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

Science.gov (United States)

Scholnik, S

1983-08-01

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.

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

Directory of Open Access Journals (Sweden)

Sarah Cannon

2017-07-01

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.

Low-fertility rate, market economy, and population control in China.

Science.gov (United States)

Wu, C; Mu, G

1996-01-01

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.

Correlations in fertility across generations: can low fertility persist?

Science.gov (United States)

Kolk, Martin; Cownden, Daniel; Enquist, Magnus

2014-01-01

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

Nutrition, fertility and steady-state population dynamics in a pre-industrial community in Penrith, northern England.

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Scott, S; Duncan, C J

1999-10-01

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.

Population ecology of feral horses in an era of fertility control management

Science.gov (United States)

Ransom, J.I.

2012-01-01

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

Nano Fertilizers

Directory of Open Access Journals (Sweden)

Hatice DAĞHAN

2017-06-01

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.

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.

2014-01-01

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

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

OpenAIRE

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

2009-01-01

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...

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

OpenAIRE

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

2017-01-01

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...

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

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Šobot Ankica

2014-01-01

(Ignjatović, et al., 2011. The gender inequality on the micro level represents an unfavorable social framework for making childbearing decisions due to relatively high economic activity of women. Apart from that, high unemployment of both female and male population in Serbia is yet another adverse circumstance for forming a family and making decisions on births. Also, a challenge in reversal of low birth rates are regional differences of socio-economic characteristics of the female population. In that sense, the share of economically inactive among women of reproductive age in Vojvodina and two regions in Central Serbia area (excluding the region of Belgrade, as well as lower fertility of employed and unemployed women in the Belgrade region, are imposed. Economic activity and employment of female population form a positive framework in reproductive behavior, if the conditions regarding the characteristics of gender regime are fulfilled. In such circumstances fertility is around the replacement rate, which represents the highest birth rate values in European welfare states. Having in mind high valuation of family and parenthood on one hand, and economic characteristics of the female population in Serbia on the other, the question is whether the economic activity of women is the area where encouragement of childbearing to more than two children could be influenced. The reply requires more in-depth analysis of relevant data, as well as more concrete empirical and better quality research.

Can human populations be stabilized?

Science.gov (United States)

Warren, Stephen G.

2015-02-01

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.

High-fertility phenotypes: two outbred mouse models exhibit substantially different molecular and physiological strategies warranting improved fertility.

Science.gov (United States)

Langhammer, Martina; Michaelis, Marten; Hoeflich, Andreas; Sobczak, Alexander; Schoen, Jennifer; Weitzel, Joachim M

2014-01-01

Animal models are valuable tools in fertility research. Worldwide, there are more than 400 transgenic or knockout mouse models available showing a reproductive phenotype; almost all of them exhibit an infertile or at least subfertile phenotype. By contrast, animal models revealing an improved fertility phenotype are barely described. This article summarizes data on two outbred mouse models exhibiting a 'high-fertility' phenotype. These mouse lines were generated via selection over a time period of more than 40 years and 161 generations. During this selection period, the number of offspring per litter and the total birth weight of the entire litter nearly doubled. Concomitantly with the increased fertility phenotype, several endocrine parameters (e.g. serum testosterone concentrations in male animals), physiological parameters (e.g. body weight, accelerated puberty, and life expectancy), and behavioral parameters (e.g. behavior in an open field and endurance fitness on a treadmill) were altered. We demonstrate that the two independently bred high-fertility mouse lines warranted their improved fertility phenotype using different molecular and physiological strategies. The fertility lines display female- as well as male-specific characteristics. These genetically heterogeneous mouse models provide new insights into molecular and cellular mechanisms that enhance fertility. In view of decreasing fertility in men, these models will therefore be a precious information source for human reproductive medicine. Translated abstract A German translation of abstract is freely available at http://www.reproduction-online.org/content/147/4/427/suppl/DC1.

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population.

Science.gov (United States)

Anderton, D L; Bean, L L

1985-05-01

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

Why does fertility remain high among certain UK-born ethnic minority women?

Directory of Open Access Journals (Sweden)

Hill Kulu

2016-12-01

Full Text Available Background: Previous research has shown high total fertility among certain UK-born ethnic minorities, but the reasons behind their high fertility have remained far from clear. Some researchers attribute their elevated fertility levels to cultural factors, whereas others argue that high fertility is the consequence of their poor education and labour market prospects. Objective: This study investigates fertility among the descendants of immigrants in the UK and examines the determinants of high fertility among certain ethnic minority groups. Methods: We use data from the Understanding Society study and apply multivariate event history analysis. Results: The analysis shows, first, that relatively high second-, third-, and fourth-birth rates are responsible for the elevated total fertility among certain UK-born minorities, especially women of Pakistani and Bangladeshi origin. There is little variation in the first-birth rates among natives and immigrant descendants. Second, although fertility differences between ethnic minorities and native British women slightly decrease once religiosity and number of siblings are controlled for, significant differences persist. We conclude that cultural factors account for some elevated fertility among ethnic groups in the UK, whereas the role of education and employment seem to be only minor. Contribution: Cultural factors account for some elevated fertility among ethnic minorities in the UK, whereas the role of education and employment seem to be negligible.

Recent fertility and mortality trends among aboriginal and nonaboriginal populations of central Siberia.

Science.gov (United States)

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

1997-06-01

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

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

DEFF Research Database (Denmark)

Jensen, Allan; Sharif, Heidi; Frederiksen, Kirsten

2009-01-01

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....

Chinese culture and fertility decline.

Science.gov (United States)

Wu, C; Jia, S

1992-01-01

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

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 ...

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

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Ondřej Šimpach

2015-03-01

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.

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

OpenAIRE

Chaurasia, Aalok Ranjan

2017-01-01

"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...

Age-Specific Mortality and Fertility Rates for Probabilistic Population Projections

OpenAIRE

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

2015-01-01

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...

Clonal structure and variable fertilization success in Florida Keys broadcast-spawning corals

Science.gov (United States)

Miller, M. W.; Baums, I. B.; Pausch, R. E.; Bright, A. J.; Cameron, C. M.; Williams, D. E.; Moffitt, Z. J.; Woodley, C. M.

2018-03-01

Keystone reef-building corals in the Caribbean are predominantly self-incompatible broadcast spawners and a majority are threatened due to both acute adult mortality and poor recruitment. As population densities decline, concerns about fertilization limitation and effective population size in these species increase and would be further exacerbated by either high clonality or gametic incompatibility of parental genotypes. This study begins to address these concerns for two Caribbean broadcasting species by characterizing clonal structure and quantifying experimental pairwise fertilization success. Orbicella faveolata showed surprisingly high and contrasting levels of clonality between two sampled sites; Acropora palmata was previously known to be highly clonal. Individual pairwise crosses of synchronously spawning genotypes of each species were conducted by combining aliquots of gamete bundles immediately after spawning, and showed high and significant variability in fertilization success. Over half of the individual crosses of O. faveolata and about one-third of A. palmata crosses yielded ≤ 40% fertilization. Total sperm concentration was quantified in only a subset of O. faveolata crosses (range of 1-6 × 107 mL-1), but showed no correlation with fertilization success. We interpret that both parental incompatibility and individual genotypes with low-quality gametes are likely to have contributed to the variable fertilization observed with important implications for conservation. Differential fertilization success implies effective population size may be considerably smaller than hoped and population enhancement efforts need to incorporate many more parental genotypes at the patch scale to ensure successful larval production than indicated by estimates based simply on preserving levels of standing genetic diversity.

Denitrification of fertilizer wastewater at high chloride concentration

DEFF Research Database (Denmark)

Ucisik, Ahmed Süheyl; Henze, Mogens

Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.......4 g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C...

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

Science.gov (United States)

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

2009-02-05

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.

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

Directory of Open Access Journals (Sweden)

Krystof Zeman

2018-02-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

Jowett, D

1959-07-04

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.

Fertility reduction programmes should accompany land reforms.

Science.gov (United States)

Atiku, J

1994-01-01

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

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 ...

Diverging patterns of fertility decline in Uruguay

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Mathías Nathan

2016-03-01

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.

The population threat.

Science.gov (United States)

Teitelbaum, M S

1992-01-01

Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

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

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Lotta Persson

2014-03-01

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

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.

Science.gov (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…

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 ...

Reverse survival method of fertility estimation: An evaluation

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Thomas Spoorenberg

2014-07-01

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

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...

The fertility decline in Kenya.

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Robinson, W C; Harbison, S F

1995-01-01

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

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

2009-01-01

, 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...

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

International Nuclear Information System (INIS)

Ozel, H.B.; Bilir, N.

2016-01-01

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)

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

Science.gov (United States)

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

2016-06-27

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.

Low twinning rate and seasonal effects on twinning in a fertile population, the Hutterites

Science.gov (United States)

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

1993-09-01

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.

Socioeconomic status and fertility decline

DEFF Research Database (Denmark)

Dribe, Martin; Breschi, Marco; Gagnon, Alain

2017-01-01

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...

In vitro assessment of sperm from bulls of high and low field fertility.

Science.gov (United States)

Al Naib, A; Hanrahan, J P; Lonergan, P; Fair, S

2011-07-01

The aim of this study was to investigate the reasons for differences in field fertility of bulls following insemination with frozen-thawed semen. The study was carried out in two separate parts over two years and comparisons were made between 5 high and 4 low fertility Holstein Friesian bulls as determined by their either 90 day non-return rate (Year 1) or calving rate (Year 2). Two high fertility Limousin bulls were included in Year 1 for comparative purposes. The ability of sperm from each bull to penetrate artificial mucus was assessed (Year 1 = 7 replicates; Year 2 = 5 replicates). Glass capillary tubes (2 per bull per replicate) were filled with artificial mucus and incubated with sperm stained in 1% Hoechst 33342 for 30 min at 37 °C. The number of sperm were subsequently counted at 10 mm intervals along the tube between 40 and 80 mm markers. Sperm mitochondrial activity of each bull was assessed by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay (4 replicates in each year). Sperm were incubated with MTT for 1 h at 37 °C following which the absorbance of formazan was read using a spectrophotometer. Sperm viability after thawing was assessed for each bull using a live/dead sperm viability kit (Year 1 = 3 replicates; Year 2 = 4 replicates). A minimum of 250 cells were assessed per bull in each replicate and classified as either live or dead. Finally, the ability of sperm to fertilize oocytes in vitro and their ability to develop to blastocyst stage embryos were assessed (5 replicates in each year involving 220 to 306 oocytes per bull). Data transformation to normalize residuals was required for mucus sperm penetration (square root) and IVF (cleavage and blastocyst rate) results (arcsin). The mean number of sperm counted at each 10 mm mark between 40 and 80 mm was higher in the high fertility (56.0; 95% CI 39.5 to 75.3) compared to the low fertility (42.9; 95% CI 29.3 to 59.1) Holstein Friesian bulls but the difference did not

Marriage and fertility in the developed countries.

Science.gov (United States)

Westoff, C F

1978-12-01

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

Understanding variation in human fertility: what can we learn from evolutionary demography?

Science.gov (United States)

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

2016-04-19

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).

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.

2008-01-01

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...

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

2000-01-01

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...

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

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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.

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

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Barbara Okun

2013-03-01

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.

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

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Verma, Ravi B.P.

2008-01-01

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

Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

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Sharat Kumar Pradhan

Full Text Available Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

Science.gov (United States)

Pradhan, Sharat Kumar; Barik, Saumya Ranjan; Sahoo, Ambika; Mohapatra, Sudipti; Nayak, Deepak Kumar; Mahender, Anumalla; Meher, Jitandriya; Anandan, Annamalai; Pandit, Elssa

2016-01-01

Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

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

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Riikka Shemeikka

2006-01-01

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 population.  Fertility 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

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 ...

Will human populations be limited by food?

Science.gov (United States)

Warren, S. G.

2016-12-01

Historical examples of demographic change, in China, Italy, Nigeria, Utah, the Philippines, 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 based on a logical fallacy in that they assume, in spite of the absence of necessary negative feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. The benign projections that have resulted from this assumption may have hindered efforts to make availability of birth-control a priority in development-aid. 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. Even if the fertility rate is maintained far in excess of 2, the population cannot grow if food is limiting. Without the agricultural advances of the 20thcentury, world population could not have grown as it did from 1.7 billion in 1900 to 6 billion in 2000. The food supply may be enhanced in the future by genetic engineering and other innovations, but it may be limited by water shortage, climate change, pollution, and energy

Implementation strategy for achieving replacement level fertility.

Science.gov (United States)

1993-01-01

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

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

OpenAIRE

Staveteig, Sarah Elizabeth

2011-01-01

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...

Socioeconomic status and fertility decline: Insights from historical transitions in Europe and North America

Science.gov (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

2016-01-01

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

[Recent population policy measures in Belgium, especially with respect to fertility].

Science.gov (United States)

Bosman, E

1985-01-01

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

Screening of whole genome sequences identified high-impact variants for stallion fertility.

Science.gov (United States)

Schrimpf, Rahel; Gottschalk, Maren; Metzger, Julia; Martinsson, Gunilla; Sieme, Harald; Distl, Ottmar

2016-04-14

Stallion fertility is an economically important trait due to the increase of artificial insemination in horses. The availability of whole genome sequence data facilitates identification of rare high-impact variants contributing to stallion fertility. The aim of our study was to genotype rare high-impact variants retrieved from next-generation sequencing (NGS)-data of 11 horses in order to unravel harmful genetic variants in large samples of stallions. Gene ontology (GO) terms and search results from public databases were used to obtain a comprehensive list of human und mice genes predicted to participate in the regulation of male reproduction. The corresponding equine orthologous genes were searched in whole genome sequence data of seven stallions and four mares and filtered for high-impact genetic variants using SnpEFF, SIFT and Polyphen 2 software. All genetic variants with the missing homozygous mutant genotype were genotyped on 337 fertile stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. Mixed linear model analysis was employed for an association analysis with de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). We screened next generation sequenced data of whole genomes from 11 horses for equine genetic variants in 1194 human and mice genes involved in male fertility and linked through common gene ontology (GO) with male reproductive processes. Variants were filtered for high-impact on protein structure and validated through SIFT and Polyphen 2. Only those genetic variants were followed up when the homozygote mutant genotype was missing in the detection sample comprising 11 horses. After this filtering process, 17 single nucleotide polymorphism (SNPs) were left. These SNPs were genotyped in 337 fertile stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. An association analysis in 216 Hanoverian stallions revealed a significant association of the splice-site disruption variant

South Korea's low fertility raises European-style issues.

Science.gov (United States)

Haub, C

1991-10-01

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.

High coffee population density to improve fertility of an oxisol

OpenAIRE

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

1999-01-01

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...

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.

Science.gov (United States)

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

2016-01-01

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.

Fertility preservation in young patients with cancer

Directory of Open Access Journals (Sweden)

Virender Suhag

2015-01-01

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.

The Middle East population puzzle.

Science.gov (United States)

Omran, A R; Roudi, F

1993-07-01

An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births

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):

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

2005-03-01

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.

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

Directory of Open Access Journals (Sweden)

Krystof Zeman

2018-05-01

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.

Decomposing trends in nonmarital fertility among Latinas.

Science.gov (United States)

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

2009-09-01

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.

Is glycosylated haemoglobin a marker of fertility?

DEFF Research Database (Denmark)

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

1999-01-01

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....

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

2015-01-01

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...

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

2016-01-01

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...

Some relations among cultural traditions, nuptiality and fertility.

Science.gov (United States)

Coale, A J

1991-01-01

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

Will sex selection reduce fertility?

Science.gov (United States)

Leung, S F

1994-01-01

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%.

Prediction of bull fertility.

Science.gov (United States)

Utt, Matthew D

2016-06-01

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.

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

2010-06-01

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.

How does variance in fertility change over the demographic transition?

Science.gov (United States)

Hruschka, Daniel J; Burger, Oskar

2016-04-19

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).

Our population predicament: a new look.

Science.gov (United States)

Van Der Tak, J; Haub, C; Murphy, E

1979-12-01

Issued to mark the Population Reference Bureau's 50th anniversary, this issue updates the story of world population presented in its popular predecessor of 1971, "Man's Population Predicament." Estimated at 1/2 billion in 1650, world population reached about 2 billion in 1930, 4 billion in 1975, and is projected to be about 6 billion in 2000. Most of today's rapid growth is occurring among the 3/4 of the world's peoples living in less developed countries where the post-World War II gap between high birth rates and falling death rates has only recently begun to narrow. This growth, coupled with high consumption in developing countries, is putting tremendous pressures on the Earth's resources, environment, and social fabric. New evidence on Europe's population transition and from China, Indonesia, and Thailand in the 1970s suggests that well-designed family planning programs can speed fertility decline but rapid worldwide attainment of replacement level fertility will also require special development efforts and measures that go beyond family planning. Current projections of the world's ultimate peak population range from 8 billion in the mid 21st century to 11 billion in about 2125, depending on when replacement-level fertility is reached. China's drive for a drastic birth rate reduction and the oil crisis might change fertility behavior more rapidly than most demographers have heretofore thought likely.

Austria: Persistent low fertility since the mid-1980s

Directory of Open Access Journals (Sweden)

Henriette Engelhardt

2008-07-01

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.

Wealth, intelligence, politics and global fertility differentials.

Science.gov (United States)

Meisenberg, Gerhard

2009-07-01

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.

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

2005-01-01

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...

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

Science.gov (United States)

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

2017-04-06

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.

Fertility and money in an OLG model

OpenAIRE

Luciano Fanti

2012-01-01

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.

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

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Michel Garenne

2013-01-01

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.

Effect of APOE ε4 allele on survival and fertility in an adverse environment.

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Eric van Exel

Full Text Available The apolipoprotein-ε4 allele (APOE-ε4 is strongly associated with detrimental outcomes in affluent populations including atherosclerotic disease, Alzheimer's disease, and reduced lifespan. Despite these detrimental outcomes, population frequencies of APOE-ε4 are high. We hypothesize that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility.This rural Ghanaian population (n = 4311 has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years and fertility after stratifying by exposure to high or low pathogen levels. Households drawing water from open wells and rivers were classified as exposed to high pathogen levels while low pathogen exposure was classified as those drawing water from borehole wells. We found a non-significant, but positive survival benefit, i.e. the hazard ratio per APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05, adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842, APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed to high pathogen levels. Compared with women not carrying an APOE-ε4 allele, those carrying one APOE-ε4 allele had on average one more child and those carrying two APOE-ε4 alleles had 3.5 more children (p = 0.018.Contrary to affluent modern-day populations, APOE-ε4 did not carry a survival disadvantage in this rural Ghanaian population. Moreover, APOE-ε4 promotes fertility in highly infectious environments. Our findings suggest that APOE-ε4 may be considered as evolutionarily

Effect of APOE ε4 allele on survival and fertility in an adverse environment.

Science.gov (United States)

van Exel, Eric; Koopman, Jacob J E; Bodegom, David van; Meij, Johannes J; Knijff, Peter de; Ziem, Juventus B; Finch, Caleb E; Westendorp, Rudi G J

2017-01-01

The apolipoprotein-ε4 allele (APOE-ε4) is strongly associated with detrimental outcomes in affluent populations including atherosclerotic disease, Alzheimer's disease, and reduced lifespan. Despite these detrimental outcomes, population frequencies of APOE-ε4 are high. We hypothesize that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility. This rural Ghanaian population (n = 4311) has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years) and fertility after stratifying by exposure to high or low pathogen levels. Households drawing water from open wells and rivers were classified as exposed to high pathogen levels while low pathogen exposure was classified as those drawing water from borehole wells. We found a non-significant, but positive survival benefit, i.e. the hazard ratio per APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05), adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842), APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed to high pathogen levels. Compared with women not carrying an APOE-ε4 allele, those carrying one APOE-ε4 allele had on average one more child and those carrying two APOE-ε4 alleles had 3.5 more children (p = 0.018). Contrary to affluent modern-day populations, APOE-ε4 did not carry a survival disadvantage in this rural Ghanaian population. Moreover, APOE-ε4 promotes fertility in highly infectious environments. Our findings suggest that APOE-ε4 may be considered as evolutionarily adaptive. Its

Fertility, kinship and the evolution of mass ideologies.

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David-Barrett, Tamas; Dunbar, Robin I M

2017-03-21

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.

Fertility and Birth Rates: Indicators of Child and Youth Well-Being. Updated. October 2016

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Child Trends, 2016

2016-01-01

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…

Cohort Fertility Patterns in the Nordic Countries

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Gunnar Andersson

2009-04-01

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.

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

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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

Declining world fertility: trends, causes, implications.

Science.gov (United States)

Tsui, A O; Bogue, D J

1978-10-01

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."

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

Science.gov (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…

Development of Malaysian women fertility index: Evidence from Shannon's entropy

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Jalil, Wan Aznie Fatihah Wan Abd; Sharif, Shamshuritawati

2017-11-01

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.

Demographic and fertility characteristics of 4 squatter settlements.

Science.gov (United States)

Yusof, K; Zulkifli, S N

1985-01-01

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

Effect of APOE ε4 allele on survival and fertility in an adverse environment

DEFF Research Database (Denmark)

van Exel, Eric; Koopman, Jacob J. E.; Bodegom, David van

2017-01-01

APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05), adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842), APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed....... METHODS AND FINDINGS: This rural Ghanaian population (n = 4311) has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years) and fertility after stratifying by exposure...... that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility...

Manipulation of the fertility of marsupials for conservation of endangered species and control of over-abundant populations.

Science.gov (United States)

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

1998-10-01

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.

Foliar Potassium Fertilizer Additives Affect Soybean Response and Weed Control with Glyphosate

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Kelly A. Nelson

2012-01-01

Full Text Available Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S, 0-0-25-17, 3-18-18-0, and 5-0-20-13 and additive rates (2.2, 8.8, and 17.6 kg K ha−1 on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1 in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1 in a low-yield year (2005 depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1 compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K (P=0.03, S (P=0.03, B (P=0.0001, and Cu (P=0.008 concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.

Differentials of fertility in North and South Gondar zones, northwest Ethiopia: A comparative cross-sectional study

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Worku Alemayehu

2008-12-01

Full Text Available Abstract Background Ethiopia is one of the most densely populated countries in Africa with an estimated population of 77.1 million in mid-2007. Uncontrolled fertility has adversely influenced the socio-economic, demographic and environmental situations of the country. It is one of the largest and poorest countries that, even in the midst of crisis, has maintained high levels of fertility. This study was aimed at investigating the most important factors influencing fertility behavior in Northwest Ethiopia. Methods A comparative cross-sectional study which included 2424 women aged 25 years and above was undertaken in the Amhara region of Northwest Ethiopia. The study subjects were grouped into high fertile and low fertile categories. There were 1011 and 1413 women in the high and low fertile groups, respectively. A multi-stage cluster sampling stratified by place of residence was employed to select the required study subjects. Both bivariate and multivariate logistic regression techniques were used to analyze the data. Results Among the 25 variables considered in this study, only 9 of them were found significantly and independently associated with the level of fertility. Women with at least secondary education were at a lower risk of high fertility with OR = 0.37 (95% CI: 0.21 to 0.64 compared to those with no formal education. However, women with primary education did not show any significant difference when compared with the same baseline group. Age at first marriage was inversely associated with the number of children ever born alive. Place of residence, household expenditure, number of children who have died, attitude towards using contraceptives, women's knowledge on the safe period, and current marital status were the other variables that showed significant associations with the level of fertility. Conclusion Female education beyond the primary level, reduced infant and child mortality, delayed marriage and correct knowledge on the safe

Birth Order and Sibling Sex Ratio in a Population with High Fertility: Are Turkish Male to Female Transsexuals Different?

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

2015-07-01

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.

Population success.

Science.gov (United States)

1982-01-01

"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

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

Science.gov (United States)

Grace, Kathryn; Sweeney, Stuart

2016-02-01

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.

Fertility decline: transition or transformation?

Science.gov (United States)

Freedman, J

1981-01-01

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.

Differentially Expressed Genes in Endometrium and Corpus Luteum of Holstein Cows Selected for High and Low Fertility Are Enriched for Sequence Variants Associated with Fertility.

Science.gov (United States)

Moore, Stephen G; Pryce, Jennie E; Hayes, Ben J; Chamberlain, Amanda J; Kemper, Kathryn E; Berry, Donagh P; McCabe, Matt; Cormican, Paul; Lonergan, Pat; Fair, Trudee; Butler, Stephen T

2016-01-01

Despite the importance of fertility in humans and livestock, there has been little success dissecting the genetic basis of fertility. Our hypothesis was that genes differentially expressed in the endometrium and corpus luteum on Day 13 of the estrous cycle between cows with either good or poor genetic merit for fertility would be enriched for genetic variants associated with fertility. We combined a unique genetic model of fertility (cattle that have been selected for high and low fertility and show substantial difference in fertility) with gene expression data from these cattle and genome-wide association study (GWAS) results in ∼20,000 cattle to identify quantitative trait loci (QTL) regions and sequence variants associated with genetic variation in fertility. Two hundred and forty-five QTL regions and 17 sequence variants associated primarily with prostaglandin F2alpha, steroidogenesis, mRNA processing, energy status, and immune-related processes were identified. Ninety-three of the QTL regions were validated by two independent GWAS, with signals for fertility detected primarily on chromosomes 18, 5, 7, 8, and 29. Plausible causative mutations were identified, including one missense variant significantly associated with fertility and predicted to affect the protein function of EIF4EBP3. The results of this study enhance our understanding of 1) the contribution of the endometrium and corpus luteum transcriptome to phenotypic fertility differences and 2) the genetic architecture of fertility in dairy cattle. Including these variants in predictions of genomic breeding values may improve the rate of genetic gain for this critical trait. © 2016 by the Society for the Study of Reproduction, Inc.

Stabilization process of human population: a descriptive approach.

Science.gov (United States)

Kayani, A K; Krotki, K J

1981-01-01

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.

Oral administration of supplementary biotin differentially influences the fertility rate and oviductal expression of avidin and avidin-related protein-2 in low- and high-fertility broiler line hens.

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Daryabari, H; Akhlaghi, A; Zamiri, M J; Pirsaraei, Z Ansari; Mianji, G Rahimi; Deldar, H; Eghbalian, A N

2015-02-01

Probable involvement of avidin and avidin-related protein-2 (AVR2) in sperm viability in the sperm storage tubules of turkeys has been suggested. The high affinity of biotin to avidin and its analogs is also well documented. The present study aimed to determine the effect of oral biotin on reproductive performance and oviductal mRNA expression of avidin and AVR2 in 2 broiler hen lines with different fertility rates. Low-fertility (line B) and high-fertility (line D) hens (n=144) were randomly allotted to receive 0 (T0), 0.30 (T1), or 0.45 (T2) mg/L biotin in drinking water from 30 through 33 wk of age. The reproductive performance of the hens was evaluated using artificial insemination. At the end of the treatment period, 24 hens per line were killed to assay the expression of avidin and AVR2 in the uterovaginal junction. Supplementary biotin increased egg production from 73.5% for T0 to 87.8% for T2. Hens administered with biotin in line B, but not in line D, showed an increase (8.4%) in fertility rate. Hatchability, chick quality, and overall embryonic mortality were not different among the experimental groups. Real-time PCR data showed that both avidin (P=0.0013) and AVR2 (Pbiotin×line interaction effect, where low-fertility line B hens receiving the high biotin level recorded respectively a 3.9 and 15.3% increase in avidin and AVR2 mRNA expression, although biotin did not affect these traits in line D hens. Control hens in line D had a dramatically higher AVR2 expression record (7.4-fold) compared with the control hens in line B. The correlation coefficients of fertility rate and avidin expression were 0.73 and 0.66 in lines B and D, respectively. However, the correlation of fertility and AVR2 (r=0.65) was significant for line D hens only. Overall, fertility rate and oviductal expression of avidin and AVR2 were dichotomously affected by oral biotin in low- and high-fertility line hens, where only low-fertility birds showed improvements in these attributes. �

On the pace of fertility decline in sub-Saharan Africa

Directory of Open Access Journals (Sweden)

David Shapiro

2017-10-01

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.

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.

An analysis of social consequences of rapid fertility decline in China.

Science.gov (United States)

Liu, Z; Liu, L

1988-12-01

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.

An investigation of the unexpectedly high fertility of secular, native-born Jews in Israel.

Science.gov (United States)

Okun, Barbara S

2016-07-01

Secular, native-born Jews in Israel enjoy the socio-economic status of many affluent populations living in other democratic countries, but have above-replacement period and cohort fertility. This study revealed a constellation of interrelated factors which together characterize the socio-economic, cultural, and political environment of this fertility behaviour and set it apart from that of other advanced societies. The factors are: a combination of state and family support for childbearing; a dual emphasis on the social importance of women's employment and fertility; policies that support working mothers within a conservative welfare regime; a family system in which parents provide significant financial and caregiving aid to their adult children; relatively egalitarian gender-role attitudes and household behaviour; the continuing importance of familist ideology and of marriage as a social institution; the role of Jewish nationalism and collective behaviour in a religious society characterized by ethno-national conflict; and a discourse which defines women as the biological reproducers of the nation. Supplementary material for this article is available at: http://dx.doi.org/10.1080/00324728.2016.1195913.

Culture of ceriodaphnia cornuta, using chicken manure as fertilizer: conversion of waste product into highly nutritive animal protein

International Nuclear Information System (INIS)

Altaf, K.; War, M.U.D.

2010-01-01

For finding a cheap and suitable feed for culture of Ceriodaphnia cornuta studies were carried out for 21 days using chicken manure as fertilizer whereupon C. cornuta population ranged between 50 +- 2 and 10,232 +- 202 Ind./L. (individuals/L). The culture peaked on the 17th day producing the maximum density of 10,232 +- 202 Ind./L. Thus chicken manure can be used as a fertilizer for mass culture of cladocerans, specially C. cornuta. (author)

Does low fertility call for new policies in some Asian countries?

Science.gov (United States)

Greenspan, A

1994-06-01

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.

Multifunctional liquid bio fertilizer as an innovative agronomic input for modern agriculture

International Nuclear Information System (INIS)

Phua Choo Kwai Hoe; Khairuddin Abdul Rahim

2010-01-01

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)

Premarital fertility in Namibia: trends, factors and consequences.

Science.gov (United States)

Garenne, Michel; Zwang, Julien

2006-03-01

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.

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 ...

Microbiological Safety of Chicken Litter or Chicken Litter-Based Organic Fertilizers: A Review

Directory of Open Access Journals (Sweden)

Zhao Chen

2014-01-01

Full Text Available Chicken litter or chicken litter-based organic fertilizers are usually recycled into the soil to improve the structure and fertility of agricultural land. As an important source of nutrients for crop production, chicken litter may also contain a variety of human pathogens that can threaten humans who consume the contaminated food or water. Composting can inactivate pathogens while creating a soil amendment beneficial for application to arable agricultural land. Some foodborne pathogens may have the potential to survive for long periods of time in raw chicken litter or its composted products after land application, and a small population of pathogenic cells may even regrow to high levels when the conditions are favorable for growth. Thermal processing is a good choice for inactivating pathogens in chicken litter or chicken litter-based organic fertilizers prior to land application. However, some populations may become acclimatized to a hostile environment during build-up or composting and develop heat resistance through cross-protection during subsequent high temperature treatment. Therefore, this paper reviews currently available information on the microbiological safety of chicken litter or chicken litter-based organic fertilizers, and discusses about further research on developing novel and effective disinfection techniques, including physical, chemical, and biological treatments, as an alternative to current methods.

Women's Agency and Fertility: Recent Evidence from Egypt.

Science.gov (United States)

Samari, Goleen

2017-08-01

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.

Bangladesh making remarkable progress in population field.

Science.gov (United States)

1998-01-01

This article describes the progress made in reducing fertility in Bangladesh, and government goals for meeting future challenges. Fertility declined from 7.0 to 3.3 children/woman during 1975-96. Contraceptive prevalence increased from 3% to about 50% during 1971-96. Population in 1997, was about 123 million. Population is expected to increase to about 210 million by the year 2020. Bangladesh is one of the most densely populated countries. About 50% of the female population are unmarried and aged under 20 years. Adolescent fertility is very high at 171 births/1000 girls aged 15-19 years. About 30% of adolescents are mothers, and another 6% are pregnant with their first child. Female age at marriage increased to 18 years. The contraceptive prevalence rate among adolescents is only 25%. 20% of total population live in urban areas. Infant, child, and maternal mortality rates are still high. The long-term goal of the government is to reduce fertility to a 2-child family norm by 2002. The plan of action focuses on improved quality of care, intensifying program efforts in low performing areas, focusing on critical underserved groups, implementing family planning services in the Health Directorate, improving performance reporting and follow-up, strengthening IEC and community mobilization, carrying out critical training, enhancing collaboration between governmental and nongovernmental groups, and improving maternal, child, and reproductive health. A National Committee for the Implementation of the aforementioned Program of Action of the ICPD was set up in October 1994.

Desired Fertility and Number of Children Born Across Time and Space.

Science.gov (United States)

Günther, Isabel; Harttgen, Kenneth

2016-02-01

Economists have often argued that high fertility rates are mainly driven by women's demand for children (and not by family planning efforts) with low levels of unwanted fertility across countries (and hence with little room for family planning efforts to reduce population growth). We study the relationship between wanted fertility and number of children born in a panel of 200 country-years controlling for country fixed effects and global time trends. In general, we find a close relationship between wanted and actual fertility, with one desired child leading to one additional birth. However, our results also indicate that in the last 20 years, the level of unwanted births has stayed at 2 across African countries but has, on average, decreased from 1 to close to 0 in other developing countries. Hence, women in African countries are less able to translate child preferences into birth outcomes than women in other developing countries, and forces other than fertility demand have been important for previous fertility declines in many developing countries. Family planning efforts only partially explain the observed temporal and spatial differences in achieving desired fertility levels.

The level and patterns of fertility among women in Kersa Demographic Surveillance and Health Research Center (KDS-HRC) Field site, Kersa District, East Ethiopia

OpenAIRE

Zelalem, Desalew; Semahegn, Agumasie; Tesfaye, Gezahegn; Sileshi, Balewgize

2015-01-01

Background Fertility is one of the three principal components of population dynamics. High fertility and rapid population growth exert negative influences on economic and social development. This study was aimed to estimate the level and trends of fertility among (15?49 years) old women in kersa demographic surveillance and health research center, kersa district Eastern Ethiopia. Methods The study was conducted at kersa demographic surveillance and health research center in kersa district, Ea...

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).

Science.gov (United States)

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

2017-12-01

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.

Canada's population: growth and dualism.

Science.gov (United States)

Beaujot, R P

1978-04-01

In Canada the current 1.3% population growth rate is causing some concern. Those concerned argue that such a rate of growth in combination with high levels of consumption could jeopardize the country's resource base and its comfortable style of living. Many Canadians are questioning high levels of immigration, for now that the fertility level is below replacement level, net immigration contributes substantially to population growth (over 1/3 in 1976). The growing proportion of non-Europeans among recent immigrants is causing resentment, and, in a tight job market, immigrants are regarded as threats to the World War 2 baby boom cohort who are now at working ages. The baby boom generation also puts stress on housing and health services, and it will increase the need for pension checks as it ages. Although French fertility is no longer high and immigration is no longer dominated by the British, the French group's 200-year struggle to preserve its identity continues on in the current effort of the Quebec government to enforce the use of French language by law within that province. Geography and climate dictate another demographic fact that divides the country and pervades its history. In addition to intense regionalism, uneven population distribution is responsible for 2 other concerns: the rapid growth of several already large cities and depopulation of many small communities. Focus in this discussion is on Canada's population growth in the past and as projected for the future, historical and current fertility, mortality and immigration trends, the search for a new immigration policy, the impact of the baby boom generation on the population's age structure and the problems this creates, and recent shifts in population distribution and in the country's ethnic and linguistic makeup. The population policy proposals evolved thus far involve to a great extent the use of immigration as a lever for achieving given population objectives.

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 ...

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

DEFF Research Database (Denmark)

Key, Jane; Best, Nicky; Joffe, Michael

2009-01-01

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...

Fertility preservation in the male pediatric population: factors influencing the decision of parents and children.

Science.gov (United States)

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

2015-09-01

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

The demographic transition: an attempt to reformulate a population theory.

Science.gov (United States)

Hofsten, E

1981-01-01

In this effort to reformulate the demographic transition theory, attention is directed to the following: Malthus and Karl Marx's criticism of his principle of population; the 1st stage of transition, i.e., high mortality, high fertility, and slow population growth; the 2nd stage of declining mortality; the 3rd stage of declining fertility; the 4th stage when mortality and fertility are both low; the growth potential; and the demographic transition in the 3rd world countries. The demographic transition theory has become popular among demographers, economists, historians, and others interested in studying the development of population over time since the end of World War 2. This interest has most likely been created by the anxiety over the population explosion in the 3rd world countries. Transition has made demographers believe that the period of rapid population growth will be automatically succeeded by a period of more or less constant population size. The question that arises is whether it is as simple as that. Demographic transition has to a great extent taken the place of Malthus' principle of population as a general theory of population. Demographic transition appears to describe in a satisfactory way the development of population which all currently industrialized countires have passed through, when going from the preindustrial to the present industrialized stage. The objectives to demographic transition as a general theory are considered. Some of the factors which have accounted for the decline in fertility in Europe may also apply to the 3rd world countries. 1 such factor is the effect of reduced infant and child mortality on the individual level. The fertility decline, caused by reduced infant and child mortality may, however, be of limited size. The great amount of unemployment in the 3rd world may affect fertility in a downward direction. The fertility decline in Europe occurred simultaneously with an industrialization process, which gradually covered the

Fertility Preservation Counseling for Pediatric and Adolescent Cancer Patients.

Science.gov (United States)

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

2016-03-01

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.

[Fertility and health in Mexico].

Science.gov (United States)

Urbina-Fuentes, M; Echánove-Fernández, E

1989-01-01

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.

Agriculture in the Fertile Crescent: Continuity and change under climate change

Science.gov (United States)

The Fertile Crescent is a highly biodiverse region where most temperate-zone agricultural species originated and were first domesticated. A favorable environment, a special plant community, and an adaptive population combined to initiate the transition from a hunter-gatherer economy to one based on ...

Population growth and development: the Kenyan experience.

Science.gov (United States)

Nyamwange, M

1995-01-01

Rapid population growth in Kenya and high fertility impacts negatively on economic development. The growth and high fertility results in declines in gross national product, per capita food consumption, and land quality; a high dependency ratio; urban crowding; and inadequate health systems. East Africa has the highest crude birth rates in Africa, and Kenya has the highest birth rate of 54/1000 population in East Africa. The African crude death rate is 50% higher than the world average, but Kenya's death rate is the lowest in East Africa and comparable to North American and European death rates. Kenya has the highest rate of natural increase of about 4%. Population growth rates rose over the decades. Kenya's average population density is well above the sub-Saharan African average and much lower than very high density countries. Population is unequally distributed. Regional densities are widely divergent, and the highest densities in Western province are well above densities in Rwanda and Burundi. Urban growth has increased, as has migration to urban areas. Nairobi has 57% of urban population. Improved health and nutrition have contributed to increased life expectancy. The desired family size is large. The impact of demographic factors on economic conditions is evident in the decline in gross national product per capita growth to under 1% during 1972-88. A slight upswing occurred during 1988-93, but other crises are emerging. Food production has not kept pace with population growth. Production has been low due to serious land degradation, short fallow periods, and traditional farming practices. Population pressure has forced families to shift agriculture onto marginal lands, and desertification has increased. A growing proportion of the population is unemployed or underemployed. Population programs should address the underlying conditions for fertility decline.

Long Term Population, City Size and Climate Trends in the Fertile Crescent: A First Approximation.

Science.gov (United States)

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

2016-01-01

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.

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

DEFF Research Database (Denmark)

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

2014-01-01

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...

How to influence fertility: the experience so far.

Science.gov (United States)

Weeks, J R

1990-09-01

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.

Preservation of Fertility Potential for Gender and Sex Diverse Individuals.

Science.gov (United States)

Johnson, Emilie K; Finlayson, Courtney

2016-01-01

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.

The cultural evolution of fertility decline

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Colleran, Heidi

2016-01-01

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

Fertility outcomes in asthma

DEFF Research Database (Denmark)

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

2016-01-01

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...

A decomposition analysis of recent fertility decline in Fiji.

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Gubhaju, B; Shahidullah, M

1990-12-01

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.

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

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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

2012-08-01

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.

Fertility, immigration, and the fight against climate change.

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Earl, Jake; Hickey, Colin; Rieder, Travis N

2017-10-01

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.

Type 2 diabetes, cardiovascular disease, and the evolutionary paradox of the polycystic ovary syndrome: a fertility first hypothesis.

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Corbett, Stephen J; McMichael, Anthony J; Prentice, Andrew M

2009-01-01

Worldwide, the high prevalence of the Polycystic Ovary Syndrome (PCOS), a heritable cause of ovarian infertility, is an evolutionary paradox, which provides insight into the susceptibility of well-fed human populations to cardiovascular disease and diabetes. We propose that PCOS, Type 2 diabetes (T2D) and the Metabolic Syndrome are modern phenotypic expressions of a metabolic genotype attuned to the dietary and energetic conditions of the Pleistocene. This metabolic "Fertility First" rather than "Thrifty" genotype persisted at high prevalence throughout the entire agrarian period-from around 12,000 years ago until 1800 AD-primarily, we contend, because it conferred a fertility advantage in an environment defined by chronic and often severe seasonal food shortage. Conversely, we argue that genetic adaptations to a high carbohydrate, low protein agrarian diet, with increased sensitivity to insulin action, were constrained because these adaptations compromised fertility by raising the lower bound of body weight and energy intake optimal for ovulation and reproduction. After 1800, the progressive attainment of dietary energy sufficiency released human populations from this constraint. This release, through the powerful mechanism of fertility selection, increased, in decades rather than centuries, the prevalence of a genotype better suited to carbohydrate metabolism. This putative mechanism for rapid and recent human evolution can explain the lower susceptibility to T2D of today's Europid populations. This hypothesis predicts that the increasing rates of diabetes and cardiovascular disease, which typically accompany economic development, will be tempered by natural, but particularly fertility, selection against the conserved ancestral genotypes that currently underpin them.

Soil fertility status and challenges in Burundi: an overview

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Kaboneka, Salvator

2015-04-01

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.

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

Directory of Open Access Journals (Sweden)

N. Helalat

2018-01-01

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

India's population: second and growing.

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Visaria, P; Visaria, L

1981-10-01

Attention in this discussion of the population of India is directed to the following: international comparisons, population pressures, trends in population growth (interstate variations), sex ratio and literacy, urban-rural distribution, migration (interstate migration, international migration), fertility and mortality levels, fertility trends (birth rate decline, interstate fertility differentials, rural-urban fertility decline, fertility differentials by education and religion, marriage and fertility), mortality trends (mortality differentials, health care services), population pressures on socioeconomic development (per capita income and poverty, unemployment and employment, increasing foodgrain production, school enrollment shortfalls), the family planning program, implementing population policy statements, what actions would be effective, and goals and prospects for the future. India's population, a total of 684 million persons as of March 1, 1981, is 2nd only to the population of China. The 1981 population was up by 136 million persons, or 24.75%, over the 548 million enumerated in the 1971 census. For 1978, India's birth and death rates were estimated at 33.3 and 14.2/1000 population, down from about 41.1 and 18.9 during the mid-1960s. India's current 5-year plan has set a goal of a birth rate of 30/1000 population by 1985 and "replacement-level" fertility--about 2.3 births per woman--by 1996. The acceleration in India's population growth has come mainly in the past 3 decades and is due primarily to a decline in mortality that has markedly outstripped the fertility decline. The Janata Party which assumed government leadership in March 1977 did not dismantle the family planning program, but emphasis was shifted to promote family planning "without any compulsion, coercion or pressures of any sort." The policy statement stressed that efforts were to be directed towards those currently underserved, mainly in rural areas. Hard targets were rejected. Over the 1978

How farmers in Switzerland perceive fertilizers from recycled anthropogenic nutrients (urine).

Science.gov (United States)

Lienert, J; Haller, M; Berner, A; Stauffacher, M; Larsen, T A

2003-01-01

We studied acceptance of a urine-based fertilizer product using a mail survey of 467 Swiss farmers. We distinguished among four production types: organic or IP farming, and with or without vegetable production. Considering that the idea of urine-based fertilizers is new, acceptance among the answering farmers was surprisingly high, with 57% explicitly stating that they thought it was a good or very good idea, and 42% willing to purchase such a product. The farmers of different production types did not differ strongly in their attitude towards urine-based fertilizers. Especially IP and vegetable farmers, who purchased additional fertilizers anyway, seem willing to accept urine-based fertilizers, hereby preferring a grainy, odorless ammonium nitrate fertilizer. Absolutely essential is a hazard-free product: 30% of all farmers had concerns regarding micropollutants. Based on fertilizer data, we demonstrate an existing demand for the nutrients N, P, and K in Switzerland, which could be partially substituted by a recycled urine product. Finally, we discuss methodological requirements of social science surveys. To obtain representative data on an entire population in a mail survey, multiple contacts with respondents are necessary. We argue that information and participation of stakeholders at an early stage is essential for successful technology transfer.

The Population Problem as Economic Disarticulation.

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Yapa, Lakshman S.

1985-01-01

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)

Fertility reduction policies and poverty in Third World countries: ethical issues.

Science.gov (United States)

Hernandez, D J

1985-01-01

This article begins with a discussion of the motivation for fertility reduction and related population policies. Next, it identifies the two major approaches to evaluating these policies in the population ethics literature: the individualistic approach and the international approach. Each approach is then characterized according to the kinds of policies evaluated, the ethical principles that are most prominent, and the major conclusions drawn. Major empirical gaps in the population ethics literature are identified, and pertinent social science issues concerning the effectiveness of family planning programs, the socioeconomic determinants of fertility, and the interpersonal or community determinants of fertility are discussed. Finally, these issues are linked with the United Nations World Population Plan of Action to identify ethical questions that warrant detailed scrutiny.

[Women, fertility, development: the case of Rwanda].

Science.gov (United States)

Kabagwira, A

1992-08-01

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

[Fertility transition in Peru].

Science.gov (United States)

Ferrando, D; Aramburu, C E

1992-12-01

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

Enteropathogenic bacterial contamination of a latosol following application of organic fertilizer

Directory of Open Access Journals (Sweden)

Pedro Alexandre Escosteguy

2015-10-01

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.

Knowledge about factors that influence fertility among Australians of reproductive age: a population-based survey.

Science.gov (United States)

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

2013-02-01

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.

Using organic matter to increase soil fertility in Burundi: potentials and limitations

Science.gov (United States)

Kaboneka, Salvator

2015-04-01

Agriculture production in Burundi is dominated by small scale farmers (0.5 ha/household) who have only very limited access to mineral inputs. In the past, farmers have relied on fallow practices combined with farm yard manures to maintain and improve soil fertility. However, due to the high population growth and high population density (370/km²), fallow practices are nowadays no longer feasible, animal manures cannot be produced in sufficient quantities to maintain soil productivity and food insecurity has become a quasi permanent reality. Most Burundian soils are characterized by 1:1 types of clay minerals (kaolinite) and are acidic in nature. Such soils are of very low cation exchange capacity (CEC). To compare the effect of % clays and % organic matter (% C), correlations tests have been conducted between the two parameters and the CEC. It was found that in high altitude kaolinitic and acidic soils, CEC was highly correlated to % C and less correlated to % clay, suggesting that organic matter could play an important role in improving fertility and productivity of these soils. Based on these findings, additional studies have been conducted to evaluate the fertilizer and soil amendment values of animal manures (cattle, goat, chicken), and leguminous (Calliandra calothyrsus, Gliricidia sepium, Senna simea, Senna spectabilis) and non-leguminous (Tithonia diversifolia) foliar biomass. It was observed that chicken manure significantly reduces Al3+ levels in acidic soils, while Tithonia diversifolia outperforms in nutrient releases compared to the commonly known leguminous agroforestry shrubs and trees indicated above. Although the above mentioned organic sources can contribute to the soil nutrients supply, the quantities potentially available on farm are generally small. The only solution is to supplement these organic sources with other organic sources (compost, organic household waste), chemical fertilizers and mineral amendments (lime) to achieve Integrated Soil

Fertility desires and fertility outcomes.

Science.gov (United States)

Bracher, M; Santow, G

1991-05-01

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

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

OpenAIRE

Fulda, B.

2015-01-01

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...

Contemporary Fertility Patterns and First-Birth Timing among Mexican-Origin Women

Science.gov (United States)

Batson, Christie D.

2013-01-01

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…

Investigating the association between HIV/AIDS and recent fertility patterns in Kenya.

Science.gov (United States)

Magadi, Monica Akinyi; Agwanda, Alfred O

2010-07-01

Findings from previous studies linking the HIV/AIDS epidemic and fertility of populations have remained inconclusive. In sub-Saharan Africa, demographic patterns point to the epidemic resulting in fertility reduction. However, evidence from the 2003 Kenya Demographic and Health Survey (KDHS) has revealed interesting patterns, with regions most adversely affected with HIV/AIDS showing the clearest reversal trend in fertility decline. While there is suggestive evidence that fertility behaviour in some parts of sub-Saharan Africa has changed in relation to the HIV/AIDS epidemic, more rigorous empirical analysis is necessary to better understand this relationship. In this paper, we examine individual and contextual community HIV/AIDS factors associated with fertility patterns in Kenya, paying particular attention to possible mechanisms of the association. Multilevel models are applied to the 2003 KDHS, introducing various proximate fertility determinants in successive stages, to explore possible mechanisms through which HIV/AIDS may be associated with fertility. The results corroborate findings from earlier studies of the fertility inhibiting effect of HIV among infected women. HIV-infected women have 40 percent lower odds of having had a recent birth than their uninfected counterparts of similar background characteristics. Further analysis suggests an association between HIV/AIDS and fertility that exists through proximate fertility determinants relating to sexual exposure, breastfeeding duration, and foetal loss. While HIV/AIDS may have contributed to reduced fertility, mainly through reduced sexual exposure, there is evidence that it has contributed to increased fertility, through reduced breastfeeding and increased desire for more children resulting from increased infant/child mortality (i.e. a replacement phenomenon). In communities at advanced stages of the HIV/AIDS epidemic, it is possible that infant/child mortality has reached appreciably high levels where the

Fertility Limitation and Child Schooling in Ouagadougou: Selective Fertility or Resource Dilution?

Science.gov (United States)

Bougma, Moussa; LeGrand, Thomas K; Kobiané, Jean-François

2015-06-01

Using original data collected in Ouagadougou, Burkina Faso, this study investigates evidence for the competing theories that fertility reductions increase children's education through either the quantity-quality tradeoff (intentionally choosing smaller families to make greater investments in education and other indicators of child quality) or resource dilution (having more children reduces resources available per child, regardless of intentionality of family size). The results provide evidence for both hypotheses: children having four or fewer siblings were significantly more likely to be enrolled in school if their mothers had intentionally stopped childbearing relative to those whose mothers wanted more children but whose childbearing was limited by subfecundity. The difference between intentional and unintentional family limitation was not significant for parities greater than five. In addition, the relationship between number of siblings and their schooling is negative, regardless of the intentionality of family-size limitation, but the strength of this negative relationship is approximately twice as high among children whose mothers intentionally limited fertility (reflecting both selection and dilution effects) than among children whose mothers were subfecund (reflecting the pure dilution effect). © 2015 The Population Council, Inc.

Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

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Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

2016-01-15

A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. Copyright © 2015. Published by Elsevier B.V.

The fertility of recent migrants to England and Wales

Directory of Open Access Journals (Sweden)

James Robards

2016-06-01

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.

Changing fertility patterns and policies in the third world.

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Mcnicoll, G

1992-01-01

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.

Fertility trends in Singapore.

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

1988-10-01

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

Swedish high school students' knowledge and attitudes regarding fertility and family building

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Ekelin Maria

2012-03-01

Full Text Available Abstract Background Infertility is a serious problem for those who suffer. Some of the risks for infertility are preventable and the individual should therefore have knowledge of them. The purposes of this study were to investigate high-school students' knowledge about fertility, plans for family building and to compare views and knowledge between female and male students. Methods A questionnaire containing 34 items was answered by 274 students. Answers from male and female students were compared using student's t-test for normally distributed variables and Mann-Whitney U-test for non-normal distributions. The chi-square test was used to compare proportions of male and female students who answered questions on nominal and ordinal scales. Differences were considered as statistically significant at a p-value of 0.05. Results Analyses showed that 234 (85% intended to have children. Female students felt parenthood to be significantly more important than male students: p = 0.01. The mean age at which the respondents thought they would like to start to build their family was 26 (± 2.9 years. Men believed that women's fertility declined significantly later than women did: p = 0.01. Women answered that 30.7% couples were involuntarily infertile and men answered 22.5%: p = 0.01. Females thought it significantly more likely that they would consider IVF or adoption than men, p = 0.01. Men felt they were more likely to abstain from having children than women: p = 0.01. Women believed that body weight influenced fertility significantly more often than men: p = 0.01 and men believed significantly more often that smoking influenced fertility: p = 0.03. Both female and male students answered that they would like to have more knowledge about the area of fertility. Conclusions Young people plan to start their families when the woman's fertility is already in decline. Improving young people's knowledge about these issues would give them more opportunity to take

Sub-Saharan Africa: population pressures on development.

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Goliber, T J

1985-02-01

The population of sub-Saharan Africa, estimated at 434 million in 1984, is expected to reach 1.4 billion by 2025. The birth rate, currently 48/1000 population, continues to increase, and the death rate, 17/1000, is declining. Rapid population growth has curtailed government efforts to provide adequate nutrition, preserve the land base essential for future development, meet the demand for jobs, education, and health services, and address overcrowding in urban areas. Low education, rural residence, and low incomes are key contributors to the area's high fertility. Other factors include women's restricted roles, early age at marriage, a need for children as a source of security and support in old age, and limited knowledge of and access to modern methods of contraception. Average desired family size, which is higher than actual family size in most countries, is 6-9 children. Although government leaders have expressed ambivalence toward development of population policies and family planning programs as a result of the identification of such programs with Western aid donors, the policy climat is gradually changing. By mid-1984, at least 13 of the 42 countries in the region had indicated that they consider current fertility rates too high and support government and/or private family planning programs to reduce fertility. In addition, 26 countries in the region provide some government family planning services, usually integrated with maternal and child health programs. However, 10 countries in the region do not support family planning services for any reason. Unfortunately, sub-Saharan Africa has not yet produced a family planning program with a measurable effect on fertility that could serve as a model for other countries in the region. Social and economic change is central to any hope of fertility reduction in sub-Saharan Africa. Lower infant and child mortality rates, rising incomes, higher education, greater economic and social opportunities for women, and increased

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

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M. Mahdi Akhgar

2015-07-01

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

Fertility Preservation for Pediatric Patients: Current State and Future Possibilities.

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

2017-07-01

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

Perspectives of displaced Syrian women and service providers on fertility behaviour and available services in West Bekaa, Lebanon.

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Kabakian-Khasholian, Tamar; Mourtada, Rima; Bashour, Hyam; Kak, Faysal El; Zurayk, Huda

2017-10-01

Prior to the conflict, Syria had relatively high fertility rates. In 2010, it had the sixth highest total fertility rate in the Arab World, but it witnessed a fertility decline before the conflict in 2011. Displacement during conflict influences fertility behaviour, and meeting the contraceptive needs of displaced populations is complex. This study explored the perspectives of women and service providers about fertility behaviour of and service provision to Syrian refugee women in Bekaa, Lebanon. We used qualitative methodology to conduct 12 focus group discussions with Syrian refugee women grouped in different age categories and 13 in-depth interviews with care providers from the same region. Our findings indicate that the displacement of Syrians to Lebanon had implications on the fertility behaviour of the participants. Women brought their beliefs about preferred family size and norms about decision-making into an environment where they were exposed to both aid and hardship. The unaffordability of contraceptives in the Lebanese privatised health system compared to their free provision in Syria limited access to family planning services. Efforts are needed to maintain health resources and monitor health needs of the refugee population in order to improve access and use of services.

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

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Sadeghi Pour Roudsari HR

2000-06-01

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.

Fertility in Islamic Republic of Iran: Levels, Trends and Differentials during Three Decades (1967-1996

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Kazem Mohammad

2002-12-01

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.

Religion, fertility and genes: a dual inheritance model.

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Rowthorn, Robert

2011-08-22

Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain 'religiosity' gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of 'cultural hitch-hiking', whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations.

Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice

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Zhong-xian LU

2007-03-01

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.

Analysis of Fusarium populations in a soybean field under different fertilization management by real-time quantitative PCR and denaturing gradient gel electrophoresis

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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...

Is fertility falling in Zimbabwe?

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Udjo, E O

1996-01-01

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.

Fertility in the Age of Demographic Maturity: An Essay

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Anatole Romaniuk

2010-01-01

Full Text Available As humanity is moving into a new age of its demographic evolution, I call it demographic maturity, the emerging demographic configurations – generational sub-replacement fertility, advanced aging and potential population implosion – call for new ways of thinking about population and new policy approaches. While we live longer and healthier, we also reproduce less and less. We are stuck in a culture of low fertility. The strong motivations for foregoing motherhood are financial: a two-salary wage is better than one even for the higher middle class. No less important is the woman’s financial independence in a societal environment where marriage as an institution is under considerable stress. Motherhood is to be rewarded adequately for its highly important social role and it has to be sufficient to reassure potential mothers of their financial concerns. What is required is a more balanced resource allocation between production and reproduction. The old welfare type hand-outs like child bonuses do not work. Societies, particularly the rich, ought to realize that to raise fertility, even to generational replacement level, not only is a much greater financial effort called for but some of the tenants of the liberal economy need to be put into question to make room for social concerns such a renewal of generations, if they want to survive as national entities. This essay advocates a stationary population as the best response to challenges such as ecological health, national identity and cohesion, and possibly world peace.

Dynamic Responses in a Plant-Insect System to Fertilization by Cormorant Feces

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Gundula Kolb

2015-04-01

Full Text Available Theoretical arguments suggest that increased plant productivity may not only increase consumer densities but also their fluctuations. While increased consumer densities are commonly observed in fertilization experiments, experiments are seldom performed at a spatial and temporal scale where effects on population fluctuations may be observed. In this study we used a natural gradient in soil fertility caused by cormorant nesting. Cormorants feed on fish but defecate on their nesting islands. On these islands we studied soil nutrient availability, plant nutrient content and the density of Galerucella beetles, main herbivores feeding on Lythrum salicaria. In a common garden experiment, we followed larval development on fertilized plants and estimated larval stoichiometry. Soil nutrient availability varied among islands, and several cormorant islands had very high N and P soil content. Plant nutrient content, however, did not vary among islands, and there was no correlation between soil and plant nutrient contents. Beetle densities increased with plant nutrient content in the field study. However, there was either no effect on temporal fluctuations in beetle density or that temporal fluctuations decreased (at high P. In the common garden experiment, we found limited responses in either larval survival or pupal weights to fertilization. A possible mechanism for the limited effect of fertilization on density fluctuations may be that the distribution of L. salicaria on nesting islands was restricted to sites with a lower N and P content, presumably because high N loads are toxic.

Quantitative Trait Loci for Fertility Traits in Finnish Ayrshire Cattle

DEFF Research Database (Denmark)

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

2008-01-01

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...

Fertility targets and policy options in Asia.

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Bulatao, R A

1984-11-01

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.

Fertilizers in cereals crops. Effect of fertilization in grain quality

International Nuclear Information System (INIS)

Melaj, Mariana

1997-01-01

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

Opting For Families: Recent Trends in the Fertility of Highly Educated Women. NBER Working Paper No. 15074

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Shang, Qingyan; Weinberg, Bruce A.

2009-01-01

Observers have argued about whether highly-educated women are opting out of their careers and for families. If so, it is natural to expect fertility to increase and, insofar as children are associated with lower employment, further declines in employment. This paper provides a comprehensive study of recent trends in the fertility of…

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

2004-01-01

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

Effect of organic and inorganic fertilizer applied together on N and P absorption and soil fertility

International Nuclear Information System (INIS)

Wang Kuibo; Yu Meiyan; Shen Xiuzhen; Wang Tongyan; Chen Xueliu; Wang Zhifen

1994-01-01

15 N trace experiments show that organic and inorganic fertilizer applied together promotes organic N mineralization and absorption. Base fertilizer is mainly for nutrition organs and spring fertilizer for reproduction organs. Organic and inorganic fertilizer applied together obtained the highest production efficiency of total N. Total P amount in wheat plant is slightly higher than that of inorganic N applied only, but P distribution in nutrition organs was slightly lower than that of inorganic N applied only. Organic and inorganic fertilizer applied together, not only promoted the production but also increased fertility of soil, so it is an important measure for wheat to obtain high production continuously

Fertility problems and risk of gestational diabetes mellitus

DEFF Research Database (Denmark)

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

2016-01-01

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...

Slovenia: Generous family policy without evidence of any fertility impact

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Milivoja Šircelj

2008-07-01

Full Text Available Slovenia was not a typical socialist country; the transformation that had started at the end of the 1980s did not cause such great turbulences as in other countries in transition. However, unfavorable consequences did accompany the transition, particularly for some segments of the population. Fertility trends in Slovenia, as seen in the total fertility rate, have not surpassed the replacement level since the end of the 1970s. The lowest level of 1.21 was reached during the 1999-2003 period. Since then, the total fertility rate has been increasing slightly. Postponement in childbearing began with cohorts born after 1960. In today's Slovenian society, on average young women achieve higher education than men, and they perceive (potential motherhood as a drawback in the labor market. Almost all parents in Slovenia are employed full-time, even those with small children. Nevertheless, the traditional gender-division of roles persists in the family. Extended education, relatively high unemployment among the young, and a shortage of adequate housing prolong the stay in the parental home. Together with insecure employment, a responsible parenthood norm, and the perceived high costs of children, this results in childbearing postponement and a lower final number of children. Slovenia has a relatively well-developed family policy, particularly on parental leave and pre-school childcare. Notwithstanding, almost no impact of family policy on fertility has ever been observed.

Population and antenatal-based HIV prevalence estimates in a high contracepting female population in rural South Africa

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Barnighausen Till

2007-07-01

Full Text Available Abstract Background To present and compare population-based and antenatal-care (ANC sentinel surveillance HIV prevalence estimates among women in a rural South African population where both provision of ANC services and family planning is prevalent and fertility is declining. With a need, in such settings, to understand how to appropriately adjust ANC sentinel surveillance estimates to represent HIV prevalence in general populations, and with evidence of possible biases inherent to both surveillance systems, we explore differences between the two systems. There is particular emphasis on unrepresentative selection of ANC clinics and unrepresentative testing in the population. Methods HIV sero-prevalence amongst blood samples collected from women consenting to test during the 2005 annual longitudinal population-based serological survey was compared to anonymous unlinked HIV sero-prevalence amongst women attending antenatal care (ANC first visits in six clinics (January to May 2005. Both surveillance systems were conducted as part of the Africa Centre Demographic Information System. Results Population-based HIV prevalence estimates for all women (25.2% and pregnant women (23.7% were significantly lower than that for ANC attendees (37.7%. A large proportion of women attending urban or peri-urban clinics would be predicted to be resident within rural areas. Although overall estimates remained significantly different, presenting and standardising estimates by age and location (clinic for ANC-based estimates and individual-residence for population-based estimates made some group-specific estimates from the two surveillance systems more predictive of one another. Conclusion It is likely that where ANC coverage and contraceptive use is widespread and fertility is low, population-based surveillance under-estimates HIV prevalence due to unrepresentative testing by age, residence and also probably by HIV status, and that ANC sentinel surveillance over

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

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

2015-04-15

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.

Theoretical explanations of the rapid fertility decline in China.

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Wu, C

1986-07-01

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.

Fertility trends in Serbia during the 1990s

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Rašević Mirjana M.

2004-01-01

Full Text Available The 1990s represent an exceptionally complex period for the population of Serbia. In addition to the impact of long-term factors, various tumultuous events affected its demographic development, such as breaking apart of former Yugoslavia, armed conflicts in the neighboring countries, sanctions imposed by the international community, social changes (transition transformation or regression, deep economic crisis, collapse of social stratification political problems, institutional crisis, and NATO military intervention. Maladjustment to the changed system of values and norms, lower level of personal attainment, feeling of insecurity, and living under permanent stress are the main features of life at an individual psychological level. Deprivation or living at the subsistence level are the main elements of the economic cost sustained by the majority of the population. How have these changes affected an individual's decision to have children? The analysis of futility indicators points to an obvious decline in the number of births across low fertility regions of Serbia. Also, the analysis has raised the question why the decline in population fertility in the low fertility regions was not even higher, bearing in mind the experiences undergone by the countries with economy in transition as well as the depth of the crisis in society. In that sense several factors come to mind. The most important are the universality of marriage socio-psychological investigations confirmed domination of the traditional character or mentality in Serbia during the 1990s, and the government’s approach to the issue of fertility improved during this time. Besides demographic needs were carefully taken into account in all amendments to the old and formulation of the new measures in the area of social policy. Mention should be made of measures ensuring employment rights of women and their entitlement to maternity leave, maternity pay, and provision of institutionalized care for

Fertilization in northern forests

DEFF Research Database (Denmark)

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

2014-01-01

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...

Kinship and the decline of fertility.

Science.gov (United States)

Zhou, Y

1996-01-01

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.

Detecting the Evolution of Deliberate Fertility Control before the Demographic Transition in Germany

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Aliaksandr Amialchuk

2012-10-01

Full Text Available BACKGROUND Pervious literature has established the existence of deliberate non-parity-specific fertility control in pre-transitional populations. However, less focus has been given to the timing of its onset. In addition, previous studies focused on the changes in fertility in response to the local prices of grains, which may be endogenous. OBJECTIVE This paper studies the emergence and evolution of deliberate fertility control by investigating the link between child mortality and economic stress on the one hand and non-parity-specific birth control on the other, in historic German villages between 1700 and 1900. METHODS Birth histories from fourteen German villages (1700-1900 and rye price series are used in a micro-level event history analysis. The fertility response of second and higher-order births to the mortality of children over age two and exogenous fluctuations in rye price are used as measures of the extent of deliberate non-parity-specific birth control. RESULTS Over the course of the demographic transition, the effect of the death of children generally increases after controlling for the effect of the death of children less than two years old. The negative fertility response to high rye prices before and in the year immediately following the price change occurred only after 1800. CONCLUSIONS The replacement and insurance effects associated with child mortality generally increased before the demographic transition. The emergence of the negative effect of high rye prices on fertility after 1800 further supports the presence and evolution of deliberate non-parity-specific fertility control before the demographic transition.

Family planning, population policy and declining birth rates in Yugoslavia.

Science.gov (United States)

Malacic, J

1989-01-01

Although Yugoslavia has below-replacement fertility (a net reproduction rate in 1986 of 0.92), there are vast regional differentials. In the less developed autonomous province of Kosovo, for example, the population has doubled in the past 30 years. By region, the net reproduction rate ranges from a low of 0.83 in Croatia to a high of 1.80 in Kosovo. Until the late 1970s, when pronatalism and centralized economic planning had weakened in influence, there was an avoidance of demographic planning and policy. In 1975, the Federal Assembly issued a document on the country's demographic patterns and goals and called on republics and autonomous provinces to adapt the document to local situations--a step that was not taken. By the 1980s, the deteriorating political, economic, and demographic situation in regions with high fertility forced more explicit attention to the formulation of a national population policy. The 1989 Resolution on Population Development Policy and Family Planning sets the goal of replacement- level fertility for both high and low fertility regions and calls for an integrated approach to population issues and socioeconomic development. Decentralization, however, has represented a major obstacle to the execution of federal policy at the republic and lower local levels. While this is a chronic problem that must be addressed on the macro level, some progress could be achieved in problematic regions such as Kosovo through educational campaigns aimed at convincing individual couples of the advantages of family size of 2-3 children.

A look at Philippine population in the year 2000.

Science.gov (United States)

Olivar, G B

1978-03-01

The major subject areas explored by the University of the Population Institute were fertility, mortality, the Filipino family and nuptiality, migration and urbanization, and the structure and growth of the labor force. Data were extracted primarily from the Philippine Censuses (1903-1970) the National Demographic Surveys of 1968 and 1973, and special surveys conducted by the Institute research team. On the basis of the findings, a range of alternative population futures is projected for the year 2000, with their respective policy implications. The estimate of the crude birthrate for 1970 placed the range at between 39.3 and 42.7. The crude birthrate may have declined by 21-23% in the last 70 years, and by almost 13% in 1960-1970 alone. On the national level, fertility rates will continue to decline if the trend of delayed marriages continues. Fertility was found to decrease with the introduction of the positive socioeconomic factors that make some regions more developed than others. The present low levels of mortality have decreased its importance in relation to fertility. Mortality prospects can be improved by several policy actions which are presented here in the order of priority. Current evidence points strongly to an increase in the proportion of single individuals who delay marriage and those not planning to marry at all. The record of internal migration in the Philippines during the 20th century has been dominated by the phenomenon of urbanization, which increased from 13% in 1903 to 33% in 1970. An effort needs to be made to achieve greater rural-urban balance. The country's high population growth has increased the number of job seekers in recent years; the expansion of the regional labor force in the 1960-1970 decade was highly correlated with the growth of regional populations. Fertility, mortality, nuptiality, migration, and urbanization are the major factors determining the growth and structure of Philippine population. Alternative projections for each

Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

DEFF Research Database (Denmark)

Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman

2016-01-01

with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N......A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground...

Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

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Simon Cool

2015-11-01

Full Text Available Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications.

Child survival and changing fertility patterns in Pakistan.

Science.gov (United States)

Sathar, Z A

1992-01-01

Pakistan is a country with high fertility and high infant and child mortality, and declines in total mortality and substantial development initiatives. The discussion considers whether fertility patterns in Pakistan can be related to changes in child mortality, and whether current and future changes in fertility influence child survival favorably. Omran's study linked large family size to child survival. Resources, which are divided, become more important deficits in households below the poverty line: a situation common in Pakistan. High fertility is associated with short birth intervals, which are related to higher infant and child mortality. In Pakistan, the spacing and mortality link was found among both poverty and higher socioeconomic households. There is some support for the notion that it is birth weight and general health that are linked to survival rather than competition for resources. Other studies link the maternal age at birth and birth order with child mortality (Alam and Cleland). Trussel argues for limiting births in high risk ages of under 20 years and over 35 years. The exact casual link is not well documented. Institutional and community factors are also considered important in influencing child survival: sanitation, potable water, access to roads, electricity, health and family planning services, and sewage. Young infants are more vulnerable to these factors. Bangladesh and some Indian states have shown that population programs and raising per captia incomes are necessary to fertility decline. In India, female autonomy, access to education, and more equal income distribution were considered more important than economic development to child survival. In Pakistan, Sathar and Kazi have linked at least 2 years of elementary, maternal education with reductions in child mortality. The pervasiveness of female illiteracy hinders the chances of child survival. Sex preferences also impact on female children. The probably impacts of declines in breast

Microbial activity and community composition during bioremediation of diesel-oil-contaminated soil: effects of hydrocarbon concentration, fertilizers, and incubation time.

Science.gov (United States)

Margesin, Rosa; Hämmerle, Marion; Tscherko, Dagmar

2007-02-01

We investigated the influence of three factors-diesel oil concentration [2500, 5000, 10,000, 20,000 mg total petroleum hydrocarbons (TPH) kg(-1) soil], biostimulation (unfertilized, inorganic fertilization with NPK nutrients, or oleophilic fertilization with Inipol EAP22), and incubation time-on hydrocarbon removal, enzyme activity (lipase), and microbial community structure [phospholipid fatty acids (PLFA)] in a laboratory soil bioremediation treatment. Fertilization enhanced TPH removal and lipase activity significantly (P 0.05). Microbial communities, as assessed by PLFA patterns, were primarily influenced by the TPH content, followed by fertilization, and the interaction of these two factors, whereas incubation time was of minor importance. This was demonstrated by three-factorial analysis of variance and multidimensional scaling analysis. Low TPH content had no significant effect on soil microbial community, independent of the treatment. High TPH content generally resulted in increased PLFA concentrations, whereby a significant increase in microbial biomass with time was only observed with inorganic fertilization, whereas oleophilic fertilization (Inipol EAP22) tended to inhibit microbial activity and to reduce PLFA contents with time. Among bacteria, PLFA indicative of the Gram-negative population were significantly (P diesel oil and fertilized with NPK after 21-38 days of incubation at 20 degrees C. The Gram-positive population was not significantly influenced by TPH content or biostimulation treatment.

Fertility and early-life mortality: Evidence from smallpox vaccination in Sweden

DEFF Research Database (Denmark)

Ager, Philipp; Hansen, Casper Worm; Jensen, Peter Sandholt

2018-01-01

The smallpox vaccination method was the paramount medical innovation of the late 18th and early 19th centuries. We exploit the introduction of the smallpox vaccine in Sweden to identify the causal effect of early-life mortality on fertility. Our analysis shows that parishes in counties with highe...... a small insignificant effect on the number of surviving children and natural population growth....

Work Title: FERTILITY PATTERN OF MEN IN THREE RURAL ...

African Journals Online (AJOL)

Farouk-Fati

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.

Census-linked Study on Ethnic Fertility Differentials in Lithuania

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Aiva Jasilioniene

2014-12-01

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.

Future Population Trends in China: 2005-2050

OpenAIRE

Chen Wei; Liu Jinju

2009-01-01

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...

Religion, fertility and genes: a dual inheritance model

Science.gov (United States)

Rowthorn, Robert

2011-01-01

Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain ‘religiosity’ gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of ‘cultural hitch-hiking’, whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations. PMID:21227968

In Search for a Pronatalist Population Policy for Turkey

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Yusuf YÜKSEL

2015-06-01

Full Text Available Turkey has witnessed high fertility rates and low mortality rates until 2000s. Young population structure, need for infrastructure for growing population and reproductive health issues were always on the agenda of policy makers throughout the history of Turkey. After the decline in total fertility rate below replacement level, vibrant discussions and search for a new policy framework began to be visible in the recent years. After the establishment of new Republic in Turkey in 1923 pronatalist policies were active until the beginning 1960s. After the First Development Plan in 1962, policy shift was towards an antinatalist direction until 2000. After a short period between 2000 and 2012 which can not be put any category in terms of fertility policy government clearly declared its position favouring pronatalist policies and mobilised bureaucracy for developing new policy options. This paper summarizes the fertility policies and demographic transition of Turkey and evaluates possible policy options

Changes in Fertility at the Population Level in the Era of ART in Rural Malawi.

Science.gov (United States)

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

2017-08-01

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.

Projected near-future levels of temperature and pCO2 reduce coral fertilization success.

Directory of Open Access Journals (Sweden)

Rebecca Albright

Full Text Available Increases in atmospheric carbon dioxide (pCO2 are projected to contribute to a 1.1-6.4°C rise in global average surface temperatures and a 0.14-0.35 reduction in the average pH of the global surface ocean by 2100. If realized, these changes are expected to have negative consequences for reef-building corals including increased frequency and severity of coral bleaching and reduced rates of calcification and reef accretion. Much less is known regarding the independent and combined effects of temperature and pCO2 on critical early life history processes such as fertilization. Here we show that increases in temperature (+3°C and pCO2 (+400 µatm projected for this century negatively impact fertilization success of a common Indo-Pacific coral species, Acropora tenuis. While maximum fertilization did not differ among treatments, the sperm concentration required to obtain 50% of maximum fertilization increased 6- to 8- fold with the addition of a single factor (temperature or CO2 and nearly 50- fold when both factors interact. Our results indicate that near-future changes in temperature and pCO2 narrow the range of sperm concentrations that are capable of yielding high fertilization success in A. tenuis. Increased sperm limitation, in conjunction with adult population decline, may have severe consequences for coral reproductive success. Impaired sexual reproduction will further challenge corals by inhibiting population recovery and adaptation potential.

Fertility of Tall Girls Treated with High-Dose Estrogen, a Dose-Response Relationship

NARCIS (Netherlands)

Hendriks, A. E. J.; Drop, S. L. S.; Laven, J. S. E.; Boot, A. M.

Context: High-dose estrogen treatment to reduce final height of tall girls increases their risk for infertility in later life. Objective: The aim was to study the effect of estrogen dose on fertility outcome of these women. Design/Setting: We conducted a retrospective cohort study of university

Are Nitrogen Fertilizers Deleterious to Soil Health?

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Bijay- Singh

2018-04-01

Full Text Available Soil is one of the most important natural resources and medium for plant growth. Anthropogenic interventions such as tillage, irrigation, and fertilizer application can affect the health of the soil. Use of fertilizer nitrogen (N for crop production influences soil health primarily through changes in organic matter content, microbial life, and acidity in the soil. Soil organic matter (SOM constitutes the storehouse of soil N. Studies with 15N-labelled fertilizers show that in a cropping season, plants take more N from the soil than from the fertilizer. A large number of long-term field experiments prove that optimum fertilizer N application to crops neither resulted in loss of organic matter nor adversely affected microbial activity in the soil. Fertilizer N, when applied at or below the level at which maximum yields are achieved, resulted in the build-up of SOM and microbial biomass by promoting plant growth and increasing the amount of litter and root biomass added to soil. Only when fertilizer N was applied at rates more than the optimum, increased residual inorganic N accelerated the loss of SOM through its mineralization. Soil microbial life was also adversely affected at very high fertilizers rates. Optimum fertilizer use on agricultural crops reduces soil erosion but repeated application of high fertilizer N doses may lead to soil acidity, a negative soil health trait. Site-specific management strategies based on principles of synchronization of N demand by crops with N supply from all sources including soil and fertilizer could ensure high yields, along with maintenance of soil health. Balanced application of different nutrients and integrated nutrient management based on organic manures and mineral fertilizers also contributed to soil health maintenance and improvement. Thus, fertilizer N, when applied as per the need of the field crops in a balanced proportion with other nutrients and along with organic manures, if available with the

The fertility myth: Israeli students' knowledge regarding age-related fertility decline and late pregnancies in an era of assisted reproduction technology.

Science.gov (United States)

Hashiloni-Dolev, Yael; Kaplan, Amit; Shkedi-Rafid, Shiri

2011-11-01

As in many advanced societies, the age at first birth and the rate of post-menopausal pregnancies in Israel are constantly increasing. Since Israeli university students are the most likely population to postpone parenthood, this study aims at evaluating their awareness of: (i) women's age-related fertility decline; (ii) age-dependent success rates of IVF technology and (iii) medical procedures allowing late and post-menopausal pregnancies. Israeli undergraduate students (n= 410), attending four academic institutions and studying in different fields, completed a structured questionnaire in the 2009/2010 academic year. Students overestimated women's chances of spontaneous pregnancy in all age groups, whereas women's chances of achieving a live birth following IVF treatment were overestimated only for ages 40 years and above. Regarding both spontaneous and IVF pregnancies, success rates of very late pregnancies (beyond 45 years and after menopause) were greatly overestimated. Only 11% of the students knew that genetic motherhood is unlikely to be achieved from the mid-40s onward, unless using oocytes frozen in advance. The findings demonstrate entrenched fertility myths among Israeli students, particularly the false belief in the possibility of late (beyond 35 years) and very late genetic motherhood. This can be explained by technological 'hype' and favorable media coverage of very late pregnancies. Since this may culminate in involuntary childlessness, it is highly important to increase the awareness of the Israeli public on the subject of fertility. However, as our sample is not representative of the Israeli student population, our findings should be tested in future studies.

Fertility and the economy.

Science.gov (United States)

Becker, G S

1992-08-01

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

Endometrial immune markers are potential predictors of normal fertility and pregnancy after in vitro fertilization.

Science.gov (United States)

Kofod, Louise; Lindhard, Anette; Bzorek, Michael; Eriksen, Jens Ole; Larsen, Lise Grupe; Hviid, Thomas Vauvert F

2017-09-01

Elucidating immune mechanisms in the endometrium, which lead to the success of implantation and pregnancy, is important in reproductive medicine. Studies of immune cell abundance have shown conflicting results, and the expression and importance of HLA class Ib proteins in pre-implantation endometrium have not yet been investigated. The study population consisted of four subgroups: a hydrosalpinx, a salpingectomy, an unexplained infertility, and a fertile control group. Endometrial samples were collected during the implantation window. Immune markers (CD56 + and CD16 + cells, FoxP3 + Tregs, HLA-G, HLA-F) were quantified in the samples. The outcome of the subsequent IVF treatment was recorded. Increased CD56 + uNK cells and high HLA-G expression served as predictor for successful pregnancy outcome. HLA-F expression was positively correlated with uNK cells, being indirectly predictive for achieving pregnancy. Endometrial uNK cell abundance in the pre-implantation endometrium seems to be important for normal fertility and pregnancy success, and they may be used as clinical markers to predict implantation success in IVF. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria.

Science.gov (United States)

Simonsen, Anna K; Han, Shery; Rekret, Phil; Rentschler, Christine S; Heath, Katy D; Stinchcombe, John R

2015-01-01

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

Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria

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Anna K. Simonsen

2015-10-01

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

Childlessness and fertility by couples' educational gender (inequality in Austria, Bulgaria, and France

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Beata Osiewalska

2017-08-01

Full Text Available Background: In modern, highly developed countries the association between education and fertility seems to be equivocal: A negative influence of education mainly applies to women, while among men the correlation is often positive or negligible. Although the gender differences have been examined in depth, couples' procreative behaviour treated as the result of a conflict between male and female characteristics is still understudied. Objective: This study aims to investigate couples' reproductive behaviour among contemporary European populations with regard to (inequality between partners' educational levels and the joint educational resources of a couple. Various measures of educational endogamy are considered. Methods: The hurdle zero-truncated Poisson model within the Bayesian framework is applied. The data comes from the first wave of the Generations and Gender Survey for Austria, Bulgaria, and France. Results: Homogamous low-educated partners have, on average, the highest fertility. The highly educated postpone childbearing and have a smaller number of children in all countries except France, where their completed fertility does not differ from that of other unions. The effect of hypergamy is insignificant and is thus similar to homogamy in medium education. Hypogamy negatively influences fertility in Bulgaria and Austria, while in France the effect is insignificant. Conclusions: The small variation in fertility due to couple-level education observed in France indicates that proper institutional support for families might help couples overcome possible obstacles and enhance fertility for all educational profiles. Contribution: This study provides a perspective on the relationship between reproductive behaviour and educational pairing in varying country-specific contexts. It reaches key conclusions on contemporary fertility regarding both childlessness and parenthood and their association with couples' different educational profiles.

The fertility transition in Cuba and the Federal Republic of Korea: the impact of organised family planning.

Science.gov (United States)

Noble, J; Potts, M

1996-04-01

South Korea and Cuba are dissimilar in religion, economy, culture and attitudes toward premarital sexual relations. In 1960, Korea instituted a national family planning programme to combat rapid population growth. Cuba explicitly rejected Malthusian policies, but made family planning universally available in 1974 in response to health needs. Both countries have undergone rapid fertility declines and today have less than replacement level fertility. Both countries have also used a similar mixture of methods, including a high prevalence of female sterilisation. Abortion has played a major role in the fertility decline of both countries, rising in the first half of the fertility transition and then falling, although remaining a significant variable in the second half. It is concluded that access to contraception, voluntary sterilisation, and safe abortion has a direct impact on fertility and has been associated with a rapid fall in family size in two very different countries.

The fertilizer nitrogen problem

Energy Technology Data Exchange (ETDEWEB)

Olson, R A; Halstead, E H

1974-07-01

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)

The fertilizer nitrogen problem

International Nuclear Information System (INIS)

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

1974-01-01

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)

The relationship between poverty and fertility in some less developed countries.

Science.gov (United States)

Chin Ptc

1985-12-01

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.

Intergenerational fertility correlations in contemporary developing counties.

Science.gov (United States)

Murphy, Michael

2012-01-01

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.

Population ageing and inter-generational relation in the MENA: what role for social policy?

NARCIS (Netherlands)

M. Meskoub (Mahmood)

2017-01-01

textabstractDeclining fertility and rising life expectancy combined with migration are changing the demographic landscape of the MENA. Earlier high fertility however will ensure a growing population in the next 20-30 years. Family structure is also changing, it is becoming smaller and of nuclear

Abundant and stable char residues in soils: implications for soil fertility and carbon sequestration.

Science.gov (United States)

Mao, J-D; Johnson, R L; Lehmann, J; Olk, D C; Neves, E G; Thompson, M L; Schmidt-Rohr, K

2012-09-04

Large-scale soil application of biochar may enhance soil fertility, increasing crop production for the growing human population, while also sequestering atmospheric carbon. But reaching these beneficial outcomes requires an understanding of the relationships among biochar's structure, stability, and contribution to soil fertility. Using quantitative (13)C nuclear magnetic resonance (NMR) spectroscopy, we show that Terra Preta soils (fertile anthropogenic dark earths in Amazonia that were enriched with char >800 years ago) consist predominantly of char residues composed of ~6 fused aromatic rings substituted by COO(-) groups that significantly increase the soils' cation-exchange capacity and thus the retention of plant nutrients. We also show that highly productive, grassland-derived soils in the U.S. (Mollisols) contain char (generated by presettlement fires) that is structurally comparable to char in the Terra Preta soils and much more abundant than previously thought (~40-50% of organic C). Our findings indicate that these oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter.

Association of single nucleotide polymorphisms in candidate genes previously related to genetic variation in fertility with phenotypic measurements of reproductive function in Holstein cows.

Science.gov (United States)

Ortega, M Sofia; Denicol, Anna C; Cole, John B; Null, Daniel J; Taylor, Jeremy F; Schnabel, Robert D; Hansen, Peter J

2017-05-01

Many genetic markers related to health or production traits are not evaluated in populations independent of the discovery population or related to phenotype. Here we evaluated 68 single nucleotide polymorphisms (SNP) in candidate genes previously associated with genetic merit for fertility and production traits for association with phenotypic measurements of fertility in a population of Holstein cows that was selected based on predicted transmitting ability (PTA) for daughter pregnancy rate (DPR; high, ≥1, n = 989; low, ≤ -1.0, n = 1,285). Cows with a high PTA for DPR had higher pregnancy rate at first service, fewer services per conception, and fewer days open than cows with a low PTA for DPR. Of the 68 SNP, 11 were associated with pregnancy rate at first service, 16 with services per conception, and 19 with days open. Single nucleotide polymorphisms in 12 genes (BDH2, BSP3, CAST, CD2, CD14, FUT1, FYB, GCNT3, HSD17B7, IBSP, OCLN, and PCCB) had significant associations with 2 fertility traits, and SNP in 4 genes (CSPP1, FCER1G, PMM2, and TBC1D24) had significant associations with each of the 3 traits. Results from this experiment were compared with results from 2 earlier studies in which the SNP were associated with genetic estimates of fertility. One study involved the same animals as used here, and the other study was of an independent population of bulls. A total of 13 SNP associated with 1 or more phenotypic estimates of fertility were directionally associated with genetic estimates of fertility in the same cow population. Moreover, 14 SNP associated with reproductive phenotype were directionally associated with genetic estimates of fertility in the bull population. Nine SNP (located in BCAS, BSP3, CAST, FUT1, HSD17B7, OCLN, PCCB, PMM2, and TBC1D24) had a directional association with fertility in all 3 studies. Examination of the function of the genes with SNP associated with reproduction in more than one study indicates the importance of steroid hormones

Methods of fertility control in cats: Owner, breeder and veterinarian behavior and attitudes.

Science.gov (United States)

Murray, Jane K; Mosteller, Jill R; Loberg, Jenny M; Andersson, Maria; Benka, Valerie A W

2015-09-01

Fertility control is important for population management of owned and unowned cats, provides health benefits at the individual level and can reduce unwanted sexually dimorphic behaviors such as roaming, aggression, spraying and calling. This article reviews the available evidence regarding European and American veterinarian, owner and pedigree cat breeder attitudes toward both surgical sterilization and non-surgical fertility control. It additionally presents new data on veterinarians' and pedigree cat breeders' use of, and attitudes toward, alternative modalities of fertility control. Within the United States and Europe, the proportion of cats reported to be sterilized varies widely. Published estimates range from 27-93% for owned cats and 2-5% for cats trapped as part of a trap-neuter-return (TNR) program. In some regions and populations of cats, non-surgical fertility control is also used. Social context, cultural norms, individual preferences, economic considerations, legislation and professional organizations may all influence fertility control decisions for cats. Particularly in Europe, a limited number of non-surgical temporary contraceptives are available for cats; these include products with regulatory approval for cats as well as some used 'off label'. Non-surgical methods remove the risk of complications related to surgery and offer potential to treat more animals in less time and at lower cost; they may also appeal to pedigree cat breeders seeking temporary contraception. However, concerns over efficacy, delivery methods, target species safety, duration and side effects exist with current non-surgical options. Research is under way to develop new methods to control fertility in cats without surgery. US and European veterinarians place high value on three perceived benefits of surgical sterilization: permanence, behavioral benefits and health benefits. Non-surgical options will likely need to share these benefits to be widely accepted by the veterinary

Population policy and the Five Year Plans.

Science.gov (United States)

Chandna, R C

1989-01-01

, traditional and modern methods in FP should be tried in order to achieve responsible behavior. The population increases in India were a result of a mortality decline starting in 1921 and a fertility decline starting in 1971. Attention must focus on high fertility areas such as Uttar Pradesh, Bihar, Madhya Pradesh, and Rajasthan. The 7th 5-year plan was important for making FP voluntary and generating an environment for fertility decline, and the 8th should establish FP as a self generating process.

Prediction of porcine male fertility

NARCIS (Netherlands)

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

2012-01-01

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

COMPLETED FERTILITY DURING THE TWENTIETH CENTURY: AN EXAMPLE FROM SIX SETTLEMENTS IN NORTHERN GREECE.

Science.gov (United States)

Zafeiris, Konstantinos N; Kaklamani, Stamatina

2018-02-06

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.

Genetics and genomics to improve fertility in high producing dairy cows

NARCIS (Netherlands)

Veerkamp, R.F.; Beerda, B.

2007-01-01

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

Forecasting the effects of fertility control on overabundant ungulates: White-tailed deer in the National Capital Region

Science.gov (United States)

Raiho, Ann M.; Hooten, Mevin B.; Bates, Scott; Hobbs, N. Thompson

2015-01-01

Overabundant populations of ungulates have caused environmental degradation and loss of biological diversity in ecosystems throughout the world. Culling or regulated harvest is often used to control overabundant species. These methods are difficult to implement in national parks, other types of conservation reserves, or in residential areas where public hunting may be forbidden by policy. As a result, fertility control has been recommended as a non-lethal alternative for regulating ungulate populations. We evaluate this alternative using white-tailed deer in national parks in the vicinity of Washington, D.C., USA as a model system. Managers seek to reduce densities of white-tailed deer from the current average (50 deer per km2) to decrease harm to native plant communities caused by deer. We present a Bayesian hierarchical model using 13 years of population estimates from 8 national parks in the National Capital Region Network. We offer a novel way to evaluate management actions relative to goals using short term forecasts. Our approach confirms past analyses that fertility control is incapable of rapidly reducing deer abundance. Fertility control can be combined with culling to maintain a population below carrying capacity with a high probability of success. This gives managers confronted with problematic overabundance a framework for implementing management actions with a realistic assessment of uncertainty.

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

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Marcos Antonio Pavan

1999-03-01

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

Male Fertility After Inguinal Hernia Mesh Repair

DEFF Research Database (Denmark)

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

2017-01-01

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....

The influence of different concentrations of bio-organic fertilizer on cucumber Fusarium wilt and soil microflora alterations.

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Nan Huang

Full Text Available Fusarium wilt is one of the main diseases of cucumber, and bio-organic fertilizer has been used to control Fusarium wilt. In this study, a pot experiment was conducted to evaluate the effects of bio-organic fertilizer applied at four levels on the suppression of Fusarium wilt disease in cucumber, the soil physico-chemical properties and the microbial communities. In comparison with the control (CK, low concentrations of bio-organic fertilizer (BIO2.5 and BIO5 did not effectively reduce the disease incidence and had little effect on soil microorganisms. High concentrations of bio-organic fertilizer (BIO10 and BIO20 significantly reduced the disease incidence by 33.3%-66.7% and the production was significantly improved by 83.8%-100.3%. The soil population of F. oxysporum f. sp. cucumerinum was significantly lower in bio-organic fertilizer treatments, especially in BIO10 and BIO20. The microorganism activity increased with the bio-organic fertilizer concentration. High-throughput sequencing demonstrated that, at the order level, Sphingomonadales, Bacillales, Solibacterales and Xylariales were significantly abundant in BIO10 and BIO20 soils. At the genus level, the abundance and composition of bacterial and fungal communities in BIO10 and BIO20 were similar, illustrating that high concentrations of bio-organic fertilizer activated diverse groups of microorganisms. Redundancy analysis (RDA showed that Xanthomonadales, Sphingomonadales, Bacillales, Orbiliales, Sordariales, and Mucorales occurred predominantly in the BIO10 and BIO20. These microorganisms were related to the organic matter, available potassium and available phosphorus contents. In conclusion, a high concentration of bio-organic fertilizer application suppressed the Fusarium wilt disease and increased cucumber production after continuous cropping might through improving soil chemical condition and manipulating the composition of soil microbial community.

Education stalls and subsequent stalls in African fertility: A descriptive overview

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Anne Goujon

2015-12-01

Full Text Available Background: Recent stalls in fertility decline have been observed in a few countries in sub-Saharan Africa, and so far no plausible common reason has been identified in the literature. This paper develops the hypothesis that these fertility stalls could be associated with stalls in the progress of education among the women of the relevant cohorts, possibly resulting partly from the Structural Adjustment Programs (SAPs of the 1980s. Methods: We descriptively link the change in the education composition of successive cohorts of young women in sub-Saharan Africa and the recent fertility stalls. We use reconstructed data on population by age, gender, and level of education from www.wittgenstein centre.org/dataexplorer, and fertility rates from the United Nations. Results: In most sub-Saharan African countries, we observe that the same countries that had fertility stalls had a stall in the progress of education, particularly for young women who were of primary school age during the 1980s, when most of the countries were under structural adjustment. Conversely, stalls in fertility are less common in countries that did not have an education stall, possibly in relation to SAPs. Conclusions: The results point to the possibility of a link between the recent fertility stalls and discontinuities in the improvement of the education of the relevant cohorts, which in turn could be related to the SAPs in the 1980s. This descriptive finding now needs to be corroborated through more detailed cohort-specific fertility analysis. If the education-fertility link can be further established, it will have important implications for the projections of population growth in affected countries.

About fertility: a constant value or changing values for the replacement threshold?

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Luigi Di Comite

2007-10-01

Full Text Available When we deal about fertility future evolution, it is generally believed – above all among people who do not deal with this topic – that in order to achieve an intrinsic rate of population natural increase equal to zero, able to ensure the constancy of its total amount over a long period (“zero population growth”, it is sufficient to reach a TFR equal, more or less, to 2.10 that must be kept steady in time having, as counterpart, fundamentally growing population for higher values and fundamentally decreasing population for values below the above mentioned level of reference (R=2.10. However, even nowadays, where the death rate is very high, in order to achieve an intrinsic rate of population natural increase equal to zero, it is necessary to start from total fertility rates, which are fundamentally as higher than 2.10 as higher is, at different ages, the mortality for women under 50. Under this consideration, we have pointed out the problem of singling out the so called replacement threshold of the TFR, assuming that it is not correct to interpret it as a fixed value, more or less equal to 2.10. In these pages we have briefly drawn – rather than demonstrated – the reader attention to the fact that for a TFR equal to 2.50 we have, considering the changes in mortality rates, values of net fertility rate which deeply vary, going from a value of 0.770 (for a life expectancy at birth equal to 20.0 years to a value of 2.426 (for a life expectancy at birth equal to 80 years as in the analysed case, and reaching a value which is very near to 2.100 for a life expectancy at birth equal to 62.5 years.

Subfertility in Women With Rheumatoid Arthritis and the Outcome of Fertility Assessments.

Science.gov (United States)

Brouwer, Jenny; Fleurbaaij, Rosalie; Hazes, Johanna M W; Dolhain, Radboud J E M; Laven, Joop S E

2017-08-01

Subfertility is frequently encountered among female rheumatoid arthritis (RA) patients and has been associated with disease activity and antirheumatic drugs. However, little is known about the results of the fertility assessments in these women. Our aim was to study the outcome of fertility assessments in subfertile women with RA. A cross-sectional study was performed in a nationwide cohort of female RA patients who were pregnant or trying to conceive between 2002 and 2010 (Pregnancy-Induced Amelioration of Rheumatoid Arthritis Study). Patients who had given consent for future contact (n = 260) received a questionnaire on reproductive history, fertility examinations, and fertility treatments. Medical files were obtained from attending gynecologists. A completed questionnaire was returned by 178 women (68%), of whom 96% had ended their efforts to conceive. Eighty-two subjects (46%) had at least 1 subfertile episode, and for 61 women a diagnosis for subfertility was available. Unexplained subfertility (48%) and anovulation (28%) were the most common gynecologic diagnoses, and both occurred more often in RA patients than reported in the general population. Women with unexplained subfertility more often used nonsteroidal antiinflammatory drugs (NSAIDs) during the periconceptional period. Seventeen percent of all pregnancies were conceived after fertility treatments. Fertility treatments had equal or higher pregnancy rates in RA compared to other subfertile populations. Unexplained subfertility is more often diagnosed in subfertile female RA patients than in the general population, and is related to periconceptional NSAID use. Despite the higher incidence of subfertility in women with RA, the outcome of fertility treatments in these women appears favorable. © 2016 The Authors. Arthritis Care & Research published by Wiley Periodicals, Inc. on behalf of American College of Rheumatology.

Family planning and fertility decline: a global overview.

Science.gov (United States)

Tabah, L

1977-01-01

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.

Reflections on fertility and postponed parenthood-interviews with highly educated women and men without children in Sweden.

Science.gov (United States)

Eriksson, Carola; Larsson, Margareta; Skoog Svanberg, Agneta; Tydén, Tanja

2013-05-01

Different reasons influence the current low birth-rate and the postponement of the birth of the first child throughout Europe. The aim of this study was to explore how highly educated women and men in Sweden reflect on fertility and postponed parenthood. We interviewed women (n = 22) and men (n = 18) who had started their professional careers and still had no children. Data were analysed with qualitative content analysis. Fertility was perceived as an unconsidered capacity, sometimes unpredictable, and different for women and men, but nevertheless taken for granted. The participants were of the opinion that fertility could be restored by assisted reproductive technologies or replaced by alternatives to a biological child. Postponed parenthood was described as an adaptation to societal changes and current discourses about parenthood as well as a consequence of a contemporary lifestyle with many competing priorities. Highly educated young women and men in contemporary Sweden have competing priorities when planning and setting goals for their lives, and having children is one of them. They describe fertility as an imperceptible and retrievable capacity and postponed parenthood as a rational adaptation to changes in society. These findings suggest that increased information about the limitations of human reproduction is needed, but also that societal support for younger parents is of utmost importance.

Socioeconomic differences in the unemployment and fertility nexus: Evidence from Denmark and Germany.

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Kreyenfeld, Michaela; Andersson, Gunnar

2014-09-01

Studies that have investigated the role of unemployment in childbearing decisions have often shown no or only barely significant results. We argue that many of these "non-findings" may be attributed to a neglect of group-specific differences in behavior. In this study, we examine how the association of unemployment and fertility varies by socio-demographic subgroups using data from the German Socio-Economic Panel (GSOEP) and from Danish population registers. We find that male unemployment is related to a postponement of first and second childbearing in both countries. The role of female unemployment is less clear at these two parities. Both male and female unemployment is positively correlated with third birth risks. More importantly, our results show that there are strong educational gradients in the unemployment and fertility nexus, and that the relationship between unemployment and fertility varies by socioeconomic group. Fertility tends to be lower during periods of unemployment among highly educated women and men, but not among their less educated counterparts. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

Science.gov (United States)

Kato, Tsuguhiko

2018-06-01

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.

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

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javad seyedmohammadi

2017-02-01

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

Low Fertility of Highly Educated Women: The Impact of Child Care Infrastructure

OpenAIRE

Schrage, Andrea

2007-01-01

Most studies of the negative correlation between fertility and education treat education as exogenously raising wages and the cost of child rearing, thus reducing fertility. I relax these assumptions in two respects. First, child costs don't increase with the value of time when external child care is used. Second, over a lifetime, education is endogenous. I model women's choice of education, fertility, and form of child care, allowing for economies of scale in parental child care. Compatibili...

Understanding the population dimension in development planning.

Science.gov (United States)

Rivera, P C

1983-01-01

In the Philippines initial efforts to adopt population policies focused on reducing rapid population growth through fertility control. The history of the national population welfare congress, which started in 1978, reflects this emphasis on family planning as a major deterrent to rapid population growth. It was only in recent years that the 2-way relationship between population and development came to be better appreciated. The 6th National Populaton Welfare Congress was a response to this need to broaden the scope of population concerns and integrate the population dimension into development planning. This viewpoint regards population not as a demand variable but as a factor that can be influenced by economic and social development. Dr. Mercedes B. Concepcion, dean of the University of the Philippines Population Institute (UPPI), discussed population trends, prospects, and problems in a paper presented before the 6th congress. In 1980, she said, the Philippine population was 48.1 million persons, up by 11.4 million persons or 31%, over the3l.7 million enumerated in 1970. While the rate of populated growth remains high, data indicate a decreasing post-World War II trend, from 3.06% in 1948-60 to 2.68% in 1975-80. The proportion of the population below 15 has dropped by 2 percentage points, while the number of persons in the working ages 15-64 has increased. In 1 of the 3 group sessions during the congress, the participants tried to define the Philippines' population distribution goals, the requirement of an urban-rural balance, and priority intervention areas. In that session 2 main papers were presented -- one on human settlements and urbanization and the other on macroeconomic policies and their spatial implications. In another sessionplanners and researchers examined the socioeconomic and demographic impact of development programs, specifically the impact of rural electrification on fertility change in Misamis Oriental, a province in Southern Philippines. In the

Fertility, Household’s size and Poverty in Nepal

OpenAIRE

François Libois; Vincent Somville

2014-01-01

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...

[Effects of Chemical Fertilizers and Organic Fertilizer on Yield of Ligusticum chuanxiong Rhizome].

Science.gov (United States)

Liang, Qin; Chen, Xing-fu; Li, Yan; Zhang, Jun; Meng, Jie; Peng, Shi-ming

2015-10-01

To study the effects of different N, P, K and organic fertilizer (OF) on yield of Ligusticum chuanxiong rhizome, in order to provide the theoretical foundation for the establishment of standardization cultivation techniques. The field plot experiments used Ligusticum chuanxiong rhizome which planted in Pengshan as material, and were studied by the four factors and five levels with quadratic regression rotation-orthogonal combination design. According to the data obtained, a function model which could predict the fertilization and yield of Ligusticum chuanxiong rhizome accurately was established. The model analysis showed that the yields of Ligusticum chuanxiong rhizome were significantly influenced by the N, P, K and OF applications. Among these factors, the order of increase rates by the fertilizers was K > OF > N > P; The effect of interaction between N and K, N and OF, K and OF on the yield of Ligusticum chuanxiong rhizome were significantly different. High levels of N and P, N and organic fertilizer, K and organic fertilizer were conducive to improve the yield of Ligusticum chuanxiong rhizome. The results showed that the optimal fertilizer application rates of N was 148.20 - 172.28 kg/hm2, P was 511.92 - 599.40 kg/hm2, K was 249.70 - 282.37 kg/hm2, and OF was 940.00 - 1 104.00 kg/hm2. N, P, K and OF obviously affect the yield of Ligusticum chuanxiong rhizome. K and OF can significantly increase the yield of Ligusticum chuanxiong rhizome. Thus it is suggested that properly high mount of K and OF and appropriate increasing N are two favorable factors for cultivating Ligusticum chuanxiong.

Genetic variants determining survival and fertility in an adverse African environment

DEFF Research Database (Denmark)

Koopman, Jacob J E; Pijpe, Jeroen; Böhringer, Stefan

2016-01-01

Human survival probability and fertility decline strongly with age. These life history traits have been shaped by evolution. However, research has failed to uncover a consistent genetic determination of variation in survival and fertility. As an explanation, such genetic determinants have been...... selected in adverse environments, in which humans have lived during most of their history, but are almost exclusively studied in populations in modern affluent environments. Here, we present a large-scale candidate gene association study in a rural African population living in an adverse environment...

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

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Anne-Dorthe Feldthusen

2015-01-01

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.

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.

2001-10-01

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

Graduating the age-specific fertility pattern using Support Vector Machines

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Anastasia Kostaki

2009-06-01

Full Text Available A topic of interest in demographic literature is the graduation of the age-specific fertility pattern. A standard graduation technique extensively used by demographers is to fit parametric models that accurately reproduce it. Non-parametric statistical methodology might be alternatively used for this graduation purpose. Support Vector Machines (SVM is a non-parametric methodology that could be utilized for fertility graduation purposes. This paper evaluates the SVM techniques as tools for graduating fertility rates In that we apply these techniques to empirical age specific fertility rates from a variety of populations, time period, and cohorts. Additionally, for comparison reasons we also fit known parametric models to the same empirical data sets.

Fertility rates in Tešanj municipality (Bosnia and Herzegovina in the second half of the 20th and the beginning of 21st century

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Kadušić Alma

2015-01-01

Full Text Available In the second half of the 20th century, demographic changes of the Tešanj municipality developed in accordance with the complex socioeconomic circumstances in this area. In the period from 1953 to 1991 the population of Tešanj municipality increased by the average annual population growth rate of 1.5%. The biggest impact on demographic trends had the positive and relatively high rates of natural increase. The natural population change of Tešanj municipality in this period was the result of the effect of biological, socioeconomic, psychological and other factors. In this period fertility significantly influenced the rates of natural increase of municipal population. The gradual decline process of the fertility rates, which has started in the 1960s and still lasts, reflected on the natural population change and population growth rates of Tešanj population. Additional decrease of the fertility and birth rates, as well as moderate increase of mortality rate was observed. This occurred due to the decrease of the total population, as well as the adverse socioeconomic circumstances after 1995, which resulted in low natural growth rates.

Determinants of birth interval in a rural Mediterranean population (La Alpujarra, Spain).

Science.gov (United States)

Polo, V; Luna, F; Fuster, V

2000-10-01

The fertility pattern, in terms of birth intervals, in a rural population not practicing contraception belonging to La Alta Alpujarra Oriental (southeast Spain) is analyzed. During the first half of the 20th century, this population experienced a considerable degree of geographical and cultural isolation. Because of this population's high variability in fertility and therefore in birth intervals, the analysis was limited to a homogenous subsample of 154 families, each with at least five pregnancies. This limitation allowed us to analyze, among and within families, effects of a set of variables on the interbirth pattern, and to avoid possible problems of pseudoreplication. Information on birth date of the mother, age at marriage, children's birth date and death date, birth order, and frequency of miscarriages was collected. Our results indicate that interbirth intervals depend on an exponential effect of maternal age, especially significant after the age of 35. This effect is probably related to the biological degenerative processes of female fertility with age. A linear increase of birth intervals with birth order within families was found as well as a reduction of intervals among families experiencing an infant death. Our sample size was insufficient to detect a possible replacement behavior in the case of infant death. High natality and mortality rates, a secular decrease of natality rates, a log-normal birth interval, and family-size distributions suggest that La Alpujarra has been a natural fertility population following a demographic transition process.

Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils

Science.gov (United States)

Braddock, J.F.

1999-01-01

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.

Human Fertility Increases with the Marital-radius

DEFF Research Database (Denmark)

Labouriau, Rodrigo; Amorim, António

2008-01-01

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...

Microbial inoculants and fertilization for bioremediation of oil in wetlands

International Nuclear Information System (INIS)

Neralla, S.; Wright, A.L.; Weaver, R.W.

1995-01-01

Bioremediation is an attractive alternative to physical methods of oil spill cleanup in wetlands where the ecosystem can be easily damaged. Because populations of oil-degrading microorganisms are usually low in wetlands, there is potential for increasing bioremediation through bioaugmentation in conjunction with N and P supplementation. Eight microbial inoculant products were added to microcosms containing soil from a salt marsh. Four of these products were also used in mesocosms containing Spartina alterniflora grown in a glasshouse. In unfertilized microcosms, the extent of oil degraded as measured by carbon dioxide evolution during 90 days, was 30% higher in the product with the highest activity than was recorded in the control with oil by 36%. None of the products when added to the fertilized soil increased activity above that of the fertilized control with oil. Addition of oil to microcosms increased populations of hydrocarbon-degrading microorganisms, but bioaugmentation products did not increase populations. Neither addition of products nor fertilization enhanced the disappearance of oil in mesocosms in the glasshouse. Approximately 50% of the weathered oil disappeared in 41 d for all treatments. Because bioaugmentation did not enhance oil degradation, it seems that natural populations of hydrocarbon-degrading microorganisms were adequate in the salt marsh soil for bioremediation

Impact of migration on fertility in sub-Saharan Africa.

Science.gov (United States)

Brockerhoff, M; Yang, X

1994-01-01

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.

The organic fertilization in the onion cultivation

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Roberto Llorente Villa

2016-02-01

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.

Fertility preservation and cancer: How many persons are concerned?

Science.gov (United States)

Le Bihan-Benjamin, Christine; Hoog-Labouret, Natalie; Lefeuvre, Delphine; Carré-Pigeon, Frédérique; Bousquet, Philippe Jean

2018-06-01

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.

Reflections on fertility and postponed parenthood—interviews with highly educated women and men without children in Sweden

Science.gov (United States)

Eriksson, Carola; Skoog Svanberg, Agneta; Tydén, Tanja

2013-01-01

Background Different reasons influence the current low birth-rate and the postponement of the birth of the first child throughout Europe. The aim of this study was to explore how highly educated women and men in Sweden reflect on fertility and postponed parenthood. Methods We interviewed women (n = 22) and men (n = 18) who had started their professional careers and still had no children. Data were analysed with qualitative content analysis. Results Fertility was perceived as an unconsidered capacity, sometimes unpredictable, and different for women and men, but nevertheless taken for granted. The participants were of the opinion that fertility could be restored by assisted reproductive technologies or replaced by alternatives to a biological child. Postponed parenthood was described as an adaptation to societal changes and current discourses about parenthood as well as a consequence of a contemporary lifestyle with many competing priorities. Conclusion Highly educated young women and men in contemporary Sweden have competing priorities when planning and setting goals for their lives, and having children is one of them. They describe fertility as an imperceptible and retrievable capacity and postponed parenthood as a rational adaptation to changes in society. These findings suggest that increased information about the limitations of human reproduction is needed, but also that societal support for younger parents is of utmost importance. PMID:23305524

Third world programs confront adolescent fertility.

Science.gov (United States)

1978-08-01

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.

Effect of famine on fertility in a rural area of Bangladesh.

Science.gov (United States)

Razzaque, A

1988-07-01

Data on household socioeconomic status collected in the 1974 census and registration data on births, deaths, and migrations for the 1974-77 period from the Demographic Surveillance System of the International Centre for Diarrheal Disease Research, Bangladesh, were used to investigate the effects of the 1974-75 famine on differential fertility in a rural population of Bangladesh. Occupation of household head was used as a measure of socioeconomic status. Overall, fertility declined by 34% over the 1975-76 period and increased by 17% in 1976-77 from the 1974-75 figure. Significantly lower fertility was observed in 1975-76, irrespective of socioeconomic status, but the lower socioeconomic groups were affected more than the higher groups. Post-famine fertility was significantly higher only in the 2 middle occupation categories. The age-specific fertility rates suggest that the famine affected all age groups. The post-famine fertility was higher than that of 1974-75 in all but those aged below 20. At age 40 and over the recovery was slight. Husband-wife separation showed an increase during the famine and particularly among the lower socioeconomic groups. The males of the lower socioeconomic households migrated to other regions to obtain food for the family, thus affecting frequency of coitus. The decline in fertility may be due to several factors: deferred marriage; increase in divorces and husband-wife separations; high fetal wastage; voluntary fertility control through contraception, abstention, or induced abortion; and infecundability. An indirect measure of marriage rate indicated that fewer couples entered into marriage in 1974-75, particularly in the lower socioeconomic groups. Both the higher and lower socioeconomic groups were affected by the famine but the precise mechanisms were not the same. At this stage, it is not feasible to estimate the contribution of each factor to the fertility decline. The lower socioeconomic groups were more affected by husband

The Rule of Organic Fertilizer on Fertilizer Efficiency and Requirement Rate for Vegetable Crop on Inceptisols Ciherang, Bogor

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Ladiyani Retno Widowati

2009-09-01

Full Text Available Utilization of organic fertilizer is an alternative to increase soil health and supply a small amount of plant nutrient. Meanwhile agricultural soil in Indonesia commonly have low organic carbon content (<2% therefore application of organic fertilizer is recommended. Based on that, the aim of the research is to measure the effectiveness of organic fertilizer on caisim (Brassica chinensis L. growth, to measure the release of N-NO3- and N-NH4+, to determine the recommendation of organic fertilizer for caisim on Incentisols Ciherang, Bogor. The research had been conducted at Research and Soil Testing Laboratory and green house of Soil Research Institute, Laladon – Bogor on April to July 2008 using soil sample of Inceptisols Ciherang, Bogor. The treatments were: Control (no fertilizer, NPK, NPK + 500 kg organic fertilizer, ¾ NPK + 500 kg organic fertilizer, ½ NPK + 500 kg organic fertilizer, ¼ NPK + 500 kg organic fertilizer, organic fertilizer 500kg, organic fertilizer 1000 kg, NPK + 750 kg organic fertilizer, and NPK + 250 kg organic fertilizer. The five replications research had been conducted with Completely Randomized Design. The result indicated thats: (1 NPK fertilizer increased with addition of organic fertilizer approved by the evidence of increasing of plant high 2-10%, leaves number 1-2%, and crop production 16-36%. The relative agronomic effectiveness (RAE of treatment NPK+various rate of organic fertilizer were higher than NPK alone with value of 136-181%. (2 The release of NH4+-N and NO3--N from anorganic fertilizer (NPK treatment in four weeks incubation period showed balance proportion with N rate. Nitrogen released from organic fertilizer in the same incubation period are 5.39 mg NH4+-N kg-1 and 12.39 mg NO3- -N kg-1. (3 The best organic fertilizer rate based on fertilizer curve for Inceptisols Cicadas-Bogor having low C and N-organic is 560 kg organic fertilizer + NPK (300 kg Urea ha-1; 50 kg SP-36 ha-1; 50 kg KCl ha-1 produce

How fast is population ageing in China?

OpenAIRE

Yinhua mai; Xiujian Peng; Wei Chen

2009-01-01

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 ...

Emotional Variation and Fertility Behavior.

Science.gov (United States)

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

2017-04-01

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.

Radioactivity in Chemical Fertilizers

International Nuclear Information System (INIS)

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

2013-01-01

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)

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

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M. I. Tajul

2013-01-01

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.

Population as an Economic Development Factor: the Case of Kosovo

OpenAIRE

Rahmije MUSTAFA-TOPXHIU; Florentina XHELILI-KRASNIQI; Justina PULA-SHIROKA

2017-01-01

Kosovo's population is a young population and is gradually entering the final stage of demographic transition, that is characterized by considerable decline in fertility, natality, mortality and natural growth. Despite demographic disturbances caused by numerous social and economic factors, the long period under Serbian occupation, major population displacement and the War of 1999, the population of Kosovo over the last hundred years have continued to increase, with high and low fluctuations....

A 660-Kb Deletion with Antagonistic Effects on Fertility and Milk Production Segregates at High Frequency in Nordic Red Cattle

DEFF Research Database (Denmark)

Kadri, Naveen Kumar; Sahana, Goutam; Charlier, Carole

The spectacular increase in productivity of dairy cattle has been accompanied by a decline in fertility. It is assumed that this reduction is due to the negative energy balance of high producing cows. We herein describe the dissection of a fertility QTL in Nordic Red cattle to a 660-Kb deletion...

Quantitative trait loci for fertility traits in Finnish Ayrshire cattle

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Viitala Sirja M

2008-03-01

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.

Fertility trends and net reproduction in Agincourt, rural South Africa, 1992-2004.

Science.gov (United States)

Garenne, Michel L; Tollman, Stephen M; Collinson, Mark A; Kahn, Kathleen

2007-08-01

To analyse trends in fertility rates and net reproduction rates in Agincourt, a rural area of South Africa located in the former homeland of Gazankulu near the Mozambican border. Trends are analysed in the context of widely available modern contraceptive methods and increasing HIV/AIDS. A health and demographic surveillance system has been in place since 1992, covering a population of approximately 70,000 persons, with an annual census update and comprehensive recording of births and deaths. It was complemented by a retrospective study of fertility at baseline. Retrospective and prospective data were used to calculate trends in fertility, survival, and net reproduction. When possible, they were compared with data from other censuses and surveys in the same ethnic group. The fertility transition has almost ended over a course of 25 years in Agincourt. The total fertility rate (TFR) averaged 6.0 in 1979 and 2.3 in 2004. Fertility declined in proportionate fashion in all age groups including adolescents in the recent period. The net reproduction rate (NRR) declined from 1.8 to 1.0 during the prospective period (1992-2004). At current rates of change in fertility and mortality, the NRR can be expected to reach 0.63 by the year 2010. The situation of a below-replacement fertility level is new for rural Africa, and is likely to have many demographic, economic and social implications. The population could decline in the country as a whole, and is nearly static in Agincourt because of negative migration flows balancing the small excess from natural increase.

The increase of the fertility of soils using the liquid organic fertilizers and fertilizers based on sugar-beet wastes.

Science.gov (United States)

Vyborova, Oxana

2010-05-01

The fertility of soil is a capacity for ensuring plants by water, nutrients, air and capacity for making optimal conditions for growth and development of plants. The result of it is a yield. The main characteristic of fertility of soil is maintenance of humus. The humus is important part of organic matter. The supporting of soil fertility is impossible by traditional methods. The amount of receiving mineral fertilizers in agriculture will not increase in future, because mineral fertilizers are very expensive. The mineral fertilizers don't influence on maintenance of total amount of humus in soil and improve the circulation of nutrients. Every hectare of fields have to receive no less than 8-10 tons of organic fertilizers, therefore we will have self-supporting balance of humus and the fertility of soils will be increasing. Consequently we are looking for new types of organic materials and we include them in modern agro technologies. One of them is an organomineral fertilizer (lignitic materials). The humic chemicals in the form of lignitic materials of natrium, potassium and ammonium are permitted for using them in agriculture at the beginning of 1984. The Department of agriculture in Russian Federation considered the problem of using humic chemicals and made a decision to use them on the fields of our country, because the lignitic materials can restore the fertility of our fields. The lignitic materials increase the amount of spore-forming bacteria, mold fungi and actinomycete. Therefore the organic decomposition occurs more strongly, the processes of humification increase the speed and the amount of humus rises in the soil. The new forming humus has a high biological activity and it improves chemical and physical soil properties. The addition of lignitic materials in soil activates different groups of microorganisms, which influence on mobilization of nutrients and transformation from potential to effective fertility. The inclusion of humic fertilizers improves

Forecasting the Effects of Fertility Control on Overabundant Ungulates: White-Tailed Deer in the National Capital Region.

Directory of Open Access Journals (Sweden)

Ann M Raiho

Full Text Available Overabundant populations of ungulates have caused environmental degradation and loss of biological diversity in ecosystems throughout the world. Culling or regulated harvest is often used to control overabundant species. These methods are difficult to implement in national parks, other types of conservation reserves, or in residential areas where public hunting may be forbidden by policy. As a result, fertility control has been recommended as a non-lethal alternative for regulating ungulate populations. We evaluate this alternative using white-tailed deer in national parks in the vicinity of Washington, D.C., USA as a model system. Managers seek to reduce densities of white-tailed deer from the current average (50 deer per km2 to decrease harm to native plant communities caused by deer. We present a Bayesian hierarchical model using 13 years of population estimates from 8 national parks in the National Capital Region Network. We offer a novel way to evaluate management actions relative to goals using short term forecasts. Our approach confirms past analyses that fertility control is incapable of rapidly reducing deer abundance. Fertility control can be combined with culling to maintain a population below carrying capacity with a high probability of success. This gives managers confronted with problematic overabundance a framework for implementing management actions with a realistic assessment of uncertainty.

Influence of Chicken Manure Fertilization on Antibiotic-Resistant Bacteria in Soil and the Endophytic Bacteria of Pakchoi

Directory of Open Access Journals (Sweden)

Qingxiang Yang

2016-06-01

Full Text Available Animal manure is commonly used as fertilizer for agricultural crops worldwide, even though it is believed to contribute to the spread of antibiotic resistance from animal intestines to the soil environment. However, it is unclear whether and how there is any impact of manure fertilization on populations and community structure of antibiotic-resistant endophytic bacteria (AREB in plant tissues. To investigate the effect of manure and organic fertilizer on endophytic bacterial communities, pot experiments were performed with pakchoi grown with the following treatments: (1 non-treated; (2 chicken manure-treated and (3 organic fertilizer-treated. Manure or organic fertilizer significantly increased the abundances of total cultivable endophytic bacteria (TCEB and AREB in pakchoi, and the effect of chicken manure was greater than that of organic fertilizer. Further, 16S rDNA sequencing and the phylogenetic analysis indicated that chicken manure or organic fertilizer application increased the populations of multiple antibiotic-resistant bacteria (MARB in soil and multiple antibiotic-resistant endophytic bacteria (MAREB in pakchoi. The identical multiple antibiotic-resistant bacterial populations detected in chicken manure, manure- or organic fertilizer-amended soil and the vegetable endophytic system were Brevundimonas diminuta, Brachybacterium sp. and Bordetella sp., suggesting that MARB from manure could enter and colonize the vegetable tissues through manure fertilization. The fact that some human pathogens with multiple antibiotic resistance were detected in harvested vegetables after growing in manure-amended soil demonstrated a potential threat to human health.

Effect of microbiological fertilizer and soil additive on yield of buckwheat (Fagopyrum esculentum Moenchunder high altitude conditions

Directory of Open Access Journals (Sweden)

Oljača Snežana

2012-01-01

Full Text Available Effect of microbiological fertilizer (Slavol and soil additives (zeolite and hydrogel on buckwheat (Fagopyrum esculentum Moench yield was investigated in this paper. Trial was set up in the village of Radijevići, Serbia in agroecological conditions of mountain Zlatar (altitude 1,065 m during a two-year period 2009 and 2010. A randomized complete block design with four replications was set up. In organic cropping system three combinations of microbiological fertilizer (Slavol with zeolite and hydrogel were used prior to sowing. Different combinations of the microbiological fertilizer and the soil additives gave positive results especially in the second year of the trial. The best combination in organic cropping system was Slavol+hydrogel with foliar application of the microbiological fertilizer, which resulted in the greatest yield of buckwheat and this treatment can be recommended to producers. Buckwheat performed very well under limited conditions of acidic soil on high altitude in organic cropping system and it can be recommended as a very suitable crop for organic producers.

Farm Population of the United States: 1975. Current Population Reports: Farm Population.

Science.gov (United States)

Banks, Vera J.; And Others

Presented via narrative and tabular data, this report includes: Population of the U.S., Total and Farm: 1960-1975; Metropolitan-Nonmetropolitan Residence of the Farm and Nonfarm Population, by Race: 1975; Fertility Characteristics of Farm and Nonfarm Women, by Race: 1975; Persons 14 Years Old and Over Employed in Agriculture, by Farm-Nonfarm…

India's population in transition.

Science.gov (United States)

Visaria, L; Visaria, P

1995-10-01

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

Determinants of fertility desire among married or cohabiting individuals in Rakai, Uganda: a cross-sectional study.

Science.gov (United States)

Matovu, Joseph K B; Makumbi, Fredrick; Wanyenze, Rhoda K; Serwadda, David

2017-01-10

Recent trends in fertility rates indicate declines in total fertility rate (TFR) in some sub-Saharan African countries. However, countries such as Uganda continue to have a persistently high TFR partly attributed to strong preferences for large family sizes. We explored the factors that influence fertility desire among married or cohabiting individuals in Rakai, a rural district in southwestern Uganda. This cross-sectional study of fertility desire (desire to have another child) was nested in a cluster-randomized demand-creation intervention trial for the promotion of couples' HIV counseling and testing uptake among married or cohabiting individuals that was conducted in Rakai district between March 1 and April 30, 2015. A total of 1490 married or cohabiting individuals, resident in three study regions with differing background HIV prevalence, were enrolled into the study. Data were collected on socio-demographic, behavioral and fertility-related characteristics. We used a modified Poisson regression model to generate prevalence ratio (PR) as a measure of association for factors that were independently associated with fertility desire. We adjusted for clustering at community level and used STATA version 14.0 for all analyses. Overall, fertility desire was high (63.1%, n = 940); higher in men (69.9%, n = 489) than women (57.1%, n = 451). More than three-quarters (78.8%, n = 1174) had 3+ biological children while slightly more than two-thirds (68.5%, n = 1020) reported an ideal family size of 5+ children. Only 30% (n = 452) reported that they had attained their desired family size. After adjusting for potential and suspected confounders, the factors that were negatively associated with fertility desire were: age 30-39 (adjusted prevalence ratio [aPR] = 0.82, 95% CI: 0.78, 0.86) and 40+ years (aPR = 0.65, 95% CI: 0.60, 0.71); having six or more biological children (aPR = 0.88, 95% CI: 0.80, 0.97); being HIV-positive (aPR = 0

Factors affecting the development of in vitro fertilization in camelids

Directory of Open Access Journals (Sweden)

Trasorras VL

2016-12-01

Full Text Available In any program of in vitro embryo production, the ultimate goal is to develop high quality embryos being able to get a normal pregnancy and finally resulting in the birth of a healthy offspring, goal not reach yet in camelids. The application of assisted reproductive techniques, such as in vitro fertilization and subsequent in vitro embryo culture, can extend the knowledge of early embryonic development and make possible the increase of the population of genetically superior animals.

Global population trends and policy options.

Science.gov (United States)

Ezeh, Alex C; Bongaarts, John; Mberu, Blessing

2012-07-14

Rapid population growth is a threat to wellbeing in the poorest countries, whereas very low fertility increasingly threatens the future welfare of many developed countries. The mapping of global trends in population growth from 2005-10 shows four distinct patterns. Most of the poorest countries, especially in sub-Saharan Africa, are characterised by rapid growth of more than 2% per year. Moderate annual growth of 1-2% is concentrated in large countries, such as India and Indonesia, and across north Africa and western Latin America. Whereas most advanced-economy countries and large middle-income countries, such as China and Brazil, are characterised by low or no growth (0-1% per year), most of eastern Europe, Japan, and a few western European countries are characterised by population decline. Countries with rapid growth face adverse social, economic, and environmental pressures, whereas those with low or negative growth face rapid population ageing, unsustainable burdens on public pensions and health-care systems, and slow economic growth. Countries with rapid growth should consider the implementation of voluntary family planning programmes as their main policy option to reduce the high unmet need for contraception, unwanted pregnancies, and probirth reproductive norms. In countries with low or negative growth, policies to address ageing and very low fertility are still evolving. Further research into the potential effect of demographic policies on other social systems, social groups, and fertility decisions and trends is therefore recommended. Copyright © 2012 Elsevier Ltd. All rights reserved.

China's Population Policy at the Crossroads: Social Impacts and Prospects

OpenAIRE

Jiang, Quanbao; Li, Shuzhuo; Feldman, Marcus W.

2013-01-01

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; ...

The role of fertile anthropogenic soils in the conservation of native and exotic agrobiodiversity in Amazonian homegardens

NARCIS (Netherlands)

Souza, de Nathalia B.; Junqueira, André Braga; Struik, Paul C.; Stomph, Tjeerdjan; Clement, Charles R.

2017-01-01

Amazonian dark earths (ADE) are anthropogenic soils mostly created between 500 and 2500 years ago by pre-Columbian populations. ADE are currently used by local people for different agricultural and agroforestry systems. Because of their high fertility they may play an important role in the

Cancer and fertility: strategies to preserve fertility.

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

2011-03-01

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.

Mortality, fertility, and the OY ratio in a model hunter-gatherer system.

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White, Andrew A

2014-06-01

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.

Induced sterility in petunia correlation between pollen and ovule fertilities

International Nuclear Information System (INIS)

Singh, I.S.

1976-01-01

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

Determinants of adolescent fertility in Malawi | Palamuleni | Gender ...

African Journals Online (AJOL)

High adolescent fertility is recognized as a global challenge given its adverse consequences. As such understanding the factors that influence adolescent fertility is critical to addressing this challenge. This study aims at examining the causes of adolescent fertility in Malawi using the 2010 Malawi Demographic and Health ...

Fertility transition: forecast for demography.

Science.gov (United States)

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

2008-08-01

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.

Genome-wide Association Studies for Female Fertility Traits in Chinese and Nordic Holsteins.

Science.gov (United States)

Liu, Aoxing; Wang, Yachun; Sahana, Goutam; Zhang, Qin; Liu, Lin; Lund, Mogens Sandø; Su, Guosheng

2017-08-16

Reduced female fertility could cause considerable economic loss and has become a worldwide problem in the modern dairy industry. The objective of this study was to detect quantitative trait loci (QTL) for female fertility traits in Chinese and Nordic Holsteins using various strategies. First, single-trait association analyses were performed for female fertility traits in Chinese and Nordic Holsteins. Second, the SNPs with P-value Nordic Holsteins. Third, the summary statistics from single-trait association analyses were combined into meta-analyses to: (1) identify common QTL for multiple fertility traits within each Holstein population; (2) detect SNPs which were associated with a female fertility trait across two Holstein populations. A large numbers of QTL were discovered or confirmed for female fertility traits. The QTL segregating at 31.4~34.1 Mb on BTA13, 48.3~51.9 Mb on BTA23 and 34.0~37.6 Mb on BTA28 shared between Chinese and Nordic Holsteins were further ascertained using a validation approach and meta-analyses. Furthermore, multiple novel variants identified in Chinese Holsteins were validated with Nordic data as well as meta-analyses. The genes IL6R, SLC39A12, CACNB2, ZEB1, ZMIZ1 and FAM213A were concluded to be strong candidate genes for female fertility in Holsteins.

Global Fertilizer and Manure, Version 1: Nitrogen Fertilizer Application

Data.gov (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...

Global Fertilizer and Manure, Version 1: Phosphorus Fertilizer Application

Data.gov (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...

Measuring P availability in soils fertilized with water-soluble P fertilizers using 32P methodologies

International Nuclear Information System (INIS)

McLaughlin, M.J.

2002-01-01

Isotope exchange kinetics was used in conjunction with standard procedures for assessing soil P status in soils fertilized with soluble phosphatic fertilizers. Soil samples were collected before fertilizer application in year 1 (one) from 23 of the 30 sites of the National Reactive Phosphate Rock project. Soil phosphorus test values were plotted against indices of pasture response to applied fertilizer, to assess the effectiveness of the various soil tests to predict site responsiveness to applied fertilizer. Isotopically exchangeable P was only weakly related to other measures of available P, with resin P having the best relationship with E values. In some samples, very large values for isotopically exchangeable P (E values) were determined in relation to P extractable by all reagents. Examination of the data however, revealed that all the samples with large E values in relation to extractable P had very low equilibrium concentrations of solution P and high buffering capacities. The best soil test, Bray 1, could account for only 50% of the variation in plant responsiveness to applied fertilizer, with Olsen and Resin tests slightly worse at 41% and the isotopic procedure at 39%. (author)

Women health seeking behaviour and its influence on their fertility performance: utilization of prenatal and postnatal care

International Nuclear Information System (INIS)

Abbasi, S.U.R.S.; Nawaz, S.; Yousif, F.N.; Zafar, M.I.

2008-01-01

Evidences regarding the effect of pre- and postnatal care on women fertility were scanty and rarely explored in countries struggling to curtail high population growth. This specialized health care enabled women for regular consultation with the health professionals and discussions with fellow women visiting clinics. It enhances their awareness, knowledge and understating about mother-child welfare during pre- and postnatal cares. This improves their control on subsequent fertility and underlines the need to explore the hidden dimension of female fertility. A doctoral level study on the determinants of marital fertility was conducted in district Faisalabad, Pakistan. It also examined the influence of pre- and postnatal care on family size in terms of children ever born. A random sample of 1051 married women was studied from 18 villages and 18 urban localities through formal survey. The study concluded that at least 5 prenatal and 2 postnatal cares proved effective in reducing marital fertility. Improved women access to specialized care, motivation through mass media, involvement of female representatives at union council level and effective use of primary support groups are the measures suggested to enhance women control on their fertility in Pakistan. (author)

Trends in the growth of population and labour force in Pakistan.

Science.gov (United States)

Hashmi, S S

1990-01-01

Trends in the growth of the population and labor force in Pakistan are examined and future prospects for growth of population and labor, particularly agriculture, are estimated. The definition of labor force as employed or seeking work after a short period of employment has led to a great disparity in results for women in the labor force. Past trends in population growth reflected a growth rate of 1.6% for the 1950's, and 2.4% in 1960. The population rose to 84.3 million in 1981 from 42.6 million in 1961, which intercensally was an increase of 3.6% per annum for 1961-72 and 3.1% per annum for 1972-81. The estimated rate for 1981-86 was 2.9%/year. The rural population doubled and the urban tripled. There was a net migration of 2.123 million to urban areas reported in the 1981 census. There is also evidence of a high sex ratio. Balochistan (7.1%) and Sindh (3.6%) provinces have the highest growth rates. Although the largest population is in the Punjab, the growth is the lowest at 2.7%. The population is primarily young -- 44.5% 15 years in 1981, which is the highest in the world. Under high, medium, and low levels of fertility, prospective trends are estimated for 2006 and 2031, and by sex every 5 years from 1981. Population under high fertility is expected to reach 270 million by 2031, which is 3.39 persons/hectare. The population/hectare of land under cultivation was 4.25 in 1981 and is expected to rise to 13.49 persons/hectare in 2031. 11 million acres could be brought under cultivation to reduce the ratio. However, there are ecological considerations as well as an employment problem. The dependency ratio under the high variant will decline from 76.8 persons 0-14 and 65 years/100 persons 15-64 years in 1986 to 70.3 in 2006 which is still considerably higher than other developing countries. It is suggested that replacement level fertility be attained as soon as possible. Under low fertility, replacement level can be reached by 2011 with strong political commitment

Plant Mating Systems Often Vary Widely Among Populations

Directory of Open Access Journals (Sweden)

Michael R. Whitehead

2018-04-01

Full Text Available Most flowering plants are hermaphroditic, yet the proportion of seeds fertilized by self and outcross pollen varies widely among species, ranging from predominant self-fertilization to exclusive outcrossing. A population's rate of outcrossing has important evolutionary outcomes as it influences genetic structure, effective population size, and offspring fitness. Because most mating system studies have quantified outcrossing rates for just one or two populations, past reviews of mating system diversity have not been able to characterize the extent of variation among populations. Here we present a new database of more than 30 years of mating system studies that report outcrossing rates for three or more populations per species. This survey, which includes 741 populations from 105 species, illustrates substantial and prevalent among-population variation in the mating system. Intermediate outcrossing rates (mixed mating are common; 63% of species had at least one mixed mating population. The variance among populations and within species was not significantly correlated with pollination mode or phylogeny. Our review underscores the need for studies exploring variation in the relative influence of ecological and genetic factors on the mating system, and how this varies among populations. We conclude that estimates of outcrossing rates from single populations are often highly unreliable indicators of the mating system of an entire species.

Women's Fertility Status Alters Other Women's Jealousy and Mate Guarding.

Science.gov (United States)

Hurst, Ashalee C; Alquist, Jessica L; Puts, David A

2017-02-01

Across three studies, we tested the hypothesis that women exhibit greater jealousy and mate guarding toward women who are in the high (vs. low) fertility phase of their cycle. Women who imagined their partner with a woman pictured at high fertility reported more jealousy than women who imagined their partner with a woman pictured at low fertility (Studies 1 and 2). A meta-analysis across studies manipulating fertility status of the pictured woman found a significant effect of fertility status on both jealousy and mate guarding. Women with attractive partners viewed fertile-phase women as less trustworthy, which led to increased mate guarding (Study 2). In Study 3, the closer women were to peak fertility, the more instances they reported of other women acting jealously and mate guarding toward them. These studies provide evidence that women selectively exhibit jealousy and mate guarding toward women who are near peak fertility.

Recent and prospective population trends in Malaysia.

Science.gov (United States)

Jones, G W; Tan, P C

1985-09-01

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.

Jobs and kids: Female employment and fertility in China

OpenAIRE

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

2013-01-01

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...

Explaining the role of proximate determinants on fertility decline among poor and non-poor in Asian countries.

Directory of Open Access Journals (Sweden)

Nabanita Majumder

Full Text Available We examined the overall contributions of the poor and non-poor in fertility decline across the Asian countries. Further, we analyzed the direct and indirect factors that determine the reproductive behaviour of two distinct population sub-groups.Data from several new rounds of DHS surveys are available over the past few years. The DHS provides cross-nationally comparable and useful data on fertility, family planning, maternal and child health along with the other information. Six selected Asian countries namely: Bangladesh, India, Indonesia, Nepal, Philippines, and Vietnam are considered for the purpose of the study. Three rounds of DHS surveys for each country (except Vietnam are considered in the present study.Economic status is measured by computing a "wealth index", i.e. a composite indicator constructed by aggregating data on asset ownership and housing characteristics using principal components analysis (PCA. Computed household wealth index has been broken into three equal parts (33.3 percent each and the lowest and the highest 33.3 percent is considered as poor and non-poor respectively. The Bongaarts model was employed to quantify the contribution of each of the proximate determinants of fertility among poor and non-poor women.Fertility reduction across all population subgroups is now an established fact despite the diversity in the level of socio-economic development in Asian countries. It is clear from the analysis that fertility has declined irrespective of economic status at varying degrees within and across the countries which can be attributed to the increasing level of contraceptive use especially among poor women. Over the period of time changing marriage pattern and induced abortion are playing an important role in reducing fertility among poor women.Fertility decline among majority of the poor women across the Asian countries is accompanied by high prevalence of contraceptive use followed by changing marriage pattern and induced

Growing population causes of unemployment.

Science.gov (United States)

1995-01-01

At the March, 1995, International Meeting on Population and Social Development in Copenhagen, during the session on unemployment, underemployment, and population it was stated that the problem of employment was the extent to which a nation's labor supply was not matched by labor demand or job opportunities. Population was thus a supply factor, and the country's economic situation was a demand factor. The demographic variables that were considered important in the supply of labor were: a) the size and rate of growth of the population, which was a function of the birth rate, the death rate, and migration; and b) the age structure of the population, which was also a product of the rate of growth of the population and its distribution. An imbalance between the supply of labor and the demand for it gave rise to unemployment and underemployment. The vicious cycle generated by a high dependency burden associated with a young age-structure led to low savings and investments, which in turn led to low economic growth and a low standard of living. This produced high fertility rates, which in turn heightened the dependency burden perpetuating the cycle. This vicious cycle could be broken at only two points: at the high fertility stage, primarily by introducing family planning programs; and at the stage of low economic growth, by adopting policies to accelerate economic growth. To be successful, however, both actions had to be pursued simultaneously. Numerous participants emphasized the global nature of the issue of unemployment and underemployment; the effects of international competition and restrictive trade policies on employment opportunities. The growing disparity between North and South had created a social injustice between countries. Several participants called for more humane policies that favored democracy and promoted human development, and asked for assistance to help create an enabling environment for social and economic development.

Perceived partner fertility desires and influence on contraceptive use.

Science.gov (United States)

Gibbs, Susannah E; Moreau, Caroline

2017-08-01

Perceived discordance of fertility desires may be more common among couples with certain sociodemographic characteristics and may lead to lower contraceptive use. Using nationally representative data from adults ages 15-49 in France in 2010, we analysed associations between sociodemographic characteristics, perceived discordance of fertility desires and contraceptive use with design-based logistic regression. Only 8% of participants perceived discordant fertility desires while 92% perceived concordance with partner fertility desire. Discordance varied by age and relationship duration and by the presence of children from previous relationships. Perceived discordance was not associated with use of a hormonal or highly effective method. Beyond own intentions, perception of a partner's fertility desires was associated with using a highly effective method among participants using any method. Engaging men and couples in family planning programmes may be important for achieving both partners' desired fertility goals.

Population dynamics of rural Ethiopia.

Science.gov (United States)

Bariabagar, H

1978-01-01

2 rounds of the national sample surveys, conducted by the central statistical office of Ethiopia during 1964-1967 and 1969-1971, provide the only comprehensive demographic data for the country and are the basis for this discussion of rural Ethiopia's population dynamics. The population of Ethiopia is predominantly rural. Agglomerations of 2000 and over inhabitants constitute about 14% of the population, and this indicates that Ethiopia has a low level of urbanization. In rural Ethiopia, international migration was negligent in the 1970's and the age structure can be assumed to be the results of past trends of fertility and mortality conditions. The reported crude birthrate (38.2), crude death rate (12.3) and infant mortality rate (90) of rural Ethiopia fall short of the averages for African countries. Prospects of population growth of rural Ethiopia would be immense. At the rate of natural increase of between 2.4 and 3.0% per annum, the population would double in 24-29 years. Regarding population issues, the programs of the National Democratic Revolution of Ethiopia faces the following main challenging problems: 1) carrying out national population censuses in order to obtain basic information for socialist planning; 2) minimizing or curtailing the existing high urban growth rates; 3) reducing rapidly growing population; and 5) mobilizing Ethiopian women to participate in the social, economic and political life of the country in order to create favorable conditions for future fertility reduction.

Impact of ART on the fertility of HIV-positive women in sub-Saharan Africa.

Science.gov (United States)

Yeatman, Sara; Eaton, Jeffrey W; Beckles, Zosia; Benton, Lorna; Gregson, Simon; Zaba, Basia

2016-09-01

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.

Effects on water chemistry, benthic invertebrates and brown trout following forest fertilization in central Sweden

International Nuclear Information System (INIS)

Goethe, L.; Soederberg, H.; Sjoelander, E.

1993-01-01

Two coniferous forest drainage areas in central Sweden were partially fertilized with ammonium nitrate and calcium ammonium nitrate respectively, both at a dose of 150 kg N per ha. During the following years observations were made on stream water chemistry, invertebrates and brown trout (Salmo trutta L.). Upstream stations were used as controls. Very high concentrations of inorganic N (up to 45 mg l -1 ) were recorded immediately after the fertilization. Thereafter, concentration decreased rapidly but remained elevated during the whole study period. Acidity conditions (pH, alkalinity, aluminium) were unaffected by both treatments. The only registered effect on the benthic fauna was a three- to five-fold increase of drifting invertebrates during the first four-five days after the treatment. However, this did not reduce the population density at the treated stations. No effects on population of trout were recorded. (22 refs., 6 figs., 3 tabs.)

[China's population policies: attempting to "resolve the wrong problem"?].

Science.gov (United States)

Ratcliffe, J W

1989-03-01

This work argues that international efforts to resolve the population problem have failed primarily because they have been based on misconceptions concerning the definition of the problem and the relationship between population growth and development. The demographic experience of the People's Republic of China since the Revolution is used to illustrate these commonly shared misconceptions. The difficulty of defining the population problem results from differing interpretations of the basic fact that poor population groups tend to have higher fertility rates and faster growth than wealthier population groups. The Western industrial nations maintain that peoples or countries are poor because they have many children; the solution to the problem would require that they be provided access to modern contraception and associated services such as population and family planning education. Many Third World countries argue on the other hand that people have many children because they are poor, a view implying that greater social and economic development will provide the solution. The disagreement as to whether rapid population growth is a cause or a consequence of underdevelopment results in part from viewing overpopulation and underdevelopment as separate and distinct problems. Results of several carefully conducted evaluation studies have demonstrated that very little of the world fertility decline in the late 1960s and early 1970s was attributable to national family planning programs. Research has shown that equitable division of national wealth, education--especially of women, some employment factors such as a lack of opportunities for children, and a reliable social security system are the most powerful determinants of fertility. The studies indicate that fertility declines are induced by models of development that stress widespread social progress rather than provision of contraceptives and associated services. Examination of the Chinese demographic experience suggests

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

Science.gov (United States)

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

2015-12-16

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.

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

2015-12-01

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.

The population slide.

Science.gov (United States)

Mukerjee, M

1998-12-01

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.

Should access to fertility treatment be determined by female body mass index?

Science.gov (United States)

Pandey, S; Maheshwari, A; Bhattacharya, S

2010-04-01

Resource allocation towards fertility treatment has been extensively debated in countries where fertility treatment is publicly-funded. Medical, social and ethical aspects have been evaluated prior to allocation of resources. Analysis of cost-effectiveness, risks and benefits and poor success rates have led to calls of restricting fertility treatment to obese women. In this debate article, we critically appraise the evidence underlying this issue and highlight the problems with such a policy. Poor success rate of treatment is unsubstantiated as there is insufficient evidence to link high body mass index (BMI) to reduction in live birth. Obstetric complications have a linear relationship with BMI but are significantly influenced by maternal age. The same is true for miscarriage rates which are influenced by the confounding factors of polycystic ovary syndrome and age. Studies have shown that the direct costs per live birth are no greater for overweight and obese women. With changing demographics over half the reproductive-age population is overweight or obese. Restricting fertility treatment on the grounds of BMI would cause stigmatization and lead to inequity, feelings of injustice and social tension as affluent women manage to bypass these draconian restrictions. Time lost and poor success of conventional weight loss strategies would jeopardize the chances of conception for many women.

Sex, sex-ratios, and the dynamics of pelagic copepod populations

DEFF Research Database (Denmark)

Kiørboe, Thomas

2006-01-01

equal adult sex ratios in field populations. Winter population densities are orders of magnitude less than the critical population density required for population persistence, but populations survive winter seasons as resting eggs in the sediment. Population growth in these species is potentially high...... because they have on average a factor of 2 higher egg production rates than other pelagic copepods. Secondly, other copepods require only one mating to stay fertile, and populations of these species have strongly female-skewed adult sex-ratios in field populations. Resting eggs have not been described...

Increasing land sustainability and productivity through soil-fertility management in the West African Sudano-Sahelian zone

International Nuclear Information System (INIS)

Bationo, A.; Vanlauwe, B.; Kimetu, J.; Kihara, J.; Abdoulaye, M.S.; Adamou, A.; Tabo, R.; Koala, S.

2005-01-01

Food production has lagged behind population growth in most parts of the West African semi-arid tropics (WASAT). One of the reasons for low food production is decline in soil fertility as a consequence of continuous cropping without fertilization. As a result, there is a negative nutrient balance in most land-use systems in WASAT. The amount of nutrients leaving the soil, through crop uptake, leaching and erosion exceeds that returned through natural processes such as atmospheric deposition and biological nitrogen fixation or through additions of inorganic and organic fertilizers. Use of mineral fertilizers by many smallholder farmers remains low because of socio-economic constraints. Lack of adequate foreign exchange to import fertilizers, poor infrastructure and poor distribution mechanisms have hampered the use of inorganic fertilizers. Organic inputs such as manure, compost and crop residues are often proposed as alternatives to mineral fertilizers, however, it is important to recognize that in most cases the use of organic inputs is part of an internal flow of nutrients within the farm and does not add nutrient from outside the farm; also, quantities available are inadequate to meet nutrient needs over large areas because of limited availability, low nutrient content of the material, and high labour demands for processing and application. The beneficial effects of combined manure and inorganic nutrients on soil fertility have been repeatedly shown, yet there is need for more research on the establishment of the fertilizer equivalency of manures, in determining the optimum combination of these two plant nutrients and in taking into account the high variability in their quality. Such information is useful in formulating decision-support systems and in establishing simple guidelines for management and utilization of the resources. This paper highlights current research results on the management of nitrogen, phosphorus and organic matter and summarizes our

Poor semen quality may contribute to recent decline in fertility rates.

Science.gov (United States)

Jensen, Tina Kold; Carlsen, Elisabeth; Jørgensen, Niels; Berthelsen, Jørgen G; Keiding, Niels; Christensen, Kaare; Petersen, Jørgen Holm; Knudsen, Lisbeth B; Skakkebaek, Niels E

2002-06-01

During past decades, we have witnessed a remarkable decline in fertility rates (number of births per 1000 women of reproductive age) in the industrialized world. It seems beyond doubt that the enormous social changes of our societies play the major role in this decline, but can it be attributed to changing social structures alone or is a reduced fecundity in the population also a factor? To address this we have focused on trends in teenage pregnancies (which to a large extent are unplanned). During the period in question fertility rates among 15-19 year old Danish women have been falling and the decline in fertility rate is not counterbalanced by an increase in the rate of induced abortion. When seen together with recent results from Denmark, which have shown that more than 30% of 19 year old men from the general population now have sperm counts in the subfertile range, we argue that this fall may not be attributable to social factors, changes in conception practices or diminished sexual activity alone. It seems reasonable also to consider widespread poor semen quality among men as a potential contributing factor to low fertility rates among teenagers. Due to the concern caused by the low sperm count among younger Danish men, the Danish Ministries of Health and Environment have launched a surveillance programme which includes an annual examination of the semen quality in 600 young Danes from the general population. We propose that researchers in other countries with low and falling fertility rates among young women should consider the possibility that semen quality of their younger male cohorts may also have deteriorated.

A population-based cohort study of the effect of Caesarean section on subsequent fertility.

Science.gov (United States)

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

2014-06-01

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

EFFECT OF SOIL SULFUR FERTILIZER AND SOME FOLIAR FERTILIZERS ON GROWTH AND YIELD OF BROCCOLI IN SALINE SOIL

Directory of Open Access Journals (Sweden)

Ali Husain JASIM

2015-12-01

Full Text Available Factorial experiment was conducted in the open fields of Agricultural College, Al-Qasim Green University during the agricultural seasons of 2013/2014 and 2014/2015 to study the effect of adding two levels of agricultural sulfur (control and add 100 kg.ha-1 and four levels of nutrient spray (without spray, high-potash fertilizer, high-phosphorus fertilizer and humic acid on growth and yield of broccoli under drip irrigation and polyethylene soil mulching in saline soil (9.6 dS.m-1. Randomized complete block design with three replicates was used. The results showed that agricultural sulfur led to increase number of leaves, leaf area, leaves chlorophyll content, diameter and weight of flower head compared to control. Spraying foliar fertilizer and its interaction with sulfur fertilizer also led to increase all of parameters above (except leaves chlorophyll content significantly compared to control treatment.

Zinc fertilization of flooded rice

International Nuclear Information System (INIS)

1981-02-01

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

In high school and pregnant: the importance of educational and fertility expectations for subsequent outcomes.

Science.gov (United States)

Yakusheva, Olga

2011-01-01

This study uses the High School and Beyond data (1980–1992) to examine the importance of educational and fertility expectations in explaining the achievement gap of adolescent mothers for over 5,500 young women from different socioeconomic backgrounds. Using a non-parametric local propensity score regression, the study finds that the economic disadvantage associated with having a child in high school is particularly large in poor socioeconomic environments; however, this disadvantage is a result of preexisting differences in the educational and fertility expectations and is not because of a diminished capacity of the socioeconomic environment to mediate the effect of an unplanned childbirth. The findings suggest that childcare assistance and other policies designed to alleviate the burden of child rearing for young mothers of low means may not produce the desired improvement in their subsequent educational and labor market outcomes. A much earlier policy intervention with a focus on fostering young women's outlook for the future is needed.

Educational differentials in cohort fertility during the fertility transition in South Korea

Directory of Open Access Journals (Sweden)

Sam Hyun Yoo

2014-05-01

Full Text Available Background: While there has been a considerable amount of research on the association between women's education and fertility rates, few of these studies have examined the pattern of fertility differentials over the course of the fertility transition. As a country that has experienced a rapid decline in fertility and marked improvements in women's educational attainment over the last several decades, South Korea represents an ideal case for studying this dynamic association. Objective: The aim of the article is to explain the pattern of fertility differentials by level of education and the contribution of the changes in women's educational attainment to the fertility decline during the fertility transition in South Korea. Methods: Drawing upon data from the Korean censuses conducted between 1970 and 2010, I analyze completed cohort fertility for women born between 1926 and 1970 using demographic-decomposition techniques and cohort parity progression ratios by level of education. Results: The differences in fertility by educational attainment have gradually declined over the transition, with fertility almost converging at a low level among recent birth cohorts. Fertility in South Korea had been declining in all of the social groups until the sub-replacement fertility was reached. The change in women's educational attainment then became an important factor in the further decline in fertility. The trend toward fewer children quickly spread from the most educated to the least educated women throughout the fertility transition. Conclusions: The transformation of fertility behaviors across social strata has been a key element in the Korean fertility transition. Although educational expansion, particularly the introduction of mass education, has contributed to falling fertility in South Korea, the role of education in fertility decline is more pronounced in the diffusion of innovative ideas and behaviors, which reduced fertility differentials across

Population change in the former Soviet Republics.

Science.gov (United States)

Haub, C

1994-12-01

Demographic trends in the former Soviet Republics and Russia are summarized and discussed in this publication. The former Soviet Republics in Europe as well as Georgia and Armenia had completed or almost completed their demographic transition before October 1991. Other Central Asian republics experienced reduced mortality, but, despite rapid declines, fertility is still above replacement level (at 3-4 children per woman). The economic and social dislocation of the breakup of the republics has hastened fertility decline. The annual population growth rate of the USSR in the mid-1980s was 0.9%; this rate declined to 0.4% in 1991, and the decline has continued. The 1991 population of the USSR was 289.1 million. Between 1989 and 1991, the crude birth rate was 18/1000 population, and the crude death rate was 10/1000. The net migration rate of -4/1000 helped to reduce growth. Total fertility in the USSR was 2.3 children in 1990. In Russia, fertility declined from 1.9 in 1990 to 1.4 in 1993. The preferred family size in Russia was 1.9 in 1990 and 1.5 in 1993. This decline occurred due to lack of confidence in the economy and insufficient income. Only 19% of women used contraception in 1990. Marriages declined after 1990. Age pyramids were similar in the republics in that there was a narrowing in the proportion aged 45-49 years, and the male population aged over 65 years was diminished, due to the effect of World War II. The cohort of those aged 20-24 years in 1992 was very small due to the small parental birth cohort. The differences in the republics was characterized as broad-based in the younger ages because of high fertility. The number of childbearing women will remain large. Life expectancy has been 70 years since the 1950s and has declined in some republics due to substandard health care, lack of job safety measures, and alcoholism. Some republics experienced increased life expectancy, but, after 1991, mortality increased. Tajikistan had the highest infant mortality

Adolescent fertility in Cuba: some reflections on its behavior by provinces and areas of residence

Directory of Open Access Journals (Sweden)

Daylin Rodríguez Javiqué

2016-07-01

Full Text Available This paper aims to describe the adolescent fertility in Cuba during the period 2010-2014 and analyze its proximate determinants both nationally and by territory. Based on the data published in Demographic Yearbook, Studies and Data of the Population and birth databases of the National Bureau of Statistics and Information (ONEI, adolescent fertility rates in Cuba are calculated according to the groups 10-14 and 15-19, by province and area of residence. In addition, data on family formation, contraception and abortion of Cuban adolescents are shown. These elements could allow hypothesizing about the behavior of adolescent fertility in Cuba. The first important result is that fertility among 15-19 years group had a slight decrease in the period; however, the 10-14 years group has increased its level. On the other hand, the analysis by area of residence shows that urban fertility has gained prominence in the Cuban provinces, with an increase between 2010 and 2012 in more than half of them. Similarly, about a third of the provinces analyzed show higher levels of adolescent fertility in urban areas than in rural areas. High rates of abortion in adolescence, which exceeds fertility rates in ten provinces of the country; early onset of sexual intercourse and first marriage, and improper use of contraceptive methods, are elements worth looking into in order to find explanations to the reproductive behavior of Cuban adolescents.

[World population and development: an important change in perspective].

Science.gov (United States)

Vallin, J

1984-10-24

The International Population Conference in Mexico City was much less controversial than the World Population Conference in Bucharest 10 years previously, in part because the message of Bucharest was widely accepted and in part because of changes that occurred in the demographic and economic situations in the succeeding decade. The UN medium population projection for 1985 has been proved quite accurate; it is not as alarming as the high projection but still represents a doubling of world population in less than 40 years. The control of fertility upon which the medium projection was predicated is well underway. The movement from high to low rates of fertility and mortality began in the 18th century in the industrial countries and lasted about 1 1/2 centuries during which the population surplus was dispersed throughout the world, especially in North and South America. The 2nd phase of movement from high to low rates currently underway in the developing countries has produced a far greater population increase. The proportion of the population in the developed areas of Europe, North America, the USSR, Japan, Australia, and New Zealand will decline from about 1/3 of the 2.5 billion world population of 1950 to 1/4 of the 3.7 billion of 1985, to 1/5 of the 4.8 billion of 2000, and probably 1/7 of the 10 billion when world population stabilizes at the end of the next century. The growth rates of developing countries are not homogeneous; the populations of China and India have roughly doubled in the past 35 years while that of Latin America has multiplied by 2 1/2. The population of Africa more than doubled in 35 years and will almost triple by 2025. The number of countries with over 50 million inhabitants, 9 in 1950, will increase from 19 in 1985 to 32 in 2025. The process of urbanization is almost complete in the industrialized countries, with about 75% of the population urban in 1985, but urban populations will continue to grow rapidly in the developing countries as rural

Type 1 diabetes risk in children born to women with fertility problems

DEFF Research Database (Denmark)

Hargreave, Marie; Kjaer, Susanne K; Jørgensen, Marit E

2016-01-01

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...

Effect of Various Organic Fertilizers Substitute Chemical Fertilizer on Cucumber Productions

International Nuclear Information System (INIS)

Piadang, Nattayana; Ratanapanit, Sittisuk; Chaowanklang, Pratuang; Ratanapanit; Nadtinee; Jaipakdee, Putinee; Ongsakitboriboon

2006-09-01

The effect of using the various organic fertilizer to substitute on the chemical fertilizer on cucumber, was carried out at Tambol Pattananikom, Amphur Pattananikom, Lopburi, Thailand, from December 1, 2005 to February 1, 2006 By using Randomized Comp let Block Design (RCBD), Contain with 4 treatments, chemical fertilizer: 16-16-16: 40 Kg/rai (Control), Pillet organic fertilizer: 50 Kg/rai, Bio extract from cow milk: 300 cc./ water 20 Ltr,.+ compost mixed in soil and bio fertilizer from the office of Atomic Energy Peace : 300 cc./water 20 Ltr. + campost mixed in soil (15 m. 2 /plot) were compared. Experiment result indicate that there were no significant differences on the yield. The highest yield of 25.91 kg/plot (27663.73 kg/rai) was obtained from chemical fertilizer, Fertilizer, followed by pillet organic fertilizer 22.88 kg/plot (2440.53 kg/rai), bio fertilizer 22.34 kg/pot (2382.93 kg/rai) and bio extract 19.03 kg/plot) (2029.87 kg/rai.

Playing the Fertility Game at Work

DEFF Research Database (Denmark)

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

2016-01-01

. 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....

Two period measures for comparing the fertility of marriage and cohabitation

Directory of Open Access Journals (Sweden)

Benoît Laplante

2015-02-01

Full Text Available Background: The diffusion of cohabitation and, presumably, of childbearing within cohabitation, inspires interest in measuring the respective contribution of childbearing within marriage and within cohabitation to overall fertility. However, there is no consensus on a proper way to do so. Objective: Contribute to the development of tools for assessing the relative importance of marriage and cohabitation to overall fertility by developing period measures closely related to age-specific fertility rates and the total fertility rate. Methods: We introduce two measures: 1 the contribution of the conjugal state (living alone, living in a cohabiting union, being married to age-specific fertility rates (CASFR and 2 the contribution of the conjugal state to the TFR (CTFR. These measures are similar in construction to the marital (legitimate fertility rates and marital (legitimate TFR, but they are weighted by the proportion of women living alone, cohabiting, or being married at each age, so that their sum is the overall TFR. Taken together, they represent the fertility of the average woman of a synthetic cohort who moves across the various conjugal states (living alone, cohabiting, being married over her life course. They provide "realistic" estimates of completed fertility within each conjugal state. Conclusions: CASFRs provide a description of the fertility, over her life course, of a synthetic woman who would have spent her reproductive years living alone, cohabiting, and being married as the average woman of the synthetic cohort. CTFR provides a decomposition of the cumulative fertility of this synthetic woman. Over her life course, she would have had exactly the number of children computed using the overall TFR, but CTFR details the proportion of these children she would have had while living alone, while cohabiting, and while being married. Comments: Despite being defined as a conditional ASR weighted by the age-specific proportion of women living

Is glycosylated haemoglobin a marker of fertility?

DEFF Research Database (Denmark)

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

1999-01-01

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...

Genome-wide association study identifies candidate genes for male fertility traits in humans.

Science.gov (United States)

Kosova, Gülüm; Scott, Nicole M; Niederberger, Craig; Prins, Gail S; Ober, Carole

2012-06-08

Despite the fact that hundreds of genes are known to affect fertility in animal models, relatively little is known about genes that influence natural fertility in humans. To broadly survey genes contributing to variation in male fertility, we conducted a genome-wide association study (GWAS) of two fertility traits (family size and birth rate) in 269 married men who are members of a founder population of European descent that proscribes contraception and has large family sizes. Associations between ∼250,000 autosomal SNPs and the fertility traits were examined. A total of 41 SNPs with p ≤ 1 × 10(-4) for either trait were taken forward to a validation study of 123 ethnically diverse men from Chicago who had previously undergone semen analyses. Nine (22%) of the SNPs associated with reduced fertility in the GWAS were also associated with one or more of the ten measures of reduced sperm quantity and/or function, yielding 27 associations with p values LRRC32, which encodes a latent transforming growth factor β (TGF-β) receptor on regulatory T cells. We suggest that mutations in these genes that are more severe may account for some of the unexplained infertility (or subfertility) in the general population. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Alternative population futures.

Science.gov (United States)

1980-01-01

The Philippines is now passing through a late demographic transitional period in which the death rate declines while the birth rate remains at a relatively high level; the population of young people under 15 rises to about 45% of the population while proportions of people of working age and old people decline. In 1970, 4 of the Philippine's 12 regions had a birth rate exceeding 40/1000; life expectancy at birth in these regions ranged from 57-64 years and population growth rates ranged from 2.6-4.2% annually. Also in 1970 40-49% of all 12 regional populations were young (under 15) and only 2-5% were old. In this transitional period there are a greater number of children in each household and thus heavier social and economic burdens occur; also the burden of youth dependency increases by more than 1/3. In the modern population structure, family burdens diminish as the average number of children surviving to age 20 becomes identical with the number of children born and great improvements in the quality of life are allowed. Population projections are based on the following assumptions: 1) decrease in mortality, either rapid or slow, 2) increase in age at marriage, 3) decline in fertility will remain at 0.7% annually, and 4) migration trends will stay the same as during the 1960-75 period. Total population is expected to reach 83.8 million by 2000, a 98% increase from 1975; a low estimate, assuming lower fertility and nuptiality, is 64.1 million, a 52% increase from 1975. The urban population will more than double its size by the year 2000 and rural population will grow from 22-65% with the fastest urbanizing regions being the Central and Southern Luzon. From 1975-2000 a 3-fold increase is expected in the number of families in Metro Manila. By 2000 a national labor force of 27.5 million is expected, more than double the 1970 level, with late entry into the labor force and declines in participation by elderly males. The various regions will see lower economic activity

Hungary: Secular fertility decline with distinct period fluctuations

Directory of Open Access Journals (Sweden)

Ferenc Kamarás

2008-07-01

Full Text Available In this study, we demonstrate from different angles that Hungarian fertility basically decreased between 1965 and 2005, but also clearly fluctuated, and showed different patterns in the different periods within this epoch. As a result, the clear communist-era family pattern of "early marriage and childbearing with two children" was replaced, but new family model(s have not yet fully emerged. We could show that profound changes in partnership behaviour -divorce and cohabitation- started before the change of the political regime, but also that changes in partnership relations accelerated after 1990, and that partnerships have become more fragile. In addition, Western-style values of "empty individualism" and consumerism were clearly present under socialism, but their motivating force was tamed by the communist system, in which population policy played a significant role. Of these institutional changes, we ascribe the greatest importance to the expansion in the educational system and the changes in the labour market. We show that, following the changes in the economic system, the conflict between family and work intensified. The synchronic consideration of values, labour market relations, economic development, and population policy; and the relationship of these factors to fertility and nuptiality trends, enabled us to formulate a developmental scheme of four phases concerning the evolution of fertility since 1965.

[Fertility transition in Brazil. Causes and consequences].

Science.gov (United States)

Carvalho, J A; Wong, L R

1992-12-01

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

[Population policy and women: the relevance of previous studies].

Science.gov (United States)

De Barbieri, M T

1983-01-01

Although Mexico has had high rates of population growth since the 1930s caused by continuing high fertility but declining infant and general mortality, and has undergone deep structural change including declining agricultural production, rapid industrialization, urbanization, and increasing urban umemployment, it was not until the 1970s that the government began to adopt measures aimed at controlling population growth. Opponents of family planning argued that economic and social development would lead to fertility decline, but its proponents believed that reducing population growth would free resources for productive investment that otherwise would have to be used to finance services for the ever-growing population. At the same time that the constitution and laws were changed to allow or promote family planning, Mexican civil and labor laws were changed to provide for equality of men and women. Some background is necessary to understand the effect of such changes in the role and status of the Mexican woman. A relationship has been noted between demographic models--the form in which a society reproduces over a given time--and the social condition of women. Women have generally been subordinated to men during known history, but recent research indicates that their history has not been as uniform as once supposed. The particular form in which each society defines the natural-biological basis of sex roles varies; social definitions of sex and gender vary depending on the extension of "natural-biological" character to specific areas and tasks. The cases of French women in the 16th-18th centuries and German women under Hitler illustrate different ways in which demographic models and the condition of women have varied within a general framework of subordination of women. But when attempts are made to change a given demographic model, the condition of women is redefined at the level of practice as well as of value orientations concerning motherhood, female labor force

Rural people's response to soil fertility decline : the Adja case (Benin)

NARCIS (Netherlands)

Brouwers, J.H.A.M.

1993-01-01

This study examines rural people's knowledge in changing conditions such as decreasing soil fertility and increasing population. It explores how farmers, who depend on rainfed agriculture and are confronted with an ever increasing population, react. The study presents the case of an ethnic

Multivariate Cholesky models of human female fertility patterns in the NLSY.

Science.gov (United States)

Rodgers, Joseph Lee; Bard, David E; Miller, Warren B

2007-03-01

Substantial evidence now exists that variables measuring or correlated with human fertility outcomes have a heritable component. In this study, we define a series of age-sequenced fertility variables, and fit multivariate models to account for underlying shared genetic and environmental sources of variance. We make predictions based on a theory developed by Udry [(1996) Biosocial models of low-fertility societies. In: Casterline, JB, Lee RD, Foote KA (eds) Fertility in the United States: new patterns, new theories. The Population Council, New York] suggesting that biological/genetic motivations can be more easily realized and measured in settings in which fertility choices are available. Udry's theory, along with principles from molecular genetics and certain tenets of life history theory, allow us to make specific predictions about biometrical patterns across age. Consistent with predictions, our results suggest that there are different sources of genetic influence on fertility variance at early compared to later ages, but that there is only one source of shared environmental influence that occurs at early ages. These patterns are suggestive of the types of gene-gene and gene-environment interactions for which we must account to better understand individual differences in fertility outcomes.

Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

Science.gov (United States)

Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

2008-02-01

People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

Multilocus genotypic data reveal high genetic diversity and low population genetic structure of Iranian indigenous sheep

International Nuclear Information System (INIS)

Vahidi, S.M.F.; Faruque, M.O.; Falahati Anbaran, M.; Afraz, F.; Mousavi, S.M.; Boettcher, P.; Joost, S.; Han, J.L.; Colli, L.; Periasamy, K.; Negrini, R.; Ajmone-Marsan, P.

2016-01-01

Full text: Iranian livestock diversity is still largely unexplored, in spite of the interest in the populations historically reared in this country located near the Fertile Crescent, a major livestock domestication centre. In this investigation, the genetic diversity and differentiation of 10 Iranian indigenous fat-tailed sheep breeds were investigated using 18 microsatellite markers. Iranian breeds were found to host a high level of diversity. This conclusion is substantiated by the large number of alleles observed across loci (average 13.83, range 7–22) and by the high within-breed expected heterozygosity (average 0.75, range 0.72–0.76). Iranian sheep have a low level of genetic differentiation, as indicated by the analysis of molecular variance, which allocated a very small proportion (1.67%) of total variation to the between-population component, and by the small fixation index (FST = 0.02). Both Bayesian clustering and principal coordinates analysis revealed the absence of a detectable genetic structure. Also, no isolation by distance was observed through comparison of genetic and geographical distances. In spite of high within-breed variation, signatures of inbreeding were detected by the FIS indices, which were positive in all and statistically significant in three breeds. Possible factors explaining the patterns observed, such as considerable gene flow and inbreeding probably due to anthropogenic activities in the light of population management and conservation programmes are discussed. (author)

Effects of Multiple Stressors on Red Abalone (Haliotis rufescens) Fertilization Success

Science.gov (United States)

Boch, C. A.; Aalto, E.; De Leo, G.; Litvin, S.; Lovera, C.; Micheli, F.; Woodson, C. B.; Monismith, S. G.; Barry, J. P.

2016-02-01

Acidification, hypoxia, and ocean warming are escalating threats in the world's coastal waters, with potentially severe consequences for marine life and ocean-based economies. In particular, eastern boundary current ecosystems, including the California Current Large Marine Ecosystem (CCLME), are experiencing large-scale declines in pH and dissolved oxygen (DO)—with the latter linked to changes in thermal stratification and shoaling of the oxygen minimum zone. To examine the consequences of ocean acidification and other climate-related changes in oceanographic conditions on nearshore marine populations within the CCLME, we are assessing the potential effects of current and future upwelling-type conditions on the population dynamics of the red abalone (Haliotis rufescens), with a focus on sensitive early life history phases (e.g., fertilization, larval development, and juvenile growth and survival) expected to be important determinants of population dynamics. Here, we present the first experimental results on the impacts of combined exposures of low pH and low DO on abalone fertilization success. Our results show that abalone fertilization success is significantly reduced when the gametes are exposed to a decrease in seawater pH from 8.0 to 7.2. Furthermore, low pH in combination with hypoxic exposure—e.g., a decrease in dissolved oxygen from 6 mg/L DO to 1 mg/L DO—does not further decrease fertilization rates, suggesting a lack of synergistic or additive effects of these multiple stressors on the reduction of fertilization success. Although the focus of this study is to characterize the effects of multiple stressors on the early life history of abalone, the implications of these results are expected to be relevant for a variety of marine taxa with similar reproductive modes.

Young female cancer patients' experiences with fertility counselling and fertility preservation

DEFF Research Database (Denmark)

Hoeg, Didde; Schmidt, Lone; Tryde Macklon, Kirsten

2016-01-01

were aware that chemotherapy could destroy their eggs. The participants described how specialized fertility counselling and fertility preservation contributed to a belief in life after cancer, which gave them hope that they would survive their cancer disease. Further, the women described how......Introduction: Fertility counselling for young women newly diagnosed with cancer is an important field of preconceptional counselling. This qualitative, small-scale study explored how young women newly diagnosed with cancer experienced specialized fertility preservation counselling and treatment...... in the public Danish health care system. Methods: Semi-structured, in-depth interviews were conducted with five women below 40 years recently diagnosed with cancer. All women received fertility counselling by a fertility specialist at the Fertility Clinic, University Hospital of Copenhagen, Denmark before...

Unrealized fertility: Fertility desires at the end of the reproductive career

Directory of Open Access Journals (Sweden)

John Casterline

2017-01-01

Full Text Available Background: 'Unrealized fertility' is a failure to achieve desired fertility. Unrealized fertility has been examined in low-fertility societies but, with the exception of research on infertility, has been neglected in research on non-Western societies. Objective: We conduct a multicountry investigation of one form of unrealized fertility, namely a reproductive career which ends with the woman desiring further children. Methods: We analyze 295,854 women aged 44‒48 in 252 surveys (DHS, RHS, PAP conducted in the period 1986-2015 in 78 countries. Two indicators of unrealized fertility are constructed: (i a comparison of ideal versus actual number of children; (ii the desire for another child. We estimate multilevel regressions with covariates at individual and aggregate levels. Results: Unrealized fertility is far more prevalent according to the first indicator than the second. It is more common among women with fewer living children and women whose first birth occurs after age 20, and it is distinctly higher in sub-Saharan Africa and lower in South Asia. The evidence on trend over the course of fertility transition is mixed: for the second indicator but not the first, the net effect is a reduction in the prevalence of unrealized fertility as fertility declines. Conclusions: Unrealized fertility occurs frequently in most societies and therefore deserves more rigorous research, especially on its consequences for emotional, social, economic, and demographic outcomes. Contribution: We provide the first comprehensive documentation of the prevalence of unrealized fertility across a broad set of contemporary non-Western societies.

[Percentage of births and fertility rates in adolescents in Mexico (2008-2012): stratification and priorization of municipalities with high risk].

Science.gov (United States)

Reyes-Pablo, Adelmo Eloy; Navarrete-Hernández, Eduardo; Canún-Serrano, Sonia; Valdés-Hernández, Javier

2015-12-01

Mexico in 2008 was designed as the first place of adolescent pregnancy at the Organization for Economic Cooperation and Development, with specific fertility rate (SFR) for 15-1 9years of age of 64.2/1,000 woman at the same age. Estimate of percentage births and SFR in adolescent population at national, state and municipal level in Mexico in 2008-2012 at the total group of adolescents 10 to 1 9 years old and by subgroups of 10-14 and 15 tol 9 years old, identifying the priority municipalities with adolescence pregnancies. Data bases of certificates of live birth and fetal death with gestational age of 22-45 weeks were joined in 2008-2012. A data base of 1 0'585,032 births in 2008-2012 was obtained, 98.9% were live births and 1.1% was stillbirths. The SFR nationwide for the period 2008-2012 were of the order of 3.l for the group of 10-1 4years, 75.3 for 15-19, 39.6 for the total group of 10-19 years and 66.1 for 20 to 49 years per 1000 women for the same age. In the last decade it has increased teen pregnancy as well as the percentage of births and the fertility rate in this age group, worrying situation for the high risk of biological, psychological and social damage that pregnancy early.

The fate of chromosomes and alleles in an allohexaploid Brassica population.

Science.gov (United States)

Mason, Annaliese S; Nelson, Matthew N; Takahira, Junko; Cowling, Wallace A; Alves, Gustavo Moreira; Chaudhuri, Arkaprava; Chen, Ning; Ragu, Mohana E; Dalton-Morgan, Jessica; Coriton, Olivier; Huteau, Virginie; Eber, Frédérique; Chèvre, Anne-Marie; Batley, Jacqueline

2014-05-01

Production of allohexaploid Brassica (2n = AABBCC) is a promising goal for plant breeders due to the potential for hybrid heterosis and useful allelic contributions from all three of the Brassica genomes present in the cultivated diploid (2n = AA, 2n = BB, 2n = CC) and allotetraploid (2n = AABB, 2n = AACC, and 2n = BBCC) crop species (canola, cabbages, mustards). We used high-throughput SNP molecular marker assays, flow cytometry, and fluorescent in situ hybridization (FISH) to characterize a population of putative allohexaploids derived from self-pollination of a hybrid from the novel cross (B. napus × B. carinata) × B. juncea to investigate whether fertile, stable allohexaploid Brassica can be produced. Allelic segregation in the A and C genomes generally followed Mendelian expectations for an F2 population, with minimal nonhomologous chromosome pairing. However, we detected no strong selection for complete 2n = AABBCC chromosome complements, with weak correlations between DNA content and fertility (r(2) = 0.11) and no correlation between missing chromosomes or chromosome segments and fertility. Investigation of next-generation progeny resulting from one highly fertile F2 plant using FISH revealed general maintenance of high chromosome numbers but severe distortions in karyotype, as evidenced by recombinant chromosomes and putative loss/duplication of A- and C-genome chromosome pairs. Our results show promise for the development of meiotically stable allohexaploid lines, but highlight the necessity of selection for 2n = AABBCC karyotypes.

Jobs and Kids: Female Employment and Fertility in Rural China

OpenAIRE

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

2010-01-01

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...

[Genetics of fertility restoration in the isocytoplasm allonuclear C-group of cytoplasmic male sterility in maize].

Science.gov (United States)

Zhao, Zhuo Fan; Huang, Ling; Liu, Yong Ming; Zhang, Peng; Wei, Gui; Cao, Mo Ju

2018-05-20

Maize is one of the first crops to produce hybrids using cytoplasmic male sterile lines. The C-type cytoplasmic male sterile (CMS-C) line is vital for hybrid seed production, and the fertility-restoration reaction along with its stability has a direct bearing on its applications. However, fertility restoration mechanism of CMS-C is complex and is still not clear so far. To further explore the factors affecting the fertility restoration of maize CMS, a series of test crosses were carried out by pollinating the isocytoplasm allonuclear CMS-C lines C48-2, Chuangzaosi and C478 with the test lines 18 bai, zi 330, 5022 and the restorer line A619, respectively. Four F 2 populations and six double-cross combinations were obtained from the self-cross of fertility restored F 1 and pollinating male-sterility-maintained F 1 with the male-fertility-restored F 1 , respectively. Meanwhile, we developed the incomplete diallel-cross combinations using the isocytoplasm allonuclear male sterile lines as maternal parents and their respective maintainer lines 48-2, huangzaosi and 478 as paternal parents. All the F 1 , F 2 and double-cross populations were planted at distinct locations in different years, and the fertility-restoration reaction was scored by field investigation and pollen staining with I 2 -IK. The results were as follows: 1) The same test line could restore the CMS-C line at a certain genetic background, but failed to restore the CMS-C line at the other genetic backgrounds, suggesting that the genetic background of CMS-C lines plays an important role in the fertility restoration. 2) The fertile-to-sterile segregation ratio of (C48-2×A619) F 2 population planted in both Sichuan and Yunnan fited well to 15:1 by the χ 2 test. However, the fertility level of individuals in Yunnan mainly belonged to the 3 and 4grades, but which in Sichuan mainly belonged to the 5 grade, indicating the environmental factors had effect on the fertility-restoration reaction of (C48-2×A619) F

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

Hoffmann, Hanne M; Mellon, Pamela L

2016-01-01

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

World population in transition.

Science.gov (United States)

Merrick, T W

1986-04-01

The world's population growth rate peaked at slightly over 2%/year in the late 1960s and in 1986 is down to 1.7% and falling. Annual numbers added continue to rise because these rates apply to a very large base, 4.9 billion in 1986. According to UN medium variant projections, world population growth will peak at 89 million/year in the late 1990s and then taper off until world population stabilizes in the late decade of the 21st century at about 10.2 billion. Close to 95% of this growth is occurring in less developed countries (LDCs) of Africa, Asia (minus Japan), and Latin America. LDC fertility rates are declining, except in sub-Saharan Africa and parts of Latin America and South Asia, but most have far to go to reach the replacement level of 2.1 births/woman. Fertility is below replacement in virtually all more developed countries. For LDCs, large numbers will be added before stabilization even after attainment of replacement level fertility because of the demographic momentum built into their large and young population bases. This complicates efforts to bridge gaps between living standards in LDCs and industrialized countries. From a new debate about whether rapid population growth deters or stimulates economic growth, a more integrated view has emerged. This view recognizes the complementary relationship between efforts to slow population growth and other development efforts; e.g., to improve health and education, upgrade women's status, increase productivity. Most effective in the increased contraceptive prevalence and fertility declines seen in many LDCs has been the combination of organized programs to increase access to family planning information and supplies with socioeconomic development that enhances the desire for smaller families.

Population and society in twentieth-century Southeast Asia.

Science.gov (United States)

Hirschman, C

1994-09-01

The historical demographic analysis in this article is a revision of a paper presented at the Conference of the Northwest Regional Consortium for Southeast Asian Studies in 1988 at the University of Oregon. The author takes the view that fertility has remained high in the Southeast Asian region due to the dynamics of colonialism and the reinforcement of traditional society. Industrialization, urbanization, and advancing education was not favored by colonial policy. The shift to planting cash crops was labor-intensive work which reinforced large families. The fertility decline after the 1960s is attributed to population pressure and the lower limits of land and production per family. Incentives for smaller families are identified as the expansion of mass education, increased consumer aspirations, and opportunities for modern sector employment. The impact of population growth is viewed as multidimensional and indicative of the conflicts between resources, obligations, and aspirations. The historical record in Southeast Asia reveals a population shortage and the risk of losing the minimum supply of labor necessary for a subsistence economy. Traditional local authorities were in need of men for waging war and producing an economic surplus. Colonial administrators imported cheap labor. As mortality declined and population increased, the societal response was migration, usually to frontier areas. New zones of wet rice production were created in lower Burma, central Siam, and Cochin China due to increased demand. Other survival strategies are identified as infinite land subdivision and multiple job holding in the off-season. Densely populated areas appeared to have lower fertility. Over the past 20 years the strategy appears to have been lower fertility coupled with acceptance of family planning, higher female educational attainment, and higher age at marriage. Southeast Asian patterns are considered indicative of the impact of wars, crises, and economic change on

JV Task-121 Electrochemical Synthesis of Nitrogen Fertilizers

Energy Technology Data Exchange (ETDEWEB)

Junhua Jiang; Ted Aulich

2008-11-30

An electrolytic renewable nitrogen fertilizer process that utilizes wind-generated electricity, N{sub 2} extracted from air, and syngas produced via the gasification of biomass to produce nitrogen fertilizer ammonia was developed at the University of North Dakota Energy & Environmental Research Center. This novel process provides an important way to directly utilize biosyngas generated mainly via the biomass gasification in place of the high-purity hydrogen which is required for Haber Bosch-based production of the fertilizer for the production of the widely used nitrogen fertilizers. Our preliminary economic projection shows that the economic competitiveness of the electrochemical nitrogen fertilizer process strongly depends upon the cost of hydrogen gas and the cost of electricity. It is therefore expected the cost of nitrogen fertilizer production could be considerably decreased owing to the direct use of cost-effective 'hydrogen-equivalent' biosyngas compared to the high-purity hydrogen. The technical feasibility of the electrolytic process has been proven via studying ammonia production using humidified carbon monoxide as the hydrogen-equivalent vs. the high-purity hydrogen. Process optimization efforts have been focused on the development of catalysts for ammonia formation, electrolytic membrane systems, and membrane-electrode assemblies. The status of the electrochemical ammonia process is characterized by a current efficiency of 43% using humidified carbon monoxide as a feedstock to the anode chamber and a current efficiency of 56% using high-purity hydrogen as the anode gas feedstock. Further optimization of the electrolytic process for higher current efficiency and decreased energy consumption is ongoing at the EERC.

[Population dynamics and development in the Caribbean].

Science.gov (United States)

Boland, B

1995-12-01

The impact is examined of socioeconomic factors on Caribbean population dynamics. This work begins by describing the socioeconomic context of the late 1980s and early 1990s, under the influence of the economic changes and crises of the 1980s. The small size, openness, dependency, and lack of diversification of the Caribbean economies have made them vulnerable to external pressures. The Bahamas and Belize had economic growth rates exceeding 5% annually during 1981-90, but most of the countries had low or negative growth. Unemployment, poverty, the structural adjustment measures adopted in the mid-1980s, and declines in social spending exacerbated general economic conditions. In broad terms, the population situation of the Caribbean is marked by diversity of sizes and growth rates. A few countries oriented toward services and tourism had demographic growth rates exceeding 3%, while at least 7 had almost no growth or negative growth. Population growth rates reflected different combinations of natural increase and migration. Crude death rates ranged from around 5/1000 to 11/1000, except in Haiti, and all countries of the region except Haiti had life expectancies of 70 years or higher. Despite fertility decline, the average crude birth rate was still relatively high at 26/1000, and the rate of natural increase was 1.8% annually for the region. Nearly half of the regional population was under 15 or over 65 years old. The body of this work provides greater detail on mortality patterns, variations by sex, infant mortality, causes of death, and implications for policy. The discussion of fertility includes general patterns and trends, age specific fertility rates, contraceptive prevalence, levels of adolescent fertility and age factors in adolescent sexual behavior, characteristics of adolescent unions, contraceptive usage, health and social consequences of adolescent childbearing, and the search for solutions. The final section describes the magnitude and causes of

High-resolution inventory of ammonia emissions from agricultural fertilizer in China from 1978 to 2008

Science.gov (United States)

Xu, P.; Liao, Y. J.; Lin, Y. H.; Zhao, C. X.; Yan, C. H.; Cao, M. N.; Wang, G. S.; Luan, S. J.

2016-02-01

The quantification of ammonia (NH3) emissions is essential to the more accurate quantification of atmospheric nitrogen deposition, improved air quality and the assessment of ammonia-related agricultural policy and climate mitigation strategies. The quantity, geographic distribution and historical trends of these emissions remain largely uncertain. In this paper, a new Chinese agricultural fertilizer NH3 (CAF_NH3) emissions inventory has been compiled that exhibits the following improvements: (1) a 1 × 1 km gridded map on the county level was developed for 2008; (2) a combined bottom-up and top-down method was used for the local correction of emission factors (EFs) and parameters; (3) the temporal patterns of historical time trends for 1978-2008 were estimated and the uncertainties were quantified for the inventories; and (4) a sensitivity test was performed in which a province-level disaggregated map was compared with CAF_NH3 emissions for 2008. The total CAF_NH3 emissions for 2008 were 8.4 TgNH3 yr-1 (a 6.6-9.8 Tg interquartile range). From 1978 to 2008, annual NH3 emissions fluctuated with three peaks (1987, 1996 and 2005), and total emissions increased from 3.2 to 8.4 Tg at an annual rate of 3.0 %. During the study period, the contribution of livestock manure spreading increased from 37.0 to 45.5 % because of changing fertilization practices and the rapid increase in egg, milk, and meat consumption. The average contribution of synthetic fertilizer, which has a positive effect on crop yields, was approximately 38.3 % (minimum: 33.4 %; maximum: 42.7 %). With rapid urbanization causing a decline in the rural population, the contribution of the rural excrement sector varied widely between 20.3 % and 8.5 %. The average contributions of cake fertilizer and straw returning were approximately 3.8 and 4.5 %, respectively, thus small and stable. Collectively, the CAF_NH3 emissions reflect the nation's agricultural policy to a certain extent. An effective approach to

Approximation to a model of sustainable fertilization in coffee

International Nuclear Information System (INIS)

Martinez, Francisco J

1999-01-01

In the actuality famous investigators of the agriculture think that the non-equilibrium and inconvenient inherent the chemical fertilizers are the result of the disorder produced by the high entropy of these fertilizers. In spite of that, much investigation's works increment the result without to decrease the chemical fertilizer doses in crops. The present work continues an investigation begun in 1994 in la Union town Department of Narino Colombia, about an organic fertilization alternative system and improvement of soils of coffee, with the purpose to find low doses of chemical fertilizers in combination with organic manures able to compete with the chemical conventional system. In the experiment found that low-middle doses of coffee pulp and production's fertilizers correspondent to 3 kg/coffee pulp/small boxes and 35 g/17-6-18-2/plant, produced 68 % more than the full doses of the module 2 of Cenicafe. The before result indicates that it's possible to decrease costs, to improve the quality and to increase significantly the coffee production, inclusive it can improve the environmental supply or history production, without high doses of chemical fertilizer

Is Buddhism the low fertility religion of Asia?

Directory of Open Access Journals (Sweden)

Vegard Skirbekk

2015-01-01

Full Text Available Background: The influence of religion on demographic behaviors has been extensively studied mainly for Abrahamic religions. Although Buddhism is the world's fourth largest religion and is dominant in several Asian nations experiencing very low fertility, the impact of Buddhism on childbearing has received comparatively little research attention. Objective: This paper draws upon a variety of data sources in different countries in Asia in order to test our hypothesis that Buddhism is related to low fertility. Methods: Religious differentials in terms of period fertility in three nations (India, Cambodia and Nepal and cohort fertility in three case studies (Mongolia, Thailand and Japan are analyzed. The analyses are divided into two parts: descriptive and multivariate analyses. Results: Our results suggest that Buddhist affiliation tends to be negatively or not associated with childbearing outcomes, controlling for education, region of residence, age and marital status. Although the results vary between the highly diverse contextual and institutional settings investigated, we find evidence that Buddhist affiliation or devotion is not related to elevated fertility across these very different cultural settings. Conclusions: Across the highly diverse cultural and developmental contexts under which the different strains of Buddhism dominate, the effect of Buddhism is consistently negatively or insignificantly related to fertility. These findings stand in contrast to studies of Abrahamic religions that tend to identify a positive link between religiosity and fertility.

Exploring the genetics of fertility restoration controlled by Rf1 in common wheat (Triticum aestivum L.) using high-density linkage maps.

Science.gov (United States)

Geyer, Manuel; Albrecht, Theresa; Hartl, Lorenz; Mohler, Volker

2018-04-01

Hybrid wheat breeding has the potential to significantly increase wheat productivity compared to line breeding. The induction of male sterility by the cytoplasm of Triticum timopheevii Zhuk. is a widely discussed approach to ensure cross-pollination between parental inbred lines in hybrid wheat seed production. As fertility restoration in hybrids with this cytoplasm is often incomplete, understanding the underlying genetics is a prerequisite to apply this technology. A promising component for fertility restoration is the restorer locus Rf1, which was first detected on chromosome 1A of the restorer accession R3. In the present study, we performed quantitative trait locus (QTL) analyses to locate Rf1 and estimate its effect in populations involving the restorer lines R3, R113 and L19. Molecular markers linked to Rf1 in these populations were used to analyse the genomic target region in T. timopheevii accessions and common wheat breeding lines. The QTL analyses revealed that Rf1 interacted with a modifier locus on chromosome 1BS and the restorer locus Rf4 on chromosome 6B. The modifier locus significantly influenced both the penetrance and expressivity of Rf1. Whereas Rf1 exhibited expressivity higher than that of Rf4, the effects of these loci were not additive. Evaluating the marker haplotype for the Rf1 region, we propose that the restoring Rf1 allele may be derived exclusively from T. timopheevii. The present study demonstrates that interactions between restorer and modifier loci play a critical role in fertility restoration of common wheat with the cytoplasm of T. timopheevii.

Plant-based fertilizers for organic vegetable production

DEFF Research Database (Denmark)

Sørensen, Jørn Nygaard; Thorup-Kristensen, Kristian

2011-01-01

To ensure high yield and quality in organic vegetable production, crops often require additional fertilizer applied during the season. Due to the risk of contamination of edible plant products from slurry, plant-based fertilizers may be used as an alternative. The purpose of our work was to develop...... fertility, the term “mobile green manures” is used for green-manure crops that are harvested in one field and then moved as a whole and used as fertilizer in other fields. To further investigate mobile-green-manure crops for use as efficient fertilizers, pot and field experiments were conducted...... with cauliflower (Brassica oleracea botrytis) and kale (Brassica oleracea sabellica) supplied with organic matter consisting of a wide range of plant species with varying nutrient concentrations. Further, field experiments were conducted with leek (Allium porrum) and celery (Apium graveolens dulce) supplied...

Young female cancer patients' experiences with fertility counselling and fertility preservation-a qualitative small-scale study within the Danish health care setting.

Science.gov (United States)

Hoeg, Didde; Schmidt, Lone; Macklon, Kirsten T

2016-07-14

Fertility counselling for young women newly diagnosed with cancer is an important field of preconceptional counselling. This qualitative, small-scale study explored how young women newly diagnosed with cancer experienced specialized fertility preservation counselling and treatment in the public Danish health care system. Semi-structured, in-depth interviews were conducted with five women below 40 years recently diagnosed with cancer. All women received fertility counselling by a fertility specialist at the Fertility Clinic, University Hospital of Copenhagen, Denmark before initiation of cancer treatment. Participants were interviewed at a place chosen by them, and interviews were recorded and transcribed verbatim. Data were analysed using systematic text condensation developed by Malterud and inspired by Giorgi's phenomenological analysis. None of the participants were aware that chemotherapy could destroy their eggs. The participants described how specialized fertility counselling and fertility preservation contributed to a belief in life after cancer, which gave them hope that they would survive their cancer disease. Further, the women described how the possibility of fertility preservation removed a huge concern and enabled them to concentrate on their cancer treatment and on getting better. Overall, the specialized fertility counselling and treatment to preserve fertility was highly valued. The women felt it gave them a choice about their future fertility. The fertility expert presented the various fertility-preserving scenarios, and the women were content that they had an actual choice.

Birth and fertility rates for states by Hispanic origin subgroups: United States, 1990 and 2000.

Science.gov (United States)

Sutton, Paul D; Mathews, T J

2006-05-01

This report presents U.S. and State-level data on births, birth rates, and fertility rates for Hispanic origin subgroups for 1990 and 2000. Data for non-Hispanic whites and non-Hispanic blacks are provided for comparison. Data are presented in detailed tables, graphs, and maps. Between 1990 and 2000, the total U.S. Hispanic population increased 58 percent, from 22,353,999 to 35,305,818. Over the same period of time, births to Hispanic mothers increased 37 percent, from 595,073 to 815,868. The smaller increases in births compared with the population resulted in a falling birth rate among Hispanic mothers (26.7 in 1990 to 23.1 births per 1,000 total population in 2000). Birth and fertility rates for Mexican, Puerto Rican, and Cuban mothers all fell between 1990 and 2000. Among the Hispanic subgroups, fertility rates in 2000 ranged from 105.1 births per 1,000 women aged 15-44 years for Mexican women to 49.3 for Cuban women. Differences in fertility exist not only between Hispanic subgroups but also within groups among States. For example, total fertility rates for Puerto Rican mothers, which estimates the number of children a group of 1,000 women will have in their lifetime, ranged in 2000 from 1,616.5 in New York to 2,403.0 in Pennsylvania.

Mental health outcomes of mothers who conceived using fertility treatment.

Science.gov (United States)

Raguz, Nikolett; McDonald, Sheila W; Metcalfe, Amy; O'Quinn, Candace; Tough, Suzanne C

2014-02-28

To compare the proportion of women with self-reported depression and anxiety symptoms at four months postpartum between mothers of singletons who conceived spontaneously and mothers who conceived with the aid of fertility treatment. The sample used for this study was drawn from The "All Our Babies Study", a community-based prospective cohort of 1654 pregnant women who received prenatal care in Calgary, Alberta. This analysis included women utilizing fertility treatment and a randomly selected 1:2 comparison group. The data was collected via three questionnaires, two of which were mailed to the participants during pregnancy and one at four months postpartum. Symptoms of depression and anxiety at four months postpartum were measured using the Edinburg Postnatal Depression Scale and the Spielberger State Anxiety Inventory. Secondary outcomes of parenting morale and perceived stress were also evaluated. Descriptive statistics were used to characterize the population. Chi square tests and in cases of small cell sizes, Fisher Exact Tests were used to assess differences in postpartum mental health symptomatology between groups. Seventy-six participants (5.9%) conceived using a form of fertility treatment. At four months postpartum, no significant differences were observed in the proportions reporting excessive depression symptoms (2.6% vs. 5.3%, p = 0.50), anxiety (8.1% vs. 16.9%, p = 0.08) or high perceived stress scores (7.9% vs. 13.3%, p = 0.23). Women who conceived with fertility treatment were less likely to score low on parenting morale compared to women who conceived spontaneously and this was particularly evident in primiparous women (12.5% vs. 33.8%, p = 0.01). There were no group differences in proportions reporting low parenting morale in multiparous women. This study suggests that at four months postpartum, the proportion of women who experience elevated symptoms of depression, anxiety or perceived stress do not differ between mothers who

An investigation of women's attitudes towards fertility and China's family planning policy.

Science.gov (United States)

Cao, Shixiong; Tian, Tao; Qi, Fan; Ma, Li; Wang, Guosheng

2010-05-01

Reducing China's population has formerly been considered a good thing because of the perceived environmental and social risks of overpopulation, but it has recently become apparent that the resulting population decline may create problems that will become increasingly serious in the future. The results of a survey of 4600 women in nineteen Chinese provinces in 2005 indicated that young age, high income, high education level, urban location and good employment all decreased a woman's willingness to bear children. The risks created by declining fertility in these groups have been intensified by China's 'one child' family planning policy. However, as a result of current trends and China's policies, the country's population will continue to age, leading to social problems and difficulties for sustainable development both in China and around the world. Therefore, China's policy-makers must begin planning to adjust their policy by encouraging women to give birth to more than one child.

Radiation doses from phosphate fertilizers

International Nuclear Information System (INIS)

Anon.

1975-01-01

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

Natural radioactivity in phosphate fertilizers

International Nuclear Information System (INIS)

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

1974-12-01

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

Kerala reaps low fertility dividends.

Science.gov (United States)

1992-01-01

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.

[Relationships between psychological well-being, lifestyle factors and fertility].

Science.gov (United States)

Lakatos, Enikő; Szabó, Gábor; F Szigeti, Judit; Balog, Piroska

2015-03-22

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.

Heritable effect of plant water availability conditions on restoration of male fertility in the ‘9E’ CMS-inducing cytoplasm of sorghum

Directory of Open Access Journals (Sweden)

Lev Aleksandrovich Elkonin

2012-05-01

Full Text Available Heritable changes of phenotype arising in plant ontogenesis by the influence of environmental factors belong to the most intriguing genetic phenomena. Studying restoration of male fertility in the ‘9E’ type of CMS-inducing cytoplasm of sorghum and related CMS-inducing cytoplasms, A4 and M35-1A, in some hybrid combinations, we found an unusual inheritance pattern: the Rf-genes functioned in the self-pollinated progenies of F1 hybrids (up to F10 but did not or poorly expressed in backcrosses of these hybrids to CMS-lines with the same cytoplasm type. In experiments on parallel growing of the same F1 hybrid combinations in the ‘dry plot’ and in the ‘irrigated plot’, it was found that high level of plant water availability during panicle and pollen developmental stages significantly increased male fertility of F1 and testcross hybrid populations, in which fertility-restoring genes were in heterozygote state, whereas in F2 populations the influences of water availability conditions cause less pronounce effects. Similarly, male-sterile F1 plants, being transferred from the ‘dry plot’ to greenhouse, produced male-fertile panicles. In addition, male-sterile plants from F2 families, which segregated-out as recessives, being transferred to greenhouse also produced male-fertile panicles. In the progenies of these revertants that were grown in field conditions and in the ‘dry plot’, stable inheritance of male fertility for 3 cycles of self-pollination was observed, and a number of stable fertile lines in the ‘9E’ cytoplasm were obtained. However, in test-crosses of these fertile lines to CMS-lines with the ‘9E’ cytoplasm restoration of male fertility was not observed, except the progeny of one revertant that behaved as fertility-restorer line. These data suggest that the functional state of fertility-restoring genes for the ‘9E’ sorghum cytoplasm is epigenetically-regulated trait established by the influence of environmental

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...

The effects of 15N-fertilizer on the yields of wheat

International Nuclear Information System (INIS)

Zhou Dechao

1985-01-01

By using 15 N-fertilizer, the effects of increasing yield and the utilization of nitrogen of N-fertilizer applied at different periods and by different methods on wheat were studied. The results were as follows: The utilization of N-fertilizer by winter wheat is dependent on the fertilizer of soil before or after winter. Strong seedlings were obtained in the high fertility soils and the application of N-fertilizer in spring is recommended. In soils of low fertility, however, application of a part of N-fertilizer before winter is recommded in order to get strong seedlings. Application of a part of N-fertilizer as base manure for spring wheat is more advantageous. Deep application of N-fertilizer losses less NH 3 than surface broadcast does

Fertility preservation in young cancer patients

Directory of Open Access Journals (Sweden)

Ariel Revel

2010-01-01

Full Text Available As a result of advances in treatment, almost 80% of children and adolescents who receive a diagnosis of cancer become long-term survivors. The increased survival rate of children and adolescents with cancer has resulted in a major interest in the long-term effects of cancer treatment on the possibility for future fertility. Currently established methods for the preservation of fertility are available only for pubertal males and females. Pubertal male cancer patients should be encouraged to freeze numerous sperm samples even when sperm count and motility are poor. In these cases, intracytoplasmic sperm injection is a powerful technique compared with intrauterine insemination since thawed sperm samples with poor parameters can produce relatively high fertilization rates resulting in normal pregnancies and deliveries. Married pubertal women should be proposed ovulation induction, follicular aspiration, and fertilization with husband sperm. Single women could benefit from vitrification of oocytes. This requires a delay of about 3 weeks in the commencement of chemotherapy to enable follicular growth. Fertility preservation for prepubertal patients is more of a problem. Young girls could be offered cryopreservation of gametes in the gonadal tissue. Cryopreservation of testicular tissue was suggested for fertility preservation for young boys, but this method is totally experimental and not currently offered. Discussing future fertility is part of the consultation of young female and male patients facing potentially gonadotoxic cancer therapy. It is the role of reproductive specialists to create various options in their laboratory to preserve fertility potential of cancer patients.

Patriarchy and fertility in Albania

Directory of Open Access Journals (Sweden)

Mathias Lerch

2013-07-01

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.

Radiometric Analysis Of Different Fertilizers Consumed In Egypt

International Nuclear Information System (INIS)

El-Bahi, S.M.; Sroor, A.T.; Mousa, W.M.; Abd El-Halim, E.S.; Shenoda, A.A.

2014-01-01

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, namely 226 Ra, 232 Th and 40 K, in different chemical fertilizers used in agricultural soil were analyzed using gamma spectrometry with a high purity germanium (HPGe) detector in order to assess the implications of the extended use of phosphate fertilizers in recent years. The radium equivalent activity (Raeq), external hazard index (Hex) and absorbed dose in air for all samples were calculated. The 226 Ra content was very high for some samples under investigation and was found to vary from 33.41 Bq/kg to 1162.39 Bq/kg. This can result in a significant radiation exposure if the rock and fertilizer are handled in places with poor ventilation that could lead to radon accumulation. The concentrations of eight elements (Cd, Cu, Fe, Mg, Mn, Ni, Pb and Zn) in the samples under investigation were determined by flame atomic absorption spectrometer (FAAS). The results showed that the fertilizer samples contained less heavy metals than those used in world wide. Accepted May 2014.

Genetic alterations affecting cholesterol metabolism and human fertility.

Science.gov (United States)

DeAngelis, Anthony M; Roy-O'Reilly, Meaghan; Rodriguez, Annabelle

2014-11-01

Single nucleotide polymorphisms (SNPs) represent genetic variations among individuals in a population. In medicine, these small variations in the DNA sequence may significantly impact an individual's response to certain drugs or influence the risk of developing certain diseases. In the field of reproductive medicine, a significant amount of research has been devoted to identifying polymorphisms which may impact steroidogenesis and fertility. This review discusses current understanding of the effects of genetic variations in cholesterol metabolic pathways on human fertility that bridge novel linkages between cholesterol metabolism and reproductive health. For example, the role of the low-density lipoprotein receptor (LDLR) in cellular metabolism and human reproduction has been well studied, whereas there is now an emerging body of research on the role of the high-density lipoprotein (HDL) receptor scavenger receptor class B type I (SR-BI) in human lipid metabolism and female reproduction. Identifying and understanding how polymorphisms in the SCARB1 gene or other genes related to lipid metabolism impact human physiology is essential and will play a major role in the development of personalized medicine for improved diagnosis and treatment of infertility. © 2014 by the Society for the Study of Reproduction, Inc.

Genetic monitoring of irradiated Drosophila populations treated with antimutagen melanine

International Nuclear Information System (INIS)

Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

1986-01-01

It was shown that viability of irradiated Drosophila is, on an average, lower than in intact populations. The fertility first decreases then increases exceeding the control level. Melanine added to the diet increases fertility and viability of both exposed and intact Drosophila populations

Use of organic fertilizer and bio fertilizer in a modern planting system to increase the productivity of vanilla plant

International Nuclear Information System (INIS)

Ahmad Nazrul Abd Wahid; Phua Choo Kwai Hoe; Shyful Azizi Abdul Rahman; Mohd Fajri Osman; Latiffah Noordin; Abdul Razak Ruslan; Maizatul Akmam Mhd Nasir; Hazlina Abdullah; Amirul Azmi Supuan; Misman Sumin; Ahamad Sahali Mardi; Khairuddin Abdul Rahim

2010-01-01

Vanilla is a plant belonging to the orchid family and native to Mexico. In Malaysia, research and cultivation of vanilla plants are becoming more popular and intensive because the plant has a high commercial value. Fertilizing of vanilla plants is important to enhance the nutrients needed by the plants for growth and vanilla pod production. In 1999, research in MARDI showed that the use of chemical fertilizer NPK (15:15:15) was suitable for vanilla plants. For plants that have not produced vanilla pods foliar fertilizer must be sprayed and foliar fertilizer application must be reduced at pod production stage. The fertilizer programme is almost similar to those of other vanilla producing countries such as Indonesia and Mexico. In Indonesia, studies on organic farming of vanilla have been conducted. They have produced chemical-free vanilla fertilizer products such as Bio-Fob, Bio-TRIBA and Organo TRIBA Compost. We in Malaysian Nuclear Agency conducted a study on the effects of organic and bio fertilizers on vanilla at the vanilla experimental plot. This plot adopts the modern system of vanilla planting. The study involved the use of organic and bio fertilizer products produced in Nuclear Malaysia such as Organik NF, plant growth promoter and phosphate solubiliser and imported commercial orchid mycorrhizal bio fertilizer from Korea. The application of these fertilizers is by placing the fertilizers on the planting media in poly bags with replications according to the treatments. Observations were made weekly for 15 weeks by measuring of parameters including the bud growth and leaf number. These data are plotted in graphical form for evaluation.(author)

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

Science.gov (United States)

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

2017-06-01

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.

Population growth is a variable open to change

Science.gov (United States)

Potts, M.

2016-12-01

The absolute number of people and the rate of population growth have an impact on climate mitigation, adaptation and possible conflict. Half the pregnancies in the US are unintended. Robust quantitative evidence from California demonstrates that improving access to family planning is the single most cost-effective way of mitigating our carbon footprint. Globally, there are 80 million unintended pregnancies annually. Many non-evidence barriers deprive women of the information and means required to separate sex from childbearing. Between 1960 and 1990, meeting the need for family planning led to a rapid fall in family size in much of Asia. Since 1990, funding for family planning has collapsed and fertility decline has stalled. The UN projects that by 2100 global population will increase by 3.8 billion (equal to world population in 1975). 80% of this growth will be in Africa. Studies project that climate change will undermine crop yields in parts of Africa, especially the Sahel. A high ratio of young males to the rest of the population is a risk factor in conflict. Today, only 1% of overseas assistance is allocated to family planning. Based on analysis of the past, doubling that investment would accelerate fertility decline, facilitating climate mitigation and adaptation, and possibly reducing conflict. Population and family planning were pushed off the international agenda by unacceptably and tragic episodes of coercion in China and India. However, there is compelling data that when voluntary family planning is widely available then family size can fall rapidly, as occurred in the Islamic Republic of Iran, where fertility fell more rapidly than in any other country in history. Family planning is listening to what women want not telling people want to do. Population growth is a variable open to change in a human rights framework. Population and family planning are variables relevant to the scientific agenda of the AGU.

Social policy and population growth in South-East Asia.

Science.gov (United States)

You Poh Seng Rao, B; Shantakumar, G

1974-01-01

Social and population policies are considered for the 10 countries comprising Southeast Asia--Burma, Indonesia, the Khmer Republic, Laos, Malaysia, the Philippines, Singapore, Thailand, North Vietnam, and South Vietnam. All but Singapore have high fertility rates and Burma, Indonesia, the Khmer Republic, Laos and the two Vietnams have high mortality rates also. Government expenditures for education and social security systems is expanding throughout the region and it is hoped that their continued growth will contribute substantially to the effective implementation of population policies. Population policies in the 5 countries which have them are discussed. These are Indonesia, Malaysia, the Philippines, Singapore, and Thailand. It is noted, however, that declaration of policy is but the first step. Strategies and programs differ from one country to the next and depend very much on the stage of development, level of literacy, degree of urbanization, and other factors. Family planning activities generally are endogenous to urban social systems but exogenous to rural social systems. Thus, the rural elite has a large role to play in making population policies an integral part of rural life. The possibility is considered of developing workable incentive packages integrating health, education, and social security benefits with suitable emphasis on fertility reduction.

Fertility awareness online: the efficacy of a fertility education website in increasing knowledge and changing fertility beliefs.

Science.gov (United States)

Daniluk, J C; Koert, E

2015-02-01

How effective is online education in increasing knowledge of fertility and assisted reproductive technologies (ART), and changing beliefs about the timing of parenthood? Exposure to an online educational intervention resulted in immediate changes in participants' beliefs about the ideal timing of parenthood, and a significant increase in their knowledge of fertility and ART treatments and options; most of these changes were not sustained over time, particularly for men. Research has identified significant gaps in men's and women's knowledge of fertility and ART, contributing to the trend to delay childbearing. Effective educational programs need to be developed, to support informed fertility and child-timing decisions. Pre-post intervention study of 199 currently childless men and women, and a 6-month follow-up of 110 of these participants. One hundred and ninety-nine childless participants between the ages of 18 and 35 were asked to complete 4 beliefs and 22 knowledge questions prior to, and immediately after, reading 10 online posts related to: fertility testing and preservation, fertility history and lifespan, the effects of health and fitness on fertility, and assisted reproduction. Six months later, 110 of the original sample repeated the 26-item survey. Participants' fertility and ART knowledge scores increased significantly immediately after the intervention, as did their confidence in their fertility and ART knowledge. Participants' beliefs about the ideal and latest age a woman or man should consider producing a child decreased. However, 6 months later, participants' beliefs and knowledge levels largely returned to their pre-intervention levels, particularly for the men in the study. The sample size and the recruitment methods may limit the generalizability of these findings. Previous studies have demonstrated the short-term efficacy of online educational approaches to increase fertility knowledge and support informed family planning decisions. Web

Degradation of soil fertility can cancel pollination benefits in sunflower.

Science.gov (United States)

Tamburini, Giovanni; Berti, Antonio; Morari, Francesco; Marini, Lorenzo

2016-02-01

Pollination and soil fertility are important ecosystem services to agriculture but their relative roles and potential interactions are poorly understood. We explored the combined effects of pollination and soil fertility in sunflower using soils from a trial characterized by different long-term input management in order to recreate plausible levels of soil fertility. Pollinator exclusion was used as a proxy for a highly eroded pollination service. Pollination benefits to yield depended on soil fertility, i.e., insect pollination enhanced seed set and yield only under higher soil fertility indicating that limited nutrient availability may constrain pollination benefits. Our study provides evidence for interactions between above- and belowground ecosystem services, highlighting the crucial role of soil fertility in supporting agricultural production not only directly, but also indirectly through pollination. Management strategies aimed at enhancing pollination services might fail in increasing yield in landscapes characterized by high soil service degradation. Comprehensive knowledge about service interactions is therefore essential for the correct management of ecosystem services in agricultural landscapes.