fertility Problem among Infertility Patients. (United States)

    Leyser-Whalen, Ophra; Greil, Arthur L; McQuillan, Julia; Johnson, Katherine M; Shrefffler, Karina M


    Only some individuals who have the medically defined condition 'infertility' adopt a self-definition as having a fertility problem, which has implications for social and behavioural responses, yet there is no clear consensus on why some people and not others adopt a medical label. We use interview data from 28 women and men who sought medical infertility treatment to understand variations in self-identification. Results highlight the importance of identity disruption for understanding the dialectical relationship between medical contact and self-identification, as well as how diagnosis acts both as a category and a process. Simultaneously integrating new medical knowledge from testing and treatment with previous fertility self-perceptions created difficulty for settling on an infertility self-perception. Four response categories emerged for adopting a self-perception of having a fertility problem: (i) the non-adopters - never adopting the self-perception pre- or post-medical contact; (ii) uncertain - not being fully committed to the self-perception pre- or post-medical contact; (iii) assuming the label - not having prior fertility concerns but adopting the self-perception post-medical contact; and (iv) solidifying a tentative identity - not being fully committed to a self-perception pre-medical contact, but fully committed post-medical contact. (A virtual abstract of this paper can be viewed at: © 2017 Foundation for the Sociology of Health & Illness.

  7. Self-emergence of Lexicon Consensus in a Population of Autonomous Agents by Means of Evolutionary Strategies (United States)

    Maravall, Darío; de Lope, Javier; Domínguez, Raúl

    In Multi-agent systems, the study of language and communication is an active field of research. In this paper we present the application of evolutionary strategies to the self-emergence of a common lexicon in a population of agents. By modeling the vocabulary or lexicon of each agent as an association matrix or look-up table that maps the meanings (i.e. the objects encountered by the agents or the states of the environment itself) into symbols or signals we check whether it is possible for the population to converge in an autonomous, decentralized way to a common lexicon, so that the communication efficiency of the entire population is optimal. We have conducted several experiments, from the simplest case of a 2×2 association matrix (i.e. two meanings and two symbols) to a 3×3 lexicon case and in both cases we have attained convergence to the optimal communication system by means of evolutionary strategies. To analyze the convergence of the population of agents we have defined the population's consensus when all the agents (i.e. the 100% of the population) share the same association matrix or lexicon. As a general conclusion we have shown that evolutionary strategies are powerful enough optimizers to guarantee the convergence to lexicon consensus in a population of autonomous agents.

  8. Mixed fertilizers incorporated in organic polimer matrix and pressed in tablets as means of enhancing the nutrients productive use in increased crop yields

    International Nuclear Information System (INIS)

    Gavriluta, I.; Borlan, Z.; Alexandrescu, A; Budoi, G.; Bireescu, L.; Bireescu, G.


    In view of increasing productive use of fertilizer nutrients in crops an admixture of brown coal dust containing up to 40 % carbon ammonia lignosulfonate with 50 % lignoles dry matter as binding agent were used to press water soluble fertilizer sources with a total of N+P 2 O 5 +K 2 O content of up to 26 % in tablets. These may be manufactured at different N:P 2 O 5 :K 2 O ratios as for instance 1:1:1; 1:0.75:0.50 etc. Brown coal and coal refuse dust were used as matrix for inclusion while lignosulfonates served for binding the ingredients when pressing them in tablets of 15-20 g dry mass each. These were tested in accurate field experiments to compare the agronomic effectiveness of equal amounts of NPK in tablets with equivalent rates of powdered sources of nutrients in the same chemical forms. NPK pressed in tablets were applied locally along the plant row, while the powdered mixed fertilizer have been thoroughly mixed in the ploughed layer. Accurate field experiments have pointed out the higher agronomical effectiveness of NPK pressed in tablets as compared to equal amounts of NPK powdered and thoroughly mixed into the ploughed layer of soil. Indicators were higher yield increases per nutrient unit and higher degrees of apparent productive use of nutrients in crops. Refs. 4 (author)

  9. Chinese culture and fertility decline. (United States)

    Wu, C; Jia, S


    Coale has suggested that cultural factors exert a significant influence on fertility reduction; countries in the "Chinese cultural circle" would be the first to show fertility decline. In China, the view was that traditional Chinese culture contributed to increased population. This paper examines the nature of the relationship between Chinese culture and fertility. Attention was directed to a comparison of fertility rates of developing countries with strong Chinese cultural influence and of fertility within different regions of China. Discussion was followed by an explanation of the theoretical impact of Chinese culture on fertility and direct and indirect beliefs and practices that might either enhance or hinder fertility decline. Emigration to neighboring countries occurred after the Qing dynasty. Fertility after the 1950s declined markedly in Japan, Singapore, Hong Kong, South Korea, Taiwan, and mainland China: all countries within the Chinese cultural circle. Other countries within the Chinese circle which have higher fertility, yet lower fertility than other non-Chinese cultural countries, are Malaysia, Thailand, and Indonesia. Within China, regions with similar fertility patterns are identified as coastal regions, central plains, and mountainous and plateau regions. The Han ethnic group has lower fertility than that of ethnic minorities; regions with large Han populations have lower fertility. Overseas Chinese in East Asian countries also tend to have lower fertility than their host populations. Chinese culture consisted of the assimilation of other cultures over 5000 years. Fertility decline was dependent on the population's desire to limit reproduction, favorable social mechanisms, and availability of contraception: all factors related to economic development. Chinese culture affects fertility reduction by affecting reproductive views and social mechanisms directly, and indirectly through economics. Confucianism emphasizes collectivism, self

  10. Conference considers low fertility. (United States)


    At present, at least 51 countries--representing 44% of the world's population--are showing below-replacement fertility rates. In some of these countries, where the number of new births is not adequate to replace aging populations, this trend is problematic. In other countries, most notably China, declining fertility has conferred significant benefits. At an Economic and Social Commission for Asia and the Pacific (ESCAP) Population Commission meeting held in New York in 1997, staff from China's State Statistical Bureau reported the country has a current total fertility rate of 1.8. The birth rate remains high, however, because of the large numbers of Chinese women in the 15-49 year reproductive age group (336 million in 1997). Also buffering the impact of a low fertility rate is a large labor surplus (130 million excess workers in rural China). To keep fertility below the replacement level, China plans to improve the quality of its family planning service, enhance poverty alleviation programs, and increase incentives for small families in rural areas. China's low fertility rate has provided an important impetus for economic development.

  11. [Fertility transition in Peru]. (United States)

    Ferrando, D; Aramburu, C E


    Data from national censuses and sample surveys are the basis for this examintion of differential fertility and the fertility transition in Peru. Changes in the level and structure of fertility in the 3 major geographic regions are compared, and the role of contraceptive usage and nuptiality changes in the fertility decline are analyzed. Peru's total fertility rate was estimated at 6.85 in 1965 and has since declined to 6.56 in 1965-70, 6.00 in 1970-75, 5.30 in 1975-80, 4.65 in 1980-85, and 4.00 in 1985-90. The fertility decline varied in intensity and timing in the geographic regions. A clear fertility decline began among upper and middle income groups in the principal cities in the 1960s, spreading gradually to the urban low income sectors. Not until the late 1970s did the fertility decline spread to the rest of the population, coinciding with the years of severe economic crisis. The urban total fertility rate declined from 6 to 3.77 during 1961-86, but rural fertility increased through 1972 to 8.12, before declining slightly to 7.62 in 1981 and more markedly to 6.65 in 1986. Sociocultural and economic differences between Peru's natural regions are appreciable, and account for the contrasts in fertility trends. The greatest changes occurred in metropolitan Lima, which already had relatively low fertility in 1961. Its total fertility rate declined 44% from 5.6 in 1961 to 3.13 in 1986. Fertility declined by slightly under 40% in the rest of the coast, by almost 25% in the jungle, and by scarcely 14% in the sierra. The total fertility rates in 1961 and 1986, respectively, were 6.38 and 4.13 on the coast, 6.64 and 6.45 in the highlands, and 7.92 and 5.97 in the lowlands. The fertility decline, especially in the lower classes, was a response initially to the process of cultural modernization which in slightly over 2 decades saw a profound transformation of Peru from a rural, Andean, illiterate, and agrarian society to an urban, coastal, literate, and commercial society

  12. A Class of Estimators for Finite Population Mean in Double Sampling under Nonresponse Using Fractional Raw Moments

    Directory of Open Access Journals (Sweden)

    Manzoor Khan


    Full Text Available This paper presents new classes of estimators in estimating the finite population mean under double sampling in the presence of nonresponse when using information on fractional raw moments. The expressions for mean square error of the proposed classes of estimators are derived up to the first degree of approximation. It is shown that a proposed class of estimators performs better than the usual mean estimator, ratio type estimators, and Singh and Kumar (2009 estimator. An empirical study is carried out to demonstrate the performance of a proposed class of estimators.

  13. Modelling strategic interventions in a population with a total fertility rate of 8.3: a cross-sectional study of Idjwi Island, DRC

    Directory of Open Access Journals (Sweden)

    Thomson Dana R


    Full Text Available Abstract Background Idjwi, an island of approximately 220,000 people, is located in eastern DRC and functions semi-autonomously under the governance of two kings (mwamis. At more than 8 live births per woman, Idjwi has one of the highest total fertility rates (TFRs in the world. Rapid population growth has led to widespread environmental degradation and food insecurity. Meanwhile family planning services are largely unavailable. Methods At the invitation of local leaders, we conducted a representative survey of 2,078 households in accordance with MEASURE DHS protocols, and performed ethnographic interviews and focus groups with key informants and vulnerable subpopulations. Modelling proximate determinates of fertility, we evaluated how the introduction of contraceptives and/or extended periods of breastfeeding could reduce the TFR. Results Over half of all women reported an unmet need for spacing or limiting births, and nearly 70% named a specific modern method of contraception they would prefer to use; pills (25.4% and injectables (26.5% were most desired. We predicted that an increased length of breastfeeding (from 10 to 21 months or an increase in contraceptive prevalence (from 1% to 30%, or a combination of both could reduce TFR on Idjwi to 6, the average desired number of children. Increasing contraceptive prevalence to 15% could reduce unmet need for contraception by 8%. Conclusions To meet women’s need and desire for fertility control, we recommend adding family planning services at health centers with NGO support, pursuing a community health worker program, promoting extended breastfeeding, and implementing programs to end sexual- and gender-based violence toward women.

  14. Libraries as a means for the integration of immigrant populations in Ávila province

    Directory of Open Access Journals (Sweden)

    María Jesús Romera Iruela


    Full Text Available Public libraries can be considered as suitable agents and places for the integration of immigrant population. Therefore, services and programs should be developed in order to give an adequate answer to their needs. This article provides some research findings for the information needs of immigrants at Ávila province. These needs are detected from three different perspectives: public libraries, educational centers, and immigrant associations. The data were collected, using ad-hoc questionnaires, in the districts and municipalities with largest immigrant presence. Several intercultural actions directed to the integration of this population are suggested in this research. Thus, amongst others, the need of a Web site with thematic information on the design of cooperative programs on intercultural education between public libraries and scholar libraries, involving both parents of immigrant students and immigrants associations


    Energy Technology Data Exchange (ETDEWEB)

    Rea, N. [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, NL-1090 GE Amsterdam (Netherlands); Gullón, M.; Pons, J. A.; Miralles, J. A. [Departament de Fisica Aplicada, Universitat d’Alacant, Ap. Correus 99, E-03080 Alacant (Spain); Perna, R. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Dainotti, M. G. [Physics Department, Stanford University, Via Pueblo Mall 382, Stanford, CA (United States); Torres, D. F. [Instituto de Ciencias de l’Espacio (ICE, CSIC-IEEC), Campus UAB, Carrer Can Magrans s/n, E-08193 Barcelona (Spain)


    A large fraction of Gamma-ray bursts (GRBs) displays an X-ray plateau phase within <10{sup 5} s from the prompt emission, proposed to be powered by the spin-down energy of a rapidly spinning newly born magnetar. In this work we use the properties of the Galactic neutron star population to constrain the GRB-magnetar scenario. We re-analyze the X-ray plateaus of all Swift GRBs with known redshift, between 2005 January and 2014 August. From the derived initial magnetic field distribution for the possible magnetars left behind by the GRBs, we study the evolution and properties of a simulated GRB-magnetar population using numerical simulations of magnetic field evolution, coupled with Monte Carlo simulations of Pulsar Population Synthesis in our Galaxy. We find that if the GRB X-ray plateaus are powered by the rotational energy of a newly formed magnetar, the current observational properties of the Galactic magnetar population are not compatible with being formed within the GRB scenario (regardless of the GRB type or rate at z = 0). Direct consequences would be that we should allow the existence of magnetars and “super-magnetars” having different progenitors, and that Type Ib/c SNe related to Long GRBs form systematically neutron stars with higher initial magnetic fields. We put an upper limit of ≤16 “super-magnetars” formed by a GRB in our Galaxy in the past Myr (at 99% c.l.). This limit is somewhat smaller than what is roughly expected from Long GRB rates, although the very large uncertainties do not allow us to draw strong conclusion in this respect.

  16. Meaning given to spirituality, religiousness and personal beliefs: explored by a sample of a Norwegian population. (United States)

    Torskenæs, Kristina B; Kalfoss, Mary H; Sæteren, Berit


    The aim of this article is to explore the meanings given to the words 'spirituality', 'religiousness' and 'personal beliefs' by a Norwegian sample of healthy and sick individuals. Studies show that a high proportion of nurses do not identify the spiritual needs of their patients, even if the nurses are educated to give care for the whole person, including the spiritual dimension. This study used an exploratory qualitative design. Qualitative data generated from six focus groups were collected in southeast Norway. The focus groups were comprised of three groups of health professionals (n = 18) and three groups of patients from different institutions (n = 15). The group discussions revealed that the meanings of spirituality, religiousness and personal beliefs were interwoven, and the participants had difficulty in finding a common terminology when expressing their meanings. Many of the participants described the spiritual dimension with feelings of awe and respect. They were dependent on spirituality in order to experience balance in life and cope with life crises. The themes and categories identified by the focus group discussion highlights that spirituality ought to be understood as a multilayered dimension. An appreciation of the spiritual dimension and it's implication in nursing may help to increase health and decrease suffering. Health professionals need to be cognizant of their own sense of spirituality to investigate the spiritual needs among their patients. This study's focus group discussions helped both patients and health professionals to improve their knowledge regarding the meanings given to the spiritual dimension. © 2015 John Wiley & Sons Ltd.

  17. Prediction of bull fertility. (United States)

    Utt, Matthew D


    Prediction of male fertility is an often sought-after endeavor for many species of domestic animals. This review will primarily focus on providing some examples of dependent and independent variables to stimulate thought about the approach and methodology of identifying the most appropriate of those variables to predict bull (bovine) fertility. Although the list of variables will continue to grow with advancements in science, the principles behind making predictions will likely not change significantly. The basic principle of prediction requires identifying a dependent variable that is an estimate of fertility and an independent variable or variables that may be useful in predicting the fertility estimate. Fertility estimates vary in which parts of the process leading to conception that they infer about and the amount of variation that influences the estimate and the uncertainty thereof. The list of potential independent variables can be divided into competence of sperm based on their performance in bioassays or direct measurement of sperm attributes. A good prediction will use a sample population of bulls that is representative of the population to which an inference will be made. Both dependent and independent variables should have a dynamic range in their values. Careful selection of independent variables includes reasonable measurement repeatability and minimal correlation among variables. Proper estimation and having an appreciation of the degree of uncertainty of dependent and independent variables are crucial for using predictions to make decisions regarding bull fertility. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Some relations among cultural traditions, nuptiality and fertility. (United States)

    Coale, A J


    Demographic transition is a period characterized by changes in mortality and fertility that accompany modernization and economic development. Typical features of age at first marriage among populations in different stages of demographic transition are described including the changes in age at marriage, the association between marriage age changes and fertility control, and the role of cultural and traditional behavior in influencing age at marriage and initiation of fertility control. In the Western model, there was a late age of marriage for women between 23 and 28 years old, and a high proportion of women who remain single until 50 years old (10-25%). The Eastern European model was one of moderately early marriage (mean age 19-22) and a small proportion remaining single (2-5%). The third model was Asian and African with early (mean age of 18 years) and universal marriage (1% unmarried). The reduction in number married was associated with reduced fertility. The differences between the Eastern and Western models were in household composition. In premodern societies, any fertility control present was governed by custom and limited biomedical influences such as duration of breast feeding and sexual abstention following a birth. These practices were not considered deliberate fertility control. The mean age of marriage in India was 14 years until 1941 and slowly reached 18.4 years in 1981. Fertility did not begin to decline until after 1960. Examples are given of the close association between marital fertility that is voluntary controlled and mean age at marriage. The influences of culture and traditions on the association between mean age of marriage and voluntary fertility control are shown by examples from the Soviet Union. The eastern part of the Soviet Union experienced a rise in mean age of marriage and an unsustained decline in marital fertility similar to that in China. There were also similarities in nuptiality and fertility between other areas in the Soviet

  19. Effect of the SOS response on the mean fitness of unicellular populations: a quasispecies approach. (United States)

    Kama, Amit; Tannenbaum, Emmanuel


    The goal of this paper is to develop a mathematical model that analyzes the selective advantage of the SOS response in unicellular organisms. To this end, this paper develops a quasispecies model that incorporates the SOS response. We consider a unicellular, asexually replicating population of organisms, whose genomes consist of a single, double-stranded DNA molecule, i.e. one chromosome. We assume that repair of post-replication mismatched base-pairs occurs with probability , and that the SOS response is triggered when the total number of mismatched base-pairs is at least . We further assume that the per-mismatch SOS elimination rate is characterized by a first-order rate constant . For a single fitness peak landscape where the master genome can sustain up to mismatches and remain viable, this model is analytically solvable in the limit of infinite sequence length. The results, which are confirmed by stochastic simulations, indicate that the SOS response does indeed confer a fitness advantage to a population, provided that it is only activated when DNA damage is so extensive that a cell will die if it does not attempt to repair its DNA.

  20. Contributions to the genetic and mean bone-marrow doses of the Australian population from radiological procedures

    International Nuclear Information System (INIS)

    Swindon, T.N.; Morris, N.D.


    The results of a national survey of radiological procedures used for diagnosis and therapy in medicine, dentistry and chiropracty are reviewed. Statistical data for the distribution and frequency of various procedures in Australian hospitals and practices are summarised, together with their associated radiation doses. Annual genetically significant and mean bone-marrow doses to the Australian population arising from these procedures are derived for the survey year of 1970. Values of 176 microgray and 651 microgray for the annual (per capita) genetic and mean bone-marrow doses respectively are reported. These compare closely with corresponding estimates in other countries with similar medical practices to those in Australia

  1. Fertility desires and fertility outcomes. (United States)

    Bracher, M; Santow, G


    An Australian 1-in-1000 national probability sample conducted in 1986 yielded 2547 women aged 20-59 who provided detailed life histories on marital unions, childbearing, and contraception. Age specific fertility rates, desired family size, differentials in desired family size, desired fertility and achieved fertility, and sequential family building are examined. The results indicate that the desired family size at 1st marriage has declined only slightly over the past 30 years. 3 children are generally desired, and ver few desire 2. The constance of fertility desires in contrasted with the fertilitydecline to below replacement levels. Several reasons are suggested for the desired family size: the desire is for a family size within the family tradition and modified by the desire to have 1 of each sex, the desire reflects less on intentions but more on normative pressure to become a parent. Marrying is self selecting on the desire for a traditional family of at least 2 children. There is a rising age at marriage as well as a decline in marriages. Desired family size exceeds completed fertility. Period factors and personal circumstances affect fertility intentions. Future inquires should explore the multiple factors relating to fertility, rather than in comparing fertility desires and actual fertility. The data collected on age specific fertility were comparable to official estimates. The fertility decline was evidenced in all groups except teenagers. The decline was nearly 50% for those 20-24 years between the 1050's-80's, 33% for ages 25-29. Marriage patterns explain this decline in part. Between 1971-76, women aged 20-25 were married 37 months out of 60 months in 1971-76 versus 25 out of 60 months in 1981-86. Within the 25 year age group, marital fertility has declined and unmarried fertility, which is low, has risen, Women in a marital union of any kind has remained stable. Fertility within de facto unions, which is lower than within marriage, is higher than

  2. Public support for river restoration funding in relation to local river ecomorphology, population density, and mean income (United States)

    SchläPfer, Felix; Witzig, Pieter-Jan


    In 1997, about 140,000 citizens in 388 voting districts in the Swiss canton of Bern passed a ballot initiative to allocate about 3 million Swiss Francs annually to a canton-wide river restoration program. Using the municipal voting returns and a detailed georeferenced data set on the ecomorphological status of the rivers, we estimate models of voter support in relation to local river ecomorphology, population density, mean income, cultural background, and recent flood damage. Support of the initiative increased with increasing population density and tended to increase with increasing mean income, in spite of progressive taxation. Furthermore, we found evidence that public support increased with decreasing "naturalness" of local rivers. The model estimates may be cautiously used to predict the public acceptance of similar restoration programs in comparable regions. Moreover, the voting-based insights into the distribution of river restoration benefits provide a useful starting point for debates about appropriate financing schemes.

  3. Common meanings of good and bad sleep in a healthy population sample. (United States)

    Dickerson, Suzanne S; Klingman, Karen J; Jungquist, Carla R


    The study's purpose was to understand the common meanings and shared practices related to good and bad sleep from narratives of a sample of healthy participants. Interpretive phenomenology was the approach to analyze narratives of the participants' everyday experiences with sleep. Participants were interviewed and asked to describe typical good and bad nights' sleep, what contributes to their sleep experience, and the importance of sleep in their lives. Team interpretations of narratives identified common themes by consensus. Medium sized city in New York State (upper west region). A sample of 30 healthy participants were from a parent study (n=300) on testing the sleep questions from the Behavioral Risk Factor Surveillance System from the Centers for Disease Control and Prevention. Interpretations of good and bad sleep. Participants described similar experiences of good and bad sleep often directly related to their ability to schedule time to sleep, fall asleep, and maintain sleep. Worrying about life stresses and interruptions prevented participants from falling asleep and staying asleep. Yet, based on current life priorities (socializers, family work focused, and optimum health seekers), they had differing values related to seeking sleep opportunities and strategizing to overcome challenges. The participants' priorities reflected the context of their main concerns and stresses in life that influenced the importance given to promoting sleep opportunities. Public health messages tailored to life priorities could be developed to promote healthy sleep practices. Copyright © 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

  4. The fertility decline in Kenya. (United States)

    Robinson, W C; Harbison, S F


    In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key

  5. Dark-matter halo mergers as a fertile environment for low-mass Population III star formation

    DEFF Research Database (Denmark)

    Bovino, S.; Latif, M. A.; Grassi, Tommaso


    While Population III (Pop III) stars are typically thought to be massive, pathways towards lower mass Pop III stars may exist when the cooling of the gas is particularly enhanced. A possible route is enhanced HD cooling during the merging of dark-matter haloes. The mergers can lead to a high ioni...

  6. Marriage season, promptness of successful pregnancy and first-born sex ratio in a historical natural fertility population - evidence for sex-dependent early pregnancy loss? (United States)

    Nonaka, K.; Desjardins, Bertrand; Charbonneau, Hubert; Légaré, Jacques; Miura, Teiji

    We investigated population-based vital records of the seventeenth and eighteenth century French Canadian population to assess the effects of marriage season on the outcome of the first births under natural fertility conditions (n=21,698 marriages). Promptness of the first successful conception after marriage differed according to marriage season; the proportion of marriages with a marriage-first birth interval of 8.0-10.0 months was lowest (34%) for marriages in August-October (P=0.001). Although the male/female sex ratio of the babies born with an interval of 8.0-10.0 months was generally higher (1.10) than those with an interval of 10.0-24.0 months (1.05), the marriages in August-October resulted in a significantly reduced sex ratio (0.96) among only the prompt conceptions (P=0.026). We discuss whether this seasonal reduction of the sex ratio could be partly explained by a clustered pregnancy loss of male zygotes in early pregnancy.

  7. Premarital fertility in Namibia: trends, factors and consequences. (United States)

    Garenne, Michel; Zwang, Julien


    Premarital fertility, defined as fertility before first marriage, was found to be highly prevalent in Namibia. According to data from the 1992 and 2000 DHS surveys, the proportion of premarital births was 43% for all births, and 60% for the first birth. This seemed to be primarily due to a late mean age at first marriage (26.4 years) and low levels of contraception before first marriage. Data were analysed using a variety of demographic methods, including multiple decrement life table and multivariate logistic models. Major variations were found by ethno-linguistic groups: Herero and Nama/Damara had the highest levels of premarital fertility (above 60%); Ovambo and Lozi had intermediate levels of premarital fertility (around 40%); Kavongo and San appeared to have kept a more traditional behaviour of early marriage and low levels of premarital fertility (around 20%). The largest ethno-linguistic group, the Ovambo, were in a special situation, with fast increasing age at marriage and average level of premarital fertility. Whites and mixed races also differed, with Afrikaans-speaking groups having a behaviour closer to the average, whereas other Europeans had less premarital fertility despite an average age at marriage. Ethnic differences remained stable after controlling for various socioeconomic factors, such as urbanization, level of education, wealth, access to mass media, and religion. Results are discussed in light of the population dynamics and political history of Namibia in the 20th century.

  8. On the pace of fertility decline in sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    David Shapiro


    Full Text Available Background: This descriptive finding examines the comparative pace of fertility decline in sub-Saharan Africa, relative to Asia, Latin America and the Caribbean, and Northern Africa. Objective: We seek to determine if fertility decline has been slower in sub-Saharan Africa than elsewhere in the developing world. Methods: United Nations 2017 estimates of national fertility are used in assessing the comparative pace of fertility decline, and the four regions are compared in terms of how far they are into their fertility transition. Results: The data shows clearly that fertility decline in sub-Saharan Africa, still at a comparatively early stage, has been considerably slower than the earlier declines in Asia, Latin America and the Caribbean, and Northern Africa at comparable stages of the transition, and displays less within-region heterogeneity than the transitions in these other regions. Conclusions: The slower pace of fertility decline in sub-Saharan Africa, in conjunction with the high current fertility levels in the region, means that in the absence of policies seeking to accelerate fertility decline, sub-Saharan Africa will continue to experience rapid population growth that in turn will constrain its development. Contribution: Presentation of data in a novel way (Figures 2‒4, and associated calculations unambiguously demonstrates the slow pace of fertility decline in sub-Saharan Africa compared with other regions of the world.

  9. Fertility preservation for girls and young women with cancer: population-based validation of criteria for ovarian tissue cryopreservation. (United States)

    Wallace, W Hamish B; Smith, Alice Grove; Kelsey, Thomas W; Edgar, Angela E; Anderson, Richard A


    Ovarian tissue cryopreservation with later reimplantation has been shown to preserve fertility in adult women, but this approach remains unproven and experimental in children and adolescents. We aimed to assess the use of the Edinburgh selection criteria for ovarian tissue cryopreservation in girls and young women with cancer to determine whether we are offering this invasive procedure to the patients who are most at risk of premature ovarian insufficiency. Cryopreservation of ovarian tissue has been selectively offered to girls and young women with cancer who met the Edinburgh selection criteria since 1996. Between Jan 1, 1996, and June 30, 2012, 410 female patients younger than 18 years at diagnosis were treated for cancer (including leukaemia and brain tumours) at the Edinburgh Children's Cancer Centre, which serves the whole South East of Scotland region. We determined the ovarian status of these patients from review of clinical records and classified them as having premature ovarian insufficiency or not, or as unable to be determined. Patients younger than 12 years at time of data cutoff (Jan 31, 2013) were excluded from the analysis. 34 (8%) of the 410 patients met the Edinburgh selection criteria and were offered ovarian tissue cryopreservation before starting cancer treatment. 13 patients declined the procedure and 21 consented, and the procedure was completed successfully in 20 patients. Of the 20 patients who had ovarian tissue successfully cryopreserved, 14 were available for assessment of ovarian function. Of the 13 patients who had declined the procedure, six were available for assessment of ovarian function. Median age at the time of follow-up for the 20 assessable patients was 16·9 years (IQR 15·5-21·8). Of the 14 assessable patients who had successfully undergone ovarian cryopreservation, six had developed premature ovarian insufficiency at a median age of 13·4 years (IQR 12·5-14·6), one of whom also had a natural pregnancy. Of the six

  10. First birth Caesarean section and subsequent fertility: a population-based study in the USA, 2000-2008. (United States)

    Kjerulff, K H; Zhu, J; Weisman, C S; Ananth, C V


    for the pregnancy and childbirth complications had little effect on the RR of not having a subsequent live birth (RR = 1.15, 95% CI: 1.11-1.19). We were unable to distinguish between women who did not have a subsequent live birth and those who moved out of the state, which may have introduced a selection bias if those who had Caesarean births were more likely to emigrate than those who delivered vaginally. In addition we were unable to measure pre-pregnancy body mass index, weight gain during pregnancy and prior infertility, which would have been helpful in our efforts to reduce selection bias. The results of this study provide further corroboration of previous studies that have reported reduced fertility subsequent to Caesarean section in comparison with vaginal delivery. This study was funded by the US National Institute of Child Health and Human Development (NICHD, R01-HD052990). No competing interests are declared.

  11. Knowledge regarding fertility preservation in cancer patients: a population-based survey among Brazilian people during the Pink October awareness event. (United States)

    Chehin, Mauricio B; Bonetti, Tatiana Cs; Serafini, Paulo C; Motta, Eduardo LA


    The aim of this study was to assess the knowledge about the risk of infertility in cancer patients after treatment, and the options for fertility preservation based on a survey carried out during the 2013 Pink October campaign. This survey was carried out during the 2013 Pink October event in the most important public park of São Paulo, Brazil. Approximately 900 people expressed interest in learning about breast cancer prevention and fertility preservation by participating in workshops, and 242 people filled out a questionnaire. Most of the respondents (78.5%) were women, and one-fourth (25%) had at least one relative with gynecological cancer. Among women over 40 years of age, 86.3% had been screened for breast cancer at some point. However, few participants (34.0%) were aware that cancer treatment can lead to infertility or had heard about fertility preservation options (22.0%). Having a relative with cancer did not influence their knowledge about fertility preservation (22.4% versus 21.3%; p=0.864). However, a higher educational level was significantly associated with more knowledge about the effects of cancer on fertility and options for fertility preservation. The majority of participants did not have knowledge about the impact of oncologic treatment on fertility and did not know that there are options to preserve fertility in cancer patients. Awareness of infertility risk factors is an essential first step to safeguard future fertility, and therefore, more educational initiatives are needed to spread knowledge about oncofertility.

  12. Communication and coping as predictors of fertility problem stress: cohort study of 816 participants who did not achieve a delivery after 12 months of fertility treatment

    DEFF Research Database (Denmark)

    Schmidt, L; Holstein, B E; Christensen, Ulla


    BACKGROUND: We investigated coping strategies and communication strategies as predictors of fertility problem stress 12 months after start of fertility treatment. METHODS: We used a prospective, longitudinal cohort design including 2250 people beginning fertility treatment with a 12-month follow......-up. Data were based on self-administered questionnaires measuring communication with partner and with other people, coping strategies: active-avoidance coping, active-confronting coping, passive-avoidance coping, meaning-based coping, and fertility problem stress. The study population included those...... participants (n = 816, men and women) who had not achieved pregnancy by assisted reproduction or delivery at follow-up. RESULTS: Among both men and women, difficulties in partner communication predicted high fertility problem stress (odds ratio for women, 3.47, 95% confidence interval 2.09-5.76; odds ratio...

  13. Fertility outcomes in asthma

    DEFF Research Database (Denmark)

    Gade, Elisabeth Juul; Thomsen, Simon Francis; Lindenberg, Svend


    Evidence is increasing of an association between asthma and aspects of female reproduction. However, current knowledge is limited and furthermore relies on questionnaire studies or small populations. In a prospective observational cohort study to investigate whether time to pregnancy, the number...... of fertility treatments, and the number of successful pregnancies differ significantly between women with unexplained infertility with and without asthma.245 women with unexplained infertility (aged 23-45 years) underwent questionnaires and asthma and allergy testing while undergoing fertility treatment. 96...... women entering the study had either a former doctor's diagnosis of asthma or were diagnosed with asthma when included. After inclusion they were followed for a minimum of 12 months in fertility treatment, until they had a successful pregnancy, stopped treatment, or the observation ended.The likelihood...


    Zafeiris, Konstantinos N; Kaklamani, Stamatina


    This study aimed to delineate temporal trends and differentials of completed fertility and their relationship with some characteristics of the marriage system in specific anthropological populations of northern Greece. The analysis was based on the life history of quinquennial and decennial birth cohorts of married women born in the 20th century who reproduced solely within the settlements studied. The variables studied were: children ever born, mean age of mother at first marriage, mean age of mother at first child (live birth), mean age of mother at last child and reproductive span. The results indicated that there were significant differences in the demographic characteristics of marriage and that there was an ongoing fertility transition in the 20th century in the populations studied. The mechanism of fertility decline was connected with the gradual reduction of the mean age of the mother at last child, the parallel decrease in the mean age at childbearing and a shortening of the reproductive span. Fertility levels at all times maintained a dynamic character imposed by local cultural, economic and social structures, which, in turn, were part of broader national and international structures, in all the populations studied. A strong trend of convergence of fertility levels was observed among the populations studied.

  15. Women's Status and Fertility in Developing Countries: Son Preference and Economic Security. World Bank Staff Working Papers No. 682 and Population and Development Series No. 7. (United States)

    Cain, Mead

    The relationship between women's status--defined in terms of the degree to which they are economically dependent on men--and fertility in developing nations is examined. After a brief introduction, part 2 discusses a particular theoretical perspective regarding fertility determinants in developing countries and explores the implications of women's…

  16. Do cycle disturbances explain the age-related decline of female fertility? Cycle characteristics of women aged over 40 years compared with a reference population of young women.

    NARCIS (Netherlands)

    Zonneveld, P. van; Scheffer, G.J.; Broekmans, F.J.; Blankenstein, M.A.; Jong, F.H. de; Looman, C.W.; Habbema, J.D.F.; Velde, E.R. te


    BACKGROUND: The cause of declining fertility with age, in women who still have regular menstrual cycles, is not clear. METHODS: Follicle development, endometrial growth and hormonal patterns were evaluated in cycles of older women (aged 41-46 years; n = 26) who previously were normally fertile, and

  17. Seasonal changes in physiological performance in wild Clarkia xantiana populations: Implications for the evolution of a compressed life cycle and self-fertilization. (United States)

    Dudley, Leah S; Hove, Alisa A; Emms, Simon K; Verhoeven, Amy S; Mazer, Susan J


    One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season drought. Here, we test two fundamental assumptions of this hypothesis in Clarkia xantiana: (1) that a seasonal decline in precipitation causes an increase in drought stress and (2) that this results in changes in physiological performance, reflecting these deteriorating conditions. We examined seasonal and interannual variation in abiotic environmental conditions (estimated by ambient temperature, relative humidity, predawn leaf water potentials, and carbon isotope ratios) and physiological traits (photosynthesis, conductance, transpiration, instantaneous water-use efficiency, ascorbate peroxidase and glutathione reductase activities, quantum yield of photosystem II, PSII potential efficiency) in field populations of C. xantiana in 2009 and 2010. In both years, plants experienced intensifying drought across the growing season. Gas exchange rates decreased over the growing season and were lower in 2009 (a relatively dry year) than in 2010, suggesting that the temporal changes from early to late spring were directly linked to the deteriorating environmental conditions. Seasonal declines in transpiration rate may have increased survival by protecting plants from desiccation. Concomitant declines in photosynthetic rate likely reduced the availability of resources for seed production late in the season. Thus, the physiological patterns observed are consistent with the conditions required for the drought escape hypothesis. © 2015 Botanical Society of America, Inc.

  18. Radioactivity in Chemical Fertilizers

    International Nuclear Information System (INIS)

    Jankovic, M.; Nikolic, J.; Pantelic, G.; Rajacic, M.; Sarap, N.; Todorovic, D.


    The fertilizers are essential in agriculture as they supply nutrients to the farming fields. One of the sources of radioactivity other than those of natural origin is mainly due to extensive use of fertilizers. The concentrations of natural radionuclides, 40K, 226Ra, 238U and 235U in different chemical fertilizers, which are part of the regular control of imported goods from the border crossing were analyzed using gamma spectrometry with a high purity germanium (HPGe) detector, relative efficiency 20 %, in order to assess the implications of the extended use of chemical fertilizers. Measurements were performed at Vinca Institute, Radiation and Environmental Protection Department. The obtained results show remarkable wide variations in the radioactivity contents of different samples. The mean (ranges) of specific activities for gamma activity of those fertilizer samples for 40K, 226Ra, 238U and 235U are 4857 (23 - 12 324) Bq/kg, 87 (4-393) Bq/kg, 220 (26-1145) Bq/kg and 15 (1.6-53) Bq/kg, respectively. The radium equivalent activity (Ra eq ) as well as the external absorbed gamma dose rate (D) for all samples was also calculated.(author)

  19. High coffee population density to improve fertility of an oxisol Densidade populacional de cafeeiros para melhorar a fertilidade de um latossolo

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Pavan


    Full Text Available The objective of this work was to evaluate the effect of coffee (Coffea arabica L. population densities on the chemical and microbiological properties of an Oxisol. The work was carried out on soil samples of 0-20 cm depth originated from an experimental site which had been used for coffee tree spacing studies during 15 years, in Paraná State, Brazil. Eight coffee tree populations were evaluated: 7143, 3571, 2381, 1786, 1429, 1190, 1020, and 893 trees/ha. Increasing plant population increased soil pH, exchangeable Ca, Mg, K, extractable P, organic carbon, moisture content and coffee root colonization by vesicular arbuscular mycorrhizal fungi, and decreased exchangeable Al and microbial biomass. Such results were attributed to better erosion control, improved plant residue management and nutrient cycling, and decreased leaching losses. Increasing coffee tree population per unit of area has shown to be an important reclamation recuperation strategy for improving fertility of the acid soils in Paraná, Brazil.O objetivo deste trabalho foi verificar os efeitos de diferentes densidades de população de cafeeiros (Coffea arabica L. nas propriedades químicas, físicas e microbiológicas do solo. Amostras de um Latossolo foram coletadas na profundidade 0-20 cm em um experimento de campo onde estavam sendo avaliadas diferentes populações de cafeeiros. Os tratamentos foram 7.143, 3.571, 2.381, 1.786, 1.429, 1.190, 1.020 e 893 covas/ha. Os resultados demonstraram que o aumento da população de plantas por unidade de área aumentou o pH, o Ca, o Mg e o K trocáveis, o P disponível, o carbono orgânico, o teor de umidade e a colonização radicular por micorrizas, e diminuiu o Al trocável e a biomassa microbiana. Foram considerados como causas da melhoria da fertilidade do solo, sob cafeeiros adensados, o adequado controle da erosão, o correto manejo dos resíduos vegetais e a baixa lixiviação dos íons. O manejo da população de cafeeiros pode

  20. The fertility of recent migrants to England and Wales

    Directory of Open Access Journals (Sweden)

    James Robards


    Full Text Available Background: Estimates of fertility for the overseas-born based on the period Total Fertility Rate (TFR suggest that levels of childbearing are significantly higher among foreign-born women than women born in the UK. However, migration and timing of subsequent family formation mean that aggregate measures of fertility based on period TFRs may not be a useful indicator of the likely completed family size that migrant women will have at the end of their reproductive lives. Objective: The paper quantifies childbearing according to duration since migration among female migrants to England and Wales arriving between 2001 and 2011, and examines how these patterns differ according to age at arrival and country of birth. Methods: Data from the Office for National Statistics Longitudinal Study, a 1Š sample of the population of England and Wales, are used to identify the reported date of arrival in the UK and to estimate childbearing prior to and subsequent to arrival. Results: Fertility rates peak in the first one to four years subsequent to arrival among migrants from Pakistan and Bangladesh. Migrants from India and Poland show a delay in childbearing after migration to England and Wales, and lower fertility rates compared to migrants from Pakistan and Bangladesh, who show high fertility after migration at least for the first five years. Conclusions: There are large differences in the timing of fertility among migrants according to age at arrival and migrant country of origin, which are likely to be related to the reason for migration. Tempo distortions among some migrant groups mean that the period TFR is not necessarily a useful summary measure of the likely lifetime fertility of migrant groups.

  1. Semen quality in sub-fertile range for a significant proportion of young men from the general German population: a co-ordinated, controlled study of 791 men from Hamburg and Leipzig

    DEFF Research Database (Denmark)

    Paasch, U.; Salzbrunn, A.; Glander, H.J.


    Population studies have shown that a high proportion of Nordic men may have so poor semen quality that they can be classified as sub-fertile according to international standards. A question is whether the Nordic data are specific for the Nordic countries or they should be seen as an expression of...... men seem to have impaired semen quality that may reduce their natural fertility. However, it remains to be investigated to what extent poor semen quality contributes to the low German fertility rates Udgivelsesdato: 2008/4......Population studies have shown that a high proportion of Nordic men may have so poor semen quality that they can be classified as sub-fertile according to international standards. A question is whether the Nordic data are specific for the Nordic countries or they should be seen as an expression...... of a general trend in Europe. We therefore carried out a prospective study of semen quality of young men raised in the former East Germany (Leipzig) and West Germany (Hamburg). To enable inter-regional comparisons, we utilized a common European research protocol previously used in studies in the Nordic...

  2. [Evaluation of thermal comfort in a student population: predictive value of an integrated index (Fanger's predicted mean value]. (United States)

    Catenacci, G; Terzi, R; Marcaletti, G; Tringali, S


    Practical applications and predictive values of a thermal comfort index (Fanger's PRV) were verified on a sample school population (1236 subjects) by studying the relationships between thermal sensations (subjective analysis), determined by means of an individual questionnaire, and the values of thermal comfort index (objective analysis) obtained by calculating the PMV index individually in the subjects under study. In homogeneous conditions of metabolic expenditure rate and thermal impedence from clothing, significant differences were found between the two kinds of analyses. At 22 degrees C mean radiant and operative temperature, the PMV values averaged 0 and the percentage of subjects who experienced thermal comfort did not exceed 60%. The high level of subjects who were dissatisfied with their environmental thermal conditions confirms the doubts regarding the use of the PMV index as a predictive indicator of thermal comfort, especially considering that the negative answers were not homogeneous nor attributable to the small thermal fluctuations (less than 0.5 degree C) measured in the classrooms.

  3. Will sex selection reduce fertility? (United States)

    Leung, S F


    Population control is one of the primary policies applied against poverty in many low income countries. The widespread prevalence of son preference in some countries such as China and India, however, works against any reduction of fertility. This is so because parents often continue to have children until they obtain the number of sons which they desire. The bias against girls has also led to higher abortion and mortality rates of female children. It is frequently argued that if sex selection methods are made available to parents so that they can control the gender of their children, population growth would be lowered and women's welfare improved. The author investigates both theoretically and numerically the impact of sex selection on fertility. A static quantity-quality model of fertility is used to compare fertility choices when parents cannot choose the gender of children versus a situation in which parents can choose gender. Empirical data are drawn from the 1976 Malaysian Family Life Survey. Analysis found that whether sex selection reduces fertility depends upon the second and third derivatives of the utility function and the child expenditure function. A numerical dynamic analysis is also presented. The simulation shows, using empirical dynamic models of fertility and the Monte Carlo integration technique, that sex selection on the firstborn child among the Chinese in Malaysia could reduce fertility by about 3%.

  4. Fertility and the economy. (United States)

    Becker, G S


    Fertility and the economy is examined in the context of the Malthusian question about the links between family choices and longterm economic growth. Micro level differences are not included not are a comprehensive range of economic or determinant variables. Specific attention is paid to income and price effects, the quality of children, overlapping generations, mortality effects, uncertainty, and economic growth. Fertility and the demand for children in linked to parental incomes and the cost of rearing children, which is affected by public policies that change the costs. Demand is also related to child and adult mortality, and uncertainty about sex of the child. Fertility in one generation affects fertility in the next. Malthusian and neoclassical models do not capture the current model of modern economies with rising income/capita and human and physical capital, extensive involvement of married women in the labor force, and declining fertility to very low levels. In spite of the present advances in firm knowledge about the relationships between fertility and economic and social variables, there is still much greater ignorance of the interactions. The Malthusian utility function that says fertility rises and falls with income did hold up to 2 centuries of scrutiny, and the Malthusian inclusion of the shifting tastes in his analysis could be translated in the modern context to include price of children. The inclusion of net cost has significant consequences, i.e., rural fertility can be higher because the cost of rearing when children contribute work to maintaining the farm is lower than in the city. An income tax deduction for children in the US reduces cost. Economic growth raises the cost of children due the time spent on child care becoming more valuable. The modern context has changed from Malthusian time, and the cost of education, training, and medical care is relevant. The implication is that a rise in income could reduce the demand for children when

  5. Fertility counseling and preservation practices in youth with lupus and vasculitis undergoing gonadotoxic therapy. (United States)

    Nahata, Leena; Sivaraman, Vidya; Quinn, Gwendolyn P


    To assess fertility counseling and preservation practices among children, adolescents, and young adults with rheumatic diseases undergoing cyclophosphamide (CTX) treatment. Retrospective chart review (2006-2016). Academic pediatric center. Male and female patients with systemic lupus erythematosus, Wegener's granulomatosis/granulomatosis with polyangiitis, or other vaculitides, receiving CTX treatment. None. Documentation of fertility counseling and fertility preservation. A total of 58 subjects met the inclusion criteria; 5 were excluded due to incomplete records, thus N = 53. Of these 75% were female (N = 40). Median age was 14 years at diagnosis and 15 years at first CTX treatment. A total of 51% of subjects (69% of males and 45% of females) had no documentation about potential fertility loss before CTX treatment. Among females where fertility counseling was documented, the only fertility preservation option discussed was leuprolide acetate (LA), which was pursued in all of these cases. Of 13 males (77% postpubertal), 3 were offered sperm banking, of whom 2 declined and the other attempted after treatment began and was azoospermic. Of 53 patients, 1 was referred to a fertility specialist. Mean cumulative CTX dose was 9.2 g in males and 8 g in females. Based on these findings, increasing awareness about infertility risk, fertility preservation options, and referral to fertility specialists is needed among pediatric rheumatologists. Prospective studies are needed to assess fertility outcomes in this patient population (including effectiveness of LA with regard to pregnancy rates [PRs]), as well as barriers/facilitators to fertility counseling and fertility preservation. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Fertility and money in an OLG model


    Luciano Fanti


    We extend the two-period-lived-agent overlapping generations model with endogenous fertility and demand for money to understand whether and how the introduction of a money sector modifies what we have so far learned about fertility behaviours. It is shown that the existence of money may tend to exacerbate existing problems of either under-population or over-population.

  7. Increasing Efficiency of Soil Fertility Map for Rice Cultivation Using Fuzzy Logic, AHP and GIS

    Directory of Open Access Journals (Sweden)

    javad seyedmohammadi


    Full Text Available Introduction: With regard to increasing population of country, need to high agricultural production is essential. The most suitable method for this issue is high production per area unit. Preparation much food and other environmental resources with conservation of biotic resources for futures will be possible only with optimum exploitation of soil. Among effective factors for the most production balanced addition of fertilizers increases production of crops higher than the others. With attention to this topic, determination of soil fertility degree is essential tobetter use of fertilizers and right exploitation of soils. Using fuzzy logic and Analytic Hierarchy Process (AHP could be useful in accurate determination of soil fertility degree. Materials and Methods: The study area (at the east of Rasht city is located between 49° 31' to 49° 45' E longitude and 37° 7' to 37° 27' N latitude in north of Guilan Province, northern Iran, in the southern coast of the Caspian sea. 117 soil samples were derived from0-30 cm depth in the study area. Air-dried soil samples were crushed and passed through a 2mm sieve. Available phosphorus, potassium and organic carbon were determined by sodium bicarbonate, normal ammonium acetate and corrected walkly-black method, respectively. In the first stage, the interpolation of data was done by kriging method in GIS context. Then S-shape membership function was defined for each parameter and prepared fuzzy map. After determination of membership function weight parameters maps were determined using AHP technique and finally soil fertility map was prepared with overlaying of weighted fuzzy maps. Relative variance and correlation coefficient criteria used tocontrol groups separation accuracy in fuzzy fertility map. Results and Discussion: With regard to minimum amounts of parameters looks some lands of study area had fertility difficulty. Therefore, soil fertility map of study area distinct these lands and present soil

  8. Associations of gender role attitudes with fertility intentions: A Japanese population-based study on single men and women of reproductive ages. (United States)

    Kato, Tsuguhiko


    Japan has been experiencing low fertility for many years. In this study, I investigated the relationship between gender role attitudes and fertility intentions among Japanese single men and women of reproductive ages. Utilizing the Longitudinal Survey of Adults in the 21st Century data, 8944 men and 7924 women aged 20-34 years with single, childless status were analyzed. Gender role attitudes were assessed by participants' preferences for the division of labor between a man and a woman: income earning, housework, and childcare. Those who preferred men to earn income and women to perform housework and childcare were considered to have traditional attitudes, whereas those who preferred women and men to share these responsibilities were considered to have egalitarian attitudes. Outcomes were fertility intentions measured by a desire to have children and ideal number of children. Logistic regression analyses were conducted. Egalitarian attitudes about income earning and housework were associated with low fertility intentions (a lesser desire for children) compared to traditional attitudes: adjusted odds ratios were 1.56 [1.36, 1.80] for men and 1.47 [1.26, 1.72] for women with income earning. Men's preference for sharing childcare responsibility was associated with high fertility intentions. Japanese society has not shifted away from the traditional division of labor despite the increase in female labor force participation. Low fertility intentions among Japanese men and women with egalitarian attitudes suggest that institutional support for balancing work and family may be necessary to improve the low fertility trend. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. A constructive mean-field analysis of multi-population neural networks with random synaptic weights and stochastic inputs. (United States)

    Faugeras, Olivier; Touboul, Jonathan; Cessac, Bruno


    We deal with the problem of bridging the gap between two scales in neuronal modeling. At the first (microscopic) scale, neurons are considered individually and their behavior described by stochastic differential equations that govern the time variations of their membrane potentials. They are coupled by synaptic connections acting on their resulting activity, a nonlinear function of their membrane potential. At the second (mesoscopic) scale, interacting populations of neurons are described individually by similar equations. The equations describing the dynamical and the stationary mean-field behaviors are considered as functional equations on a set of stochastic processes. Using this new point of view allows us to prove that these equations are well-posed on any finite time interval and to provide a constructive method for effectively computing their unique solution. This method is proved to converge to the unique solution and we characterize its complexity and convergence rate. We also provide partial results for the stationary problem on infinite time intervals. These results shed some new light on such neural mass models as the one of Jansen and Rit (1995): their dynamics appears as a coarse approximation of the much richer dynamics that emerges from our analysis. Our numerical experiments confirm that the framework we propose and the numerical methods we derive from it provide a new and powerful tool for the exploration of neural behaviors at different scales.

  10. Sexuality and fertility in men with hypospadias; improved outcome. (United States)

    Örtqvist, L; Fossum, M; Andersson, M; Nordenström, A; Frisén, L; Holmdahl, G; Nordenskjöld, A


    The aim of this study was to investigate sexual function and fertility in adult men born with hypospadias. Patients born with hypospadias, age-matched controls, and a group of circumcised men completed a questionnaire constructed to reflect their psychosexual situation and fertility. Core gender identity, sexual orientation, and gender role behavior was also assessed. 167 patients [63% distal, 24% mid shaft and 13% proximal, mean age 34 (19-54) years], 169 controls from the general population [mean age 33 (19-48) years] and 47 controls circumcised because of phimosis (mean age 26 [19-44]) participated and completed the questionnaire. There were no differences in having a partner, reported fertility, age at sexarche (mean age 17.8), number of sex partners or sexual interest between the patients and controls. More patients than controls reported anejaculation. Reported glanular sensitivity was lower in hypospadias patients and circumcised controls compared with non-circumcised controls. The odds of being satisfied with their sexual life increased with a higher penile perception score in patients (OR = 1.54, p = 0.01). There was no association with penile length. Sexual orientation, core gender identity and gender role behavior were sex-typical in both patients and controls. Patients with proximal hypospadias had a lower reported fertility, experienced anejaculation more often, and were less satisfied with their sexual life. Men born with hypospadias have a good long-term outcome concerning sexual function and fertility. Men born with proximal hypospadias have a more impaired outcome concerning both sexual function and fertility. As satisfaction with genital appearance is important for sexual life satisfaction, clinical, and psychological follow-up into adulthood is especially important in boys born with proximal hypospadias. © 2016 American Society of Andrology and European Academy of Andrology.

  11. A new means of communication with the populations: the Extremadura Regional Government Radiological Monitoring alert WEB Page

    International Nuclear Information System (INIS)

    Baeza, A.; Vasco, J.; Miralles, Y.; Torrado, L.; Gil, J. M.


    In 1990, the Junta (Regional government) of Extremadura encharged the University of Extremadura with the desogm and phased implementation of the Radiological Warning Network of Extremadura, initially limited to the proximity of the Almaraz Nuclear Power Plant. Since then, its structure and objectives have been steadily broadened, but always with priority given to the correct operation of the existing infrastructure. The network currently consists of the following installations. Around the cited nuclear plant, there are seven gamma dosimetry stations, two stations of continuous monitoring of radio iodines and radio particles, two automated meteorology stations, and two stations of continuous monitoring of radiation levels in the water of the River Tagas. Outside this zone, there are three gamma dosimetry stations and two for the continuous monitoring of radiosonde and radio particles. There is also a mobile laboratory equipped with an aerosol trap, a gamma dose rate monitor, and a portable germanium detector, with which it is possible in a minimally reasonable time to reach any location where it is necessary to determine the radiological status. All the information generated by the cited stations and the mobile laboratory are transmitted to the logistic centre located in the Physics Department of the Veterinary Faculty of Caceres, and to the network's strategic centre in the General Directorate for the Environment of the Agriculture and Environment council of the Junta of Extremadura. From the beginning of its operation, particular attention was paid to finding different means of providing the population with basic, truthful, and accessible periodic information on the radiological status of the zones covered by the network. Therefore, as well as sending to the Assembly (Parliament) of Extremadura summaries of the reports that are periodically presented to the Junta, an initial attempt was made to inform the population directly by including in the journal Extremadura

  12. How to influence fertility: the experience so far. (United States)

    Weeks, J R


    Even though fertility in the US is 2, the population grows each year by 2.5 million people due to natural increase and immigration. The US has never had a formal population policy to influence its birth rate. Yet the US government advises other nations, especially developing nations, how they should go about reducing their fertility. Instead the US can learn from population policies of direct disincentives, such as no income tax allowance for 3 children. In Indonesia, the president and Islamic religious leaders strongly support family planning. In Mexico, both the public and private sectors provide family planning services. The US does not have experience in influencing fertility declines, since fertility declined due to economic development over a period of time. Some scholars claim that there are 3 preconditions for a sustained decline in fertility, all of which have significance for setting population policies. The 1st is called rational choice in which conditions are such in a society that women can make their own decision. For example, the existence of legislation that guarantees women the right to act in their own interest, including the right to make their own reproductive decisions. The 2nd involves policies or conditions that motivate individuals and/or couples to limit family size. Incentives and disincentives can provide the needed motivation. For example, the government pays a woman for not having a child for a specific interval. The last precondition includes the necessity of having means available to limit family size. These means include knowledge of contraceptive methods and accessibility to them.

  13. The Population Problem as Economic Disarticulation. (United States)

    Yapa, Lakshman S.


    Overpopulation exists when people lack the basic means of subsistence, or when there is massive and permanent unemployment. Population problems of developing countries are examined, and causes of high rates of fertility are discussed. The utilization of productive resources in solving population problems is also examined. (RM)

  14. Preservation of Fertility Potential for Gender and Sex Diverse Individuals. (United States)

    Johnson, Emilie K; Finlayson, Courtney


    Gender and sex diverse individuals-transgender individuals and those with disorders of sex development (DSD)-both face medical treatments that may impair biological fertility potential. Young DSD patients also often have abnormal gonadal development. Fertility preservation for these populations has historically been poorly understood and rarely addressed. Future fertility should be discussed with gender and sex diverse individuals, particularly given recent advances in fertility preservation technologies and evolving views of fertility potential. Key ethical issues include parental proxy decision-making and uncertainty regarding prepubertal fertility preservation technologies. Many opportunities exist for advancing fertility-related care and research for transgender and DSD patients.

  15. Demographic and fertility characteristics of 4 squatter settlements. (United States)

    Yusof, K; Zulkifli, S N


    The demographic and fertility profiles of 4 squatter areas, 2 with Sang Kancil, a community development project designed specifically for squatter settlements in Kuala Lumpur, are described. Data were taken from a census conducted in 1982. Figure 1 maps out the location of the study areas in the Federal Territory. The squatter household (5.4 members) varied little from the average Malaysian household. The average age of the male head of household was 40 years, i.e., not within the high fertility group; the mean duration of stay was 10 years. Household income/month averaged M$760, falling between estimates for urban and rural mean. Comparing the data on the 2 squatter areas, the non-Sang Kancil head of household was, on average, slightly older and had stayed about 2 years longer than his Sang Kancil counterpart. These differences were statistically significant. Both areas were comparable with regard to household income and size. Ethnically, the Sang Kancil areas were predominantly Malay, comprising 86% of total households. The control areas had a more mixed ethnic structure. From 1978-81, annual increases in total population had been fairly uniform, at around 2%, in non-Sang Kancil Areas. Yet, the Sang Kancil population experienced a growth spurt in 1980, which subsequently declined and appeared to level off. 1982 figures were disregarded in this analysis as they were based on a 1/2 year enumeration only. The age distribution pattern of all squatter areas combined was fairly similar to the national distribution pyramid but for a higher proportion of people in the 15-44 age group than national figures. The proportion of dependents, 0-14 years, was comparable despite having more people in this fertile age group. The proportion of infants (0-11 months) in the control population was constant, but there was a decline down to control values by the end of the surveyed period in the Sang Kancil group. In the toddler group, decreases were evident for both populations

  16. Urbanization and Fertility Rates in Ethiopia | Tadesse | Ethiopian ...

    African Journals Online (AJOL)

    Fertility rates are important determinants of both overall population growth and ... in turn have important consequences for economic growth, poverty reduction, and ... Ethiopia currently has one of the highest fertility rates in the world, although ...

  17. Cohort fertility and educational expansion in the Czech Republic during the 20th century

    Directory of Open Access Journals (Sweden)

    Krystof Zeman


    Full Text Available Background: During the 20th century the Czech Republic went through profound changes in female employment, gender roles, population and family policies, and public childcare. The educational structure of the female population changed tremendously. At the same time, completed cohort fertility fluctuated between 1.8 and 2.2 children per woman. Objective: This article analyses the changes in the level of completed cohort fertility by education, during educational expansion in the Czech population under the economic, cultural, and institutional background of the state socialist regime, and after its breakdown. Methods: The changes in the level of completed cohort fertility by education are analysed by means of decomposition, complemented by the analysis of parity composition. Results: During the 20th century, education-specific completed cohort fertility increased, rather than declined. Fertility levels converged upwards, contributing to high uniformity within educational categories. The overall changes in fertility levels were driven by changes in the educational structure. These trends resulted in the dominance of the two-child family, while large families were disappearing and childlessness dropped to the biological minimum. Conclusions: An egalitarian economic system with traditional family-friendly policies, in combination with a family-unfriendly labour market, developed into a male breadwinner model of low gender equity. Future family policies should focus on the reconciliation of work and family. Contribution: The study contributes to the discussion on links between education and fertility, adding a new picture to the mosaic of country-level analyses. The Czech Republic is an example of a country with high educational homogeneity of fertility behaviour where the education-specific levels of fertility converged upwards.

  18. Infertility Treatment and Fertility-Specific Distress: A Longitudinal Analysis of a Population-Based Sample of U.S. Women (United States)

    Greil, Arthur L.; McQuillan, Julia; Lowry, Michele; Shreffler, Karina M.


    Because research on infertile women usually uses clinic-based samples of treatment seekers, it is difficult to sort out to what extent distress is the result of the condition of infertility itself and to what extent it is a consequence of the experience of infertility treatment. We use the National Survey of Fertility Barriers, a two-wave national probability sample of U.S. women, to disentangle the effects of infertility and infertility treatment on fertility-specific distress. Using a series of ANOVAs, we examine 266 infertile women who experienced infertility both at Wave 1 and at Wave 2, three years later. We compare eight groups of infertile women based on whether or not they have received treatment and on whether or not they have had a live birth. At Wave 1, infertile women who did not receive treatment and who had no live birth reported lower distress levels than women who received treatment at Wave 1 only, regardless of whether their infertility episode was followed by a live birth. At Wave 2, women who received no treatment have significantly lower fertility-specific distress than women who were treated at Wave 1 or at Waves 1 and 2, regardless of whether there was a subsequent live birth. Furthermore, fertility-specific distress did not increase over time among infertile women who did not receive treatment. The increase in fertility-specific distress was significantly higher for women who received treatment at Wave 2 that was not followed by a live birth than for women who received no treatment or for women who received treatment at Wave 1 only. These patterns suggest that infertility treatment is associated with levels of distress over and above those associated with the state of being infertile in and of itself. PMID:21645954

  19. Fertility Clinic Success Rates (United States)

    ... Defects ART and Autism 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet ... Additional Information About ART in the United States. Fertility Clinic Tables Introduction to Fertility Clinic Tables [PDF - ...

  20. Adubação mineral e orgânica e a densidade populacional de Thrips tabaci Lind. (Thysanoptera: Thripidae em cebola Mineral and organic fertilization and onion thrips, Thrips tabaci Lind. (Thysanoptera: Thripidae population density

    Directory of Open Access Journals (Sweden)

    Paulo Antonio de Souza Gonçalves


    Full Text Available O efeito da adubação mineral e orgânica sobre a densidade populacional de Thrips tabaci Lind. em cebola, Allium cepa L., foi avaliado na Estação Experimental de Ituporanga, SC (Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, entre agosto e dezembro de 1998. Os tratamentos foram níveis de adubação mineral com N, P2O5 e K2O em dose recomendada e três vezes a recomendada, adubação orgânica e a testemunha foi a ausência de adubação. Os tratamentos foram as seguintes doses de nutrientes: 1 30 + 120 + 60kg ha-1 de NPK; 2 90 + 360 + 180kg ha-1 de NPK; 3 75kg ha-1 de N; 4 225kg ha-1 de N; 5 80kg ha-1 de P2O5; 6 240kg ha-1 de P2O5; 7 60kg ha-1 de K2O; 8 180kg ha-1 de K2O; 9 75kg ha-1 de N + 80kg ha-1 de P2O5 (esterco de suíno + fosfato natural; 10 225kg ha-1 de N + 240kg ha-1 de P2O5 (esterco de suíno + fosfato natural; 11 37,5kg ha-1 de N + 40kg ha-1 de P2O5 (esterco de suíno + fosfato natural; testemunha sem adubação. Nenhuma das fontes e níveis de adubação apresentaram nível populacional de T. tabaci superior à testemunha sem adubo.The effect of the mineral and organic fertilization on onion thrips, Thrips tabaci Lind., population density was evaluated at Ituporanga Experiment Station, EPAGRI, Santa Catarina State, Brazil, between August and December 1998. The treatments were different levels of mineral fertilization with N, P2O5 and K2O at recommended rate and three times recommended rate, the organic fertilization and without fertilization was check. The treatments in nutrient rate were: 30 + 120 + 60kg NPK ha-1; 90 + 360 + 180kg NPK ha-1; 75kg N ha-1; 225kg N ha-1; 80kg P2O5 ha-1; 240kg P2O5 ha-1; 60kg K2O ha-1; 180kg K2O ha-1; 75kg N ha-1 + 80kg P2O5 ha-1 (swine manure + phosphate rock; 225kg N + 240kg P2O5 ha-1 (swine manure + phosphate rock; 37,5kg N + 40kg P2O5 ha-1 (swine manure + phosphate rock; check without fertilizer. The onion thrips population density was similar among treatments with

  1. Assessing population structure of European Anchovy (Engraulis encrasicolus in the Central Mediterranean by means of traditional morphometry

    Directory of Open Access Journals (Sweden)

    A. Traina


    Full Text Available For the first time the structure of the anchovy stock was investigated in the Strait of Sicily: sampling locations were in Sicily, in Tunisia and in the Adriatic Sea. A morphological approach to stock discrimination which involves morphometric landmarks analysis was adopted. The aim of this work is to describe any morphological variations between the samples areas and individuate possible different populations in order to obtain useful information for management of shared resources between Tunisian and Italian waters. Furthermore sexual dimorphism was investigated. Results of morphometric landmarks may suggest a high level of overlapping among Sicily and Tunisia. Instead, between the Sicilian and Adriatic population, it was observed a certain degree of isolation, suggesting the existence of two anchovy sub-populations connected by a possible migration of a small number of individuals. No differences between male and female individuals was observed. Results support the likely existence of an anchovy metapopulation with several sub-populations, one inhabiting the northern and southern parts of the Strait of Sicily. From a management perspective and under the ‘precautionary approach’, these sub-populations should be treated as shared stocks and conserved.

  2. Effects of elevated mean and extremely high temperatures on the physio-ecological characteristics of geographically distinctive populations of Cunninghamia lanceolata (United States)

    Zhou, Ting; Jia, Xiaorong; Liao, Huixuan; Peng, Shijia; Peng, Shaolin


    Conventional models for predicting species distribution under global warming scenarios often treat one species as a homogeneous whole. In the present study, we selected Cunninghamia lanceolata (C. lanceolata), a widely distributed species in China, to investigate the physio-ecological responses of five populations under different temperature regimes. The results demonstrate that increased mean temperatures induce increased growth performance among northern populations, which exhibited the greatest germination capacity and largest increase in the overlap between the growth curve and the monthly average temperature. However,tolerance of the southern population to extremely high temperatures was stronger than among the population from the northern region,shown by the best growth and the most stable photosynthetic system of the southern population under extremely high temperature. This result indicates that the growth advantage among northern populations due to increased mean temperatures may be weakened by lower tolerance to extremely high temperatures. This finding is antithetical to the predicted results. The theoretical coupling model constructed here illustrates that the difference in growth between populations at high and low latitudes and altitudes under global warming will decrease because of the frequent occurrence of extremely high temperatures.

  3. Fertility trends in Singapore. (United States)

    Singh, K; Viegas, O; Ratnam, S S


    In 1966, the Singapore National Family Planning and Population Program established the goal of reaching replacement fertility by 1990 and zero population growth by the year 2030. To achieve this goal, the government relied on a series of incentives and disincentives to discourage births above the 3rd birth order, including tax relief for the 1st 3 children only, paid medical leave for women undergoing sterilization after the 3rd or subsequent birth, monetary stipends in some cases where the mother is sterilized after the 1st or 2nd birth, and increasing accouchement charges for increasing birth orders. Also important to demographic planning were liberalization of Singapore's abortion legislation and more aggressive promotion of contraception. As a result of these efforts, Singapore's crude birth rate has declined from 29.5/1000 population in 1965 to 16.6/1000 in 1985. Also observed have been dramatic declines in infant mortality in this same period, from 26.2/1000 live births to 9.3/1000, and in maternal mortality, from 52/100,000 live births to 10/100,000. In 1985, 42% of total births were to women in the 25-29-year age group. The numbers of 4th and later births fell by 90% between 1966 and 1985. The total fertility rate has declined from 4.6/woman in 1965 to 3.1 in 1970 to 1.6 in 1986. Below replacement level fertility was achieved in 1975, in part because of government policy but also as a result of cultural and socioeconomic factors such as increasing female labor force participation rates, a break-up of the extended family system, a rise in the age at 1st marriage, and rises in educational attainment. The drop in fertility was contributed mainly by the higher socioeconomic class, more affluent, and educated Singaporeans. Thus, in 1981, the government introduced certain pronatalist policies and incentives to encourage better educated women to produce more children, e.g., tax relief and the elimination of monetary incentives to sterilization acceptors above a

  4. “Cultral” or “Kulturnichesky” Populism? (on the Meaning of Concepts in the History of Russian Populist Studies

    Directory of Open Access Journals (Sweden)

    Mokshin Gennadiy Nikolaevich


    Full Text Available The article is devoted to the origin and content of the concept of “cultural” and “kulturnichesky” populism in the Russian populist studies. Both terms appeared in the early twentieth century to refer to the right wing of the liberal populism. But they reflect different interpretations of the populist ideology: wide (of populism and narrow (of marxism. The term “cultural populism” (originated from “cultural work” reflects the desire of right-wing populists to create sociocultural prerequisites for changing the existing social order. The term “kulturnichesky populism” (from the German “kulturträger”, by the recognition of the Marxists themselves, was designed to discredit the populist program of social work in the countryside, allegedly aimed at reconciliation with reality. Most modern scholars following the tradition continue to use the concept of “kulturnichesky populism” and “cultural work”, sharing their biased interpretation. Not by chance in the scientific and educational literature, culturalpopulism direction is still associated with indifference with respect to political life and at the same time petty-bourgeois liberalism. According to the author, this approach not only distorts the ideas of populists-uplifters but also diminishes their contribution to the development of populist ideas of 1880-1890s. Therefore, for specialists in the history of legal populism it is recommended to use a more correct terms “cultural populism” and “cultural work”.

  5. The mean active bone marrow dose to the adult population of the United States from diagnostic radiology

    International Nuclear Information System (INIS)

    Shleien, B.; Tucker, T.T.; Johnson, D.W.


    Estimates, based on an empirical model and computer program, have been calculated and are presented on the mean active bone marrow dose to adults from diagnostic radiography, fluoroscopy, and dental radiography as practiced in the United States in 1970. The annual per capita mean active bone marrow dose in 1970 to adults from the above practices is estimated to be 103 mrad; 77 percent, 20 percent, and 3 percent from radiographic, fluoroscopic and dental examinations respectively. Examinations of the upper and lower abdomen contribute approximately 39 percent each to the total mean active bone marrow dose for adults; those of the pelvis 4 percent; the thorax 12 percent; and head and neck examinations (including dental) contribute about 6 percent. The per capita mean active bone marrow dose for various age groups is discussed. Contributions to the dose within a given age group from different examinations indicate that in the 15-34 year old age group Lumbar and Lumbosacral Spine examinations contribute most to the mean active bone marrow dose. Thereafter Upper G I Series and Barium Enemas are the highest contributors. Comparisons are made with results of the 1964 U.S. X-ray survey and similar surveys from other nations

  6. A Microsoft® Excel Simulation Illustrating the Central Limit Theorem's Appropriateness for Comparing the Difference between the Means of Any Two Populations (United States)

    Moen, David H.; Powell, John E.


    Using Microsoft® Excel, several interactive, computerized learning modules are developed to illustrate the Central Limit Theorem's appropriateness for comparing the difference between the means of any two populations. These modules are used in the classroom to enhance the comprehension of this theorem as well as the concepts that provide the…

  7. Wealth, intelligence, politics and global fertility differentials. (United States)

    Meisenberg, Gerhard


    Demographic trends in today's world are dominated by large fertility differentials between nations, with 'less developed' nations having higher fertility than the more advanced nations. The present study investigates whether these fertility differences are related primarily to indicators of economic development, the intellectual level of the population, or political modernity in the form of liberal democracy. Results obtained with multiple regression, path models and latent variable models are compared. Both log-transformed GDP and measures of intelligence independently reduce fertility across all methods, whereas the effects of liberal democracy are weak and inconsistent. At present rates of fertility and mortality and in the absence of changes within countries, the average IQ of the young world population would decline by 1.34 points per decade and the average per capita income would decline by 0.79% per year.

  8. Reverse survival method of fertility estimation: An evaluation

    Directory of Open Access Journals (Sweden)

    Thomas Spoorenberg


    Full Text Available Background: For the most part, demographers have relied on the ever-growing body of sample surveys collecting full birth history to derive total fertility estimates in less statistically developed countries. Yet alternative methods of fertility estimation can return very consistent total fertility estimates by using only basic demographic information. Objective: This paper evaluates the consistency and sensitivity of the reverse survival method -- a fertility estimation method based on population data by age and sex collected in one census or a single-round survey. Methods: A simulated population was first projected over 15 years using a set of fertility and mortality age and sex patterns. The projected population was then reverse survived using the Excel template FE_reverse_4.xlsx, provided with Timæus and Moultrie (2012. Reverse survival fertility estimates were then compared for consistency to the total fertility rates used to project the population. The sensitivity was assessed by introducing a series of distortions in the projection of the population and comparing the difference implied in the resulting fertility estimates. Results: The reverse survival method produces total fertility estimates that are very consistent and hardly affected by erroneous assumptions on the age distribution of fertility or by the use of incorrect mortality levels, trends, and age patterns. The quality of the age and sex population data that is 'reverse survived' determines the consistency of the estimates. The contribution of the method for the estimation of past and present trends in total fertility is illustrated through its application to the population data of five countries characterized by distinct fertility levels and data quality issues. Conclusions: Notwithstanding its simplicity, the reverse survival method of fertility estimation has seldom been applied. The method can be applied to a large body of existing and easily available population data

  9. Determinants of fertility in Namibia | Indongo | African Journal of ...

    African Journals Online (AJOL)

    In-depth studies on fertility in Namibia have been lacking so far. This examines the fertility trends in Namibia over the past 2 decades and examines fertility differentials across the various sub-groups of Namibia population, and factors affecting such differentials using NDHS data. Estimates of the amount of variance in the ...

  10. Determinants of fertility in Ethiopia | Ayele | African Health Sciences

    African Journals Online (AJOL)

    Background: The most important elements to determine the rate of population growth is fertility. Fertility is the main element to affect the welfare of mother. The survival of a child can be affected by high fertility and shorter birth intervals. Methods: For this study, the linear mixed model was used to determine factors affecting ...

  11. India's population in transition. (United States)

    Visaria, L; Visaria, P


    This demographic profile of India addresses fertility, family planning, and economic issues. India is described as a country shifting from economic policies of self-reliance to active involvement in international trade. Wealth has increased, particularly at higher educational levels, yet 25% still live below the official poverty line and almost 66% of Indian women are illiterate. The government program in family planning, which was instituted during the early 1950s, did not change the rate of natural increase, which remained stable at 2.2% over the past 30 years. 1993 marked the first time the growth rate decline to under 2%. The growth rate in 1995 was 1.9%. The total population is expected double in 36 years. Only Nigeria, Pakistan, and Bangladesh had a higher growth rate and higher fertility in 1995. India is geographically diverse (with the northern Himalayan mountain zone, the central alluvial plains, the western desert region, and the southern peninsula with forest, mountains, and plains). There are regional differences in the fertility rates, which range from replacement level in Kerala and Goa to 5.5 children in Uttar Pradesh. Fertility is expected to decline throughout India due to the slower pace of childbearing among women over the age of 35 years, the increase in contraceptive use, and increases in marriage age. Increased educational levels in India and its state variations are related to lower fertility. Literacy campaigns are considered to be effective means of increasing the educational levels of women. Urbanization is not expected to markedly affect fertility levels. Urban population, which is concentrated in a few large cities, remains a small proportion of total population. Greater shifts are evident in the transition from agriculture to other wage labor. Fertility is expected to decline as women's share of labor force activity increases. The major determinant of fertility decline in India is use of family planning, which has improved in access

  12. Global Fertilizer and Manure, Version 1: Nitrogen Fertilizer Application (United States)

    National Aeronautics and Space Administration — The Nitrogen Fertilizer Application dataset of the Global Fertilizer and Manure, Version 1 Data Collection represents the amount of nitrogen fertilizer nutrients...

  13. Global Fertilizer and Manure, Version 1: Phosphorus Fertilizer Application (United States)

    National Aeronautics and Space Administration — The Phosphorus Fertilizer Application dataset of the Global Fertilizer and Manure, Version 1 Data Collection represents the amount of phosphorus fertilizer nutrients...

  14. Male fertility in cystic fibrosis.

    LENUS (Irish Health Repository)

    Chotirmall, S H


    Infertility rates among males with cystic fibrosis (CF) approximate 97%. No information is currently available within Ireland determining an understanding of fertility issues and the best methods of information provision to this specialized group. This study aimed to determine understanding and preferred approaches to information provision on fertility issues to Irish CF males. A Descriptive Study utilizing prospective coded questionnaires was mailed to a male CF cohort (n=50). Sections included demographics, fertility knowledge & investigation. Response rate was 16\\/50 (32%). All were aware that CF affected their fertility. More than two-thirds (n=11) were able to provide explanations whilst only one-third (n=5) provided the correct explanation. Significant numbers stated thoughts of marriage and a future family. Half have discussed fertility with a healthcare professional (HCP). Mean age of discussion was 21.9 years. One third preferred an earlier discussion. The commonest first source for information was written material which was also the preferred source. Three-quarters requested further information preferring again, written material. Significant gaps in sex education of Irish CF males exist. Discussion should be initiated by HCPs and centre-directed written material devised to address deficiencies.

  15. Evaluation of Fertility Model by Using Path Analysis in Hamadan City in 2004

    Directory of Open Access Journals (Sweden)

    M. Mahdi Akhgar


    Full Text Available Introduction & Objective: The most important indicator of population growth is fertility. Fertil-ity is influenced by selection of individual, social, economic, demographic, cultural and bio-logical factors. The purpose of this study is to investigate the factors affecting fertility (num-ber of live births. Materials & Methods: This was a cross- sectional study of the correlation matrix, which is based on a sample of 500 households in the two-stage random sampling method. First, a question-naire was adjusted and then was provided to interviewers for recording some demographics information and birthrate. To examine the relationship between these variables and fertility model, the most important influential variables on fertility were selected based on the theo-retical model and using socio-economic and demographic variables influencing on fertility. The data were then analyzed by the path analysis using LISREL software. Results: Mean±SD of parity in 500 married women was 2.18±0.904 in Hamadan city. Among the variables, couple education (total effect -0.421 and the number of unwanted pregnancy (total effect 0.27 had the highest effect on fertility, respectively; while husband’s marriage age (total effect -0.00365 had the lowest effects on parity. Conclusion: This study shows that high education is a deterrent factor to live births and also shows that the rise of live births is unwanted among families. Also, it can be concluded from the findings of this study that culture of trend towards early marriage and childbearing which are associated with the promotion of education for women and men can significantly increase the pregnancy order to prevent the lack of active and aging population. (Sci J Hamadan Univ Med Sci 2015; 22 (2: 122-128

  16. Male Fertility Issues (United States)

    Fertility issues are common in boys and men getting cancer treatment. Fertility preservation options include sperm banking, testicular shielding, testicular sperm extraction (TESE), and testicular tissue freezing. Support and clinical trials are listed.

  17. K-means cluster analysis of rehabilitation service users in the Home Health Care System of Ontario: examining the heterogeneity of a complex geriatric population. (United States)

    Armstrong, Joshua J; Zhu, Mu; Hirdes, John P; Stolee, Paul


    To examine the heterogeneity of home care clients who use rehabilitation services by using the K-means algorithm to identify previously unknown patterns of clinical characteristics. Observational study of secondary data. Home care system. Assessment information was collected on 150,253 home care clients using the provincially mandated Resident Assessment Instrument-Home Care (RAI-HC) data system. Not applicable. Assessment information from every long-stay (>60 d) home care client that entered the home care system between 2005 and 2008 and used rehabilitation services within 3 months of their initial assessment was analyzed. The K-means clustering algorithm was applied using 37 variables from the RAI-HC assessment. The K-means cluster analysis resulted in the identification of 7 relatively homogeneous subgroups that differed on characteristics such as age, sex, cognition, and functional impairment. Client profiles were created to illustrate the diversity of this geriatric population. The K-means algorithm provided a useful way to segment a heterogeneous rehabilitation client population into more homogeneous subgroups. This analysis provides an enhanced understanding of client characteristics and needs, and could enable more appropriate targeting of rehabilitation services for home care clients. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Quantifying the contribution of statins to the decline in population mean cholesterol by socioeconomic group in England 1991 - 2012: a modelling study.

    Directory of Open Access Journals (Sweden)

    Chris Kypridemos

    Full Text Available Serum total cholesterol is one of the major targets for cardiovascular disease prevention. Statins are effective for cholesterol control in individual patients. At the population level, however, their contribution to total cholesterol decline remains unclear. The aim of this study was to quantify the contribution of statins to the observed fall in population mean cholesterol levels in England over the past two decades, and explore any differences between socioeconomic groups.This is a modelling study based on data from the Health Survey for England. We analysed changes in observed mean total cholesterol levels in the adult England population between 1991-92 (baseline and 2011-12. We then compared the observed changes with a counterfactual 'no statins' scenario, where the impact of statins on population total cholesterol was estimated and removed. We estimated uncertainty intervals (UI using Monte Carlo simulation, where confidence intervals (CI were impractical. In 2011-12, 13.2% (95% CI: 12.5-14.0% of the English adult population used statins at least once per week, compared with 1991-92 when the proportion was just 0.5% (95% CI: 0.3-1.0%. Between 1991-92 and 2011-12, mean total cholesterol declined from 5.86 mmol/L (95% CI: 5.82-5.90 to 5.17 mmol/L (95% CI: 5.14-5.20. For 2011-12, mean total cholesterol was lower in more deprived groups. In our 'no statins' scenario we predicted a mean total cholesterol of 5.36 mmol/L (95% CI: 5.33-5.40 for 2011-12. Statins were responsible for approximately 33.7% (95% UI: 28.9-38.8% of the total cholesterol reduction since 1991-92. The statin contribution to cholesterol reduction was greater among the more deprived groups of women, while showing little socio-economic gradient among men.Our model suggests that statins explained around a third of the substantial falls in total cholesterol observed in England since 1991. Approximately two thirds of the cholesterol decrease can reasonably be attributed non

  19. Mortality, fertility, and the OY ratio in a model hunter-gatherer system. (United States)

    White, Andrew A


    An agent-based model (ABM) is used to explore how the ratio of old to young adults (the OY ratio) in a sample of dead individuals is related to aspects of mortality, fertility, and longevity experienced by the living population from which the sample was drawn. The ABM features representations of rules, behaviors, and constraints that affect person- and household-level decisions about marriage, reproduction, and infant mortality in hunter-gatherer systems. The demographic characteristics of the larger model system emerge through human-level interactions playing out in the context of "global" parameters that can be adjusted to produce a range of mortality and fertility conditions. Model data show a relationship between the OY ratios of living populations (the living OY ratio) and assemblages of dead individuals drawn from those populations (the dead OY ratio) that is consistent with that from empirically known ethnographic hunter-gatherer cases. The dead OY ratio is clearly related to the mean ages, mean adult mortality rates, and mean total fertility rates experienced by living populations in the model. Sample size exerts a strong effect on the accuracy with which the calculated dead OY ratio reflects the actual dead OY ratio of the complete assemblage. These results demonstrate that the dead OY ratio is a potentially useful metric for paleodemographic analysis of changes in mortality and mean age, and suggest that, in general, hunter-gatherer populations with higher mortality, higher fertility, and lower mean ages are characterized by lower dead OY ratios. Copyright © 2014 Wiley Periodicals, Inc.

  20. Family planning and fertility decline: a global overview. (United States)

    Tabah, L


    Family planning and development policy concerns are not incompatible. The emphasis on development policies at the 1974 World Population Conference at Bucharest did not mean that world governments had lost interest in the population and family planning issue. Although worldwide attitudes toward family planning have become more and more favorable, this has not yet meant great impact on world demographic trends. The "inertia factor," i.e., the effects of high birthrates in the previous generation, will camouflage declining birthrates for some time to come. The trend of fertility reduction which was perceptible only among small populations a few years ago is also becoming manifest in larger Third World countries. Mortality rate declines have slowed down but there is no rising mortality due to starvation in any country. At present, food demand exceeds availability for 80% of the Third World population. It is predicted that the food deficit will increase 70% by the year 2000.

  1. Assessment of testicular volume: A comparison of fertile and sub-fertile West African men

    Directory of Open Access Journals (Sweden)

    K.H. Tijani


    Conclusion: Testicular volume on scrotal ultrasound correlates well with severity of oligospermia in men with sub-fertility. While the critical mean testicular volume necessary for adequate spermatogenesis has not been determined, it appears there is an optimal testicular volume of 18–20 ml at which spermatogenesis is at its peak in sub-fertile Nigerian men.

  2. Cancer and fertility: strategies to preserve fertility. (United States)

    Diedrich, K; Fauser, B C J M; Devroey, P


    Fertility preservation is a key component of cancer management in young people. The Fourth Evian Annual Reproduction Workshop Meeting was held in April 2009 to discuss cancer and fertility in young adults. Specialists in oncology, assisted reproduction, embryology and clinical genetics presented published data and ongoing research on cancer and fertility, with particular focus on strategies to preserve fertility. This report is based on the expert presentations and group discussions, supplemented with publications from literature searches and the authors' knowledge. Fertility preservation should be considered for all young people undergoing potentially gonadotoxic cancer treatment. A variety of options are required to facilitate safe and effective fertility preservation for individual patients. Sperm banking is a simple and low-cost intervention. Embryo cryopreservation is the only established method of female fertility preservation. Oocyte cryopreservation offers a useful option for women without a male partner. Emergency ovarian stimulation and cryopreservation of ovarian tissue (followed by tissue transplantation or in-vitro maturation of oocytes) are experimental techniques for women who require urgent cancer treatment. Further prospective studies are required to validate cryopreservation of oocytes and ovarian tissue, in-vitro maturation of oocytes and new vitrification techniques and to identify any long-term sequelae of slow freezing of embryos. Copyright © 2010 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  3. Phospholipid fatty acid patterns of microbial communities in paddy soil under different fertilizer treatments

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi-chun; WANG Guang-huo; YAO Huai-ying


    The microbial communities under irrigated rice cropping with different fertilizer treatments, including control (CK), PK, NK, NP, NPK fertilization, were investigated using phospholipid fatty acid (PLFA) profile method. The results of this study revealed that the fertilizer practice had an impact on the community structure of specific microbial groups. The principal components analysis (PCA) showed that proportion of the actinomycete PLFAs (10Me 18:0 and 10Me 16:0) were the lowest in the PK treatment and the highest in the NPK treatment, which means that soil nitrogen status affected the diversity of actinomycetes, whereas nitrogen cycling was related to the actinomycets. Under CK treatment, the ratio of Gram-positive to Gram-negative bacteria was lower compared with that in fertilizer addition treatments, indicating that fertilizer application stimulated Gram-positive bacterial population in paddy soil. The fatty acid 18:2ω6, 9, which is considered to be predominantly of fungal origin, was at low level in all the treatments. The ratio of cy19:0 to 18:1ω7, which has been proposed as an indicator of stress conditions, decreased in PK treatment. Changes of soil microbial community under different fertilizer treatments of paddy soil were detected in this study; however, the causes that lead to changes in the microbial community still needs further study.

  4. Cohort fertility decline in low fertility countries: Decomposition using parity progression ratios

    Directory of Open Access Journals (Sweden)

    Krystof Zeman


    Full Text Available Background: The long-term decline in cohort fertility in highly developed countries has been widely documented. However, no systematic analysis has investigated which parity contributed most to the fertility decline to low and very low levels. Objective: We examine how the contribution of changing parity progression ratios varied across cohorts, countries, and broader regions in Europe, North America, Australia, and East Asia. We pay special attention to countries that reached very low completed cohort fertility, below 1.75 children per woman. Methods: Using population censuses and large-scale surveys for 32 low fertility countries, we decompose the change in completed cohort fertility among women born between 1940 and 1970. The decomposition method takes into account the sequential nature of childbearing as a chain of transitions from lower to higher parities. Results: Among women born between 1940 and 1955, the fertility decline was mostly driven by reductions in the progression ratios to third and higher-order births. By contrast, among women born between 1955 and 1970, changes in fertility showed distinct regional patterns: in Central and Eastern Europe they were fuelled by falling second-birth rates, whereas in the German-speaking countries, Southern Europe, and East Asia decreases in first-birth rates played the major role. Conclusions: Pathways to low and very low fertility show distinct geographical patterns, which reflect the diversity of the cultural, socioeconomic, and institutional settings of low fertility countries. Contribution: Our study highlights the importance of analysing parity-specific components of fertility in order to understand fertility change and variation. We demonstrate that similar low levels of completed cohort fertility can result from different combinations of parity-specific fertility rates.

  5. Cohort Fertility Patterns in the Nordic Countries

    Directory of Open Access Journals (Sweden)

    Gunnar Andersson


    Full Text Available Previous analyses of period fertility suggest that the trends of the Nordic countries are sufficiently similar to speak of a common "Nordic fertility regime". We investigate whether this assumption can be corroborated by comparing cohort fertility patterns in the Nordic countries. We study cumulated and completed fertility of Nordic birth cohorts based on the childbearing histories of women born in 1935 and later derived from the population registers of Denmark, Finland, Norway, and Sweden. We further explore childbearing behaviour by women's educational attainment. The results show remarkable similarities in postponement and recuperation between the countries and very small differences in completed fertility across educational groups. Median childbearing age is about 2-3 years higher in the 1960-64 cohort than in the 1950-54 cohort, but the younger cohort recuperates the fertility level of the older cohort at ages 30 and above. A similar pattern of recuperation can be observed for highly educated women as compared to women with less education. An interesting finding is that of a positive relationship between educational level and the final number of children when women who become mothers at similar ages are compared. Country differences in fertility outcome are generally rather low. Childlessness is highest in Finland and lowest in Norway, and the educational differentials are largest in Norway. Despite such differences, the cohort analyses in many ways support the notion of a common Nordic fertility regime.

  6. [Is health really the most important value? - Results of a representative survey of the German general population concerning the subjective meaning of health]. (United States)

    Hinz, A; Hübscher, U; Brähler, E; Berth, H


    The aim of this study was to investigate which meaning is attributed to health by the general population. Furthermore, the relationship between health satisfaction and health importance was also analysed. A sample of 4,808 representatively selected subjects from the general German population judged the importance and the satisfaction with several life domains, including health, using the questions on life satisfaction FLZ (M). Moreover, sociodemographic variables (sex, age, socioeconomic status) and psychological variables (self-esteem, resilience, anxiety and depression) were collected. Health is the most important life domain. The importance of health increases with increasing age. However, there are no sex differences and SES (socio-economic status) differences concerning the importance of health. Subjective satisfaction with health and health importance are only marginally correlated (r=0.08). High degrees of self-esteem and resilience are associated with a high importance of health. Anxiety and depression show only weak relationships to the importance of health. In the German general population health has a very high subjective significance. This is not only true for handicapped or ill people, but for all subsamples of the society. Therefore, a general plea for an understanding of the importance of health is not necessary, not even for subgroups. Preventive activity can be based on the general understanding of the meaning of health, but it should pursue specific health- related goals for target groups. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Fertility decline: transition or transformation? (United States)

    Freedman, J


    This essay argues on the basis of evidence from Northern Rwanda that economic theories of fertility which fail to take into account the value of children for reproducing a community's social relations are of limited value in traditional noncapitalist or peasant societies. Regarding the transition to low fertility as an adjustment of the population to available resources ignores the fact that many families in the developing world regard their children as absolute values, not values relative to other resources, and therefore the transition to lower fertility is a dramatic change rather than an adjustment. The Kiga of Rwanda have in the last 20 years or so become differentiated into a group of richer households with excess land and a labor shortage and poorer households with excess labor and a land shortage. In the face of severe material shortages, the poorer families continue to desire and have almost as many children as the richer. Among women aged 25-35, the poorer group had on average 5.5 children while the wealthier had 3.9 on average. Kiga families are embedded in larger social units which provide social insurance against misfortune, and having many children thus reconstitutes a social value which minimizes the impact of misfortune. High fertility appears to occur in social economies where there is no reasonable motivation for reducing family size; where high value is placed on the survival of the collectivity and on the reproduction of concrete social relations, the only rational behavior is to have many children.

  8. The economics of fertility. (United States)

    Loraine, J A


    The statement that economics and fertility are closely interrelated is a truism. The classical economists--Adam Smith, Thomas Malthus, Karl Marx, John Stuart Mill and John Maynard Keynes appreciated this fact, and their reviews are recounted and their prescience is assessed. Adam Smith (1723-1790) was primarily concerned with the desire of humankind to better his/her material conditions. Although he did not put forward a specific population policy, the tenet of his writing is pronatalist. Economic advantages would accrue to parents by the production of many children. Yet, underneath Smith's optimism, there was an apocalyptic vision of the distant future, i.e., the "steady state" when resources would be depleted or near exhaustion, when capital accumulation would have ceased, and living standards would be dropping vertiginously. In his 1st "Essay on Population" Malthus maintained that "the power of population is infinitely greater than the power of the earth to produce subsistence of men." Malthus can be complimented on his prescience. There is little question that the planet of today is grossly overpopulated and that a great gulf exists between numbers of people and their aspirations and the resources which the earth can provide for them. Malthus was particularly concerned about the population food dilemma, and that is still much in evidence in 1982. 2 concomitants of overpopulation--excessive urbanization and joblessness--could not be foreseen by Malthus. Marx did not deny the basic tenet promulgated by Malthus but to him this was simply an artifact of capitalist society which required "enormous reserves of proletarians" in order to maintain its odius system. Officially Communist governments remain in a Marxist straitjacket regarding the population issue. Mills approach was strongly antinatalist; he saw little need for an increase in human numbers. Mills was concerned that because of unlimited population growth and wealth the earth would lose much of its

  9. Fertility and sexual function in female Hodgkin lymphoma survivors of reproductive age. (United States)

    Eeltink, Corien M; Incrocci, Luca; Witte, Birgit I; Meurs, Saskia; Visser, Otto; Huijgens, Peter; Verdonck-de Leeuw, Irma M


    To assess the perceived fertility status and to determine the association between perceived fertility status and sexual function, as reported by young female Hodgkin lymphoma survivors. Young female Hodgkin lymphoma survivors are at risk of infertility and impaired sexual function. However, little is known about their awareness of infertility and its association with sexual functioning. A descriptive questionnaire survey. In this cross-sectional study, a survey was completed by female Hodgkin lymphoma survivors (40 years). Outcome measures included self-reported fertility status and sexual problems and the internationally validated Female Sexual Function Index. In total, 36 survivors were included (mean age 32 years, SD 4). Eighteen women (50%) thought themselves fertile. Eight survivors (22%) who perceived themselves as being infertile were more often treated with alkylator-based chemotherapy, and 63% reported sexual dysfunction. Ten survivors (28%) were not aware as to whether they were fertile or not; seven of these would like to have children. The reported fertility status was related to age and chemotherapy regimen. Regarding sexuality, 14 (39%) of the female Hodgkin lymphoma survivors reported one or more sexual problem and none reported recovery. Female sexual dysfunction according to the Female Sexual Function Index was reported by 11 (31%) survivors. Almost 30% of Hodgkin lymphoma survivors do not know whether they are fertile or not. Overall sexual dysfunction is common in Hodgkin lymphoma survivors and comparable to the general population. However, a lack of desire was significantly more often reported in female Hodgkin lymphoma survivors. To prevent assumed infertility and unintended childlessness by postponing parenthood in young female survivors, awareness of fertility status is needed. There is also a need to routinely assess sexual function and provide adequate interventions to improve arousal and lubrication problems. © 2013 John Wiley & Sons Ltd.

  10. Global radiological impact of the phosphate fertilizers

    International Nuclear Information System (INIS)

    Morales, Rudnei Karam; Alves, Rex Nazare


    About ninety percent of the products obtained in the phosphate industry are directly used in agriculture as fertilizers. The uranium, thorium and radium content in phosphate fertilizers pollute the soil, water and air, creating risks due to associated natural radiation. This work shows the concentration of radionuclides present in various products of the national and American phosphate fertilizers industry, and compared them with worldwide mean values. The radiological impact of the products on the environment is evaluated and suggestions are presented in order to minimize the risks due to radioactivity. (author)

  11. The "amazing" fertility decline: Islam, economics, and reproductive decision making among working-class Moroccan women. (United States)

    Hughes, Cortney L


    Often it is understood that Islam prohibits family planning because the Qur'an does not explicitly address contraception. Public health and development officials have recently congratulated the Muslim world for decreases in fertility given the supposed constraints placed on reproductive healthcare by Islam, while popular culture writers have warned the West of threats by young Muslims if the population goes uncontrolled. This article draws on data collected through interviews with working-class women seeking reproductive healthcare at clinics in Rabat, Morocco, and with medical providers to challenge the link between Islamic ideology and reproductive practices and the correlation among Islam, poverty, and fertility. Morocco, a predominantly Muslim country, has experienced a dramatic decrease in fertility between the 1970s and today. I argue that patients and providers give new meanings to modern reproductive practices and produce new discourses of reproduction and motherhood that converge popular understandings of Islam with economic conditions of the Moroccan working class.

  12. Tunisia: high fertility stalls development. (United States)

    Barberis, M


    Despite government policy enacted in 1964 to reduce fertility in order to hasten socioeconomic progress, population pressures continue to impair development in Tunisia. The birth rate fell 20% over the last 2 decades, but this accomplishment has been outweighed by a 50% decline in mortality rates. As a result, the rate of natural population increase has remained relatively constant at 2.5%/year. The initial decline in fertility that followed introduction of the national family planning program appears to have reached a plateau, explained in part by the resurgence of conservatism and religious fundamentalism and the consequent emphasis on women's childbearing roles. Unemployment in rural areas has led to widespread migration and unemployment is as high as 20% in the nonagricultural sector. Many young Tunisians lack adequate educational preparation to enter the labor force; in 1982, 27% of new job entrants could not read or write. The government's plan to decentralize development to stabilize population and achieve equilibrium between regions has been thwarted by the pace of population growth and limited resources. The rural regions where population is increasing the fastest are also the most difficult to reach with family planning programs. On the other hand, there have been some successes in this area when services have been adapted to the lifestyle and traditions of those in these isolated rural villages.

  13. Stabilization process of human population: a descriptive approach. (United States)

    Kayani, A K; Krotki, K J


    An attempt is made to inquire into the process of stabilization of a human population. The same age distribution distorted by past variations in fertility is subjected to several fixed schedules of fertility. The schedules are different from each other monotonically over a narrow range. The primary concern is with the process, almost year by year, through which the populations become stable. There is particular interest in the differential impact in the same original age distribution of the narrowly different fixed fertility schedules. The exercise is prepared in 3 stages: general background of the process of stabilization; methodology and data used; and analysis and discussion of the stabilization process. Among the several approaches through which the analysis of stable population is possible, 2 are popular: the integral equation and the projection matrix. In this presentation the interest is in evaluating the effects of fertility on the stabilization process of a population. Therefore, only 1 initial age distribution and only 1 life table but a variety of narrowly different schedules of fertility have been used. Specifically, the U.S. 1963 female population is treated as the initial population. The process of stabilization is viewed in the light of the changes in the slopes between 2 successive age groups of an age distribution. A high fertility schedule with the given initial age distribution and mortality level overcomes the oscillations more quickly than the low fertility schedule. Simulation confirms the intuitively expected positive relationship between the mean of the slope and the level of fertility. The variance of the slope distribution is an indicator of the aging of the distribution.

  14. Research on the Fertility Of Bulgarian Women

    Directory of Open Access Journals (Sweden)



    Full Text Available The research on the dynamics of fertility for women in Bulgaria has been carried out through analyzing the distributions of the age-specific fertility rates. For this purpose we have used all four parameters of the statistical distribution - the arithmetic mean, the standard deviation, the coefficient of asymmetry and the coefficient of excess. The experimental research has been carried out as an aggregate for all children and separately for the first, the second and the third birth-order.

  15. Does low fertility call for new policies in some Asian countries? (United States)

    Greenspan, A


    Over the past 2 decades, Japan, China, Singapore, Hong Kong, and South Korea have completed a demographic transition from high birth and death rates and runaway population growth to reduced fertility and mortality and population growth approaching replacement levels. Among the outcomes of fertility decline, 3 have particularly far reaching effects: 1) Changes in family types and structures. Marriage and family formation are postponed, childbearing is compressed into a narrow reproductive span that begins later and ends earlier, and higher-order births become rare. Large families are replaced by small ones, and joint and extended families tend to be replaced by nuclear families. 2) Shifts in the proportions of young and old. Declining fertility means that the population as a whole becomes older. Decreases in the proportion of children provides an opportunity to increase the coverage of education. Increases in the proportion of the elderly means higher medical costs and social and economic problems about care of the aged. 3) Changes in the work force. There is concern that low fertility and shortages of workers will cause investment labor-intensive industries to shift to countries with labor surpluses. Another outcome may be an increase in female participation in the work force. The potential consequences of rapid fertility decline have sparked debate among population experts and policy makers throughout Asia. Current family planning programs will emphasize: 1) offering a choice of methods to fit individual preferences; 2) strengthening programs for sexually active unmarried people; 3) encouraging child spacing and reproductive choice rather than simply limiting the number of births; 4) making information available on the side effects of various family planning methods; 5) providing special information and services to introduce new methods; and 6) promoting the maternal and child health benefits of breast feeding and birth spacing.

  16. The Cost of Raising Fertility

    DEFF Research Database (Denmark)

    Kurjanska, Malgorzata; Lyngsie, Jacob

    the extent to which maternity benefits may have positive externalities for employers, such as increased employee loyalty. Relying on population wide registry data, we carry out multiple group comparisons (e.g. by comparing women who gave birth with those who adopted children, women with children that require......In recent years, Europe has entered a crisis of fertility. One policy solution that countries can, and some have moved to adopt to deal with low fertility rates, is to increase labor benefits granted to new parents, with a particular focus on extending maternity, not paternity, leave. We explore...... more or less in-home care, etc.). We test the extent to which reduced occupational mobility for women with children is a result of an increased sense of loyalty that may accompany generous maternity leave benefits. We also analyze whether employee loyalty brought on by maternity benefits are influenced...

  17. Emotional Variation and Fertility Behavior. (United States)

    Axinn, William G; Ghimire, Dirgha J; Smith-Greenaway, Emily


    Emotional influences on fertility behaviors are an understudied topic that may offer a clear explanation of why many couples choose to have children even when childbearing is not economically rational. With setting-specific measures of the husband-wife emotional bond appropriate for large-scale population research matched with data from a long-term panel study, we have the empirical tools to provide a test of the influence of emotional factors on contraceptive use to limit fertility. This article presents those tests. We use long-term, multilevel community and family panel data to demonstrate that the variance in levels of husband-wife emotional bond is significantly associated with their subsequent use of contraception to avert births. We discuss the wide-ranging implications of this intriguing new result.

  18. Intergenerational fertility correlations in contemporary developing counties. (United States)

    Murphy, Michael


    To estimate the magnitude of intergenerational continuities in total and effective fertility among women in a group of 46 contemporary developing countries. Information collected from 93,000 women aged 45-49 for estimation of maternal mortality in the demographic and health surveys (DHS) program is analyzed using Pearson product moment intergenerational fertility correlations. A positive but usually small intergenerational correlation is found for both completed fertility (CFS, total number of children born) and effective fertility (EFS, number of children surviving to age of reproduction). Although the developing countries are mainly located in sub-Saharan Africa, a similar pattern appears to hold for the Asian and Latin American countries included. Women in the second generation with no education have a stronger relationship with their parents' fertility than women with some education. The relationship is also stronger in rural than in urban areas and in countries with lower levels of development. Intergenerational correlations of completed fertility in both generations are marginally stronger than for effective fertility largely because the number of a woman's total sibs is more strongly related to her subsequent childbearing than her number of adult sibs. Values of intergenerational correlations for these countries are similar to published values for a number of Western pretransitional populations, but well below values in contemporary developed societies. Copyright © 2012 Wiley Periodicals, Inc.

  19. Fertility transition: forecast for demography. (United States)

    Caputo, M; Nicotra, M; Gloria-Bottini, E


    change in the present strong tendency to demographic decline. The basic notion of memory functions is widely recognized in sciences, for example, in the evolutionary theory of Darwin. Here, we introduce into the equations governing population growth a memory mechanism and a perturbation, and we estimate the reactions of the system to perturbations caused by environmental changes and subsequent delayed effects, such as those that appear in the birth rate beginning in 1965 and 1975. The mathematical modeling of the effects of perturbations of the fertility rate in the Italian population, with the introduction of a mathematical memory formalism, suggests that the effect is strongly reduced, with a relaxation time of about 10 years when the fertility rate approaches a stable value.

  20. Low fertility awareness in United States reproductive-aged women and medical trainees: creation and validation of the Fertility & Infertility Treatment Knowledge Score (FIT-KS). (United States)

    Kudesia, Rashmi; Chernyak, Elizabeth; McAvey, Beth


    To create, validate, and use a fertility awareness survey based on current U.S. Cross-sectional study. Not applicable. Phase 1 included U.S. women ages 18-45; phase 2 included female medical students and obstetrics and gynecology trainees at two urban academic programs. Survey including demographics, the Fertility & Infertility Treatment Knowledge Score (FIT-KS) instrument, and General Nutrition Knowledge Questionnaire. Knowledge of natural fertility and infertility treatments. The FIT-KS was validated through detailed item and validity analyses. In phase 1, 127 women participated; their median age was 31 years, and 43.7% had children. Their mean FIT-KS score was 16.2 ± 3.5 (55.9% correct). In phase 2, 118 medical trainees participated; their median age was 25 years, and 12.4% had children. Their mean FIT-KS score was 18.8 ± 2.1 (64.9% correct), with year of training correlating to a higher score (r=0.40). Participant awareness regarding lifestyle factors varied, but it was particularly low regarding the effects of lubricants. The majority underestimated the spontaneous miscarriage rate and overestimated the fecundability of 40-year-old women. There was general overestimation of success rates for assisted reproductive technologies, particularly among medical trainees. The FIT-KS is validated to current U.S. data for use in both general and medical populations as a quick assessment of fertility knowledge. The knowledge gaps demonstrated in this study correlate with national trends in delayed childbearing and time to initiate treatment. For medical trainees, these results raise concerns about the quality of fertility counseling they may be able to offer patients. Greater educational outreach must be undertaken to enhance fertility awareness. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Estimation of population doses from diagnostic medical examinations in Japan, 1974. III. Per caput mean marrow dose and leukemia significant dose

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Maruyama, T; Kumamoto, Y [National Inst. of Radiological Sciences, Chiba (Japan)


    The mean per capita marrow dose and leukemia-significant dose from radiographic and fluoroscopic examinations in Japan have been estimated based on a 1974 nation wide survey of randomly sampled hospitals and clinics. To determine the mean marrow dose to an individual from a certain exposure of a given type of examination, the active marrow in the whole body was divided into 119 parts for an adult and 103 for a child. Dosimetric points on which the individual marrow doses were determined were set up in the center of each marrow part. The individual marrow doses at the dosimetric points in the beams of practical diagnostic x-rays were calculated on the basis of the exposure data on the patients selected in the nation wide survey, using depth dose curves experimentally determined for diagnostic x-rays. The mean individual marrow dose was averaged over the active marrow by summing, for each dosimetric point, the product of the fraction of active marrow exposed and the individual marrow dose at the dosimetric point. The leukemia significant dose was calculated by adopting a weighting factor that is, a leukemia significant factor. The factor was determined from the shape of the time-incidence curve for radiation-induced leukemia from the Hiroshima A-bomb and from the survival statistics for the average population. The resultant mean per capita marrow dose from radiographic and fluoroscopic examination was 37.0 and 70.0 mrad/person/year, respectively, with a total of 107.05 mrad/person/year. The leukemia significant dose was 32.1 mrad/person/year for radiographic examination and 61.2 mrad/person/year, with a total of 93.3. These values were compared with those of 1960 and 1969.

  2. Genetic Relationship between Culling, Milk Production, Fertility, and Health Traits in Norwegian Red Cows

    DEFF Research Database (Denmark)

    Holtsmark, M; Heringstad, B; Madsen, P


    First-lactation records on 836,452 daughters of 3,064 Norwegian Red sires were used to examine associations between culling in first lactation and 305-d protein yield, susceptibility to clinical mastitis, lactation mean somatic cell score (SCS), nonreturn rate within 56 d in heifers and primiparous......, including functional traits such as health and fertility, most of the genetic variation in culling will probably be covered by other traits in the breeding goal. However, in populations where data on health and fertility is scarce or not available at all, selection against early culling may be useful...... cows, and interval from calving to first insemination. A Bayesian multivariate threshold-linear model was used for analysis. Posterior mean of heritability of liability to culling of primiparous cows was 0.04. The posterior means of the genetic correlations between culling and the other traits were -0...

  3. Protect Your Fertility (United States)

    ... your teens and early twenties can affect your fertility for years to come. This prevention guide was written by ... loss of testic- ulor size, see your doctor. Fertility is something that you ... approximately 40 percent of infertile couples, the male partner is ...

  4. Fertilization in northern forests

    DEFF Research Database (Denmark)

    Hedwall, Per Ola; Gong, Peichen; Ingerslev, Morten


    resources into food, health and industrial products and energy. Fertilization in Sweden and Finland is currently practiced by extensive fertilization regimens where nitrogen fertilizers are applied once, or up to three times, during a rotation period, mainly in mature forest. This type of fertilization...... gives, in most cases, a small and transient effect on the environment as well as a high rate of return to the forest owner with low-economic risk. The increase in biomass production, however, is relatively small and consequently the impact on the processing industry and the bioeconomy is limited. More...... in combination with present management systems and, almost instantly, enhances forest productivity. There may, however, be both economic and environmental constraints to large-scale applications of fertilizers in forest. Here we review the literature concerning biomass production of forests under different...

  5. Population Size Predicts Lexical Diversity, but so Does the Mean Sea Level --Why It Is Important to Correctly Account for the Structure of Temporal Data. (United States)

    Koplenig, Alexander; Müller-Spitzer, Carolin


    In order to demonstrate why it is important to correctly account for the (serial dependent) structure of temporal data, we document an apparently spectacular relationship between population size and lexical diversity: for five out of seven investigated languages, there is a strong relationship between population size and lexical diversity of the primary language in this country. We show that this relationship is the result of a misspecified model that does not consider the temporal aspect of the data by presenting a similar but nonsensical relationship between the global annual mean sea level and lexical diversity. Given the fact that in the recent past, several studies were published that present surprising links between different economic, cultural, political and (socio-)demographical variables on the one hand and cultural or linguistic characteristics on the other hand, but seem to suffer from exactly this problem, we explain the cause of the misspecification and show that it has profound consequences. We demonstrate how simple transformation of the time series can often solve problems of this type and argue that the evaluation of the plausibility of a relationship is important in this context. We hope that our paper will help both researchers and reviewers to understand why it is important to use special models for the analysis of data with a natural temporal ordering.

  6. Means of evaluation of population dose from the natural background of radiation for control of the exposure of environment of nuclear power plants

    International Nuclear Information System (INIS)

    Pensko, J.


    Given in this paper are the method and the results of calculation of the average value of the equivalent of the dose of the natural background of radiation, affecting the gonads and the bone marrow of the inhabitants of one of the regions of Poland, chosen as an example. These values weighed on a number of more important environmental factors, amounts to 78.0 mrem/years for gonads and 72.1 mrem/year for bone marrow. The value of the total population dose for the investigated region, from these sources of radiation, does not exceed 1.2 x 10 4 man-rem/year. Calculations were performed mainly on the base of the results of measurements of the exposure dose rate by a scintillation monitor from aboard an airplane, using also the numerous measurements of the dose at the height of 1 m over the earth's surface, done by means of a high-pressure ionization chamber, and the results of gamma spectrometric analysis of samples of soil. In calculations, coefficients of transformation of the exposure dose into the dose absorbed by various tissues, and the time spent indoors, were taken into consideration. For this purpose, using a proper coefficient of building screen has been suggested. This method can be used for estimating the average population dose, from the external radiation originating from natural and artificial radioactive sources, present in the environment of nuclear power plants. (author)

  7. Human rights to in vitro fertilization. (United States)

    Zegers-Hochschild, Fernando; Dickens, Bernard M; Dughman-Manzur, Sandra


    The Inter-American Court of Human Rights (the Court) has ruled that the Supreme Court of Costa Rica's judgment in 2000 prohibiting in vitro fertilization (IVF) violated the human right to private and family life, the human right to found and raise a family, and the human right to non-discrimination on grounds of disability, financial means, or gender. The Court's conclusions of violations contrary to the American Convention on Human Rights followed from its ruling that, under the Convention, in vitro embryos are not "persons" and do not possess a right to life. Accordingly, the prohibition of IVF to protect embryos constituted a disproportionate and unjustifiable denial of infertile individuals' human rights. The Court distinguished fertilization from conception, since conception-unlike fertilization-depends on an embryo's implantation in a woman's body. Under human rights law, legal protection of an embryo "from conception" is inapplicable between its creation by fertilization and completion of its implantation in utero. © 2013.

  8. Analysis of the Relationship between CGB5 155G/C Polymorphism and in vitro Fertilization-embryo Transfer Outcome (IVF-ET in the Iranian Population

    Directory of Open Access Journals (Sweden)

    Bahareh Babaei Houlari


    Full Text Available Abstract Background: Successful pregnancy depends on the ability of the embryo to achieve appropriate extent of trophoblastic proliferation and invasion into maternal endometrium as well as, once implanted, to induce its own blood supply. Beta Human chorionic gonadotropin (β-hCG, enhances blastocyst implantation, uterine vascularization, and angiogenesis, as well as regulates maintenance of uterine quiescence and immunological adaptation during pregnancy. The β-subunit of hCG is encoded by CGB3, CGB6, CGB5, CGB7 and CGB8 genes. The aim of this study was to evaluate the association of CGB5-G/C polymorphism and the clinical outcomes in women who underwent IVF-ET procedures. Materials and Methods: A total of 200 patients undergoing IVF-ET (100 patients with positive and 100 patients with negative IVF-ET outcome were included in this study. Genotyping of CGB5 at -155G/C polymorphic site was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP. Statistical analysis was performed using the MedCalc software. Results: Our findings show that the CC genotype of the CGB5 -155G/C polymorphism is associated with decreased risk of IVF-ET failure (OR=0.29; 95%CI=0.1-0.85; p=0.02. However, the allelic distribution of the CGB5 -155G/C is not significantly different between two groups (χ2=1.46; p=0.22. Conclusion: The results of this study suggested that CGB5 (-155G/C CC genotype has a protective effect on IVF-ET outcome. More studies with larger sample sizes on different populations are necessary to elucidate the underlying mechanisms which can explain the associations found between the GGB5 gene polymorphisms and IVF-ET outcome.

  9. Declining world fertility: trends, causes, implications. (United States)

    Tsui, A O; Bogue, D J


    This Bulletin examines the evidence that the world's fertility has declined in recent years, the factors that appear to have accounted for the decline, and the implications for fertility and population growth rates to the end of the century. On the basis of a compilation of estimates available for all nations of the world, the authors derive estimates which indicate that the world's total fertility rate dropped from 4.6 to 4.1 births per woman between 1968 and 1975, thanks largely to an earlier and more rapid and universal decline in the fertility of less developed countries (LDCs) than had been anticipated. Statistical analysis of available data suggests that the socioeconomic progress made by LDCs in this period was not great enough to account for more than a proportion of the fertility decline and that organized family planning programs were a major contributing factor. The authors' projections, which are compared to similar projections from the World Bank, the United Nations, and the U.S. Bureau of the Census, indicate that, by the year 2000, less than 1/5 of the world's population will be in the "red danger" circle of explosive population growth (2.1% or more annually); most LDCs will be in a phase of fertility decline; and many of them -- along with most now developed countries -- will be at or near replacement level of fertility. The authors warn that "our optimistic prediction is premised upon a big IF -- if (organized) family planning (in LDCs) continues. It remains imperative that all of the developed nations of the world continue their contribution to this program undiminished."

  10. Radiation doses from phosphate fertilizers

    International Nuclear Information System (INIS)



    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer coverage of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words, a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  11. Natural radioactivity in phosphate fertilizers

    International Nuclear Information System (INIS)

    Arndt, J.; Aurand, K.; Ruehle, H.; Schmier, H.; Wolter, R.


    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer covering of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  12. The impact of differences between patient and general population EQ-5D-3L values on the mean tariff scores of different patient groups. (United States)

    Little, Matthew H R; Reitmeir, Peter; Peters, Annette; Leidl, Reiner


    Health states can be valued by those who currently experience a health state (experienced health states [EHS]) or by the general public, who value a set of given health states (GHS) described to them. There has been debate over which method is more appropriate when making resource allocation decisions. This article informs this debate by assessing whether differences between these methods have an effect on the mean EQ-5D-3L tariff scores of different patient groups. The European tariff based on GHS valuations was compared with a German EHS tariff. Comparison was made in the context of EQ-5D-3L health states describing a number of diagnosed chronic diseases (stroke, diabetes, myocardial infarction, and cancer) taken from the Cooperative Health Research in the Augsburg Region population surveys. Comparison was made of both the difference in weighting of the dimensions of the EQ-5D-3L and differences in mean tariff scores for patient groups. Weighting of the dimensions of the EQ-5D-3L were found to be systematically different. The EHS tariff gave significantly lower mean scores for most, but not all, patient groups despite tariff scores being lower for 213 of 243 EQ-5D-3L health states using the GHS tariff. Differences were found to vary between groups, with the largest change in difference being 5.45 in the multiple stoke group. The two tariffs have systematic differences that in certain patient groups could drive the results of an economic evaluation. Therefore, the choice as to which is used may be critical when making resource allocation decisions. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  13. Fertility Preservation for Pediatric Patients: Current State and Future Possibilities. (United States)

    Johnson, Emilie K; Finlayson, Courtney; Rowell, Erin E; Gosiengfiao, Yasmin; Pavone, Mary Ellen; Lockart, Barbara; Orwig, Kyle E; Brannigan, Robert E; Woodruff, Teresa K


    This review provides an overview of pediatric fertility preservation. Topics covered include the patient populations who could benefit, the current state of fertility preservation options and research, and considerations related to ethics and program development. A broad Embase® and PubMed® search was performed to identify publications discussing investigational, clinical, ethical and health care delivery issues related to pediatric fertility preservation. Relevant publications were reviewed and summarized. Populations who could benefit from fertility preservation in childhood/adolescence include oncology patients, patients with nononcologic conditions requiring gonadotoxic chemotherapy, patients with differences/disorders of sex development and transgender individuals. Peripubertal and postpubertal fertility preservation options are well established and include cryopreservation of oocytes, embryos or sperm. Prepubertal fertility preservation is experimental. Multiple lines of active research aim to develop technologies that will enable immature eggs and sperm to be matured and used to produce a biological child in the future. Ethical challenges include the need for parental proxy decision making and the fact that fertility preservation procedures can be considered not medically necessary. Successful multidisciplinary fertility preservation care teams emphasize partnerships with adult colleagues, prioritize timely consultations and use standardized referral processes. Some aspects of fertility preservation are not covered by insurance and out-of-pocket costs can be prohibitive. Pediatric fertility preservation is an emerging, evolving field. Fertility preservation options for prepubertal patients with fertility altering conditions such as cancer and differences/disorders of sex development are currently limited. However, multiple lines of active research hold promise for the future. Key considerations include establishing a multidisciplinary team to provide


    African Journals Online (AJOL)


    The UN Millennium Project aims to reduce poverty, hunger, and disease while promoting ... Fertility is not mentioned anywhere within the eight goals, but population growth ... findings reveal a total fertility rate (TFR) of 7.97, which surpasses the TFR of 7.3 reported from ... world and the largest in sub-Saharan Africa, with an.

  15. Levels and proximate determinants of fertility in Butajira District ...

    African Journals Online (AJOL)

    Background: Uncontrolled population growth is evidenced mainly because of the high fertility. Improving maternal and child health services in Ethiopia were one of the main aims of the health extension program. The impediment of early marriage was revised in the national family code which claims assessment of fertility ...

  16. Perchlorate in Fertilizers

    National Research Council Canada - National Science Library

    Eldridge, J. E; Tsui, D. T; Mattie, D. R; Crown, J; Scott, R; Blackman, T


    ...) methods for perchlorate analysis in lawn and garden fertilizers. Seven government, private, and commercial laboratories participated in the analysis of 34 aqueous suspensions of the test materials, using similar ion chromatography systems...

  17. Commercial Phosporus Fertilizer Purchased (United States)

    U.S. Environmental Protection Agency — Amounts of fertilizer P2O5 purchased by states in individual years 2003, 2005, 2007, 2009 and 2011, and the % change in average amounts purchased per year from...

  18. Commercial Nitrogen Fertilizer Purchased (United States)

    U.S. Environmental Protection Agency — Amounts of fertilizer nitrogen (N) purchased by states in individual years 2003, 2005, 2007, 2009 and 2011, and the % change in average amounts purchased per year...

  19. Cancer and fertility preservation

    DEFF Research Database (Denmark)

    Lambertini, Matteo; Del Mastro, Lucia; Pescio, Maria C


    In the last years, thanks to the improvement in the prognosis of cancer patients, a growing attention has been given to the fertility issues. International guidelines on fertility preservation in cancer patients recommend that physicians discuss, as early as possible, with all patients...... of reproductive age their risk of infertility from the disease and/or treatment and their interest in having children after cancer, and help with informed fertility preservation decisions. As recommended by the American Society of Clinical Oncology and the European Society for Medical Oncology, sperm...... data have become available, and several issues in this field are still controversial and should be addressed by both patients and their treating physicians.In April 2015, physicians with expertise in the field of fertility preservation in cancer patients from several European countries were invited...

  20. Queering the fertility clinic. (United States)

    Mamo, Laura


    A sociologist examines contemporary engagements of queer bodies and identities with fertility biomedicine. Drawing on social science, media culture, and the author's own empirical research, three questions frame the analysis: 1. In what ways have queers on the gendered margins moved into the center and become implicated or central users of biomedicine's fertility offerings? 2. In what ways is Fertility Inc. transformed by its own incorporation of various gendered and queered bodies and identities? And 3. What are the biosocial and bioethical implications of expanded queer engagements and possibilities with Fertility Inc.? The author argues that "patient" activism through web 2.0 coupled with a largely unregulated free-market of assisted reproduction has included various queer identities as "parents-in-waiting." Such inclusions raise a set of ethical tensions regarding how to be accountable to the many people implicated in this supply and demand industry.

  1. Sperm preparation for fertilization

    NARCIS (Netherlands)

    Gadella, B.M.


    Description This book contains 19 chapters that discuss theoretical and applied andrology for domestic, zoo and wild animals. Topics include semen and its constituents; sperm production and harvest; determinants of sperm morphology; sperm preparation for fertilization; practical aspects of semen

  2. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    Ecology and the. Environment ... agents (pollinators), the next step before fertilization is to se- .... the embryo sac are referred to as pollen-pistil interaction and play ..... evolutionary success of flowering plants when compared to other groups of ...

  3. Is glycosylated haemoglobin a marker of fertility?

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter


    We performed a follow-up study of time to pregnancy in a population of first-time pregnancy planners without previous reproductive experience. The objective of this paper is to report and discuss a finding of a strong relationship between glycosylated haemoglobin (HbA1C) and fertility. A total...

  4. Playing the Fertility Game at Work

    DEFF Research Database (Denmark)

    Ciliberto, Federico; Miller, Amalia Rebecca; Nielsen, Helena Skyt


    . Allowing for heterogeneous effects by worker type, we find that positive effects dominate across worker types defined by age or education. Negative effects dominate within age groups and among low-education types. Policy simulations show that these estimated effects make the distribution of where women...... work an important consideration, beyond simply if they work, in predicting population fertility....

  5. Immunosuppressive drugs and fertility


    Leroy, Clara; Rigot, Jean-Marc; Leroy, Maryse; Decanter, Christine; Le Mapihan, Kristell; Parent, Anne-Sophie; Le Guillou, Anne-Claire; Yakoub-Agha, Ibrahim; Dharancy, Sébastien; Noel, Christian; Vantyghem, Marie-Christine


    Immunosuppressive drugs are used in the treatment of inflammatory and autoimmune diseases, as well as in transplantation. Frequently prescribed in young people, these treatments may have deleterious effects on fertility, pregnancy outcomes and the unborn child. This review aims to summarize the main gonadal side effects of immunosuppressants, to detail the effects on fertility and pregnancy of each class of drug, and to provide recommendations on the management of patients who are seen prior ...

  6. Organic Biochar Based Fertilization (United States)

    Schmidt, Hans-Peter; Pandit, Bishnu Hari; Cornelissen, Gerard; Kammann, Claudia


    Biochar produced in cost-efficient flame curtain kilns (Kon-Tiki) was nutrient enriched either with cow urine or with dissolved mineral (NPK) fertilizer to produce biochar-based fertilizers containing between 60-100 kg N, 5-60 kg P2O5 and 60-100 kg K2O, respectively, per ton of biochar. In 21 field trials nutrient-enriched biochars were applied at rates of 0.5 to 2 t ha-1 into the root zone of 13 different annual and perennial crops. Treatments combining biochar, compost and organic or chemical fertilizer were evaluated; control treatments contained the same amounts of nutrients but without biochar. All nutrient-enriched biochar substrates improved yields compared to their respective no-biochar controls. Biochar enriched with dissolved NPK produced on average 20% ± 5.1% (N=4) higher yields than standard NPK fertilization without biochar. Cow urine-enriched biochar blended with compost resulted on average in 123% ± 76.7% (N=13) higher yields compared to the organic farmer practice with cow urine-blended compost and outcompeted NPK-enriched biochar (same nutrient dose) by 103% ± 12.4% (N=4) on average. 21 field trials robustly revealed that low-dosage root zone application of organic biochar-based fertilizers caused substantial yield increases in rather fertile silt loam soils compared to traditional organic fertilization and to mineral NPK- or NPK-biochar fertilization. This can likely be explained by the nutrient carrier effect of biochar causing a slow nutrient release behavior, more balanced nutrient fluxes and reduced nutrient losses especially when liquid organic nutrients are used for the biochar enrichment. The results promise new pathways for optimizing organic farming and improving on-farm nutrient cycling.

  7. Kerala reaps low fertility dividends. (United States)


    Unlike much of India, the state of Kerala has promoted the development of human resources, resulting in lower fertility rates. If current UN projections are correct, India will overtake China as the most populous nation in the world by 2025. Within India, however, great differences exist in fertility rates, reflecting the level of commitment from state governments. In India, state governments control much of the policy and spending on health, education, etc. While the state of Kerala has been among the most committed to human resource development in the developing world, India's 5 northern states (Rajasthan, Uttar Pradesh, Madhya Pradesh, Bihar, and Orissa) have been among the least committed. As a result, Kerala's fertility rate has fallen to 2.3 children/women--a rate lower than that of Thailand, China, the formers USSR, or Ireland. Kerala has a contraceptive prevalence rate 3 times the national average and the lowest infant mortality rate in all of India--only 26/1000 live births (infant mortality is 4-5 times higher in the 5 northern states). Only 27% of Kerala's population lives in poverty, compared to 34-49.5% in the northern states. Real incomes and industrialization have been growing faster in Kerala. And industrialization does not appear to have come at the expense of the environment. 2 factors are responsible for Kerala' accomplishments: 1) State government support of human development--the state has invested in health, education, and has conducted a land reform benefiting 3 million landless peasants. 2) The status of women--in Kerala, women are viewed as an asset, not a liability (as in the north). Kerala's female literacy is 66%, compared to 11-21% in the northern states. Kerala also enjoys the highest level of female labor force participation (35%) anywhere in India.

  8. Fertility among female hairdressers. (United States)

    Axmon, Anna; Rylander, Lars; Lillienberg, Linnea; Albin, Maria; Hagmar, Lars


    The study investigated whether working as a hairdresser has a negative impact on fertility, measured as time to pregnancy and miscarriage risk. Self-administered questionnaires were sent to 5289 Swedish hairdressers (response rate 50%) and to 5299 age-matched women from the general Swedish population (response rate 54%). Information was collected on time to pregnancy or trying time for women who had tried, but failed, to conceive at the time of the study. The outcome of the pregnancy was determined and categorized as either miscarriage or stillbirth or live birth. The hairdressers were compared with the referents with respect to these two outcomes. Within the hairdresser cohort, the effects of hair treatments, as well as physical workload and stress were investigated. The hairdressers were less successful than the reference cohort in conceiving (fecundability ratio 0.91, 95% confidence interval 0.83-0.99). The effect was reduced after first-month conceptions were excluded, the indication being that the effect may be the result of birth control bias. Within the hairdresser cohort, a self-perceived stressful work situation seemed to prolong the time to pregnancy. No effects were found for the different chemical hair treatments. There was no cohort difference with respect to miscarriage risk (odds ratio 1.12, 95% confidence interval 0.88-1.42), but miscarriage risks were increased for most of the hair treatments and for self-perceived stressful work situations. However, none of these effects were statistically significant. The present study indicates a negative impact on time to pregnancy and miscarriage risk for working as a hairdresser".

  9. Development of Malaysian women fertility index: Evidence from Shannon's entropy (United States)

    Jalil, Wan Aznie Fatihah Wan Abd; Sharif, Shamshuritawati


    A fertility rate is a measure of the average number of children a woman will have during her childbearing years. Malaysia is now facing a population crisis and the fertility rate continues to decline. This situation will have implications for the age structure of the population where percentages of senior citizens are higher than percentages of people aged below 5 years old. Malaysia is expected to reach aging population status by the year 2035. As the aging population has a very long average life expectancy, the government needs to spend a lot on medical costs for senior citizens and need to increase budgets for pensions. The government may be required to increase tax revenues to support the growing older population. The falling fertility rate requires proper control by relevant authorities, especially through planning and implementation of strategic and effective measures. Hence, this paper aims to develop a fertility index using Shannon's entropy method. The results show that Selangor, Johor, and Sarawak are among the states with the highest values of the fertility index. On the other end of the spectrum, Terengganu, W.P. Labuan, and Perlis are ranked in the last positions according to the fertility index. The information generated from the results in this study can be used as a primary source for the government to design appropriate policies to mitigate dwindling fertility rates among Malaysian women.

  10. Fertility desires among men and women living with HIV/AIDS in Nairobi slums: a mixed methods study.

    Directory of Open Access Journals (Sweden)

    Eliud Wekesa

    Full Text Available Fertility desires require new understanding in a context of expanding access to antiretroviral therapy for people living with HIV/AIDS in Sub-Saharan Africa. This paper studies the fertility desires and their rationales, of slum-dwelling Kenyan men and women living with HIV/AIDS who know their serostatus, but have different antiretroviral therapy treatment statuses. It addresses two research questions: How do people living with HIV/AIDS consider their future fertility? What factors contribute to an explanation of fertility desires among people living with HIV/AIDS.A mixed methods study (survey [n = 513] and in-depth interviews [n = 41] with adults living with HIV/AIDS living in Nairobi slums was conducted in 2010. Regression analyses assess independent relationships between fertility desires and socio-demographic factors. Analyses of in-depth interviews are used to interpret the statistical analyses of fertility desires.Our analyses show that fertility desires are complex and ambivalent, reflecting tensions between familial and societal pressures to have children versus pressures for HIV (re-infection prevention. More than a third (34% of men and women living with HIV expressed future fertility desires; however, this is significantly lower than in the general population. Factors independently associated with desiring a child among people living with HIV/AIDS were age, sex, number of surviving children, social support and household wealth of the respondent.Increasing access to ART is changing the context of future childbearing for people living with HIV/AIDS. Prevailing values mean that, for many people living with HIV/AIDS, having children is seen as necessary for a "normal" and healthy adult life. However, the social rewards of childbearing conflict with moral imperatives of HIV prevention, presenting dilemmas about the "proper" reproductive behaviour of people living with HIV/AIDS. The health policy and service delivery implications of

  11. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fishereis Resource Management, Lapwai, ID)


    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 2000 annual report covers the fourth year of sampling of this multi-year study. In 2000 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon rivers. The Snake River was sampled between Lower Granite Dam (rkm 174) and the mouth of the Salmon River (rkm 303), and the Salmon River was sampled from its mouth upstream to Hammer Creek (rkm 84). A total of 53,277 hours of setline effort and 630 hours of hook-and-line effort was employed in 2000. A total of 538 white sturgeon were captured and tagged in the Snake River and 25 in the Salmon River. Since 1997, 32.8 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 48 cm to 271 cm and averaged 107 cm. In the Salmon River, white sturgeon ranged in total length from 103 cm to 227 cm and averaged 163 cm. Using the Jolly-Seber open population estimator, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,725 fish, with a 95% confidence interval of 1,668-5,783. A total of 10 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 54.7 km (34 miles) downstream to 78.8 km (49 miles) upstream; however, 43.6 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of


    African Journals Online (AJOL)


    women of the reproductive age of 15-49 years with Davis and Blake framework ... fertility forming the theoretical orientation for the study. The mean age of ... Keywords: socio-economic factors, fertility, proximate variables, Abia State .... aspirations, individualization and changes in gender roles – which may particularly have.

  13. Fertility and hatchability of Japanese quail eggs under semi arid ...

    African Journals Online (AJOL)

    Some factors affecting the fertility and hatchability of Japanese quail eggs were studied at the Poultry Unit of the University of Maiduguri Livestock Teaching and Research Farm. A total of 1850 eggs were used for the study and data collected were subjected to Analysis of Variance. The mean values of fertility, hatchability of ...

  14. Some chemical parameters of a fertilized productive pond | Nwamba ...

    African Journals Online (AJOL)

    There was no significant variation (P>0.05) in the conductivity (ionic content) of the pond water whether fertilized or unfertilized. The increased in the mean values of free carbon dioxide during the fertilized period was attributed to increased rate of decomposition of organic matter and a concomitant release of carbon dioxide.

  15. Human Fertility Increases with the Marital-radius

    DEFF Research Database (Denmark)

    Labouriau, Rodrigo; Amorim, António


    We report a positive association between marital radius (distance between mates' birthplaces) and fertility detected in a large population. Spurious association due to socioeconomic factors is discarded by a conditional analysis involving income, education, and urbanicity. Strong evidence...

  16. Is glycosylated haemoglobin a marker of fertility?

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, T K; Bonde, J P


    We performed a follow-up study of time to pregnancy in a population of first-time pregnancy planners without previous reproductive experience. The objective of this paper is to report and discuss a finding of a strong relationship between glycosylated haemoglobin (HbA1C) and fertility. A total...... concentration of inhibin A. No association was found between HbA1C and psychosocial distress. The reduced fertility among women with high HbA1C may be due to an association with subclinical polycystic ovaries as indicated by the hormonal profile....

  17. Fertility targets and policy options in Asia. (United States)

    Bulatao, R A


    The 3rd Asian and Pacific Population Conference in Colombo in 1982 recommended that countries review and modify existing demographic targets and goals for reducing birth and death rates in order to attain low levels as early as possible and to attain replacement level by the year 2000. The demographic goals of selected Asian countries (Bangladesh, Indonesia, Korea, Thailand, India, Pakistan, and the Philippines are assessed and compared to World Bank population projections. It also discusses the underlying rationale for setting fertility targets, and considers what government actions could make them more achievable. 6 stages for controlling population are distinguished: 1) collection and publication of reliable demographic data; 2) enunciation of an official policy to reduce population growth; 3) development of appropriate institutions to integrate demographic projections into economic plans; 4) promotion of family planning; 5) provision of incentives and disincentives, including elimination of all implicit and explicit subsidies for child bearing; and 6) restitution of birth quotas requiring permission for each child born. Principles to maintain and accelerate fertility declines to meet demographic targets include creating appropriate and equitable development policies, increasing the standard of family planning programs, confronting organizational problems, providing easier and more equal access to contraceptive methods, exploring innovative approaches to encourage smaller families and making a firm political commitment to population control. Rapid fertility decline will also require financial commitment. Willingness to spend the necessary amounts, and the capacity to spend them as well, will determine whether the countries of Asia enter the next century in control of their population.

  18. Taking Exception. Reduced mortality leads to population growth: an inconvenient truth. (United States)

    Shelton, James D


    Reduced mortality has been the predominant cause of the marked global population growth over the last 3/4 of a century. While improved child survival increases motivation to reduce fertility, it comes too little and too late to forestall substantial population growth. And, beyond motivation, couples need effective means to control their fertility. It is an inconvenient truth that reducing child mortality contributes considerably to the population growth destined to compromise the quality of life of many, particularly in sub-Saharan Africa. Vigorous child survival programming is of course imperative. Wide access to voluntary family planning can help mitigate that growth and provide many other benefits.

  19. Sexuality and fertility in women with Addison's disease. (United States)

    Erichsen, Martina M; Husebye, Eystein S; Michelsen, Trond M; Dahl, Alv A; Løvås, Kristian


    Females with primary adrenal insufficiency (Addison's disease) have reduced levels of circulating androgens, which are allegedly important for sexual functioning. The aim was to determine peripheral androgen status, sexual functioning, and birth rates in Addison's disease females. In a postal survey, all 269 females in the Norwegian Addison's registry were invited to complete the Sexual Activity Questionnaire (SAQ) and registration of childbirths. Blood samples were analyzed for 5alpha-androstane-3alpha,17beta-diol-3-glucuronide (3alpha-Diol-G) and compared with blood donor levels. The SAQ scores were compared with 740 age-matched controls from the general population and 234 women subjected to risk-reducing salpingo-oophorectomy. Fertility was estimated as standardized incidence ratio for birth; the expected number of births was estimated from population statistics. The SAQ was completed by 174 (65%) of the Addison's patients. Those not taking DHEA had significantly lower 3alpha-Diol-G levels than blood donors (mean, 0.53 vs. 2.2 ng/ml; P Addison's disease females were equally sexually active as the controls, but they reported significantly higher pleasure and less discomfort. They reported lower pleasure but less discomfort than the risk-reducing salpingo-oophorectomy women. The fertility was significantly reduced in females with Addison's disease; 54 children were born to mothers with established diagnosis (87.5 expected), yielding a standardized incidence ratio for birth of 0.69 (confidence interval, 0.52-0.86). Despite androgen depletion, females with Addison's disease do not report impaired sexuality. The fertility is reduced after the diagnosis is made; the reasons for this remain unknown.


    African Journals Online (AJOL)

    Dr. K.E. Law-Ogbomo

    main plot, defoliation (sub-plot) and time of defoliation (sub- sub plot). ... using analysis of variance procedure for split – split plot design and means were ... The interaction between NPK fertilizer application and defoliation was only .... yield components (number of dry pod per plant, number of seeds per pod and plant).

  1. Socioeconomic status and fertility decline: Insights from historical transitions in Europe and North America (United States)

    Dribe, Martin; Breschi, Marco; Gagnon, Alain; Gauvreau, Danielle; Hanson, Heidi A.; Maloney, Thomas N.; Mazzoni, Stanislao; Molitoris, Joseph; Pozzi, Lucia; Smith, Ken R.; Vézina, Hélène


    We have good knowledge of the timing of the historical fertility transitions in different regions, but we know much less regarding specific features and causes. In this study, we used longitudinal micro-level data for five local populations in Europe and North America to study the relationship between socioeconomic status and fertility during the transition. Using the same analytical model and identical class scheme, we examined the development of socioeconomic differences in marital fertility and related it to common theories on fertility behaviour. Our results do not provide support for the hypothesis of universally high fertility among the upper classes in pre-transitional society but support the idea that they acted as forerunners in the transition by reducing their fertility before other groups. Farmers and unskilled workers were latest to start to limit their fertility. Apart from this regularity, the patterns of class differences in fertility varied significantly among populations. PMID:27884093

  2. Evaluate Potenial Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A.; Hesse, Jay A. (Nez Perce Tribe, Department of Fisheries Management, Lapwai, ID)


    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This report presents a summary of results from the 1997-2002 Phase II data collection and represents the end of phase II. From 1997 to 2001 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon. A total of 1,785 white sturgeon were captured and tagged in the Snake River and 77 in the Salmon River. Since 1997, 25.8 percent of the tagged white sturgeon have been recaptured. Relative density of white sturgeon was highest in the free-flowing segment of the Snake River, with reduced densities of fish in Lower Granite Reservoir, and low densities the Salmon River. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir, the free-flowing Snake River and the Salmon River (Chi-Square test, P<0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 30 percent since the 1970's. Using the Jolly-Seber model, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,483 fish, with a 95% confidence interval of 1,208-7,477. Total annual mortality rate was estimated to be 0.14 (95% confidence interval of 0.12 to 0.17). A total of 35 white sturgeon were fitted with radio-tags during 1999-2002. The movement of these fish ranged from 53 km (33 miles) downstream to 77 km (48 miles) upstream; however, 38.8 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No

  3. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Tuell, Michael A.; Everett, Scott R. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)


    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 1999 annual report covers the third year of sampling of this multi-year study. In 1999 white sturgeon were captured, marked and population data were collected in the Snake and Salmon rivers. A total of 33,943 hours of setline effort and 2,112 hours of hook-and-line effort was employed in 1999. A total of 289 white sturgeon were captured and tagged in the Snake River and 29 in the Salmon River. Since 1997, 11.1 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 27 cm to 261 cm and averaged 110 cm. In the Salmon River, white sturgeon ranged in total length from 98 cm to 244 cm and averaged 183.5 cm. Using the Jolly-Seber model, the abundance of white sturgeon < 60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 1,823 fish, with a 95% confidence interval of 1,052-4,221. A total of 15 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 6.4 km (4 miles) downstream to 13.7 km (8.5 miles) upstream; however, 83.6 percent of the detected movement was less than 0.8 kilometers (0.5 miles). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River

  4. Fertility reduction programmes should accompany land reforms. (United States)

    Atiku, J


    Changes in population size both affect and are affected by the rate of development. With the total world population estimated to be 5.7 billion in mid-1994 and annual growth at 1.7%, declines in total fertility rates and overall growth rates in developing countries have not been sufficient to precipitate a decline in actual numbers. The population of developing countries has doubled from 1962 to 1994. The highest growth rates are expected to be in sub-Saharan Africa, but the largest absolute increase in population is expected to occur in Asia. Uganda's population has increased from 4.9 to 16.7 million from 1948 to 1991. At the current rate of increase (2.5%) and taking AIDS into account, Uganda's population is expected to double in 28 years. Rapid population growth in developing countries can be explained by the following factors: 1) high levels of morbidity and mortality which threaten child survival and encourage large families; 2) early marriage which extends reproductive activity; 3) a high value placed on children, especially sons; 4) unmet needs for family planning; 5) widespread poverty which causes children to be viewed as old age security; and 6) population momentum which would contribute to growth even if replacement fertility were achieved because of the current age-sex structure of the population. The impact of rapid population growth on development requires further study, but some things are clear. Economic development is hindered when the number of dependent and poor individuals in a population increases. High rates of fertility result in poor infant and maternal health. The provision of social welfare services and the capacity for providing basic services such as health care, education, safe water, and sanitation is strained by rapid population growth. Also, the quality of the environment is adversely affected by rapid population growth. Population policies should be developed for each country and should emphasize activities to improve individual

  5. Male Fertility After Inguinal Hernia Mesh Repair

    DEFF Research Database (Denmark)

    Kohl, Andreas Pagh; Andresen, Kristoffer; Rosenberg, Jacob


    OBJECTIVE:: To determine whether patients who receive an inguinal hernia repair father the same number of children as the background population. BACKGROUND:: Although the effect of inguinal hernia repair on male fertility has previously been investigated through indirect measures, no previous...... studies have evaluated the final measure of male fertility, which is the number of children fathered by patients. METHODS:: Prospectively collected data on 32,621 male patients between the ages of 18 and 55 years who received 1 or more inguinal hernia repairs during the years 1998 to 2012 were found in 5...... hernia repair using Lichtenstein technique or laparoscopic approach did not father fewer children than expected. Thus, inguinal hernia repair using Lichtenstein or laparoscopic approach did not impair male fertility....

  6. Kinship and the decline of fertility. (United States)

    Zhou, Y


    China's family planning and population control policies, together with the move toward a more market-oriented economy since the 1980s, have led to significant change in people's reproductive values and behavior and a substantial decline in fertility. Traditional kinship in China, its terminology, and the impact of fertility decline on kinship in China and Chinese society are discussed. The decline in fertility is affecting or will affect China's kinship system, the corresponding pattern of terminology, and the social structure. In the more market-oriented economy which has been developing in China, the simplification of the kinship system will help change the structure of Chinese society and weaken the traditional patriarchal culture. A more individualized, contractualized social structure and relationships will result.

  7. Marriage and fertility in the developed countries. (United States)

    Westoff, C F


    Most developed countries have reached zero population growth or less and, while population projections have often proved badly off-target, it seems that currently low fertility levels are the result of a long-term trend, which was interrupted in the last 100 years only by the still-unexplained postwar baby boom, and which will probably continue. The declining trend has accompanied economic development and modernization, which have transformed the economic value of children, making them a drain on resources rather than a source of income. The concomitant social changes seem largely irreversible: urban economy, the decline in traditional authority, universal, prolonged education, equality of women, low infant mortality, high consumer demands and sophisticated birth control technology are all here to stay. The theory that fertility exhibits a cyclical pattern based on people's perception of their degree of economic and social opportunity ignores the other elements affecting fertility behavior, especially the radical change in the status and expectations of women. Several trends in marriage and reproductive behavior in the U.S., Denmark and Sweden reinforce the presumption that fertility will remain low: declining number of marriages; postponement of marriage; increased tendency for unmarried couples to live together; instability of marriage shown by high divorce rates and declining remarriage rates; and increasing economic activity by women. The traditional institution of marriage is losing its economic, sexual, sociological and parenting rationales. Thus, declining fertility is both cause and consequence of changes in marriage. In Europe, where the decline is more advanced than in the U.S., governments are concerned that population growth will be too low and have instituted social welfare measures to induce and facilitate childbearing and childrearing. As women become more career-oriented, greater incentives will have to be provided. Manipulating immigration quotas

  8. Soil seed-bank germination patterns in natural pastures under different mineral fertilizer treatments

    Directory of Open Access Journals (Sweden)

    Anna Iannucci


    Full Text Available Degraded native grasslands in Mediterranean areas can be improved by encouraging seedling regeneration from soil seed banks using chemical fertilization. The effect of mineral fertilizers on soil seed banks was studied in natural pastures at two locations in southern Italy: Carpino and Rignano Garganico. The aim was to determine if nitrogen (N, phosphorus (P and combined nitrogen and phosphorus (NP fertilization can promote increased soil seed density. The seed-bank size and composition were analysed over two growth cycles (2004-2006 at two periods of the year: at the early summer and at the early autumn. The plant species were classified into three functional groups: grasses, legumes and other species (all other dicots. A two-pool model (ephemeral and base pools derived from the germination patterns was developed to quantify the dynamics of the germinated seed populations. The mean total seed number in the seed bank ranged from 2,915 to 4,782 seed m-2 with higher values in early summer than in early autumn. Mineral fertilizer applications increased the seed-bank size (by 27%, 23% and 46%, for N, P and NP, respectively and modified the composition in both localities. The three plant functional groups showed different potentials for ephemeral and persistent seed-bank production; however, within each plant group, the proportion between the ephemeral and base pool fractions did not change with fertilizer application. These data show that mineral fertilization can have positive effects on the seed-bank size of ungrazed natural pastures, and can be used to improve degraded Mediterranean pastures.

  9. Decomposing trends in nonmarital fertility among Latinas. (United States)

    DeLeone, Felicia Yang; Lichter, Daniel T; Strawderman, Robert L


    For Latinos, high rates of nonmarital fertility reinforce economic inequality and slow the pace of social and economic incorporation into American society. Changes in the nonmarital fertility ratio--nonmarital births as a percentage of all births (NMFR)--among women aged 15-44 over the period 1994-2005 were partitioned into three components: changes in marital and in nonmarital fertility, and in the proportion of women who were married. Annual birth data were drawn from the national Natality Detail File, and population estimates were drawn from the Current Population Surveys. Analyses were conducted for blacks, whites and Latinas, as well as for selected subgroups of Latinas; differences in NMFRs between racial and ethnic groups were also calculated. NMFRs were largely unchanged between 1994 and 2002, and then began to rise; they averaged 43% for Latinas, 69% for blacks and 23% for whites over the study period. In 2005, 48% of births to Latinas were nonmarital. Most of the rise in Latinas' NMFR was linked to a decline in marriage. Among foreign-born Latinas, a six-percentage-point increase in the NMFR was due mostly to a rise in nonmarital fertility and a decline in marital fertility, which offset the beneficial effects of a rising marriage rate. The difference between Latinas' and whites' NMFRs was largely attributed to Latinas' higher nonmarital fertility, whereas the difference between blacks' and whites' NMFRs was driven mostly by lower marriage rates among blacks. Efforts to reduce out-of-wedlock childbearing among Latinas are needed, and programs should promote healthy marriages, especially among foreign-born Latinas.

  10. The fertilizer nitrogen problem

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R A; Halstead, E H


    A world-wide fossil fuel crisis has surfaced in the past year by reason of shortage and high cost, which is felt throughout all segments of human society. Nor has the agriculture sector, with its very high demand for energy to supply its power, machinery, fertilizer, processing and transport, escaped the energy crisis. Among the agricultural inputs, fertilizer nitrogen is one of major concern. This commodity is currently in extremely short supply, world prices having more than doubled in the past year alone. Serious as this situation is to agricultural production in the highly developed countries of the world, it is a real disaster to the production potential of the developing countries. The birth of the 'Green Revolution' in those countries in the last ten years came about from an amalgamation of higher yielding varieties, improved pest and disease control, better crop watering practices, and the introduction of fertilizer nitrogen. Shortcomings in any one of these requisites invalidates the entire package. (author)

  11. The fertilizer nitrogen problem

    International Nuclear Information System (INIS)

    Olson, R.A.; Halstead, E.H.


    A world-wide fossil fuel crisis has surfaced in the past year by reason of shortage and high cost, which is felt throughout all segments of human society. Nor has the agriculture sector, with its very high demand for energy to supply its power, machinery, fertilizer, processing and transport, escaped the energy crisis. Among the agricultural inputs, fertilizer nitrogen is one of major concern. This commodity is currently in extremely short supply, world prices having more than doubled in the past year alone. Serious as this situation is to agricultural production in the highly developed countries of the world, it is a real disaster to the production potential of the developing countries. The birth of the 'Green Revolution' in those countries in the last ten years came about from an amalgamation of higher yielding varieties, improved pest and disease control, better crop watering practices, and the introduction of fertilizer nitrogen. Shortcomings in any one of these requisites invalidates the entire package. (author)

  12. Census-linked Study on Ethnic Fertility Differentials in Lithuania

    Directory of Open Access Journals (Sweden)

    Aiva Jasilioniene


    Full Text Available Fertility transformations observed since the early 1990s and their determinants have been rather thoroughly investigated in Lithuania. There are fairly numerous national and international studies devoted to this topic, mainly based on survey data. However, none of these studies looks into the effect of ethnicity on fertility. It is, to a large extent, caused by limitations of sample survey data. This study demonstrates potentials of census-linked fertility data to estimate robust and nationally representative parity-specific period fertility measures by ethnicity. The findings of this first systematic study of ethnicity-specific fertility differentials in Lithuania indicate that ethnicity does matter for fertility even in such ethnically homogenous country as Lithuania. Fertility among Lithuanians is higher than in the other ethnic groups, especially among Russians. Lower fertility in the Russian ethnic group is mainly explained by differences in the risk of having the second child. Importantly, this disadvantage remains significant even after controlling for selected compositional characteristics including urban-rural place of residence and education. The approach used in this study may be applied for Latvia and Estonia, where national minorities constitute substantial shares of the entire populations and significantly contribute to overall fertility levels.

  13. Fertility Preservation Counseling for Pediatric and Adolescent Cancer Patients. (United States)

    Campbell, Jessica E; Assanasen, Chatchawin; Robinson, Randal D; Knudtson, Jennifer F


    Fertility preservation for children and young adults with cancer is an important part of comprehensive patient care. In 2013, the American Society of Clinical Oncology (ASCO) released updated clinical practice guidelines addressing fertility preservation. This study aimed to evaluate if pediatric oncologists were performing fertility preservation counseling, if the new guidelines were being adopted, and how reproductive endocrinologists can educate this patient population and their providers. A cross-sectional study was performed from May 26, 2014, to August 26, 2014. An online survey addressing fertility preservation practice patterns was created and provided to the members of the Children's Oncology Group (COG). Thirty-five percent of the 234 respondents reported reading the new 2013 ASCO guidelines. Ninety-five percent of providers reported mentioning fertility preservation options prior to treatment, most commonly including referral to a reproductive endocrinologist (28%), and sperm banking (57%). The most commonly reported barrier to fertility preservation counseling was the cost of treatment. Fertility preservation counseling is being performed by pediatric oncology providers. Familiarity of the ASCO guidelines is limited, revealing that the established methods for fertility preservation in women--embryo and oocyte cryopreservation--may be offered less than experimental methods in this younger patient population. Such differences in apparent practice patterns highlight the need for more education for providers.

  14. Understanding variation in human fertility: what can we learn from evolutionary demography? (United States)

    Sear, Rebecca; Lawson, David W; Kaplan, Hillard; Shenk, Mary K


    Decades of research on human fertility has presented a clear picture of how fertility varies, including its dramatic decline over the last two centuries in most parts of the world. Why fertility varies, both between and within populations, is not nearly so well understood. Fertility is a complex phenomenon, partly physiologically and partly behaviourally determined, thus an interdisciplinary approach is required to understand it. Evolutionary demographers have focused on human fertility since the 1980s. The first wave of evolutionary demographic research made major theoretical and empirical advances, investigating variation in fertility primarily in terms of fitness maximization. Research focused particularly on variation within high-fertility populations and small-scale subsistence societies and also yielded a number of hypotheses for why fitness maximization seems to break down as fertility declines during the demographic transition. A second wave of evolutionary demography research on fertility is now underway, paying much more attention to the cultural and psychological mechanisms underpinning fertility. It is also engaging with the complex, multi-causal nature of fertility variation, and with understanding fertility in complex modern and transitioning societies. Here, we summarize the history of evolutionary demographic work on human fertility, describe the current state of the field, and suggest future directions. © 2016 The Author(s).

  15. Can human populations be stabilized? (United States)

    Warren, Stephen G.


    Historical examples of demographic change, in China, Italy, Nigeria, Utah, Easter Island, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are wrong because they assume, in spite of the absence of necessary feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food.

  16. Bulgaria: Ethnic differentials in rapidly declining fertility

    Directory of Open Access Journals (Sweden)

    Dimiter Philipov


    Full Text Available This chapter provides a detailed description of the fertility changes in Bulgaria during recent decades and discusses possible reasons and consequences. It also gives an overview of the steps that the government has undertaken to offset the considerable decline in fertility. Before the fall of communism, fertility trends in Bulgaria were stable and characterized by a nearly universal entry into parenthood, dominance of a two-child family model, an early start and early end of childbearing, stable mean ages at entry into childbearing and marriage, and low percentages of non-marital births. During the 1990s and in the first years of the new century, we observe a marked, rapid change in fertility behaviour. Together with the severe decline in overall fertility rates, demographic data reveal a significant postponement of entry into motherhood and marriage, a decline of the two-child family model, and an emergence of new family forms. Most research attributes these changes to the particular political and social situation in Bulgaria since 1989.

  17. Globalization and Contemporary Fertility Convergence. (United States)

    Hendi, Arun S


    The rise of the global network of nation-states has precipitated social transformations throughout the world. This article examines the role of political and economic globalization in driving fertility convergence across countries between 1965 and 2009. While past research has typically conceptualized fertility change as a country-level process, this study instead employs a theoretical and methodological framework that examines differences in fertility between pairs of countries over time. Convergence in fertility between pairs of countries is hypothesized to result from increased cross-country connectedness and cross-national transmission of fertility-related schemas. I investigate the impact of various cross-country ties, including ties through bilateral trade, intergovernmental organizations, and regional trade blocs, on fertility convergence. I find that globalization acts as a form of social interaction to produce fertility convergence. There is significant heterogeneity in the effects of different cross-country ties. In particular, trade with rich model countries, joint participation in the UN and UNESCO, and joining a free trade agreement all contribute to fertility convergence between countries. Whereas the prevailing focus in fertility research has been on factors producing fertility declines, this analysis highlights specific mechanisms-trade and connectedness through organizations-leading to greater similarity in fertility across countries. Globalization is a process that propels the spread of culturally laden goods and schemas impinging on fertility, which in turn produces fertility convergence.

  18. The population slide. (United States)

    Mukerjee, M


    The level of total fertility in Bangladesh has fallen from 7 in 1975 to 3 today, the sharpest fertility transition in South Asia. Fertility decline in Bangladesh and Nepal follows such transition occurring first in Sri Lanka, then in India. While in Western countries, levels of fertility began to fall once an advanced stage of development had been reached, these new declines in South Asia are not directly correlated with indicators of development such as increased literacy or the alleviation of poverty. Bangladesh has experienced major fertility decline despite being one of the world's 20 poorest countries. Fertility decline in Bangladesh may be attributed to a combination of an effective government family planning program, a general desire among Bangladesh's population to bear fewer children, reductions in mortality, the availability of microcredit, changes in women's status, and the provision of health and family planning information over the radio 6 hours per day.

  19. Socioeconomic determinants of fertility: selected Mexican regions, 1976-1977. (United States)

    Pick, J B; Butler, E W; Pavgi, S


    Cumulative fertility is analyzed for 4 regions of Mexico, based on World Fertility Survey data of 1976-77; the state of Baja California, the Northwest region, the State of Jalisco, and the Northeast region. Based on stepwise regression methodology, the study compares results for 12 subsamples of married respondents, 3 age categories by 4 regions. The dependent variables are children ever born and children ever born in the last 5 years. Migration, urban, educational, and occupational variables are included as independent variables. Regression results reveal level of education is the major, and negative, influence on fertility. Other results include specific negative effects for prior occupation, size of place of residence, and childhood place of residence. Fertility effects appear different for migration origin and destination regions, but more similar for younger ages. Effects of migration on fertility are small. Mean fertility as measured by children ever born was 4.34 for the 1976-77 World Fertility Survey samples versus 3.69 for the Mexican census of 1980. Fertility varied somewhat by region with the highest and lowest values in Jalisco and the Northeast, respectively. Expected age-related changes in fertility were noted.

  20. The cultural evolution of fertility decline (United States)

    Colleran, Heidi


    Cultural evolutionists have long been interested in the problem of why fertility declines as populations develop. By outlining plausible mechanistic links between individual decision-making, information flow in populations and competition between groups, models of cultural evolution offer a novel and powerful approach for integrating multiple levels of explanation of fertility transitions. However, only a modest number of models have been published. Their assumptions often differ from those in other evolutionary approaches to social behaviour, but their empirical predictions are often similar. Here I offer the first overview of cultural evolutionary research on demographic transition, critically compare it with approaches taken by other evolutionary researchers, identify gaps and overlaps, and highlight parallel debates in demography. I suggest that researchers divide their labour between three distinct phases of fertility decline—the origin, spread and maintenance of low fertility—each of which may be driven by different causal processes, at different scales, requiring different theoretical and empirical tools. A comparative, multi-level and mechanistic framework is essential for elucidating both the evolved aspects of our psychology that govern reproductive decision-making, and the social, ecological and cultural contingencies that precipitate and sustain fertility decline. PMID:27022079

  1. Fertilizing Southern Hardwoods (United States)

    W. M. Broadfoot; A. F. Ike


    If present trends continue, fertilizing may soon be economically feasible in southern hardwood stands. Demands for the wood are rising, and the acreage alloted for growing it is steadily shrinking. To supply anticipated requests for information, the U. S. Forest Service has established tree nutrition studies at the Southern Hardwoods Laboratory in Stoneville,...

  2. Hispanic Adolescent Fertility. (United States)

    Darabi, Katherine F.; And Others


    Discusses fertility of Hispanic adolescents in the United States. Summarizes what is known about sexuality, contraception, pregnancy, and childbearing among male and female Hispanics of various countries of origin. Indicates Hispanic adolescent birthrates fall between those of non-Hispanic Whites and Blacks, but there is considerable within-group…

  3. Fertilizer micro-dosing

    International Development Research Centre (IDRC) Digital Library (Canada)

    Localized application of small quantities of fertilizer (micro-dosing), combined with improved planting pits for rainwater harvesting, has generated greater profits and food security for women farmers in the Sahel. • Women are 25% more likely to use combined applications, and have expanded areas of food crops (cowpea,.

  4. Fertility Treatments for Females (United States)

    ... on: The underlying cause of the problem The woman's age Her history of previous pregnancies How long she has had infertility issues The presence or absence of male factor infertility Fertility treatments are most likely to benefit women whose infertility is due to problems with ovulation. ...

  5. Nutrition and fertility. (United States)

    Pinelli, G; Tagliabue, A


    The first studies about fertility and nutrition date back to the 70ies and already showed a strict relation among female fertility, weight and body composition. However, the mechanisms of this connection started to be explained only after leptin's discovery. According to some authors' opinion, leptin could interact with reproductive axis at multiple sites with stimulatory effects at the hypothalamus and pituitary and stimulatory or inhibitory actions at the gonads. Leptin could play a role in other physiologic processes such as menstruation and pregnancy, and could initiate the complex process of puberty. It has been showed that conditions in which nutritional status is suboptimal, such as eating disorders, exercise induced amenhorrea, functional hypothalamic amenhorrea and polycystic ovarian syndrome, are associated with abnormal leptin levels. These conditions, are characterized by severe changes in body composition and dietary habits. Since leptin is regulated by body composition and dietary factors, (such as energy intake and macronutrient composition), a strict connection between nutritional intake and fertility regulated by leptin is confirmed. This review focuses on the current knowledge about nutritional factors that influence leptin levels. Since clinical and subclinical nutritional imbalance can determine the development and the maintenance of neuroendocrine and metabolic aberrations, studies on fertility need a deeper attention about dietary habits and nutritional status.

  6. Fertility and Infertility. (United States)

    Orgebin-Crist, Marie-Claire; And Others

    In this report, emphasis is placed on major research developments in the reproductive sciences, their impact on the health of individuals as well as on that of society, and on current trends that may provide new opportunities for future research in fertility and infertility. In the first section, major developments in the reproductive sciences are…

  7. Fertility preservation: a challenge for IVF-clinics. (United States)

    Dahhan, Taghride; Mol, Femke; Kenter, Gemma G; Balkenende, Eva M E; de Melker, Annemieke A; van der Veen, Fulco; Dancet, Eline A F; Goddijn, Mariëtte


    Acute fertility preservation for women is an interdisciplinary treatment that requires adequate information provision and early referral. This quality management project aimed to improve fertility preservation care by using a practical tool: Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis. Quality management project was executed between May 2011 and July 2013. This project has been executed in a university affiliated IVF-clinic in cooperation with two oncological sites and used a four-step strategy: (1) monitoring baseline referral process, (2) exploring baseline fertility preservation program by Strengths, Weaknesses, Opportunities and Threats' (SWOT)-analysis, (3) setting up a new fertility preservation program and (4) evaluating the new fertility preservation program by means of SWOT-analysis. During the three-months monitoring period, fertility preservation was requested for a total of 126 women. The mean age of the women was 33.8 years old (range 1-42 years old). Most requests came from women who wanted to cryopreserve oocytes because of age-related decline of fertility (n=90; 71%). Most requests for acute fertility preservation concerned women with breast cancer (n=16; 57%). Information leaflets and pre-consultation questionnaires for women improved the quality of first fertility preservation consultation as evaluated by final SWOT-analysis. Collaboration with oncological centres and information about fertility preservation improved the referral process. SWOT-analysis proved useful for setting up a new fertility preservation-program and can be recommended as a tool to improve the management and organisation of new types of reproductive care. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Implementation strategy for achieving replacement level fertility. (United States)


    The recommendation of the Bali Declaration on Population and Sustainable Development at the ESCAP regional conference was to adopt strategies for attaining replacement-level fertility of 2.1 or 2.2 children by 2010. East Asian countries, except Mongolia and the Democratic People's Republic of Korea, and the Southeast Asian countries Singapore and Thailand have already reached replacement-level fertility. Most larger Oceanic countries have also done so. Only South Asian Sri Lanka and southern India have attained replacement level. The following conditions slow or hinder the goal, but they do not provide an "absolute" barrier to fertility decline: social welfare schemes and old age security, son preference, lack of government family planning, poverty, relatively high mortality, low status of women, and education status. Theories of demographic transition have postulated that economic and social development initially brings a decline in mortality, and later brings a decline in fertility; and high fertility was an adaptation to high mortality. Policy gets caught in the lag between mortality and fertility decline. Eventually the cultural motives for high fertility are undercut by social and economic development. Although the generalization that economic growth slows fertility is true for South Asia, the correlation is uneven. Forceful government-sponsored family planning programs in Bangladesh and China may lead the way to strategies for decline in ESCAP region. A Thailand study suggested important factors were fundamental social change, the increased cost of children, cultural acceptance of birth control, a latent demand for fertility control, and government efforts in family planning. ESCAP countries have in common relatively high morality and inadequate public health programs, patriarchal structures, and limited female autonomy, poverty and landlessness, lack of community cohesiveness, and inadequate family planning programs. Weaknesses in programs are attributed to

  9. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Cord Injury Medical Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries ... Coping with a New Injury Robin Dorman, PsyD Sex and Fertility After Spinal Cord Injury Diane M. ...

  10. Sex and Fertility After SCI (United States)

    ... Cord Injury Medical Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries ... Coping with a New Injury Robin Dorman, PsyD Sex and Fertility After Spinal Cord Injury Diane M. ...

  11. Agriculture: Nutrient Management and Fertilizer (United States)

    Fertilizers and soil amendments can be derived from raw materials, composts and other organic matter, and wastes, such as sewage sludge and certain industrial wastes. Overuse of fertilizers can result in contamination of surface water and groundwater.

  12. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Resources Peer Counseling Blog About Media Donate close search Understanding Spinal Cord Injury What is a Spinal ... male fertility? play_arrow Where can people get information on sex and fertility after a spinal cord ...

  13. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Medical Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries Spinal Cord ... a New Injury Robin Dorman, PsyD Sex and Fertility After Spinal Cord Injury Diane M. Rowles, MS, ...

  14. Foods That Can Affect Fertility (United States)

    ... That Can Affect Fertility Print Email Foods That Can Affect Fertility By Caroline Kaufman, MS, RDN Published ... the American Society for Reproductive Medicine. While couples can't control all of the causes of infertility, ...

  15. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... male fertility? play_arrow Where can people get information on sex and fertility after a spinal cord ... health care products or services, or control the information found on external websites. The Hill Foundation is ...

  16. Fertility in Namibia. Changes in fertility levels in North-Central Namibia 1960-2001, including an assessment of the impact of HIV

    Directory of Open Access Journals (Sweden)

    Riikka Shemeikka


    Full Text Available The aim of this study was to estimate the development of fertility in North-Central Namibia, former Ovamboland, from 1960 to 2001. Special attention was given to the onset of fertility decline and to the impact of the HIV epidemic on fertility. An additional aim was to introduce parish registers as a source of data for fertility research in Africa.  Data used consisted of parish registers from Evangelical Lutheran congregations, the 1991 and 2001 Population and Housing Censuses, the 1992 and 2000 Namibia Demographic and Health Surveys, and the HIV sentinel surveillances of 1992-2004. Both period and cohort fertility were analysed. The P/F ratio method was used when analysing census data. The impact of HIV infection on fertility was estimated indirectly by comparing the fertility histories of women who died at an age of less than 50 years with the fertility of other women. The impact of the HIV epidemic on fertility was assessed both among infected women and in the general populationFertility in the study population began to decline in 1980. The decline was rapid during the 1980s, levelled off in the early 1990s at the end of war of independence and then continued to decline until the end of the study period. According to parish registers, total fertility was 6.4 in the 1960s and 6.5 in the 1970s, and declined to 5.1 in the 1980s and 4.2 in the 1990s. Adjustment of these total fertility rates to correspond to levels of fertility based on data from the 1991 and 2001 censuses resulted in total fertility declining from 7.6 in 1960-79 to 6.0 in 1980-89, and to 4.9 in 1990-99. The decline was associated with increased age at first marriage, declining marital fertility and increasing premarital fertility. Fertility among adolescents increased, whereas the fertility of women in all other age groups declined.  During the 1980s, the war of independence contributed to declining fertility through spousal separation and delayed marriages. Contraception

  17. The Meaning of Meaning, Etc. (United States)

    Nilsen, Don L. F.

    This paper attempts to dispel a number of misconceptions about the nature of meaning, namely that: (1) synonyms are words that have the same meanings, (2) antonyms are words that have opposite meanings, (3) homonyms are words that sound the same but have different spellings and meanings, (4) converses are antonyms rather than synonyms, (5)…

  18. Intelligence in Bali--A Case Study on Estimating Mean IQ for a Population Using Various Corrections Based on Theory and Empirical Findings (United States)

    Rindermann, Heiner; te Nijenhuis, Jan


    A high-quality estimate of the mean IQ of a country requires giving a well-validated test to a nationally representative sample, which usually is not feasible in developing countries. So, we used a convenience sample and four corrections based on theory and empirical findings to arrive at a good-quality estimate of the mean IQ in Bali. Our study…

  19. Aspects on gametogenesis, fertilization and embryogenesis of two deep-sea polychaetes from Eastern Atlantic cold seeps (United States)

    Gaudron, S. M.; Hourdez, S.; Olu, K.


    We investigated two gonochoristic species of annelid polychaetes (one siboglinid and one polynoid) from cold seeps that ranged from 525 m to 3300 m in depth (Guiness, Worm Hole and Regab pockmarks) on the Gabon and Congo continental margins (Gulf of Guinea). Different aspects of gametogenesis (oocyte diameter, presence of ovisac, spermatozoa shape, and fecundity), fertilization (in vitro fertilization experiments: IVF) and embryogenesis (cleavage rate) were studied. The sampled siboglinid was a new species of Lamellibrachia and the second population of this genus in the Eastern Atlantic. Mean oocyte diameter was about 100 μm and fully-grown primary oocytes were stored in an ovisac, as in other studied siboglinids. The presence of a single spermatozoon was noted within an oviduct, indicating a possible internal fertilization. The rate of cell division at 6 °C was one cleavage every 20 h. Embryos developed normally to the blastula stage after 5-d post-fertilization at atmospheric pressure suggesting some pressure tolerance. The second polychaete was the scale-worm Branchipolynoe cf. seepensis that lives in commensalism in the mantle cavity of Bathymodiolus aff. boomerang. Anatomical reproductive features were similar to those described in B. seepensis from hydrothermal vents on Mid-Atlantic Ridge, with lecithotrophic larval development and continuous gametogenesis. We performed the first IVF carried out on gametes for any deep-sea polynoid species. Fertilization and development occurred but a number of abnormalities were observed demonstrating a limitation to embryogenesis at atmospheric pressure. The rate of cell division was three times faster at 8 °C than at 4 °C with a maximum stage of 8-cells reached after 72 h post-fertilization. We surprisingly observed some oocytes from the negative seawater control during IVF experiments cleaved to the 2-cell stage, demonstrating the possible occurrence of internal fertilization prior to IVF experiment or the accidental

  20. Effects of Different Fertilizing Formulae on Potato

    Directory of Open Access Journals (Sweden)

    Giovanna Cucci


    Full Text Available Trials conducted on potato fertilization at different rates of nitrogen, phosphorus and potassium have shown that the elements able to influence the marketable tuber yield are nitrogen and phosphorus. The potato dry matter, which reflects other quality aspects such as the specific gravity and the starch content, increases with nitrogen fertilization till 150-200 kg ha-1 of nitrogen; beyond those rates values remain nearly unchanged. Dry matter increases also with the application of phosphorus and at low potassium rates. The objective of the research was to test the effect of different rates of N P K fertilizer on yield and some quality traits of potato. The test was conducted at the Campus of the Agricultural Faculty, Bari University, Italy. It involved the comparison of 6 fertilizing formulae N1 P1 K1, N1 P2 K1, N2 P1 K1, N2 P2 K1, N3 P1 K1, N3 P2 K1, obtained from the factorial combination of three nitrogen levels (N = 100-200-300 kg ha-1 and two phosphorus rates (P2O5 = 50-100 kg ha-1 against an unfertilized control N0P0K0. The dose of potassium was constant for all fertilizing formulae (K2O = 300 kg ha-1. The highest total and marketable yields of tubers per plant have been observed at the two highest fertilizing levels (N3 P1 K1, N3 P2 K1, which are not statistically different so that the best treatments is shown to be N3 P1 K1; the trend was similar for the mean weight of tubers. With the various treatments, no difference was observed in terms of yield of tubers belonging to the two first size classes (< 35mm and 35-55mm; what has increased with the fertilizing levels is the yield of tubers greater than 55 mm. Tuber specific gravity show, as expected, a positive correlation with the dry matter percentage. Both parameters increased shifting from the control to the N2 P2 K1 and decreased at the highest N level, without any difference being observed with the change in the P rate. The highest starch percentage (20.5% was also observed in the

  1. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Provider Pocket Guides Provider Guides Fertility Preservation for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed ... Patient Pocket Guides Patient Guides Fertility Preservation for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed ...

  2. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed with Cancer Fertility Preservation for Children Diagnosed ... for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed with Cancer Fertility Preservation for Children Diagnosed ...

  3. Fertility Preservation for Children Diagnosed with Cancer (United States)

    ... Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu ... with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for ...

  4. Third world programs confront adolescent fertility. (United States)


    Recently, there have been efforts to identify workable youth programs and effective research projects that could deal with the problem of adolescent fertility. Typical objectives identified at various conferences concerned with this problem included the following: 1) focus attention on the adverse medical and socioeconomic efforts of early pregnancy; 2) draw attention to the current dimensions of adolescent fertility and its changing patterns; 3) encourage development of programs; and 4) impress decision makers with the importance of programs for adolescents. These conferences express a sense of urgency in developing programs before teen-age pregnancy reaches epidemic proportions. Most of the projects already underway are still pilot efforts and have an impact on a very small sector of the population. Yet, they are positive steps toward a solution of the rising problems of adolescent fertility and help to identify workable solutions. A few of these projects -- underway in Colombia, Argentina, Chile, Cost Rica, Guatemala and Mexico -- are reviewed. The consensus of all conferences held to date has been that cross-cultural interchanges is crucial to the spread of programs and ideas that can be adapted to local conditions. 2 key recommendations have emerged from a meeting of donor and support agencies held in Washington, D.C. in May: 1) a major conference should take place during the International Year of the Child (1979) that would focus on early sexual activity and fertility and 2) an Adolescent Fertility Council should be appointed. An Adolescent Fertility Council would provide a structure to correlate and stimulate interaction, while recognizing that country and culture specific programs are essential.

  5. Culture’s Influence: Regionally Differing Social Milieus and Variations in Fertility Rates


    Fulda, B.


    How can we understand subnational differences in fertility rates? The most common explanations see the key to these differences in the socio-structural composition of a region’s population and its structural conditions. However, such explanations fail to account for fertility rate differences in regions with similar populations and structures. This paper analyzes two social milieus in southern Germany and argues that variations in their fertility rates can only be understood through their cul...

  6. Irrigation and fertilization effects on Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Damage levels and pupal weight in an intensively-managed pine plantation.

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, David, R.; Nowak, John, T.; Fettig, Christopher, J.


    The widespread application of intensive forest management practices throughout the southeastern U.S. has increased loblolly pine, Pinus taeda L., yields and shortened conventional rotation lengths. Fluctuations in Nantucket pine tip moth, Rhyacionia frustrana (Comstock), population density and subsequent damage levels have been linked to variations in management intensity. We examined the effects of two practices, irrigation and fertilization, on R. frustrana damage levels and pupal weights in an intensively-managed P. taeda plantation in South Carolina. Trees received intensive weed control and one of the following treatments; irrigation only. fertilization only, irrigation + fertilization, or control. Mean whole-tree tip moth damage levels ranged from <1 to 48% during this study. Damage levels differed significantly among treatments in two tip moth generations in 2001, but not 2000. Pupal weight was significantly heavier in fertilization compared to the irrigation treatment in 2000, but no significant differences were observed in 2001. Tree diameter. height. and aboveground volume were significantly greater in the irrigation + fertilization than in the irrigation treatment after two growing seasons. Our data suggest that intensive management practices that include irrigation and fertilization do not consistently increase R. frustrana damage levels and pupal weights as is commonly believed. However, tip moth suppression efforts in areas adjacent to our study may have partially reduced the potential impacts of R. frustrana on this experiment.

  7. Analysis of plant height between male sterile plants obtained by space flight and male fertile plants in Maize

    International Nuclear Information System (INIS)

    Cao Moju; Huang Wenchao; Pan Guangtang; Rong Tingzhao; Zhu Yingguo


    F 2 fertility segregation population and the sister-cross fertility segregation population, which descended from the male sterile material, were analysed by their plant height of different growing stage between 2 populations of male sterile plants and male fertile plants. The plant height of different fertility plants come to the significance at 0.01 level in different stage through the whole growing period. The differences become more and more large with the development of plants, the maximum difference happens in adult stage. The increasing amount of different stage also shows significance at 0.01 level between two kinds of different fertility plants

  8. Using fertile couples as embryo donors: An ethical dilemma. (United States)

    Alizadeh, Leila; Omani Samani, Reza


    The use of donated embryos has offered hope for infertile couples who have no other means to have children. In Iran, fertility centers use fertile couples as embryo donors. In this paper, the advantages and disadvantages of this procedure will be discussed. We conclude that embryo-donation should be performed with frozen embryos thus preventing healthy donors from being harmed by fertility drugs. There must be guidelines for choosing the appropriate donor families. In countries where commercial egg donation is acceptable, fertile couples can be procured as embryo donors thus fulfilling the possible shortage of good quality embryos. Using frozen embryos seems to have less ethical, religious and legal problems when compared to the use of fertile embryo donors.

  9. Fertility in midlife women. (United States)

    Yoldemir, T


    Reduced maternal fertility is the consequence of depletion of follicles with maternal aging. In a 35-year-old woman, approximately 9.1% of the residual follicle pool disappears annually without entering into the growing stage, whereas, in a 45-year-old woman, this number triples. After the age of 35 years, the frequency of aneuploidies in oocytes increases sharply. Roughly 50-70% of mature oocytes from a 40-year-old woman have chromosomal abnormalities. The clinical pregnancy and implantation rates are lower in midlife women. Various controlled ovarian stimulation interventions have been suggested for the management of women in advanced age, most of whom are likely to be poor-responder patients. Currently, systematic reviews and meta-analyses suggest that there is insufficient evidence to recommend most of the treatments proposed to improve pregnancy rates in these poor responders. Minimal stimulation or natural cycle in vitro fertilization may be offered, without compromising the already existing pregnancy results.

  10. [Stress and fertility]. (United States)

    Ősapay, György; Ősapay, Klára


    In Western countries, sperm quality and fertility of men significantly worsened. Female infertility does not show a better trend either. Subtle defects in the reproductive functions can not be explained by the current methods, and "unexplained infertility" is becoming a more common diagnosis. Every year 1 million couples seek expensive and time consuming fertility treatment in the world. Deeper understanding of an unhealthy lifestyle and the environmental damages may lead to personalized treatments to increase the chance of conception.The effects of various stressors on the male and female reproductive performance were scientifically substantiated by Selye and coworkers in 1976. Cognitive therapy methods can be applied against emotional stressors, supplementation by antioxidants against reactive oxygen compounds, and administration of vitamins and trace elements, especially when deficiency is found, may help before medical intervention on a rational and economical way in the fight against infertility.

  11. Quantitative Trait Loci for Fertility Traits in Finnish Ayrshire Cattle

    DEFF Research Database (Denmark)

    Schulman, Nina F; Sahana, Goutam; Lund, Mogens S


    A whole genome scan was carried out to detect quantitative trait loci (QTL) for fertility traits in Finnish Ayrshire cattle. The mapping population consisted of 12 bulls and 493 sons. Estimated breeding values for days open, fertility treatments, maternal calf mortality and paternal non-return rate...... combinations, which were observed significant in the regression method. Twenty-two chromosome-wise significant QTL were detected. Several of the detected QTL areas were overlapping with milk production QTL previously identified in the same population. Multi-trait QTL analyses were carried out to test...... if these effects were due to a pleiotropic QTL affecting fertility and milk yield traits or to linked QTL causing the effects. This distinction could only be made with confidence on BTA1 where a QTL affecting milk yield is linked to a pleiotropic QTL affecting days open and fertility treatments...

  12. Fertility problems and risk of gestational diabetes mellitus

    DEFF Research Database (Denmark)

    Holst, Signe; Kjær, Susanne K; Jørgensen, M. E.


    Objective To determine whether women with a history of fertility problems have a higher risk of gestational diabetes mellitus (GDM) than women without a history of fertility problems after adjustment for maternal factors. Design Nationwide population-based cohort study. Setting Not applicable...... of diabetes, level of education, and smoking during pregnancy. Result(s) In total, 7,433 (2%) pregnant women received a diagnosis of GDM. Multivariate analysis showed that pregnant women with a history of fertility problems had a statistically significantly higher risk of GDM than pregnant women without...

  13. Fertility preservation 2 (United States)

    De Vos, Michel; Smitz, Johan; Woodruff, Teresa K


    Enhanced long-term survival rates of young women with cancer and advances in reproductive medicine and cryobiology have culminated in an increased interest in fertility preservation methods in girls and young women with cancer. Present data suggest that young patients with cancer should be referred for fertility preservation counselling quickly to help with their coping process. Although the clinical application of novel developments, including oocyte vitrification and oocyte maturation in vitro, has resulted in reasonable success rates in assisted reproduction programmes, experience with these techniques in the setting of fertility preservation is in its infancy. It is hoped that these and other approaches, some of which are still regarded as experimental (eg, ovarian tissue cryopreservation, pharmacological protection against gonadotoxic agents, in-vitro follicle growth, and follicle transplantation) will be optimised and become established within the next decade. Unravelling the complex mechanisms of activation and suppression of follicle growth will not only expand the care of thousands of women diagnosed with cancer, but also inform the care of millions of women confronted with reduced reproductive fitness because of ageing. PMID:25283571

  14. Soil and fertilizer nitrogen

    International Nuclear Information System (INIS)

    Winteringham, F.P.W.


    As a result of the intensified practices and effectively diminishing land resources per capita, increasing weights of both native soil- and added fertilizer-nitrogen will be lost to agriculture and its products, and will find their way into the environment. Soil-nitrogen levels and contingent productivity can nevertheless be maintained in the face of these losses on the basis of improved soil-N management. In some local situations nitrate levels in water for drinking purposes are likely to continue rising. In some cases agriculture and clearance practices are only one of several sources. In others they are clearly mainly responsible. In developing countries these losses represent those of a relatively increasingly costly input. This is due to the fact that industrial fertilizer nitrogen production is a particularly high energy-consuming process. In the more advanced industrialized countries they represent an addition to the problems and costs of environmental quality and health protection. The programmes, information and data reviewed here suggest that these problems can be contained by improved and extended soil and water management in agriculture on the basis of existing technology. In particular there appears to be enormous scope for the better exploitation of existing legumes both as non-legume crop alternatives or as biofertilizers which also possess more desirable C:N ratios than chemical fertilizer

  15. Fertility impairment in radiotherapy

    Directory of Open Access Journals (Sweden)

    Marta Biedka


    Full Text Available Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient’s sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning.

  16. Contemporary Fertility Patterns and First-Birth Timing among Mexican-Origin Women (United States)

    Batson, Christie D.


    This article examines first-birth timing among Mexican women in the United States over two birth cohorts. Currently, Mexican women are one of a small group that maintains above-replacement fertility in the United States, contributing to both Mexican population growth and overall national population growth. Yet, the fertility timing of Mexican…

  17. Low fertilization rates in a pelagic copepod caused by sexual selection?

    DEFF Research Database (Denmark)

    Ceballos, Sara; Sichlau, Mie Hylstofte; Heuschele, Jan


    We studied female fertilization status in North Sea summer populations and laboratory cultures of the marine copepod Temora longicornis and found fractions of fertilized females in both field and laboratory populations that were much smaller (<50%) than predicted by a theoretical model that assum...

  18. Jobs and Kids: Female Employment and Fertility in Rural China


    Hai Fang; Karen N. Eggleston; John A. Rizzo; Richard J. Zeckhauser


    Data on 2,355 married women from the 2006 China Health and Nutrition Survey are used to study how female employment affects fertility in China. China has deep concerns with both population size and female employment, so the relationship between the two should be better understood. Causality flows in both directions. A conceptual model shows how employment prospects affect fertility. Then a well-validated instrumental variable isolates this effect. Female employment reduces a married woman's p...

  19. Jobs and kids: Female employment and fertility in China


    Fang, Hai; Eggleston, Karen N.; Rizzo, John A.; Zeckhauser, Richard J.


    Data on 2,355 married women from the 2006 China Health and Nutrition Survey are used to study how female employment affects fertility in China. China has deep concerns with both population size and female employment, so the relationship between the two should be better understood. Causality flows in both directions. A conceptual model shows how employment prospects affect fertility. Then a well-validated instrumental variable isolates this effect. Female employment reduces a married woman’s...

  20. Fertility, Household’s size and Poverty in Nepal


    François Libois; Vincent Somville


    Population control policies keep on attracting a lot of attention. The main argument in favour of a reduction in fertility rates, is that having more children contributes directly to a household’s poverty. Using the last three rounds of the Nepal Living Standards Surveys, we investigate the links between household’s fertility decisions and their consequent achievements in incomes and consumption. In contradiction with the popular presumptions, we find that having more children does not have a...

  1. [Association of the meaning of life with satisfaction, the occurrence of subjective complaints and the family's economic status in the population of lower secondary school students]. (United States)

    Zawadzka, Dorota; Stalmach, Magdalena; Oblacińska, Anna; Tabak, Izabela

    Feeling of meaning in life is extremely crucial factor of mental health. The lack of it can result in various disorders. Many authors, especially those connected with current of humanistic psychology underline the teenagers' life sense. The aim of the paper was to examine the level of satisfaction with life, the frequency of psychosomatic complaints by junior high school students as well as the estimation of economical status of family and the analysis of meaning in life with above mentioned factors. The research was carried out in 2015 at 70 schools from all over the country, in group of 3695 lower secondary school students of I-III classes at the age of 13-17 (M=14,9; SD=0,87). The analysis connected with meaning in life using the shorten version of Purpose in Life Test (PIL) as well as analysis of life satisfaction using Cantril scale were taken up. What is more, the subjective physical complaints using single-factor shorten scale and economic status of family with the usage of material resources FAS scale (Family Affluence Scale) were examined. The statistical analysis included a one-way analysis of variance (ANOVA), t-student test post-hoc test as well as multivariate logistic regression model. The average level of meaning in life among the examined students was 24,7 points (the summary scale 0-36 points), the boys achieved higher score than girls. The students satisfied with life (t=28,0; plife than students who were dissatisfied with their life, often or fairly suffer from health complaints and live in families of at most average level of affluence. The meaning in life is positively connected with satisfaction with life, lack of subjective complaints and family affluence. Because there is a lack of analysis linked with school teenagers' meaning in life in Polish literature, another research involved not only shorten but also full version of this tool should be conducted.

  2. Thin and fat cows, and the nonlinear genetic relationship between body condition score and fertility. (United States)

    Tiezzi, F; Maltecca, C; Cecchinato, A; Penasa, M; Bittante, G


    Thin and fat cows are often credited for low fertility, but body condition score (BCS) has been traditionally treated as a linear trait when genetic correlations with reproductive performance have been estimated. The aims of this study were to assess genetic parameters for fertility, production, and body condition traits in the Brown Swiss population reared in the Alps (Bolzano-Bozen Province, Italy), and to investigate the possible nonlinearity among BCS and other traits by analyzing fat and thin cows. Records of BCS measured on a 5-point scale were preadjusted for year-season and days in milk at scoring, and were considered positive (1) for fat cows if they exceeded the value of 1 residual standard deviation or null (0) otherwise, whereas positive values for thin cows were imputed to records below -1 residual standard deviation. Fertility indicators measured on first- and second-parity cows were interval from parturition to first service, interval from first service to conception, interval from parturition to conception, number of inseminations to conception, conception at first service, and nonreturn rate at 56 d after first service. Production traits were peak milk yield, lactation milk yield, and lactation length. Data were from 1,413 herds and included 16,324 records of BCS, fertility, and production for first-parity, and 10,086 fertility records for second-parity cows. Animals calved from 2002 to 2007 and were progeny of 420 artificial insemination bulls. Genetic parameters for the aforementioned traits were obtained under univariate and bivariate threshold and censored linear sire models implemented in a Bayesian framework. Posterior means of heritabilities for BCS, fat cows, and thin cows were 0.141, 0.122, and 0.115, respectively. Genetic correlations of body condition traits with contemporary production were moderate to high and were between -0.556 and 0.623. Body condition score was moderately related to fertility in first (-0.280 to 0.497) and second

  3. Radioactivity in chemical and organic fertilizer used in Egypt

    International Nuclear Information System (INIS)

    Abbady, A.G.E.; Yousef, A.M.M.; Abbady, A.; El-Taher, A.


    The Egypt Chemical factories (ECF); such as Talkha, Sues, Abo Qeyer, Kafer Elzayat, and Assuit factories, produces and markets a range of phosphate based fertilizers, including Simple Super Phosphate (SSP) fertilizer, Triple Super Phosphate (TSP) fertilizer and Urea. Phosphate fertilizers produced by ECF are derived from phosphate ore. In addition to phosphate minerals, these ores can contain significant amounts of a wide range of impurities, including heavy metals and naturally occurring radionuclides. This study was carried out to determine the content of radionuclides in fertilizer products produced by ECF and some organic fertilizer (animal manure) includes cow, sheep and chicken fertilizer. In both samples (Chemical and organic fertilizers), the activity concentrations of Ra 2 26 are higher than those Th 2 32. The radioactivity of 226 R a in chemical fertilizers ranged from 21.6 ± 3.6 to 111.2 ± 8.9 Bq kg-1, phosphate fertilizers TSP contained high contents of 226 R a. The average radioactivity of 226 R a in TSP was 79.3 ± 7.4 Bq kg-1, in SSP 51.2 ± 5 Bq kg-1, and in Urea 35.1± 3.5 Bq kg-1. The activity of 232 T h in the different fertilizers ranged from 1.3 ± 1.1 to 9.9 ± 3.2 Bq kg-1,the highest activity observed in SSP fertilizer. The activity of 40 K was found to be great in the TSP fertilizer, which contained a mean activity 478.1± 21.3 Bq kg-1. With respect to organic fertilizers the average radioactivity of 226 R a, 232 T h and 40 K are 40 ± 1.6 Bq kg-1, 3.1± 1.2 and 427.1± 20 Bq kg-1. The data are discussed and compared with those given in the literatures. This study could be useful as baseline data for radiation exposure to fertilizers, and their impact on human health

  4. Fertility behavior in rural and urban Indonesia. (United States)

    Chernichovsky, D; Newlon, B; Sigit, H


    The cross-sectional picture of urban and rural fertility which emerges from recently published Indonesian national level data from the 1976 Intercensal Survey are described. The data reveal only small differences in the average numbers of children ever born or children surviving of ever married women (or mothers) in urban and rural areas of Indonesia. In urban areas, ever married mothers had a standardized average of 3.4 children ever born, and in rural areas 3.3 These averages cannot reveal any differences in past and present childbearing levels. The fertility of urban women, as opposed to rural women, appeared more highly associated with indicators which tend to directly or indirectly depress the average number of children ever born: a higher age at 1st marriage; a higher level of "sterility;" a higher survival ratio of children born; and a higher level of educational attainment. At least some of these factors might be regarded as associated with modernizing trends in the urban areas: increased accessibility to educational facilities; the opening of female opportunities outside the home so that marriage occurs later in life; and a better health environment so that there is less pregnancy wastage and time spent in bearing children. These factors help to provide an incentive to women to limit their fertility; knowledge of contraception methods provides a means. The depressing factors most highly associated with average rural fertility do not appear associated with modernization but with traditional folk customs regarding acceptable behavior. The inflating effects of early marriage are offset by a greater prevalence of marital disruption. This may reflect a cultural acceptability. The reasons may include adolescent or true sterility leading to disunion, the outmigration of a partner, or some other form of disharmony. Female labor force participation is more prevalent in rural than urban areas. There are both traditional and modern aspects to be seen in its

  5. Genocide, Nuptiality, and Fertility in Rwanda and Bosnia-Herzegovina


    Staveteig, Sarah Elizabeth


    How does exposure to genocide affect nuptiality and fertility among the surviving population? Genocides in Rwanda and in Bosnia-Herzegovina in the early 1990s caused high levels of population displacement, trauma, and death, along with a dramatic decline in the standard of living. In Rwanda, genocide also reduced the sex ratio of the marriage-aged population, while in Bosnia, despite the high proportion of male casualties, the overall sex ratio of the marriage-age population did not decline s...

  6. Asociación entre la tasa de autofecundación y la frecuencia de larvas malformadas en poblaciones cultivadas del ostión del norte Argopecten purpuratus (Lamarck, 1819 Association between self-fertilization rates and the frequency of malformed larvae in farmed populations of the northern scallop Argopecten purpuratus (Lamarck, 1819

    Directory of Open Access Journals (Sweden)

    Christopher Concha


    separately from the fifth or later spawning pulses. Oocytes were fertilized with sperm from another individual, forming families of complete siblings. Selfing rates were verified by the proportion of cleaving oocytes in a non-fertilized sample. Self-fertilization ranged from 0 to 100% among families, with a normal distribution. The proportion of malformed larvae was distributed randomly among the families analyzed, but was negatively correlated - moderately but significantly - with the selfing rate and the mean water temperature of the culture. These results suggest that self-fertilization in scallop families can favor greater homeostasis of larval development.

  7. Population Subdivision of Japanese Flounder Paralichthys olivaceus in the Pacific Coast of Tohoku Japan Detected by Means of Mitochondrial Phylogenetic Information

    Directory of Open Access Journals (Sweden)

    Yuya Shigenobu


    Full Text Available This study deals with mitochondrial phylogenetic information of Japanese flounder in the Pacific coast of Tohoku Japan to estimate the genetic population subdivision that was undetectable by conventional population statistics. We determined complete sequences of mitochondrial NADH dehydrogenase subunit-2 (ND2 and subunit-5 (ND5 genes for 151 individuals from northern (Aomori and Iwate prefectures, 40–41°N and southern (Miyagi and Fukushima prefectures, 37–38°N waters. Samples from both waters showed high genetic diversity, including 126 haplotypes. These haplotypes were located at mixed and nested positions on an inferred phylogenetic tree, and traditional F-statistics indicated no significant population divergence (φST = −0.00335, p > 0.05, corroborating our previous study. Three variable sites, however, showed significant base composition heterogeneity between samples from the northern and southern waters (Fisher’s exact-test, p < 0.01. Nucleotide substitutions at the three sites converged on an apical clade, which consisted of the five southern individuals, whereas its sister clade consisted only of the three northern individuals. This phylogenetic information corroborates previous ecological studies indicating the presence of separate stocks in the northern and southern waters.

  8. PERSPECTIVE: Dust, fertilization and sources (United States)

    Remer, Lorraine A.


    Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory ( Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the

  9. Preliminary assessment on exposure of four typical populations to potentially toxic metals by means of skin wipes under the influence of haze pollution. (United States)

    Cao, Zhiguo; Wang, Mengmeng; Chen, Qiaoying; Zhang, Yajie; Dong, Wenjing; Yang, Tianfang; Yan, Guangxuan; Zhang, Xin; Pi, Yunqing; Xi, Benye; Bu, Qingwei


    To investigate the exposure risk of human beings to nine potentially toxic metals (PTMs), namely, Cu, Cr, Zn, As, Cd, Pb, Ni, Mn, and Co, skin wipe samples were collected from four types of populations, namely, children, undergraduates, security guards, and professional drivers, under different haze pollution levels in Xinxiang, China by using Ghost wipes. The Ghost wipes were quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Generally, Zn (ND-1350μg/m 2 for undergraduates, ND-2660μg/m 2 for security guards, ND-2460μg/m 2 for children, and ND-2530μg/m 2 for professional drivers) showed the highest concentration among the four populations, followed by Cu (0.02-83.4μg/m 2 for undergraduates, ND-70.2μg/m 2 for security guards, 23.2-487μg/m 2 for children, and ND-116μg/m 2 for professional drivers). As (ND-5.7μg/m 2 for undergraduates, ND-2.3μg/m 2 for security guards, ND-21.1μg/m 2 for children, and ND-11.0μg/m 2 for professional drivers) and Co (ND-6.0μg/m 2 for undergraduates, ND-7.9μg/m 2 for security guards, ND-13.4μg/m 2 for children, and ND-2.1μg/m 2 for professional drivers) showed the lowest concentrations in all populations. Remarkable differences were found among the four populations and PTM levels decreased in the following order: children, professional drivers, security guards, and undergraduates. Gender variation was discovered for undergraduates and children. Generally, PTM contamination in skin wipes collected during a light haze pollution level was generally higher than that during a heavy haze pollution level, but PTM contamination was comparable between the two haze pollution levels for children. Non-carcinogenic exposure risks to As, Cd, and Pb for all populations were higher than those for the other six elements but all of them were within the acceptable safety threshold, indicating no apparent non-carcinogenic risk. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hoefs, Nancy (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)


    During 1997 the first phase of the Nez Perce Tribe White Sturgeon Project was completed and the second phase was initiated. During Phase I the ''Upper Snake River White Sturgeon Biological Assessment'' was completed, successfully: (1) compiling regional white sturgeon management objectives, and (2) identifying potential mitigation actions needed to rebuild the white sturgeon population in the Snake River between Hells Canyon and Lower Granite dams. Risks and uncertainties associated with implementation of these potential mitigative actions could not be fully assessed because critical information concerning the status of the population and their habitat requirements were unknown. The biological risk assessment identified the fundamental information concerning the white sturgeon population that is needed to fully evaluate the effectiveness of alternative mitigative strategies. Accordingly, a multi-year research plan was developed to collect specific biological and environmental data needed to assess the health and status of the population and characterize habitat used for spawning and rearing. In addition, in 1997 Phase II of the project was initiated. White sturgeon were captured, marked, and population data were collected between Lower Granite Dam and the mouth of the Salmon River. During 1997, 316 white sturgeon were captured in the Snake River. Of these, 298 were marked. Differences in the fork length frequency distributions of the white sturgeon were not affected by collection method. No significant differences in length frequency distributions of sturgeon captured in Lower Granite Reservoir and the mid- and upper free-flowing reaches of the Snake River were detected. The length frequency distribution indicated that white sturgeon between 92 and 183 cm are prevalent in the reaches of the Snake River that were sampled. However, white sturgeon >183 have not changed markedly since 1970. I would speculate that some factor other than past over

  11. Relationships between nutrient-related plant traits and combinations of soil N and P fertility measures. (United States)

    Fujita, Yuki; van Bodegom, Peter M; Witte, Jan-Philip M


    Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, therefore, examined the effect of different soil fertility measures on the strength of fertility-trait relationships in 134 natural plant communities. In particular, for eight plot-mean traits we examined (1) whether different elements (N or P) have contrasting or shared influences, (2) which timescale of fertility measures (e.g. mineralization rates for one or five years) has better predictive power, and (3) if integrated fertility measures explain trait variation better than individual fertility measures. Soil N and P had large mutual effects on leaf nutrient concentrations, whereas they had element-specific effects on traits related to species composition (e.g. Grime's CSR strategy). The timescale of fertility measures only had a minor impact on fertility-trait relationships. Two integrated fertility measures (one reflecting overall fertility, another relative availability of soil N and P) were related significantly to most plant traits, but were not better in explaining trait variation than individual fertility measures. Using all fertility measures together, between-site variations of plant traits were explained only moderately for some traits (e.g. 33% for leaf N concentrations) but largely for others (e.g. 66% for whole-canopy P concentration). The moderate relationships were probably due to complex regulation mechanisms of fertility on traits, rather than to a wrong choice of fertility measures. We identified both mutual (i.e. shared) and divergent (i.e. element-specific and stoichiometric) effects of soil N and P on traits, implying the importance of explicitly

  12. Ethnic Dimensions of Guatemala's Stalled Transition: A Parity-Specific Analysis of Ladino and Indigenous Fertility Regimes. (United States)

    Grace, Kathryn; Sweeney, Stuart


    In some contemporary populations, fertility levels appear to plateau, with women maintaining a consistently high level of fertility for a relatively extended period. Because this plateau does not reflect the historical patterns observed in Europe, the focus of most studies on fertility patterns, mechanisms underlying the plateau and the reinstatement of a decline have not been fully explored and are not fully understood. Through the construction of fertility histories of 25,000 women using multiple years of health survey data, we analyze some of the components of stalled fertility as they pertain to Guatemala, the only Central American country to have experienced a stalled fertility decline.

  13. Convergence in fertility of South Africans and Mozambicans in rural South Africa, 1993–2009

    Directory of Open Access Journals (Sweden)

    Michel Garenne


    Full Text Available Background: Although there are significant numbers of people displaced by war in Africa, very little is known about long-term changes in the fertility of refugees. Refugees of the Mozambican civil war (1977–1992 settled in many neighbouring countries, including South Africa. A large number of Mozambican refugees settled within the Agincourt sub-district, underpinned by a Health and Socio-demographic Surveillance Site (AHDSS, established in 1992, and have remained there. The AHDSS data provide a unique opportunity to study changes in fertility over time and the role that the fertility of self-settled refugee populations plays in the overall fertility level of the host community, a highly relevant factor in many areas of sub-Saharan Africa. Objectives: To examine the change in fertility of former Mozambican self-settled refugees over a period of 16 years and to compare the overall fertility and fertility patterns of Mozambicans to host South Africans. Design: Prospective data from the AHDSS on births from 1993 to 2009 were used to compare fertility trends and patterns and to examine socio-economic factors that may be associated with fertility change. Results: There has been a sharp decline in fertility in the Mozambican population and convergence in fertility patterns of Mozambican and local South African women. The convergence of fertility patterns coincides with a convergence in other socio-economic factors. Conclusion: The fertility of Mozambicans has decreased significantly and Mozambicans are adopting the childbearing patterns of South African women. The decline in Mozambican fertility has occurred alongside socio-economic gains. There remains, however, high unemployment and endemic poverty in the area and fertility is not likely to decrease further without increased delivery of family planning to adolescents and increased education and job opportunities for women.

  14. Fertility and marriage behavior in Israel: Diversity, change, and stability

    Directory of Open Access Journals (Sweden)

    Barbara Okun


    Full Text Available BACKGROUND Based on aggregate statistics, the population of Israel, as compared to all or most other developed societies, has very high levels of fertility and marriage (e.g. TFR of 2.96 in 2009 and only 9.7Š never married among women aged 40-44 in 2009. However, studying aggregate demographic measures is problematic, because Israel is an extremely heterogeneous society, with family formation patterns differing greatly across numerically important social groups. Until now, little has been documented about the basic fertility and marriage behavior of different population groups. OBJECTIVE We describe the fertility and marriage behavior of populations in Israel, broken down by nationality, religion, religiosity and nativity-status. Although our main focus is on a detailed presentation of fertility patterns, we also look at marriage behavior, as it is closely related to fertility in Israel. METHODS We analyze recently available annual data from the Israel Social Surveys for 2002-2009, which, for the first time in several decades,, provides detailed information on family and household demographic behavior and direct information on level of religiosity. We focus primarily on comparisons across cohorts born from the late 1940s to the late 1960s and between periods in the early and late 2000s. RESULTS We provide a detailed portrait of striking diversity in fertility and marriage behavior across population groups, along with important patterns of change and stability across cohorts and over time. We document findings and differential patterns, some unexpected, regarding comparisons across groups and across cohorts. CONCLUSIONS The descriptive findings form the basis for a clearer understanding of fertility and marriage patterns in different population subgroups in Israel. In addition, the reported results suggest many questions for future research, which are outlined in the paper.

  15. Immunosuppressive drugs and fertility. (United States)

    Leroy, Clara; Rigot, Jean-Marc; Leroy, Maryse; Decanter, Christine; Le Mapihan, Kristell; Parent, Anne-Sophie; Le Guillou, Anne-Claire; Yakoub-Agha, Ibrahim; Dharancy, Sébastien; Noel, Christian; Vantyghem, Marie-Christine


    Immunosuppressive drugs are used in the treatment of inflammatory and autoimmune diseases, as well as in transplantation. Frequently prescribed in young people, these treatments may have deleterious effects on fertility, pregnancy outcomes and the unborn child. This review aims to summarize the main gonadal side effects of immunosuppressants, to detail the effects on fertility and pregnancy of each class of drug, and to provide recommendations on the management of patients who are seen prior to starting or who are already receiving immunosuppressive treatment, allowing them in due course to bear children. The recommendations for use are established with a rather low level of proof, which needs to be taken into account in the patient management. Methotrexate, mycophenolate, and le- and teri-flunomide, cyclophosphamide, mitoxanthrone are contraindicated if pregnancy is desired due to their teratogenic effects, as well as gonadotoxic effects in the case of cyclophosphamide. Anti-TNF-alpha and mTOR-inhibitors are to be used cautiously if pregnancy is desired, since experience using these drugs is still relatively scarce. Azathioprine, glucocorticoids, mesalazine, anticalcineurins such as cyclosporine and tacrolimus, ß-interferon, glatiramer-acetate and chloroquine can be used during pregnancy, bearing in mind however that side effects may still occur. Experience is limited concerning natalizumab, fingolimod, dimethyl-fumarate and induction treatments. Conclusion: At the time of prescription, patients must be informed of the possible consequences of immunosuppressants on fertility and of the need for contraception. Pregnancy must be planned and the treatment modified if necessary in a pre-conception time period adapted to the half-life of the drug, imperatively in relation with the prescriber of the immunosuppressive drugs.

  16. Analysis of semen parameters in male referrals: impact of reference limits, stratification by fertility categories, predictors of change, and comparison of normal semen parameters in subfertile couples. (United States)

    Baker, Karen; Li, Jianbo; Sabanegh, Edmund


    To [1] determine the impact of semen reference limits on referrals for male fertility evaluations, [2] analyze the stratification of subjects based on published "normal" thresholds, [3] analyze the odds of changing fertility categories during serial tests and thereby the potential impact of inherent variability of semen parameters on referrals, and [4] determine variable(s) predictive of change. Retrospective chart review. Academic referral center for male fertility. New encounters in a male fertility clinic over a 5-year period that straddles the publication of World Health Organization (WHO) 2010 reference values. None. Demographic and clinical variables, semen values, and fertility categories as follows: BE (below WHO 2010 criteria), BTWN (above WHO 2010 but below WHO 1999 criteria), and N (above WHO 1999 criteria). A total of 82.3% of initial semen tests were categorized as BE, and the predominance of this category was unchanged by publication of the WHO 2010 criteria. Men with initial semen analysis categorized as BTWN or N represented 16.2% and 1.5% of the referral population, respectively. Subjects initially categorized as BTWN were more likely to change fertility categories, and overwhelmingly this migration was downward. Analysis of normal individual semen parameters revealed statistically worse mean concentration and motility when at least one other parameter fell below the WHO 2010 criteria. Men with semen results above reference criteria are underrepresented, indicating that reference limits influence referral patterns for male fertility evaluations. Normal mean concentration and motility were lower in men with at least one other individual semen parameter below the 2010 criteria, suggesting global dysfunction in spermatogenesis. Published by Elsevier Inc.

  17. Ethnicity and fertility in Nigeria. (United States)

    Kollehlon, Konia T


    Using a sample of Hausa-Fulani, Yoruba, Ibo, and all other women from the 1990 Nigerian Demographic and Health Survey, this study examines ethnic fertility differentials in Nigeria within the context of the social characteristics and cultural hypotheses. Among all women, we find the net fertility of Hausa-Fulani women to be lower than that of Other women; with no statistically significant difference in the net fertility of Ibo, Yourba, and Other women. But, among currently married women, we find the net fertility of Hausa-Fulani and Yoruba women to be lower than that of Other women, while the net fertility of Ibo women is higher than that of Other women. Overall, the findings of this study are more consistent with the cultural hypothesis, because statistically significant fertility differentials by ethnicity remain, even after controlling for selected socioeconomic and demographic variables.

  18. Temporal Trends in Fertility Rates

    DEFF Research Database (Denmark)

    Jensen, Martin Blomberg; Priskorn, Lærke; Jensen, Tina Kold


    OBJECTIVE: Increasing age at first childbirth has been suggested to increase the risk for infertility. Our objective is to determine whether women above thirty years of age historically have been able to sustain fertility rates above replacement level. DESIGN: A descriptive nationwide Danish study...... to determine total and age specific fertility rates. RESULTS: Total fertility rate (TFR) decreased from 4.1 to 1.8 children per woman and age specific fertility also decreased from 1901 to 2014. Women aged 30-34, 35-39 or 40-44 years in the first decade of the 20th century had higher fertility rates than...... for 10% of TFR in 1901 compared with 4% in 2014 despite usage of assisted reproduction. CONCLUSION: This nationwide study shows that women above 30 years of age historically have been able to sustain fertility rates above replacement level. This implies that other factors besides age are strong...

  19. Fertility and age

    Directory of Open Access Journals (Sweden)

    Korula George


    Full Text Available The changing social scenario together with economic growth and an increase in job opportunities has to a great extent reduced gender inequality and has resulted in more and more older women seeking help from infertility clinics. Fertility and aging have always been closely linked and the age of the female partner remains the single most important factor in predicting success with treatment. Although tests for the ovarian reserve are an important informative tool and are helpful in selecting treatment options, they are poor predictors of the outcome.

  20. Edxrf determination of major and minor elements in compound fertilizers

    DEFF Research Database (Denmark)

    Christensen, Leif Højslet; Rasmussen, Leif W.


    The combination of the energy-dispersive x-ray fluorescence technique and a backscatter/fundamental parameter-based matrix correction approach provides a new and unique solution to elemental analyses of fertilizers. This is demonstrated by means of results obtained for three reference materials...... and a range of in-house fertilizers. The results further demonstrate problems of sample preparation as well as the precision and accuracy of the method....

  1. Gamma spectrometry analysis of fertilizers used in Costa Rica

    International Nuclear Information System (INIS)

    Loria, L.G.; Jimenez, R.; Badilla, M.


    Using the low level gamma spectrometry technique, the specific activity of natural and artificial isotopes present in national consumption fertilizers, supplied by local dealers, was quantified. The most outstanding isotope found in some of the fertilizers is U 235 , with an specific activity higher than the expected in this kind of product, which might mean that this isotope comes from imported raw material. (Author) [es

  2. Does fertility decrease household consumption?


    Jungho Kim; Henriette Engelhardt; Alexia Fürnkranz-Prskawetz; Arnstein Aassve


    This paper presents an empirical analysis of the relationship between fertility and a direct measure of poverty for Indonesia, a country, which has experienced unprecedented economic growth and sharp fertility declines over recent decades. It focuses on illustrating the sensitivity of the effect of fertility on household consumption with respect to the equivalence scale by applying the propensity score matching method. The analysis suggests that a newborn child decreases household consumption...

  3. [Fertility transition in Brazil. Causes and consequences]. (United States)

    Carvalho, J A; Wong, L R


    This work examines the determinants and most important consequences of the Brazilian fertility decline. Brazil's total fertility rate declined from 6.2 in 1940 to around 3.5 in 1985. the decline began in the 1960s and amounted to 45% in about 20 years. The most rapid drop began in the late 1970s, with much of it concentrated in 2 specific periods: 1970-75 and 1980-85. The early period coincided with Brazil's so-called "Economic Miracle", a period of rapid growth accompanied however by deteriorating living conditions for the poorest population sectors. The second period coincided with the international economic crisis of the early 1980s, which was felt more strongly in Brazil than elsewhere in Latin America because of Brazil's greater degree of industrialization and closer integration into the world economy. Most of the fertility decline has been accomplished by use of just two contraceptive methods, oral contraceptives and sterilization, which together account for around 85% of contraceptive usage throughout Brazil. The third most common method, rhythm, accounts for just 6%. No reliable data on abortion are available, but it appears to be a common practice equally accessible to all socioeconomic strata despite greater associated health risks for poorer women. Brazil's fertility transition appears to have been a response to the process of proletarianization and urbanization underway in the country as well as to particular circumstances in the country. The most evident and immediate consequence of the continuous fertility decline over more than 20 years is the change in the age structure of the population. The proportions of children under 5 will decline from 14.4% in 1980 to 9.2% in 2010. The proportion aged 5-14 will decline from 24.5% to 17.4%, while the proportion aged 65 and over will increase from 4.0% to 5.6%. Brazil's recent demographic changes are scarcely reflected in development plans and political and social projects. There is almost no mention of the new

  4. Reconstruction of the diet of a pre hispanic population sector of Cuauhnahuac, Morelos by means of the chemical elements analysis in skeletal rests

    International Nuclear Information System (INIS)

    Brito, L.; Garza, I.; Banos, L.; Chaire, F.


    The goal of this work was diet reconstruction of 25 pre hispanic residents of Cuauhnahuac, tributary town of the mexicas, during the Late Pos classic period (1350-1521 a.C.). The analysis included human skull samples proceeding from human femur, tibia and fibula. The applied technique was X-ray fluorescence spectrometry (XRF) to know the mineral concentrations, which are closely related with the quality and quantity of the consumed food. The main indicative elements are strontium (Sr), that denotes the consumption of vegetables, zinc (Zn), that shows the consumption of animal proteins, and magnesium (Mg), associated with Meso american food resources. The results indicate the existence of differences in the diet among the same population's individuals, probably because social stratification determined the power resources acquisition. (Author) 28 refs., 7 tabs., 2 figs

  5. Fertility differentials in rural Bangladesh. (United States)

    Khan, H T; Islam, S M; Khan, H M; Bari, R


    "Data from two sources in rural Bangladesh have been used in this study to examine the differentials in fertility by selected socio-economic and demographic factors. Results [indicate] that age at first marriage, education of spouses and availability of electricity in the household...have [an] inverse relationship with fertility. Higher fertility is observed for Muslim women than for non-Muslims. It has been found that fertility is the lowest to those women whose husbands are service holders and the highest for agriculture." excerpt

  6. Fertilization compatibility of spawning corals (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set includes experimental results of fertilization assays to characterize genetic compatibility between individual parental genotypes. Targeted species...

  7. Population policy. (United States)


    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  8. Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils (United States)

    Braddock, J.F.


    A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.

  9. Austria: Persistent low fertility since the mid-1980s

    Directory of Open Access Journals (Sweden)

    Henriette Engelhardt


    Full Text Available This chapter offers an in-depth analysis of fertility in Austria, a country which has experienced a low and relatively stable fertility level and a gradual postponement of childbearing since the mid-1980s. We begin by summarising Austrian population trends in the post-World War II period and highlighting recent relatively high migration levels. We outline the long history of sub-replacement fertility and high childlessness in Austria and look in detail at recent parity-specific developments, trends in family size, delayed childbearing and persistent fertility differences by education level, country of origin and religious affiliation. The chapter then summarises main trends in family-related behaviour, including the changing patterns of leaving parental home, the rise in cohabitation, the decline in marriage and the rise of divorce and the diversity in non-marital childbearing, which has a long tradition in many parts of the country. We discuss the development of family policies in Austria and their relationship to fertility during the past decades. Social policies in Austria provide only a limited support for a reconciliation of childrearing and employment among mothers with children below the age of three. A combination of one of the highest family spending rates among the OECD countries and the low fertility rates indicate that structural constraints (such as the availability of childcare constitute part of the explanation of low fertility.

  10. Immigrant fertility in Sweden, 2000-2011: A descriptive note

    Directory of Open Access Journals (Sweden)

    Lotta Persson


    Full Text Available Background: Modern Scandinavian population registers provide excellent data sources that allow a user to quickly gain an impression of the level of fertility and its structure across subpopulations. This may also allow the analyst to check a feature of the much-cited disruption hypothesis, at least in part. Objective: The purpose of this note is to exploit this potential to give an overview of the structure of recent total fertility after immigration to Sweden from various groups of sending countries, separately for males and females. In the process we demonstrate to what extent the post-migration fertility compensation which is part of the fertility disruption hypothesis is fulfilled in our study population. Due to the nature of our data we have refrained from studying fertility before migration. Methods: Based on data from a combination of two Swedish administrative registers (the Historic Population Register and the Multi-Generation Register that cover both men and women in the entire population for the years 2000-2011, we compute and plot TFR-like age-cumulated fertility levels, specific for years since immigration, for six groups of sending countries, separately for men and women. Results: We find that the post-migration fertility compensation specified as part of the fertility disruption hypothesis is visibly confirmed in our Swedish study population for female European immigrants from non-EU countries and for female immigrants from non-European countries with a low or medium UN Human Development Index, but not so for other female immigrants, i.e. not for those who come from a Nordic country or from a non-Nordic EU country, and not for female immigrants from a non-European country with a high Human Development Index, including the United States. We find mild but less conclusive evidence for the same feature for males. Conclusions: This shows that at least as far as post-migration fertility compensation is concerned, the disruption

  11. Fertility of Czech Females Could Be Lower than Expected: Trends in Future Development of Age-Specific Fertility Rates up to the Year 2050

    Directory of Open Access Journals (Sweden)

    Ondřej Šimpach


    Full Text Available Fertility is an essential aspect of reproduction or population replacement of each country. The challenge for demographers is to model fertility and also to estimate its potential future level for the purposes of population projections. In the case of the Czech Republic we have the population projections provided by the Czech Statistical Office (CZSO with overlooking of the total fertility rate in low, medium and high variant. These estimates despite being based on expert judgments, seem to be too positive compared to the past development of the time series of age-specific fertility rates. The aim of this paper is to assess the situation of fertility in the Czech Republic, to analyse the past development of the time series of age-specific fertility rates using one-dimensional Box-Jenkins models and multidimensional stochastic Lee-Carter approach. Together with found trend in time series and principal components estimated by Lee-Carter’s model a forecasts of age-specific fertility rates up to the year 2050 is constructed. Th ese rates are lower than those provided by CZSO in its three variants of the Czech Republic’s population projection, and therefore we discuss the causes at the end of the paper. We would like to point out that the potential future development of Czech females fertility could be lower than which are currently expected.

  12. Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants. (United States)


    Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Change in mean blood pressure is the main driver of the worldwide change in

  13. Population success. (United States)


    "The commitment to population programs is now widespread," says Rafael Salas, Executive Director of the UNFPA, in its report "State of World Population." About 80% of the total population of the developing world live in countries which consider their fertility levels too high and would like them reduced. An important impetus came from the World Conference of 1974. The Plan of Action from the conference projected population growth rates in developing countries of 2.0% by 1985. Today it looks as though this projection will be realized. While in 1969, for example, only 26 developing countries had programs aimed at lowering or maintaining fertility levels, by 1980 there were 59. The International Population Conference, recently announced by the UN for 1984, will, it is hoped, help sustain that momentum. Cuba is the country which has shown the greatest decline in birth rate so far. The birth rate fell 47% between 1965-1970 and 1975-1980. Next came China with a 34% decline in the same period. After these came a group of countries--each with populations of over 10 million--with declines of between 15 and 25%: Chile, Colombia, India, Indonesia, the Republic of Korea, Malaysia and Thailand. Though birth rates have been dropping significantly the decline in mortality rates over recent years has been less than was hoped for. The 1974 conference set 74 years as the target for the world's average expectation of life, to be reached by the year 2000. But the UN now predicts that the developing countries will have only reached 63 or 64 years by then. High infant and child mortality rates, particularly in Africa, are among the major causes. The report identifies the status of women as an important determinant of family size. Evidence from the UNFPA-sponsored World Fertility Survey shows that in general the fertility of women decreases as their income increases. It also indicates that women who have been educated and who work outside the home are likely to have smaller families

  14. Altura de planta e componentes do rendimento do feijoeiro em função de população de plantas, adubação e calagem Common bean plant height and primary yield components affected by plant population, fertilization and liming

    Directory of Open Access Journals (Sweden)

    Antonio Barbara de Souza


    Full Text Available Com o objetivo de investigar os efeitos de populações de plantas e níveis de adubação e calagem sobre a altura e os componentes do rendimento de grãos do feijoeiro (Phaseolus vulgaris L. em um solo Podizólico Vermelho Amarelo distrófico, de baixa fertilidade natural, foram conduzidos três experimentos de campo em Lavras - MG. Nos dois primeiros, utilizaram-se a cv. Pérola e delineamento experimental em blocos casualizados, com quatro repetições, no arranjo fatorial 4x4, envolvendo quatro populações: 120, 180, 240 e 300 mil plantas.ha-1 e quatro níveis de adubação e calagem: 0, 1/3, 2/3 e 3/3 das doses de fertilizantes e calcário recomendadas para o nível 2 de tecnologia pela Comissão de Fertilidade do Solo do Estado de Minas Gerais. No terceiro ensaio, o arranjo fatorial foi 2x4x4, envolvendo duas cultivares, Pérola e Carioca, quatro populações, 100, 200, 300 e 400 mil plantas.ha-1; e quatro níveis de adubação e calagem 0, 1/2, 2/2 e 3/2 das doses. O incremento da população de plantas reduziu a altura e o número de vagens por planta e o incremento dos níveis de adubação e calagem elevou a altura, o número de vagens por planta, o número de grãos por vagem e a massa média do grão.With a view to defining the plant density and level of fertilization and liming for the bean crop ( Phaseolus vulgaris L. in a natural low fertility soil (distrophic Red Yellow Podzolic, three field experiments were carried out in Lavras - MG. In the two first experiments the cultivar Pérola was utilized and the randomized block experimental design, with four replications and 4x4 factorial arrangement, involving four populations (120, 180, 240 and 300 thousand plants.ha-1 and four levels of fertilization and liming (0, 1/3, 2/3 and 3/3 of the recommended doses of fertilizers and limistone for the level 2 of technology by the Comissão de Fertilidade do Solo do Estado de Minas Gerais was adopted. In the third trial, the factorial

  15. Household Fertilizers Use and Soil Fertility Management Practices ...

    African Journals Online (AJOL)

    Household Fertilizers Use and Soil Fertility Management Practices in Vegetable Crops Production: The Case of Central Rift Valley of Ethiopia. ... rate, which could leads to pollution of the environment from over dose application and from runoff in to the water bodies and leaching in to the ground water with economic loss.

  16. Fertile ground? : soil fertility management and the African smallholder

    NARCIS (Netherlands)

    Misiko, M.


    Keywords: smallholder farmers, soil fertility, experimentation, "inconvenience", realist.The focus in this thesis is to form a view of how well soil fertility research performs within the ever shifting smallholder contexts. This study examined application of agro-ecological

  17. Visualization and modeling of sub-populations of compositional data: statistical methods illustrated by means of geochemical data from fumarolic fluids (United States)

    Pawlowsky-Glahn, Vera; Buccianti, Antonella

    In the investigation of fluid samples of a volcanic system, collected during a given period of time, one of the main goals is to discover cause-effect relationships that allow us to explain changes in the chemical composition. They might be caused by physicochemical factors, such as temperature, pressure, or non-conservative behavior of some chemical constituents (addition or subtraction of material), among others. The presence of subgroups of observations showing different behavior is evidence of unusually complex situations, which might render even more difficult the analysis and interpretation of observed phenomena. These cases require appropriate statistical techniques as well as sound a priori hypothesis concerning underlying geological processes. The purpose of this article is to present the state of the art in the methodology for a better visualization of compositional data, as well as for detecting statistically significant sub-populations. The scheme of this article is to present first the application, and then the underlying methodology, with the aim of the first motivating the second. Thus, the first part has the goal to illustrate how to understand and interpret results, whereas the second is devoted to expose how to perform a study of this kind. The case study is related to the chemical composition of a fumarole of Vulcano Island (southern Italy), called F14. The volcanic activity at Vulcano Island is subject to a continuous program of geochemical surveillance from 1978 up to now and the large data set of observations contains the main chemical composition of volcanic gases as well as trace element concentrations in the condensates of fumarolic gases. Out of the complete set of measured components, the variables H2S, HF and As, determined in samples collected from 1978 to 1993 (As is not available in recent samples) are used to characterize two groups in the original population, which proved to be statistically distinct. The choice of the variables is

  18. Theoretical explanations of the rapid fertility decline in China. (United States)

    Wu, C


    A 1982 population census recorded China's fertility rate in 1982 at 2.6; recent statistics of China's State Statistics Bureau record China's 1984 birth rate at 17 per 1000 and the total fertility rate at 1.94. Wu Cangping asserts that this world-recognized rapid fertility decline is not due to any compulsory governmental restrictions on fertility, but to the people's willingness to control fertility voluntarily. He cites a number of socioeconomic factors contributing to this voluntary decline in China's birth rates: 1) change of family function; 2) decline of mortality, particularly infant mortality; 3) improvement in the educational level; 4) improvement in women's social status, especially increased employment; 5) better social security services for the elderly; 6) the preference for modern ways of production and life; and 7) the availability of information on population and birth control. He attributes these factors to the socialist system with its nationalized production, centralized planning of the national economy, and the even distribution system which prevents polarization of earning. In addition, reforms have been carried out in all aspects of social life and recent advances have been made in science and technology. All of these factors have resulted in a more rapid fertility transition in China as compared to that of developed countries in their past and that of developing countries at present.

  19. Analysis of the effectiveness of fertilizer subsidy policy and its effect on rice production in Karanganyar Regency (United States)

    Mulyadiana, A. T.; Marwanti, S.; Rahayu, W.


    The research aims to know the factors which affecting rice production, and to know the effectiveness of fertilizer subsidy policy on rice production in Karanganyar Regency. The fertilizer subsidy policy was based on four indicators of fertilizer subsidy namely exact price, exact place, exact time, and exact quantity. Data was analyzed using descriptive quantitative and qualitative and multiple linear regression. The result of research showed that fertilizer subsidy policy in Karanganyar Regency evaluated from four indicators was not effective because the distribution of fertilizer subsidy to farmers still experience some mistakes. The result of regression analysis showed that production factors such as land area, use of urea fertilizer, use of NPK fertilizer, and effectiveness of fertilizer subsidy policy had positive correlation and significant influence on rice production, while labor utilization and use of seeds factors had no significant effect on rice production in Karanganyar Regency. This means that if the fertilizer subsidy policy is more effective, rice production is also increased.

  20. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)


    In 1998 white sturgeon (Acipenser transmontanus) were captured, marked, and population data were collected in the Snake River between Lower Granite Dam and the mouth of the Salmon River. A total of 13,785 hours of setline effort and 389 hours of hook-and-line effort was employed in 1998. Of the 278 white sturgeon captured in the Snake River, 238 were marked for future identification. Three sturgeon were captured in the Salmon River and none were captured in the Clearwater River. Since 1997, 6.9% of the tagged fish have been recovered. Movement of recaptured white sturgeon ranged from 98.5 kilometers downstream to 60.7 kilometers upstream, however, less than 25% of the fish moved more than 16 kilometers (10 miles). In the Snake River, white sturgeon ranged in total length from 51.5 cm to 286 cm and averaged 118.9 cm. Differences were detected in the length frequency distributions of sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). In addition, the proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 37% since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir were slightly larger than white sturgeon in the free-flowing Snake River.

  1. Methodological issues in analyzing time trends in biologic fertility: protection bias

    DEFF Research Database (Denmark)

    Key, Jane; Best, Nicky; Joffe, Michael


    One method of assessing biologic fertility is to measure time to pregnancy (TTP). Accidental pregnancies do not generate a valid TTP value and lead to nonrandom missing data if couples experiencing accidental pregnancies are more fertile than the general population. If factors affecting the rate...... of fertility trends in Europe over the past 50 years. Couples experiencing accidental pregnancies tended to be more fertile than the general population. However, trends in accidental pregnancy rates were inconsistent across countries and were insufficient to produce substantial bias in fertility trends...... of accidental pregnancies, such as availability of effective contraception and induced abortion, vary over time, then the result may be protection bias in the estimates of fertility time trends. Six European data sets were analyzed to investigate whether evidence of protection bias exists in TTP studies...

  2. Fertility and the changing female educational attainment in Croatia

    Directory of Open Access Journals (Sweden)

    Čipin Ivan


    Full Text Available This paper investigates the aggregate relationship between cohort fertility and female educational attainment in Croatia. Numerous demographic studies have examined the link between fertility and the level of education. However, newer research indicates that the field of education might also play a role when trying to explain fertility behavior. We contribute to existing literature on macro-level factors related to reproductive outcomes by considering both the level and field of education as possible sources of cohort fertility differentials. The main goal of the present study is to assess the effect of structural changes in educational attainment on cohort fertility decline by means of demographic decomposition techniques. Our analysis is based on detailed 2011 Census data, which provide information on the number of livebirths by mother’s year of birth, birth order, marital status and educational attainment (i.e. the level and field of education. The results of our decomposition analyses reveal the dominance of the structural effect in explaining the overall completed fertility decline in Croatia. We assumed that the changing distribution of women by field of education at least partially accounts for the observed patterns in completed fertility but found no strong evidence in support of the outlined hypothesis.

  3. What if fertility decline is not permanent? The need for an evolutionarily informed approach to understanding low fertility. (United States)

    Burger, Oskar; DeLong, John P


    'Demographic transition theory' assumes that fertility decline is irreversible. This commonly held assumption is based on observations of recent and historical reductions in fertility that accompany modernization and declining mortality. The irreversibility assumption, however, is highly suspect from an evolutionary point of view, because demographic traits are at least partially influenced by genetics and are responsive to social and ecological conditions. Nonetheless, an inevitable shift from high mortality and fertility to low mortality and fertility is used as a guiding framework for projecting human population sizes into the future. This paper reviews some theoretical and empirical evidence suggesting that the assumption of irreversibility is ill-founded, at least without considerable development in theory that incorporates evolutionary and ecological processes. We offer general propositions for how fertility could increase in the future, including natural selection on high fertility variants, the difficulty of maintaining universal norms and preferences in a large, diverse and economically differentiated population, and the escalating resource demands of modernization. © 2016 The Author(s).

  4. Behaviour of lactic acid bacteria populations in Pecorino di Carmasciano cheese samples submitted to environmental conditions prevailing in the gastrointestinal tract: evaluation by means of a polyphasic approach. (United States)

    Ricciardi, Annamaria; Blaiotta, Giuseppe; Di Cerbo, Alessandro; Succi, Mariantonietta; Aponte, Maria


    The survival of the autochthonous microflora, of samples collected during Pecorino di Carmasciano cheese manufacturing, was evaluated along the passage through a model mimicking the gastro-intestinal tract. The aim was the selection of lactic acid bacteria potentially able to arrive alive and metabolically active to the colon. The dynamics of lactic microbiota, throughout simulated digestion of cheese samples, were evaluated by means of an approach PCR-DGGE-based. Dominant species after cheese digestion could be related to the Lactobacillus plantarum and Lactobacillus casei groups. Sixty-three strains, which survived to simulated gastro-intestinal transit, were further evaluated for technological features and tolerance to human digestion in several experimental conditions, according to routinely used protocols. Bacterial survival appeared to be, more than strain-specific, strongly affected by experimental conditions, i.e. some strains showed an acceptable survival when resuspended in skim milk but not in ewe milk and vice versa. Nevertheless according to data, one gram of fresh Pecorino di Carmasciano cheese may convey to human colon about the same amount of viable LAB of a probiotic drink. Although it cannot be assumed that lactobacilli introduced with Pecorino have beneficial effects on the host, the healthy impact of autochthonous lactic acid bacteria of naturally fermented food has a broad consensus in the current literature. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Changing fertility patterns and policies in the third world. (United States)

    Mcnicoll, G


    Different patterns of fertilty transition are apparent in developing countries. Theories of fertility decline are appropriate because demographic analysis has become situation specific rather than general. Pretransition fertility patterns and the onset of decline are provided. Fertility transition patterns are also supplied, including a regional overview for Latin America, east and Southeast Asia, South Asia, West Asia and North Africa, and sub-Saharan Africa. The specialized cases of China, India, Bangladesh, Thailand and Indonesia, and Brazil are also presented. The fertility determinant models of Bongaarts, Davis and Blake, Hobcraft and Little, Ryder, and Henry are used as examples of proximate determinant models. Data collection was possible on a grand scale with contraceptive knowledge, attitudes, and practice (KAP) surveys and the World Fertility Surveys and Demographic and Health Surveys. Criticism has focused on the scope of these surveys which provide at best proximate determinants and differentiate fertility by standard socioeconomic factors. Data are also obtained on small populations from piecing together records and from quasi-anthropological fieldwork. Historical demography relies on family reconstitution. Longitudinal studies are few in number. The largest and most effective fieldwork station is at Matlab in Bangladesh. Caldwell has provided anthropological methods applicable to fertility study and makes use of teamwork. In Latin America, fertility has fallen by 40% since the 1960s. Bolivia, Guatemala, Honduras, Nicaragua, El Salvador, and Haiti have changed very little. Taiwan and South Korea provide examples of economic growth with equity in East and Southeast Asia. In heterogenous South Asia, decline has been slow and uneven. West Asia and North Africa have high fertility with the exception of Egypt which is in the early stages of transition. The smallest declines are found in sub-Saharan Africa, and are complicated by the AIDS epidemic.

  6. [Impact of backward sexual viewpoints on population development]. (United States)

    Wang, B


    In the development of human society, the reproductive function was considered the sole purpose of sexual activities. Any other purposes were deemed abnormal or deviant. The prevalence of that viewpoint reflected the needs during the transformation from hunting to farming as major means of production of the society and the needs for large populations under the socioeconomic conditions of rural society. With the low level of productivity in a family-oriented economy, further development depended on the number of labor hands in the family. The wars for extension of territory and for survival need a constant supply of soldiers. Under such circumstances, the need for large populations implied the importance of fertility behavior in sexual relations. In the rural farming societies, fertility was important in strengthening and developing the family wealth, status, and family structure. Blood relations were emphasized in rural society for family inheritance, for expansion of family influence, and for old age support. The rapid decline of fertility in Europe at the beginning of this century was proposed by some Chinese scholars as the result of their citizens pursuing individual happiness including in sexual relations. The use of contraceptives prevented couples from being overburdened with children. These concepts on sexual relations facilitated the decline of fertility. The necessary social and economic conditions and advances in technology are already present for the changes of the traditional concepts toward sexual relations. The united efforts of social agencies in promoting these changes will be an efficient ensure in regulating the speed of population growth.

  7. Prediction of porcine male fertility

    NARCIS (Netherlands)

    Broekhuijse, M.L.W.J.|info:eu-repo/dai/nl/313871728


    Life starts with fertilisation. Variation in fertility is caused by both farm and sow related parameters and boar and semen related parameters. Therefore, achieving high fertility is not obvious. Predominantly, artificial insemination (AI) is used for breeding pigs. The advantage of AI is that you

  8. Fertility treatment in obese women

    NARCIS (Netherlands)

    Koning, A.M.H.


    Overweight and obesity are increasing worldwide. This has major adverse consequences for health in general and fertility in women in particular. With the increasing number of women in reproductive age being obese, there is also an increasing need for fertility treatment. And with more pregnant women

  9. Fertility drugs and ovarian cancer. (United States)

    Ali, Aus Tariq


    The aetiology of ovarian cancer is multifactorial with both endogenous and exogenous risk factors playing an important role. The exact pathogenesis of ovarian cancer is still not well understood, despite the number of hypotheses published. Due to an increase in the number of women using fertility drugs, much attention has been focused on the long-term health effects of such drugs. Although fertility drugs facilitate the ovulation process, it is however associated with a significant increase in hormone concentrations, placing exposed women at increased risk of gynaecological cancer. Many clinical and epidemiological studies have examined the association between fertility drugs and ovarian cancer risk. Results from these studies have been contradictory, as some studies have reported an increased risk of ovarian cancer while others reported no increased risk. Nevertheless, recent studies have shown that women who used fertility drugs and did not conceive had a higher risk of developing ovarian cancer, compared to women who used fertility drugs and conceived and delivered successfully. This review discusses the effect of fertility drugs on the risk of developing ovarian cancer, providing details on four possible scenarios associated with fertility treatment. In addition, the limitations of previous studies and their impact on our understanding of the association between fertility drugs and ovarian cancer also have been highlighted. Copyright© Bentham Science Publishers; For any queries, please email at

  10. Fertilizing Douglas-fir forests. (United States)

    Richard E. Miller; Roger D. Right


    This report supplements a slide-tape presentation of the same title. Part I of the report describes the current practice of nitrogen fertilization of Douglas-fir forests in western Washington and Oregon and the effects of this fertilization on tree growth and water quality. Part II discusses factors that affect costs and revenues from investments in forest...

  11. Menstrual cycle pattern and fertility

    DEFF Research Database (Denmark)

    Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik


    To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss.......To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss....

  12. Childbearing trends in Iceland, 1982-2013: Fertility timing, quantum, and gender preferences for children in a Nordic context

    Directory of Open Access Journals (Sweden)

    Ari Klængur Jónsson


    Full Text Available Background: Iceland is one of the most gender-equal countries in the world, but one that does not seem to have experienced the same fertility fluctuations as most other countries, following the enhanced role of women in society. Objective: In this study we examine the childbearing trends in Iceland during 1982-2013 by analysing the progressions to parities one, two, and three. We also investigate whether there is evidence of gender preferences for children among Icelandic parents. Methods: Official individual longitudinal register data is used, covering the total female population born in Iceland between 1941 and 1997. The data is analysed by means of event history analysis. Results: We find evidence of tendencies to postpone motherhood during the period, with increases in fertility for women in their 30s and 40s. The propensity to have a second and a third child has not declined; on the contrary, these birth intensities have increased since the mid-1980s. Estimates suggest that Icelandic parents prefer to have daughters. Conclusions: During a period of increased educational attainment and postponed family formation, the resilience of Icelandic fertility is intriguing. Contribution: The study provides the first comprehensive overview of fertility trends in Iceland.

  13. Impact of fertilization and granular insecticides on the incidence of tobacco aphid, myzus persicae (sulz)

    International Nuclear Information System (INIS)

    Razaq, A.; Hussain, N.; Khalil, S.K.; Alamzeb


    Field studies were conducted on the control of tobacco aphid, Myzus persicase (Sulz) with four granular insecticides, viz, Furadan 3% G, Diazinon 5% g, Thiodan 5% g and Larsban 5% g, with and without NPK fertilization. The aphid population was significantly higher in the fertilized plots compared to the non-fertilized ones. All the four insecticides significantly reduced the aphids density compared to the check. Furada 3% gave best results for the control of this pest. (author)

  14. [Fertility and health in Mexico]. (United States)

    Urbina-Fuentes, M; Echánove-Fernández, E


    Fertility, health, and family planning are not independent factors, but rather involve a series of biological and social mechanisms in close interaction with one another. The impact that a high fertility rate has on health is reflected mainly in a rise in the rates of maternal and child mortality. Similarly, fertility has a greater negative effect upon the health of groups characterized by high reproductive risk, high parity, short intergenesic intervals, and unwanted pregnancies. On the other hand, family planning -and specifically the use of contraceptive methods-helps to achieve a lowering of the fertility rate and also has a positive effect on maternal-child health. This situation can be observed in the case of Mexico, where fertility rates and tendencies, as well as maternal and child mortality, have been reduced during the past decade.

  15. Isotope studies on rice fertilization

    International Nuclear Information System (INIS)


    The aim of the report is to provide practical information on the efficient utilization of nitrogen fertilizers in rice production. Results obtained from field investigations during the years 1970 to 1974 in ten countries (Bangladesh, Burma, Indonesia, Republic of Korea, Sri Lanka, Taiwan, Thailand, Vietnam, India, Philippines), using 15 N-labelled nitrogen fertilizers (ammonium sulfate, urea) are given. The experiments, which were conducted both during the dry and wet seasons, included comparison of varieties, effect of placement, source and time of nitrogen fertilizer application on the yield and quality of rice. The data from the project is presented in table form. In most of the experiments, the addition of nitrogen increased the rice grain yield. The role of soil nitrogen vs. fertilizer nitrogen is compared, and it is concluded that the physiological growth stage at which fertilizer-derived nitrogen is absorbed is of great importance

  16. Enteropathogenic bacterial contamination of a latosol following application of organic fertilizer

    Directory of Open Access Journals (Sweden)

    Pedro Alexandre Escosteguy


    Full Text Available Poultry manure is used as fertilizer in natura, but little is known about whether it contaminates the soil with pathogenic organisms. The aim of this study was to assess the effects of organic, organomineral and mineral fertilizers on soil contamination by enteric pathogens, using poultry manure as the organic fertilizer. Manure was applied in field experiments at rates of 7.0 ton. ha-1 (maize crop, 2008/2009, 8.0 ton. ha-1 (wheat crop, 2009 and 14 ton. ha-1 (maize crop, 2010/2011. Organomineral fertilizer was applied at the same rates but was comprised of 50% manure and 50% mineral fertilizer. At 30 and 70 days after fertilization, the organic fertilizer and the upper 0-5 cm layer of the soil were tested for the presence of helminth eggs and larvae and enteropathogenic bacteria. Fecal and non-fecal coliforms (Escherichia coli and Clostridium perfringes were found in the organic fertilizer, but neither Salmonella spp. nor enteroparasites were detected. The population of enteropathogenic bacteria in the soil was similar among the treatments for all crops at both evaluation times. The population of thermotolerant coliforms in the organic fertilizer was larger than the maximum level allowed in Brazil, but neither the organic or nor the organomineral fertilizer contaminated the soil.

  17. Are women with obesity and infertility willing to attempt weight loss prior to fertility treatment? (United States)

    Sacha, C R; Page, C M; Goldman, R H; Ginsburg, E S; Zera, C A

    To assess attitudes towards weight loss interventions in patients seeking infertility treatment. We evaluated prior weight loss experiences, attitudes towards future interventions by body mass index (BMI), and willingness to delay fertility treatment for weight loss interventions stratified by BMI using logistic regression amongst women ≤45years old with infertility over three months or recurrent pregnancy loss. The average age of our convenience sample of respondents (148 of 794 eligible women, 19%) was 34.5 years old, with a mean BMI of 26.7±7.4kg/m 2 , including 37 with a BMI >30kg/m 2 (25%). Most women had attempted conception over 1year. The majority of women with overweight or obesity were attempting weight loss at the time of survey completion (69%). While 47% of these women reported interest in a supervised medical weight loss program, 92% of overweight women and 84% of women with obesity were not willing to delay fertility treatment more than 3 months to attempt weight loss. Most women with obesity and infertility in our population are unwilling to postpone fertility treatment for weight loss interventions. Copyright © 2017 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  18. [Association between the decline in global fertility rate and the incorporation of women to the workforce]. (United States)

    Stefanelli, María de Los Ángeles; Valenzuela, María Teresa; Cárcamo, Marcela; Urquidi, Cinthya; Cavada, Gabriel; San Martín P, Pamela


    The global fertility rate (GFR) is defined as the mean number of children that a woman could have in a hypothetical cohort, not exposed to death during the fertile period. GFR has fallen from 3.4 to 1.9 children per women in the period 1970-2010. To explore the relationship between the fall in GFR and the incorporation of women to work in the period 1960-2011. Data from the National Statistics Institute was used. GRF was calculated using specific fertility rates for each year considering women aged 15 to 49 years. Work rates were obtained from yearly vital statistics reports. Between 1960 and 2011, GRF decreased from 5.5 to 1.9 in Chile. The first inflection occurred in 1970. In the same period, female workforce increased from 22.4 to 40.2%. To motivate the participation of female work-force without decrease the GRF allowing population replacement, it is suggested the need to create new public policies with benefits and support from the state.

  19. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... options further? Fertility Preservation - Where Does It Fit? Options for Fertility Preservation The following diagram gives a brief description of fertility preservation options available to children diagnosed with cancer before and ...

  20. Induced sterility in petunia correlation between pollen and ovule fertilities

    International Nuclear Information System (INIS)

    Singh, I.S.


    An estimation of ovular fertility in petunia was carried out in order to show an eventual correlation between pollen and ovule fertilities. Two lines, TL-h 1 and Sf-1a, their F 1 hybrid and some pollen sterile plants isolated in M 1 after mutagenic treatments were vegetatively maintained in greenhouse. Data pollen fertility, number of ovules per ovary and number of seeds per capsule were obtained from each genotype. The ovule fertility was calculated as follows: mean number of seeds per capsule/mean number of ovules per ovary x 100. The analysis of variance detected: a highly significance variance component among genotypes, a highly significant differences between the sexes, and, a highly significant genotypes x sexes interaction. A highly significant positive correlation coefficient was found between pollen and ovule fertilities. Thus, it can be concluded that pollen and ovule fertilities may be affected in the same direction in the different mutant clones studied, but in a different manner from genotype to genotype [fr

  1. Multifunctional liquid bio fertilizer as an innovative agronomic input for modern agriculture

    International Nuclear Information System (INIS)

    Phua Choo Kwai Hoe; Khairuddin Abdul Rahim


    Liquid bio fertilizer is increasingly available in the market as one of the alternatives to chemical and organic fertilizers as well as solid substrate-based bio fertilizers. One of the benefits from bio fertilizer is the contribution from population of microorganisms available. These microorganisms may enhance the plant growth and create healthy rhizosphere. The advantage of a liquid bio fertilizer is that no solid carrier is needed. These products are also developed for potential application in modern agriculture such as soil less farming systems, viz. fertigation and hydroponics. Traditionally, liquid bio fertilizer is produced from fermentation of effective microorganisms which was recommended to be used within three months. Therefore, the development of low-cost and long shelf-life liquid bio fertilizers was conducted at Malaysian Nuclear Agency (Nuclear Malaysia). Three bio fertilizer inoculum (phosphate solubilising bacteria and plant growth promoting bacteria) were developed into four formulations of liquid bio fertilizers. The liquid bio fertilizers were kept at low temperatures (9 ± 2 degree Celsius) and room temperatures (28 ± 2 degree Celsius) for shelf-life study. Nutrient broth liquid bio fertilizer kept at low temperatures showed significantly high survival rates after storage for six months as compared to other formulations and treatments. (author)

  2. Phosphate fertilizer influence on {sup 238} U content in vegetables

    Energy Technology Data Exchange (ETDEWEB)

    Lauria D, C.; Rodrigues S, J.I. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Rio de Janeiro-RJ (Brazil); Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN) Av. Prof. Luiz Freire 200 Cidade Universitaria Recife-PE (Brazil)]. e-mail:


    Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of {sup 238} U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of {sup 238} U have been carried out by conventional fluorimetric method. The geometric mean of {sup 238} U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in

  3. Phosphate fertilizer influence on 238 U content in vegetables

    International Nuclear Information System (INIS)

    Lauria D, C.; Rodrigues S, J.I.; Ribeiro, F.C.A.


    Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of 238 U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of 238 U have been carried out by conventional fluorimetric method. The geometric mean of 238 U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in organic management

  4. A decomposition analysis of recent fertility decline in Fiji. (United States)

    Gubhaju, B; Shahidullah, M


    Over the period 1966-86, both the Fijian and Indian populations of Fiji demonstrated declines in fertility. Differentials in the decline were, however, noted with the total fertility rate (TFR) of the Fijian population declining by 26% over the period compared to a 50% decline in the Indian TFR. Moreover, rate declines were not smooth and consistent over the period. Faster fertility decline was experienced in the 1st decade for both groups, slowing in the 2nd decade for Indian women, and stabilizing among the Fijians. This paper decomposes these differential changes in fertility rate into marital structure and marital fertility. The study was conducted using data from the censuses of 1966, 1976, and 1986. For the period 1966-76, declines in marital fertility contributed most to overall TFR decline for both ethnic groups. Marital structure had a reducing effect upon TFR among Indian women in the 1st decaed, but not during the 2nd. Fijian women experienced an overall negative impact from marital structure. Contraception plays an important role in limiting fertility in these 2 populations. Accordingly, differentials in acceptance were noticed, the family planning acceptance rate for Indians being almost twice that of Fijians; 35.6% and 18.7%, respectively in 1986. Compared to Indian women, Fijian women were more literate, more economically active, had higher life expectancies, and experience lower infant mortality rates. Nonetheless, they are not motivated to use family planning. Motivational, cultural, religious, and behavioral factors are suggested as causal factors determining acceptance and use of modern contraceptive methods.

  5. Fertilizers in cereals crops. Effect of fertilization in grain quality

    International Nuclear Information System (INIS)

    Melaj, Mariana


    In the last years the yields of the maize cultivation in the Pampeana production region have constantly increased, foreseeing higher increases of yield in the next years. Such increase is due, between other motives, to the use of hybrids of higher potential yield. There is a direct relation between the yield potential of a genotype and the nutrients demand, fact that constitutes one of the geneticists concerns. Maize hybrids reach its maximum expression when the plant is cultivated in good supplied soils with balanced quantities of nutrients that in several cases are reached with the practice of fertilization. The quantitative and qualitative vegetal response to the use of phosphate fertilizers depend of soils, of the environmental conditions, of fertilizer and the way of its application as well as of the maize hybrid that was used. To direct the practice of fertilization towards the reposition of the soil nutrients extracted by genotypes of high yield without producing excesses that increase costs and put in danger the environment, it is necessary to know the real coefficient used by the plants of the phosphorus available in the soils. The isotopic methodology allows to distinguish the phosphorus coming from two nutrient sources: soil and fertilizer, even in the juvenile phase of vegetal development and to evaluate the efficiency of fertilizers in plant nutrition. The objective of the present work was to evaluate the use of phosphorus coming from one of the phosphorus source available (soil, fertilizer), that should allow to increase and make more specific the knowledge's level of the different maize hybrids. This is obtained by determination of the grade of use of nutrient (of the soil) and of the nutrient of fertilizers, evaluating the qualitative and quantitative responses to fertilization

  6. How fast is population ageing in China?


    Yinhua mai; Xiujian Peng; Wei Chen


    Using adjusted 2000 population census data, this paper conducts China's population projections to 2050. Three fertility and four mortality scenarios yield 12 sets of results. Despite the below-replacement fertility, China's population will continue growing for many years. However, there are substantial differences among the twelve scenarios. The maximum population could range from less than 1.4 billion to more than 1.6 billion. One of the notable trends is the rapid population ageing. By the ...

  7. Greenhouse Gas Emissions from Solid and Liquid Organic Fertilizers Applied to Lettuce. (United States)

    Toonsiri, Phasita; Del Grosso, Stephen J; Sukor, Arina; Davis, Jessica G


    Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (NO) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha) on NO emissions and to track CO emissions from a lettuce field ( L.). The study was conducted in 2013 and 2014 and compared preplant-applied solid fertilizers (feather meal and blood meal) and multiple applications of liquid fertilizers (fish emulsion and cyano-fertilizer). Three days a week, NO and CO emissions were measured twice per day in 2013 and once per day in 2014 using a closed-static chamber, and gas samples were analyzed by gas chromatography. Preplant-applied solid fertilizers significantly increased cumulative NO emissions as compared with control, but multiple applications of liquid fertilizers did not. Emission factors for NO ranged from 0 to 0.1% for multiple applications of liquid fertilizers and 0.6 to 11% for preplant-applied solid fertilizers, which could be overestimated due to chamber placement over fertilizer bands. In 2014, solid fertilizers with higher C/N ratios (3.3-3.5) resulted in higher CO emissions than liquid fertilizers (C/N ratio, 0.9-1.5). Therefore, organic farmers should consider the use of multiple applications of liquid fertilizers as a means to reduce soil greenhouse gas emissions while maintaining high yields. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. [Hormone regulation of male fertility]. (United States)

    Anselmo, J G


    An innocuous, sure, reversible means of male fertility control which does not disturb the libido is being sought. 20 healthy volunteers from ages 20 to 36 participated, using a 2nd form of protection when necessary. 10 received implants of 60 mg testosterone equally divided into 3 tubes, and began oral ingestion of 100 mg weekly, divided into daily doses, of R2323 (13-ethyl-17-hydroxy-gonen 4,9,11, trien-3-one) until the sperm became ineffective. Then oral doses were given according to personal requirements from 50 to 25 mg. The 2nd series of 10 received no testosterone implants, but followed the same scheme for oral ingestion. All patients but 1 reduced their sperm count and 80% were low enough to consider the sperm inactive. For those who used the hormone treatment as the only protection against pregnancy, no pregnancy occurred. Of the 1st group, 2 had excessive weight gain, 3 felt their libido reduced, and 1 had pain in the nipples and 1 had pain in the hepatic region. Recuperation of normal sperm characteristics was slow, especially motility and vitality. The spermogram is so altered during treatment that any accidental pregnancy could result in a defective egg and serious complications. It should definitely be avoided.

  9. Population growth and its implications

    Directory of Open Access Journals (Sweden)

    Badii, M. H.


    Full Text Available Human populations have grown at an unprecedented rate over the past three centuries. By 2001, the world population stood at 6.2 billion people. If the current trend of 1.4 % per year persists, the population will double in 51years. Most of that growth will occur in the less developed countries of Asia, Africa, and Latin America. There is a serious concern that the number of humans in the world and our impact on the environment will overload the life support systems of the earth. The crude birth rate is the number of births in a year divided by the average population. A more accurate measure of growth is the general fertility rate, which takes into account the age structure and fecundity of the population. The crude birth rate minus the crude death rate gives the rate of natural increase. When this rate reaches a level at which people are just replacing themselves, zero population growth is achieved. In the more highly developed countries of the world, growth has slowed are even reversed in recent years so that without immigration from other areas, population would be declining. The change from high birth and death rates that accompanies in industrialization is called a demographic transition. Many developing nations have already begun this transition. Death rates have fallen, but birth rates remain high. Some demographers believe that as infant mortality drops and economic development progresses so that people in these countries can be sure of secure future, they will complete the transition to a stable population or a high standard living. While larger populations bring many problems, they also may be a valuable resource of energy, intelligence, and enterprise that will make it possible to overcome resource limitation problems. A social just view argues that a more equitable distribution of wealth might reduce both excess population growth and environmental degradation. We have many more options now for controlling fertility than were available

  10. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for Children Diagnosed with Cancer Ask Your Doctor Information for ...

  11. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for Children Diagnosed with Cancer Ask Your Doctor Information for Patients Many adult ...

  12. Endoscopic Vasectomy of Male Feral Pigeons (Columba livia) as a Possible Method of Population Control. (United States)

    Heiderich, Elisabeth; Schildger, Bernd; Lierz, Michael


    To evaluate whether single-entry endoscopic vasectomy of male feral pigeons (Columba livia) significantly reduced fertility and would potentially be valuable for control of feral pigeon populations, 252 male feral pigeons were caught in the city of Berne and endoscopically vasectomized. In this procedure, approximately 1 cm of the deferent duct was removed bilaterally. Rapid, uneventful recoveries occurred in 94% (237/252) of the pigeons, whereas 6% (15/252) died because of complications associated with the procedure, consisting of perforation of the ureter (9/15), major hemorrhage (5/15), and respiratory arrest (1/15). Mean anesthesia time was 23±6 minutes. The vasectomized males were habituated to 2 pigeon houses together with fertile females. Another pigeon house with fertile pairs acted as control. All eggs laid were candled weekly to assess fertility. In the 2 pigeon houses with vasectomized males, the mean fertilization rate was 0.9% (5/563), while in the control pigeon house, the rate was 100% (39/39). The results indicate that endoscopic vasectomy of male feral pigeons may be a promising tool for field control of feral pigeon populations, especially in combination with other methods such as pigeon houses.

  13. Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice

    Directory of Open Access Journals (Sweden)

    Zhong-xian LU


    Full Text Available Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers (Nilaparvata lugens and Sogatella furcifera, leaffolder (Cnaphalocrocis medinalis, and stem borers (Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesamia inferens were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

  14. Fertility preservation: a pilot study to assess previsit patient knowledge quantitatively. (United States)

    Balthazar, Ursula; Fritz, Marc A; Mersereau, Jennifer E


    To provide a quantitative assessment of patient knowledge about fertility and fertility preservation treatment options before the initial fertility preservation consultation at a university-based fertility preservation center. Prospective pilot survey containing 13 items assessing patient knowledge about fertility preservation, including the available treatment options and their requirements, success rates, and associated risks. University-based IVF center. Women aged 18 to 41 years with illnesses requiring treatments posing a serious threat to future fertility who were referred for fertility preservation consultation between April 2009 and June 2010. None. Knowledge score. Forty-one eligible patients were identified, and all completed surveys before their consultation. A knowledge score was generated for each patient with 1 point awarded for each correct answer. Overall, patients had poor previsit fertility preservation knowledge (mean score 5.9±2.7). Higher knowledge scores were correlated with personal experience with infertility and previous exposure to fertility preservation treatment information. There was no correlation between knowledge score and age, relationship status, pregnancy history, education, or income. Patients seen for fertility preservation consultation at our university-based center generally tend to be in their early 30s, white, well educated, and married. Previsit knowledge about fertility preservation treatment options was poor and did not correlate with age, education, and relationship status. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Comparison of unenriched versus 15N-enriched fertilizer as a tracer for N fertilizer uptake

    International Nuclear Information System (INIS)

    Meints, V.W.; Shearer, G.; Kohl, D.H.; Kurtz, L.T.


    A greenhouse experiment was conducted on three soils with differing cropping and fertilization histories to determine whether unenriched fertilizer N can be used in the same manner as 15 N-enriched fertilizer to estimate the amount of plant N derived from fertilizer. Estimates using unenriched fertilizer N were compared with estimates using two 15 N enrichment levels. Use of unenriched fertilizer N led to underestimation of the amount of fertilizer N in the plant material in four of six cases when compared to 15 N-enriched fertilizer. Standard deviations of the estimates of fertilizer-derived N in plant material were considerably greater when unenriched fertilizer was used. (U.S.)

  16. Gender Trouble and Its Impact on Fertility Intentions

    Directory of Open Access Journals (Sweden)

    Irene M. Tazi-Preve


    Full Text Available It is often an underlying assumption that the new role of women and in general the trend toward a more egalitarian view of the concept of partnership is a main factor behind the low fertility rates in rich countries. The aim of this paper is to test the consequences of gender (inequity on the desire of women and men to have (further children by using gender inequity as an important category within population science. In our assumptions we want to test whether an unequal distribution of household chores and childcare duties has a negative effect on the desire to have children. Another assumption examines the potential correlation that the perception of (inequality of women and men in society or the acceptance of government measures to ensure equal rights might have with the desire to have children. The data are derived from the recent Austrian survey Population Policy Acceptance Survey. The assumptions are tested by means of logistic regression analysis. The results show that it is new men who are likely to express a wish for children, rather than those who live in traditional partnership models.

  17. [Women, fertility, development: the case of Rwanda]. (United States)

    Kabagwira, A


    Rwanda's high fertility rate and very rapid population growth have a negative impact on the welfare of women. Traditionally, women in Rwanda won the respect of their in-laws by having many children, on whom they depended for social status, help in agricultural work, and support in old age. Women also played a very important role in agricultural production in addition to their daily household activities. Migration of men and young people to urban areas has left many women totally in charge of agricultural production and has further deprived them of their limited leisure time. Low income, legal obstacles, literacy, custom and other factors limit women's resulting from their inferior social and juridical status conditions their reproductive behavior despite the development of a family planning program dating to 1981. The low level of female education is an important factor; 33% of women vs. 61% of men are literate. 25% of Rwanda's budget is devoted to education, but population growth has impeded progress Illiteracy implies a lack of receptivity to new ideas, including family planning. A 1983 fertility study in Rwanda showed that marriage age increased with education, from 18.8 years for illiterate women to 19.5 for those within 3-5 years. The number of children declined with the educational attainment of the mother, as did infant mortality rates. Considering the physical labor that women carry out, their repeated pregnancies are a handicap to the promotion of their own and their family's health. The prevailing high fertility exacerbates nutritional problems; some 20% of infants weigh less that 2.5 kg at birth. Efforts have recently been made to recognize the contribution of women and to elevate their status, such as improving their access to education, raising the legal marriage to 21, and prohibiting polygamy. The National Office of Population was created in 1981 to study population problems and take action to resolve them. The national population policy adopted in

  18. Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria. (United States)

    Simonsen, Anna K; Han, Shery; Rekret, Phil; Rentschler, Christine S; Heath, Katy D; Stinchcombe, John R


    Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia), a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community, either directly

  19. Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria

    Directory of Open Access Journals (Sweden)

    Anna K. Simonsen


    Full Text Available Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia, a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community

  20. Mater certa est, pater numquam: What can Facebook Advertising Data Tell Us about Male Fertility Rates?


    Rampazzo, Francesco; Zagheni, Emilio; Weber, Ingmar; Testa, Maria Rita; Billari, Francesco


    In many developing countries, timely and accurate information about birth rates and other demographic indicators is still lacking, especially for male fertility rates. Using anonymous and aggregate data from Facebook's Advertising Platform, we produce global estimates of the Mean Age at Childbearing (MAC), a key indicator of fertility postponement. Our analysis indicates that fertility measures based on Facebook data are highly correlated with conventional indicators based on traditional data...

  1. Should fertility clinics divest themselves of pornography? (United States)

    Murphy, Timothy F


    Some commentators object to the way in which fertility clinics make pornography available to men as an aid to masturbation when those men produce sperm for evaluation, storage or IVF. These objections typically rely on claims that pornography is generally harmful to women, unnecessary and dissociates sexual acts from conception. In light of these objections, certain commentators want fertility clinics to divest themselves of pornography, but these objections to pornography are not morally convincing. In general, pornography can have psychological value to men masturbating 'on demand' in clinical contexts. Not all erotica must, either, work to the disadvantage of women in its means of production or social effects. Moreover, the sexuality expressed in masturbation has a value of its own, and conception apart from sexual intercourse is morally defensible on its own. Divestment from pornography would do little to constrain the putative harms of pornography because clinics consume only a fractional amount of the total amount of pornography available. The provision of pornography is a defensible clinical practice, even if it is not absolutely necessary to all men in producing a sperm sample important to their fertility or their interests in donating gametes.

  2. The impact of freedom on fertility decline. (United States)

    Campbell, Martha M; Prata, Ndola; Potts, Malcolm


    Although fertility decline often correlates with improvements in socioeconomic conditions, many demographers have found flaws in demographic transition theories that depend on changes in distal factors such as increased wealth or education. Human beings worldwide engage in sexual intercourse much more frequently than is needed to conceive the number of children they want, and for women who do not have access to the information and means they need to separate sex from childbearing, the default position is a large family. In many societies, male patriarchal drives to control female reproduction give rise to unnecessary medical rules constraining family planning (including safe abortion) or justifying child marriage. Widespread misinformation about contraception makes women afraid to adopt modern family planning. The barriers to family planning can be so deeply infused that for many women the idea of managing their fertility is not considered an option. Conversely, there is evidence that once family planning is introduced into a society, then it is normal consumer behaviour for individuals to welcome a new technology they had not wanted until it became realistically available. We contend that in societies free from child marriage, wherever women have access to a range of contraceptive methods, along with correct information and backed up by safe abortion, family size will always fall. Education and wealth can make the adoption of family planning easier, but they are not prerequisites for fertility decline. By contrast, access to family planning itself can accelerate economic development and the spread of education.

  3. Should fertility clinics divest themselves of pornography?

    Directory of Open Access Journals (Sweden)

    Timothy F Murphy


    Full Text Available Some commentators object to the way in which fertility clinics make pornography available to men as an aid to masturbation when those men produce sperm for evaluation, storage or IVF. These objections typically rely on claims that pornography is generally harmful to women, unnecessary and dissociates sexual acts from conception. In light of these objections, certain commentators want fertility clinics to divest themselves of pornography, but these objections to pornography are not morally convincing. In general, pornography can have psychological value to men masturbating ‘on demand’ in clinical contexts. Not all erotica must, either, work to the disadvantage of women in its means of production or social effects. Moreover, the sexuality expressed in masturbation has a value of its own, and conception apart from sexual intercourse is morally defensible on its own. Divestment from pornography would do little to constrain the putative harms of pornography because clinics consume only a fractional amount of the total amount of pornography available. The provision of pornography is a defensible clinical practice, even if it is not absolutely necessary to all men in producing a sperm sample important to their fertility or their interests in donating gametes.

  4. Fertility outcome in male and female patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

    Directory of Open Access Journals (Sweden)

    Mahdi Kamoun


    Conclusion: Fertility in male and female patients with CAH is reduced. Early and adequate glucocorticoid therapy along with good compliance, careful monitoring of androgen levels and continuous psychological management could contribute to improved fertility rates in this population, even among those with the severe variant.

  5. The Role of socioeconomic factors in fertility of Umuahia women in ...

    African Journals Online (AJOL)

    Rapid population growth arising from high fertility has been argued as being disadvantageous to the economic growth of countries especially the developing country like Nigeria. This paper examines the role of socioeconomic factors in fertility. The study elicited information from 500 women of the reproductive age of 15-49 ...

  6. Fertility and Birth Rates: Indicators of Child and Youth Well-Being. Updated. October 2016 (United States)

    Child Trends, 2016


    Tracking trends in fertility and birth rates is essential in planning for the current and future needs of multiple generations. Sustained high fertility rates lead to disproportionately large populations of young dependents, driving demand for supports for young families, for additional schools, and for affordable child care. For example, during…

  7. Zinc fertilization of flooded rice

    International Nuclear Information System (INIS)


    Local scientists studied Zn fertilization of flooded rice soils in Bangladesh, India, Indonesia, the Republic of Korea, Egypt, the Philippines, Thailand and Turkey. Diagnosis of Zn deficiency was carried out for submerged rice soils. Soil maps were prepared, designating areas as low, medium and high in Zn, based on Zn extraction with DTPA and HCl solutions and on rice leaf analysis. The effectiveness of various Zn fertilizer sources and methods of application in field and greenhouse experiments was measured, using 65 Zn. The percent Zn derived from fertilizer was shown to be a much more sensitive measure of efficiency than yield or total uptake

  8. Women's Agency and Fertility: Recent Evidence from Egypt. (United States)

    Samari, Goleen


    Fertility reached a two decade high of 3.5 births per woman in Egypt in 2014. Lower status of women is associated with higher fertility. Majority of the studies on women's agency and fertility rely on individual level cross-sectional data from South Asia, which limits the understanding of variation among communities and the direction of the relationship between women's agency and fertility in other global contexts. This study examines the relationship between women's agency and fertility longitudinally and among communities in the most populous country in the Middle East - Egypt. For 3,795 ever married women 15 to 49 years old in the 2006 and 2012 Egyptian Labor Market Panel Survey, multilevel models are estimated for having given birth and number of births between 2006 and 2012. Contrary to expectation, women with more agency with greater participation in household decision-making and mobility are, in fact, more likely to have had a birth and have a greater total number of births. Only women with more egalitarian attitudes are associated with fewer births. Community membership explains 5% of the variation in fertility. Since social norms in Egypt favor a higher number of births and labor market participation among women is low, women with agency could be fulfilling social expectations of having children and choosing to have more children.

  9. [Relationships between psychological well-being, lifestyle factors and fertility]. (United States)

    Lakatos, Enikő; Szabó, Gábor; F Szigeti, Judit; Balog, Piroska


    10 to 15% of the Hungarian fertile age population struggles with reproductivity problems. Previous researches have shown that psychological well-being and lifestyle factors play a pivotal role in overall health status, which is closely related to fertility. The aim of the study was to examine fertility-related psychological and lifestyle factors in a Hungarian sample. 194 women (115 infertile and 79 fertile) took part in the study. Standardized, validated questionnaires were used for the assessment of psychological factors and self-administered questions were used for exploring lifestyle factors. The results show that infertile women are younger (33.98±4.89 vs. 36.43±5.81 years, pfertile counterparts. The number of their depressive (BDI 14.00±12.21 vs. 7.79±9.17, p40.25±10.65, pfertile women. Findings related to lifestyle factors show that lower level of fluid consumption (1.71±0.67 vs. 1.95±0.68, pfertile group (OR = 1.65, CI = 2.58-1.06), independently of body mass index and age. The results confirm the findings of international researches showing that women struggling with infertility are in worse psychological condition than their fertile counterparts. The authors conclude that the findings demand further investigations and follow-up studies in order to more specifically determine the relationship between fluid consumption and fertility.

  10. Effects of nitrogen fertilization on forest trees in relation to insect resistance and to red-listed insect species

    International Nuclear Information System (INIS)

    Glynn, C.; Herms, D.A.


    Ecosystems worldwide are experiencing unprecedented nitrogen enrichment through fertilization and pollution. While longterm ecological consequences are difficult to predict, it seems that plants and animals adapted to nitrogen-limited environments are at particular risk from these changes. This report summarizes the limited body of literature which addresses this important topic. From a herbivoreAes perspective, fertilization increases the nutritional quality of host plant tissues. In some cases fertilization has lead to decreased production of defensive compounds. How this affects populations of insects is unclear because fertilization affects not only herbivores but their natural enemies. This report outlines how fertilization affects tree processes such as growth, photosynthesis, and production of defensive compounds. The many factors that affect insect repsonse to fertilization and the difficulties in assessing how fertilization affects insect populations are discussed

  11. China's Population Policy at the Crossroads: Social Impacts and Prospects


    Jiang, Quanbao; Li, Shuzhuo; Feldman, Marcus W.


    China's total fertility rate fell below replacement level in the 1990s. From the 1970s the fertility rate declined dramatically, mainly as a consequence of the national population policy whose aim has been to limit birth numbers, control population growth and boost economic growth. Having achieved such a low fertility rate, how will China's population policy evolve in the future? This paper first reviews the history of China's population policy since 1970 in terms of three stages: 1970-1979; ...

  12. Semen collection and fertility in naturally fertile sandhill cranes (United States)

    Chen, G.; Gee, G.F.; Nicolich, Jane M.; Taylor, J.A.; Urbanek, R.P.; Stahlecker, D.W.


    Aviculturists often ask if semen collection will interfere with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had produced fertile eggs in previous years and were in out-of-doors pens scattered throughout different pen complexes, within auditory range but physically isolated. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection did not affect semen quality or quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm live, sperm number per collection, and male response to semen collection exhibited significant daily variation (P semen collection began 13 days before the first egg in the experimental group, we observed no differences in the date of first egg laid or in fertility between experimental and control groups. Also, we observed no differences in the interval between clutches or in the percentage of broken eggs between experimental and control groups. Sires consistently producing better semen samples produced fewer fertile eggs than sires producing poorer semen samples (r = 0.60).

  13. [Nutrition and fertility]. (United States)

    Szostak-Węgierek, Dorota


    There is a growing body of evidence that nutritional habits may have a significant effect on both male and female fertility. Maintenance of normal body mass may be effective in the prevention of infertility resulting from ovulatory disorders. Underweight and, to a larger degree, overweight and/or obesity, are related to the enhanced risk of infertility. Insulin resistance is an important pathogenic mechanism that may impair ovulation. Adequate intake of monounsaturated fatty acids, derived mainly from vegetable fats, as well as avoidance of trans isomers of unsaturated fatty acids which are present in industrially produced cakes and sweets, crisps, fast-foods, powdered soups and hard margarines, may be effective in the prevention of infertility in females. Choice of plant rather than animal sources of proteins, decrease in glycemic load of the diet, use of dietary supplements containing iron and folic acid, could also be beneficial. Avoidance of vitamin B12 deficiency and its supplementation seem to be important in the prevention of early miscarriages. Sufficient intake of antioxidants also promotes female reproductive functions. Free radical processes play an important role in the development of male factor infertility. It was shown that proper intake or supplementation with antioxidants may be effective in its prevention and treatment. Such nutrients as zinc, selenium and folic acid act beneficially on sperm quality. A well-balanced diet seems to play an important role in the prevention of infertility in both sexes.

  14. Agronomic performance of male-sterile and fertile maize genotypes at two plant populations Performace agronômica de genótipos macho-estéreis e férteis de milho em duas densidades de semeadura

    Directory of Open Access Journals (Sweden)

    Luís Sangoi


    Full Text Available This experiment was conducted in 1994 at Ames, Iowa, US to test whether cytoplasmic male-sterility can be used to decrease barrenness and to increase grain yield of maize at two plant populations. Four genotypes were tested: a hybrid (NK 6330 and an inbred, wifh sterile and fertile counterparts. Each genotype owas evaluated at plant populations equivalent to 25,000 and 75,000 pl. ha-1. Hybrids produced higher grain yield than inbreds at both plant populations. Gram yield was higher at 75,000 than at 25,000 pl. ha-1. No difference in gram yield, number of ears per plant, number of grains per ear, tassel length, and tassel number of branches was found between sterile and fertile counterparts of the inbred and hybrid, regardiess of plant population. Fertile genotypes bore heavier tassels at anthesis than their sterile counterparts. Adequate precipitation distribution and high fertility level in the soil probably decreased competition between tassel and ears, mitigating potential yield benefits of suppressing genetically pollen production.Este experimento foi conduzido em Ames, Iowa, US durante o ano agrícola de 1994, tendo como objetivo avaliar se a macho-esterelidade genético-citoplasmática pode ser utilizada para aumentar o rendimento de grãos de milho em diferentes populações de planta. Quatro genótipos foram utilizados: um híbrido (NK 6330 e uma linhagem, ambos em suas versões fértil e macho-estéril. Cada genótipo foi avaliado em duas densidades de semeadura, equivalentes a 25.000 e 75.000 pl.ha-1. Os híbridos produziram maiores rendimentos de grão do que as linhagens nas duas populações utilizadas. O rendimento de grãos por área foi maior em 75.000 do que em 25.000 pl.ha-1. Nenhuma diferença significativa em termos de rendimento de grãos, número de espigas por planta, número de grãos por espiga, comprimento e número de ramos do pendão, foi observada entre genótipos férteis e macho-estéreis, independentemente da

  15. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Sex and Fertility ... injury? What is a Spinal Cord Injury? SCI Medical Experts People Living With SCI Personal Experiences By ...

  16. Determinants of fertility in Namibia

    African Journals Online (AJOL)

    AJRH Managing Editor

    This examines the fertility trends in Namibia over the past 2 decades .... contraceptive use was small because of the late age at first ..... limited flexibility in terms of maternity leave conditions ... Longer periods in education have increased the.

  17. In vivo fertilization of banana

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares


    Full Text Available The aim of this research was to study the in vivo fertilization process of banana cultivars. The diploid hybrid (AA 091087-01 was the male progenitor. Flower samples were checked for fertilization from the first to the twentieth day after pollination. The size of the diploid ovules increased gradually at the beginning of the seed formation process. On the other hand, in the AAA triploids (Cavendish subgroup, the not fertilized ovules were aborted. In the AAB triploids (Prata subgroup some ovules were fertilized. The flowers of Grand Naine, Nanicão and 'Pacovan' cultivars presented necrosis in the distal part of the ovary on the first day after pollination. Necrosis can hinder pollen tube growth towards the ovule, which might be related to the low seed yield in 'Pacovan' cultivars and to the absence of seeds in the Cavendish subgroup cultivars.

  18. Preserving Fertility while Battling Cancer (United States)

    Some oncologists neglect to discuss the possibility of treatment-related infertility with patients of reproductive age. Researchers are developing decision aids to help patients make an informed, carefully considered decision about fertility.

  19. Determinants of fertility in Ethiopia

    African Journals Online (AJOL)

    be access to education, media, and providing employment opportunities in the modern economic sector. Besides .... and religion shows that muslim women have 1.7% high- er fertility ... traditional social and economic systems continue, the.

  20. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries Spinal Cord Injury 101 David Chen, ...

  1. IVF-In Vitro Fertilization. (United States)

    Kieffer, George H.


    Issues surrounding the controversial topic of in vitro fertilization and artificial manipulation of reproduction are discussed. The author examines the moral and ethical implications and presents results of a survey of various religious groups. (SA)

  2. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries Spinal Cord Injury ... 2525 SIGN UP FOR OUR NEWSLETTER Your email address * This iframe contains the logic ...

  3. Is fertility falling in Zimbabwe? (United States)

    Udjo, E O


    With an unequalled contraceptive prevalence rate in sub-Saharan Africa, of 43% among currently married women in Zimbabwe, the Central Statistical Office (1989) observed that fertility has declined sharply in recent years. Using data from several surveys on Zimbabwe, especially the birth histories of the Zimbabwe Demographic and Health Survey, this study examines fertility trends in Zimbabwe. The results show that the fertility decline in Zimbabwe is modest and that the decline is concentrated among high order births. Multivariate analysis did not show a statistically significant effect of contraception on fertility, partly because a high proportion of Zimbabwean women in the reproductive age group never use contraception due to prevailing pronatalist attitudes in the country.

  4. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Sex and Fertility After Spinal Cord Injury Adult Injuries Spinal Cord Injury 101 David ...

  5. (ajst) pedological characteristics, general fertility

    African Journals Online (AJOL)


    Key words: Pedological characteristics, fertility, soil classification, benchmark soils, Morogoro. District, Tanzania ... rigorous soil mapping to show their spatial distribution. Although at the ... experience bimodal rainfall pattern characterized by two .... evaluated based on the standards set by EUROCONSULT ... crop growth.

  6. Policy Implications of the Variations in Ghana's Fertility Transition ...

    African Journals Online (AJOL)

    The results of three consecutive Demographic and Health Surveys (GDHS), carried out in 1986, 1993, 1998, show that Ghana's population has been experiencing a fertility transition. An analysis of the data, however, indicates that there are wide and increasing differentials in both the timing and trends in the process among ...

  7. Fertility Behaviour of Men and Women in Three Communities in ...

    African Journals Online (AJOL)

    The UN Millennium Project aims to reduce poverty, hunger, and disease while promoting education, health, gender equity, and environmental sustainability. Fertility is not mentioned anywhere within the eight goals, but population growth rates profoundly impact the achievability of all goals by increasing the budgets ...

  8. Educational and social class assortative mating in fertile British couples. (United States)

    Krzyżanowska, Monika; Mascie-Taylor, C G Nicholas


    Positive assortative mating for education and social position has been widely reported in a number of countries, but very few studies have tested whether or not educational or social class homogamy is related to differential fertility. This study examined the relationship between educational and social class assortative mating and fertility in a British national cohort. The analyses were based on 7452 husband-wife pairs from the British National Child Development Study (NCDS). The mean fertility was 3.22 children per couple; the number of children significantly increased from higher to lower social classes and from the more educated to the less educated. The extent of assortative mating for social class and educational level was related to fertility; as educational assortative mating decreased so did the average number of children, whereas the opposite trend was observed for social class. When assortative mating for education and social class were considered together, educational assortative mating was the more significant predictor of the number of children and educationally homogamous couples had higher fertility independent of their social class assortative mating. The relationship between assortative mating and fertility for education and social class appeared to be acting in the opposite direction.

  9. Type 1 diabetes risk in children born to women with fertility problems

    DEFF Research Database (Denmark)

    Hargreave, Marie; Kjaer, Susanne K; Jørgensen, Marit E


    INTRODUCTION: While some studies have indicated that children born following fertility treatment are at an increased risk for insulin resistance and higher blood glucose levels, no study to date has investigated the risk of type 1 diabetes. In this large population-based cohort study we aim...... to assess the association between maternal fertility problems and the risk of type 1 diabetes in children. MATERIAL AND METHODS: Information on all children, born in Denmark from 1987 to 2010, was extracted from the Civil Registration System and linked with the Danish Infertility Cohort to identify maternal......%) were born to women with fertility problems. In all, 313 children born to women with fertility problems (0.36%) and 5176 children born to women without fertility problems (0.28%) were diagnosed with type 1 diabetes. The risk of type 1 diabetes was not affected by maternal fertility status (hazard ratio...

  10. Fertility in Islamic Republic of Iran: Levels, Trends and Differentials during Three Decades (1967-1996

    Directory of Open Access Journals (Sweden)

    Kazem Mohammad


    The detailed nature of these data collected for each birth enabled fertility rates to be calculated for exact periods before the survey, for exact calendar years. Higher fertility rates were found for the period 10-15 and 15-20 years preceding the survey. These high fertility levels are probably due to some socio-economic changes in favor of higher level of fertility immediately after the 1979 revolution. However the results of the present survey show during 1967-1996, the TFR1 had dropped from 6.38 to 2.88 (an expected TFR based on fertility behavior during 1992-96. This decline was probably due to delay in marriage and policy changes in favor of population control particularly since 1987. Despite this potential fertility decline in recent years, Iran is expected to face a baby boom as the offspring who were born during the 1976-86 reach to the reproductive age in the coming decades.

  11. Regime shift in fertilizer commodities indicates more turbulence ahead for food security.

    Directory of Open Access Journals (Sweden)

    James J Elser

    Full Text Available Recent human population increase has been enabled by a massive expansion of global agricultural production. A key component of this "Green Revolution" has been application of inorganic fertilizers to produce and maintain high crop yields. However, the long-term sustainability of these practices is unclear given the eutrophying effects of fertilizer runoff as well as the reliance of fertilizer production on finite non-renewable resources such as mined phosphate- and potassium-bearing rocks. Indeed, recent volatility in food and agricultural commodity prices, especially phosphate fertilizer, has raised concerns about emerging constraints on fertilizer production with consequences for its affordability in the developing world. We examined 30 years of monthly prices of fertilizer commodities (phosphate rock, urea, and potassium for comparison with three food commodities (maize, wheat, and rice and three non-agricultural commodities (gold, nickel, and petroleum. Here we show that all commodity prices, except gold, had significant change points between 2007-2009, but the fertilizer commodities, and especially phosphate rock, showed multiple symptoms of nonlinear critical transitions. In contrast to fertilizers and to rice, maize and wheat prices did not show significant signs of nonlinear dynamics. From these results we infer a recent emergence of a scarcity price in global fertilizer markets, a result signaling a new high price regime for these essential agricultural inputs. Such a regime will challenge on-going efforts to establish global food security but may also prompt fertilizer use practices and nutrient recovery strategies that reduce eutrophication.

  12. Coevolution of interacting fertilization proteins.

    Directory of Open Access Journals (Sweden)

    Nathaniel L Clark


    Full Text Available Reproductive proteins are among the fastest evolving in the proteome, often due to the consequences of positive selection, and their rapid evolution is frequently attributed to a coevolutionary process between interacting female and male proteins. Such a process could leave characteristic signatures at coevolving genes. One signature of coevolution, predicted by sexual selection theory, is an association of alleles between the two genes. Another predicted signature is a correlation of evolutionary rates during divergence due to compensatory evolution. We studied female-male coevolution in the abalone by resequencing sperm lysin and its interacting egg coat protein, VERL, in populations of two species. As predicted, we found intergenic linkage disequilibrium between lysin and VERL, despite our demonstration that they are not physically linked. This finding supports a central prediction of sexual selection using actual genotypes, that of an association between a male trait and its female preference locus. We also created a novel likelihood method to show that lysin and VERL have experienced correlated rates of evolution. These two signatures of coevolution can provide statistical rigor to hypotheses of coevolution and could be exploited for identifying coevolving proteins a priori. We also present polymorphism-based evidence for positive selection and implicate recent selective events at the specific structural regions of lysin and VERL responsible for their species-specific interaction. Finally, we observed deep subdivision between VERL alleles in one species, which matches a theoretical prediction of sexual conflict. Thus, abalone fertilization proteins illustrate how coevolution can lead to reproductive barriers and potentially drive speciation.

  13. Fertility behavior in developing economies: an investment approach. (United States)

    Chernichovsky, D


    By studying intergenerational benefits from children, this paper shows that the economic analysis of fertility behavior in developing economics can provide a systematic discussion of this behavior. The major hypotheses set forth are: 1) the effect of income on fertility depends on the source and timing of income; 2) in a lifetime context, parents, or would-be parents, who have higher incomes at young ages compared with the income they anticipate at old age, are expected to have a higher demand for children; and 3) the reverse of the latter is predicted for parents who anticipate relatively higher incomes at old age. These hypotheses follow the idea that, in the absence of other appropriate means for intertemporal transfers of wealth, parents even out the lifetime welfare through fertility behavior. Under these circumstances, fertility rates are expected to increase in communities where children abandon their traditional commitments to their aging parents, as may happen during periods of economic and cultural transition. A decline in mortality rates will induce lower fertility. This model suggests that a tax-financed social security scheme along with family planning will be conducive to a reduction in fertility. A test on data from an Indian village in 1968-69 suggests that in a traditional setting there is a correlation between household welfare, measured by income or assets, and the presence of grown children. Income has a positive effect on fertility when the parents' incomes comes from labor rather than human and nonhuman capital which provides income at later stages of life. Longitudinal data depicting income, savings, and fertility patterns over time should prove more promising in exploring the issues discussed.

  14. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... website. Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open ... Diagnosed with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation ...

  15. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu ... with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for ...

  16. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu Reprotopia_Main_Menu ... Cancer Fertility Preservation for Children Diagnosed with Cancer Patient Pocket Guides Patient Pocket Guides Patient Guides Fertility ...

  17. Impact of ART on the fertility of HIV-positive women in sub-Saharan Africa. (United States)

    Yeatman, Sara; Eaton, Jeffrey W; Beckles, Zosia; Benton, Lorna; Gregson, Simon; Zaba, Basia


    Understanding the fertility of HIV-positive women is critical to estimating HIV epidemic trends from surveillance data and to planning resource needs and coverage of prevention of mother-to-child transmission services in sub-Saharan Africa. In the light of the considerable scale-up in antiretroviral therapy (ART) coverage over the last decade, we conducted a systematic review of the impact of ART on the fertility outcomes of HIV-positive women. We searched Medline, Embase, Popline, PubMed and African Index Medicus. Studies were included if they were conducted in sub-Saharan Africa and provided estimates of fertility outcomes (live births or pregnancies) among women on ART relative to a comparison group. Of 2070 unique references, 18 published papers met all eligibility criteria. Comparisons fell into four categories: fertility of HIV-positive women relative to HIV-negative women; fertility of HIV-positive women on ART compared to those not yet on ART; fertility differences by duration on ART; and temporal trends in fertility among HIV-positive women. Evidence indicates that fertility increases after approximately the first year on ART and that while the fertility deficit of HIV-positive women is shrinking, their fertility remains below that of HIV-negative women. These findings, however, were based on limited data mostly during the period 2005-2010 when ART scaled up. Existing data are insufficient to characterise how ART has affected the fertility of HIV-positive women in sub-Saharan Africa. Improving evidence about fertility among women on ART is an urgent priority for planning HIV resource needs and understanding HIV epidemic trends. Alternative data sources such as antenatal clinic data, general population cohorts and population-based surveys can be harnessed to understand the issue. © 2016 John Wiley & Sons Ltd.

  18. Genetics and genomics to improve fertility in high producing dairy cows

    NARCIS (Netherlands)

    Veerkamp, R.F.; Beerda, B.


    Improving dairy cow fertility by means of genetic selection is likely to become increasingly important, since it is now well established that declining fertility cannot only be arrested by improved management. Profit margins per kg milk produced are decreasing, therefore farmers need to reduce cost

  19. Fertilization and Embryo Development of Fresh and Cryopreserved Sibling Oocytes

    Directory of Open Access Journals (Sweden)

    Robert F. Casper


    Full Text Available Background: Oocyte cryopreservation is potentially the best way to preserve female fertility forunmarried women or young girls at risk of losing ovarian function. The aim of this study was tocompare fertilization and embryo development in frozen-thawed oocytes to their fresh siblings inwomen undergoing in vitro fertilization (IVF and embryo transfer (ET.Materials and Methods: Eleven infertile women undergoing infertility treatment, between theages of 24 to 37 years (mean ± SD = 31.6 ± 3.5, were included in this study. Mature oocytesfrom each patient were randomized into cryopreserved and fresh groups prior to intracytoplasmicsperm injection (ICSI. One hundred and thirty nine oocytes were retrieved, of which 105 were atmetaphase II (MII. Forty- five fresh MII oocytes were kept in culture whereas their sibling 60 MIIoocytes were cryopreserved using a slow cooling protocol. The frozen oocytes remained in LN2for 2 hours before thawing. ICSI was performed 1-2 hours after thawing for frozen oocytes and 4-5hours after retrieval for fresh oocytes. Fertilization and embryo development were compared.Results: Following thawing, 31 oocytes (51.6 % survived and 22 fertilized (79% while 32 freshoocytes fertilized upon ICSI (71%. The mean ± SE scores for embryos developing from frozenthawedoocytes were significantly lower at 48 and 72 hours post-ICSI than for embryos resultingfrom fresh oocytes (p<0.05.Conclusion: Our data demonstrated that oocyte freezing resulted in acceptable survival ratesfollowing cryopreservation, and similar fertilization rates following ICSI as compared to the freshsibling oocytes. However the number of blastomeres and the embryo quality on day three wassuperior in embryos from fresh oocytes when compared to the frozen oocytes.

  20. An analysis of social consequences of rapid fertility decline in China. (United States)

    Liu, Z; Liu, L


    Rapid fertility decline in China has brought about 2 direct effects: 1) the natural increase of the population has slowed down, and 2) the age structure has changed from the young to the adult type. These 2 effects have caused a series of economic and social consequences. Rapid fertility decline increases the gross national product per capita and accelerates the improvement of people's lives. Rapid fertility decline slows population growth and speeds up the accumulation of capital and the development of the economy. Since 1981, accumulation growth has exceeded consumption growth. Fertility decline alleviates the enrollment pressure on primary and secondary schools, raises the efficiency of education funds, and promotes the popularization of education. The family planning program strengthens the maternal and child health care and the medical care systems. As the result of economic development, the people's nutritional levels are improving. The physical quality of teenagers has improved steadily. The change in the age structure will alleviate the tension of rapid population growth and benefit population control in the next century. Fertility decline forces the traditional attitude toward childbearing from "more children, more happiness" to improved quality of children. The rapid fertility decline has caused a great deal of concern both inside and outside China about the aging of the population. The labor force, however, will continue to grow for the next 60 years. At present, China's population problems are still those of population growth.

  1. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; King Saud University, Riyadh


    Full text: Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples were collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration were measured. The annual addition of these elements in soil due to soil fertilization were calculated and discussed. (author)

  2. Effects of different fertilizers on methane emission from paddy field of ...

    African Journals Online (AJOL)


    Methane (CH4) emissions from Chinese paddy soil (Zhejiang province) were ... 52, 20 and 19 times, respectively of that given by control, and among chemical fertilizers it was ... The rapid increase of the world population over the past.

  3. Patriarchy and fertility in Albania

    Directory of Open Access Journals (Sweden)

    Mathias Lerch


    Full Text Available BACKGROUND Theories of fertility collapse in the post-socialist era imply a decline in the moral primacy of traditional social institutions. Yet gender inequality actually increased in many countries, and there is a scarcity of empirical evidence for the role played by traditional social institutions in reproductive decision-making. OBJECTIVE We investigate whether patriarchal institutions sustained the fertility levels in Albania. The geography of marriage and family enlargement is related to the importance of patriarchy in kinship organisation and in the public sphere. To account for this spatial relationship we test the evidence for different pathways in patriarchal influence on reproductive decision-making including social effects, socialisation in patriarchal ideals, and the promotion of male fertility. METHODS We reconstruct reproductive histories from the 2001 Census and use data on attitudes and fertility intentions from the Reproductive and Health Survey 2002. Multilevel logistic regressions on marriage and (the intention of higher order births are used. RESULTS A majority of women endorsed patriarchal ideals and fertility transition was less advanced in more patriarchal municipalities. Patriarchal kinship organisation promoted early marriages and high fertility, which is shown to be achieved by social learning among peers and intergenerational social influences respectively, as well as by women's socialisation and a stopping behaviour in childbearing dominated by son-preference. Although gender inequality in the public sphere has also sustained the level of fertility and decreased the risk of marriage, it was not accounted for by these pathways of patriarchal influence. CONCLUSIONS Despite Albania's gradual opening to the world in a period of economic and political crisis, traditional social institutions remain important for family behaviours.

  4. Fertility, immigration, and the fight against climate change. (United States)

    Earl, Jake; Hickey, Colin; Rieder, Travis N


    Several philosophers have recently argued that policies aimed at reducing human fertility are a practical and morally justifiable way to mitigate the risk of dangerous climate change. There is a powerful objection to such "population engineering" proposals: even if drastic fertility reductions are needed to prevent dangerous climate change, implementing those reductions would wreak havoc on the global economy, which would seriously undermine international antipoverty efforts. In this article, we articulate this economic objection to population engineering and show how it fails. We argue, first, that the economic objection paints an inaccurate picture of the complicated relationship between demographic change and economic growth, and second, that any untoward economic effects of fertility reduction can be mitigated with additional policies. Specifically, we argue that supplementing fertility reduction with policies that facilitate the emigration of younger people from developing nations to developed nations could allow for both global reductions in GHG emissions and continued economic stability. Further, we show that moral arguments against such unprecedented increases in immigration are unsuccessful. We conclude that population engineering is a practical and morally justifiable tool for addressing the twin evils of climate change and global poverty. © 2017 John Wiley & Sons Ltd.

  5. Modeling the Effect of Oil Price on Global Fertilizer Prices

    NARCIS (Netherlands)

    P-Y. Chen (Ping-Yu); C-L. Chang (Chia-Lin); C-C. Chen (Chi-Chung); M.J. McAleer (Michael)


    textabstractThe main purpose of this paper is to evaluate the effect of crude oil price on global fertilizer prices in both the mean and volatility. The endogenous structural breakpoint unit root test, the autoregressive distributed lag (ARDL) model, and alternative volatility models, including the


    African Journals Online (AJOL)

    In an cxperiment under extcnsive conditions it was obsewed thart 729oof dry .... a b c Within the body of the table, means having the same superscript do not differ ... Fertilization and conception rate of dry Africander cows on high and low ...

  7. Level and differentials of fertility in Awassa town, Southern Ethiopia ...

    African Journals Online (AJOL)

    Regarding proximate determinants of fertility, the mean age at first marriage and duration of postpartum infecundability were 17.75 years and 12.3 months, respectively. Further, Contraceptive Prevalence Rate among married women was 41.2% and Total Abortion Rate was 0.02. Sociodemographic characteristics of mothers ...

  8. The relationship between poverty and fertility in some less developed countries. (United States)

    Chin Ptc


    The author investigates the extent to which both absolute and relative poverty affect population growth in developing countries. Aggregate data from U.N. sources for 26 countries at various stages of the fertility transition are used. The results indicate that the most significant steps in reducing fertility would be more effective provision of basic human needs and reforms in land tenure. The need to distinguish between absolute and relative poverty in formulating population policies is noted.

  9. Humus and soil fertility (United States)

    Kevin T. Smith


    Humus is a Latin word, meaning on or in the ground, but what is humus in the context of tree and landscape care? Is humus the same as soil organic matter? With the increased emphasis on biologically-based products for sustainable landscapes and tree care, the sources and quality of humus products have greatly increased in recent years.

  10. Organization of measures on protection of population and territories against weapons of mass destruction: brief analysis of laboratory control and conditions of personnel protective means of respiratory organs in the Republic of Tajikistan

    International Nuclear Information System (INIS)

    Kamalov, D.D.; Makhmadov, T.F.; Stotskiy, D.F.


    and territory protection from mass-destruction weapon. Organization of actions on population and territory protection is caused on geographical location of Tajikistan. There is a number of some states near Tajikistan that have nuclear weapon: India, China, Pakistan. The basic actions for protection of the population and territories from weapons of mass destruction are: maintenance and accumulation of means of an individual defense, creation of stocks; creation and restoration of protective constructions of a civil defense; evacuation actions planning; restoration of system of monitoring and the laboratory control of a civil defense of Republic Tajikistan; according to the Government Regulation N 527 and dated on 31"s"t of October, 2008 the 'Emergency situations and civil defense system development 2009-2014' Program was adopted. According to the Plan of the events within this Programme Committee of emergency situations and civil defense under the Government of Republic of Tajikistan provides a stage-by-stage realization of the actions for protection of population and territories from mass-destruction weapon. One of the important actions is provision and accumulation of the means of personal protection, keeping of this means. The means of personal protections are laboratory tested by the specialists of the Committee of emergency situations and civil defense. Analytical data of the Committee of emergency situations and civil defense allows making some conclusions concerning experienced storage of the means of personal protection. A general analysis of laboratory test indicates that: laboratory tests of filtering boxes indicate the preservation of air flow resistance and waterproof due to the adherence to the rules of keeping; laboratory tests of the front parts of the gas masks and their hardness and waterproof, and the waterproof of the valves show that the front part is dependent on meteorological character of the region of storage at long-term keeping. Conclusions

  11. The theoretical and political framing of the population factor in development. (United States)

    Campbell, Martha; Bedford, Kathleen


    The silence about population growth in recent decades has hindered the ability of those concerned with ecological change, resource scarcity, health and educational systems, national security, and other global challenges to look with maximum objectivity at the problems they confront. Two central questions about population--(1) is population growth a problem? and (2) what causes fertility decline?--are often intertwined; if people think the second question implies possible coercion, or fear of upsetting cultures, they can be reluctant to talk about the first. The classic and economic theories explaining the demographic transition assume that couples want many children and they make decisions to have a smaller family when some socio-economic change occurs. However, there are numerous anomalies to this explanation. This paper suggests that the societal changes are neither necessary nor sufficient for family size to fall. Many barriers of non-evidence-based restrictive medical rules, cost, misinformation and social traditions exist between women and the fertility regulation methods and correct information they need to manage their family size. When these barriers are reduced, birth rates tend to decline. Many of the barriers reflect a patriarchal desire to control women, which can be largely explained by evolutionary biology. The theoretical explanations of fertility should (i) attach more weight to the many barriers to voluntary fertility regulation, (ii) recognize that a latent desire to control fertility may be far more prevalent among women than previously understood, and (iii) appreciate that women implicitly and rationally make benefit-cost analyses based on the information they have, wanting modern family planning only after they understand it is a safe option. Once it is understood that fertility can be lowered by purely voluntary means, comfort with talking about the population factor in development will rise.

  12. Biological parameters and fertility life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae on strawberry

    Directory of Open Access Journals (Sweden)

    E. S. Araujo

    Full Text Available Abstract This study provides the first contribution of the biology and life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae, an important strawberry pest throughout the world. This species lives in the crown and leaf petioles of the plant. It is difficulty to rear this species in laboratory due to protocooperation with ants observed only in the field. We studied the life cycle of A. forbesi on the leaves of the Albion strawberry cultivar at 25 ± 2 °C, 60 ± 10% relative humidity, and a 12-h photophase. The experiment was randomised with 100 replicates. The parameters of the fertility life table were calculated using TabVida. In the population studied, 25% and 46% had four and three instars, respectively. A mean of 1.43 nymphs per female per day was generated. The mean reproductive period was seven days and the mean longevity was 10 days. In every 11 days there is a generation of A. forbesi, where each female has the potential to generate between 6 to 9 individuals daily, increasing its population by 1.2 times. The average life cycle was 16.8 days. High viability observed in all instars and the resulting values of R0, rm and λ suggest that A. forbesi has the capacity to increase their numbers in a short period of time, while generating high populations in strawberry crops, requiring differential management.

  13. Obesity: modern man's fertility nemesis. (United States)

    Cabler, Stephanie; Agarwal, Ashok; Flint, Margot; du Plessis, Stefan S


    The obesity pandemic has grown to concerning proportions in recent years, not only in the Western World, but in developing countries as well. The corresponding decrease in male fertility and fecundity may be explained in parallel to obesity, and obesity should be considered as an etiology of male fertility. Studies show that obesity contributes to infertility by reducing semen quality, changing sperm proteomes, contributing to erectile dysfunction, and inducing other physical problems related to obesity. Mechanisms for explaining the effect of obesity on male infertility include abnormal reproductive hormone levels, an increased release of adipose-derived hormones and adipokines associated with obesity, and other physical problems including sleep apnea and increased scrotal temperatures. Recently, genetic factors and markers for an obesity-related infertility have been discovered and may explain the difference between fertile obese and infertile obese men. Treatments are available for not only infertility related to obesity, but also as a treatment for the other comorbidities arising from obesity. Natural weight loss, as well as bariatric surgery are options for obese patients and have shown promising results in restoring fertility and normal hormonal profiles. Therapeutic interventions including aromatase inhibitors, exogenous testosterone replacement therapy and maintenance and regulation of adipose-derived hormones, particularly leptin, may also be able to restore fertility in obese males. Because of the relative unawareness and lack of research in this area, controlled studies should be undertaken and more focus should be given to obesity as an etiolgy of male infertility.

  14. Fertility preservation in Turner syndrome. (United States)

    Grynberg, Michaël; Bidet, Maud; Benard, Julie; Poulain, Marine; Sonigo, Charlotte; Cédrin-Durnerin, Isabelle; Polak, Michel


    Premature ovarian insufficiency is a relatively rare condition that can appear early in life. In a non-negligible number of cases the ovarian dysfunction results from genetic diseases. Turner syndrome (TS), the most common sex chromosome abnormality in females, is associated with an inevitable premature exhaustion of the follicular stockpile. The possible or probable infertility is a major concern for TS patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The severely reduced follicle pool even during prepubertal life represents the major limit for fertility preservation and is the root of numerous questions regarding the competence of gametes or ovarian tissue crybanked. In addition, patients suffering from TS show higher than usual rates of spontaneous abortion, fetal anomaly, and maternal morbidity and mortality, which should be considered at the time of fertility preservation and before reutilization of the cryopreserved gametes. Apart from fulfillment of the desire of becoming genetic parents, TS patients may be potential candidates for egg donation, gestational surrogacy, and adoption. The present review discusses the different options for preserving female fertility in TS and the ethical questions raised by these approaches. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Future Population Trends in China: 2005-2050


    Chen Wei; Liu Jinju


    Using China's 2000 census data, this paper conducts population projection under different fertility scenarios to gauge the likely trends in China's future population change. The range of fertility assumptions captures the uncertainty of current fertility estimates as well as the likely trends under the family planning policy and economic development. Only one mortality scenario is applied and net international migration is assumed to be null in the population projection. Future life tables ar...

  16. Low Fertility Preservation Utilization Among Transgender Youth. (United States)

    Nahata, Leena; Tishelman, Amy C; Caltabellotta, Nicole M; Quinn, Gwendolyn P


    Research demonstrates a negative psychosocial impact of infertility among otherwise healthy adults, and distress among adolescents facing the prospect of future infertility due to various medical conditions and treatments that impair reproductive health. Guidelines state that providers should counsel transgender youth about potential infertility and fertility preservation (FP) options prior to initiation of hormone therapy. The purpose of this study was to examine the rates of fertility counseling and utilization of FP among a cohort of adolescents with gender dysphoria seen at a large gender clinic. An Institutional Review Board-approved retrospective review of electronic medical records was conducted of all patients with ICD-9/10 codes for gender dysphoria referred to Pediatric Endocrinology for hormone therapy (puberty suppression and/or cross-sex hormones) from January 2014 to August 2016. Seventy-eight patients met inclusion criteria. Five children were prepubertal, no hormone therapy was considered, and they were therefore excluded. Of the remaining 73 patients, 72 had documented fertility counseling prior to initiation of hormone therapy and 2 subjects attempted FP; 45% of subjects mentioned a desire or plan to adopt, and 21% said they had never wanted to have children. Utilization rates of FP are low among transgender adolescents. More research is needed to understand parenthood goals among transgender youth at different ages and developmental stages and to explore the impact of gender dysphoria on decision-making about FP and parenthood. Discussions about infertility risk, FP, and other family building options should be prioritized in this vulnerable adolescent population. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  17. Status of fertility control in Egypt. (United States)

    Hefnawi, F I


    The concern for fertility control is not alien to the cultural and religious heritage of Egypt. Historically, Egyptian interest in fertility dates to the Pharoahs. Contraceptive recipes written at least 15-18 centuries B.C. have been found. Romans may have borrowed some of the more effective methods from Egypt when it became part of the Roman Empire as evidenced by the decline in size of aristocratic Roman families at the beginning of the Christian era. Muslim conquerors of Egypt encouraged fertility control. In the 9th century differences of opinion about the legality of contraception appeared among the interpreters of Islamic law. Some methods found in the writings of Muslim doctors as al-Razi and Avicenna still survive in the folk medicine of Egypt. In modern times use of barrier methods of contraception were encouraged by family planning organizations in Egypt. The medical profession was not deeply involved since these methods did not require much medical assistance. In 1936 a religiouss verdict declared contraception to be a lawful act of Islam. National programs in family planning in the 1960's encouraged the use of the Lippes Loop IUD. The medical problem of blood loss associated with the IUD caused anxiety because of the high incidence of anemia in the female Egyptian population. There was also a cultural limitation on the wide use of the IUD. "Spotting" due to the IUD resulted in females being ritually unclean and therefore unfit to pray or observe the Islamic fast. The Pill, initially favored caused complications due to its effect on breast milk which is the universal source of nutrition for infants in Egypt. Replacement of the Pill by depo-provera injections during the post partum period of lactation is a practical solution. Permanent sterilization is limited to females and only performed when medically indicated. Abortion is illegal and permitted only as a therapeutic measure.

  18. Dairy intake in relation to in vitro fertilization outcomes among women from a fertility clinic. (United States)

    Afeiche, M C; Chiu, Y-H; Gaskins, A J; Williams, P L; Souter, I; Wright, D L; Hauser, R; Chavarro, J E


    Is dairy food consumption associated with live birth among women undergoing infertility treatment? There was a positive association between total dairy food consumption and live birth among women ≥35 years of age. Dairy food intake has been previously related to infertility risk and measures of fertility potential but its relation to infertility treatment outcomes are unknown. Our study population comprised a total of 232 women undergoing 353 in vitro fertilization (IVF) treatment cycles between February 2007 and May 2013, from the Environment and Reproductive Health study, an ongoing prospective cohort. Diet was assessed before assisted reproductive technology (ART) treatment using a validated food frequency questionnaire. Study outcomes included ovarian stimulation outcomes (endometrial thickness, estradiol levels and oocyte yield), fertilization rates, embryo quality measures and clinical outcomes (implantation, clinical pregnancy and live birth rates). We used generalized linear mixed models with random intercepts to account for multiple ART cycles per woman while simultaneously adjusting for age, caloric intake, BMI, race, smoking status, infertility diagnosis, protocol type, alcohol intake and dietary patterns. The age- and calorie-adjusted difference in live birth between women in the highest (>3.0 servings/day) and lowest (Switzerland and completed this work while at the Harvard School of Public Health. The other authors declare no conflicts of interest. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email:

  19. Fertility and cancer therapy

    International Nuclear Information System (INIS)

    Maguire, L.C.


    With increased survival of increasing numbers of cancer patients as a result of therapy, the consequences, early and late, of the therapies must be realized. It is the treating physician's duty to preserve as much reproductive potential as possible for patients, consistent with adequate care. With radiotherapy this means shielding the gonads as much as possible, optimal but not excessive doses and fields, oophoropexy, or sperm collection and storage prior to irradiation. With chemotherapy it means the shortest exposure to drugs consistent with best treatment and prior to therapy the collection and storage of sperm where facilities are available. At present this is still an experimental procedure. Artificial insemination for a couple when the male has received cancer therapy is another alternative. Finally, it is the responsibility of physicians caring for patients with neoplasms to be knowledgeable about these and all other effects of therapy so that patients may be counseled appropriately and understand the implications of therapy for their life

  20. Analyzing indicator microorganisms, antibiotic resistant Escherichia coli, and regrowth potential of foodborne pathogens in various organic fertilizers. (United States)

    Miller, Cortney; Heringa, Spencer; Kim, Jinkyung; Jiang, Xiuping


    This study analyzed various organic fertilizers for indicator microorganisms, pathogens, and antibiotic-resistant Escherichia coli, and evaluated the growth potential of E. coli O157:H7 and Salmonella in fertilizers. A microbiological survey was conducted on 103 organic fertilizers from across the United States. Moisture content ranged from approximately 1% to 86.4%, and the average pH was 7.77. The total aerobic mesophiles ranged from approximately 3 to 9 log colony-forming units (CFU)/g. Enterobacteriaceae populations were in the range of fertilizer, respectively, whereas E. coli O157:H7 grew approximately 4.6, 4.0, 4.0, and 4.8 log CFU/g, respectively. Our results revealed that the microbiological quality of organic fertilizers varies greatly, with some fertilizers containing antibiotic resistant E. coli and a few supporting the growth of foodborne pathogens after reintroduction into the fertilizer.

  1. Fertility preservation and cancer: How many persons are concerned? (United States)

    Le Bihan-Benjamin, Christine; Hoog-Labouret, Natalie; Lefeuvre, Delphine; Carré-Pigeon, Frédérique; Bousquet, Philippe Jean


    A significant proportion of cancer survivors experience chronic health sequelae, one of them being fertility impairment. However, even if many reports, guidelines and positions papers focus on fertility preservation and its needs, access to fertility preservation is not currently offered to all the patients concerned, and the targeted population is not well counted. A cross sectional study was conducted using the French cancer cohort, a cohort covering the whole French population and including around 7 million of cancer patients. Women under the age of 40 and men under the age of 60 included in the cancer cohort in 2013 who had, in the first year, cancer surgery, chemotherapy or radiotherapy were considered. Patients treated by surgery alone for cancers in locations distant from the reproductive organs, or being treated for a cancer the past 3 years were excluded. The number of patients concerned by fertility preservation was estimated at a national and regional level, and by cancer types. 40,000 patients - 30,000 men under the age of 60 years and 10,000 women under the age of 40 years - were identified. A second estimation concerning women under the age of 35 and men under 50 reduced the number of patients to 17,200-10,400 men and 6800 women. The most frequent locations were malignant neoplasm of lymphoid and hematopoietic tissue, lung cancer, cervix uteri, prostate and colorectal cancer. In 2014, around 5 400 persons had a preservation. Around 17,200 cancer patients of reproductive age should be informed about the fertility preservation options available. Medical professionals have to better integrate in their daily practice fertility preservation. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Fertility effects of cancer treatment. (United States)

    Marsden, Donald E; Hacker, Neville


    Cancer sufferers are a subfertile group, and most treatments have the potential to adversely affect gonadal function. As cancer treatment becomes more effective and survival rates improve there are more cancer survivors in the reproductive age group for whom parenting is an important consideration. This article outlines the effects on fertility of cancer treatments and techniques to minimise the risk of infertility. The overall prospects for younger cancer sufferers to either retain their fertility or have genetic offspring is now better than ever before, due to advances in assisted reproductive technology, the appropriate use of fertility sparing surgery and other techniques to reduce the toxicity of therapy on the reproductive organs. These advances raise new moral and ethical concerns that must be considered before advising cancer sufferers of the options for preserving reproductive capacity.

  3. Crystallographic properties of fertilizer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.


    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  4. Impact of migration on fertility in sub-Saharan Africa. (United States)

    Brockerhoff, M; Yang, X


    Much lower levels of fertility in urban than rural areas throughout sub-Saharan Africa imply that fertility decline in the region may be facilitated by rapid urbanization and rural-to-urban migration. The present study uses data from Demographic and Health Surveys in six countries--Ghana, Kenya, Mali, Senegal, Togo and Uganda--to assess the impact of long-term rural-urban female migration on fertility. Results of logit analyses indicate that in most countries women who leave the countryside represent the higher fertility segment of the rural population in the years before migration. Migrants' risk of conception declines dramatically in all countries around the time of migration and remains lower in the long run among most migrant groups than among rural and urban nonmigrants. Descriptive analyses suggest that the decline in migrant fertility is related to the rapid and pronounced improvement in standard of living experienced by migrants after settling in the urban area and may be due in part to temporary spousal separation.

  5. A cross-over in Mexican and Mexican-American fertility rates: Evidence and explanations for an emerging paradox

    Directory of Open Access Journals (Sweden)

    Patrick Heuveline


    Full Text Available Against a backdrop of two new developments in the fertility behavior of the Mexican- Origin population in the U.S., the present discussion will update contemporary Mexican-Origin fertility patterns and address several theoretical weaknesses in the current approach to minority group fertility. Data come from six national surveys (three from Mexico and three from the U.S. that cover a twenty-five year period (1975-2000. The findings demonstrate dramatic decreases in the fertility rates in Mexico at the same time that continuous increases have been documented in the fertility rates of third-or-later generation Mexican-Americans in the U.S., particularly at younger ages. These changes necessitate a reexamination of the ubiquitous theory that Mexican pronatalist values are responsible for the high fertility rates found within the Mexican-Origin population in the U.S. Instead, they point to the increasing relevance of framing the fertility behavior of the Mexican-Origin population within a racial stratification perspective that stresses the influence of U.S. social context on fertility behavior. As a step in this direction, the analysis examines fertility patterns within the Mexican-Origin population in the U.S. Special attention is given to the role of nativity/generational status in contributing to within group differences.

  6. Recombinant follitropin alfa/lutropin alfa in fertility treatment

    Directory of Open Access Journals (Sweden)

    Ahmed Gibreel


    Full Text Available Ahmed Gibreel1, Siladitya Bhattacharya21School of Medicine and Dentistry, University of Aberdeen; 2Aberdeen Maternity Hospital, Aberdeen, UKAbstract: Recombinant human follicle stimulating hormone (rFSH and luteinizing hormone (LH, also known as follitropin alpha and lutropin alpha, are manufactured by genetic engineering techniques which ensure high quality and batch to batch consistency. Follitropin alpha can be used for controlled ovarian hyperstimulation in assisted reproduction, ovulation induction for WHO group I and II anovulatory infertility and in men with hypogonadotrophic hypogonadism (HH or idiopathic oligo-asthenospermia. Current evidence suggests superiority of urinary human menopausal gonadotropin (HMG over follitropin alpha in controlled ovarian hyperstimulation for IVF in terms of live birth rate per couple. Addition of lutropin to follitropin alpha in an unselected IVF population does not appear to confer any benefit; however, it may have a role in ovulation induction in women with hypothalamic hypogonadism. Urinary HMG preparations (especially currently available highly purified preparations are more cost effective than rFSH in terms of cost per ongoing pregnancy. However, women using rFSH injection pen devices have higher levels of satisfaction as compared to those using urinary HMG by means of conventional syringes.Keywords: infertility, follicle stimulating hormone, luteinizing hormone, follitropin alpha, lutropin alpha, in-vitro fertilization, urinary gonadotrophins

  7. Unmet need and fertility decline: a comparative perspective on prospects in sub-Saharan Africa. (United States)

    Casterline, John B; El-Zeini, Laila O


    This study assesses how changes in unmet need for family planning have contributed to contemporary fertility declines, and the implications of this historical record for further fertility decline, especially in sub-Saharan Africa. We examine joint trends at the national level in fertility, unintended fertility, and unmet need. We bring unintended fertility into the analysis because the underlying rationale for reducing unmet need is to avert unintended pregnancies and births. The association over time between unmet need and fertility is investigated using survey data from 45 countries in Africa, Asia, and Latin America and the Caribbean from the mid-1970s to the present. The empirical analysis finds that reduction in unmet need, especially unmet need for limiting, is strongly associated with fertility decline in Latin America and the Caribbean and in Asia and North Africa. Fertility decline in sub-Saharan Africa is weakly associated with trends in unmet need (and satisfaction of demand). We propose that the stark regional difference is due to measurement problems and to the fundamentally different character of fertility decline in sub-Saharan Africa, itself reflective of basic differences in pretransition reproductive regimes. © 2013 The Population Council, Inc.

  8. Local population extinction and vitality of an epiphytic lichen in fragmented old-growth forest. (United States)

    Ockinger, Erik; Nilsson, Sven G


    The population dynamics of organisms living in short-lived habitats will largely depend on the turnover of habitat patches. It has been suggested that epiphytes, whose host plants can be regarded as habitat patches, often form such patch-tracking populations. However, very little is known about the long-term fate of epiphyte individuals and populations. We estimated life span and assessed environmental factors influencing changes in vitality, fertility, abundance, and distribution of the epiphytic lichen species Lobaria pulmonaria on two spatial scales, individual trees and forest patches, over a period of approximately 10 years in 66 old-growth forest fragments. The lichen had gone extinct from 7 of the 66 sites (13.0%) where it was found 10 years earlier, even though the sites remained unchanged. The risk of local population extinction increased with decreasing population size. In contrast to the decrease in the number of occupied trees and sites, the mean area of the lichen per tree increased by 43.0%. The number of trees with fertile ramets of L. pulmonaria increased from 7 (approximately 1%) to 61 (approximately 10%) trees, and the number of forest fragments with fertile ramets increased from 4 to 23 fragments. The mean annual rate of L. pulmonaria extinction at the tree level was estimated to be 2.52%, translating into an expected lifetime of 39.7 years. This disappearance rate is higher than estimated mortality rates for potential host trees. The risk of extinction at the tree level was significantly positively related to tree circumference and differed between tree species. The probability of presence of fertile ramets increased significantly with local population size. Our results show a long expected lifetime of Lobaria pulmonaria ramets on individual trees and a recent increase in vitality, probably due to decreasing air pollution. The population is, however, declining slowly even though remaining stands are left uncut, which we interpret as an

  9. Fertility prognosis for infertile couples

    DEFF Research Database (Denmark)

    Bostofte, E; Bagger, P; Michael, A


    OBJECTIVE: To develop a fertility prognosis model for infertile couples. DESIGN: Prospective follow-up study. PARTICIPANTS: In the period November 30, 1977 to June 1, 1985, 321 consecutive couples were investigated for infertility at Hvidovre University Hospital. Investigation of the female...... MEASURE: The Cox regression model was used to predict the time required to conceive based on informations provided by fertility investigations. RESULTS: Three of 16 prognostic variables (the period of infertility, the female infertility factor, and the P-test) possess significant prognostic information...

  10. Evaluation of haplotype diversity of Achatina fulica (Lissachatina) [Bowdich] from Indian sub-continent by means of 16S rDNA sequence and its phylogenetic relationships with other global populations. (United States)

    Ayyagari, Vijaya Sai; Sreerama, Krupanidhi


    Achatina fulica (Lissachatina fulica) is one of the most invasive species found across the globe causing a significant damage to crops, vegetables, and horticultural plants. This terrestrial snail is native to east Africa and spread to different parts of the world by introductions. India, a hot spot for biodiversity of several endemic gastropods, has witnessed an outburst of this snail population in several parts of the country posing a serious threat to crop loss and also to human health. With an objective to evaluate the genetic diversity of this snail, we have sampled this snail from different parts of India and analyzed its haplotype diversity by means of 16S rDNA sequence information. Apart from this, we have studied the phylogenetic relationships of the isolates sequenced in the present study in relation with other global populations by Bayesian and Maximum-likelihood approaches. Of the isolates sequenced, haplotype 'C' is the predominant one. A new haplotype 'S' from the state of Odisha was observed. The isolates sequenced in the present study clustered with its conspecifics from the Indian sub-continent. Haplotype network analyses were also carried out for studying the evolution of different haplotypes. It was observed that haplotype 'S' was associated with a Mauritius haplotype 'H', indicating the possibility of multiple introductions of A. fulica to India.

  11. Male fertility in Greece: Trends and differentials by education level and employment status

    Directory of Open Access Journals (Sweden)

    Alexandra Tragaki


    Full Text Available Background: More than downplayed, the role of men in the demographic analysis of reproduction has been entirely neglected. However, male fertility can be an important issue for exploring how economic and employment uncertainties relate to fertility and family dynamics. Objective: This paper intends to study fertility variations over time, relying solely on data referring to father's socio-demographic characteristics; in particular, their age, education level, and employment status. Methods: We use a combination of Labor Force Survey and Demographic Statistics data on population and Vital Statistics on births to estimate male fertility indicators and fertility differentials by education level and employment status, for the period 1992-2011 in Greece. In addition, over-time developments in male TFR are separated into structural (education-specific and employment-specific distributions and behavioral (fertility, per se changes. Results: We find that the male fertility level is declining, the fertility pattern is moving into higher ages, and the reproduction period for men is getting shorter. From 1992 up to 2008, changes in male fertility were mostly driven by behavioral rather than compositional factors. However, the decline of male fertility over the period of economic recession (2008-2011 is largely attributed to the continuous decrease in the proportions of employed men. Conclusions: The study suggests that male fertility merits further exploration. In particular, years of economic downturn and countries where household living standards are mostly associated with male employment, a father's employability is likely to emerge as an increasingly important factor of fertility outcomes.

  12. Biotransformation of Organic Waste into High Quality Fertilizer

    DEFF Research Database (Denmark)

    Bryndum, Sofie

    Agriculture faces several challenges of future provision of nutrients such as limited P reserves and increasing prices of synthetic fertilizers and recycling of nutrients from organic waste can be an important strategy for the long-term sustainability of the agricultural systems. Organically...... and S, is often low; and (3) the unbalanced composition of nutrients rarely matches crop demands. Therefore the objective of this project was to investigate the potential for (1) recycling nutrients from agro-industrial wastes and (2) compost biotransformation into high-quality organic fertilizers...... other uses into fertilizer use would be unlikely. An estimated ~50 % of the total organic waste pool, primarily consisting of animal manure and waste from the processing of sugar cane, coffee, oil palm and oranges, is currently being re-used as “fertilizers”, meaning it is eventually returned...

  13. The organic fertilization in the onion cultivation

    Directory of Open Access Journals (Sweden)

    Roberto Llorente Villa


    Full Text Available The present work was developed in the UBPC “The Coast”, belonging to the Miscellaneous Crops Enterprise of Campechuela municipality, Granma province, during the period from November to March of the year 2010 – 2011. It was carried out in a reddish brown fersialitic soil, according with the new genetic classification of the soils of Cuba MINAGRI, (2000, with the objective of studying and evaluating the influence of different organic fertilizers in the growth, development and yield in the cultivation of onion, variety Texas Early Grain. For this reason it was necessary to work on blocks with 4 treatments and 4 replies. The treatments applied were: treatment 1 (vermicompost, treatment 2 (cow dung, treatment 3 (cachaça and treatment 4 (control, those were applied in a solid way. The growth variables that were evaluated were number of leaves, height of the plant, equatorial diameter, polar diameter and fresh weight of the bulb. The yield was also evaluated in t.ha-1 per treatment. High yields are achieved with the application of organic fertilizer, among 27 and 30 t.ha-1, this is an alternative for the sustainable production of this product which is highly demanded by the population.

  14. Radiation exposure due to agricultural uses of phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; AL-Sewaidan, H.A.


    Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. Over the last decades, the land reclamation and agriculture activities in Saudi Arabia and other countries have been widely expanded. Therefore, the usage of chemical fertilizers is increased. Selected phosphate fertilizers samples were collected and the specific activities of NORM were measured using a gamma ray spectrometer based on a hyper pure germanium detector and alpha spectrometer based on surface barrier detector. The obtained results show remarkable wide variations in the radioactivity contents of the different phosphate fertilizer samples. The mean (ranges) of specific activities for 226 Ra, 210 Po, 232 Th and 40 K, and radium equivalent activity are 75 (3-283), 25 (0.5-110), 23 (2-74), 2818 (9-6501) Bq/kg and 283 (7-589) Bq/kg, respectively. Based on dose calculations, the increment of the public radiation exposure due to the regular agricultural usage of phosphate fertilizers is negligible. Its average value 1 m above the ground is about 0.12 nGy/h where the world average value due to the NORM in soil is 51 nGy/h. Direct radiation exposures of the farmers due to phosphate fertilizers application was not considered in our study

  15. Soil Fertility Status on Organic Paddy Experiment

    Directory of Open Access Journals (Sweden)



    Full Text Available The study aims to determine fertility status of the soil after organic paddy experiments using kinds and doses of organic fertilizers. Experiment was conducted at greenhouse laboratory in Faculty of Agriculture Sebelas Maret University Surakarta. Experimental design used completely randomized design with 9 kinds of treatment was replicated 3 times. Experiments were the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations that are based on fulfilling nutrient requirements of 120 kg N ha-1. Result shows that the use of cow manure, Azolla fertilizers and Azolla inoculum had no effect on changes of soil fertility status. Soil fertility status was not significantly correlated with cow manure (0,16ns, Azolla fertilizer (0,26ns and Azolla inoculum (0,16ns. Average of final soil fertility status included fertile category, which was similar as the initial soil fertility status. Average of final soil properties of treatment but nevertheless was relatively higher than in no treatment, indicating the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations had greater impact to soil properties. Cow manure despite increased available K2O and dry grain, but it did not significantly increase the soil fertility status from fertile to very fertile. This was presumably due to the relatively short experiment period, only one planting season had not given significant effect to soil properties. Implication of this study is the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations although did not increase the soil fertility status but could maintain soil fertility status as the initial conditions before planting.

  16. [Effect of mineral N fertilizer reduction and organic fertilizer substitution on soil biological properties and aggregate characteristics in drip-irrigated cotton field. (United States)

    Li, Rui; Tai, Rui; Wang, Dan; Chu, Gui-Xin


    A four year field study was conducted to determine how soil biological properties and soil aggregate stability changed when organic fertilizer and biofertilizer were used to reduce chemical fertilizer application to a drip irrigated cotton field. The study consisted of six fertilization treatments: unfertilized (CK); chemical fertilizer (CF, 300 kg N·hm -2 ; 90 kg P2O5 · hm -2 , 60 kg K2 O·hm -2 ); 80% CF plus 3000 kg·hm -2 organic fertilizer (80%CF+OF); 60% CF plus 6000 kg·hm -2 organic fertilizer (60%CF+OF); 80% CF plus 3000 kg·hm -2 biofertilizer (80%CF+BF); and 60% CF plus 6000 kg·hm -2 biofertilizer (60%CF+BF). The relationships among soil organic C, soil biological properties, and soil aggregate size distribution were determined. The results showed that organic fertilizer and biofertilizer both significantly increased soil enzyme activities. Compared with CF, the biofertilizer treatments increased urease activity by 55.6%-84.0%, alkaline phosphatise activity by 53.1%-74.0%, invertase activity by 15.1%-38.0%, β-glucosidase activity by 38.2%-68.0%, polyphenoloxidase activity by 29.6%-52.0%, and arylsulfatase activity by 35.4%-58.9%. Soil enzyme activity increased as the amount of organic fertilizer and biofertilizer increased (i.e., 60%CF+OF > 80%CF+OF, 60%CF+BF > 80%CF+BF). Soil basal respiration decreased significantly in the order BF > OF > CF > CK. Soil microbial biomass C and N were 22.3% and 43.5% greater, respectively, in 60%CF+BF than in CF. The microbial biomass C:N was significantly lower in 60%CF+BF than in CF. The organic fertilizer and the biofertilizer both improved soil aggregate structure. Soil mass in the >0.25 mm fraction was 7.1% greater in 80%CF+OF and 8.0% greater in (60%CF+OF) than in CF. The geometric mean diameter was 9.2% greater in 80%CF+BF than in 80%CF+OF. Redundancy analysis and cluster analysis both demonstrated that soil aggregate structure and biological activities increased when organic fertilizer and biofertilizer were

  17. Balanced Fertilization Decreases Environmental Filtering on Soil Bacterial Community Assemblage in North China

    Directory of Open Access Journals (Sweden)

    Youzhi Feng


    Full Text Available Although increasing evidences have emerged for responses of soil microorganisms to fertilizations, the knowledge regarding community assemblages that cause variations in composition is still lacking, as well as the possible feedback to soil fertility. Phylogenetic conservatism of species indicates their similar environmental preferences and/or function traits and phylogenetic signals further can infer community assemblages and influenced ecological processes. Here, we calculated the mean pairwise phylogenetic distance and nearest relative index, characterizing phylogenetic signal and the undergone ecological process to evaluate the community assembly of soil bacterial phylotypes in 20-year fertilized soils. The bacterial community assembly is structured by environmental filtering, regardless of fertilization regime. Soil phosphorous (P availability imposes selection on community assemblage and influences their community turnover among fertilizations. When P nutrient lacks, the effect of environmental filtering becomes stronger, hence bacterial functional traits become more coherent; this process results into increased intraspecific interactions characterized by co-occurrence network analysis. In contrast, when P nutrient becomes abundant, the environmental selection is mitigated; function traits are evened. This process reduces intraspecific interactions and increases carbon sequestration efficiency, which is finally of great favor to the increases in soil fertility. This study has made the first attempt, at the bacterial level, to understand how fertilization affects agroecosystems. When more phylogenetic information on how nutrient cycling-related microbes respond to fertilization becomes available, the systematic knowledge will eventually provide guidance to optimal fertilization strategies.

  18. Quantitative trait loci for fertility traits in Finnish Ayrshire cattle

    Directory of Open Access Journals (Sweden)

    Viitala Sirja M


    Full Text Available Abstract A whole genome scan was carried out to detect quantitative trait loci (QTL for fertility traits in Finnish Ayrshire cattle. The mapping population consisted of 12 bulls and 493 sons. Estimated breeding values for days open, fertility treatments, maternal calf mortality and paternal non-return rate were used as phenotypic data. In a granddaughter design, 171 markers were typed on all 29 bovine autosomes. Associations between markers and traits were analysed by multiple marker regression. Multi-trait analyses were carried out with a variance component based approach for the chromosomes and trait combinations, which were observed significant in the regression method. Twenty-two chromosome-wise significant QTL were detected. Several of the detected QTL areas were overlapping with milk production QTL previously identified in the same population. Multi-trait QTL analyses were carried out to test if these effects were due to a pleiotropic QTL affecting fertility and milk yield traits or to linked QTL causing the effects. This distinction could only be made with confidence on BTA1 where a QTL affecting milk yield is linked to a pleiotropic QTL affecting days open and fertility treatments.

  19. Soil fertility status and challenges in Burundi: an overview (United States)

    Kaboneka, Salvator


    Landlocked and thousands miles away from international sea ports, Burundi is one of the poorest country in the world. 58% of the population suffers chronic malnutrition, 67% live in absolute poverty (MDG report 2012). 90% of the estimated 10 million people depends on subsistence agriculture, on about 3 million ha of cultivable land. The average size of a family farm is less than 0.5 ha which has to support a family of typically 7 people . As a consequence, fallow practices are no longer possible and continuous land cultivation leads to enormous soil losses by erosion. As much as 100-200 metric tons per hectare of soil losses have been reported on the hill sides of the Mumirwa region, whose landscape is currently so degraded that the local community now say that "stones grow" in the zone. In medium to high altitude areas, about 1 million of ha are acidic (pH poverty of the population is such that access to fertilizers and adoption of sustainable practices is very weak. We believe that the main challenge to soil productivity in Burundi is more socio-economic than technical, and farmers should be helped with simple tools that should be linked to their indigenous knowledge about soil fertility. Sustainable management of soil fertility is the key challenge for farmers to optimize a sustainable yield. Key words: micro nutrient, soil fertility, nutrient depletion, soil acidity.

  20. Fertility, kinship and the evolution of mass ideologies. (United States)

    David-Barrett, Tamas; Dunbar, Robin I M


    Traditional human societies are organised around kinship, and use kinship networks to generate large scale community projects. This is made possible by a combination of linguistic kin recognition, a uniquely human trait, which is mediated by the reliability of kin as collaborators. When effective fertility falls, this results in two simultaneous effects on social networks: there are fewer kin that can be relied on, and the limiting effect of the local kin-clustering becomes stronger. To capture this phenomenon, we used a model of kinship lineages to build populations with a range of fertility levels combined with a behavioural synchrony model to measure the efficiency of collective action generated on kin networks within populations. Our findings suggest that, whenever effective cooperation depends on kinship, falling fertility creates a crisis when it results in too few kin to join the community project. We conclude that, when societies transition to small effective kin networks, due to falling fertility, increased relative distance to kin due to urbanisation or high mortality due to war or epidemics, they will be able to remain socially cohesive only if they replace disappearing kin networks with quasi-kin alternatives based on membership of guilds or clubs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. South Korea's low fertility raises European-style issues. (United States)

    Haub, C


    A demographic revolution has taken place in South Korea as evidenced by the marked decline in total fertility rate (TFR) from 6 in 1960 to the 1987 level of 1.6. South Korea holds the record for low fertility among developing countries, with women in South Korea averaging fewer children in their lifetimes than do women in Europe. The 1987 TFR for South Korea was even less than that of Sweden, Norway, and France. Emphasizing high initial rates of contraceptive use, family planning (FP) has been a strong component of South Korea's 5-year plans since 1962. Strong governmental support backed the efforts of a large group of FP workers who provided free contraceptives from private physicians. High discontinuation rates resulted, however, and the abortion rate has soared to equal the number of live births. Albeit a developing nation, South Korea now faces the challenges of below replacement fertility more typical of more developed countries. Current fertility levels indicate population increase to approximately 50 million by 2020, followed by a slow decline. While reducing pressure on limited resources, population decline and demographic aging will also demand allocation of a higher proportion of government funds to medical care, and potentially threaten South Korea's competitiveness in the world labor market. Having effected decreases in population growth and fertility, the government reduced the annual sterilization target in 1986 from 300,000 to 60,000 by 1991, and will increasingly turn to the private sector and national health insurance for service provision to all but the poor. A 2-child family norm may be promoted, FP programs expanded to the unmarried and legislation developed to eliminate the preference for sons. Delivery systems may also be reorganized to encourage continued use of contraceptive methods.

  2. Recent and prospective population trends in Malaysia. (United States)

    Jones, G W; Tan, P C


    Recent population trends in Malaysia are reviewed, with the focus on Peninsular Malaysia. Separate consideration is given to population growth between 1970 and 1980; mortality trends; period and cohort fertility trends; factors affecting fertility, including changes in age structure, nuptiality, and other socioeconomic and demographic changes; and the recent development of a pro-natalist policy involving a goal of a population of 70 million by 2050.

  3. [Population: evolution of Rwandan attitudes or the adaptation of the Rwanda population to population growth]. (United States)

    Ngendakumana, M


    A consequence of the increasing pressure on Rwanda's ecosystem resulting from population growth has been that demographic factors have played a significant role in modifying attitudes and beliefs of the population. The history of Rwanda demonstrates a constant struggle for survival in the face of increasing population pressure. Migration, colonization of new agricultural lands, adoption of new crops and new forms of animal husbandry have been responses to population pressures. Recent unprecedented population growth has exceeded the capacity of older systems of cultivation and combinations of agricultural and animal husbandry to support the population. Smaller animals have largely replaced the cattle that once roamed freely in extensive pastures, and new techniques of stabling animals, use of organic or chemical fertilizers, and new tools adapted to the shrinking size of farm plots have represented responses to the new demographic realities. The concept of the family is likewise undergoing modification in the face of population growth and modernization. Children, who once were valued as a source of labor and constrained to conform to the wishes of the parents in return for the eventual inheritance of the goods and livelihood, now increasingly look beyond the household for education and employment. Family land holdings have become too small to support all the members with a claim on them. The greater distances between family members inevitably mean that relations between them lose closeness. The choice of a marriage partner is increasingly assumed by the young people themselves and not by their families. Old traditions of food sharing and hospitality have been curtailed because of the increasing scarcity of food. Despite the changes engendered by increasing population pressure, pronatalist sentiments are still widespread. But the desire to assure the future of each child rather than to await his services, a new conception of women less dependent on their reproductive

  4. Soil fertility and plant nutrition

    International Nuclear Information System (INIS)

    Menzel, R.G.; Smith, S.J.


    The applications of isotopic and related techniques, including autoradiography, radiation absorption, radiation scattering and activation analysis, in investigations on soil fertility and plant nutrition are discussed. The unique information that can be obtained with isotopes and radiation techniques is indicated. The advantages and disadvantages of these techniques are discussed in relation to other methods of obtaining similar information. (U.K.)

  5. Plant fertilization: maximizing reproductive success. (United States)

    Dresselhaus, Thomas; Sprunck, Stefanie


    Sperm competition does not occur in flowering plants as typically only a single pair of sperm cells is delivered for double fertilization. Two recent reports show that plants are capable of avoiding reproductive failure when defective sperm cells are released. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Fertilization Mechanisms in Flowering Plants. (United States)

    Dresselhaus, Thomas; Sprunck, Stefanie; Wessel, Gary M


    Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Strong families and declining fertility

    NARCIS (Netherlands)

    Hilevych, Yuliya


    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  8. Sex and Fertility After SCI

    Medline Plus

    Full Text Available ... arrow How does caregiving for your partner often affect romantic relationships? play_arrow What are the common treatments for ... play_arrow How does a spinal cord injury affect male fertility? play_arrow Where can people get information on sex and ... Contact Us Terms of Use Site Map ...

  9. Mycorrhizas and tropical soil fertility

    NARCIS (Netherlands)

    Cardoso, I.M.; Kuyper, T.W.


    Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping

  10. Fertilization of SRC willow. II

    DEFF Research Database (Denmark)

    Sevel, L; Ingerslev, Morten; Nord-Larsen, Thomas


    impacts of different doses of mineral fertilizer, manure and sewage sludge in a commercially grown SRC willow stand. We examined macro nutrient and heavy metal leaching rates and calculated element balances to evaluate the environmental impact. Growth responses were reported in a former paper (Sevel et al...

  11. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... fertility preservation is important. These key points can help start the conversation: Cancer and cancer treatment may ... several resources listed on the reverse that can help you locate a fertility preservation specialist to discuss ...

  12. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... fertility preservation center closest to you Visit the Pediatric Oncofertility Research Foundation Visit the Patient Navigator Website ... Ginsberg JP. New advances in fertility preservation for pediatric cancer patients. Curr Opin Pediatr. 2010;23:9- ...

  13. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... fertility preservation and the ability to have a future family are important. Understanding there may be fertility ... specialist in a timely manner can improve their future quality of life. Introduction You may not be ...

  14. Determinants of adolescent fertility in Ethiopia

    African Journals Online (AJOL)

    Bernt Lindtjorn

    demographic and economic determinants whereas Bongaarts model was used to determine proximate determinants fertility. ... Organization defines the age group of 10-19 and 15-24 ..... In urban areas, 24% of marital fertility was prevented.

  15. Fertilizer and briquetting and carbonisation plants

    Energy Technology Data Exchange (ETDEWEB)

    Rangachary, P T


    The fertilizer plant and the briquetting and carbonisation plant of the Neyveli Lignite Corporation's complex in Neyveli, Tamil Nadu, India, and the processes used in each to produce fertilizers, smokeless fuels and tar products are described.

  16. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu Reprotopia_ ... Northwestern University © 2015 Northwestern University Contact Northwestern ... Information University Policies Oncofertility Consortium ...

  17. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Cancer Ask Your Doctor Information for Patients Many adult survivors of childhood cancer feel fertility preservation and ... Fertility preservation and adolescent cancer patients: lessons from adult survivors of childhood cancer and their parents. Cancer ...

  18. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Fertil Steril. 2013; 100:1224-31. Chow EJ, et al. Pregnancy after chemotherapy in male and female ... Cancer . Urology. 2016;91:190-6. Loren AW, et al. Fertility preservation for patients with cancer: American ...

  19. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... available and having your child see a reproductive specialist in a timely manner can improve their future ... Can you refer us to a fertility preservation specialist to discuss my child’s options further? Fertility Preservation - ...

  20. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... health. You may feel uncomfortable discussing issues of reproduction with your child. Ask Your Doctor Discussing fertility ... American Society for Reproductive Medicine. Fertility preservation and reproduction in patients facing gonadotoxic therapies: a committee opinion. ...