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Sample records for nonmarital fertility relates

  1. Nonmarital Fertility and the Effects of Divorce Rates on Youth Suicide Rates

    Science.gov (United States)

    Messner, Steven F.; Bjarnason, Thoroddur; Raffalovich, Lawrence E.; Robinson, Bryan K.

    2006-01-01

    Using pooled, time-series data for a sample of 15 developed nations, we assess the effect of divorce rates on gender-specific suicide rates for youths aged 15-19 with models of relative cohort size, lagged nonmarital fertility, and an interaction term for divorce rates and nonmarital fertility. The results reveal that, for young men, relative…

  2. Nonmarital Fertility, Union History, and Women's Wealth.

    Science.gov (United States)

    Painter, Matthew; Frech, Adrianne; Williams, Kristi

    2015-02-01

    We use more than 20 years of data from the National Longitudinal Survey of Youth 1979 to examine wealth trajectories among mothers following a nonmarital first birth. We compare wealth according to union type and union stability, and we distinguish partners by biological parentage of the firstborn child. Net of controls for education, race/ethnicity, and family background, single mothers who enter into stable marriages with either a biological father or stepfather experience significant wealth advantages over time (more than $2,500 per year) relative to those who marry and divorce, cohabit, or remain unpartnered. Sensitivity analyses adjusting for unequal selection into marriage support these findings and demonstrate that race (but not ethnicity) and age at first birth structure mothers' access to later marriage. We conclude that not all single mothers have equal access to marriage; however, marriage, union stability, and paternity have distinct roles for wealth accumulation following a nonmarital birth.

  3. Single Mothers, Single Fathers: Gender Differences in Fertility after a Nonmarital Birth

    OpenAIRE

    Guzzo, Karen Benjamin; Hayford, Sarah R.

    2010-01-01

    Research on nonmarital fertility has focused almost exclusively on unmarried mothers, due in part to a lack of fertility information for men. Cycle 6 of the National Survey of Family Growth allows exploration of nonmarital fertility for both genders. We compare the characteristics of unmarried first-time mothers (n = 2,455) and fathers (n = 797), use event history techniques to model second birth hazards, and examine the distribution of men’s and women’s second births across types of relation...

  4. Single Mothers, Single Fathers: Gender Differences in Fertility after a Nonmarital Birth

    Science.gov (United States)

    Guzzo, Karen Benjamin; Hayford, Sarah R.

    2010-01-01

    Research on nonmarital fertility has focused almost exclusively on unmarried mothers, due in part to a lack of fertility information for men. Cycle 6 of the National Survey of Family Growth allows exploration of nonmarital fertility for both genders.The authors compare the characteristics of unmarried first-time mothers (n = 2,455) and fathers (n…

  5. Single Mothers, Single Fathers: Gender Differences in Fertility after a Nonmarital Birth

    Science.gov (United States)

    Guzzo, Karen Benjamin; Hayford, Sarah R.

    2010-01-01

    Research on nonmarital fertility has focused almost exclusively on unmarried mothers, due in part to a lack of fertility information for men. Cycle 6 of the National Survey of Family Growth allows exploration of nonmarital fertility for both genders.The authors compare the characteristics of unmarried first-time mothers (n = 2,455) and fathers (n…

  6. Cohabitation, post-conception unions, and the rise in nonmarital fertility.

    Science.gov (United States)

    Lichter, Daniel T; Sassler, Sharon; Turner, Richard N

    2014-09-01

    The majority of U.S. nonmarital births today are to cohabiting couples. This study focuses on transitions to cohabitation or marriage among pregnant unmarried women during the period between conception and birth. Results using the newly-released 2006-2010 National Survey of Family Growth show that nonmarital pregnancy is a significant precursor to cohabitation before childbirth (18%), exceeding transitions to marriage (5%) by factor of over three. For pregnant women, the boundaries between singlehood, cohabitation, and marriage are highly fluid. The results also reveal substantial variation in post-conception cohabiting and marital unions; e.g., disproportionately low percentages of black single and cohabiting women transitioned into marriage, even when conventional social and economic risk factors are controlled. The multivariate analyses also point to persistent class differences in patterns of family formation, including patterns of cohabitation and marriage following conception. Poorly educated women, in particular, are much more likely to become pregnant as singles living alone or as partners in cohabiting unions. But compared with college-educated women, pregnancies are less likely to lead to either cohabitation or marriage. This paper highlights the conceptual and technical challenges involved in making unambiguous interpretations of nonmarital fertility during a period of rising nonmarital cohabitation.

  7. Socioeconomic Variation in the Effect of Economic Conditions on Marriage and Nonmarital Fertility in the United States: Evidence From the Great Recession.

    Science.gov (United States)

    Schneider, Daniel; Hastings, Orestes P

    2015-12-01

    The United States has become increasingly characterized by stark class divides in family structure. Poor women are less likely to marry than their more affluent counterparts but are far more likely to have a birth outside of marriage. Recent theoretical and qualitative work at the intersection of demography and cultural sociology suggests that these patterns are generated because poor women have high, nearly unattainable, economic standards for marriage but make a much weaker connection between economic standing and fertility decisions. We use the events of the Great Recession, leveraging variation in the severity of the crisis between years and across states, to examine how exposure to worse state-level economic conditions is related to poor women's likelihood of marriage and of having a nonmarital birth between 2008 and 2012. In accord with theory, we find that women of low socioeconomic status (SES) exposed to worse economic conditions are indeed somewhat less likely to marry. However, we also find that unmarried low-SES women exposed to worse economic conditions significantly reduce their fertility; economic standing is not disconnected from nonmarital fertility. Our results suggest that economic concerns were connected to fertility decisions for low-SES unmarried women during the Great Recession.

  8. Nonmarital Fertility, Family Structure, and the Early School Achievement of Young Children from Different Race/Ethnic and Immigration Groups

    Science.gov (United States)

    Crosnoe, Robert; Wildsmith, Elizabeth

    2011-01-01

    Working from a life course perspective, this study examined the links between mothers' fertility and relationship statuses and children's early school achievement and how these links varied by race/ethnicity and immigration status. Analyses of nationally representative data from the Early Childhood Longitudinal Study-Kindergarten Cohort revealed…

  9. Religiosity and the Transition to Nonmarital Parity

    Science.gov (United States)

    Smith, Scott James

    2014-01-01

    Nonmarital parity is associated with several negative outcomes, including health problems, educational problems, and poverty. Understanding the risk and protective factors associated with nonmarital parenthood can inform policy and interventions, reducing both the incidences and associated consequences. The current study focuses on how intrinsic and extrinsic religiosity (the degree to which individuals or groups employ religious ideology in forming values and making decisions) are related to the timing of nonmarital parity using discrete time hazard modeling of a nationally representative sample of adolescent females (N=7,367) from the National Longitudinal Study of Adolescent Health. The majority of the sample (86 %) claimed a religious affiliation and almost a third (32 %) had a nonmarital birth during the study. Even though the majority of the sample is White (67 %), Black and Hispanic females were more likely to experience a nonmarital birth. Results indicate that intrinsic and extrinsic religiosity and religious affiliation assert protective effects for some populations while religious affiliation increases risk in the full model. Recommendations for policy, intervention, and future research are offered. PMID:25298755

  10. Non-marital pregnancy and the second demographic transition in Australia in historical perspective

    Directory of Open Access Journals (Sweden)

    Gordon Carmichael

    2014-03-01

    Full Text Available Background: Australia has remarkably detailed data on non-marital pregnancy dating from 1908. They both offer insight into long-term trends in childbearing resulting from non-marital sexual activity and reveal in historical context key features of the second demographic transition and its genesis. Objective: Trends are traced in rates of non-marital conception of children ultimately born both outside and within marriage. A range of related indices is also presented in examining how demographic behaviour surrounding non-marital pregnancy (i helped generate the second demographic transition and (ii unfolded as a component of it. Methods: Core indices are rates of non-marital conception partitioned into additive components associated with marital and non-marital confinement. Data on non-marital and early marital births (at marriage durations 0-7 months are lagged back 38 weeks to a date of and age at conception basis to facilitate a common, unmarried, population at risk. Results: Post-war weakening of parental oversight of courtship was a fundamental trigger to the broader rejection of normative and institutional values that underpinned the second demographic transition. In tandem with denying the unmarried access to oral contraception it generated rampant youthful non-marital pregnancy, which undermined Judeo-Christian values, especially once abortion law reform occurred. Conclusions: Childbearing following non-marital conception transitioned rapidly after the 1960s from primarily the unintended product of youthful intercourse in non-coresidential relationships to mainly intended behaviour at normative reproductive ages in consensual unions. Family formation increasingly mixed non-marital births and premaritally and/or maritally conceived marital births.

  11. Maybe I Do: Interpersonal Commitment and Premarital or Nonmarital Cohabitation

    Science.gov (United States)

    Stanley, Scott M.; Whitton, Sarah W.; Markman, Howard J.

    2004-01-01

    Explanations for the risks associated with premarital and nonmarital cohabitation (e.g., higher rates of breakup and divorce, lower relationship satisfaction, and greater risk for violent interaction) have focused on levels of conventionality, including attitudes about commitment to the institution of marriage. However, relatively little attention…

  12. Recent Trends and Variations in Nonmarital Childbearing.

    Science.gov (United States)

    Ventura, Stephanie

    1997-01-01

    Describes the increase in nonmarital childbearing in the United States in the past 50 years. Considers age differences in nonmarital childbearing and the disproportionate numbers of poorly educated unmarried mothers. Maintains that changes in sexual behavior of unmarried people and declines in marriages of unmarried pregnant women contributed to…

  13. Mothers' Repartnering after a Nonmarital Birth

    Science.gov (United States)

    Bzostek, Sharon H.; McLanahan, Sara S.; Carlson, Marcia J.

    2012-01-01

    This article examines the prevalence, predictors and outcomes of unmarried mothers' repartnering patterns following a nonmarital birth. Results indicate that, within five years after a birth, approximately two-thirds of unmarried mothers end their relationship with the focal child's biological father, and more than half of these mothers enter new…

  14. University Students' Experiences of Nonmarital Breakups: A Grounded Theory

    Science.gov (United States)

    Hebert, Sarah; Popadiuk, Natalee

    2008-01-01

    Prior nonmarital breakup research has been focused on negative outcomes, rarely examining the personal growth aspects of this experience. In this study, we used a qualitative grounded theory methodology to explore the changes that university students reported experiencing as a result of a heterosexual nonmarital breakup and how those changes…

  15. The relationship between academic achievement and nonmarital teenage childbearing: evidence from the panel study of income dynamics.

    Science.gov (United States)

    Lou, Cary; Thomas, Adam

    2015-06-01

    Females who do well in school are less likely than those who do poorly to experience a nonmarital teenage birth. However, little is known about which dimensions of academic achievement are the most strongly related to teenage childbearing, or about whether the relationship between achievement and childbearing varies according to the presence of other behavioral problems. Individual-level and family-level data from the Panel Study of Income Dynamics, combined with information on contextual state-level economic and policy measures, were used to study nonmarital childbearing between the ages of 16 and 19 among 701 females who turned 16 between 2000 and 2007. Multivariate logistic regression analyses examined the relationship between the probability of nonmarital teenage childbearing and age-standardized scores on academic assessments of letter-word identification, passage comprehension and applied problem-solving ability. Scores on the passage comprehension and applied problem-solving subtests were strongly associated with the probability of experiencing a nonmarital teenage birth among respondents who had relatively few behavioral problems. For this group, an increase of one standard deviation in the score on either assessment was associated with a reduction of about 50% in the risk of experiencing a nonmarital teenage birth. However, no evidence was found of an equivalent relationship among respondents with more pronounced behavioral problems or for the letter-word identification assessment. Future research should continue to explore the possibility that improvements in academic achievement may help to reduce the rate of nonmarital teenage childbearing. Copyright © 2015 by the Guttmacher Institute.

  16. Pornography consumption and non-marital sexual behaviour in a sample of young Indonesian university students

    DEFF Research Database (Denmark)

    Hald, Gert Martin; Mulya, Teguh Wijaya

    2013-01-01

    Using a sample of Indonesian university students and a cross sectional design, this study investigated prevalence rates and patterns of pornography consumption in Indonesia, a religious, sexually conservative, Muslim-majority nation with strict anti-pornography laws. Further, the association...... between pornography consumption and common non-marital sexual behaviours was explored. The study found that in this sample, pornography is as widely and readily consumed as in comparable international studies predominantly utilising Western background samples from more sexually liberal and less religious...... countries with very few laws on pornography. Gender differences in patterns of pornography consumption were pronounced and comparable with findings in international counterpart studies. For men only, pornography consumption was found to significantly predict common sexual behaviours in non-marital relations...

  17. Pornography consumption and non-marital sexual behaviour in a sample of young Indonesian university students.

    Science.gov (United States)

    Hald, Gert Martin; Mulya, Teguh Wijaya

    2013-01-01

    Using a sample of Indonesian university students and a cross sectional design, this study investigated prevalence rates and patterns of pornography consumption in Indonesia, a religious, sexually conservative, Muslim-majority nation with strict anti-pornography laws. Further, the association between pornography consumption and common non-marital sexual behaviours was explored. The study found that in this sample, pornography is as widely and readily consumed as in comparable international studies predominantly utilising Western background samples from more sexually liberal and less religious countries with very few laws on pornography. Gender differences in patterns of pornography consumption were pronounced and comparable with findings in international counterpart studies. For men only, pornography consumption was found to significantly predict common sexual behaviours in non-marital relations. The study is the first to provide insights into prevalence rates and patterns of pornography consumption and its association with common non-marital sexual behaviours in a sexually conservative, Muslim-majority nation with strict anti-pornography laws.

  18. Environmental Issues Related to Chemical Fertilizer Use in China

    Institute of Scientific and Technical Information of China (English)

    CAOZHIHONG

    1996-01-01

    The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use.On the one hand.the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs.On the other hand.the production and consumption of chemical fertilizers in China are obviously not balanced.In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies.Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasuing soil productivity and keeping sustainable agriculture development but also in minimizing their detrimental effects on the environment.

  19. Age-Related Factors That Influence Fertility

    Science.gov (United States)

    ... can be found at the NICHD Pregnancy Loss topic page . Committee on Gynecologic Practice of American College of ... 2012, from http://www.nichd.nih.gov/health/topics/pregnancyloss/researchinfo/Pages/default.aspx [top] « Lifestyle Factors That Influence Fertility ...

  20. Neighborhood Poverty and Nonmarital Fertility: Spatial and Temporal Dimensions

    Science.gov (United States)

    South, Scott J.; Crowder, Kyle

    2010-01-01

    Data from 4,855 respondents to the Panel Study of Income Dynamics were used to examine spatial and temporal dimensions of the effect of neighborhood poverty on teenage premarital childbearing. Although high poverty in the immediate neighborhood increased the risk of becoming an unmarried parent, high poverty in surrounding neighborhoods reduced…

  1. NEIGHBORHOOD POVERTY AND NONMARITAL FERTILITY: SPATIAL AND TEMPORAL DIMENSIONS

    OpenAIRE

    South, Scott J.; Crowder, Kyle

    2010-01-01

    Data from 4,855 respondents to the Panel Study of Income Dynamics were used to examine spatial and temporal dimensions of the effect of neighborhood poverty on teenage premarital childbearing. Although high poverty in the immediate neighborhood increased the risk of becoming an unmarried parent, high poverty in surrounding neighborhoods reduced this risk. The effect of local neighborhood poverty was especially pronounced when surrounding neighborhoods were economically advantaged. Measuring e...

  2. Fertility-related research needs among women at the margins.

    Science.gov (United States)

    Schwartz, Sheree R; Baral, Stefan

    2015-05-01

    Fertility-related research encompasses fertility intentions, preconception care, research amongst pregnant women, and post-partum outcomes of mothers and children. However, some women remain under-represented within this domain of study. Women frequently missing within fertility-related research include those who are already the most vulnerable to health disparities, including female sex workers, lesbian, gay, bisexual, and transgender women, women living with HIV, and women who use drugs. Yet characterization of the needs of these women is important, given their unique fertility-related concerns, including risks and barriers to care emanating from social stigmas and discrimination. This synthesis provides an overview of fertility-related evidence, highlighting where there are clear research gaps among marginalized women and the potential implications of these data shortfalls. Overall, research among marginalized women to date has addressed pregnancy prevention and in some cases fertility intentions, but the majority of studies have focused on post-conception pregnancy safety and the well-being of the child. However, among female sex workers specifically, data on pregnancy safety and the well-being of the child are largely unavailable. Within each marginalized group, preconception care and effectiveness of conception methods are consistently understudied. Ultimately, the absence of epidemiologic, clinical and programmatic evidence limits the availability and quality of reproductive health services for all women and prevents social action to address these gaps. Copyright © 2015. Published by Elsevier Ltd.

  3. Nonmarital Childbearing, Union History, and Women's Health at Midlife.

    Science.gov (United States)

    Williams, Kristi; Sassler, Sharon; Frech, Adrianne; Addo, Fenaba; Cooksey, Elizabeth

    2011-06-01

    Despite high rates of nonmarital childbearing in the U.S., little is known about the health of women who have nonmarital births. We use data from the NLSY79 to examine differences in age 40 self-assessed health between women who had a premarital birth and those whose first birth occurred within marriage. We then differentiate women with a premarital first birth according to their subsequent union histories and estimate the effect of marrying or cohabiting versus remaining never-married on midlife self-assessed health, paying particular attention to the paternity status of the mother's partner and the stability of marital unions. To partially address selection bias, we employ multivariate propensity score techniques. Results suggest that premarital childbearing is negatively associated with midlife health for white and black (but not Hispanic) women. We find no evidence that these negative health consequences of nonmarital childbearing are mitigated by either marriage or cohabitation for black women. For other women, only enduring marriage to the biological father is associated with better health than remaining unpartnered.

  4. Has Adolescent Childbearing Been Eclipsed by Nonmarital Childbearing?

    Directory of Open Access Journals (Sweden)

    Anne Martin

    2015-10-01

    Full Text Available Adolescent childbearing has received decreasing attention from academics and policymakers in recent years, which may in part reflect the decline in its incidence. Another reason may be its uncoupling from nonmarital childbearing. Adolescent childbearing became problematized only when it began occurring predominantly outside marriage. In recent decades, there have been historic rises in the rate of nonmarital childbearing, and importantly, the rise has been steeper among older mothers than among adolescent mothers. Today, two out of five births are to unmarried women, and the majority of these are to adults, not adolescents. Nonmarital childbearing is in and of itself associated with lower income and poorer maternal and child outcomes. However, unmarried adolescent mothers might face more difficulties than unmarried adult mothers due to their developmental status, education, living arrangements, and long-term prospects for work. If this is true, then the focus on adolescent mothers ought to continue. We suggest several facets of adolescent motherhood deserving of further study, and recommend that future research use unmarried mothers in their early 20s as a realistic comparison group.

  5. Coparenting experiences in African American families: an examination of single mothers and their nonmarital coparents.

    Science.gov (United States)

    Gonzalez, Michelle; Jones, Deborah; Parent, Justin

    2014-03-01

    African American youth from single-mother homes continue to be overrepresented in statistics on risk behavior and delinquency, a trend that many be attributed to father-absence, socioeconomic disadvantage, and compromises in parenting more typical of single than two-parent families. Yet, this risk-focused perspective ignores a long-standing strength of the African American community, the involvement and potential protective impact of extended family members in childrearing. This study describes the experiences of 95 African American single mothers and their nonmarital coparents who participated in a study of African American single-mother families with an 11-16-year-old child. Specifically, the study examines: (a) the extent to which nonmarital coparents are involved in childrearing; (b) the relative levels of risk (i.e., depression, mother-coparent conflict) and protective (i.e., parenting) associated with maternal and coparent involvement; and (c) how similarly and/or differently coparent and mother variables operate with regard to youth externalizing problems. Findings reveal that a range of family members and other adults actively participate in childrearing in African American single-mother families, coparents do not differ from mothers on certain study variables (i.e., depression and mother-coparent conflict) but do for others (parenting), and coparent involvement is associated with youth adjustment in ways that are similar to our more established understanding of maternal involvement. The potential clinical implications of the findings are discussed and future research directions are highlighted.

  6. Lone mothers and their network support: Sociodemographic research of nonmarital parenthood in Serbia

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    Stanković Biljana

    2014-01-01

    Full Text Available The aim of this paper is to identify and describe the difficulties faced by families with nonmarital children (especially single-parent, available help and support, participation of the father in raising a child, and expected institutional help. That represents a first step toward better understanding of these families. The paper presents part of the results of research carried out in Belgrade with the aim of insight into the phenomenon of nonmarital childbearing at the individual level. It was conducted on a sample of 100 respondents, mothers of nonmarital children, who attend preschool. The survey was anonymous, carried out by the interview method. For this purpose a questionnaire with more than 50 questions was made, standardized to a great extent. In this paper, the focus is on the hardships and needs of the group of lone mothers. Though some issues take into account the answers of all respondents (21 cohabited mothers and 79 lone mothers, the analysis is largely related to the experiences and reflections of lone mothers. The 2011 Census data on prevalence of consensual unions and characteristics of persons living in them, as well as earlier data on the acknowledgment of paternity, do not indicate that nonmarital childbearing in Serbia takes place primarily in stable unions. It is realistic to assume that a large percentage of mothers with nonmarital children are lone mothers. The research results are generally consistent with the findings of relevant studies from our and foreign countries. As the largest difficulties, lone mothers emphasize financial problems, unemployment, housing difficulties, and child care, as well as a pronounced feeling of loneliness. Most of them in solving problems and rising children rely on their parents and siblings, with whom they often live in the same household. Every fifth lone mother when faced with a major problem, and every ninth in everyday raising a child can count on the father of the child. About a

  7. Relative Efficacy of Liquid Nitrogen Fertilizers in Dryland Spring Wheat

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    Olga S. Walsh

    2016-01-01

    Full Text Available The study was conducted in 2012 and 2013 at three locations in North Central and Western Montana (total of 6 site-years to evaluate the relative efficacy of three liquid nitrogen (N fertilizer sources, urea ammonium nitrate (UAN, 32-0-0, liquid urea (LU, 21-0-0, and High NRGN (HNRGN, 27-0-0-1S, in spring wheat (Triticum aestivum L.. In addition to at-seeding urea application at 90 kg N ha−1 to all treatments (except for the unfertilized check plot, the liquid fertilizers were applied utilizing an all-terrain vehicle- (ATV- mounted stream-bar equipped sprayer at a rate of 45 kg N ha−1 at Feekes 5 growth stage (early tillering. Three dilution ratios of fertilizer to water were accessed: 100/0 (undiluted, 66/33, and 33/66. The effects of N source and the dilution ratio (fertilizer/water on N uptake (NUp, N use efficiency (NUE, spring wheat grain yield (GY, grain protein (GP content, and protein yield (PY were assessed. The dilution ratios had no effect on GY, GP, PY, NUp, and NUE at any of the site-years in this study. Taking into account agronomic and economic factors, LU can be recommended as the most suitable liquid N fertilizer source for spring wheat cropping systems of the Northern Great Plains.

  8. Bull Fertility and Its Relation with Density Gradient Selected Sperm

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    Allouche Lynda ,

    2017-01-01

    Full Text Available Background Sperm selection method is usually used to collect these cells for in vitro-assisted reproduction. Few studies reported the relationship of in vivo fertility and semen parameters after sperm selection; hence, the present study attempted to assess different semen parameters after post-thaw or sperm selection, using density gradient separation BoviPure®, to predict in vivo fertility. Materials and Methods In this experimental study, frozen semen quality of four Montbeliarde bulls were assessed after post-thaw (PT or after sperm selection (SSp, using density gradient separation BoviPure®, to predict the fertility rate in vivo. In addition to PT or SSp, semen was examined for concentration, motility, morphology abnormalities, viability, acrosome and plasma membrane integrities. Fertility was measured as non-return rates within 56 days after the first insemination (NRR or as corrected NRR, expressed as CNRR, to the factors influencing fertility using linear mixed model. Non-parametric Kruskal-Wallis test was performed to compare semen parameter variables. Fertility rates were compared using Chi-square test. Pearson correlation analysis was used to test the relationship between CNRR and semen parameters. Data was analysed using SPSS package program, version 21.0. Results Most of the examined bulls exhibited a high fertility rate (3/4 bulls, 62.1- 81.8% for NRR or 67.2-98.5% for CNRR. Fertility rate, expressed as CNRR, was significantly related to semen parameters after SSp, but not after PT. Thus, CNRR was increased with decrease of total motility, progressive spermatozoa and abaxial implantation frequencies after SSp (r=-0.999, P=0.001; r=-0.990, P=0.010; r=-0.988, P= 0.012, respectively; while, CNRR was decreased with decrease of SSp immotile spermatozoa (r=+0.995, P=0.005, underlying that maximal limit of determined immotile spermatozoa is 47%. Conclusion High frequencies of total and progressive motility spermatozoa, and abaxial

  9. Relation between diabetes mellitus and male fertility

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    Andy Petroianu

    2009-12-01

    Full Text Available Objective: The objective of the present study was to verify if there is any relation between diabetes mellitus and male infertility. Methods: the spermograms of 43 non-diabetic subjects and 12 diabetic patients (type 1 and 2 aged 20-60 years were compared. Spermiological findings in diabetic patients were compared with those of normal individuals of the same age. Serum testosterone, prolactin, follicle-stimulant hormone, luteinizing hormone, glucose and glycosilated hemoglobin were assayed in diabetic patients. Rresults: Six diabetic patients (four type 1 and two type 2 presented chronic complications attributed to neuropathy and vascular insufficiency. No difference was observed in the semen characteristics (odor, color, viscosity and pH between the control group and the diabetic patients. There were no differences between seminal concentrations and percentage of motile spermatozoa during the first hour of observation in the two groups (p < 0.05. Impotence was reported by four diabetic patients (33.3%. Erectile failure was associated with diabetic microangiopathy and neuropathy. There were no controls with impotence. No significant hormonal changes were found in the diabetic patients. Cconclusions: The present results suggest that neuropathy and vascular insufficiency  may be  implicated in sexual dysfunction in type 1 and 2 diabetic patients, without significantly affecting the hypothalamic-pituitary-gonadal axis.

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

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    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.

  11. Men's knowledge, attitudes and behaviours relating to fertility.

    Science.gov (United States)

    Hammarberg, Karin; Collins, Veronica; Holden, Carol; Young, Kate; McLachlan, Robert

    2017-07-01

    The increasingly common practice in high-income countries to delay childbearing to the fourth and fifth decades of life increases the risk of involuntary childlessness or having fewer children than desired. Older age also increases the risk of age-related infertility, the need for ART to conceive, and obstetric and neonatal complications. Existing research relating to childbearing focusses almost exclusively on women, and in public discourse declining fertility rates are often assumed to be the result of women delaying childbearing to pursue other life goals such as a career and travel. However, evidence suggests that the lack of a partner or a partner willing to commit to parenthood is the main reason for later childbearing. To better understand men's contributions to childbearing decisions and outcomes, the literature pertaining to men's fertility-related knowledge, attitudes and behaviours was reviewed. The electronic databases of Medline, Embase and PsycINFO were searched to identify investigations of men's knowledge, attitudes and behaviours relating to fertility, infertility, reproductive health or childbearing using relevant fertility keyword search terms. Studies were included if they had investigated factors associated with men's fertility-related knowledge, attitudes and behaviours, had been conducted in a high-income country and were published in an English language peer-reviewed journal between January 2005 and August 2016. The search yielded 1349 citations. Of these, 47 papers representing 43 unique studies were included in the review. Where response rate was reported, it ranged between 13 and 94%. Studies varied in terms of research design; inclusion and exclusion criteria; recruitment strategies; adequacy of sample size; recruitment and retention rates and data collection tools. However, findings were consistent and indicate that men almost universally value parenthood, want and expect to become fathers, and aspire to have at least two children. Yet

  12. Relationship-Specific Investments, Family Chaos, and Cohabitation Dissolution Following a Non-marital Birth.

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    Kamp Dush, Claire M

    2011-12-01

    Predictors of two types of cohabitation dissolution, dissolution with a continued romantic relationship and without (i.e. breakup), were examined using data from mothers cohabiting at the time of a non-marital birth in the Fragile Families and Child Wellbeing Study (n = 1624). Life tables indicated 64% of unions dissolved within 5 years; of these, 76% broke-up. Black mothers had the highest rates of dissolution. Maximum likelihood discrete-time event history results revealed that younger mothers were more likely to experience cohabitation dissolution into a breakup. Fewer relationship-specific investments and more family chaos were also associated with greater risk of cohabitation dissolution into a breakup. Mothers' multipartnered fertility and fewer relationship-specific investments were associated with greater risk of cohabitation dissolution with a continued romantic relationship. Post-dissolution, mothers who maintained a romantic relationship were more likely to reenter a union with their former partner while mothers whose union broke-up most often remained so.

  13. Relationship-Specific Investments, Family Chaos, and Cohabitation Dissolution Following a Non-marital Birth

    Science.gov (United States)

    Kamp Dush, Claire M.

    2011-01-01

    Predictors of two types of cohabitation dissolution, dissolution with a continued romantic relationship and without (i.e. breakup), were examined using data from mothers cohabiting at the time of a non-marital birth in the Fragile Families and Child Wellbeing Study (n = 1624). Life tables indicated 64% of unions dissolved within 5 years; of these, 76% broke-up. Black mothers had the highest rates of dissolution. Maximum likelihood discrete-time event history results revealed that younger mothers were more likely to experience cohabitation dissolution into a breakup. Fewer relationship-specific investments and more family chaos were also associated with greater risk of cohabitation dissolution into a breakup. Mothers’ multipartnered fertility and fewer relationship-specific investments were associated with greater risk of cohabitation dissolution with a continued romantic relationship. Post-dissolution, mothers who maintained a romantic relationship were more likely to reenter a union with their former partner while mothers whose union broke-up most often remained so. PMID:22081737

  14. Relationships between nutrient-related plant traits and combinations of soil N and P fertility measures.

    Directory of Open Access Journals (Sweden)

    Yuki Fujita

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

  15. Relationships between nutrient-related plant traits and combinations of soil N and P fertility measures.

    Science.gov (United States)

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

    2013-01-01

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

  16. Adolescent Fertility: National File [Machine-Readable Data File].

    Science.gov (United States)

    Moore, Kristin A.; And Others

    This computer file contains recent cross sectional data on adolescent fertility in the United States for 1960, 1965, 1970, 1975 and 1980-85. The following variables are included: (1) births; (2) birth rates; (3) abortions; (4) non-marital childbearing; (5) infant mortality; and (6) low birth weight. Data for both teenagers and women aged 20-24 are…

  17. SURVEY OF FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

    Science.gov (United States)

    The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

  18. Physical properties of fertilizer in relation to handling and spreading.

    NARCIS (Netherlands)

    Hofstee, J.W.

    1993-01-01

    The influence of physical properties of fertilizer on the handling and spreading is studied. The reviewed properties are particle size and particle size distribution, coefficient of friction, coefficient of restitution, particle strength and aerodynamic resistance. Further a measuring procedure base

  19. Age-varying associations between nonmarital sexual behavior and depressive symptoms across adolescence and young adulthood.

    Science.gov (United States)

    Vasilenko, Sara A

    2017-02-01

    Research has demonstrated associations between adolescent sexual behavior and depressive symptoms, but no single study has examined individuals at different ages throughout adolescence and young adulthood in order to determine at what ages sexual behavior may be associated with higher or lower levels of depressive symptoms. Using nationally representative longitudinal data and an innovative method, the time-varying effect model (TVEM), which examines how the strength of an association changes over time, this study examines how nonmarital sexual intercourse is associated with depressive symptoms at different ages, which behaviors and contexts may contribute to these associations, and whether associations differ for male and female participants. Findings indicate that sexual behavior in adolescence is associated with a higher level of depressive symptoms, particularly for female adolescents, and this association is relatively consistent across different partner types and adolescent contexts. Associations between sexual behavior and depressive symptoms in young adulthood are more dependent on partner factors and adolescent contexts; sexual behavior in young adulthood is associated with fewer depressive symptoms for women who have sex with a single partner and for men whose parents did not strongly disapprove of adolescent sexual behavior. Findings suggest that delaying sexual behavior into young adulthood may have some benefits for mental health, although contextual and relationship factors also play a role. (PsycINFO Database Record

  20. Decreasing nonmarital births and strengthening marriage to reduce poverty.

    Science.gov (United States)

    Amato, Paul R; Maynard, Rebecca A

    2007-01-01

    Since the 1970s, the share of U.S. children growing up in single-parent families has doubled, a trend that has disproportionately affected disadvantaged families. Paul Amato and Rebecca Maynard argue that reversing that trend would reduce poverty in the short-term and, perhaps more important, improve children's growth and development over the long term, thus reducing the likelihood that they would be poor when they grew up. The authors propose school and community programs to help prevent nonmarital births. They also propose to lower divorce rates by offering more educational programs to couples before and during marriage. Amato and Maynard recommend that all school systems offer health and sex education whose primary message is that parenthood is highly problematic for unmarried youth. They also recommend educating young people about methods to prevent unintended pregnancies. Ideally, the federal government would provide tested curriculum models that emphasize both abstinence and use of contraception. All youth should understand that unintended pregnancies are preventable and have enormous costs for the mother, the father, the child, and society. Strengthening marriage, argue the authors, is also potentially an effective strategy for fighting poverty. Researchers consistently find that premarital education improves marital quality and lowers the risk of divorce. About 40 percent of couples about to marry now participate in premarital education. Amato and Maynard recommend doubling that figure to 80 percent and making similar programs available for married couples. Increasing the number of couples receiving services could mean roughly 72,000 fewer divorces each year, or around 65,000 fewer children entering a single-parent family every year because of marital dissolution. After seven or eight years, half a million fewer children would have entered single-parent families through divorce. Efforts to decrease the share of children in single-parent households, say the

  1. Kelp growth on an ocean farm in relation to fertilizing

    Energy Technology Data Exchange (ETDEWEB)

    Gerard, V.A.; North, W.J.

    1980-01-01

    Results of fertilizing experiments on the test farm supported previous evidence that low macronutrient supplies limit kelp growth in offshore surface water. Enhanced N contents of blade tissues from adult and juvenile plants and enhanced growth of juvenile plants indicates that artificially upwelled deep water could provide a suitable source of nutrients. However, measurement of harvestable production depends on our ability to prevent damage to plants by currents and abrasion, which would be edge effects on a large-scale ocean farm. Three adult Macrocystis plants have been held successfully on the test farm for one year by locating them away from major structural elements. At least ten times that many plants, suitably protected and fertilized with deep water, are necessary to accomplish the immediate goal of determining yield. The test farm is now being redesigned to meet these requirements.

  2. Marital Quality and Divorce Decisions: How Do Premarital Cohabitation and Nonmarital Childbearing Matter?

    Science.gov (United States)

    Tach, Laura M.; Halpern-Meekin, Sarah

    2012-01-01

    This study used the 1979 cohort of the National Longitudinal Survey of Youth (N = 3,481) to test whether the association between marital quality and divorce is moderated by premarital cohabitation or nonmarital childbearing status. Prior research identified lower marital quality as a key explanation for why couples who cohabit or have children…

  3. Relationship-Specific Investments, Family Chaos, and Cohabitation Dissolution Following a Nonmarital Birth

    Science.gov (United States)

    Kamp Dush, Claire M.

    2011-01-01

    Predictors of two types of cohabitation dissolution, dissolution with a continued romantic relationship and without (i.e., breakup), were examined using data from mothers cohabiting at the time of a nonmarital birth in the Fragile Families and Child Wellbeing Study (N = 1,624). Life tables indicated 64% of unions dissolved within 5 years; of…

  4. Proposed amendments to the legal proposition on establishment of non-marital paternity from 1855

    Directory of Open Access Journals (Sweden)

    Kulauzov Maša M.

    2015-01-01

    Full Text Available Proposed amendments to the article 130 of Serbian Civil Code (henceforth: SCC of 1844 regarding establishment of non-marital paternity were scrutinized in this paper. Originally, establishment of non-marital paternity was granted, but with significant restriction that presumed parent could have been declared the father of an illegitimate child only if he had recognized paternity. That is the reason why in 1855 the Supreme Court suggested amendment to the provision concerning determination of paternity. According to proposed modification, evidence that presumed father was on intimate terms with child's mother in the time of conception should have been sufficient for establishment of paternity. As non-marital relationships were condemned in patriarchal Serbian 19th century society, illegitimate children were considered a product of sin and family disgrace. Hence, the Ministry of Justice, the State Council and Prince Aleksandar Karađorđević were not interested in bettering their position by widening possibilities of determination of fatherhood. Subsequently, in 1868 the amendment was passed by which non-marital paternity could not have been established by a court order, subject to certain exceptions (if one raped or abducted a woman, and the time of conception coincided with the time of abduction or rape. Since 1868 paternity could have been determined solely subject to the consent, i.e. recognition of the illegitimate father.

  5. Relationship-Specific Investments, Family Chaos, and Cohabitation Dissolution Following a Nonmarital Birth

    Science.gov (United States)

    Kamp Dush, Claire M.

    2011-01-01

    Predictors of two types of cohabitation dissolution, dissolution with a continued romantic relationship and without (i.e., breakup), were examined using data from mothers cohabiting at the time of a nonmarital birth in the Fragile Families and Child Wellbeing Study (N = 1,624). Life tables indicated 64% of unions dissolved within 5 years; of…

  6. The Relation Between Adult Dark Spermatogonia and Other Parameters of Fertility Potential in Cryptorchid Testes

    DEFF Research Database (Denmark)

    Thorup, Jørgen Mogens; Kvist, Kolja; Clasen-Linde, Erik

    2013-01-01

    The fertility potential of boys with cryptorchidism may be related to the number of adult dark spermatogonia per tubular transverse section in testicular biopsies taken at orchiopexy. Placental-like alkaline phosphatase positive gonocytes in testes within year 1 of life indicate preserved ability...... for germ cell transformation. We related these parameters to the total number of tubular germ cells and other factors associated with fertility potential....

  7. Comments on "Some Relations Among Cultural Traditions, Nuptiality and Fertility".

    Science.gov (United States)

    Krotki, K J

    1991-01-01

    Facts employed in formulating Ansley Coale's interpretation of European historical demographic transition have largely been in the public domain for a long time. Coale's achievement, however, in bringing pertinent information together to form a theoretical framework is applauded, and is acknowledged as being an important contribution to the traditional use of demographic transition. Beyond this general interest and broad approval, the author critiques various points of Coale's thesis. First, he notes the need to be suspicious of high correlations found between mean age at 1st marriage and total fertility rate. Second, he is unsure of the role played by servants in explaining the comparatively later marriage age of western Europeans. Finally, the author considers marked fertility declines in China, Taiwan, and Korea. These declines run strongly counter to the traditional cultures of these countries. Moreover, the high life expectations at birth, strong episodic economic development in Taiwan and Korea, and serious autocratic government interference in China are atypical of experiences in most developing countries. Traditional family planning in these 3 countries was simply a facilitator of demographic transition. The experiences of China, Taiwan, Korea, and Bangladesh support the ineffectiveness of imposing programs from either within or outside of a country.

  8. Three Decades of Nonmarital First Births among Fathers Aged 15-44 in the United States. NCHS Data Brief. Number 204

    Science.gov (United States)

    Martinez, Gladys M.

    2015-01-01

    Nonmarital childbearing in the United States increased from the 1940s to the 1990s, peaked in 2007-2008, and declined in 2013 (1-3). In 2013, the nonmarital birth rate was 44.8 births per 1,000 unmarried women aged 15-44. Using data from the National Survey of Family Growth (NSFG), this study examines nonmarital first births reported by fathers…

  9. Spatial variability of soil fertility and its relation with cocoa yield

    Directory of Open Access Journals (Sweden)

    Railton O. dos Santos

    Full Text Available ABSTRACT The knowledge on the spatial variability of soil properties and crops is important for decision-making on agricultural management. The objective of this study was to evaluate the spatial variability of soil fertility and its relation with cocoa yield. The study was conducted over 14 months in an area cultivated with cocoa. A sampling grid was created to study soil chemical properties and cocoa yield (stratified in season, off-season and annual. The data were analyzed using descriptive and exploratory statistics, and geostatistics. The chemical attributes were classified using fuzzy logic to generate a soil fertility map, which was correlated with maps of crop yield. The soil of the area, except for the western region, showed possibilities ranging from medium to high for cocoa cultivation. Soil fertility showed positive spatial correlation with cocoa yield, and its effect was predominant only for the off-season and annual cocoa.

  10. Temperature and rainfall are related to fertility rate after spring artificial insemination in small ruminants

    Science.gov (United States)

    Abecia, J. A.; Arrébola, F.; Macías, A.; Laviña, A.; González-Casquet, O.; Benítez, F.; Palacios, C.

    2016-10-01

    A total number of 1092 artificial inseminations (AIs) performed from March to May were documented over four consecutive years on 10 Payoya goat farms (36° N) and 19,392 AIs on 102 Rasa Aragonesa sheep farms (41° N) over 10 years. Mean, maximum, and minimum ambient temperatures, mean relative humidity, mean solar radiation, and total rainfall on each insemination day were recorded. Overall, fertility rates were 58 % in goats and 45 % in sheep. The fertility rates of the highest and lowest deciles of each of the meteorological variables indicated that temperature and rainfall had a significant effect on fertility in goats. Specifically, inseminations that were performed when mean (68 %), maximum (68 %), and minimum (66 %) temperatures were in the highest decile, and rainfall was in the lowest decile (59 %), had a significantly ( P AI in spring. It remains to be determined whether scheduling the dates of insemination based on forecasted temperatures can improve the success of AI in goats and sheep.

  11. Fertility, Relative Wages, and Labor Market Decisions: A Case of Female Teachers

    Science.gov (United States)

    Shin, Jaeun; Moon, Sangho

    2006-01-01

    This paper examines the effects of fertility and relative wages on occupational choice (teaching versus non-teaching) and labor force participation decisions of female college graduates using selectivity-corrected panel estimations. We find that the presence of a new born baby is not particularly important to the choice of occupation, but…

  12. The relative nature of fertilization success: Implications for the study of post-copulatory sexual selection

    Directory of Open Access Journals (Sweden)

    García-González Francisco

    2008-05-01

    Full Text Available Abstract Background The determination of genetic variation in sperm competitive ability is fundamental to distinguish between post-copulatory sexual selection models based on good-genes vs compatible genes. The sexy-sperm and the good-sperm hypotheses for the evolution of polyandry require additive (intrinsic effects of genes influencing sperm competitiveness, whereas the genetic incompatibility hypothesis invokes non-additive genetic effects. A male's sperm competitive ability is typically estimated from his fertilization success, a measure that is dependent on the ability of rival sperm competitors to fertilize the ova. It is well known that fertilization success may be conditional to genotypic interactions among males as well as between males and females. However, the consequences of effects arising from the random sampling of sperm competitors upon the estimation of genetic variance in sperm competitiveness have been overlooked. Here I perform simulations of mating trials performed in the context of sibling analysis to investigate whether the ability to detect additive genetic variance underlying the sperm competitiveness phenotype is hindered by the relative nature of fertilization success measurements. Results Fertilization success values render biased sperm competitive ability values. Furthermore, asymmetries among males in the errors committed when estimating sperm competitive abilities are likely to exist as long as males exhibit variation in sperm competitiveness. Critically, random effects arising from the relative nature of fertilization success lead to an underestimation of underlying additive genetic variance in sperm competitive ability. Conclusion The results show that, regardless of the existence of genotypic interactions affecting the output of sperm competition, fertilization success is not a perfect predictor of sperm competitive ability because of the stochasticity of the background used to obtain fertilization success

  13. Responses of Nitrogen and related enzyme Activities to Fertilization in Rhizosphere of Wheat

    Institute of Scientific and Technical Information of China (English)

    YUANLING; YUSHANGQI; 等

    1997-01-01

    In the present experiment,wheat seedlings(Trticucum aestivum L.)were grown on a purple soil with various fertilizer treatments in order to investigate the responses of nitrogen and related enzyme activities in the rhizosphere,The results revealed the increments of both organic matter and total N in the soil with the proximity to the growing roots,especially in treatment of supplying pig manure in combination with chemical fertilizer,suggesting that they could ome from root and microorganism exudation which could be intensified by inorganic-organic fertiliztion,being of benefit to improving the physical and bilogical envi-ronment in the rhizosphere of wheat.Much more inorganic N was observed in the fertilized soils surrounding wheat roots than in the CK treatment ,indicating ,the improvement of crop N supply in the rhizosphere of wheat by fertilization. The activities of invertase,urease and protease in the root zone were greatly enhanced as compared to those in the other parts of soil except that the urease activities were similar in the rhizospher and nonrhi-zosphere of the CK and pig manure treatments,indicating that invertase and protese could be produced by growing roots and rhizosphere microorganisms,in contrast to urease which could be stimulated by urea,Also,significant increment of chemical fertilizer combined with pig manure,suggested that fertilization not only accelerated the renewal of organic matter bu also enhanced bioavailability of organic N in that soil zone .This could be the reason why the total amount of inorganic N available for plants was increased more obviously in the rhizosphere of wheat of the fertilizaton treatments than in taht of the CK treatment.

  14. Conventional semen parameters and DNA fragmentation in relation to fertility status in a Greek population.

    Science.gov (United States)

    Evgeni, Evangelini; Lymberopoulos, George; Gazouli, Maria; Asimakopoulos, Byron

    2015-05-01

    Our study aimed to investigate the possible correlations between conventional seminal parameters and DNA fragmentation in specific groups of Greek men, selected in relation to their fertility history and to verify the validity of the recent WHO reference values for the basic semen analysis in this population. A total of 770 subject data were evaluated in three distinct groups: fertile men with children naturally conceived within one year of unprotected intercourse (n=78), subfertile men, having achieved pregnancies either naturally or by Assisted Reproduction Techniques, not resulting in live births (n=153) and infertile men, failing to produce either pregnancies or children (n=539). Semen volume, sperm concentration, total count, rapid and total progressive motility and morphology were evaluated following the World Health Organization (2010) methods. DNA fragmentation was assessed by the Sperm Chromatin Dispersion assay. The 5th percentile, as well as the 95% confidence intervals (CI) for each parameter, were calculated by the method of bootstrapping. Statistical correlations between the examined parameters were sought using the Spearman R test (pDNA fragmentation and sperm concentration, total count, progressive motility (rapid and total) and normal morphology in subfertile and infertile men (pDNA fragmentation in our group of fertile men. Concordance was established between the reference limits issued by the WHO 2010 for the basic semen parameters and semen quality of fertile men in the studied population. The variability of correlations established between DNA fragmentation and the conventional seminal profile in relation to fertility status indicates that they are independent attributes of semen quality, justifying the assessment of both during a comprehensive evaluation of male infertility. Moreover, the WHO 2010 reference limits were found adequately descriptive of seminal normality in Greek men. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Long-term fertilization alters the relative importance of nitrate reduction pathways in salt marsh sediments

    Science.gov (United States)

    Peng, Xuefeng; Ji, Qixing; Angell, John H.; Kearns, Patrick J.; Yang, Hannah J.; Bowen, Jennifer L.; Ward, Bess B.

    2016-08-01

    Salt marshes provide numerous valuable ecological services. In particular, nitrogen (N) removal in salt marsh sediments alleviates N loading to the coastal ocean. N removal reduces the threat of eutrophication caused by increased N inputs from anthropogenic sources. It is unclear, however, whether chronic nutrient overenrichment alters the capacity of salt marshes to remove anthropogenic N. To assess the effect of nutrient enrichment on N cycling in salt marsh sediments, we examined important N cycle pathways in experimental fertilization plots in a New England salt marsh. We determined rates of nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) using sediment slurry incubations with 15N labeled ammonium or nitrate tracers under oxic headspace (20% oxygen/80% helium). Nitrification and denitrification rates were more than tenfold higher in fertilized plots compared to control plots. By contrast, DNRA, which retains N in the system, was high in control plots but not detected in fertilized plots. The relative contribution of DNRA to total nitrate reduction largely depends on the carbon/nitrate ratio in the sediment. These results suggest that long-term fertilization shifts N cycling in salt marsh sediments from predominantly retention to removal.

  16. Perceptions of oocyte banking from women intending to circumvent age-related fertility decline.

    Science.gov (United States)

    de Groot, Marije; Dancet, Eline; Repping, Sjoerd; Goddijn, Mariette; Stoop, Dominic; van der Veen, Fulco; Gerrits, Trudie

    2016-12-01

    Women can now opt to bank their oocytes with the intention of increasing their chances of achieving a pregnancy after their fertility has declined. This exploratory study aimed to gain insight into how women, considering oocyte banking to circumvent age-related fertility decline, perceive this intervention. We conducted a qualitative study in a Dutch university medical center and held in-depth interviews with women on the waiting list for oocyte banking. We recorded the interviews, transcribed them verbatim and used thematic analysis. All women were financially independent and lived in single-person urban households. They opted for oocyte banking because they wished to share parenthood with a future partner rather than becoming a single parent. This strong desire was key in their interpretation of all aspects of the intervention. Women set aside information about the limited success rates and potential risks, as they were optimistic about their own prognosis, thought that the chances for success were equally likely as the chances it would fail, and because of "anticipatory regret". They perceived oocyte banking as a "helping hand" to achieve shared parenthood. Although women found the costs of the intervention high, they were willing to invest their money to increase their chances for shared parenthood. Oocyte banking allows women to circumvent age-related fertility decline. The prospect of potential shared parenthood overrules the perceived health risks and burden. Health professionals should take this into account when informing potential users of oocyte banking. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  17. [Effects of phosphorous fertilizers on phytoavailability of cadmium in its contaminated soil and related mechanisms].

    Science.gov (United States)

    Liu, Zhao-Bing; Ji, Xiong-Hui; Peng, Hua; Tian, Fa-Xiang; Wu, Jia-Mei; Shi, Li-Hong

    2012-06-01

    To explore an effective measure to ensure the safety of rice quality in cadmium (Cd)-contaminated farmland, a pot culture experiment was conducted to study the effects of of low Cd content (Cd fertilizers with an application rate of 0.10 or 0.20 g P2O5 x kg(-1) on the phytoavailability of Cd in its contaminated p add y soil, with the related mechanisms discussed. Compared with no phosphorous fertilization, applying 0.10 P2O5 x kg(-1) of calcium magnesium phosphate (CMP) and monopotassium phosphate (MKP) increased soil pH and decreased soil available Cd content significantly, and CMP and calcium superphosphate (CSP) decreased the Cd accumulation in rice significantly. When the application rate was up to 0.20 g P2O5 x kg(-1), calcium hydrogen phosphate (CHP) increased the soil pH and decreased the soil available Cd content significantly, and CMP, MKP, and CHP decreased the DTPA-extractable soil Cd content by 11.8%, 9.8%, and 11.8%, and the NH4 OAc-extractable soil Cd content by 9.5%, 7.1%, and 7.1%, respectively. All test phosphorous fertilizers could significantly decrease the stem and leaf Cd contents, with a decrement of 24.9%-50.8%, and except CHP, the others could significantly decrease the Cd content of brown rice. With the application CMP and CSP, the Cd content of brown rice was close to the National Hygienic Standard for Grains (GB 2715-2005). Among the test phosphorous fertilizers, those can increase soil pH (CMP, MKP, and CHP) could significantly decrease the availability of soil Cd significantly, and those containing calcium (CMP and CSP) were more effective in decreasing the Cd accumulation in rice. The efficiency of the phosphorous fertilizers was mainly determined by their chemical properties. Alkaline calcium-containing phosphorous fertilizers were more effective in decreasing the Cd absorption and accumulation in rice plant in Cd-contaminated farmland.

  18. Parenting as a “Package Deal”: Relationships, Fertility, and Nonresident Father Involvement Among Unmarried Parents

    OpenAIRE

    TACH, LAURA; Mincy, Ronald; Edin, Kathryn

    2010-01-01

    Fatherhood has traditionally been viewed as part of a “package deal” in which a father’s relationship with his child is contingent on his relationship with the mother. We evaluate the accuracy of this hypothesis in light of the high rates of multiple-partner fertility among unmarried parents using the Fragile Families and Child Wellbeing Study, a recent longitudinal survey of nonmarital births in large cities. We examine whether unmarried mothers’ and fathers’ subsequent relationship and pare...

  19. LYZL6, an acidic, bacteriolytic, human sperm-related protein, plays a role in fertilization

    Science.gov (United States)

    Huang, Peng; Li, Wenshu; Yang, Zhifang; Zhang, Ning; Xu, Yixin; Bao, Jianying; Jiang, Deke; Dong, Xianping

    2017-01-01

    Lysozyme-like proteins (LYZLs) belong to the c-type lysozyme/α-lactalbumin family and are selectively expressed in the mammalian male reproductive tract. Two members, human sperm lysozyme-like protein (SLLP) -1 and mouse LYZL4, have been reported to contribute to fertilization but show no bacteriolytic activity. Here, we focused on the possible contribution of LYZL6 to immunity and fertilization. In humans, LYZL6 was selectively expressed by the testis and epididymis and became concentrated on spermatozoa. Native LYZL6 isolated from sperm extracts exhibited bacteriolytic activity against Micrococcus lysodeikticus. Recombinant LYZL6 (rLYZL6) reached its peak activity at pH 5.6 and 15 mM of Na+, and could inhibit the growth of Gram-positive, but not Gram-negative bacteria. Nevertheless, the bacteriolytic activity of rLYZL6 proved to be much lower than that of human lysozyme under physiological conditions. Immunodetection with a specific antiserum localized the LYZL6 protein on the postacrosomal membrane of mature spermatozoa. Immunoneutralization of LYZL6 significantly decreased the numbers of human spermatozoa fused with zona-free hamster eggs in a dose-dependent manner in vitro. Thus, we report here for the first time that LYZL6, an acidic, bacteriolytic and human sperm-related protein, is likely important for fertilization but not for the innate immunity of the male reproductive tract. PMID:28182716

  20. Evaluating the relative contributions of hydroperiod and soil fertility on growth of south Florida mangroves

    Science.gov (United States)

    Krauss, K.W.; Doyle, T.W.; Twilley, R.R.; Rivera-Monroy, V. H.; Sullivan, J.K.

    2006-01-01

    Low and high water periods create contrasting challenges for trees inhabiting periodically flooded wetlands. Low to moderate flood durations and frequencies may bring nutrient subsidies, while greater hydroperiods can be energetically stressful because of oxygen deficiency. We tested the hypothesis that hydroperiod affects the growth of mangrove seedlings and saplings in a greenhouse experiment by varying flood duration while keeping salinity and soil fertility constant. We measured the growth of mangrove trees along a hydroperiod gradient over a two-year period by tracking fine-scale diameter increment. Greenhouse growth studies indicated that under a full range of annual flood durations (0-8760 h/year), hydroperiod alone exerted a significant influence on growth for one species, Laguncularia racemosa, when flooding was imposed for two growing seasons. Field evaluations, on the other hand, indicated that increased flood duration may provide nutrient subsidies for tree growth. Diameter growth was related curvilinearly to site hydroperiod, including flood duration and frequency, as well as to salinity and soil fertility. An analysis of soil physico-chemical parameters suggests that phosphorus fertility, which was also linked directly to hydroperiod, is likely to influence growth on south Florida mangrove sites. The physical removal of phosphorus by greater flood frequencies from upland sources and/or addition of phosphorus from tidal flooding balanced against increased soil aeration and reduced water deficits may be an extremely important growth determinant for south Florida mangroves. ?? Springer 2006.

  1. Intercropping enhances productivity and maintains the most soil fertility properties relative to sole cropping.

    Science.gov (United States)

    Wang, Zhi-Gang; Jin, Xin; Bao, Xing-Guo; Li, Xiao-Fei; Zhao, Jian-Hua; Sun, Jian-Hao; Christie, Peter; Li, Long

    2014-01-01

    Yield and nutrient acquisition advantages are frequently found in intercropping systems. However, there are few published reports on soil fertility in intercropping relative to monocultures. A field experiment was therefore established in 2009 in Gansu province, northwest China. The treatments comprised maize/faba bean, maize/soybean, maize/chickpea and maize/turnip intercropping, and their correspoding monocropping. In 2011 (the 3rd year) and 2012 (the 4th year) the yields and some soil chemical properties and enzyme activities were examined after all crop species were harvested or at later growth stages. Both grain yields and nutrient acquisition were significantly greater in all four intercropping systems than corresponding monocropping over two years. Generally, soil organic matter (OM) did not differ significantly from monocropping but did increase in maize/chickpea in 2012 and maize/turnip in both years. Soil total N (TN) did not differ between intercropping and monocropping in either year with the sole exception of maize/faba bean intercropping receiving 80 kg P ha-1 in 2011. Intercropping significantly reduced soil Olsen-P only in 2012, soil exchangeable K in both years, soil cation exchangeable capacity (CEC) in 2012, and soil pH in 2012. In the majority of cases soil enzyme activities did not differ across all the cropping systems at different P application rates compared to monocrops, with the exception of soil acid phosphatase activity which was higher in maize/legume intercropping than in the corresponding monocrops at 40 kg ha-1 P in 2011. P fertilization can alleviate the decline in soil Olsen-P and in soil CEC to some extent. In summary, intercropping enhanced productivity and maintained the majority of soil fertility properties for at least three to four years, especially at suitable P application rates. The results indicate that maize-based intercropping may be an efficient cropping system for sustainable agriculture with carefully managed

  2. Intercropping enhances productivity and maintains the most soil fertility properties relative to sole cropping.

    Directory of Open Access Journals (Sweden)

    Zhi-Gang Wang

    Full Text Available Yield and nutrient acquisition advantages are frequently found in intercropping systems. However, there are few published reports on soil fertility in intercropping relative to monocultures. A field experiment was therefore established in 2009 in Gansu province, northwest China. The treatments comprised maize/faba bean, maize/soybean, maize/chickpea and maize/turnip intercropping, and their correspoding monocropping. In 2011 (the 3rd year and 2012 (the 4th year the yields and some soil chemical properties and enzyme activities were examined after all crop species were harvested or at later growth stages. Both grain yields and nutrient acquisition were significantly greater in all four intercropping systems than corresponding monocropping over two years. Generally, soil organic matter (OM did not differ significantly from monocropping but did increase in maize/chickpea in 2012 and maize/turnip in both years. Soil total N (TN did not differ between intercropping and monocropping in either year with the sole exception of maize/faba bean intercropping receiving 80 kg P ha-1 in 2011. Intercropping significantly reduced soil Olsen-P only in 2012, soil exchangeable K in both years, soil cation exchangeable capacity (CEC in 2012, and soil pH in 2012. In the majority of cases soil enzyme activities did not differ across all the cropping systems at different P application rates compared to monocrops, with the exception of soil acid phosphatase activity which was higher in maize/legume intercropping than in the corresponding monocrops at 40 kg ha-1 P in 2011. P fertilization can alleviate the decline in soil Olsen-P and in soil CEC to some extent. In summary, intercropping enhanced productivity and maintained the majority of soil fertility properties for at least three to four years, especially at suitable P application rates. The results indicate that maize-based intercropping may be an efficient cropping system for sustainable agriculture with carefully

  3. Evaluation of organical fertilizers in relation to minimalization of air polution by greenhouse gases and amonia

    Directory of Open Access Journals (Sweden)

    Patrik Burg

    2006-01-01

    Full Text Available Agricultural production presents one of the biggest producers of greenhouse gases. Between the most significant belongs carbon dioxide (CO2, methane (CH4, nitrous oxide (N2O, ozon (O3 and hydrogen sulphide (H2S. The work deals with classification of quantity by liberate emissions in relation to different variants of fertilization by cultivation of horticultural crops (head cabbage. For the metering was exploited gas analyzer INNOVA 1312. The results demonstrate significant difference between experimental variants by quantity of liberate emission, but also in the height of production.

  4. Nonmarital romantic relationship commitment and leave behavior: the mediating role of dissolution consideration.

    Science.gov (United States)

    Vanderdrift, Laura E; Agnew, Christopher R; Wilson, Juan E

    2009-09-01

    Two studies investigated the process by which individuals in nonmarital romantic relationships characterized by low commitment move toward enacting leave behaviors. Predictions based on the behavioral, goal, and implementation intention literatures were tested using a measure of dissolution consideration developed for this research. Dissolution consideration assesses how salient relationship termination is for an individual while one's relationship is intact. Study 1 developed and validated a measure of dissolution consideration and Study 2 was a longitudinal test of the utility of dissolution consideration in predicting the enactment of leave behaviors. Results indicated that dissolution consideration mediates the association between commitment and enacting leave behaviors, is associated with taking more immediate action, and provides unique explanatory power in leave behavior beyond the effect of commitment alone. Collectively, the findings suggest that dissolution consideration is an intermediate step between commitment and stay/leave behavior in close relationships.

  5. New state fertility-related laws dropped sharply in 1980 to lowest total since 1972.

    Science.gov (United States)

    1981-02-01

    State legislatures enacted less fertility-related legislation in 1980 than in any year since 1972. 28 new laws were passed in 1980, compared to 61 in 1979. The drop in new laws was caused by a lack of abortion legislation. From 1973, when the Supreme Court legalized abortion, through 1980, states have passed a total of 191 abortion-related laws covering abortion, from the aspect of informed consent to protection of the fetus to Medicaid funding. Abortion dominated the field in 1980's legislation also. There was no legislation dealing with the problems of teen pregnancy. California voted to authorize minors over 12 to consent to hospital, surgical, and medical care for the diagnosis and treatment of venereal diseases and specified that the minor's parents will not be liable for expenses. There was no initiative by state legislatures in sex education. Only Maryland, New Jersey, Kentucky, and the District of Columbia require schools to offer sex education. The number of new laws pertaining to insurance coverage of fertility related medical services doubled from 1979 to 1980. In 1980, Alabama, Idaho, Oklahoma, and Tennessee joined the list of states requesting Congress to call a constitutional convention to propose an antiabortion amendment. Alabama, Idaho, and Oklahoma seek an amendment to outlaw abortion except to save a woman's life.

  6. Impact of DNA mismatch repair system alterations on human fertility and related treatments.

    Science.gov (United States)

    Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

    2016-01-01

    DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

  7. Associations between feed efficiency, sexual maturity and fertility-related measures in young beef bulls.

    Science.gov (United States)

    Fontoura, A B P; Montanholi, Y R; Diel de Amorim, M; Foster, R A; Chenier, T; Miller, S P

    2016-01-01

    The beef industry has emphasized the improvement of feed utilization, as measured by modeling feed intake through performance traits to calculate residual feed intake (RFI). Evidence supports an inverse relationship between feed efficiency and reproductive function. The objective of this study was to determine the relationship of reproductive assessments and RFI unadjusted (RFI(Koch)) or adjusted for body composition (RFI(us)) and the relationship among fertility-related parameters. In total, 34 crossbred bulls were housed together for 112 days of performance evaluation, followed by assessment of scrotum IR imaging, scrotal circumference, testes ultrasonography and semen quality parameters at 377±33.4 days of age. Bulls were slaughtered at 389±34.0 days of age, and analyses of carcass composition, biometrics and histomorphometry of the testis and epididymis were conducted. Bulls were grouped into two subpopulations based on divergence of RFI, and within each RFI model either by including 50% of the population (Halves, high and low RFI, n=17) or 20.6% extremes of the population (Tails, high and low RFI, n=7). The means of productive performance and fertility-related measures were compared through these categories. Pearson's correlation was calculated among fertility-related measures. In the Halves subpopulation of the RFI(us), sperm of low-RFI bulls had decreased progressive motility (47.30% v. 59.90%) and higher abundance of tail abnormalities (4.30% v. 1.80%) than that of high-RFI bulls. In the Tails subpopulation of the RFI(Koch), low RFI displayed less variation in the scrotum surface temperature (0.62°C v. 1.16°C), decreased testis echogenicity (175.50 v 198.00 pixels) and larger (60.90 v. 56.80 mm(2)) but less-developed seminiferous tubules than high-RFI bulls. The evaluation of fertility-related parameters indicated that a higher percentage of immature seminiferous tubules was correlated with occurrence of sperm with distal droplets (r=0.59), a larger

  8. Carotenoid Accumulation by Carrot Storage Roots in Relation to Nitrogen Fertilization Level

    Directory of Open Access Journals (Sweden)

    Marek GAJEWSKI

    2010-06-01

    Full Text Available The accumulation of carotenoid compounds in carrot (Daucus carota L. roots of five cultivars, in relation to different nitrogen fertilization levels was investigated. The experiment was carried out at the Warsaw University of Life Sciences. Carrot cultivars ‘Karotan’ F1, ‘Trafford’ F1, ‘Krakow’ F1, ‘Komarno’ F1 and ‘HY 7842’ were used in the study. Nitrogen fertilization was applied as urea form, in doses ranging from 0 to 120 kg N ha–1, and on two terms: pre-sowing and in the middle of the growing season. The carrot seeds were sown at the beginning of May and the roots were harvested in mid-October at maturity. Total carotenoids and β-carotene contents in the carrot roots were determined after the harvest by means of the standard spectrophotometric method. CIE L*a*b* colour parameters of the roots and the juice, as well as dry matter in the roots were determined. Results of the experiment showed that carotenoid accumulation in the roots was significantly affected by carrot genotype. ‘HY7842’ carrot showed the highest accumulation of total carotenoids and β-carotene. Nitrogen in the rates applied, did not significantly influence carotenoid content in the roots. Moderate correlation between carotenoid content and colour a* parameter (redness intensity of the roots and the juice was found.

  9. The impact of bariatric surgery on obesity-related infertility and in vitro fertilization outcomes.

    Science.gov (United States)

    Tan, Orkun; Carr, Bruce R

    2012-12-01

    Obesity-related infertility is one of the most common problems of reproductive-age obese women who desire childbearing. The various types of bariatric surgeries have proved effective in controlling excessive weight gain, improving fertility, and preventing certain maternal and fetal complications in these women. This article summarizes the current evidence regarding the impact of bariatric surgery on obesity-related infertility and in vitro fertilization (IVF) outcomes. We have also attempted to draw conclusions about maternal and fetal risks and the benefits of bariatric surgery. Laparoscopic adjustable gastric banding and Roux-en-Y procedures are the two most commonly performed bariatric surgeries. Bariatric surgery was believed to improve menstrual irregularity and increase ovulation rate in anovulatory obese women, which lead to increased pregnancy rates. Although there are data in the literature suggesting the improvement of both the ovulatory function and the spontaneous pregnancy rates in obese women who lost weight after bariatric surgery, most of these are case-control studies with a small number of patients. The data are insufficient to determine an ideal time interval for pregnancy after bariatric surgery; however, the general consensus is that pregnancy should be delayed 12 to 18 months after bariatric surgery to avoid nutritional deficiencies. Few data exist regarding IVF success rates in women who have undergone bariatric surgery. One pairwise study discussed five patients who underwent bariatric surgery followed by IVF that resulted in three term pregnancies in three patients after the first IVF cycle. Many studies reported reductions in obesity-related pregnancy complications such as gestational diabetes and hypertensive disorders after bariatric surgery. Although data are inconsistent, some studies reported increased rate of preterm delivery and small for gestational age infants after bariatric surgery. Pregnancies after bariatric surgery may be

  10. Declining health disadvantage of non-marital children: Explanation of the trend in the Czech Republic 1990-2010

    Directory of Open Access Journals (Sweden)

    Martina Stipkova

    2013-10-01

    Full Text Available Background: There has been a rapid spread of non-marital childbearing in the Czech Republic during the last two decades. At the same time, the low birth weight rates of children born to married and unmarried mothers have converged. Objective: The goal is to explain the diminishing gap in low birth weight. Two explanations are assessed: the changing selection of unmarried mothers from disadvantaged socio-demographic groups, and increasing social support for unmarried mothers. Methods: Data from birth register are analysed. Marital status (married vs. unmarried disparities in low birth weight are modelled using logistic regression. Further analyses are then performed with a detailed measurement of partnership status. This detailed variable is partially missing and is thus supplemented with multiple imputation. Results: The main explanation for the narrowing gap between the outcomes of children born to married and unmarried mothers is the increasing social support for unmarried mothers. Unmarried motherhood has become less detrimental to a child's birth weight net of maternal demographic characteristics. The decline in selection from disadvantaged socio-demographic groups has also contributed to the convergence. However, the convergence of birth weight trends towards marital children seems to refer mostly to children of partnered mothers, with children of single mothers lagging behind. Conclusions: The positive trends in the health of non-marital children are interpreted as being the result of the increasing institutionalisation of parenthood in non-marital unions. However, this does not apply to unpartnered motherhood, which continues to represent a health disadvantage.

  11. Parenting as a "package deal": relationships, fertility, and nonresident father involvement among unmarried parents.

    Science.gov (United States)

    Tach, Laura; Mincy, Ronald; Edin, Kathryn

    2010-02-01

    Fatherhood has traditionally been viewed as part of a "package deal" in which a father's relationship with his child is contingent on his relationship with the mother. We evaluate the accuracy of this hypothesis in light of the high rates of multiple-partner fertility among unmarried parents using the Fragile Families and Child Wellbeing Study, a recent longitudinal survey of nonmarital births in large cities. We examine whether unmarried mothers' and fathers' subsequent relationship and parenting transitions are associated with declines in fathers' contact with their nonresident biological children. We find that father involvement drops sharply after relationships between unmarried parents end. Mothers 'transitions into new romantic partnerships and new parenting roles are associated with larger declines in involvement than fathers' transitions. Declines in fathers' involvement following a mother's relationship or parenting transition are largest when children are young. We discuss the implications of our results for the well-being of nonmarital children and the quality of nonmarital relationships faced with high levels of relationship instability and multiple-partner fertility.

  12. Spermatozoal traits and sperm competition in Atlantic salmon: relative sperm velocity is the primary determinant of fertilization success.

    Science.gov (United States)

    Gage, Matthew J G; Macfarlane, Christopher P; Yeates, Sarah; Ward, Richard G; Searle, Jeremy B; Parker, Geoffrey A

    2004-01-06

    Sperm competition occurs when sperm from more than one male compete for fertilizations. This form of post-copulatory sexual selection is recognized as a significant and widespread force in the evolution of male reproductive biology and as a key determinant of differential male reproductive success. Despite its importance, however, detailed mechanisms of sperm competition at the gamete level remain poorly understood. Here, we use natural variation in spermatozoal traits among wild Atlantic salmon (Salmo salar), a species naturally adapted to sperm competition, to examine how the relative influences of sperm (i) number, (ii) velocity, (iii) longevity, and (iv) total length determine sperm competition success. Atlantic salmon fertilize externally, and we were therefore able to conduct controlled in vitro fertilization competitions while concurrently measuring spermatozoal traits within the aqueous micro-environment to which salmon gametes are naturally adapted. Microsatellite DNA fingerprinting revealed that a male's relative sperm velocity was the primary determinant of sperm competition success. There was no significant relationship between fertilization success and either relative sperm number or total length; sperm longevity showed an inverse relationship with competition success. These relationships were consistent for two experimental repeats of the in vitro fertilization competitions. Our results therefore show, under the natural microenvironment for salmon gametes, that relative sperm velocity is a key spermatozoal component for sperm competition success. Atlantic salmon sperm can be considered to enter a competition analogous to a race in which the fastest sperm have the highest probability of success.

  13. Efficient Management of Nitrogen Fertilizers for Flooded Rice in Relation to Nitrogen Transformations in Flooded Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUZHAO-LIANG

    1992-01-01

    Recent progresses in efficient management of nitrogen fertilizers for flooded rice in relation to nitrogen transformations in flooded soil were reviewed.Considerable progress has been achieved in the investigation on the mechanism of ammonia loss and the factors affecting it .However,little progress has been obtained in the investigations on nitrification-denitrification loss owing to the lack of method for estimating the fluxes of gaseous N products.Thus,so far the management practices developed or under investigation primarily for reducing ammonia loss are feasible or promising,while those for reducing nitrification-denitrification loss seem obscure,except the point deep placement. In addition,it was emphasized that the prediction of soil N supply and the recommendation of the optimal rate of N application based on it are only semi-quantitative.The priorities in research for improving the prediction are indicated.

  14. Assessment of non-marital sexual behaviours of men in Bangladesh: a methodological experiment using a modified confidential ballot-box method.

    Science.gov (United States)

    Chowdhury, M E; Alam, N; Anwar, I; Ahmed, A; Saidel, T; Mallick, P S; Kelly, R; Streatfield, P K

    2012-03-01

    This study assessed the effectiveness of a modified ballot-box method (MBBM) in eliciting non-marital sexual behaviours compared with face-to-face interview (FTFI). A cross-sectional survey collected data from men aged 18-49 years in Bangladesh using a multistage cluster sampling method. In total, 3499 and 3623 respondents were interviewed by MBBM and FTFI, respectively. In the MBBM, pre-recorded questions were administered using a portable audio-cassette player with two pairs of headphones used concurrently by the respondent and the interviewer. Overall, 18% of the respondents had non-marital sexual exposure in the past year. The MBBM elicited higher responses of non-marital sex (adjusted odds ratio (aOR) 1.3, 95% confidence interval [CI]: 1.1, 1.5) compared with FTFI. The interview methods did not, however, revealed significant differences in response to condom-use rates and the number of non-marital sexual partners. The MBBM is more effective than the FTFI method in eliciting higher responses rates of non-marital sexual contacts and may be recommended for reliable estimates of sexual behaviours.

  15. Vegetation dynamics using AVHRR/NDVI: Regional climate, carbon dioxide fertilization and crop yield relations

    Science.gov (United States)

    Lim, Chai Kyung

    Vegetation development is closely related to climate factors, and, therefore, it is important to understand how it responds to global climate changes. For the last two decades it has been possible to monitor vegetation development at continental or global scales utilizing remote sensing Normalized Difference Vegetation Index (NDVI) data. We have developed a frequency analysis method to investigate land's vegetation greenness change and its response to the El Nino Southern Oscillation (ENSO). We found an ENSO influence on a tropical forest, southern semi-deciduous forest and a northeastern mixed forest. Our analysis shows the annual trends in vegetation greenness respond more sensitively than averaging methods. Atmospheric CO2 increase is another concern for climate change, for which fertilization effect on land vegetation has been suggested. Atmospheric CO2 and NDVI have a seasonal pattern of negative correlation, which makes it difficult to discern any positive influence of CO2 on vegetation. We adopted the concept of the rate of change in atmospheric CO2 concentration and NDVI to overcome this set pattern, and to reveal undergoing fluctuations. We found evidence that suggests a CO2 fertilization effect in some arctic and sub arctic regions and northern and inland parts of the eastern humid temperate zones in North America. Although NDVI reveals the vegetation greenness only at a fixed time and location, we have transformed NDVI effectively to describe the vegetation growth dynamics in the form of a new index, Normalized Growth Index (NGI). Utilizing NGI, we found the vegetation growth during the growing season is highly negatively correlated with the initial minimum vegetation greenness. One needs to be careful when comparing Net Primary Production (NPP) using NDVI between different types of vegetation, because the same NDVI value can imply the existence of different biomass due to different Leaf Area Index (LAI). To overcome this difficulty we have developed

  16. Relation between N fertilization and N{sub 2}O release in different crop rotations

    Energy Technology Data Exchange (ETDEWEB)

    Stoeven, K.; Kohrs, K.; Schnug, E. [Federal Research Central Agency, Braunschweig (Germany)

    2002-07-01

    The influence of N-fertilization and crop species on the release of the greenhouse gas N{sub 2}O was investigated at two sites in northern Germany from June 1994 till October 1996. The N{sub 2}O release was measured daily. The results were correlated to the nitrate and ammonia content of the soil as well as to fertilizer type, crop species and soil moisture. The results of the investigations showed no effect of N-fertilizer type or crop species on the N{sub 2}O release. Main result of this work is that lowering the N fertilization to about 50% of the standard could reduce the N{sub 2}O release.

  17. A study of artificial insemination in relation to fertility and hatchability in white Leghorn birds.

    Science.gov (United States)

    Dubey, R A; Johari, D C; Singh, R P; Singh, B P

    1977-02-01

    To each of 24 cocks, 3 hens were alloted for artifical insemination. Seman was collected by the massage method. Freshly collected semen (.1 ml) was introduced into the oviduct of each hen every week. All eggs were incubated. On the 7th day of incubation, eggs were tested and infertile ones removed. On the 18th day eggs containing live embryos were kept for hatching. On the 21st days the number of chicks hatched was recorded. 86.3% or 667 eggs were fertile and 69.8% of them hatched. Fertility was similar to natural mating. There was a statistically significant difference in fertility between cocks but hatchability of fertile eggs was similar. It is suggested that artificial insemination may be used as a practical mating system for caged birds.

  18. Relationship between reproductive allocation and relative abundance among 32 species of a Tibetan alpine meadow: effects of fertilization and grazing.

    Directory of Open Access Journals (Sweden)

    Kechang Niu

    Full Text Available BACKGROUND: Understanding the relationship between species traits and species abundance is an important goal in ecology and biodiversity science. Although theoretical studies predict that traits related to performance (e.g. reproductive allocation are most directly linked to species abundance within a community, empirical investigations have rarely been done. It also remains unclear how environmental factors such as grazing or fertilizer application affect the predicted relationship. METHODOLOGY: We conducted a 3-year field experiment in a Tibetan alpine meadow to assess the relationship between plant reproductive allocation (RA and species relative abundance (SRA on control, grazed and fertilized plots. Overall, the studied plant community contained 32 common species. PRINCIPAL FINDINGS: At the treatment level, (i RA was negatively correlated with SRA on control plots and during the first year on fertilized plots. (ii No negative RA-SRA correlations were observed on grazed plots and during the second and third year on fertilized plots. (iii Seed size was positively correlated with SRA on control plots. At the plot level, the correlation between SRA and RA were not affected by treatment, year or species composition. CONCLUSIONS/SIGNIFICANCE: Our study shows that the performance-related trait RA can negatively affect SRA within communities, which is possibly due to the tradeoffs between clonal growth (for space occupancy and sexual reproduction. We propose that if different species occupy different positions along these tradeoffs it will contribute to biodiversity maintenance in local communities or even at lager scale.

  19. Plate Tectonics Constrained by Evidence-Based Magmatic Temperatures and Phase Relations of Fertile Lherzolite (Invited)

    Science.gov (United States)

    Green, D. H.; Falloon, T.

    2010-12-01

    In order to understand Earth’s plate tectonics we must interpret the most direct probes for mantle composition and temperature distribution i.e. the primitive basaltic magmas and peridotites representing partial melts and mantle residues. An evidence-based approach to identification of parental magmas and determination of their temperatures requires glass and phenocryst compositions and experimentally calibrated Fe/Mg partitioning between olivine and melt. We have compared magmatic crystallization temperatures between ‘hot-spot’(proposed to be plume-related) and normal mid-ocean ridge basalt (MORB) parental liquids, by examining three representative magmatic suites from both ocean island (Hawaii, Iceland, and Réunion) and mid-ocean ridge settings (Cocos-Nazca, East Pacific Rise, and Mid-Atlantic Ridge). We have glass and olivine phenocryst compositions, including volatile (H2O) contents, and have calculated parental liquid compositions at 0.2GPa by incrementally adding olivine back into the glass compositions until a liquid in equilibrium with the most-magnesian olivine phenocryst composition is obtained. The results of these calculations demonstrate that there is very little difference (maximum of ~20°C) between the ranges of crystallization temperatures of the parental liquids (MORB:1243-1351°C versus OIB:1286-1372°C) when volatile contents are taken into account. However while lacking temperature contrast, the source regions for ‘hot-spot’ parental magmas contain geochemical signatures of old subducted crust/lithosphere. The mantle depths of origin determined for both the MORB and OIB suites are similar (MORB:1-2 GPa; OIB:1-2.5 GPa). Calculations of mantle potential temperatures (Tp) are model dependent, particularly to melt fraction from an inferred source. Assuming similar fertile lherzolite sources, the differences in Tp values between the hottest MORB and the hottest ocean island tholeiite sources are ~80°C. These differences disappear if the

  20. Paternal Urinary Concentrations of Parabens and Other Phenols in Relation to Reproductive Outcomes among Couples from a Fertility Clinic

    Science.gov (United States)

    Dodge, Laura E.; Williams, Paige L.; Williams, Michelle A.; Missmer, Stacey A.; Toth, Thomas L.; Calafat, Antonia M.

    2015-01-01

    Background Human exposure to phenols, including bisphenol A and parabens, is widespread. Evidence suggests that paternal exposure to environmental chemicals may adversely affect reproductive outcomes. Objectives We evaluated associations of paternal phenol urinary concentrations with fertilization rate, embryo quality, implantation, and live birth. Methods Male–female couples who underwent in vitro fertilization (IVF) and/or intrauterine insemination (IUI) cycles in a prospective study of environmental determinants of fertility and pregnancy outcomes were included. The geometric mean of males’ specific gravity–adjusted urinary phenol concentrations measured before females’ cycle was quantified. Associations between male urinary phenol concentrations and fertilization rate, embryo quality, implantation, and live birth were investigated using generalized linear mixed models to account for multiple cycles per couple. Results Couples (n = 218) underwent 195 IUI and 211 IVF cycles. Paternal phenol concentrations were not associated with fertilization or live birth following IVF. In adjusted models, compared with the lowest quartile of methyl paraben, paternal concentrations in the second quartile were associated with decreased odds of live birth following IUI (adjusted odds ratio = 0.19; 95% CI: 0.04, 0.82). Conclusions To our knowledge, these are some of the first data on the association of paternal urinary phenol concentrations with reproduction and pregnancy outcomes. Although these results do not preclude possible adverse effects of paternal paraben exposures on such outcomes, given the modest sample size, further understanding could result from confirmation using a larger and more diverse population. Citation Dodge LE, Williams PL, Williams MA, Missmer SA, Toth TL, Calafat AM, Hauser R. 2015. Paternal urinary concentrations of parabens and other phenols in relation to reproductive outcomes among couples from a fertility clinic. Environ Health Perspect 123

  1. Temperature Difference Between the Air and Organs of Rice Plant and Its Relation to Spikelet Fertility

    Institute of Scientific and Technical Information of China (English)

    YAN Chuan; DING Yan-feng; LIU Zheng-hui; WANG Qiang-sheng; LI Gang-hua; HE Ying; WANG Shao-hua

    2008-01-01

    Based on the experiment of measuring panicles and leaves, air temperature, and humidity above the canopy of rice cultivars after heading in 2005 and 2006, we investigated the temperature difference (TD) between the air and organs of rice plant and its relationship with spikelet fertility. The results showed that TDs between the air and organs of rice varied with air temperature, air humidity, and plant type. For similar air humidity, TDs were lower at the air temperature of 28.5℃ than at higher temperature of 35.5℃, whereas for the same air temperature, the TDs decreased as the air humidity increased. TDs were also affected by plant type of the cultivars. Erect panicle cultivars showed higher TDs than those with droopy panicles under similar climatic conditions, and cultivars with panicles above flag leaf (PAFL) had higher TDs than those with panicles below the flag leaf (PBFL). Cultivars grown in a location with lower air humidity and higher temperature, such as Taoyuan, China, had higher spikelet fertility than those in higher humidity under the similar air temperature during the grain filling stage. This is partially attributed to the larger TDs under the lower humidity. Row-spacing and the ratio of basal-tillering to panicle-spikelet fertilizer showed a significant influence on TD and subsequently on spikelet fertility, suggesting the possibility of increasing spikelet fertility by agronomic management.

  2. The impact of social relations among men and women in fertility treatment on the decision to terminate treatment

    DEFF Research Database (Denmark)

    Vassard, Ditte; Lund, Rikke; Pinborg, Anja;

    2012-01-01

    clinics during their initial visit and follow-up data were collected after 1 year. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study group (n = 777; 427 women, 350 men) consisted of patients who did not achieve a live birth or an ongoing pregnancy during follow-up. Social support and strain from......STUDY QUESTION: Do social support and social strain from social relations have an impact on the decision to terminate fertility treatment among men and women after 1 year of unsuccessful treatment? SUMMARY ANSWER: Several functional aspects of social relations show an impact on the probability...... to terminate treatment; social support from family significantly decreases the probability to terminate and experience of conflicts or problematic communication with the partner significantly increases the probability to terminate treatment. WHAT IS KNOWN ALREADY: Fertility patients can experience...

  3. The value of Anti-Mullerian hormone in low and extremely low ovarian reserve in relation to live birth after in vitro fertilization

    NARCIS (Netherlands)

    Reijnders, I.F.; Nelen, W.L.D.M.; Hout, J. in't; Herwaarden, A.E. van; Braat, D.D.M.; Fleischer, K.

    2016-01-01

    OBJECTIVE: To determine the relation of Anti-Mullerian hormone (AMH) with live birth after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in women with (extremely) low ovarian reserve. STUDY DESIGN: This study was a retrospective cohort study in a Dutch tertiary fertility

  4. The value of Anti-Mullerian hormone in low and extremely low ovarian reserve in relation to live birth after in vitro fertilization

    NARCIS (Netherlands)

    Reijnders, I.F.; Nelen, W.L.D.M.; Hout, J. in't; Herwaarden, A.E. van; Braat, D.D.M.; Fleischer, K.

    2016-01-01

    OBJECTIVE: To determine the relation of Anti-Mullerian hormone (AMH) with live birth after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in women with (extremely) low ovarian reserve. STUDY DESIGN: This study was a retrospective cohort study in a Dutch tertiary fertility c

  5. Development of a forecasting tool to guide field management decisions related to fertilizer and manure

    Science.gov (United States)

    Managing the timing of fertilizer and manure application is critical to protecting water quality in the Chesapeake Bay watershed. While modern nutrient management tools are designed to help farmers with their long-term field management planning, they do not support daily decisions on when and where...

  6. Diffusion and Adoption of Innovations in Fertilizer-Related Agricultural Production Technology in Developing Countries.

    Science.gov (United States)

    Byrnes, Kerry J.

    This monograph reviews a wide range of research literature on the diffusion and adoption of innovations in agricultural production technology in the developing countries, with particular emphasis on the practice of using commercially purchased, inorganic fertilizer as a source of plant nutrients. It is intended that the report's documentation of…

  7. ION CHROMATOGRAPHIC DETERMINATION OF PERCHLORATE ION: ANALYSIS OF FERTILIZERS AND RELATED MATERIALS

    Science.gov (United States)

    A solid fertilizer sample is dissolved or leached to solutilize the perchlorate as the aqueous anion. If needed, the liquid is filtered or centrifuged. The rsulting solution is subjected to ion chromatography using an adaptation of EPA Method 314.0. Preliminary screenng is requir...

  8. Extended Axiomatic Conjoint Measurement: A Solution to a Methodological Problem in Studying Fertility-Related Behaviors.

    Science.gov (United States)

    Nickerson, Carol A.; McClelland, Gary H.

    1988-01-01

    A methodology is developed based on axiomatic conjoint measurement to accompany a fertility decision-making model. The usefulness of the model is then demonstrated via an application to a study of contraceptive choice (N=100 male and female family-planning clinic clients). Finally, the validity of the model is evaluated. (TJH)

  9. Sociocultural factors influencing decision-making related to fertility among the Kanuri tribe of north-eastern Nigeria

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    Abdulkarim G. Mairiga

    2010-03-01

    Full Text Available Background: The Kanuri tribe is found in the Lake Chad basin. However, the majority of the tribe lives in Borno State, Nigeria. Before this study was undertaken, factors related to fertility decisions among the tribe were not known. Objectives: This study is aimed at describing and documenting the sociocultural factors affecting decisions related to fertility among the Kanuri tribe. Method: The study applied the qualitative research method. In-depth interviews and focus-group discussions were used as data collection methods. Analysis was done manually.Results: Children among the Kanuri were highly valued and desired irrespective of their gender. The ideal family size, according to most of the respondents, was 16 children. Kanuri men are polygamous and can marry up to four wives in order to form large families. However, it is an abomination among Kanuri women to fall pregnant in quick succession; a phenomenon they termed konkomi. Other reasons for child-spacing were related to child welfare and maternal well-being. Methods for child-spacing included prolonged breastfeeding (Nganji yaye, ornaments in various forms and shapes, spiritual invocations and dried herbs (Nganji Yandeye. Few Kanuri women practiced modern methods of family planning. Conclusion: Trends in fertility among the Kanuri tribe need to be monitored regularly and appropriate measures be taken to introduce and promote modern family planning and child health services to ensure a healthier family life.

  10. Assessment of sperm quality traits in relation to fertility in boar semen

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    Zilinskas Henrikas

    2009-12-01

    Full Text Available Abstract Background Several studies have been published where sperm plasma membrane integrity correlated to fertility. In this study we describe a simple fluorometer-based assay where we monitored the fluorescence intensity of artificially membrane-ruptured spermatozoa with a fixed time staining with fluorescent DNA dyes. Methods Membrane-impermeant fluorescent dyes Hoechst 33258 (H258 and propidium iodide (PI were used to measure the fluorescence of the nucleus in artificially membrane ruptured spermatozoa and membrane-permeant dye Hoechst 33342 (H342 was used to measure fluorescence of intact spermatozoa. The concentration of spermatozoa in insemination doses varied from 31.2 × 106/ml to 50 × 106/ml and the average value was 35 × 106/ml. Each boar was represented by three consecutive ejaculates, collected at weekly intervals. Nonreturn rate within 60 days of first insemination (NR % and litter size (total number of piglets born of multiparous farrowings were used as fertility measures. Results Sperm fluorescence intensity of H258 and H342, but not the fluorescence intensity of PI-stained spermatozoa correlated significantly with the litter size of multiparous farrowings, values being r = - 0.68 (P Conclusions The increase in fluorescence values of membrane-ruptured H258 and unruptured H342-stained spermatozoa in boar AI doses can be associated with smaller litter size after AI. This finding indicates that the fluorescence properties of the sperm nucleus could be used to select for AI doses with greater fertilizing potential.

  11. Fertility-related quality of life from two RCT cohorts with infertility: unexplained infertility and polycystic ovary syndrome.

    Science.gov (United States)

    Santoro, Nanette; Eisenberg, Esther; Trussell, J C; Craig, LaTasha B; Gracia, Clarisa; Huang, Hao; Alvero, Ruben; Casson, Peter; Christman, Gregory; Coutifaris, Christos; Diamond, Michael; Jin, Susan; Legro, Richard S; Robinson, Randal D; Schlaff, William D; Zhang, Heping

    2016-10-01

    Does fertility-related quality of life (FertiQOL) differ by infertility diagnosis between women with polycystic ovary syndrome (PCOS) and their partners, compared with couples with unexplained infertility (UI)? Women with PCOS report lower QOL than those with UI, whereas males with UI report lower QOL than males with PCOS partners. The fertility-specific QOL survey, FertiQOL, has been used to examine fertility-related QOL in a number of worldwide cohorts. Few data have addressed fertility-related QOL as a function of infertility diagnosis. Overall, men report better QOL than women with infertility, and there is variation in FertiQOL scores across different samples from different countries. This was a prospective, cohort study derived from two concurrent, randomized clinical trials, and designed to examine QOL in infertile females with PCOS and UI at the time of enrollment compared with each other and their male partners; to compare concordance FertiQOL scores in this study across other worldwide cohorts; and to determine if baseline FertiQOL was associated with pregnancy outcome. Women with PCOS and their partners (n = 733 and n = 641, respectively), and couples with UI (n = 865 women and 849 men) completed a validated fertility-specific QOL survey (FertiQOL) at the time of the study screening visit. PCOS women were randomized to either clomiphene citrate or letrozole treatment; couples with UI were randomized to clomiphene citrate, letrozole or gonadotrophin plus IUI. FertiQOL results were compiled by diagnosis (PCOS or UI) and compared by diagnosis and sex using Wilcoxon Rank-Sum testing. Relationships between baseline FertiQOL and pregnancy outcomes were examined using logistic regression. Multivariable models were performed to assess the association between FertiQOL scores and key participant characteristics. Women with PCOS had lower total FertiQOL scores (72.3 ± 14.8) than those with UI (77.1 ± 12.8; P Pharmaceuticals and Roche Diagnostics; R.S.L. reports

  12. Low-income mothers as "othermothers" to their romantic partners' children: women's coparenting in multiple partner fertility relationships.

    Science.gov (United States)

    Burton, Linda M; Hardaway, Cecily R

    2012-09-01

    In this article, we investigated low-income mothers' involvement in multiple partner fertility (MPF) relationships and their experiences as "othermothers" to their romantic partners' children from previous and concurrent intimate unions. Othermothering, as somewhat distinct from stepmothering, involves culturally-scripted practices of sharing parenting responsibilities with children's biological parents. We framed this investigation using this concept because previous research suggests that many low-income women practice this form of coparenting in their friend and kin networks. What is not apparent in this literature, however, is whether women unilaterally othermother their romantic partners' children from different women. How often and under what circumstances do women in nonmarital MPF intimate unions with men coparent their partners' children from other relationships? We explored this question using a modified grounded theory approach and secondary longitudinal ethnographic data on 256 low-income mostly unmarried mothers from the Three-City Study. Results indicated that 78% of the mothers had been or were involved in MPF unions and while most had othermothered the children of their friends and relatives, 89% indicated that they did not coparent their partners' children from any MPF relationship. Mothers' reasons for not doing so were embedded in: (a) gendered scripts around second families, or "casa chicas"; (b) the tenuous nature of pass-through MPF relationships; and (c) mothers' own desires for their romantic partners to child-swap. Implications of this research for family science and practice are discussed.

  13. Molecular and Cellular Mechanisms of Sperm-Oocyte Interactions Opinions Relative to in Vitro Fertilization (IVF

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    George Anifandis

    2014-07-01

    Full Text Available One of the biggest prerequisites for pregnancy is the fertilization step, where a human haploid spermatozoon interacts and penetrates one haploid oocyte in order to produce the diploid zygote. Although fertilization is defined by the presence of two pronuclei and the extraction of the second polar body the process itself requires preparation of both gametes for fertilization to take place at a specific time. These preparations include a number of consecutive biochemical and molecular events with the help of specific molecules and with the consequential interaction between the two gametes. These events take place at three different levels and in a precise order, where the moving spermatozoon penetrates (a the outer vestments of the oocyte, known as the cumulus cell layer; (b the zona pellucida (ZP; where exocytosis of the acrosome contents take place and (c direct interaction of the spermatozoon with the plasma membrane of the oocyte, which involves a firm adhesion of the head of the spermatozoon with the oocyte plasma membrane that culminates with the fusion of both sperm and oocyte membranes (Part I. After the above interactions, a cascade of molecular signal transductions is initiated which results in oocyte activation. Soon after the entry of the first spermatozoon into the oocyte and oocyte activation, the oocyte’s coat (the ZP and the oocyte’s plasma membrane seem to change quickly in order to initiate a fast block to a second spermatozoon (Part II. Sometimes, two spermatozoa fuse with one oocyte, an incidence of 1%–2%, resulting in polyploid fetuses that account for up to 10%–20% of spontaneously aborted human conceptuses. The present review aims to focus on the first part of the human sperm and oocyte interactions, emphasizing the latest molecular and cellular mechanisms controlling this process.

  14. Relation of the male gametes with embryo sec cells. The hypothesis of double fertilization

    Directory of Open Access Journals (Sweden)

    N. S. Belayeva

    2014-01-01

    Full Text Available The sperms one after another get out of synergids. The front sperm gets the first into the egg cell attraction zone and then the sperm comes into contact with egg membrane. At this moment Attraction ceases and the second sperm is led by a current of cytoplasma to the central nucleus. In the egg cell the sperm nucleus is led to the nucleus by cytoplasmic current too. After fertilization the character of cytoplasmic motion changes, because of a cell membrane damage. The presence of the sperm in the female nuclei may also serve as a regulating factor.

  15. Endometrial receptivity: clinical assessment in relation to fertility, infertility, and antifertility.

    Science.gov (United States)

    Makker, Annu; Singh, M M

    2006-11-01

    Fertility in humans and other mammalian species depends absolutely on synchronous events that render the developing blastocyst and the receiving uterus competent for implantation. Endometrial receptivity is defined as the period during which the endometrial epithelium acquires functional, but transient, ovarian steroid-dependent status supportive to blastocyst acceptance and implantation. Once inside the uterus, the blastocyst is surrounded by an intact luminal epithelium, which is considered to act as barrier to its attachment, except for this short period of high endometrial receptivity to blastocyst signal(s). Its transport and permeability properties, in conjunction with cellular action of the endometrium and the embryo, have been suggested to influence creation and maintenance of informational and nutritional status of uterine luminal milieu. This period, also termed as the 'window of implantation,' is limited to days 20-24 of menstrual cycle in humans. However, establishment of endometrial receptivity is still a biological mystery that remains unsolved despite marked advances in our understanding of endometrial physiology following extensive research associated with its development and function. This review deals with various structural, biochemical, and molecular events in the endometrium coordinated within the implantation window that constitute essential elements in the repertoire that signifies endometrial receptivity and is aimed to achieve a better understanding of its relationship to fertility, infertility, and for the development of targeted antifertility agents for human use and welfare.

  16. Alfalfa (Medicago sativa L.) seed yield in relation to phosphorus fertilization and honeybee pollination.

    Science.gov (United States)

    Al-Kahtani, Saad Naser; Taha, El-Kazafy Abdou; Al-Abdulsalam, Mohammed

    2017-07-01

    This investigation was conducted at the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia, during the alfalfa growing season in 2014. The study aimed to evaluate the impact of phosphorus fertilization and honeybee pollination on alfalfa seed production. The experiment was divided into 9 treatments of open pollination, honeybee pollination, and non-pollination with three different levels (0, 300 or 600 kg P2O5/ha/year) of triple super phosphate. All vegetative growth attributes of Hassawi alfalfa were significantly higher in the non-insect pollination plots, while the yield and yield component traits were significantly higher with either open pollination or honeybee pollination in parallel with the increasing level of phosphorus fertilizer up to 600 kg P2O5/ha/year in light salt-affected loamy sand soils. There was no seed yield in Hassawi alfalfa without insect pollination. Therefore, placing honeybee colonies near the fields of Hassawi alfalfa and adding 600 kg P2O5/ha/year can increase seed production.

  17. Alfalfa (Medicago sativa L. seed yield in relation to phosphorus fertilization and honeybee pollination

    Directory of Open Access Journals (Sweden)

    Saad Naser Al-Kahtani

    2017-07-01

    Full Text Available This investigation was conducted at the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia, during the alfalfa growing season in 2014. The study aimed to evaluate the impact of phosphorus fertilization and honeybee pollination on alfalfa seed production. The experiment was divided into 9 treatments of open pollination, honeybee pollination, and non-pollination with three different levels (0, 300 or 600 kg P2O5/ha/year of triple super phosphate. All vegetative growth attributes of Hassawi alfalfa were significantly higher in the non-insect pollination plots, while the yield and yield component traits were significantly higher with either open pollination or honeybee pollination in parallel with the increasing level of phosphorus fertilizer up to 600 kg P2O5/ha/year in light salt-affected loamy sand soils. There was no seed yield in Hassawi alfalfa without insect pollination. Therefore, placing honeybee colonies near the fields of Hassawi alfalfa and adding 600 kg P2O5/ha/year can increase seed production.

  18. Canine gestation length: variation related to time of mating and fertile life of sperm.

    Science.gov (United States)

    Concannon, P; Whaley, S; Lein, D; Wissler, R

    1983-10-01

    Variation in canine gestation length was studied in a Beagle colony (n = 290) in which apparent gestation length, estimated as the interval from the day of first mating to the day of parturition, ranged from 57 to 72 days, and averaged 65.3 +/- 0.2 days. The interval from the day of the peak in luteinizing hormone (LH) to parturition was less variable and ranged from 64 to 66 days and averaged 65.1 +/- 0.1 days (n = 54). Apparent gestation lengths less than or equal to 61 days all resulted from mating greater than or equal to 3 days after the LH peak; those greater than or equal to 68 days all followed initial or single matings occurring greater than or equal to 2 days before the LH peak. Fertile single matings 3 days before the LH peak provided evidence that the potential postcoital fertile longevity of canine sperm is at least 6 days and thus contributed, along with variability in the onset of estrus, to the observed variation in apparent gestation length in the dog. The limited range in the interval from the day of the preovulatory LH peak to the day of parturition (64, 65, or 66 days) demonstrates a considerable regularity in the sequential events of gestation in the dog.

  19. Arylsulphatase activity and sulphate content in relation to crop rotation and fertilization of soil

    Science.gov (United States)

    Siwik-Ziomek, Anetta; Lemanowicz, Joanna; Koper, Jan

    2016-07-01

    The aim of the study was to investigate the effect of varying rates of FYM (0, 20, 40, 60 Mg ha-1) and nitrogen N0, N1, N2, and N3 on the content of sulphate sulphur (VI) and the activity of arylsulphatase, which participates in the transformations of this element in Haplic Luvisol. The study report is based on a long-term field experiment with two different crop rotations: A - recognized as exhausting the humus from soil and B - recognized as enriching the soil with humus. During the cultivation of the plants, the soil was sampled four times from corn and a red clover cultivar and grass. The FYM fertilization rate for which the highest arylsulphatase activity and the content of sulphates were identified was 60 Mg ha-1. An inhibitory effect of high rates (90 and 135 kg N ha-1) of ammonium nitrate on the arylsulphatase activity was also observed. A significant correlation between the content of carbon, nitrogen, and sulphates and the arylsulphatase activity was recorded. The investigation on the effect of combined application of farmyard manure and mineral nitrogen fertilization on the activity of arylsulphatase participating in the sulphur cycling was launched to examine the problem in detail.

  20. Evaluation of buffalo semen by Trypan blue/Giemsa staining and related fertility in vitro

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    B. Gasparrini

    2010-02-01

    Full Text Available The aim of this work was to verify the feasibility of an easy, quick double staining technique for evaluation of frozen-thawed semen to predict the fertilizing capability in vitro of buffalo bulls. In Experiment 1, frozen-thawed semen from 6 bulls was stained with double Trypan blue/ Giemsa and the incidence of acrosome-intact live (AIL, acrosome-intact dead (AID, acrosome-lost live (ALL and acrosome-lost dead (ALD sperm was recorded. In Experiment 2, sperm from the same bulls were used to fertilize in vitro matured oocytes. The data obtained confirm that there is a strong “bull effect” in buffalo species, with differences in the percentage of AIL sperm at thawing, in cleavage and blastocyst rates among bulls. Interestingly, it was found that this staining technique can be used for a preliminary screening to select semen to use for IVF, as shown by the correlation existent between the percentages of acrosome-intact viable sperm cells at thawing and the blastocyst yields for 4/6 bulls.

  1. Biomass yield and energy analysis of soybean production in relation to fertilizer-NPK and organic manure

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, K.G.; Hati, K.M.; Misra, A.K. [Division of Soil Physics, Indian Institute of Soil Science (ICAR), Nabibagh, Berasia Road, Bhopal 462 038, Madhya Pradesh (India)

    2009-12-15

    The study attempts to quantify the root biomass and density, nodulation, crop biomass and grain yield of soybean, to analyze crop growth and energy (renewable and non-renewable) inputs in relation to fertilizer-NPK and organic manure. Observations were recorded from soybean grown with no fertilizer, NPK and NPK + FYM (farmyard manure). The root biomass (BM{sub root}) increased significantly with NPK + FYM compared to NPK and control. The trend of BM{sub root} was best fitted with a third order polynomial. Root length density was higher in NPK + FYM. Biomass of stem, petiole and leaf were significantly greater in NPK + FYM than other treatments, relative contribution to total biomass at physiological maturity were stem 29%, petiole 9%, leaf 17% and pod 46%; quadratic regression models best represented the stem, petiole and leaf biomass data. A maximum LAI of 4.88, total biomass of 633 g m{sup -2} at maturity, CGR of 18.4 g m{sup -2} d{sup -1} were recorded in NPK + FYM. Grain yields increased by 72.5 and 98.5%, and stover yields by 56.0 and 94.8% in NPK and NPK + FYM, respectively over control. Though the total energy input in NPK + FYM was greater than those in NPK and control, the share of renewable energy was much higher with greater net energy output and non-renewable energy productivity in NPK + FYM than NPK. The use efficiency of non-renewable energy was also higher in NPF + FYM. Thus, a combination of NPK-fertilizer and organic manure (FYM) could be the viable nutrient management option for soybean production. (author)

  2. 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.

    Science.gov (United States)

    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 (Pavidin 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. © 2015 Poultry Science Association Inc.

  3. Comparison of age-related changes in anti-Müllerian hormone levels and other ovarian reserve tests between healthy fertile and infertile population.

    Science.gov (United States)

    Bozkurt, Banu; Erdem, Mehmet; Mutlu, Mehmet Firat; Erdem, Ahmet; Guler, Ismail; Mutlu, Ilknur; Oktem, Mesut

    2016-09-01

    In this study, we aimed to determine whether anti-Müllerian hormone (AMH) levels vary between fertile and infertile populations and compare them with basal follicle-stimulating hormone (FSH) levels and antral follicle count (AFC). This was a prospective study that included 177 primarily infertile patients who underwent IVF treatment and 162 healthy fertile patients admitted to our clinic for benign diseases. FSH and AMH levels and the AFC of the infertile and fertile populations were compared between the age categories age were evaluated. AFC and AMH levels did not differ between the fertile and infertile groups in all age categories. AMH was inversely correlated with age in both the fertile and infertile populations. However, AFC revealed a stronger correlation with age in both the fertile and infertile populations compared with basal FSH and AMH. Age was positively correlated with basal FSH and inversely correlated with AMH and AFC. In conclusion, there was no significant difference between the fertile and infertile populations in terms of AMH or AFC. The decrease in ovarian reserve in infertile patients is directly related to age, not infertility.

  4. [Effects of applying different kind fertilizers on enzyme activities related to carbon, nitrogen, and phosphorus cycles in reddish paddy soil].

    Science.gov (United States)

    Xu, Li-Li; Wang, Qiu-Bing; Zhang, Xin-Yu; Sun, Xiao-Min; Dai, Xiao-Qin; Yang, Feng-Ting; Bu, Jin-Feng; Wang, Hui-min

    2013-04-01

    Based on the long-term fixed position experimental data from Qianyanzhou Ecological Experiment Station, Chinese Academy of Sciences in 1998, this paper analyzed the effects of applying different kind fertilizers (straw, ST; pig manure, OM; and chemical fertilizer, NPK) on the nutrients (C, N, and P) status and the activities of related enzymes ( beta-1,4-glucosidase, betaG; beta-1,4-N-acetylglucosaminidase, NAG; L-leucine aminopeptidase, LAP; and acid phosphatase, AP) in reddish paddy soil. With the application of OM, the activities of soil betaG, NAG, and LAP increased significantly, as compared with other treatments, and were 1.4, 2. 6, and 1.9 times higher than the control (CK) , respectively. Applying OM also improved the ratio of soil organic carbon to total nitrogen (C/N), but decreased the soil betaG/(NAG+LAP) ratio, suggesting that pig manure could benefit the degradation of soil cellulose and the accumulation of soil organic carbon. Applying NPK increased the activities of soil betaG, NAG, and LAP, but decreased the AP activity, with a decrement of 34% as compared with CK. Under the application of NPK, the soilbetaG/AP and (NAG+ LAP)/AP ratios increased, but the ratios of soil organic carbon to total phosphorus (C/P) and of soil total nitrogen to total phosphorus (N/P) decreased, indicating that chemical fertilizers could induce the accumulation of soil inorganic phosphorus, and inhibit the microbial functions of degrading polysaccharides and phosphate phospholipids.

  5. On the relative effect of spawning asynchrony, sperm quantity and sperm quality on paternity under sperm competition in an external fertilizer

    Directory of Open Access Journals (Sweden)

    Torvald Blikra Egeland

    2015-07-01

    Full Text Available How much of a fitness benefit is obtained by dominant males of external fertilizers from releasing ejaculates in synchrony with female egg-release when engaging in sperm competition, and what is the most important sperm trait for paternity in these situations? The Arctic charr (Salvelinus alpinus is an external fertilizer experiencing intense male-male competition over reproductive opportunities including sperm competition. To compensate for their disadvantage the sneaker males, which often spawn out of synchrony with the female, produce more and faster sperm than the guarding males. We used controlled in vitro fertilization trials with experimentally produced dominant and subordinate, sneaker males to test what effect relative synchrony in gamete release, sperm quality (i.e., motility and velocity and sperm quantity have on a male’s fertilization success in pair-wise sperm competitions. When the sneaker males released ejaculates after the guarding male there was no overall difference in fertilization success. The quality (i.e., motility and velocity of a male’s sperm relative to that of the competing male was the best predictor of male fertilization success regardless of their mating tactic and spawning synchrony. The relative number of sperm cells also had an effect on fertilization success, but mainly when the dominant and sneaker male ejaculated synchronously. Our close imitation of natural sperm competition in charr shows that the sneaker males of external fertilizing species may fully compensate for their disadvantaged mating role by producing ejaculates of higher quality - an adjustment strangely not met by dominants.

  6. Strategy of specification of management areas: rice grain yield as related to soil fertility

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    Flávio Carlos Dalchiavon

    2013-02-01

    Full Text Available It is well-known nowadays that soil variability can influence crop yields. Therefore, to determine specific areas of soil management, we studied the Pearson and spatial correlations of rice grain yield with organic matter content and pH of an Oxisol (Typic Acrustox under no- tillage, in the 2009/10 growing season, in Selvíria, State of Mato Grosso do Sul, in the Brazilian Cerrado (longitude 51º24' 21'' W, latitude 20º20' 56'' S. The upland rice cultivar IAC 202 was used as test plant. A geostatistical grid was installed for soil and plant data collection, with 120 sampling points in an area of 3.0 ha with a homogeneous slope of 0.055 m m-1. The properties rice grain yield and organic matter content, pH and potential acidity and aluminum content were analyzed in the 0-0.10 and 0.10-0.20 m soil layers. Spatially, two specific areas of agricultural land management were discriminated, differing in the value of organic matter and rice grain yield, respectively with fertilization at variable rates in the second zone, a substantial increase in agricultural productivity can be obtained. The organic matter content was confirmed as a good indicator of soil quality, when spatially correlated with rice grain yield.

  7. Age-related effects of body mass on fertility and litter size in roe deer

    Science.gov (United States)

    Jerina, Klemen; Pokorny, Boštjan

    2017-01-01

    We analysed effects of females’ body mass and age on reproductive capacity of European roe deer (Capreolus capreolus) in a large sample set of 1312 females (305 yearlings and 1007 adults), hunted throughout Slovenia, central Europe, in the period 2013–2015. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea), although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova) even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition. PMID:28403161

  8. Stress and stress-related hormones during in-vitro fertilization treatment.

    Science.gov (United States)

    Harlow, C R; Fahy, U M; Talbot, W M; Wardle, P G; Hull, M G

    1996-02-01

    Whether stress and infertility are linked as cause or consequence is unclear, and there is no consensus on the most appropriate methods for measuring stress in infertile women. To address this question, we measured changes in biochemical and questionnaire-based assessments of stress in infertile women. Median baseline, follicular phase and pre-operative serum prolactin (229, 311 and 457 mIU/l) cortisol (278, 369 and 496 nmol/l) and state anxiety score (38, 40 and 49) respectively all increased during stimulated in-vitro fertilization (IVF) treatment. There was no such increase in a control group having similar laparoscopic surgery unrelated to infertility, or in women having unstimulated IVF without laparoscopy, suggesting that anxiety levels are greatest in stimulated IVF, increase as a result of the treatment, and are adequately reflected by state anxiety scores. Baseline serum prolactin in unstimulated IVF (384 mIU/l) was significantly higher than control (177 mIU/l), although this was not reflected in serum cortisol or state anxiety score. Trait anxiety was constant within and between groups, suggesting that stress is not contributing greatly to the infertility. Women who achieved a pregnancy had similar state anxiety scores to those who failed, suggesting that the degree of anxiety observed during IVF treatment is unlikely to influence the chance of pregnancy. There was a trend towards lower trait anxiety in women who became pregnant, but the numbers were small.

  9. Associations of hypoosmotic swelling test, relative sperm volume shift, aquaporin7 mRNA abundance and bull fertility estimates.

    Science.gov (United States)

    Kasimanickam, R K; Kasimanickam, V R; Arangasamy, A; Kastelic, J P

    2017-02-01

    Mammalian sperm are exposed to a natural hypoosmotic environment during male-to-female reproductive tract transition; although this activates sperm motility in vivo, excessive swelling can harm sperm structure and function. Aquaporins (AQPs) is a family of membrane-channel proteins implicated in sperm osmoregulation. The objective was to determine associations among relative sperm volume shift, hypoosmotic swelling test (HOST), sperm aquaporin (AQP) 7 mRNA abundances, and sire conception rate (SCR; fertility estimate) in Holstein bulls at a commercial artificial insemination center. Three or four sires for each full point SCR score from -4 to +4 were included. Each SCR estimate for study bulls (N = 30) was based on > 500 services (mean ± SEM) of 725 ± 13 services/sire). Sperm from a single collection day (two ejaculates) from these commercial Holstein bulls were used. Relative mRNA expression of AQP7 in sperm was determined by polymerase chain reaction. Mean relative sperm volume shift and percentage of sperm reacted in a HOST (% HOST) were determined (400 sperm per bull) after incubating in isoosmotic (300 mOsm/kg) and hypoosmotic (100 mOsm/kg) solutions for 30 min. There was no correlation between %HOST and SCR (r = 0.28 P > 0.1). However, there was a positive correlation between relative sperm volume shift and SCR (r = 0.65, P 2) fertility sire groups. In conclusion, bulls with higher SCR had significantly greater AQP7 mRNA abundance in frozen-thawed sperm. This plausibly contributed to greater regulation of sperm volume shift, which apparently conferred protection from detrimental swelling and impaired functions. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. THE CONTENT OF POLYPHENOLS IN FRUIT OF HIGHBUSH BLUEBERRY (VACCINIUM CORYMBOSUM L. RELATING TO DIFFERENT FERTILIZER APPLICATION

    Directory of Open Access Journals (Sweden)

    Michal Medvecký

    2015-02-01

    Full Text Available Six varieties of high blueberries (Vaccinium corymbosum L. grown on a plantation of research station in Krivá, that is located in the northern part of Slovakia, was examined to determine the content of polyphenols in the fruit depending on the three variants of fertilization. The first variant was realized with the application of organic fertilization, second one with mineral fertilizers and third variant was left without fertilization. The content of total polyphenols (TP was determined spectrophotometrically using Folin-Ciocalteau reagent. The total polyphenol content ranged from 2522.90 mg.kg-1 to 4960.20 mg.kg-1 in the variant with organic fertilization. In the variant with mineral fertilization the total polyphenol content ranged from 2278.25 mg.kg-1 to 3350.23 mg.kg-1. In the variant without fertilization was concentration of total polyphenols from 2503.63 mg.kg-1 to 3790.48 mg.kg-1. Statistical evaluation of the results confirmed a very weak correlation between polyphenols and one variety of different fertilization on the level of significance (p <0.05. Statistically significant effect on the level of significance (p <0.05 in Tukey's test was confirmed at the Patriot variety of organic and mineral fertilization and the mineral fertilization and control variant.

  11. Fertility Preservation for Female

    Institute of Scientific and Technical Information of China (English)

    Jack Huang; Seang Lin Tan; Ri-Cheng Chian

    2006-01-01

    Preservation of female fertility is an important issue today. However, there are few effective clinical options for preserving female fertility. Firstly, conventional in vitro fertilization (IVF) followed by embryo cryopreservation is an accepted procedure but is not applicable to all women. Embryo freezing is suitable only for women with a male partner and may not be acceptable to some patients due to moral and religious reasons. Ovarian tissue freezing is another option of female fertility preservation but is an invasive procedure and the efficacy of this technique remains to be determined.Oocyte cryopreservation is also method for fertility preservation. Egg freezing is minimally invasive and can avoid the ethical and moral concerns related to cryopreservation of embryos. However, conventional slow freezing/rapid thawing methods are associated with low survival of oocytes. Recent development in vitrification of oocytes appears promising. Therefore, vitrification of unfertilized eggs may be a novel method to preserve female fertility.

  12. Evaluation of genetic components in traits related to superovulation, in vitro fertilization, and embryo transfer in Holstein cattle.

    Science.gov (United States)

    Parker Gaddis, K L; Dikmen, S; Null, D J; Cole, J B; Hansen, P J

    2017-04-01

    The objectives of this study were to estimate variance components and identify regions of the genome associated with traits related to embryo transfer in Holsteins. Reproductive technologies are used in the dairy industry to increase the reproductive rate of superior females. A drawback of these methods remains the variability of animal responses to the procedures. If some variability can be explained genetically, selection can be used to improve animal response. Data collected from a Holstein dairy farm in Florida from 2008 to 2015 included 926 superovulation records (number of structures recovered and number of good embryos), 628 in vitro fertilization records (number of oocytes collected, number of cleaved embryos, number of high- and low-quality embryos, and number of transferrable embryos), and 12,089 embryo transfer records (pregnancy success). Two methods of transformation (logarithmic and Anscombe) were applied to count variables and results were compared. Univariate animal models were fitted for each trait with the exception of pregnancy success after embryo transfer. Due to the binary nature of the latter trait, a threshold liability model was fitted that accounted for the genetic effect of both the recipient and the embryo. Both transformation methods produced similar results. Single-step genomic BLUP analyses were performed and SNP effects estimated for traits with a significant genetic component. Heritability of number of structures recovered and number of good embryos when log-transformed were 0.27 ± 0.08 and 0.15 ± 0.07, respectively. Heritability estimates from the in vitro fertilization data ranged from 0.01 ± 0.08 to 0.21 ± 0.15, but were not significantly different from zero. Recipient and embryo heritability (standard deviation) of pregnancy success after embryo transfer was 0.03 (0.01) and 0.02 (0.01), respectively. The 10-SNP window explaining the largest proportion of variance (0.37%) for total structures collected was located on

  13. Assessing infertility-related stress: the factor structure of the Fertility Problem Inventory in Italian couples undergoing infertility treatment.

    Science.gov (United States)

    Donarelli, Zaira; Gullo, Salvatore; Lo Coco, Gianluca; Marino, Angelo; Scaglione, Piero; Volpes, Aldo; Allegra, Adolfo

    2015-01-01

    The factor structure of the Fertility Problem Inventory (FPI) and its invariance across gender were examined in Italian couples undergoing infertility treatment. About 1000 subjects (both partners of 500 couples) completed two questionnaires prior to commencing infertility treatment at a private Clinic in Palermo, Italy. Confirmatory Factor Analysis demonstrated that the original factor structure of the FPI was partially confirmed. Two correlated factors (Infertility Life Domains and Importance of Parenthood) were obtained via a post hoc Exploratory Factor Analysis. Finally, the invariance of this factor structure across gender was confirmed. The study supported the relevance of two interrelated factors specific to infertility stress which could help clinicians to focus on the core infertility-related stress domains of infertile couples.

  14. Fertility Awareness

    Science.gov (United States)

    ... I Help Someone Who's Being Bullied? Volunteering Fertility Awareness KidsHealth > For Teens > Fertility Awareness Print A A A What's in this article? ... español Monitoreo de fertilidad What Is It? Fertility awareness is a way to prevent pregnancy by not ...

  15. Drainage, liming and fertilization of organic soils. 1. Long-term effects on acid/base relations

    Energy Technology Data Exchange (ETDEWEB)

    Braekke, F.H. [Norges Landbrukshoegskole, Aas (Norway). Dept. of Forest Sciences

    1999-06-01

    Long-term changes of the acid/base relations of organic soils after drainage, fertilization and/or liming at three experimental sites - two ombrogenous and one soligenous - in south-central Norway are discussed. These sites were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Drainage at the ombrogenous sites caused: insignificant shifts of pH, higher bulk densities to 40 cm depth, higher ash percentage, higher contents of N and P to 20 cm depth and reduced concentrations of total Ca, K, Mg, Na, Al and Fe in soil layers deeper than 20 cm. The soligenous site was not effectively drained; despite this, pH dropped about 0.5 unit in the surface and subsurface soil layers of the control plots, while small changes were measured for most other soil variables. The suggested reason for the pH drop is limited sulphide oxidation in the upper 20 cm drained layer. Base saturation at actual soil pH, when all treatments were included, was estimated with good precision by four regressors: pH, extractable Al, extractable Fe and extractable Ca (R{sup 2} = 0.90-0.95). Similar models explained 97-99% of the variation in base saturation at soil pH = 7.0. The lime effects at the properly drained oligotrophic sites were proportional to applied doses; for pH to 40 cm, base saturation to 60 cm, and Ca concentration to 60 cm depth. At the less well-drained soligenous site, effects were limited to the upper 30 cm layer. Both drainage and liming caused higher cation exchange capacities and proper drainage seems to be a prerequisite for the liming effect. Estimated recovery of calcium to 60 cm depth was 64-79% at the ombrogenous sites and 42-46% at the soligenous site 28 refs, 3 figs, 8 tabs

  16. Nitrous oxide emission related to ammonia-oxidizing bacteria and mitigation options from N fertilization in a tropical soil

    NARCIS (Netherlands)

    Soares, Johnny R.; Cassman, N.; Kielak, A.M.; Pijl, A.S.; do Carmo, J.B.; Lourenço, Késia S.; Laanbroek, H.J.; Cantarella, H.; Kuramae, E.E.

    2016-01-01

    Nitrous oxide (N2O) from nitrogen fertilizers applied to sugarcane has high environmental impact on ethanol production. This study aimed to determine the main microbial processes responsible for the N2O emissions from soil fertilized with different N sources, to identify options to mitigate N2O emis

  17. Obesity-related health status is a better predictor of pregnancy with fertility treatment than body mass index: a prospective study.

    Science.gov (United States)

    Paterson, N; Sharma, A M; Maxwell, C; Greenblatt, E M

    2016-08-01

    This study assessed whether an obesity-related health status instrument (Edmonton obesity scoring system - EOSS) or body mass index (BMI) better predicted pregnancy rates in overweight women undergoing fertility treatments. A prospective cohort study was conducted on patients with a BMI ≥ 25 kg m(-2) undergoing a fertility treatment cycle (ovulation induction, superovulation, or in vitro fertilization). Obesity-related health status including blood pressure, blood work, health history, and functional assessment were assessed. A total of 101 patients were included in the study with an average age of 36.3 ± 4.2 years and a mean BMI of 31.8 ± 5.2 kg m(-2) . EOSS was found to be statistically predictive of pregnancy rate/cycle (OR 0.51, 95% CI 0.27-0.94; P = 0.03), whereas BMI was not (OR 0.95, 95% CI 0.86-1.05). A similar trend was seen for clinical pregnancy rate/cycle started. However, the association between clinical pregnancy rates and EOSS or BMI did not reach statistical significance (OR 0.53, P = 0.06 and OR 0.98, P = 0.62 respectively). Our results demonstrated that EOSS better predicted pregnancy rates after fertility treatments than BMI. In fact, for every EOSS stage increased by one unit, the odds of pregnancy were approximately halved. A multi-centre study powered for live birth is warranted to establish effective pre-fertility management of overweight women.

  18. Semen quality of fertile US males in relation to their mothers' beef consumption during pregnancy

    National Research Council Canada - National Science Library

    Swan, S.H; Liu, F; Overstreet, J.W; Brazil, C; Skakkebaek, N.E

    2007-01-01

    BACKGROUND To look at possible long-term risks from anabolic steroids and other xenobiotics in beef, we examined mens' semen quality in relation to their mother's self-reported beef consumption during pregnancy. METHODS...

  19. Physical properties, fuel characteristics and P-fertilizer production related to animal slurry and products from separation of animal slurry

    DEFF Research Database (Denmark)

    Thygesen, Ole; Johnsen, Tina; Triolo, Jin Mi

    of cattle slurry, contained too little P to be suitable for fertilizer production, as did pig slurry, to which sulphuric acid had been added prior to separation. Low solubility of P means the ashes should be treated before being used as a fertilizer. The acid consumption in a simple fertilizer production......The purpose of this study was twofold: firstly to examine the relationship between dry matter content (DM) and specific gravity (SG) and viscosity in slurry and the liquid fraction from slurry separation, and secondly to investigate the potential of energy production from combustion of manure fibre...... from slurry separation and phosphorus (P) fertilizer production from recycling of the ash. Manure fibre has a positive calorific value and may be used as a CO2-neutral fuel for combustion. The ashes from combustion are rich in P, an essential fertilizer compound. The study is based on samples of animal...

  20. Changes in marriage and fertility behavior. Behavior versus attitudes of young adults.

    Science.gov (United States)

    Moore, K A; Stief, T M

    1991-03-01

    Hoping to determine whether recent changes in marriage and fertility behavior are simply temporary or more permanent, the attitudes and values of young adults were compared to the recent trends. The data come from the 1987 wave of the National Survey of Children, which has tracked a nationally representative sample of young people since 1976. The following behaviors and their corresponding attitudes are discussed: sexual activity, pregnancy, nonmarital childbearing, abortion, marriage and cohabitation, and divorce. Also considered are how blacks and whites differ in their behavior and attitudes. Since the 1970s, the incidence of premarital intercourse has increased substantially among adolescents and has resulted in a rise in the pregnancy rate. Adolescents strongly disapprove of sexual activity among younger teens, but accept it for older adolescents. Nonmarital childbearing increased by about 50% from 1970 to 1987. Adolescents, however, generally hold negative attitudes toward adolescent pregnancy, and the majority of sexually experienced teens report wanting to avoid pregnancy. In 1985, over 40% of teens who became pregnant obtained an abortion. Adolescents are divided on the acceptability of abortion -- except in instances of rape, in which case most accept abortion. Young adults strongly favor delayed marriage and oppose divorce, feeling that couples should not get married unless they intend to stay together for life. About 1/2 of young adults approve of cohabitation and only 1/5 are opposed to nonmarital childbearing. Based on the policy implications of the findings, it is concluded that the attitudes and values of young adults do not reflect the demise of the family, as has been predicted.

  1. Identification of Candidate Genes and Biosynthesis Pathways Related to Fertility Conversion by Wheat KTM3315A Transcriptome Profiling

    Directory of Open Access Journals (Sweden)

    Lingli Zhang

    2017-04-01

    Full Text Available The Aegilops kotschyi thermo-sensitive cytoplasmic male sterility (K-TCMS system may facilitate hybrid wheat (Triticum aestivum L. seed multiplication and production. The K-TCMS line is completely male sterile during the normal wheat-growing season, whereas its fertility can be restored in a high-temperature environment. To elucidate the molecular mechanisms responsible for male sterility/fertility conversion and candidate genes involved with pollen development in K-TCMS, we employed RNA-seq to sequence the transcriptomes of anthers from K-TCMS line KTM3315A during development under sterile and fertile conditions. We identified 16840 differentially expressed genes (DEGs in different stages including15157 known genes (15135 nuclear genes and 22 plasmagenes and 1683 novel genes. Bioinformatics analysis identified possible metabolic pathways involved with fertility based on KEGG pathway enrichment of the DEGs expressed in fertile and sterile plants. We found that most of the genes encoding key enzyme in the phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were significant upregulated in uninucleate, binuclate or trinucleate stage, which both interact with MYB transcription factors, and that link between all play essential roles in fertility conversion. The relevant DEGs were verified by quantitative RT-PCR. Thus, we suggested that phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were involved in fertility conversion of K-TCMS wheat. This will provide a new perspective and an effective foundation for the research of molecular mechanisms of fertility conversion of CMS wheat. Fertility conversion mechanism in thermo-sensitive cytoplasmic male sterile/fertile wheat involves the phenylpropanoid biosynthesis pathway, jasmonate biosynthesis pathway, and MYB transcription factors.

  2. Soil microbes and plant fertilization.

    Science.gov (United States)

    Miransari, Mohammad

    2011-12-01

    With respect to the adverse effects of chemical fertilization on the environment and their related expenses, especially when overused, alternative methods of fertilization have been suggested and tested. For example, the combined use of chemical fertilization with organic fertilization and/or biological fertilization is among such methods. It has been indicated that the use of organic fertilization with chemical fertilization is a suitable method of providing crop plants with adequate amount of nutrients, while environmentally and economically appropriate. In this article, the importance of soil microbes to the ecosystem is reviewed, with particular emphasis on the role of plant growth-promoting rhizobacteria, arbuscular mycorrhizal fungi, and endophytic bacteria in providing necessary nutrients for plant growth and yield production. Such microbes are beneficial to plant growth through colonizing plant roots and inducing mechanisms by which plant growth increases. Although there has been extensive research work regarding the use of microbes as a method of fertilizing plants, it is yet a question how the efficiency of such microbial fertilization to the plant can be determined and increased. In other words, how the right combination of chemical and biological fertilization can be determined. In this article, the most recent advances regarding the effects of microbial fertilization on plant growth and yield production in their combined use with chemical fertilization are reviewed. There are also some details related to the molecular mechanisms affecting the microbial performance and how the use of biological techniques may affect the efficiency of biological fertilization.

  3. 体外受精-胚胎移植术IVF受精失败相关因素研究%Related factors for fertilization failure in vitro fertilization and embryo transplantation

    Institute of Scientific and Technical Information of China (English)

    梁莹; 亓蓉; 李淑贤; 周莉; 吴晓茜

    2013-01-01

    目的:研究体外受精-胚胎移植(IVF-ET)受精失败相关因素.方法:回顾性分析2007~2010年期间接受IVF治疗患者104例,其中IVF正常受精组(NF组)63例和IVF受精失败组(FF组)41例.对两组年龄、不孕年限、获卵数、MⅡ卵子数、绒毛膜促性腺激素(hCG)日雌二醇(E2)水平、黄体生成素(LH)水平、手术日处理后的向前运动精子数、优胚数、原发不孕所占比例、妊娠率进行两组比较,并且应用非条件二分类Logistic多因素回归分析可能影响受精的因素.结果:手术日处理后的向前运动精子数、优胚数、原发不孕所占比例、妊娠率两组比较有统计学差异(P<0.05).患者的年龄、不孕症的年限、MⅡ卵子数与受精障碍无相关性.手术日处理后的向前运动精子数、不孕症的类型(原发,继发)与E2水平与受精障碍有关.手术日处理后的向前运动精子数、继发不孕、E2水平是受精失败的保护因素.结论:体外受精-胚胎移植术IVF受精失败与手术日处理后的向前运动精子数、不孕症的类型(原发,继发)和E2水平相关.%Objective:To explore fertilization failure related factors for in vitro fertilization and embryo transplantation (IVF).Methods:Retrospective analysis of 2007 ~ 2010 during the IVF treatment was executed.104 cases were selected including 63 cases in normal fertilization IVF group (NFH) and 41 cases in normal fertilization IVF group (NFH).Age,duration of infertility,attaining the egg number,M Ⅱ egg number,HCG day estradiol levels,LH levels,surgery,treatment after the forward movement of sperm number,optimal embryo number,proportion of primary infertility,pregnancy rate of two groups were compared.Unconditioned and application binary classification logistic multifactor regressionanalysis was used to explore the possible factors which affected fertilization.Results:Differences in forward movement sperm number after treatment,optimal embryo number

  4. How contemporary human reproductive behaviors influence the role of fertility-related genes: the example of the p53 gene.

    Directory of Open Access Journals (Sweden)

    Rosa Maria Corbo

    Full Text Available Studies on human fertility genes have identified numerous risk/protective alleles involved in the occurrence of reproductive system diseases causing infertility or subfertility. Investigations we carried out in populations at natural fertility seem to suggest that the clinical relevance that some fertility genes are now acquiring depends on their interaction with contemporary reproductive behaviors (birth control, delayed childbearing, and spacing birth order, among others. In recent years, a new physiological role in human fertility regulation has emerged for the tumor- suppressor p53 gene (P53, and the P53 Arg72Pro polymorphism has been associated with recurrent implantation failure in humans. To lend support to our previous observations, we examined the impact of Arg72Pro polymorphism on fertility in two samples of Italian women not selected for impaired fertility but collected from populations with different (premodern and modern reproductive behaviors. Among the women at near-natural fertility (n = 98, the P53 genotypes were not associated with different reproductive efficiency, whereas among those with modern reproductive behaviors (n = 68, the P53 genotypes were associated with different mean numbers of children [Pro/Pro = 0.75fertility genes may have become "detrimental" following exposure to modern reproductive patterns and might therefore be associated with reduced reproductive success. Set within an evolutionary framework, this change could lead to the selection of a set of gene variants fitter to current reproductive behaviors as the

  5. The evolution of transposable elements in natural populations of self-fertilizing Arabidopsis thaliana and its outcrossing relative Arabidopsis lyrata

    Directory of Open Access Journals (Sweden)

    Gaut Brandon S

    2010-01-01

    Full Text Available Abstract Background Transposable Elements (TEs make up the majority of plant genomes, and thus understanding TE evolutionary dynamics is key to understanding plant genome evolution. Plant reproductive systems are diverse and mating type variation is one factor among many hypothesized to influence TE evolutionary dynamics. Here, we collected a large TE-display data set in self-fertilizing Arabidopsis thaliana, and compared it to data gathered in outcrossing Arabidopsis lyrata. We analyzed seven TE families in four natural populations of each species to tease apart the effects of mating system, demography, transposition, and selection in determining patterns of TE diversity. Results Measures of TE band differentiation were largely consistent across TE families. However, patterns of diversity in A. thaliana Ac elements differed significantly from that other TEs, perhaps signaling a lack of recent transposition. Across TE families, we estimated higher allele frequencies and lower selection coefficients on A. thaliana TE insertions relative to A. lyrata TE insertions. Conclusions The differences in TE distributions between the two Arabidopsis species represents a synthesis of evolutionary forces that include the transposition dynamics of individual TE families and the demographic histories of populations. There are also species-specific differences that could be attributed to the effects of mating system, including higher overall allele frequencies in the selfing lineage and a greater proportion of among population TE diversity in the outcrossing lineage.

  6. Apolipoprotein E (ApoE) polymorphism is related to differences in potential fertility in women: a case of antagonistic pleiotropy?

    Science.gov (United States)

    Jasienska, Grazyna; Ellison, Peter T; Galbarczyk, Andrzej; Jasienski, Michal; Kalemba-Drozdz, Malgorzata; Kapiszewska, Maria; Nenko, Ilona; Thune, Inger; Ziomkiewicz, Anna

    2015-03-22

    The alleles that are detrimental to health, especially in older age, are thought to persist in populations because they also confer some benefits for individuals (through antagonistic pleiotropy). The ApoE4 allele at the ApoE locus, encoding apolipoprotein E (ApoE), significantly increases risk of poor health, and yet it is present in many populations at relatively high frequencies. Why has it not been replaced by natural selection with the health-beneficial ApoE3 allele? ApoE is a major supplier of cholesterol precursor for the production of ovarian oestrogen and progesterone, thus ApoE has been suggested as the potential candidate gene that may cause variation in reproductive performance. Our results support this hypothesis showing that in 117 regularly menstruating women those with genotypes with at least one ApoE4 allele had significantly higher levels of mean luteal progesterone (144.21 pmol l(-1)) than women with genotypes without ApoE4 (120.49 pmol l(-1)), which indicates higher potential fertility. The hormonal profiles were based on daily data for entire menstrual cycles. We suggest that the finding of higher progesterone in women with ApoE4 allele could provide first strong evidence for an evolutionary mechanism of maintaining the ancestral and health-worsening ApoE4 allele in human populations.

  7. Desired Numbers of Children, Fertility Preferences and Related Factors among Couples Who Referred to Pre-Marriage Counseling in Alborz Province, Iran

    Directory of Open Access Journals (Sweden)

    Razieh Lotfi

    2017-09-01

    Full Text Available Background The Islamic Republic of Iran has experienced a dramatic decrease in fertility rates in the past three decades. One of the main issues in the field of fertility is the couple’s preferences and the desire to bear children. This study aimed to determine desired number of children, fertility preference, and related factors among people referring pre-marriage counseling to clarify their presumed behavior in case of fertility. Materials and Methods This study was a descriptive analytic cross-sectional survey, conducted during 8 months. The participants were 300 couples came to pre-marriage counseling centers of two health centers of Karaj and asked to complete a 22 items questionnaire about of demographic characteristics, participants’ interest, preference about fertility, and economic situation. Results Majority of the males were between the ages of 20-30 years (66.6% while majority of the females were below 25 years of age (57%. About 17 percent of men and 22.3 percent of women stated that they want to have 1 child and equally 52.7 percent of men and 52.7 percent of women wanted to have 2 children. The only factor that contributed to the female participant’s decision for a desirable number of children was the number of siblings that they have. In male participants with an increasing age at marriage and aspiration for higher educational level, the time interval between marriage and the birth of the first child has increased. There was a convergence in desired number of children in male and female participants. Conclusion Majority of the participants express their desire to have only one or two children in future but in considering the fact that what one desires does not always come into reality, the risk of reduced fertility is generally present in the community. Appropriate policies should be implemented in order to create a favorable environment for children.

  8. The relative importance of fertilization and soil erosion on C-dynamics in agricultural landscapes of NE Germany

    Science.gov (United States)

    Pohl, Madlen; Hoffmann, Mathias; Hagemann, Ulrike; Jurisch, Nicole; Remus, Rainer; Sommer, Michael; Augustin, Jürgen

    2016-04-01

    The hummocky ground moraine landscape of north-east Germany is characterized by distinct small-scale soil heterogeneity on the one hand, and intensive energy crop cultivation on the other. Both factors are assumed to significantly influence gaseous C exchange, and thus driving the dynamics of soil organic carbon stocks in terrestrial, agricultural ecosystems. However, it is not yet clear to which extent fertilization and soil erosional status influence soil C dynamics and whether one of these factors is more relevant than the other. We present seasonal and dynamic soil C balances of biogas maize for the growing season 2011, recorded at different sites located within the CarboZALF experimental area. The sites differ regarding soils (non-eroded Albic Luvisols (Cutanic), extremely eroded Calcaric Regosol and depositional Endogleyic Colluvic Regosol,) and applied fertilizer (100% mineral N fertilizer, 50% mineral and 50% N organic fertilizer, 100% organic N fertilizer). Fertilization treatments were established on the Albic Luvisol (Cutanic). Net-CO2-exchange (NEE) and ecosystem respiration (Reco) were measured every four weeks using a dynamic flow-through non-steady-state closed manual chamber system. Gap filling was performed based on empirical temperature and PAR dependency functions to derive daily NEE values. At the same time, daily above-ground biomass production (NPP) was estimated based on biomass samples and final harvest, using a sigmoidal growth function. In a next step, dynamic soil C balances were generated as the balance of daily NEE and NPP considering the initial C input due to N fertilizers. The resulted seasonal soil C balances varied from strong C losses at the Endogleyic Colluvic Regosol (602 g C m-2) to C gains at the Calcaric Regosol (-132 g C m-2). In general, soils exerted a stronger impact on seasonal and dynamic C balances compared to differences in applied N fertilizer. There are indications that inter-annual variations in climate conditions

  9. Loblolly Pine Productivity and Water Relations in Response to Throughfall Reduction and Fertilizer Application on a Poorly Drained Site in Northern Florida

    Directory of Open Access Journals (Sweden)

    Maxwell G. Wightman

    2016-09-01

    Full Text Available Loblolly pine (Pinus taeda L. forests are of great ecological and economic value in the southeastern United States, where nutrient availability frequently limits productivity. The impact of fertilizer application on the growth and water relations of loblolly pine has been investigated by numerous studies; however, few field experiments have examined the effects of drought. Drought is of particular interest due to the potential for climate change to alter soil water availability. In this study, we investigated the impact of fertilizer application and a 30% reduction in throughfall on loblolly pine productivity, transpiration, hydraulic conductance, and stomatal conductance. The study was installed in a ten-year-old loblolly pine plantation on a somewhat poorly drained site in northern Florida. Throughfall reduction did not impact tree productivity or water relations of the trees. This lack of response was attributed to abundant rainfall and the ability of trees to access the shallow water table at this site. Fertilizer application increased basal area production by 20% and maximum leaf area index by 0.5 m2∙m−2, but it did not affect whole-tree hydraulic conductance or the sensitivity of stomatal conductance to vapor pressure deficit. During the spring, when leaf area and vapor pressure deficit were high, the fertilizer-only treatment increased monthly transpiration by 17% when compared to the control. This relationship, however, was not significant during the rest of the year.

  10. Free-radical production after post-thaw incubation of ram spermatozoa is related to decreased in vivo fertility.

    Science.gov (United States)

    Del Olmo, Enrique; Bisbal, Alfonso; García-Álvarez, Olga; Maroto-Morales, Alejandro; Ramón, Manuel; Jiménez-Rabadán, Pilar; Anel-López, Luis; Soler, Ana J; Garde, J Julián; Fernández-Santos, María R

    2015-11-01

    The aim of the present study was to evaluate the effect of sperm reactive oxygen species (ROS) production and DNA changes on male fertility. For that purpose, six rams with significantly different pregnancy rates were used; these were classified as having high fertility, i.e. 59.4% average pregnancy rate, or low fertility, i.e. 23.1% average pregnancy rate. Sperm quality was assessed after a two-step process of sample thawing followed by an incubation of 2h, either in the freezing extender (37°C) or after dilution in synthetic oviductal fluid (SOF; 38°C, 5%CO2). Sperm viability (YO-PRO-1), ROS production (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein acetyl ester (CM-H2DCFDA)) and undamaged chromatin (sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling, chromomycin A3) were evaluated by flow cytometry. Although no significant differences in sperm viability were observed, our results showed increased ROS production during incubation in the freezing extender as well as in SOF medium. Comparison between fertility groups showed significant differences in ROS production after 2h of incubation for the two treatments. Regarding DNA integrity, our results showed no significant differences either between treatments and incubation times or fertility groups. Linear regression analysis showed that ROS production determined by CM-H2DCFDA was a good indicator parameter for in vivo male fertility of SOF-incubated samples, yielding a fair correlation between both parameters (r=-0.92). These results indicate that detection of ROS production by CM-H2DCFDA and flow cytometry after 2h of incubation in SOF could be a useful procedure for predicting fertility of ram spermatozoa.

  11. The spatial distribution of acid phosphatase activity in ectomycorrhizal tissues depends on soil fertility and morphotype, and relates to host plant phosphorus uptake.

    Science.gov (United States)

    Alvarez, Maricel; Huygens, Dries; Díaz, Leila Milena; Villanueva, Claudia Añazco; Heyser, Wolfgang; Boeckx, Pascal

    2012-01-01

    Acid phosphatase (ACP) enzymes are involved in the mobilization of soil phosphorus (P) and polyphosphate accumulated in the fungal tissues of ectomycorrhizal roots, thereby influencing the amounts of P that are stored in the fungus and transferred to the host plant. This study evaluated the effects of ectomycorrhizal morphotype and soil fertility on ACP activity in the extraradical mycelium (ACP(myc)), the mantle (ACP(mantle)) and the Hartig net region (ACP(Hartig)) of ectomycorrhizal Nothofagus obliqua seedlings. ACP activity was quantified in vivo using enzyme-labelled fluorescence-97 (ELF-97) substrate, confocal laser microscopy and digital image processing routines. There was a significant effect of ectomycorrhizal morphotype on ACP(myc), ACP(mantle) and ACP(Hartig), while soil fertility had a significant effect on ACP(myc) and ACP(Hartig). The relative contribution of the mantle and the Hartig net region to the ACP activity on the ectomycorrhizal root was significantly affected by ectomycorrhizal morphotype and soil fertility. A positive correlation between ACP(Hartig) and the shoot P concentration was found, providing evidence that ACP activity at the fungus:root interface is involved in P transfer from the fungus to the host. It is concluded that the spatial distribution of ACP in ectomycorrhizas varies as a function of soil fertility and colonizing fungus.

  12. [Dynamics of microbial biomass C in a black soil under long-term fertilization and related affecting factors].

    Science.gov (United States)

    Li, Dongpo; Wu, Zhijie; Chen, Lijun; Zhu, Ping; Ren, Jun; Peng, Chang; Liang, Chenghua

    2004-08-01

    The effect of long-term fertilization on the dynamics of microbial biomass C in a typical black soil of Northeastern China was studied in a field trail treated by different fertilizations. The results showed that the amount of soil microbial biomass C under different fertilizations varied significantly with growth stages. It was the highest in farmyard manure (M2 and M4) treatments, with a less seasonal fluctuation, second in NPK treatment, the peak at sowing period, and the lowest in CK, the peak at wax maturity stage. No significant correlation was found between the dynamic changes of soil microbial biomass C and soil biological, physical and chemical properties in all treatments, but the correlation of soil microbial biomass C with the contents of N, P and K in plants and that of crude protein in grain was significantly positive.

  13. Soil fertility in relation to slope position and agricultural land use: a case study of Umbulo Catchment in southern Ethiopia.

    Science.gov (United States)

    Moges, Awdenegest; Holden, Nicholas M

    2008-11-01

    A study was conducted in southern Ethiopia to evaluate the nutrient status on smallholder farms with respect to land use class (garden, grassland, and outfield) and slope position (upper, middle, and lower). Soil physical and chemical properties were quantified using soil samples collected at two depths (0-15 and 15-30 cm). Available phosphorous was significantly different among the three land use classes. However, organic carbon and total nitrogen were lower in the outfield compared to the garden and grass land but not significantly different. The lower than expected nutrient status of the garden and grassland, which receive almost all available organic supplements, was attributed to the overall low availability of these inputs. Similarly, pH and cation exchange capacity were not significantly different among the different land use classes. However, the sum of the exchangeable cations was significantly higher in the garden compared to the outfields. Comparison at landscape level revealed that the sand fraction was significantly greater, whereas the silt fractions were significantly smaller, on the lower slopes relative to the middle slopes. Moreover, the organic carbon, total nitrogen, cation exchange capacity, Ca, and Mg values were significantly less on lower slopes than upper and middle slopes. Perhaps this is because of leaching and the effect of deposition of coarser sediments from the prevailing gully system. Overall, the fertility of the soil was adequate for supporting smallholder farming, but consideration must be given to reducing pressure on the land resources, addressing erosion problems, and providing a line of credit for purchasing inputs.

  14. WILL FERTILITY REBOUND IN JAPAN

    OpenAIRE

    Creina Day

    2012-01-01

    Fertility and per capita income are now positively associated across most high income OECD countries. Low fertility and a gender wage gap persist in Japan. This paper presents an original model where endogenous increases in childcare prices and gender equity in capital allocation play important roles in the effect of per capita income growth and rising female relative wages on fertility. Results suggest Japan has cause for optimism. Economic growth will raise female relative wages where capit...

  15. Egg freezing for age-related fertility decline: preventive medicine or a further medicalization of reproduction? Analyzing the new Israeli policy.

    Science.gov (United States)

    Shkedi-Rafid, Shiri; Hashiloni-Dolev, Yael

    2011-08-01

    In December 2009, the Israel National Bioethics Council (INBC) issued recommendations permitting egg freezing to prevent both disease- and age-related fertility decline. The INBC report forms the basis of Israel's new policy regarding egg freezing. This article analyzes the medical section of the INBC's recommendations, comparing it with guidelines formulated by medical regulatory bodies in Europe and the United States. Our findings suggest that the INBC's recommendations consider age-related fertility decline to be a medical problem, and hence treat the new technology favorably, as preventive medicine, which we perceive as another instance of medicalization. The technology's risks are downplayed by the INBC, unlike the positions of medical organizations in both Europe and the United States, which consider the new technology experimental. This may culminate in raising false hopes about women's possible late genetic motherhood leading to involuntary future childlessness.

  16. Histology of testicular biopsies taken at operation for bilateral maldescended testes in relation to fertility in adulthood

    DEFF Research Database (Denmark)

    Cortes, Dina; Thorup, Jørgen Mogens

    1991-01-01

    /T% values of the patients were positively correlated to maximal sperm density and to volume of pair of testes and negatively correlated to serum FSH. It seems reasonable to use these histological parameters as prognostic indices of fertility potential. In adulthood only 11 patients had sperm density greater...

  17. Nitrous oxide emission related to ammonia-oxidizing bacteria and mitigation options from N fertilization in a tropical soil

    Science.gov (United States)

    Soares, Johnny R.; Cassman, Noriko A.; Kielak, Anna M.; Pijl, Agata; Carmo, Janaína B.; Lourenço, Kesia S.; Laanbroek, Hendrikus J.; Cantarella, Heitor; Kuramae, Eiko E.

    2016-07-01

    Nitrous oxide (N2O) from nitrogen fertilizers applied to sugarcane has high environmental impact on ethanol production. This study aimed to determine the main microbial processes responsible for the N2O emissions from soil fertilized with different N sources, to identify options to mitigate N2O emissions, and to determine the impacts of the N sources on the soil microbiome. In a field experiment, nitrogen was applied as calcium nitrate, urea, urea with dicyandiamide or 3,4 dimethylpyrazone phosphate nitrification inhibitors (NIs), and urea coated with polymer and sulfur (PSCU). Urea caused the highest N2O emissions (1.7% of N applied) and PSCU did not reduce cumulative N2O emissions compared to urea. NIs reduced N2O emissions (95%) compared to urea and had emissions comparable to those of the control (no N). Similarly, calcium nitrate resulted in very low N2O emissions. Interestingly, N2O emissions were significantly correlated only with bacterial amoA, but not with denitrification gene (nirK, nirS, nosZ) abundances, suggesting that ammonia-oxidizing bacteria, via the nitrification pathway, were the main contributors to N2O emissions. Moreover, the treatments had little effect on microbial composition or diversity. We suggest nitrate-based fertilizers or the addition of NIs in NH4+-N based fertilizers as viable options for reducing N2O emissions in tropical soils and lessening the environmental impact of biofuel produced from sugarcane.

  18. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  19. Strong families and declining fertility: a comparative study of family relations and reproductive careers in Soviet Ukraine

    NARCIS (Netherlands)

    Hilevych, Yuliya

    2016-01-01

    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  20. Natural fertility in the Philippines.

    Science.gov (United States)

    Aquino, E G

    1982-01-01

    The hypothesis that modernization trends in the Philippines led to an increase in fecundity and natural fertility between 1953-1972 was tested, using data from the 1973 National Demographic Survey. More specifically, it was hypothesized that increases in education, income levels, urbanization, female labor force participation, and other factors exerted a positive influence on the population's health and nutritional status and increased the risk of pregnancy by diminishing the strength of sexual taboos and by decreasing the incidence of breastfeeding. These changes, in turn, had a positive impact on natural fertility. Natural fertility was defined as marital fertility in the absence of specific efforts to control fertility. The use of natural fertility instead of fecundity allowed for the influence of behavioral patterns, such as breastfeeding and sexual taboos, on fertility. Period analysis of age specific marital fertility rates for each 5 year period between 1953-72 and cohort analysis of age specific marital fertility rates for the birth cohorts, aged 55-59, 50-54, 45-49, 40-44, and 35-39 in 1973 were undertaken. The effect of fertility control was determined by using an index derived from an equation provided by Coale and Trussell. Findings of both the period and cohort analysis supported the hypothesis. Period analysis revealed that natural fertility increased between 1953-57 and 1969-72 by 10% and that the greatest increase occurred during the 1950s when Philippine society experienced major modernization changes. The increases in natural fertility were accompanied by corresponding increases in fertility regulation in each time period. These trends tended to cancel each other out and resulted in a relatively stable total marital fertility rate throughout the time period. Cohort analysis revealed that only the total marital fertility rate of the youngest cohort was influenced by fertility regulation. The level of natural fertility for all cohorts as a group

  1. Menstrual cycle pattern and fertility

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  2. 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

  3. Characterization of fertility related antisperm antibodies-a step towards causal treatment of immunological infertility and immuno-contraception

    Institute of Scientific and Technical Information of China (English)

    Gerhard Haidl

    2010-01-01

    @@ Antisperm antibodies (ASA)occur in men and women and may significantly impair fertility. The identification of functionally rele-vant antigens of ASA is important for establishing causal treatment options on the one hand and may,on the other hand, enhance the de-velopment of tools for immunocon-traception. One candidate protein is addressed in an article of Wang et al. [1] published in Asian Journal of Andrology.

  4. Germany: Family diversity with low actual and desired fertility

    Directory of Open Access Journals (Sweden)

    Jürgen Dorbritz

    2008-07-01

    Full Text Available Germany is a low-fertility country with a rapidly ageing population, and will remain so for the foreseeable future. There are several reasons for this trend. Germany is among the countries with the highest rates of childlessness in the world, and childlessness has become widely accepted. This is illustrated by changes in living arrangements. A broad range of living arrangements has been added to the basic model of marriage with children; namely, single living, non-marital cohabitation, lone parenthood, patchwork families and living apart together. A culture of individualism has spread in Germany which forms the basis for widespread decisions against family formation. The desired number of children has become low and family policy is considered to be a failure in terms of its influence on fertility. German family policy has had a traditional orientation centred on monetary support to families and on the promotion of the male breadwinner model. Women have been largely forced to choose between family and work, and leave the labour market when a child is born. The still prevailing concept of family policy does not help to reduce the pressure to choose between work and family life, and thus makes it easier to decide not to have children, especially for highly educated women. A change in family policy is needed which will enable couples to choose between the breadwinner-housewife and the reconciliation model. Gradually, this change is starting to take place.

  5. DNA synthesis and microtubule assembly-related events in fertilized Paracentrotus lividus eggs: reversible inhibition by 10 mM procaine.

    Science.gov (United States)

    Raymond, M N; Foucault, G; Coffe, G; Pudles, J

    1986-04-01

    This report describes the effects of 10 mM procaine on microtubule assembly and on DNA synthesis, as followed by [3H]colchicine binding assays and [3H]thymidine incorporation respectively, in fertilized Paracentrotus lividus eggs. In the absence of microtubule assembly inhibitors, about 25% of the total egg tubulin is submitted to two cycles of polymerization prior to the first cell division, this polymerization process precedes DNA synthesis. If the zygotes are treated with 10 mM procaine in the course of the cell cycle, tubulin polymerization is inhibited or microtubules are disassembled. DNA synthesis is inhibited when procaine treatment is performed 10 min, before the initiation of the S-period. However, when the drug is applied in the course of this synthetic period, the process is normally accomplished, but the next S-period becomes inhibited. Moreover, procaine treatment increases the cytoplasmic pH of the fertilized eggs by about 0.6 to 0.8 pH units. This pH increase precedes microtubule disassembly and inhibition of DNA synthesis. Washing out the drug induces a decrease of the intracellular pH which returns to about the same value as that of the fertilized egg controls. This pH change is then followed by the reinitiation of microtubule assembly, DNA synthesis and cell division. Our results show that the inhibition of both tubulin polymerization and DNA synthesis in fertilized eggs treated with 10 mM procaine, appears to be related to the drug-induced increase in cytoplasmic pH.

  6. Histology of testicular biopsies taken at operation for bilateral maldescended testes in relation to fertility in adulthood

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J

    1991-01-01

    /T% values of the patients were positively correlated to maximal sperm density and to volume of pair of testes and negatively correlated to serum FSH. It seems reasonable to use these histological parameters as prognostic indices of fertility potential. In adulthood only 11 patients had sperm density greater...... than or equal to 20 million/ml, 37 had normal serum FSH and 29 had bilateral testicular volume greater than or equal to 15 ml. Patients with both testes originally placed in the superficial inguinal pouch at surgical exploration had a higher maximal sperm density than the rest of the study group....

  7. Pro-oxidative and anti-oxidative imbalance in human semen and its relation with male fertility

    Institute of Scientific and Technical Information of China (English)

    NicolasGarrido; MarcosMeseguer; CarlosSimon; AntonioPellicer; JoséRemohi

    2004-01-01

    Oxidative stress is a common condition suffered by biological systems in aerobic conditions.Human semen also has its own molecular guard against the free radicals created by normal respiratory process or from immune reactions.The equilibrium of the creation and scavenging of free radicals is mandatory in the spermatozoa to fertilize and initiate a full-term pregnancy.The paper is a systematic review of publications that evaluate oxidative stress in semen.The Cochrane Library,Medline (1966-2003),Embase (1988-2003),SciSearch (1981-2003) and the conference papers were searched,When sperm samples from fertile and infertile males were analyzed,some of the mechanisms that determine the oxidative stress level were found to be impaired while others were unaltered.In conclusion,the literature as a whole provides contradictory findings and it is necessary to carry out more work to identify all the enzymatic and non-enzymatic systems involved in oxidative stress in the ejaculate,in order to develop new diagnostic systems and therapeutic strategies for combating detrimental free radical imbalance in the semen.(Asian J Androl 2004 Mar;6:59-65)

  8. Are fire, soil fertility and toxicity, water availability, plant functional diversity, and litter decomposition related in a Neotropical savanna?

    Science.gov (United States)

    Carvalho, Gustavo Henrique; Batalha, Marco Antônio; Silva, Igor Aurélio; Cianciaruso, Marcus Vinicius; Petchey, Owen L

    2014-07-01

    Understanding how biodiversity and ecosystem functioning respond to changes in the environment is fundamental to the maintenance of ecosystem function. In realistic scenarios, the biodiversity-ecosystem functioning path may account for only a small share of all factors determining ecosystem function. Here, we investigated the strength to which variations in environmental characteristics in a Neotropical savanna affected functional diversity and decomposition. We sought an integrative approach, testing a number of pairwise hypotheses about how the environment, biodiversity, and functioning were linked. We used structural equation modelling to connect fire frequency, soil fertility, exchangeable Al, water availability, functional diversity of woody plants, tree density, tree height, and litter decomposition rates in a causal chain. We found significant effects of soil nutrients, water availability, and Al on functional diversity and litter decomposition. Fire did not have a significant direct effect on functional diversity or litter decomposition. However, fire was connected to both variables through soil fertility. Functional diversity did not influence rates of litter decomposition. The mediated effects that emerged from pairwise interactions are encouraging not only for predicting the functional consequences of changes in environmental variables and biodiversity, but also to caution against predictions based on only environmental or only biodiversity change.

  9. Quality in Modern Nordic Working Life—Investigating Three Related Research Perspectives and Their Possible Cross-Fertilization

    Directory of Open Access Journals (Sweden)

    Stine Jacobsen

    2013-09-01

    Full Text Available Nordic working life balance is important in the context of a highly developed welfare state, budget collaboration between the State and municipalities, and a unified labor movement. In working life studies, various research perspectives create meaning around and propose solutions for the many quality issues of modern working life. Welfare research, working environment research, and human resource management (HRM research attack the multiple challenges of working life in different ways and share the overall objective of solving issues in modern working life. Research from the three perspectives, however, tends to compartmentalize life spheres. They conceptualize the modern working person as an individual, employee, or citizen, neglecting the complexity of lived life where all three spheres blur together, which possibly reflects the difficulty of making modern work life function well. This article is based on a structured literature review of the three main research perspectives (welfare, working environment, and HRM. We review existing international research, observing where the three perspectives show overlaps and identify 24 studies which cross-fertilize in the sense that two or more of the perspectives are applied at the same time in the same study. Our results show that while the perspectives share a common interest in solving the problems of the overlapping working life (OWL, they do so with different methods and criteria for success, and offer different solutions. We propose the concept “OWL” to analyze how working life studies create meaning around quality issues of modern working life. OWL’s main focus is the multiple challenges faced by working people who are simultaneously individuals, citizens, and employees. We arrive at two main cross-disciplinary themes: boundary and quality. The boundary theme reflects an approach to solving the issues of modern working life through improvements of the working life balance. The quality theme

  10. Women's education and fertility behaviour.

    Science.gov (United States)

    1993-12-01

    The education of women results in changes in women's health status, family well being, and fertility decline. The aim of human rights and social justice is also served by increasing women's educational levels. A review of the trends in developing countries has shown that there is a strong correlation between advanced female education (10 or more years) and lower fertility. Data for 26 countries was presented in table form for total fertility rates by years of education. There were many differences in the patterns of fertility by educational level based on country level of development. The data appeared to show stronger correlations between fertility and education in more prosperous societies; culture and social structure also influenced fertility. Partial primary education has been shown in some countries to be related to increased fertility. A UN study found a curvilinear relationship between fertility and education in 14 out of 38 countries with World Fertility Surveys. There were only 3 countries with Demographic and Health Surveys which showed the curvilinear pattern. The UN study confirmed that maternal education was related to shorter durations of postpartum abstinence and short durations of lactation. Caution was urged in interpreting that an increase in a few years of schooling in a dominant rural, illiterate population would facilitate rapid fertility decline. A critical threshold effect for educational attainment was found in mainly the least developed countries. Female education has direct and indirect effects on fertility. Education may affect breast feeding patterns, contraceptive use, social norms about small families, later age at marriage, and later age at first birth. The suggestion was that education provided for reproductive choice and reduces the gap between actual and desired family size. At the country and individual level of analysis, contraceptive use was linked with education. Effective contraceptive use was still however impeded by

  11. Certain Less Invasive Infertility Treatments Associated with Different Levels of Pregnancy-Related Anxiety in Pregnancies Conceived via In Vitro Fertilization

    Science.gov (United States)

    Stevenson, Eleanor Lowndes; Sloane, Richard

    2017-01-01

    Background: Research supports that in vitro fertilization causes anxiety and that anxiety can continue into the resulting pregnancy. Most women who have IVF will have a less invasive treatment for infertility prior to IVF; however, it is unclear if specific less invasive treatment cycles impact anxiety that is experienced in the pregnancy resulting from IVF. Methods: A prospective study was conducted for women who became pregnant via IVF, and data was collected about reported previous non-IVF treatment cycles as well as Pregnancy Related Anxiety Measure. Latent Class Analysis was conducted A p-value of ≤0.05 was considered significant. Results: 144 subjects participated and were highly educated, affluent, married, and primarily white. The LCA process yielded two groups that on average had similar levels on most items except for use of intra uterine insemination and/or ovarian stimulation. This information was used to generate four exhaustive and mutually exclusive groups: Stimulation Only (stim-only), Stimulation and Intra uterine Insemination (stim-IUI), Intra uterine Insemination only (IUI only), or No Treatment (No Tx). ANOVA found that those in the Stim Only group had statistically significantly higher PRAM scores than the Stim IUI (p=0.0036), the IUI only group (p=0.05), and the No Tx group (p=0.0013). Conclusion: Women who become pregnant via IVF and had a history of non-in vitro fertilization cycles that only involved ovarian stimulation experienced more pregnancy-specific anxiety in the pregnancy that results from in vitro fertilization.

  12. Soil Fertility Status on Organic Paddy Experiment

    Directory of Open Access Journals (Sweden)

    Mujiyo

    2015-07-01

    Full Text Available The study aims to determine fertility status of the soil after organic paddy experiments using kinds and doses of organic fertilizers. Experiment was conducted at greenhouse laboratory in Faculty of Agriculture Sebelas Maret University Surakarta. Experimental design used completely randomized design with 9 kinds of treatment was replicated 3 times. Experiments were the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations that are based on fulfilling nutrient requirements of 120 kg N ha-1. Result shows that the use of cow manure, Azolla fertilizers and Azolla inoculum had no effect on changes of soil fertility status. Soil fertility status was not significantly correlated with cow manure (0,16ns, Azolla fertilizer (0,26ns and Azolla inoculum (0,16ns. Average of final soil fertility status included fertile category, which was similar as the initial soil fertility status. Average of final soil properties of treatment but nevertheless was relatively higher than in no treatment, indicating the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations had greater impact to soil properties. Cow manure despite increased available K2O and dry grain, but it did not significantly increase the soil fertility status from fertile to very fertile. This was presumably due to the relatively short experiment period, only one planting season had not given significant effect to soil properties. Implication of this study is the use of cow manure, Azolla fertilizer, Azolla inoculum and its combinations although did not increase the soil fertility status but could maintain soil fertility status as the initial conditions before planting.

  13. Fertility incentives and disincentives.

    Science.gov (United States)

    Financioglu, N

    1984-06-01

    Some 40 countries use some form of incentives and disincentives in support of population policies, about half with the aim of reducing fertility and half with the aim of increasing it. These schemes range from limitations on tax and family allowances or maternity benefits after a given family size has been reached to payments to acceptors of fertility control methods. Some schemes aim to eliminate or reduce the cost and inconvenience people may face in achieving their fertility preferences, whereas others contain an element of deterrence. It is difficult to isolate and measure the impact of incentives on fertility from the effects of other factors such as family planning service availability or modernization. Studies in pronatalist countries suggest that incentive schemes produce short-term fertility increases without a change in average family size. Monetary incentives must be constantly increased to keep pace with inflation, placing a heavy burden on government budgets. Administrative capacity to operate the scheme is critical in terms of both manpower and efficient systems for record keeping, monitoring, and close supervision to prevent abuse. There is also considerable debate on the moral and ethical implications of incentives and disincentives as policy tools. Incentives offered for the acceptance of a particular fertility control method potentially contravene the principle of voluntary and informed consent. In addition, the relative value of the reward is greater for those in the lower income groups. The discriminatory nature of certain types of incentives and disincentives is illustrated by measures introduced in Singapore that give highest priority in school enrollment to the children of highly educated mothers with 2-3 children. This ruling is expected to further intensify the controversy surrounding incentive and disincentive schemes.

  14. A synthetic biosocial model of fertility transition: testing the relative contribution of embodied capital theory, changing cultural norms, and women's labor force participation.

    Science.gov (United States)

    Snopkowski, Kristin; Kaplan, Hillard

    2014-07-01

    This article presents a biosocial model of fertility decline, which integrates ecological-economic and informational-cultural hypotheses of fertility transition in a unified theoretical framework. The model is then applied to empirical data collected among 500 women from San Borja, Bolivia, a population undergoing fertility transition. Using a combination of event history analysis, multiple regression, and structural equation modeling, we examine the pathways by which education responds to birth cohort, parental education and network ties, and how age at first birth and total fertility, in turn, respond to birth cohort, social network ties, education, expectations about parental investment, work, and contraceptive use. We find that in addition to secular trends in education, respondent's education is associated with the education of parents, the investment she received from them, and the education of older siblings. Total fertility has dropped over time, partly in response to increased education; moreover, the behavior of other women in a woman's social network predicts both initiation of reproduction and total fertility, while expected parental investment in offspring negatively predicts total fertility. Involvement in paid work that is incompatible with childcare is associated with a later age of first reproduction, but not subsequent fertility. Contraceptive use partially mediates the effect of education and birth cohort on total fertility, but is not a mediator of the effect of social network or expected parental investment on total fertility. Overall, the empirical results provide support for a biosocial model of fertility decline, particularly the embodied capital and cultural pathways. © 2014 Wiley Periodicals, Inc.

  15. 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

  16. Fertility Desire and Reproductive Health

    African Journals Online (AJOL)

    Understanding fertility desire and reproductive health care needs of HIV positive men and women in the era ... and related consequences. ... inform national policy decisions on PMTCT, HIV ... The study population was included proportional to.

  17. Effect of urea fertilizer application on soluble protein and free amino acid content of cotton petioles in relation to silverleaf whitefly (Bemisia argentifolii) populations.

    Science.gov (United States)

    Bi, J L; Toscano, N C; Madore, M A

    2003-03-01

    The impact of urea nitrogen fertilization on silverleaf whitefly, Bemisia argentifolii Bellows & Perring, population dynamics was examined in field-grown cotton (Gossypium hirsutum L.). Five urea nitrogen treatments were tested, consisting of soil applications of 0, 112, 168, and 224 kg nitrogen per hectare, and acombined soil-foliar application of 112:17 kg nitrogen per hectare. A positive response was observed between N application rates and the measured levels of nitrate N in petioles from mature cotton leaves. Similarly, a positive response was observed between N application rates and the numbers of adult and immature whiteflies appearing during population peaks. To determine whether these positive responses were related, we measured the levels of dietary N compounds (proteins and free amino acids) that would be available for insect nutrition in cotton petioles at the different N application rates. Sampling dates and N application treatments affected levels of soluble proteins in cotton petioles, and interactions between sampling dates and treatments were significant. Across all sampling dates, the relationship between N application rates and levels of soluble proteins was linear. Sampling dates also affected levels of total and individual free amino acids. Fertilizer treatments only affected levels of total amino acids, aspartate, asparagine, and arginine plus threonine. Levels of aspartate or asparagine and the N application rates were linearly correlated. No significant correlations were observed between levels of dietary N compounds in cotton petioles and numbers of whiteflies, either adults or immatures, on the cotton plants.

  18. A general description of additive and nonadditive elements of sperm competitiveness and their relation to male fertilization success.

    Science.gov (United States)

    Engqvist, Leif

    2013-05-01

    A complete understanding of male reproductive success, and thus sexual selection, often requires an insight into male success in sperm competition. Genuine conclusions on male sperm competitiveness can only be made in real competitive situations. However, statistical analyses of sperm competitiveness from fertilization success data have been shown to be problematic. Here, I first outline a comprehensive general description of the different additive and nonadditive elements relevant for the outcome of sperm competition staged between two males. Based on this description, I will highlight two main problems that are frequently encountered in experiments aiming at estimating sperm competitiveness. First, I focus on potential problems when using standardized competitors versus random mating trials, because trials with standardized competitors do not allow generalization if male-male interactions are important. Second, I illustrate the necessity to analyze data on the logit scale rather than on raw proportions, because only the logit scale allows a clean separation of additive and nonadditive effects (i.e., male × male and female × male interactions).

  19. Understanding fertilization through intracytoplasmic sperm injection (ICSI)

    Science.gov (United States)

    Neri, Queenie V.; Lee, Bora; Rosenwaks, Zev; Machaca, Khaled; Palermo, Gianpiero D.

    2014-01-01

    Summary Since the establishment of in vitro fertilization, it became evident that almost half of the couples failed to achieve fertilization and this phenomenon was attributed to a male gamete dysfunction. The adoption of assisted fertilization techniques particularly ICSI has been able to alleviate male factor infertility by granting the consistent ability of a viable spermatozoon to activate an oocyte. Single sperm injection, by pinpointing the beginning of fertilization, has been an invaluable tool in clarifying the different aspects of early fertilization and syngamy. However, even with ICSI some couples fail to fertilize due to ooplasmic dysmaturity in relation to the achieved nuclear maturation marked by the extrusion of the first polar body. More uncommon are cases where the spermatozoa partially or completely lack the specific oocyte activating factor. In this work, we review the most relevant aspects of fertilization and its failure through assisted reproductive technologies. Attempts at diagnosing and treating clinical fertilization failure are described. PMID:24290744

  20. Effect of Excess Fertilizer Phosphorus on Some Chemical Properties of Paddy Soil Drived from Red Soil and Its Relation to Rice Growth

    Institute of Scientific and Technical Information of China (English)

    NIWUZHONG; HENIANZU

    1997-01-01

    A filed experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejing Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P(15 kg P hm-2)could increase the content of soil available P at the tillering stage of early rice,the contents of N,P and K in the shoots of early rice at primary growth stages,and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains,which,was mainly related to the higher contents of reduced,non-reduced and total sugar in the shoot at the heading stage, And early rice supplied with excessive P could not yield more than that applied with adequate, P de to the reduction in the valid grain percentage and weight per thousead grains. In addition,one-time excess P supply at a rate as high as 90 kg P hm-2 could not improve the soil P fertility in case the soil available P content was lower than the initial(3.74mg kg-1 soil) after an early rice-late rice rotaion,and made a decline in the grain yield increased by per kilogram fertilzer P.Thus,one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.

  1. Fertility in female childhood cancer survivors

    DEFF Research Database (Denmark)

    De Bruin, Marie L; Van Dulmen-den Broeder, Eline; Van den Berg, Marleen H

    2009-01-01

    chemotherapy and radiotherapy may have an adverse effect on ovarian function, ovarian reserve and uterine function, clinically leading to sub-fertility, infertility, premature menopause and/or adverse pregnancy outcomes. Here we will first address normal female fertility and methods to detect decreased...... fertility. Hence we will focus on direct effects as well as late fertility-related adverse effects caused by chemotherapy and radiotherapy, and we will conclude with a summary of current options for fertility preservation in female childhood cancer survivors....

  2. Serum hepatic enzyme activity in relation to semen quality and serum reproductive hormone levels among Estonian fertile Men.

    Science.gov (United States)

    Ehala-Aleksejev, K; Punab, M

    2016-01-01

    The aim of this study was to investigate the relations of basic semen parameters and reproductive hormones with alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). In addition, to examine possible interaction between adiposity, alcohol consumption, and liver tests in relation to male reproductive health, standard semen analysis was performed and serum levels of reproductive hormones and liver tests were measured in 245 male partners of pregnant women at a University Hospital Andrology Centres in Estonia. Quartile analysis revealed that after adjustment for covariates GGT was negatively related to sperm concentration and total sperm count. These significant changes appeared from a GGT >35.5 U/L. Next to these changes ALT was not related to sperm parameters. Both enzymes, GGT and ALT, were not related to reproductive hormones. Alcohol consumption was positively related to GGT and in cases with elevated GGT alcohol use was negatively related to sperm concentration and total sperm count. Alcohol consumption was positively related to body mass index (BMI) and waist circumference (WC). Our findings also confirm results of previous studies that BMI and WC are associated positively with ALT and GGT. According to the study, increased GGT activity might represent a possible connection between adiposity, alcohol consumption, and semen quality.

  3. VARIATION IN CREOSOTEBUSH (LARREA TRIDENTATA) CANOPY MORPHOLOGY IN RELATION TO HABITAT, SOIL FERTILITY AND ASSOCIATED ANNUAL PLANT COMMUNITIES

    Science.gov (United States)

    Differences in creosotebush (Larrea tridentata) crown morphology may reflect changes in the relative demand for water vs. nutrient resources, coinciding with shrub growth and development Creosotebushes with inverted cone-shaped crowns were more abundant in water-limited environme...

  4. Serum hepatic enzyme activity in relation to semen quality and serum reproductive hormone levels among Estonian fertile Men

    National Research Council Canada - National Science Library

    Ehala‐Aleksejev, K; Punab, M

    2016-01-01

    ...‐glutamyl transferase (GGT). In addition, to examine possible interaction between adiposity, alcohol consumption, and liver tests in relation to male reproductive health, standard semen analysis was performed and serum levels...

  5. The value of Anti-Müllerian hormone in low and extremely low ovarian reserve in relation to live birth after in vitro fertilization.

    Science.gov (United States)

    Reijnders, Igna F; Nelen, Willianne L D M; IntHout, Joanna; van Herwaarden, Antonius E; Braat, Didi D M; Fleischer, Kathrin

    2016-05-01

    To determine the relation of Anti-Müllerian hormone (AMH) with live birth after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in women with (extremely) low ovarian reserve. This study was a retrospective cohort study in a Dutch tertiary fertility clinic. Between January 2009 and March 2012, AMH levels were measured in infertile women when ≥36 years of age or when showing clinical signs of diminished ovarian reserve, before they underwent IVF or ICSI treatment. Ultimately, 156 women with (extremely) low ovarian reserve were included and evaluated for cumulative live birth rates. Of each woman, only one treatment cycle was analyzed, either the one in which she became pregnant or her first treatment cycle if she did not reach pregnancy. The relation between AMH and live birth was evaluated with multivariable logistic regression analysis. A ROC curve was composed to evaluate the discriminative value of AMH in relation to live birth after IVF/ICSI. Thirty-three out of 156 women (21.2%) gave live birth. Live birth was significantly lower in women with AMH ≤0.1ng/ml (4/37 women; 10.8%) or AMH >0.1-0.4ng/ml (7/42 women; 16.7%), compared to women with AMH >0.4-1.05ng/ml (22/77 women; 28.6%), plive birth (per 0.1ng/ml increase in AMH value, Odds ratio 1.21; 95% CI 1.07-1.36). The level of AMH is related to live birth after IVF/ICSI in women with (extremely) low ovarian reserve. The live birth rate in women with AMH >0.4ng/ml was significantly higher than in women with AMH ≤0.4ng/ml. AMH could serve as a tool in the pre-treatment counseling for pregnancy and live birth chances in women with (extremely) low ovarian reserve. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. 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...

  7. The different surrogate measures of adiposity in relation to semen quality and serum reproductive hormone levels among Estonian fertile men.

    Science.gov (United States)

    Ehala-Aleksejev, K; Punab, M

    2015-03-01

    The objective of this study was to investigate the relations of basic semen parameters and reproductive hormones with different surrogate measures of adiposity: body mass index (BMI), body fat percentage (BF%), waist circumference (WC) and waist-to-height ratio (WHtR). Standard semen analysis was performed and serum levels of reproductive hormones were measured in 260 male partners of pregnant women at a university hospital andrology centres in Estonia. Quartile analysis revealed that all adiposity markers were negatively related to sex hormone-binding globulin and total testosterone levels. After adjustment for covariates a high BF%, WC and WHtR were negatively associated with total sperm count. The BF% was also negatively related to semen volume. These significant changes occurred from a BF% ≥ 23.4%, WC > 98 cm and WHtR > 0.54. Next to these changes the BMI was not related to sperm parameters. This study shows that semen quality is affected by central adiposity and confirms earlier findings that adiposity markedly changes serum sex hormone levels. Further studies are required to find out what is the best body composition marker showing most clearly the relationships between adiposity, semen characteristics and sex hormone levels.

  8. Evaluation of genetic components in traits related to superovulation, in vitro fertilization, and embryo transfer in Holstein cattle

    Science.gov (United States)

    The objectives of this study were to estimate variance components and identify regions of the genome associated with traits related to embryo transfer in Holsteins. Reproductive technologies are used in the dairy industry to increase the reproductive rate of superior females. A drawback of these met...

  9. The fertility of internal migrants to Kinshasa.

    Science.gov (United States)

    Anglewicz, Philip; Corker, Jamaica; Kayembe, Patrick

    2017-01-01

    The rapid population growth of many African cities has important implications for population health, yet little is known about factors contributing to increasing population, such as the fertility of internal migrants. We examine whether in-migrants to Kinshasa have different fertility patterns than lifetime Kinshasa residents, and identify characteristics of migrants that may explain differences in fertility. We also use detailed migration histories to examine whether fertility differs by features of migration. We use representative data from the PMA2020 Project for 2197 women in Kinshasa, including 340 women who moved to Kinshasa. We examine differences between migrants and non-migrants in fertility and other fertility-related characteristics. We also examine whether fertility differs by duration of residence in Kinshasa, number of lifetime moves, age at first migration, urban/rural classification of birthplace, and the distinction between intra-Kinshasa migration and migration to Kinshasa.. Migrants have significantly higher fertility than permanent Kinshasa residents, but the difference is relatively small in magnitude. This higher fertility appears due in part to patterns of contraceptive use among migrants. There is noteworthy heterogeneity among migrants: higher fertility among migrants is associated with longer duration in Kinshasa, more lifetime moves, urban-Kinshasa migration, older age at first migration, and moving to Kinshasa from outside (as opposed to intra-Kinshasa migration).

  10. 常规IVF中受精失败相关因素及后续处理结果分析%Factors Relating with Fertilization Failure and Subsequent Treatment Outcomes in Conventional IVF-ET Cycles

    Institute of Scientific and Technical Information of China (English)

    王凤英; 俞炽阳; 何畏; 李玉艳; 张觇宇; 屈宗银; 龙玲

    2009-01-01

    Objective: To analyze the factors relating with fertilization failure in conventional IVF cycles so as to increase the fertilization rate for further clinical treatment. Methods: Relating factors of patients with fertilization failure or low fertilization rate in conventional IVF cycles and the further treatment outcomes were retrospectively analyzed. Results: In 438 conventional IVF cycles, there were 30 cycles (6.85%) with fertilization rate <25% (group A). Among these 30 cycles, rescue ICSI or repeated IVF was carried out at d 1 in 12 cycles, and finally there were 20 cycles with embryo transfer, but no clinical pregnancy was obtained. The sperm density, motility, grade a motility, percentage of progressive motile sperm (PMS), total progressive motile sperm count (TPMSC) and the separated sperm motility, percentage of PMS, concentration in group A were significantly lower than those in normal fertilization rate group (group B) (all P<0.05). The number of retrieved oocytes had no significant difference between group A and group B, but the oocyte number at M_I and GV stage in group A was significantly more as compared with those in group B (all P<0.01). The other factors relating with fertilization failure included sever teratospermia, bacterial contaminant semen, oocyte development block and so on. Among patients with fertilized-failure result of sperm factors, 7 patients were fertilized with ICSI in the next cycles, and there were 5 patients with clinical pregnancy. Conclusion: Many factors are related with fertilization failure. However, low semen parameters or poor sperm quality and immature oocytes are main factors. Outcome of recuse ICSI at d 1 or repeated IVF is poor. ICSI selected in the next cycle may give satisfactory outcomes for fertilization failure patient relating with sperm factors.%目的:分析常规IVF受精失败原因,以进一步提高IVF受精率.方法:回顾性分析常规IVF中受精率低下或受精失败患者的各种因

  11. Moribund sperm in frozen-thawed semen, and sperm motion end points post-thaw and post-swim-up, are related to fertility in Holstein AI bulls.

    Science.gov (United States)

    Shojaei, H; Kroetsch, T; Wilde, R; Blondin, P; Kastelic, J P; Thundathil, J C

    2012-03-15

    The objectives were to compare testicular physical characteristics and post-thaw sperm characteristics and their associations with fertility in Holstein bulls used for AI. Ten Holstein bulls (4-5 y old) were classified as either high-fertility (HF) or low-fertility (LF; n = 5 each), based on adjusted 56-d non-return rates [non-return rate (NRR); range (mean ± SD): 55.6 ± 4.6 to 71.8 ± 1.3%). Testicular physical characteristics were not significantly different between the two groups. Four ejaculates were collected from each bull and cryopreserved. Several indexes of sperm motion (based on computer-assisted sperm analysis) at post-thaw and post-swim-up were correlated with NRR. Sperm from HF bulls were in transition to a hyperactivated motility pattern, whereas those from LF bulls had only a forward progressive motility pattern. In HF vs LF bulls, there was a greater percentage of viable sperm after thawing (60.6 ± 9.7 vs 49.5 ± 8.0%, P fertility (r = 0.45, P fertility. In conclusion, fertility of Holstein bulls maintained in a commercial AI center was not predicted by testicular physical characteristics, but it was associated with differences in moribund sperm in the inseminate, as well as characteristics of sperm post-thaw and after swim-up. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Development of new method and protocol for cryopreservation related to embryo and oocytes freezing in terms of fertilization rate: A comparative study including review of literature

    Science.gov (United States)

    Barik, Mayadhar; Bajpai, Minu; Patnaik, Santosh; Mishra, Pravash; Behera, Priyamadhaba; Dwivedi, Sada Nanda

    2016-01-01

    Background: Cryopreservation is basically related to meritorious thin samples or small clumps of cells that are cooled quickly without loss. Our main objective is to establish and formulate an innovative method and protocol development for cryopreservation as a gold standard for clinical uses in laboratory practice and treatment. The knowledge regarding usefulness of cryopreservation in clinical practice is essential to carry forward the clinical practice and research. Materials and Methods: We are trying to compare different methods of cryopreservation (in two dozen of cells) at the same time we compare the embryo and oocyte freezing interms of fertilization rate according to the International standard protocol. Results: The combination of cryoprotectants and regimes of rapid cooling and rinsing during warming often allows successful cryopreservation of biological materials, particularly cell suspensions or thin tissue samples. Examples include semen, blood, tissue samples like tumors, histological cross-sections, human eggs and human embryos. Although presently many studies have reported that the children born from frozen embryos or “frosties,” show consistently positive results with no increase in birth defects or development abnormalities is quite good enough and similar to our study (50–85%). Conclusions: We ensure that cryopreservation technology provided useful cell survivability, tissue and organ preservation in a proper way. Although it varies according to different laboratory conditions, it is certainly beneficial for patient's treatment and research. Further studies are needed for standardization and development of new protocol. PMID:27512686

  13. Transition cow: interaction with fertility.

    Science.gov (United States)

    Formigoni, A; Trevisi, E

    2003-09-01

    In recent years a progressive worsening of fertility indices in dairy cow herds has been observed. Several factors (genetic, dietary and management) seem to be more related to poor fertility than milk yield level. The degree and the length of the energy deficit during the transition period are inversely related to reproductive indices (e.g. conception rate is fertility in several ways. Excess of rumen degradable proteins, apart from negative energy balance, negatively affects reproductive activity. Conversely, some nutrients (i.e. some polyunsaturated fatty acids or some amino acids) seem to show positive effects on fertility. Finally, the relationship between health status, often compromised during the transition period, and fertility efficiency is discussed. The release of cytokines seems to be related directly and indirectly (mainly by the change in usual hepatic metabolism to the malfunction of reproductive apparatus. Quick recovery of reproductive activity requires the adoption of strategies around calving to cover the higher environmental and nutritive requirements and to prevent disorders of any kind.

  14. Air pollution and human fertility rates.

    Science.gov (United States)

    Nieuwenhuijsen, Mark J; Basagaña, Xavier; Dadvand, Payam; Martinez, David; Cirach, Marta; Beelen, Rob; Jacquemin, Bénédicte

    2014-09-01

    Some reports have suggested effects of air pollution on semen quality and success rates of in vitro fertilization (IVF) in humans and lower fertility rates in mice. However, no studies have evaluated the impact of air pollution on human fertility rates. We assessed the association between traffic related air pollution and fertility rates in humans in Barcelona, Spain (2011-2012). We hypothesized that higher air pollution levels would be associated with lower fertility rates. We calculated the general fertility rate which is the number of live births per 1000 women between the ages of 15 and 44 years per census tract. We used land use regression (LUR) modeling to estimate the air pollution concentrations (particulate matter, NO2/NOx) per census tract. We used Besag-York-Mollié models to quantify the relationship between air pollution and fertility rates with adjustment for a number of potential confounders such as maternal age and area level socio-economic status. We found a statistically significant reduction of fertility rates with an increase in traffic related air pollution levels, particularly for the coarse fraction of particulate matter (IRR=0.87 95% CI 0.82, 0.94 per IQR). This is the first study in humans to show an association between reduced fertility rates and higher traffic related air pollution levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments.

    Science.gov (United States)

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

    2015-01-01

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

  16. [Effects of different long-term fertilization on the activities of enzymes related to carbon, nitrogen, and phosphorus cycles in a red soil].

    Science.gov (United States)

    Fan, Miao-zhen; Yin, Chang; Fan, Fen-liang; Song, A-lin; Wang, Bo-ren; Li, Dong-chu; Liang, Yong-chao

    2015-03-01

    Using a microplate fluorimetric assay method, five fertilization treatments, i.e. no-fertilizer control (CK) , sole application of nitrogen (N), balanced application of nitrogen, phosphorus, and potassium fertilizer (NPK), application of pig manure (M), and combination of pig manure with balanced chemical fertilizer (MNPK) were selected to investigate the effects of different long-term fertilization regimes on the activity of five enzymes (β-1, 4-glucosidase, βG; cellobiohydrolase, CBH; β-1, 4-xylosidase, βX; β-1, 4-N-acetylglucosaminidase, NAG; acid phosphatase, AP) in a red soil sampled from Qiyang, Hunnan Province. The results showed that compared with CK treatment, N treatment had no impact on βG, βX, CBH, and NAG activities but reduced AP activity, while NPK, M and MNPK treatments increased the activities of all the five enzymes. Correlation analysis indicated that all the five enzyme activities were positively correlated with the content of nitrate (r=0.465-0.733) , the content of available phosphorus (r=0.612-0.947) , soil respiration (r=0.781-0.949) and crop yield (r=0.735-0.960), while βG, CBH and AP were positively correlated with pH (r= 0.707-0.809), only AP was significantly correlated with dissolvable organic carbon (r = -0.480). These results suggested that the activities of the measured enzymes could be used as indicators of red soil fertility under different fertilization regimes, but the five enzymes tested provided limited information on the degree of acidification induced by application of mineral nitrogen.

  17. [The impact of obesity on fertility].

    Science.gov (United States)

    Pesant, M-H; Wunder, D; Pralong, F; Giusti, V

    2010-03-31

    There are many negative impacts of obesity on fertility. Obese couples present decreased sperm count, decreased ovulation and conception rates, increased erectile dysfunction and spontaneous abortion rate as well as increased maternal and foetal complications of pregnancy. Moreover, obesity tends to decrease response to fertility treatments. Fortunately, intensive lifestyle modifications can restore fertility while decreasing pregnancy complications risk. With the increasing trend of obesity to affect young populations, taking care of these infertile couples rapidly is capital to restore fertility and decrease its related pregnancy complications.

  18. Cancer and fertility : strategies to preserve fertility

    NARCIS (Netherlands)

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

    2011-01-01

    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 pub

  19. Cancer and fertility : strategies to preserve fertility

    NARCIS (Netherlands)

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

    Fertility preservation is a key component of cancer management in young people. The Fourth Evian Annual Reproduction Workshop Meeting was held in April 2009 to discuss cancer and fertility in young adults. Specialists in oncology, assisted reproduction, embryology and clinical genetics presented

  20. Age and Fertility

    Science.gov (United States)

    ... method of assisted reproduction that involves combining an egg with sperm in a laboratory dish. If the egg fertilizes ... produced by the testes that fertilize a woman’s egg. The sperm head carries genetic material (chromosomes), the midpiece produces ...

  1. Plant fertilizer poisoning

    Science.gov (United States)

    Plant fertilizers and household plant foods are used to improve plant growth. Poisoning can occur if someone swallows these products. Plant fertilizers are mildly poisonous if small amounts are swallowed. ...

  2. Fertility Clinic Success Rates

    Science.gov (United States)

    ... and Autism 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet Share Compartir 2013 ART Fertility Clinic Success Rates Report [PDF - 1MB] Bookmarks and thumbnails are ...

  3. In vitro fertilization (IVF)

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007279.htm In vitro fertilization (IVF) To use the sharing features on this page, please enable JavaScript. In vitro fertilization (IVF) is the joining of a woman's egg ...

  4. Use of heterospermic inseminations and paternity testing to evaluate the relative contributions of common sperm traits and seminal plasma proteins in boar fertility.

    Science.gov (United States)

    Flowers, W L; Deller, F; Stewart, K R

    2016-11-01

    The objective of this study was to evaluate relationships between common semen quality estimates including sperm motility, sperm morphology, spontaneous capacitation status and seminal plasma proteins and boar fertility using heterospermic inseminations and subsequent paternity testing. All boars (n=12) used in the study had excellent semen quality (≥70% normal sperm) that resulted in average farrowing rates and litter sizes of 88.9±0.7% and 11.7±0.1 pigs, respectively. Their ejaculates were combined to make heterospermic insemination doses in such a way that each boar was tested against all of his contemporaries. The proportion of piglets sired by each individual was used to separate boars into three fertility groups: High (71.6±4.8%; n=3); Medium (51.6±3.8%; n=6); and Low (25.2%±5.3%; n=3). Ejaculates from High fertility boars had more motile sperm with normal acrosomes that moved faster in a straight-line and were more likely to undergo an acrosome reaction (p≤0.05) compared with their counterparts in the Low fertility group. Ejaculates from High fertility boars contained the greatest concentrations of three seminal plasma proteins (25.9kD/5.9pI; 55.1kD/4.8pI; and 70.1kD/5.2pI; p≤0.05), whereas concentrations of a 19.1kD/6.8pI were highest in semen from Low fertility boars (p≤0.05). Multiple regression analyses indicated that concentrations of the 25.9kD/5.9pI seminal plasma protein explained 66% of the variation observed in the proportion of pigs sired within a litter among boars (p≤0.00001). These results demonstrate that heterospermic inseminations and subsequent paternity testing is an effective technique for defining relationships between common semen quality tests and fertility, especially in situations where reproductive performance of all the boars is high. Motility, normal acrosome morphology, average linear velocity of motile sperm, and the proportion of sperm capable of an acrosome reaction were all positively associated with boar

  5. 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.

  6. 5 Assessment of fertility status.cdr

    African Journals Online (AJOL)

    Administrator

    coconut yield is generally related to the fertility status of the soil, a study was conducted to evaluate the fertility status of soils supporting ... Mean organic matter status 22.1 1.9 gkg was moderate. ... surface moisture drains down slope, which.

  7. Cancer and fertility: strategies to preserve fertility.

    Science.gov (United States)

    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.

  8. Fertility preservation in Turner syndrome.

    Science.gov (United States)

    Grynberg, Michaël; Bidet, Maud; Benard, Julie; Poulain, Marine; Sonigo, Charlotte; Cédrin-Durnerin, Isabelle; Polak, Michel

    2016-01-01

    Premature ovarian insufficiency is a relatively rare condition that can appear early in life. In a non-negligible number of cases the ovarian dysfunction results from genetic diseases. Turner syndrome (TS), the most common sex chromosome abnormality in females, is associated with an inevitable premature exhaustion of the follicular stockpile. The possible or probable infertility is a major concern for TS patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The severely reduced follicle pool even during prepubertal life represents the major limit for fertility preservation and is the root of numerous questions regarding the competence of gametes or ovarian tissue crybanked. In addition, patients suffering from TS show higher than usual rates of spontaneous abortion, fetal anomaly, and maternal morbidity and mortality, which should be considered at the time of fertility preservation and before reutilization of the cryopreserved gametes. Apart from fulfillment of the desire of becoming genetic parents, TS patients may be potential candidates for egg donation, gestational surrogacy, and adoption. The present review discusses the different options for preserving female fertility in TS and the ethical questions raised by these approaches.

  9. Crystallographic properties of fertilizer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  10. Relative validity of a semi-quantitative, web-based FFQ used in the ‘Snart Forældre’ cohort – a Danish study of diet and fertility

    DEFF Research Database (Denmark)

    Knudsen, Vibeke Kildegaard; Hatch, Elizabeth E.; Cueto, Heidi

    2015-01-01

    Objective: To assess the relative validity of a semi-quantitative, web-based FFQ completed by female pregnancy planners in the Danish ‘Snart Forældre’ study. Design: We validated a web-based FFQ based on the FFQ used in the Danish National Birth Cohort against a 4 d food diary (FD) and assessed...... and nutrients and, thus, provides a solid basis for investigating associations between diet and fertility....

  11. The Decline of the Breast: An Examination of Its Impact on Fertility and Health, and Its Relation to Socioeconomic Status. Cornell International Nutrition Monograph Series, Number 10 (1982).

    Science.gov (United States)

    Latham, Michael C., Ed.

    The three papers in this collection discuss, respectively, the relationship of breastfeeding to human fertility, strategies to improve feeding of infants and young children, and infant feeding options for Thai professional women residing in Bangkok. Specific topics addressed in the first paper include the physiological role of lactation on…

  12. Primogeniture and fertility: fertility models with unequal bequest.

    Science.gov (United States)

    Parsons, D O

    1984-01-01

    Models of the family which incorporate bequest inequality into the fertility decision were developed. Following a discussion on this topic by H.J. Habakkuk, discussion focuses on preindustrial and early industrial England and Western Europe. An attempt was made to develop fertility models which do not assume that all children are treated equally but instead recognize the special role that the eldest child often plays in the family. The fertility consequences of primogeniture are explored in 2 different fertility models. In the initial behavioral model due to Habakkuk, fertility is a function of marriage age and marriage age is a function of time required for one's capital to reach some social minimum required for household formation. In such a model it is possible to show that an increasingly unequal bequest between children will reduce aggregate fertility in the following generation. The introduction of explicit fertility choice considerably complicates the model. The effect of greater relative bequests to the eldest child, if motivated by parental preference, depends on the role children other than the eldest play in the family. If parents would normally choose to have more children the larger the total bequest they intend to bestow on all their children, the effect of primogeniture will be to reduce fertility. The wealth parents allocate to the eldest with primogeniture has an impact on the other children equivalent to a general decline in family bequests. Similar conclusions hold if the shift of wealth to the eldest is the result of a legal constraint that a specified share of the estate be allocated to the eldest. Yet, if the constraint is posed as a required proportionality between the wealth of the eldest and the average wealth of other children, the effect of primogeniture laws (or conversely equality laws) is ambiguous. The same negative wealth effect exists for the younger children as wealth is diverted to the eldest. A positive fertility effect also

  13. Ammonia fluxes in relation to cutting and fertilization of an intensively managed grassland derived from an inter-comparison of gradient measurements

    Directory of Open Access Journals (Sweden)

    C. Milford

    2009-05-01

    Full Text Available Quantification of ammonia (NH3 land-atmosphere exchange is required for atmospheric modelling and assessment of nitrogen deposition, yet flux measurement methods remain highly uncertain. To address this issue, a major inter-comparison of ammonia fluxes over intensively managed grassland was conducted during the GRAMINAE Integrated Experiment held in Braunschweig, Germany. In order to provide a robust dataset of ammonia exchange with the vegetation, four independent continuous flux gradient systems were operated. Three independently operated continuous wet denuders systems (AMANDA were compared with a Wet Effluent Diffusion Denuder (mini-WEDD system. Measurements were made at two distances from an adjacent livestock farm, allowing effects of advection to be quantified in a real landscape setting. Data treatment included filtering for instrument failure, disturbed wind sectors and unsuitable micrometeorological conditions, with corrections made for storage and advection errors.

    The inter-comparison demonstrated good agreement in measured ammonia concentrations and fluxes (relative standard error <20% for some periods, although the performance of the ammonia analyzers were variable, with much poorer agreement on particular days. However, by using four systems, the inter-comparison was able to provide a robust mean estimate of continuous ammonia fluxes through the experiment. The observed fluxes were: a small bi-directional fluxes prior to cutting (−64 to 42 ng NH3 m−2 s−1, b larger diurnally-varying emissions following cutting (−49 to 703 ng NH3 m−2 s−1 and c much larger emissions following fertilizer application (0 to 3820 ng NH3 m−2 s−1. The results are a salutary reminder of the uncertainty in unreplicated ammonia flux measurements, while the replication of the present study provides a uniquely robust dataset for

  14. 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......Forests of northern ecosystems respond slowly to management activities and the possibilities to increase the growth in a short-term perspective and meet swift increases in society's demand for biomass are small. An exception among the silvicultural measures is fertilization which can be applied...... 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...

  15. 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.

  16. A model based investigation of the relative importance of CO2-fertilization, climate warming, nitrogen deposition and land use change on the global terrestrial carbon uptake in the historical period

    Science.gov (United States)

    Devaraju, N.; Bala, G.; Caldeira, K.; Nemani, R.

    2016-07-01

    In this paper, using the fully coupled NCAR Community Earth System Model (CESM1.0.4), we investigate the relative importance of CO2-fertilization, climate warming, anthropogenic nitrogen deposition, and land use and land cover change (LULCC) for terrestrial carbon uptake during the historical period (1850-2005). In our simulations, between the beginning and end of this period, we find an increase in global net primary productivity (NPP) on land of about 4 PgCyr-1 (8.2 %) with a contribution of 2.3 PgCyr-1 from CO2-fertilization and 2.0 PgCyr-1 from nitrogen deposition. Climate warming also causes NPP to increase by 0.35 PgCyr-1 but LULCC causes a decline of 0.7 PgCyr-1. These results indicate that the recent increase in vegetation productivity is most likely driven by CO2 fertilization and nitrogen deposition. Further, we find that this configuration of CESM projects that the global terrestrial ecosystem has been a net source of carbon during 1850-2005 (release of 45.1 ± 2.4 PgC), largely driven by historical LULCC related CO2 fluxes to the atmosphere. During the recent three decades (early 1970s to early 2000s), however, our model simulations project that the terrestrial ecosystem acts as a sink, taking up about 10 PgC mainly due to CO2 fertilization and nitrogen deposition. Our results are in good qualitative agreement with recent studies that indicate an increase in vegetation production and water use efficiency in the satellite era and that the terrestrial ecosystem has been a net sink for carbon in recent decades.

  17. Impact of metabolic disorders on the relation between overweight/obesity and incident myocardial infarction and ischaemic stroke in fertile women

    DEFF Research Database (Denmark)

    Andersen, S S; Andersson, C; Berger, S M

    2015-01-01

    AIMS: Whether overweight is a risk factor for cardiovascular disease in the absence of metabolic disorders remains under debate and is largely unexamined in young women. We evaluated the risk of myocardial infarction and ischaemic stroke in fertile women conditional on time-dependent presence...... and smoking, the risk of the composite outcome of myocardial infarction and ischaemic stroke was assessed with metabolic disorders (i.e. hypertensive conditions, abnormal glucose metabolism and/or dyslipidaemia) included as time-dependent variables. RESULTS: The population comprised 261,489 women with median.......1 (CI = 67.6-112.2) and IRR 4.24 (CI = 5 3.11-5.79) in overweight. CONCLUSIONS: The risk of myocardial infarction and ischaemic stroke was more strongly associated with the presence of metabolic disorders than with overweight per se in fertile women. Targeting prevention of metabolic disorders might...

  18. A Model-based Estimate of the Relative Importance of Climate warming, CO2-fertilization and Nitrogen Deposition to Global Terrestrial Carbon Uptake (Invited)

    Science.gov (United States)

    Bala, G.; Narayanappa, D.; Chaturvedi, R.; Caldeira, K.; Nemani, R. R.

    2013-12-01

    Global carbon budget studies indicate that the terrestrial ecosystems have remained a large sink for carbon in recent decades despite deforestation activities. Carbon uptake due to CO2- fertilization, N deposition and regrowth of mid-latitude forests are believed to be the key drivers. In this study, we assess the importance of N deposition by performing idealized near-equilibrium simulations using the Community Land Model 4.0 (CLM4). In our 1000-year equilibrium simulations, only 12-17% of the deposited Nitrogen is assimilated into the ecosystem and the corresponding carbon uptake can be inferred from a C:N ratio of 20:1. We calculate the sensitivity of the terrestrial biosphere for CO2-fertilization, climate warming and N deposition as changes in total ecosystem carbon for unit changes in global mean atmospheric CO2 concentration, global mean temperature and Tera grams of Nitrogen deposition per year, respectively. Based on these sensitivities, it is estimated that about 242 PgC could have been taken up by land due to the CO2 fertilization effect and an additional 175 PgC taken up as a result of the increased N deposition since the pre-industrial period. Because of climate warming, terrestrial ecosystem could have lost about 152 PgC during the same period. Therefore, since preindustrial times terrestrial carbon losses due to warming may have been approximately compensated by effects of increased N deposition, whereas the effect of CO2-fertilization is approximately indicative of the current increase in terrestrial carbon stock. Our simulations also suggest that the sensitivity of carbon storage to increased N deposition decreases beyond current levels, indicating climate warming effects on carbon storage may overwhelm N deposition effects in the future.

  19. 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.

  20. Con A-binding protein Zn-α2-glycoprotein on human sperm membrane is related to acrosome reaction and sperm fertility.

    Science.gov (United States)

    Liu, Y; Qu, F; Cao, X; Chen, G; Guo, Q; Ying, X; Guo, W; Lu, L; Ding, Z

    2012-04-01

    Fertilization, the recognition and fusion between spermatozoa and oocyte, involves various molecules on the spermatozoa and oocyte membranes. Concanavalin A (ConA)-binding proteins may be one of the molecules involved in mammal spermatozoa fertilization; however, their structure and function remain largely unknown. Here, we initially identified a ConA-binding protein, Zn-α2-glycoprotein (ZAG), involved in regulating the acrosome reaction (AR) of human spermatozoa. ZAG is localized on the pre-equatorial region covering the acrosome, neck and tail (some parts of middle piece and principal piece respectively) regions of the acrosome intact human spermatozoa, and disappears in the acrosomal region of the acrosome-reacted spermatozoa. Polyclonal antibodies against human recombinant ZAG significantly reduced the AR and sperm capability binding to human zona pellucida or penetration into zona-free hamster oocytes. Furthermore, assessment of the signaling pathways regulated by ZAG revealed that ZAG affects sperm AR through both the cAMP/PKA and PKC pathways. These results indicate that ZAG, which is present on the human sperm membrane, plays a critical role in the AR and subsequently, may be involved in sperm fertility.

  1. Fertilization in echinoderms.

    Science.gov (United States)

    Santella, Luigia; Vasilev, Filip; Chun, Jong T

    2012-08-31

    For more than 150 years, echinoderm eggs have served as overly favored experimental model systems in which to study fertilization. Sea urchin and starfish belong to the same phylum and thus share many similarities in their fertilization patterns. However, several subtle but fundamental differences do exist in the fertilization of sea urchin and starfish, reflecting their phylogenetic bifurcation approximately 500 million years ago. In this article we review some of the seminal and recent findings that feature similarities and differences in sea urchin and starfish at fertilization.

  2. Fertilizer Use and Water Quality.

    Science.gov (United States)

    Reneau, Fred; And Others

    This booklet presents informative materials on fertilizer use and water quality, specifically in regard to environmental pollution and protection in Illinois. The five chapters cover these topics: Fertilizer and Water Quality, Fertilizer Use, Fertilizers and the Environment, Safety Practices, and Fertilizer Management Practices. Key questions are…

  3. Fertilizer Use and Water Quality.

    Science.gov (United States)

    Reneau, Fred; And Others

    This booklet presents informative materials on fertilizer use and water quality, specifically in regard to environmental pollution and protection in Illinois. The five chapters cover these topics: Fertilizer and Water Quality, Fertilizer Use, Fertilizers and the Environment, Safety Practices, and Fertilizer Management Practices. Key questions are…

  4. [Effects of applying nitrogen fertilizer and fertilizer additive on rice yield and rice plant nitrogen uptake, translocation, and utilization].

    Science.gov (United States)

    Li, Wen-jun; Xia, Yong-qiu; Yang, Xiao-yun; Guo, Miao; Yan, Xiao-yuan

    2011-09-01

    A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P 0.05). The N translocation rate after anthesis and the N fertilizer use efficiency decreased with increasing N application rate. Applying fertilizer additive further improved the rice yield, accumulative absorbed N, N translocation rate after anthesis, and N fertilizer use efficiency, and this effect was more evident when the N application rate was equal to or greater than 200 kg x hm(-2). Relatively high rice yield and N use efficiency were achieved when applying 150 kg x hm(-2) of N fertilizer without the application of fertilizer additive.

  5. Correlations in fertility across generations: can low fertility persist?

    Science.gov (United States)

    Kolk, Martin; Cownden, Daniel; Enquist, Magnus

    2014-03-22

    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.

  6. France: High and stable fertility

    Directory of Open Access Journals (Sweden)

    Clémentine Rossier

    2008-07-01

    Full Text Available The current total fertility rate in France is around 1.9 children per woman. This is a relatively high level by current European standards and makes France an outlier, despite the fact that its other demographic trends, especially conjugal behaviour, and social and economic trends are not very different from other Western European countries. France can serve as a counterfactual test case for some of the hypotheses advanced to explain the current low level of fertility in most European countries (delay in fertility, decline in marriage, increased birth control, greater economic uncertainty. France's fertility level can be partly explained by its active family policy introduced after the Second World War, and adapted in the 1980s to accommodate women's entry into the labour force. This policy is the result of a battle, fuelled by pro-natalism, between the conservative supporters of family values and the promoters of state-supported individual equality. French family policy thus encompasses a wide range of measures based on varying ideological backgrounds, and it is difficult to classify in comparison to the more precisely focused family policies of other European welfare states. The active family policy seems to have created especially positive attitudes towards two- or three child families in France.

  7. 大岗山不同海拔毛竹林土壤肥力的灰色关联度分析%Grey relation analysis of soil fertility of moso bamboo forests at different altitudes in Dagang Mountain

    Institute of Scientific and Technical Information of China (English)

    薛沛沛; 王兵; 牛香

    2013-01-01

    为了确定不同海拔毛竹林的土壤肥力状况,选择土壤理化性质、微生物性质和酶活性作为土壤肥力评价因子,运用灰色关联度分析方法定量分析毛竹林的土壤肥力,并进行综合排序。结果表明:5个海拔毛竹林土壤肥力关联度的大小依次为700 m >600 m>500 m>400 m>300 m。关联度与土壤化学性质、真菌和放线菌数量以及土壤淀粉酶、β-葡糖苷酶和多酚氧化酶呈正向相关关系。因此,土壤化学性质与土壤酶活性可以作为土壤肥力快速评价指标。%In order to determine the soil fertility of Moso bamboo forests at different altitudes in Dagang Mountain , soil physical and chemical properties , microbial properties and enzymatic activities were chosen as assessment indicators . Soil fertility was analyzed quantitatively by grey relational analysis , and ranked by correlation degrees comprehensively . The results showed that the order of soil fertility in Moso bamboo forests at different altitudes was 700 m>600 m>500 m>400 m>300 m.Correlation degree had a positive correlation with soil chemical properties , the number of bacteri-um, actinomycetes , activities of amylase ,β-glucosidase and polyphenol oxidase .Consequently , we concluded that soil chemical properties and soil enzymatic activities can be used as indicators for assessing soil fertility rapidly .

  8. Family systems and fertility

    NARCIS (Netherlands)

    Moenkediek, Bastian

    2016-01-01

    This thesis studies the role of regional family organization principles, so called family systems, for explaining fertility behaviours in different parts of Europe. Studying family systems and its impact on fertility is important, because many aspects of societal life, such as the organization of we

  9. 设施土壤栽培番茄配方施肥策略与指标研究%Studies on Fertilization Strategy and Related Indexes for Tomato Facility Soil Cultivation

    Institute of Scientific and Technical Information of China (English)

    高杰云; 王丽英; 严正娟; 贾伟; 陈清

    2014-01-01

    Due to diverse facility vegetable planting seasons, growth periods and yield levels, its high income character has resulted in excessive fertilization in facility cultivation, which has led to soil nutrient over accumulaion, soil acidification, and secondary salinization.Very high ariation of soil available nitrogen content in rootzone limited the use of soil mineral nitrogen testing and nitrogen recommendation during the whole growing period.Taking greenhouse tomato(Lycopersicon esculentum Mill.) in northern China as an example and based on the data from our experiments and published literatures, this paper provides strategy of specific formula for fertilization in soil-bound greenhouse tomato, according to fertilization and nutrient uptake characteristics, including determining the total nutrient requirements of different seasons’ tomato by target yield; determining the chemical fertilizers (N, Pand K) quantities based on optimum rate of organic manure and soil nutrient levels; selecting special fertilizer formulas for tomato in different growth periods based on the characteristics of nutrient uptake and fertilization schedule in the whole growth period of tomato, which was matched into irrigation schedule.The two-year demonstration results of the recommended strategy and related index in Beijing suburbs showed that the inputs of N, P2O and K2O fertilizer, and water were saved by 42.7%, 59.1%, 41.5% and 21.0%, respectively as compared with the conventional practices, while the tomato yields increased by 13.4% on average with recommended fertilization strategies.%设施蔬菜种植茬口多,生育期和产量水平变异大,其高收益特征造成设施栽培过量施肥问题十分普遍,往往导致设施菜田土壤养分累积、土壤酸化和次生盐渍化,而频繁灌溉追肥的特点导致根层土壤有效氮变化十分剧烈,不宜在生育期内采用测土方法进行推荐施肥。本文以北方设施番茄为例,针对其施肥投

  10. Fertility decline in Paraguay.

    Science.gov (United States)

    Ishida, Kanako; Stupp, Paul; Melian, Mercedes

    2009-09-01

    Recent reproductive health surveys show that the fertility rate in Paraguay decreased precipitously from 4.3 lifetime births per woman in 1995-98 to 2.9 births in 2001-04. In this study, we establish data consistency between the 1998 and 2004 surveys by comparing a series of cohort-specific period rates and use the Bongaarts framework of proximate determinants of fertility to demonstrate that an increase in the contraceptive prevalence rate (CPR) between 1998 and 2004 fully accounts for the fertility decline. Decomposition of rates shows that changes in group-specific CPRs explain a greater proportion of the change in the overall CPR than do changes in population composition by educational attainment, urban residence, region, and language spoken at home. Finally, we show that younger cohorts of women in 2004 reported ideal completed fertility desires of less than 2.9 births, suggesting that the fertility rate is likely to continue to decrease.

  11. [Socioeconomic variables and fertility].

    Science.gov (United States)

    Arguello, O

    1980-08-01

    While making comparative analyses of data collected by the World Fertility Survey regarding Latin America, a group of investigators of CELADE (Centro Latinoamericano de Demografia) realized that the selection of economic variables for the study of fertility had serious limitations. Such limitations did not allow the elaboration of a theory which took into account the complicated process of fertility, in all its socioeconomic, cultural, and psychological manifestations. Thus, this paper intends to lay the theoretical basis for the selection of all relevant variables, distinguishing, for example, the average fertility of women according to area of residence, place of early socialization, migrant status, social status, occupation of husband, level of instruction, occupation, and all changes in occupational activities of women in fertile age.

  12. [Demographic analysis of family-related life cycles of Austrian women: a multidimensional model of marriage, fertility, and divorce behavior in the years 1976-1986].

    Science.gov (United States)

    Aufhauser, E; Lutz, W

    1989-01-01

    Summary results are presented from a research project designed to investigate the family life cycle of Austrian women by using a multidimensional model of marriage, fertility, and divorce. Data are from the 1976 and 1986 microcensuses. Topics discussed include the impact of illegitimate birth on women's future marital status, the relationship between number of children and the probability of divorce and of remarriage, the average number of years spent in different phases of the family life cycle, and the implications of current behavior patterns for future family structure in Austria.

  13. Basics of soil fertility management

    OpenAIRE

    Berner, Alfred

    2013-01-01

    The brochure highlights the soil fertility from various scientific and farming perspectives. Its aims to supplement practical observations of farmers, to encourage them to reconsider their relation to their soil and to practice a truly sustainable soil culture. The booklet tries to achieve this goal by providing information on soil matter such as important soil organisms and soil characteristics like root density, soil structure and alkalinity and by showing possibilities of how to ass...

  14. Effects of self-fertilization, environmental stress and exposure to xenobiotics on fitness-related traits of the freshwater snail Lymnaea stagnalis.

    Science.gov (United States)

    Coutellec, Marie-Agnès; Lagadic, Laurent

    2006-03-01

    Genetic and ecological factors may interact in their effects on fitness. Such interactions are thus to be expected between inbreeding and exposure of a population to a toxicant. The magnitude of inbreeding depression is thought to increase in stressful environments. To test this hypothesis, we investigated the combined effects of environmental conditions and inbreeding on fitness in the self-fertile snail Lymnaea stagnalis, using a stress gradient (0-2) applied to a 100 isolated and paired lineages: laboratory control (0), outdoor microcosm control (1) and pesticide exposure under outdoor microcosm conditions (2). Outdoor stress conditions were maintained for 28 days prior to measurements of fitness traits (fecundity, hatching success, and size at hatching) under laboratory conditions, so that delayed environmental effects could be estimated. Under laboratory control conditions, we found significant initial family level heterogeneity for most measured traits, including physiological performances as assessed through energetic biomarkers. Whatever the environmental conditions, inbreeding depression was very low for progeny performances. Negative values of self-fertilization depression (SFD) were obtained. Unexpectedly, SFD showed a negative relationship with the assumed stress intensity, reflecting a higher sensitivity under pairing than under selfing, mostly due to parental fecundity. This suggests that stressful conditions may favour selfing. Stress intensity increased the distribution limits of both depression indices, suggesting that changes in fitness are less predictable in a population under stress. Implications of such findings for environmental risk assessment of pesticides are discussed.

  15. Sustaining food self-sufficiency of a nation: The case of Sri Lankan rice production and related water and fertilizer demands.

    Science.gov (United States)

    Davis, Kyle Frankel; Gephart, Jessica A; Gunda, Thushara

    2016-04-01

    Rising human demand and climatic variability have created greater uncertainty regarding global food trade and its effects on the food security of nations. To reduce reliance on imported food, many countries have focused on increasing their domestic food production in recent years. With clear goals for the complete self-sufficiency of rice production, Sri Lanka provides an ideal case study for examining the projected growth in domestic rice supply, how this compares to future national demand, and what the associated impacts from water and fertilizer demands may be. Using national rice statistics and estimates of intensification, this study finds that improvements in rice production can feed 25.3 million Sri Lankans (compared to a projected population of 23.8 million people) by 2050. However, to achieve this growth, consumptive water use and nitrogen fertilizer application may need to increase by as much as 69 and 23 %, respectively. This assessment demonstrates that targets for maintaining self-sufficiency should better incorporate avenues for improving resource use efficiency.

  16. [Prolactin and male fertility].

    Science.gov (United States)

    Schreiber, G; Börner, A; Lauterbach, H; Thiel, W

    1983-03-01

    On 68 selected patients with disturbances of the potentia generandi et/sive coeundi (25 males with healthy metabolism and 43 males with diabetes) as well as 14 control persons PRL, LH, FSH, testosterone and oestradiol were determined radioimmunologically and the results were ascribed to sexological, clinical, spermatological and testo-histological findings. A statistically secure correlation was found between PRL values and disturbance of the libido as well as the presence of a gynaecomasty. PRL did not correlate with the spermatological variables volume of ejaculate, relative and absolute number of spermatozoa and motility. PRL did also not correlate with the testohistological findings. A relation between PRL and the peptide hormones LH and FSH as well as the steroid hormones testosterone and oestradiol could not be ascertained. Therefore the diagnostic values of a PRL determination is much limited; the pertinency of a hyperprolactinaemia may be increased by the proof of the symptoms reduction of libido and gynaecomasty with simultaneous disturbance of fertility. In our opinion the definition of hyperprolactinaemia needs revision, since at only determination of the basal value of more than 800 mU/l no more frequently pathologically andrological findings are to be observed than below 200 mU/l.

  17. Effect of long-term fertilization on soil nitrate distribution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A thirteen years long-term field fertilizer experiment was conducted to monitor the effect of different fertilization on soil nitrate distribution. The results showed: (1) Applying relative excessive N fertilizer could result large quantities of NO3- residue and NO3- movement downward in soil profiles; amending phosphate fertilizer or organic manure with nitrogen fertilizer together could significantly improve the status of NO3- leaching downward due to the balanced uptake of nutrients by crops. (2) Appropriate amounts of nitrogen fertilizer which was equal or smaller than the optimal fertilization rate could not result in more NO3- leaching in Northern China. (3) Precipitation influenced the amounts and depth of soil NO3- leaching: NO3- could move to 80 cm depth or below at autumn or at the next spring when rainfall was higher during the rainy season through July to September in North China.

  18. 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

  19. Perpetual postponers? Women's, men's and couple's fertility intentions and subsequent fertility behaviour.

    Science.gov (United States)

    Berrington, Ann

    2004-01-01

    In this article data from the British Household Panel Study (BHPS) are used to analyse gender differences in fertility intentions, and the correspondence between fertility intentions and subsequent fertility behaviour. By exploiting couple-level data, we examine whether partners have conflicting preferences for future fertility. Focusing on women who remain childless in their thirties we look at socio-demographic factors related to the intention to remain childless, or to start a family later on in life. By following up women over time, the characteristics of women who go on to have a child later on in life are considered. The importance of having a partner and the fertility intention of that partner in predicting whether a birth will occur are also examined.

  20. First record of Ginkgo-related fertile organs (Hamshawvia, Stachyopitys) and leaves (Baiera, Sphenobaiera) in the Triassic of Brazil, Santa Maria formation

    Science.gov (United States)

    Barboni, Ronaldo; Dutra, Tânia Lindner

    2015-11-01

    This paper describes new ginkgophytes recently discovered in a new exposure of the original type section of the Passo das Tropas Member, Santa Maria Formation, linked to Paraná Basin succession. The well-preserved fossils come from a very fine red laminated mudstone representing a lacustrine interval, within a broader low-sinuosity fluvial succession. The material occurs in a Dicroidium-dominated assemblage and is represented by the leaves Baiera and Sphenobaiera, accompanied by the fertile structures Hamshawvia and Stachyopytis. Cuticle fragments preserved on leaf impressions of Sphenobaiera schenkii show xeromorphic features. The geology, paleogeography and paleoclimate of the Passo das Tropas Member (PTM), Santa Maria Formation, is discussed. By comparing these ginkgophytes with those from other Gondwanan assemblages, the Brazilian deposits earlier assigned to Anisian-Ladinian age can now be extended to the Carnian age.

  1. Comparative transcript profiling of a male sterile cybrid pummelo and its fertile type revealed altered gene expression related to flower development.

    Directory of Open Access Journals (Sweden)

    Bei-Bei Zheng

    Full Text Available Male sterile and seedless characters are highly desired for citrus cultivar improvement. In our breeding program, a male sterile cybrid pummelo, which could be considered as a variant of male fertile pummelo, was produced by protoplast fusion. Herein, ecotopic stamen primordia initiation and development were detected in this male sterile cybrid pummelo. Histological studies revealed that the cybrid showed reduced petal development in size and width, and retarded stamen primordia development. Additionally, disorganized cell proliferation was also detected in stamen-like structures (fused to petals and/or carpel. To gain new insight into the underlying mechanism, we compared, by RNA-Seq analysis, the nuclear gene expression profiles of floral buds of the cybrid with that of fertile pummelo. Gene expression profiles which identified a large number of differentially expressed genes (DEGs between the two lines were captured at both petal primordia and stamen primordia distinguishable stages. For example, nuclear genes involved in nucleic acid binding and response to hormone synthesis and metabolism, genes required for floral bud identification and expressed in particular floral whorls. Furthermore, in accordance with flower morphology of the cybrid, expression of PISTILLATA (PI was reduced in stamen-like structures, even though it was restricted to correct floral whorls. Down-regulated expression of APETALA3 (AP3 coincided with that of PI. These finding indicated that, due to their whorl specific effects in flower development, citrus class-B MADS-box genes likely constituted 'perfect targets' for CMS retrograde signaling, and that dysfunctional mitochondria seemed to cause male sterile phenotype in the cybrid pummelo.

  2. ON RELATION OF SOIL MOISTURE TO DEVELOPMENT OF RICE BLAST DISEASE WITH SPECIAL REFERENCE TO RESULTS OF INOCULATION EXPERIMENTS ON LEAVES AND SPIKE PEDICELS OF PLANTS GROWN IN SOILS DIFFERING IN MOISTURE AND IN AMOUNTS OF SILICA AND FERTILIZER,

    Science.gov (United States)

    moisture content, and fertilizer and silica application. The susceptibility of the rice plant to rice blast disease varied inversely with the moisture...content of the soil irrespective of the amount of fertilizer or silica applied or of the stage of growth of the plant. Dryness of the soil tended to...fertilization were more easily infected than plants grown on irrigated soil with double the amount of fertilizer . This proves that even with double the

  3. Optimizing Natural Fertility

    Science.gov (United States)

    ... heavy alcohol consumption (> 2 drinks per day), heavy caffeine consumption, and the use of recreational drugs such as marijuana have all been associated with reduced fertility. Therefore, women (and ... alcohol and caffeine use, and avoid smoking and all recreational drugs ...

  4. Commercial Nitrogen Fertilizer Purchased

    Data.gov (United States)

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

  5. Chapter VII. Predicting Fertility

    Science.gov (United States)

    Section 2. Visual and Microscopic Approaches for Differentiating Unfertilized Germinal Discs and Early dead Embryos from Pre-Incubated Blastoderms Section 3. Predicting the Duration of fertility by Counting Sperm in the Outer Perivitelline Layer of Laid Eggs...

  6. Cancer and fertility preservation

    DEFF Research Database (Denmark)

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

    2016-01-01

    cryopreservation and embryo/oocyte cryopreservation are standard strategies for fertility preservations in male and female patients, respectively; other strategies (e.g. pharmacological protection of the gonads and gonadal tissue cryopreservation) are considered experimental techniques. However, since then, new......In the last years, thanks to the improvement in the prognosis of cancer patients, a growing attention has been given to the fertility issues. International guidelines on fertility preservation in cancer patients recommend that physicians discuss, as early as possible, with all patients...... of reproductive age their risk of infertility from the disease and/or treatment and their interest in having children after cancer, and help with informed fertility preservation decisions. As recommended by the American Society of Clinical Oncology and the European Society for Medical Oncology, sperm...

  7. Commercial Phosporus Fertilizer Purchased

    Data.gov (United States)

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

  8. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system.

    Science.gov (United States)

    Kim, Youngjin; Chekli, Laura; Shim, Wang-Geun; Phuntsho, Sherub; Li, Sheng; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-06-01

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water flux and reverse salt flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulfate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less salt accumulation, relatively higher water flux, and higher dilution capacity of draw solution. Given toxicity of sulfate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR.

  9. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system

    KAUST Repository

    Kim, Youngjin

    2016-02-09

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water flux and reverse salt flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulphate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less salt accumulation, relatively higher water flux, and higher dilution capacity of draw solution. Given toxicity of sulphate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR.

  10. Vitamin D and female fertility.

    Science.gov (United States)

    Lerchbaum, Elisabeth; Rabe, Thomas

    2014-06-01

    Apart from the well known effects of vitamin D on maintaining calcium homeostasis and promoting bone mineralization, there is some evidence suggesting that vitamin D also modulates human reproductive processes. We will review the most interesting and relevant studies on vitamin D and female fertility published over the past year. In the past year, several observational studies reported a better in-vitro fertilization outcome in women with sufficient vitamin D levels (≥30 ng/ml), which was mainly attributed to vitamin D effects on the endometrium. One randomized controlled trial found an increased endometrial thickness in women with polycystic ovary syndrome (PCOS) receiving vitamin D during intrauterine insemination cycles. Further, vitamin D supplementation had a beneficial effect on serum lipids in PCOS women. Vitamin D treatment improved endometriosis in a rat model and increased vitamin D intake was related to a decreased risk of incident endometriosis. Vitamin D was also favorably associated with primary dysmenorrhea, uterine leiomyoma, and ovarian reserve in late reproductive aged women. In women undergoing in-vitro fertilization, a sufficient vitamin D level (≥30 ng/ml) should be obtained. Vitamin D supplementation might improve metabolic parameters in women with PCOS. A high vitamin D intake might be protective against endometriosis.

  11. 大白菜育性相关蛋白差异表达%Differencial Expression of Fertility-related Proteins in Chinese Cabbage

    Institute of Scientific and Technical Information of China (English)

    毕青; 周雪; 冀瑞琴; 冯辉

    2015-01-01

    为揭示复等位基因遗传的大白菜雄性不育分子机制,通过基于质谱的蛋白质组学同位素相对标记与绝对定量技术技术( iTRAQ),开展了大白菜核基因雄性不育蛋白质组学研究,以找到不育与可育材料中差异表达蛋白,从蛋白水平来进一步揭示大白菜雄性不育的分子遗传机制。通过研究,共发现了358个差异蛋白,其中可育中上调表达的蛋白有226个,下调表达的蛋白有132个,GO 分析结果表明,鉴定的蛋白质组数据具有较好的生物学功能覆盖范围。通过双向电泳验证,差异蛋白点差异特性与 iTRAQ结果类似,表明 iTRAQ用于差异蛋白分析结果可靠。%To better understand the molecular mechanisms of multiple-allele-inherited male sterility in Chinese cabbage( Brassica rapa L. ssp pekinensis),the iTRAQ quantitation technique based on mass spectrometry were used to study the differencial expression between proteins fertile- and sterile-buds. This research would provide the basis for analyzing the molecular mechanism of multiple-allele-inherited male sterility in Chinese cabbage. In this re-search,a total of 358 differencial expressed proteins(226 up-expressed and 132 down-expressed proteins in fertile buds)were found and Gene Ontology( GO)analysis showed that the proteins identified data has better coverage of biological functions. It is verified by two-dimensional electrophoresis(2-DE). This results is consistent with iTRAQ technique,which indicated that using iTRAQ to analyze protein profile is reliable.

  12. [Variations of soil fertility level in red soil region under long-term fertilization].

    Science.gov (United States)

    Yu, Han-qing; Xu, Ming-gang; Lü, Jia-long; Bao, Yao-xian; Sun, Nan; Gao, Ju-sheng

    2010-07-01

    Based on the long-term (1982-2007) field experiment of "anthropogenic mellowing of raw soil" at the Qiyang red soil experimental station under Chinese Academy of Agricultural Sciences, and by using numerical theory, this paper studied the variations of the fertility level of granite red soil, quaternary red soil, and purple sandy shale soil under six fertilization patterns. The fertilization patterns included non-fertilization (CK), straw-returning without fertilizers (CKR), chemical fertilization (NPK), NPK plus straw-return (NPKR), rice straw application (M), and M plus straw-return (MR). The soil integrated fertility index (IFI) was significantly positively correlated with relative crop yield, and could better indicate soil fertility level. The IFI values of the three soils all were in the order of NPK, NPKR > M, MR > CK, CKR, with the highest value in treatment NPKR (0.77, 0.71, and 0.71 for granite red soil, quaternary red soil, and purple sandy shale soil, respectively). Comparing with that in the treatments of no straw-return, the IFI value in the treatments of straw return was increased by 6.72%-18.83%. A turning point of the IFI for all the three soils was observed at about 7 years of anthropogenic mellowing, and the annual increasing rate of the IFI was in the sequence of purple sandy shale soil (0.016 a(-1)) > quaternary red clay soil (0.011 a(-1)) > granite red soil (0.006 a(-1)). It was suggested that a combined application of organic and chemical fertilizers and/or straw return could be an effective and fast measure to enhance the soil fertility level in red soil region.

  13. 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...

  14. Sotho fertility symbolism.

    Science.gov (United States)

    Murray, C

    1980-01-01

    This paper deals with the traditional beliefs and mythical folklore of the Sotho-Tswana ethnic tribes of South Africa. Their ritual practices are predominantly concerned with the weather, the vicissitudes of the seasonal cycle, and, especially the rain-making powers of certain individuals. It is well known that rain, in all civilizations, is a symbol of fertility. Thus, adolescent girls and young women, as mediators of the association between water and fertility, can be relied upon to bring the clouds and torrential downpours. The characteristic Sesotho explanation that babies come from the river is clearly an allusion to the water of the womb, and the river is generally recognized as a methaphor of the womb. Also, the onset of menarche involves rituals having to do with the drawing and pouring of water, another clear allusion to the beginning of fertility.

  15. Couples' fertility decision-making

    Directory of Open Access Journals (Sweden)

    Petra Stein

    2014-06-01

    Full Text Available Background: The decision about whether to start a family within a partnership can be viewed as a result of an interaction process. The influence of each of the partners in a couple differs depending on their individual preferences and intentions towards having children. Both of the partners additionally influence each other's fertility intentions and preferences. Objective: We specify, estimate, and test a model that examines the decision about whether to have a child as a choice that is made jointly by the two partners. The transition to the birth of a (further child is investigated with the explicit consideration of both the female partner and the male partner in the partnership context. Methods: An approach for modelling the interactive influences of the two actors in the decision-making process was proposed. A trivariate distribution consisting of both the female and the male partners' fertility intentions, as well as the joint generative decision, was modelled. A multivariate non-linear probit model was chosen and the problem of identification in estimating the relative effects of the actors was resolved. These parameters were used to assess the relative importance of each of the partners' intentions in the decision. We carried out the analysis with MPLUS. Data from the panel of intimate relationships and family dynamics (pairfam was used to estimate the model. Results: The biographical context of each of the partners in relation to their own as well as to their partner's fertility intentions was found to be of considerable importance. Of the significant individual and partner effects, the male partner was shown to have the greater influence. But the female partner was found to have stronger parameters overall and she ultimately has a veto power in the couple's final decision.

  16. 常规IVF-ET中完全体外受精失败发生的相关因素的探讨%Factors Relating with Fertilization Failure in Conventional IVF-ET Cycles

    Institute of Scientific and Technical Information of China (English)

    朱元; 顾亦凡; 卢光琇

    2013-01-01

    Objective: To analyze the factors relating with fertilization failure in conventional IVF cycles. Methods: The total fertilization failure rate of 2 429 IVF cycles were retrospectively analyzed. Risk factors were identified by univariate and multivariate logistic regression analyses. Results: The total fertilization failure rate of conventional IVF-ET rate was 5.7% (139/2 429). The percentage of morphologically normal sperm (11.1±5.8% vs 13.4 ± 5.3%), progressive motility (47.4 ± 10.5% vs 50.1 ± 8.6%), percentage of couple primary infertility (79.1% vs 44.3%), percentage of female primary infertility (69.1% vs 36.3%), percentage of male primary infertility (74.8% vs 41.7%), percentage of without oviduct obstruction patients (30.2% vs 13.6%) and percentage of couples primary infertility (79.1% vs 44.3%) of the fertilization failure patients were significantly different from those of the fertilized patients (P<0.05). Besides, higher total fertilization failure rate was found in couples with isolated teratozoospermia than in couples with normal percentage of morphologically normal sperm (15.0% vs 5.2%). After that, it was found by multivariate logistic regression analyses that many factors including percentage of morphologically normal sperm, sperm concentration, couples primary infertility and female infertility years were related with fertilizatimfailure.Conchusion:Patients with low percentage of morphologically normal sperm (<4%), low sperm concentration and motility, male primary infertility, female primary infertility, without oviduct obstruction, long female infertility years or/and couples primary infertility are at high risk of fertilization failure. More attention should be paid to these patients for avoiding the fertilization failure.%目的:探讨IVF-ET完全体外受精失败发生的相关危险因素.方法:回顾性分析行常规体外受精-胚胎移植(IVF-ET)的2 429个周期.应用单因素及多因素Logistic回归分析夫妇之间受孕史

  17. [An analysis of major proximate determinants of our fertility].

    Science.gov (United States)

    Chen, W

    1989-01-01

    The sample survey of fertility, in Shanghai city and Shanxi and Hebei provinces of China in 1985, provided plentiful data about fertility, marriage, contraceptive usage and breastfeeding in terms of The World Fertility Survey Model. The data, along with Bongaarts' model, was utilized to analyze the relation between several proximate determinants and fertility changes. When comparing these three geographic areas, the largest difference was breastfeeding and the smallest one was non- contraceptive usage. It was very different from the results of The World Fertility Survey in developing countries in 1977. The difference of marriage indexes among three areas was close to that of breastfeeding; but for the effects on induction of fertility, marriage index surpassed breastfeeding. There were two models showing effective efficacy on fertility decline. One was the Shanghai model, in which much more effect came from marriage delay, accounting for 71%; another was the Hebei model, induction of fertility was caused by contraceptive usage, about 53%. Both indicated that the major factor affecting fertility decline was the family planning program. Otherwise, it seemed to indicate that different factors such as social, economic development indirectly decreased fertility through family planning programs.

  18. Adolescent fertility: worldwide concerns.

    Science.gov (United States)

    Senderowitz, J; Paxman, J M

    1985-04-01

    There is growing concern over the adverse health, social, economic, and demographic effects of adolescent fertility. Morbidity and mortality rates ar significantly higher for teenage mothers and their infants, and early initiation of childbearing generally means truncated education, lower future family income, and larger completed family size. Adolescent fertility rates, which largely reflect marriage patterns, range from 4/1000 in Mauritania; in sub-Saharan Africa, virtually all rates are over 100. In most countries, adolescent fertility rates are declining due to rising age at marriage, increased educational and economic opportunities for young women, changes in social customs, increased use of contraception, and access to abortion. However, even if fertility rates were to decline dramatically among adolescent women in developing countries, their sheer numbers imply that their fertility will have a major impact on world population growth in the years ahead. The number of women in the world ages 15-19 years is expected to increase from 245 million in 1985 to over 320 million in the years 2020; 82% of these women live in developing countries. As a result of more and earlier premarital sexual activity, fostered by the lengthening gap between puberty and marriage, diminished parental and social controls, and increasing peer and media pressure to be sexually active, abortion and out-of-wedlock childbearing are increasing among teenagers in many developed and rapidly urbanizing developing countries. Laws and policies regarding sex education in the schools and access to family planning services by adolescents can either inhibit or support efforts to reduce adolescent fertility. Since contraceptive use is often sporadic and ineffective among adolescents, family planning services are crucial. Such programs should aim to reduce adolescents' dependence on abortion through preventive measures and increase awareness of the benefits of delayed sexual activity. Similarly, sex

  19. [Cryptorchism and fertility. Our experience].

    Science.gov (United States)

    Bondavalli, C; Visentini, E; Pegoraro, C; Schiavon, L; Dall'Oglio, B; Parma, A

    1989-09-01

    The relationship between cryptorchidism and fertility has been suggested in a lot of ways but hasn't been clearly demonstrated. In our Institute from 1981 until 1987, 352 orchidopexies had been performed. Out of these, 31 patients were studied with respect to the current age, the age at the surgery, the absence of varicocele and the possible iatrogenic damages. The rate of dispermia among the subjects studied, was 43% whereas 57% had normospermia. 3 out of 4 patients operated for bilateral undescended testis were azoospermic. The volume of unaffected testis is directly related to the health of the seminal status.

  20. Menstrual cycle pattern and fertility

    DEFF Research Database (Denmark)

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

    1999-01-01

    OBJECTIVE: To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss. DESIGN: Prospective follow-up study. SETTING: Healthy couples recruited throughout Denmark. PATI...... 0.09-0.68). When the combined effect of cycle variation and cycle length was assessed, cycle variation was a persistent strong predictor of fecundity. CONCLUSION(S): The mechanisms of the present findings probably are female functional disturbances in ovulation, conception, implantation...

  1. Population pressure and fertility in pre-transition Thailand.

    Science.gov (United States)

    VanLandingham, M; Hirschman, C

    2001-11-01

    Before the demographic transition in Thailand, fertility was high, but not uniformly so. As in other pre-transition settings, Thai fertility responded to pressures and opportunities created by socioeconomic structure and land availability. Drawing upon provincial data from the 1947 and 1960 censuses of Thailand, we find a strong 'frontier effect' on Thai fertility in the 1950s. Fertility was higher in sparsely settled frontier provinces and lower in provinces with higher population density relative to cultivatable land. This finding is robust and holds up with controls for agricultural employment, land quality, and the sex ratio (an indicator of sex-selective migration). The effect of population pressure lowers the likelihood of marriage and of marital fertility. The findings from Thailand are consistent with the research of Easterlin on the nineteenth century United States and with other pre-transition societies. We suggest how demographic transition theory might be broadened to include fertility dynamics in pre-transition societies.

  2. 体外授精—胚胎移植后异位妊娠相关因素研究进展%Related Factors of Ectopic Pregnancy after in Vitro Fertilization and Embryo Transfer

    Institute of Scientific and Technical Information of China (English)

    王桂玲; 任春娥

    2013-01-01

    近年来,随着体外授精一胚胎移植(IVF-ET)技术的蓬勃开展,IVF-ET后异位妊娠(EP)的发病率也随之升高.IVF-ET后EP发生的相关危险因素包括输卵管因素、子宫内膜异位症、授精方式、胚胎移植技术及控制性超排卵等,其中最主要的危险因素是由输卵管因素引起的输卵管功能紊乱.对具有以上危险因素的患者,在行IVF-ET治疗前,应尽量减少危险因素的影响,以提高临床妊娠率,并减少异位妊娠的发生率.本文就近年来对IVF-ET后EP发生的相关危险因素的研究作一综述.%With the development of in vitro fertilization — embryo transfer (1VF— ET), the incidence of ectopic pregnancy (EP) after IVF—ET is increased. The related risk factors for EP after IVF—ET included tubal factor, endometriosis, fertilization, embryo transfer technology and controlled ovarian hyperstimulation and so on, which the major risk factors are caused by fallopian tubal dysfunction. In order to improve the clinical pregnancy rate, and reduce the incidence of ectopic pregnancy, before IVF—ET treatment, for patients with these risk factors, should minimize the impact of risk factors. This article covers the related risk factors of EP after IVF—ET.

  3. Genetics, genomics and fertility

    Science.gov (United States)

    In order to enhance the sustainability of dairy businesses, new management tools are needed to increase the fertility of dairy cattle. Genomic selection has been successfully used by AI studs to screen potential sires and significantly decrease the generation interval of bulls. Buoyed by the success...

  4. Fertility and Infertility.

    Science.gov (United States)

    Orgebin-Crist, Marie-Claire; And Others

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

  5. Fertility and Infertility.

    Science.gov (United States)

    Orgebin-Crist, Marie-Claire; And Others

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

  6. Sperm preparation for fertilization

    NARCIS (Netherlands)

    Gadella, B.M.

    2014-01-01

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

  7. Mobility, Fertility, and Residential Crowding

    Science.gov (United States)

    Morris, Earl W.

    1977-01-01

    Regression analyses predicting fertility and mobility in a sample of a metropolitan county in New York State indicate that residential mobility serves to release the negative pressure that residential crowding might exert on fertility behavior. (Author)

  8. Agriculture: Nutrient Management and Fertilizer

    Science.gov (United States)

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

  9. Sex and Fertility After SCI

    Science.gov (United States)

    ... About Blog Facing Disability Jeff Shannon Donate Experts \\ Sex and Fertility After Spinal Cord Injury Topics Adult ... Spasticity, Physical Therapy-Lokomat Spasticity, Physical Therapy-Lokomat Sex and Fertility After Spinal Cord Injury Sex and ...

  10. Cohort fertility in Western Europe: comparing fertility trends in recent birth cohorts.

    Science.gov (United States)

    Hopflinger, F

    1984-01-01

    A comparative study of fertility levels among cohorts of women born in 1940, 1945, 1950, 1955, and 1960 in 16 European countries was undertaken using vital statistics data. The average number of live birth/woman for each of the 5 cohorts by age 20, 25, 30, and 35 was computed by cumulating age-specific fertility rates of women born in specific years. Median age at childbirth and completed fertility were estimated for the 3 oldest cohorts (1940, 1945, and 1950). 2 estimations of completed fertility were made. 1 was based on the assumption of a constant age-specific fertility rate, and the other was based on a relational Gompertz model. Where possible cohort fertility was disaggregated by birth order. Since the data for the countries was not fully comparable, it was not possible to use sophisticated analytical techniques. Other limits of the study were that fertility, especially for the more recent cohorts was incomplete, parity specific data was not available for all the countries, and open cohorts rather than closed cohorts were used. The analysis indicated that completed cohort fertility was lower for the 1950 cohort than for the 1940 cohort in all 16 countries. For the 1940 cohort, only Germany's estimated completed fertility was less than 2.00. For the other 15 countries, estimated completed fertility ranged from 2.04 (Finland) to 3.36 (Ireland). For the 1950 cohort, estimated completed fertility was less than 2.00 in 8 of the countries. Estimated completed fertility was lowest in Finland and Switzerland (1.82) and highest in Ireland (3.33). No marked increase in childlessness was observed, and for the 1940 and 1950 cohorts, childlessness did not exceed 20% in any of the countries and was considerably less than 20% in most of the countries. There was a trend toward delayed childbearing in most of the countries. An examination of available parity data for the 1940 and 1950 cohorts lead to the conclusion that the major factor contributing toward the decline in

  11. Fertility intentions and risk management: exploring the fertility decline in Eastern Europe during transition.

    Science.gov (United States)

    Rodin, Johnny

    2011-03-01

    Between 1985 and 1995, fertility in Eastern Europe declined from 2.2 children per woman to merely 1.5 on region-average. Previous research has emphasized mainly the economic turmoil during transition or the influx of new ideas regarding fertility and family relations. This article suggests that applying a risk management perspective on fertility patterns may put additional light on the reasons behind the fertility decline in post-communist Europe. The complexity of modern social systems has made people increasingly dependent on the state for risk evaluation and risk management. The article formulates the hypothesis that transition itself disrupted the mental models that helped people to navigate among the risks associated to having and raising children. Left to their own devices, women in Eastern Europe became more inclined to postpone childbirth or discard this option altogether.

  12. ENDURING ECONOMIC HARDSHIP, WOMEN'S EDUCATION, MARRIAGE AND FERTILITY TRANSITION IN KINSHASA.

    Science.gov (United States)

    Shapiro, David

    2015-03-01

    This paper examines fertility transition in Kinshasa, capital of the Democratic Republic of the Congo (DRC) and second-largest city in sub-Saharan Africa. Shapiro (1996) documented the onset of fertility transition in the city, using data from 1990. Women's education was strongly inversely related to fertility, beginning with secondary schooling, and increases in women's education were important in initiating fertility transition in the city. The paper uses data from the 2007 Demographic and Health Survey in the DRC to examine fertility in Kinshasa and assess fertility transition since 1990, a period characterized by severe adverse economic conditions in the DRC. Fertility transition has continued at a strong pace. In part this reflects increased educational attainment of women, but it appears also to be largely a consequence of enduring economic hardship. The ongoing fertility decline has been accompanied by substantial delays in entry to marriage and childbearing, reflecting adverse economic conditions, which in turn have contributed to continuing declines in fertility.

  13. Socio-economic 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

    2017-03-01

    The timings of historical fertility transitions in different regions are well understood by demographers, but much less is known regarding their specific features and causes. In the study reported in this paper, we used longitudinal micro-level data for five local populations in Europe and North 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 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 do support the idea that the upper classes acted as forerunners by reducing their fertility before other groups. Farmers and unskilled workers were the latest to start limiting their fertility. Apart from these similarities, patterns of class differences in fertility varied significantly between populations.

  14. Balancing guava nutrition with liming and fertilization

    Directory of Open Access Journals (Sweden)

    Amanda Hernandes

    2012-12-01

    Full Text Available Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg and fertilizers (N-K on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.

  15. Economic recession and fertility in the developed world.

    Science.gov (United States)

    Sobotka, Tomáš; Skirbekk, Vegard; Philipov, Dimiter

    2011-01-01

    This article reviews research on the effects of economic recessions on fertility in the developed world. We study how economic downturns, as measured by various indicators, especially by declining GDP levels, falling consumer confidence, and rising unemployment, were found to affect fertility. We also discuss particular mechanisms through which the recession may have influenced fertility behavior, including the effects of economic uncertainty, falling income, changes in the housing market, and rising enrollment in higher education, and also factors that influence fertility indirectly such as declining marriage rates. Most studies find that fertility tends to be pro-cyclical and often rises and declines with the ups and downs of the business cycle. Usually, these aggregate effects are relatively small (typically, a few percentage points) and of short durations; in addition they often influence especially the timing of childbearing and in most cases do not leave an imprint on cohort fertility levels. Therefore, major long-term fertility shifts often continue seemingly uninterrupted during the recession—including the fertility declines before and during the Great Depression of the 1930s and before and during the oil shock crises of the 1970s. Changes in the opportunity costs of childbearing and fertility behavior during economic downturn vary by sex, age, social status, and number of children; childless young adults are usually most affected. Furthermore, various policies and institutions may modify or even reverse the relationship between recessions and fertility. The first evidence pertaining to the recent recession falls in line with these findings. In most countries, the recession has brought a decline in the number of births and fertility rates, often marking a sharp halt to the previous decade of rising fertility rates.

  16. Fertility attitudes and the fear of death.

    Science.gov (United States)

    Hoelter, J W; Whitlock, J L; Epley, R J

    1979-12-01

    An attempt to test empirically the general proposition that fear of death is related to certain attitudes about fertility, particularly expected number of children. Analysis of data collected from 355 undergraduates at a midwestern U.S. university showed this proposition to be generally supported and dependent, in part, on respondents' sex. Those who are more fearful of death tend to perceive procreation as a means for others to reduce fear of death, and also tend to expect having a greater number of children than those whose fear is less. Although the interrelationships of the variables appears somewhat complex, they provide an empirical reference for further research linking mortality to fertility.

  17. Social mobility and fertility

    Directory of Open Access Journals (Sweden)

    Gianpiero Dalla Zuanna

    2007-12-01

    Full Text Available Intra- and inter-generational social mobility have in the past played an important role in attempts to explain fertility behaviour, and continue to do so today. The opinions expressed by social scientists in the first part of the 20th century are renewed and confirmed. More specifically: (1 intra-generational social mobility has been reinforced by the personal well-being aspirations and job careers of women; (2 status anxiety parents feel for their children pushes fertility down in large areas of the developed world (mainly in southern European and eastern Asian countries. Therefore, the provocative idea of Ariès that in the rich world, the child-king has now been replaced by the couple-queen does not perfectly hold.

  18. Fertility, Migration, and Altruism

    OpenAIRE

    2000-01-01

    Consider migration to a higher income region as a human capital investment in which parents bear migration costs and children share returns. Migrants from a population with heterogeneous intergenerational discount rates will be self-selected on intergenerational altruism. Thus, immigrants may be self-selected on fertility. Soviet Jews who migrate to Israel despite high migration costs have significantly more children than members of the same birth cohort who migrate later when costs are low. ...

  19. Slow-Release Fertilizer

    Science.gov (United States)

    1998-01-01

    Under an SBIR (Small Business Innovative Research), ZeoponiX, Inc., introduced ZeoPro. This product is used as a fertilizer/soil amendment for golf courses, ball fields, greenhouse and horticultural uses. A combination of superior growth medium and soil conditioner allow for nutrient supplementation and high efficiency delivery of nutrients throughout the plant. ZeoPro provides a balanced nutrient system for major, minor, and trace nutrients.

  20. Comparative study of antiinflammatory drugs and sulphasalazine in relation to prostaglandin E and 19 hydroxylated prostaglandin E levels and human male fertility.

    Science.gov (United States)

    Freixa, R; Roselló Catafau, J; Gelpí, E; Iglesias Cortit, J L; Ballescá, J L; de Paz, J L; Iglesias Guiu, J; Gonzalez Merlo, J; Puig Parellada, P

    1984-12-01

    The effect of lysine salicylate, flurbiprofen and sulphasalazine on human seminal prostaglandin profiles of six normal individuals was studied. All of them were treated with pharmacological doses of the three agents for four days with rest periods of eighteen days in between. Sulphasalazine produced less prostaglandin (PG) inhibition relative to the other two antiinflammatory drugs but in contrast only sulphasalazine induced sperm changes. Infertility status associated with the ingestion of therapeutic levels of sulphasalaziane is not directly related to the endogenous PGEs and 19-OH PGEs, the major prostanoids in human semen. PG determinations were carried out using gas chromatographic (GC) techniques.

  1. The fertility decline in Kenya.

    Science.gov (United States)

    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

  2. IN VITRO FERTILIZATION

    Directory of Open Access Journals (Sweden)

    Hadawale N. M

    2011-07-01

    Full Text Available First written document dealing with infertility may be found in the Kahoun papyrus (oldest Egyptian medical text, dated to 2200-1950 BC. The early attribution of infertility to women persisted for centuries and was often considered divine punishment.Infertility means 1 year of well-timed, unprotected intercourse without a pregnancy. The study shows about 10-15% of population is infertile. And 15-20% of couple have unexplained infertility (work-up is negative. Normally women are born with their lifetime egg supply, the Fertility initially declines at age 27.Significant decline at age 37-38. The chances of pregnancies are rare after age 44 besides this defect in female ovary, fallopian tube, uterus, and fibroid tumour causes infertility in female.Abnormality in sperm production and abnormality in sperm function causes infertility in male.To overcome the infertility egg are harvested from womens ovary and fertilized in laboratory with the sperm the embryos are then transfer into uterus known as In Vitro Fertilization.

  3. Environmental friendly nitrogen fertilization

    Institute of Scientific and Technical Information of China (English)

    Avi; Shaviv

    2005-01-01

    With the huge intensification of agriculture and the increasing awareness to human health and natural resources sustainability, there was a shift towards the development of environmental friendly N application approaches that support sustainable use of land and sustain food production.The effectiveness of such approaches depends on their ability to synchronize plant nitrogen demand with its supply and the ability to apply favored compositions and dosages of N-species.They are also influenced by farming scale and its sophistication, and include the following key concepts: (i) Improved application modes such as split or localized ("depot") application; (ii) use of bio-amendments like nitrification and urease inhibitors and combinations of (i) and (ii); (iii) use of controlled and slow release fertilizers; (iv) Fertigation-fertilization via irrigation systems including fully automated and controlled systems; and (v) precision fertilization in large scale farming systems. The paper describes the approaches and their action mechanisms and examines their agronomic and environmental significance. The relevance of the approaches for different farming scales, levels of agronomic intensification and agro-technical sophistication is examined as well.

  4. [Recent and future trends in general fertility in Venezuela].

    Science.gov (United States)

    Papail, J

    1983-01-01

    Data from the 1977 Venezuela Fertility survey were used to assess recent trends in fertility and to attempt an understanding of future fertility based on observed trends. Between 1951-61, the total fertility rate increased from 5.96 to 6.61. In the 1960s, the fertility of women aged 15-30 years declined somewhat and the use of contraception and sterilization became more widespread, so that by 1971 the total fertility rate fell to 5.58. It is possible that the 1977 fertility survey slightly underrepresented women in the Caracas area, which would tend to overestimate fertility at the national level. The small sample size of 4361 women aged 15-44 involved considerable fluctuations in fertility rates from year to year. The risk of errors resulting from the method of retrospective reporting of live births appeared to be small since the recall period was relatively short. A series of quinquennial rates for women aged 15-39 was constructed for each age group from 1968-77. Fertility rates estimated for 1971 and 1976 respectively from the Venezuela Fertility Survey results using a moving average for 3 years were 120.7 and 105.1 for women 15-19, 259.0 and 225.1 for women 20-24, 255.0 and 213.1 for women 25-29, 214.3 and 167.7 for women 30-34, and 150.0 and 103.6 for women 35-39. The results were quite close to fertility rates estimated in other sources. The 1977 fertility survey indicated a trend toward later age at marriage and a correlation of ideal family size with age. The ideal number of children was 4.2 for the total sample, 5 children for women aged 35-39 years, 4.5 for those aged 30-34, 3.9 for those 25-29, and 3.5 for those aged 20-24. 55% of women in union stated they wanted no more children. 46% of women exposed to risk of pregnancy used a modern method of contraception; the proportion varied from 40% of those with 1 child to 56% with 4 children. The fertility decline, reduced ideal family size, and use of modern contraception were closely associated with

  5. Development of the knowledge of fertility and fertility preservation scale

    Directory of Open Access Journals (Sweden)

    McNees P

    2012-04-01

    Full Text Available Angela Jukkala1, Karen Meneses1, Andres Azuero1, June Cho1, Patrick McNees1,21School of Nursing, 2School of Health Professions, University of Alabama at Birmingham, Birmingham, AL, USAObjective: Infertility is a severe and often underestimated consequence of successful treatment for breast cancer. Ensuring young breast cancer survivors receive patient-centered health information on the impact of treatment on fertility and fertility preservation options in a timely manner is a critical component of high quality nursing care. The objective of this manuscript is to report the process used to develop and examine the reliability and validity of an instrument to measure a breast cancer survivor’s self-assessed knowledge of fertility and fertility preservation.Design: A scale development and descriptive study.Setting: Online and global.Participants: Ninety-two young breast cancer survivors (ages 25–45 years.Methods: Participants completed the Knowledge of Fertility and Fertility Preservation (KF Scale as part of their participation in a larger study, the Fertility Cancer Project (FCP.Results: An exploratory factor analysis revealed five domains: normal reproductive function; general information about fertility; cancer treatment factors affecting fertility; infertility information; and alternative parenting options. A confirmatory factor analysis confirmed the validity of the construct with a demonstrated good fit between the factor structure of the new scale and the observed data. Many participants self-assessed their overall knowledge of fertility and fertility preservation as “a little” and the majority rated their knowledge of infertility information as “a little”.Conclusion: The KF Scale can be used to provide useful information to support health care professionals in the development of patient-centered education that is responsive to the unique needs of each young breast cancer survivor. The initial testing of the KF Scale indicates

  6. The impact of poverty on fertility in Peninsular Malaysia: a cohort analysis.

    Science.gov (United States)

    Teo, P

    1991-02-01

    Data from the 1980 census of Malaysia are used to analyze the impact of the New Economic Policy (NEP), formulated in 1970, on reducing ethnic fertility differentials and inequalities in wealth. The relationship between fertility and income differentials is explored. The author concludes that the NEP has had relatively little impact on either reducing fertility or achieving income equity.

  7. 49 CFR 1300.5 - Additional publication requirement for agricultural products and fertilizer.

    Science.gov (United States)

    2010-10-01

    ... agricultural products and fertilizer. 1300.5 Section 1300.5 Transportation Other Regulations Relating to... fertilizer. (a) With respect to transportation of agricultural products (including grain, as defined in 7 U.S.C. 75, and all products thereof) and fertilizer, a rail carrier shall publish, make available,...

  8. [Research advances on controlled-release mechanisms of nutrients in coated fertilizers].

    Science.gov (United States)

    Zhang, Haijun; Wu, Zhijie; Liang, Wenju; Xie, Hongtu

    2003-12-01

    Using encapsulation techniques to coat easily soluble fertilizers is an important way to improve fertilizer use efficiency while reduce environmental hazards. Based on a wide range of literature collection on coated fertilizer research, the theories, processes, and characters of nutrient controlled-release from coated fertilizer were discussed, and the factors affecting nutrient controlled-release and the mathematical simulations on it were reviewed. The main tendencies related to this research in China were also put forward.

  9. Antioxidative effects of cerium dioxide nanoparticles ameliorate age-related male infertility: optimistic results in rats and the review of clinical clues for integrative concept of men health and fertility.

    Science.gov (United States)

    Kobyliak, Nazarii M; Falalyeyeva, Tetyana M; Kuryk, Olena G; Beregova, Tetyana V; Bodnar, Petro M; Zholobak, Nadiya M; Shcherbakov, Oleksandr B; Bubnov, Rostyslav V; Spivak, Mykola Ya

    2015-01-01

    Male infertility has largely idiopathic, multifactorial origin. Oxidative stress is a major factor that affects spermatogenesis, in particular in aging. Cerium dioxide nanoparticles (CNPs) due to their antioxidative properties are promising to impact on the development of male infertility. The aims of this study were to investigate the effects of CNPs on fertility parameters in 24-month male rats and to overview relevant literature in the field of personalized treatments, predictive diagnosis, and preventive measures for male health and fertility. We included 30 24-month-old male rats. After a week of adaptation to the standard diet, the rats were randomly divided into three groups with ten rats in each. Group 1 (controls) received only a standard diet. The rats of group 2 and 3 in adjunct to the standard diet during 10 days received intragastrically 10 % sodium citrate and citrate-coated CNPs in dose 1 mg/kg, respectively. We assessed sex hormones, epididymal sperm parameters and spermatogenesis, ultrasound, and morphological data of rat reproductive organs. After a 10-day administration of CNPs, we revealed significant decrease of lipid peroxidation product levels in serum and increase of catalase and SOD activity, associated with increase of sperm count (p < 0.001) and improvement in quantitative sperm parameters (motility, viability, and percentage of spermatozoa). We found no significant changes between sperm quantitative parameters in citrate-treated rats and controls and observed age-related decrease of activated Leydig cell number and focal atrophy of the seminiferous tubules. In CNP group, we observed regeneration of seminiferous tubules, increase number and activation of Leydig cells, and 2.5-fold significant increase of serum testosterone. Ultrasound data showed the slight increase of linear measurement and volume of rat testes in CNP group. Review highlights the benefits for predictive diagnosis, preventive measures, and personalized approaches to

  10. Fertility preservation: a challenge for IVF-clinics.

    Science.gov (United States)

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

    2015-11-01

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

  11. Temporal Trends in Fertility Rates

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  12. Economic development and fertility change in Mexico, 1950-1970.

    Science.gov (United States)

    Hicks, W W

    1974-08-01

    This paper is an attempt to isolate the determinants of fertility in Mexico. Of the variables included, two are significant in accounting for differences in the level of completed fertility in the 32 "states" in 1970. They are the share of the labor force in agriculture, which is directly related to fertility, and the percentage of the population speaking an indigenous language, which shows an inverse relationship.The most important factors acting to reduce total fertility rates over time are increases in life expectancy and declines in the share of the labor force in agriculture. However, based on the estimated linear relationship, these two variables by themselves are not adequate to achieve a rapid decline in fertility in the future.

  13. Environmental fate of natural radioactive contaminants in fertilizers and phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Batalha, Marcia Salamoni; Genuchten, Martinus Theodorus van, E-mail: msbatalha@oi.com.b, E-mail: rvangenuchten@yahoo.co [Federal University of Rio de Janeiro (LTTC/COPPE/UFRJ), RJ (Brazil). Dept. of Mechanical Engineering. Lab. de Transmissao e Tecnologia do Calor; Bezerra, Camila Rosa, E-mail: camila.rosabz@gmail.co [Federal University of Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Dept. of Civil Engineering; Pontedeiro, Elizabeth May, E-mail: bettymay@cnen.gov.b [Brazilian Nuclear Energy Commission (CNEN), Rio de Janeiro, RJ (Brazil)

    2010-07-01

    Agricultural soils often require the use of fertilizers and soil conditioners for optimal production. Phosphate fertilizers produced from igneous phosphate rock often contain small amounts of natural radionuclides (notably uranium and thorium), while the byproduct phosphogypsum (dihydrated calcium sulfate) is typically enriched in radium and lead. It is important to understand the long-term fate of these radionuclides when routinely applied via fertilizers ({sup 238}U and {sup 234}U) and phosphogypsum as an amendment ({sup 226}Ra and {sup 210}Pb) to agricultural lands. This study addresses the results of modeling their transport in a typical Cerrado soil profile. The HYDRUS-1D code was used to compare possible soil and groundwater pollution scenarios following the long term use of fertilizers and phosphogypsum in agricultural operations. Results using the equilibrium transport approach suggest that radionuclide concentrations originating from the use of phosphate fertilizers and phosphogypsum are relatively modest and will not pose a major risk to polluting underlying groundwater resources. (author)

  14. Fertility and age

    Directory of Open Access Journals (Sweden)

    Korula George

    2010-01-01

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

  15. Soil Fertility in relation to Landscape Position and Land Use/Cover Types: A Case Study of the Lake Kivu Pilot Learning Site

    Directory of Open Access Journals (Sweden)

    Majaliwa Mwanjalolo Jackson-Gilbert

    2015-01-01

    Full Text Available This study determined the change and distribution of land-uses/covers along the landscape, and evaluated the nutrient status of the top soil layer in the Lake Kivu Pilot Learning Site (LKPLS benchmarked micro-catchments. Soil physical and chemical properties were quantified using triplicate soil samples collected from each land-use/cover at two depths (0–15 and 15–30 cm in three LK PLS Learning Innovation Platform (IP sites (Bufundi in Uganda, Mupfuni-Shanga in D.R. Congo, Gataraga in Rwanda. Small scale agriculture has increased in all the benchmarked micro-catchments at the expense of other land-uses/covers. In the settlement areas land-use/cover distribution along the landscape varied across sites and countries; the major one being eucalyptus woodlots, wetland, and perennials and annuals crops in Bufundi; annuals and perennials crops in Mupfuni-Shanga; and annuals crops in Gataraga. Perennial crops tended to occur at the footslope and valley bottoms, while the annuals occurred at the upper backslopes and summits. Available P and K were relatively higher and C/N ratio (7.28 was the lowest in Mupfuni Shanga. Annual crops had the lowest available P and N across site (P<0.05. The key nutrients N, P and K were below the critical values for plant growth for Bufundi.

  16. International fertility change: new data and insights from the developmental idealism framework.

    Science.gov (United States)

    Thornton, Arland; Binstock, Georgina; Yount, Kathryn M; Abbasi-Shavazi, Mohammad Jalal; Ghimire, Dirgha; Xie, Yu

    2012-05-01

    Many scholars have offered structural and ideational explanations for the fertility changes occurring around the world. This paper focuses on the influence of developmental idealism-a schema or set of beliefs endorsing development, fertility change, and causal connections between development and fertility. Developmental idealism is argued to be an important force affecting both population policy and the fertility behavior of ordinary people. We present new survey data from ordinary people in six countries-Argentina, China, Egypt, Iran, Nepal, and the United States-about the extent to which developmental idealism is known and believed. We ask individuals if they believe that fertility and development are correlated, that development is a causal force in changing fertility levels, and that fertility declines enhance the standard of living and intergenerational relations. We also ask people about their expectations concerning future trends in fertility in their countries and whether they approve or disapprove of the trends they expect. The data show widespread linkage in the minds of ordinary people between fertility and development. Large fractions of people in these six settings believe that fertility and development are correlated, that development reduces fertility, and that declines in fertility foster development. Many also expect and endorse future declines in fertility.

  17. Nitrogen balance dynamics during 2000-2010 in the Yangtze River Basin croplands, with special reference to the relative contributions of cropland area and synthetic fertilizer N application rate changes.

    Science.gov (United States)

    Wang, Lijuan; Zheng, Hua; Zhao, He; Robinson, Brian E

    2017-01-01

    With the increases of cropland area and fertilizer nitrogen (N) application rate, general N balance characteristics in regional agroecosystems have been widely documented. However, few studies have quantitatively analyzed the drivers of spatial changes in the N budget. We constructed a mass balance model of the N budget at the soil surface using a database of county-level agricultural statistics to analyze N input, output, and proportional contribution of various factors to the overall N input changes in croplands during 2000-2010 in the Yangtze River Basin, the largest basin and the main agricultural production region in China. Over the period investigated, N input increased by 9%. Of this 87% was from fertilizer N input. In the upper and middle reaches of the basin, the increased synthetic fertilizer N application rate accounted for 84% and 76% of the N input increase, respectively, mainly due to increased N input in the cropland that previously had low synthetic fertilizer N application rate. In lower reaches of the basin, mainly due to urbanization, the decrease in cropland area and synthetic fertilizer N application rate nearly equally contributed to decreases in N input. Quantifying spatial N inputs can provide critical managerial information needed to optimize synthetic fertilizer N application rate and monitor the impacts of urbanization on agricultural production, helping to decrease agricultural environment risk and maintain sustainable agricultural production in different areas.

  18. 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.

  19. ORGANIC CARBON CONTENTS AND STOCKS IN PARTICLE SIZE FRACTIONS OF A TYPIC HAPLUDOX FERTILIZED WITH PIG SLURRY AND SOLUBLE FERTILIZER

    Directory of Open Access Journals (Sweden)

    Maria Sueli Heberle Mafra

    2015-08-01

    Full Text Available The use of pig slurry (PS as fertilizer can affect the soil quality and increase total stocks of soil organic carbon (TOC. However, the effects of PS on TOC amount and forms in the soil are not fully understood, particularly in areas under no-tillage (NT. The purpose of this study was to determine TOC contents and stocks in the particulate (POC and mineral-associated C fractions (MAC of an Oxisol after nine years of maize-oat rotation under NT, with annual applications of PS, soluble fertilizer and combined fertilization (pig slurry + soluble fertilizer. The experiment was initiated in 2001 in Campos Novos, Santa Catarina, with the following treatments: PS at rates of 0 (without fertilization - PS0; 25 (PS25; 50 (PS50; 100 (PS100; and 200 m3 ha-1yr-1 (PS200; fertilization with soluble fertilizer (SF; and mixed fertilization (PS + SF. The TOC content was determined in samples of six soil layers to a depth of 40 cm, and the POC and MAC contents in four layers to a depth of 20 cm. From the rate of 50 m3 ha-1yr-1 and upwards, the soil TOC content and stock increased according to the PS rates in the layers to a depth of 10 cm. The POC and MAC contents and stocks were higher in the surface layers, with a clear predominance of the second fraction, but a greater relative amplitude in the contents of the first fraction.

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

    NARCIS (Netherlands)

    Misiko, M.

    2007-01-01

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

  1. Cancer treatment: fertility and sexual side effects in women

    Science.gov (United States)

    ... Alternative Names Radiotherapy - fertility; Radiation - fertility; Chemotherapy - fertility; Sexual dysfunction - cancer treatment References American Cancer Society. Fertility and women with cancer. Updated November 6, 2013. www.cancer. ...

  2. Female fertility affects men's linguistic choices.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Coyle

    Full Text Available We examined the influence of female fertility on the likelihood of male participants aligning their choice of syntactic construction with those of female confederates. Men interacted with women throughout their menstrual cycle. On critical trials during the interaction, the confederate described a picture to the participant using particular syntactic constructions. Immediately thereafter, the participant described to the confederate a picture that could be described using either the same construction that was used by the confederate or an alternative form of the construction. Our data show that the likelihood of men choosing the same syntactic structure as the women was inversely related to the women's level of fertility: higher levels of fertility were associated with lower levels of linguistic matching. A follow-up study revealed that female participants do not show this same change in linguistic behavior as a function of changes in their conversation partner's fertility. We interpret these findings in the context of recent data suggesting that non-conforming behavior may be a means of men displaying their fitness as a mate to women.

  3. From desires to behavior: Moderating factors in a fertility transition

    Directory of Open Access Journals (Sweden)

    Sarah R. Hayford

    2012-05-01

    Full Text Available BACKGROUND Extensive research in both developed and developing countries has shown that preferences and intentions for future childbearing predict behavior. However, very little of this research has examined high-fertility contexts in sub-Saharan Africa. In particular, the factors that increase or decrease correspondence between fertility desires and behavior in these settings are not well understood. OBJECTIVE This article documents the degree to which the desire to stop childbearing predicts fertility behavior over the short term among married women in rural southern Mozambique, a context where fertility transition is still in the early stages. Analyses test the moderating powers of individual, household, and community characteristics. METHODS Analyses use data from a longitudinal survey of married women of reproductive age (N=1678 carried out in 2006 and 2009 in rural areas of southern Mozambique. Logistic regression models are estimated to predict childbearing between 2006 and 2009 based on desires to stop childbearing and characteristics measured in 2006. RESULTS As expected, the desire to stop childbearing is strongly predictive of fertility behavior. Household wealth, local adult AIDS mortality, and being married to an unsuccessful labor migrant are associated with higher correspondence between reported desire to stop childbearing and fertility behavior. CONCLUSIONS Both factors related to the ability to carry out desires to stop childbearing and factors related to the strength and consistency of these desires moderate the association between desires and behaviors. Future research should expand measurement of fertility preferences to incorporate their strength and consistency as well as direction.

  4. From desires to behavior: Moderating factors in a fertility transition.

    Science.gov (United States)

    Hayford, Sarah R; Agadjanian, Victor

    2012-05-31

    Extensive research in both developed and developing countries has shown that preferences and intentions for future childbearing predict behavior. However, very little of this research has examined high-fertility contexts in sub-Saharan Africa. In particular, the factors that increase or decrease correspondence between fertility desires and behavior in these settings are not well understood. This article documents the degree to which the desire to stop childbearing predicts fertility behavior over the short term among married women in rural southern Mozambique, a context where fertility transition is still in the early stages. Analyses test the moderating powers of individual, household, and community characteristics. Analyses use data from a longitudinal survey of married women of reproductive age (N=1678) carried out in 2006 and 2009 in rural areas of southern Mozambique. Logistic regression models are estimated to predict childbearing between 2006 and 2009 based on desires to stop childbearing and characteristics measured in 2006. As expected, the desire to stop childbearing is strongly predictive of fertility behavior. Household wealth, local adult AIDS mortality, and being married to an unsuccessful labor migrant are associated with higher correspondence between reported desire to stop childbearing and fertility behavior. Both factors related to the ability to carry out desires to stop childbearing and factors related to the strength and consistency of these desires moderate the association between desires and behaviors. Future research should expand measurement of fertility preferences to incorporate their strength and consistency as well as direction.

  5. Family Systems and Fertility Intentions

    NARCIS (Netherlands)

    Mönkediek, Bastian; Bras, Hilde

    2017-01-01

    Family systems, as normative frameworks in which family processes unfold, are believed to exert a major influence on fertility. While a number of studies have addressed family system effects on family size and the timing of births, the question of how family systems influence fertility intentions

  6. ASSESSMENT OF PERCHLORATE IN FERTILIZERS

    Science.gov (United States)

    Perchlorate has been positively detected only in those materials known to be derived from Chilean caliche, which constitute less than 0.2% of U.S. fertilizer application. The data obtained in the preponderance of investigations suggest that fertilizers do not contribute to envir...

  7. Children Procedures and Treatment (Fertility Issues)

    Medline Plus

    Full Text Available ... approach the subject of fertility preservation with their cancer-stricken child? How is the Oncofertility Consortium addressing the fertility preservation needs of children? How do cancer and cancer treatment affect a child's fertility? Why ...

  8. Children Procedures and Treatment (Fertility Issues)

    Medline Plus

    Full Text Available ... approach the subject of fertility preservation with their cancer-stricken child? How is the Oncofertility Consortium addressing the fertility preservation needs of children? How do cancer and cancer treatment affect a child's fertility? Why ...

  9. Internal fertilization in an oviparous frog.

    Science.gov (United States)

    Townsend, D S; Stewart, M M; Pough, F H; Brussard, P F

    1981-04-24

    Eleutherodactylus coqui, an oviparous frog, undergoes internal fertilization. If this mode of fertilization occurs in other species of anurans, interpretations of anuran reproductive strategies based on the assumption of external fertilization must be reviewed.

  10. Fertility and Commuting Behaviour in Germany

    Directory of Open Access Journals (Sweden)

    Johannes Huinink

    2012-12-01

    Full Text Available Fertility behaviour is closely related to other dimensions of the individual life course, which are strongly interrelated themselves. Regarding the impact of job-related spatial mobility, empirical findings show a negative correlation between having children and commuting, particularly for women. Up to now, fertility intentions have not been thoroughly investigated in this respect. Longitudinal studies are lacking, too. In this paper, the effects of commuting arrangements of men and women on the intention of having a child within the next two years as well as the probability of realising this intention are addressed. The assumption is, that after accounting for other important factors (employment status, level of qualification, type of consensual union, number of children, residential mobility, medium- and long-distance commuting is negatively related to the fertility intention of women and its realisation. For men, effects are assumed to be nonexistent or even slightly positive. Longitudinal data from the first three waves of the German “Panel Analysis of Intimate Relationships and Family Dynamics” (pairfam are used to test the hypotheses. Firstly, a cross-sectional, multivariate probit-regression (with correlated errors on the intention to have a child within two years, on being childless and on medium- and long- distance commuting is applied. The model shows no significant correlation between commuting and the intention to have a child; it does however show a correlation between medium- and long distance commuting and the probability of women to be childless. Secondly, a longitudinal difference model on changing fertility intentions between panel wave 1 and wave 3 is estimated. For women, a positive effect can be found of interrupting medium- and long-distance commuting or, surprisingly, continuing medium- and long-distance commuting on the intention to have a child within two years. Thirdly, for men and women who reported a fertility

  11. [Thyroid gland and fertility].

    Science.gov (United States)

    Andreeva, P

    2014-01-01

    It is well-known that the thyroid hormones are associated with a number of aspects of the human reproduction. Both states, hyperthyroidism and hypothyroidism, have significant effect on the estrogen and androgen metabolism, the menstrual function and on fertility. The role of thyroid hormones (TH) during infertility has been little exploited. Interesting facts are that TH deficiency is more common in women with polycystic ovary syndrome (PCOS) and in certain cases with unexplained infertility. There are very few studies on the effect and paracrine regulation of TH and its receptors in the female reproductive tract. This report provides an overview of the most common thyroid disorders and their impact on ovarian function and reproductive performance in women as well as in cases with infertility and the implementation of assisted reproductive technologies (ART).

  12. Double fertilization in Helianthus

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    J. Telżyńska

    2015-01-01

    Full Text Available After controlled pollination of Helianthus annuus L. florets, the whole course of fertilization is described and documented on 24 microphotos. The timing of events is evaluated. The average cell cycle in the proembryo is 2 hours and the nuclear cycle in endosperm - 60 minutes.Plasmoptysis is suggested as the mechanism of pollen tube opening in the synergid. The structure of the thread-like sperm nucleus is interpreted as an end to end union of chromosomes, and the morphological changes of the sperm nuclei are explained as folding and coiling, based on a spiralization mechanism of chromosomes. Cytochemical observations indicating ribosome formation in the course of the nuclear cycles in the endosperm are described. The mechanisms accelerating nuclear cycles in the endosperm are discussed.

  13. General aspects of fertility and infertility.

    Science.gov (United States)

    Damario, Mark A

    2014-01-01

    Fertility rates have been declining in most Western nations over the past several decades, although it is not entirely clear if an increased rate of infertility substantially contributes to this. As compared to other species, the reproductive efficiency of humans is relatively low. Factors related to fertility include age, exposure to sexually transmitted diseases, frequency of intercourse, coital timing, as well as diet and lifestyle habits. Infertility is considered a disease due to its major disruption of major organ systems and life functions. An infertility evaluation is recommended after 12 months or more of regular, unprotected intercourse and may be considered after 6 months for those female patients over the age of 35 or with other known abnormalities. A proper infertility evaluation is a comprehensive examination of possibly identifiable infertility factors of both female and male partners, lending itself to the most appropriate and potentially effective treatment.

  14. Migrant fertility differentials in Ecuador.

    Science.gov (United States)

    Rundquist, F; Brown, L A

    1989-01-01

    The effects of migration on fertility in Ecuador were analyzed by subdividing migrant categories into permanent-, return-, circular-, and non-migrants, and context factors into 6 socioeconomic and agrarian variables. The study is introduced with a conceptual framework that explains personal intermediate variables and their influence on fertility in terms of demographic transition theory, and then defines the influences of selection for fertility, disruption of marital unions, and socialization into fertility norms at the origin vs. assimilation of norms at the destination. Migrants are usually better educated, younger and upwardly mobile, all selecting for lower fertility. Migration disrupts formation of marital unions, and causes separation of spouses, lowering fertility. Data for this study were from the 1974 and 1982 Ecuadorian Population Censuses. The contextual variables analyzed were urban/rural; manufacturing/agricultural; mineral extraction/economic recession; long/recent agricultural settlement; domestic/export crop; and large/medium sized farm. The analysis of personal attributes showed that fertility increased over the range on non-migrants through circular-, return- to permanent-migrants, a finding explained by degrees of disruption of unions. Higher fertility was associated with less education, lower economic participation, higher prevalence of marriage, longer residence and older ages. Regression analysis also showed that personal attributes outweighed contextual factors: thus age, marriage rates, residence time, education and economic activity were significant. Contextual factors were important only for non-migrants, except for destination variables which affected return-migrants and origin variables which affected circular-migrants. Low fertility was associated with urbanization, industrialization, mineral extraction, large farms, recent farm settlement and export crops. The results indicate cear influences of modernity and place influences on

  15. Diversity in the fertilization envelopes of echinoderms.

    Science.gov (United States)

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L; Ramos, Isabela; Wessel, Gary M

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium-induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here, we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all, of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, and rendezvin. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs decreased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, but different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation for cell surface changes in sea urchins has been shifted to later in oogenesis, and perhaps reflects the meiotic differences among the species-sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxons in which eggs have completed meiosis prior to fertilization.

  16. Diversity in the fertilization envelopes of echinoderms

    Science.gov (United States)

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L.; Wessel, Gary M.

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, rendezvin, and ovoperoxidase. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs deceased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, and different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation of the cell surface changes in sea urchins has been shifted to later in oogenesis and perhaps reflects the meiotic differences among the species–sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxa in which eggs have completed meiosis prior to fertilization. PMID:23331915

  17. Biological and behavioral determinants of fertility in Tierra del Fuego.

    Science.gov (United States)

    Pascual, J; García-Moro, C E; Hernández, M

    2005-05-01

    The reproductive history of 182 women in postreproductive life or near menopause from the Chilean part of Tierra del Fuego was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement, and their reproductive years were spent on the island. Path analysis was applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. Age at menarche is relatively late, and the age of the women at first birth is mainly determined by their late age at marriage. The use of contraception is related to both spacing and stopping behaviors. The late age of women at marriage, the rhythm of conception, and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego. Copyright 2004 Wiley-Liss, Inc.

  18. DEVELOPMENT OF MICROFLORA IN APPLE ROOT RHIZOSPERE WHEN FERTILIZING

    Directory of Open Access Journals (Sweden)

    Kuzin A. I.

    2015-09-01

    Full Text Available The problem of environmental safety of agricultural products and agro-technical measures is very urgent now. Various agrochemicals are widely used in agricultural production: plant protection preparations, fertilizers, stimulants and plant growth regulators, etc. One possible solution of this problem may be a partial replacement of mineral fertilizers by bacterial ones. The aim of our research was to determine the effect of different fertilizers and methods of their application on the quantity of microorganisms in the apple root rhizosphere soil. The research was carried out according to conventional methods. In our experiment, we determined the number of microorganisms in the rhizosphere of the roots of apple trees, nitrogen, phosphorus and potassium in the leaves; hydrolysable nitrogen, available phosphorus and exchangeable potassium in soil and crop yield. The highest yield was obtained by fertigation in our research. Application bacterial fertilizer to the soil ensured yield increase at the level of mineral fertilizer application. Application of fertilizers in general, in the studied application rates provided optimum level of nitrogen, phosphorus and potassium content in the leaves and soil. By use of fertigation and bacterial fertilizers were high and relatively stable numbers of microorganisms in the rhizosphere of the apple trees. The number of microorganisms in the rhizosphere had a positive correlation with yield and the content of nutrients in soil and in leaves

  19. Fertility and the changing female educational attainment in Croatia

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    Čipin Ivan

    2016-01-01

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

  20. Female fertility loss and preservation: threats and opportunities.

    Science.gov (United States)

    Salama, M; Winkler, K; Murach, K F; Seeber, B; Ziehr, S C; Wildt, L

    2013-03-01

    Ovarian aging and cytotoxic treatments are the most common causes for fertility loss in women. With increasing numbers of young female survivors following cytotoxic cancer treatments, the issue of fertility preservation has assumed greater importance. We review the literature on the causes of female fertility loss as well as the recent advances in fertility preservation options and strategies that might be of interest to oncologists. Currently, several methods and techniques exist for fertility preservation of female patients with cancer including embryo freezing, ovarian protection techniques, oocyte cryopreservation, ovarian tissue cryopreservation followed by autotransplantation, and recently in vitro culture of ovarian tissue, follicles, and oocytes. Each method or technique has advantages and disadvantages related to current success rate, required delay in cancer treatment, sperm requirement, and risk of reintroducing cancer cells. To date, embryo freezing is the only established method successfully and widely used for fertility preservation of female patients with cancer. The other methods are promising but still considered experimental. Patient awareness, physician knowledge, early counseling, costs management, international registry, interdisciplinary networks, and research development are necessary to improve the current care in the field of female fertility preservation.

  1. Energy metabolism and fertility: a balance preserved for female health.

    OpenAIRE

    Sara Della Torre; Valeria Benedusi; Roberta Fontana; Adriana Maggi

    2013-01-01

    In female animals, energy metabolism and fertility are tightly connected, and reciprocally regulated. However, the relative contributions of metabolic and reproductive pathways have changed over the course of evolution. In oviparous animals, metabolic factors take precedence over fertility, enabling egg production to be inhibited in a nutritionally poor environment. By contrast, in placental mammals, the opposite occurs: the need to feed a developing embryo and neonate forces metabolic pathwa...

  2. Familial roles and fertility: some labour policy aspects.

    OpenAIRE

    Oppong C

    1982-01-01

    ILO pub-WEP pub. Working paper comprising a literature survey on trends in relationships between fertility patterns, family social roles and labour policy - referring to an earlier ILO investigation (KC Doctor, "Employment and labour policies in relation to fertility patterns", 1972), reviews the impact of social change on parental and sex roles, equal opportunities, traditional division of labour, decision making, family planning, family budget, social protection, social security, etc., and ...

  3. 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.

  4. Research Progress in the Effect and Mechanism of Fertilization Measures on Soil Fertility

    Institute of Scientific and Technical Information of China (English)

    Dongfeng; HUANG; Limin; WANG; Weihua; LI; Xiaoxuan; QIU

    2015-01-01

    This paper firstly summarized the domestic and foreign research progress in the relationship between fertilization measures and soil fertility. It elaborated the relationship between fertilization measures and basic physical and chemical properties,soil enzyme activity,soil microorganism fertility index,and soil animal fertility index. It pointed out future researches about the relationship between fertilization measures and soil fertility include:( i) the relationship between fine and high efficient input of organic fertilizer and soil fertility,( ii) in-depth research of soil zoology fertility index,( iii) soil biology about long-term fertilization,and( iv) soil fertilization and agricultural diffused pollution. It is intended to provide scientific reference for improving farmland soil fertility and maintaining excellent ecological environment of farmland through proper fertilization measures.

  5. Utilization of third-party in vitro fertilization in the United States.

    Science.gov (United States)

    Kushnir, Vitaly A; Darmon, Sarah K; Shapiro, Alice J; Albertini, David F; Barad, David H; Gleicher, Norbert

    2017-03-01

    The use of in vitro fertilization that includes third-party in vitro fertilization is increasing. However, the relative contribution of third-party in vitro fertilization that includes the use of donor oocytes, sperm, or embryo and a gestational carrier to the birth cohort after in vitro fertilization is unknown. The purpose of this study was to examine the contribution of third-party in vitro fertilization to the in vitro fertilization birth cohort over the past decade. This retrospective analysis investigated 1,349,874 in vitro fertilization cycles that resulted in 421,525 live births and 549,367 liveborn infants in the United States from 2004-2013. Cycles were self-reported by fertility centers to a national registry: Society for Assisted Reproductive Technologies Clinic Outcome Reporting System. Third-party in vitro fertilization accounted for 217,030 (16.1%) of all in vitro fertilization cycles, 86,063 (20.4%) of all live births, and 115,024 (20.9%) of all liveborn infants. Overall, 39.7% of third-party in vitro fertilization cycles resulted in a live birth, compared with 29.6% of autologous in vitro fertilization cycles. Use of third-party in vitro fertilization increased with maternal age and accounted for 42.2% of all in vitro fertilization cycles and 75.3% of all liveborn infants among women >40 years old. Oocyte donation was the most common third-party in vitro fertilization technique, followed by sperm donation. Over the study period, annual cycle volume and live birth rates gradually increased for both autologous in vitro fertilization and third-party in vitro fertilization (Pvitro fertilization modalities were used, followed by oocyte donation. Third-party in vitro fertilization use and efficacy have increased over the past decade, now comprising >20% of the total in vitro fertilization birth cohort. In women who are >40 years old, third-party in vitro fertilization has become the dominant treatment. Copyright © 2016 Elsevier Inc

  6. Aerogammaspectrometric anomalies (K, eU and eTh) from Araras region (SP) and its relations with pedogenetic processes and phosphate fertilizers; Anomalias aerogamaespectrometricas (K, eU e eTh) da quadricula de Araras (SP) e suas relacoes com processos pedogeneticos e fertilizantes fosfatos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Jocelyn Lopes de; Ferreira, Francisco Jose Fonseca, E-mail: jocelyn_informatica@yahoo.com.br, E-mail: jocelyn.souza@utp.br, E-mail: francisco.ferreira@ufpr.br [Universidade Federal do Parana (LPGA/UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Pesquisas em Geofisica Aplicada

    2005-07-15

    Radionuclides are present in the raw materials utilized in the manufacturing of some fertilizers and, consequently, the redistribution of uranium, thorium and potassium by agricultural activities may lead to the contamination of intensively fertilized soils. Airborne gamma-ray data on K, eU and Th have shown the coincidence of aerogammaspectrometric anomalies and diabase sills in the Araras region (SP). This area is situated between the coordinates latitude 22 deg 00'/22 deg 30' South and longitude 47 deg 00' and 47 deg 30' West. As the contents of radionuclides in basic rocks are low and aerial gamma-ray surveys reveal gamma radiation from the 30 cm of the soil profile (coinciding with topsoil), interest has been raised to investigate which soils are included in the anomalies reported, as well as what sort of agricultural activity is carried out, in order to attest whether the source of radioactivity originated from the chemical fertilizers applied, thus establishing the main purpose of the present research. Integration by GIS has revealed that (1) eU and eTh anomalies occur on latossolos roxos massively fertilized with phosphates, on the level and elevated parts of the terrain; (2) high levels of uranium are associated with clay particle size in regoliths developed on diabase sills; (3) potassium and thorium anomalies follow Quaternary alluviums which extend along the banks of the Moji river, the occurrence of anomalous K accounting for the presence of feldspars in the included soils, and the occurrence of eTh related to local fertilization and to the transport of clays and iron oxides from the uppermost parts of the terrain, where the Latossolos Roxos under sugarcane are located. Radiochemical analyses of U and Th in fertilizers were in agreement with the literature, and it has been observed the influence of the geological genesis of the source of the raw material utilized in the production of the fertilizer, as well as the increase in

  7. Births to single mothers: Age- and education-related changes in Poland between 1985 and 2010

    Directory of Open Access Journals (Sweden)

    Zuzanna Brzozowska

    2014-05-01

    Full Text Available Background: In Poland the share of non-marital births has increased steadily for more than two decades. Studies differentiating between births to unmarried partnered and unpartnered women are rare. Objective: This paper examines the age- and education-related changes in the share of births tounpartnered women in a setting characterised by a rising non-marital birth ratio. Methods: I use Polish birth registers for the years 1985 to 2011, which cover all births between 1985 and 2010 and contain some information on the parents (e.g., date of birth, education, and marital status at the time of the child's birth. Results: In the analysed period the share of births to unpartnered women was stable at a level of 3Š-5Š of all births. Substantial increases were only noted among the least educated and teenage mothers, whose values exceeded 20Š and 30Š, respectively, in 2010. The share of teenagers among unpartnered mothers rose from around a quarter to more thanone-third. Conclusions: In Poland the share of births to unpartnered women remained stable in the period 1985-2010, but the number of the youngest and least educated mothers in this share increased.

  8. Fertilizer characterization: isotopic data (N, S, O, C, and Sr).

    Science.gov (United States)

    Vitòria, Laura; Otero, Neus; Soler, Albert; Canals, Angels

    2004-06-15

    A detailed isotopic characterization (delta15N(Ntotal), delta15N(NO3), delta18O(NO3), delta34S(SO4), delta18O(SO4), (delta13C(Ctotal), and 87Sr/86Sr) of 27 commercial fertilizers used in Spain is presented in this paper. Results together with a compilation of fertilizer isotopic published data are used for two purposes: (i) to identify the origin of the primary constituents and raw materials used in fertilizer manufacture and relate these data with their heavy metals and rare earth elements (REE) contents; (ii) to compare the fertilizer isotopic signatures with natural values and other anthropogenic pollutants and evaluate the usefulness of multi-isotopic analyses to trace fertilizer contaminations in future study cases. Isotope data permit us to know, in most cases, the origin of the primary constituents of fertilizers, and the 87Sr/86Sr ratio distinguishes the origin of the phosphate content--phosphorites or carbonatites--which in turn implies a qualitatively defined and potentially contaminant presence of REE and heavy metals in fertilizers. Delta15N, delta34S, and 87Sr/86Sr have already been used to trace fertilizer contaminations. Their utility can be improved by the coupled use of delta15N(NO3)-delta18O(NO3) and delta34S(SO4)-delta18O(SO4) to evaluate the fractionation processes that can affect contaminants. Moreover, multi-isotopic analyses, using heavy isotopes, allow us to see beyond the fractionation effects to the fertilizer stable isotope signatures and a better distinction from other anthropogenic contaminants.

  9. Male fertility, obesity, and bariatric surgery.

    Science.gov (United States)

    Reis, Leonardo Oliveira; Dias, Fernando Goulart Fernandes

    2012-08-01

    Obesity has become a new worldwide health problem with significant impact not only on cardiovascular diseases but also on many other related disorders, highlighting infertility. Obesity may adversely affect male reproduction by endocrinologic, thermal, genetic, and sexual mechanisms. There is good evidence that obesity can be associated with reduced sperm concentrations, but studies about sperm motility, morphology, and DNA fragmentation have been less numerous and more conflicting. Although weight loss is the cornerstone of the treatment of obesity-related infertility, with promising results in restoring fertility and normal hormonal profiles, bariatric surgery impact on male fertility is still unclear and until now there is not enough data to support the informed consent in this scenario. Physicians are encouraged to highlight possible positive and/or negative impacts concerning male capacity of fertilization when informing patients. A balanced judgment and a personalized case-by-case management with patient involvement in decisions are fundamental in this setting and indication of cryopreservation of semen samples should be considered in selected circumstances. Well-structured trials controlled for confounders including female factors and based on solid outcomes (ie, birth rates) must urgently come up to clarify this emerging scenario.

  10. Reproduction, fertility and socio-economic development

    Directory of Open Access Journals (Sweden)

    Meshkani Z

    1997-07-01

    Full Text Available The rapid growth of population in the third world countries specially in recent decades has posed an important social problem. There have been some attempts to propose solutions for this problem by scientists from various disciplines. However, it seems that an integrated approach calling for collaboration of various efforts can be more fruitful. In this work, we study the relation of women fertility and socio-economical indices along with government's programmed efforts in the third world countries. Employing a statistical approach, we show that development indices such as gross national product, infant mortality rate, education enrolment, and access to mass media along with government's programmed efforts are effective in reducing the fertility rate, but more important is the interaction between these factors. Thus, an integrated approach emerges as a better solution to population control

  11. Sleep, sleep disturbance, and fertility in women.

    Science.gov (United States)

    Kloss, Jacqueline D; Perlis, Michael L; Zamzow, Jessica A; Culnan, Elizabeth J; Gracia, Clarisa R

    2015-08-01

    Sleep and sleep disturbances are increasingly recognized as determinants of women's health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible.

  12. 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

    random mating. Such low fertilization rates are normally related to environmental factors such as poor food or low densities, which we could not confirm in our experiment. Male density was negatively related to fertilization rate, and a large fraction of males did not mate in laboratory incubations. We...... therefore suggest that sexual selection, through mate choice or male–male competition could account for low fertilization rates of females in populations of pelagic copepods during some periods of the year...

  13. Caste, socio-economic status and fertility -- a study of proximate determinants of fertility in village Riwasa.

    Science.gov (United States)

    Arora, G

    1985-10-01

    The intermediary variables of ritual stratification, i.e., caste, and secular stratification, i.e., socioeconomic status, were examined to explain fertility in a survey of 140 fertile women in Riwasa village, Bhiwani District, Haryana state, India, in 1981. The subjects interviewed were equally divided among 17 castes on the basis of untouchability. The intermediary variables evaluated were caste-consciousness, modernization, conformity to family ethical codes and husband-wife communication. The fertility indices were live births, living children, expected additional births and ideal family size. Results were expressed in percentages. Results of the survey confirmed previous findings that fertility was inversely related to caste and socioeconomic status. These associations were explained here, however, by the behavior of the intermediary variables. Fertility was inversely related to level of modernization and to husband-wife communication. Although caste-consciousness and conformity to family ethical codes were directly related to fertility, even among the higher castes. There were no differences in this study population between high and middle socioeconomic class, probably because the high socioeconomic group in this village resembled middle class in typical urban settings.

  14. Fertilization of SRC willow. II

    DEFF Research Database (Denmark)

    Sevel, L; Ingerslev, Morten; Nord-Larsen, Thomas

    2014-01-01

    Short rotation coppice (SRC) willow is an emerging cropping system in focus for production of biomass for energy. To increase production, the willow is commonly fertilized, but studies have shown differing effects of fertilization on biomass production, ranging from almost no response...... impacts of different doses of mineral fertilizer, manure and sewage sludge in a commercially grown SRC willow stand. We examined macro nutrient and heavy metal leaching rates and calculated element balances to evaluate the environmental impact. Growth responses were reported in a former paper (Sevel et al....... “Fertilization of SRC Willow, I: Biomass Production Response” Bioenergy Research, 2013). Nitrogen leaching was generally low, between 1 and 7 kg N ha−1 year−1 when doses of up to 120 kg N ha−1 year−1 were applied. Higher doses of 240 and 360 kg N ha−1 as single applications caused leaching of 66 and 99 kg N ha−1...

  15. Food security: Fertilizing hidden hunger

    Science.gov (United States)

    Müller, Christoph; Elliott, Joshua; Levermann, Anders

    2014-07-01

    Atmospheric CO2 fertilization may go some way to compensating the negative impact of climatic changes on crop yields, but it comes at the expense of a deterioration of the current nutritional value of food.

  16. IVF-In Vitro Fertilization.

    Science.gov (United States)

    Kieffer, George H.

    1980-01-01

    Issues surrounding the controversial topic of in vitro fertilization and artificial manipulation of reproduction are discussed. The author examines the moral and ethical implications and presents results of a survey of various religious groups. (SA)

  17. The Fertility Transition in Bavaria

    OpenAIRE

    Brown, John C.; Timothy W. Guinnane

    2001-01-01

    The decline of human fertility that occurred in Europe and North America in the nineteenth century, and elsewhere in the twentieth century, remains a topic of debate largely because there is no accepted explanation for the event. Disagreement persists in part because researchers have rarely used the detailed quantitative information necessary to form adequate tests of alternative theories. This paper uses district-level data from Bavaria to study the correlates of the decline of fertility in ...

  18. Ovarian fluid allows directional cryptic female choice despite external fertilization.

    Science.gov (United States)

    Alonzo, Suzanne H; Stiver, Kelly A; Marsh-Rollo, Susan E

    2016-08-16

    In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female's reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible.

  19. Marital moratorium and fertility control in China.

    Science.gov (United States)

    Tien, H Y

    1970-11-01

    a context of revolutionary change, and involved persons who have committed themselves to transforming the Chinese family. This prior commitment was mainly responsible for the relative lack of controversy about marital postponement as a means of fertility control. (4) Use of contraception is private, hidden from open view. But postponement of marriage is public and may be a source of inter-generational and interpersonal conflict. In China and other parallel situations, a decision to delay marriage is in itself against tradition. In this sense, a full-scale marital moratorium cannot but be more than a partial assault on the hold that the family has over its offspring. This must be unequivocally reflected in discussions of fertility control policy everywhere.

  20. Facts at a Glance: [Report on 1992 Data on Teen Fertility in the United States].

    Science.gov (United States)

    Moore, Kristin, Comp.; And Others

    This fact sheet contains data on teen pregnancy. The folowing information is provided: teen birth rate, 1960-1992; number of births to teens, 1960-1992; percent of non-marital teen births, 1960-1992; births to unmarried women, by age group, 1992; international comparison on teen birth rate; abortion rate among U.S. teens, 1973-1990; pregnancy…

  1. Children Procedures and Treatment (Fertility Issues)

    Science.gov (United States)

    ... approach the subject of fertility preservation with their cancer-stricken child? How is the Oncofertility Consortium addressing the fertility preservation needs of children? How do cancer and cancer treatment affect a child's fertility? Why should fertility preservation be a priority ...

  2. Educational and social class assortative mating in fertile British couples.

    Science.gov (United States)

    Krzyżanowska, Monika; Mascie-Taylor, C G Nicholas

    2014-01-01

    Positive assortative mating for education and social position has been widely reported in a number of countries, but very few studies have tested whether or not educational or social class homogamy is related to differential fertility. This study examined the relationship between educational and social class assortative mating and fertility in a British national cohort. The analyses were based on 7452 husband-wife pairs from the British National Child Development Study (NCDS). The mean fertility was 3.22 children per couple; the number of children significantly increased from higher to lower social classes and from the more educated to the less educated. The extent of assortative mating for social class and educational level was related to fertility; as educational assortative mating decreased so did the average number of children, whereas the opposite trend was observed for social class. When assortative mating for education and social class were considered together, educational assortative mating was the more significant predictor of the number of children and educationally homogamous couples had higher fertility independent of their social class assortative mating. The relationship between assortative mating and fertility for education and social class appeared to be acting in the opposite direction.

  3. Reflections on fertility dynamics in Romania.

    Science.gov (United States)

    Bratu, Eugenia Claudia; Minca, Dana Galieta

    2012-01-01

    Aims to highlight the changes occurred in the evolution of the fertility phenomenon in Romania, focusing on developments in the general fertility rate, total fertility rate, number of live births, and on the construction of specific indicators to reveal the source of demographic change. Several theories on the factors that may cause fertility decline it were outlined, underlining the presence of these factors during fertility dynamics in our country. After 1990, population decline may be explained by a close inter-relationship between economic theories (worsening economic conditions lead to decreased fertility) and the second demographic transition (postponement of births, fertility change model).

  4. A False Fertility Transition: The Case of American Blacks. Papers of the East-West Population Institute, No. 90.

    Science.gov (United States)

    Wright, Paul; Pirie, Peter

    The decline in black fertility after the Civil War to its lowest level about the year 1936 does not fit the typical demographic transition pattern in which fertility declines postdate the initiation of mortality declines. Instead, for blacks much of the fertility decline (56 percent) was due to "involuntary infertility" related to venereal…

  5. [[Trends in marriage and fertility in Japan: major findings from the Tenth Japanese National Fertility Survey

    Science.gov (United States)

    Atoh, M; Takahashi, S; Nakano, E; Watanabe, Y; Kojima, H; Kaneko, R

    1993-10-01

    The authors review trends in marriage and fertility in Japan, using data from the 1993 Japanese National Fertility Survey. Information is included on age at marriage, arranged and voluntary marriages, length of time from initial meeting to marriage, changes in age at marriage, fertility, socioeconomic differentials in fertility, and fertility preferences. (SUMMARY IN ENG)

  6. High fertility Gambians in low fertility Spain: The dynamics of child accumulation across transnational space

    Directory of Open Access Journals (Sweden)

    Papa Sow

    2007-05-01

    Full Text Available Based on an analysis of the Spanish census and the January 1, 2005 municipal register and on exploratory fieldwork in Catalonia, this paper combines ethnography and demography, in conjunction with current Spanish reunification law, to examine the dynamics of what appears to be high fertility among Gambian immigrants living in Spain. We suggest that this high fertility rate reflects several things. One is the high costs of living in Spain for an unskilled, often-undocumented, but also relatively-longstanding SubSaharan group from a homeland with high rates of fertility: a homeland with which close ties remain vital for migrants in highly marginal conditions. Another is the replacement, in some cases, of older wives by younger ones from Africa, resulting in high rates of reproduction for short slices of time by a circulating pool of young women. We focus, however, on the role of Spanish and European policies themselves in shaping these numbers, particularly those policies that place restrictions on the free movement of people. We conclude that the most interesting demographic facet of this population may not be high fertility but rather the paradoxical dynamics of child accumulation in particular geographic regions as an artifact of Spanish law itself.

  7. Effect of Organic Fertilizer Application on Expression of Key Genes Related to Carbon and Nitrogen Metabolism in Flue-cured Tobacco at Maturity Stage%施用有机肥对成熟期烤烟碳氮代谢关键基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    连文力; 杨胜男; 贾宏昉; 崔红

    2016-01-01

    为了探明有机肥用量对烤烟碳氮代谢途径关键基因表达的影响,设置3种有机肥施用量(0、200、600 kg/667 m2)来分析烤烟成熟期叶片碳氮代谢相关关键基因的表达水平。结果表明:施用有机肥显著降低了碳代谢途径中蔗糖合成酶基因( SUS)、蔗糖磷酸合成酶基因( SPS)、颗粒结合型淀粉合成酶基因( GBSSI)和淀粉分支酶基因( SBE)的表达水平,3个处理表现为:CK>C200>C600。通过对氮代谢途径关键基因硝酸还原酶( NITR)、亚硝酸还原酶( NIR)、谷氨酸脱氢酶( GDH)和谷氨酰胺合成酶( GS)中一个重要家族成员( GLN1-3)的表达分析表明:施用适量(200 kg/667 m2)有机肥对氮代谢途径关键基因的表达量影响不显著,仅在高用量(600 kg/667 m2)有机肥条件下表现出抑制。因此,通过添加不同有机肥用量对烤烟碳氮代谢关键基因的表达分析可以看出,有机肥处理下的碳氮代谢基因表达量明显受到抑制,且与有机肥的施用量呈正相关性,有机肥对碳代谢途径的影响大于氮代谢。%In order to determine the effects of organic fertilizer application on carbon and nitrogen metabolism key genes ex-pressions of flue-cured tobacco, different organic fertilizer applications(0, 200, 600 kg/667 m2) were set in this study, which analyzed carbon and nitrogen metabolism related genes expressions of flue-cured tobacco in maturity.The results showed that su-crose synthase ( SUS) , sucrose phosphate synthase ( SPS) , granule-bound starch synthase ( GBSSI) and starch branching en-zyme ( SBE) were decreased conspicuously by applying organic fertilizer and three treatments were as follows:CK>C200>C600. The expressions of nitrogen metabolism related genes nitrate reductase ( NITR) , nitrite reductase( NIR) , glutamate dehydrogenase ( GDH) and an important family members( GLN1-3) of glutamine synthesis enzymes( GS

  8. Fertility in female survivors of Hodgkin's lymphoma

    Directory of Open Access Journals (Sweden)

    Irene Biasoli

    2012-01-01

    Full Text Available Currently, Hodgkin's lymphoma is one of the most curable types of cancer. Patients are often young and so the long-term morbidities of treatment have become of increasing concern. Among these, infertility is one of the most challenging consequences for patients in reproductive age. Premature ovarian failure in premenopausal women is a serious long-term sequel of the toxicity of chemotherapy. The main consequence of this syndrome is infertility, but women also present other symptoms related to estrogen deprivation. Different rates of impaired gonadal function are reported, depending on the patient's age, stage of disease, dose and intensity of chemotherapy and the use of radiation therapy. The most established strategy in female infertility is cryopreservation of embryos after in vitro fertilization. Additionally, the use of oral contraceptives or gonadotropinreleasing hormone analogs (GnRH-a during treatment is under study. This review will provide a general overview of the main studies conducted to evaluate the infertility rate among female Hodgkin's lymphoma survivors and risk factors associated to treatment, different end-point definitions for evaluating fertility and also a brief description of the available strategies for fertility preservation.

  9. Fertility and Commuting Behaviour in Germany

    Directory of Open Access Journals (Sweden)

    Johannes Huinink

    2012-12-01

    Firstly, a cross-sectional, multivariate probit-regression (with correlated errors on the intention to have a child within two years, on being childless and on medium- and long- distance commuting is applied. The model shows no significant correlation between commuting and the intention to have a child; it does however show a correlation between medium- and long distance commuting and the probability of women to be childless. Secondly, a longitudinal difference model on changing fertility intentions between panel wave 1 and wave 3 is estimated. For women, a positive effect can be found of interrupting medium- and long-distance commuting or, surprisingly, continuing medium- and long-distance commuting on the intention to have a child within two years. Thirdly, for men and women who reported a fertility intention in the first wave, a longitudinal Heckman-selection probit-regression on the probability of having a child between wave 1 and wave 3 is estimated. It shows negative effects of medium- and long-distance commuting on having a child. Taken together, these findings support the assumption that commuting plays a characteristically different role in different phases of the fertility-related decision process.

  10. The epididymis, cytoplasmic droplets and male fertility

    Institute of Scientific and Technical Information of China (English)

    Trevor G Cooper

    2011-01-01

    The potential of spermatozoa to become motile during post-testicular maturation,and the relationship between the cytoplasmic droplet and fertilizing capacity are reviewed.Post-testicular maturation of spermatozoa involves the autonomous induction of motility,which can occur in vivo in testes with occluded excurrent ducts and in vitro in testicular explants,and artefactual changes in morphology that appear to occur in the testis in vitro.Both modifications may reflect time-dependent oxidation of disulphide bonds of head and tail proteins.Regulatory volume decrease(RVD),which counters sperm swelling at ejaculation,is discussed in relation to loss of cytoplasmic droplets and consequences for fertility.It is postulated that:(i)fertile males possess spermatozoa with sufficient osmolytes to drive RVD at ejaculation,permitting the droplet to round up and pinch off without membrane rupture; and(ⅱ)infertile males possess spermatozoa with insufficient osmolytes so that RVD is inadequate,the droplet swells and the resulting flagellar angulation prevents droplet loss.Droplet retention at ejaculation is a harbinger of infertility caused by failure of the spermatozoon to negotiate the uterotubal junction or mucous and reach the egg.In this hypothesis,the epididymis regulates fertility indirectly by the extent of osmolyte provision to spermatozoa,which influences RVD and therefore droplet loss.Man is an exception,because ejaculated human spermatozoa retain their droplets.This may reflect their short midpiece,approximating head length,permitting a swollen droplet to extend along the entire midpiece; this not only obviates droplet migration and flagellar angulation but also hampers droplet loss.

  11. Self-incompatibility systems: barriers to self-fertilization in flowering plants.

    Science.gov (United States)

    Rea, Anne C; Nasrallah, June B

    2008-01-01

    Flowering plants (angiosperms) are the most prevalent and evolutionarily advanced group of plants. Success of these plants is owed to several unique evolutionary adaptations that aid in reproduction: the flower, the closed carpel, double fertilization, and the ultimate products of fertilization, seeds enclosed in the fruit. Angiosperms exhibit a vast array of reproductive strategies, including both asexual and sexual, the latter of which includes both self-fertilization and cross-fertilization. Asexual reproduction and self-fertilization are important reproductive strategies in a variety of situations, such as when mates are scarce or when the environment remains relatively stable. However, reproductive strategies promoting cross-fertilization are critical to angiosperm success, since they contribute to the creation of genetically diverse populations, which increase the probability that at least one individual in a population will survive given changing environmental conditions. The evolution of several physical and genetic barriers to self-fertilization or fertilization among closely related individuals is thus widespread in angiosperms. A major genetic barrier to self-fertilization is self-incompatibility (SI), which allows female reproductive cells to discriminate between "self" and "non-self" pollen, and specifically reject self pollen. Evidence for the importance of SI in angiosperm evolution lies in the highly diverse set of mechanisms used by various angiosperm families for recognition of self pollen tube development and preventing self-fertilization.

  12. Satisfaction with life as an antecedent of fertility: Partner + Happiness = Children?

    Directory of Open Access Journals (Sweden)

    Nick Parr

    2010-04-01

    Full Text Available This paper examines the relationships between satisfaction with life in general, particular domains of life, the partner, and parental relationships with existing children, and subsequent fertility. The data are from 2,948 women and 2,622 men aged 15 to 44 years from a longitudinal survey of the household population in Australia. For both sexes a strong positive relationship between prior satisfaction with life and fertility two years later is found. Men's satisfaction with their partner and with their partner's relationship with existing children are positively related to fertility. Fertility is also related to age, parity, marital status, education, employment and birthplace.

  13. 水、氮对岷江柏幼苗水分利用率及相关因子的影响%Effects of Different Levels of N-fertilizer and Water Conditions on Water Use Efficiency and Related Factors of Cupressus chengiana Seedlings

    Institute of Scientific and Technical Information of China (English)

    邵芳丽; 宫渊波; 关灵; 张振恒

    2011-01-01

    A pot experiment was conducted for Cupressus chengiana, which is the major species for afforestation in Minjiang arid valley. Experimental conditions were designed as three levels of N-fertilizer and four levels of soil water content. Net pho-tosynthetic rate, transpiration rate and other related factors were measured with Li-6400 portable photosynthesis system. Results showed that, after N-fertilizer application, the net photosynthesis rate and water use efficiency of C. Chengiana seedlings increased and transpiration rate decreased. At the 5% moisture gradient, N-fertilizer could remarkably improve the net photosynthesis rate and water use efficiency. The transpiration rate of the seedlings for the three levels of N-fertilizer application was very low due to the limit of soil water content, indicating that N-fertilizer had little impact on transpiration rate. However, N-fertilizer inhibited the transpiration rate of the seedlings to some extent compared with the N-unferti-lized seedlings.%以岷江干旱河谷区的主要造林树种岷江柏(Cupressus chengiana S.Y.Hu)幼苗作为研究对象,采用盆栽方法,对其进行了3个氮水平4个水分梯度的正交试验设计.采用Li-6400便携式光合测定仪,测定不同土壤含水量、不同施氮量条件下岷江柏幼苗的净光合速率、蒸腾速率等.结果表明:氮肥能够提高岷江柏幼苗的净光合速率和瞬时水分利用率,降低苗木蒸腾速率.在土壤含水量为5%的情况下,氮肥的施用大大提高了苗木的净光合速率和瞬时水分利用率;由于受土壤含水量的限制,各个氮水平上的苗木蒸腾速率均很低,氮肥对苗木蒸腾速率的影响则较小,而相对于未施氮苗木,氮肥在一定程度上抑制了苗木的蒸腾速率.

  14. The economics of fertility.

    Science.gov (United States)

    Loraine, J A

    1982-01-01

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

  15. High Suburban Fertility: Evidence from Four Northern European Countries

    Directory of Open Access Journals (Sweden)

    Gunnar Andersson

    2009-12-01

    Full Text Available This study examines fertility variation across different residential contexts in four Northern European countries: Denmark, Finland, Norway and Sweden. We move beyond the conventional urban-rural focus of most previous studies of within-nation variations in fertility by distinguishing between urban centres and suburbs of cities and towns. We base our study on aggregate and individual-level register data and our analysis shows that fertility levels are significantly higher in suburbs than in urban centres; this pattern has persisted over the past quarter of a century for all four countries. A parity-specific analysis of Swedish register data reveals that total fertility varies between central cities and suburbs due to the relatively high first- and second-birth propensities in the suburbs. Further analysis shows that fertility variation between the central cities and suburbs persists after controlling for women's socioeconomic characteristics. We discuss the role of various factors in accounting for high suburban fertility including omitted individual characteristics, contextual factors and selective residential moves of couples planning to have a child.

  16. 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.

  17. Short- and long-term effects of unemployment on fertility.

    Science.gov (United States)

    Currie, Janet; Schwandt, Hannes

    2014-10-14

    Scholars have been examining the relationship between fertility and unemployment for more than a century. Most studies find that fertility falls with unemployment in the short run, but it is not known whether these negative effects persist, because women simply may postpone childbearing to better economic times. Using more than 140 million US birth records for the period 1975-2010, we analyze both the short- and long-run effects of unemployment on fertility. We follow fixed cohorts of US-born women defined by their own state and year of birth, and relate their fertility to the unemployment rate experienced by each cohort at different ages. We focus on conceptions that result in a live birth. We find that women in their early 20s are most affected by high unemployment rates in the short run and that the negative effects on fertility grow over time. A one percentage point increase in the average unemployment rate experienced between the ages of 20 and 24 reduces the short-run fertility of women in this age range by six conceptions per 1,000 women. When we follow these women to age 40, we find that a one percentage point increase in the unemployment rate experienced at ages 20-24 leads to an overall loss of 14.2 conceptions. This long-run effect is driven largely by women who remain childless and thus do not have either first births or higher-order births.

  18. Effect of education on marital fertility in four Muslim populations.

    Science.gov (United States)

    Ahmad, S

    1985-01-01

    A comprehensive review of literature using cross national and cross regional studies did not reveal any systematic relationship between edcuation and fertility. This analysis--based on data collected in the mid-70s as part of the World Fertility Survey program in 4 Moslem populations--Bangladesh, Java, Jordan, and Pakistan--shows an inconsistent effect of education on marital fertility. Respondents were currently married and in their 1st marriage. "Level of education" divided women into 3 groups: no education, 1-5 years, and 6+ years. An inverted U-shape relationship between female education and current fertility was noticeable in Bangladesh and Java; an inverse relationship was supported by data from Jordan and Pakistan. Cumulative fertility, after controlling for duration of marriage, was found to be inversely related to 6+ years of education of the women in 3 populations, the exception being Java, where women with 6+ years of education show higher fertility than their counterparts. Analysis of variance showed a significant effect of wife-husband education on number of children ever born in all populations, except Pakistan. Multiple classification analysis did not reveal an appreciable difference in number of children ever born among the wife-husband education groups in Bangladesh, but a significant difference was noticed in Java and Jordan. In Pakistan, the education categories showed similar levels of fertility. The differences in fertility or lack of it by wife-husband level of education in these 4 Moslem populations were, to a large extent, explained by the interplay between the duration of breast feeding and the current use of efficient contraceptive methods.

  19. Low forager fertility: demographic characteristic or methodological artifact?

    Science.gov (United States)

    Early, J D

    1985-09-01

    Anthropological literature has long held that traditional foraging populations have low fertility levels. This research examines the number of live births per woman for 9 non-western forager groups who have been investigated in the last 20 years. Data are derived from 1) birth registration systems, 2) surveys conducted during short stays with the group, and 3) surveys conducted as part of longer ethnographic studies. Fertility rates for the groups are 1) 3.5 for the Kiunga area of Papula, New Guinea, 2) 4.2 for Northern Territory Australian aborigines, 3) 5.0 for Cayapo groups in Brazil, 4) 5.3 for Hiowe people of New Guinea, 5) 5.7 for 3 Xavante groups in Brazil, 6) 6.0 for West Alaskan Eskimos, 7) 6.9 for Nunamiut Eskimos of Alaska, 8) 7.6 for the Bisman-Asmat group of Indonesian New Guinea, and 9) 8.4 for the Winikina Warao of Venezuela. Since fertility rates are highest when ethnographic studies, which allow for question clarification, memory recall, and cross-checking, are used, the author believes that high fertility rates most accurately represent forager societies. Research on the Dobe ]Kung (fertility rate - 4.7), may contradict these findings, but the author believes that the ]Kung fertility rates are higher than reported because of infanticide practices, sexual abstinence during lactation, and disease related fertility problems. In summary, the study finds high fertility (7-9 births) in traditional foraging societies. Although the study examines small populations, correlation strength and overall consistency help verify the results.

  20. Economic and social correlates of female employment and fertility.

    Science.gov (United States)

    Herrin, A N

    1979-01-01

    This study tested a theoretical model that views female employment and fertility decisions as jointly determined by biologic, sociologic, economic, and demographic factors that determine the circumstances of individual women, families, and the labor market. The data were drawn from a multistage stratified sample of 1926 married women of childbearing age in southern Philippines. The independent variables analyzed included the exogenous wage rates of both the wife and husband, the age of the wife, the number of children ever born per year of marriage, and residence (urban or rural). Also analyzed were the social variables of time conflict, normative conflict, work commitment, and wife's relative dominance in household decision making. An exogenous change in female wage rates increased the percent of time spent in paid employment but had an insignificant effect on fertility. In contrast, a change in the male wage rate reduce female employment and current fertility. Women in municipal poblacions had lower current fertility and significantly higher labor force participation than women in rural or urban settings. Women who perceived that children interfere with work were more likely to bear a child in the study period and less likely to participate in the labor force. The husband's attitude toward female employment reduced labor force participation, but did not increase current fertility. Finally, women who play a major role in household decision making had both increased labor force participation and increased fertility. There was some variation in these trends by age cohort. A positive coefficient of the female wage on fertility was observed among women 20-29 and 40-49 years, while a negative coefficient existed for women 30-39 years. It is concluded that a common set of economic and social factors jointly determine current female employment and fertility decisions.

  1. Wheat and Rice Growth Stages and Fertilization Regimes Alter Soil Bacterial Community Structure, but Not Diversity

    Directory of Open Access Journals (Sweden)

    Jichen Wang

    2016-08-01

    Full Text Available Maintaining soil fertility and the microbial communities that determine fertility is critical to sustainable agricultural strategies, and the use of different organic fertilizer regimes represents an important practice in attempts to preserve soil quality. However, little is known about the dynamic response of bacterial communities to fertilization regimes across crop growth stages. In this study, we examined microbial community structure and diversity across eight representative growth stages of wheat-rice rotation under four different fertilization treatments: no nitrogen fertilizer (NNF, chemical fertilizer (CF, organic-inorganic mixed fertilizer (OIMF and organic fertilizer (OF. Quantitative PCR (QPCR and high-throughput sequencing of bacterial 16S rRNA gene fragments revealed that growth stage as the best predictor of bacterial community abundance and structure. Additionally, bacterial community compositions differed between wheat and rice rotations. Relative to soils under wheat rotation, soils under rice rotation contained higher relative abundances (RA of anaerobic and mesophilic microbes and lower RA of aerophilic microbes. With respect to fertilization regime, NNF plots had a higher abundance of nitrogen–fixing Cyanobacteria. OIMF had a lower abundance of ammonia-oxidizing Thaumarchaeota compared with CF. Application of chemical fertilizers (CF and OIMF treatments significantly increased the abundance of some generally oligotrophic bacteria such those belonging to the Acidobacteria, while more copiotrophic of the phylum Proteobacteria increased with organic fertilizer application. A high correlation coefficient was found when comparing RA of Acidobacteria based upon QPCR versus sequence analysis, yet poor correlations were found for the Alpha- and Beta- Proteobacteria, highlighting the caution required when interpreting these molecular data. In total, crop, fertilization scheme and plant developmental stage all influenced soil

  2. Fertilization and early seed formation.

    Science.gov (United States)

    Dumas, Christian; Rogowsky, Peter

    2008-10-01

    The double fertilization of flowering plants is a complex process, encompassing multiple steps. From its discovery more than a century ago, many useful descriptive approaches have been employed to better unveil specific steps/mechanisms. More recently, the development of an in vitro assay developed in our laboratory, has allowed a better understanding of this phenomenon. However, in vitro methods may show some limitations. The search for complementary strategies, especially with the search of mutants affected in the fertilization step allowed one to elucidate this critical and unique phenomenon in living organisms. Genes involved in pollen tube guidance or pollen discharge in synergids have been identified, as well as genes exhibiting differential expression in sperm, egg and central cells before and after fertilization. A calcium wave proved to correspond to the first cellular event seen after cytoplasmic fusion in the fertilized egg cell or zygote, which develops into a multi-cellular organism with an elaborate body plan. The development of the fertilized central cell into a nourishing tissue (endosperm) starts with the formation of the coenocyte, a multinuclear single cell unique in the plant kingdom, cellularization occurring later on. The balance of the paternal and maternal genomes, which is under the control of the FIS polycomb group complex, was found to be of the utmost importance for the successful development of the seed.

  3. Male fertility in cystic fibrosis.

    LENUS (Irish Health Repository)

    Chotirmall, S H

    2011-04-05

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

  4. [The decline of fertility in Western Europe. II. Which fertility rate would be desirable in France? (author's transl)].

    Science.gov (United States)

    Calot, G

    1977-01-01

    A way to try and assess the significance of such or such level in long term fertility is to work out population projections based on a variety of assumptions and to compare their different implications. The age pyramids of France until 2100 that derive from four contrasted evolutions of fertility are studied in the present article: completed fertility in birth cohorts ranging from 1.4 to 2.6 children per woman. While some demographic parameters are not much sensitive to the assumption made for the fertility level (e.g. percent of economically active people in total population), others are closely related to fertility (such as total number of inhabitants, percent of younger people or of older people in total population, annual rate of entry into economically active population). In France, where population density is much lower than in most neighbouring countries, a fertility level that would lay at -- or a little higher than -- replacement (i.e. 2.1 children per woman) can be considered as a desirable target.

  5. [Fate and balance of bulk blending controlled release fertilizer nitrogen under continuous cropping of mustard].

    Science.gov (United States)

    Zhang, Pan-Pan; Fan, Xiao-Lin

    2012-10-01

    Under the conditions of applying water soluble fertilizer and its bulk blending with controlled release fertilizer (BB-CRF), and by using micro-lysimeter, this paper quantitatively studied the nitrogen (N) uptake by mustard, the soil N losses from N2O emission, leaching and others, and the N residual in soil in three rotations of continuously cropped mustard. In the treatment of BB-CRF with 25% of controlled release nitrogen, the N uptake by mustard increased with rotations, and the yield by the end of the experiment was significantly higher than that in the treatment of water soluble fertilizer. The cumulated N2O emission loss and the N leaching loss were obviously higher in treatment water soluble fertilizer than in treatment BB-CRF. NO3(-)-N was the primary form of N in the leachate. In relative to water soluble fertilizer, BB-CRF altered the fates of fertilizer nitrogen, i.e., the N uptake by mustard and the N residual in soil increased by 75.4% and 76.0%, and the N leaching loss and other apparent N losses decreased by 27.1% and 66.3%, respectively. The application of BB-CRF could be an effective way to reduce the various losses of fertilizer N while increase the fertilizer N use efficiency, and the controlled release fertilizer is the environmentally friendly fertilizer with the property of high N use efficiency.

  6. Socioeconomic status and fertility before, during, and after the demographic transition: An introduction

    Directory of Open Access Journals (Sweden)

    Martin Dribe

    2014-07-01

    Full Text Available Background: Despite a long interest in the historical fertility transition, there is still a lack of knowledge about disaggregated patterns that could help us understand the mechanisms behind the transition. In previous research the widely held view is that there was a change in the association between social status and fertility in conjunction with the fertility transition, implying that fertility went from being positively connected to social status (higher status was connected with higher fertility to being negatively associated with fertility. Objective: The aim of this collection is to study socioeconomic patterns in the fertility transition in a variety of contexts using similar approaches and measures of socioeconomic status. Methods: All contributions use different kinds of micro-level socioeconomic and demographic data and statistical models in the analysis. Data either come from census-like records or population registers. Conclusions: There is no consistent evidence for the hypothesis that socioeconomic status was positively related to fertility before the demographic transition. While such a correlation was clearly present in some contexts it was clearly not in other contexts. There is more unanimous support for the idea that the upper-and middle classes acted as forerunners in the transition, while especially farmers were late to change their fertility behavior. It is also evident that both parity-specific stopping and prolonged birth intervals (spacing were important in the fertility transition.

  7. Effects of Previous Crop Management, Fertilization Regime and Water Supply on Potato Tuber Proteome and Yield

    Directory of Open Access Journals (Sweden)

    Carlo Leifert

    2013-01-01

    Full Text Available There is increasing concern about the sustainability and environmental impacts of mineral fertilizer use in agriculture. Increased recycling of nutrients via the use of animal and green manures and fertilizers made from domestic organic waste may reduce reliance on mineral fertilizers. However, the relative availability of nutrients (especially nitrogen is lower in organic compared to mineral fertilizers, which can result in significantly lower yields in nutrient demanding crops such as potato. It is therefore important to gain a better understanding of the factors affecting nutrient use efficiency (yield per unit fertilizer input from organic fertilizers. Here we show that (a previous crop management (organic vs. conventional fertilization and crop protection regimes, (b organic fertilizer type and rate (composted cattle manure vs. composted chicken manure pellets and (c watering regimes (optimized and restricted significantly affected leaf chlorophyll content, potato tuber N-concentration, proteome and yield. Protein inference by gel matching indicated several functional groups significantly affected by previous crop management and organic fertilizer type and rate, including stress/defense response, glycolysis and protein destination and storage. These results indicate genomic pathways controlling crop responses (nutrient use efficiency and yield according to contrasting types and rates of organic fertilizers that can be linked to the respective encoding genes.

  8. Effects of selected fertilizers on the life history of Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B.

    Science.gov (United States)

    England, K M; Sadof, C S; Cañnas, L A; Kuniyoshi, C H; Lopez, R G

    2011-04-01

    We tested the effects among a purportedly sustainable water-soluble fertilizer, a conventional water-soluble fertilizer, an alternation of these, a controlled-release fertilizer, and a clear water control on the life-history traits of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae; =Bemisia argentifolii Bellows & Perring) biotype B reared on poinsettia (Euphorbia pulcherrima Willdenow ex Klotzch). Free amino acids in petioles were measured to estimate plant nutrient assimilation and phloem nutritional quality for B. tabaci biotype B. The sustainable fertilizer produced plants with the highest concentration of amino acids. In contrast, fecundity of whiteflies was lowest in plants treated with the sustainable fertilizer and the water control. The relationship between total amino acids in phloem and survival was significantly quadratic, with the highest survival at intermediate levels. Fecundity, however, was negatively correlated with total amino acid content of the maternal host plant. Variation in total amino acid concentration in petioles of plants treated within fertilizer treatments makes it difficult to predict whether a particular fertilizer will produce plants with enough amino acids to deleteriously affect both survivorship and fecundity and yet yield a plant of good quality. Despite this limitation, we can conclude that the use of this sustainable fertilizer will not cause increases in whitefly populations relative to plants fertilized with water-soluble and slow-release fertilizers that deliver the same level of nitrogen to the plant.

  9. [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

  10. Soil Fertility Gradient in the Restinga Ecosystem

    Science.gov (United States)

    América Castelar da Cunha, Joana; Casagrande, José Carlos; Soares, Marcio Roberto; Martins Bonilha, Rodolfo

    2013-04-01

    The restinga ecosystem (coastal plain vegetation) can be termed as a set of plant communities that suffer strong influenced by fluvial and marine factors and is characterized as an ecosystem of great biological diversity, therefore, represents areas of great importance in the context of ecological preservation. The degradation processes from many forms of anthropogenic disturbances that has taken place since the colonization of the country, made studies on the characterization and dynamics of soil fertility of these areas even more important in relation to the maintenance of its biodiversity and conservation. The sites studied were the Cardoso Island and Comprida Island, and in these, we analyzed four physiognomies, restinga, low restinga, dune and antedune (from continent to ocean). Chemical analyses were performed and soil salinity in these areas in depths 0-5; 0-10; 0-20; 20-40; 40-60 cm. In all soils the cationic exchange capacity was intimately associated with the concentration of soil organic matter, which makes this parameter essential to the maintenance of soil fertility of these areas; in more superficial layers (0-20 cm) there was an increase of pH and base saturation and decline of organic matter, aluminum saturation and cationic exchange capacity in the nearby sea, physiognomies what determines the existence of fertility gradient towards the continent-coast; restinga forests showed a chemical standard that is heavily marked by sandy texture, high degree of leaching, nutrient poverty, low base saturation, high saturation by aluminum and acidity, opposite conditions to soils of the dunes and antedunes, with the exception of sandy texture; despite the existence of a chemical gradient of fertility among the physiognomies studied it is possible to determine the soil acts more strongly as a physical support than as provider of fertility; as for salinity, soil collected in Cardoso Island did not present salinity in any depth, a fact which can be explained due

  11. [Social differentials of fertility in Latin America and Mexico].

    Science.gov (United States)

    Tuiran, R

    1991-01-01

    Analysis of fertility differentials has been utilized for 3 different purposed in sociodemographic research: as an exploratory procedure designed to identify the principal determinants of reproductive behavior; as a strategy to describe and interpret the process of fertility decline and identify the sectors leading the change; and as a means of projecting future fertility trends. The systematic study of differential fertility began in Mexico and Latin America in the late 1950s, following the models of European and North American research guided by theories of modernization and the demographic transition. Latin American studies attempted to verify the existence of differences in reproductive behavior according to certain socioeconomic characteristics, assuming that the sectors most fully incorporated in the processes of modernization and development would lead the fertility decline. Studies in Mexico have demonstrated that total fertility rates decrease systematically as the size of the place of residence increases and as the level of education increases, although the association with education is not strictly lineal. Various studies have confirmed that economically active women have lower fertility than inactive women, although cross-sectional analyses have had little success in establishing the direction of causality. Evidence exists that in Mexico as elsewhere the initial stage in the transition is accompanied by an increase in the absolute and/or relative magnitude of fertility differences among women in the extreme categories of residence, education, or employment. The magnitude of the differences declines as the transition progresses. Using the method proposed by Bongaarts or 1 of its variants, different studies have emphasized the importance of contraception and nuptiality as factors in total fertility rate differentials by socioeconomic characteristics. The theoretical and methodological limitations of differential analysis should not be overlooked. A common

  12. Fertility potential after unilateral orchiopexy

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J M; Lindenberg, S

    1996-01-01

    similar fertility potentials were found in adulthood. Five of the 65 patients (7.7%, 95% confidence limits 2.5 to 17%) may experience infertility, representing 33% of both groups with less than 1% of the age matched number of spermatogonia per tubular transverse section (approximately no germ cells......) in the biopsy specimen at orchiopexy. CONCLUSIONS: Between ages 2 and 12 years the timing of unilateral orchiopexy may vary without an effect on subsequent fertility potential. When biopsy at surgery lacks germ cells, there is an approximately 33% age independent risk of subsequent infertility. Otherwise...

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

    Directory of Open Access Journals (Sweden)

    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

  14. 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

  15. Influence of bio-fertilizers on the availability of nutrients (N, P and K in soil in relation to growth and yield of Stevia rebaudiana grown in South India

    Directory of Open Access Journals (Sweden)

    K Das

    2008-03-01

    Full Text Available Summary: A field experiment was conducted at Ripponpet (Dist. Karnataka, India in an acidic soil (pH 6.10 to study the response of Stevia plant by the application of bio-fertilizers. The results showed the amount of available nitrogen (N, phosphorus (P and potassium (K contents in soil have been found to increase significantly up to third month and thereafter, the amount of the same decreased with the progress of the plant growth up to sixth month irrespective of treatments. However, the results further envisaged that the total yield of fresh biomass has been recorded an increase up to sixth month, being highest in the combined application of bio-fertilizers over that of their corresponding sole applications. The percent increase of bio-mass yield was recorded highest (22.14% in the treatment when all the bio-fertilizers were applied together.   Industrial relevance: The demand of Stevia is increasing widely due to its non caloric nature and usages as sugar supplement. The leaves are having commercial importance due to presence of di-terpene sweet glycosides which are 300-400 times sweeter than sugar without any side effects. The plant was domesticated in India in last 20th century from the wide source. So there is a need to set up certain protocols for cultivation of Stevia in various soil conditions so that farmers can be benefited by selling, and industries also can get healthy leaves throughout the year for isolate the active components and can formulate economical market products.

  16. Comprehensive evaluation of soil fertility in karst area by GIS and improved Grey Relation Model:A case study in Fengdu county karst area,Chongqing%基于 GIS 和改进灰色关联模型的岩溶区土壤肥力评价--以重庆市丰都县岩溶区为例

    Institute of Scientific and Technical Information of China (English)

    孙宇; 高明; 王丹; 邓炜; 陈成龙

    2014-01-01

    文章在 GIS 技术支持下,以重庆市丰都县岩溶区为研究对象,根据该县的地形特征、土地利用现状及土壤类型等共采集316个土壤样品,在此基础上,通过主成分分析法、隶属度函数等方法改进的灰色关联模型,对丰都县土壤肥力进行综合评价,并利用地统计学方法揭示其空间变异特征。结果表明:土壤肥力综合指数处于0.352~0.881之间,均值为0.579;其空间变异具有一阶趋势,去除趋势后所剩残差表现出较弱的空间相关性;研究区总体土壤肥力质量中等偏上,其中Ⅱ、Ⅲ、Ⅳ等级的土壤肥力分布面积分别占总区域面积的10.61%、31.09%、35.94%;土壤常规养分和微量元素养分的综合肥力贡献率分别为76.77%和23.23%。这表明将土壤微量元素养分同时纳入土壤肥力评价指标体系是合理可行的,利用改进的灰色关联模型能较好地定量化评价土壤综合肥力,地统计学方法能更好地揭示土壤肥力的空间变异。%Soil fertility evaluation can provide the basis for rational fertilization and agricultural production structure adjustment.Under the technical support of GIS,we take Fengdu county karst area as research ob-ject and collected 31 6 soil sample of this county,according to topographical features,land use status and soil types.In this paper,we report organic matter,total nitrogen,available nitrogen,available phosphorus,a-vailable potassium,available sulfur,available cuprum,available iron,available manganese,available zinc, available boron content and pH for all soil samples.Based on data,we evaluated the soil fertility of the coun-ty by using Grey Relation Model improved by principal component analysis and membership function,and discussed the special distribution characteristics by using statistical methods.The study shows that the soil integrated fertility index (IFI )in the study area ranged from 0.352 to 0.881 with the average value

  17. A GIS-Based Database Management Package for Fertilizer Recommendations in Paddy Fields

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lian-Qing; SHI Zhou; WANG Ren-Chao; J. BAILEY

    2004-01-01

    Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.

  18. Gonadal damage and options for fertility preservation in female and male cancer survivors

    Institute of Scientific and Technical Information of China (English)

    Theodoros Maltaris; Heinz Koelbl; Rudolf Seufert; Franklin Kiesewetter; Matthias W. Beckmann; Andreas Mueller; Ralf Dittrich

    2006-01-01

    It is estimated that in 2010, 1 in every 250 adults will be a childhood cancer survivor. Today, oncological surgery,radiotherapy and chemotherapy achieve relatively high rates of remission and long-term survival, yet are often detrimental to fertility. Quality of life is increasingly important to long-term survivors of cancer, and one of the major quality-of-life issues is the ability to produce and raise normal children. Developments in the near future in the emerging field of fertility preservation in cancer survivors promise to be very exciting. This article reviews the published literature, discusses the effects of cancer treatment on fertility and presents the options available today thanks to advances in assisted-reproduction technology for maintaining fertility in male and female patients undergoing this type of treatment. The various diagnostic methods of assessing the fertility potential and the efficacy of in vitro fertilization (IVF) after cancer treatment are also presented.

  19. Social structure and U.S. inter-state fertility differentials in 1900.

    Science.gov (United States)

    Guest, A M

    1981-11-01

    This paper investigates the importance of agricultural land shortages versus modernization of the society in influencing inter-state differentials in fertility in 1900, when the United States was in mid-transition. Urbanization and manufacturing characteristics of states were the strongest correlates of variations in the index of total fertility because urban-industrialism depressed both the probability of marriage and marital fertility. Other modern characteristics of American states were also important in understanding variations in marital fertility. Low labor force employment of children and farm mechanization, integrally related characteristics, seemed to depress levels of marital fertility in many parts of the United States, independent of the urban-industrial system. Agricultural land opportunity had little overall effect on marital fertility; however, it was quite important in understanding variations in patterns of marriage.

  20. 金乡大蒜氮磷钾营养吸收特点与合理施肥研究%Research on Absorption Characteristics of Nitrogen, Potassium and Phosphorus and Relational Fertilization of Jinxiang Garlic

    Institute of Scientific and Technical Information of China (English)

    崔艳秋; 王乃建; 苏遵鹏; 贺莉

    2015-01-01

    以金乡大蒜为试材,通过氮磷钾配方试验研究覆膜大蒜的养分吸收特点及最佳施肥量与施用方法。结果表明,金乡大蒜生长过程中,吸氮最多,钾次之,磷最少,吸收比例为N∶P2O5∶K2O=1∶0.36∶0.70。氮、钾吸收高峰在鳞茎膨大期,磷吸收高峰在蒜薹伸长期。金乡大蒜施用氮磷钾均有增产效果,最佳施用量为N 436.95 kg/hm2,P2 O5213.34 kg/hm2, K2 O 336.74 kg/hm2。氮、钾肥施用方法均以2/3底施+1/3追施效果最好。%The “3414” design was used to study the nutrient absorption characteristics and the optimum fertilization amount and method for mulched Jinxiang garlic .The results showed that during the growth of Jinx-iang garlic , the absorption of nitrogen was the most , and then potassium and phosphorus .The absorption ratio of nitrogen, phosphorus and potassium was 1∶0.36∶0.70.The absorption peaks of nitrogen and potassium were both in the bulbing period , and the phosphorus absorption peak was in the garlic sprout elongation peri-od .The application of nitrogen , phosphorus and potassium all could increase the garlic yield , and the optimal fertilization amounts were 436.95 kg/hm2 of N, 213.34 kg/hm2 of P2O5, and 336.74 kg/hm2 of K2O.The best fertilization method of both nitrogen and potassium was 2/3 as base fertilizer and 1/3 for topdressing .

  1. Alternate partial root-zone irrigation improves fertilizer-N use efficiency in tomatoes

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Jensen, Lars Stoumann

    2013-01-01

    The objective of this study was to investigate the comparative effects of alternative partial root-zone irrigation (PRI) and deficit irrigation (DI) on fertilizer-N use efficiency in tomato plants under mineral N and organic N fertilizations. The plants were grown in split-root pots in a climate...... significantly higher fertilizer-N use efficiency and soil N availability as well as enhanced plant’s N acquisition ability in the PRI treatment. Analysis across the irrigation treatments showed that the mineral N fertilizer treatment (MinN) significantly increased N yield, ANUE and ANRE relative to the organic...

  2. Fertility potential after unilateral orchiopexy

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J M; Lindenberg, S

    1996-01-01

    ) in the biopsy specimen at orchiopexy. CONCLUSIONS: Between ages 2 and 12 years the timing of unilateral orchiopexy may vary without an effect on subsequent fertility potential. When biopsy at surgery lacks germ cells, there is an approximately 33% age independent risk of subsequent infertility. Otherwise...

  3. Socioeconomic status and fertility decline

    DEFF Research Database (Denmark)

    Dribe, Martin; Breschi, Marco; Gagnon, Alain

    2017-01-01

    The timings of historical fertility transitions in different regions are well understood by demographers, but much less is known regarding their specific features and causes. In the study reported in this paper, we used longitudinal micro-level data for five local populations in Europe and North ...

  4. Fertility potential after unilateral orchiopexy

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J M; Lindenberg, S

    1996-01-01

    PURPOSE: We evaluated whether adult fertility potential was better when unilateral orchiopexy was done at ages 2 to 6 years or later, and we identified those at risk for infertility. MATERIALS AND METHODS: Unilateral orchiopexy was performed simultaneously with testicular biopsy in 11 patients 2....

  5. Strong families and declining fertility

    NARCIS (Netherlands)

    Hilevych, Yuliya

    2016-01-01

    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  6. The Cost of Raising Fertility

    DEFF Research Database (Denmark)

    Kurjanska, Malgorzata; Lyngsie, Jacob

    supporting an increase in Europe’s fertility rate, increasing maternity leave may also exacerbate gender inequalities tied to childrearing. Relying on alternative measures of in-home gender inequalities (e.g. gender conservatism), initial results provide compelling evidence that maternity benefits do affect...

  7. Fertility potential after unilateral orchiopexy

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J M; Lindenberg, S

    1996-01-01

    PURPOSE: We evaluated whether adult fertility potential was better when unilateral orchiopexy was done at ages 2 to 6 years or later, and we identified those at risk for infertility. MATERIALS AND METHODS: Unilateral orchiopexy was performed simultaneously with testicular biopsy in 11 patients 2...

  8. (AJST) PEDOLOGICAL CHARACTERISTICS, GENERAL FERTILITY ...

    African Journals Online (AJOL)

    Administrator

    Department of Soil Science, P.O. Box 3008, Morogoro, TANZANIA. 2Graduate ... 3Center for Cooperative Research and Development, Kobe University, ... Key words: Pedological characteristics, fertility, soil classification, benchmark soils, Morogoro. District .... density was determined using core sample method (Blake,.

  9. Mycorrhizas and tropical soil fertility

    NARCIS (Netherlands)

    Cardoso, I.M.; Kuyper, T.W.

    2006-01-01

    Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping system

  10. Mycorrhizas and tropical soil fertility

    NARCIS (Netherlands)

    Cardoso, I.M.; Kuyper, T.W.

    2006-01-01

    Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping system

  11. Fertilization Mechanisms in Flowering Plants.

    Science.gov (United States)

    Dresselhaus, Thomas; Sprunck, Stefanie; Wessel, Gary M

    2016-02-08

    Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.

  12. Fertilization Mechanisms in Flowering Plants

    Science.gov (United States)

    Dresselhaus, Thomas; Sprunck, Stefanie; Wessel, Gary M.

    2016-01-01

    Compared to the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells they interact and fuse with two dimorphic female gametes (egg and central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca2+ is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes including mammals. PMID:26859271

  13. CURTAILING FERTILIZER SCARCITY AND CLIMATE CHANGE; AN ...

    African Journals Online (AJOL)

    Osondu

    2012-05-29

    May 29, 2012 ... on average thereby using very low rates of chemical fertilizers. Organic materials used by ... The fertilizer issue is more so, considering the current global food ... use profitability through higher commodity prices received by ...

  14. Children Procedures and Treatment (Fertility Issues)

    Medline Plus

    Full Text Available ... Story Share my story! Children Procedures and Treatment Is ovarian tissue cryopreservation available to girls under 18? ... fertility preservation with their cancer-stricken child? How is the Oncofertility Consortium addressing the fertility preservation needs ...

  15. Psychological aspects of male fertility treatment

    DEFF Research Database (Denmark)

    Mikkelsen, Alice Toft; Madsen, Svend Aage; Humaidan, Peter

    2013-01-01

    To explore and to identify the possible need for psychological communicative support in men undergoing fertility treatment.......To explore and to identify the possible need for psychological communicative support in men undergoing fertility treatment....

  16. Fertility preservation after chemotherapy for Hodgkin lymphoma

    NARCIS (Netherlands)

    van der Kaaij, Marleen A. E.; van Echten-Arends, Jannie; Simons, Arnold H. M.; Kluin-Nelemans, Hanneke C.

    2010-01-01

    Treatment for Hodgkin lymphoma can negatively affect fertility. This review summarizes data on fertility after chemotherapy in adult patients. Alkylating chemotherapy, especially if containing procarbazine and/or cyclophosphamide, is most harmful to gonadal functioning. Alkylating regimens cause pro

  17. Response of Maize Plant to Phosphorus Fertilization on Typic Distrudepts

    Directory of Open Access Journals (Sweden)

    Antonius Kasno

    2009-05-01

    Full Text Available On the acid soil, phosphorus nutrients become critical for agricultural crops growth. At the present, price of fertilizers significantly increase and fertilizers are not available. These conditions can affect on soil productivity and crop production. The objective of these research were to study the response of maize (Zea mays L. to phosphate fertilizers on Inceptisol. The research was conducted in Cicadas Village on Typic Dystrudept. Experiment was conducted in a randomized completely block design, with 8 treatments and three replications. Treatments consisted of 6 dosages of P fertilizers, which were P source is SP-36 WIKA Agro 0, 10, 20, 40, 60 and 80 kg ha-1. SP-36 and Tunisia rock phosphate (40 kg P ha-1 were used for standard. Pioneer 12 variety of maized was used as an indicator. Plot size was 5 m x 6 m and the maize was planting with distance of 75 cm x 20 cm with one seed per hole. The results showed that organic C and N, P (extracted by Bray 1, K and CEC on the soil were low. Phosphate fertilizers significantly increased which was P extracted by HCl 25% from 24 to 67 mg P 100 g-1 soil and which were extracted by Bray 1 increased from 0,87 to 63.31 mg P kg-1 soil. Phosphate fertilizers significantly increased plant height from 175.2 cm become to 221.1 cm. Plant height of maize using SP-36 WIKA Agro fertilizer (210.6 cm was similar to plant heigh using SP-36 fertilizer (213.4 cm but less height from Tunisia rock phosphate. The yield of maize on SP-36 WIKA Agro (4.94 t ha-1 were linely higher than SP-36 (4.69 t ha-1, significantly was higher than that of Tunisia rock phosphate. Maximum dosage of SP-36 fertilizer was 66.67 kg P ha-1, and optimum dosage was 42 kg P ha-1. Value of Relative Agronomic Effectiveness SP-36 WIKA Agro fertilizer was heigher than SP-36.

  18. 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.

  19. Period and cohort dynamics in fertility norms at the onset of the demographic transition in Kenya 1978-1998.

    Science.gov (United States)

    White, R G; Hall, C; Wolff, B

    2007-05-01

    A characteristic of African pre-transitional fertility regimes is large ideal family size. This has been used to support claims of cultural entrenchment of high fertility. Yet in Kenya fertility rates have fallen. In this paper this fall is explored in relation to trends in fertility norms and attitudes using four sequential cross-sectional surveys spanning the fertility transition in Kenya (1978, 1984, 1989 and 1998). The most rapid fall in the reported ideal family size occurred between 1984 and 1989, whilst the most rapid fall in the total fertility rate occurred 5 to 10 years later, between 1989 and 1998. Thus these data, spanning the fertility transition in Kenya, support the traditional demographic model that demand for fertility limitation drives fertility decline. These data also suggest that the decline in fertility norms over time was partly a period effect, as the reported ideal family size was seen to fall simultaneously in all age cohorts, and partly a cohort effect, as older age cohorts reporting higher ideal family sizes were replaced by younger cohorts reporting lower ideal family sizes. These data also suggest that a new fertility norm of four children may have developed by 1989 and continued until 1998. This is consistent with, and perhaps could have been used to predict, the stall in the Kenyan fertility decline after 1998.

  20. Fertilization of Northern Hardwoods

    Science.gov (United States)

    R. Lea; D.G. Brockway

    1986-01-01

    Northern hardwoods grow over a considerable range of climatic and edaphic conditions and exhibit a wide range in productivity.Many northern hardwood forests are capable of high production relative to other forest types, but are often slow to reach maximum productivity because of low nutrient availability.Altering the patterns of biomass accumulation so that managers...

  1. Soil phosphorus availability and soybean response to phosphorus starter fertilizer

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2014-10-01

    Full Text Available Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis. No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Children Procedures and Treatment (Fertility Issues)

    Medline Plus

    Full Text Available ... preservation needs of children? How do cancer and cancer treatment affect a child's fertility? Why should fertility preservation be a priority for my child? How does ovarian tissue cryopreservation differ for children ... What can a girl's cancer doctor do to protect her fertility? What can ...

  4. Air pollution and human fertility rates

    NARCIS (Netherlands)

    Nieuwenhuijsen, Mark J.; Basagaña, Xavier; Dadvand, Payam; Martinez, David; Cirach, Marta; Beelen, Rob; Jacquemin, Bénédicte

    2014-01-01

    Background: Some reports have suggested effects of air pollution on semen quality and success rates of in vitro fertilization (IVF) in humans and lower fertility rates in mice. However, no studies have evaluated the impact of air pollution on human fertility rates. Aims: We assessed the association

  5. Fertilization increases paddy soil organic carbon density

    Institute of Scientific and Technical Information of China (English)

    Shao-xian WANG; Xiao-jun LI; Xin-qiang LIANG; Qi-xiang LUO; Fang FAN; Ying-xu CHEN; Zu-zhang LI; Huo-xi SUN; Tian-fang DAI; Jun-nan WAN

    2012-01-01

    Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC)sequestration.We sampled soils from a long-term (25 years) paddy experiment in subtropical China.The experiment included eight treatments:(1) check,(2) PK,(3) NP,(4) NK,(5) NPK,(6) 7F:3M (N,P,K inorganic fertilizers+30% organic N),(7) 5F:5M (N,P,K inorganic fertilizers+50% organic N),(8) 3F:7M (N,P,K inorganic fertilizers+70% organic N).Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment.The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha.The SOC densities of all fertilizer treatments were greater than that of the check.Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers.The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues.Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization.Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.

  6. Air pollution and human fertility rates

    NARCIS (Netherlands)

    Nieuwenhuijsen, Mark J.; Basagaña, Xavier; Dadvand, Payam; Martinez, David; Cirach, Marta; Beelen, Rob|info:eu-repo/dai/nl/30483100X; Jacquemin, Bénédicte

    2014-01-01

    Background: Some reports have suggested effects of air pollution on semen quality and success rates of in vitro fertilization (IVF) in humans and lower fertility rates in mice. However, no studies have evaluated the impact of air pollution on human fertility rates. Aims: We assessed the association

  7. [Fertility of black women: conjectures and questions].

    Science.gov (United States)

    Bercovich, A M

    1987-08-01

    Fertility change in Brazil is analyzed using data from censuses from 1940 to 1980 and the PNAD surveys of 1976 and 1984. Topics covered include regional fertility differentials, differences by ethnic group and color, and the impact of educational status on marital fertility. Consideration is given to methodological problems.

  8. Europe the continent with the lowest fertility

    NARCIS (Netherlands)

    Baird, D. T.; Collins, J.; Evers, J. L. H.; Leridon, H.; Lutz, W.; Velde, E. Te; Thevenon, O.; Crosignani, P. G.; Devroey, P.; Diedrich, K.; Fauser, B. C. J. M.; Fraser, L.; Geraedts, J. P. M.; Gianaroli, L.; Glasier, A.; Sunde, A.; Tarlatzis, B.; Van Steirteghem, A.; Veiga, A.

    2010-01-01

    INTRODUCTION: Although fertility rates are falling in many countries, Europe is the continent with the lowest total fertility rate (TFR). This review assesses trends in fertility rates, explores possible health and social factors and reviews the impact of health and social interventions designed to

  9. Fertilization increases paddy soil organic carbon density.

    Science.gov (United States)

    Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

    2012-04-01

    Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.

  10. Determinants of Fertility Differential in Korea.

    Science.gov (United States)

    Shin, Eui Hang; And Others

    1981-01-01

    Analyzes the causal relationships of the fertility differentials of 2200 married women in a small Korean town. Notes the effect on fertility of socioeconomic status, age at first marriage, family background, and various family planning strategies (contraception, abortion). Discusses a process model on fertility. (Author/SB)

  11. 7 CFR 2902.22 - Fertilizers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Fertilizers. 2902.22 Section 2902.22 Agriculture... Fertilizers. (a) Definition. Products formulated or processed to provide nutrients for plant growth and/or beneficial bacteria to convert nutrients into plant usable forms. Biobased fertilizers, which are likely...

  12. Abortion Legalization and Life-Cycle Fertility

    Science.gov (United States)

    Ananat, Elizabeth Oltmans; Gruber, Jonathan; Levine, Phillip

    2007-01-01

    The early-1970s abortion legalization led to a significant drop in fertility. We investigate whether this decline represented a delay in births or a permanent reduction in fertility. We combine Census and Vital Statistics data to compare the lifetime fertility of women born in early-legalizing states, whose peak childbearing years occurred in the…

  13. Predicting dropout in fertility care: a longitudinal study on patient-centredness

    NARCIS (Netherlands)

    Huppelschoten, A.G.; Dongen, A.J.C.M. van; Philipse, I.C.; Hamilton, C.J.C.M.; Verhaak, C.M.; Nelen, W.L.D.M.; Kremer, J.A.M.

    2013-01-01

    STUDY QUESTION: Are clinic factors, including patients' experiences with patient-centred care, associated with dropout in fertility care? SUMMARY ANSWER: Clinic factors, including patients' experiences with patient-centred care, are not related to dropout. WHAT IS KNOWN ALREADY: In fertility care, a

  14. The long-term effect of the timing of fertility decline on population size

    NARCIS (Netherlands)

    O'Neill, BC; Scherbov, S; Lutz, W

    1999-01-01

    Existing long-range population projections imply that the timing of the fertility transition has a relatively unimportant effect on long-term population size when compared with the impact of the level at which fertility is assumed eventually to stabilize. However, this note shows that the effect of

  15. Structural and diffusion effects in the Dutch fertility transition, 1870-1940

    NARCIS (Netherlands)

    Bras, H.

    2014-01-01

    Background: Ever since the Princeton European Fertility Project, structural and diffusion effects on fertility behavior have been juxtaposed. However, we still hardly know what the relative effects were of shifting socio-economic conditions and shifts in sociability in explaining the historical

  16. The long-term effect of the timing of fertility decline on population size

    NARCIS (Netherlands)

    O'Neill, BC; Scherbov, S; Lutz, W

    1999-01-01

    Existing long-range population projections imply that the timing of the fertility transition has a relatively unimportant effect on long-term population size when compared with the impact of the level at which fertility is assumed eventually to stabilize. However, this note shows that the effect of

  17. Structural and diffusion effects in the Dutch fertility transition, 1870-1940

    NARCIS (Netherlands)

    Bras, H.

    2014-01-01

    Background: Ever since the Princeton European Fertility Project, structural and diffusion effects on fertility behavior have been juxtaposed. However, we still hardly know what the relative effects were of shifting socio-economic conditions and shifts in sociability in explaining the historical fert

  18. [Spatial pattern of soil fertility in Bashan tea garden: a prediction based on environmental auxiliary variables].

    Science.gov (United States)

    Qin, Le-feng; Yang, Chao; Lin, Fen-fang; Yang, Ning; Zheng, Xin-yu; Xu, Hong-wei; Wang, Ke

    2010-12-01

    Taking topographic factors and NDVI as auxiliary variables, and by using regression-kriging method, the spatial variation pattern of soil fertility in Bashan tea garden in the hilly area of Fuyang City was explored. The spatial variability of the soil fertility was mainly attributed to the structural factors such as relative elevation and flat/vertical curvature. The lower the relative elevation, the worse the soil fertility was. The overall soil fertility level was relatively high, and the area with lower soil fertility only accounted for 5% of the total. By using regression-kriging method with relative elevation as auxiliary variable, the prediction accuracy of soil fertility was obviously higher than that by using ordinary kriging method, with the mean error and root mean square error being 0. 028 and 0. 108, respectively. It was suggested that the prediction method used in this paper could fully reflect the effects of environmental variables on soil fertility , improve the prediction accuracy about the spatial pattern of soil fertility, and provide scientific basis for the precise management of tea garden.

  19. The effects of irrigation and fertilization on specific gravity of loblolly pine

    Science.gov (United States)

    K. R. Love-Myers; Alexander Clark; L. R. Schimleck; P. M. Dougherty; R. F. Daniels

    2010-01-01

    The effects of two treatments, irrigation and fertilization, were examined on specific gravity (SG)-related wood properties of loblolly pine trees (Pinus taeda L.) grown in Scotland County, North Carolina. The effects on the core as a whole, on the juvenile core, on the mature core, and from year to year were all analyzed. The results indicate that fertilization...

  20. Urban fertility responses to local government programs: Evidence from the 1923-1932 U.S.

    Directory of Open Access Journals (Sweden)

    Jonathan Fox

    2015-02-01

    Full Text Available Background: During the 1920s and early 1930s, U.S. fertility declined overall but with large regional variations. Changes in foreign born populations explain only part of this. Differences in public health and poverty relief programs may further help explain these declines because of their potential impact on fertility determinants, in particular on breastfeeding and child mortality. Objective: We investigate whether public health investments in child health (conservation of child life programs and poverty relief (outdoor care of poor or charity for children and mothers affected fertility for U.S. cities over 100,000 persons between 1923 and 1932. Methods: We analyze data covering 64 cities between 1923-1932 that include birth information from the U.S. Birth, Stillbirth and Infant Mortality Statistics volumes and city financial information from the Financial Statistics of Cities volumes. Time and city fixed-effects models are used to identify the impact of public investments on fertility. Results: Fixed effects estimates indicating the conservation of child life programs explain about 10 percent of the fertility change between 1923 and 1932. Outdoor care of poor did not seem to be related to fertility. Investments in charity for children and mothers were associated with fertility increases, possibly because poorer areas experienced relative increases in both higher fertility and charitable spending. Conclusions: Public spending on child health was strongly related to decreasing fertility in the U.S. during the 1920s, possibly because of increased breastfeeding and decreased child mortality. This leads to a better understanding of the 1920s fertility decline and highlights how public policy may affect fertility.

  1. Status competition, inequality, and fertility: implications for the demographic transition.

    Science.gov (United States)

    Shenk, Mary K; Kaplan, Hillard S; Hooper, Paul L

    2016-04-19

    The role that social status plays in small-scale societies suggests that status may be important for understanding the evolution of human fertility decisions, and for understanding how such decisions play out in modern contexts. This paper explores whether modelling competition for status--in the sense of relative rank within a society--can help shed light on fertility decline and the demographic transition. We develop a model of how levels of inequality and status competition affect optimal investment by parents in the embodied capital (health, strength, and skills) and social status of offspring, focusing on feedbacks between individual decisions and socio-ecological conditions. We find that conditions similar to those in demographic transition societies yield increased investment in both embodied capital and social status, generating substantial decreases in fertility, particularly under conditions of high inequality and intense status competition. We suggest that a complete explanation for both fertility variation in small-scale societies and modern fertility decline will take into account the effects of status competition and inequality. © 2016 The Author(s).

  2. Fertility Decline in Rural China: A Comparative Analysis

    Science.gov (United States)

    Harrell, Stevan; Yuesheng, Wang; Hua, Han; Santos, Gonçalo D.; Yingying, Zhou

    2014-01-01

    Many models have been proposed to explain both the rapidity of China’s fertility decline after the 1960s and the differential timing of the decline in different places. In particular, scholars argue over whether deliberate policies of fertility control, institutional changes, or general modernization factors contribute most to changes in fertility behavior. Here the authors adopt an ethnographically grounded behavioral–institutional approach to analyze qualitative and quantitative data from three different rural settings: Xiaoshan County in Zhejiang (East China), Ci County in Hebei (North China), and Yingde County in Guangdong (South China). The authors show that no one set of factors explains the differential timing and rapidity of the fertility decline in the three areas; rather they must explain differential timing by a combination of differences in social–cultural environments (e.g., spread of education, reproductive ideologies, and gender relations) and politico-economic conditions (e.g., economic development, birth planning campaigns, and collective systems of labor organization) during the early phases of the fertility decline. PMID:21319442

  3. Male fertility in Greece: Trends and differentials by education level and employment status

    Directory of Open Access Journals (Sweden)

    Alexandra Tragaki

    2014-07-01

    Full Text Available Background: More than downplayed, the role of men in the demographic analysis of reproduction has been entirely neglected. However, male fertility can be an important issue for exploring how economic and employment uncertainties relate to fertility and family dynamics. Objective: This paper intends to study fertility variations over time, relying solely on data referring to father's socio-demographic characteristics; in particular, their age, education level, and employment status. Methods: We use a combination of Labor Force Survey and Demographic Statistics data on population and Vital Statistics on births to estimate male fertility indicators and fertility differentials by education level and employment status, for the period 1992-2011 in Greece. In addition, over-time developments in male TFR are separated into structural (education-specific and employment-specific distributions and behavioral (fertility, per se changes. Results: We find that the male fertility level is declining, the fertility pattern is moving into higher ages, and the reproduction period for men is getting shorter. From 1992 up to 2008, changes in male fertility were mostly driven by behavioral rather than compositional factors. However, the decline of male fertility over the period of economic recession (2008-2011 is largely attributed to the continuous decrease in the proportions of employed men. Conclusions: The study suggests that male fertility merits further exploration. In particular, years of economic downturn and countries where household living standards are mostly associated with male employment, a father's employability is likely to emerge as an increasingly important factor of fertility outcomes.

  4. Cadmium and zinc in soil solution extracts following the application of phosphate fertilizers.

    Science.gov (United States)

    Lambert, Raphaël; Grant, Cynthia; Sauvé, Sébastien

    2007-06-01

    This study investigated the solubility of cadmium and zinc in soils after the application of phosphate fertilizers containing those two metals. The solubility of cadmium and zinc was assessed by measuring their concentration in soil water extracts. Three monoammonium phosphate fertilizers containing various amounts of metals were applied on cultivated fields for 3 years at three different rates. In order to investigate the effects of long-term applications of fertilizers on the solubility of Cd and Zn, a similar design was used to apply contaminated fertilizers to soils in a laboratory experiment using a single fertilizer addition equivalent to 15 years of application. Phosphate fertilizers increased the concentration of Cd in soil extracts compared to control in 87% and 80% of the treatments in field and laboratory experiments respectively. Both increasing the rate of application and using fertilizer containing more Cd lead to higher Cd concentrations in extracts for the field and the laboratory experiments. The addition of the equivalent of 15 years of fertilizer application in the laboratory results in higher Cd concentration in extracts compared to the field experiment. For Zn, the fertilizer treatments enhanced the metal solution concentration in 83% of field treatments, but no significant correlations could be found between Zn inputs and its concentration in solution. In the laboratory, fertilizer additions increase the Zn concentrations in 53% of the treatments and decrease it in most of the other treatments. The decrease in Zn concentrations in the laboratory trial is attributed to the higher phosphate concentrations in the soil solution; which is presumed to have contributed to the precipitation of Zn-phosphates. For both trials, the metal concentrations in soil extracts cannot be related to the Zn concentration in the fertilizer or the rate of application. The high Zn to Cd ratio is presumably responsible for the Cd increase in the soil extracts due to

  5. Diet and fertility in cattle

    Directory of Open Access Journals (Sweden)

    Petrujkić Tihomir

    2003-01-01

    Full Text Available The diet of high-yield dairy cows process a very complex and acute problem. Much new knowledge in the area of production and preparation of feedstuffs, diet technology, and the interactions that occur between the components of the nutritive feed ration are required in order to resolve this problem. It is necessary constantly to coordinate feed norms with genetic potential which is ever changing and advanced. The observed problems must be resolved using multidisciplinary methods so that a diet can yield good health, and that health contribute to better reproduction and possibilities for more successful breeding and improved performance in cattle farming. In certain countries, thanks to their geographic position and climatic conditions which allow rainfall throughout the year, a natural green diet can be applied, which provides large numbers of green mass components, and with additives which can be supplemented relatively easily. This type of diet is not possible in our farms. It is very important to know which feedstuff components are laking for certain categories of cattle. The used ration must be constant and administered to animals of certain age or production characteristics in order to improve production results at cattle farms. A great problem occurs when diet is reduced due to dried grass and the resulting stress in animals. A 50% diet reduction in young cattle often results in the occurrence of respiratory diseases. Following 10-14 days of treatment, the disease disappears in young animals, but the energy deficit leads to the weakening (depression of the immune system. Even a so-called high-energy diet often causes respiratory diseases. A diet deficient in proteins also affects cows after lactation, as opposed to a normative diet, and a reduced protein diet disturbs the microbial activity in the rumen and the synthesis of compounds which are important for both the cow and the calf, making room for the incidence of metabolic diseases, most

  6. [Variations of IR-spectra of three coating materials before and after spraying on urea fertilizer].

    Science.gov (United States)

    Liu, Xing-bin; Chen, Li-jun; Wu, Zhi-jie; Zhang, Guang-na

    2009-09-01

    Coated fertilizer is a hot spot in the domain of fertilizer research. Related researches mainly focused on the action mechanisms of coating materials in controlling the nutrient release from coated fertilizers, but less information is available on the structural variation of the coating materials before and after spraying on fertilizers, which is the key to whether we can directly use coating materials to extrapolate its mechanisms in controlling coated fertilizers' nutrient release. With polylactic acid (PLA), poly (butynelenes succinate) (PBS), and polycarbonate (PC) as test materials, the variations of their IR spectra before and after spraying on urea fertilizer were determined, which was aimed to supply theoretical basis for further studying the action mechanisms of coating materials in controlling coated fertilizers nutrient release. The results showed that PLA and PC had less variation in their IR spectra before and after spraying on urea fertilizer, while PBS acted in reverse, suggesting that the former two coating materials could be directly used for studying the patterns of nutrient release from coated fertilizers.

  7. USE OF VITREOUS FERTILIZERS WITH SLOW RELEASE OF NUTRIENTS IN VITICULTURE

    Directory of Open Access Journals (Sweden)

    M. Ion

    2012-04-01

    Full Text Available An experiment was conducted to study the possibility of using vitreous fertilizers made from waste from the glass industry in vineyards fertilization. Six recipes were tested having as composition the basic elements: P2O5 (43.5%, K2O (32.6%, MgO (18.5% and CaO (5.4%, plus the presence of some micronutrients (B, Fe, Zn, Mo, Mn as oxide form. The efficiency of these fertilizers was made in comparison both with an unfertilized plot and an fertilized plot with NPK applied on the base of optimal rates. The experimental results have shown that this type of fertilizers can replace the use of common chemical fertilizers, their effect on the fertility and productivity of grapevine being relative similar, the benefit consisting of slow release over a long period of time of the nutrients from their composition with positive effects in preventing environmental pollution. The presence of micronutrients in their composition determined even higher yields (by 10-19% as compare to chemical fertilization and a higher content (by 8-45 % of anthocyanins in grapes when vitreous fertilizers had B, Fe, Zn and Mo in their composition.

  8. Prices, Wages and Fertility in Pre-Industrial England

    DEFF Research Database (Denmark)

    Klemp, Marc

    A two-sector Malthusian model is formulated in terms of a cointegrated vector autoregressive (CVAR) model on error correction form. The model allows for both agricultural product wages and relative prices to affect fertility. The model is estimated using new data for the pre-industrial period...... in England, and the analysis reveals a strong, positive effect of agricultural wages as well as a small and, surprisingly, positive effect of real agricultural prices on fertility. Furthermore, it is demonstrated that there is constant returns to scale with respect to labour in the manufacturing sector...... and strongly decreasing returns to scale in the agricultural sector....

  9. Modelling and simulations of controlled release fertilizer

    Science.gov (United States)

    Irfan, Sayed Ameenuddin; Razali, Radzuan; Shaari, Ku Zilati Ku; Mansor, Nurlidia

    2016-11-01

    The recent advancement in controlled release fertilizer has provided an alternative solution to the conventional urea, controlled release fertilizer has a good plant nutrient uptake they are environment friendly. To have an optimum plant intake of nutrients from controlled release fertilizer it is very essential to understand the release characteristics. A mathematical model is developed to predict the release characteristics from polymer coated granule. Numerical simulations are performed by varying the parameters radius of granule, soil water content and soil porosity to study their effect on fertilizer release. Understanding these parameters helps in the better design and improve the efficiency of controlled release fertilizer.

  10. Nutrient and toxic element soil concentrations during repeated mineral and compost fertilization treatments in a Mediterranean agricultural soil.

    Science.gov (United States)

    Baldantoni, Daniela; Morra, Luigi; Saviello, Giovanni; Alfani, Anna

    2016-12-01

    Agricultural soils of semi-arid Mediterranean areas are often subjected to depletion of their chemical, physical, and biological properties. In this context, organic fertilization, in addition to providing nutrients for a longer time in respect to mineral fertilization, improves many other characteristics related to soil fertility. Moreover, the combined use of organic and mineral fertilizers may promote a more sustainable crop production. However, a concern on the long-term use of organic fertilizers arises in relation to the possible accumulation of toxic elements in soil and their transfer to human beings. For this reason, a long-term study on nutrient and toxic element total concentrations and availabilities during fertilization treatments was carried out. In particular, mineral NPK fertilized soils, soils amended with biowaste compost, soils amended with biowaste compost plus mineral nitrogen, and unfertilized soils were analyzed for 11 chemical elements. The results highlighted that temporal variations in total and bioavailable concentrations of both nutrients and toxic elements, occurring also in unfertilized soils, are wider than those related to fertilization treatments. Anyway, soil amendments with biowaste compost, alone or in combination with mineral fertilizers, reduce Cu bioavailability but improve K, Fe, Mn, and Zn availabilities, excluding at the same time a long-term accumulation in soil. Total and bioavailable toxic element concentrations (apart from available Cd) do not vary in relation to fertilization treatments.

  11. Relation between soil P test values and mobilization of dissolved and particulate P from the plough layer of typical Danish soils from a long-term field experiment with applied P fertilizers

    DEFF Research Database (Denmark)

    Glæsner, Nadia Andersen; Kjærgaard, Charlotte; Rubæk, Gitte Holton

    2013-01-01

    Accumulation of phosphorus (P) in agricultural topsoils can contribute to leaching of P which may cause eutrophication of surface waters. An understanding of P mobilization processes in the plough layer is needed to improve agricultural management strategies. We compare leaching of total dissolved...... and particulate P through the plough layer of a typical Danish sandy loam soil subjected to three different P fertilizer regimes in a long-term field experiment established in 1975. The leaching experiment used intact soil columns (20 cm diameter, 20 cm high) during unsaturated conditions. The three soils had...... in particulate P (PP) with increasing labile P content was modest and statistically insignificant. We found concentrations up to 1.5 mg TP/L for the plough layer of this typical Danish sandy loam soil. This highlights that even a moderate labile P content can be a potential source of TDP from the plough layer...

  12. Fertility in the mothers of firstborn homosexual and heterosexual men.

    Science.gov (United States)

    Blanchard, Ray

    2012-06-01

    This study tested the balancing selection hypothesis, that is, genes predisposing men to homosexuality escape elimination from the population because the decreased fertility of men with the heritable form of homosexuality is offset by an increased fertility among biological relatives who carry the same genetic variants. The index subjects (probands) were 40,197 firstborn heterosexual men and 4,784 firstborn homosexual men retrieved from six archival data sets, all of which had previously been used in published research. The measure of familial (specifically, parental) fertility was the proband's number of younger siblings. The results directly contradicted the prediction of the balancing selection hypothesis. In four of the six samples, the homosexual probands had significantly fewer younger siblings; in the other two samples, the means were not significantly different. It is possible that mothers who produce a homosexual son at their first delivery include a biologically distinct subpopulation of mothers of homosexual sons.

  13. The demand for children as a factor in fertility trends.

    Science.gov (United States)

    Lee, A C

    1989-01-01

    Research studies conducted in the Philippines in 1987 indicate that various factors influence family size preferences and decisions. For instance, surveys found that child mortality, child sex preferences, and parental desire for security in old-age were positively correlated with fertility. On the other hand, maternal education, and the desire for financial and occupational status were inversely related to fertility. As the demand for children is a major determinant in fertility trends, it is important to understand the factors involved in the demand for children. Many of these factors can be subject to policy management, namely, improved education, health, nutrition, and greater participation of women in the labor force. Smaller families may become more desirable if favorable political, economic, and social climates are instituted.

  14. [Fertility preservation in children and teenagers with cancer].

    Science.gov (United States)

    Sudour-Bonnange, Hélène; Tabone, Marie-Dominique; Thomas-Teinturier, Cécile; Pacquement, Hélène; Oberlin, Odile; Marec-Berard, Perrine; Laurence, Valérie; Aubier, Françoise; Duranteau, Lise; Bernier-Chastagner, Valérie; Michel, Gérard; Rives, Nathalie; Berger, Claire

    2013-01-01

    Given the excellent survival rate of children and teenagers treated for cancer, careful should be given in order to minimize long-term late effects of treatments and to improve quality of life. In this regard, fertility preservation is particularly important. Age, sex and concomitant therapies have an impact on the level of risk of hypofertility, with a stronger risk for chemotherapeutic regimens including alkylating agents, and gonads or hypothalamo-pituitary axis radiotherapy. Assessment of gonadotoxic impact of treatment strategy and fertility preservation techniques are crucial for limiting late effects. The objective of this literature review is to develop guidance for pediatric oncologists and hematologists relative to fertility preservation methods, in children and teenagers receiving gonadotoxic treatment. Specific follow-up after treatment is also proposed.

  15. Child care subsidies with endogenous education and fertility

    NARCIS (Netherlands)

    Reijnders, Laurie S.M.

    2014-01-01

    What are the effects of child care subsidies on education, fertility and the sectoral allocation of the labour force? In a general equilibrium setting the availability of affordable professional child care will have an impact on the relative supplies of educated and uneducated workers and the cross-

  16. Effects of organic and chemical fertilizer on plant nutritional status and soil fertility of tomatoes grown under greenhouse condition

    OpenAIRE

    DEMİRTAŞ, Elif Işıl; ÖKTÜREN ASRİ, Filiz; Cevdet Fehmi ÖZKAN; Nuri ARI

    2012-01-01

    The effect of some plant originated liquid organic fertilizer on soil fertility and plant nutritional status of tomato plants were investigated. The experiment was planned to compare the control, organic fertilizer, chemical fertilizer, 1/1chemical+organic fertilizer, ½chemical+organic fertilizer, chemical fertilizer+foliar organic fertilizer application. The trial was conducted in randomised complete block design with four replications. Plant and soil samples were analyzed. According to the ...

  17. Qualidade do inhame 'Da Costa' em função das épocas de colheita e da adubação orgânica Da Costa yam quality in relation to harvest time and organic fertilization

    Directory of Open Access Journals (Sweden)

    Ademar P. de Oliveira

    2002-03-01

    Full Text Available Foi desenvolvido um trabalho na EMEPA em João Pessoa, entre setembro/98 e junho/99, com o objetivo de quantificar o teor de matéria seca, de amido e de cinzas em rizomas do inhame, cultivar Da Costa, em função das épocas de colheita e da adubação orgânica, em solo Podzólico Vermelho-Amarelo, textura arenosa. Estudaram-se níveis de esterco bovino (5; 10; 15 e 20 t/ha e de esterco de galinha (2,8; 5,6; 8,4 e 11,2 t/ha, duas épocas de colheita (sete e nove meses após o plantio e uma testemunha, sem resíduo orgânico. Os tratamentos foram arranjados como fatorial 2x4x2+1, no delineamento de blocos casualizados, com quatro repetições. O teor de matéria seca nos rizomas aumentou com a maturidade do cará-da-costa, passando de 33% em rizomas colhidos aos sete meses, para 36% em rizoma colhidos aos nove meses. Os teores de matéria seca nos rizomas colhidos aos sete meses decresceram de 35,80% e 34,71%, respectivamente, na ausência de estercos para 30,03% e 29,25%, respectivamente, com as doses de 20 t/ha de esterco bovino e de 11,2 t/ha de esterco de galinha. Na colheita realizada aos sete meses, o teor de amido foi de 26%, elevando-se para 29% na colheita aos noves meses. O teor de amido, na colheita realizada aos nove meses, aumentou com as doses de esterco de galinha, atingindo o máximo de 31,6% com a dose de 4,8 t/ha. O teor de cinzas nos rizomas não foi influenciado pelas épocas de colheita, mas naqueles colhidos aos nove meses, o teor aumentou com as doses de esterco bovino e de galinha, atingindo o máximo de 0,78 e 0,67%, respectivamente, nas doses de 12,8 e 6,7 t/ha.An experiment was carried out in EMEPA, João Pessoa, Brazil between September 98 and June 99 to quantify the dry matter, starch and ash content of yam rhizomes, cv. Da Costa, in relation to harvest time and organic fertilization. The area consisted of a red-yellow podzolic sandy soil. Four levels of cattle manure (5; 10; 15 and 20 t/ha, four levels of chicken

  18. Sperm macromolecules associated with bull fertility.

    Science.gov (United States)

    Kaya, Abdullah; Memili, Erdoğan

    2016-06-01

    Bull fertility, ability of the sperm to fertilize and activate the egg that sustain embryo development, is vitally important for effective and efficient production of cattle. Fertility is a complex trait with low heritability. Despite recent advances in genomic selection and possibility of enormous paternal benefits to profitable cattle production, there exist no reliable tests for evaluating semen quality and predicting bull fertility. This review focuses on sperm macromolecules such as transcripts, proteins and the epigenome, i.e., the functional genome that are associated with bull fertility. Generating new information in these systems is important beyond agriculture because such progress advances the fundamental science of the mammalian male gamete while at the same time introduces biotechnology into livestock production. Sperm macromolecules and epigenome markers associated with bull fertility can be used alone or in combination with the current SNP microarrays to determine sperm quality and to indicate bull fertility.

  19. Fertility prognosis for infertile couples

    DEFF Research Database (Denmark)

    Bostofte, E; Bagger, P; Michael, A

    1993-01-01

    OBJECTIVE: To develop a fertility prognosis model for infertile couples. DESIGN: Prospective follow-up study. PARTICIPANTS: In the period November 30, 1977 to June 1, 1985, 321 consecutive couples were investigated for infertility at Hvidovre University Hospital. Investigation of the female...... MEASURE: The Cox regression model was used to predict the time required to conceive based on informations provided by fertility investigations. RESULTS: Three of 16 prognostic variables (the period of infertility, the female infertility factor, and the P-test) possess significant prognostic information....... The period of infertility and the P-test are best scored as continuous variables, whereas the female infertility factor are best categorized in four classes, i.e., normal, ovulation or cervical disorder, anatomic disorder, or a combination of disorders. CONCLUSIONS: The three prognostic variables...

  20. Biomediated continuous release phosphate fertilizer

    Science.gov (United States)

    Goldstein, Alan H.; Rogers, Robert D.

    1999-01-01

    A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed.

  1. Combined fertility and embryotoxicity study.

    Science.gov (United States)

    Reynaud, Lucie; Marsden, Edward

    2013-01-01

    Under normal circumstances, fertility and embryotoxicity studies are run separately according to the ICH S5(R2) guideline for the detection of toxicity to reproduction of medicinal products (1). However, the flexible approach of the S5(R2) guideline also allows the reproduction stages covered in the fertility and embryo-fetal development studies (stages A to D) to be combined into a single study design. The administration period covers the pre-mating and gestation phases through to closure of the hard palate. The principal advantages of the combined study include reductions in the number of animals required and cost. Although the rat is the routine species of choice, the mouse may also be used.

  2. Economic Impact of Net Carbon Payments and Bioenergy Production in Fertilized and Non-Fertilized Loblolly Pine Plantations

    Directory of Open Access Journals (Sweden)

    Prativa Shrestha

    2015-08-01

    Full Text Available Sequestering carbon in forest stands and using woody bioenergy are two potential ways to utilize forests in mitigating emissions of greenhouse gases (GHGs. Such forestry related strategies are, however, greatly influenced by carbon and bioenergy markets. This study investigates the impact of both carbon and woody bioenergy markets on land expectation value (LEV and rotation age of loblolly pine (Pinus taeda L. forests in the southeastern United States for two scenarios—one with thinning and no fertilization and the other with thinning and fertilization. Economic analysis was conducted using a modified Hartman model. The amount of carbon dioxide (CO2 emitted during various activities such as management of stands, harvesting, and product decay was included in the model. Sensitivity analysis was conducted with a range of carbon offset, wood for bioenergy, and forest product prices. The results showed that LEV increased in both management scenarios as the price of carbon and wood for bioenergy increased. However, the results indicated that the management scenario without fertilizer was optimal at low carbon prices and the management scenario with fertilizer was optimal at higher carbon prices for medium and low forest product prices. Carbon payments had a greater impact on LEV than prices for wood utilized for bioenergy. Also, increase in the carbon price increased the optimal rotation age, whereas, wood prices for bioenergy had little impact. The management scenario without fertilizer was found to have longer optimal rotation ages.

  3. Human Capital, Fertility and Growth

    OpenAIRE

    Galor, Oded

    2006-01-01

    The demographic transition that swept the world in the past 140 years has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed. The rise in the demand for human capital in the second phase of industrialization brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to c...

  4. The fertility revolution in China.

    Science.gov (United States)

    Vlassoff, C; Shah, I

    1990-10-01

    As a result of a concerted government effort, China has undergone one of the most rapid fertility transitions in history. At present, the 1- child family is the norm in urban areas such as Beijing and Shanghai, while there are an average of 2 children per family in rural areas. There is now concern that this urban-rural discrepancy will lead to serious labor shortages and inadequate family resources to care for the elderly in Chinese cities. Stricter enforcement of the 1-child policy is rural areas, combined with relaxation of fertility disincentives in the cities, may be required. Another concern is the failure of modernization and intensive education to reduce the traditional preference for male children. Over 50% of respondents in fertility surveys express a desire for their first child to be a boy; only 5% prefer a girl. On the other hand, impressive progress has been made in introducing family planning programs in ways that do not assault traditional values. Although the average age at marriage in China--well over 20 years--is similar to that in developed countries, traditional marriage customs, such as co-residence with parents after marriage, remain intact. Similarly, while young people now have greater freedom of choice in the selection of a marriage partner and arranged marriages are now illegal, parents remain an important part of family decision making. Finally, China has not followed the pattern observed in other countries where declining fertility and increased women's status have reduced the extent and duration of breastfeeding. Rather, it appears that the 1 child norm has actually increased the duration of breastfeeding since the last child tends to be nursed for longer periods.

  5. Molecular aspects of mammalian fertilization

    Institute of Scientific and Technical Information of China (English)

    Hector Serrano; Dolores Garcia-Suarez

    2001-01-01

    Mammalian fertilization is a highly regulated process, much of which are not clearly understood. Here we present some information in order to elaborate a working hypothesis for this process, beginning with the sperm modifications in the epidydimis up to sperm and egg plasmalemma interaction and fusion. We also discuss the still poorly understood capacitation process, the phenomenon of sperm chemo-attraction that brings the capacitated sperm to interact with the oocyte vestments and certain aspects of the acrosome reaction.

  6. Root carbon input in organic and inorganic fertilizer-based systems

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2012-01-01

    C input to remain scant. This study aimed at determining macro-root C input and topsoil root related respiration in response to nutrient management and soil fertility building measures. Methods We sampled roots and shoots of cereals and catch crops in inorganic and organic fertilizer-based arable...... season of winter wheat by subtracting soil respiration from soil with and without exclusion of roots. Results Catch crop roots accounted for more than 40 % of total plant C. For spring barley in 2008 and spring wheat in 2010, root C was higher in the organic than in the inorganic fertilizer-based systems...... was higher (31–131 %) in inorganic than in organic fertilizer-based systems. Conclusions Our findings show that macro-roots of both cereal crops and catch crops play a relatively larger role in organically managed systems than in mineral fertilizer based systems; and that the use of fixed biomass S/R ratios...

  7. Effect of biochar plus fertilizer on the rhizospheric functional bacteria related to the nitrogen transformation in soybean%生物黑炭与化肥配施对大豆根际氮素转化相关功能菌的影响

    Institute of Scientific and Technical Information of China (English)

    刘志华; 李晓梅; 姜振峰; 张少良; 王嘉翼; 刘航; 王宏燕

    2014-01-01

    Biochar made by maize straw at 450 ℃ insulated from oxygen was set as materials. Five experimental treatments were as follows:Control with no fertilizer and biochar application, fertilizer treatment (N 100 mg·kg-1, P 100 mg·kg-1, K 150 mg·kg-1 with no biochar application), fertilizer with few biochar (N 100 mg·kg-1, P 100 mg·kg-1, K 150 mg·kg-1 with 1%biochar), fertilizer with moderate biochar (N 100 mg·kg-1, P 100 mg·kg-1, K 150 mg·kg-1 with 5%biochar) and fertilizer with mass biochar (N 100 mg·kg-1, P 100 mg·kg-1, K 150 mg·kg-1 with 10%biochar). The present study was proceeded to analyze the amounts of the functional bacteria, pH and available nitrogen related to nitrogen transformation of rhizosphere in soybean. The results showed that pH of rhizosphere increased significantly, and dosage effect was observed in amount of azotobacteria, ammonification bacteria and nitrobacteria when fertilizer plus biochar was applied. Moreover, 5% biochar application was favorable to increase the amount of bacteria related to nitrogen transformation in soybean rhizosphere. The results above can offer the evidence to reveal the microbial mechanism of biochar effect on the nutritive substance in soybean rhizosphere.%研究以玉米秸秆源450℃无氧条件制备的生物黑炭为试验材料,设5个处理,即对照(CK,0%)、化肥处理(F,0%生物黑炭+常规施肥,N 100 mg·kg-1、P 100 mg·kg-1、K 150 mg·kg-1)、低量生物黑炭与化肥配施(1%BF,1%生物黑炭+常规施肥)、中等生物黑炭与化肥配施(5%BF,5%生物黑炭+常规施肥)和高量生物黑炭与化肥配施(10%BF,10%生物黑炭+常规施肥)(质量分数)等,研究生物黑炭与化肥配施对大豆根际氮素转化过程中相关功能菌数量、pH及速效氮含量的影响。结果表明,生物黑炭与化肥配施显著增加大豆根际pH;生物黑炭与化肥配施对根际固氮菌数量、氨化细菌数量和硝化细菌数

  8. Wheat and Rice Growth Stages and Fertilization Regimes Alter Soil Bacterial Community Structure, But Not Diversity.

    Science.gov (United States)

    Wang, Jichen; Xue, Chao; Song, Yang; Wang, Lei; Huang, Qiwei; Shen, Qirong

    2016-01-01

    Maintaining soil fertility and the microbial communities that determine fertility is critical to sustainable agricultural strategies, and the use of different organic fertilizer (OF) regimes represents an important practice in attempts to preserve soil quality. However, little is known about the dynamic response of bacterial communities to fertilization regimes across crop growth stages. In this study, we examined microbial community structure and diversity across eight representative growth stages of wheat-rice rotation under four different fertilization treatments: no nitrogen fertilizer (NNF), chemical fertilizer (CF), organic-inorganic mixed fertilizer (OIMF), and OF. Quantitative PCR (QPCR) and high-throughput sequencing of bacterial 16S rRNA gene fragments revealed that growth stage as the best predictor of bacterial community abundance and structure. Additionally, bacterial community compositions differed between wheat and rice rotations. Relative to soils under wheat rotation, soils under rice rotation contained higher relative abundances (RA) of anaerobic and mesophilic microbes and lower RA of aerophilic microbes. With respect to fertilization regime, NNF plots had a higher abundance of nitrogen-fixing Cyanobacteria. OIMF had a lower abundance of ammonia-oxidizing Thaumarchaeota compared with CF. Application of chemical fertilizers (CF and OIMF treatments) significantly increased the abundance of some generally oligotrophic bacteria such those belonging to the Acidobacteria, while more copiotrophic of the phylum Proteobacteria increased with OF application. A high correlation coefficient was found when comparing RA of Acidobacteria based upon QPCR vs. sequence analysis, yet poor correlations were found for the α- and β- Proteobacteria, highlighting the caution required when interpreting these molecular data. In total, crop, fertilization scheme and plant developmental stage all influenced soil microbial community structure, but not total levels of alpha

  9. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

    Science.gov (United States)

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

  10. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees.

    Science.gov (United States)

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees.

  11. Structural modeling of age specific fertility curves in Peninsular Malaysia: An approach of Lee Carter method

    Science.gov (United States)

    Hanafiah, Hazlenah; Jemain, Abdul Aziz

    2013-11-01

    In recent years, the study of fertility has been getting a lot of attention among research abroad following fear of deterioration of fertility led by the rapid economy development. Hence, this study examines the feasibility of developing fertility forecasts based on age structure. Lee Carter model (1992) is applied in this study as it is an established and widely used model in analysing demographic aspects. A singular value decomposition approach is incorporated with an ARIMA model to estimate age specific fertility rates in Peninsular Malaysia over the period 1958-2007. Residual plots is used to measure the goodness of fit of the model. Fertility index forecast using random walk drift is then utilised to predict the future age specific fertility. Results indicate that the proposed model provides a relatively good and reasonable data fitting. In addition, there is an apparent and continuous decline in age specific fertility curves in the next 10 years, particularly among mothers' in their early 20's and 40's. The study on the fertility is vital in order to maintain a balance between the population growth and the provision of facilities related resources.

  12. Bayesian inference of baseline fertility and treatment effects via a crop yield-fertility model.

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    Hungyen Chen

    Full Text Available To effectively manage soil fertility, knowledge is needed of how a crop uses nutrients from fertilizer applied to the soil. Soil quality is a combination of biological, chemical and physical properties and is hard to assess directly because of collective and multiple functional effects. In this paper, we focus on the application of these concepts to agriculture. We define the baseline fertility of soil as the level of fertility that a crop can acquire for growth from the soil. With this strict definition, we propose a new crop yield-fertility model that enables quantification of the process of improving baseline fertility and the effects of treatments solely from the time series of crop yields. The model was modified from Michaelis-Menten kinetics and measured the additional effects of the treatments given the baseline fertility. Using more than 30 years of experimental data, we used the Bayesian framework to estimate the improvements in baseline fertility and the effects of fertilizer and farmyard manure (FYM on maize (Zea mays, barley (Hordeum vulgare, and soybean (Glycine max yields. Fertilizer contributed the most to the barley yield and FYM contributed the most to the soybean yield among the three crops. The baseline fertility of the subsurface soil was very low for maize and barley prior to fertilization. In contrast, the baseline fertility in this soil approximated half-saturated fertility for the soybean crop. The long-term soil fertility was increased by adding FYM, but the effect of FYM addition was reduced by the addition of fertilizer. Our results provide evidence that long-term soil fertility under continuous farming was maintained, or increased, by the application of natural nutrients compared with the application of synthetic fertilizer.

  13. Early abortion related factors of fresh embryo transplant in vitro fertilization%体外受精中新鲜移植周期早期流产临床相关性数据分析

    Institute of Scientific and Technical Information of China (English)

    马天仲; 宋丽君; 唐棣; 张维; 黄日艳; 牛艳茹

    2016-01-01

    目的:分析研究体外受精胚胎移植及卵胞浆单精子显微注射(IVF-ET/ICSI)技术助孕后发生早期流产的相关临床因素。方法选取2013年1月~2015年8月进行 IVF-ET/ICSI 治疗后新鲜移植周期并临床妊娠202例,妊娠结局分为早期流产组和继续妊娠组,分析比较组间相关临床资料。结果 IVF-ET/ICSI 助孕治疗新鲜周期移植后流产率为13.86%。早期流产组在女方年龄,不孕年限,降调总量,促性腺激素(Gn)总量、使用天数,Gn 启动日促卵泡成熟激素(FSH)、促黄体生成素(LH)、雌二醇(E2)水平,注射人绒毛膜促性腺激素(HCG)日卵泡数、E2、LH、孕酮(P)水平,获卵数,MII 卵子成熟率,总受精率,移植胚胎数,优胚率,囊胚形成率和着床率,用药方案,是否添加 LH,受精方式与继续妊娠组相比,差异均无统计学意义(P >0.05)。早期流产组胚胎绒毛染色体检测异常率为66.67%。结论 IVF-ET/ICSI 中早期流产主要因素为胚胎染色体异常遗传因素,而与其他临床及治疗因素无关,须扩大样本量来进一步研究。%Objective To analyze impact factors after in vitro fertilization and embryo transfer and intracytoplasmic sperm in-jection treatment of early abortion.Methods Two hundred and two pregnancy cases of fresh transfer after IVF-ET/ICSI treatment were collected,pregnancy outcome were divided into group of early abortion and the group of continued pregnancy,and clinically relevant data were compared between the two groups.Results The abortion rate was 13.86% in fresh transfer after IVF-ET/ICSI treatment.The difference of age of the woman,duration of infertility,total dose of down-regulation,Gn total dose,Gn injection days,levels of FSH/LH/E2 on Gn start date,number of follicles on HCG injection day,levels of E2 /LH/P,oocytes number,MII oocyte maturation rate,total fertility rate,number of

  14. EFFECT OF ELECTRIC FERTILIZER ON SOIL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-qin; WANG Ji-hong

    2004-01-01

    Electric fertilizer, I. E. Exerting electric field on plants during growing season instead of chemical fertilizer, is a kind of physical fertilizer, and the third kind of fertilizer with developmental prospect after inorganic fertilizer and organic fertilizer. For the purpose of studying the changes of physical and chemical properties of soil after exerting electric field, five treatments with different applications of chemical fertilizer were arranged on the black soil in Yushu City of Jilin Province by randomized block method, and electric field was exerted on plants every ten days during the growing season. Through sample analysis the paper arrives at following conclusions: 1) Exerting electric field can make soil's granular structure increase, bulk density decrease, moisture capacity increase,thus improving the perviousness of soil. 2) Exerting electric field can make microorganism's number increase and activity strengthen, thus activating nutrient and increasing organic matter content. 3) Exerting electric field with 0.1A medium has the best effect. So the chemical fertilizer can be saved. Therefore, we can say that the application of electric fertilizer is favorable for decreasing chemical poison, improving soil, relaxing the contradiction between the supply and demand of chemical fertilizer, and decreasing production cost of agriculture and forestry.

  15. Modelling the constraints on consanguineous marriage when fertility declines

    Directory of Open Access Journals (Sweden)

    Bilal Barakat

    2014-01-01

    Full Text Available Background: Consanguinity - or marriage between close blood relatives, in particular first cousins - is widely practised and even socially encouraged in many countries. However, in the face of fertility transition where the number of cousins eligible to marry declines, how might such constraints on consanguinity develop in the future? Objective: Numerous studies have stated that the practice cannot continue at present levels and in ist present form in the face of fertility transition. However, the future impact of fertility transition on availability of cousins to marry has not yet been quantified. Methods: We perform a simulation exercise using past and projected net reproduction rates (NRRs derived from the UN. We calculate the average number of cousins of the opposite sex as a function of the average number of children, the average probability of an individual having at least one eligible paternal cousin of the opposite sex, and conclude with an examination of constraints on consanguineous marriage in selected countries under different fertility assumptions. Results: Current and projected fertility levels in Middle Eastern countries will create challenging constraints on the custom once today's birth cohorts reach marriageable age. Conclusions: Either consanguinity prevalence will diminish significantly, or the institution will be forced to adapt by becoming more coercive in the face of reduced choice or at the expense of other social preferences (such as for an older groom wedding a younger bride. Fertility decline affects prospects for social change not only through its well-known consequences for mothers but also through shaping marriage conditions for the next generation.

  16. Male fertility potential alteration in rheumatic diseases: a systematic review

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    Bruno Camargo Tiseo

    2016-02-01

    Full Text Available ABSTRACT Background Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. Materials and Methods A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. Results A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Conclusions Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy.

  17. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization.

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    Jorgelina Buschiazzo

    Full Text Available Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1 a decrease of the fertilization rate and index; and (2 a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.

  18. [Fertility pattern of contemporary peasant and population control].

    Science.gov (United States)

    Huang, Z

    1991-04-01

    The fertility decline among people in rural areas of China where 80% of the country's population reside is the key issue in the solution of population problems in China. But the current fertility in rural areas is far above the level of government population policy requirement. Field studies and newspaper reports in some rural provinces in 1989 suggested that the prevalent family pattern among farmers is 2 sons and 1 daughter. In order to have at least 1 son, some rural families would keep having children even if they have to pay fines. The fertility aspiration of rural families could be attributed to numerous factors. The Chinese culture believes in sons to carry on family lineage. Children, especially sons, are means of old age support to rural farmers. Rural children start to contribute to family income or family welfare from a young age whereas the cost of raising children is relatively low. And the flow of wealth is generally considered in favor of parents. Because level of child mortality is still high in rural areas, farmers would want to have more children to ensure that enough survive to adulthood. Contraception failure is another cause of excessive fertility. Women who become accidentally pregnant when contraceptive methods are used would find it an excuse to have the child. The implication of contraceptive failure to fertility should not be ignored. It was estimated that with 85-90% contraceptive effectiveness, a women would have 1.2-2.4 accidental pregnancies in her life time. The difference in the acceptance of the current government population policy between urban and rural areas suggests that it is important to produce political, economic, and cultural changes which subsequently induce changes in fertility. Development of an education system and introduction of means of old age support in rural areas would be the necessary steps to achieve this goal.

  19. Male fertility potential alteration in rheumatic diseases: a systematic review

    Science.gov (United States)

    Tiseo, Bruno Camargo; Cocuzza, Marcello; Bonfá, Eloisa; Srougi, Miguel; Clovis, A

    2016-01-01

    ABSTRACT Background Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. Materials and Methods A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. Results A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Conclusions Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy. PMID:27120778

  20. New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China.

    Science.gov (United States)

    Zhang, Wei-Feng; Dou, Zheng-Xia; He, Pan; Ju, Xiao-Tang; Powlson, David; Chadwick, Dave; Norse, David; Lu, Yue-Lai; Zhang, Ying; Wu, Liang; Chen, Xin-Ping; Cassman, Kenneth G; Zhang, Fu-Suo

    2013-05-21

    Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world's population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China's participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China's use of N fertilizer, we quantify the carbon footprint of China's N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20-63%, amounting to 102-357 Tg CO2-eq annually. Such reduction would decrease China's total GHG emissions by 2-6%, which is significant on a global scale.

  1. Denitrification potential under different fertilization regimes is closely coupled with changes in the denitrifying community in a black soil.

    Science.gov (United States)

    Yin, Chang; Fan, Fenliang; Song, Alin; Cui, Peiyuan; Li, Tingqiang; Liang, Yongchao

    2015-07-01

    Preferable inorganic fertilization over the last decades has led to fertility degradation of black soil in Northeast China. However, how fertilization regimes impact denitrification and its related bacterial community in this soil type is still unclear. Here, taking advantage of a suit of molecular ecological tools in combination of assaying the potential denitrification (DP), we explored the variation of activity, community structure, and abundance of nirS and nirK denitrifiers under four different fertilization regimes, namely no fertilization control (N0M0), organic pig manure (N0M1), inorganic fertilization (N1M0), and combination of inorganic fertilizer and pig manure (N1M1). The results indicated that organic fertilization increased DP, but inorganic fertilization had no impacts. The increase of DP was mirrored by the shift of nirS denitrifiers' community structure but not by that of nirK denitrifiers'. Furthermore, the change of DP coincided with the variation of abundances of both denitrifiers. Shifts of community structure and abundance of nirS and nirK denitrifiers were correlated with the change of soil pH, total nitrogen (TN), organic matter (OM), C:P, total phosphorus (TP), and available phosphorus (Olsen P). Our results suggest that the change of DP under these four fertilization regimes was closely related to the shift of denitrifying bacteria communities resulting from the variation of properties in the black soil tested.

  2. Mating Success, Longevity, and Fertility of Diabrotica virgifera virgifera LeConte (Chrysomelidae: Coleoptera in Relation to Body Size and Cry3Bb1-Resistant and Cry3Bb1-Susceptible Genotypes

    Directory of Open Access Journals (Sweden)

    Bryan Wade French

    2015-11-01

    Full Text Available Insect resistance to population control methodologies is a widespread problem. The development of effective resistance management programs is often dependent on detailed knowledge regarding the biology of individual species and changes in that biology associated with resistance evolution. This study examined the reproductive behavior and biology of western corn rootworm beetles of known body size from lines resistant and susceptible to the Cry3Bb1 protein toxin expressed in transgenic Bacillus thuringiensis maize. In crosses between, and within, the resistant and susceptible genotypes, no differences occurred in mating frequency, copulation duration, courtship duration, or fertility; however, females mated with resistant males showed reduced longevity. Body size did not vary with genotype. Larger males and females were not more likely to mate than smaller males and females, but larger females laid more eggs. Moderately strong, positive correlation occurred between the body sizes of successfully mated males and females; however, weak correlation also existed for pairs that did not mate. Our study provided only limited evidence for fitness costs associated with the Cry3Bb1-resistant genotype that might reduce the persistence in populations of the resistant genotype but provided additional evidence for size-based, assortative mating, which could favor the persistence of resistant genotypes affecting body size.

  3. Nitrous oxide emission and denitrifier communities in drip-irrigated calcareous soil as affected by chemical and organic fertilizers.

    Science.gov (United States)

    Tao, Rui; Wakelin, Steven A; Liang, Yongchao; Hu, Baowei; Chu, Guixin

    2017-08-31

    The effects of consecutive application of chemical fertilizer with or without organic fertilizer on soil N2O emissions and denitrifying community structure in a drip-irrigated field were determined. The four fertilizer treatments were (i) unfertilized, (ii) chemical fertilizer, (iii) 60% chemical fertilizer plus cattle manure, and (iv) 60% chemical fertilizer plus biofertilizer. The treatments with organic amendments (i.e. cattle manure and biofertilizer) reduced cumulative N2O emissions by 4.9-9.9%, reduced the N2O emission factor by 1.3-42%, and increased denitrifying enzyme activities by 14.3-56.2%. The nirK gene copy numbers were greatest in soil which received only chemical fertilizer. In contrast, nirS- and nosZ-copy numbers were greatest in soil amended with chemical fertilizer plus biofertilizer. Chemical fertilizer application with or without organic fertilizer significantly changed the community structure of nirK-type denitrifiers relative to the unfertilized soil. In comparison, the nirS- and nosZ-type denitrifier genotypes varied in treatments receiving organic fertilizer but not chemical fertilizer alone. The changes in the denitrifier communities were closely associated with soil organic carbon (SOC), NO3(-), NH4(+), water holding capacity, and soil pH. Modeling indicated that N2O emissions in this soil were primarily associated with the abundance of nirS type denitrifying bacteria, SOC, and NO3(-). Overall, our findings indicate that (i) the organic fertilizers increased denitrifying enzyme activity, increased denitrifying-bacteria gene copy numbers, but reduced N2O emissions, and (ii) nirS- and nosZ-type denitrifiers were more sensitive than nirK-type denitrifiers to the organic fertilizers. Copyright © 2017. Published by Elsevier B.V.

  4. 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.

  5. Period Fertility in Russia since 1930

    Directory of Open Access Journals (Sweden)

    2002-06-01

    Full Text Available In this paper we present a detailed demographic analysis of the change of period fertility that occurred since 1930, based on individual retrospective data, collected in the most recent (five percent microcensus of the Russian Federation from 1994. We assess the influence of external events on the level and distribution of (period fertility. For the years prior to 1950 our information on age specific fertility is not complete, but using fertility models acceptable estimates can be constructed. The Coale-Trussell model is particularly suited for producing detailed and robust estimates of interpretable parameters of the fertility distribution. Although none of the observed crises in Russia succeeded in exerting a decisive influence on the course of the fertility transition, political events often had profound short-term effects.

  6. Proximate determinants of fertility in Taiwan area.

    Science.gov (United States)

    Lo, S R; Chen, C H

    1987-06-01

    To establish base line data and to evaluate the impacts of induced abortion on fertility in Taiwan before and after legalization, and induced abortion prevalence survey was conducted. 12,516 samples of married women age 15-49 were covered to represent all of Taiwan. Bongaarts' model of proximate determinants of fertility is applied to the survey data to analyze the relationships among total fertility rate, total fecundity, and the indices of the proximate determinants on nonmarriage, contraception, induced abortion, and lacatation. The index of contraception appears to have the greatest (47%) effect on the recent decline of total fertility rate (TFR). Contraception also has the greatest effect on fertility decline among different urbanization areas: 45% for large cities; 46% for urbantownships; and 50% for rural areas. The effects of the proportion of married on the fertility of the 3 areas are 45%, 40%, and 40%, respectively. For induced abortion, the effect is 13% in urban townships and 11% in large cities.

  7. Fertility assurance through extrapair fertilization, and male parental effort.

    Science.gov (United States)

    Fishman, Michael A; Stone, Lewi

    2002-07-01

    Extrapair paternity (EPP) has been observed in many formally monogamous species. Male pursuit of extrapair fertilizations (EPF) is explained by the advantages of having offspring that receive essential paternal care from other males. Because females are capable of exercising a degree of control over the post-copulatory sperm competition, EPP's persistence indicates that females benefit from EPF. Thus, EPP involves cooperation between mated females and extrapair males. On the other hand, mated males exhibit a spectrum of anti-cuckolding strategies. Hence, extrapair attributes of diverse species and populations reported in the literature are particular solutions of evolutionary games involving gender-specific cuckolding/anti-cuckolding strategies. Here we use game theoretical methods to study the effect of male paternal effort conserving strategies in situations where females seek EPF for reasons of genetic compatibility and/or in pursuit of genetic diversity for their offspring. Our results indicate that in these circumstances pursuit of EPF is the only evolutionary stable female strategy. Males, on the other hand, have two, mutually exclusive, evolutionary stable strategies: males that restrict parental care regardless of their mate's fidelity, and males that never restrict parental care. That is, when females seek EPF for reasons of fertility assurance and/or genetic diversity, the conditional male strategy--therein the male's parental efforts are based on his certainty of paternity--loses in competition with the unconditional strategies.

  8. [Regional difference of NPK fertilizers application and environmental risk assessment in Jiangsu Province, China].

    Science.gov (United States)

    Liu, Qin-pu

    2015-05-01

    It is of great importance to have a deep understanding of the spatial distribution of NPK fertilizers application and the potential threat to the ecological environment in Jiangsu Province, which is helpful for regulating the rational fertilization, strengthening the fertilizer use risk management and guidance, and preventing agricultural non-point pollution. Based on the environmental risk assessment model with consideration of different impacts of N, P, K fertilizers on environment, this paper researched the regional differentiation characteristic and environmental risk of intensity of NPK fertilizer usages in Jiangsu. Analystic hierarchy process ( AHP) was used to determine the weithts of N, P, K. The environmental safety thresholds of N, P, K were made according to the standard of 250 kg · hm(-2) for the construction of ecological counties sponsered by Chinese government and the proportion of 1:0.5:0.5 for N:P:K surposed by some developed countries. The results showed that the intensity of NPK fertilizer application currently presented a gradually increasing trend from south to north of Jiangsu, with the extremum ratio of 3.3, and the extremum ratios of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer were 3.3, 4.5 and 4.4, respectively. The average proportion of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of 13 cities in Jiangsu was 1:0.39:0.26. Their proportion was relatively in equilibrium in southern Jiangsu, but the nutrient structure disorder was serious in northern Jiangsu. In Jiangsu, the environmental risk index of fertilization averaged at 0.69 and in the middle-range of environmental risk. The environmental risk index of fertilizer application in southern and central Jiangsu was respectively at the low and moderate levels, while that of cities in northern Jiangsu was at the moderate, serious or severe level. In Jiangsu, the regional difference of fertilizer application and environmental risk assessment were

  9. SOLUTION OF DIFFERENTIAL EQUATIONS OF INTERACTION BETWEEN CONICAL-HELICAL AGITATOR WITH MINERAL FERTILIZER

    Directory of Open Access Journals (Sweden)

    S. Nukeshev

    2012-01-01

    Full Text Available It has been established that existing mineral fertilizer spreaders do not fully meet technical requirements. In order to ensure continuous and reliable fertilizer dosing it is necessary to destruct bridges above exhaust ports and facilitate forced fertilizer feed to the spreader.The results of theoretical investigations on conical-helical agitator-bridge breaking cone of mineral fertilizers have made it possible to establish interdependence of the motion path of an elementary volume of mineral fertilizers along helical spiral coil of the agitator and its relative speed on functional and technological parameters such as cone-generating angle to its axis,  an angle of lead, a radius of helical surface, coefficients of external and internal friction and an angular velocity. Modifying the above-mentioned parameters it is possible to select the optimum combinations depending on the accepted criteria for  efficient turning. 

  10. Fertility and family policy in Norway - A reflection on trends and possible connections

    Directory of Open Access Journals (Sweden)

    2004-06-01

    Full Text Available Below replacement fertility in many countries has lead to a renewed public interest in policies that may encourage young people to have more children. The Nordic countries are sometimes in focus in this respect, as their fertility rates remain relatively high in spite of very high female labour force participation. The key question is therefore whether there is a connection between generous public policies that facilitate childbearing and employment, and fertility. Using Norway as example and reviewing existing research evidence I conclude that generous family policies may be necessary, but not sufficient, to sustain fertility at a reasonable level. In particular, adverse macroeconomic conditions and rising unemployment have counteracting effects, as demonstrated by falling fertility rates in Sweden in the mid-1990s.

  11. Soil sorption and leaching of active ingredients of Lumax® under mineral or organic fertilization.

    Science.gov (United States)

    Pinna, Maria Vittoria; Roggero, Pier Paolo; Seddaiu, Giovanna; Pusino, Alba

    2014-09-01

    The study describes the soil sorption of the herbicide Lumax®, composed of S-metolachlor (MTC), terbuthylazine (TBZ), and mesotrione (MST), as influenced by mineral and organic fertilizers. The investigation was performed on a sandy soil of an agricultural area designated as a Nitrate Vulnerable Zone, where mineral and organic fertilizers were applied for many years. Two organic fertilizers, cattle manure and slurry, respectively, and a mineral fertilizer with a nitrification inhibitor, Entec®, were compared. According to the experiments, performed with a batch method, the sorption conformed to Freundlich model. The extent of sorption of Lumax® ingredients was closely related to their octanol-water partition coefficient Kow. The respective desorption was hysteretic. Leaching trials were carried out by using water or solutions of DOM or Entec® as the eluants. Only the elution with the mineral fertilizer promoted the leaching of Lumax® active ingredients.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; YU Xiao-ping; Kong-luen HEONG; HU Cui

    2007-01-01

    Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers (Nilaparvata lugens and Sogatella furcifera), leaffolder (Cnaphalocrocis medinalis), and stem borers (Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesamia inferens) were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

  14. Endogenous fertility, mortality and growth.

    Science.gov (United States)

    Blackburn, K; Cipriani, G P

    1998-01-01

    This paper presents a model that illustrates the joint determination of population and development. "Economic and demographic outcomes are determined jointly in a choice-theoretic model of fertility, mortality and capital accumulation.... In addition to choosing savings and births, parents may reduce (infant) deaths by incurring expenditures on health-care which is also provided by the government. A generalised production technology accounts for long-run endogenous growth with short-run transitional dynamics. The analysis yields testable time series and cross-section implications which accord with the empirical evidence on the relationship between demography and development."

  15. [Effects of fertilization on the P accumulation and leaching in vegetable greenhouse soil].

    Science.gov (United States)

    Zhao, Ya-jie; Zhao, Mu-qiu; Lu, Cai-yan; Shi, Yi; Chen, Xin

    2015-02-01

    A packed soil column experiment was conducted to investigate the effect of different fertilization practices on phosphorus (P) accumulation and leaching potential in a vegetable greenhouse soil with different fertility levels. The results showed that the leaching loss of total P in the leachates elevated with the increment of leaching time while the accumulative leaching loss of total P was relatively low, indicating P was mainly accumulated in the soil instead of in the leachate. At the end of the leaching experiment, soil fertility and fertilization treatment affected the content of total phosphorus and Olsen-P significantly. Compared with the low-level-fertility soil, the contents of total P and Olsen-P increased by 14.3% and 12.2% in the medium-level-fertility soil, 33.3% and 37.7% in the high-level-fertility soil. Total P in the combined application of poultry manure and chemical fertilizer (M+NPK) was elevated by 5.7% and 4.3%, compared with the NPK and M treatment. Compared with NPK treatment, Olsen-P in M and M + NPK treatments augmented by 13.0% and 3.1%, respectively. Soil total P and Olsen-P mainly accumulated in the 0-10 cm and 10-20 cm soil layers, and much less in the 20-40 cm soil layer.

  16. Europe's fertility transition: new evidence and lessons for today's developing world.

    Science.gov (United States)

    Van De Walle, E; Knodel, J

    1980-02-01

    Statistics of population dynamics in pre-fertility transition Europe, especially Western Europe, are diagrammed, tabulated, and graphed. A description of new sources of information, refined concepts on Europe's fertility transition, and ways of measuring the actual practice of family limitation are explained. New findings in the field indicate that the past was largely characterized by natural fertility. Factors such as the period of lactation and seasonal migration influenced total fertility differences. The transition from high to low fertility and mortality represented a shift from natural fertility to family limitation. Differences in the start and speed of the fertility decline are determined more by cultural than by socioeconomic conditions. This process began in Western Europe, under varying socioeconomic conditions, during the 1880-1910 period and was irreversible once it started. It is generally agreed that many areas of the developing world are currently undergoing a fertility transition. Both birth and death rates in these countries are higher than levels ever were in pre-transition Europe. However, the new findings relating to the transition in Europe lead experts to believe that this curent transition will follow the same courese. A certain level of socioeconomic development is not a precondition. Family planning programs, even in underdeveloped areas, can be effective.

  17. The Effect of Gender Policies on Fertility: The Moderating Role of Education and Normative Context.

    Science.gov (United States)

    Baizan, Pau; Arpino, Bruno; Delclòs, Carlos Eric

    In this paper, we aim to assess the extent to which individual-level completed fertility varies across contexts characterized by policies supporting different gender division of labor models. We examine key labor market and care policies that shape gender relations in households and in the public domain. We also consider the role of gender norms, which can act as both a moderator and a confounding factor for policy effects. We hypothesize that, by facilitating role compatibility and reducing the gendered costs of childrearing, policies that support gender equality lead to an increase in fertility levels and to a reduction in fertility differentials by the level of education. Using individual-level data from the European Union Survey on Income and Living Conditions for 16 countries, combined with country-level data, we analyze completed fertility through multilevel Poisson's models. We find that the national level of childcare coverage is positively associated with fertility. Family allowances, prevalence of women's part-time employment and length of paid leaves were also found to be positively associated with completed fertility, though the associations were not statistically significant. These variables show a significant positive pattern according to education. A high number of average working hours for men are negatively associated with completed fertility and show a strong negative pattern by educational level. The prevalence of gender-egalitarian norms is highly predictive of fertility levels, yet we found no consistent evidence of a weaker association of gender-equality policies in countries where egalitarian values are less prevalent.

  18. [Effects of different potassium fertilizer application periods on the yield and quality of Fuji apple].

    Science.gov (United States)

    Lu, Yong-li; Yang, Xian-long; Li, Ru; Li, Shui-li; Tong, Yan-an

    2015-04-01

    In order to ascertain the effects of potassium fertilizer application periods on apple production, we conducted a field experiment and analyzed the differences in apple yield, fruit quality, potassium fertilizer use efficiency, and nutrient concentrations in leaves and fruits among treatments with differences in timing of potassium application. The results indicated that, compared with no potassium-applied treatment (CK), all potassium fertilizer application treatments significantly increased the apple yield by 4.3%-33.2%, meanwhile, it also obviously improved the fruit quality. In comparison with the application of 100% potassium fertilizer as a base, the application of 50% or 100% of potassium fertilizer at the fruit enlargement stage (the remaining 50% applied as a base or after flowering) significantly increased the apple yield by 20.5% - 27.7% and improved the fruit quality. Compared with the application 100% potassium fertilizer at the stage of fruit enlargement, the evenly split application as base flowering stage and at the fruit enlargement: stage not only contributed to a higher yield, better quality and higher potassium use efficiency, but also maintained a relatively stable potassium concentration level in leaves. However, the split potassium fertilizer application at the flowering and fruit enlargement stages resulted in the significant decrease in concentration of calcium in fruit, which would be negative to fruit quality. In conclusion, our research suggested that evenly split application of potassium fertilizer as a base and at the fruit enlargement stage was the suitable period for apple production in Fuji apple orchards in this region.

  19. Accumulation of macronutrients by weed and corn in coexistence in soil with different fertility managements

    Directory of Open Access Journals (Sweden)

    Christiane Augusta Diniz Melo

    2015-04-01

    Full Text Available The understanding of weed interference on crops is very important in agricultural systems. However, there is little known about the influence of soil fertility management in competitive relations between plants. The objective of this study was to evaluate the effects of mutual interference between weeds and corn on the content of macronutrients under different soil fertility managements. The experimental test was conducted in a greenhouse, considering four soil fertility managements (with calcium and magnesium silicate and fertilization; with limestone and fertilization; without correction of acidity, but with fertilization; without correction of acidity and without fertilization and eleven crops (five arrangements of competition between Zea mays and the weeds Urochloa brizantha, Ipomoea grandifolia, Conyza canadensis, Hyptis suaveolens and Bidens pilosa, plus the six species in monoculture. Corn had reductions exceeding 50% in the content of all macronutrients under interference of U. brizantha. Additionally, U. brizantha and B. pilosa in competition with corn has high ability to extract macronutrients in the four soil conditions. Calcium and magnesium silicate and limestone influenced variable on nutrient accumulation by weeds in monoculture or under interference. Corn grown in soil amended with silicate suffered greater competition with weeds compared to grown in soil amended with lime. U. brizantha was the specie most damaging to the crop. B. pilosa showed high potential for nutrient cycling in the four soil fertility management.

  20. Carbon Turnover in Alaskan Tundra Soils: Effects of Organic Matter Quality, Temperature, Moisture and Fertilizer

    National Research Council Canada - National Science Library

    Gaius R. Shaver; A. E. Giblin; K. J. Nadelhoffer; K. K. Thieler; M. R. Downs; J. A. Laundre; E. B. Rastetter

    2006-01-01

    .... This study describes how soil C loss is related to temperature, moisture and chemical composition of organic matter in Alaskan tundra soils, including soils that were fertilized annually for 8 years prior to the study...

  1. Toward replacement fertility in Egypt and Tunisia.

    Science.gov (United States)

    Eltigani, Eltigani E

    2009-09-01

    Egypt and Tunisia began their fertility transition at almost identical fertility levels and at roughly the same time period, yet the difference in the pace of decline has been such that the total fertility rate (TFR) in Tunisia reached replacement level by the year 2001, whereas the TFR in Egypt remains above three live births per woman. This article draws on the secondary literature and on several nationally representative surveys from the two countries between 1978 and 2005 to provide empirical evidence of the difference in the pace of fertility decline and to analyze the determinants of the differential. Findings include (a) variation across the two countries in the consistency of fertility decline among the segments of the population leading the transition; (b) that the success of each country's family planning program was influenced by the role of political leaders and the extent of the program's integration within socioeconomic development objectives; (c) that the impact of contraception on TFR decline became an important factor in the mid-1980s; and (d) that the greatest determinant of the discrepancy in the pace of fertility decline is the disparity in age at marriage, which rose more significantly in Tunisia than in Egypt. The latter finding indicates that reaching replacement fertility in Egypt hinges primarily on further declines in marital fertility, resulting from reduction of wanted fertility and from an expansion of family planning program coverage and improved efficiency of service delivery and use.

  2. Fertility behaviour of recent immigrants to Israel

    Directory of Open Access Journals (Sweden)

    2004-03-01

    Full Text Available The fertility practices of immigrants are a particularly interesting field of study for demographers, providing an insight into the fertility behaviour of individuals when both the society and the individual undergo a period of rapid change. This paper describes and compares the fertility behaviour of two large groups of immigrants, from the former Soviet Union (FSU and from Ethiopia to Israel in the last 20 years. The changes in fertility behaviour undergone in the same society and at the same time by two very different groups are examined. The findings reveal that the fertility behaviour of immigrants is indeed changing. The fertility of FSU immigrants is increasing and that of the Ethiopian immigrants decreasing, with accompanying changes in the proximate determinants of fertility. Although the fertility of immigrants is becoming more similar to that of the receiving society, the methods employed to achieve the fertility change are not necessarily similar, and, in some cases, diverge from the norms of the receiving society.

  3. Fertility Awareness Counseling for Adolescent Girls; Guiding Conception: The Right Time, Right Weight, and Right Way.

    Science.gov (United States)

    Kudesia, Rashmi; Talib, Hina J; Pollack, Staci E

    2017-02-01

    To provide a detailed summary of fertility awareness counseling pearls for healthy teens and those with fertility-relevant comorbidities, and to assist providers in offering such counseling to adolescents and young adult women. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Comprehensive literature review of English-language studies relating to fertility in pediatric and adolescent female patients (ages 13-21 years), and evidence-based dialogue guide. The literature indicates that although adolescents are interested in discussing sexuality and reproduction, this is commonly overlooked during the standard office medical visit. As a result, adolescents often turn to less reliable sources and hold a variety of reproductive misconceptions and a sense of lack of control over future fertility. We found no studies that examined the routine provision of fertility awareness counseling with healthy adolescents. There are a multitude of specific gynecologic and medical conditions that have ramifications for fertility. We detail these comprehensively, and provide a dialogue guide to assist with fertility awareness counseling for the female adolescent, containing specific information and indications for referral. Providers caring for adolescent girls have the opportunity to enhance fertility awareness as part of a larger reproductive health conversation that adolescents desire, and from which they might benefit. Identifying potential future fertility issues, understanding age-related fertility decline, and aiding in health optimization before future conception might empower the adolescent to make informed reproductive decisions. We provide an algorithm to use with adolescents to discuss the "right time, right weight, right way" to pursue childbearing. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  4. Postponement and Recuperation in Cohort Fertility:Austria, Germany and Switzerland in a European Context

    Directory of Open Access Journals (Sweden)

    Tomáš Sobotka

    2012-09-01

    Full Text Available Across developed countries, cohorts of women born after World War II have seen a shift of childbearing towards later ages and a concomitant decline in fertility level. We study this shift using the notions of fertility postponement (fertility decline at younger ages and subsequent recuperation (a compensatory fertility increase at higher reproductive ages. We apply order-specific data and extend and elaborate on two broad approaches to this process: 1 a basic benchmark model extensively used by Tomas Frejka and his colleagues and 2 a relational model proposed by Ron Lesthaeghe (2001. Our work focuses especially on three predominantly German-speaking countries, Austria, Germany and Switzerland, and compares them with selected European countries and the United States. We illustrate the usefulness of these two approaches for constructing projection scenarios of completed cohort fertility among women of reproductive age. Using three key indicators of the postponement transition – initial fertility level, absolute fertility decline at younger ages, and the relative degree of fertility “recuperation” at older ages – we demonstrate that each of these components is salient for explaining contemporary cross-country differences in cohort fertility. Recuperation is especially important, but is also clearly patterned by birth order: whereas all the countries analysed have experienced a vigorous recovery of delayed first births, pronounced differentials are observed with regard to the recuperation of second and particularly of third and later births. In line with the differentials observed, projected values of completed fertility in five European countries vary widely for the cohorts born in the early 1980s, ranging from 1.3 in the lowest scenario for Spain to over 1.8 in the highest scenario for the Czech Republic.

  5. 氮利用率和氮转化率评价氮肥肥效比较研究%Comparative research of evaluation nitrogen fertilizer efficiency be- tween nitrogen use efficiency and fertilizer yield method

    Institute of Scientific and Technical Information of China (English)

    侯彦林; 周燕; 周炜

    2013-01-01

    external N; using N fertilizer yield and external N was the method of scientific evaluation N fertilizer efficiency; ③ using N fertilizer relative conversion to evaluate fertilizer efficiency and guide fertilization not considering external N when concrete practicing fertilization;guidance fertilization semi-quantitatively can be realized by referencing optimum nitrogen application rate of long-term experiment even without determining soil N using N fertilizer yield.

  6. Like daughter, like son? Fertility decline and the transformation of gender systems in the family

    Directory of Open Access Journals (Sweden)

    Keera Allendorf

    2012-10-01

    Full Text Available BACKGROUND An important question for population research is whether fertility decline transforms gender systems. OBJECTIVE This paper contributes to answering this broad question by examining how fertility decline may change the relative value and roles of daughters versus sons in families. First, I outline theoretical pathways, suggesting that a key factor is the gender composition of families. As fertility declines, the proportion of families with children of only one gender increases, which may facilitate greater gender symmetry between daughters and sons. Second, I explore how fertility decline may be transforming the relative value and roles of sons and daughters in practice in one place. METHODS The analysis draws primarily on semi-structured interviews with 30 respondents living in one Indian village. RESULTS In recent decades, fertility has declined to at least replacement levels. Respondents also perceive changes in the gender system, including less son preference, more equal schooling for sons and daughters, more freedom in marriage and pre-marital relationships, and perhaps greater daughter support of parents in old age. CONCLUSIONS The results describe changes in the relative value, treatment, and behavior of sons and daughters that are consistent with the theorized effects of fertility decline. Future research is needed, however, to determine whether fertility decline makes a unique causal contribution to changes in the gender system.

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

    OpenAIRE

    Sam Hyun Yoo

    2014-01-01

    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...

  8. Obesity is a risk factor for atrial fibrillation among fertile young women

    DEFF Research Database (Denmark)

    Karasoy, Deniz; Jensen, Thomas Bo; Hansen, Morten Lock

    2013-01-01

    Obesity has been associated with increased risk of atrial fibrillation (AF), but whether this risk is also prevalent in younger individuals is unknown. We therefore investigated the risk of AF in relation to body mass index (BMI) among young fertile women.......Obesity has been associated with increased risk of atrial fibrillation (AF), but whether this risk is also prevalent in younger individuals is unknown. We therefore investigated the risk of AF in relation to body mass index (BMI) among young fertile women....

  9. Frustrated fertility: a population paradox.

    Science.gov (United States)

    Mcfalls Ja, J

    1979-05-01

    This Bulletin examines the causes of subfecundity -- the diminished ability to reproduce -- and its effect today and in the past on the fertility, or actual reproductive performance, of individuals and, hence, populations. By definition, all real populations are subfecund since all experience some degree of involuntary biological factors affecting coitus, conception, or the ability to carry a conceptus to live birth which reduces their fecundity below the estimated biological population maximum of 15 children per woman. Affecting both men and women, these factors fall into 5 categories: genetic factors such as blood group incompatibilities and inherited sickle cell anemia or diabetes; psychopathology, including psychic stress and behavioral disorders (e.g., drug and alcohol abuse); infectious diseases such as gonorrhea, malaria, tuberculosis, and postabortion infection; malnutrrition, including the chronic undernutrition of the 3rd World and the overnutrition of developed societies; and hazards posed by increasing amounts of radiation and toxic chemicals in the environment. Reducing subfecundity requires improved living conditions, avoidance of or protection from known hazards, and adoption of medical advances which now can help 40 to 60% of subfecund couples. But even in the U.S. fertility would certainly rise among the 15% of couples now estimated to be involuntarily childless and the 10% who have fewer children than they want, and among disadvantaged groups, and teenagers.

  10. A lunar effect on fertility.

    Science.gov (United States)

    Criss, T B; Marcum, J P

    1981-01-01

    Data from individual birth records for 140,000 live births occurring in New York City in 1968 provide evidence that the folkloric beliefs in the moon's influence on human reproduction found in many societies may have a factual basis. Records were arranged sequentially by day of occurrence and time series were constructed for total births and for 5 categories of spontaneous births: total, female, male, black, and white. A Fourier spectrum was calculated for each time series. Cross amplitude spectra were computed for 2 pairs of independent time series, male and female and black and white births, to minimize the effects of weekly variation, and cross correlations were calculated between a time series generated for the study a sine wave at exactly the frequency of the lunar cycle with its maximum value assigned to the 3rd quarter) and each of the other 6 series. A small but systematic variation of births over a period of 29.53 days, the length of the lunar cycle, with peak fertility at 3rd quarter, was found in the 4 independent time series and remained after weekly variation was removed. The finding itself provides little guidance as to the timing or nature of the moon's influence, but recent research suggests a connection between menstrual regularity and light. The timing of the fertility peak at 3rd quarter suggests that the period of decreasing illumination immediately after full moon may precipitate ovulation.

  11. Fertility and pregnancy in vasculitis.

    Science.gov (United States)

    Pagnoux, Christian; Mahendira, Dharini; Laskin, Carl A

    2013-02-01

    Despite the rarity of vasculitides, fertility and pregnancy outcome in the setting of vasculitis have become a major topic of interest within the past decade. The potential impact of vasculitis therapies, particularly cyclophosphamide, has been examined to some extent, but data are limited on the possible impact of the disease itself on fertility. Ideally, pregnancy should be planned when the vasculitis is in remission. The outcome for mothers and newborns is usually good when vasculitis is known before the pregnancy and is in remission, but every pregnant woman must be monitored by a specialised health-care team consisting of obstetricians specialised in high-risk births and internists/rheumatologists with expertise in managing these rare conditions. Most maternal complications during pregnancy are indeed due to vasculitis damage: hypertension in Takayasu arteritis (TAK) or granulomatosis with polyangiitis (GPA)/microscopic polyangiitis (MPA) with renal insufficiency, asthma or cardiac damage in eosinophilic granulomatosis with polyangiitis (EGPA) and subglottic and/or bronchial stenosis(es) in GPA. Pregnancy loss can occur in about 10% of cases in GPA, up to 20% in EGPA, 20-30% in Behçet's disease and up to 25% in TAK, and several studies found high rates of preterm births, at least with some vasculitides. Vasculitis manifestations in newborns from mothers with known vasculitis are very rare and usually transient.

  12. Mexican plants and human fertility.

    Science.gov (United States)

    Crabbe, P

    1979-07-01

    Synthetic steroids are obtainable cheaply and in abundance from sapogenins, substances originating from plants of the Discorea family. Some 40 years ago, Russell Marker, an American chemist, discovered this source, which grows abundantly in Mexican jungles and is now exploited and cultivated commercially. Today synthetic steroids prepared from extracts from a wide range of vegetable sources are used in the treatment of rheumatoid arthritis, allergies, inflammatory diseases, sterility, and various heart conditions, and form the basis of modern oral contraceptives. Nevertheless, oral contraceptives in current use are still fairly costly, and women have to be educated in their use. What is needed urgently is a cheaper contraceptive pill with a long-term effect, and research is continuing. For example, scientists from the People's Republic of China have reported significant anti-fertility effects associated with 2 substances, anordin and dinordin, prepared with steroids derived from the sisal plants Agave sisilana and Agave americana. These agents, whose anti-fertility properties have been confirmed by scientists in Sweden and the United States, constitute a new family of contraceptives with the great advantage of having to be taken only once or twice instead of 20 times per month necessary with the ordinary pill. Also from China, scientists have reported the effectiveness of gossypol as an orally administered male contraceptive, although gossypol is not a steroid. It may become, however, a leading candidate for a male contraceptive.

  13. Ovarian reserve tests in the prediction of the fertile lifespan and current fertility

    NARCIS (Netherlands)

    Depmann, M

    2016-01-01

    Widely used ovarian reserve tests do not predict age at menopause or current fertility This thesis assesssed the capacity of ovarian reserve tests in the prediction of the fertile life span and current fertility. Ovarian reserve tests of interest were anti-Müllerian hormone (AMH), the antral follicl

  14. Ovarian reserve tests in the prediction of the fertile lifespan and current fertility

    NARCIS (Netherlands)

    Depmann, M

    2016-01-01

    Widely used ovarian reserve tests do not predict age at menopause or current fertility This thesis assesssed the capacity of ovarian reserve tests in the prediction of the fertile life span and current fertility. Ovarian reserve tests of interest were anti-Müllerian hormone (AMH), the antral

  15. Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and lts lnfluences on Cotton Yield in the Yangtze River Valley

    Institute of Scientific and Technical Information of China (English)

    Naiyin XU; Jian Ll

    2014-01-01

    Objective] The historical evolution pattern of nitrogen (N), phosphorus (P) and potassium (K) fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

  16. Sperm motility of externally fertilizing fish and amphibians.

    Science.gov (United States)

    Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

    2015-01-01

    We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P fish sperm (~150 seconds), with the longevities of both marine and freshwater fish being significantly (P fish (140 μm/s) or freshwater fish (135 μm/s) sperm. The longevity of the sperm of giant salamanders (Cryptobranchoidea) of approximately 600 seconds was greater than that of freshwater fish sperm but much lower than anuran sperm. Our research and information from the literature showed that higher osmolarities promote greater longevity in anuran sperm, and some freshwater fish sperm, and that anuran and cryptobranchid sperm maintained membrane integrity long after the cessation of motility, demonstrating a preferential sharing of energy reserves toward the maintenance of membrane integrity. The maintenance of the membrane integrity of anuran sperm in fresh water for up to 6 hours showed an extremely high osmotic tolerance relative to fish sperm. The very high longevity and osmotic tolerance of anuran sperm and high longevity of cryptobranchid sperm, relative to those of freshwater fish, may reflect the complex fertilization history of amphibian sperm in general and anurans reversion from internal to external fertilization. Our findings provide a greater understanding of the reproductive biology of externally fertilizing fish and amphibians, and a

  17. A Bibliometric Analysis on “Fertility Rate” Research Trends

    Directory of Open Access Journals (Sweden)

    Shalini Nagaratnam

    2016-07-01

    Full Text Available The systematic literature search on the fertility rate was performed on articles from the Web of Science compiled by the Institute of Scientific Information (ISI to provide major publication characteristics. All articles related to Fertility from year 1980 to 2011 were analyzed with the bibliometric approach using non-parametrics techniques. Total Citation, Citation per year and Cited References were significantly different between the 80’s, 90’s and 2000’s, with more than a 100% increase in the number of publication. The association between number of authors and citation per year were significantly weak. Number of publication in a journal posed a poor negative association with the citation per year. Similarity between Authors Keyword and KeyWords Plus® do not promote the increase in citation per year. The author’s affiliation and country of publication would be an interesting exploration for future fertility research. The bibiliometric analyses on Fertility is rather new and vital, as the key finding will provide researchers guidance in the literature search and future publication.

  18. Fertility, kinship and the evolution of mass ideologies.

    Science.gov (United States)

    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.

  19. Discussing the Determination Standard of Recovery Efficiency of Nitrogen Fertilizer

    Directory of Open Access Journals (Sweden)

    TIAN Chang-yu

    2016-07-01

    Full Text Available Recovery efficiency of nitrogen fertilizer(REN is an important index for the increasing crop yield and reducing environmental benefits of nitrogen fertilizer. But the determination and calculation methods of REN have some problems to study. They are lower rate and higher variability of the rate than it should be. The long-term nitrogen fertilizer location test had been taken since 2007 to analyze the nitrogen uptake rate of wheat year after year and the REN rate was calculated annually. A reasonable measurement specification of REN determination method was put forward. The REN measurement specification was:(1The wheat nitrogen uptake of CK kept relatively stable after a few years; (2The wheat nitrogen uptake ratio of fetilized treatment retained stable; (3REN must be used the average of 3 years of steady period value. With this measurement specification of REN determination method, REN rate was in the range of 69.2%~76.2%(Wheat when applied nitrogen fertilizer in range of 120~180 kg N·hm-2. REN determination method should follow this specification. In this case the correct and reasonable REN parameter can be measured. The reasonable REN can be applied in scientific research and production.

  20. Women's empowerment and fertility: a review of the literature.

    Science.gov (United States)

    Upadhyay, Ushma D; Gipson, Jessica D; Withers, Mellissa; Lewis, Shayna; Ciaraldi, Erica J; Fraser, Ashley; Huchko, Megan J; Prata, Ndola

    2014-08-01

    Women's empowerment has become a focal point for development efforts worldwide and there is a need for an updated, critical assessment of the existing evidence on women's empowerment and fertility. We conducted a literature review on studies examining the relationships between women's empowerment and several fertility-related topics. Among the 60 studies identified for this review, the majority were conducted in South Asia (n = 35) and used household decision-making as a measure of empowerment (n = 37). Overall, the vast majority of studies found some positive associations between women's empowerment and lower fertility, longer birth intervals, and lower rates of unintended pregnancy, but there was some variation in results. In many studies, results differed based on the measure of empowerment used, sociopolitical or gender environment, or sub-population studied. This article is one of the first evaluations of the literature assessing the relationships between women's empowerment and fertility. We identify several key issues that merit further investigation.

  1. Hypogonadism and fertility issues following primary treatment for testicular cancer.

    Science.gov (United States)

    Oldenburg, Jan

    2015-09-01

    The majority of testicular cancer (TC) patients are cured and expected to live for decades after treatment, such that knowledge about hypogonadism and fertility issues is particularly important for the group of testicular cancer survivors (TCSs). Hypogonadism and fertility issues are related to treatment intensity. In order to give an overview about hypogonadism in testicular cancer survivors (TCSs) the literature was reviewed. Testicular dysfunction was defined as inadequate spermatogenesis, as reflected by increased levels of Follicle Stimulating Hormone (FSH) and reduced fertility and/with or without insufficient testosterone (T) production with or without compensatory increased Luteinizing Hormone (LH) levels. Hypogonadism may lead to reduced sexual functioning and well-being, fertility problems, muscle weakness, loss of energy, and depression. Furthermore, hypogonadism also increases the risk of osteoporosis and is associated with the metabolic syndrome and cardiovascular disease (CVD). The hypothesized "Testicular Dysgenesis Syndrome" comprising low sperm counts, hypospadias, cryptorchidism, and finally TC, probably contributes to hypogonadism independent of applied TC treatment. Recently, an increased risk of accelerated hormonal ageing has been reported in TCSs in the very long term, i.e. 20 years after TC treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Effect of organic fertilizers on maize production in Eastern Georgia

    Science.gov (United States)

    Jolokhava, Tamar; Kenchiashvili, Naira; Tarkhnishvili, Maia; Ghambashidze, Giorgi

    2016-04-01

    Maize remains to be the most important cereal crop in Georgia. Total area of arable land under cereal crops production equals to 184 thousands hectares (FAO statistical yearbook, 2014), from which maize takes the biggest share. Leading position of maize among other cereal crops is caused by its dual purpose as food and feed product. In Spite of a relatively high production of maize to other cereals there is still a high demand on it, especially as feed for animal husbandry. The same tendency is seen in organic production, where producers of livestock and poultry products require organically grown maize, the average yield of which is much less than those produced conventionally. Therefore, it is important to increase productivity of maize in organic farms. Current study aimed to improve maize yield using locally produced organic fertilizers and to compare them to the effect of mineral fertilizers. The study was carried out in Eastern Georgia under dry subtropical climate conditions on local hybrid of maize. This is the first attempt to use hybrid maize (developed with organic plant breeding method) in organic field trials in Georgia. The results shown, that grain yield from two different types of organic fertilizers reached 70% of the yields achieved with industrial mineral fertilizers. As on farm level differences between organic and conventional maize production are much severe, the results from the field trials seems to be promising for future improvement of organic cereal crop production.

  3. Effects of organic and chemical fertilizer on plant nutritional status and soil fertility of tomatoes grown under greenhouse condition

    Directory of Open Access Journals (Sweden)

    Elif Işıl DEMİRTAŞ

    2012-06-01

    Full Text Available The effect of some plant originated liquid organic fertilizer on soil fertility and plant nutritional status of tomato plants were investigated. The experiment was planned to compare the control, organic fertilizer, chemical fertilizer, 1/1chemical+organic fertilizer, ½chemical+organic fertilizer, chemical fertilizer+foliar organic fertilizer application. The trial was conducted in randomised complete block design with four replications. Plant and soil samples were analyzed. According to the results of analysis, combinations of organic and chemical fertilizer generally gave more positive results.

  4. Fertility determinants in Indonesia: a sequential analysis of the proximate determinants.

    Science.gov (United States)

    Ananta, A; Lim, T; Molyneaux, J W; Kantner, A

    1992-06-01

    Data drom the Indonesian Contraceptive Prevalence Survey in 1987 was used to examine the extent to which socioeconomic factors affect the direct association between proximate determinants and fertility. The Bongaarts framework was applied to individual level data on married women who had at least on birth between 1982 and 1987. The fertility measure was the probability of having a birth in the last 12 months before the survey. Proximate determinants were breast feeding, fertile period (non-amenorrhea), sexual exposure, and contraceptive use. Socioeconomic variables were husband's education, wife's education, husband's occupation, religion, urban/rural status, and region of residence. The logit regression analysis is controlled by the age of the respondent and number of children ever born at the time of the survey. There is a possibility that socioeconomic variables may have a direct impact on fertility and the logit framework does not model perfectly the true stochastic model. Thus, a regression is specified in which the probability of experiencing a birth is regressed on both proximate determinants and socioeconomic determinants and on socioeconomic determinants alone. Results show that fertility is lower when the duration of breast feeding and level of contraceptive use is higher. Fertility is higher when the length of the fertile period and sexual exposure is higher. Education showed no significant impact on duration of breast feeding, but when both parents' education is considered, women's lack of education is related to having longer fertile periods (an average of 64 months). When the wife's education is considered alone, women with no schooling and less education have 56-44 more months of sexual exposure. The husband's education considered alone followed the same pattern. As level of parents' education rose, the probability of contraception increased. Women have shorter fertile periods when husbands are farmers. Religion explains duration of breast feeding

  5. Effect of Fertilization on Soil Fertility and Wheat Yield of Dryland in the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    HAO Ming-De; FAN Jun; WEI Xiao-Rong; PEN Lin-Fa; LAI Lu

    2005-01-01

    Long-term fertility experiments have become an important tool for investigating the sustainability of cropping systems.Therefore, a long-term (18-year) fertilization experiment was conducted in Changwu County, Shaanxi Province, China,to ascertain the effect of the long-term application of chemical fertilizers and manure on wheat yield and soil fertility in the Loess Plateau, so as to provide a scientific basis for sustainable land management. The experiment consisted of nine fertilizer treatments with three replicates arranged in a completely randomized design: 1) CK (no fertilizer); 2) N (N 120 kg ha-i); 3) P (P 26.2 kg ha-1); 4) NP (N 120, P 26.2 kg ha-1); 5) M (manure 75 t ha-1); 6) NM (N 120 kg ha-1,manure 75 t ha-1); 7) PM (P 26.2 kg ha-1, manure 75 t ha-1); 8) NPM (N 120, P 26.2 kg ha-1, manure 75 t ha-1);and 9) fallow (no fertilizer, no crop). N fertilizer was applied in the form of urea and P was applied as calcium super phosphate. The results showed that precipitation had a large effect on the response of wheat yield to fertilization. Manure (M), NP, PM, NM, and NPM treatments significantly increased (P < 0.05) average yield. In the NP, PM, NM and NPM treatments, the percentage increases in yield due to fertilization were highest in normal years, and lowest in the drought years. Long-term P application enhanced soil available P markedly, and manure applications contributed more to soil fertility than chemical fertilizers alone. Chemical fertilizers applied together with manure distinctly improved soil fertility.The results also showed that the soil nutrient concentration changed mainly in the 0-60 cm layers and fertilization and planting only slightly affected soil nutrients below the 100 cm layers.

  6. Fertility Desires among Women Living with HIV

    Science.gov (United States)

    Cook, Ryan; Potter, JoNell Efantis; Miron-Shatz, Talya; Chakhtoura, Nahida; Spence, Andrew; Byrne, Margaret M.

    2016-01-01

    Objective Rates of pregnancy among women living with HIV (WLHIV) have increased with the availability of effective HIV treatment. Planning for pregnancy and childbirth is an increasingly important element of HIV care. Though rates of unintended pregnancies are high among women in general, among couples affected by HIV, significant planning and reproductive decisions must be considered to prevent negative health consequences for WLHIV and their neonates. To gain insight into this reproductive decision-making process among WLHIV, this study explored women’s knowledge, attitudes and practices regarding fertility planning, reproductive desires, and safer conception practices. It was hypothesized that pregnancy desires would be influenced by partners, families, the potential risk of HIV transmission to infants, and physicians’ recommendations. Methods WLHIV of childbearing age were recruited from urban South Florida, and completed an assessment of demographics (N = 49), fertility desires and a conjoint survey of factors associated with reproductive decision-making. Results Using conjoint analysis, we found that different decision paths exist for different types of women: Younger women and those with less education desired children if their partners wanted children; reproductive desires among those with less education, and with less HIV pregnancy-related knowledge, displayed a trend toward additional emphasis on their family’s desires. Conversely, older women and those with more education appeared to place more importance on physician endorsement in their plans for childbearing. Conclusions Results of this study highlight the importance of ongoing preconception counselling for all women of reproductive age during routine HIV care. Counselling should be tailored to patient characteristics, and physicians should consider inclusion of families and/or partners in the process. PMID:27610626

  7. Relativity

    CERN Document Server

    Brewster, Hilary D

    2009-01-01

    The theory of relativity has become a cornerstone of modern physics. Over the course of time it has been scrutinized in a multitude of experiments and has always been verified with high accuracy. The correctness of this theory can no longer be called into question. Right after its discovery by Albert Einstein in 1905, special relativity was only gradually accepted because it made numerous predictions contradicting common sense, fervently castigated by Einstein, and also defied experiment for too long a time. It was only with the advent of particle or high energy physics that matter could be ac

  8. Relativity

    CERN Document Server

    Einstein, Albert

    2013-01-01

    Time magazine's ""Man of the Century"", Albert Einstein is the founder of modern physics and his theory of relativity is the most important scientific idea of the modern era. In this short book, Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory that has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the most popular and useful exposition of Einstein's immense contribution to human knowledge.With a new foreword by Derek Raine.

  9. Nitrous oxide emission from highland winter wheat field after long-term fertilization

    Directory of Open Access Journals (Sweden)

    X. R. Wei

    2010-10-01

    Full Text Available Nitrous oxide (N2O is an important greenhouse gas. N2O emissions from soils vary with fertilization and cropping practices. The response of N2O emission to fertilization of agricultural soils plays an important role in global N2O emission. The objective of this study was to assess the seasonal pattern of N2O fluxes and the annual N2O emissions from a rain-fed winter wheat (Triticum aestivum L. field in the Loess Plateau of China. A static flux chamber method was used to measure soil N2O fluxes from 2006 to 2008. The study included 5 treatments with 3 replications in a randomized complete block design. Prior to initiating N2O measurements the treatments had received the same fertilization for 22 years. The fertilizer treatments were unfertilized control (CK, manure (M, nitrogen (N, nitrogen + phosphorus (NP, and nitrogen + phosphorus + manure (NPM. Soil N2O fluxes in the highland winter wheat field were highly variable temporally and thus were fertilization dependent. The highest fluxes occurred in the warmer and wetter seasons. Relative to CK, m slightly increased N2O flux while N, NP and NPM treatments significantly increased N2O fluxes. The fertilizer induced increase in N2O flux occurred mainly in the first 30 days after fertilization. The increases were smaller in the relatively warm and dry year than in the cold and wet year. Combining phosphorous and/or manure with mineral N fertilizer partly offset the nitrogen fertilizer induced increase in N2O flux. N2O fluxes at the seedling stage were mainly controlled by nitrogen fertilization, while fluxes at other plant growth stages were influenced by plant and environmental conditions. The cumulative N2O emissions were always higher in the fertilized treatments than in the non-fertilized treatment (CK. Mineral and manure

  10. Nitrous oxide emission from highland winter wheat field after long-term fertilization

    Directory of Open Access Journals (Sweden)

    X. R. Wei

    2010-06-01

    Full Text Available Nitrous oxide (N2O is an important greenhouse gas. N2O emissions from soils vary with fertilization and cropping practices. The response of N2O emission to fertilization of agricultural soils plays an important role in global N2O emission. The objective of this study was to assess the seasonal pattern of N2O fluxes and the annual N2O emissions from a rain-fed winter wheat (Triticum aestivum L. field in the Loess Plateau of China. A static flux chamber method was used to measure soil N2O fluxes from 2006 to 2008. The study included 5 treatments with 3 replications in a randomized complete block design. Prior to initiating N2O measurements the treatments had received the same fertilization for 22 years. The fertilizer treatments were unfertilized control (CK, manure (M, nitrogen (N, nitrogen + phosphorus (NP, and nitrogen + phosphorus + manure (NPM. Soil N2O fluxes in the highland winter wheat field were highly variable temporally and thus were fertilization dependent. The highest fluxes occurred in the warmer and wetter seasons. Relative to CK, M slightly increased N2O flux while N, NP and NPM treatments significantly increased N2O fluxes. The fertilizer induced increase in N2O flux occurred mainly in the first 30 days after fertilization. The increases were smaller in the relatively warm and dry year than in the cold and wet year. Combining phosphorous and/or manure with mineral N fertilizer partly offset the nitrogen fertilizer induced increase in N2O flux. N2O fluxes at the seedling stage were mainly controlled by nitrogen fertilization, while fluxes at other plant growth stages were influenced by plant and environmental conditions. The cumulative N2O emissions were always higher in the fertilized treatments than in the non-fertilized treatment (CK. Mineral and manure

  11. 年轻乳腺癌患者治疗后生育相关问题进展%Advances in fertility - related issues of young women with breast cancer after treatment

    Institute of Scientific and Technical Information of China (English)

    封伟亮; 杨红健

    2016-01-01

    近年来年轻乳腺癌的发病人数逐年上升,很多女性患者在确诊为乳腺癌时还未生育或者仍有生育愿望。随着现代医学的进步和多学科治疗的规范,乳腺癌患者的生存期越来越长,但乳腺癌综合治疗带来的副作用对生活质量的影响也越来越大,尤其是对那些年轻乳腺癌患者更为明显,她们更渴望回归正常的生活,渴望怀孕成为母亲。长期以来,由于害怕妊娠会对乳腺癌预后造成危害,医患双方均对乳腺癌治疗后的妊娠存在诸多疑虑而不敢付诸实践。本综述基于已有的循证医学证据,从多方面证实乳腺癌治疗后妊娠是可行的、安全的、值得关注的,希望为以后的临床实践提供参考。%Breast cancer is one of the most prevalent cancers in women in our country. Young women with breast cancer have distinct concerns and issues compared with older women,including queries regarding fertility and preg-nancy. For a long period of there is a persistent belief that a pregnancy after breast cancer may increase the risk of cancer recurrence,these uncertainties have contributed to both physicians and patients against pregnancy. This review encompasses an overview of the current existing evidence,confirm the pregnancy after breast cancer treatment is feasi-ble,safe hope to provide a reference for future clinical practice.

  12. Impact of Long-Term Fertilization on Cropland Soil Fauna Community at Loess Soil, Shannxi, China

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-hua; YANG Xue-yun; ZHANG Fu-dao; GU Qiao-zhen; SUN Ben-hua; MA Lu-jun

    2005-01-01

    The relationship between long-term fertilization and cropland soil fauna was studied at the station's experiment research network for soil fertility and fertilizers in Loess soil of Shannxi Provincefrom Jul. 2001 to Oct. 2002. Six types of long-term fertilizer were carried out for this study including non-fertilizer (CK), abandonment (ABAND), nitrogenous and phosphors and potassium fertilizers combined (NPK), straw and NPK (SNPK), organic material and NPK (MNPK) and 1.5 times MNPK (1.5MNPK). 72 soil samples were collected and 5 495 species of cropland soil fauna obtained by handsorting and Cobb methods at 4 times, belonging to 6 Phyla, 11 Classes, 22 Orders, 2 Superfamilies, 61 Families and 35 Genera. The result showed that different fertilizer had significantly impacted on the cropland soil fauna (F = 2.24, P<0.007). The number of the cropland soil fauna was related to the soil physicochemical properties caused by long-term fertilization. The result by principal component analysis, focusing on the number of 15 key soil fauna species group's diversity, evenness of community and the total soil fauna individuals indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different from that of the cropland soil fauna, in which, SNPK and NPK had the positive effect on cropland soil fauna, and MNPK and 1.5 MNPK had the negative affect, others could not be explained. By principal component I,the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significant, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the minimum one was -1.0904, that means the 6 types of fertilization did not affect evenly the cropland soil fauna.

  13. Crop rotation-dependent yield responses to fertilization in winter oilseed rape (Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Tao Ren

    2015-10-01

    Full Text Available Differences in soil physical, chemical and biological properties between paddy–upland and continuous upland rotations will influence nutrient relations and crop growth. With the aim of estimating rapeseed yield performance in response to fertilization in rice–rapeseed (RR and cotton–rapeseed (CR rotations, on-farm experiments were conducted at 70 sites across Hubei province, central China. The economically optimal fertilizer rates of winter oilseed rape in different rotations were determined. Field experiments showed that previous crops significantly influenced seed yields. Without N fertilization, seed yields were significantly lower for the RR rotation than for the CR rotation. The average yield increase ratio and agronomic efficiency associated with nitrogen (N fertilization in the RR rotation were 96.6% and 6.56 kg kg− 1, significantly higher than those in the CR rotation. No seed yield differences were detected between the two rotations under phosphorus (P and potassium (K fertilization. In contrast to the CR rotation, N fertilizer played a more vital role in maintaining high seed yields in the RR rotation owing to the lower indigenous soil N supply. Compared with local N fertilizer recommendation rates for the RR rotation, on average an additional 18 kg N ha− 1 was recommended according to the economically optimal N fertilizer rate (EONFR. In contrast, the EONFR was 14 kg N ha− 1 lower than the locally recommended N fertilizer rate for the CR rotation. There were no differences between the two rotations for the average economically optimal P and K fertilization rates. Consequently, the average EONFR of winter oilseed rape could be reduced if cotton rather than rice preceded the winter oilseed rape.

  14. Crop rotation-dependent yield responses to fertilization in winter oilseed rape(Brassica napus L.)

    Institute of Scientific and Technical Information of China (English)

    Tao; Ren; Hui; Li; Jianwei; Lu; Rongyan; Bu; Xiaokun; Li; Rihuan; Cong; Mingxing; Lu

    2015-01-01

    Differences in soil physical, chemical and biological properties between paddy–upland and continuous upland rotations will influence nutrient relations and crop growth. With the aim of estimating rapeseed yield performance in response to fertilization in rice–rapeseed(RR) and cotton–rapeseed(CR) rotations, on-farm experiments were conducted at 70 sites across Hubei province, central China. The economically optimal fertilizer rates of winter oilseed rape in different rotations were determined. Field experiments showed that previous crops significantly influenced seed yields. Without N fertilization,seed yields were significantly lower for the RR rotation than for the CR rotation. The average yield increase ratio and agronomic efficiency associated with nitrogen(N)fertilization in the RR rotation were 96.6% and 6.56 kg kg- 1, significantly higher than those in the CR rotation. No seed yield differences were detected between the two rotations under phosphorus(P) and potassium(K) fertilization. In contrast to the CR rotation, N fertilizer played a more vital role in maintaining high seed yields in the RR rotation owing to the lower indigenous soil N supply. Compared with local N fertilizer recommendation rates for the RR rotation, on average an additional 18 kg N ha- 1was recommended according to the economically optimal N fertilizer rate(EONFR). In contrast, the EONFR was 14 kg N ha- 1lower than the locally recommended N fertilizer rate for the CR rotation. There were no differences between the two rotations for the average economically optimal P and K fertilization rates. Consequently, the average EONFR of winter oilseed rape could be reduced if cotton rather than rice preceded the winter oilseed rape.

  15. Crop rotation-dependent yield responses to fertilization in winter oilseed rape (Brassica napus L.)

    Institute of Scientific and Technical Information of China (English)

    Tao Ren; Hui Li; Jianwei Lu; Rongyan Bu; Xiaokun Li; Rihuan Cong; Mingxing Lu

    2015-01-01

    Differences in soil physical, chemical and biological properties between paddy–upland and continuous upland rotations will influence nutrient relations and crop growth. With the aim of estimating rapeseed yield performance in response to fertilization in rice–rapeseed (RR) and cotton–rapeseed (CR) rotations, on-farm experiments were conducted at 70 sites across Hubei province, central China. The economically optimal fertilizer rates of winter oilseed rape in different rotations were determined. Field experiments showed that previous crops significantly influenced seed yields. Without N fertilization, seed yields were significantly lower for the RR rotation than for the CR rotation. The average yield increase ratio and agronomic efficiency associated with nitrogen (N) fertilization in the RR rotation were 96.6% and 6.56 kg kg−1, significantly higher than those in the CR rotation. No seed yield differences were detected between the two rotations under phosphorus (P) and potassium (K) fertilization. In contrast to the CR rotation, N fertilizer played a more vital role in maintaining high seed yields in the RR rotation owing to the lower indigenous soil N supply. Compared with local N fertilizer recommendation rates for the RR rotation, on average an additional 18 kg N ha−1 was recommended according to the economically optimal N fertilizer rate (EONFR). In contrast, the EONFR was 14 kg N ha−1 lower than the locally recommended N fertilizer rate for the CR rotation. There were no differences between the two rotations for the average economically optimal P and K fertilization rates. Consequently, the average EONFR of winter oilseed rape could be reduced if cotton rather than rice preceded the winter oilseed rape.

  16. Dioxin levels in fertilizers from Belgium: determination and evaluation of the potential impact on soil contamination.

    Science.gov (United States)

    Elskens, M; Pussemier, L; Dumortier, P; Van Langenhove, K; Scholl, G; Goeyens, L; Focant, J F

    2013-06-01

    Dioxins are harmful persistent organic pollutants (POPs) to which humans are exposed mostly via the consumption of animal products. They can enter the food chain at any stage, including crop fertilization. Fertilizers belong to several categories: synthetic chemicals providing the essential elements (mostly N, P and K) that are required by the crops but also organic fertilizers or amendments, liming materials, etc. Ninety-seven samples of fertilizers were taken in Belgium during the year 2011 and analyzed after a soft extraction procedure for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) using GC-IDHRMS. Only small qualitative differences could be observed between the main fertilizer categories since the PCDD:PCDF:DL-PCB average ratio obtained with the results expressed in TEQ was often close to 30:30:40 (typically for sewage sludge) or 40:30:30 (typically for compost). The median dioxin levels determined were generally lower than recorded previously and were the highest for sewage sludge and compost (5.6 and 5.5 ng TEQ/kg dry weight (dw), respectively). The levels in other fertilizers were lower including manure for which the median value was only 0.2 ng TEQ/kg dw. Several fertilization scenarios relying on the use of those fertilizers were assessed taking into consideration the application conditions prevailing in Belgium. From this assessment it could be concluded that the contribution of fertilizers to the overall soil contamination will be low by comparison of other sources of contamination such as atmospheric depositions. At the field scale, intensive use of compost and sewage sludge will increase dramatically the dioxin inputs compared with other fertilization practices but this kind of emission to the soil will still be relatively low compared to the dioxin atmospheric depositions.

  17. Soil greenhouse gas emissions affected by irrigation, tillage, crop rotation, and nitrogen fertilization.

    Science.gov (United States)

    Sainju, Upendra M; Stevens, William B; Caesar-Tonthat, Thecan; Liebig, Mark A

    2012-01-01

    Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO, NO, and CH emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and nonirrigated) and five cropping systems (conventional-tilled malt barley [ L.] with N fertilizer [CT-N], conventional-tilled malt barley with no N fertilizer [CT-C], no-tilled malt barley-pea [ L.] with N fertilizer [NT-PN], no-tilled malt barley with N fertilizer [NT-N], and no-tilled malt barley with no N fertilizer [NT-C]). The GHG fluxes varied with date of sampling and peaked immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO and NO fluxes were greater in CT-N under the irrigated condition, but CH uptake was greater in NT-PN under the nonirrigated condition than in other treatments. Although tillage and N fertilization increased CO and NO fluxes by 8 to 30%, N fertilization and monocropping reduced CH uptake by 39 to 40%. The NT-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO and NO emissions and increasing CH uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO emissions along with NO and CH fluxes is needed.

  18. Cohort Fertility Patterns in the Nordic Countries

    Directory of Open Access Journals (Sweden)

    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.

  19. Fertilizer and Lime: Why They Are Used.

    Science.gov (United States)

    McCaslin, Judith Strand

    This unit teaching guide is designed to help teachers explain the principles of fertilizer and lime use. The first of four major sections is a teaching outline keyed to transparency masters and student handouts. Thirteen major areas are covered in the teaching outline: (1) plant needs; (2) uses of fertilizer; (3) nutrients for plant growth; (4)…

  20. Stable Development of Phosphate Fertilizer Sector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The rapid growth of China's economy in recent years gave rise to a sound external environment for the development of the phosphate fertilizer industry. With quite a few state agricultural incentives, the initiative of farmers in grain production is much higher, and consumption of phosphate fertilizers has increased constantly.