Comparison of the effects of thermal stress and CO₂-driven acidified seawater on fertilization in coral Acropora digitifera.

PubMed

Iguchi, Akira; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

2015-08-01

Global warming (GW) and ocean acidification (OA) have been recognized as severe threats for reef-building corals that support coral reef ecosystems, but these effects on the early life history stage of corals are relatively unknown compared with the effects on calcification of adult corals. In this study, we evaluated the effects of thermal stress and CO2-driven acidified seawater on fertilization in a reef-building coral, Acropora digitifera. The fertilization rates of A. digitifera decreased in response to thermal stress compared with those under normal seawater conditions. In contrast, the changes of fertilization rates were not evident in the acidified seawater. Generalized Linear Mixed Model (GLMM) predicted that sperm/egg crosses and temperature were explanatory variables in the best-fitted model for the fertilization data. In the best model, interactions between thermal stress and acidified seawater on the fertilization rates were not selected. Our results suggested that coral fertilization is more sensitive to future GW than OA. Taking into consideration the previous finding that sperm motility of A. digitifera was decreased by acidified seawater, the decrease in coral cover followed by that of sperm concentration might cause the interacting effects of GW and OA on coral fertilization.

Changes to Extender, Cryoprotective Medium, and In Vitro Fertilization Improve Zebrafish Sperm Cryopreservation.

PubMed

Matthews, Jennifer L; Murphy, Joy M; Carmichael, Carrie; Yang, Huiping; Tiersch, Terrence; Westerfield, Monte; Varga, Zoltan M

2018-01-25

Sperm cryopreservation is a highly efficient method for preserving genetic resources. It extends the reproductive period of males and significantly reduces costs normally associated with maintenance of live animal colonies. However, previous zebrafish (Danio rerio) cryopreservation methods have produced variable outcomes and low post-thaw fertilization rates. To improve post-thaw fertilization rates after cryopreservation, we developed a new extender and cryoprotective medium (CPM), introduced quality assessment (QA), determined the optimal cooling rate, and improved the post-thaw in vitro fertilization process. We found that the hypertonic extender E400 preserved motility of sperm held on ice for at least 6 h. We implemented QA by measuring sperm cell densities with a NanoDrop spectrophotometer and sperm motility with computer-assisted sperm analysis (CASA). We developed a CPM, RMMB, which contains raffinose, skim milk, methanol, and bicine buffer. Post-thaw motility indicated that the optimal cooling rate in two types of cryogenic vials was between 10 and 15°C/min. Test thaws from this method produced average motility of 20% ± 13% and an average post-thaw fertilization rate of 68% ± 16%.

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

ERIC Educational Resources Information Center

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…

Adolescent Fertility: State File [Machine-Readable Data File].

ERIC Educational Resources Information Center

Moore, Kristin A.; And Others

This computer file contains recent cross sectional data on adolescent fertility by state 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 years are…

Sperm function and assisted reproduction technology

PubMed Central

MAAß, GESA; BÖDEKER, ROLF‐HASSO; SCHEIBELHUT, CHRISTINE; STALF, THOMAS; MEHNERT, CLAAS; SCHUPPE, HANS‐CHRISTIAN; JUNG, ANDREAS; SCHILL, WOLF‐BERNHARD

2005-01-01

The evaluation of different functional sperm parameters has become a tool in andrological diagnosis. These assays determine the sperm's capability to fertilize an oocyte. It also appears that sperm functions and semen parameters are interrelated and interdependent. Therefore, the question arose whether a given laboratory test or a battery of tests can predict the outcome in in vitro fertilization (IVF). One‐hundred and sixty‐one patients who underwent an IVF treatment were selected from a database of 4178 patients who had been examined for male infertility 3 months before or after IVF. Sperm concentration, motility, acrosin activity, acrosome reaction, sperm morphology, maternal age, number of transferred embryos, embryo score, fertilization rate and pregnancy rate were determined. In addition, logistic regression models to describe fertilization rate and pregnancy were developed. All the parameters in the models were dichotomized and intra‐ and interindividual variability of the parameters were assessed. Although the sperm parameters showed good correlations with IVF when correlated separately, the only essential parameter in the multivariate model was morphology. The enormous intra‐ and interindividual variability of the values was striking. In conclusion, our data indicate that the andrological status at the end of the respective treatment does not necessarily represent the status at the time of IVF. Despite a relatively low correlation coefficient in the logistic regression model, it appears that among the parameters tested, the most reliable parameter to predict fertilization is normal sperm morphology. (Reprod Med Biol 2005; 4: 7–30) PMID:29699207

Development of a new fertility prediction model for stallion semen, including flow cytometry.

PubMed

Barrier Battut, I; Kempfer, A; Becker, J; Lebailly, L; Camugli, S; Chevrier, L

2016-09-01

Several laboratories routinely use flow cytometry to evaluate stallion semen quality. However, objective and practical tools for the on-field interpretation of data concerning fertilizing potential are scarce. A panel of nine tests, evaluating a large number of compartments or functions of the spermatozoa: motility, morphology, viability, mitochondrial activity, oxidation level, acrosome integrity, DNA integrity, "organization" of the plasma membrane, and hypoosmotic resistance, was applied to a population of 43 stallions, 33 of which showing widely differing fertilities (19%-84% pregnancy rate per cycle [PRC]). Analyses were performed either within 2 hours after semen collection or after 24-hour storage at 4 °C in INRA96 extender, on three to six ejaculates for each stallion. The aim was to provide data on the distribution of values among said population, showing within-stallion and between-stallion variability, and to determine whether appropriate combinations of tests could evaluate the fertilizing potential of each stallion. Within-stallion repeatability, defined as intrastallion correlation (r = between-stallion variance/total variance) ranged between 0.29 and 0.84 for "conventional" variables (viability, morphology, and motility), and between 0.15 and 0.81 for "cytometric" variables. Those data suggested that analyzing six ejaculates would be adequate to characterize a stallion. For most variables, except those related to DNA integrity and some motility variables, results differed significantly between immediately performed analyses and analyses performed after 24 hours at 4 °C. Two "best-fit" combinations of variables were determined. Factorial discriminant analysis using a first combination of seven variables, including the polarization of mitochondria, acrosome integrity, DNA integrity, and hypoosmotic resistance, permitted exact determination of the fertility group for each stallion: fertile, that is, PRC higher than 55%; intermediate, that is, 45% < PRC less than 55%; or subfertile, that is, PRC less than 45%. Linear regression using another combination of 20 variables, including motility, viability, oxidation level, acrosome integrity, DNA integrity, and hypoosmotic resistance, accounted for 94.2% of the variability regarding fertility and was used to calculate a prediction of the PRC with a mean standard deviation of 3.1. The difference between the observed fertility and the calculated value ranged from -4.2 to 5.0. In conclusion, this study enabled to determine a new protocol for the evaluation of stallion semen, combining microscopical observation, computer-assisted motility analysis and flow cytometry, and providing a high level of fertility prediction. Copyright © 2016 Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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 < 0.0001) higher proportion of does that became pregnant than did the ewes in the lowest decile (56, 54, 58, and 49 %, respectively). In sheep, the fertility rates of the highest decile of mean (62 %), maximum (62 %), and minimum (52 %) temperature, RH (52 %), THI (53 %), and rainfall (45 %) were significantly higher ( P < 0.0001) than were the fertility rates among ewes in the lowest decile (46, 45, 45, 45, 46, and 43 %, respectively). In conclusion, weather was related to fertility in small ruminants after 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.

Achieving fertility control through woman’s autonomy and access to maternal healthcare: Are we on track? In-depth analysis of PDHS-2012-13

PubMed Central

Hassan, Sehar-un-Nisa; Siddiqui, Salma; Mahmood, Ayeshah

2015-01-01

Background and Objective: Fertility control preferences and maternal healthcare have recently become a major concern for developing nations with evidence suggesting that low fertility control rates and poor maternal healthcare are among major obstructions in ensuring health and social status for women. Our objective was toanalyze the factors that influence women’s autonomy, access to maternal healthcare, and fertility control preferences in Pakistan. Methods: Data consisted of 11,761 ever-married women of ages 15-49 years from PDHS, 2012-13. Variables included socio-demographics, women’s autonomy, fertility control preferences and access to maternal healthcare. Results: Findings from multivariate analysis showed that women’s younger age, having less than three number of children and independent or joint decision-making (indicators of high autonomy) remained the most significant predictors for access to better quality maternal healthcare and better fertility control preferences when other variables were controlled. Conclusion: Women’s access to good quality maternal health care and fertility control preferences are directly and indirectly influenced by their demographic characteristics and decision-making patterns in domestic affairs. PMID:26870096

Young Men With Cancer Experience Low Referral Rates for Fertility Counseling and Sperm Banking.

PubMed

Grover, Natalie S; Deal, Allison M; Wood, William A; Mersereau, Jennifer E

2016-05-01

With improved cancer survival rates and the current trend of delaying parenthood, fertility is a growing issue among cancer patients. The purpose of this study was to evaluate the incidence of fertility counseling and sperm banking in reproductive-age male cancer patients and to assess factors that influence counseling and banking. Male patients ages 13 to 50 years who received a new cancer diagnosis from January 1, 2013, to May 1, 2015, and planned to initiate curative chemotherapy at our center were identified. Documentation of fertility counseling and sperm cryopreservation was abstracted from the medical record. Univariable and multivariable logistic regression modeling was used to examine variables associated with fertility counseling and sperm banking. Of 201 patients who fit the study criteria, 59 (29%) received fertility counseling and 23 (11%) attempted sperm banking. All patients who banked sperm had documentation of fertility counseling. Younger patients were significantly more likely to be counseled, with mean ages of 27.4 and 40.4 years for counseled and noncounseled patients, respectively (P < .001). Among counseled patients, those with a lower median income (P = .038) or who had Medicaid or no insurance (P = .042) were less likely to bank sperm. In a multivariable logistic regression model, older age (5-year odds ratio, 0.61; P < .001) and presence of comorbidities (odds ratio, 0.15; P = .03) remained significantly associated with a lower counseling rate. There is a low rate of fertility counseling and referral for sperm banking in young men with cancer receiving chemotherapy. Further work is needed to develop interventions to improve fertility counseling rates and opportunities for sperm banking. Copyright © 2016 by American Society of Clinical Oncology.

Graduation of fertility schedules: an analysis of fertility patterns in London in the 1980s and an application to fertility forecasts.

PubMed

Congdon, P

1990-08-01

London's average total fertility rate (TFR) stood at 1.75. Using a cluster analysis to compare the 1985-1987 fertility patterns of different boroughs of London, demographers learned that 5 natural groupings occurred. 4 boroughs in a central London cluster have the distinction of having a low TFR (1.38) and late fertility (average age of 29.58 years). The researchers attributed these occurrences to the high levels of employment and career attachment and low rates of marriage among women in this cluster. 2 inner city boroughs constituted the smallest cluster and had the largest TFR (2.37), mainly due to high numbers of births to the ethnic minorities. The largest cluster consisted of 12 boroughs located mainly along the periphery with 2 centrally located boroughs (TFR, 1.79). Some of the upper class outer boroughs characterized another cluster with a TFR of 1.61. Another cluster made up of inner and outer boroughs in east and southeast London had a ample proportion of manual worker (TFR, 2.04). Social class most likely accounted for the contrast in TFRs between the 2 aformentioned clusters. Demographers observed that cyclical fluctuation of fertility occurred as opposed to secular trends. Due to these fluctuations, demographers used autoregressive moving average forecast models to time series of the fertility variables in London since 1952. They also applied structural time series models which included regression variables and the influence of cyclical and/or trend behavior. The results showed that large cohorts and the increase in female economic activity caused a delay in the modal age of births and a reduction in the number of births.

Short amplexus duration in a territorial anuran: a possible adaptation in response to male-male competition.

PubMed

Chuang, Ming-Feng; Bee, Mark A; Kam, Yeong-Choy

2013-01-01

Mating duration is a reproductive behaviour that can impact fertilization efficiency and offspring number. Previous studies of factors influencing the evolution of mating duration have focused on the potential role of internal sperm competition as an underlying source of selection; most of these studies have been on invertebrates. For vertebrates with external fertilization, such as fishes and frogs, the sources of selection acting on mating duration remain largely unknown due, in part, to the difficulty of observing complete mating behaviours in natural conditions. In this field study, we monitored breeding activity in a population of the territorial olive frog, Rana adenopleura, to identify factors that affect the duration of amplexus. Compared with most other frogs, amplexus was short, lasting less than 11 min on average, which included about 8 min of pre-oviposition activity followed by 3 min of oviposition. We evaluated the relationship between amplexus duration and seven variables: male body size, male condition, operational sex ratio (OSR), population size, clutch size, territory size, and the coverage of submerged vegetation in a male's territory. We also investigated the influence of these same variables, along with amplexus duration, on fertilization rate. Amplexus duration was positively related with clutch size and the degree of male-bias in the nightly OSR. Fertilization rate was directly related to male body size and inversely related to amplexus duration. Agonistic interactions between males in amplexus and intruding, unpaired males were frequent. These interactions often resulted in mating failure, prolonged amplexus duration, and reduced fertilization rates. Together, the pattern of our findings indicates short amplexus duration in this species may be an adaptive reproductive strategy whereby males attempt to reduce the risks of mating and fertilization failures and territory loss resulting from male-male competition.

Toward a New Model of Fertility: The Effects of the World Economic System and the Status of Women on Fertility Behavior.

ERIC Educational Resources Information Center

Ward, Kathryn B.

A relationship exists between high birth rates and the lowered status of women in developing nations, resulting from their country's economic development. Research was based on data from various sources on 34 developed nations and 92 developing nations throughout the world. Variables included income inequality, foreign trade structure and…

Proximate determinants of fertility in peninsular Malaysia.

PubMed

Tey, Nai Peng; Ng, Sor Tho; Yew, Siew Yong

2012-05-01

The continuing decline in fertility despite a contraction in contraceptive use in Peninsular Malaysia since the mid-1980s has triggered considerable interest in the reasons behind this phenomenon, such as increase in abortion, sterility, and out-of-wedlock pregnancy. Fertility decline has been attributed to rapid socioeconomic development, which can only influence fertility through the intermediate variables. Application of vital statistics, population census, and survey data of Peninsular Malaysia on Bongaarts's model vindicates that marriage postponement and contraceptive use are the 2 most important proximate determinants of fertility, but the effects are not uniform across the ethnic groups. For instance, the predicted total fertility rate for Chinese and Malays are 2.9 and 1.6, respectively, compared with the observed level of 3.0 and 1.9. Postpartum infecundability and abortion also play a part in explaining ethnic fertility differentials. The fertility inhibiting effects of these proximate determinants have significant implications on reproductive health and future population growth.

Sperm quality variables as indicators of bull fertility may be breed dependent.

PubMed

Morrell, Jane M; Nongbua, Thanapol; Valeanu, Sabina; Lima Verde, Isabel; Lundstedt-Enkel, Katrin; Edman, Anders; Johannisson, Anders

2017-10-01

A means of discriminating among bulls of high fertility based on sperm quality is needed by breeding centers. The objective of the study was to examine parameters of sperm quality in bulls of known fertility to identify useful indicators of fertility. Frozen semen was available from bulls of known fertility (Viking Genetics, Skara, Sweden): Swedish Red (n=31), Holstein (n=25) and Others (one each of Charolais, Limousin, Blonde, SKB). After thawing, the sperm samples were analyzed for motility (computer assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity and reactive oxygen species. A fertility index score based on the adjusted 56-day non-return rate for >1000 inseminations was available for each bull. Multivariate data analysis (Partial Least Squares Regression and Orthogonal Partial Least Squares Regression) was performed to identify variables related to fertility; Pearson univariate correlations were made on the parameters of interest. Breed of bull affected the relationship of sperm quality variables and fertility index score, as follows: Swedish Red: %DNA Fragmentation Index, r=-0.56, P<0.01; intact plasma membrane, r=0.40, P<0.05; membrane damaged, not acrosome reacted, r=-0.6, P<0.01; Linearity, r=0.37, P<0.05; there was a trend towards significance for Wobble, r=0.34, P=0.08. Holstein: Linearity was significant r=0.46, P<0.05; there was a trend towards significance for Wobble, r=0.45, P=0.08. In conclusion, breed has a greater effect on sperm quality than previously realized; different parameters of sperm quality are needed to indicate potential fertility in different breeds. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of Socio-Health Factors on Life Expectancy in the Low and Lower Middle Income Countries

PubMed Central

MONDAL, Md. Nazrul Islam; SHITAN, Mahendran

2013-01-01

Abstract Background This study is concerned with understanding the impact of demographic changes, socioeconomic inequalities, and the availability of health factors on life expectancy (LE) in the low and lower middle income countries. Methods The cross-country data were collected from 91 countries from the United Nations agencies in 2012. LE is the response variable with demographics (total fertility rate, and adolescent fertility rate), socioeconomic status (mean year of schooling, and gross national income per capita), and health factors (physician density, and HIV prevalence rate) are as the three main predictors. Stepwise multiple regression analysis is used to extract the main factors. Results The necessity of more healthcare resources and higher levels of socioeconomic advantages are more likely to increase LE. On the other hand, demographic changes and health factors are more likely to increase LE by way of de-cease fertility rates and disease prevalence. Conclusion These findings suggest that international efforts should aim at increasing LE, especially in the low income countries through the elimination of HIV prevalence, adolescent fertility, and illiteracy. PMID:26060637

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

PubMed

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 < 0.0001) higher proportion of does that became pregnant than did the ewes in the lowest decile (56, 54, 58, and 49 %, respectively). In sheep, the fertility rates of the highest decile of mean (62 %), maximum (62 %), and minimum (52 %) temperature, RH (52 %), THI (53 %), and rainfall (45 %) were significantly higher (P < 0.0001) than were the fertility rates among ewes in the lowest decile (46, 45, 45, 45, 46, and 43 %, respectively). In conclusion, weather was related to fertility in small ruminants after 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.

Female employment reduces fertility in rural Senegal.

PubMed

Van den Broeck, Goedele; Maertens, Miet

2015-01-01

Economic growth and modernization of society are generally associated with fertility rate decreases but which forces trigger this is unclear. In this paper we assess how fertility changes with increased labor market participation of women in rural Senegal. Evidence from high-income countries suggests that higher female employment rates lead to reduced fertility rates but evidence from developing countries at an early stage of demographic transition is largely absent. We concentrate on a rural area in northern Senegal where a recent boom in horticultural exports has been associated with a sudden increase in female off-farm employment. Using survey data we show that employed women have a significantly higher age at marriage and at first childbirth, and significantly fewer children. As causal identification strategy we use instrumental variable and difference-in-differences estimations, combined with propensity score matching. We find that female employment reduces the number of children per woman by 25%, and that this fertility-reducing effect is as large for poor as for non-poor women and larger for illiterate than for literate women. Results imply that female employment is a strong instrument for empowering rural women, reducing fertility rates and accelerating the demographic transition in poor countries. The effectiveness of family planning programs can increase if targeted to areas where female employment is increasing or to female employees directly because of a higher likelihood to reach women with low-fertility preferences. Our results show that changes in fertility preferences not necessarily result from a cultural evolution but can also be driven by sudden and individual changes in economic opportunities.

Female Employment Reduces Fertility in Rural Senegal

PubMed Central

2015-01-01

Economic growth and modernization of society are generally associated with fertility rate decreases but which forces trigger this is unclear. In this paper we assess how fertility changes with increased labor market participation of women in rural Senegal. Evidence from high-income countries suggests that higher female employment rates lead to reduced fertility rates but evidence from developing countries at an early stage of demographic transition is largely absent. We concentrate on a rural area in northern Senegal where a recent boom in horticultural exports has been associated with a sudden increase in female off-farm employment. Using survey data we show that employed women have a significantly higher age at marriage and at first childbirth, and significantly fewer children. As causal identification strategy we use instrumental variable and difference-in-differences estimations, combined with propensity score matching. We find that female employment reduces the number of children per woman by 25%, and that this fertility-reducing effect is as large for poor as for non-poor women and larger for illiterate than for literate women. Results imply that female employment is a strong instrument for empowering rural women, reducing fertility rates and accelerating the demographic transition in poor countries. The effectiveness of family planning programs can increase if targeted to areas where female employment is increasing or to female employees directly because of a higher likelihood to reach women with low-fertility preferences. Our results show that changes in fertility preferences not necessarily result from a cultural evolution but can also be driven by sudden and individual changes in economic opportunities. PMID:25816301

Fertility effects of abortion and birth control pill access for minors.

PubMed

Guldi, Melanie

2008-11-01

This article empirically assesses whether age-restricted access to abortion and the birth control pill influence minors' fertility in the United States. There is not a strong consensus in previous literature regarding the relationship between laws restricting minors' access to abortion and minors' birth rates. This is the first study to recognize that state laws in place prior to the 1973 Roe v. Wade decision enabled minors to legally consent to surgical treatment-including abortion-in some states but not in others, and to construct abortion access variables reflecting this. In this article, age-specific policy variables measure either a minor's legal ability to obtain an abortion or to obtain the birth control pill without parental involvement. I find fairly strong evidence that young women's birth rates dropped as a result of abortion access as well as evidence that birth control pill access led to a drop in birth rates among whites.

Economic Efficiency On Overseeding Grasslands From Preajba - Gorj County In 2014

NASA Astrophysics Data System (ADS)

Dragoş Mihai, Medelete; Radu Lucian, Pânzaru

2015-09-01

This study was achieved using the support of strategic project "Support Scholarships University in Romania by the European Doctoral and Post-doctoral (SCHOLARSHIPS DOC-POSTDOC)", ID 133255. The paper emphasizes the importance of meadows and hayfields production, considering that their value can be increased using over-seeding and organic-mineral fertilizers. Experience is located in the Experimental Center for Meadows Culture -Preajba, Gorj County, on natural meadow of Agrostis capillaris, over-seeded with Red clover. The production have increase with fertilizer dose, but maximum economic efficiency was found on variant that use only organically fertilizer. It should be noted that organic fertilizers are used in the first year only partially by plants. The indicators of economic efficiency used are: raw product, variable costs, fixed costs, production costs, and the indices: total expenditure rate of profit, income taxes, net profit and net profit rate.

The impacts of health, education, family planning and electrification programs on fertility, mortality and child schooling in East Java, Indonesia.

PubMed

Wirakartakusumah, M D

1988-06-01

This paper examines the effects of public health, family planning, education, electrification, and water supply programs on fertility, child mortality, and school enrollment decisions of rural households in East Java, Indonesia. The theoretical model assumes that parents maximize a utility function, subject to 1) a budget constraint that equates income with expenditures on children (including schooling and health inputs), and 2) a production function that relates health inputs to child survival possibilities. Public programs affect prices of contraceptives, schooling and health inputs, and environmental conditions that in turn affect child survival. Data are taken from the 1980 East Java Population Survey, the Socio-economic Survey, and the Detailed Village Census. The final sample consists of 3170 rural households with married women of childbearing age. Ordinary least squares and logit regressions of recent fertility, child mortality, and school enrollment on program and household variables yielded the following findings. 1) The presence of maternal and child health clinics reduced fertility but not mortality. 2) The presence of public health centers strongly reduced mortality but not fertility. 3) The presence of contraceptive distribution centers had no effect on fertility. 4) School attendance rates were influenced positively by the availability of primary and secondary schools. 5) Health and family planning programs had no effects on schooling. 6) The availability of public latrines reduced fertility and mortality. 7) The water supply variable did not affect the dependent variables when ordinary least squares techniques were applied but had statistically significant impact when logit methods were used. 8) Electricity supply had little effect on the dependent variables. 9) The mother's schooling had a strong positive correlation with children's schooling but no effect on fertility or mortality. 10) Household expenditures were related positively to school attendance and negatively to mortality. 11) There was little or no interaction between household variables and presence of government programs. 12) Subprovincial area measures of service availability appeared more appropriate for public health and family planning services, while village-level measures appeared more appropriate for schooling.

Estrogen supplementation to progesterone as luteal phase support in patients undergoing in vitro fertilization: systematic review and meta-analysis.

PubMed

Zhang, Xiao-Mei; Lv, Fang; Wang, Pin; Huang, Xia-Man; Liu, Kai-Feng; Pan, Yu; Dong, Nai-Jun; Ji, Yu-Rong; She, Hong; Hu, Rong

2015-02-01

Meta-analyses have found conflicting results with respect to the use of progesterone or progesterone plus estrogen as luteal phase support for in vitro fertilization (IVF) protocols involving gonadotropins and/or gonadotropin-releasing hormone analogs. The aim of the present study was to perform an updated meta-analysis on the efficacy of progesterone versus progesterone plus estrogen as luteal phase support. We searched the MEDLINE, Cochrane Library, and Google Scholar databases (up to March 18, 2014). The search terms were (estrogen OR estradiol OR oestradiol) AND (progesterone) AND (IVF OR in vitro fertilization) AND (randomized OR prospective). We did not limit the form of estrogen and included subjects who contributed more than 1 cycle to a study. The primary outcome was clinical pregnancy rate. Secondary outcomes were ongoing pregnancy rate, fertilization rate, implantation rate, and miscarriage rate. A total of 11 articles were included in the present analysis, with variable numbers of studies assessing each outcome measure. Results of statistical analyses indicated that progesterone plus estrogen treatment was more likely to result in clinical pregnancy than progesterone alone (pooled odds ratio 1.617, 95% confidence interval 1.059-2.471; P = 0.026). No significant difference between the 2 treatment regimens was found for the other outcome measures. Progesterone plus estrogen for luteal phase support is associated with a higher clinical pregnancy rate than progesterone alone in women undergoing IVF, but other outcomes such as ongoing pregnancy rate, fertilization rate, implantation rate, and miscarriage rate are the same for both treatments.

Intraspecific variation in fine root respiration and morphology in response to in situ soil nitrogen fertility in a 100-year-old Chamaecyparis obtusa forest.

PubMed

Makita, Naoki; Hirano, Yasuhiro; Sugimoto, Takanobu; Tanikawa, Toko; Ishii, Hiroaki

2015-12-01

Soil N fertility has an effect on belowground C allocation, but the physiological and morphological responses of individual fine root segments to variations in N availability under field conditions are still unclear. In this study, the direction and magnitude of the physiological and morphological function of fine roots in response to variable in situ soil N fertility in a forest site were determined. We measured the specific root respiration (Rr) rate, N concentration and morphology of fine root segments with 1-3 branching orders in a 100-year-old coniferous forest of Chamaecyparis obtusa. Higher soil N fertility induced higher Rr rates, root N concentration, and specific root length (SRL), and lower root tissue density (RTD). In all fertility levels, the Rr rates were significantly correlated positively with root N and SRL and negatively with RTD. The regression slopes of respiration with root N and RTD were significantly higher along the soil N fertility gradient. Although no differences in the slopes of Rr and SRL relationship were found across the levels, there were significant shifts in the intercept along the common slope. These results suggest that a contrasting pattern in intraspecific relationships between specific Rr and N, RTD, and SRL exists among soils with different N fertility. Consequently, substantial increases in soil N fertility would exert positive effects on organ-scale root performance by covarying the Rr, root N, and morphology for their potential nutrient and water uptake.

Soviet fertility, labor-force participation, and marital stability.

PubMed

Kuniansky, A

1983-06-01

A simultaneous-equations model of Soviet fertility and labor-force participation is estimated from a cross section of 72 oblast's of the Russian Republic (RSFSR) reported in the 1970 census. The construction of the model is based on the neoclassical theory of household behavior. Simulated changes capture effects of policy changes in the exogenous variables on Soviet fertility and the female labor supply. The exogenous variables investigated are child care facilities (CC), urbanization ratio (URB), male education (MALED), and female education (FEMED). It was found that an increase in FEMED affects labor force participation (LFP) directly and indirectly through impact on birth rate (BR). Increase in CC raise both LFP and BR; increases in FEMED causes womens withdrawal from the labor force and one would expect this to raise BR; however, FEMED raises the opportunity costs of fertility sufficiently to neutralize this effect. Increasing urbanization does not affect participation in a significant way, but it does retard fertility. This effect works through LFP's impact on BR and the indirect effect working through marital stability. A final set of simulations captured the impact of upward shocks of LFP, BR, and the ratio of divorces to marriages (DIV/MAR) on the endogenous variables. Such changes could occur through changes in abortion laws, tightening of divorce laws, or changes in labor legislation. Participation is reduced by the fertility shock, just as fertility is retarded by the LPF and marital stability shocks. Evidence of a backward-bending labor-supply curve was also found. The model is illustrated by tables and charts.

Wealth, intelligence, politics and global fertility differentials.

PubMed

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.

Fertility following CIDR based synchronization regimens in anoestrous Nili-Ravi buffaloes.

PubMed

Naseer, Z; Ahmad, E; Singh, J; Ahmad, N

2011-10-01

The objective of this study was to compare oestrus expression and fertility rate in used and new controlled internal drug releasing (CIDR) device treated anoestrous buffaloes. Furthermore, to determine the timing of ovulation, and fertility rate in estradiol benzoate (EB) and GnRH-administered CIDR-treated anoestrous Nili-Ravi buffaloes. In experiment 1, buffaloes received either a used CIDR (UCIDR, n = 35) or a new CIDR (NCIDR, n = 36) for 7 day and PGF2α on day 6. Oestrous expression was similar (p > 0.05) between UCIDR (88.5%) and NCIDR (96.6%) buffaloes. The pregnancy rate did not differ (p > 0.05) because of treatment (37.1% in UCIDR vs 36.6% in NCIDR). In experiment 2, buffaloes (n = 55) received CIDR device for 7 days and PGF2α, on day 6 and randomly assigned into three treatment groups: (i) CIDR-EB (n = 17) received EB on day 8, (ii) CIDR-GnRH (n = 18) received GnRH on day 9 and (iii) control (n = 20) received no further treatment. Mean interval from CIDR removal to ovulation in CIDR-EB, CIDR-GnRH and CIDR group were 61.3 ± 0.8, 64.9 ± 1.8 and 65.1 ± 16.7 h, respectively. However, the buffaloes in the CIDR-EB and CIDR-GnRH group had lesser variability in the timing of ovulation compared to control. The pregnancy rate of both CIDR-EB group (58%) and CIDR-GnRH group (61%) were tended to be higher (p < 0.1) than control (30%). In conclusion, compared to NCIDR devices, previously UCIDR devices are equally effective to induce oestrus in anoestrous buffaloes resulting optimal pregnancy rate. Administration of EB and GnRH after CIDR removal results in tighter synchrony (less variability) and improved fertility in anoestrous buffaloes. CIDR based synchronization regimens have great potential in fertility improvement in anoestrous buffaloes. © 2011 Blackwell Verlag GmbH.

Natural and artificial spawning strategies with fresh and cryopreserved semen in Rhamdia quelen: Reproductive parameters and genetic variability of offspring.

PubMed

Goes, Marcio Douglas; Reis Goes, Elenice Souza Dos; Ribeiro, Ricardo Pereira; Lopera-Barrero, Nelson Maurício; Castro, Pedro Luiz de; Bignotto, Thaís Souto; Bombardelli, Robie Allan

2017-01-15

This study evaluated the reproductive parameters and genetic variability of offspring of Rhamdia quelen from mating by natural spawning and by controlled fertilization with fresh and cryopreserved semen. After hormonal manipulation, three R quelen pairs were used for natural spawning in high-flow tanks, three pairs were used for mating with fresh semen, and another three pairs were used with cryopreserved semen. Matings were performed in triplicate. For matings with fresh and cryopreserved semen, semen from each male was used to individually fertilize oocytes from each female. Pools of semen and oocytes were made, and aliquots of these gametes were taken for fertilization. No differences (P > 0.05) were detected for absolute or relative fecundity, fertilization rate, or egg hatching rate. The use of fresh semen led to a higher (P < 0.01) percentage of normal larvae. The use of fresh semen in pooled mating resulted in a greater effective number of alleles and a higher expected heterozygosity. Offspring from natural spawning presented higher observed heterozygosity and a lower inbreeding coefficient. The highest inbreeding coefficient was found in offspring from individual matings using fresh semen. Regarding paternal contributions, a single male dominated in matings with fresh semen, whereas two males dominated in natural spawning and matings using cryopreserved semen. The use of gamete pools for mating and natural spawning resulted in higher genetic variability of offspring, and mating using cryopreserved semen found no effects on genetic variability of offspring but did reduce the percentage of normal larvae. Other reproductive parameters were not influenced by spawning strategies. Copyright © 2016. Published by Elsevier Inc.

Fertility decline and social service access: reconciling behavioral and medical models.

PubMed

Weinstein, J

1978-01-01

In this summary of fertility literature the author attempts to differentiate between the effects of behavioral and medical models of family planning programs on the fertility rate. This is done by determining the effects of access to social welfare services by assessment of: the function of children within the family life survey conducted in the Cameroons are also used. It was found that 7 interdependent elements of social service are involved: 1) general health care; 2) social security for sick and aged; 3) employment training and opportunities for adults; 4) literacy and education; 5) communication and transportation systems; 6) housing and infrastructure; 7) child care and welfare. The presence of these elements is shown to accompany low fertility while their absence is expressed in high rates of child bearing. These elements are major variables in both the nomological and public policy senses. 2 additional components are knowledge of and favorable attitudes towards effective means of fertility control plus effective mechanical, chemical, or natural means of limiting fertility. The concept of fertility norm and its impact on the fertility rate is explained as being the result of the collective force which social affiliations exert on people to reproduce in a certain way. The "stopping rule" is that which will fulfill the fertility norm. An example of this is a culture which continues child bearing until a son has been born and then controls reproduction after this has happened. Such factors must be considered for family planning programs to succeed in these cultures. Therefore fertility levels are found to be the product of prevailing norms and technical ability to achieve these norms. Improvement in levels of access to social services can bring about the lowering of these norms.

Estimating the impact of birth control on fertility rate in sub-Saharan Africa.

PubMed

Ijaiya, Gafar T; Raheem, Usman A; Olatinwo, Abdulwaheed O; Ijaiya, Munir-Deen A; Ijaiya, Mukaila A

2009-12-01

Using a cross-country data drawn from 40 countries and a multiple regression analysis, this paper examines the impact of birth control devices on the rate of fertility in sub-Saharan Africa. Our a-priori expectations are that the more women used birth control devices, the less will be the fertility rate in sub-Saharan Africa. The result obtained from the study indicates that except for withdrawal method that fall contrary to our expectation other variables (methods) like the use of pills, injection, intra uterine device (IUD), condom/diaphragm and cervical cap, female sterilization and periodic abstinence/rhythm fulfilled our a-priori expectations. These results notwithstanding, the paper suggests measures, such as the need for massive enlightenment campaign on the benefit of these birth control devices, the frequent checking of the potency of the devices and good governance in the delivery of the devices

How does variance in fertility change over the demographic transition?

PubMed Central

Hruschka, Daniel J.; Burger, Oskar

2016-01-01

Most work on the human fertility transition has focused on declines in mean fertility. However, understanding changes in the variance of reproductive outcomes can be equally important for evolutionary questions about the heritability of fertility, individual determinants of fertility and changing patterns of reproductive skew. Here, we document how variance in completed fertility among women (45–49 years) differs across 200 surveys in 72 low- to middle-income countries where fertility transitions are currently in progress at various stages. Nearly all (91%) of samples exhibit variance consistent with a Poisson process of fertility, which places systematic, and often severe, theoretical upper bounds on the proportion of variance that can be attributed to individual differences. In contrast to the pattern of total variance, these upper bounds increase from high- to mid-fertility samples, then decline again as samples move from mid to low fertility. Notably, the lowest fertility samples often deviate from a Poisson process. This suggests that as populations move to low fertility their reproduction shifts from a rate-based process to a focus on an ideal number of children. We discuss the implications of these findings for predicting completed fertility from individual-level variables. PMID:27022082

Interactive effects of substrate, hydroperiod, and nutrients on seedling growth of Salix nigra and Taxodium distichum

USGS Publications Warehouse

Day, Richard H.; Doyle, T.W.; Draugelis-Dale, R. O.

2006-01-01

The large river swamps of Louisiana have complex topography and hydrology, characterized by black willow (Salix nigra) dominance on accreting alluvial sediments and vast areas of baldcypress (Taxodium distichum) deepwater swamps with highly organic substrates. Seedling survival of these two wetland tree species is influenced by their growth rate in relation to the height and duration of annual flooding in riverine environments. This study examines the interactive effects of substrate, hydroperiod, and nutrients on growth rates of black willow and baldcypress seedlings. In a greenhouse experiment with a split-split-plot design, 1-year seedlings of black willow and baldcypress were subjected to two nutrient treatments (unfertilized versus fertilized), two hydroperiods (continuously flooded versus twice daily flooding/draining), and two substrates (sand versus commercial peat mix). Response variables included height, diameter, lateral branch count, biomass, and root:stem ratio. Black willow growth in height and diameter, as well as all biomass components, were significantly greater in peat substrate than in sand. Black willow showed a significant hydroperiod-nutrient interaction wherein fertilizer increased stem and root biomass under drained conditions, but flooded plants did not respond to fertilization. Baldcypress diameter and root biomass were higher in peat than in sand, and the same two variables increased with fertilization in flooded as well as drained treatments. These results can be used in Louisiana wetland forest models as inputs of seedling growth and survival, regeneration potential, and biomass accumulation rates of black willow and baldcypress.

The relationship between poverty and fertility in Peninsular Malaysia: a district analysis.

PubMed

Teo Cheok Chin, P

1989-01-01

An analysis of the poverty-fertility association in Peninsular Malaysia indicates that the decision to replace the 1970 New Economic Policy, aimed at redistributing income, with a policy based on economic growth through foreign investment may create serious demographic problems for the country. Although the country's crude birth rate fell from 40/1000 in 1950 to 30.3/1000 in 1975, the Malays (55%) of the population experienced only a 3% decline in this period and rural-urban differentials in fertility remained. Data from the 1980 Malaysian census on variables related to absolute and relative poverty confirm the serious nature of Malay rural poverty. Stepwise regression models for the urban-rural and Malay-Chinese factors used the following variables: % Malay, household possession dissimilarity index, ratio of Malay to non-Malay workers who are self-employed and unpaid family workers, ratio of Malay to non-Malay who own their housing, education dissimilarity index, employment rate dissimilarity, households with sanitation, households with electricity, households with piped water, per capita expenditures for basic needs, per capita expenditure for redistributing wealth, average education, median age at marriage, female labor force participation, % of child workers, % married, % rural, and % in agriculture. The partial correlation of the Malay-Chinese component with fertility was 0.42 while the urban-rural correlation was 0.33, suggesting that the ethnic factor is operable even in conditions of rural poverty. Urban poverty can be ameliorated by the provision of infrastructural facilities and Chinese poverty is reduced by the level of modernization, while Malay poverty is responsive to income redistribution. Unless the government reconsiders its policy, the high fertility rates in the impoverished, largely Malay, rural northwest, northeast, central, and east parts will persist.

Climate variability and nitrogen rate interactions affecting corn nitrogen use efficiency in Alabama

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) fertilization is an important practice to increase yield; however, plant–soil interactions to in-season changes in climatic conditions result on site-specific responses of corn to nitrogen rates. The objective of this study was to evaluate the effect of different climatic conditions and...

Relationship between conventional semen characteristics, sperm motility patterns and fertility of Andalusian donkeys (Equus asinus).

PubMed

Dorado, J; Acha, D; Ortiz, I; Gálvez, M J; Carrasco, J J; Díaz, B; Gómez-Arrones, V; Calero-Carretero, R; Hidalgo, M

2013-12-01

Sperm quality has an important role in determining fertility. The aims of this study were to compare the conventional sperm parameters, plus the characteristics of the motility patterns of the different sperm subpopulations, of donkey donors with different fertility level, and to determine their relationships to fertility. Thirty ejaculates from 6 Andalusian donkeys were assessed for gel-free volume, pH, sperm concentration, motility and morphology. The fertility of donkeys was classified on the basis of pregnancy rates per cycle, where donkeys with a per cycle pregnancy rate ≥60% were considered to be "fertile" (n=3) and those with a per cycle pregnancy rate <40% were categorized to be "sub-fertile" (n=3). Significant differences (P<0.001) between the "fertile" and the "sub-fertile" group were found for total and progressive motility, and for straight line velocity. Sperm variables associated (P<0.05) with an increase in percent pregnant per cycle included total motility (r=0.37), progressive motility (r=0.53), curvilinear velocity (r=0.44), straightness (r=0.39), beat cross frequency (r=0.44), and gel-free volume (r=0.53). Four sperm subpopulations (sP) were identified in fresh semen: sP1 (slow and non-progressive spermatozoa, 20%), sP2 (moderately slow but progressive spermatozoa, 71.2%), sP3 (highly active but non-progressive spermatozoa, 2.9%), and sP4 (highly active and progressive spermatozoa, 5.9%). The lowest percentage (3.1%; P<0.001) of sP4 spermatozoa was observed in the "sub-fertile" group. Three of the sperm subpopulations were related (P<0.05) to fertility (sP2, r=0.54; sP3, r=0.45; sP4, r=0.56). In conclusion, we were able to relate the fertility of donkeys with in vitro measures of sperm motility using computer-assisted sperm analysis techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

Impacts of agricultural management and climate change on future soil organic carbon dynamics in North China Plain.

PubMed

Wang, Guocheng; Li, Tingting; Zhang, Wen; Yu, Yongqiang

2014-01-01

Dynamics of cropland soil organic carbon (SOC) in response to different management practices and environmental conditions across North China Plain (NCP) were studied using a modeling approach. We identified the key variables driving SOC changes at a high spatial resolution (10 km × 10 km) and long time scale (90 years). The model used future climatic data from the FGOALS model based on four future greenhouse gas (GHG) concentration scenarios. Agricultural practices included different rates of nitrogen (N) fertilization, manure application, and stubble retention. We found that SOC change was significantly influenced by the management practices of stubble retention (linearly positive), manure application (linearly positive) and nitrogen fertilization (nonlinearly positive) - and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly positive effects, while precipitation had negligible impacts on SOC dynamics under current irrigation management. The effects of increased N fertilization on SOC changes were most significant between the rates of 0 and 300 kg ha-1 yr-1. With a moderate rate of manure application (i.e., 2000 kg ha-1 yr-1), stubble retention (i.e., 50%), and an optimal rate of nitrogen fertilization (i.e., 300 kg ha-1 yr-1), more than 60% of the study area showed an increase in SOC, and the average SOC density across NCP was relatively steady during the study period. If the rates of manure application and stubble retention doubled (i.e., manure application rate of 4000 kg ha-1 yr-1 and stubble retention rate of 100%), soils across more than 90% of the study area would act as a net C sink, and the average SOC density kept increasing from 40 Mg ha-1 during 2010s to the current worldwide average of ∼ 55 Mg ha-1 during 2060s. The results can help target agricultural management practices for effectively mitigating climate change through soil C sequestration.

Impacts of Agricultural Management and Climate Change on Future Soil Organic Carbon Dynamics in North China Plain

PubMed Central

Wang, Guocheng; Li, Tingting; Zhang, Wen; Yu, Yongqiang

2014-01-01

Dynamics of cropland soil organic carbon (SOC) in response to different management practices and environmental conditions across North China Plain (NCP) were studied using a modeling approach. We identified the key variables driving SOC changes at a high spatial resolution (10 km×10 km) and long time scale (90 years). The model used future climatic data from the FGOALS model based on four future greenhouse gas (GHG) concentration scenarios. Agricultural practices included different rates of nitrogen (N) fertilization, manure application, and stubble retention. We found that SOC change was significantly influenced by the management practices of stubble retention (linearly positive), manure application (linearly positive) and nitrogen fertilization (nonlinearly positive) – and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly positive effects, while precipitation had negligible impacts on SOC dynamics under current irrigation management. The effects of increased N fertilization on SOC changes were most significant between the rates of 0 and 300 kg ha−1 yr−1. With a moderate rate of manure application (i.e., 2000 kg ha−1 yr−1), stubble retention (i.e., 50%), and an optimal rate of nitrogen fertilization (i.e., 300 kg ha−1 yr−1), more than 60% of the study area showed an increase in SOC, and the average SOC density across NCP was relatively steady during the study period. If the rates of manure application and stubble retention doubled (i.e., manure application rate of 4000 kg ha−1 yr−1 and stubble retention rate of 100%), soils across more than 90% of the study area would act as a net C sink, and the average SOC density kept increasing from 40 Mg ha−1 during 2010s to the current worldwide average of ∼55 Mg ha−1 during 2060s. The results can help target agricultural management practices for effectively mitigating climate change through soil C sequestration. PMID:24722689

Prediction of the fertility of stallion frozen-thawed semen using a combination of computer-assisted motility analysis, microscopical observation and flow cytometry.

PubMed

Battut, I Barrier; Kempfer, A; Lemasson, N; Chevrier, L; Camugli, S

2017-07-15

Spermatozoa from some stallions do not maintain an acceptable fertility after freezing and thawing. The selection of frozen ejaculates that would be suitable for insemination is mainly based on post-thaw motility, but the prediction of fertility remains limited. A recent study in our laboratory has enabled the determination of a new protocol for the evaluation of fresh stallion semen, combining microscopical observation, computer-assisted motility analysis and flow cytometry, and providing a high level of fertility prediction. The purpose of the present experiment was to perform similar investigations on frozen semen. A panel of tests evaluating a large number of compartments or functions of the spermatozoa was applied to a population of 42 stallions, 33 of which showing widely differing fertilities (17-67% pregnancy rate per cycle [PRC]). Variability was evaluated by calculating the coefficient of variation (CV=SD/mean) and the intra-class correlation or "repeatability" for each variable. For paired variables, mean within-stallion CV% was significantly lower than between-stallion CV%, which was significantly lower than total CV%. Within-ejaculate repeatability, determined by analysing 6 straws for each of 10 ejaculates, ranged from 0.60 to 0.97. Within-stallion repeatability, determined by analysing at least 5 ejaculates for each of 38 stallions, ranged from 0.12 to 0.95. Principal component regression using a combination of 25 variables, including motility, morphology, viability, oxidation level, acrosome integrity, DNA integrity and hypoosmotic resistance, accounted for 94.5% of the variability regarding fertility, and was used to calculate a prediction of the PRC with a mean standard deviation of 2.2. The difference between the observed PRC and the calculated value ranged from -3.4 to 4.2. The 90% confidence interval (90CI) for the prediction of the PRC for the stallions of unknown fertility ranged from 8 to 30 (mean = 17). The best-fit model using only motility variables, evaluated after 10 min at 36 °C and 2 h at 36 °C or room temperature, accounted for only 74.2% of the variability. The difference between the observed PRC and the calculated value ranged from -7.2 to 14. The 90CI for the prediction of the PRC for the stallions of unknown fertility ranged from 23 to 48 (mean = 33). In conclusion, this study demonstrated that an appropriate combination of computer-assisted motility analysis, microscopical observation and flow cytometry can provide a higher prediction of fertility than motility analysis alone. Copyright © 2017 Elsevier Inc. All rights reserved.

An empirical investigation of female labor-force participation, fertility, age at marriage, and wages in Korea.

PubMed

Lee, B S; Mcelwain, A M

1985-07-01

The Korean experience raises questions about the assumption that successful economic development and equitable income distribution are preconditions for rapid fertility declines. During the 1960-70 decade, the total fertility rate in Korea declined by 36% and the crude birth rate fell by 33%, in the absence of significant economic development. This paper uses data from the 1974 Korean Fertility Survey to explore the relationships between the factors responsible for this rapid fertility decline. A simultaneous equation model of fertility, age at marriage, extent of labor force participation during marriage, quality of children, and wages is developed and tested. Rather than to provide definitive measures of these interrelationships, the aim was to investigate the utility of treating several variables as being jointly determined. The results suggest that parental education affects fertility by influencing age at marriage, implying that adult education programs will have little effect on marital fertility. There was some evidence that working women whose jobs are compatible with child care have more children than nonworking women, a finding that should be considered in planning increased job opportunities for women. Urbanized women and those who work before marriage tend to marry later than their less urbanized counterparts or women who do not work prior to marriage. Finally, women who used modern methods of birth control had significantly lower fertility than nonusers of modern methods. There is concern that the Government has reduced budgetary appropriations to family planning since the goal of reducing the annual population growth rate from 3% in 1960 to 2% in 1970 was achieved. It is suggested that family planning expenditures should be deployed to areas such as urban slums that have not yet been reached by family planning programs.

Estimating family planning program effects on U.S. fertility rates.

PubMed

Cutright, P; Jaffe, F S

1977-08-01

An evaluation was undertaken of the effects on U. S. fertility rates of the national family planning program. 1968-1969 family planning enrollment data were linked to 1970 census data in the same areas to derive an objective measure of the impact of organized clinical family planning programs on the 1969-70 fertility rates of subgroups of women defined by age, race, marital status, economic status, and racial composition of their area. Multivariate modelling was used to control for spurious effects of irrelevant variables. Results of the multivariate modelling show significant reductions of marital fertility among the low socioeconomic groups served by the program; no effects were exhibited by groups not served. Cumulative fertility of all groups, black and white, at all age and socioeconomic levels was affected by the program. A plausible explanation for these results lies in antecedent factors which led to the presence or absence of family planning clinics in any particular area in 1969 and its 1969 enrollment level. Communities more favorably disposed to provision of birth control services would have been more likely than other areas to apply for federal funding of family planning programs when it became available in the middle 1960s. Due to an earlier start, their programs were flourishing by 1969.

Less than 50% nitrogen retention 1-year after high N additions to Pacific Northwest Douglas-fir forests

NASA Astrophysics Data System (ADS)

Michelsen-Correa, S.; Harrison, R. B.

2017-12-01

In Pacific Northwest forests, N is known to be a limiting nutrient particularly in Douglas-fir (Pseudotsuga menziesii) ecosystems. Fertilizers are commonly applied to increase productivity in commercially managed forests. Despite known N limitations, Douglas-fir uptake of applied fertilizers is typically low and highly variable depending on environmental site conditions of a particular forest. We measured N recovery within a 1-year time frame at five sites using a fertilizer enriched in 15N as a tracer. Comparisons were also made between Enhanced Efficiency Fertilizers (EEFs) and an unformulated urea fertilizer to determine if N recovery is improved with fertilizers designed to limit volatile losses of ammonia. Retention was low across all sites and fertilizer types with a mean of 39.0% recovered after 1-year. The largest fertilizer pool was the top 20cm of mineral soil. The use of EFFs as a management tool to improve N use efficiency at the five sites in our study is not supported by our results as no significant differences in total 1-year N recovery or tree uptake of N were observed between treatments. The low N recovery after 1-year but simultaneous increases in above ground biomass support a model of N loss where the ecosystem can continue to accumulate biomass with simultaneous leaching and gaseous losses of N. This conclusion contrasts with the commonly held assumption that fertilization of N limited Douglas-fir forests, should yield negligible losses of N and high recovery of the applied fertilizer. Additionally, we conclude that management decisions regarding fertilizer use efficiency and the benefits of fertilization need to be site specific due to the variable N recovery rates based on site factors as opposed to fertilizer treatment type. Finally, despite differences in the size of available soil N pools the amount of N recovered in the above group pools (i.e. bole wood and foliage) were not significantly different between sites. N uptake by the plants pools may have been at its maximum, thus additional N in the soil pools would not make a difference in terms of productivity over just one year. It remains to be seen what the longer-term impacts of the fertilizer treatments are, as the sites with a larger reservoir of plant available N are expected to maintain their growth rates for longer than the sites with lower N recovery.

Growth and physiology of aspen supplied with different fertilizer addition rates

Treesearch

Mark D. Coleman; Richard E. Dickson; J.G. Isebrands

1998-01-01

Variable internal plant nutrient content may confound plant response to environmental stress. Plant nutrient content may be controlled with relative addition rate techniques in solution culture. However, because raising large numbers of plants in flowing solution culture is difficult. we investieated the feasibility of raisine plants in soil mix using relative...

[Panel data analysis of health status in Northeast Brazil].

PubMed

Sousa, Tanara Rosângela Vieira; Leite Filho, Paulo Amilton Maia

2008-10-01

To assess health status determinants in Brazil's Northeast states. Study carried out based on panel data analysis of aggregated information for municipalities. Data was obtained from the United Nations Development Program Atlas of Human Development and Brazilian National Treasury Department for the years 1991 and 2000. Health status indicator was infant mortality rate and health determinants were the following variables: per capita health and sanitation expenditure; number of physicians per inhabitant; access to drinking water; fertility rate; illiteracy rate; percentage of adolescent mothers; per capita income; and Gini coefficient. Infant mortality rates in Northeast Brazil were reduced by 31.8%, during the period studied, slightly above the national average. However, in some states, such as Rio Grande do Norte, Bahia, Ceará and Alagoas, the reduction was more significant. This can be attributed to improvement in some indicators that are main determinants of infant mortality rate reduction: greater access to education, reduction of fertility rates, increased income, and access to drinking water. Brazilian states that showed greater gains in access to drinking water, education, income and reduction of fertility rates were also the ones that achieved major reductions in mortality of children under a year of age.

Modeling Spatial and Temporal Variability in Ammonia Emissions from Agricultural Fertilization

NASA Astrophysics Data System (ADS)

Balasubramanian, S.; Koloutsou-Vakakis, S.; Rood, M. J.

2013-12-01

Ammonia (NH3), is an important component of the reactive nitrogen cycle and a precursor to formation of atmospheric particulate matter (PM). Predicting regional PM concentrations and deposition of nitrogen species to ecosystems requires representative emission inventories. Emission inventories have traditionally been developed using top down approaches and more recently from data assimilation based on satellite and ground based ambient concentrations and wet deposition data. The National Emission Inventory (NEI) indicates agricultural fertilization as the predominant contributor (56%) to NH3 emissions in Midwest USA, in 2002. However, due to limited understanding of the complex interactions between fertilizer usage, farm practices, soil and meteorological conditions and absence of detailed statistical data, such emission estimates are currently based on generic emission factors, time-averaged temporal factors and coarse spatial resolution. Given the significance of this source, our study focuses on developing an improved NH3 emission inventory for agricultural fertilization at finer spatial and temporal scales for air quality modeling studies. Firstly, a high-spatial resolution 4 km x 4 km NH3 emission inventory for agricultural fertilization has been developed for Illinois by modifying spatial allocation of emissions based on combining crop-specific fertilization rates with cropland distribution in the Sparse Matrix Operator Kernel Emissions model. Net emission estimates of our method are within 2% of NEI, since both methods are constrained by fertilizer sales data. However, we identified localized crop-specific NH3 emission hotspots at sub-county resolutions absent in NEI. Secondly, we have adopted the use of the DeNitrification-DeComposition (DNDC) Biogeochemistry model to simulate the physical and chemical processes that control volatilization of nitrogen as NH3 to the atmosphere after fertilizer application and resolve the variability at the hourly scale. Representative temporal factors are being developed to capture crop-specific NH3 emission variability by combining knowledge of local crop management practices with high resolution cropland and soil maps. This improved spatially and temporally dependent NH3 emission inventory for agricultural fertilization is being prepared as a direct input to a state of the art air quality model to evaluate the effects of agricultural fertilization on regional air quality and atmospheric deposition of reactive nitrogen species.

Observations on preferential flow and horizontal transport of nitrogen fertilizer in the unsaturated zone

USGS Publications Warehouse

Wilkison, D.H.; Blevins, D.W.

1999-01-01

A study site underlain by a claypan soil was instrumented to examine the transport of fertilizer nitrogen (N) under corn (Zea mays L.) cultivation. The study was designed to examine N transport within the unsaturated zone and in interflow (the saturated flow of water on top of the claypan). A 15N- labeled fertilizer (labeled N), bromide (Br), and chloride (Cl) were used as field tracers. Rapid or prolonged infiltration events allowed water and dissolved solutes to perch on the claypan for brief periods. However, a well- developed network of preferential flow paths quickly diverted water and solutes through the claypan and into the underlying glacial till aquifer. Excess fertilizer N in the unsaturated zone supplied a continuous, but declining input of N to ground water for a period of 15 mo after a single fertilizer application. Calculated solute velocities through the claypan matrix (6.4 x 10-6 cm s-1) were similar to horizontal transport rates along the claypan (3.5 to 7.3 x 10-6 cm s-1) but much slower than infiltration rates determined for preferential flow paths (1.67 x 10-3 cm s-1). These flow paths accounted for 35% of the transport. A seasonally variable, dual mode of transport (matrix and preferential flow) prevented the claypan from being an effective barrier to vertical transport. Simulations of selected field observations, conducted using the variably saturated two- dimensional flow and transport model, VS2DT, confirmed the presence of a dual flow regime in the claypan.

Reproductive trade-offs in extant hunter-gatherers suggest adaptive mechanism for the Neolithic expansion

PubMed Central

Viguier, Sylvain; Dyble, Mark; Smith, Daniel; Salali, Gul Deniz; Thompson, James; Vinicius, Lucio; Migliano, Andrea Bamberg

2016-01-01

The Neolithic demographic transition remains a paradox, because it is associated with both higher rates of population growth and increased morbidity and mortality rates. Here we reconcile the conflicting evidence by proposing that the spread of agriculture involved a life history quality–quantity trade-off whereby mothers traded offspring survival for increased fertility, achieving greater reproductive success despite deteriorating health. We test this hypothesis by investigating fertility, mortality, health, and overall reproductive success in Agta hunter-gatherers whose camps exhibit variable levels of sedentarization, mobility, and involvement in agricultural activities. We conducted blood composition tests in 345 Agta and found that viral and helminthic infections as well as child mortality rates were significantly increased with sedentarization. Nonetheless, both age-controlled fertility and overall reproductive success were positively affected by sedentarization and participation in cultivation. Thus, we provide the first empirical evidence, to our knowledge, of an adaptive mechanism in foragers that reconciles the decline in health and child survival with the observed demographic expansion during the Neolithic. PMID:27071109

Fertility after intrauterine device removal: a pilot study.

PubMed

Stoddard, Amy M; Xu, Hanna; Madden, Tessa; Allsworth, Jenifer E; Peipert, Jeffrey F

2015-06-01

Despite high efficacy, only 7.7% of women in the United States currently using contraception use an IUD. There is little published contemporary data about fertility rates after IUD use, especially in nulliparous women and women using the hormonal IUD. We recruited sexually active women 18 to 35 years of age enrolled in the Contraceptive CHOICE Project who had discontinued a contraceptive method and desired pregnancy. In this pilot project, we enrolled 69 former IUD users (19 copper and 50 levonorgestrel) and 42 former non-IUD users. Pregnancy rates at 12 months were similar between the two groups; 81% of IUD users became pregnant compared to 70% of non-IUD users (p = 0.18). In the Cox model, there was no difference in the time to pregnancy in IUD users compared to non-IUD users (HRadj 1.19, 95% CI 0.74-1.92). African American race was the only variable associated with reduced fertility (HRadj 0.40, 95% CI 0.24-0.67). We found no difference in 12-month pregnancy rates or time to pregnancy between former IUD users and users of other contraceptive methods. However, there was a clinically and statistically significant reduction in fertility in African American women.

Examining the impacts of increased corn production on groundwater quality using a coupled modeling system.

PubMed

Garcia, Valerie; Cooter, Ellen; Crooks, James; Hinckley, Brian; Murphy, Mark; Xing, Xiangnan

2017-05-15

This study demonstrates the value of a coupled chemical transport modeling system for investigating groundwater nitrate contamination responses associated with nitrogen (N) fertilizer application and increased corn production. The coupled Community Multiscale Air Quality Bidirectional and Environmental Policy Integrated Climate modeling system incorporates agricultural management practices and N exchange processes between the soil and atmosphere to estimate levels of N that may volatilize into the atmosphere, re-deposit, and seep or flow into surface and groundwater. Simulated values from this modeling system were used in a land-use regression model to examine associations between groundwater nitrate-N measurements and a suite of factors related to N fertilizer and groundwater nitrate contamination. Multi-variable modeling analysis revealed that the N-fertilizer rate (versus total) applied to irrigated (versus rainfed) grain corn (versus other crops) was the strongest N-related predictor variable of groundwater nitrate-N concentrations. Application of this multi-variable model considered groundwater nitrate-N concentration responses under two corn production scenarios. Findings suggest that increased corn production between 2002 and 2022 could result in 56% to 79% increase in areas vulnerable to groundwater nitrate-N concentrations ≥5mg/L. These above-threshold areas occur on soils with a hydraulic conductivity 13% higher than the rest of the domain. Additionally, the average number of animal feeding operations (AFOs) for these areas was nearly 5 times higher, and the mean N-fertilizer rate was 4 times higher. Finally, we found that areas prone to high groundwater nitrate-N concentrations attributable to the expansion scenario did not occur in new grid cells of irrigated grain-corn croplands, but were clustered around areas of existing corn crops. This application demonstrates the value of the coupled modeling system in developing spatially refined multi-variable models to provide information for geographic locations lacking complete observational data; and in projecting possible groundwater nitrate-N concentration outcomes under alternative future crop production scenarios. Published by Elsevier B.V.

Multilevel models of fertility determination in four Southeast Asian countries: 1970 and 1980.

PubMed

Hirschman, C; Guest, P

1990-08-01

Using microdata from the 1970 and 1980 censuses, we specify and test multilevel models of fertility determination for four Southeast Asian societies--Indonesia, Peninsular Malaysia, the Philippines, and Thailand. Social context is indexed by provincial characteristics representing women's status, the roles of children, and infant mortality. These contextual variables are hypothesized to have direct and indirect (through individual socioeconomic characteristics) effects on current fertility. The contextual variables account for a modest but significant share of individual variation in fertility and about one-half of the total between area variation in fertility. The women's status contextual variables, particularly modern sector employment, have the largest and most consistent effect on lowered fertility. The results based on the other contextual variables provide mixed support for the initial hypotheses.

Socio-Economic Factors Influencing on Total Fertility Rate in Iran: A Panel Data Analysis for the Period of 2002–2012

PubMed Central

Jafari, Hasan; Jaafaripooyan, Ebrahim; Vedadhir, Abou Ali; Foroushani, Abbas Rahimi; Ahadinejad, Bahman; Pourreza, Abolghasem

2016-01-01

Introduction Over the last few decades, total fertility rate (TFR) has followed a downward trend in Iran. The consequences of this trend from the perspectives of some are negative. Considering the macro-population policies in recent years, this study aimed to examine the effect of some macro socio-economic variables, including divorce, marriage, urbanization, and unemployment rate on TFR in Iran from 2002 to 2012. Methods This time series research was conducted in 2015 using the databases of the National Organization for Civil Registration (NOCR) and the Statistical Center of Iran. The study population was the related data of provinces in the selected variables. The main methods used in the research were the common unit root test, Pedroni Cointegration test, redundant fixed effects tests, correlated random effects-Hausman test, and panel least squares of fixed effects. In order to determine the suitable model for estimating panel data, likelihood ratio and Huasman tests were done using Eviews software, and the fixed effects regression model was chosen as the dominant model. Results The results indicated that the divorce rate had a negative and significant effect on TFR (p < 0.05). A positive and significant relationship between marriage rate and TFR variables also was observed (p < 0.05). Urbanization rate (p = 0.24) and unemployment rate (p = 0.36) had no significant relationship with TFR. According to F statistic, significance of the overall model also was confirmed (p < 0.001). Conclusion Due to the lower effect of the studied factors on the reduction of TFR, it seems that variables other than the ones studied, as well as cultural factors and values, might be fundamental factors for this change in the country. PMID:27504172

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

PubMed

Polo, V; Luna, F; Fuster, V

2000-10-01

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

Relative importance of demographic, socioeconomic and health factors on life expectancy in low- and lower-middle-income countries.

PubMed

Mondal, Md Nazrul Islam; Shitan, Mahendran

2014-01-01

We attempted to identify the pathways by which demographic changes, socioeconomic inequalities, and availability of health factors influence life expectancy in low- and lower-middle-income countries. Data for 91 countries were obtained from United Nations agencies. The response variable was life expectancy, and the determinant factors were demographic events (total fertility rate and adolescent fertility rate), socioeconomic status (mean years of schooling and gross national income per capita), and health factors (physician density and human immunodeficiency virus [HIV] prevalence rate). Path analysis was used to determine the direct, indirect, and total effects of these factors on life expectancy. All determinant factors were significantly correlated with life expectancy. Mean years of schooling, total fertility rate, and HIV prevalence rate had significant direct and indirect effects on life expectancy. The total effect of higher physician density was to increase life expectancy. We identified several direct and indirect pathways that predict life expectancy. The findings suggest that policies should concentrate on improving reproductive decisions, increasing education, and reducing HIV transmission. In addition, special attention should be paid to the emerging need to increase life expectancy by increasing physician density.

Relative Importance of Demographic, Socioeconomic and Health Factors on Life Expectancy in Low- and Lower-Middle-Income Countries

PubMed Central

Mondal, Md. Nazrul Islam; Shitan, Mahendran

2014-01-01

Background We attempted to identify the pathways by which demographic changes, socioeconomic inequalities, and availability of health factors influence life expectancy in low- and lower-middle-income countries. Methods Data for 91 countries were obtained from United Nations agencies. The response variable was life expectancy, and the determinant factors were demographic events (total fertility rate and adolescent fertility rate), socioeconomic status (mean years of schooling and gross national income per capita), and health factors (physician density and human immunodeficiency virus [HIV] prevalence rate). Path analysis was used to determine the direct, indirect, and total effects of these factors on life expectancy. Results All determinant factors were significantly correlated with life expectancy. Mean years of schooling, total fertility rate, and HIV prevalence rate had significant direct and indirect effects on life expectancy. The total effect of higher physician density was to increase life expectancy. Conclusions We identified several direct and indirect pathways that predict life expectancy. The findings suggest that policies should concentrate on improving reproductive decisions, increasing education, and reducing HIV transmission. In addition, special attention should be paid to the emerging need to increase life expectancy by increasing physician density. PMID:24390415

Effects of fertilizer on inorganic soil N in East Africa maize systems: vertical distributions and temporal dynamics.

PubMed

Tully, Katherine L; Hickman, Jonathan; McKenna, Madeline; Neill, Christopher; Palm, Cheryl A

2016-09-01

Fertilizer applications are poised to increase across sub-Saharan Africa (SSA), but the fate of added nitrogen (N) is largely unknown. We measured vertical distributions and temporal variations of soil inorganic N following fertilizer application in two maize (Zea mays L.)-growing regions of contrasting soil type. Fertilizer trials were established on a clayey soil in Yala, Kenya, and on a sandy soil in Tumbi, Tanzania, with application rates of 0-200 kg N/ha/yr. Soil profiles were collected (0-400 cm) annually (for three years in Yala and two years in Tumbi) to examine changes in inorganic N pools. Topsoils (0-15 cm) were collected every 3-6 weeks to determine how precipitation and fertilizer management influenced plant-available soil N. Fertilizer management altered soil inorganic N, and there were large differences between sites that were consistent with differences in soil texture. Initial soil N pools were larger in Yala than Tumbi (240 vs. 79 kg/ha). Inorganic N pools did not change in Yala (277 kg/ha), but increased fourfold after cultivation and fertilization in Tumbi (371 kg/ha). Intra-annual variability in NO - 3 -N concentrations (3-33 μg/g) in Tumbi topsoils strongly suggested that the sandier soils were prone to high leaching losses. Information on soil inorganic N pools and movement through soil profiles can h vulnerability of SSA croplands to N losses and determine best fertilizer management practices as N application rates increase. A better understanding of the vertical and temporal patterns of soil N pools improves our ability to predict the potential environmental effects of a dramatic increase in fertilizer application rates that will accompany the intensification of African croplands. © 2016 by the Ecological Society of America.

Demand impact and policy implications from taxing nitrogen fertilizer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foltz, J.C.

1992-12-01

Recent concern has focused on nitrogen fertilizer as a potential contaminant of groundwater. A demand function for fertilizer was developed using the quantity of fertilizer purchased, corn yield, real price of nitrogen fertilizer, lagged fertilizer purchases, a land value variable and the real price of corn as explanatory variables. Short and long-run price elasticities of demand were estimated to be inelastic. Support was found for the hypothesis that demand for nitrogen fertilizer has become more price inelastic over time. From a policy standpoint, a tax on nitrogen fertilizer may not be the most effective method to reduce consumption.

Successful outcomes achieved in assisted reproduction cycles using sperm with high levels of high DNA stainability.

PubMed

Speyer, Barbara E; Pizzey, Arnold R; Abramov, Benjamin; Saab, Wael; Doshi, Alpesh; Sarna, Urvashi; Harper, Joyce C; Serhal, Paul

2015-01-01

The sperm chromatin structure assay (SCSA) has been proposed as a useful addition to the battery of tests routinely used to explore semen quality and hence to give an indication of the likelihood of a successful pregnancy. As usually performed at present, the assay yields two main sperm variables, the DNA fragmentation index (DFI) and the high DNA stainability (HDS). In the present study 275 patients undergoing 215 in vitro fertilization (IVF) and 215 intracytoplasmic sperm injection (ICSI) cycles were studied with the purpose of defining the clinical significance of HDS in IVF and ICSI cycles. Using the Spearman correlation test there were no significant statistical relationships between %HDS and fertilization rate, rate of embryo growth, blastocyst rate, implantation rate, or live birth rate. Rate of pregnancy loss showed a negative relationship significant at the 0.05 level which is unexplained. It is not known whether the normal practice of using processed sperm for fertilization plays any part in this lack of a negative effect of HDS level upon the stages of the cycle. A total of 16 patients with HDS levels >28% had an average live birth rate of 47.8% and an average pregnancy loss of 8.7%, which compared favourably with the group of patients as a whole.

A Robust Profitability Assessment Tool for Targeting Agricultural Investments in Developing Countries: Modeling Spatial Heterogeneity and Uncertainty

NASA Astrophysics Data System (ADS)

Quinn, J. D.; Zeng, Z.; Shoemaker, C. A.; Woodard, J.

2014-12-01

In sub-Saharan Africa, where the majority of the population earns their living from agriculture, government expenditures in many countries are being re-directed to the sector to increase productivity and decrease poverty. However, many of these investments are seeing low returns because they are poorly targeted. A geographic tool that accounts for spatial heterogeneity and temporal variability in the factors of production would allow governments and donors to optimize their investments by directing them to farmers for whom they are most profitable. One application for which this is particularly relevant is fertilizer recommendations. It is well-known that soil fertility in much of sub-Saharan Africa is declining due to insufficient nutrient inputs to replenish those lost through harvest. Since fertilizer application rates in sub-Saharan Africa are several times smaller than in other developing countries, it is often assumed that African farmers are under-applying fertilizer. However, this assumption ignores the risk farmers face in choosing whether or how much fertilizer to apply. Simply calculating the benefit/cost ratio of applying a given level of fertilizer in a particular year over a large, aggregated region (as is often done) overlooks the variability in yield response seen at different sites within the region, and at the same site from year to year. Using Ethiopia as an example, we are developing a 1 km resolution fertilizer distribution tool that provides pre-season fertilizer recommendations throughout the agricultural regions of the country, conditional on seasonal climate forecasts. By accounting for spatial heterogeneity in soil, climate, market and travel conditions, as well as uncertainty in climate and output prices at the time a farmer must purchase fertilizer, this stochastic optimization tool gives better recommendations to governments, fertilizer companies, and aid organizations looking to optimize the welfare benefits achieved by their investments.

The effect of dual-hemisphere breeding on stallion fertility.

PubMed

Walbornn, S R; Love, C C; Blanchard, T L; Brinsko, S P; Varner, D D

2017-05-01

Breeding records were analyzed from 24 Thoroughbred stallions that were subjected to dual-hemisphere breeding (DH), including novice (first-year; NOV; n = 11) and experienced (EXP; n = 13) stallions. Fertility variables included seasonal pregnancy rate, pregnancy rate per cycle, and first-cycle pregnancy rate. In addition, values for book size, total number of covers, distribution of mare type (maiden, foaling, and barren) within a stallion's book, cycles per mare, and mare age were examined. Some data were also categorized by mare type (maiden-M, foaling-F, and barren-B). Five separate analyses of the data were performed. For Analyses 1-3, the effects of hemisphere (northern hemisphere [NH] vs. southern hemisphere [SH]) and breeding order (refers to the first [O1] or second [O2] season within the first year of dual-hemisphere breeding) were examined for all stallions (combined group [CG]), NOV stallions only, and EXP stallions only, respectively. Fertility values were generally higher in the SH than the NH (P < 0.05), whereas book size, total number of covers, and cycles per mare were higher in the NH than the SH (P < 0.05). Book size and total covers were negatively correlated to first cycle pregnancy rate (r = -0.57, r = -0.71, respectively; P < 0.05) for NOV stallions. Pregnancy rate per cycle was also negatively correlated with total covers (r = -0.58; P < 0.05) for NOV stallions. Similar trends were noted for Groups CG and EXP, but the relationship was not as marked as for NOV stallions. The fertility of O1 was generally similar to O2 (P > 0.05). For Analysis 4, fertility of DH breeding seasons was compared to single hemisphere (SIN) breeding seasons within the same 16 stallions and was found to be similar between the two groups (P > 0.05). For Analysis 5, the effect of the number of consecutive DH breeding seasons on fertility was examined and was found to remain unchanged (P > 0.05). In summary, no adverse effects of DH breeding on fertility were detected. Fertility was higher when stallions were bred in the SH, as compared to the NH. Potential reasons for higher fertility achieved in the SH were smaller book sizes and better mare reproductive quality. Copyright © 2017. Published by Elsevier Inc.

Normalized difference vegetation index (NDVI) variation among cultivars and environments

USDA-ARS?s Scientific Manuscript database

Although Nitrogen (N) is an essential nutrient for crop production, large preplant applications of fertilizer N can result in off-field loss that causes environmental concerns. Canopy reflectance is being investigated for use in variable rate (VR) N management. Normalized difference vegetation index...

Modeling global annual N2O and NO emissions from fertilized fields

NASA Astrophysics Data System (ADS)

Bouwman, A. F.; Boumans, L. J. M.; Batjes, N. H.

2002-12-01

Information from 846 N2O emission measurements in agricultural fields and 99 measurements for NO emissions was used to describe the influence of various factors regulating emissions from mineral soils in models for calculating global N2O and NO emissions. Only those factors having a significant influence on N2O and NO emissions were included in the models. For N2O these were (1) environmental factors (climate, soil organic C content, soil texture, drainage and soil pH); (2) management-related factors (N application rate per fertilizer type, type of crop, with major differences between grass, legumes and other annual crops); and (3) factors related to the measurements (length of measurement period and frequency of measurements). The most important controls on NO emission include the N application rate per fertilizer type, soil organic-C content and soil drainage. Calculated global annual N2O-N and NO-N emissions from fertilized agricultural fields amount to 2.8 and 1.6 Mtonne, respectively. The global mean fertilizer-induced emissions for N2O and NO amount to 0.9% and 0.7%, respectively, of the N applied. These overall results account for the spatial variability of the main N2O and NO emission controls on the landscape scale.

Multivariate areal analysis of the impact and efficiency of the family planning programme in peninsular Malaysia.

PubMed

Tan Boon Ann

1987-06-01

The findings of the final phase of a 3-phase multivariate areal analysis study undertaken by the Economic and Social Commission for Asia and the Pacific (ESCAP) in 5 countries of the Asian and Pacific Region, including Malaysia, to examine the impact of family planning programs on fertility and reproduction are reported. The study used Malaysia's administrative district as the unit of analysis because the administration and implementation of socioeconomic development activities, as well as the family planning program, depend to a large extent on the decisions of local organizations at the district or state level. In phase 1, existing program and nonprogram data were analyzed using the multivariate technique to separate the impact of the family planning program net of other developmental efforts. The methodology in the 2nd phase consisted of in-depth investigation of selected areas in order to discern the dynamics and determinants of efficiency. The insights gained in phase 2 regarding dynamics of performance were used in phase 3 to refine the input variables of the phase 1 model. Thereafter, the phase 1 analysis was repeated. Insignificant variables and factors were trimmed in order to present a simplified model for studying the impact of environmental, socioeconomic development, family planning programs, and related factors on fertility. The inclusion of a set of family planning program and development variables in phase 3 increased the predictive power of the impact model. THe explained variance for total fertility rate (TFR) of women under 30 years increased from 71% in phase 1 to 79%. It also raised the explained variance of the efficiency model from 34% to 70%. For women age 30 years and older, their TFR was affected directly by the ethnic composition variable (.76), secondary educational status (-.45), and modern nonagricultural occupation (.42), among others. When controlled for other socioeconomic development and environmental indicators, the nonagricultural activities had a positive direct effect on TFR. No direct effects were found to come from other socioeconomic development indicators, once these factors were controlled. The 3 factors that had direct effects on the fertility of women below age 30 were ethnic composition (.33), contraceptive pevalence (-.32), and secondary educational status (-.25). Other family planning program variables (contraceptive knowledge) and socioeconomic development indicators (exposure to modernization as measured by television ownership and health/living conditions as measured by infant mortality rate) affected fertility significantly but indirectly.

Fusion of spectral and electrochemical sensor data for estimating soil macronutrients

USDA-ARS?s Scientific Manuscript database

Rapid and efficient quantification of plant-available soil phosphorus (P) and potassium (K) is needed to support variable-rate fertilization strategies. Two methods that have been used for estimating these soil macronutrients are diffuse reflectance spectroscopy in visible and near-infrared (VNIR) w...

Bayes plus Brass: Estimating Total Fertility for Many Small Areas from Sparse Census Data

PubMed Central

Schmertmann, Carl P.; Cavenaghi, Suzana M.; Assunção, Renato M.; Potter, Joseph E.

2013-01-01

Small-area fertility estimates are valuable for analysing demographic change, and important for local planning and population projection. In countries lacking complete vital registration, however, small-area estimates are possible only from sparse survey or census data that are potentially unreliable. Such estimation requires new methods for old problems: procedures must be automated if thousands of estimates are required, they must deal with extreme sampling variability in many areas, and they should also incorporate corrections for possible data errors. We present a two-step algorithm for estimating total fertility in such circumstances, and we illustrate by applying the method to 2000 Brazilian Census data for over five thousand municipalities. Our proposed algorithm first smoothes local age-specific rates using Empirical Bayes methods, and then applies a new variant of Brass’s P/F parity correction procedure that is robust under conditions of rapid fertility decline. PMID:24143946

A GIS-based fuzzy classification for mapping the agricultural soils for N-fertilizers use.

PubMed

Assimakopoulos, J H; Kalivas, D P; Kollias, V J

2003-06-20

Special attention should be paid to the choice of the proper N-fertilizer, in order to avoid a further acidification and degradation of acid soils and at the same time to improve nitrogen use efficiency and to limit the nitrate pollution of the ground waters. Therefore, the risk of leaching of the fertilizer and of the acidification of the soils must be considered prior to any N-fertilizer application. The application of N-fertilizers to the soil requires a good knowledge of the soil-fertilizer relationship, which those who are planning the fertilization policy and/or applying it might not have. In this study, a fuzzy classification methodology is presented for mapping the agricultural soils according to the kind and the rate of application of N-fertilizer that should be used. The values of pH, clay, sand and carbonates soil variables are estimated at each point of an area by applying geostatistical techniques. Using the pH values three fuzzy sets: "no-risk-acidification"; "low-risk-acidification"; and "high-risk-acidification" are produced and the memberships of each point to the three sets are estimated. Additionally, from the clay and sand values the membership grade to the fuzzy set "risk-of-leaching" is calculated. The parameters and their values, which are used for the construction of the fuzzy sets, are based on the literature, the existing knowledge and the experimentation, of the soil-fertilizer relationships and provide a consistent mechanism for mapping the soils according to the type of N-fertilizers that should be applied and the rate of applications. The maps produced can easily be interpreted and used by non-experts in the application of the fertilization policy at national, local and farm level. The methodology is presented through a case study using data from the Amfilochia area, west Greece.

Viability and fertilizing capacity of cryopreserved sperm from three North American acipenseriform species: A retrospective study

USGS Publications Warehouse

Horvath, A.; Wayman, W.R.; Dean, J.C.; Urbanyi, B.; Tiersch, T.R.; Mims, S.D.; Johnson, D.; Jenkins, J.A.

2008-01-01

Populations of sturgeon across the globe are threatened due to unregulated harvest and habitat loss, and the status varies among species across North America. Ready access to viable and functional sperm would contribute to recovery programmes for these species. In this study, we examined the motility, viability (cell membrane integrity) of cryopreserved sperm from three North American acipenseriform species and fertilizing capacity. Milt samples were collected from captive shortnose sturgeon (Acipenser brevirostrum), wild paddlefish (Polyodon spathula) and pallid sturgeon (Scaphirhynchus albus) and cryopreserved using combinations of Modified Tsvetkova's (MT) extender, Original Tsvetkova's extender, and modified Hanks' balanced salt solution, along with the cryoprotectants methanol (MeOH) or dimethyl sulfoxide (DMSO). A dual-staining technique using the fluorescent stains SYBR-14 and propidium iodide was employed with flow cytometry to determine the percentages of spermatozoa that were viable by virtue of having intact membranes. The percentage of viable spermatozoa ranged from 5% to 12% in shortnose sturgeon, 30-59% in paddlefish, and 44-58% in pallid sturgeon. In the first experiment with shortnose sturgeon sperm, methanol allowed for higher values for dependent variables than did DMSO, and sperm viability generally correlated with post-thaw motility. However, fertilization rate, neurulation, or hatching rates were independent from these factors. In the second experiment with shortnose sturgeon, 5% MeOH combined with MT yielded higher values for all parameters tested than the other combinations: viability was correlated with motility, fertilization rate, and hatching rate. Overall, viability and post-thaw motility was not affected by the use of hyperosmotic extenders (OT) or cryoprotectants (DMSO), but their use decreased fertilization percentages. For paddlefish sperm (experiment 3), MT combined with 10% MeOH was clearly a good choice for cryopreservation; viability and motility results were correlated, but independent of fertilization. For pallid sturgeon sperm (experiment 4), MT with 5-10% MeOH showed significantly higher sperm quality and fertilization parameters. Membrane integrity can be used as a predictor of fertilization by cryopreserved sperm, however additional sperm quality parameters, supplementary to motility and membrane integrity, would be useful in the refining and optimizing cryopreservation protocols with acipenseriform sperm. ?? 2008 Blackwell Verlag, Berlin.

Effective freezing rate for semen cryopreservation in endangered Mediterranean brown trout (Salmo trutta macrostigma) inhabiting the Biferno river (South Italy).

PubMed

Iaffaldano, Nicolaia; Di Iorio, Michele; Manchisi, Angelo; Esposito, Stefano; Gibertoni, Pier Paolo

2016-10-01

This study was designed to determine: (i) the in vitro effects of different freezing rates on post-thaw semen quality of Mediterranean brown trout (Salmo trutta macrostigma) from the Biferno river; and (ii) the in vivo fertilization and hatching percentage of freezing rate giving rise to the best post-thaw semen quality. Pooled semen samples were diluted 1:3 (v:v) in a freezing extender composed of 300 mM glucose, 10% egg yolk and 10% dimethyl sulfoxide (DMSO). The extended semen was packaged in 0.25 ml plastic straws and frozen at different heights above the liquid nitrogen surface (1, 5 or 10 cm) for 10 min to give three different freezing rates. Semen samples were thawed at 30°C for 10 s. The variables assessed after thawing were sperm motility, duration of motility and viability. Our results clearly indicate a significant effect of freezing rate on post-thaw semen quality. Semen frozen 5 cm above the liquid nitrogen surface showed the best quality after freezing/thawing. Based on these in vitro data, 2 groups of 200 eggs were fertilized with fresh semen or semen frozen 5 cm above the liquid nitrogen surface. Fertilization and hatching rates recorded for eggs fertilized with frozen semen were significantly lower (25.4% and 22.5%, respectively) than the ones obtained using fresh semen (87.8% and 75.5%, respectively). An effective freezing protocol will allow for the creation of a sperm cryobank to recover the original population of Mediterranean brown trout in the Biferno river.

Subtle membrane changes in cryopreserved bull semen in relation with sperm viability, chromatin structure, and field fertility.

PubMed

Januskauskas, A; Johannisson, A; Rodriguez-Martinez, H

2003-09-01

This study investigated the use of annexin-V/PI assay to assess sub lethal changes in bull spermatozoa post-thawing, and to further relate these changes to results obtained by fluorometric assessment of sperm viability and sperm chromatin structure assay (SCSA), as well as field fertility (as 56-day non-return rates, 56-day NRR) after AI. Frozen-thawed semen samples were obtained from 18 Swedish Red and White bulls (one to three semen batches/bull) and fertility data was based on 6900 inseminations. The annexin-V/PI assay revealed that post-thaw semen samples contained on average 41.8+/-7.5% annexin-V-positive cells. Most of the annexin-V-positive cells were dying cells, i.e. also PI-positive. The incidence of annexin-V-positive cells was negatively related (r=-0.59, P<0.01) to the percentage of viable cells, as detected by fluorometry. The incidence of annexin-V-positive spermatozoa significantly correlated to the SCSA variable xalphat (r=0.53, P<0.05). The incidence of annexin-V-negative, dead cells was the only annexin-V/PI assay variable that correlated significantly with fertility both at batch (r=-0.40, P<0.05), and bull (r=-0.56, P<0.05) levels. Among sperm viability variables, subjectively assessed sperm motility (r=0.52-0.59, P<0.01), CASA-assessed sperm motility (r=0.43-0.61, P<0.05), and the incidence of live spermatozoa, expressed as total numbers (r=0.39-0.54, P<0.05), or percentage values (r=0.68-0.68, P<0.01), correlated significantly with field fertility both at batch, and bull levels. Among the SCSA variables, only the COMP alphat correlated significantly (r=0.33-0.51, P<0.05) with fertility results. The results indicate a certain proportion of bull spermatozoa express PS on their surface after thawing, e.g. they have altered membrane function, and that the incidence of such cells is inversely correlated to sperm viability, and positively correlated to abnormal sperm chromatin condensation since they eventually undergo necrosis.

[Demographic aspects in indigenous communities of 3 regions of Colombia].

PubMed

Piñeros-Petersen, M; Ruiz-Salguero, M

1998-01-01

To obtain demographic indicators for some indigenous communities in Colombia situated in three different regions of the country: the Caribbean, the Amazonian basin and the Andes. Demographic variables gathered in a KAP (knowledge, attitude and practices) survey among the indigenous population in 1993 and 1994 were analyzed. The survey included 11,522 Indian. 45% of the population is under age 15; overall rate of fertility is 6.5 children per woman, and death rate in 1990 was 63.3 children per 1,000 live births. Life expectancy at birth was 57.8 years for women and 55.4 years for men. The indicators differ substantially from the national figures. Although the indigenous population seems to be undergoing a process of demographic transition, there are marked differences between regions, with significantly higher fertility and infant mortality rates for the Caribbean region.

Uncertainty in the profitability of fertilizer management based on various sampling designs.

NASA Astrophysics Data System (ADS)

Muhammed, Shibu; Ben, Marchant; Webster, Richard; Milne, Alice; Dailey, Gordon; Whitmore, Andrew

2016-04-01

Many farmers sample their soil to measure the concentrations of plant nutrients, including phosphorus (P), so as to decide how much fertilizer to apply. Now that fertilizer can be applied at variable rates, farmers want to know whether maps of nutrient concentration made from grid samples or from field subdivisions (zones within their fields) are merited: do such maps lead to greater profit than would a single measurement on a bulked sample for each field when all costs are taken into account? We have examined the merits of grid-based and zone-based sampling strategies over single field-based averages using continuous spatial data on wheat yields at harvest in six fields in southern England and simulated concentrations of P in the soil. Features of the spatial variation in the yields provide predictions about which sampling scheme is likely to be most cost effective, but there is uncertainty associated with these predictions that must be communicated to farmers. Where variograms of the yield have large variances and long effective ranges, grid-sampling and mapping nutrients are likely to be cost-effective. Where effective ranges are short, sampling must be dense to reveal the spatial variation and may be expensive. In these circumstances variable-rate application of fertilizer is likely to be impracticable and almost certainly not cost-effective. We have explored several methods for communicating these results and found that the most effective method was using probability maps that show the likelihood of grid-based and zone-based sampling being more profitable that a field-based estimate.

Recreating a functioning forest soil in reclaimed oil sands in northern alberta: an approach for measuring success in ecological restoration.

PubMed

Rowland, S M; Prescott, C E; Grayston, S J; Quideau, S A; Bradfield, G E

2009-01-01

During oil-sands mining all vegetation, soil, overburden, and oil sand is removed, leaving pits several kilometers wide and up to 100 m deep. These pits are reclaimed through a variety of treatments using subsoil or a mixed peat-mineral soil cap. Using nonmetric multidimensional scaling and cluster analysis of measurements of ecosystem function, reclamation treatments of several age classes were compared with a range of natural forest ecotypes to discover which treatments had created ecosystems similar to natural forest ecotypes and at what age this occurred. Ecosystem function was estimated from bioavailable nutrients, plant community composition, litter decomposition rate, and development of a surface organic layer. On the reclamation treatments, availability of nitrate, calcium, magnesium, and sulfur were generally higher than in the natural forest ecotypes, while ammonium, P, K, and Mn were generally lower. Reclamation treatments tended to have more bare ground, grasses, and forbs but less moss, lichen, shrubs, trees, or woody debris than natural forests. Rates of litter decomposition were lower on all reclamation treatments. Development of an organic layer appeared to be facilitated by the presence of shrubs. With repeated applications of fertilizers, measured variables for the peat-mineral amendments fell within the range of natural variability at about 20 yr. An intermediate subsoil layer reduced the need for fertilizer and conditions resembling natural forests were reached about 15 yr after a single fertilizer application. Treatments over tailings sand receiving only one application of fertilizer appeared to be on a different trajectory to a novel ecosystem.

Nutrient movement in a 104-year old soil fertility experiment

USDA-ARS?s Scientific Manuscript database

Alabama’s “Cullars Rotation” experiment (circa 1911) is the oldest, continuous soil fertility experiment in the southern U.S. Treatments include 5 K variables, P variables, S variables, soil pH variables and micronutrient variables in 14 treatments involving a 3-yr rotation of (1) cotton-winter legu...

Effect of Expansion of Fertilization Width on Nitrogen Recovery Rate in Tea Plants

NASA Astrophysics Data System (ADS)

Nonaka, Kunihiko; Hirono, Yuhei; Watanabe, Iriki

In cultivation of tea plants, large amounts of nitrogen, compared to amounts used for other crops, have been used for fertilization, resulting in degradation of the soil environment between hedges and an increase in concentrations of nitrate nitrogen in surrounding water systems. To reduce the environmental load, new methods of fertilizer application are needed. This report deals with the effect of expansion of fertilization width on nitrogen recovery rate in tea plants. In the test field, 15 N-labeled ammonium sulfate had been applied over custom fertilization by between-hedges fertilization (fertilization width of 15cm) and wide fertilization (fertilization width of 40cm), nitrogen recovery rates were compared. Expansion of fertilization width resulted in an approximately 30% increase in nitrogen recovery rate compared to that in the case of fertilization between hedges. Increases in nitrogen recovery rates were observed with fallapplied fertilization, spring-applied fertilization, pop-up fertilizer application, and summerapplied fertilization.

Prostate cancer incidence and agriculture practices in Georgia, 2000-2010.

PubMed

Welton, Michael; Robb, Sara W; Shen, Ye; Guillebeau, Paul; Vena, John

2015-01-01

Georgia has prostate cancer incidence rates consistently above the national average. A notable portion of Georgia's economy is rooted in agricultural production, and agricultural practices have been associated with an increased risk of prostate cancer. Statistical analyses considered county age-adjusted prostate cancer incidence rates as the outcome of interest and three agricultural variables (farmland as percent of county land, dollars spent per county acre on agriculture chemicals, and dollars spent per county acre on commercial fertilizers) as exposures of interest. Multivariate linear regression models analyzed for each separately. Data were obtained from National Cancer Institute Surveillance, Epidemiology and End Results (SEER) 2000-2010, United States Department of Agriculture (USDA) 1987 Agriculture Survey, and 2010 US Census. In counties with equal to or greater than Georgia counties' median percent African-American population (27%), dollars per acre spent on agriculture chemicals was significantly associated (P = 0.04) and dollars spent of commercial fertilizers was moderately associated (P = 0.07) with elevated prostate cancer incidence rates. There was no association between percent of county farmland and prostate cancer rates. This study identified associations between prostate cancer incidence rates, agriculture chemical expenditure, and commercial fertilizer expenditure in Georgia counties with a population comprised of more than 27% of African Americans.

Biophysical studies of spermatozoa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pistenma, David Andrew

1970-12-01

The objectives of this thesis include characterization of spermatozoa according to several physical properties (morphology, size, electrophoretic mobility, sedimentation rate and specific gravity), correlation of these properties with several biological properties (viability, intrinsic motility, fertilizing capacity, antigenicity and genetic composition) and an evaluation of interrelationships among these properties and with selected experimental variables.

Maize yield response to nitrogen as influenced by spatio-temporal variations of soil-water-topography dynamics

USDA-ARS?s Scientific Manuscript database

Reducing N loss from agricultural lands and applying N fertilizer at rates that satisfy both economic and environmental objectives is critical for sustainable agricultural management. This study investigated spatial variability in maize yield response to N and its controlling factors along a typical...

Precision agriculture: Data to knowledge decision

USDA-ARS?s Scientific Manuscript database

From the development of the first viable variable-rate fertilizer systems in the upper Midwest USA, precision agriculture is now about two decades old. In that time, new technologies have come into play, but the overall goal of using spatial data to create actionable knowledge that can then be used ...

Socioeconomic determinants of fertility: selected Mexican regions, 1976-1977.

PubMed

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

1988-01-01

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

Recovery of photosynthesis in 1-year-old needles of unfertilized and fertilized Norway spruce (Picea abies (L.) Karst.) during spring.

PubMed

Strand, M; Lundmark, T

1995-03-01

Photosynthetic O(2) evolution and chlorophyll a fluorescence were measured in 1-year-old needles of unfertilized and fertilized trees of Norway spruce (Picea abies (L.) Karst.) during recovery of photosynthesis from winter inhibition in northern Sweden. Measurements were made under laboratory conditions at 20 degrees C. In general, the CO(2)-saturated rate of O(2) evolution was higher in needles of fertilized trees than in needles of unfertilized trees over a wide range of incident photon flux densities. Furthermore, the maximum photochemical efficiency of photosystem (PS) II, as indicated by the ratio of variable to maximum fluorescence (F(V)/F(M)) was higher in needles of fertilized trees than in needles of unfertilized trees. The largest differences in F(V)/F(M) between the two treatments occurred before the main recovery of photosynthesis from winter inhibition in late May. The rate of O(2) evolution was higher in needles of north-facing branches than in needles of south-facing branches in the middle of May. Simultaneous measurements of O(2) exchange and chlorophyll fluorescence indicated that differences in the rate of O(2) evolution between the two treatments were paralleled by differences in the rate of PS II electron transport determined by chlorophyll fluorescence. We suggest that, during recovery of photosynthesis from winter inhibition, the balance between carbon assimilation and PS II electron transport was maintained largely by adjustments in the nonphotochemical dissipation of excitation energy within PS II.

Examining the impacts of increased corn production on ...

EPA Pesticide Factsheets

This study demonstrates the value of a coupled chemical transport modeling system for investigating groundwater nitrate contamination responses associated with nitrogen (N) fertilizer application and increased corn production. The coupled Community Multiscale Air Quality Bidirectional and Environmental Policy Integrated Climate modeling system incorporates agricultural management practices and N exchange processes between the soil and atmosphere to estimate levels of N that may volatilize into the atmosphere, re-deposit, and seep or flow into surface and groundwater. Simulated values from this modeling system were used in a land-use regression model to examine associations between groundwater nitrate-N measurements and a suite of factors related to N fertilizer and groundwater nitrate contamination. Multi-variable modeling analysis revealed that the N-fertilizer rate (versus total) applied to irrigated (versus rainfed) grain corn (versus other crops) was the strongest N-related predictor variable of groundwater nitrate-N concentrations. Application of this multi-variable model considered groundwater nitrate-N concentration responses under two corn production scenarios. Findings suggest that increased corn production between 2002 and 2022 could result in 56% to 79% increase in areas vulnerable to groundwater nitrate-N concentrations ≥ 5 mg/L. These above-threshold areas occur on soils with a hydraulic conductivity 13% higher than the rest of the domain. Additio

[Live-birth rates by age of mother and total fertility rates by urban and rural areas].

PubMed

Kaneko, T; Shiraishi, N; Kasahara, R

1983-07-01

Live birth rates by age of mother and total fertility rates by urban and rural areas in Japan are generally decreasing. Japanese women ages 15-49 were studied. Graphs presenting fertility rates according to age in 1975 and 1980 in urban and rural areas show that fertility rates are considerably higher in rural areas than in urban centers (by as much as 20% for the 25-29 age group). In a table showing urban/rural total fertility rates and distributions among prefectures in 1975 and 1980, the prefecture with the highest total fertility rate (2.88495 in 1975 and 2.37804 in 1980) is Okinawa and the lowest total fertility rate is found in Tokyo (1.62287 in 1975 and 1.43693 in 1980). The average total fertility rate in 1980 was 1.82849; in urban centers it was 1.78919 and rural areas, 1.92105. Finally, a comparison of total fertility rates by urban and rural areas and by age shows that in 1975 the rural fertility rate was .16 higher than that of urban areas, and that in 1980 all fertility rates (total, urban, and rural) were lower, with the rural fertility rate decreasing at the same rate as did the urban fertility rate in 1975. It is interesting to note that between 1975-1980 birth rates have been decreasing in both urban and rural areas in all age groups except for the 30-34 year old group which in urban centers was higher in 1980 than in rural areas. This can be attributed to the recent trend among Japanese women of delaying childbirth.

An analytical comparison of fertility rate among women in Beijing with different social and economic characteristics.

PubMed

Hao, H; Gaoling; Shen, Q

1993-01-01

In Beijing, the total fertility rate (TFR) fluctuated between 1.3 and 1.8 in the 1980s, and in 1989 it was 1.3. A preliminary survey of 10% of the city's population involved 1,086,000 people, including 299,700 women aged 15-50. Samples of these women were used in group-specific comparisons of fertility rates in 1989. Women in agricultural residence made up 43.2% of the total, whose TFR was 1.822, vs. 0.925 for women in nonagricultural residence. The average childbearing age for agricultural women was 16 years, and their fertility was declining gradually after the age of 28 as opposed to the precipitous after 28 among nonagricultural women. 54% of the agricultural group had 1 child, 48% had 2 children, and 6% had 3 or more children. In contrast, 98% of nonagricultural women had 1 child. Among employed women, 30.7% were in production and transport, 2.6% were farmers, forest workers, and fishers and 20.5% were professional and technical personnel, with the rest being employed in services, post and telecommunications, civil service, and business. The TFR of unemployed women (mostly housewives with a TFR of 3.42) was 2.367, vs. 1.224 for agricultural women. More than 90% of these housewives were agricultural women. A multivariate analysis with the dependent variable of live births to individual women found that, except for age and housewife (or not) status, all variables were negative. In contrast to illiterates, farmers, forest workers, and fisher women, women with higher educational levels and in other occupations had few children. The average number of children born to women with elementary school education was 0.5 less than among illiterates, and 1 less among university graduates than among illiterates. Elementary and junior high school education had the highest marginal impact. The family planning program has been successful in Beijing in lowering fertility, with further declines expected. However, rural women still had more than 1 child at an early age; this phenomenon, as well as raising their educational level, should be the focus of the program.

Energy: It is life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arques, P.

1998-07-01

The relationships that seem to exist between energy and man are presented in this paper. Habitually, social coefficients are connected to the gross domestic product; some parameters with correlations are: birth rate, infant mortality rate, death rate, literacy, etc. Along with energy these define the optimal energy consumption per capita; the author presents the correlation between these parameters and energy consumed per capita. There exists a high correlation between energy consumption per capita and gross domestic product per capita. The set of parameters considered are correlated with similar values relative to these two parameters. Using data collected on a groupmore » of the different countries of the world, a table of 165 countries and 22 variables has been drawn up. From the [Country x variable] matrix, a correlation table is calculated and a factorial analysis is applied to this matrix. The first factorial plan comprises 57% of the information contained in this table. Results from this first factorial plan are presented. These parameters are analyzed: influence of a country's latitude on its inhabitants' consumption; relationship between consumed energy and gross domestic product; women's fertility rate; birth rate per 1000 population; sex ratio; life expectancy at birth; rate of literacy; death rate; population growth rate. Finally, it is difficult to define precise criteria for: an optimal distribution of population according to age, but with a power consumed of above 300 W per capita, the population becomes younger; the birth rate per 1000 population; the total fertility rate per woman; the population growth rate. The authors determine that optimal energy is approximately between 200 W and 677 W inclusive.« less

SOCIAL DETERMINANTS OF LOW FERTILITY IN BRAZIL.

PubMed

Castanheira, Helena Cruz; Kohler, Hans-Peter

2017-11-01

An increasing number of developing countries are experiencing below replacement fertility rates. Although the factors associated with low fertility in developed countries have been widely explored in the literature, studies of low fertility in middle- and low-income countries continue to be rare. To help fill this gap, Brazil was used as a case study to assess whether human development, gender equality and the ability of mothers with young children to work are associated with the likelihood of married or cohabiting women to have a child. For this purpose, multilevel logistic regressions were estimated using the 1991, 2000 and 2010 Brazilian Demographic Censuses. It was found that human development was negatively associated with fertility in the three periods analysed. Gender equality and the ability of mothers with young children to work were positively associated with the odds of having higher order births in Brazil in 2000 and 2010. In 1991, these variables were not associated with higher order births, and gender equality was negatively associated with first births. The positive association found in 2000 and 2010 may constitute a reversal of the relationship that in all likelihood prevailed earlier in the demographic transition when gender equality was most likely negatively correlated with fertility levels.

Physiological indicators of nitrogen response in short-rotation sycamore plantations. [Platanus occidentalis L

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tschaplinski, T.J.; Norby, R.J.

1989-04-01

American sycamore (Platanus occidentalis L.) seedlings were grown in the field under urea-nitrogen fertilization regimes to identify physiological variables that characterize the growth responses. Treatments included trees fertilized at the beginning of the growing season with 450 kg N/ha, trees fertilized periodically (three times during the growing season) at 37.5 kg N/ha, and unfertilized controls. Above ground biomass accumulation in the heaviest nitrogen treatment was three times that of the controls, and nearly as much growth occurred when less nitrogen was added periodically. Photosynthesis, chlorophyll concentrations, and growth increased rapidly after a midseason application of a small amount of nitrogen,more » but not to a late-season application. There was no evidence that fertilization extended the physiologically active season or increased susceptibility to drought or cold. Sycamore leaves accumulated sucrose and mannose in response to water and cold stress in all treatments. Photosynthetic pigment concentrations, net photosynthetic rate, and leaf nitrate reductase activity were sensitive indicators of nitrogen fertilization, but foliar concentrations of nitrate, total nitrogen, soluble carbohydrate and soluble protein were not.« less

Maize (Zea mays L.) yield response to nitrogen as influenced by spatio-temporal variations of soil-water-topography dynamics

USDA-ARS?s Scientific Manuscript database

Reducing nitrogen (N) loss from agricultural lands and applying N fertilizer at rates that satisfy both economic and environmental objectives is critical for sustainable agricultural management. This study investigated spatial variability in maize yield response to N and its controlling factors alon...

Contextual determinants of induced abortion: a panel analysis.

PubMed

Llorente-Marrón, Mar; Díaz-Fernández, Montserrat; Méndez-Rodríguez, Paz

2016-01-01

Analyze the contextual and individual characteristics that explain the differences in the induced abortion rate, temporally and territorially. We conducted an econometric analysis with panel data of the influence of public investment in health and per capita income on induced abortion as well as a measurement of the effect of social and economic factors related to the labor market and reproduction: female employment, immigration, adolescent fertility and marriage rate. The empirical exercise was conducted with a sample of 22 countries in Europe for the 2001-2009 period. The great territorial variability of induced abortion was the result of contextual and individual socioeconomic factors. Higher levels of national income and investments in public health reduce its incidence. The following sociodemographic characteristics were also significant regressors of induced abortion: female employment, civil status, migration, and adolescent fertility. Induced abortion responds to sociodemographic patterns, in which the characteristics of each country are essential. The individual and contextual socioeconomic inequalities impact significantly on its incidence. Further research on the relationship between economic growth, labor market, institutions and social norms is required to better understand its transnational variability and to reduce its incidence.

Effect of Governance Indicators on Under-Five Mortality in OECD Nations: Generalized Method of Moments.

PubMed

Emamgholipour, Sara; Asemane, Zahra

2016-01-01

Today, it is recognized that factors other than health services are involved in health improvement and decreased inequality so identifying them is the main concern of policy makers and health authorities. The aim of this study was to investigate the effect of governance indicators on health outcomes. A panel data study was conducted to investigate the effect of governance indicators on child mortality rate in 27 OECD countries from 1996 to 2012 using the Generalized Method of Moments (GMM) model and EVIEWS.8 software. According to the results obtained, under-five mortality rate was significantly related to all of the research variables (p < 0.05). One percent increase in under-five mortality in the previous period resulted in a 0.83% increase in the mortality rate in the next period, and a 1% increase in total fertility rate, increased the under-five mortality rate by 0.09%. In addition, a 1% increase in GDP per capita decreased the under-five mortality rate by 0.07%, and a 1% improvement in control of corruption and rule of law indicators decreased child mortality rate by 0.05 and 0.08%, respectively. Furthermore, 1% increase in public health expenditure per capita resulted in a 0.03% decrease in under-five mortality rate. The results of the study suggest that considering control variables, including GDP per capita, public health expenditure per capita, total fertility rate, and improvement of governance indicators (control of corruption and rule of law) would decrease the child mortality rate.

Selection Experiments in the Penna Model for Biological Aging

NASA Astrophysics Data System (ADS)

Medeiros, G.; Idiart, M. A.; de Almeida, R. M. C.

We consider the Penna model for biological aging to investigate correlations between early fertility and late life survival rates in populations at equilibrium. We consider inherited initial reproduction ages together with a reproduction cost translated in a probability that mother and offspring die at birth, depending on the mother age. For convenient sets of parameters, the equilibrated populations present genetic variability in what regards both genetically programmed death age and initial reproduction age. In the asexual Penna model, a negative correlation between early life fertility and late life survival rates naturally emerges in the stationary solutions. In the sexual Penna model, selection experiments are performed where individuals are sorted by initial reproduction age from the equilibrated populations and the separated populations are evolved independently. After a transient, a negative correlation between early fertility and late age survival rates also emerges in the sense that populations that start reproducing earlier present smaller average genetically programmed death age. These effects appear due to the age structure of populations in the steady state solution of the evolution equations. We claim that the same demographic effects may be playing an important role in selection experiments in the laboratory.

Diffusion Performance of Fertilizer Nutrient through Polymer Latex Film.

PubMed

An, Di; Yang, Ling; Liu, Boyang; Wang, Ting-Jie; Kan, Chengyou

2017-12-20

Matching the nutrient release rate of coated fertilizer with the nutrient uptake rate of the crop is the best way to increase the utilization efficiency of nutrients and reduce environmental pollution from the fertilizer. The diffusion property and mechanism of nutrients through the film are the theoretical basis for the product pattern design of coated fertilizers. For the coated fertilizer with a single-component nutrient, an extended solution-diffusion model was used to describe the difference of nutrient release rate, and the release rate is proportional to the permeation coefficient and the solubility of the nutrient. For the double- and triple-component fertilizer of N-K, N-P, and N-P-K, because of the interaction among nutrient molecules and ions, the release rates of different nutrients were significantly affected by the components in the composite fertilizer. Coating the single-component fertilizer (i.e., nitrogen fertilizer, phosphate fertilizer, and potash fertilizer) first and subsequently bulk blending is expected to be a promising way to adjust flexibly the nutrient release rate to meet the nutrient uptake rate of the crop.

Comparison of fertilization outcome between microdrop and open insemination methods in non-male factor IVF patients.

PubMed

Li, Yubin; Li, Tao; Mai, Qingyun; Long, Lingli; Ou, Jianping

2014-06-01

Both microdrop and open methods are commonly used for in vitro fertilization (IVF) protocols for embryo culture as well as oocyte insemination. However, few comparative studies evaluating the microdrop or open method of insemination on the fertilization outcome and subsequent embryo development have been performed. A randomized study was conducted to compare microdrop and open fertilization with respect to fertilization rate and embryo development among non-male factor patients undergoing in vitro fertilization and embryo transfer (IVF-ET). The results presented in this study demonstrate that the fertilization failure rate [total fertilization failure rate (TFF) plus low fertilization rate (<25% oocytes fertilized)] in the microdrop insemination group was higher than in the open insemination group (11.9% versus 3.3%, p < 0.001), while the good quality embryo rate and pregnancy rate did not differ significantly between the groups. As a highly complicated process involving many extrinsic and intrinsic factors, further studies are needed to confirm the effects of these insemination methods on the rate of fertilization failure.

The value of reproductive tract scoring as a predictor of fertility and production outcomes in beef heifers.

PubMed

Holm, D E; Thompson, P N; Irons, P C

2009-06-01

In this study, 272 beef heifers were studied from just before their first breeding season (October 15, 2003), through their second breeding season, and until just after they had weaned their first calves in March, 2005. This study was performed concurrently with another study testing the economic effects of an estrous synchronization protocol using PG. Reproductive tract scoring (RTS) by rectal palpation was performed on the group of heifers 1 d before the onset of their first breeding season. The effect of RTS on several fertility and production outcomes was tested, and the association of RTS with the outcomes was compared with that of other input variables such as BW, age, BCS, and Kleiber ratio using multiple or univariable linear, logistic, or Cox regression. Area under the curve for receiver operating characteristic analysis was used to compare the ability of different input variables to predict pregnancy outcome. After adjustment for BW and age, RTS was positively associated with pregnancy rate to the 50-d AI season (P < 0.01), calf weaning weight (r = 0.22, P < 0.01), and pregnancy rate to the subsequent breeding season (P < 0.01), and negatively associated with days to calving (r = 0.28, P < 0.01). Reproductive tract scoring was a better predictor of fertility than was Kleiber ratio and similar in its prediction of calf weaning weight. It was concluded from this study that RTS is a predictor of heifer fertility, compares well with other traits used as a predictor of production outcomes, and is likely to be a good predictor of lifetime production of the cow.

Fertilizer performance of liquid fraction of digestate as synthetic nitrogen substitute in silage maize cultivation for three consecutive years.

PubMed

Sigurnjak, I; Vaneeckhaute, C; Michels, E; Ryckaert, B; Ghekiere, G; Tack, F M G; Meers, E

2017-12-01

Following changes over recent years in fertilizer legislative framework throughout Europe, phosphorus (P) is taking over the role of being the limiting factor in fertilizer application rate of animal manure. This results in less placement area for spreading animal manure. As a consequence, more expensive and energy demanding synthetic fertilizers are required to meet crop nutrient requirements despite existing manure surpluses. Anaerobic digestion followed by mechanical separation of raw digestate, results in liquid fraction (LF) of digestate, a product poor in P but rich in nitrogen (N) and potassium (K). A 3-year field experiment was conducted to evaluate the impact of using the LF of digestate as a (partial) substitute for synthetic N fertilizer. Two different fertilization strategies, the LF of digestate in combination with respectively animal manure and digestate, were compared to the conventional fertilization regime of raw animal manure with synthetic fertilizers. Results from the 3-year trial indicate that the LF of digestate may substitute synthetic N fertilizers without crop yield losses. Through fertilizer use efficiency assessment it was observed that under-fertilization of soils with a high P status could reduce P availability and consequently the potential for P leaching. Under conditions of lower K application, more sodium was taken up by the crop. In arid regions, this effect might reduce the potential risk of salt accumulation that is associated with organic fertilizer application. Finally, economic and ecological benefits were found to be higher when LF of digestate was used as a synthetic N substitute. Future perspectives indicate that nutrient variability in bio-based fertilizers will be one of the greatest challenges to address in the future utilization of these products. Copyright © 2017 Elsevier B.V. All rights reserved.

Using the product threshold model for estimating separately the effect of temperature on male and female fertility.

PubMed

Tusell, L; David, I; Bodin, L; Legarra, A; Rafel, O; López-Bejar, M; Piles, M

2011-12-01

Animals under environmental thermal stress conditions have reduced fertility due to impairment of some mechanisms involved in their reproductive performance that are different in males and females. As a consequence, the most sensitive periods of time and the magnitude of effect of temperature on fertility can differ between sexes. The objective of this study was to estimate separately the effect of temperature in different periods around the insemination time on male and on female fertility by using the product threshold model. This model assumes that an observed reproduction outcome is the result of the product of 2 unobserved variables corresponding to the unobserved fertilities of the 2 individuals involved in the mating. A total of 7,625 AI records from rabbits belonging to a line selected for growth rate and indoor daily temperature records were used. The average maximum daily temperature and the proportion of days in which the maximum temperature was greater than 25°C were used as temperature descriptors. These descriptors were calculated for several periods around the day of AI. In the case of males, 4 periods of time covered different stages of the spermatogenesis, the transit through the epididymus of the sperm, and the day of AI. For females, 5 periods of time covered the phases of preovulatory follicular maturation including day of AI and ovulation, fertilization and peri-implantational stage of the embryos, embryonic and early fetal periods of gestation, and finally, late gestation until birth. The effect of the different temperature descriptors was estimated in the corresponding male and female liabilities in a set of threshold product models. The temperature of the day of AI seems to be the most relevant temperature descriptor affecting male fertility because greater temperature records on the day of AI caused a decrease in male fertility (-6% in male fertility rate with respect to thermoneutrality). Departures from the thermal zone in temperature descriptors covering several periods before AI until early gestation had a negative effect on female fertility, with the pre- and peri-implantational period of the embryos being especially sensitive (from -5 to -6% in female fertility rate with respect to thermoneutrality). The latest period of gestation was unaffected by the temperature. Overall, magnitude and persistency of the temperatures reached in the conditions of this study do not seem to be great enough to have a large effect on male and female rabbit fertility.

Decent wage is more important than absolution of debts: A smallholder socio-hydrological modelling framework

NASA Astrophysics Data System (ADS)

Pande, Saket; Savenije, Hubert

2015-04-01

We present a framework to understand the socio-hydrological system dynamics of a small holder. Small holders are farmers who own less than 2 ha of farmland. It couples the dynamics of 6 main variables that are most relevant at the scale of a small holder: local storage (soil moisture and other water storage), capital, knowledge, livestock production, soil fertility and grass biomass production. The hydroclimatic variability is at sub-annual scale and influences the socio-hydrology at annual scale. The model incorporates rule-based adaptation mechanisms (for example: adjusting expenditures on food and fertilizers, selling livestocks etc.) of small holders when they face adverse socio-hydrological conditions, such as low annual rainfall, higher intra-annual variability in rainfall or variability in agricultural prices. We apply the framework to understand the socio-hydrology of a sugarcane small holder in Aurangabad, Maharashtra. This district has witnessed suicides of many sugarcane farmers who could not extricate themselves out of the debt trap. These farmers lack irrigation and are susceptible to fluctuating sugar prices and intra-annual hydro-climatic variability. We study the sensitivity of annual total capital averaged over 30 years, an indicator of small holder wellbeing, to initial capital that a small holder starts with and the prevalent wage rates. We find that a smallholder well being is low (below Rs 30000 per annum, a threshold above which a smallholder can afford a basic standard of living) and is rather insensitive to initial capital at low wage rates. Initial capital perhaps matters to small holder livelihoods at higher wage rates. Further, the small holder system appears to be resilient at around Rs 115/mandays in the sense that small perturbations in wage rates around this rate still sustains the smallholder above the basic standard of living. Our results thus indicate that government intervention to absolve the debt of farmers is not enough. It must invest in local storages that can buffer intra-annual variability in rainfall in tandem and good wages for alternative sources of income.

Use-effectiveness of fertility awareness among the urban poor.

PubMed

Dorairaj, K

1984-01-01

The efficacy, the ability of Indian women to use the Billings' Ovulation Method, and its effectiveness in helping them to control their fertility was studied in a sample of urban poor living in the Delhi slums. No attempt was made to develop a design which would rigorously test the acceptability of the method because the study was concerned with: the question of the ability of poor women to define fertility and to avoid an unwanted pregnancy by avoiding sexual relations during the fertility period; and the efficacy and use-effectiveness of the modified method which had not been tested. The study, which extended over 36 months, recruited a sample of 5752 eligible acceptors of fertility living in the urban slums. Natural family planning (NFP) use requires recurrent decision making at 2 stages: in the beginning of the menstrual cycle to check for signs of fertility; and to abstain from sexual relations in the fertility period. Age was an important variable in the use of sexual abstinence oriented methods and fertility determining methods. 192 of the acceptors were below 19 years, 1545 between 20-24 years, 2089 between 25-29 years, 1236 between 30-34 years, 520 between 35-39 years, and 170 between 40-44 years. Of 4380 of the 5302 acceptors in Treatment 1 who began to use the method after menstruation, 7 (0.16%) had a profuse discharge and could not distinguish the change in mucus because of cervicitis which was treated in cycle 2. 663 (5.4%) acceptors did not see or feel fertile mucus but noticed patches of infertile mucus throughout the cycle. 419 (69.19%) of them had a family income of less than Rs300 and 25 (3.77%) were open cases of pulmonary tuberculosis. 16 acceptors (0.37%) noticed wetness and lubrication characteristic of fertile type mucus for about 2 hours, 145 (3.31%) for 3-4 hours, and 218 (4.98%) for nearly half a day. 867 (19.79%) had 1 day, 406 (9.27%) 1-1/2 days, 939 (21.44%) for 2 days, 291 (6.64%) 2-1/2 days, 636 (14.52%) for 3 days and 187 (4.27%) 3-1/2 to 4 days of fertile mucus. 1 acceptor had 5 days of fertile mucus. 4 acceptors failed to check regularly and therefore may have missed the fertile period. In Treatment 2 the initial decision to accept the use of the method was made by the 450 husbands before instructing their wives. The continuation rate of 91.86% for 12 months with a standard error of 0.67% was surprisingly high for a sample with low literacy and occupational status, low female work participation rates, small family size and a preference for sons with low motivation to use other methods. There were 9 unplanned pregnancies classified as method failures--pregnancies which occurred in acceptors who followed the method accoring to the instruction but got pregnant. The 1 year efficacy rate (life table analysis) was 99.86%. The 1-year use-effectiveness rate was 97.43% for the 5752 cohort. The high efficacy rate of the method can be due to 2 factors: the correct identification of the fertile mucus; and the ability to clearly distinguish between infertile and fertile mucus.

Soil extracellular enzyme activities, soil carbon and nitrogen storage under nitrogen fertilization: A meta-analysis

DOE PAGES

Jian, Siyang; Li, Jianwei; Chen, Ji; ...

2016-07-08

Nitrogen (N) fertilization affects the rate of soil organic carbon (SOC) decomposition by regulating extracellular enzyme activities (EEA). Extracellular enzymes have not been represented in global biogeochemical models. Understanding the relationships among EEA and SOC, soil N (TN), and soil microbial biomass carbon (MBC) under N fertilization would enable modeling of the influence of EEA on SOC decomposition. Based on 65 published studies, we synthesized the activities of α-1,4-glucosidase (AG), β-1,4-glucosidase (BG), β-d-cellobiosidase (CBH), β-1,4-xylosidase (BX), β-1,4-N-acetyl-glucosaminidase (NAG), leucine amino peptidase (LAP), urease (UREA), acid phosphatase (AP), phenol oxidase (PHO), and peroxidase (PEO) in response to N fertilization. Here, themore » proxy variables for hydrolytic C acquisition enzymes (C-acq), N acquisition (N-acq), and oxidative decomposition (OX) were calculated as the sum of AG, BG, CBH and BX; AG and LAP; PHO and PEO, respectively.« less

The Application Of Liquid Fertilizer Made Of Traditional Market Organic Wastes On Growth Of Setaria Grass (Setaria splendida Stapf)

NASA Astrophysics Data System (ADS)

Hendarto, Eko; Suwarno

2018-02-01

There are hugh amount of traditional market organic wastes that may polute the environment. In general, the wastes are utilized for compost making and liquid fertilizer as well for plant. The use of liquid fertilizer from organic wastes of traditional markets opens up opportunities for misplaced cultivation of Setaria grass (Setaria splendida Stapf), which is required by ruminant farms. This research was conducted to evaluate the best mixture of water to the fertilizer in term of its effectiveness on the variables and experimental method using Completely Randomized Design. The treatments were: 6 doses of mixtures namely 0, 10, 20, 30, 40 and 50 liters of water, each of which was mixed with 10 liters of liquid fertilizer. The variables measured were the height, the numbers of tillers, the numbers of leaves, and canopy. The results of the study showed that the doses of water in the fertilizer did not indicate any significant differences (P > 0.05) on all variables being studied, however, the linear equation showed that greater concentrations of water in the fertilizer tended to decrease the growth of Setaria grass. Suggested use of water on the liquid fertilizer mixture should be not greater than 30 l - 10 l fertilizer.

Air pollution and human fertility rates.

PubMed

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.

Changes in fine-root production, phenology and spatial distribution in response to N application in irrigated sweet cherry trees.

PubMed

Artacho, Pamela; Bonomelli, Claudia

2016-05-01

Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha(-1)), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110-180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70-80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source-sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Changes in fine-root production, phenology and spatial distribution in response to N application in irrigated sweet cherry trees

PubMed Central

Artacho, Pamela; Bonomelli, Claudia

2016-01-01

Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha−1), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110–180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70–80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source–sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees. PMID:26888890

Fertility, income distribution, and economic growth: theory and cross-country evidence.

PubMed

Galor, O; Zang, H

1997-05-01

The authors perform discriminatory, empirical tests of a theoretical model that predicts that family size adversely affects output per capita and nonsteady state growth rates. Neoclassical models posit that adverse output and nonsteady growth rates are affected by labor force growth (LFG) or population growth (PG). This study tests whether family size (FS) will be more significant than LFG or PG in explaining differences in economic growth (EG) rates across countries during 1960-88. A proxy variable for the public education system was used to separate government interventions on human capital formation from market forces. Data were obtained for 73 countries, which exclude centrally planned economies, oil-producing countries, and those with less than 1 million population. The empirical test is run with 58-country, 45-country, and 96-country samples to test for robustness and reliability. The empirical test supports the theoretical model. It demonstrates that equal distribution of income and smaller FS enhance EG. With income inequality, the effect of FS was significant, and the effect of the LFG rate or PG rate was insignificant. With a given FS, LFG was positively correlated with EG. A reduction of the net fertility rate by one point would increase the worker output growth rate by 0.25%, and the differences in growth rates between high- and low-fertility countries would be 1%. An increase in the income share of the bottom 60% would increase the growth rate of worker output by about 1%. Higher investments in public or private education would be conducive to growth.

Plant growth-promoting rhizobacteria allow reduced application rates of chemical fertilizers.

PubMed

Adesemoye, A O; Torbert, H A; Kloepper, J W

2009-11-01

The search for microorganisms that improve soil fertility and enhance plant nutrition has continued to attract attention due to the increasing cost of fertilizers and some of their negative environmental impacts. The objectives of this greenhouse study with tomato were to determine (1) if reduced rates of inorganic fertilizer coupled with microbial inoculants will produce plant growth, yield, and nutrient uptake levels equivalent to those with full rates of the fertilizer and (2) the minimum level to which fertilizer could be reduced when inoculants were used. The microbial inoculants used in the study were a mixture of plant growth-promoting rhizobacteria (PGPR) strains Bacillus amyloliquefaciens IN937a and Bacillus pumilus T4, a formulated PGPR product, and the arbuscular mycorrhiza fungus (AMF), Glomus intraradices. Results showed that supplementing 75% of the recommended fertilizer rate with inoculants produced plant growth, yield, and nutrient (nitrogen and phosphorus) uptake that were statistically equivalent to the full fertilizer rate without inoculants. When inoculants were used with rates of fertilizer below 75% of the recommended rate, the beneficial effects were usually not consistent; however, inoculation with the mixture of PGPR and AMF at 70% fertility consistently produced the same yield as the full fertility rate without inoculants. Without inoculants, use of fertilizer rates lower than the recommended resulted in significantly less plant growth, yield, and nutrient uptake or inconsistent impacts. The results suggest that PGPR-based inoculants can be used and should be further evaluated as components of integrated nutrient management strategies.

Rooster Semen Cryopreservation: Effect of Pedigree Line and Male Age on Post-Thaw Sperm Function

USDA-ARS?s Scientific Manuscript database

The fertility rates of cryopreserved poultry semen are highly variable and not reliable for use in preservation of commercial genetic stocks. Our objective was to evaluate the cryosurvival of semen from 8 pedigreed layer lines at the onset and end of production. Semen from 160 roosters (20/line) was...

Scaling leaf respiration with nitrogen and phosphorus in tropical forests across two continents.

PubMed

Rowland, Lucy; Zaragoza-Castells, Joana; Bloomfield, Keith J; Turnbull, Matthew H; Bonal, Damien; Burban, Benoit; Salinas, Norma; Cosio, Eric; Metcalfe, Daniel J; Ford, Andrew; Phillips, Oliver L; Atkin, Owen K; Meir, Patrick

2017-05-01

Leaf dark respiration (R dark ) represents an important component controlling the carbon balance in tropical forests. Here, we test how nitrogen (N) and phosphorus (P) affect R dark and its relationship with photosynthesis using three widely separated tropical forests which differ in soil fertility. R dark was measured on 431 rainforest canopy trees, from 182 species, in French Guiana, Peru and Australia. The variation in R dark was examined in relation to leaf N and P content, leaf structure and maximum photosynthetic rates at ambient and saturating atmospheric CO 2 concentration. We found that the site with the lowest fertility (French Guiana) exhibited greater rates of R dark per unit leaf N, P and photosynthesis. The data from Australia, for which there were no phylogenetic overlaps with the samples from the South American sites, yielded the most distinct relationships of R dark with the measured leaf traits. Our data indicate that no single universal scaling relationship accounts for variation in R dark across this large biogeographical space. Variability between sites in the absolute rates of R dark and the R dark  : photosynthesis ratio were driven by variations in N- and P-use efficiency, which were related to both taxonomic and environmental variability. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Climate factors affecting fertility after cervical insemination during the first months of the breeding season in Rasa Aragonesa ewes

NASA Astrophysics Data System (ADS)

Santolaria, P.; Yániz, J.; Fantova, E.; Vicente-Fiel, S.; Palacín, I.

2014-09-01

This study was carried out to examine the impact of several climate variables on the pregnancy rate after cervical artificial insemination (AI) of Rasa Aragonesa ewes. Data were derived from 8,977 inseminations in 76 well-managed flocks performed during the first month of the breeding season (July to October). The following data were recorded for each animal: farm, year, month of AI, parity, lambing-treatment interval, inseminating ram, AI technician, and climatic variables such as mean, maximum and minimum temperature, mean and maximum relative humidity, rainfall, and mean and maximum temperature-humidity index (THI) for each day from day 12 before AI to day 14 post-AI. Means were furthermore calculated for the following periods around AI (day 0): -12 to 0, -2 to 0, AI day, 0 to 2, and 0 to 14. Logistic regression analysis indicated that the likelihood of pregnancy decreased when maximum temperature in the 2 days prior to AI was higher than 30 °C (by a factor of 0.81). Fertility was also lower for primiparous ewes and in multiparous ewes with more than five previous parturitions. Other factors with significant impact on fertility were flock, technician, inseminating ram, and a lambing-AI interval longer than 240 days. It was concluded that the 2 days prior to AI seems to be the period when heat stress had the greatest impact on pregnancy rate in Rasa Aragonesa ewes.

Sperm DNA damage or progressive motility: which one is the better predictor of fertilization in vitro?

PubMed

Simon, Luke; Lewis, Sheena E M

2011-06-01

Sperm progressive motility has been reported to be one of the key factors influencing in vitro fertilization rates. However, recent studies have shown that sperm DNA fragmentation is a more robust predictor of assisted reproductive outcomes including reduced fertilization rates, embryo quality, and pregnancy rates. This study aimed to compare the usefulness of sperm progressive motility and DNA damage as predictive tools of in vitro fertilization rates. Here, 136 couples provided 1,767 eggs with an overall fertilization rate of 64.2%. The fertilization rate in vitro correlated with both sperm progressive motility (r² = 0.236; P = 0.002) and DNA fragmentation (r² = -0.318; P < 0.001). The relative risk of a poor fertilization rate was 9.5 times higher in sperm of men with high DNA fragmentation (>40%) compared with 2.6 times in sperm with poor motility (<40%). Further, sperm DNA fragmentation gave a higher specificity (93.3%) in predicting the fertilization rate than progressive motility (77.8%). Finally, the odds ratio to determine fertilization rate (>70%) was 4.81 (1.89-12.65) using progressive motility compared with 24.18 (5.21-154.51) using DNA fragmentation. This study shows that fertilization rates are directly dependent upon both sperm progressive motility and DNA fragmentation, but sperm DNA fragmentation is a much stronger test.

Modelling crop yield, soil organic C and P under variable long-term fertilizer management in China

NASA Astrophysics Data System (ADS)

Zhang, Jie; Xu, Guang; Xu, Minggang; Balkovič, Juraj; Azevedo, Ligia B.; Skalský, Rastislav; Wang, Jinzhou; Yu, Chaoqing

2016-04-01

Phosphorus (P) is a major limiting nutrient for plant growth. P, as a nonrenewable resource and the controlling factor of aquatic entrophication, is critical for food security and human future, and concerns sustainable resource use and environmental impacts. It is thus essential to find an integrated and effective approach to optimize phosphorus fertilizer application in the agro-ecosystem while maintaining crop yield and minimizing environmental risk. Crop P models have been used to simulate plant-soil interactions but are rarely validated with scattered long-term fertilizer control field experiments. We employed a process-based model named Environmental Policy Integrated Climate model (EPIC) to simulate grain yield, soil organic carbon (SOC) and soil available P based upon 8 field experiments in China with 11 years dataset, representing the typical Chinese soil types and agro-ecosystems of different regions. 4 treatments, including N, P, and K fertilizer (NPK), no fertilizer (CK), N and K fertilizer (NK) and N, P, K and manure (NPKM) were measured and modelled. A series of sensitivity tests were conducted to analyze the sensitivity of grain yields and soil available P to sequential fertilizer rates in typical humid, normal and drought years. Our results indicated that the EPIC model showed a significant agreement for simulating grain yields with R2=0.72, index of agreement (d)=0.87, modeling efficiency (EF)=0.68, p<0.01 and SOC with R2=0.70, d=0.86, EF=0.59, and p<0.01. EPIC can well simulate soil available P moderately and capture the temporal changes in soil P reservoirs. Both of Crop yields and soil available were found more sensitive to the fertilizer P rates in humid than drought year and soil available P is closely linked to concentrated rainfall. This study concludes that EPIC model has great potential to simulate the P cycle in croplands in China and can explore the optimum management practices.

The combination of kinetic and flow cytometric semen parameters as a tool to predict fertility in cryopreserved bull semen.

PubMed

Gliozzi, T M; Turri, F; Manes, S; Cassinelli, C; Pizzi, F

2017-11-01

Within recent years, there has been growing interest in the prediction of bull fertility through in vitro assessment of semen quality. A model for fertility prediction based on early evaluation of semen quality parameters, to exclude sires with potentially low fertility from breeding programs, would therefore be useful. The aim of the present study was to identify the most suitable parameters that would provide reliable prediction of fertility. Frozen semen from 18 Italian Holstein-Friesian proven bulls was analyzed using computer-assisted semen analysis (CASA) (motility and kinetic parameters) and flow cytometry (FCM) (viability, acrosomal integrity, mitochondrial function, lipid peroxidation, plasma membrane stability and DNA integrity). Bulls were divided into two groups (low and high fertility) based on the estimated relative conception rate (ERCR). Significant differences were found between fertility groups for total motility, active cells, straightness, linearity, viability and percentage of DNA fragmented sperm. Correlations were observed between ERCR and some kinetic parameters, and membrane instability and some DNA integrity indicators. In order to define a model with high relation between semen quality parameters and ERCR, backward stepwise multiple regression analysis was applied. Thus, we obtained a prediction model that explained almost half (R 2=0.47, P<0.05) of the variation in the conception rate and included nine variables: five kinetic parameters measured by CASA (total motility, active cells, beat cross frequency, curvilinear velocity and amplitude of lateral head displacement) and four parameters related to DNA integrity evaluated by FCM (degree of chromatin structure abnormality Alpha-T, extent of chromatin structure abnormality (Alpha-T standard deviation), percentage of DNA fragmented sperm and percentage of sperm with high green fluorescence representative of immature cells). A significant relationship (R 2=0.84, P<0.05) was observed between real and predicted fertility. Once the accuracy of fertility prediction has been confirmed, the model developed in the present study could be used by artificial insemination centers for bull selection or for elimination of poor fertility ejaculates.

Potential Application of Silica Mineral from Dieng Mountain in Agriculture Sector to Control the Release Rate of Fertilizer Elements

NASA Astrophysics Data System (ADS)

Solihin; Mursito, Anggoro Tri; Dida, Eki N.; Erlangga, Bagus D.; Widodo

2017-07-01

Silica mineral, which comes along with geothermal fluid in Dieng, is a product of erosion, decomposition and dissolution of silicon oxide based mineral, which is followed by precipitation to form silica mineral. This silica cell structure is non crystalline, and it contains 85,60 % silicon oxide, 6.49 volatile elements, and also other oxide elements. Among the direct potential application of this silica is as raw material in slow release fertilizer. Silica in compacted slow release fertilizer is able control the release rate of fertilizer elements. Two type of slow release fertilizer has been made by using silica as the matrix in these slow release fertilizer. The first type is the mixing of ordinary solid fertilizer with Dieng silica, whereas the second one is the mixing of disposal leach water with Dieng silica. The release test shows that both of these modified fertilizers have slow release fertilizer characteristic. The release rate of fertilizer elements (magnesium, potassium, ammonium, and phosphate) can be significantly reduced. The addition of kaolin in the first type of slow release fertilizer makes the release rate of fertilizer elements can be more slowed down. Meanwhile in the second type of slow release fertilizer, the release rate is determined by ratio of silica/hydrogel. The lowest release rate is achieved by sample that has highest ratio of silica/hydrogel.

Metabolomic markers of fertility in bull seminal plasma

PubMed Central

Dinh, Thu; Kaya, Abdullah; Topper, Einko; Moura, Arlindo Alencar

2018-01-01

Metabolites play essential roles in biological systems, but detailed identities and significance of the seminal plasma metabolome related to bull fertility are still unknown. The objectives of this study were to determine the comprehensive metabolome of seminal plasma from Holstein bulls and to ascertain the potential of metabolites as biomarkers of bull fertility. The seminal plasma metabolome from 16 Holstein bulls with two fertility rates were determined by gas chromatography-mass spectrometry (GC-MS). Multivariate and univariate analyses of the data were performed, and the pathways associated with the seminal plasma metabolome were identified using bioinformatics approaches. Sixty-three metabolites were identified in the seminal plasma of all bulls. Fructose was the most abundant metabolite in the seminal fluid, followed for citric acid, lactic acid, urea and phosphoric acid. Androstenedione, 4-ketoglucose, D-xylofuranose, 2-oxoglutaric acid and erythronic acid represented the least predominant metabolites. Partial-Least Squares Discriminant Analysis (PLSDA) revealed a distinct separation between high and low fertility bulls. The metabolites with the greatest Variable Importance in Projection score (VIP > 2) were 2-oxoglutaric acid and fructose. Heat-map analysis, based on VIP score, and univariate analysis indicated that 2-oxoglutaric acid was less (P = 0.02); whereas fructose was greater (P = 0.02) in high fertility than in low fertility bulls. The current study is the first to describe the metabolome of bull seminal plasma using GC-MS and presented metabolites such as 2-oxoglutaric acid and fructose as potential biomarkers of bull fertility. PMID:29634739

Determinants of fertility in Rwanda in the context of a fertility transition: a secondary analysis of the 2010 Demographic and Health Survey.

PubMed

Ndahindwa, Vedaste; Kamanzi, Collins; Semakula, Muhammed; Abalikumwe, François; Hedt-Gauthier, Bethany; Thomson, Dana R

2014-12-13

Major improvements to Rwanda's health system, infrastructure, and social programs over the last decade have led to a rapid fertility transition unique from other African countries. The total fertility rate fell from 6.1 in 2005 to 4.6 in 2010, with a 3-fold increase in contraceptive usage. Despite this rapid national decline, many women still have large numbers of children. This study investigates predictors of fertility during this fertility transition to inform policies that improve individuals' reproductive health and guide national development. We used Poisson regression to separately model number of children born to ever married/cohabitated women (n = 8,309) and never married women (n = 1,220) age 15 to 49 based on 2010 Rwanda Demographic and Health Survey data. We used backward stepwise regression with a time offset to identify individual and household factors associated with woman's fertility level, accounting for sampling weights, clustering, and stratification. In ever married/cohabitating women, high fertility was significantly associated (p < 0.05) with the following variables: unmet need for contraception (IRR = 1.07), women's desire for children (5+ versus 0-2 children: IRR = 1.22), woman's number of siblings (8-20 versus 0-4: IRR = 1.03), and couples who desired different numbers of children (husband wants more: IRR = 1.04; husband wants fewer: IRR = 1.04). Low fertility in ever married/cohabitating women was associated with women's education (higher versus no education: IRR = 0.66), household wealth (highest versus lowest quintile: IRR = 0.93), and delayed sexual debut (25+ versus 8-18 years: IRR = 0.49). In never married women, low fertility was associated with education (higher versus no education: IRR = 0.22), household wealth (highest versus lowest quintile: IRR = 0.58), delayed sexual debut (25-49 versus 8-18 years: IRR = 0.43), and having an unmet need for contraception (IRR = 0.69). Although the study design does not allow causal conclusions, these results suggest several strategies to further reduce Rwanda's national fertility rate and support families to achieve their desired fertility. Strategies include policies and programs that promote delayed sexual debut via educational and economic opportunities for women, improved access to reproductive health information and services at schools and via health campaigns, and involvement of men in family planning decision making.

Association of suicide rates of elderly persons with fertility rates.

PubMed

Shah, Ajit

2008-04-01

A negative correlation between societal suicide rates and social integration has been reported, but rarely specifically examined for suicide rates of the elderly although suicide rates of elderly persons are among the highest. The associations of suicide rates of elderly persons and fertility rates for 81 countries were examined using data from the World Health Organisation and United Nations. Fertility rates were considered a proxy measure for social integration. Multiple regression analysis indicated that suicide rates for males and females in the age bands 65-74 years and 75+ years were independently (negative) correlated with fertility rates. Fertility rates, as a measure of social integration, may interact with, modify and mediate the effect of cultural factors on suicide rates of elderly persons.

Using a Decision Support System to Optimize Production of Agricultural Crop Residue Biofeedstock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed L. Hoskinson; Ronald C. Rope; Raymond K. Fink

2007-04-01

For several years the Idaho National Laboratory (INL) has been developing a Decision Support System for Agriculture (DSS4Ag) which determines the economically optimum recipe of various fertilizers to apply at each site in a field to produce a crop, based on the existing soil fertility at each site, as well as historic production information and current prices of fertilizers and the forecast market price of the crop at harvest, for growing a crop such as wheat, potatoes, corn, or cotton. In support of the growing interest in agricultural crop residues as a bioenergy feedstock, we have extended the capability ofmore » the DSS4Ag to develop a variable-rate fertilizer recipe for the simultaneous economically optimum production of both grain and straw, and have been conducting field research to test this new DSS4Ag. In this paper we report the results of two years of field research testing and enhancing the DSS4Ag’s ability to economically optimize the fertilization for the simultaneous production of both grain and its straw, where the straw is an agricultural crop residue that can be used as a biofeedstock.« less

Microdose follicular flare: a viable alternative for normal responding patients undergoing in vitro fertilization?

PubMed Central

Levens, Eric D.; Whitcomb, Brian W.; Kort, Jonathan D.; Materia-Hoover, Donna; Larsen, Frederick W.

2009-01-01

Objective To compare cycle outcomes among normal responding patients ≤30 years receiving microdose follicular flare (MDF) and long-luteal agonist (LL). Design Retrospective cohort study. Setting Military-based ART center. Patients First, autologous ART cycles among 499 women ≤30 years old from 01/1999 to 12/2005. Interventions Following OCP administration prior to cycle start, patients were non-randomly assigned to either LL or MDF for LH surge suppression. LL received 1 mg/d leuprolide acetate (LA) on cycle day 21, which was reduced to 0.25 mg/day 10–14 days later. MDF received LA (40 μg BID) beginning 3 days after discontinuing OCPs. Both groups received a combination of hMG and rFSH. Main Outcome Measures Primary outcomes were implantation, clinical pregnancy and live birth rates; in cycle variables included peak E2, oocytes retrieved, oocyte maturity, and fertilization rate. Results Multivariable models controlling for confounding by treatment indication found no significant differences between groups in implantation (MDF:36%; LL:38%), clinical pregnancy (MDF:53%; LL:56%), and live birth rates (MDF:47%; LL:50%). No differences were observed in peak E2, oocytes retrieved, oocyte maturity, fertilization rate, or embryos transferred. Conclusions MDF use among normal responding ART patients produced no differences in cycle outcome when compared to LL. Resultantly, MDF may be a viable alternative for normal responding patients. PMID:18249365

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jian, Siyang; Li, Jianwei; Chen, Ji

Nitrogen (N) fertilization affects the rate of soil organic carbon (SOC) decomposition by regulating extracellular enzyme activities (EEA). Extracellular enzymes have not been represented in global biogeochemical models. Understanding the relationships among EEA and SOC, soil N (TN), and soil microbial biomass carbon (MBC) under N fertilization would enable modeling of the influence of EEA on SOC decomposition. Based on 65 published studies, we synthesized the activities of α-1,4-glucosidase (AG), β-1,4-glucosidase (BG), β-d-cellobiosidase (CBH), β-1,4-xylosidase (BX), β-1,4-N-acetyl-glucosaminidase (NAG), leucine amino peptidase (LAP), urease (UREA), acid phosphatase (AP), phenol oxidase (PHO), and peroxidase (PEO) in response to N fertilization. Here, themore » proxy variables for hydrolytic C acquisition enzymes (C-acq), N acquisition (N-acq), and oxidative decomposition (OX) were calculated as the sum of AG, BG, CBH and BX; AG and LAP; PHO and PEO, respectively.« less

Impact and determinants of sex preference in Nepal.

PubMed

Leone, Tiziana; Matthews, Zoë; Dalla Zuanna, Gianpiero

2003-06-01

Gender discrimination and son preference are key demographic features of South Asia and are well documented for India. However, gender bias and sex preference in Nepal have received little attention. 1996 Nepal Demographic and Health Survey data on ever-married women aged 15-49 who did not desire any more children were used to investigate levels of gender bias and sex preference. The level of contraceptive use and the total fertility rate in the absence of sex preference were estimated, and logistic regression was performed to analyze the association between socioeconomic and demographic variables and stopping childbearing after the birth of a son. Commonly used indicators of gender bias, such as sex ratio at birth and sex-specific immunization rates, do not suggest a high level of gender discrimination in Nepal. However, sex preference decreases contraceptive use by 24% and increases the total fertility rate by more than 6%. Women's contraceptive use, exposure to the media, parity, last birth interval, educational level and religion are linked to stopping childbearing after the birth of a boy, as is the ethnic makeup of the local area. The level of sex preference in Nepal is substantial. Sex preference is an important barrier to the increase of contraceptive use and decline of fertility in the country; its impact will be greater as desired family size declines.

The paradoxical relationship between stallion fertility and oxidative stress.

PubMed

Gibb, Zamira; Lambourne, Sarah R; Aitken, Robert J

2014-09-01

The relationship between stallion fertility and oxidative stress remains poorly understood. The purpose of this study was to identify criteria for thoroughbred fertility assessment by performing a logistical regression analysis using "dismount" sperm parameters as predictors and weekly per-cycle conception rate as the dependent variable. Paradoxically, positive relationships between fertility and oxidative stress were revealed, such that samples that produced pregnancies exhibited higher rates of 8-hydroxy-2'-deoxyguanosine release (1490.2% vs. 705.5 pg/ml/24 h) and lower vitality (60.5% vs. 69.6%) and acrosome integrity (40.2% vs. 50.1%) than those that did not. We hypothesized that the most fertile spermatozoa exhibited the highest levels of oxidative phosphorylation (OXPHOS), with oxidative stress simply being a by-product of intense mitochondrial activity. Accordingly, an experiment to investigate the relationship between oxidative stress and motility was conducted and revealed positive correlations between mitochondrial ROS and total motility (R² = 0.90), rapid motility (R² = 0.89), average path velocity (VAP; R² = 0.59), and curvilinear velocity (VCL; R² = 0.66). Similarly, lipid peroxidation was positively correlated with total motility (R² = 0.46), rapid motility (R² = 0.51), average path velocity (R² = 0.62), and VCL (R² = 0.56), supporting the aforementioned hypothesis. The relative importance of OXPHOS in supporting the motility of equine spermatozoa was contrasted with human spermatozoa, which primarily utilize glycolysis. In this study, mitochondrial inhibition significantly reduced the velocity (P < 0.01) and ATP (P < 0.05) content of equine, but not human, spermatozoa, emphasizing the former's relative dependence on OXPHOS. The equine is the first mammal in which such a positive relationship between oxidative stress and functionality has been observed, with implications for the management of stallion fertility in vitro and in vivo. © 2014 by the Society for the Study of Reproduction, Inc.

Nitrogen input from residential lawn care practices in suburban watersheds in Baltimore county, MD

Treesearch

Neely L. Law; Lawrence E. Band; J. Morgan Grove

2004-01-01

A residential lawn care survey was conducted as part of the Baltimore Ecosystem Study, a Long-term Ecological Research project funded by the National Science Foundation and collaborating agencies, to estimate the nitrogen input to urban watersheds from lawn care practices. The variability in the fertilizer N application rates and the factors affecting the application...

Contextual determinants of induced abortion: a panel analysis

PubMed Central

Llorente-Marrón, Mar; Díaz-Fernández, Montserrat; Méndez-Rodríguez, Paz

2016-01-01

ABSTRACT OBJECTIVE Analyze the contextual and individual characteristics that explain the differences in the induced abortion rate, temporally and territorially. METHODS We conducted an econometric analysis with panel data of the influence of public investment in health and per capita income on induced abortion as well as a measurement of the effect of social and economic factors related to the labor market and reproduction: female employment, immigration, adolescent fertility and marriage rate. The empirical exercise was conducted with a sample of 22 countries in Europe for the 2001-2009 period. RESULTS The great territorial variability of induced abortion was the result of contextual and individual socioeconomic factors. Higher levels of national income and investments in public health reduce its incidence. The following sociodemographic characteristics were also significant regressors of induced abortion: female employment, civil status, migration, and adolescent fertility. CONCLUSIONS Induced abortion responds to sociodemographic patterns, in which the characteristics of each country are essential. The individual and contextual socioeconomic inequalities impact significantly on its incidence. Further research on the relationship between economic growth, labor market, institutions and social norms is required to better understand its transnational variability and to reduce its incidence. PMID:27007684

[Factors affecting infant mortality (author's transl)].

PubMed

Chackiel, J

1982-04-01

The purpose of this paper is to analyze the differentials and detect factors affecting infant mortality on the basis of data obtained from the fertility surveys from those countries participating in the World Fertility Survey. In particular, this includes the surveys carried out in Colombia, Peru, Costa Rica, Panama, and the Dominican Republic. 3 types of explanatory variables may be considered from the information available: 1) context variables related to the mother's environment; 2) socioeconomic variables based on the educational and economic characteristics of the mother and her last husband; and 3) biological factors (from each woman's pregnancy history) such as mother's age at birth of the child, order of birth, interbirth interval, etc. The countries, whether high or low mortality, present great differences in child mortality in most of the variables considered. In Panama and Costa Rica there are population sectors with infant mortality rates of around 100/1000 live births, whereas in Peru these are over 150/1000 (children from mothers without education, low agricultural strata, etc.). Besides presenting the differentials, a methodological test is made through the application to Costa Rica and Peru of the Proportional Hazards Model which permits analysis of the effects of variables when acting simultaneously upon mortality in early childhood. The variables which show the highest disparity in mortality level are: natural region among the context variables, education of mother among the socioeconomic variables, and interbirth interval and maternal age at birth of their children among the biological ones.

Radial growth rate increases in naturally occurring ponderosa pine trees: a late-20th century CO2 fertilization effect?

PubMed

Soulé, Peter T; Knapp, Paul A

2006-01-01

The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to 'step' increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement. We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman's correlation was used to relate site stress to growth-rate changes. Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates. Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions.

Fertility Clinic Success Rates

MedlinePlus

... 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 available within ...

Nitrogen Fertilization Elevated Spatial Heterogeneity of Soil Microbial Biomass Carbon and Nitrogen in Switchgrass and Gamagrass Croplands

NASA Astrophysics Data System (ADS)

Jian, S.; Li, J.; Guo, C.; Hui, D.; Deng, Q.; Yu, C. L.; Dzantor, K. E.; Lane, C.

2017-12-01

Nitrogen (N) fertilizers are widely used to increase bioenergy crop yield but intensive fertilizations on spatial distributions of soil microbial processes in bioenergy croplands remains unknown. To quantify N fertilization effect on spatial heterogeneity of soil microbial biomass carbon (MBC) and N (MBN), we sampled top mineral horizon soils (0-15cm) using a spatially explicit design within two 15-m2 plots under three fertilization treatments in two bioenergy croplands in a three-year long fertilization experiment in Middle Tennessee, USA. The three fertilization treatments were no N input (NN), low N input (LN: 84 kg N ha-1 in urea) and high N input (HN: 168 kg N ha-1 in urea). The two crops were switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.). Results showed that N fertilizations little altered central tendencies of microbial variables but relative to LN, HN significantly increased MBC and MBC:MBN (GG only). HN possessed the greatest within-plot variances except for MBN (GG only). Spatial patterns were generally evident under HN and LN plots and much less so under NN plots. Substantially contrasting spatial variations were also identified between croplands (GG>SG) and among variables (MBN, MBC:MBN > MBC). No significant correlations were identified between soil pH and microbial variables. This study demonstrated that spatial heterogeneity is elevated in microbial biomass of fertilized soils likely by uneven fertilizer application, the nature of soil microbial communities and bioenergy crops. Future researchers should better match sample sizes with the heterogeneity of soil microbial property (i.e. MBN) in bioenergy croplands.

Plant Growth-promoting Rhizobacteria Allow Reduced Application Rates of Chemical Fertilizers

USDA-ARS?s Scientific Manuscript database

Efforts to reduce fertilizer rates while increasing nutrient uptake to maintain high yields are very important due to the increasing cost of fertilizers and their potential negative environmental impacts. The objectives of this study were to determine (i) if reduced rates of inorganic fertilizer cou...

Effect of fertility on secondary sex ratio and twinning rate in Sweden, 1749-1870.

PubMed

Fellman, Johan; Eriksson, Aldur W

2015-02-01

We analyzed the effect of total fertility rate (TFR) and crude birth rate (CBR) on the number of males per 100 females at birth, also called the secondary sex ratio (SR), and on the twinning rate (TWR). Earlier studies have noted regional variations in TWR and racial differences in the SR. Statistical analyses have shown that comparisons between SRs demand large data sets because random fluctuations in moderate data are marked. Consequently, reliable results presuppose national birth data. Here, we analyzed historical demographic data and their regional variations between counties in Sweden. We built spatial models for the TFR in 1860 and the CBR in 1751-1870, and as regressors we used geographical coordinates for the provincial capitals of the counties. For both variables, we obtained significant spatial variations, albeit of different patterns and power. The SR among the live-born in 1749-1869 and the TWR in 1751-1860 showed slight spatial variations. The influence of CBR and TFR on the SR and TWR was examined and statistical significant effects were found.

Variability in in vitro fertilization outcomes of prepubertal goat oocytes explained by basic semen analyses.

PubMed

Palomo, M J; Quintanilla, R; Izquierdo, M D; Mogas, T; Paramio, M T

2016-12-01

This work analyses the changes that caprine spermatozoa undergo during in vitro fertilization (IVF) of in vitro matured prepubertal goat oocytes and their relationship with IVF outcome, in order to obtain an effective model that allows prediction of in vitro fertility on the basis of semen assessment. The evolution of several sperm parameters (motility, viability and acrosomal integrity) during IVF and their relationship with three IVF outcome criteria (total penetration, normal penetration and cleavage rates) were studied in a total of 56 IVF replicates. Moderate correlation coefficients between some sperm parameters and IVF outcome were observed. In addition, stepwise multiple regression analyses were conducted that considered three grouping of sperm parameters as potential explanatory variables of the three IVF outcome criteria. The proportion of IVF outcome variation that can be explained by the fitted models ranged from 0.62 to 0.86, depending upon the trait analysed and the variables considered. Seven out of 32 sperm parameters were selected as partial covariates in at least one of the nine multiple regression models. Among these, progressive sperm motility assessed immediately after swim-up, the percentage of dead sperm with intact acrosome and the incidence of acrosome reaction both determined just before the gamete co-culture, and finally the proportion of viable spermatozoa at 17 h post-insemination were the most frequently selected sperm parameters. Nevertheless, the predictive ability of these models must be confirmed in a larger sample size experiment.

Europe the continent with the lowest fertility.

PubMed

2010-01-01

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 increase fertility rates. Searches were done in medical and social science databases for the most recent evidence on relevant subject headings such as TFR, contraception, migration, employment policy and family benefits. Priorities, omissions and disagreements were resolved by discussion. The average TFR in Europe is down to 1.5 children per woman and the perceived ideal family size is also declining. This low fertility rate does not seem directly caused by contraception since in Northern and Western Europe the fertility decline started in the second half of the 1960s. Factors impacting on lower fertility include the instability of modern partnerships and value changes. Government support of assisted human reproduction is beneficial for families, but the effect on TFR is extremely small. Government policies that transfer cash to families for pregnancy and child support also have small effects on the TFR. Societal support for families and for couples trying to conceive improves the lives of families but makes no substantial contribution to increased fertility rates.

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

PubMed

Baker, Karen; Li, Jianbo; Sabanegh, Edmund

2015-01-01

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

Why organic resources and current fertilizer formulations in Southern Africa cannot sustain maize productivity: Evidence from a long-term experiment in Zimbabwe.

PubMed

Mtangadura, Tongai J; Mtambanengwe, Florence; Nezomba, Hatirarami; Rurinda, Jairos; Mapfumo, Paul

2017-01-01

Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on soil chemical properties and maize (Zea mays L.) productivity. Crotalaria juncea (high quality), Calliandra calothyrsus (medium quality), cattle manure (variable quality), maize stover and Pinus patula sawdust (both low quality) were incorporated into soil at 4.0 t C ha-1 (high rate) and 1.2 t C ha-1 (low rate) at the start of each cropping season for nine consecutive years. At both high and low application rates, each of the five organic resources was applied in combination with or without mineral nitrogen (N) fertilizer at 120 kg N ha-1. The nine-year period saw maize grain yields declining by 22% to 84% across treatments despite increases in soil organic carbon, total N and available P from 6% to 80%. Crotalaria, Calliandra and manure led to a less steep yield decline. Exchangeable calcium (Ca), magnesium (Mg) and potassium (K), and soil pH explained much of the variation in yield patterns observed under the different organic resource applications. Maize grain yield was positively correlated with exchangeable Ca (r = 0.51), Mg (r = 0.62) and K (r = 0.53), and soil pH (r = 0.49), but negatively correlated with other soil properties over the 9-year period. We concluded that declining soil exchangeable basic cations were the underlying causes of decreasing maize productivity, and was aggravated by use of low rates of organic resource inputs, particularly with N fertilization. Current nutrient management and fertilizer recommendations that emphasize inorganic N, P and K significantly undervalue the role played by organic resources in sustainability of maize cropping systems in southern Africa.

Why organic resources and current fertilizer formulations in Southern Africa cannot sustain maize productivity: Evidence from a long-term experiment in Zimbabwe

PubMed Central

Mtangadura, Tongai J.

2017-01-01

Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on soil chemical properties and maize (Zea mays L.) productivity. Crotalaria juncea (high quality), Calliandra calothyrsus (medium quality), cattle manure (variable quality), maize stover and Pinus patula sawdust (both low quality) were incorporated into soil at 4.0 t C ha-1 (high rate) and 1.2 t C ha-1 (low rate) at the start of each cropping season for nine consecutive years. At both high and low application rates, each of the five organic resources was applied in combination with or without mineral nitrogen (N) fertilizer at 120 kg N ha-1. The nine-year period saw maize grain yields declining by 22% to 84% across treatments despite increases in soil organic carbon, total N and available P from 6% to 80%. Crotalaria, Calliandra and manure led to a less steep yield decline. Exchangeable calcium (Ca), magnesium (Mg) and potassium (K), and soil pH explained much of the variation in yield patterns observed under the different organic resource applications. Maize grain yield was positively correlated with exchangeable Ca (r = 0.51), Mg (r = 0.62) and K (r = 0.53), and soil pH (r = 0.49), but negatively correlated with other soil properties over the 9-year period. We concluded that declining soil exchangeable basic cations were the underlying causes of decreasing maize productivity, and was aggravated by use of low rates of organic resource inputs, particularly with N fertilization. Current nutrient management and fertilizer recommendations that emphasize inorganic N, P and K significantly undervalue the role played by organic resources in sustainability of maize cropping systems in southern Africa. PMID:28797062

Net Mineralization Response to Fertilizer Application and Site-Specific Setting in a No-Till Dryland Wheat Agroecosystem in the Pacific Northwest (USA)

NASA Astrophysics Data System (ADS)

Bruner, Emily A.; Brown, David J.; Carpenter-Boggs, Lynn

2015-04-01

Application of nitrogen (N) fertilizers is pivotal to maintaining agricultural productivity. Nutrient management is typically guided by a combined assessment of crop yield requirements, residual soil inorganic N concentration, and predicted N supply from organic matter. However, laboratory assays employed to forecast mineralization potential do not reflect in situ processes occurring in soils, processes that can vary spatially within a field. Furthermore, fertilizer application alters biogeochemical cycles through a variety of mechanisms including priming effects and microbial community alterations. This study investigates in-situ ammonification/nitrification rates utilizing mineralization cores as part of a five-year Site-Specific Climate-Friendly Farming (SCF) project. In-depth accounting of nitrate and ammonium production and flux was possible via a six bag mixed-bed ion exchange resin system. Soil cores (7.5 cm diameter by 15 cm deep) were isolated from the surrounding soil by three resin bags sealed in the top and bottom of individual plastic cylinders. Fifteen locations were selected across a commercial direct-seed wheat field based on statistical clustering of primary and secondary topographic variables. In each location surface soil-resin cores were installed in fertilized and unfertilized plots immediately after spring planting and removed before harvest. In situ ammonification/nitrification rates will be analyzed as a function of both fertilizer application and site-specific environmental characteristics as determined from soil moisture monitoring, soil characterization, and crop analysis at each measurement location. This site-specific information on N transformations and availability can then be used to guide site-specific crop management.

Artificial fertilization by intracytoplasmic sperm injection in a teleost fish, the medaka (Oryzias latipes).

PubMed

Otani, Satoshi; Iwai, Toshiharu; Nakahata, Shingo; Sakai, Chiharu; Yamashita, Masakane

2009-01-01

Intracytoplasmic sperm injection (ICSI) is a technique that has been successfully used for assisting reproduction in mammals. However, this method is still not reliable in nonmammalian species, including teleosts. We succeeded in producing medaka individuals by ICSI with a rate of 13.4% (28 hatched embryos out of 209 eggs fertilized by ICSI), the best value reported so far in teleosts, including zebrafish and Nile tilapia. Although the technique was based on that developed for mammalian eggs, some critical modifications were made to adjust it to the medaka egg, which has a thick and hard envelope (the chorion) and a single sperm entry site (the micropyle). Medaka ICSI was performed by injecting a demembranated spermatozoon into an egg cytoplasm through the micropyle 10-15 sec after egg activation induced by a piezo-actuated vibration, the site and timing of sperm penetration being consistent with those in normal fertilization in medaka. To increase the efficiency of ICSI in medaka, we found that the fertilization by ICSI should precisely mimic the fertilization by insemination with intact sperm, both spatially and temporally. The success rate of ICSI was highly variable in batches of eggs (ranging from 0% to 56%), suggesting that the conditions of eggs are important factors in stabilizing the production of individuals by ICSI. The success in medaka ICSI provides a basis for future research to understand the basic mechanisms in gamete biology of teleosts as well as for development of new technology that can yield valuable applications in fisheries science.

EXAMINING THE TEMPORAL VARIABILITY OF AMMONIA AND NITRIC OXIDE EMISSIONS FROM AGRICULTURAL PROCESSES

EPA Science Inventory

This paper examines the temporal variability of airborne emissions of ammonia from livestock operations and fertilizer application and nitric oxide from soils. In the United States, the livestock operations and fertilizer categories comprise the majority of the ammonia emissions...

Those ubiquitous fertility trends: United States, 1945-1979.

PubMed

Sweet, J A; Rindfuss, R R

1983-01-01

1970-79 US fertility trends among differnet racial, regional, age, educational, parity, and socioeconomic subgroups in the population were examined, using own children data from the 1976 Survey of Income and Education (SIE) and the March Current Population Surveys (CPS) from 1968-80. In addition, cross-sectional differences in fertility for the subgroups were compared for 1970 and 1976, using multiple regression analysis. 1st, the appropriateness of using fertility rates obtained from own children data was assessed by comparing fertility rates obtained from the SIE data with those derived from vital statistic and census data. The comparative analysis confirmed that the SIE data yielded an accurate estimate of period fertility rates for currently married women, provided the subgroup samples were sufficiently large. CPS fertility estimates were also judged to be accurate if data from 3 adjacent survey years was pooled to increase sample size. Fertility trends for 5 educational groups were assessed separately for 1967-73. During this periold, there was a marked decline in fertility for all 5 groups; for the group with 5-8 years of education the decline was only 14%, but for the other 4 groups, which included women with 9-16 or more years of education, the decline in fertility ranged from 26-29%. In assessing the 1970-76 trends, the sample was restricted to own children, aged 3 years or less, of currently married women, under 40 years of age. Among whites, there was an overall 20% decline in fertility between 1970-76 and an overall fertility increase of about 2% between 1976-79. These trends were observed in all 28 white subgroups. A similar pattern was observed for blacks. There was an overall fertility decline of 24% between 1970-76, and this decline was apparent for all subgroups except women with college degrees. Betwen 1976-79, black fertility rates, unlike white rates, continued to decline, but the rate of decline was only 3%. Furthermore, the decline in almost all the black subgroups was markedly less than in the 1970-76 periold, and for many of the subgroups the trend was reversed and fertility increased. In summary, the fertility trends noted for 1970-79 were pervasive for almost all the subgroups for both blacks and whites; i.e., there was a marked decline in fertility between 1970-76 and than a reversal or slowing down of the decline during the 1976-79 for all black and white subgroups. Cross-sectional fertility differences in the subgroups in 1970 and in 1979 were quite similar, and fertility rates differed markedly for the separate subgroups. These differences do not, of course, explain the pervasive trends observed in the analysis of the fertility rates over time. A similar study assessing fertility trends among subgroups for the early 1940's through the late 1960s also revealed the pervasive nature of period fertility trends. Demographers have not as yet been able to explain these shifts in fertility that cut across all subgroups in the US and which also characterize the period fertility rates in other developed countries. Tables provided information on 1) total fertility rates by educational level and by geographical region for 1945-1975; 2) % change in number of own children less than 3 years of age among women under age 40 by maternal age, maternal education, initial parity, geographical region, and husband's income; and 3) mean number of own children less than 3 years of age among women under age 40 by maternal age, education, parity, region, and husband's income.

Impact of public programs on fertility and gender specific investment in human capital of children in rural India: cross sectional and time series analyses.

PubMed

Duraisamy, P; Malathy, R

1991-01-01

Cross sectional and time series analyses are conducted with 1971 and 1981 rural district level data for India in order to estimate variations in program impacts on household decisionmaking concerning fertility, child mortality, and schooling; to analyze how the variation in public program subsidies and services influences sex specific investments in schooling; and to examine the bias in cross sectional estimates by employing fixed effects methodology. The theory of household production uses the framework development by Rosenzweig and Wolpin. The utility function is expressed as a function of families' desired number of children, sex specific investment in human capital of children measured by schooling of males and females, and a composite consumption good. Budget constraints are characterized in terms of the biological supply of births or natural fertility, the number of births averted by fertility control, exogenous money income, the prices of number of children, contraceptives, child schooling, and consumption of goods. Demand functions are constructed from maximizing the utility function subject to the budget constraint. Data constitute 40% of the total districts and 50% of the rural population. The empirical specification of the linear model and variable description are provided. Other explanatory variables included are adult educational attainment; % of scheduled castes and tribes and % Muslim; and % rural population. Estimation methods are described and justification is provided for the use of ordinary least squares and fixed effects methods. The results of the cross sectional analysis reveal that own-program effects of family planning and primary health centers reduced family size in 1971 and 81. The increase in secondary school enrollment is evidenced in only 1971. There is a significant effect of family planning (FP) clinics on the demand for surviving children only in 1971. The presence of a seconary school in a village reduces the demand for children in both years. Primary health centers (PHC) and hospitals in a village only encourage boys and girls schooling in 1981. Doubling the number of PHCs/1000 population would reduce the total fertility rate from 4.05 to 3.85. Doubling secondary schools alone would reduce the total fertility rate to 3.75. A 12% decline in fertility or a 20% decrease in populaiton growth would be realized with this doubling. Promotion of female higher education would reduce family size and increase the schooling of females, to equalize the enrollments between the sexes. Muslim population increases fertility and reduces schooling for both sexes. The panel results suggest that the effects of hospitals are overstated cross sectionally, and the effects of FP and secondary schools are understated. Both analyses showed increases in schools to improve female educational attainment.

Ammonia Emissions from Agriculture in China

NASA Astrophysics Data System (ADS)

Chen, Y.; Zhang, L.; Zhao, Y.; Huang, B.

2016-12-01

Ammonia (NH3) is an important alkaline pollutant in the atmosphere and it has various environmental and climatic effects. We will present an improved bottom-up estimate of ammonia emissions from agriculture in China at 0.5°×0.5° horizontal resolution and monthly variability. Ammonia emissions from fertilizer use are derived using data of crop planting area, fertilizer application time and rate for 18 main crops. Ammonia emission factors from fertilizer use are estimated as a function of soil properties such as soil pH, cation exchange capacity (CEC), and agricultural activity information such as crop type, fertilizer type, and application mode. We further consider ambient temperature and wind speed to account for the meteorological influences on ammonia emission factors of fertilizer use. We also estimate the ammonia emission from livestock over China using the mass-flow methodology. The derived ammonia emissions in China for the year 2005 are 4.55 Tg NH3 from fertilizer use and 6.96 Tg from livestock. Henan and Jiangsu provinces are the two largest emitting areas for ammonia from fertilizer use (470 Gg NH3 and 365 Gg NH3). Henan (621 Gg NH3) and Shandong (533 Gg NH3) have the largest ammonia emissions from livestock. Both ammonia emissions from fertilizer use and livestock have distinct seasonal variations; peaking in June for fertilizer use (822 Gg NH3) and in July for livestock (1244 Gg NH3), and are both lowest in January (80 Gg and 241 Gg, respectively). Combining with other ammonia source (eg. human waste and transport) estimates from the REAS v2.1 emission inventory, we show that total ammonia emissions in China for the year 2005 are 14.0 Tg NH3 a-1. Comparisons with satellite measurements of ammonia columns will also be presented.

Meteorological variables affect fertility rate after intrauterine artificial insemination in sheep in a seasonal-dependent manner: a 7-year study.

PubMed

Palacios, C; Abecia, J A

2015-05-01

A total number of 48,088 artificial inseminations (AIs) have been controlled during seven consecutive years in 79 dairy sheep Spanish farms (41° N). Mean, maximum and minimum ambient temperatures (Ts), temperature amplitude (TA), mean relative humidity (RH), mean solar radiation (SR) and total rainfall of each insemination day and 15 days later were recorded. Temperature-humidity index (THI) and effective temperature (ET) have been calculated. A binary logistic regression model to estimate the risk of not getting pregnant compared to getting pregnant, through the odds ratio (OR), was performed. Successful winter inseminations were carried out under higher SR (P < 0.01) and summer inseminations under lower SR values (P < 0.05). Successful inseminations during the summer were performed under significantly lower maximum T (P < 0.01), while winter inseminations resulted in pregnancy when they were carried out under higher maximum (P < 0.05) and minimum Ts (P < 0.01). Up to five meteorological variables presented OR >1 (maximum T, ET and rainfall on AI day, and ET and rainfall on day 15), and two variables presented OR <1 (SR on AI day and maximum T on day 15). However, the effect of meteorological factors affected fertility in opposite ways, so T becomes a protective or risk factor on fertility depending on season. In conclusion, the percentage of pregnancy after AI in sheep is significantly affected by meteorological variables in a seasonal-dependent manner, so the parameters such as temperature reverse their effects in the hot or cold seasons. A forecast of the meteorological conditions could be a useful tool when AI dates are being scheduled.

Meteorological variables affect fertility rate after intrauterine artificial insemination in sheep in a seasonal-dependent manner: a 7-year study

NASA Astrophysics Data System (ADS)

Palacios, C.; Abecia, J. A.

2015-05-01

A total number of 48,088 artificial inseminations (AIs) have been controlled during seven consecutive years in 79 dairy sheep Spanish farms (41° N). Mean, maximum and minimum ambient temperatures ( Ts), temperature amplitude (TA), mean relative humidity (RH), mean solar radiation (SR) and total rainfall of each insemination day and 15 days later were recorded. Temperature-humidity index (THI) and effective temperature (ET) have been calculated. A binary logistic regression model to estimate the risk of not getting pregnant compared to getting pregnant, through the odds ratio (OR), was performed. Successful winter inseminations were carried out under higher SR ( P < 0.01) and summer inseminations under lower SR values ( P < 0.05). Successful inseminations during the summer were performed under significantly lower maximum T ( P < 0.01), while winter inseminations resulted in pregnancy when they were carried out under higher maximum ( P < 0.05) and minimum Ts ( P < 0.01). Up to five meteorological variables presented OR >1 (maximum T, ET and rainfall on AI day, and ET and rainfall on day 15), and two variables presented OR <1 (SR on AI day and maximum T on day 15). However, the effect of meteorological factors affected fertility in opposite ways, so T becomes a protective or risk factor on fertility depending on season. In conclusion, the percentage of pregnancy after AI in sheep is significantly affected by meteorological variables in a seasonal-dependent manner, so the parameters such as temperature reverse their effects in the hot or cold seasons. A forecast of the meteorological conditions could be a useful tool when AI dates are being scheduled.

Population, internal migration, and economic growth: an empirical analysis.

PubMed

Moreland, R S

1982-01-01

The role of population growth in the development process has received increasing attention during the last 15 years, as manifested in the literature in 3 broad categories. In the 1st category, the effects of rapid population growth on the growth of income have been studied with the use of simulation models, which sometimes include endogenous population growth. The 2nd category of the literature is concerned with theoretical and empirical studies of the economic determinants of various demographic rates--most usually fertility. Internal migration and dualism is the 3rd population development category to recieve attention. An attempt is made to synthesize developments in these 3 categories by estimating from a consistent set of data a 2 sector economic demographic model in which the major demographic rates are endogenous. Due to the fact that the interactions between economic and demographic variables are nonlinear and complex, the indirect effects of changes in a particular variable may depend upon the balance of numerical coefficients. For this reason it was felt that the model should be empirically grounded. A brief overview of the model is provided, and the model is compared to some similar existing models. Estimation of the model's 9 behavior equations is discussed, followed by a "base run" simulation of a developing country "stereotype" and a report of a number of policy experiments. The relatively new field of economic determinants of demographic variables was drawn upon in estimating equations to endogenize demographic phenomena that are frequently left exogenous in simulation models. The fertility and labor force participation rate functions are fairly standard, but a step beyong existing literature was taken in the life expectancy and intersectorial migration equations. On the economic side, sectoral savings functions were estimated, and it was found that the marginal propensity to save is lower in agriculture than in nonagriculture. Testing to see the effect of a population's age structure on savings rather than assuming a particular direction as Coale-Hoover and Simon do in their models, it was found that a higher proportion of children compete with savings in agriculture but complement savings in industrial areas. This was consistent with the economic value of children in agricultural and nonagricultural regions of less developed countries. The estimated production functions showed that marginal products of labor were considerably higher in agriculture than in nonagriculture. As with other simulation models, the effect of reducing fertility was to accelerate income growth. Reductions in rural fertility were more equitable and raised the overall level of per capita income more than similar efforts directed to urban areas only.

Emissions of N2O and NO from fertilized fields: Summary of available measurement data

NASA Astrophysics Data System (ADS)

Bouwman, A. F.; Boumans, L. J. M.; Batjes, N. H.

2002-12-01

Information from 846 N2O emission measurements in agricultural fields and 99 measurements for NO emissions was summarized to assess the influence of various factors regulating emissions from mineral soils. The data indicate that there is a strong increase of both N2O and NO emissions accompanying N application rates, and soils with high organic-C content show higher emissions than less fertile soils. A fine soil texture, restricted drainage, and neutral to slightly acidic conditions favor N2O emission, while (though not significant) a good soil drainage, coarse texture, and neutral soil reaction favor NO emission. Fertilizer type and crop type are important factors for N2O but not for NO, while the fertilizer application mode has a significant influence on NO only. Regarding the measurements, longer measurement periods yield more of the fertilization effect on N2O and NO emissions, and intensive measurements (≥1 per day) yield lower emissions than less intensive measurements (2-3 per week). The available data can be used to develop simple models based on the major regulating factors which describe the spatial variability of emissions of N2O and NO with less uncertainty than emission factor approaches based on country N inputs, as currently used in national emission inventories.

Did fertility go up after the Oklahoma City bombing? An analysis of births in metropolitan counties in Oklahoma, 1990-1999.

PubMed

Rodgers, Joseph Lee; St John, Craig A; Coleman, Ronnie

2005-11-01

Political and sociocultural events (e.g., Brown v. Board of Education in 1954 and the German reunification in 1989) and natural disasters (e.g., Hurricane Hugo in 1989) can affect fertility. In our research, we addressed the question of whether the Oklahoma City bombing in April 1995, a man-made disaster, influenced fertility patterns in Oklahoma. We defined three theoretical orientations--replacement theory, community influence theory, and terror management theory--that motivate a general expectation of birth increases, with different predictions emerging from time and geographic considerations. We used two different empirical methodologies. First, we fitted dummy-variable regression models to monthly birth data from 1990 to 1999 in metropolitan counties. We used birth counts to frame the problem and general fertility rates to address the problem formally. These analyses were organized within two design structures: a control-group interrupted time-series design and a difference-in-differences design. In these analyses, Oklahoma County showed an interpretable, consistent, and significant increase in births. Second, we used graphical smoothing models to display these effects visually. In combination, these methods provide compelling support for a fertility response to the Oklahoma City bombing. Certain parts of each theory helped us organize and understand the pattern of results.

A parsimonious characterization of change in global age-specific and total fertility rates

PubMed Central

2018-01-01

This study aims to understand trends in global fertility from 1950-2010 though the analysis of age-specific fertility rates. This approach incorporates both the overall level, as when the total fertility rate is modeled, and different patterns of age-specific fertility to examine the relationship between changes in age-specific fertility and fertility decline. Singular value decomposition is used to capture the variation in age-specific fertility curves while reducing the number of dimensions, allowing curves to be described nearly fully with three parameters. Regional patterns and trends over time are evident in parameter values, suggesting this method provides a useful tool for considering fertility decline globally. The second and third parameters were analyzed using model-based clustering to examine patterns of age-specific fertility over time and place; four clusters were obtained. A country’s demographic transition can be traced through time by membership in the different clusters, and regional patterns in the trajectories through time and with fertility decline are identified. PMID:29377899

Models to compare management options for a protogynous fish.

PubMed

Heppell, Selina S; Heppell, Scott A; Coleman, Felicia C; Koenig, Christopher C

2006-02-01

Populations of gag (Mycteroperca microlepis), a hermaphroditic grouper, have experienced a dramatic shift in sex ratio over the past 25 years due to a decline in older age classes. The highly female-skewed sex ratio can be predicted as a consequence of increased fishing mortality that truncates the age distribution, and raises some concern about the overall fitness of the population. Management efforts may need to be directed toward maintenance of sex ratio as well as stock size, with evaluations of recruitment based on sex ratio or male stock size in addition to the traditional female-based stock-recruitment relationship. We used two stochastic, age-structured models to heuristically compare the effects of reducing fishing mortality on different life history stages and the relative impact of reductions in fertilization rates that may occur with highly skewed sex ratios. Our response variables included population size, sex ratio, lost egg fertility, and female spawning stock biomass. Population growth rates were highest for scenarios that reduced mortality for female gag (nearshore closure), while improved sex ratios were obtained most quickly with spawning reserves. The effect of reduced fertility through sex ratio bias was generally low but depended on the management scenario employed. Our results demonstrate the utility of evaluation of fishery management scenarios through model analysis and simulation, the synergistic interaction of life history and response to changes in mortality rates, and the importance of defining management goals.

The conflicting effects of delayed marriage and declining divorce rates on cumulative fertility in Indonesia.

PubMed

Palmore, J A; Singarimbun, M

1992-01-01

The impact of nuptiality patterns on fertility in Indonesia is examined with multivariate analysis controlling for 8 socioeconomic variables. Data were obtained from the 1987 Indonesian Contraceptive Prevalence Survey. Marriage is usually universal by age 35, and in this study all women 30 years had been married at least once. 20% were married at 15 years and 45% married at 18 years. For those married more than once, prevalence of 1st marriage was 7% for women 15-24 years, 15% for 25-34 years, and 29% for 35-49 years. In 1976 and 1987, the age at 1st marriage and number of times married were both strongly and negatively correlated. The % never marrying between 15-49 years rose from 21.5% to 26.4% between 1980-87. Cumulative fertility w as related to both age at 1st marriage and number of times married. Muslim women, women in Java and Bali, and rural women all marry at younger ages. 27% of the variance in age at 1st marriage is explained by women aged 25-34, current residence, region, religion, language, education, and work or not before marriage. The number of times married is also associated with socioeconomic characteristics without control, i.e., Muslim women 25-34 years were 3 times more likely to have been married more than once than in other faiths. With controls for socioeconomic factors, only 13% of the variance is explained and being Muslim has no statistically significant effect. The important net effects were being interviewed in Balinese, age, and age at 1st marriage. In the analysis of cumulative fertility, age at 1st marriage consistently is related to cumulative fertility in almost every socioeconomic group when age and number of times married is controlled for. Women married more than once have lower fertility. 36% of the variance is explained by all the variables. Being married more than once leads to having 2.1 fewer children. A 5-year delay in marriage leads to .75-1.1 fewer children. When other variables are controlled for, neither educational level nor prior work experience has a statistically significant effect on cumulative fertility. In the contraception analysis, women married more than once used contraception less. Among women 35-49, those marrying later had higher contraceptive use, but in general contraceptive use declined with age. More information is needed on why marriage patterns are changing.

Fertilizer-derived uranium and sulfur in rangeland soil and runoff: A case study in central Florida

USGS Publications Warehouse

Zielinski, R.A.; Orem, W.H.; Simmons, K.R.; Bohlen, P.J.

2006-01-01

Fertilizer applications to rangeland and pastures in central Florida have potential impact on the nutrient-sensitive ecosystems of Lake Okeechobee and the Northern Everglades. To investigate the effects of fertilizer applications, three soil profiles from variably managed and improved rangeland, and four samples of surface runoff from both fertilized and unfertilized pasture were collected. In addition to determining nutrient concentrations, isotopic analyses of uranium (U) and sulfur (S) were performed to provide isotopic evidence for U derived from historically applied phosphate (P)-bearing fertilizer ( 234 U 238U activity ratio =1.0 ?? 0.05), and Sderived from recently applied ammonium sulfate fertilizer(??34 S=3.5permil).The distribution and mobility of fertilizer-derived U in these samples is considered to be analogous to that of fertilizer-derived phosphate.Variations of U concentrations and 234 U/238 U activity ratios in soils indicate contribution of fertilizer-derived U in the upper portions of the fertilized soil (15-}34 percent of total U). The U isotope data for runoff from the fertilized field also are consistent with some contribution from fertilizer-derived U. Parallel investigations of S showed no consistent chemical or isotopic evidence for significant fertilizer-derived sulfate in rangeland soil or runoff. Relatively abundant and isotopically variable S present in the local environment hinders detection of fertilizer-derived sulfate. The results indicate a continuing slow-release of fertilizer-derived U and, by inference, P, to the P-sensitive ecosystem, and a relatively rapid release of sulfate of possible natural origin. ?? Springer 2006.

The global burden of congenital heart disease.

PubMed

Hoffman, Julien Ie

2013-05-01

Although the incidence of congenital heart disease (CHD) is similar worldwide, the burden of supporting these patients falls more heavily on countries with high fertility rates. In a country with a fertility rate of about eight per woman, the population has to support four times as many children with CHD as in a country with a fertility rate of two. Countries with the highest fertility rates tend to have the lowest incomes per capita, thus accentuating the disparity. Countries with high fertility rates have more children with congenital heart disease per wage earner. Improving local health services and controlling infectious diseases (diarrhoeal illness, rheumatic fever, measles, rotoviral infection) are important but are mere 'band-aids' compared to improving education, empowering women and reducing birth rates.

Female Labor Supply and Fertility in Iran: A Comparison Between Developed, Semi Developed and Less Developed Regions.

PubMed

Emamgholipour Sefiddashti, Sara; Homaie Rad, Enayatollah; Arab, Mohamad; Bordbar, Shima

2016-02-01

Female labor supply has been changed dramatically in the recent yr. In this study, we examined the effects of development on the relationship between fertility and female labor supply. We used data of population and housing census of Iran and estimated three separate models. To do this we employed Logistic Regressions (BLR). The estimation results of our study showed that there was a negative relationship between fertility rate and female labor supply and there are some differences for this relationship in three models. When fertility rate increases, FLS would decreases. In addition, for higher fertility rates, the woman might be forced to work more because of the economic conditions of her family; and negative coefficients of the fertility rate effects on FLS would increase with a diminishing rate.

Natural fertility in whooping cranes and Mississippi sandhill cranes at Patuxent Wildlife Research Center

USGS Publications Warehouse

Nicolich, Jane M.; Gee, G.F.; Ellis, D.H.; Hereford, Scott G.

2001-01-01

The first fertile whooping crane (Grus americana; WC) egg produced through natural breeding at Patuxent Wildlife Research Center (Patuxent) was laid in 1991. Prior to that time, all fertile whooping crane eggs were the result of artificial insemination. Since 1991, eight different whooping crane pairs at Patuxent have produced fertile eggs through natural breeding. Mean fertility averages over years for each pair range from 40% to 93%. Fertility rates for each pair also vary greatly between years, from 0% to 100% but the causes of the variance are unknown. Experiences with natural fertility in Mississippi sandhill cranes (G. canadensis pulla; MSC) have been similar. Annual natural fertility rates averaged from 21% to 89% and fertility averages for each of 7 pairs also varied greatly between years. Rearing methods have not determined success in natural breeding for either species. Both hand-reared and parent-reared pairs have been fertile. Wing condition, however, has been an important factor affecting natural fertility. Becausce artificial insemination (AI) generally results in higher fertility rates than natural breeding, Al should continue for some pairs.

In vitro fertilization of in vitro-matured equine oocytes: effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer.

PubMed

Hinrichs, K; Love, C C; Brinsko, S P; Choi, Y H; Varner, D D

2002-07-01

Three experiments were conducted to evaluate the effect of oocyte and sperm treatments on rates of in vitro fertilization (IVF) in the horse and to determine the capacity of in vitro-matured horse oocytes to be fertilized in vivo. There was no effect of duration of oocyte maturation (24 vs. 42 h) or calcium ionophore concentration during sperm capacitation (3 microM vs. 7.14 microM) on in vitro fertilization rates. Oocytes matured in 100% follicular fluid had significantly higher fertilization (13% to 24%) than did oocytes matured in maturation medium or in 20% follicular fluid (0% to 12%; P < 0.05). There was no significant difference in fertilization rate among 3 sperm treatments utilizing 7.14 microM calcium ionophore (12% to 21%). Of in vitro-matured oocytes recovered 40-44 h after transfer to the oviducts of inseminated mares, 77% showed normal fertilization (2 pronuclei to normal cleavage). Cleavage to 2 or more cells was seen in 22% of oocytes matured in follicular fluid and 63% of oocytes matured in maturation medium; this difference was significant (P < 0.05). We conclude that in vitro-matured horse oocytes are capable of being fertilized at high rates in the appropriate environment and that in vitro maturation of oocytes in follicular fluid increases fertilization rate in vitro but reduces embryo development after fertilization in vivo. Further work is needed to determine the optimum environment for sperm capacitation and IVF in the horse.

Nitrate, ascorbic acid, mineral and antioxidant activities of Cosmos caudatus in response to organic and mineral-based fertilizer rates.

PubMed

Hassan, Siti Aishah; Mijin, Salumiah; Yusoff, Umi Kalsom; Ding, Phebe; Wahab, Puteri Edaroyati Megat

2012-06-28

The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P₂O₅:8% K₂O) and inorganic fertilizer (15% N, 15% P₂O₅, 15% K₂O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h⁻¹. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer.

Effects of nitrogen source and rate and method of fertilizer application on yield and fruit size in 'Bluecrop' highbush blueberry

USDA-ARS?s Scientific Manuscript database

A study was done to determine the effects of N source and rate and two common methods of fertilizer application on yield and fruit size in a maturing field of highbush blueberry. Plants were fertilized by drip fertigation or with granular fertilizer using urea or ammonium sulfate applied at a rate o...

Identifying the Macro-Level Drivers of Adolescent Fertility Rate in Latin America: The Role of School-Based Sexuality Education

ERIC Educational Resources Information Center

Avellaneda, Claudia N.; Dávalos, Eleonora

2017-01-01

This study seeks to explain macrolevel drivers of adolescent fertility rate using a panel data set derived from 17 Latin American countries over a period of 16 years (1997-2012). While many studies of adolescent fertility have focused on individual-level explanations, this study explores whether adolescent fertility rate is correlated to…

[Fertility in rural and urban areas of Mexico].

PubMed

Garcia Y Garma, I O

1989-01-01

Data from 6 fertility surveys conducted in Mexico between 1969-87 were used to compare rural and urban fertility and to determine whether a significant level of contraceptive usage could be achieved in rural areas despite their lack of socioeconomic development. Age-specific marital fertility rates were calculated for the 4 national-level and 2 rural fertility surveys. The index of fertility control developed by Coale and Trussel was calculated for rural, urban, and all areas. The marital total fertility rate in rural areas declined from 10.6 in 1970 to 7.4 in 1982, a decline of 2.5% annually. From 1982-87 the annual rate of decline in rural fertility slowed to 1.6%, reaching 6.8 children in 1987. The urban marital total fertility rate declined from 7.72 in 1976 to 5.03 in 1987, while the marital total fertility rate for Mexico as a whole declined from 9.04 in 1976 to 5.85 in 1987. The indices of fertility control showed slowly increasing use of contraception in rural areas starting from the very low level of 1969. The urban index of fertility control showed some contraceptive use for all age groups in all surveys. The increases in contraceptive usage were considerable in rural areas from 1976-82 and much less marked in urban areas. From 1982-87 the inverse was observed and the fertility decline in urban areas was more marked. The condition of natural fertility found in rural areas in 1969 subsequently disappeared. Over time, fertility decline and use of contraception have intensified. Contraception is widely practiced in urban areas and is continuing to become more prevalent. The rural fertility decline in 1976-82 suggests that at least sometimes increases in fertility control are more important in rural areas than in urban areas. The theory of modernization, which holds that fertility decline in developed countries is attributable to factors associated with the process of modernization, thus comes into question. However, it is probable that a sustained fertility decline in the most depressed rural areas will be achieved only with substantial socioeconomic change.

Single gene and gene interaction effects on fertilization and embryonic survival rates in cattle.

PubMed

Khatib, H; Huang, W; Wang, X; Tran, A H; Bindrim, A B; Schutzkus, V; Monson, R L; Yandell, B S

2009-05-01

Decrease in fertility and conception rates is a major cause of economic loss and cow culling in dairy herds. Conception rate is the product of fertilization rate and embryonic survival rate. Identification of genetic factors that cause the death of embryos is the first step in eliminating this problem from the population and thereby increasing reproductive efficiency. A candidate pathway approach was used to identify candidate genes affecting fertilization and embryo survival rates using an in vitro fertilization experimental system. A total of 7,413 in vitro fertilizations were performed using oocytes from 504 ovaries and semen samples from 10 different bulls. Fertilization rate was calculated as the number of cleaved embryos 48 h postfertilization out of the total number of oocytes exposed to sperm. Survival rate of embryos was calculated as the number of blastocysts on d 7 of development out of the number of total embryos cultured. All ovaries were genotyped for 8 genes in the POU1F1 signaling pathway. Single-gene analysis revealed significant associations of GHR, PRLR, STAT5A, and UTMP with survival rate and of POU1F1, GHR, STAT5A, and OPN with fertilization rate. To further characterize the contribution of the entire integrated POU1F1 pathway to fertilization and early embryonic survival, a model selection procedure was applied. Comparisons among the different models showed that interactions between adjacent genes in the pathway revealed a significant contribution to the variation in fertility traits compared with other models that analyzed only bull information or only genes without interactions. Moreover, some genes that were not significant in the single-gene analysis showed significant effects in the interaction analysis. Thus, we propose that single genes as well as an entire pathway can be used in selection programs to improve reproduction performance in dairy cattle.

Effects of deep-horn AI on fertilization and embryo production in superovulated cows and heifers

PubMed Central

Carvalho, P.D.; Souza, A.H.; Sartori, R.; Hackbart, K.S.; Dresch, A.R.; Vieira, L.M.; Baruselli, P.S.; Guenther, J.N.; Fricke, P.M.; Shaver, R.D.; Wiltbank, M.C.

2018-01-01

The primary objective of this study was to determine the effect of site of semen deposition on fertilization rate and embryo quality in superovulated cows. The hypothesis was that deposition of semen into the uterine horns would increase the fertilization rate compared with deposition of semen into the uterine body. The secondary objective was to evaluate the effect of uterine environment on fertilization rate and embryo quality. It was hypothesized that subclinical endometritis at the onset of superstimulation would decrease the fertilization rates and embryo quality. In experiment 1, 17 superovulated heifers were randomly assigned to receive artificial insemination (AI) into the uterine body or uterine horns. The total number of fertilized structures and fertilization rate from superovulated heifers was increased (P = 0.04 and P = 0.02, respectively) when semen was deposited into the uterine horns compared with the uterine body. Other embryo characteristics did not differ based on the site of semen deposition. In experiment 2, 14 lactating dairy cows were superovulated twice and were randomly assigned to receive AI into the uterine body or deep into the uterine horns using a crossover design. Neither fertilization rate nor any other embryo characteristics were improved when semen was placed deep into the uterine horns compared with the uterine body. In experiment 3, 72 superovulated lactating dairy cows were randomly assigned to receive AI into the uterine body or uterine horns. Before initiation of superstimulatory treatments, an endometrial cytology sample was collected from each cow. Ova/embryos were collected by a nonsurgical technique at 70 ± 3 days in milk. Similar to experiment 2, neither fertilization rate nor any other embryo characteristics differed based on the site of semen deposition in experiment 3. The percentage of cows with subclinical endometritis did not differ between treatments. Interestingly, there was a tendency (P = 0.09) for a reduction in embryo recovery rate and a reduction (P = 0.01) in the fertilization rate for cows with subclinical endometritis. In conclusion, deposition of semen into the uterine horns rather than into the uterine body did not improve the fertilization rate or embryo quality in superovulated cows. Subclinical endometritis decreased the fertilization rate in superovulated cows. PMID:24084230

Disparities in fertility-sparing surgery in adolescent and young women with stage I ovarian dysgerminoma.

PubMed

Stafman, Laura L; Maizlin, Ilan I; Dellinger, Matthew; Gow, Kenneth W; Goldfarb, Melanie; Nuchtern, Jed G; Langer, Monica; Vasudevan, Sanjeev A; Doski, John J; Goldin, Adam B; Raval, Mehul; Beierle, Elizabeth A

2018-04-01

In many cancers, racial and socioeconomic disparities exist regarding the extent of surgery. For ovarian dysgerminoma, fertility-sparing (FS) surgery is recommended whenever possible. The aim of this study was to investigate rates of FS versus non-fertility-sparing (NFS) procedures for stage I ovarian dysgerminoma in adolescents and young adults (AYAs) by ethnicity/race and socioeconomic status. The National Cancer Data Base was queried for patients with ovarian dysgerminoma from 1998 to 2012. After selecting patients aged 15-39 y with stage I disease, a multivariate regression analysis was performed, and rates of FS and NFS procedures were compared, first according to ethnicity/race, and then by socioeconomic surrogate variables. Among the 687 AYAs with stage I ovarian dysgerminoma, there was no significant difference in rates of FS and NFS procedures based on ethnicity/race alone (P = 0.17), but there was a significant difference in procedure type for all three socioeconomic surrogates. The uninsured had higher NFS rates (30%) than those with government (21%) or private (19%) insurance (P = 0.036). Those in the poorest ZIP codes had almost twice the rate of NFS procedures (31%) compared with those in the most affluent ZIP codes (17%). For those in the least-educated regions, 24% underwent NFS procedures compared to 14% in the most-educated areas (P = 0.027). AYAs with stage I ovarian dysgerminoma in lower socioeconomic groups were more likely to undergo NFS procedures than those in higher socioeconomic groups, but there was no difference in rates of FS versus NFS procedures by ethnicity/race. Approaches aimed at reducing socioeconomic disparities require further examination. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Nitrogen Fertilization on Synthesis of Primary and Secondary Metabolites in Three Varieties of Kacip Fatimah (Labisia Pumila Blume)

PubMed Central

Ibrahim, Mohd Hafiz; Jaafar, Hawa Z.E.; Rahmat, Asmah; Rahman, Zaharah Abdul

2011-01-01

A split plot 3 by 4 experiment was designed to examine the impact of 15-week variable levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) on the characteristics of total flavonoids (TF), total phenolics (TP), total non structurable carbohydrate (TNC), net assimilation rate, leaf chlorophyll content, carbon to nitrogen ratio (C/N), phenyl alanine lyase activity (PAL) and protein content, and their relationships, in three varieties of Labisia pumila Blume (alata, pumila and lanceolata). The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effect observed. As nitrogen levels increased from 0 to 270 kg N/ha, the production of TNC was found to decrease steadily. Production of TF and TP reached their peaks under 0 followed by 90, 180 and 270 kg N/ha treatment. However, net assimilation rate was enhanced as nitrogen fertilization increased from 0 to 270 kg N/ha. The increase in production of TP and TF under low nitrogen levels (0 and 90 kg N/ha) was found to be correlated with enhanced PAL activity. The enhancement in PAL activity was followed by reduction in production of soluble protein under low nitrogen fertilization indicating more availability of amino acid phenyl alanine (phe) under low nitrogen content that stimulate the production of carbon based secondary metabolites (CBSM). The latter was manifested by high C/N ratio in L. pumila plants. PMID:21954355

Temporal and spatial changes in plankton respiration and biomass in the Canary Islands region: the effect of mesoscale variability

NASA Astrophysics Data System (ADS)

Arístegui, Javier; Montero, María F.

2005-02-01

The temporal and spatial variabilities in the abundance and respiratory activity of plankton communities (<200 μm) were studied during three seasonal cruises around Gran Canaria Island (Canary Islands), a region of high mesoscale variability. Marked seasonal changes in respiratory activity, plankton community structure, and the ratio of heterotrophic to autotrophic biomass can be largely explained by hydrographic changes at the mesoscale level. Wind/current shearing at the flanks of the island enhances plankton respiration, presumably as the consequence of an increase in turbulence. Counter-paired cyclonic and anticyclonic eddies generated downstream of the island act as a two-way biological pump, increasing plankton production by nutrient pumping into the euphotic zone and accelerating the transport of organic matter into the aphotic zone, respectively. Coastal upwelling waters invading the Canary region in the form of filaments can transport either water with low plankton respiration and large phytoplankton cells or water with high respiratory rates associated with small cells. Plankton respiration was closely related to the abundance of Synechococcus type cyanobacteria and heterotrophic nanoflagellates during the three periods, but was only correlated with chlorophyll during the most fertile season, suggesting that respiration was mainly linked to microbial food web processes. Size-fractionated studies showed that 51-67% of the respiratory activity was due to picoplankton cells (<2 μm). Respiration rates (average values: 113±18 to 187±87 mmol C m -2 d -1) matched primary production rates during the fertile period, but were up to one order of magnitude higher during the rest of the year. Substantial inputs of organic matter from the coastal upwelling would be necessary to balance the large annual heterotrophic deficit in the region of study.

Demographic, socio-economic, and cultural factors affecting fertility differentials in Nepal.

PubMed

Adhikari, Ramesh

2010-04-28

Traditionally Nepalese society favors high fertility. Children are a symbol of well-being both socially and economically. Although fertility has been decreasing in Nepal since 1981, it is still high compared to many other developing countries. This paper is an attempt to examine the demographic, socio-economic, and cultural factors for fertility differentials in Nepal. This paper has used data from the Nepal Demographic and Health Survey (NDHS 2006). The analysis is confined to ever married women of reproductive age (8,644). Both bivariate and multivariate analyses have been performed to describe the fertility differentials. The bivariate analysis (one-way ANOVA) was applied to examine the association between children ever born and women's demographic, socio-economic, and cultural characteristics. Besides bivariate analysis, the net effect of each independent variable on the dependent variable after controlling for the effect of other predictors has also been measured through multivariate analysis (multiple linear regressions). The mean numbers of children ever born (CEB) among married Nepali women of reproductive age and among women aged 40-49 were three and five children, respectively. There are considerable differentials in the average number of children ever born according to women's demographic, socio-economic, and cultural settings. Regression analysis revealed that age at first marriage, perceived ideal number of children, place of residence, literacy status, religion, mass media exposure, use of family planning methods, household headship, and experience of child death were the most important variables that explained the variance in fertility. Women who considered a higher number of children as ideal (beta = 0.03; p < 0.001), those who resided in rural areas (beta = 0.02; p < 0.05), Muslim women (beta = 0.07; p < 0.001), those who had ever used family planning methods (beta = 0.08; p < 0.001), and those who had a child-death experience (beta = 0.31; p < 0.001) were more likely to have a higher number of CEB compared to their counterparts. On the other hand, those who married at a later age (beta = -0.15; p < 0.001), were literate (beta = -0.05; p < 0.001), were exposed to both (radio/TV) mass media (beta = -0.05; p < 0.001), were richest (beta = -0.12; p < 0.001), and were from female-headed households (beta = -0.02; p < 0.05) had a lower number of children ever born than their counterparts. The average number of children ever born is high among women in Nepal. There are many contributing factors for the high fertility, among which are age at first marriage, perceived ideal number of children, literacy status, mass media exposure, wealth status, and child-death experience by mothers. All of these were strong predictors for CEB. It can be concluded that programs should aim to reduce fertility rates by focusing on these identified factors so that fertility as well as infant and maternal mortality and morbidity will be decreased and the overall well-being of the family maintained and enhanced.

Method of euthanasia influences the oocyte fertilization rate with fresh mouse sperm.

PubMed

Hazzard, Karen C; Watkins-Chow, Dawn E; Garrett, Lisa J

2014-11-01

In vitro fertilization (IVF) is used to produce mouse embryos for a variety of reasons. We evaluated the effect of the method of euthanasia on the fertilization rate in 2 different IVF protocols. Oocytes collected from C57BL/6J female mice euthanized by CO2 inhalation or cervical dislocation were used in IVF with fresh sperm from either wild-type or genetically engineered C57BL/6J. Compared with CO2 inhalation, cervical dislocation improved the resulting rate of fertilization by 18% in an IVF method using Cook media and by 13% in an IVF method using methyl-B cyclodextrin and reduced glutathione. The lower fertilization rate due to euthanasia by CO2 inhalation was accompanied by changes in blood pH and body temperature despite efforts to minimize temperature drops. In our hands, euthanasia by cervical dislocation improved fertilization rates and consequently reduced the number of egg-donor mice required.

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

ERIC Educational Resources Information Center

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…

Dissolved Organic Carbon in Leachate after Application of Granular and Liquid N-P-K Fertilizers to a Sugarcane Soil.

PubMed

Pittaway, P A; Melland, A R; Antille, D L; Marchuk, S

2018-05-01

The progressive decline of soil organic matter (SOM) threatens the sustainability of arable cropping worldwide. Residue removal and burning, destruction of protected microsites, and the acceleration of microbial decomposition are key factors. Desorption of SOM by ammonia-based fertilizers from organomineral complexes in soil may also play a role. A urea- and molasses-based liquid fertilizer formulation and a urea-based granular formulation were applied at recommended and district practice rates, respectively, to soil leaching columns, with unfertilized columns used as controls. The chemistry of leachate collected from the columns, filled with two sandy soils differing in recent cropping history, was monitored over eight successive wet-dry drainage events. The pH, electrical conductivity, and concentration and species of N in leachate was compared with the concentration and aromaticity of dissolved organic C (DOC) to indicate if salt solutions derived from the two fertilizers extracted SOM from clay mineral sites. Cation exchange capacity and exchangeable cations in the soil were monitored at the start and end of the trial. Fertilizer application increased DOC in leachate up to 40 times above the control, but reduced aromaticity (specific ultraviolet light absorbance at 253.7 nm). Dissolved organic C was linearly proportional to leachate NH-N concentration. Exchangeable Ca and Mg in soil from fertilized columns at the end of both trials were significantly lower than in unfertilized soil, indicating that ammonium salt solutions derived from the fertilizers extracted cations and variably charged organic matter from soil mineral exchange sites. Desorption of organic matter and divalent cations from organomineral sites by ammonia-based fertilizers may be implicated in soil acidification. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Anti-Müllerian Hormone (AMH) and fertility management in agricultural species.

PubMed

Mossa, F; Jimenez-Krassel, F; Scheetz, D; Weber-Nielsen, M; Evans, A C O; Ireland, J J

2017-07-01

A reliable, easy to assess marker for fertility in agricultural species would be highly desirable and Anti-Müllerian Hormone (AMH) is a promising candidate. This review summarizes recent findings concerning AMH and its role in fertility management, mainly in cattle. It focuses on (1) alterations in circulating AMH concentrations from birth to puberty and during estrous cycles; (2) correlation of circulating AMH concentrations with ovarian follicle numbers and ovarian reserve; (3) factors that impact circulating AMH concentrations; (4) use of AMH as a predictor of fertility. Circulating AMH concentrations can be easily and reliably measured with a single blood sample in adult cattle because AMH varies minimally during the estrous cycle and is repeatable across multiple cycles. Circulating AMH concentrations are positively associated with several measures of fertility. Dairy heifers with low compared with higher AMH concentrations subsequently had lower pregnancy rates, higher probability of being culled after birth of their first calf and shorter herd longevity. Also, AMH is predictive of response to superovulation in cattle and sheep. Several factors contribute to the variability in AMH concentrations among individuals; for example, beef cattle have higher AMH than dairy cattle. Nutritional imbalances, disease and endocrine disruptors during fetal life may negatively program the size of the ovarian reserve and consequently serum AMH concentrations and potential fertility in adulthood. We conclude that AMH may be a predictor of fertility and herd longevity in cattle, whereas in sheep and other farm species, the potential association between AMH and reproductive performance remains largely unexplored.Free Italian abstract: An Italian translation of this abstract is freely available at http://www.reproduction-online.org/content/154/1/R1/suppl/DC1. © 2017 Society for Reproduction and Fertility.

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

PubMed

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

2007-03-01

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

[Fertility and health in Mexico].

PubMed

Urbina-Fuentes, M; Echánove-Fernández, E

1989-01-01

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

Lifetime reproductive output over two generations in patients with psychosis and their unaffected siblings: the Uppsala 1915-1929 Birth Cohort Multigenerational Study.

PubMed

MacCabe, J H; Koupil, I; Leon, D A

2009-10-01

Schizophrenic patients have fewer offspring than the general population but it is unclear whether (i) this persists for more than one generation, (ii) the reduced fertility is compensated by increased fertility in unaffected relatives, (iii) sociodemographic factors confound or interact with the association, and (iv) patients with affective psychosis have a similar fertility disadvantage. This study measured biological fitness over two generations in patients with schizophrenia or affective psychosis, and their unaffected siblings. We conducted a historical cohort study using a Swedish birth cohort of 12 168 individuals born 1915-1929 and followed up until 2002. We compared biological fitness over two generations in patients with schizophrenia (n=58) or affective psychosis (n=153), and their unaffected siblings, with the population, adjusting for a range of sociodemographic variables from throughout the lifespan. Patients with schizophrenia had fewer children [fertility ratio (FR) 0.42, 95% confidence interval (CI) 0.29-0.61] and grandchildren (FR 0.51, 95% CI 0.33-0.80) than the population. Some of this reduction was related to lower marriage rates in schizophrenic patients. The unaffected siblings of schizophrenic patients showed no evidence of any compensatory increase in fitness, but there was a trend towards enhanced fertility among the offspring of schizophrenia patients. Patients with affective psychosis and their relatives did not differ from the general population on any fertility measure. Schizophrenia, but not affective psychosis, is associated with reduced biological fertility; this disadvantage is partly explained by marital status and persists into the second generation.

Tropical legume crop rotation and nitrogen fertilizer effects on agronomic and nitrogen efficiency of rice.

PubMed

Rahman, Motior M; Islam, Aminul M; Azirun, Sofian M; Boyce, Amru N

2014-01-01

Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m(-2) preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m(-2). No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m(-2) achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13-23% higher grain yield than rice after fallow rotation with 8 g N m(-2). The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m(-2) can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m(-2). The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

Covariation in Plant Functional Traits and Soil Fertility within Two Species-Rich Forests

PubMed Central

Liu, Xiaojuan; Swenson, Nathan G.; Wright, S. Joseph; Zhang, Liwen; Song, Kai; Du, Yanjun; Zhang, Jinlong; Mi, Xiangcheng; Ren, Haibao; Ma, Keping

2012-01-01

The distribution of plant species along environmental gradients is expected to be predictable based on organismal function. Plant functional trait research has shown that trait values generally vary predictably along broad-scale climatic and soil gradients. This work has also demonstrated that at any one point along these gradients there is a large amount of interspecific trait variation. The present research proposes that this variation may be explained by the local-scale sorting of traits along soil fertility and acidity axes. Specifically, we predicted that trait values associated with high resource acquisition and growth rates would be found on soils that are more fertile and less acidic. We tested the expected relationships at the species-level and quadrat-level (20×20 m) using two large forest plots in Panama and China that contain over 450 species combined. Predicted relationships between leaf area and wood density and soil fertility were supported in some instances, but the majority of the predicted relationships were rejected. Alternative resource axes, such as light gradients, therefore likely play a larger role in determining the interspecific variability in plant functional traits in the two forests studied. PMID:22509355

Phosphorus Fertilizer Rate, Soil P Availability, and Long-Term Growth Response in a Loblolly Pine Plantation on a Weathered Ultisol

Treesearch

D. Andrew Scott; Christine M. Bliss

2012-01-01

Phosphorus is widely deficient throughout the southern pine region of the United States. Growth responses to P fertilization are generally long-lasting in a wide range of soil types, but little is known about fertilization rates and long-term P cycling and availability. In 1982, exceptionally high P fertilization rates (0, 81, 162, and 324 kg P ha-1...

The fates of 15N-labeled fertilizer in a wheat-soil system as influenced by fertilization practice in a loamy soil

NASA Astrophysics Data System (ADS)

Chen, Zhaoming; Wang, Huoyan; Liu, Xiaowei; Lu, Dianjun; Zhou, Jianmin

2016-10-01

Appropriate fertilization practice is crucial to achieve maximum wheat grain yield with minimum nitrogen (N) loss. A field 15N micro-plot experiment was conducted to determine the effects of application methods [split application (SA) and band application (BA)] and N rates (60, 150 and 240 kg ha-1) on the wheat grain yield, urea-15N fate and N efficiency in Jiangyan County, China. At high N rates, wheat grain yield was significantly higher for SA than BA treatment, but there was no difference at the lower N rates. Plant N derived from fertilizer was higher in SA than in BA treatment. The high N fertilizer application increased total N uptake by wheat derived from fertilizer, but wheat plant N derived from soil was not affected by the N rate. Fertilizer-N recovery in SA treatment was higher than in BA treatment. Residual N recovery in the 0-80 cm soil layer was 31-51%, which decreased with increasing N rate. The highest N loss was found for BA treatment at the N application of 240 kg ha-1. The one-time BA of N fertilizer, especially for higher N rates, led to reduced wheat grain yield and N efficiency, and increased the N loss.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Comparison of normal and abnormal fertilization of in vitro-matured human oocyte according to insemination method.

PubMed

Park, Ju Hee; Jee, Byung Chul; Kim, Seok Hyun

2016-04-01

Our purpose was to compare the normal fertilization rate, multi-pronuclei (PN) formation rate, and embryonic development of in vitro-matured oocytes between conventional insemination and intracytoplasmic sperm injection (ICSI). A total of 213 stimulated in vitro fertilization (IVF) cycles were selected, in which at least one immature oocyte was obtained (from 2010 to 2014). Immature oocytes were assigned to germinal vesicle (GV)-stage or metaphase I (MI)-stage oocyte groups. Cycles with obligatory ICSI due to male-factor infertility were excluded. Cycles were divided into two groups according to fertilization method: there were 97 cycles with conventional insemination and 116 cycles with ICSI. After in vitro maturation of 324 GV-stage oocytes and 341 MI-stage oocytes, the fertilization rate, multi-PN formation rate, and embryonic development were compared according to the fertilization method. The normal fertilization rate was similar in the conventional insemination and the ICSI both in GV-derived and MI-derived oocytes. Both fertilization methods resulted in a similar multi-PN formation rate in GV-derived oocytes; however, in MI-derived oocytes, the multi-PN formation rate was zero with ICSI and this was significantly lower than that with conventional insemination (9.6%, P = 0.001). In non-male-factor infertility, ICSI should be considered when MI oocytes are matured. © 2016 Japan Society of Obstetrics and Gynecology.

Rooster semen cryopreservation: effect of pedigree line and male age on postthaw sperm function.

PubMed

Long, J A; Bongalhardo, D C; Pelaéz, J; Saxena, S; Settar, P; O'Sullivan, N P; Fulton, J E

2010-05-01

The fertility rates of cryopreserved poultry semen are highly variable and not reliable for use in preservation of commercial genetic stocks. Our objective was to evaluate the cryosurvival of semen from 8 pedigreed layer lines at 2 different ages: the onset and end of commercial production. Semen from 160 roosters (20/line) was frozen individually with 11% glycerol at 6 and 12 mo of age. Glycerol was removed from thawed semen by Accudenz gradient centrifugation. The viability of thawed sperm from each male was determined using fluorescent live-dead staining and flow cytometry; sperm velocity parameters were measured using computerized motion analysis. The fertilizing ability of thawed sperm was evaluated in vitro by assessing hydrolysis of the inner perivitelline membrane. The postthaw function of sperm from the elite lines varied widely, despite the fact that fresh semen from all of these lines typically yielded high fertility rates. The percentage of thawed sperm with intact plasma membranes ranged from 27.8 + or - 2.1 to 49.6 + or - 1.9 and varied among lines and between age groups. Thawed sperm from 2 lines consistently demonstrated the highest and lowest motility parameters, whereas the velocity parameters of the remaining 6 lines varied widely. The mean number of hydrolysis points per square millimeter of inner perivitelline membrane ranged from 12.5 + or - 4.1 (line 2) to 103.3 + or - 30.2 (line 6). Age effects were observed for 4 out of 8 lines; however, improved postthaw sperm function at 12 mo of age was not consistent for all 3 assays. These results demonstrate variability among pedigreed lines in withstanding glycerol-based semen cryopreservation and provide a model for delineating genotypic and phenotypic factors affecting sperm cryosurvival.

Estimate of changes in agricultural terrestrial nitrogen pathways and ammonia emissions from 1850 to present in the Community Earth System Model

NASA Astrophysics Data System (ADS)

Riddick, Stuart; Ward, Daniel; Hess, Peter; Mahowald, Natalie; Massad, Raia; Holland, Elisabeth

2016-06-01

Nitrogen applied to the surface of the land for agricultural purposes represents a significant source of reactive nitrogen (Nr) that can be emitted as a gaseous Nr species, be denitrified to atmospheric nitrogen (N2), run off during rain events or form plant-useable nitrogen in the soil. To investigate the magnitude, temporal variability and spatial heterogeneity of nitrogen pathways on a global scale from sources of animal manure and synthetic fertilizer, we developed a mechanistic parameterization of these pathways within a global terrestrial land model, the Community Land Model (CLM). In this first model version the parameterization emphasizes an explicit climate-dependent approach while using highly simplified representations of agricultural practices, including manure management and fertilizer application. The climate-dependent approach explicitly simulates the relationship between meteorological variables and biogeochemical processes to calculate the volatilization of ammonia (NH3), nitrification and runoff of Nr following manure or synthetic fertilizer application. For the year 2000, approximately 125 Tg N yr-1 is applied as manure and 62 Tg N yr-1 is applied as synthetic fertilizer. We estimate the resulting global NH3 emissions are 21 Tg N yr-1 from manure (17 % of manure production) and 12 Tg N yr-1 from fertilizer (19 % of fertilizer application); reactive nitrogen runoff during rain events is calculated as 11 Tg N yr-1 from manure and 5 Tg N yr-1 from fertilizer. The remaining nitrogen from manure (93 Tg N yr-1) and synthetic fertilizer (45 Tg N yr-1) is captured by the canopy or transferred to the soil nitrogen pools. The parameterization was implemented in the CLM from 1850 to 2000 using a transient simulation which predicted that, even though absolute values of all nitrogen pathways are increasing with increased manure and synthetic fertilizer application, partitioning of nitrogen to NH3 emissions from manure is increasing on a percentage basis, from 14 % of nitrogen applied in 1850 (3 Tg NH3 yr-1) to 17 % of nitrogen applied in 2000 (21 Tg NH3 yr-1). Under current manure and synthetic fertilizer application rates we find a global sensitivity of an additional 1 Tg NH3 (approximately 3 % of manure and fertilizer) emitted per year per °C of warming. While the model confirms earlier estimates of nitrogen fluxes made in a range of studies, its key purpose is to provide a theoretical framework that can be employed within a biogeochemical model, that can explicitly respond to climate and that can evolve and improve with further observation.

A sociohydrological model for smallholder farmers in Maharashtra, India

NASA Astrophysics Data System (ADS)

Pande, Saket; Savenije, Hubert H. G.

2016-03-01

We present a sociohydrological model that can help us to better understand the system dynamics of a smallholder farmer. It couples the dynamics of the six main assets of a typical smallholder farmer: water storage capacity, capital, livestock, soil fertility, grazing access, and labor. The hydroclimatic variability, which is a main driver and source of uncertainty of the smallholder system, is accounted for at subannual scale. The model incorporates rule-based adaptation mechanisms of smallholders (for example, adjusting expenditures on food and fertilizers and selling livestocks) when farmers face adverse sociohydrological conditions, such as low annual rainfall, occurrence of dry spells, or variability of input or commodity prices. We have applied the model to analyze the sociohydrology of a cash crop producing smallholder in Maharashtra, India, in a semisynthetic case study setting. Of late, this region has witnessed many suicides of farmers who could not extricate themselves out of the debt trap. These farmers lacked irrigation and were susceptible to fluctuating commodity prices and climatic variability. We studied the sensitivity of a smallholder's capital, an indicator of smallholder well-being, to two types of cash crops (cotton and sugarcane), water storage capacity, availability of irrigation, initial capital that a smallholder starts with, prevalent wage rates, and access to grazing. We found that (i) smallholders with low water storage capacities and no irrigation are most susceptible to distress, (ii) a smallholder's well-being is low at low wage rates, (iii) wage rate is more important than absolution of debt, (iv) well-being is sensitive to water storage capacity up to a certain level, and (v) well-being increases with increasing area available for livestock grazing. Our results indicate that government intervention to absolve the debt of farmers or to invest in local storage to buffer rainfall variability may not be enough. In addition, alternative sources of income may need to be provided, for instance by ensuring minimum wages or by providing more access to grazing areas.

Does nitrogen fertilizer application rate to corn affect nitrous oxide emissions from the rotated soybean crop?

PubMed

Iqbal, Javed; Mitchell, David C; Barker, Daniel W; Miguez, Fernando; Sawyer, John E; Pantoja, Jose; Castellano, Michael J

2015-05-01

Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha, the recommended rate of 135 kg N ha, and a high rate of 225 kg N ha); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye ( L.) cover crop to interact with N fertilizer rate to affect NO emissions from both crops. The cover crop did not consistently affect NO emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean NO flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0-225 kg N ha) did not affect mean NO flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean NO flux rates from the soybean crops that received 135 and 225 kg N ha N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on NO emissions are not easily generalizable. When N fertilizer affects NO emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced NO emissions are altered or only spread across a greater period of time. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

[Effect of the same amount of faba bean fresh straw returning with different ratios of chemi- cal fertilizer on single cropping late rice].

PubMed

Wang, Jian-hong; Zhang, Xian; Cao, Kai; Hua, Jin-wei

2015-05-01

A field experiment was conducted on paddy soil derived from alluvial materials at Bihu Town, Lishui City, Zhejiang Province, China to explore the effects of combined application of faba bean fresh straw and different-rate chemical fertilizer on nutrient uptake, nutrient use efficiencies, and yields of single cropping late rice and to determine the optimal rate of chemical fertilizer under the condition of application of faba bean fresh straw at the rate of 15 t · hm(-2) (GM15) in 2012, April to December. The experiments consisted of 7 treatments: CK (no fertilizers) , CF (conventional chemical fertilizer rate) , and combined application of 15 t · hm(-2) of faba bean fresh straw and 0%, 20%, 40%, 60% and 80% of the conventional chemical fertilizer rate. The results showed that the highest total uptake amounts of N, P and K by the aboveground part were obtained from the treatments of GM15 + 60%CF and GM15 + 80% CF, but the highest nutrient agronomy use efficiencies of N, P and K in rice grains were obtained from the treatments of GM15 + 60% CF and GM15 + 40% CF. The agronomy use efficiencies and physiological use efficiencies of N, P, and K were significantly correlated with rice grain yields, thus they could be used for accurate comprehensive evaluation of fertilizer efficiencies of N, P, and K. Compared with no fertilizer treatment, the treatments of 100% CF and combined application of faba bean fresh straw and different-rate chemical fertilizer increased rice gain yields by 25.0% and 6.1%-29.2%, respectively. In the cropping system of faba bean-single cropping late rice, returning of 15 t · hm2 faba bean fresh straw to the paddy field did not result in the runt seedling of rice. From the point of improving fertilizer use efficiency and reducing environmental risk perspective, the optimum rate of chemical fertilizer was 60% of the conventional chemical fertilizer rate when 15 t · h(-2) of faba bean fresh straw was applied.

[The theory of the demographic transition as a reference for demo-economic models].

PubMed

Genne, M

1981-01-01

The aim of the theory of demographic transition (TTD) is to better understand the behavior and interrelationship of economic and demographic variables. There are 2 types of demo-economic models: 1) the malthusian models, which consider demographic variables as pure exogenous variables, and 2) the neoclassical models, which consider demographic variables as strictly endogenous. If TTD can explore the behavior of exogenous and endogenous demographic variables, it cannot demonstrate neither the relation nor the order of causality among the various demographic and economic variables, but it is simply the theoretical framework of a complex social and economic phenomenon which started in Europe in the 19th Century, and which today can be extended to developing countries. There are 4 stages in the TTD; the 1st stage is characterized by high levels of fecundity and mortality; the 2nd stage is characterized by high fecundity levels and declining mortality levels; the 3rd stage is characterized by declining fecundity levels and low mortality levels; the 4th stage is characterized by low fertility and mortality levels. The impact of economic variables over mortality and birth rates is evident for mortality rates, which decline earlier and at a greater speed than birth rates. According to reliable mathematical predictions, around the year 1987 mortality rates in developing countries will have reached the low level of European countries, and growth rate will be only 1.5%. If the validity of demo-economic models has not yet been established, TTD has clearly shown that social and economic development is the factor which influences demographic expansion.

Enhanced fertility prediction of cryopreserved boar spermatozoa using novel sperm function assessment

USDA-ARS?s Scientific Manuscript database

Cryopreserved semen is seldom used for commercial porcine artificial insemination (AI) despite many advantages that cryopreservation provides. Compared to fresh semen, the fertility of frozen-thawed boar sperm is more variable but usually less. Predicting the fertility of individual ejaculates for s...

The impact of monetary incentives on general fertility rates in Western Australia.

PubMed

Langridge, Amanda T; Nassar, Natasha; Li, Jianghong; Jacoby, Peter; Stanley, Fiona J

2012-04-01

There has been widespread international concern about declining fertility rates and the long-term negative consequences particularly for industrialised countries with ageing populations. In an attempt to boost fertility rates, the Australian Government introduced a maternity payment known as the Baby Bonus. However, major concerns have been raised that such monetary incentives would attract teenagers and socially disadvantaged groups. Population-level data and generalised linear models were used to examine general fertility rates between 1995 and 2006 by socioeconomic group, maternal age group, Aboriginality and location in Western Australia prior to and following the introduction of the Baby Bonus in July 2004. After a steady decline in general fertility rates between 1995 and 2004, rates increased significantly from 52.2 births per 1000 women, aged between 15 and 49 years, in 2004 to 58.6 births per 1000 women in 2006. While there was an overall increase in general fertility rates after adjusting for maternal socio-demographic characteristics, there were no significant differences among maternal age groups (p=0.98), between Aboriginal and non-Aboriginal women(p=0.80), maternal residential locations (p=0.98) or socioeconomic groups (p=0.68). The greatest increase in births were among women residing in the highest socioeconomic areas who had the lowest general fertility rate in 2004 (21.5 births per 1000 women) but the highest in 2006 (38.1 births per 1000 women). Findings suggest that for countries with similar social, economic and political climates to Australia, a monetary incentive may provide a satisfactory solution to declining general fertility rates.

Testing tree indicator species for classifying site productivity in southern Appalachian hardwood stands

Treesearch

W. Henry McNab; David L. Loftis; R.M. Shefield

2002-01-01

Composite indices of site moisture and fertility regimes, site variables, and individual tree species were tested for their relationship with site productivity on forest survey plots in the southern Appalachian Mountains. Mew annual basal area increment was significantly associated with the fertility index and site variables including elevation, slope gradient, and...

Conference considers low fertility.

PubMed

1997-01-01

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

Sources of genetic and phenotypic variance in fertilization rates and larval traits in a sea urchin.

PubMed

Evans, Jonathan P; García-González, Francisco; Marshall, Dustin J

2007-12-01

In nonresource based mating systems females are thought to derive indirect genetic benefits by mating with high-quality males. Such benefits can be due either to the intrinsic genetic quality of sires or to beneficial interactions between maternal and paternal haplotypes. Animals with external fertilization and no parental care offer unrivaled opportunities to address these hypotheses. With these systems, cross-classified breeding designs and in vitro fertilization can be used to disentangle sources of genetic and environmental variance in offspring fitness. Here, we employ these approaches in the Australian sea urchin Heliocidaris erythrogramma and explore how sire-dam identities influence fertilization rates, embryo viability (survival to hatching), and metamorphosis, as well as the interrelationships between these potential fitness traits. We show that fertilization is influenced by a combination of strong maternal effects and intrinsic male effects. Our subsequent analysis of embryo viability, however, revealed a highly significant interaction between parental genotypes, indicating that partial incompatibilities can severely limit offspring survival at this life-history stage. Importantly, we detected no significant relationship between fertilization rates and embryo viability. This finding suggests that fertilization rates should not be inferred from hatching rates, which is commonly practiced in species in which it is not possible to estimate fertilization at conception. Finally, we detected significant additive genetic variance due to sires in rates of juvenile metamorphosis, and a positive correlation between fertilization rates and metamorphosis. This latter finding indicates that the performance of a male's ejaculate in noncompetitive IVF trials predicts heritable offspring traits, although the fitness implications of variance in rates of spontaneous juvenile metamorphosis have yet to be determined.

Different Places, Different Stories: A Study of Spatial Heterogeneity of County-Level Fertility in China

PubMed Central

Wang, Donghui; Chi, Guangqing

2018-01-01

Background China has been characterized by persistently low fertility rates since the 1990s. Existing literature has examined the relationships of fertility levels with social, economic, and policy-related determinants. However, the possible spatial variations in these relationships have not been investigated. Objective The purpose of this study is to examine the potential spatially varying relationships between county-level fertility rates and policy and socioeconomic factors in China. Methods Using geocoded 2010 county-level census data, this study adopts the geographically weighted regression (GWR) method to identify place-specific relationships between county-level total fertility rate (TFR) and socioeconomics and policy-related factors. Conclusions We find relationships between TFR and widely used social, economic, and policy-related factors (rural Hukou, ethnic minority, female education, net migration rate, poor living standard, sex ratio at birth, and fertility policy compliance ratio) vary spatially in terms of the direction, strength, and magnitude. The spatial variation is largely due to the difference in local characteristics. The differences and the complexities of localities cannot be told by a single story of either government intervention or socioeconomic development. Contribution This study extends the existing fertility research in China by explicitly recognizing the spatial heterogeneity in the impacts of policy and socioeconomic factors on the local fertility rate. This study sets the stage for future research that will contextually analyze varying fertility rates at the sub-national level in China and other countries. PMID:29593449

The role of traditional organization on family planning acceptance in Indonesia.

PubMed

Ancok, D

1991-01-01

The nature of and the reasons for the decline in Indonesian fertility and the utilization of the village traditional organization, banjar, in the family planning (FP) program are discussed. The total fertility rate computed from census data shows a decline in fertility from 5.6 in the mid-1960s to 4.1 for 1981-1984, a 28% decline in 15 years. A further 23% decline evidenced in the Contraceptive Prevalence Survey appeared as 4.3 children reproductive woman in 1981-83 and 3.3 between 1984-87. The success of the FP program in contributing a major impact on the decline is attributed to a strong political commitment to antinatalist policy which meant increased allocation to FP when government income was declining, effective organizational structure, and effective strategies such as the mobilization of traditional village organizations. The impact of FP can also be seen in the increase in the number of family acceptors. Another source of the fertility decline is due to the impact of development. 1) Improvement in education has contributed to fertility decline in the increase in the number graduating from elementary and secondary school, the increased value of children, the acceptance of new ideas, the postponement of marriage, and the increase in the never-married group. 2) The decline in the infant mortality rate from 142 in 1971 to 70.2/1000 births in 1982-87 due to the improvement in health facilities and service also contributed to fertility decline. 3) The growth in the number of women participating in the nonagricultural labor force has also contributed to fertility decline. To what extent each has contributed to the decline has not been empirically tested. Molyneaux' study is cited for demonstrating that both socioeconomic variables and contraceptive use, which are affected by socioeconomic variables and family planning, have influenced the fertility decline. Households with electricity, children engaged in the labor force, and frequency of mobile medical team visits had no effect. Another study found field worker and supervisor activities and community contraceptive distributors to be significant factors affecting contraceptive prevalence. The use of traditional organizations can be effective in other countries if the community conditions are the same. The following traditional organizations are described: simpan pinjam (savings and loan associations), arisan (rotating credit association), perkumpulan kematian (burial association), lumbung paceklik (emergency rice stores), kebatinan (mysticism group), pengajian (prayer group), and banjar (a residential group of 100 household heads). The banjar takes care of every aspect of a person's life and is compulsory and meets regularly. a 1976 study indicated the banjar as ideal for use in promoting FP, particularly if dynamic. Modern organizations at the village level, which were used to involve new acceptors, are also described. The Paguyuban KB (Family Planning Acceptors Group) promoted the program and was responsible for contraceptive distribution.

Relationship between sperm quality traits and field-fertility of porcine semen

PubMed Central

Lymberopoulos, A. G.; Khalifa, T. A. A.

2010-01-01

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 108 sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 106 sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 109 spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity. PMID:20458156

Quality of Pinzgau bull spermatozoa following different periods of cryostorage.

PubMed

Chrenek, P; Spaleková, E; Olexikova, L; Makarevich, A; Kubovicova, E

2017-04-01

The aim of this work was to examine the influence of cryostorage duration of Pinzgau bull's insemination doses (IDs) on some sperm traits. The IDs were frozen by a slow freezing method and stored in liquid nitrogen for different periods: less than 8 years (group 1), 8-13 years (group 2) and 14-18 years (group 3). Motility (CASA), pathological sperm rate (Giemsa staining), apoptotic (Yo-Pro-1-positive) and necrotic (propidium iodide-positive) cell occurrence and fertilizing ability (penetration/fertilization test) of spermatozoa were evaluated post-thaw. The average post-thaw sperm motility in all examined groups was over 40%. No significant influence of storage length either on the sperm total motility or progressive movement was revealed. In each tested group the average rate of malformed spermatozoa did not exceed 20%. No effect of cryostorage length on the occurrence of apoptotic or necrotic sperm was noted. Similarly, penetrating/fertilizing ability of sperm did not differ among the groups, excepting differences in the rate of pronuclei (PN) formation. In group 1, 72.9% of eggs showed two visible PN following 20 h incubation with sperm, whilst in groups 2 and 3 only 67 and 54.5% of zygotes, respectively, had both PN at this time. These results revealed no influence of storage time on the bull spermatozoa in all parameters excepting the rate of PN formation. As high inter-male variability was observed in the susceptibility of bull sperm to cryostorage, individual differences should be taken into account when semen from individual bulls is to be stored for a long time.

Transferability and inter-laboratory variability assessment of the in vitro bovine oocyte fertilization test.

PubMed

Tessaro, Irene; Modina, Silvia C; Crotti, Gabriella; Franciosi, Federica; Colleoni, Silvia; Lodde, Valentina; Galli, Cesare; Lazzari, Giovanna; Luciano, Alberto M

2015-01-01

The dramatic increase in the number of animals required for reproductive toxicity testing imposes the validation of alternative methods to reduce the use of laboratory animals. As we previously demonstrated for in vitro maturation test of bovine oocytes, the present study describes the transferability assessment and the inter-laboratory variability of an in vitro test able to identify chemical effects during the process of bovine oocyte fertilization. Eight chemicals with well-known toxic properties (benzo[a]pyrene, busulfan, cadmium chloride, cycloheximide, diethylstilbestrol, ketoconazole, methylacetoacetate, mifepristone/RU-486) were tested in two well-trained laboratories. The statistical analysis demonstrated no differences in the EC50 values for each chemical in within (inter-runs) and in between-laboratory variability of the proposed test. We therefore conclude that the bovine in vitro fertilization test could advance toward the validation process as alternative in vitro method and become part of an integrated testing strategy in order to predict chemical hazards on mammalian fertility. Copyright © 2015 Elsevier Inc. All rights reserved.

Sperm preparation through Sephadex™ filtration improves in vitro fertilization rate of buffalo oocytes.

PubMed

Husna, A U; Azam, A; Qadeer, S; Awan, M A; Nasreen, S; Shahzad, Q; Fouladi-Nashta, A; Khalid, M; Akhter, S

2018-04-01

Routinely, swim-up method is used to separate high-quality sperm; however, long processing time and close cell-to-cell contact during the centrifugation step are inevitable elements of oxidative stress to sperm. The objective was to evaluate Sephadex ™ and glass wool filtration to separate motile, intact and viable sperm for in vitro fertilization in buffalo. The cumulus-oocyte complexes (COCs) were collected from ovaries of slaughtered buffaloes by aspiration and matured for 24 hr in CO 2 incubator at 38.5°C and 5% CO 2 . Matured COCs were rinsed twice in fertilization TALP and placed in the pre-warmed fertilization medium without sperm. Cryopreserved buffalo semen was thawed at 37°C for 30 s and processed through Sephadex ™ , glass wool filtration and swim-up (control). Total and motile sperm recovery rates were assessed, resuspended in fertilization TALP and incubated for 15-20 min in CO 2 incubator. Samples prepared by each method were divided into two aliquots: one aliquot was studied for sperm quality (progressive motility, membrane integrity, viability, liveability), while the other was subjected to co-incubation with sets of 10-15 in vitro matured oocytes. Data on sperm quality were analysed by ANOVA, while in vitro fertilizing rates were compared by chi-squared test using SPSS-20. Least significant difference (LSD) test was used to compare treatment means. Glass wool filtration yielded higher total and motile sperm recovery rate, while Sephadex ™ filtration improved (p < .05) sperm quality (progressive motility, membrane integrity, viability, liveability). Sperm preparation through Sephadex filtration yielded higher in vitro fertilization rate in terms of cleavage rate compared to glass wool filtration and swim-up (control). In conclusion, cryopreserved Nili-Ravi buffalo sperm selected through Sephadex filtration showed improved quality and yielded better fertilization rates (cleavage rate) of in vitro matured/fertilized oocytes. Sephadex filtration could be a promising technique for use in in vitro fertilization in buffalo. © 2017 Blackwell Verlag GmbH.

Tropical Legume Crop Rotation and Nitrogen Fertilizer Effects on Agronomic and Nitrogen Efficiency of Rice

PubMed Central

Rahman, Motior M.; Islam, Aminul M.; Azirun, Sofian M.; Boyce, Amru N.

2014-01-01

Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m−2 preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m−2. No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m−2 achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13–23% higher grain yield than rice after fallow rotation with 8 g N m−2. The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m−2 can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m−2. The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility. PMID:24971378

Too Materialistic to Get Married and Have Children?

PubMed Central

Li, Norman P.; Lim, Amy J. Y.; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism’s relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks. PMID:25955502

Too materialistic to get married and have children?

PubMed

Li, Norman P; Lim, Amy J Y; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism's relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks.

Long-Term Effect of Exposure to a Friend's Adolescent Childbirth on Fertility, Education, and Earnings.

PubMed

Kapinos, Kandice A; Yakusheva, Olga

2016-09-01

To examine the long-term effect of a female adolescent's exposure to a peer's childbirth on fertility, schooling, and earnings. Estimating causal peer effects in fertility is challenging because the exposure variable (peer pregnancy and childbirth) is nonrandomly assigned. Miscarriages in early pregnancy occur spontaneously in a significant proportion of pregnancies and, therefore, create a natural experiment within which the causal effect of childbirth can be examined. This exploratory study compared adjusted fertility, educational, and labor market outcomes of female adolescents whose adolescent pregnant friend gave birth to female adolescents whose pregnant friend miscarried. Longitudinal data from the National Longitudinal Study of Adolescent Health were analyzed using logistic, ordinal logistic, linear, and log-linear regressions. Females whose adolescent pregnant friends gave birth (instead of miscarried) had decreased adolescent sexual activity, pregnancy, and teen childbearing and increased educational attainment, but there were no significant long-term effects on total fertility or differences in labor market outcomes, relative to females whose pregnant adolescent friend miscarried. Adolescent females appear to learn vicariously from teen childbearing experiences of their friends, resulting in delayed childbearing and higher educational attainment. Interventions that expose adolescents to the reality of teen motherhood may be an effective way of reducing the rates of teen childbearing and improving schooling. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

A socio-hydrological comparative assessment explaining regional variances in suicide rate amongst farmers in Maharashtra, India

NASA Astrophysics Data System (ADS)

den Besten, Nadja I.; Pande, Saket; Savenije, Hubert H. G.

2016-05-01

Maharashtra is one of the states in India that has witnessed one of the highest rates of farmer suicides as proportion of total number of suicides. Most of the farmer suicides in Maharashtra are from semi-arid divisions such as Marathwada where cotton has been historically grown. Other dominant crops produced include cereals, pulses, oilseeds and sugarcane. Cotton (fibers), oilseeds and sugarcane providing highest value addition per unit cultivated area and cereals and pulses the least. Hence it is not surprising that smallholders take risks growing high value crops without "visualising" the risks it entails such as those corresponding to price and weather shocks.We deploy recently developed smallholder socio-hydrology modelling framework to understand the underlying dynamics of the crisis. It couples the dynamics of six main variables that are most relevant at the scale of a smallholder: water storage capacity (root zone storage and other ways of water storage), capital, livestock, soil fertility and fodder biomass. The hydroclimatic variability is accounted for at sub-annual scale and influences the socio-hydrology at annual scale. The model incorporates rule-based adaptation mechanisms (e.g., adjusting expenditures on food and fertilizers, selling livestocks) of smallholders when they face adverse conditions, such as high variability in rainfall or in agricultural prices. The model is applied to two adjoining divisions of Maharashtra: Marathwada and Desh. The former is the division with relatively higher farmer suicide rates than the latter. Diverse spatial data sets of precipitation, potential evaporation, soil, agricultural census based farm inputs, cropping pattern and prices are used to understand the dynamics of small farmers in these divisions, and to attribute farmer distress rates to soil types, hydroclimatic variability and crops grown.Comparative socio-hydrologic assessment across the two regions confirms existing narratives: low (soil) water storage capacities, no irrigation and poor access to alternative sources of incomes are to blame for the crisis, suggesting that smart indigenous solutions such as rain-water harvesting and better integration of smallholder systems to efficient agricultural supply chains are needed to tackle this development challenge.

Method of Euthanasia Influences the Oocyte Fertilization Rate with Fresh Mouse Sperm

PubMed Central

Hazzard, Karen C; Watkins-Chow, Dawn E; Garrett, Lisa J

2014-01-01

In vitro fertilization (IVF) is used to produce mouse embryos for a variety of reasons. We evaluated the effect of the method of euthanasia on the fertilization rate in 2 different IVF protocols. Oocytes collected from C57BL/6J female mice euthanized by CO2 inhalation or cervical dislocation were used in IVF with fresh sperm from either wild-type or genetically engineered C57BL/6J. Compared with CO2 inhalation, cervical dislocation improved the resulting rate of fertilization by 18% in an IVF method using Cook media and by 13% in an IVF method using methyl-B cyclodextrin and reduced glutathione. The lower fertilization rate due to euthanasia by CO2 inhalation was accompanied by changes in blood pH and body temperature despite efforts to minimize temperature drops. In our hands, euthanasia by cervical dislocation improved fertilization rates and consequently reduced the number of egg-donor mice required. PMID:25650969

Strategies for narrowing the maize yield gap of household farms through precision fertigation under irrigated conditions using CERES-Maize model.

PubMed

Liu, Jiangang; Wang, Guangyao; Chu, Qingquan; Chen, Fu

2017-07-01

Nitrogen (N) application significantly increases maize yield; however, the unreasonable use of N fertilizer is common in China. The analysis of crop yield gaps can reveal the limiting factors for yield improvement, but there is a lack of practical strategies for narrowing yield gaps of household farms. The objectives of this study were to assess the yield gap of summer maize using an integrative method and to develop strategies for narrowing the maize yield gap through precise N fertilization. The results indicated that there was a significant difference in maize yield among fields, with a low level of variation. Additionally, significant differences in N application rate were observed among fields, with high variability. Based on long-term simulation results, the optimal N application rate was 193 kg ha -1 , with a corresponding maximum attainable yield (AY max ) of 10 318 kg ha -1 . A considerable difference between farmers' yields and AY max was observed. Low agronomic efficiency of applied N fertilizer (AE N ) in farmers' fields was exhibited. The integrative method lays a foundation for exploring the specific factors constraining crop yield gaps at the field scale and for developing strategies for rapid site-specific N management. Optimization strategies to narrow the maize yield gap include increasing N application rates and adjusting the N application schedule. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Value of children and fertility: Results from a cross-cultural comparative survey in eighteen areas in Asia, Africa, Europe and America.

PubMed

Nauck, Bernhard

2014-09-01

For explaining cross-cultural differences in fertility behavior, this paper conjoins three complementary approaches: the 'demand'-based economic theory of fertility (ETF), a revised version of the 'supply'-based 'value-of-children' (VOC)-approach as a special theory of the general social theory of social production functions and the framing theory of variable rationality. A comprehensive model is specified that encompasses the variable efficiency of having children for the optimization of physical well-being and of social esteem of (potential) parents; it also accounts for the variable rationality of fertility decisions. The model is tested with a data set that comprises information on VOC and fertility of women within the social settings of 18 areas (Peoples Republic of China, North and South India, Indonesia, Palestine, Israel, Turkey, Ghana, South Africa, East and West Germany, the Czech Republic, France, Russia, Poland, Estonia, the United States and Jamaica). Latent class analysis is used to establish a measurement model for the costs and benefits of children and to analyze area differences by a two-level multinomial-model. Two-level Cox-regressions are used to estimate the effects of perceived costs and benefits of children, individual resources and context opportunities, with births of different parity as dependents. This simultaneous test in a cross-cultural context goes beyond the current state of fertility research and provides evidence about the cross-cultural validity of the model, the systematic effects of VOC on fertility and the changing rationality of fertility decisions during demographic transition and socio-economic change. Copyright © 2014 Elsevier Ltd. All rights reserved.

Water and Temperature Stresses Impact Canola (Brassica napus L.) Fatty Acid, Protein, and Yield over Nitrogen and Sulfur.

PubMed

Hammac, W Ashley; Maaz, Tai M; Koenig, Richard T; Burke, Ian C; Pan, William L

2017-12-06

Interactive effects of weather and soil nutrient status often control crop productivity. An experiment was conducted to determine effects of nitrogen (N) and sulfur (S) fertilizer rate, soil water, and atmospheric temperature on canola (Brassica napus L.) fatty acid (FA), total oil, protein, and grain yield. Nitrogen and sulfur were assessed in a 4-yr study with two locations, five N rates (0, 45, 90, 135, and 180 kg ha -1 ), and two S rates (0 and 17 kg ha -1 ). Water and temperature were assessed using variability across 12 site-years of dryland canola production. Effects of N and S were inconsistent. Unsaturated FA, oleic acid, grain oil, protein, and theoretical maximum grain yield were highly related to water and temperature variability across the site-years. A nonlinear model identified water and temperature conditions that enabled production of maximum unsaturated FA content, oleic acid content, total oil, protein, and theoretical maximum grain yield. Water and temperature variability played a larger role than soil nutrient status on canola grain constituents and yield.

Differential effect of wealth quintile on modern contraceptive use and fertility: evidence from Malawian women

PubMed Central

2014-01-01

Background High fertility and wide inequality in wealth distribution are phenomenal problems in sub-Saharan Africa. Modern Contraceptives (MC) are useful for limiting fertility, but are not always easily accessible in Malawi. This study examines the gap in MC use and fertility between women in the richest and poorest Wealth Quintile (WQ). Methods The study was cross-sectional in design and utilized Malawi DHS dataset, 2010. It focused on women of reproductive age. The dependent variables are ever and current use of MC. Chi-square and multinomial logistic regression were used for the analysis. Results Mean children ever born by women in the poorest and richest WQs were 3.94 ± 2.7 and 2.82 ± 2.3 respectively (p < 0.001). The adjusted total fertility rate (Adj.TFR) was higher among women in the poorest (Adj.TFR = 7.60) WQ than the richest (Adj.TFR = 4.45). The prevalence of ever use of MC was higher among women in the richest WQ (82.4%) than the poorest (66.8%) (p < 0.001). Similar pattern exists for current use of MC; 58.5% and 45.9% for women in the richest and poorest WQs respectively (p < 0.001). Women in the richest WQ were more likely to ever use (OR = 2.36; C.I = 2.07-2.69, p < 0.001) and currently using (OR = 1.66; C.I = 1.40-1.97, p < 0.001) MC than their counterparts in the poorest WQ. Slight reduction in odd-ratio of MC use among women in richest WQ resulted when socio-demographic variables were used as control. Conclusion Fertility was higher and the use of MC was lower among women in the poorest than their counterparts in the richest WQ. Ensuring availability of MC at little or no cost may bridge the gap in contraceptive use between women in the poorest and richest WQ in Malawi. PMID:24602452

Factors associated with fertility moderation in India.

PubMed

Sharma, S; Singhal, D S; Sharma, B B; Gupta, Y P

1991-04-01

The authors analyze intermediate variables associated with fertility decline in India from the 1960s to 1988. The focus is on comparisons among states as revealed primarily by data on couples protected from unwanted pregnancies by family planning methods. Variables considered include female age at marriage, female literacy, infant mortality, poverty, expenditure on health and family welfare, and income. Data are from official sources.

Application of a ready-to-use calcium ionophore increases rates of fertilization and pregnancy in severe male factor infertility.

PubMed

Ebner, Thomas; Köster, Maria; Shebl, Omar; Moser, Marianne; Van der Ven, Hans; Tews, Gernot; Montag, Markus

2012-12-01

To analyze whether a ready-to-use calcium ionophore improves outcomes, from fertilization to live birth, in patients with severe male factor infertility. Artificial oocyte activation offered to applicable patients over a 20-month period. Specialized in vitro fertilization (IVF) centers in Austria and Germany. Twenty-nine azoospermic and 37 cryptozoospermic men. Mature oocytes treated with a ready-to-use Ca(2+)-ionophore (GM508 Cult-Active) immediately after intracytoplasmic sperm injection (ICSI). Rates of fertilization, implantation, clinical pregnancy, and live birth. Patients had had 88 previous cycles without artificial activation that resulted in a fertilization rate of 34.7%, 79 transfers (89.8%), and 5 pregnancies, which all spontaneously aborted except one. After artificial oocyte activation, the fertilization rate was 56.9%. In terms of fertilization rate, both azoospermic (64.4%) and cryptozoospermic (48.4%) men statistically significantly benefited from use of the ionophore. In 73 transfer cycles, positive β-human chorionic gonadotropin levels were observed in 34 cases (46.6%) and 29 cycles (39.7%) that ended with a clinical pregnancy. The corresponding implantation rate was 33.3%. Four spontaneous abortions occurred (11.8%), and 32 healthy children were born. This is the first prospective multicenter study on artificial oocyte activation in severe male factor infertility. Present data indicate that a ready-to-use calcium ionophore can yield high fertilization and pregnancy rates for this particular subgroup. In addition to fertilization failure after ICSI, severe male factor infertility is an additional area for application of artificial oocyte activation. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Nitrous oxide emissions in Midwest US maize production vary widely with band-injected N fertilizer rates, timing and nitrapyrin presence

NASA Astrophysics Data System (ADS)

Burzaco, Juan P.; Smith, Doug R.; Vyn, Tony J.

2013-09-01

Nitrification inhibitors have the potential to reduce N2O emissions from maize fields, but optimal results may depend on deployment of integrated N fertilizer management systems that increase yields achieved per unit of N2O lost. A new micro-encapsulated formulation of nitrapyrin for liquid N fertilizers became available to US farmers in 2010. Our research objectives were to (i) assess the impacts of urea-ammonium nitrate (UAN) management practices (timing, rate and nitrification inhibitor) and environmental variables on growing-season N2O fluxes and (ii) identify UAN treatment combinations that both reduce N2O emissions and optimize maize productivity. Field experiments near West Lafayette, Indiana in 2010 and 2011 examined three N rates (0, 90 and 180 kg N ha-1), two timings (pre-emergence and side-dress) and presence or absence of nitrapyrin. Mean cumulative N2O-N emissions (Q10 corrected) were 0.81, 1.83 and 3.52 kg N2O-N ha-1 for the rates of 0, 90 and 180 kg N ha-1, respectively; 1.80 and 2.31 kg N2O-N ha-1 for pre-emergence and side-dress timings, respectively; and 1.77 versus 2.34 kg N2O-N ha-1 for with and without nitrapyrin, respectively. Yield-scaled N2O-N emissions increased with N rates as anticipated (averaging 167, 204 and 328 g N2O-N Mg grain-1 for the 0, 90 and 180 kg N ha-1 rates), but were 22% greater with the side-dress timing than the pre-emergence timing (when averaged across N rates and inhibitor treatments) because of environmental conditions following later applications. Overall yield-scaled N2O-N emissions were 22% lower with nitrapyrin than without the inhibitor, but these did not interact with N rate or timing.

Effects of pre-incubation of eggs in fresh water and varying sperm concentration on fertilization rate in sterlet sturgeon, Acipenser ruthenus.

PubMed

Siddique, Mohammad Abdul Momin; Butts, Ian Anthony Ernest; Psenicka, Martin; Linhart, Otomar

2015-08-01

Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs and explore how pre-incubation of eggs in freshwater for 0min, 0.5min, 1min, and 10min interacts with different sperm ratios. Fertilization success ranged from 29.7% at 430:1 to 84.2% at 430,000:1. Pre-incubation time had no effect on fertilization success at 430,000:1 and 43,000:1 sperm to egg ratios, while it was significant at the 4300:1 and 430:1 ratios. The use of adequate experimental suboptimal sperm to egg ratio revealed a positive effect of pre-incubation time, such that at the 430:1 ratio, 0.5min pre-incubation increased the fertilization rate than 10min. At 0min pre-incubation the proportion of fertilized eggs increased at the 430,000:1 ratio, while at 1min fertilization increased at the 4300:1 ratio. At the 10min pre-incubation time, fertilization increased at the 43,000:1 ratio. Moreover, at the 0.5min pre-incubation time, the 43,000:1 ratio increased the fertilization rate than the 430:1 ratio. Generally, for 430:1 ratio, the fertilization rate is lower than in control. Transmission electron microscopy showed that pre-incubation of eggs in water for <10min does not trigger a cortical reaction or the formation of a perivitelline space. Results suggest that with a low sperm to egg ratio 0.5 to 1min pre-incubation of eggs in freshwater prior to fertilization can enhance fertilization rate of sterlet. Copyright © 2015 Elsevier B.V. All rights reserved.

Determinants of rural and urban fertility differentials in Nigeria.

PubMed

Chimere-Dan, O

1990-07-01

Whatever proximate variables are examined, their differential effects on rural and urban fertility are small. This indicates that no major disturbance has taken place in urban or rural reproductive norms. However, two possible reasons for the converging pattern of rural and urban fertility in Nigeria are identified. One is that urban mothers in the first half of the childbearing age range have higher fertility than their rural counterparts. The other is that breast-feeding and post-partum abstinence, which are the major determinants of marital fertility, exert a more depressing influence on rural than urban fertility.

[Research advances on regulating soil nitrogen loss by the type of nitrogen fertilizer and its application strategy.

PubMed

Zhou, Wei; Lyu, Teng Fei; Yang, Zhi Ping; Sun, Hong; Yang, Liang Jie; Chen, Yong; Ren, Wan Jun

2016-09-01

Unreasonable application of nitrogen fertilizer to cropland decreases nitrogen use efficiency of crop. A large amount of nitrogen loss to environment through runoff, leaching, ammonia volati-lization, nitrification-denitrification, etc., causes water and atmospheric pollution, poses serious environmental problems and threatens human health. The type of nitrogen fertilizer and its application rate, time, and method have significant effects on nitrogen loss. The primary reason for nitrogen loss is attributed to the supersaturated soil nitrogen concentration. Making full use of environmental nitrogen sources, reducing the application rate of chemical nitrogen fertilizers, applying deep placement fertilizing method, and applying organic fertilizers with chemical nitrogen fertilizers, are effective practices for reducing nitrogen loss and improving nitrogen use efficiency. It is suggested that deve-loping new high efficiency nitrogen fertilizers, enhancing nitrogen management, and strengthening the monitoring and use of environmental nitrogen sources are the powerful tools to decrease nitrogen application rate and increase efficiency of cropland.

Male Infertility Is Responsible for Nearly Half of the Extinction Observed in the Mouse Collaborative Cross

PubMed Central

Shorter, John R.; Odet, Fanny; Aylor, David L.; Pan, Wenqi; Kao, Chia-Yu; Fu, Chen-Ping; Morgan, Andrew P.; Greenstein, Seth; Bell, Timothy A.; Stevans, Alicia M.; Feathers, Ryan W.; Patel, Sunny; Cates, Sarah E.; Shaw, Ginger D.; Miller, Darla R.; Chesler, Elissa J.; McMillian, Leonard; O’Brien, Deborah A.; de Villena, Fernando Pardo-Manuel

2017-01-01

The goal of the Collaborative Cross (CC) project was to generate and distribute over 1000 independent mouse recombinant inbred strains derived from eight inbred founders. With inbreeding nearly complete, we estimated the extinction rate among CC lines at a remarkable 95%, which is substantially higher than in the derivation of other mouse recombinant inbred populations. Here, we report genome-wide allele frequencies in 347 extinct CC lines. Contrary to expectations, autosomes had equal allelic contributions from the eight founders, but chromosome X had significantly lower allelic contributions from the two inbred founders with underrepresented subspecific origins (PWK/PhJ and CAST/EiJ). By comparing extinct CC lines to living CC strains, we conclude that a complex genetic architecture is driving extinction, and selection pressures are different on the autosomes and chromosome X. Male infertility played a large role in extinction as 47% of extinct lines had males that were infertile. Males from extinct lines had high variability in reproductive organ size, low sperm counts, low sperm motility, and a high rate of vacuolization of seminiferous tubules. We performed QTL mapping and identified nine genomic regions associated with male fertility and reproductive phenotypes. Many of the allelic effects in the QTL were driven by the two founders with underrepresented subspecific origins, including a QTL on chromosome X for infertility that was driven by the PWK/PhJ haplotype. We also performed the first example of cross validation using complementary CC resources to verify the effect of sperm curvilinear velocity from the PWK/PhJ haplotype on chromosome 2 in an independent population across multiple generations. While selection typically constrains the examination of reproductive traits toward the more fertile alleles, the CC extinct lines provided a unique opportunity to study the genetic architecture of fertility in a widely genetically variable population. We hypothesize that incompatibilities between alleles with different subspecific origins is a key driver of infertility. These results help clarify the factors that drove strain extinction in the CC, reveal the genetic regions associated with poor fertility in the CC, and serve as a resource to further study mammalian infertility. PMID:28592496

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

ERIC Educational Resources Information Center

Child Trends, 2016

2016-01-01

Tracking trends in fertility and birth rates is essential in planning for the current and future needs of multiple generations. Sustained high fertility rates lead to disproportionately large populations of young dependents, driving demand for supports for young families, for additional schools, and for affordable child care. For example, during…

Relationship between gender role attitude and fertility rate in women referring to health centers in Mashhad in 2013.

PubMed

Golmakani, Nahid; Fazeli, Elham; Taghipour, Ali; Shakeri, Mohammad Taghi

2015-01-01

Fertility rate apparently is a non-interventional behavior, but in practice, it is influenced by social values and norms in which culture and traditional beliefs play a significant role. In this regard, some studies have shown that gender roles can be associated with reproductive behaviors. With regard to the importance of annual reduction of population growth rate and its outcomes, the present study was performed to determine the relationship between gender role attitude and fertility rate in women referring to Mashhad health centers in 2013. The present study is an analytical cross-sectional and multistage sampling study performed on 712 women. Data were collected by a questionnaire consisting of two sections: Personal information and gender role attitude questionnaire that contained two dimensions, i.e. gender stereotypes and gender egalitarianism. Its validity was determined by content validity and its reliability by internal consistency (r = 0.77). Data were analyzed by SPSS software version 16. Initial analysis of the data indicated that there was a significant relationship between acceptance of gender stereotypes (P = 0.008) and gender egalitarianism (P < 0.001), and fertility. There was also a direct association between acceptance of gender stereotypes and fertility rate (r = 0.13) and an indirect association between egalitarianism and fertility rate (r = -0.15). The results of the present study indicate that there is an association between gender role attitude and fertility. Paying attention to women's attitude is very important for successful planning in the improvement of fertility rate and population policy.

Practices, perceptions, and implications of fertilizer use in East-Central China.

PubMed

Yang, Xiaoying; Fang, Shubo

2015-11-01

Face-to-face interviews (n = 553) were conducted in five counties in East-Central China to study farmers' fertilizer application behaviors, decision-making processes, attitudes towards adopting better fertilizer application technologies, and environmental consciousness. The survey results revealed widespread fertilizer misapplication and highly variable application behaviors in the study regions. The lack of scientific knowledge on fertilizers and the absence of guidance from agricultural extension services have forced the farmers to rely on personal judgment and advice from fertilizer dealers and friends to make decisions in fertilizer application. Overall, farmers have been idiosyncratic in fertilizer application with limited adoption of better fertilizer application technologies. There are great potentials for reducing pollutant load from agricultural runoff through promoting scientific fertilizer application in the regions. However, farmers' diverse preferences over agricultural extension programs necessitate an integrated approach emphasizing farmer involvement throughout the development of such programs for promoting better fertilizer application practices.

Self-fertilization, long-distance flash invasion and biogeography shape the population structure of Pseudosuccinea columella at the worldwide scale.

PubMed

Lounnas, M; Correa, A C; Vázquez, A A; Dia, A; Escobar, J S; Nicot, A; Arenas, J; Ayaqui, R; Dubois, M P; Gimenez, T; Gutiérrez, A; González-Ramírez, C; Noya, O; Prepelitchi, L; Uribe, N; Wisnivesky-Colli, C; Yong, M; David, P; Loker, E S; Jarne, P; Pointier, J P; Hurtrez-Boussès, S

2017-02-01

Population genetic studies are efficient for inferring the invasion history based on a comparison of native and invasive populations, especially when conducted at species scale. An expected outcome in invasive populations is variability loss, and this is especially true in self-fertilizing species. We here focus on the self-fertilizing Pseudosuccinea columella, an invasive hermaphroditic freshwater snail that has greatly expanded its geographic distribution and that acts as intermediate host of Fasciola hepatica, the causative agent of human and veterinary fasciolosis. We evaluated the distribution of genetic diversity at the largest geographic scale analysed to date in this species by surveying 80 populations collected during 16 years from 14 countries, using eight nuclear microsatellites and two mitochondrial genes. As expected, populations from North America, the putative origin area, were strongly structured by selfing and history and harboured much more genetic variability than invasive populations. We found high selfing rates (when it was possible to infer it), none-to-low genetic variability and strong population structure in most invasive populations. Strikingly, we found a unique genotype/haplotype in populations from eight invaded regions sampled all over the world. Moreover, snail populations resistant to infection by the parasite are genetically distinct from susceptible populations. Our results are compatible with repeated introductions in South America and flash worldwide invasion by this unique genotype/haplotype. Our study illustrates the population genetic consequences of biological invasion in a highly selfing species at very large geographic scale. We discuss how such a large-scale flash invasion may affect the spread of fasciolosis. © 2016 John Wiley & Sons Ltd.

Development of a phosphorus index for pastures fertilized with poultry litter--factors affecting phosphorus runoff.

PubMed

DeLaune, Paul B; Moore, Philip A; Carman, Dennis K; Sharpley, Andrew N; Haggard, Brian E; Daniel, Tommy C

2004-01-01

Currently, several state and federal agencies are proposing upper limits on soil test phosphorus (P), above which animal manures cannot be applied, based on the assumption that high P concentrations in runoff are due to high soil test P. Recent studies show that other factors are more indicative of P concentrations in runoff from areas where manure is being applied. The original P index was developed as an alternative P management tool incorporating factors affecting both the source and transport of P. The objective of this research was to evaluate the effects of multiple variables on P concentrations in runoff water and to construct a P source component of a P index for pastures that incorporates these effects. The evaluated variables were: (i) soil test P, (ii) soluble P in poultry litter, (iii) P in poultry diets, (iv) fertilizer type, and (v) poultry litter application rate. Field studies with simulated rainfall showed that P runoff was affected by the amount of soluble P applied in the fertilizer source. Before manure applications, soil test P was directly related to soluble P concentrations in runoff water. However, soil test P had little effect on P runoff after animal manure was applied. Unlike most other P indices, weighting factors of the P source components in the P index for pastures are based on results from runoff studies conducted under various management scenarios. As a result, weighting factors for the P source potential variables are well justified. A modification of the P index using scientific data should strengthen the ability of the P index concept to evaluate locations and management alternatives for P losses.

The fertility decline in Kenya.

PubMed

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 features of reform appear to be political stability, public sector programs, and supply of contraception through the health service.

Effects of Long-term Fertilization on Potassium Fixation Capacity in Brown Soil

NASA Astrophysics Data System (ADS)

Li, Na; Guo, Chunlei; Wang, Yue; Gao, Tianyi; Yang, Jinfeng; Han, Xiaori

2018-01-01

This study concentrated on the research of features of fixation. The objective of this study was to provide theoretical foundation of rational application of potassium fertilizer along with improving fertilizer availability ratio. A 32 years long-term experiment was conducted to evaluate the effects of fertilizer application on potassium changes and the factors affecting K fixation on brown soil by simulation in laboratory. When the concentration of exogenous potassium was in range of 400∼4000 mg·kg-1, potassium fixation capacity increased along with the rise of concentration of exogenous potassium, whereas K fixation rate reduced; Compared with no-potassium fertilizer, application of potassium fertilizer and organic fertilizer reduced soil potassium fixation capacity. Potassium rate and fixation-release of potassium character in soil should be taken into comprehensive consideration for rational fertilization to maintain or improve soil fertility for increasing potassium fertilizers efficiency in agriculture.

Fertility in Gyr Cows (Bos indicus) with Fixed Time Artificial Insemination and Visual Estrus Detection Using a Classification Table

PubMed Central

Ramírez-Iglesia, Lilido Nelson; Roman Bravo, Rafael María; Díaz de Ramirez, Adelina; Torres, Leandro J.

2014-01-01

The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which were assigned to NSE-AI and in this group a modified table was used. Response variable was first service fertility rate (FSF), which was coded 1 for pregnant and 0 for empty. Predictor variables were AIP, postpartum anestrus, daily milk yield, body condition score at AI and calving number. Statistical analyses included association chi-square tests and logistic regression. Results showed an overall 41.94% FSF and a significant association was detected (P < 0.05) between FSF and daily milk yield; pregnancy rates were 42.20% and 41.67% for the SC-FTAI and NSE-IA groups, respectively (P > 0.05). The odds ratio for the effect of AIP was only 1.050, suggesting no differences in FSF between groups. The NSE-AI protocol can enhance both the technique of VO and reproductive efficiency. Further validation of the table is required. PMID:26464929

[Effects of long-term fertilization on microbial biomass carbon and nitrogen and on carbon source utilization of microbes in a red soil].

PubMed

Sun, Feng-xia; Zhang, Wei-hua; Xu, Ming-gang; Zhang, Wen-ju; Li, Zhao-qiang; Zhang, Jing-ye

2010-11-01

In order to explore the effects of long-term fertilization on the microbiological characters of red soil, soil samples were collected from a 19-year long-term experimental field in Qiyang of Hunan, with their microbial biomass carbon (MBC) and nitrogen (MBN) and microbial utilization ratio of carbon sources analyzed. The results showed that after 19-year fertilization, the soil MBC and MBN under the application of organic manure and of organic manure plus inorganic fertilizers were 231 and 81 mg x kg(-1) soil, and 148 and 73 mg x kg(-1) soil, respectively, being significantly higher than those under non-fertilization, inorganic fertilization, and inorganic fertilization plus straw incorporation. The ratio of soil MBN to total N under the application of organic manure and of organic manure plus inorganic fertilizers was averagely 6.0%, significantly higher than that under non-fertilization and inorganic fertilization. Biolog-ECO analysis showed that the average well color development (AWCD) value was in the order of applying organic manure plus inorganic fertilizers = applying organic manure > non-fertilization > inorganic fertilization = inorganic fertilization plus straw incorporation. Under the application of organic manure or of organic manure plus inorganic fertilizers, the microbial utilization rate of carbon sources, including carbohydrates, carboxylic acids, amino acids, polymers, phenols, and amines increased; while under inorganic fertilization plus straw incorporation, the utilization rate of polymers was the highest, and that of carbohydrates was the lowest. Our results suggested that long-term application of organic manure could increase the red soil MBC, MBN, and microbial utilization rate of carbon sources, improve soil fertility, and maintain a better crop productivity.

Carbon dioxide emissions from semi-arid soils amended with biochar alone or combined with mineral and organic fertilizers.

PubMed

Fernández, José M; Nieto, M Aurora; López-de-Sá, Esther G; Gascó, Gabriel; Méndez, Ana; Plaza, César

2014-06-01

Semi-arid soils cover a significant area of Earth's land surface and typically contain large amounts of inorganic C. Determining the effects of biochar additions on CO2 emissions from semi-arid soils is therefore essential for evaluating the potential of biochar as a climate change mitigation strategy. Here, we measured the CO2 that evolved from semi-arid calcareous soils amended with biochar at rates of 0 and 20tha(-1) in a full factorial combination with three different fertilizers (mineral fertilizer, municipal solid waste compost, and sewage sludge) applied at four rates (equivalent to 0, 75, 150, and 225kg potentially available Nha(-1)) during 182 days of aerobic incubation. A double exponential model, which describes cumulative CO2 emissions from two active soil C compartments with different turnover rates (one relatively stable and the other more labile), was found to fit very well all the experimental datasets. In general, the organic fertilizers increased the size and decomposition rate of the stable and labile soil C pools. In contrast, biochar addition had no effects on any of the double exponential model parameters and did not interact with the effects ascribed to the type and rate of fertilizer. After 182 days of incubation, soil organic and microbial biomass C contents tended to increase with increasing the application rates of organic fertilizer, especially of compost, whereas increasing the rate of mineral fertilizer tended to suppress microbial biomass. Biochar was found to increase both organic and inorganic C contents in soil and not to interact with the effects of type and rate of fertilizer on C fractions. As a whole, our results suggest that the use of biochar as enhancer of semi-arid soils, either alone or combined with mineral and organic fertilizers, is unlikely to increase abiotic and biotic soil CO2 emissions. Copyright © 2014 Elsevier B.V. All rights reserved.

Economic development and family size.

PubMed

Rios, R J

1991-01-01

The demographic transition in Latin America has resulted in increased family size rather than the Western European model of reduced family size. In 1905, both fertility and mortality were high in Latin America, but mortality declined more rapidly in Latin America than in Europe. In 1905, the crude birth rate for 15 selected countries averaged 44/1000 population. Western fertility at a comparable transition point was much lower at 30/1000. Between 1905 and 1960, fertility declines were evident in Uruguay, Argentina, Cuba, and Chile. Between 1960 and 1985, fertility declines appeared in Costa Rica, Panama, Brazil, and Colombia. Fertility declines were smaller in the other Latin American countries. Crude birth rates declined markedly by 1985 but may overestimate fertility decline, which is more accurately measured by standardized birth rates. Fertility decline was evident in Argentina, Chile, and Costa Rica for standardized birth rates, survivorship ratio, and births surviving past the age of 15 years. Theoretically, families are expected to reduce family size when survivorship is assured; when mortality is 25%, only four children need be planned instead of six when mortality is 50%. A result of falling mortality is a cheaper cost of producing children, which may stimulate parents to raise bigger families. Western fertility decline has been attributed to mortality decline, urbanization, increased female labor force participation, rising wages, and more efficient contraception. Comparable economic development in Latin America has not resulted in large enough changes to encourage family size limitation. A table of fertility and economic indicators for selected countries in Latin America and Europe reflects the inverse relationship between income growth, urban growth, and growth in female educational status and fertility. The regression equation explains 60% of the variation in fertility rates among Latin American countries. Explanatory power increases to 75% when female high school enrollment is added to per capita gross national product. Fertility declines in Latin America in the future will be dependent on economic development, educational advancement for women, and a reduction in rural population.

[Variation characteristics of maize yield and fertilizer utilization rate on an upland yellow soil under long term fertilization].

PubMed

Luo, Long-Zao; Li, Yu; Zhang, Wen-An; Xiao, Hou-Jun; Jiang, Tai-Ming

2013-10-01

An analysis was made on the 16-year experimental data from the long term fertilization, experiment of maize on a yellow soil in Guizhou of Southwest China. Four treatments, i. e. , no fertilization (CK), chemical fertilization (165 kg N x hm(-2), 82.5 kg P2O5 x hm(-2), and 82.5 kg K2O x hm(-2), NPK), organic manure (30555 kg x hm(-2), M), and combined applicatioin of chemical fertilizers and organic manure (NPKM), were selected to analyze the variation trends of maize yield and fertilizer use efficiency on yellow soil under effects of different long term fertilization modes, aimed to provide references for evaluating and establishing long term fertilization mode and promote the sustainable development of crop production. Overall, the maize yield under long term fertilization had an increasing trend, with a large annual variation. Treatment NPKM had the best yield-increasing effect, with the maize yield increased by 4075.71 kg x hm(-2) and the increment being up to 139.2%. Long term fertilization increased the fertilizer utilization efficiency of maize. In treatment M, the nitrogen and phosphorus utilization rates were increased significantly by 35.4% and 18.8%, respectively. Treatment NPK had obvious effect in improving potassium utilization rate, with an increment of 20% and being far higher than that in treatments M (8.7%) and NPKM (9.2%). The results showed that long term fertilization, especially the combined application of chemical fertilizers and organic manure, was of great importance in increasing crop yield and fertilizer use efficiency.

Assessment of impact of climate change and adaptation strategies on maize production in Uganda

NASA Astrophysics Data System (ADS)

Kikoyo, Duncan A.; Nobert, Joel

2016-06-01

Globally, various climatic studies have estimated a reduction of crop yields due to changes in surface temperature and precipitation especially for the developing countries which is heavily dependent on agriculture and lacks resources to counter the negative effects of climate change. Uganda's economy and the wellbeing of its populace depend on rain-fed agriculture which is susceptible to climate change. This study quantified the impacts of climate change and variability in Uganda and how coping strategies can enhance crop production against climate change and/or variability. The study used statistical methods to establish various climate change and variability indicators across the country, and uses the FAO AquaCrop model to simulate yields under possible future climate scenarios with and without adaptation strategies. Maize, the most widely grown crop was used for the study. Meteorological, soil and crop data were collected for various districts representing the maize growing ecological zones in the country. Based on this study, it was found that temperatures have increased by up to 1 °C across much of Uganda since the 1970s, with rates of warming around 0.3 °C per decade across the country. High altitude, low rainfall regions experience the highest level of warming, with over 0.5 °C/decade recorded in Kasese. Rainfall is variable and does not follow a specific significant increasing or decreasing trend. For both future climate scenarios, Maize yields will reduce in excess of 4.7% for the fast warming-low rainfall climates but increase on average by 3.5% for slow warming-high rainfall regions, by 2050. Improved soil fertility can improve yields by over 50% while mulching and use of surface water management practices improve yields by single digit percentages. The use of fertilizer application needs to go hand in hand with other water management strategies since more yields as a result of the improved soil fertility leads to increased water stress, especially for the dry climates.

Race-Ethnic Differences in the Non-marital Fertility Rates in 2006-2010.

PubMed

Kim, Yujin; Raley, R Kelly

2015-02-01

Research in the 1980s pointed to the lower marriage rates of blacks as an important factor contributing to race differences in non-marital fertility. Our analyses update and extend this prior work to investigate whether cohabitation has become an important contributor to this variation. We use data from the 2006-2010 National Survey of Family Growth (NSFG) and to identify the relative contribution of population composition (i.e. percent sexually active single and percent cohabiting) versus rates (pregnancy rates, post-conception marriage rates) to race-ethnic variation in non-marital fertility rates (N=7,428). We find that the pregnancy rate among single (not cohabiting) women is the biggest contributor to race-ethnic variation in the non-marital fertility rate and that contraceptive use patterns among racial minorities explains the majority of the race-ethnic differences in pregnancy rates.

The effectiveness of family-planning programmes.

PubMed

Mauldin, W P

1989-01-01

By the mid-1960s, countries that accounted for 66% of the population of developing countries had adopted policies designed to reduce their rates of population growth; by 1986, the corresponding figure had reached 78%. In the developing regions as a whole, fertility has fallen by more than 30% since 1950. Contraceptive use has risen sharply, and there has been more than 10-fold increase in the number of couples in developing countries who use contraceptives. There is a very strong association between use of contraception and fertility in developing countries. Social and economic modernization is also taking place, although quite unevenly in the developing regions, so that the relationship of modernization is fertility is not very easy to demonstrate. In general, the experience of the developing countries suggest that a strong family- planning program effort can, and does, lead to a more rapid fertility decline than would be likely based only on socioeconomic variables. The effectiveness of family-planning programs can be enhanced by increasing the range of choice of contraceptive methods offered. However, it is difficult to disentangle the various factors that contribute to the effectiveness of family-planning programs. The public sector is the main supplier of family-planning services in most developing countries, and there is no clear trend towards the reliance on the private sector.

Men's body mass index in relation to embryo quality and clinical outcomes in couples undergoing in vitro fertilization.

PubMed

Colaci, Daniela S; Afeiche, Myriam; Gaskins, Audrey J; Wright, Diane L; Toth, Thomas L; Tanrikut, Cigdem; Hauser, Russ; Chavarro, Jorge E

2012-11-01

To evaluate the association between men's body mass index (BMI), early embryo quality, and clinical outcomes in couples undergoing in vitro fertilization (IVF). Prospective cohort study. Fertility clinic in an academic medical center. 114 couples who underwent 172 assisted reproduction cycles. None. Fertilization rate, embryo quality, implantation rate, clinical pregnancy rate, and live birth rate. The fertilization rate was higher among obese men than among normal weight men in conventional IVF cycles. No statistically significant associations were found between men's BMI and the proportion of poor-quality embryos on day 3, slow embryo cleavage rate, or accelerated embryo cleavage rate. Men's BMI was unrelated to positive β-human chorionic gonadotropin rate, clinical pregnancy rate, or live-birth rate per embryo transfer. Among couples undergoing intracytoplasmic sperm injection, the odds of live birth in couples with obese male partners was 84% lower than the odds in couples with men with normal BMI. Our data suggest a possible deleterious effect of male obesity on the odds of having a live birth among couples undergoing intracytoplasmic sperm injection. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Genetic variability in arbuscular mycorrhizal fungi compatibility supports the selection of durum wheat genotypes for enhancing soil ecological services and cropping systems in Canada.

PubMed

Singh, A K; Hamel, C; Depauw, R M; Knox, R E

2012-03-01

Crop nutrient- and water-use efficiency could be improved by using crop varieties highly compatible with arbuscular mycorrhizal fungi (AMF). Two greenhouse experiments demonstrated the presence of genetic variability for this trait in modern durum wheat ( Triticum turgidum L. var. durum Desf.) germplasm. Among the five cultivars tested, 'AC Morse' had consistently low levels of AM root colonization and DT710 had consistently high levels of AM root colonization, whereas 'Commander', which had the highest colonization levels under low soil fertility conditions, developed poor colonization levels under medium fertility level. The presence of genetic variability in durum wheat compatibility with AMF was further evidenced by significant genotype × inoculation interaction effects in grain and straw biomass production; grain P, straw P, and straw K concentrations under medium soil fertility level; and straw K and grain Fe concentrations at low soil fertility. Mycorrhizal dependency was an undesirable trait of 'Mongibello', which showed poor growth and nutrient balance in the absence of AMF. An AMF-mediated reduction in grain Cd under low soil fertility indicated that breeding durum wheat for compatibility with AMF could help reduce grain Cd concentration in durum wheat. Durum wheat genotypes should be selected for compatibility with AMF rather than for mycorrhizal dependency.

Determination of total arsenic and arsenic(III) in phosphate fertilizers by hydride generation atomic absorption spectrometry after ultrasound-assisted extraction based on a control acid media.

PubMed

Rezende, Helen Cristine; Coelho, Nivia Maria Melo

2014-01-01

An ultrasound-assisted extraction procedure was developed for determination of inorganic arsenic (As) in phosphate fertilizer by hydride generation atomic absorption spectrometry. The variables that affect the hydride generation step were optimized, including the reducer, acid, sample flow rate, and concentrations of the acid and reducer. The determination of As(lll) was performed through the simple control of solution pH with a 0.5 M citric acid-sodium citrate buffer solution at pH 4.5, and total As was determined after a pre-reduction reaction with 1.0% (w/v) thiourea. Ultrasound-assisted acid extraction was performed, and the parameters sonication time and acid and Triton X-114 concentrations were optimized using a 23 factorial design and central composite design. LODs for As(lll) and total As were 0.029 and 0.022 microg/L, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successfully applied in the determination of inorganic As in phosphate fertilizer samples.

Pregnancy outcome using general anesthesia versus spinal anesthesia for in vitro fertilization.

PubMed

Azmude, Azra; Agha'amou, Shahrzad; Yousefshahi, Fardin; Berjis, Katayoun; Mirmohammad'khani, Majid; Sadaat'ahmadi, Farahnaz; Ghods, Kamran; Dabbagh, Ali

2013-09-01

There is a considerable rate of fertility failure and this causes a great burden of untoward effects for patients. Usually a considerable number of these patients undergo anesthesia for their treatment. This study was designed to compare the effects of general and spinal anesthesia on these patients. In a randomized clinical trial, after taking informed written consent from the patients, 200 patients entered the study; 100 in each. During a 2 year period, women aged 20 to 40 years entered the study (one group receiving spinal anesthesia and the other, receiving general anesthesia). Ovum retrieval protocols were the same. Nonparametric and parametric analyses were used for data analysis. P value less than 0.05 was considered significant. There was no difference between the two groups regarding demographic variables. 15 of 100 patients (15%) in the general anesthesia group and 27 of 100 patients (27%) in the spinal anesthesia group had successful pregnancy after IVF; so, spinal anesthesia increased significantly the chance of IVF success (P value < 0.001; Chi Square). The results of this study demonstrated that spinal anesthesia increased the chance of fertilization success.

The impact of cross-border reproductive care or 'fertility tourism' on NHS maternity services.

PubMed

McKelvey, A; David, A L; Shenfield, F; Jauniaux, E R

2009-10-01

High order multiple pregnancies have substantial morbidity and mortality. Fertility treatment is commonly responsible for their conception and is available globally with variable regulation. We investigated cross-border fertility treatment in these pregnancies in a UK fetal medicine unit, recording mode of conception, country of fertility treatment, reason for non-UK treatment and fetal reduction. Over an 11-year period, 109 women had a high order multiple pregnancy. Ninety-four women (86%) conceived with fertility treatment of whom 24 (26%) had this performed overseas. Cross-border fertility treatment poses an increasing challenge to obstetricians. National data on its occurrence is urgently needed.

Temperature Sensitivity of Soil Respiration to Nitrogen Fertilization: Varying Effects between Growing and Non-Growing Seasons

PubMed Central

Liu, Qingfang; Wang, Rui; Li, Rujian; Hu, Yaxian; Guo, Shengli

2016-01-01

Nitrogen (N) fertilization has a considerable effect on food production and carbon cycling in agro-ecosystems. However, the impacts of N fertilization rates on the temperature sensitivity of soil respiration (Q10) were controversial. Five N rates (N0, N45, N90, N135, and N180) were applied to a continuous winter wheat (Triticum aestivum L.) crop on the semi-arid Loess Plateau, and the in situ soil respiration was monitored during five consecutive years from 2008 to 2013. During the growing season, the mean soil respiration rates increased with increasing N fertilization rates, peaking at 1.53 μmol m−2s−1 in the N135 treatment. A similar dynamic pattern was observed during the non-growing season, yet on average with 7.3% greater soil respiration rates than the growing season. In general for all the N fertilization treatments, the mean Q10 value during the non-growing season was significantly greater than that during the growing season. As N fertilization rates increased, the Q10 values did not change significantly in the growing season but significantly decreased in the non-growing season. Overall, N fertilization markedly influenced soil respirations and Q10 values, in particular posing distinct effects on the Q10 values between the growing and non-growing seasons. PMID:27992576

Does being overweight affect seminal variables in fertile men?

PubMed

Taha, Emad A; Sayed, Sohair K; Gaber, Hisham D; Abdel Hafez, Hatem K; Ghandour, Nagwa; Zahran, Asmaa; Mostafa, Taymour

2016-12-01

The effect of being overweight on seminal variables was assesed in 165 fertile men. Participants were divided into three groups: fertile men with normal body mass index (BMI) (18.5-24.9 kg/m 2 ), fertile overweight men (BMI 25-29.9 kg/m 2 ) and fertile obese men (BMI >30 kg/m 2 ). Medical history was taken, a clinical examination conducted. Semen analysis was undertaken and BMI measured. Seminal reactive oxygen species (ROS) was estimated by chemiluminescent assay, sperm vitality by the hypo-osmotic swelling test and sperm DNA fragmentation by propidium iodide staining with flowcytometry. Fertile obese men had significantly lower sperm concentration, progressive sperm motility and sperm normal morphology, with significantly higher seminal ROS and sperm DNA fragmentation compared with fertile normal-weight men and overweight men (all P < 0.05). BMI was negatively correlated with sperm concentration (r = -0.091; P = 0.014), progressive sperm motility (r = -0.697; P = 0.001), normal sperm morphology (r = -0.510; P = 0.001), sperm vitality (r = -0.586; P = 0.001), but positively correlated with sperm DNA fragmentation percentage (r = 0.799; P = 0.001) and seminal ROS (r = 0.673; P = 0.001). Increased BMI was found to affect semen parameters negatively even in fertile men. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Sperm count as a surrogate endpoint for male fertility control.

PubMed

Benda, Norbert; Gerlinger, Christoph

2007-11-30

When assessing the effectiveness of a hormonal method of fertility control in men, the classical approach used for the assessment of hormonal contraceptives in women, by estimating the pregnancy rate or using a life-table analysis for the time to pregnancy, is difficult to apply in a clinical development program. The main reasons are the dissociation of the treated unit, i.e. the man, and the observed unit, i.e. his female partner, the high variability in the frequency of male intercourse, the logistical cost and ethical concerns related to the monitoring of the trial. A reasonable surrogate endpoint of the definite endpoint time to pregnancy is sperm count. In addition to the avoidance of the mentioned problems, trials that compare different treatments are possible with reasonable sample sizes, and study duration can be shorter. However, current products do not suppress sperm production to 100 per cent in all men and the sperm count is only observed with measurement error. Complete azoospermia might not be necessary in order to achieve an acceptable failure rate compared with other forms of male fertility control. Therefore, the use of sperm count as a surrogate endpoint must rely on the results of a previous trial in which both the definitive- and surrogate-endpoint results were assessed. The paper discusses different estimation functions of the mean pregnancy rate (corresponding to the cumulative hazard) that are based on the results of sperm count trial and a previous trial in which both sperm count and time to pregnancy were assessed, as well as the underlying assumptions. Sample size estimations are given for pregnancy rate estimation with a given precision.

Advances in development reverse fertility declines.

PubMed

Myrskylä, Mikko; Kohler, Hans-Peter; Billari, Francesco C

2009-08-06

During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman). In many highly developed countries, the trend towards low fertility has also been deemed irreversible. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge. Here we show, using new cross-sectional and longitudinal analyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development-fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.

Fertilization and Colors of Plastic Mulch Affect Biomass and Essential Oil of Sweet-Scented Geranium

PubMed Central

Silva, Anderson de Carvalho; dos Santos, Wallace Melo; Prata, Paloma Santana; Alves, Péricles Barreto

2014-01-01

Sweet-scented geranium (Pelargonium graveolens L'Hér), a plant belonging to the Geraniaceae family, has medicinal and aromatic properties and is widely used in the cosmetic, soap, perfume, aromatherapy, and food industries. The aim of this study was to evaluate the influence of fertilization and the use of different colors of plastic mulch on sweet-scented geranium biomass and essential oil. Three colors of plastic mulch (black, white, and silver-colored) and a control without plastic mulch were assessed along with three fertilizers (20,000 L·ha−1 of cattle manure; 1,000 kg·ha−1 of NPK 3-12-6; and 20,000 L·ha−1 of cattle manure + 1,000 kg·ha−1 of NPK 3-12-6 fertilizer) and a control without fertilizer. The absence of a soil cover negatively influenced the agronomical variables, while coverage with plastic mulch was associated with increased biomass. The use of fertilizer had no effect on the evaluated agronomic variables. When cattle manure and NPK 3-12-6 were used together, combined with white or black plastic mulch, the highest yields of essential oil were obtained. For the silver-colored plastic mulch, higher amounts of essential oil (6,9-guaiadien) were obtained with mineral fertilizer. PMID:24757440

Assessing variable rate nitrogen fertilizer strategies within an extensively instrument field site using the MicroBasin model

NASA Astrophysics Data System (ADS)

Ward, N. K.; Maureira, F.; Yourek, M. A.; Brooks, E. S.; Stockle, C. O.

2014-12-01

The current use of synthetic nitrogen fertilizers in agriculture has many negative environmental and economic costs, necessitating improved nitrogen management. In the highly heterogeneous landscape of the Palouse region in eastern Washington and northern Idaho, crop nitrogen needs vary widely within a field. Site-specific nitrogen management is a promising strategy to reduce excess nitrogen lost to the environment while maintaining current yields by matching crop needs with inputs. This study used in-situ hydrologic, nutrient, and crop yield data from a heavily instrumented field site in the high precipitation zone of the wheat-producing Palouse region to assess the performance of the MicroBasin model. MicroBasin is a high-resolution watershed-scale ecohydrologic model with nutrient cycling and cropping algorithms based on the CropSyst model. Detailed soil mapping conducted at the site was used to parameterize the model and the model outputs were evaluated with observed measurements. The calibrated MicroBasin model was then used to evaluate the impact of various nitrogen management strategies on crop yield and nitrate losses. The strategies include uniform application as well as delineating the field into multiple zones of varying nitrogen fertilizer rates to optimize nitrogen use efficiency. We present how coupled modeling and in-situ data sets can inform agricultural management and policy to encourage improved nitrogen management.

Temporal Trends in Fertility Rates: A Nationwide Registry Based Study from 1901 to 2014.

PubMed

Blomberg Jensen, Martin; Priskorn, Lærke; Jensen, Tina Kold; Juul, Anders; Skakkebaek, Niels Erik

2015-01-01

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. A descriptive nationwide Danish study using birth registries from 1901-2014. Information on women's age at childbirth was obtained by using records from primary, secondary and tertiary institutions. Mothers to 8,024,969 live births. Mothers were stratified according to age at childbirth to determine total and age specific fertility rates. 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 the corresponding five year younger age groups (25-29, 30-34 and 35-39, respectively) have had for the last 65 years. On average, women gave birth to two children after the age of 30 and one or more child after 35 years of age in the beginning of the 1900s. Furthermore, women more than 40 years of age accounted for 10% of TFR in 1901 compared with 4% in 2014 despite usage of assisted reproduction. 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 determinants of fertility in women above 30 years of age.

Abandoned Ideology: How the Iranian Revolution Failed Islamic Economics and Embraced Populism

DTIC Science & Technology

2010-09-01

adolescent fertility rates between 2000 and 2008 (Appendix E). Further, the government apparently achieved these reductions through education and...access to contraception rather than coercive means found elsewhere. This signals the 161 Amuzegar...at birth, total (years) 69 70 71 .. Fertility rate, total (births per woman) 2.3 2.1 2.0 .. Adolescent fertility rate (births per 1,000 women ages

Container longleaf pine seedling morphology in response to varying rates of nitrogen fertilization in the nursery and subsequent growth after outplanting

Treesearch

D. Paul Jackson; R. Kasten Dumroese; James P. Barnett; William B. Patterson

2007-01-01

A fertilization rate of 2 or 3 mg nitrogen (N) per week for 20 weeks yielded longleaf pine (Pinus palustris) seedlings grown inside a greenhouse that survived well and produced good root collar diameter (RCD) growth the first year after outplanting. Of a range of fertilization rates (0.5 to 4 mg N/week), the 2 mg rate yielded seedlings that did not...

Fertility of American women: June 1987.

PubMed

Bachu, A

1988-05-01

In 1957, at the peak of the Baby Boom, 4.3 million children were born, and the fertility rate reached 123 births/1000 women aged 15-44 years old. In 1987, 30 years later, there were 3.7 million births, resulting in a fertility rate of 71/1000 women 18-44 years old. Statistics on the childbearing and birth expectations of American women contained in this report are based on data collected in the June 1987 supplement to the Current Population Survey. Among women who had a child in the year preceding the June 1987 survey, 51% were in the labor force in June 1987 as compared with 31% in June 1976. Labor force participation rates for women with newborns were higher for women with 4 or more years of college (63%) than for women who completed less than 12 years of school (38%). The fertility rate for women 30-34 years old in 1987 was 74.1/1000 women, compared with the 1980 rate of 60/1000. 24% of women in their early 30s were childless, somewhat less than 26% in 1985, yet still higher than the 1980 rate of 20%. Hispanic women in 1987 had an estimated fertility rate of 95.8, significantly higher than the fertility rate for non-Hispanic women (68.8). Women 18-34 years old in 1987 expected to have an average of 2.1 children in their lifetime.

Female labor force behavior and fertility in the United States.

PubMed

Lehrer, E; Nerlove, M

1986-01-01

This article critically reviews the literature on fertility and female labor force behavior in the US, with particular emphasis on recent quantitative research by economists, demographers, and sociologists. It examines the empirical evidence regarding the influence on fertility and female employment of certain key variables, i.e., the value of female time, husband's income, and relative economic status; addresses the issue of whether there is direct causality between fertility and female labor supply; reviews simultaneous equations models and a new approach to the study of causality; discusses decisionmaking models; considers factors that may mediate the fertility-labor nexus, including child care arrangements, husband's income, wife's education, and the convenience of employment; and concludes with consideration of changes over time in the association between fertility and female employment. Economic theory suggests that an increase in the opportunity cost of children should be associated with a decrease in family size. For the US, the fact that the mother's education and other measures of the value of female time have a negative impact on fertility has been interpreted in this was and confirmed with many bodies of data. Most studies find also that indicators of the value of female time affect employment positively. Coefficients associated with measures of husband's income on female employment. In sum, the evidence suggests that at least part of the negative relationship between fertility and female employment may be traced to the fact that that these variables are influenced in opposite directions by changes in the value of female time and relative economic status. Whether changes in husband's income contribute to the negative association is less clear at this time. In 1950, the labor force participation rate for married women with children under 6 years of age was 11.9%; it was 28.3% for those with children 6-17 years of age. By 1960, the figures had risen respectively to 18.6% and 39.0% and by 1983 to 49.9% and 63.8%. The traditional pattern of post-school work, interruption of employment; and possibly a subsequent return to the labor force has been eroding, with women remaining more closely attached to the labor force during the childrearing years. If, as is likely, this trend continues, one may expect a move toward convergence in the male and female occupational distributions and a narrowing in the wage differential between the sexes. The implications that women's increased commitment to market activities may have in terms of income distribution among families and the quantity and quality of time spent on child care are less clear at the present time and require close attention. As Ryder (1980) documents, changes in the timing of births have come to be the primary driving force behind movements of period fertility in the US.

Artificial oocyte activation in intracytoplasmic sperm injection cycles using testicular sperm in human in vitro fertilization.

PubMed

Kang, Hee Jung; Lee, Sun-Hee; Park, Yong-Seog; Lim, Chun Kyu; Ko, Duck Sung; Yang, Kwang Moon; Park, Dong-Wook

2015-06-01

Artificial oocyte activation (AOA) is an effective method to avoid total fertilization failure in human in vitro fertilization-embryo transfer (IVF-ET) cycles. AOA performed using a calcium ionophore can induce calcium oscillation in oocytes and initiate the fertilization process. We evaluated the usefulness of AOA with a calcium ionophore in cases of total fertilization failure in previous cycles and in cases of severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. The present study describes 29 intracytoplasmic sperm injection (ICSI)-AOA cycles involving male factor infertility at Cheil General Hospital from January 2006 to June 2013. Patients were divided into two groups (control, n=480; AOA, n=29) depending on whether or not AOA using a calcium ionophore (A23187) was performed after testicular sperm extraction-ICSI (TESE-ICSI). The AOA group was further split into subgroups according to sperm motility after PF treatment: i.e., motile sperm-injected (n=12) and non-motile sperm-injected (n=17) groups (total n=29 cycles). The good embryo rate (52.3% vs. 66.9%), pregnancy rate (20.7% vs. 52.1%), and delivery rate (10.3% vs. 40.8%) were lower in the PF/AOA group than in the control group. When evaluating the effects of restoration of sperm motility after PF treatment on clinical outcomes there was no difference in fertilization rate (66.6% vs. 64.7% in non-motile and motile sperm, respectively), pregnancy rate (17.6% vs. 33.3%), or delivery rate (5.9% vs. 16.7%) between the two groups. We suggest that oocyte activation is a useful method to ensure fertilization in TESE-ICSI cycles regardless of restoration of sperm motility after PF treatment. AOA may be useful in selected patients who have a low fertilization rate or total fertilization failure.

Artificial oocyte activation in intracytoplasmic sperm injection cycles using testicular sperm in human in vitro fertilization

PubMed Central

Kang, Hee Jung; Lee, Sun-Hee; Park, Yong-Seog; Lim, Chun Kyu; Ko, Duck Sung; Yang, Kwang Moon

2015-01-01

Objective Artificial oocyte activation (AOA) is an effective method to avoid total fertilization failure in human in vitro fertilization-embryo transfer (IVF-ET) cycles. AOA performed using a calcium ionophore can induce calcium oscillation in oocytes and initiate the fertilization process. We evaluated the usefulness of AOA with a calcium ionophore in cases of total fertilization failure in previous cycles and in cases of severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. Methods The present study describes 29 intracytoplasmic sperm injection (ICSI)-AOA cycles involving male factor infertility at Cheil General Hospital from January 2006 to June 2013. Patients were divided into two groups (control, n=480; AOA, n=29) depending on whether or not AOA using a calcium ionophore (A23187) was performed after testicular sperm extraction-ICSI (TESE-ICSI). The AOA group was further split into subgroups according to sperm motility after PF treatment: i.e., motile sperm-injected (n=12) and non-motile sperm-injected (n=17) groups (total n=29 cycles). Results The good embryo rate (52.3% vs. 66.9%), pregnancy rate (20.7% vs. 52.1%), and delivery rate (10.3% vs. 40.8%) were lower in the PF/AOA group than in the control group. When evaluating the effects of restoration of sperm motility after PF treatment on clinical outcomes there was no difference in fertilization rate (66.6% vs. 64.7% in non-motile and motile sperm, respectively), pregnancy rate (17.6% vs. 33.3%), or delivery rate (5.9% vs. 16.7%) between the two groups. Conclusion We suggest that oocyte activation is a useful method to ensure fertilization in TESE-ICSI cycles regardless of restoration of sperm motility after PF treatment. AOA may be useful in selected patients who have a low fertilization rate or total fertilization failure. PMID:26161332

Rising up: Fertility trends in Egypt before and after the revolution

PubMed Central

el-Shitany, Atef; Sholkamy, Hania; Benova, Lenka

2018-01-01

In 2014, Egypt’s Demographic and Health Survey (EDHS) documented an increase in the total fertility rate (TFR) to 3.5, up from a low of 3.0 recorded by the 2008 EDHS. The increase has been anecdotally attributed to the social upheaval following Egypt’s January 2011 revolution, but little is known about when fertility first began to increase and among which sub-groups of women. Using birth histories from seven rounds of EDHS (1992–2014), this study reconstructed fertility rates for single years from 1990–2013 and examined patterns of childbearing in five-year birth cohorts of women. We found that the decline in fertility reversed in 2007, earlier than postulated, plateaued and then increased again in 2013. The increase in TFR coincided with a convergence of fertility rates across education levels, and there is evidence of a shift toward childbearing at younger ages among more educated women, which may be inflating period measures of fertility. PMID:29346389

County-level estimates of nitrogen and phosphorus fertilizer use in the United States, 1945 to 1985

USGS Publications Warehouse

Alexander, Richard B.; Smith, Richard A.

1990-01-01

Estimates of nitrogen and phosphorus fertilizer use were made for counties in the United States for the period 1945 to 1985. County fertilizer use estimates were obtained through the disaggregation of state-level fertilizer use in proportion to the amount of state fertilized acreage reported to exist in counties. Numerical values of nitrogen and phosphorus fertilizer use by county are not presented in the text of this report because of the size of the data file, but are available in machine-readable form upon request. Graphical summaries of national, state, and county nitrogen and phosphorus fertilizer use are presented to briefly describe the spatial and temporal variability that exist in the data.

Using soil enzymes to explain observed differences in the response of soil decomposition to nitrogen fertilization

NASA Astrophysics Data System (ADS)

Stone, M.; Weiss, M.; Goodale, C. L.

2010-12-01

Soil microbes produce extracellular enzymes that degrade a variety of carbon-rich polymers contained within soil organic matter (SOM). These enzymes are key regulators of the terrestrial carbon cycle. However, basic information about the kinetics of extracellular enzymes and key environmental variables that regulate their catalytic ability is lacking. This study aims to clarify the mechanisms by which microbial carbon-degrading enzymes drive different responses to nitrogen (N) fertilization in soil decomposition at two sites with long-term N fertilization experiments, the Bear Brook (BB) forest in Maine and Fernow Forest (FF) in West Virginia. We examined a suite of cellulolytic and lignolytic enzymes that break down common SOM constituents. We hypothesized that enzymes derived from the site with a higher mean annual temperature (FF) would be more heat-tolerant, and retain their catalytic efficiency (Km) as temperature rises, relative to enzymes from the colder environment (BB). We further hypothesized that cellulolytic enzyme activity would be unaffected by N, while oxidative enzyme activity would be suppressed in N-fertilized soils. To test these hypotheses and examine the interactive effects of temperature and N, we measured enzyme activity in unfertilized and N-fertilized soils under a range of laboratory temperature manipulations. Preliminary results show a significant decrease in cellulolytic enzyme efficiency with temperature at the colder site (BB), as well as a significant increase in efficiency due to N-fertilization for two cellulolytic enzymes. Oxidative enzyme activity shows a marginally significant reduction due to N-fertilization at BB. These results suggest that soil warming may produce a negative feedback on carbon turnover in certain climates, while N-fertilization may alter the relative decomposition rates of different soil organic matter constituents. FF activity will be analyzed in a similar manner and the two sites will be compared in order to fully assess our hypotheses.

Agricultural growth, the status of women, and fertility.

PubMed

Whittington, L A; Stapleton, D C

1995-08-01

This study tests the hypothesis that fertility is affected differently by economic growth depending upon the specific sector (agriculture, manufacturing, heavy industry, and services) where growth occurred. The hypothesis is that fertility responses are not identical across sectors. The sample includes 51 World Bank member countries in varying stages of development. The econometric model pertains to 1965-88 and the percentage change in the total fertility rate (TFR). During the study period the average TFR declined by over 22%, but the extent of change varied by country and included, for instance, countries such as Ethiopia that experienced fertility increases from 5.8 to 6.5. Hong Kong's TFR declined by 66% from 4.7 to 1.6. Analysis included measures of changes in gross domestic product (GDP) for each of the four sectors and change in real per capita exports in agricultural commodities, resources, and manufactured products. Changes in educational status and changes in infant mortality were also included in some models. There were mixed results for the impact of total GDP. Sectoral analysis shows a positive, small significant impact on TFR from changes in the GDP per capita in agriculture (domestic and export products), and a negative, small significant impact from manufacturing growth. Heavy industry and services produced insignificant impact. In the model with only domestic consumption, results show a stronger coefficient and continued significance for agricultural productivity, agricultural exports, and manufacturing changes per capita. Manufacturing exports produced a negative, insignificant impact. The null hypothesis is rejected only in models comparing aggregate GDP in agriculture and manufacturing industries plus control variables (excluding heavy industry and services). Only secondary education was a negative, significant determinant of fertility. Infant mortality was insignificant when sectoral growth and education were included in the model. The evidence supports the thesis that growth depending on the sector leads to fertility decline, and economic growth has a negative effect on fertility if employment opportunities for women are improved.

[Effects of fertilization method and nitrogen application rate on soil nitrogen vertical migration in a Populus xeuramericana cv. 'Guariento' plantation].

PubMed

Dai, Teng-fei; Xi, Ben-ye; Yan, Xiao-li; Jia, Li-ming

2015-06-01

A field experiment was conducted to investigate the effects of fertilization methods, i.e., drip (DF) and furrow fertilization (GF), and nitrogen (N) application rates (25, 50, 75 g N · plant(-1) · time(-1)) on the dynamics of soil N vertical migration in a Populus x euramericana cv. 'Guariento' plantation. The results showed that soil NH4(+)-N and NO3(-)-N contents decreased with the increasing soil depth under different fertilization methods and N application rates. In the DF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-40 cm soil layer, and their contents ascended firstly and then descended, reaching their maximum values at the 5th day (211.1 mg · kg(-1)) and 10th day (128.8 mg · kg(-1)) after fertilization, respectively. In the GF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-20 cm layer, and the content of soil NO3(-)-N rose gradually and reached its maximum at the 20th day (175.7 mg · kg(-1)) after fertilization, while the NH4(+)-N content did not change significantly after fertilization. Overall, N fertilizer had an effect within 20 days in the DF treatment, and more than 20 days in the GF treatment. In the DF treatment, the content and migration depth of soil NH4(+)-N and NO3(-)-N increased with the N application rate. In the GF treatment, the NO3(-)-N content increased with the N application rate, but the NH4(+)-N content was not influenced. Under the DF treatment, the hydrolysis rate, nitrification rate and migration depth of urea were higher or larger than that under the GF treatment, and more N accumulated in deep soil as the N application rate increased. Considering the distribution characteristics of fine roots and soil N, DF would be a better fertilization method in P. xeuramericana cv. 'Guariento' plantation, since it could supply N to larger distribution area of fine roots. When the N application rate was 50 g · tree(-1) each time, nitrogen mainly distributed in the zone of fine roots and had no risk of deep leaching, consequently improving the fertilizer utilization efficiency.

The effect of immature oocytes quantity on the rates of oocytes maturity and morphology, fertilization, and embryo development in ICSI cycles.

PubMed

Halvaei, Iman; Ali Khalili, Mohammad; Razi, Mohammad Hossein; Nottola, Stefania A

2012-08-01

The goal was to evaluate the role of the number of retrieved immature oocytes on mature oocyte counts and morphology, and also the rates of fertilization and embryo development in ICSI cycles. 101 ICSI cycles were included in this prospective evaluation. Patients were divided into 2 groups of A (≤ 2 immature oocytes) and B (> 2 immature oocytes). In sub-analysis, the impacts of the number of GV and MI oocytes were assessed on the rates of fertilization and embryo development. Also, correlations between the numbers of immature and mature oocytes, as well as maternal age between two groups were analyzed. Assessments of oocyte morphology, fertilization, embryo quality and development were done accordingly. There was no correlation between the immature oocytes quantity with the number of mature ones. There were insignificant differences for embryo development between two groups, but fertilization rate was higher in group A (P = 0.03). In sub-analysis, insignificant differences were observed between two groups of ≤ and >2 GV and MI oocytes for rates of fertilization and embryo development. Also, the rates of clinical pregnancy and delivery were insignificant between groups. The rate of morphologically abnormal oocytes had no significant difference between two groups, except for wide perivitelline space (PVS) which was higher in group A (P = 0.03). There was no significant difference for maternal age between two groups. In cases with few retrieved immature oocytes, rates of fertilization and incidence of wide PVS may increase, although immature oocytes may not have any negative impacts on early embryo development, or the rates on number of mature oocytes.

The influences of CO2 fertilization and land use change on the total aboveground biomass in Amazonian tropical forest

NASA Astrophysics Data System (ADS)

Castanho, A. D.; Zhang, K.; Coe, M. T.; Costa, M. H.; Moorcroft, P. R.

2012-12-01

Field observations from undisturbed old-growth Amazonian forest plots have recently reported on the temporal variation of many of the physical and chemical characteristics such as: physiological properties of leaves, above ground live biomass, above ground productivity, mortality and turnover rates. However, although this variation has been measured, it is still not well understood what mechanisms control the observed temporal variability. The observed changes in time are believed to be a result of a combination of increasing atmospheric CO2 concentration, climate variability, recovery from natural disturbance (drought, wind blow, flood), and increase of nutrient availability. The time and spatial variability of the fertilization effect of CO2 on above ground biomass will be explored in more detail in this work. A precise understanding of the CO2 effect on the vegetation is essential for an accurate prediction of the future response of the forest to climate change. To address this issue we simultaneously explore the effects of climate variability, historical CO2 and land-use change on total biomass and productivity using two different Dynamic Global Vegetation Models (DGVM). We use the Integrated Biosphere Simulator (IBIS) and the Ecosystem Demography Model 2.1 (ED2.1). Using land use changes database from 1700 - 2008 we reconstruct the total carbon balance in the Amazonian forest in space and time and present how the models predict the forest as carbon sink or source and explore why the model and field data diverge from each other. From 1970 to 2005 the Amazonian forest has been exposed to an increase of approximately 50 ppm in the atmospheric CO2 concentration. Preliminary analyses with the IBIS and ED2.1 dynamic vegetation model shows the CO2 fertilization effect could account for an increase in above ground biomass of 0.03 and 0.04 kg-C/m2/yr on average for the Amazon basin, respectively. The annual biomass change varies temporally and spatially from about 0.01 - 0.08 Kg-C/m2/yr, indicating a significant combined effect of the physical environment and climatological variability. The change in biomass due to CO2 fertilization in this study is comparable to the lower limit of the change that has been observed in the field (0.04 - 0.085 kg-C/m2/yr), which suggests that other factors must also be considered to explain the total amount of biomass change observed in the field.

Amino acid uptake by temperate tree species characteristic of low- and high-fertility habitats.

PubMed

Scott, Emily E; Rothstein, David E

2011-10-01

The relationship between inorganic nitrogen (N) cycling and plant productivity is well established. However, recent research has demonstrated the ability of plants to take up low molecular weight organic N compounds (i.e., amino acids) at rates that often rival those of inorganic N forms. In this study, we hypothesize that temperate forest tree species characteristic of low-fertility habitats will prefer amino acids over species characteristic of high-fertility habitats. We measured the uptake of (15)N-labeled amino acids (glycine, glutamine, arginine, serine), ammonium (NH(4)(+)), and nitrate (NO(3)(-)) by four tree species that commonly occur in eastern North America, where their abundances have been correlated with inorganic N availability. Specific uptake rates of amino acids were largely similar for all tree species; however, high-fertility species took up NH(4)(+) at rates more than double those of low-fertility species, rendering amino acid N relatively more important to the N nutrition of low-fertility species. Low-fertility species acquired over four times more total N from arginine compared to NH(4)(+) and NO(3)(-); high-fertility species acquired the most N from NH(4)(+). Arginine had the highest uptake rates of any amino acid by all species; there were no significant differences in uptake rates of the remaining amino acids. Our results support the idea that the dominant species in a particular habitat are those best able to utilize the most available N resources.

IQ and Fertility: A Cross-National Study

ERIC Educational Resources Information Center

Shatz, Steven M.

2008-01-01

Many studies have found a small to moderate negative correlation between IQ and fertility rates. However, these studies have been limited to the United States and some European countries. The present study was a between-nation study using national IQ scores and national fertility rates. There were strong negative correlations found between…

Reproductive decisions in the lives of West Bank Palestinian women: Dimensions and contradictions.

PubMed

Pell, Stephanie

2017-02-01

Palestinian women have one of the highest fertility rates in the world, averaging 4.38 births per woman. However, Palestinian fertility patterns are distinct from those of other developing nations, in that high fertility rates coexist alongside high levels of education and low levels of infant mortality - both of which have been established elsewhere as predictors of low total fertility rates. This study explores the dimensions and context of the contradictions between fertility predictors and rates, isolating main factors that shape Palestinian reproductive behaviour. Furthermore, while this study addresses factors that influence the high fertility in the Palestinian Territories, it also addresses factors that contribute to the steady decline of this trend. In-depth interviews were conducted with Palestinian women in urban refugee communities and key informant interviews with experts on Palestinian reproductive health. The findings indicate that five factors shape women's reproductive behaviour: (1) the fear of losing one's children in the ongoing conflict; (2) socio-economic factors including poverty and density of space; (3) the marital relationship; (4) religious values; and (5) generational differences. These results highlight the influence of socio-political conditions on reproductive behaviour and the significance of women's agency in manoeuvring their fertility outcomes.

South Asian women with polycystic ovary syndrome exhibit greater sensitivity to gonadotropin stimulation with reduced fertilization and ongoing pregnancy rates than their Caucasian counterparts.

PubMed

Palep-Singh, M; Picton, H M; Vrotsou, K; Maruthini, D; Balen, A H

2007-10-01

Polycystic ovary syndrome (PCOS) is a heterogeneous syndrome. In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is required for PCOS cases that are refractory to standard ovulation induction or have co-existing infertility factors in women with PCOS and Tubal factor subfertility. Assess ethnic variations in response to IVF/ICSI treatment. Observational Comparative study in a University hospital fertility clinic in women with PCOS and Tubal factor subfertility. Women with PCOS (Asians: AP=104; Caucasians: CP=220) and those with tubal factor infertility seeking fertility treatment were assessed (Asians: AC=84; Caucasians: CC=200). Six hundred and eight fresh IVF or ICSI cycles using long protocol of GnRHa suppression and resulting in a fresh embryo transfer were compared. The primary endpoint was to assess the dose of gonadotropins used in the cycles. The secondary outcomes were: total number of oocytes retrieved, fertilization and ongoing clinical pregnancy rates. We found that the South Asian women presented at a younger age for the management of sub-fertility. An extended stimulation phase and Caucasian ethnicity showed an inverse correlation with the number of oocytes retrieved in the PCOS subgroup. Caucasian ethnicity was associated with a higher fertilization rate however increase in body mass index (BMI) and the laboratory technique of IVF appeared to have a negative impact on fertilization rates in the PCOS subgroup. Commencing down regulation on day 1 of the cycles was negatively associated with fertilization rates in the tubal group. In terms of clinical pregnancy rates, the Caucasian PCOS had a 2.5 times (95% CI: 1.25-5) higher chance of an ongoing clinical pregnancy as compared with their Asian counterpart. Also, a unit increase in the basal FSH concentration reduced the odds of pregnancy by 18.6% (95% CI: 1.8-32.6%) in the PCOS group. The Asian PCOS have a greater sensitivity to gonadotropin stimulation with lower fertilization and ongoing clinical pregnancy rates as compared with their Caucasian counterparts.

Spectral-agronomic relationships of corn, soybean and wheat canopies

NASA Technical Reports Server (NTRS)

Bauer, M. E. (Principal Investigator); Daughtry, C. S. T.; Vanderbilt, V. C.

1981-01-01

During the past six years several thousand reflectance spectra of corn, soybean, and wheat canopies were acquired and analyzed. The relationships of biophysical variables, including leaf area index, percent soil cover, chlorophyll and water content, to the visible and infrared reflectance of canopies are described. The effects on reflectance of cultural, environmental, and stress factors such as planting data, seeding rate, row spacing, cultivar, soil type and nitrogen fertilization are also examined. The conclusions are that several key agronomic variables including leaf area index, development stage and degree of stress are strongly related to spectral reflectance and that it should be possible to estimate these descriptions of crop condition from satellite acquired multispectral data.

Transpiration efficiency of a tropical pioneer tree (Ficus insipida) in relation to soil fertility.

PubMed

Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Turner, Benjamin L; Marshall, John D

2007-01-01

The response of whole-plant water-use efficiency, termed transpiration efficiency (TE), to variation in soil fertility was assessed in a tropical pioneer tree, Ficus insipida Willd. Measurements of stable isotope ratios (delta(13)C, delta(18)O, delta(15)N), elemental concentrations (C, N, P), plant growth, instantaneous leaf gas exchange, and whole-plant water use were used to analyse the mechanisms controlling TE. Plants were grown individually in 19 l pots with non-limiting soil moisture. Soil fertility was altered by mixing soil with varying proportions of rice husks, and applying a slow release fertilizer. A large variation was observed in leaf photosynthetic rate, mean relative growth rate (RGR), and TE in response to experimental treatments; these traits were well correlated with variation in leaf N concentration. Variation in TE showed a strong dependence on the ratio of intercellular to ambient CO(2) mole fractions (c(i)/c(a)); both for instantaneous measurements of c(i)/c(a) (R(2)=0.69, P <0.0001, n=30), and integrated estimates based on C isotope discrimination (R(2)=0.88, P <0.0001, n=30). On the other hand, variations in the leaf-to-air humidity gradient, unproductive water loss, and respiratory C use probably played only minor roles in modulating TE in the face of variable soil fertility. The pronounced variation in TE resulted from a combination of the strong response of c(i)/c(a) to leaf N, and inherently high values of c(i)/c(a) for this tropical tree species; these two factors conspired to cause a 4-fold variation among treatments in (1-c(i)/c(a)), the term that actually modifies TE. Results suggest that variation in plant N status could have important implications for the coupling between C and water exchange in tropical forest trees.

Trypan blue/giemsa staining to assess sperm membrane integrity in salernitano stallions and its relationship to pregnancy rates.

PubMed

Serafini, R; Longobardi, V; Spadetta, M; Neri, D; Ariota, B; Gasparrini, B; Di Palo, R

2014-02-01

Aim of this study was to test the reliability of Trypan blue/Giemsa staining to evaluate sperm membrane integrity, acrosomal intactness and morphology in stallion to verify whether it could be applied in vitro as useful tool for sperm fertilizing ability. Fertility data on inseminated mares were collected to evaluate the relationship of sperm quality to pregnancy rates. Forty-one ejaculates were collected from 3 stallions of Salernitano Horse Breed and evaluated for gross appearance, volume, visual motility and membrane integrity with Trypan blue/Giemsa staining and thirty-five mares were inseminated during the breeding season from April to July. Differences among stallions were found in volume, sperm concentration (p < 0.05) and visual motility (p < 0.01). A decrease in sperm motility, concentration (p < 0.05) and total sperm number was found in June-July (p < 0.01). Live sperm with intact acrosome (LSIA) and proximal droplets (PD) were lower (p < 0.01) in June-July, while acrosome reacted sperm (ARS) percentage increased (p < 0.05). No fertility differences were found among stallions with an average fertility per cycle of 44.6% and a pregnancy rate of 68.6%. Higher percentages of LSIA were found in the ejaculates used to inseminate mares that became pregnant vs those used in mares not pregnant (p < 0.05). The significance of LSIA as test variable to verify the reliability of Trypan blue/Giemsa staining was confirmed by Receiver operating characteristic ROC analysis and the sensitivity of the test was 85% at a cut-off value of 48% LSIA. Trypan blue-Giemsa showed to be an accurate method that can be applied on field to evaluate sperm membrane integrity and to identify poor-quality ejaculates. © 2013 Blackwell Verlag GmbH.

Failure of fertility therapy and subsequent adverse cardiovascular events

PubMed Central

Udell, Jacob A.; Lu, Hong; Redelmeier, Donald A.

2017-01-01

BACKGROUND: Infertility may indicate an underlying predisposition toward premature cardiovascular disease, yet little is known about potential long-term cardiovascular events following fertility therapy. We investigated whether failure of fertility therapy is associated with subsequent adverse cardiovascular events. METHODS: We performed a population-based cohort analysis of women who received gonadotropin-based fertility therapy between Apr. 1, 1993, and Mar. 31, 2011, distinguishing those who subsequently gave birth and those who did not. Using multivariable Poisson regression models, we estimated the relative rate ratio of adverse cardiovascular events associated with fertility therapy failure, accounting for age, year, baseline risk factors, health care history and number of fertility cycles. The primary outcome was subsequent treatment for nonfatal coronary ischemia, stroke, transient ischemic attack, heart failure or thromboembolism. RESULTS: Of 28 442 women who received fertility therapy, 9349 (32.9%) subsequently gave birth and 19 093 (67.1%) did not. The median number of fertility treatments was 3 (interquartile range 1–5). We identified 2686 cardiovascular events over a median 8.4 years of follow-up. The annual rate of cardiovascular events was 19% higher among women who did not give birth after fertility therapy than among those who did (1.08 v. 0.91 per 100 patient-years, p < 0.001), equivalent to a 21% relative increase in the annual rate (95% confidence interval 13%–30%). We observed no association between event rates and number of treatment cycles. INTERPRETATION: Fertility therapy failure was associated with an increased risk of long-term adverse cardiovascular events. These women merit surveillance for subsequent cardiovascular events. PMID:28385819

REGULATION OF GEOGRAPHIC VARIABILITY IN HAPLOID:DIPLOD RATIOS OF BIPHASIC SEAWEED LIFE CYCLES(1).

PubMed

da Silva Vieira, Vasco Manuel Nobre de Carvalho; Santos, Rui Orlando Pimenta

2012-08-01

The relative abundance of haploid and diploid individuals (H:D) in isomorphic marine algal biphasic cycles varies spatially, but only if vital rates of haploid and diploid phases vary differently with environmental conditions (i.e. conditional differentiation between phases). Vital rates of isomorphic phases in particular environments may be determined by subtle morphological or physiological differences. Herein, we test numerically how geographic variability in H:D is regulated by conditional differentiation between isomorphic life phases and the type of life strategy of populations (i.e. life cycles dominated by reproduction, survival or growth). Simulation conditions were selected using available data on H:D spatial variability in seaweeds. Conditional differentiation between ploidy phases had a small effect on the H:D variability for species with life strategies that invest either in fertility or in growth. Conversely, species with life strategies that invest mainly in survival, exhibited high variability in H:D through a conditional differentiation in stasis (the probability of staying in the same size class), breakage (the probability of changing to a smaller size class) or growth (the probability of changing to a bigger size class). These results were consistent with observed geographic variability in H:D of natural marine algae populations. © 2012 Phycological Society of America.

In vitro fertilization with cryopreserved spermatozoa in small pieces of gonad of the scallop Argopecten purpuratus (Lamarck, 1819).

PubMed

Dupré, Enrique; Covarrubias, Alejandra; Goldstein, Merari; Guerrero, Alicia; Rojas, Herman

2016-10-01

The aim of this work was to evaluate the fertilization rates through the first cleavage, obtained with fresh oocytes inseminated with sperm cryopreserved at different freezing rates (-8.8,-10 and -12 °C/min) and at two thawing rates, using cryoprotectant solution (Me2SO, at 1 M, 2 M, 3 M, 4 M and 5 M with or without egg yolk and sucrose). Sperm contained in small pieces of male gonad were frozen at the three freezing rates, stored in liquid nitrogen and later the samples were thawed at two rates by immersing the samples in water at 50 °C (rapid) or 30 °C. Control fertilization rates ranged from 69.2 ± 2.8%-45.5% ± 1.6%. To determine the best concentration of the cryoprotectant (between 1 M and 5 M), in a first step, a freezing of -15 °C/min and a rapid thawing was used. Fertilization rates ranged between 9.6 ± 2.5% and 34.6± 12.2% and the highest percentages of fertilized oocytes (34.6%) was obtained with 3 M concentration with cryoaditive. The second step, using 3 M Me2SO with cryoadditive, determined that the freezing rate -8.8 °C/min produces the best result 29 ± 2.9% of fertilized oocytes corresponding to 59.2 ± 9.1% compared to controls. Although there were no significant differences among the different freezing rates, the fertilization rate tended to be higher with a lower freezing rate. Comparing the results of the present study, which used a cryoprotective solution composed of Me2SO and a cryoadditive, to those of other studies that used Me2SO without cryoadditives, suggests that the addition of a cryoadditive to the cryoprotectant Me2SO improves the fertilizing capacity of the sperm of Argopecten purpuratus after being cryopreserved. Copyright © 2016 Elsevier Inc. All rights reserved.

Predictive capacity of sperm quality parameters and sperm subpopulations on field fertility after artificial insemination in sheep.

PubMed

Santolaria, P; Vicente-Fiel, S; Palacín, I; Fantova, E; Blasco, M E; Silvestre, M A; Yániz, J L

2015-12-01

This study was designed to evaluate the relevance of several sperm quality parameters and sperm population structure on the reproductive performance after cervical artificial insemination (AI) in sheep. One hundred and thirty-nine ejaculates from 56 adult rams were collected using an artificial vagina, processed for sperm quality assessment and used to perform 1319 AI. Analyses of sperm motility by computer-assisted sperm analysis (CASA), sperm nuclear morphometry by computer-assisted sperm morphometry analysis (CASMA), membrane integrity by acridine orange-propidium iodide combination and sperm DNA fragmentation using the sperm chromatin dispersion test (SCD) were performed. Clustering procedures using the sperm kinematic and morphometric data resulted in the classification of spermatozoa into three kinematic and three morphometric sperm subpopulations. Logistic regression procedures were used, including fertility at AI as the dependent variable (measured by lambing, 0 or 1) and farm, year, month of AI, female parity, female lambing-treatment interval, ram, AI technician and sperm quality parameters (including sperm subpopulations) as independent factors. Sperm quality variables remaining in the logistic regression model were viability and VCL. Fertility increased for each one-unit increase in viability (by a factor of 1.01) and in VCL (by a factor of 1.02). Multiple linear regression analyses were also performed to analyze the factors possibly influencing ejaculate fertility (N=139). The analysis yielded a significant (P<0.05) relationship between sperm viability and ejaculate fertility. The discriminant ability of the different semen variables to predict field fertility was analyzed using receiver operating characteristic (ROC) curve analysis. Sperm viability and VCL showed significant, albeit limited, predictive capacity on field fertility (0.57 and 0.54 Area Under Curve, respectively). The distribution of spermatozoa in the different subpopulations was not related to fertility. Copyright © 2015 Elsevier B.V. All rights reserved.

Mineralization dynamics in soil fertilized with seaweed-fish waste compost.

PubMed

Illera-Vives, Marta; López-Fabal, Adolfo; López-Mosquera, M Elvira; Ribeiro, Henrique M

2015-12-01

Seaweed and fish waste can be composted together to obtain fertilizer with high organic matter and nutrient contents. The nutrients, however, are mostly in organic form and must be mineralized to make them available to plants. The objective of this work was to establish a usage guideline for the compost by studying its mineralization dynamics. Also, the release of inorganic N and C from soil fertilized with the compost was monitored and modelled. C and N were released throughout the assay, to an extent significantly dependent on fertilizer rate. Mineralization of both elements fitted a first-order exponential model, and each fertilizer rate required using a specific fitting model. An increased rate favoured mineralization (especially of carbon). After 90 days, 2.3% of C and 7.7% of N were mineralized (and 23.3% of total nitrogen made plant available) with the higher rate. C mineralization was slow because organic matter in the compost was very stable. On the other hand, the relatively high initial content in mineral N of the compost increased gradually by the effect of mineralization. The amount of N available would suffice to meet the requirements of moderately demanding crops at the lower fertilizer rate, and even those of more demanding crops at the higher rate. © 2015 Society of Chemical Industry.

Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils

PubMed Central

Yu, Hailing; Gao, Qiang; Shao, Zeqiang; Ying, Anning; Sun, Yuyang; Liu, Jingwei; Mao, Wei; Zhang, Bin

2016-01-01

In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha-1) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha-1), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand. PMID:26992097

Rising rates, changing relationships: caesarean section and its correlates in South Korea, 1988-2000.

PubMed

Lee, Sang-Il; Khang, Young-Ho; Yun, Sungcheol; Jo, Min-Woo

2005-06-01

To examine the trends in the relationship between caesarean section rates in South Korea and its correlates. Five rounds (1988, 1991, 1994, 1997 and 2000) of population-based National Fertility and Family Health Survey of South Korea. South Korea. Sample Mothers (N= 9184) aged 15-44 years. Caesarean rates were calculated according to correlates and then directly adjusted to five-year age and parity groups. Distribution of all samples (9184 mothers) was standard, producing age- and parity-adjusted caesarean rates. Linear trends of correlates with caesarean rates were examined for ordinal variables such as education, income, urbanisation level (area of residence) and level of prenatal visits. Age- and parity-adjusted caesarean section rates. As caesarean rates rose by year, the relationship of caesarean section with education, occupation and area of residence has been reversed. Associations between caesarean rates, income level, place of delivery and level of prenatal visit were found in 1988 but disappeared by 2000. In 2000, relatively low caesarean rates were found in variables that will be more prevalent in the future, such as higher maternal education, higher maternal occupation and residence in big cities. Caesarean rates may have reached a plateau in South Korea. No maternal or health service factors were detected to further increase the proportion of caesarean deliveries.

Work and family roles of Soviet women: historical trends and cross-section analysis.

PubMed

Ofer, G; Vinokur, A

1985-01-01

Changes in the way of life of USSR women over the last 2 generations are very similar to those experienced by women in most industrialized and industializing societies. The rate of participation of women in the labor force increased substantially, and this movement was accompanied by a marked rise in the level of women's general and professional education. As a result, women occupy more white collar positions than they did in older generations, but these developments have created a double burden for most women who complain that increased resonsibilities outside the home have not been synchronized with an adequate increase in men's sharing household responsibilities. Historical explanations for changes in women's role particularly emphasize the nature of relationships between participation, wages, incomes, fertility, education and labor market conditions. The long term changes of these major variables, since the 1920s, along with an investigation based on an income survey of 1000 immigrant families, are studied in this paper. Cross sectional analysis examines a longer life cycle, participation decisions, and relates them to decisions on fertility and education. Fertility rates among the Jewish immigrants are much higher and labor participation rates of women much lower than for the rest of the population. Some of the main features of the long trends since 1926 are: 1) of the overall measures of participation of women, only those in the 15-54 and 20-54 age ranges show some increase over the 1926-1980 period, 2) sharp rises in specific participation rates for 25-44 and 45-54 age groups since 1950, and for urban women overall, 3) only a small fraction of the total increase in participation can be attributed to the increase in the proportion of single women, and 4) by 1980 the overall female participation figure rose to 80%--and 88% for the 20-54 age group--the difference reflecting the sharp decline in 15-19 age group participation. While the short run decision about participation is heavily determined by the expected wage, other family income, and the presence of small children, longer term decisions about participation are influenced by the level of education and by fertility--decisions normally made early in life. Although women's schooling is rapidly catching up with men's, their relative wages have hardly increased because the extra pressure of home and work responsibilities results in high divorce rates, lower fertility, and lower investment in human capital and effort on the job.

Male fertility: psychiatric considerations.

PubMed

Hall, Elise; Burt, Vivien K

2012-02-01

To examine: 1) current knowledge on normal biologic variation of seminal parameters; 2) how stress and psychological factors affect sperm quality in fertile and infertile males; and 3) how mental illness and psychopharmacologic agents can affect male fertility. English-language Medline, Embase, and Psycinfo were searched for relevant publications (from 1970 to January 2011) for systematic review. None. None. None. Possible effects of stress, mood, and psychotropic medications on male factor fertility. Male-factor infertility is influenced by myriad factors (obesity, tobacco, etc.). Stress alone may reduce testosterone levels and spermatogenesis. Infertility assessment and treatment can lead to distress and negatively affect sperm samples. Available research has failed to control for potentially confounding variables. Although some trends have been identified, larger-scale studies that adequately control all confounding variables are needed before conclusions can be made about the relationship between stress, psychotropic agents, and male infertility. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

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

PubMed Central

Wang, Lijuan; 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. PMID:28678841

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.

PubMed

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.

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

PubMed

Schlegel, P N; Palermo, G D; Alikani, M; Adler, A; Reing, A M; Cohen, J; Rosenwaks, Z

1995-08-01

To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Location or Hukou: What Most Limits Fertility of Urban Women in China?

PubMed Central

Liang, Yun

2017-01-01

Abstract China's fertility rate is below replacement level. The government is attempting to increase this rate by relaxing the one‐child policy. China faces a possible tradeoff because further urbanization is needed to raise incomes but may reduce future fertility. We decompose China's rural–urban fertility gaps using both de facto and de jure criteria for defining the urban population. The fertility‐depressing effects of holding urban hukou are more than three times larger than effects of urban residence. Less of the rural–urban fertility gap by hukou status is due to differences in characteristics than is the case for the fertility gap by place of residence. PMID:29081975

An improved Brass correlational fertility model.

PubMed

Zhang, E; Chen, J

1995-01-01

Demographers have for years tried to establish a mathematical model capable of accurately describing patterns of fertility change. William Brass's Gompertz correlational fertility model is based upon a standard age-specific fertility pattern correlated to the age-specific fertility rate of the area under study with the purpose of simulating the actual age-specific fertility rate of the area. While the Brass correlational fertility model has solved many problems in quantitative studies of fertility and has been applied in population simulation and prediction, it has been unsatisfactory in analyzing fertility changes in China. The authors therefore developed a parity-specific correlational model to better reflect the situation of rapid fertility decline in China. This modified model better describes the impact of current family planning policy in China. Moreover, satisfactory results can be obtained by simulating and analyzing fertility in recent years, and major parameters can be identified by using demographically definite and readily manageable indicators. These indicators can clearly reflect the goals of the country's family planning policy, such as the average age at child-bearing, median age at child-bearing, early reproduction ratio, and percentage of the second child.

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

PubMed

Sutton, Paul D; Mathews, T J

2006-05-01

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

Female married illiteracy as the most important continual determinant of total fertility rate among districts of Empowered Action Group States of India: Evidence from Annual Health Survey 2011-12.

PubMed

Kumar, Rajesh; Dogra, Vishal; Rani, Khushbu; Sahu, Kanti

2017-01-01

District level determinants of total fertility rate in Empowered Action Group states of India can help in ongoing population stabilization programs in India. Present study intends to assess the role of district level determinants in predicting total fertility rate among districts of the Empowered Action Group states of India. Data from Annual Health Survey (2011-12) was analysed using STATA and R software packages. Multiple linear regression models were built and evaluated using Akaike Information Criterion. For further understanding, recursive partitioning was used to prepare a regression tree. Female married illiteracy positively associated with total fertility rate and explained more than half (53%) of variance. Under multiple linear regression model, married illiteracy, infant mortality rate, Ante natal care registration, household size, median age of live birth and sex ratio explained 70% of total variance in total fertility rate. In regression tree, female married illiteracy was the root node and splits at 42% determined TFR <= 2.7. The next left side branch was again married illiteracy with splits at 23% to determine TFR <= 2.1. We conclude that female married illiteracy is one of the most important determinants explaining total fertility rate among the districts of an Empowered Action Group states. Focus on female literacy is required to stabilize the population growth in long run.

Post-fertilization physiology and growth performance of loblolly pine clones

Treesearch

N.T. King; J.R. Seiler; T.R. Fox; KurtH Johnsen

2008-01-01

The physiological processes leading to enhanced growth of loblolly pine (Pinus taeda L.) following fertilization are not clearly understood. Part of the debate revolves around the temporal response of net photosynthetic rate (An) to fertilization and whether the An response is always positive. We measured light-saturated photosynthetic rate (Asat), dark respiration...

[Development and evaluation of fertilizers cemented and coated with organic-inorganic materials].

PubMed

Xiao, Qiang; Wang, Jia-Chen; Zuo, Qiang; Zhang, Lin; Liu, Bao-Cun; Zhao, Tong-Ke; Zou, Guo-Yuan; Xu, Qiu-Ming

2010-01-01

Four kinds of organic-inorganic cementing and coating materials were prepared by a coating method using water as the solvent, and the corresponding cemented and coated fertilizers (B2, PS, F2, and F2F) were produced by disc pelletizer. The tests on the properties of these fertilizers showed that the granulation rate, compression strength, and film-forming rate were B2 > PS > F2 > F2F. Soil column leaching experiment showed that the curve of accumulated nitrogen-dissolving rate was the gentlest for B2. In 48 days, the accumulated nitrogen-dissolving rate was in the order of B2, 54.65% < PS, 56.16% < F2, 59.47%, < F2F, 63.12%. Field experiment showed that compared with the same application amount of NPK, all the test fertilizers had better effects on corn yield, among which, B2 was the best, with the corn yield and fertilizer use efficiency increased by 19.72% and 20.30%, respectively. The yield-increasing effect of other test fertilizers was in the order of PS > F2 > F2F.

Depression of belowground respiration is more pronounced than enhancement of photosynthesis during the first year after nitrogen fertilization of a mature Pacific Northwest Douglas-fir forest

NASA Astrophysics Data System (ADS)

Chen, B.; Black, T. A.; Jassal, R.; Nesic, Z.; Bruemmer, C.

2008-05-01

Nitrogen (N) additions to forest have shown variable effects on both respiration and photosynthesis. With increasing rates of anthropogenic N deposition, there is a strong need to understand the ecosystem response to N inputs. We investigated how N fertilization affects the ecosystem carbon (C) balance of a 57-year-old coast Douglas-fir stand in British Columbia, Canada, based on eddy-covariance (EC) and soil-chamber (fertilized and control plots) measurements and process-based modeling. The stand was fertilized by helicopter with urea at 200 kg N ha-1 in January 2007. A land surface model (Ecosystem Atmosphere Simulation Scheme, EASS) was combined with an ecosystem model (Boreal Ecosystem Productivity Simulator, BEPS) and a coupled C and N subroutine was incorporated into the integrated EASS-BEPS model in this study. This half-hourly time step model was run continuously for the period from 2001 to 2007 in two scenarios: with and without fertilization. Modeled C fluxes without fertilization [net ecosystem productivity (NEP), gross primary productivity (GPP), ecosystem respiration (Re) and belowground respiration (Rs)] agreed well with EC and soil chamber measurements over diurnal, seasonal and annual time scales for 2001 to 2006; while simulated NEP, GPP, Re and Rs with fertilization reasonably followed EC and chamber measurements in 2007 (545 vs. 520, 2163 vs. 2155, 1618 vs. 1635, and 920 vs. 906 g C m-2 yr-1, respectively). Comparison of EC-determined C fluxes in 2007 with model simulations without fertilization suggests that annual Re decreased by 6.7% (1635 vs. 1752 g C m-2), gross primary productivity (GPP) increased by 6.8% (2155 vs. 2017 g C m-2), and annual NEP increased by 96.2% (520 vs. 265 g C m-2) due to fertilization. The modeled reduction in Rs (9.6%, comparing modeled values without and with fertilization: 1008 vs. 920 g C m-2 yr-1) is consistent with that measured using the soil chambers (~11.5%, comparing CO2 effluxes from control and fertilized plots measured from late summer to fall). The model also indicated that the effect of fertilization on aboveground (leaf and stem) respiration was very small. These experimental and modeling results suggest N fertilization significantly increased NEP mainly as a result of strongly reduced Rs (~10-12%) and moderately enhanced GPP (~6.8%) in the first year after fertilization.

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

NASA Astrophysics Data System (ADS)

Jalil, Wan Aznie Fatihah Wan Abd; Sharif, Shamshuritawati

2017-11-01

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

Psychological profile of women with infertility: A comparative study

PubMed Central

Poddar, Shuvabrata; Sanyal, Nilanjana; Mukherjee, Urbi

2014-01-01

Background: An endeavour to probe into the psychological profile of infertile women in a comparative stance with the fertile women is not very common. This study is an attempt to explore the possible non-apparent personality factors which contribute to the unexplained pain of infertility. Methods: The main objectives of the present study were (a) to examine whether infertile women are different from fertile women in terms of selected psychological variables- narcissistic components, dimensions of attachment style and uses of defensive manoeuvres; and (b) whether the primary infertile women (n=18) are different from the secondary infertile women (n=12) with respect to those variables. A total of 60 individuals (30 infertile women and 30 matched fertile women) were assessed through Attachment Style Questionnaire (ASQ), Narcissistic Personality Inventory (NPI) and Defense Style Questionnaire (DSQ-40). General Health Questionnaire (GHQ) was administered on to the fertile women to rule out the psychiatric morbidity. Results: Findings revealed that infertile women group differed from fertile women group with respect to narcissism, dimensions of attachment style and uses of defense mechanism. The primary infertile group also showed marked difference from the secondary infertile group with respect to those variables. Conclusions: This study endeavours to enrich the knowledge regarding the personality dynamics of infertile women to design psychotherapeutic programme to aid their well-being, help them to cherish the flavour of parenthood and improve their quality of life. PMID:25788801

Repeated evolution and reversibility of self-fertilization in the volvocine green algae.

PubMed

Hanschen, Erik R; Herron, Matthew D; Wiens, John J; Nozaki, Hisayoshi; Michod, Richard E

2018-02-01

Outcrossing and self-fertilization are fundamental strategies of sexual reproduction, each with different evolutionary costs and benefits. Self-fertilization is thought to be an evolutionary "dead-end" strategy, beneficial in the short term but costly in the long term, resulting in self-fertilizing species that occupy only the tips of phylogenetic trees. Here, we use volvocine green algae to investigate the evolution of self-fertilization. We use ancestral-state reconstructions to show that self-fertilization has repeatedly evolved from outcrossing ancestors and that multiple reversals from selfing to outcrossing have occurred. We use three phylogenetic metrics to show that self-fertilization is not restricted to the tips of the phylogenetic tree, a finding inconsistent with the view of self-fertilization as a dead-end strategy. We also find no evidence for higher extinction rates or lower speciation rates in selfing lineages. We find that self-fertilizing species have significantly larger colonies than outcrossing species, suggesting the benefits of selfing may counteract the costs of increased size. We speculate that our macroevolutionary results on self-fertilization (i.e., non-tippy distribution, no decreased diversification rates) may be explained by the haploid-dominant life cycle that occurs in volvocine algae, which may alter the costs and benefits of selfing. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Impaired fertilizing ability of superoxide dismutase 1-deficient mouse sperm during in vitro fertilization.

PubMed

Tsunoda, Satoshi; Kawano, Natsuko; Miyado, Kenji; Kimura, Naoko; Fujii, Junichi

2012-11-01

The oxidative modification of gametes by a reactive oxygen species is a major deleterious factor that decreases the successful rate of in vitro fertilization. Superoxide dismutase 1 (SOD1) plays a pivotal role in antioxidation by scavenging the superoxide anion, and its deficiency causes infertility in female mice, but the significance of the enzyme in male mice remains unclear. In the present study, we characterized Sod1(-/-) (Sod1-KO) male reproductive organs and compiled the first report of the impaired fertilizing ability of Sod1-KO sperm in in vitro fertilization. Insemination of wild-type oocytes with Sod1-KO sperm exhibited lower rates of fertility compared with insemination by wild-type sperm. The low fertilizing ability found for Sod1-KO sperm was partially rescued by reductant 2-mercaptoethanol, which suggested the oxidative modification of sperm components. The numbers of motile and progressive sperm decreased during the in vitro fertilization process, and a decline in ATP content and elevation in lipid peroxidation occurred in the Sod1-KO sperm in an incubation time-dependent manner. Tyrosine phosphorylation, which is a hallmark for sperm capacitation, was also impaired in the Sod1-KO sperm. These results collectively suggest that machinery involved in sperm capacitation and motility are vulnerable to oxidative damage during the in vitro fertilization process, which could increase the rate of inefficient fertilization.

[Nitrogen Loss Through Different Ways in Cropland Under Conventional Fertilization: An In-situ Study of Summer Maize Season in the Middle and Lower Reaches of the Yangtze River].

PubMed

Sang, Meng-meng; Fan, Hui; Jiang, Shan-shan; Jiang, Jing-yan

2015-09-01

In order to better understand the characteristics of nitrogen loss through different pathways under conventional fertilization conditions, a field experiment was conducted to investigate the variations of N2O emission, NH3 volatilization, N losses through surface runoff and leaching caused by the application of nitrogen fertilizers during summer maize growing season in the Middle and Lower reaches of the Yangtze River, China. Our results showed that when compound fertilizer was used as basal fertilizer at the nitrogen rate of 150 kg.hm-2, and urea with the same level of fertilizing as topdressing, the N2O emission coefficient in the entire growing season was 3. 3%, NH3 volatilization loss rate was 10. 2%, and nitrogen loss rate by leaching and surface runoff was 11. 2% and 5. 1%, respectively. In addition, leaching was the main pathway of nitrogen loss after basal fertilizer, while NH, volatilization and nitrogen leaching accounted for the majority of nitrogen loss after topdressing, which suggested that nitrogen loss from different pathways mainly depended on the type of nitrogen fertilizer. Taken together, it appears to be effective to apply the new N fertilizer with low ammonia volatilization instead of urea when maize needs topdressing, so as to reduce N losses from N fertilizer.

Effects of different nitrogen reduction modes on yield of spring maize and nitrate - N residue in soils of the southern Loess Plateau

NASA Astrophysics Data System (ADS)

Dang, Tinghui; Dong, Qiang

2017-04-01

【Objectives】Excessive fertilization in farmland caused nitrate leaching and accumulation in soil, which not only reduced the fertilizer utilization rate, but also had potential environmental problems. The effects of different nitrogen reduction modes on yield of spring maize and soil NO3-N in the southern Loess Plateau were discussed, and scientific fertilization suggestions were put forward, which were of great significance to instruct local maize fertilization and protect environment safety. 【Methods】A field experiment was conducted in the south of the Loess Plateau for three years. Spring maize was planted with half plastic film mulching in one crop per annum．The experiment consisted of 5 N fertilization treatments: control treatment (CK),conventional N fertilization rate (Con), optimal N fertilizationⅠ(OptⅠ), optimal N fertilizationⅡ (Opt Ⅱ) and optimal N fertilization Ⅲ(Opt Ⅲ), The changes of yield of maize, nitrogen uptake and soil NO3-N were measured.【Results】The results showed that, compared with the conventional fertilization, the grain yield and N uptake of maize had no significant change under the three optimal N fertilization application models, the rate of the grain yield's change is 100 300kg/hm2. Compared with the conventional fertilization, agronomic efficiency of fertilizer-nitrogen and N partial fertilizer productivity were increased by 20.2% 23.2% and 21.9% 23.7%, respectively. The accumulation of nitrate nitrogen in profile (0－200 cm) decreased by 90.7 kg / hm2, 97.3 kg / hm2, 100.7 kg / hm2 ,respectively, with the decreases of 44.7%, 47.9% and 49.6% respectively.【Conclusions】The optimum nitrogen fertilization pattern did not affect spring maize yield and N uptake, and could improve agronomic efficiency of fertilizer-nitrogen and N partial fertilizer productivity. Under the same nitrogen application rate, the effects of adding nitrification inhibitor or slow-release fertilizer on nitrate-N residue were not obvious. The amount of nitrogen applied, the mode and type of fertilization had a certain effect on the migration of nitrate nitrogen. Optimized N - application model could significantly reduce the NO3—N residue in soil profile. It is suggested to reduce the amount of nitrogen fertilizer by 20% on the basis of the traditional nitrogen fertilizer when the spring maize is planted with half plastic film mulching, which can guarantee the yield and protect the environment.

Cryopreservation of common carp (Cyprinus carpio) sperm in 1.2 and 5 ml straws and occurrence of haploids among larvae produced with cryopreserved sperm.

PubMed

Horváth, Akos; Miskolczi, Edit; Mihálffy, Szilvia; Osz, Katalin; Szabó, Krisztián; Urbányi, Béla

2007-06-01

Experiments were carried out on the cryopreservation of common carp (Cyprinus carpio) sperm in order to test the suitability of using 1.2 and 5 ml straws and to investigate the ploidy of malformed larvae found among the hatched progeny. In the first set of experiments, the effect of freezing time was investigated on the hatch rate of embryos. The highest hatch rate for 1.2 ml straws was 69+/-16% at the freezing time of 4 min, and 39+/-27% for 5 ml straws at 5 min. In the second set, the effect different egg volumes fertilized with one straw of sperm on the hatch rate and the rate of malformed larvae was investigated. The highest hatch rate with 1.2 ml straws (86+/-12%) was observed when 10 g of eggs were fertilized with one straw, whereas with 5 ml straws the hatch rate was highest (65+/-18%) when 40 g of eggs were fertilized. The highest rate of malformed larvae (15+/-9%) was found in the control, whereas the highest rate of malformed larvae among the groups fertilized with cryopreserved sperm (13+/-7%) was found in the 1x dose group fertilized with 5 ml straw. The chromosome numbers of malformed larvae were investigated and haploids were found among those hatched from eggs fertilized with cryopreserved sperm whereas only diploids were found in the controls.

Control of the estrous cycle to improve fertility for fixed-time artificial insemination in beef cattle: a review.

PubMed

Lamb, G C; Dahlen, C R; Larson, J E; Marquezini, G; Stevenson, J S

2010-04-01

Early estrus-synchronization protocols focused on regressing the corpus luteum (CL) with an injection of PGF(2alpha) followed by detection of estrus or involved the use of exogenous progestins that prevent estrus from occurring. Later, protocols combining the use of PGF(2alpha) and exogenous progestins were developed. Gonadotropin-releasing hormone was utilized to control follicular waves, synchronize ovulation, or to luteinize large dominant follicles. Our research aimed to develop reliable protocols that 1) relied solely on fixed-timed AI (TAI); 2) required a maximum of 3 animal handlings, and 3) were successful in estrous-cycling and noncycling females. In cows, insertion of an intravaginal progesterone insert during the 7-d interval between the initial GnRH and PGF(2alpha) injections enhanced pregnancy rates by 9 to 10%. In a multi-location study, a TAI protocol yielded pregnancy rates similar to a protocol involving detection of estrus plus a fixed-time clean-up AI for females not detected in estrus (54 vs. 58%, respectively, for cows and 53 vs. 57%, respectively, for heifers). Initiation of estrous cycles in noncycling cows is likely the primary manner in which beef producers may improve fertility in response to estrus synchronization and TAI protocols. Treatment of noncycling females with progesterone and GnRH increases the percentage of cycling females and improves fertility to a TAI, but inducing cyclicity with hCG failed to enhance fertility in TAI protocols. Supplementing progesterone after TAI failed to increase pregnancy rates in beef cattle. In contrast, administration of hCG 7 d after TAI induced an accessory CL, increased progesterone, and tended to enhance pregnancy rates. Development of TAI protocols that reduce the hassle factors associated with ovulation synchronization and AI provide cattle producers efficient and effective tools for capturing selective genetic traits of economic consequences. Location variables, however, which may include differences in pasture and diet, breed composition, body condition, postpartum interval, climate, and geographic location, affect the success of TAI protocols.

Effect of in-utero diethylstilboestrol exposure on human oocyte quality and fertilization in a programme of in-vitro fertilization.

PubMed

Kerjean, A; Poirot, C; Epelboin, S; Jouannet, P

1999-06-01

Genital tract abnormalities and adverse pregnancy outcome are well known in women exposed in utero to diethylstilboestrol (DES). Data about adverse reproductive performance in women exposed to DES have been published, including controversial reports of menstrual dysfunction, poor responses after ovarian stimulation, oocyte maturation and fertilization abnormalities. We compared oocyte quality, in-vitro fertilization results and embryo quality for women exposed in utero to DES with a control group. Between 1989 and 1996, 56 DES-exposed women who had 125 in-vitro fertilization (IVF) attempts were retrospectively compared to a control group of 45 women with tubal disease, who underwent 73 IVF attempts. Couples suffering from male infertility were excluded. The parameters compared were oocyte quality (maturation abnormalities, immature oocyte, mature oocyte), fertilization and cleavage rate (per treated and metaphase II oocytes), and embryo quality (number and grade). We found no significant difference in oocyte maturational status, fertilization rates, cleavage rates, embryo quality and development between DES-exposed subjects and control subjects. These results suggest that in-utero exposure to DES has no significant influence on oocyte quality and fertilization ability as judged during IVF attempts.

Improving Rice Modeling Success Rate with Ternary Non-structural Fertilizer Response Model.

PubMed

Li, Juan; Zhang, Mingqing; Chen, Fang; Yao, Baoquan

2018-06-13

Fertilizer response modelling is an important technical approach to realize metrological fertilization on rice. With the goal of solving the problems of a low success rate of a ternary quadratic polynomial model (TPFM) and to expand the model's applicability, this paper established a ternary non-structural fertilizer response model (TNFM) based on the experimental results from N, P and K fertilized rice fields. Our research results showed that the TNFM significantly improved the modelling success rate by addressing problems arising from setting the bias and multicollinearity in a TPFM. The results from 88 rice field trials in China indicated that the proportion of typical TNFMs that satisfy the general fertilizer response law of plant nutrition was 40.9%, while the analogous proportion of TPFMs was only 26.1%. The recommended fertilization showed a significant positive linear correlation between the two models, and the parameters N 0 , P 0 and K 0 that estimated the value of soil supplying nutrient equivalents can be used as better indicators of yield potential in plots where no N or P or K fertilizer was applied. The theoretical analysis showed that the new model has a higher fitting accuracy and a wider application range.

Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

NASA Astrophysics Data System (ADS)

Li, Jing; Pang, Shaojun; Liu, Feng; Shan, Tifeng; Gao, Suqin

2013-07-01

During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S. japonica, at 12°C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

Timing of favorable conditions, competition and fertility interact to govern recruitment of invasive Chinese tallow tree in stressful environments.

PubMed

Gabler, Christopher A; Siemann, Evan

2013-01-01

The rate of new exotic recruitment following removal of adult invaders (reinvasion pressure) influences restoration outcomes and costs but is highly variable and poorly understood. We hypothesize that broad variation in average reinvasion pressure of Triadica sebifera (Chinese tallow tree, a major invader) arises from differences among habitats in spatiotemporal availability of realized recruitment windows. These windows are periods of variable duration long enough to permit establishment given local environmental conditions. We tested this hypothesis via a greenhouse mesocosm experiment that quantified how the duration of favorable moisture conditions prior to flood or drought stress (window duration), competition and nutrient availability influenced Triadica success in high stress environments. Window duration influenced pre-stress seedling abundance and size, growth during stress and final abundance; it interacted with other factors to affect final biomass and germination during stress. Stress type and competition impacted final size and biomass, plus germination, mortality and changes in size during stress. Final abundance also depended on competition and the interaction of window duration, stress type and competition. Fertilization interacted with competition and stress to influence biomass and changes in height, respectively, but did not affect Triadica abundance. Overall, longer window durations promoted Triadica establishment, competition and drought (relative to flood) suppressed establishment, and fertilization had weak effects. Interactions among factors frequently produced different effects in specific contexts. Results support our 'outgrow the stress' hypothesis and show that temporal availability of abiotic windows and factors that influence growth rates govern Triadica recruitment in stressful environments. These findings suggest that native seed addition can effectively suppress superior competitors in stressful environments. We also describe environmental scenarios where specific management methods may be more or less effective. Our results enable better niche-based estimates of local reinvasion pressure, which can improve restoration efficacy and efficiency by informing site selection and optimal management.

Timing of Favorable Conditions, Competition and Fertility Interact to Govern Recruitment of Invasive Chinese Tallow Tree in Stressful Environments

PubMed Central

Gabler, Christopher A.; Siemann, Evan

2013-01-01

The rate of new exotic recruitment following removal of adult invaders (reinvasion pressure) influences restoration outcomes and costs but is highly variable and poorly understood. We hypothesize that broad variation in average reinvasion pressure of Triadica sebifera (Chinese tallow tree, a major invader) arises from differences among habitats in spatiotemporal availability of realized recruitment windows. These windows are periods of variable duration long enough to permit establishment given local environmental conditions. We tested this hypothesis via a greenhouse mesocosm experiment that quantified how the duration of favorable moisture conditions prior to flood or drought stress (window duration), competition and nutrient availability influenced Triadica success in high stress environments. Window duration influenced pre-stress seedling abundance and size, growth during stress and final abundance; it interacted with other factors to affect final biomass and germination during stress. Stress type and competition impacted final size and biomass, plus germination, mortality and changes in size during stress. Final abundance also depended on competition and the interaction of window duration, stress type and competition. Fertilization interacted with competition and stress to influence biomass and changes in height, respectively, but did not affect Triadica abundance. Overall, longer window durations promoted Triadica establishment, competition and drought (relative to flood) suppressed establishment, and fertilization had weak effects. Interactions among factors frequently produced different effects in specific contexts. Results support our ‘outgrow the stress’ hypothesis and show that temporal availability of abiotic windows and factors that influence growth rates govern Triadica recruitment in stressful environments. These findings suggest that native seed addition can effectively suppress superior competitors in stressful environments. We also describe environmental scenarios where specific management methods may be more or less effective. Our results enable better niche-based estimates of local reinvasion pressure, which can improve restoration efficacy and efficiency by informing site selection and optimal management. PMID:23967212

The effects of ingested petroleum on oviposition and some aspects of reproduction in experimental colonies of mallard ducks (Anas platyrhynchos)

USGS Publications Warehouse

Holmes, W.N.; Cavanaugh, K.P.; Cronshaw, J.

1978-01-01

Compared to unmated mallard ducks fed an uncontaminated diet, unmated birds given food contaminated with 3 ml South Louisiana crude oil per 100 g dry weight showed an 84% decline in the daily rate of oviposition, a 33% decrease in egg-shell thickness and at autopsy more than 82% of the ovarian mass consisted of atretic follicles. Similar studies on groups of mated females showed that although the addition of 1 ml South Louisiana crude oil/100 g dry food had no effect on the daily rate of oviposition, none of the eggs had been fertilized while a concentration of 3 ml South Louisiana crude oil/100 g dry food suppressed the daily rate of oviposition significantly. Less than 25% of these eggs had been fertilized and only 40% of the fertilized eggs yielded viable ducklings. In both of these groups of mated birds, normal patterns of oviposition, fertilization and hatchability were restored after removal of petroleum from the diet. The addition of 1 ml Kuwait crude oil/100 g dry food had no effect on the rate of oviposition, the incidence of fertility or the hatchability of the fertilized eggs. The addition of 3 ml oil/100 g dry food completely abolished oviposition, but a normal rate of oviposition was restored when the concentration of the crude oil was reduced from 3 to 1 ml/100 g dry food. However, the incidence of fertilization remained low and none of the fertilized eggs gave rise to viable ducklings. Kuwait crude oil had no effect on shell thickness.

Characterization of turf practices in five North Carolina communities.

PubMed

Osmond, Deanna L; Hardy, David H

2004-01-01

Limited information exists on specific urban lawn care practices in the United States. We conducted a door-to-door lawn care survey in five North Carolina communities to determine suburban fertilizer, pesticide, and water use. These communities, Cary, Goldsboro, Kinston, New Bern, and Greenville, are mostly located within the Neuse River basin, a nutrient-sensitive water resource. Residents in Cary used lawn care companies more than twice as frequently as residents in the other communities (43 compared with 20%). Cary had the smallest mean lawn size (445 m2), while the largest was in Goldsboro (1899 m2). Tall fescue [Festuca arundinacea Schreb.] was the predominant grass type in Cary (99%), and centipedegrass [Eremochloa ophiuroides (Munro) Hack.] or centipedegrass mixtures were the predominant grass types in Greenville and New Bern. Kinston had the lowest fertilizer usage with only 54% of the residents using fertilizer; Cary had the highest rate of 83%. The average N fertilizer rate applied to the lawns was dissimilar ranging from 24 to 151 kg N ha(-1). Analysis of variance results for fertilizer rates and household income indicated a significant difference (P < 0.05) in application rate between high- and medium-income levels and the low-income level. Cary, Goldsboro, and Greenville had approximately the same number of fertilizer applications per year (1.5), whereas the average number of fertilizer applications per year in New Bern was 3.0. Most household residents (53%) used instructions on the bag and either grass type and/or lawn area to guide them on fertilizer application rates.

A decomposition analysis of recent fertility decline in Fiji.

PubMed

Gubhaju, B; Shahidullah, M

1990-12-01

Over the period 1966-86, both the Fijian and Indian populations of Fiji demonstrated declines in fertility. Differentials in the decline were, however, noted with the total fertility rate (TFR) of the Fijian population declining by 26% over the period compared to a 50% decline in the Indian TFR. Moreover, rate declines were not smooth and consistent over the period. Faster fertility decline was experienced in the 1st decade for both groups, slowing in the 2nd decade for Indian women, and stabilizing among the Fijians. This paper decomposes these differential changes in fertility rate into marital structure and marital fertility. The study was conducted using data from the censuses of 1966, 1976, and 1986. For the period 1966-76, declines in marital fertility contributed most to overall TFR decline for both ethnic groups. Marital structure had a reducing effect upon TFR among Indian women in the 1st decaed, but not during the 2nd. Fijian women experienced an overall negative impact from marital structure. Contraception plays an important role in limiting fertility in these 2 populations. Accordingly, differentials in acceptance were noticed, the family planning acceptance rate for Indians being almost twice that of Fijians; 35.6% and 18.7%, respectively in 1986. Compared to Indian women, Fijian women were more literate, more economically active, had higher life expectancies, and experience lower infant mortality rates. Nonetheless, they are not motivated to use family planning. Motivational, cultural, religious, and behavioral factors are suggested as causal factors determining acceptance and use of modern contraceptive methods.

Culture and fertility in the Nepal Himalayas: a test of a hypothesis.

PubMed

Ross, J L

1984-01-01

In the Nepal Himalayas the Tibetan sociocultural system of fraternal polyandry (the form of marriage where 1 woman has 2 or more brothers as husbands) reduces aggregate fertility whereas Hindu marriage patterns appear to maximize fertility since there is very early and universally monogamous marriages. Over an 18-month period, reseach in the upper reaches of the Humla Distrist of northwestern Nepal focused upon 2 culturally distinct but geographically contiguous communities. 1 is Nepali speaking and high-caste Hindu; the other, Tibetan speaking and Buddhist. The 2 populations present a relatively unique natural laboratory in which several key factors (geographic, environmental and economic) are controlled. Population dynamics in these 2 communities are principally determined by patterns of fertility and mortality. A summary of a number of characteristics of the population dynamics of these 2 populations (e.g., age at 1st birth, birth interval, crude birth rate, completed fertility rate, general fertility rate, % children surviving), shows that they are more alike than dissimilar. Fertility levels between the Hindu and Tibetan population are virtually the same. While Tibetan fraternal polyandry does reduce aggregate fertility, the hypothesis that the Tibetans would have a substantially lower fertility rate than the Hindus is false, because the effects of fraternal polyandry are roughly balanced by the effects of post-widowhood celibacy among the Hindus. This study points up an important issue often overlooked in demographic analysis. Aggregate statistics such as the completed fertility rate, while important, can be deceptive, since very different factors can produce the same result at any given point in time. Diachronically, however, these underlying facotrs may change very differently. For example, fraternal poyandry is highly susceptiable to change because of the constant reevaluation of the opportunity costs associated with its practice. Anticipating the potential cause and directions of future change illustrates an important point. It is imperative in demographic analysis to elucidate the sociocultural factors underlying the reproductive performance of the populations. Culture and population dynamics are intimately intertwined in these communities.

Economic recession and fertility in the developed world.

PubMed

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.

Does climate variability influence the demography of wild primates? Evidence from long-term life-history data in seven species.

PubMed

Campos, Fernando A; Morris, William F; Alberts, Susan C; Altmann, Jeanne; Brockman, Diane K; Cords, Marina; Pusey, Anne; Stoinski, Tara S; Strier, Karen B; Fedigan, Linda M

2017-11-01

Earth's rapidly changing climate creates a growing need to understand how demographic processes in natural populations are affected by climate variability, particularly among organisms threatened by extinction. Long-term, large-scale, and cross-taxon studies of vital rate variation in relation to climate variability can be particularly valuable because they can reveal environmental drivers that affect multiple species over extensive regions. Few such data exist for animals with slow life histories, particularly in the tropics, where climate variation over large-scale space is asynchronous. As our closest relatives, nonhuman primates are especially valuable as a resource to understand the roles of climate variability and climate change in human evolutionary history. Here, we provide the first comprehensive investigation of vital rate variation in relation to climate variability among wild primates. We ask whether primates are sensitive to global changes that are universal (e.g., higher temperature, large-scale climate oscillations) or whether they are more sensitive to global change effects that are local (e.g., more rain in some places), which would complicate predictions of how primates in general will respond to climate change. To address these questions, we use a database of long-term life-history data for natural populations of seven primate species that have been studied for 29-52 years to investigate associations between vital rate variation, local climate variability, and global climate oscillations. Associations between vital rates and climate variability varied among species and depended on the time windows considered, highlighting the importance of temporal scale in detection of such effects. We found strong climate signals in the fertility rates of three species. However, survival, which has a greater impact on population growth, was little affected by climate variability. Thus, we found evidence for demographic buffering of life histories, but also evidence of mechanisms by which climate change could affect the fates of wild primates. © 2017 John Wiley & Sons Ltd.

Effect of inorganic nitrogenous fertilizer on productivity of recently reclaimed saline sodic soils with and without biofertilizer.

PubMed

Mehdi, S M; Sarfraz, M; Shabbir, G; Abbas, G

2007-07-15

Saline sodic soils after reclamation become infertile due to leaching of most of the nutrients along with salts from the rooting medium. Microbes can play a vital role in the productivity improvement of such soils. In this study a saline sodic field having EC, 6.5 dS m(-1), pH, 9.1 and gypsum requirement (GR) 3.5 tons acre(-1) was reclaimed by applying gypsum at the rate of 100% GR. Rice and wheat crops were transplanted/sown for three consecutive years. Inorganic nitrogenous fertilizer was used with and without biofertilizers i.e., Biopower (Azospirillum) for rice and diazotroph inoculums for wheat. Nitrogen was applied at the rate of 0, 75% of recommended dose (RD), RD, 125% of RD and 150% of RD. Recommended dose of P without K was applied to all the plots. Biopower significantly improved Paddy and straw yield of rice over inorganic nitrogenous fertilizer. In case of wheat diazotroph inoculum improved grain and straw yield significantly over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for rice and wheat production in recently reclaimed soils. Nitrogen concentration and its uptake by paddy, grain and straw were also increased by biopower and diazotroph inoculum over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for nitrogen concentration and its uptake by paddy, grain and straw. Total soil N, available P and extractable K were increased while salinity/sodicity parameters were decreased with the passage of time. The productivity of the soil was improved more by biofertilizers over inorganic N fertilizers.

Urinary paraben concentrations and in vitro fertilization outcomes among women from a fertility clinic.

PubMed

Mínguez-Alarcón, Lidia; Chiu, Yu-Han; Messerlian, Carmen; Williams, Paige L; Sabatini, Mary E; Toth, Thomas L; Ford, Jennifer B; Calafat, Antonia M; Hauser, Russ

2016-03-01

To explore the relationship between urinary paraben concentrations and IVF outcomes among women attending an academic fertility center. Prospective cohort study. Fertility clinic in a hospital setting. A total of 245 women contributing 356 IVF cycles. None. Quantification of urinary concentrations of parabens by isotope-dilution tandem mass spectrometry, and assessment of clinical endpoints of IVF treatments abstracted from electronic medical records at the academic fertility center. Total and mature oocyte counts, proportion of high-quality embryos, fertilization rates, and rates of implantation, clinical pregnancy, and live births. The geometric means of the urinary concentrations of methylparaben, propylparaben, and butylparaben in our study population were 133, 24, and 1.5 μg/L, respectively. In models adjusted for age, body mass index, race/ethnicity, smoking status, and primary infertility diagnosis, urinary methylparaben, propylparaben, and butylparaben concentrations were not associated with IVF outcomes, specifically total and mature oocyte counts, proportion of high embryo quality, and fertilization rates. Moreover, no significant associations were found between urinary paraben concentrations and rates of implantation, clinical pregnancy, and live births. Urinary paraben concentrations were not associated with IVF outcomes among women undergoing infertility treatments. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Nursery response of Acacia koa seedlings to container size, irrigation method, and fertilization rate

Treesearch

R. Kasten Dumroese; Anthony S. Davis; Douglass F. Jacobs

2011-01-01

Planting koa (Acacia koa A. Gray) in Hawai'i, USA aids in restoration of disturbed sites essential to conservation of endemic species. Survival and growth of planted seedlings under vegetative competition typically increases with initial plant size. Increasing container size and fertilizer rate may produce larger seedlings, but high fertilization can lead to...

Pregnancy rates and gravid uterine parameters in single, twin and triplet pregnancies in naturally bred ewes and ewes after transfer of in vitro produced embryos.

PubMed

Grazul-Bilska, Anna T; Pant, Disha; Luther, Justin S; Borowicz, Pawel P; Navanukraw, Chainarong; Caton, Joel S; Ward, Marcy A; Redmer, Dale A; Reynolds, Lawrence P

2006-05-01

The objectives of this study were to: (1) evaluate the pregnancy rates after transfer of embryos produced in the presence or absence of epidermal growth factor (EGF) during in vitro maturation, and (2) compare several variables of the gravid uterus on day 140 after fertilization in single, twin and triplet pregnancies in ewes (n = 12) bred naturally and in ewes (n = 18) after transfer of embryos produced in vitro. Oocytes collected from FSH-treated ewes (n = 18) were collected from all visible follicles and cultured in maturation medium with or without EGF. Oocytes were then fertilized in vitro by frozen-thawed semen. On day 5 after fertilization, embryos with > or = 16 cells were transferred to recipient ewes (n = 39). In addition 12 ewes were bred naturally. Pregnancy was verified by real-time ultrasonography on day 45 or later after embryo transfer (ET) or breeding. On day 140 of pregnancy, the reproductive tract was collected from all ewes and the following parameters were determined: the number, sex, weight and crown to rump length (CRL) of fetuses, weights of gravid uterus and fetal membranes, and weight and number of placentomes. Presence of EGF in maturation medium increased (P < 0.04) cleavage rates (78% versus 59%) and percentage of > or = 16 cell embryos on day 5 after fertilization (62% versus 40%). Pregnancy rates tended to be greater (P < 0.1) after transfer of embryos matured in the presence of EGF (52%) than in the absence of EGF (39%). EGF presence in maturation medium did not affect any variables of gravid uterus or fetal weight. For single pregnancies in naturally bred ewes and ewes after ET all uterine variables were similar. For twin pregnancies, weight of gravid uterus, weight of uterus plus fetal membranes, total weight of placentomes/ewe, mean weight of individual placentome, mean weight of fetus, total fetal weight/ewe and CRL were greater (P < 0.0001-0.04) for ewes after ET than for ewes bred naturally. The weights of gravid uterus, fluid, uterus plus fetal membranes, fetal membranes, total placentomes/ewe, mean weight of individual placentome and total fetal weight/ewe were greater (P < 0.0001-0.08) for triplet pregnancies in ewes after ET than single and twin pregnancies in ewes naturally bred or after ET. The number of placentomes/fetus was greatest (P < 0.0001-0.06) in single pregnancies in ewes bred naturally and after ET fewer in twin pregnancies in ewes bred naturally and after ET and fewest in triplet pregnancies in ewes after ET. The total number of placentomes/ewe was greatest (P < 0.0001-0.06) for twin pregnancies in ewes naturally bred, fewer in single pregnancies in ewes naturally bred and twin and triplet pregnancies after ET, and fewest in single pregnancies in ewes after ET. The mean weight of fetus was greater (P < 0.0001-0.07) in single pregnancies in ewes naturally bred or after ET than in twin or triplet pregnancies in ewes naturally bred or after ET. The CRL was the lowest (P < 0.01) in twin pregnancies in ewes bred naturally. For pregnancies after natural breeding and after ET, the number of fetuses/ewe was negatively correlated (P < 0.03-0.0001) with the weight of placentomes/fetus, the number of placentomes/fetus, the mean weight of the fetus and CRL, and was positively correlated (P < 0.0001-0.05) with weight of gravid uterus, the total number of placentomes/ewe and total fetal weight/ewe. These data demonstrate that the presence of EGF in maturation medium increases the rates of cleavage and early embryonic development, and has a tendency to enhance rates of pregnancy but does not affect variables of the gravid uteri in ewes after transfer of in vitro produced embryos. Transfer of embryos produced in vitro affected some uterine variables in twin but not single pregnancies to compare with pregnancies after natural breeding. In addition, culture conditions in the present experiment did not create large offspring syndrome. The low number of placentomes/fetus seen in triple pregnancies appears to be compensated for by the increase in the weight of each individual placentome.

Reproductive Management for Optimal Oocyte Development to Enhance Fertility

USDA-ARS?s Scientific Manuscript database

There are multiple steps associated with the ovulatory follicle that affect oocyte growth, fertilization, embryo development and establishment of pregnancy. When estrous cycles are manipulated with assisted reproductive technologies and ovulation induced, some of these variables become more importa...

First records of a field experiment on fertilizer effects on methane emission from rice fields in Hunan-Province (PR China)

NASA Astrophysics Data System (ADS)

Wassmann, R.; Wang, M. X.; Shangguan, X. J.; Xie, X. L.; Shen, R. X.; Wang, Y. S.; Papen, H.; Rennenberg, H.; Seiler, W.

Fertilizer effects on methane emission from Chinese rice fields were investigated by a praxis-oriented approach applying balanced amendments of N, P and K. The data set obtained covered the emission rates of app. one month in early rice and one month in late rice 1991. An intercomparison between the 4 treatments showed pronounced differences in the magnitudes of methane emission rates. The combined organic/mineral fertilizer application, commonly used as local farming practice, resulted in relatively high seasonal averages of methane emission rates (26.5 mg CH4 m-2 h-1 in early rice and 50.1 mg CH4 m-2 h-1 in late rice). The lowest emission rates were observed in the plot with pure mineral fertilization (6.5 mg CH4 m-2 h-1 in early rice and 14.3 mg CH4 m-2 h-1 in late rice). Pure organic fertilizers by unfermented substances yielded the highest methane emission rates of all field trials (38.6 mg CH4 m-2 h-1 in early rice and 56.2 CH4 m-2 h-1 in late rice). The fertilization with fermented material derived from biogas generators resulted in substantially lower emission rates than the other trials with organic amendments, the seasonal averages corresponded to 15.9 mg CH4 m-2 h-1 (early rice) and 22.5 mg CH4 m-2 h-1 (late rice). Interpretation of the results can be obtained from the different potentials of these fertilizers for methane production. Based on this concept the different methane emission rates observed with organic/mineral, pure mineral and pure unfermented-organic fertilizers could directly be attributed to the different quantities of organic matter incorporated into the soil. The low methane emission from the plot treated with fermented material could be explained by a depletion of potential methane precursors resulting from the preceding fermentation. The results of this investigation provide evidence that the extensive use of specific chemical fertilizers and the application of sludge from the operation of biogas generators could lead to a net reduction of the methane emission from rice fields.

Childlessness patterns in Taiwan.

PubMed

Poston Dl

1988-06-01

Taiwan is a newly developed and industrialized area, and along with Korea, Brazil, Argentina, and a few other countries, belongs in a special class of recently industrialized areas. Taiwan has been undergoing large-scale modernization since the 1950s when the Nationalist government 1st began to implement land reform programs and today is 1 of the showcase of newly developed areas of the world. Demographic transition theory shows that fertility is negatively associated with modernization. During the past 3 decades, fertility in Taiwan has followed this pattern in a dramatic manner. Studies of childlessness conducted in Western countries have shown also that as the modernizing influences continue, fertility declines, and childlessness increases as it becomes more and more voluntary. Subregions with the highest levels of modernization and the lowest fertility rates should therefore be characterized by the highest levels of childlessness, particularly among younger women, and vice versa. Given the levels of socioeconomic and demographic development in Taiwan and its subregions circa 1980, as well as its variability among the hsiens and major cities, the author would expect to find higher levels of childlessness in the more developed localities, and lower levels in the less developed subregions. This hypothesis is tested with data from the 1980 Census of Population and Housing: General Report, Taiwan--Fukien Area (Republic of China, 1982) and the 1980 Taiwan--Fukien Demographic Fact Book (Republic of China, 1980).

Analysis of the interaction among rice, weeds, inorganic fertilizer, and a herbivore in a composite farming paddy ecosystem.

PubMed

Wu, Zhaohua; Wang, Yi; Zhou, Xiaoli; Zhou, Tiejun

2018-06-01

As one of the Globally Important Agricultural Heritage Systems (GIAHS), rice field composite farming is an ecological measure in rice production, which can reduce the amount of chemical fertilizers, pesticides and herbicides. This research studies the interaction among rice, weed, inorganic fertilizer and herbivore in a composite farming paddy ecosystem. We develop a differential equation model to analyze the relations and interactions among those components. Results show the existence of an equilibrium for paddy and weed extinction, one or two equilibria for rice extinction, an equilibrium for weed extinction, and an equilibrium for rice and weed coexistence. Based on the obtained stability conditions of these equilibria, measures are proposed to avoid the existence or the stability of equilibria for rice extinction. Other measures are proposed to lead to a stable equilibrium for weed extinction, which is the most desirable result in rice production. Conditions for maximizing the yield of rice are also obtained by taking the relative mortality of rice as variable. In addition, we discover the existence of Hopf bifurcation phenomenon in the system, and develop the critical value of Hopf bifurcation by taking the artificial fertilizer rate as the bifurcation parameter. Our findings provide effective guidance and insights for rice production in a composite farming paddy ecosystem. Copyright © 2018 Elsevier Inc. All rights reserved.

Female education and fertility in Bangladesh.

PubMed

Martin, L G

1987-05-01

Slowing the growth of the 100 million plus population of Bangladesh remains a major challenge. Fertility and mortality declined only slightly during the 1970s and the population continues to grow at an annual rate of over 2.5%, implying a doubling time of about 25 years. This article briefly reviews the theoretical link between education and fertility, the educational situation in Bangladesh, and the projects's design and its effects as evaluated by a US Agency for International Development (AID) International Science and Technology Institute team. Nearly all women are married by age 25 in Bangladesh, but more educated women marry later than the less educatted ones. Age at marriage has the greatest effect of all the variables on children ever born; given the association between age at marriage and education, it can be argued that education does indeed affect fertility. In 1982, USAID began funding a pilot project by the Bangladesh Association for Community Education to provide secondary scholarships for girls in Chandpur District. Only 30% of the secondary school completers had married by the time of the survey, in comparison to 76% of the secondary dropouts, 77% of the primary school completers, and 66% of those with no school. Clearly, there is much to be done in reducing population pressure and raising the standard of living in Bangladesh, and raising the status of women through education could be a valuable component in such efforts.

Long Term Sugarcane Crop Residue Retention Offers Limited Potential to Reduce Nitrogen Fertilizer Rates in Australian Wet Tropical Environments.

PubMed

Meier, Elizabeth A; Thorburn, Peter J

2016-01-01

The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues ('trash'). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a 'trash blanket' in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer rates for crops when trash was retained (≤20 kg N ha(-1) per plant or ratoon crop) while maintaining ≥95% of maximum yields. While these savings in N fertilizer use were modest at the field scale, they were potentially important when aggregated at the regional level.

Effects of Simulated Mobile Phone Electromagnetic Radiation on Fertilization and Embryo Development.

PubMed

Chen, Hong; Qu, Zaiqing; Liu, Wenhui

2017-04-01

This study investigated the effects of 935-MHz electromagnetic radiation (ER) on fertilization and subsequent embryonic development in mice. Ovulating mice were irradiated at three ER intensities for 4 h/day (d) or 2 h/d for three consecutive days; the ova were then harvested for in vitro fertilization to observe the 6-h fertilization rate (6-FR), 72-h morula rate (72-MR), and 110-h blastula rate (110-BR). Compared with the control group, the 6-FR, 72-MR, and 110-BR were decreased in the low ER intensity group, but the differences were not significant; in the mid- and high-intensity ER groups, 72-MR and 110-BR in the 4 h/d and 2 h/d subgroups were decreased, showing significant differences compared with the control group. Moreover, the comparison between 4 h/d and 2 h/d subgroups showed significant differences. Mid- and high-intensity ER at 935 MHz can reduce the fertilization rate in mice, and reduce the blastulation rate, thus reducing the possibility of embryo implantation.

Female married illiteracy as the most important continual determinant of total fertility rate among districts of Empowered Action Group States of India: Evidence from Annual Health Survey 2011–12

PubMed Central

Kumar, Rajesh; Dogra, Vishal; Rani, Khushbu; Sahu, Kanti

2017-01-01

Background: District level determinants of total fertility rate in Empowered Action Group states of India can help in ongoing population stabilization programs in India. Objective: Present study intends to assess the role of district level determinants in predicting total fertility rate among districts of the Empowered Action Group states of India. Material and Methods: Data from Annual Health Survey (2011-12) was analysed using STATA and R software packages. Multiple linear regression models were built and evaluated using Akaike Information Criterion. For further understanding, recursive partitioning was used to prepare a regression tree. Results: Female married illiteracy positively associated with total fertility rate and explained more than half (53%) of variance. Under multiple linear regression model, married illiteracy, infant mortality rate, Ante natal care registration, household size, median age of live birth and sex ratio explained 70% of total variance in total fertility rate. In regression tree, female married illiteracy was the root node and splits at 42% determined TFR <= 2.7. The next left side branch was again married illiteracy with splits at 23% to determine TFR <= 2.1. Conclusion: We conclude that female married illiteracy is one of the most important determinants explaining total fertility rate among the districts of an Empowered Action Group states. Focus on female literacy is required to stabilize the population growth in long run. PMID:29416999

Assessment of forestry best management practices II: patterns in stream biological endpoints in terms of natural variability and fertilization

Treesearch

Camille Flinders; Daniel L. McLaughlin; Larry Korhnak; William J. Arthurs; Joan Ikoma; Matthew J. Cohen; Erik B. Schilling

2016-01-01

Watersheds dominated by forest cover typically have high quality water. In managed forests, fertilizers may be periodically applied during the growing period. The Florida Forest Service has developed Best Management Practices (BMPs) for managed forests to minimize the potential impacts of forestry operations, including fertilization, to forest streams and maintain ...

Ethnicity and fertility in Nigeria.

PubMed

Kollehlon, Konia T

2003-01-01

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

Design and experiment on 2KF-15 type disc cutter and shallow fertilization machine in rubber plantation

NASA Astrophysics Data System (ADS)

Deng, Yiguo; Zhang, Yuan; Wang, Yeqin

2017-12-01

At present, the trenching and fertilization machine has a serious weed plug problem when trenching and fertilization operation in rubber plantation. So a disc cutter and shallow fertilization machine in rubber plantation named 2KF-15 was designed, the design scheme used the front disc cutter cutting the grass, while using the rear of the disc furrow to trenching, the prototype of a disc anti-plugging trenching and shallow fertilization machine was completed. Afterwards, a series of trenching and fertilization field experiments were carried out, and the results showed that the ditching depth of this machine could achieve from 131 to 176 mm, and the average depth could reach 156 mm, the ditching depth stability coefficient could achieve 90.3%; The fertilizer amount of this machine could achieve from 113.2 to 156.4 kg/hm2, the average fertilizer amount reach 134.2kg/hm2, the fertilizer amount stability coefficient could achieve 89.6%, the fertilizer broken rate was 0%, the fertilizer coverage rate of 98.4%;The situation of fertilizer accumulation occurred less by using this machine, and the fertilization performance was relatively stable. This new designed machine for trenching, fertilization and covering the soil were carried out at the same time. So the number of operations could be effectively reduced. This new designed machine does not only meet the agronomic requirements of rubber plantation fertilization, but also provides a reference for the trenching and fertilization operation in other.

[Mitigation effect of several controlled-release N fertilizers on ammonia volatilization and related affecting factors].

PubMed

Sun, Kejun; Mao, Xiaoyun; Lu, Qiming; Jia, Aiping; Liao, Zongwen

2004-12-01

By using static absorption and soil column leaching methods, this paper studied the behaviors of several controlled-release N fertilizers in soil under laboratory conditions. The results showed that under the application rate of 450 mg x kg(-1), total ammonia volatilization from three controlled-release fertilizers decreased by 49.7%, 28.0% and 71.2%, respectively, in comparing with common urea. When the application rate was 600 mg x kg(-1), total ammonia volatilization decreased by 34.6%, 12.3%, 69.9%, respectively. Controlled-release fertilizers could markedly reduce total ammonia volatilization from soil and decrease environment pollution via fertilization. The results also indicated that total ammonia volatilization correlated significantly with soil urease activity, pH value and N leaching rate. The correlation coefficient between total ammonia volatilization and accumulated N leaching rate was 0.9533, and that between total ammonia volatilization and soil urease activity and pH value was 0.9533 and 0.9908, respectively.

Soil-test N recommendations augmented with PEST-optimized RZWQM simulations

USGS Publications Warehouse

Malone, R.W.; Jaynes, D.B.; Ma, Liwang; Nolan, B.T.; Meek, D.W.; Karlen, D.L.

2010-01-01

Improved understanding of year-to-year late-spring soil nitrate test (LSNT) variability could help make it more attractive to producers. We test the ability of the Root Zone Water Quality Model (RZWQM) to simulate watershed-scale variability due to the LSNT, and we use the optimized model to simulate long-term field N dynamics under related conditions. Autoregressive techniques and the automatic parameter calibration program PEST were used to show that RZWQM simulates significantly lower nitrate concentration in discharge from LSNT treatments compared with areas receiving fall N fertilizer applications within the tile-drained Walnut Creek, Iowa, watershed (>5 mg N L-1 difference for the third year of the treatment, 1999). This result is similar to field-measured data from a paired watershed experiment. A statistical model we developed using RZWQM simulations from 1970 to 2005 shows that early-season precipitation and early-season temperature account for 90% of the interannual variation in LSNT-based fertilizer N rates. Long-term simulations with similar average N application rates for corn (Zea mays L.) (151 kg N ha-1) show annual average N loss in tile flow of 20.4, 22.2, and 27.3 kg N ha -1 for LSNT, single spring, and single fall N applications. These results suggest that (i) RZWQM is a promising tool to accurately estimate the water quality effects of LSNT; (ii) the majority of N loss difference between LSNT and fall applications is because more N remains in the root zone for crop uptake; and (iii) year-to-year LSNT-based N rate differences are mainly due to variation in early-season precipitation and temperature. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Multiple deleterious effects of experimentally aged sperm in a monogamous bird

USGS Publications Warehouse

White, J.; Wagner, R.H.; Helfenstein, F.; Hatch, Shyla A.; Mulard, Hervé; Naves, L.C.; Danchin, E.

2008-01-01

Sperm aging is known to be detrimental to reproductive performance. However, this apparently general phenomenon has seldom been studied in an evolutionary context. The negative impact of sperm aging on parental fitness should constitute a strong selective pressure for adaptations to avoid its effects. We studied the impact of sperm aging on black-legged kittiwakes (Rissa tridactyla), a monogamous seabird. Kittiwakes comprise a model system because (i) of evidence that females eject their mates' sperm to prevent fertilization by sperm that would be old and degraded by the time of fertilization and result in reduced reproductive performance and (ii) the lack of extra-pair fertilization in this species makes cryptic female choice an unlikely explanation of postcopulatory sperm ejection by females. We experimentally manipulated the age of the sperm fertilizing kittiwake eggs by fitting males with anti-insemination rings for variable periods of time preceding egg-laying. We found evidence that sperm aging negatively affected four sequential stages of reproduction: fertilization potential, rate of embryonic development, embryonic mortality, and chick condition at hatching. These results may be produced by a continuum of a single process of sperm aging that differentially affects various aspects of development, depending on the degree of damage incurred to the spermatozoa. The marked impact of sperm age on female fitness may thus drive postcopulatory sperm ejection by females. These results provide experimental evidence of deleterious effects of sperm aging on a nondomestic vertebrate, underlining its taxonomic generality and its potential to select for a wide array of adaptations. ?? 2008 by The National Academy of Sciences of the USA.

Time to next pregnancy in spontaneous pregnancies versus treatment cycles in fertile patients with recurrent pregnancy loss.

PubMed

Perfetto, Candice O; Murugappan, Gayathree; Lathi, Ruth B

2015-01-01

The current standard of care for management of patients with recurrent pregnancy loss is expectant management. However, the emotional impact of pregnancy losses and the urgency to conceive often leads couples to consider a variety of fertility treatments. The objective of this study is to report the time to next pregnancy and subsequent live birth and miscarriage rates in fertile patients with recurrent pregnancy loss (RPL) who choose to attempt spontaneous conception compared to those that opt to pursue fertility treatment. Retrospective cohort study of one hundred and fifty-eight fertile RPL patients treated at a university-based fertility center. Patients were followed for a minimum of 6 months. Patients were encouraged to attempt spontaneous conception, but allowed to initiate fertility treatments (ovarian stimulation, insemination, IVF or PGS) according to their preferences. Main outcome measures were time to next pregnancy and pregnancy outcome. For those patients who achieved a spontaneous conception, 88% conceived within 6 months, with a median time of 2 months and range of 1-10 months. Patients using IUI, IVF and PGS conceived in a median of 3, 4 and 5 months, respectively. The live birth rate and clinical miscarriage rate was not improved with any fertility treatment. In the fertile RPL patient population, there does not appear to be a benefit to proceeding directly with fertility treatment. Patients should be encouraged to attempt spontaneous conception for at least 6 months.

Aqueous and gaseous nitrogen losses induced by fertilizer application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, C.; Maggi, F.; Riley, W.J.

2009-01-15

In recent years concern has grown over the contribution of nitrogen (N) fertilizer use to nitrate (NO{sub 3}{sup -}) water pollution and nitrous oxide (N{sub 2}O), nitric oxide (NO), and ammonia (NH{sub 3}) atmospheric pollution. Characterizing soil N effluxes is essential in developing a strategy to mitigate N leaching and emissions to the atmosphere. In this paper, a previously described and tested mechanistic N cycle model (TOUGHREACT-N) was successfully tested against additional observations of soil pH and N{sub 2}O emissions after fertilization and irrigation, and before plant emergence. We used TOUGHREACT-N to explain the significantly different N gas emissions andmore » nitrate leaching rates resulting from the different N fertilizer types, application methods, and soil properties. The N{sub 2}O emissions from NH{sub 4}{sup +}-N fertilizer were higher than from urea and NO{sub 3}{sup -}-N fertilizers in coarse-textured soils. This difference increased with decreases in fertilization application rate and increases in soil buffering capacity. In contrast to methods used to estimate global terrestrial gas emissions, we found strongly non-linear N{sub 2}O emissions as a function of fertilizer application rate and soil calcite content. Speciation of predicted gas N flux into N{sub 2}O and N{sub 2} depended on pH, fertilizer form, and soil properties. Our results highlighted the need to derive emission and leaching factors that account for fertilizer type, application method, and soil properties.« less

Scenario analysis of fertilizer management practices for N2O mitigation from corn systems in Canada.

PubMed

Abalos, Diego; Smith, Ward N; Grant, Brian B; Drury, Craig F; MacKell, Sarah; Wagner-Riddle, Claudia

2016-12-15

Effective management of nitrogen (N) fertilizer application by farmers provides great potential for reducing emissions of the potent greenhouse gas nitrous oxide (N 2 O). However, such potential is rarely achieved because our understanding of what practices (or combination of practices) lead to N 2 O reductions without compromising crop yields remains far from complete. Using scenario analysis with the process-based model DNDC, this study explored the effects of nine fertilizer practices on N 2 O emissions and crop yields from two corn production systems in Canada. The scenarios differed in: timing of fertilizer application, fertilizer rate, number of applications, fertilizer type, method of application and use of nitrification/urease inhibitors. Statistical analysis showed that during the initial calibration and validation stages the simulated results had no significant total error or bias compared to measured values, yet grain yield estimations warrant further model improvement. Sidedress fertilizer applications reduced yield-scaled N 2 O emissions by c. 60% compared to fall fertilization. Nitrification inhibitors further reduced yield-scaled N 2 O emissions by c. 10%; urease inhibitors had no effect on either N 2 O emissions or crop productivity. The combined adoption of split fertilizer application with inhibitors at a rate 10% lower than the conventional application rate (i.e. 150kgNha -1 ) was successful, but the benefits were lower than those achieved with single fertilization at sidedress. Our study provides a comprehensive assessment of fertilizer management practices that enables policy development regarding N 2 O mitigation from agricultural soils in Canada. Copyright © 2016 Elsevier B.V. All rights reserved.

Natural conception rates in subfertile couples following fertility awareness training.

PubMed

Frank-Herrmann, P; Jacobs, C; Jenetzky, E; Gnoth, C; Pyper, C; Baur, S; Freundl, G; Goeckenjan, M; Strowitzki, T

2017-04-01

To analyze cumulative pregnancy rates of subfertile couples after fertility awareness training. A prospective observational cohort study followed 187 subfertile women, who had received training in self-observation of the fertile phase of the menstrual cycle with the Sensiplan method, for 8 months. The women, aged 21-47 years, had attempted to become pregnant for 3.5 years on average (range 1-8 years) before study entry. Amenorrhea, known tubal occlusion and severe male factor had been excluded. An additional seven women, who had initially been recruited, became pregnant during the cycle immediately prior to Sensiplan training: this is taken to be the spontaneous pregnancy rate per cycle in the cohort in the absence of fertility awareness training. The cumulative pregnancy rate of subfertile couples after fertility awareness training was 38% (95% CI 27-49%; 58 pregnancies) after eight observation months, which is significantly higher than the estimated basic pregnancy rate of 21.6% in untrained couples in the same cohort. For couples who had been seeking to become pregnant for 1-2 years, the pregnancy rate increased to 56% after 8 months. A female age above 35 (cumulative pregnancy rate 25%, p = 0.06), couples who had attempted to become pregnant for more than 2 years (cumulative pregnancy rate 17%, p < 0.01), all significantly reduce the chances of conceiving naturally at some point. Training women to identify their fertile window in the menstrual cycle seems to be a reasonable first-line therapy in the management of subfertility.

A demographic explanation for the recent rise in European fertility.

PubMed

Bongaarts, John; Sobotka, Tomáš

2012-01-01

Between 1998 and 2008 European countries experienced the first continent-wide increase in the period total fertility rate (TFR) since the 1960s. After discussing period and cohort influences on fertility trends, we examine the role of tempo distortions of period fertility and different methods for removing them. We highlight the usefulness of a new indicator: the tempo- and parity-adjusted total fertility rate (TFRp*). This variant of the adjusted total fertility rate proposed by Bongaarts and Feeney also controls for the parity composition of the female population and provides more stable values than the indicators proposed in the past. Finally, we estimate levels and trends in tempo and parity distribution distortions in selected countries in Europe. Our analysis of period and cohort fertility indicators in the Czech Republic, Netherlands, Spain, and Sweden shows that the new adjusted measure gives a remarkable fit with the completed fertility of women in prime childbearing years in a given period, which suggests that it provides an accurate adjustment for tempo and parity composition distortions. Using an expanded dataset for ten countries, we demonstrate that adjusted fertility as measured by TFRp* remained nearly stable since the late 1990s. This finding implies that the recent upturns in the period TFR in Europe are largely explained by a decline in the pace of fertility postponement. Other tempo-adjusted fertility indicators have not indicated such a large role for the diminishing tempo effect in these TFR upturns. As countries proceed through their postponement transitions, tempo effects will decline further and eventually disappear, thus putting continued upward pressure on period fertility. However, such an upward trend may be obscured for a few years by the effects of economic recession.

The effect of poultry manure application rate and AlCl(3) treatment on bacterial fecal indicators in runoff.

PubMed

Brooks, J P; Adeli, A; McLaughlin, M R; Miles, D M

2012-12-01

Increasing costs associated with inorganic fertilizer have led to widespread use of broiler litter. Proper land application, typically limiting nutrient loss, is essential to protect surface water. This study was designed to evaluate litter-borne microbial runoff (heterotrophic plate count bacteria, staphylococci, Escherichia coli, enterococci, and Clostridium perfringens) while applying typical nutrient-control methods. Field studies were conducted in which plots with high and low litter rates, inorganic fertilizer, AlCl(3)-treated litter, and controls were rained on five times using a rain generator. Overall, microbial runoff from poultry litter applied plots was consistently greater (2-5 log(10) plot(-1)) than controls. No appreciable effect on microbial runoff was noted from variable litter application rate or AlCl(3) treatments, though rain event, not time, significantly affected runoff load. C. perfringens and staphylococci runoff were consistently associated with poultry litter application, during early rain events, while other indicators were unreliable. Large microbial runoff pulses were observed, ranging from 10(2) to 10(10) CFU plot(-1); however, only a small fraction of litter-borne microbes were recoverable in runoff. This study indicated that microbial runoff from litter-applied plots can be substantial, and that methods intended to reduce nutrient losses do not necessarily reduce microbial runoff.

Study on nitrogen load reduction efficiency of agricultural conservation management in a small agricultural watershed.

PubMed

Liu, Xiaoli; Chen, Qiuwen; Zeng, Zhaoxia

2014-01-01

Different crops can generate different non-point source (NPS) loads because of their spatial topography heterogeneity and variable fertilization application rates. The objective of this study was to assess nitrogen NPS load reduction efficiency by spatially adjusting crop plantings as an agricultural conservation management (ACM) measure in a typical small agricultural watershed in the black soil region in northeast China. The assessment was undertaken using the Soil and Water Assessment Tool (SWAT). Results showed that lowland crops produce higher nitrogen NPS loads than those in highlands. It was also found that corn gave a comparatively larger NPS load than soybeans due to its larger fertilization demand. The ACM assessed was the conversion of lowland corn crops into soybean crops and highland soybean crops into corn crops. The verified SWAT model was used to evaluate the impact of the ACM action on nitrogen loads. The results revealed that the ACM could reduce NO3-N and total nitrogen loads by 9.5 and 10.7%, respectively, without changing the area of crops. Spatially optimized regulation of crop planting according to fertilizer demand and geological landscapes can effectively decrease NPS nitrogen exports from agricultural watersheds.

Pregnancy Outcome Using General Anesthesia Versus Spinal Anesthesia for In Vitro Fertilization

PubMed Central

Azmude, Azra; Agha'amou, Shahrzad; Yousefshahi, Fardin; Berjis, Katayoun; Mirmohammad'khani, Majid; Sadaat'ahmadi, Farahnaz; Ghods, Kamran; Dabbagh, Ali

2013-01-01

Background There is a considerable rate of fertility failure and this causes a great burden of untoward effects for patients. Usually a considerable number of these patients undergo anesthesia for their treatment. Objectives This study was designed to compare the effects of general and spinal anesthesia on these patients. Patients and Methods In a randomized clinical trial, after taking informed written consent from the patients, 200 patients entered the study; 100 in each. During a 2 year period, women aged 20 to 40 years entered the study (one group receiving spinal anesthesia and the other, receiving general anesthesia). Ovum retrieval protocols were the same. Nonparametric and parametric analyses were used for data analysis. P value less than 0.05 was considered significant. Results There was no difference between the two groups regarding demographic variables. 15 of 100 patients (15%) in the general anesthesia group and 27 of 100 patients (27%) in the spinal anesthesia group had successful pregnancy after IVF; so, spinal anesthesia increased significantly the chance of IVF success (P value < 0.001; Chi Square). Conclusions The results of this study demonstrated that spinal anesthesia increased the chance of fertilization success. PMID:24282775

Effects of Fertilization on the Vegetation Dynamics of Yougn Loblolly Pine Plantations

Treesearch

Ryan McKnight; Eric Heitzman

2004-01-01

We examined growth of loblolly pine (Pinus taeda L.) and non-pine vegetation in three 4- to 6-year-old plantations in Arkansas, Mississippi, and Louisiana that were fertilized with varying rates of N and P. Two years after treatment, pine d.b.h. growth had generally increased with fertilization rate, with significant differences in Arkansas and...

[Effects of controlled release nitrogen fertilizer application on dry matter accumulation and nitrogen balance of summer maize].

PubMed

Si, Dong-Xia; Cui, Zhen-Ling; Chen, Xin-Ping; Lü, Fu-Tang

2014-06-01

Effects of four controlled release nitrogen (N) fertilizers, including two kinds of polyester coated urea (Ncau, CRU) and phosphate (NhnP) and humic acid (NhnF) coated urea on assimilates accumulation and nitrogen balance of summer maize were investigated in a mode of one-time fertilization at the regional N recommended rate. The results showed that the N release curves of the two controlled release fertilizers CRU and Ncau matched well with the summer maize N uptake. Compared with the regional N recommendation rate, CRU could increase maize yield by 4.2% and Ncau could maintain the same yield level. CRU significantly increased the dry matter accumulation rate after anthesis of summer maize, but Ncau markedly increased the dry matter accumulated ratio before anthesis. Meanwhile, CRU could reduce the apparent N losses by 19 kg N x hm(-2) in the case of large precipitation. However, NhnF and NhnP caused the yield losses by 0.1%-8.9%, and enhanced the apparent N losses. Therefore, both CRU and Ncau with one-time fertilization could be a simplified alternative to the "total control, staging regulation" fertilization technique at the regional N recommended rate for summer maize production.

Faster fertilization rate in conspecific versus heterospecific matings in house mice.

PubMed

Dean, Matthew D; Nachman, Michael W

2009-01-01

Barriers to gene flow can arise at any stage in the reproductive sequence. Most studies of reproductive isolation focus on premating or postzygotic phenotypes, leaving the importance of differences in fertilization rate overlooked. Two closely related species of house mice, Mus domesticus and M. musculus, form a narrow hybrid zone in Europe, suggesting that one or more isolating factors operate in the face of ongoing gene flow. Here, we test for differences in fertilization rate using laboratory matings as well as in vitro sperm competition assays. In noncompetitive matings, we show that fertilization occurs significantly faster in conspecific versus heterospecific matings and that this difference arises after mating and before zygotes form. To further explore the mechanisms underlying this conspecific advantage, we used competitive in vitro assays to isolate gamete interactions. Surprisingly, we discovered that M. musculus sperm consistently outcompeted M. domesticus sperm regardless of which species donated ova. These results suggest that in vivo fertilization rate is mediated by interactions between sperm, the internal female environment, and/or contributions from male seminal fluid. We discuss the implications of faster conspecific fertilization in terms of reproductive isolation among these two naturally hybridizing species.

Total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta are significantly correlated with fertilization rates after intracytoplasmic sperm injection.

PubMed

Yelumalai, Suseela; Yeste, Marc; Jones, Celine; Amdani, Siti N; Kashir, Junaid; Mounce, Ginny; Da Silva, Sarah J Martins; Barratt, Christopher L; McVeigh, Enda; Coward, Kevin

2015-09-01

To study the relationship of total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta, with fertilization rates after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Laboratory study; controls vs. patients after IVF (n = 27) or ICSI (n = 17) treatment. Fertility center. A total of 44 semen samples, subjected to either IVF or ICSI treatment. Oocyte collection, ICSI or IVF, determination of sperm concentration and motility, and immunocytochemical analyses of phospholipase C zeta (PLCζ). None. Percentages of sperm exhibiting PLCζ. Significant positive correlation between ICSI fertilization rates and total levels, localization patterns, and the proportion (percentage) of sperm exhibiting PLCζ. Total levels, localization patterns, and the proportion of sperm exhibiting PLCζ are correlated with fertilization rates for ICSI, but not for IVF. Evaluating total levels, localization patterns, and proportions of PLCζ may represent a useful diagnostic tool for clinical purposes in men for whom IVF is not advised or has previously failed. This clinical study further supports the fundamental role of PLCζ in the oocyte activation process. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Rheumatic diseases and pregnancy: a national survey about practice patterns among rheumatologists and obstetricians.

PubMed

Fayad, Fouad; Ziade, Nelly; Karam, Ghada Abi; Ghaname, Wadih; Khamashta, Munther

2018-05-24

Management of rheumatic diseases (RD) is often problematic in pregnant patients, hence the need for guideline implementation. This survey-based study aimed to assess beliefs among obstetricians and rheumatologists about managing RD in pregnant Lebanese patients. Questionnaires were completed by a representative sample of rheumatologists and obstetricians practicing throughout Lebanon. Collected data included physicians' information, opinion on pregnancy in RD patients, compatible drugs with fertility, pregnancy and breastfeeding, references used in their clinical management, referral to specialists, and knowledge about guidelines. Qualitative variables were analysed using Chi-square or Fisher's exact tests, and quantitative variables using Wilcoxon or Student t-tests. Results were matched against a scoring system based on the EULAR/BSR guidelines. p-value <0.05 indicated statistical significance. Analysis showed high response rates of physicians, especially among rheumatologists. Overall, physicians practice was in concordance with international guidelines and only few misconceptions were reported. Systemic lupus erythematosus (SLE) was associated with risk on fertility, foetal malformation and eclampsia while anti-phospholipid (APL) syndrome was associated with miscarriage and vasculitis with eclampsia. Spondyloarthritis was considered 'safe' in pregnancy. Most physicians think that cyclophosphamide, leflunomide, methotrexate, mycophenolate mofetil and azathioprine compromise fertility, pregnancy, and breastfeeding. Our data showed relatively good concordance of the physicians' beliefs with the current literature and recommendations. However, we identified misconceptions about anti-rheumatic drugs safety in pregnancy and discrepancy between rheumatologists and obstetricians practices; hence the need for promoting collaboration between both specialties and disseminating knowledge to physicians and patients in the Middle East region.

Health system determinants of infant, child and maternal mortality: A cross-sectional study of UN member countries

PubMed Central

2011-01-01

Objective Few studies have examined the link between health system strength and important public health outcomes across nations. We examined the association between health system indicators and mortality rates. Methods We used mixed effects linear regression models to investigate the strength of association between outcome and explanatory variables, while accounting for geographic clustering of countries. We modelled infant mortality rate (IMR), child mortality rate (CMR), and maternal mortality rate (MMR) using 13 explanatory variables as outlined by the World Health Organization. Results Significant protective health system determinants related to IMR included higher physician density (adjusted rate ratio [aRR] 0.81; 95% Confidence Interval [CI] 0.71-0.91), higher sustainable access to water and sanitation (aRR 0.85; 95% CI 0.78-0.93), and having a less corrupt government (aRR 0.57; 95% CI 0.40-0.80). Out-of-pocket expenditures on health (aRR 1.29; 95% CI 1.03-1.62) were a risk factor. The same four variables were significantly related to CMR after controlling for other variables. Protective determinants of MMR included access to water and sanitation (aRR 0.88; 95% CI 0.82-0.94), having a less corrupt government (aRR 0.49; 95%; CI 0.36-0.66), and higher total expenditures on health per capita (aRR 0.84; 95% CI 0.77-0.92). Higher fertility rates (aRR 2.85; 95% CI: 2.02-4.00) were found to be a significant risk factor for MMR. Conclusion Several key measures of a health system predict mortality in infants, children, and maternal mortality rates at the national level. Improving access to water and sanitation and reducing corruption within the health sector should become priorities. PMID:22023970

Human oocyte calcium analysis predicts the response to assisted oocyte activation in patients experiencing fertilization failure after ICSI.

PubMed

Ferrer-Buitrago, M; Dhaenens, L; Lu, Y; Bonte, D; Vanden Meerschaut, F; De Sutter, P; Leybaert, L; Heindryckx, B

2018-01-10

Can human oocyte calcium analysis predict fertilization success after assisted oocyte activation (AOA) in patients experiencing fertilization failure after ICSI? ICSI-AOA restores the fertilization rate only in patients displaying abnormal Ca2+ oscillations during human oocyte activation. Patients capable of activating mouse oocytes and who showed abnormal Ca2+ profiles after mouse oocyte Ca2+ analysis (M-OCA), have variable responses to ICSI-AOA. It remains unsettled whether human oocyte Ca2+ analysis (H-OCA) would yield an improved accuracy to predict fertilization success after ICSI-AOA. Sperm activation potential was first evaluated by MOAT. Subsequently, Ca2+ oscillatory patterns were determined with sperm from patients showing moderate to normal activation potential based on the capacity of human sperm to generate Ca2+ responses upon microinjection in mouse and human oocytes. Altogether, this study includes a total of 255 mouse and 122 human oocytes. M-OCA was performed with 16 different sperm samples before undergoing ICSI-AOA treatment. H-OCA was performed for 11 patients who finally underwent ICSI-AOA treatment. The diagnostic accuracy to predict fertilization success was calculated based on the response to ICSI-AOA. Patients experiencing low or total failed fertilization after conventional ICSI were included in the study. All participants showed moderate to high rates of activation after MOAT. Metaphase II (MII) oocytes from B6D2F1 mice were used for M-OCA. Control fertile sperm samples were used to obtain a reference Ca2+ oscillation profile elicited in human oocytes. Donated human oocytes, non-suitable for IVF treatments, were collected and vitrified at MII stage for further analysis by H-OCA. M-OCA and H-OCA predicted the response to ICSI-AOA in 8 out of 11 (73%) patients. Compared to M-OCA, H-OCA detected the presence of sperm activation deficiencies with greater sensitivity (75 vs 100%, respectively). ICSI-AOA never showed benefit to overcome fertilization failure in patients showing normal capacity to generate Ca2+ oscillations in H-OCA and was likely to be beneficial in cases displaying abnormal H-OCA Ca2+ oscillations patterns. The scarce availability of human oocytes donated for research purposes is a limiting factor to perform H-OCA. Ca2+ imaging requires specific equipment to monitor fluorescence changes over time. H-OCA is a sensitive test to diagnose gamete-linked fertilization failure. H-OCA allows treatment counseling for couples experiencing ICSI failures to either undergo ICSI-AOA or to participate in gamete donation programs. The present data provide an important template of the Ca2+ signature observed during human fertilization in cases with normal, low and failed fertilization after conventional ICSI. This work was supported by the Flemish fund for scientific research (FWO-Vlaanderen, G060615N). The authors have no conflict of interest to declare. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

How big are educational and racial fertility differentials in the U.S.?

PubMed

Yang, Yang; Morgan, S Philip

2003-01-01

Using pooled data from the 1980, 1985, 1990 and 1995 CPS and 1988 and 1995 NSFG surveys, we show that shifts in fertility timing have occurred disproportionately for the more educated and for whites (compared to the less educated and to African Americans). Such timing shifts imply that the underlying period quantum of fertility is considerably higher for college-educated women and for whites than suggested by the standard total fertility rate. Applying the Bongaarts-Feeney model (1998), we decompose observed racial and educational differences in age-order-specific fertility rates and TFR into tempo and quantum components. We find that a modest part of educational differences and a substantial part of racial difference in period fertility can be attributed to differential changes in tempo. Analysis by race and education shows a clear interaction: higher fertility among African Americans is confined to the less educated.

Elective oocyte cryopreservation for deferred childbearing.

PubMed

Goldman, Kara N; Grifo, Jamie A

2016-12-01

Elective oocyte cryopreservation for deferred childbearing has gained popularity worldwide, commensurate with increased knowledge regarding age-related fertility decline. The purpose of this review is to summarize recent data regarding trends in delayed childbearing, review recent findings surrounding age-related fertility decline, acknowledge significant gaps in knowledge among patients and providers regarding fertility decline and review outcomes following elective oocyte cryopreservation. Despite an inevitable decline in fertility and increase in miscarriage with increasing female age, there is a growing worldwide trend to delay childbearing. Patients and providers alike demonstrate large gaps in knowledge surrounding age-related fertility decline. Oocyte cryopreservation is clinically approved for medically indicated fertility preservation, but a growing number of women are using oocyte cryopreservation to defer childbearing and maintain reproductive autonomy. Mounting data support the efficacy and safety of oocyte cryopreservation when used to electively defer childbearing, with recent studies demonstrating rates of euploidy, implantation and live birth rates equivalent to in-vitro fertilization (IVF) with fresh oocytes. Oocyte cryopreservation provides women with an option to defer childbearing and maintain reproductive autonomy, with IVF success rates on par with fresh IVF. However, it is critical that patients understand the limitations of oocyte cryopreservation. Greater education regarding age-related fertility decline should be geared toward patients and providers to prevent unintended childlessness.

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.

PubMed

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 (P<0.0001) expressions were influenced by a biotin×line interaction effect, where low-fertility line B hens receiving the high biotin level recorded respectively a 3.9 and 15.3% increase in avidin and AVR2 mRNA expression, although biotin did not affect these traits in line D hens. Control hens in line D had a dramatically higher AVR2 expression record (7.4-fold) compared with the control hens in line B. The correlation coefficients of fertility rate and avidin expression were 0.73 and 0.66 in lines B and D, respectively. However, the correlation of fertility and AVR2 (r=0.65) was significant for line D hens only. Overall, fertility rate and oviductal expression of avidin and AVR2 were dichotomously affected by oral biotin in low- and high-fertility line hens, where only low-fertility birds showed improvements in these attributes. © 2015 Poultry Science Association Inc.

From low to high fertility in Sulawesi (Indonesia) during the colonial period: explaining the 'first fertility transition'.

PubMed

Henley, David

2006-11-01

This paper examines the past transition from low to high fertility which, in Indonesia as elsewhere, preceded the return to lower birth rates. Data from two parts of the island of Sulawesi where fertility rose during the colonial period are used to explain both why it rose, and why it was originally low. Economic conditions, it is argued, were the most important factors, affecting fertility via the supply of income and the demand for labour. Two schematic models of the 'first fertility transition' are proposed. In areas with low population densities and area-extensive forms of agriculture responsive to commercial stimuli, birth rates rose as the growth of commerce raised levels of prosperity, facilitated marriage, and undermined institutions such as debt-slavery which had previously acted to restrict marital fertility. In densely populated areas with labour-intensive agriculture and heavy state taxation in labour, fertility rose in response to demands for women's (and possibly child) labour that did not necessarily lead to gains in income.

[Results, dilemmas, and suggestions concerning the demographic transition theory: causes of the decline of fertility in the nineteenth century].

PubMed

Diez Medrano, J

1985-11-01

This article discusses results of recent research on the fertility transition and some weak points in current knowledge whose further study could help orient research on Spain's fertility transition. The only completely valid conclusion to date on the demographic transition is that fertility and mortality are high in traditional societies and low in industrialized societies. It is clear that the demographic transition and modernization are inseparable, but the causal mechanisms producing the demographic changes remain unclear. The theory of demographic transition initially accorded great weight to the dual processes of urbanization and industrialization as causes of fertility decline, but the very early onset of the transition in France and the occurrence of fertility decline among peasants in Hungary constitute exceptions to the rule. The discovery by the Princeton group of researchers that there was no strong association between urbanization-industrialization and fertility decline in the European provinces they studied cast further doubt on the explanatory power of socioeconomic explanations. Recourse to cultural factors has been made in recent years, but few variables have been operationalized except language, religion, and political attitudes, and the weight of such variables has been found to have varied. Ideologic factors related to the crumbling of barriers to social mobility, the primacy of the individual, the importance attributed to education, and similar factors have been adduced to explain the transition. The diffusion of basic contraceptive knowledge or of the idea that family size is amenable to control has recently been advanced as a factor explaining fertility declines, but little empirical evidence is offered in support except that referring to the influence of family planning programs in developing countries, and the relevance of such data to earlier fertility transitions remains questionable. Demographic variables such as delayed age at marriage or infant mortality do not seem to have been universally significant. It is likely that the early declines of fertility represented both an adjustment to a new set of conditions and a diffusion of the idea of fertility control as a means of aspiring to the benefits of the industrial revolution. A microsociological focus permitting family reconstruction and deduction of individual-level characteristics, greater recourse to the methodologies of neighboring disciplines such as history, and very careful use of comparisons with present-day developing societies undergoing transitions might lead to an increased explanatory power for transition theory. Above all, the theoretical foundations of work in the area should be carefully formulated in order that progress in the area may continue.

Reproductive change in Bangladesh: evidence from recent data.

PubMed

Amin, R; Chowdhury, J; Ahmed, A U; Hill, R B; Kabir, M

1993-12-01

This analysis pertains to an examination of fertility trends, differences, contraceptive use, and fertility preferences in Bangladesh. Data were obtained from the 1969 National Impact Survey of Family Planning; the 1975 and 1989 Bangladesh Fertility Surveys; and the 1983, 1985, and 1991 Contraceptive Prevalence Surveys. Age specific fertility rates (ASFR), current pregnancy rates, and the mean number of children ever born (CEB) are the estimated fertility measures. The P/F ratios show a significant fertility decline since 1983. Total marital fertility declined from 7 births in the 1960s to 5.2 in the late 1980s. The average number of CEB declined from 4.3 in 1969 to 3.7 in 1991. The percentage of pregnant women declined from 13.3 to 10.6. The ASFR declined primarily among older married women. Fertility declined among all groups including landowners and landless, the educated and the uneducated, rural and urban populations. The extent of decline varies by group. The total marital fertility rate (TMFR) declined more for the educated and the urban populations. Chittagong region had the higher fertility regardless of the period. TMFR was lower among contraceptive users compared to nonusers. The increase in contraceptive use was from 4 to 40% between 1969 and 1991. The following factors affected the extent of fertility decline: contraceptive use, reduced child mortality concomitant with extended lactation and amenorrhea, increased malnutrition, and/or improvements in child survival. Fertility was depressed under conditions of increased poverty, which may stimulate contraceptive use and lead to malnutrition and subfecundity. The higher Chittagong fertility pattern is not explained by regional comparisons of pregnancy wastage, stillbirths, and induced abortion. Desire for no more children increased from 46 to 58% during 1969-91. The average preferred family size is declining. High density and deep-seated poverty explain fertility decline in regions other than Chittagong. Demand for contraception may increase with increases in family planning home visits and educational opportunities.

Improving Water Use Efficiency of Lettuce (Lactuca sativa L.) Using Phosphorous Fertilizers.

PubMed

Alkhader, Asad M F; Abu Rayyan, Azmi M

2013-01-01

A greenhouse pot experiment was conducted to evaluate the effect of phosphorous (P) fertilizers application to an alkaline calcareous soil on the water use efficiency (WUE) of lettuce cultivar "robinson" of iceberg type. Head fresh and dry weights, total water applied and WUE were affected significantly by the P fertilizer type and rate. P fertilizers addition induced a significant enhancement in the WUE and fresh and dry weights of the crop. A local phosphate rock (PR) applied directly was found to be inferior to the other types of P fertilizers (Mono ammonium phosphate (MAP), Single superphosphate (SSP), and Di ammonium phosphate ((DAP)). MAP fertilizer at 375 and 500 kg P2O5/ha application rates recorded the highest significant values of head fresh weight and WUE, respectively.

Estimating the probability of elevated nitrate (NO2+NO3-N) concentrations in ground water in the Columbia Basin Ground Water Management Area, Washington

USGS Publications Warehouse

Frans, Lonna M.

2000-01-01

Logistic regression was used to relate anthropogenic (man-made) and natural factors to the occurrence of elevated concentrations of nitrite plus nitrate as nitrogen in ground water in the Columbia Basin Ground Water Management Area, eastern Washington. Variables that were analyzed included well depth, depth of well casing, ground-water recharge rates, presence of canals, fertilizer application amounts, soils, surficial geology, and land-use types. The variables that best explain the occurrence of nitrate concentrations above 3 milligrams per liter in wells were the amount of fertilizer applied annually within a 2-kilometer radius of a well and the depth of the well casing; the variables that best explain the occurrence of nitrate above 10 milligrams per liter included the amount of fertilizer applied annually within a 3-kilometer radius of a well, the depth of the well casing, and the mean soil hydrologic group, which is a measure of soil infiltration rate. Based on the relations between these variables and elevated nitrate concentrations, models were developed using logistic regression that predict the probability that ground water will exceed a nitrate concentration of either 3 milligrams per liter or 10 milligrams per liter. Maps were produced that illustrate the predicted probability that ground-water nitrate concentrations will exceed 3 milligrams per liter or 10 milligrams per liter for wells cased to 78 feet below land surface (median casing depth) and the predicted depth to which wells would need to be cased in order to have an 80-percent probability of drawing water with a nitrate concentration below either 3 milligrams per liter or 10 milligrams per liter. Maps showing the predicted probability for the occurrence of elevated nitrate concentrations indicate that the irrigated agricultural regions are most at risk. The predicted depths to which wells need to be cased in order to have an 80-percent chance of obtaining low nitrate ground water exceed 600 feet in the irrigated agricultural regions, whereas wells in dryland agricultural areas generally need a casing in excess of 400 feet. The predicted depth to which wells need to be cased to have at least an 80-percent chance to draw water with a nitrate concentration less than 10 milligrams per liter generally did not exceed 800 feet, with a 200-foot casing depth typical of the majority of the area.

Narrowing the agronomic yield gap with improved nitrogen use efficiency: a modeling approach.

PubMed

Ahrens, T D; Lobell, D B; Ortiz-Monasterio, J I; Li, Y; Matson, P A

2010-01-01

Improving nitrogen use efficiency (NUE) in the major cereals is critical for more sustainable nitrogen use in high-input agriculture, but our understanding of the potential for NUE improvement is limited by a paucity of reliable on-farm measurements. Limited on-farm data suggest that agronomic NUE (AE(N)) is lower and more variable than data from trials conducted at research stations, on which much of our understanding of AE(N) has been built. The purpose of this study was to determine the magnitude and causes of variability in AE(N) across an agricultural region, which we refer to as the achievement distribution of AE(N). The distribution of simulated AE(N) in 80 farmers' fields in an irrigated wheat system in the Yaqui Valley, Mexico, was compared with trials at a local research center (International Wheat and Maize Improvement Center; CIMMYT). An agroecosystem simulation model WNMM was used to understand factors controlling yield, AE(N), gaseous N emissions, and nitrate leaching in the region. Simulated AE(N) in the Yaqui Valley was highly variable, and mean on-farm AE(N) was 44% lower than trials with similar fertilization rates at CIMMYT. Variability in residual N supply was the most important factor determining simulated AE(N). Better split applications of N fertilizer led to almost a doubling of AE(N), increased profit, and reduced N pollution, and even larger improvements were possible with technologies that allow for direct measurement of soil N supply and plant N demand, such as site-specific nitrogen management.

Comparison of Carbon Sequestration Rates and Energy Balance of Turf in the Denver Urban Ecosystem and an Adjacent Native Grassland

NASA Astrophysics Data System (ADS)

Thienelt, T. S.; Anderson, D. E.; Powell, K. M.

2011-12-01

Urban ecosystems are currently characterized by rapid growth, are expected to continually expand and, thus, represent an important driver of land use change. A significant component of urban ecosystems is lawns, potentially the single largest irrigated "crop" in the U.S. Beginning in March of 2011 (ahead of the growing season), eddy covariance measurements of net carbon exchange and evapotranspiration along with energy balance fluxes were conducted for a well-watered, fertilized lawn (rye-bluegrass-mix) in metropolitan Denver and for a nearby tallgrass prairie (big bluestem, switchgrass, cheatgrass, blue grama). Due to the semi-arid climate conditions of the Denver region, differences in management (i.e., irrigation and fertilization) are expected to have a discernible impact on ecosystem productivity and thus on carbon sequestration rates, evapotranspiration, and the sensible and latent heat partitioning of the energy balance. By mid-July, preliminary data indicated that cumulative evapotranspiration was approximately 270 mm and 170 mm for urban and native grasslands, respectively, although cumulative carbon sequestration at that time was similar for both (approximately 40 mg/m2). However, the pattern of carbon exchange differed between the grasslands. Both sites showed daily net uptake of carbon starting in late May, but the urban lawn displayed greater diurnal variability as well as greater uptake rates in general, especially following fertilization in mid-June. In contrast, the trend of carbon uptake at the prairie site was occasionally reversed following strong convective precipitation events, resulting in a temporary net release of carbon. The continuing acquisition of data and investigation of these relations will help us assess the potential impact of urban growth on regional carbon sequestration.

Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

PubMed

Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

2014-01-01

Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

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

PubMed

Schkolnik, S

1983-08-01

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

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

PubMed Central

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

2017-01-01

Introduction: HIV reduces fertility through biological and social pathways, and antiretroviral treatment (ART) can ameliorate these effects. In northern Malawi, ART has been available since 2007 and lifelong ART is offered to all pregnant or breastfeeding HIV-positive women. Methods: Using data from the Karonga Health and Demographic Surveillance Site in Malawi from 2005 to 2014, we used total and age-specific fertility rates and Cox regression to assess associations between HIV and ART use and fertility. We also assessed temporal trends in in utero and breastfeeding HIV and ART exposure among live births. Results: From 2005 to 2014, there were 13,583 live births during approximately 78,000 person years of follow-up of women aged 15–49 years. The total fertility rate in HIV-negative women decreased from 6.1 [95% confidence interval (CI): 5.5 to 6.8] in 2005–2006 to 5.1 (4.8–5.5) in 2011–2014. In HIV-positive women, the total fertility rate was more stable, although lower, at 4.4 (3.2–6.1) in 2011–2014. In 2011–2014, compared with HIV-negative women, the adjusted (age, marital status, and education) hazard ratio was 0.7 (95% CI: 0.6 to 0.9) and 0.8 (95% CI: 0.6 to 1.0) for women on ART for at least 9 months and not (yet) on ART, respectively. The crude fertility rate increased with duration on ART up to 3 years before declining. The proportion of HIV-exposed infants decreased, but the proportion of ART-exposed infants increased from 2.4% in 2007–2010 to 3.5% in 2011–2014. Conclusions: Fertility rates in HIV-positive women are stable in the context of generally decreasing fertility. Despite a decrease in HIV-exposed infants, there has been an increase in ART-exposed infants. PMID:28653969

Can we still learn something from the relationship between fertility and mother's employment? Evidence from developing countries.

PubMed

Cáceres-Delpiano, Julio

2012-02-01

In this work, I study the impact of fertility on mothers' employment for a sample of developing countries. Using the event of multiple births as an instrumental variable (IV) for fertility, I find that having children has a negative impact on female employment. In addition, three types of heterogeneity are found. First, the magnitude of the impact depends on the birth at which the increase in fertility takes place. Second, the types of jobs affected by a fertility shock (multiple births) are jobs identified with a higher degree of informality, such as self-employment or unpaid jobs. Finally, the heterogeneity analysis reveals that an unexpected change in fertility is stronger at a higher education level of the mother and in urban areas.

Soil fertility assessment in the 3 PG model using site index in the southeastern United States

Treesearch

Santosh Subedi; Thomas R. Fox

2016-01-01

Soil fertility is one of the most important, yet least understood aspects of forest ecosystems. Study of soil fertility in forest ecosystems is complicated by the complex relationship between soil properties and stand productivity and immense variability in properties and characteristics of soils within relatively small geographic areas. Furthermore, the deep rooting...

Follicular fluid dehydroepiandrosterone sulfate is a credible marker of oocyte maturity and pregnancy outcome in conventional in vitro fertilization cycles.

PubMed

Chimote, Natachandra M; Nath, Nirmalendu M; Chimote, Nishad N; Chimote, Bindu N

2015-01-01

To investigate if the level of dehydroepiandrosterone sulfate (DHEA-s) in follicular fluid (FF) influences the competence of oocytes to fertilize, develop to the blastocyst stage, and produce a viable pregnancy in conventional in vitro fertilization (IVF) cycles. Prospective study of age-matched, nonpolycystic ovary syndrome (PCOS) women undergoing antagonist stimulation protocol involving conventional insemination and day 5 blastocyst transfer. FF levels of DHEA-s and E2 were measured by a radio-immuno-assay method using diagnostic kits. Fertilization rate, embryo development to the blastocyst stage and live birth rate were main outcome measures. Cycles were divided into pregnant/nonpregnant groups and also into low/medium/high FF DHEA-s groups. Statistical analysis was done by GraphPad Prism V software. FF DHEA-s levels were significantly higher in pregnant (n = 111) compared to nonpregnant (n = 381) group (1599 ± 77.45 vs. 1372 ± 40.47 ng/ml; P = 0.01). High (n = 134) FF DHEA-s group had significantly higher percentage of metaphase II (MII) oocytes (91.5 vs. 85.54 vs. 79.44%, P < 0.0001), fertilization rate (78.86 vs. 74.16 vs. 71.26%, P < 0.0001), cleavage rate (83.67 vs. 69.1 vs. 66.17%, P = 0.0002), blastocyst formation rate (37.15 vs. 33.01 vs. 26.95%, P < 0.0001), and live birth rate (29.85 vs. 22.22 vs. 14.78%, P = 0.017) compared to medium (n = 243) and low (n = 115) FF DHEA-s groups, respectively despite comparable number of oocytes retrieved and number of blastocysts transferred. FF DHEA-s levels correlated significantly with the attainment of MII oocytes (Pearson r = 0.41) and fertilization rates (Pearson r = 0.35). FF DHEA-s level influences the oocyte maturation process and is predictive of fertilization, embryo development to the blastocyst stage and live birth rates in non-PCOS women undergoing conventional IVF cycles.

Long-term Nutrient Fertilization Increases CO2 Loss in Arctic Tundra

NASA Astrophysics Data System (ADS)

Graham, L. M.; Natali, S.; Rastetter, E. B.; Shaver, G. R.; Risk, D. A.; Loranty, M. M.; Jastrow, J. D.

2015-12-01

As anthropogenic climate change warms the Arctic, organic carbon (C) trapped in permafrost is at an increased risk of being released to the atmosphere as carbon dioxide (CO2). At the same time, higher rates of decomposition may increase nutrient availability and enhance plant growth, leading to an uptake of C that may offset respiratory losses. Arctic tundra ecosystems are highly nitrogen (N) limited, and the indirect effects of warming on nutrient availability will be the most likely outcome of increased temperature on plant productivity. This study aims to understand the effects of nutrient addition on arctic CO2 and H2O exchange in a tundra ecosystem at Toolik Lake Field Station, Alaska. The nutrient addition experiment, which began in 2006, is comprised of 7 fertilization treatments: 0.5, 1, 2, 5, and 10 g m-2 of N as NO3- and NH4+ (1:1) with 0.25, 0.5, 1, 2.5, and 5 g m-2 of phosphorus as PO43-; 5 g m-2 of N as NO3-; 5 g m-2 of N as NH4+, and one control plot. Plot-level CO2 and H2O exchange was measured at 5 light levels 7 times over a four-week period in June and July 2015. We measured ecosystem CO2 and H2O exchange using a rectangular plexiglass chamber (0.49 m2) that was connected to an infrared gas analyzer (LI-840). Other ecosystem variables measured include thaw depth, soil moisture and temperature, and normalized difference vegetation index. After 10 years of nutrient addition, fertilization significantly altered ecosystem C cycling. Soil respiration was greatest in the highest fertilization treatment (2.97 μmol m-2 s-1), increasing linearly with nutrient level at a rate of 0.133 μmol m-2 s-1 per g m-2 of N added (R2=0.914). Net CO2 uptake was greatest under highest fertilization (-2.06 μmol m-2 s-1), decreasing linearly with nutrient addition at a rate of -0.068 μmol m-2 s-1 per g m-2 of N added (R2=0.687). These results suggest that as nutrients become more available under a warmer climate, plant productivity increases may not offset respiratory losses, leading to a positive feedback to global climate.

Sperm traits in farmed and wild Atlantic salmon Salmo salar.

PubMed

Camarillo-Sepulveda, N; Hamoutene, D; Lush, L; Burt, K; Volkoff, H; Fleming, I A

2016-02-01

Differences in sperm metabolism and morphology between wild and non-local farmed Atlantic salmon Salmo salar were assessed by measuring metabolic enzyme activities and length of sperm flagella. No differences were observed between wild and farmed S. salar sperm with regards to cell counts or any of the biochemical variables assessed. Flagella of sperm cells were significantly longer in wild than farmed S. salar; however, this did not result in higher energy levels or different fertilization rates. © 2015 The Fisheries Society of the British Isles.

Zinc transformations in neutral soil and zinc efficiency in maize fertilization.

PubMed

Alvarez, Jose M; Gonzalez, Demetrio

2006-12-13

The effect of six Zn sources (Zn-phenolate, Zn-EDDHA, Zn-EDTA, Zn-lignosulfonate, Zn-polyflavonoid, and Zn-glucoheptonate) was studied by applying different Zn levels to a representative Calcic Haploxeralf neutral soil (the predominant clay is montmorillonite) in incubation and greenhouse experiments. Zinc soil behavior was evaluated by sequential DTPA and Mehlich-3 extraction procedures. In the incubation experiment, the highest percentage recovery values of Zn applied to soil occurred in the water-soluble plus exchangeable fraction (29%) in fertilization with 20 mg of Zn kg(-1) of Zn-EDTA fertilizer. In the greenhouse experiment with maize (Zea mays L.), a comparison of different Zn carriers showed that the application of six fertilizers did not significantly increase the plant dry matter yield among fertilizer treatments. The highest yield occurred when 20 mg of Zn kg(-1) was applied as Zn-EDDHA fertilizer (79.4 g per pot). The relative effectiveness of the Zn sources in increasing Zn concentration in plants was in the following order: Zn-EDTA (20 mg kg(-1)) > Zn-EDDHA (20 mg kg(-1)) approximately Zn-EDTA (10 mg kg(-1)) > Zn-EDDHA (10 mg kg(-1)) approximately Zn-phenolate (both rates) approximately Zn-polyflavonoid (both rates) approximately Zn-lignosulfonate (both rates) approximately Zn-glucoheptonate (both rates) > untreated Zn. The highest amounts of Zn taken up by the plants occurred when Zn was applied as Zn-EDTA fertilizer (20 mg kg(-1), 7.44 mg of Zn per pot; 10 mg kg(-1) Zn rate, 3.93 mg of Zn per pot) and when Zn was applied as Zn-EDDHA fertilizer (20 mg kg(-1) Zn rate, 4.66 mg Zn per pot). After the maize crop was harvested, sufficient quantities of available Zn remained in the soil (DTPA- or Mehlich-3-extractable Zn) for another harvest.

Over 150 years of long-term fertilization alters spatial scaling of microbial biodiversity

DOE PAGES

Liang, Yuting; Wu, Liyou; Clark, Ian M.; ...

2015-04-07

Spatial scaling is a critical issue in ecology, but how anthropogenic activities like fertilization affect spatial scaling is poorly understood, especially for microbial communities. Here, we determined the effects of long-term fertilization on the spatial scaling of microbial functional diversity and its relationships to plant diversity in the 150-year-old Park Grass Experiment, the oldest continuous grassland experiment in the world. Nested samples were taken from plots with contrasting inorganic fertilization regimes, and community DNAs were analyzed using the GeoChip-based functional gene array. The slopes of microbial gene-area relationships (GARs) and plant species-area relationships (SARs) were estimated in a plot receivingmore » nitrogen (N), phosphorus (P), and potassium (K) and a control plot without fertilization. Our results indicated that long-term inorganic fertilization significantly increased both microbial GARs and plant SARs. Microbial spatial turnover rates (i.e., z values) were less than 0.1 and were significantly higher in the fertilized plot (0.0583) than in the control plot (0.0449) (P < 0.0001). The z values also varied significantly with different functional genes involved in carbon (C), N, P, and sulfur (S) cycling and with various phylogenetic groups (archaea, bacteria, and fungi). Similarly, the plant SARs increased significantly (P < 0.0001), from 0.225 in the control plot to 0.419 in the fertilized plot. Soil fertilization, plant diversity, and spatial distance had roughly equal contributions in shaping the microbial functional community structure, while soil geochemical variables contributed less. These results indicated that long-term agricultural practice could alter the spatial scaling of microbial biodiversity. Determining the spatial scaling of microbial biodiversity and its response to human activities is important but challenging in microbial ecology. Most studies to date are based on different sites that may not be truly comparable or on short-term perturbations, and hence, the results observed could represent transient responses. This study examined the spatial patterns of microbial communities in response to different fertilization regimes at the Rothamsted Research Experimental Station, which has become an invaluable resource for ecologists, environmentalists, and soil scientists. The current study is the first showing that long-term fertilization has dramatic impacts on the spatial scaling of microbial communities. By identifying the spatial patterns in response to long-term fertilization and their underlying mechanisms, this study makes fundamental contributions to predictive understanding of microbial biogeography.« less

Over 150 years of long-term fertilization alters spatial scaling of microbial biodiversity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Yuting; Wu, Liyou; Clark, Ian M.

Spatial scaling is a critical issue in ecology, but how anthropogenic activities like fertilization affect spatial scaling is poorly understood, especially for microbial communities. Here, we determined the effects of long-term fertilization on the spatial scaling of microbial functional diversity and its relationships to plant diversity in the 150-year-old Park Grass Experiment, the oldest continuous grassland experiment in the world. Nested samples were taken from plots with contrasting inorganic fertilization regimes, and community DNAs were analyzed using the GeoChip-based functional gene array. The slopes of microbial gene-area relationships (GARs) and plant species-area relationships (SARs) were estimated in a plot receivingmore » nitrogen (N), phosphorus (P), and potassium (K) and a control plot without fertilization. Our results indicated that long-term inorganic fertilization significantly increased both microbial GARs and plant SARs. Microbial spatial turnover rates (i.e., z values) were less than 0.1 and were significantly higher in the fertilized plot (0.0583) than in the control plot (0.0449) (P < 0.0001). The z values also varied significantly with different functional genes involved in carbon (C), N, P, and sulfur (S) cycling and with various phylogenetic groups (archaea, bacteria, and fungi). Similarly, the plant SARs increased significantly (P < 0.0001), from 0.225 in the control plot to 0.419 in the fertilized plot. Soil fertilization, plant diversity, and spatial distance had roughly equal contributions in shaping the microbial functional community structure, while soil geochemical variables contributed less. These results indicated that long-term agricultural practice could alter the spatial scaling of microbial biodiversity. Determining the spatial scaling of microbial biodiversity and its response to human activities is important but challenging in microbial ecology. Most studies to date are based on different sites that may not be truly comparable or on short-term perturbations, and hence, the results observed could represent transient responses. This study examined the spatial patterns of microbial communities in response to different fertilization regimes at the Rothamsted Research Experimental Station, which has become an invaluable resource for ecologists, environmentalists, and soil scientists. The current study is the first showing that long-term fertilization has dramatic impacts on the spatial scaling of microbial communities. By identifying the spatial patterns in response to long-term fertilization and their underlying mechanisms, this study makes fundamental contributions to predictive understanding of microbial biogeography.« less

Soil Fertilization Leads to a Decline in Between-Samples Variability of Microbial Community δ13C Profiles in a Grassland Fertilization Experiment

PubMed Central

Veresoglou, Stavros D.; Thornton, Barry; Menexes, George; Mamolos, Andreas P.; Veresoglou, Demetrios S.

2012-01-01

Gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure the 13C/12C ratios of PLFAs at natural abundance levels from a temperate grassland nitrogen (N) and phosphorus (P) factorial fertilization experiment in northern Greece. In each plot two rhizosphere samples were derived centred around individual Agrostis capillaris and Prunella vulgaris plants. It was hypothesized that the isotopic signal of microbes that preferentially feed on recalcitrant litter such as fungi would be modified by fertilization more strongly than that of opportunistic microbes using labile C. Microbial community δ13C was affected by both P and N fertilization regime and plant species identity. However, we have been unable to detect significant nutrient effects on individual groups of microbes when analyzed separately in contrast to our original hypothesis. Intra-treatment variability, as evaluated from Hartley’s F max tests in the five first PCA components axes as well as the size of the convex hulls in PCA scoreplots and Mahalanobis distances, was considerably higher in the non-fertilized controls. Moreover, a significant relationship was established between the change in PLFA abundances and their respective changes in δ13C for the aggregate of samples and those simultaneously fertilized with N and P. We conclude that use of compound specific isotope analysis in the absence of labelling represents a valuable and overlooked tool in obtaining an insight of microbial community functioning. PMID:22962602

Reduced rates of controlled-release fertilizer lower potential nitrogen leaching from a Wisconsin bare-root tree nursery

Treesearch

Ryosuke Fujinuma; Nick J. Balster; Hyung-Kyung. Lee

2011-01-01

Controlled-release fertilizer (CRF) typically increases nitrogen (N) fertilizer uptake and lowers N lost from the rooting zone via leaching. However, questions remain as to whether lower rates of CRF could further increase this efficiency, especially in sandy bare-root nurseries in Wisconsin. We hypothesized that: 1) a reduced CRF application at 60 percent of the...

Revised Birth and Fertility Rates for the 1990s and New Rates for Hispanic Populations, 2000 and 2001: United States.

ERIC Educational Resources Information Center

Hamilton, Brady E.; Sutton, Paul D.; Ventura, Stephanie J.

2003-01-01

This report presents revised birth and fertility rates for 1991-1999, plus previously published rates for 2000-2001, based on populations consistent with the April 1, 2000 census. Revised rates for Hispanic subgroups are also included. Rates are presented by age, race, and Hispanic origin of mother; by age, race, Hispanic origin, and marital…

Influences of selected socioeconomic and demographic variables on fertility in Bangladesh.

PubMed

Islam, S M; Khan, H T

1995-06-01

"The data used in this study are from the 1989 Bangladesh Fertility Survey (1989 BFS), which was conducted...by the National Institute of Population Research and Training (NIPORT)....A two-stage probability sample design was used for the survey.... It has been found that female age at marriage has a significant direct negative influence on fertility. Thus, raising the age at marriage by implementing a minimum-age marriage law is likely to lower fertility on a national scale. Duration of breast-feeding is also found to have a significant direct negative effect on fertility....Fetal loss appears to have a significant direct positive effect on fertility...which means that mothers who have experienced fetal loss are found to have higher fertility.... Maternal mortality is also high in Bangladesh. Therefore, it is essential to provide primary health care, particularly maternal and child health care, for surviving children." excerpt

Marital fertility and income: moderating effects of the Church of Jesus Christ of Latter-day Saints religion in Utah.

PubMed

Stanford, Joseph B; Smith, Ken R

2013-03-01

Utah has the highest total fertility of any state in the United States and also the highest proportion of population affiliated with the Church of Jesus Christ of Latter-day Saints (the LDS or Mormon Church). Data were used from the 1996 Utah Health Status Survey to investigate how annual household income, education and affiliation with the LDS Church affect fertility (children ever born) for married women in Utah. Younger age and higher education were negatively correlated with fertility in the sample as a whole and among non-LDS respondents. Income was negatively associated with fertility among non-LDS respondents. However, income was positively correlated with fertility among LDS respondents. This association persisted when instrumental variables were used to address the potential simultaneous equations bias arising from the potential endogeneity of income and fertility. The LDS religion's pronatalist stance probably encourages childbearing among those with higher income.

Population growth is a variable open to change

NASA Astrophysics Data System (ADS)

Potts, M.

2016-12-01

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

Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields.

PubMed

Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping; Zhao, Xing; Ye, Xinyi

2016-09-15

The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375kgN/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH4 mainly appeared at the vegetative phase, and emission peaks of CO2, and N2O mainly appeared at reproductive phase of rice growth. The CO2 flux was significantly correlated with soil temperature, while the CH4 flux was influenced by logging water remaining period and N2O flux was significantly associated with nitrogen application rates. This study showed that 225kgN/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO2-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89t/ha in paddy fields. Copyright © 2016 Elsevier B.V. All rights reserved.

Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.

PubMed

Dougherty, Warwick J; Nicholls, Paul J; Milham, Paul J; Havilah, Euie J; Lawrie, Roy A

2008-01-01

Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales. Total P concentrations in runoff were high (0.86-11.13 mg L(-1)) even from the control plot (average 1.94 mg L(-1)). Phosphorus fertilizer significantly (P < 0.001) increased runoff P concentrations (average runoff P concentrations from the P(20), P(40), and P(80) treatments were 2.78, 3.32, and 5.57 mg L(-1), respectively). However, the magnitude of the effect of P fertilizer varied between runoff events (P < 0.01). Further analysis revealed the combined effects on runoff P concentration of P rate, P rate x number of applications (P < 0.001), P rate x time since fertilizer (P < 0.001), dung P (P < 0.001), time since grazing (P < 0.05), and pasture biomass (P < 0.001). A conceptual model of the sources of P in runoff comprising three components is proposed to explain the mobilization of P in runoff and to identify strategies to reduce runoff P concentrations. Our data suggest that the principal strategy for minimizing runoff P concentrations from grazed dairy pastures should be the maintenance of soil P at or near the agronomic optimum by the use of appropriate rates of P fertilizer.

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

PubMed

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 competitive displacement by Zn. Finally, the observed acidification of soils with fertilizer application will also contribute to metal solubilisation.

Empirical findings on socioeconomic determinants of fertility differentials in Costa Rica.

PubMed

Carvajal, M J; Geithman, D T

1986-01-01

"This paper seeks to (1) identify socioeconomic variables that are expected to generate fertility differentials; (2) hypothesize the direction and magnitude of the effect of each variable by reference to a demand-for-children model; and (3) test empirically the model using evidence from Costa Rica. The estimates are obtained from a ten-percent systematic random sample of all Costa Rican individual-family households. There are 15,924 families in the sample...." The authors specifically seek "to capture the effects of changing relative prices and available income and time constraints on parental preferences for children. Least-squares estimates show statistically significant relationships between household fertility and opportunity cost of time, parental education, occurrence of an extended family, medical care, household sanitation, economic sector of employment, and household stock of nonhuman capital." excerpt

Novel and traditional traits of frozen-thawed porcine sperm related to in vitro fertilization success

USDA-ARS?s Scientific Manuscript database

Cryopreserved semen allows the use of single ejaculates for repeated analyses, potentially improving in vitro fertilization (IVF) consistency by eliminating inter-ejaculate variability observed with fresh semen. However, the freezing and thawing processes result in compromised sperm function and IVF...

Zebrafish reproduction: revisiting in vitro fertilization to increase sperm cryopreservation success.

PubMed

Hagedorn, Mary; Carter, Virginia L

2011-01-01

Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 10(6) cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 10(6) motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization.

Zebrafish Reproduction: Revisiting In Vitro Fertilization to Increase Sperm Cryopreservation Success

PubMed Central

Hagedorn, Mary; Carter, Virginia L.

2011-01-01

Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 106 cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 106 motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization. PMID:21698162

Coapplication of Chicken Litter Biochar and Urea Only to Improve Nutrients Use Efficiency and Yield of Oryza sativa L. Cultivation on a Tropical Acid Soil

PubMed Central

Maru, Ali; Haruna, Osumanu Ahmed; Charles Primus, Walter

2015-01-01

The excessive use of nitrogen (N) fertilizers in sustaining high rice yields due to N dynamics in tropical acid soils not only is economically unsustainable but also causes environmental pollution. The objective of this study was to coapply biochar and urea to improve soil chemical properties and productivity of rice. Biochar (5 t ha−1) and different rates of urea (100%, 75%, 50%, 25%, and 0% of recommended N application) were evaluated in both pot and field trials. Selected soil chemical properties, rice plants growth variables, nutrient use efficiency, and yield were determined using standard procedures. Coapplication of biochar with 100% and 75% urea recommendation rates significantly increased nutrients availability (especially P and K) and their use efficiency in both pot and field trials. These treatments also significantly increased rice growth variables and grain yield. Coapplication of biochar and urea application at 75% of the recommended rate can be used to improve soil chemical properties and productivity and reduce urea use by 25%. PMID:26273698

Analysis of limited fertility in intracytoplasmic sperm injection of sperm obtained by electroejaculation

PubMed Central

Nakamura, Yoshihiro; Kitamura, Masaya; Nishimura, Kenji; Tsujimura, Akira; Takeyama, Masami; Kondoh, Nobuyuki; Miyazaki, Kazunori; Okuyama, Akihiko

2004-01-01

Background and Aims:  We correlated findings in semen from patients with ejaculatory dysfunction with results of in vitro fertilization using their electroejaculated sperm. Methods and Results:  Electroejaculation was carried out in six patients with the above‐mentioned criteria for a total of eight times. Sperm was obtained in six attempts. Intracytoplasmic injection of these sperm was performed in 156 eggs. Sixty‐seven eggs were fertilized; most of these were injected with motile sperm. Two women became pregnant, both after injection with motile sperm. As previously reported, electroejaculated sperm showed low motility and a low fertilization rate, but even motile sperm had a low fertilization rate. Conclusion:  The results of the present study suggest the importance in fertilization of undetermined factors in addition to sperm motility. (Reprod Med Biol 2004; 3: 9–12) PMID:29662380

Reduced glutathione enhances fertility of frozen/thawed C57BL/6 mouse sperm after exposure to methyl-beta-cyclodextrin.

PubMed

Takeo, Toru; Nakagata, Naomi

2011-11-01

Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that methyl-beta-cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of methyl-beta-cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-beta-cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, 2-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using methyl-beta-cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse sperm.

Intragenomic conflict in populations infected by Parthenogenesis Inducing Wolbachia ends with irreversible loss of sexual reproduction

PubMed Central

2010-01-01

Background The maternally inherited, bacterial symbiont, parthenogenesis inducing (PI) Wolbachia, causes females in some haplodiploid insects to produce daughters from both fertilized and unfertilized eggs. The symbionts, with their maternal inheritance, benefit from inducing the production of exclusively daughters, however the optimal sex ratio for the nuclear genome is more male-biased. Here we examine through models how an infection with PI-Wolbachia in a previously uninfected population leads to a genomic conflict between PI-Wolbachia and the nuclear genome. In most natural populations infected with PI-Wolbachia the infection has gone to fixation and sexual reproduction is impossible, specifically because the females have lost their ability to fertilize eggs, even when mated with functional males. Results The PI Wolbachia infection by itself does not interfere with the fertilization process in infected eggs, fertilized infected eggs develop into biparental infected females. Because of the increasingly female-biased sex ratio in the population during a spreading PI-Wolbachia infection, sex allocation alleles in the host that cause the production of more sons are rapidly selected. In haplodiploid species a reduced fertilization rate leads to the production of more sons. Selection for the reduced fertilization rate leads to a spread of these alleles through both the infected and uninfected population, eventually resulting in the population becoming fixed for both the PI-Wolbachia infection and the reduced fertilization rate. Fertilization rate alleles that completely interfere with fertilization ("virginity alleles") will be selected over alleles that still allow for some fertilization. This drives the final resolution of the conflict: the irreversible loss of sexual reproduction and the complete dependence of the host on its symbiont. Conclusions This study shows that dependence among organisms can evolve rapidly due to the resolution of the conflicts between cytoplasmic and nuclear genes, and without requiring a mutualism between the partners. PMID:20667099

The secretory products of Trichomonas vaginalis decrease fertilizing capacity of mice sperm in vitro

PubMed Central

Roh, Jaesook; Lim, Young-Su; Seo, Min-Young; Choi, Yuri; Ryu, Jae-Sook

2015-01-01

Trichomonas vaginalis infection is one of the most prevalent sexually transmitted infections in humans and is now recognized as an important cause of infertility in men. There is little information about the effect of extracellular polymeric substances (EPS) from T. vaginalis on sperm, but previous reports do not provide a conclusive description of the functional integrity of the sperm. To investigate the impact of EPS on the fertilizing capacity of sperm, we assessed sperm motility, acrosomal status, hypo-osmotic swelling, and in vitro fertilization rate after incubating the sperm with EPS in vitro using mice. The incubation of sperm with EPS significantly decreased sperm motility, viability, and functional integrity in a concentration and time-dependent manner. These effects on sperm quality also resulted in a decreased fertilization rate in vitro. This is the first report that demonstrates the direct negative impact of the EPS of T. vaginalis on the fertilization rate of sperm in vitro. However, further study should be performed using human sperm to determine if EPS has similar negative impact on human sperm fertilizing capacity in vitro. PMID:25578937

Discrimination of the effects on zebrafish reproduction from pollutants in drinking water via female, via male and/or via fecundation water.

PubMed

Martínez-Sales, M; García-Ximénez, F; Espinós, F J

2016-08-01

The lack of preventive policy legislation and the low removal rate of organic pollutants in conventional potabilization treatments lead to some of them being present in drinking water. The problem arises because some of these substances have detrimental effects on human reproduction health, via females, via males or even both. In this work, we established the zebrafish as a bioindicator of these types of substances with the goal of discriminating the effects through three different pathways: male, female or water where the fertilization took place. For this purpose, four parameters were analysed: fertility rate, hatching rate and survival and abnormalities rates. So, for each parameter two groups were formed, according to whether adult males or females were reared in bottled spring water (Z) or tap water (B) and if the in vitro fertilization took place in water Z or B. Results revealed a decline in the fertility and hatching rate in water B, due to a water effect. The most plausible explanation could be the presence of substances which affect the micropyle and chorion. Moreover, a decrease in the fertility rate due to an effect over the female was also observed, but in this case by an alteration of the oocyte quality.

International investigation into the relationship between social expenditure for family and total fertility rate.

PubMed

Motoki, Airi; Shinohara, Ryoji; Yamagata, Zentaro

2016-01-01

Purpose Declining birth rates are an important social issue worldwide, and allocating resources to benefits for child-rearing households is a necessary countermeasure. In this study, we investigate and compare the relationship between child-related social security costs and total fertility rate internationally.Method In 2011, the ratios of family- and elderly-related social spending to gross domestic product (GDP) were recorded in 34 Organisation for Economic Co-operation and Development (OECD) member countries. The former was designated as the percentage allocated to members of the population between the ages of 0 and 14 (young population ratio), and the latter was designated as the percentage allocated to members of the population over the age of 65 (elderly population ratio). We compared these two factors for every country and performed correlation and partial correlation analyses of total fertility rates and family-related social spending to GDP adjusted by population proportion to examine the relationship between the two.Results The comparison of the youth and elderly populations' spending ratios in the total social spending to GDP ratio revealed that OECD countries had an average family-related social spending ratio of 0.13 and an average elderly-related social spending ratio of 0.47. Comparatively, Japan has a family-related social spending ratio of 0.10 and an elderly-related social spending ratio of 0.45. In the correlation analysis for total fertility rates and family-related social spending to GDP ratio, the benefits-in-kind to GDP ratio and total fertility rates indicated a trend toward correlation (r=0.32, P=0.06). In addition, the results for the partial correlation between family-related social spending to GDP ratio and total fertility rates showed a significant correlation between the two. When divided into cash benefits and benefits-in-kind, the partial correlation analysis of the GDP ratios and total fertility rates revealed a significant correlation (r=0.51, P<0.01). Benefits-in-kind (r=0.45, P<0.01) had a stronger correlation than did cash benefits (r=0.39, P=0.03).Conclusion In an international comparison accounting for economic standards, the social security cost of children and child-rearing families in Japan was low. Further, in terms of social security spending, increasing benefits-in-kind, such as improving childcare services or preschool education, is one factor that improves the total fertility rate.

Long Term Sugarcane Crop Residue Retention Offers Limited Potential to Reduce Nitrogen Fertilizer Rates in Australian Wet Tropical Environments

PubMed Central

Meier, Elizabeth A.; Thorburn, Peter J.

2016-01-01

The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues (‘trash’). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a ‘trash blanket’ in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer rates for crops when trash was retained (≤20 kg N ha–1 per plant or ratoon crop) while maintaining ≥95% of maximum yields. While these savings in N fertilizer use were modest at the field scale, they were potentially important when aggregated at the regional level. PMID:27462340

Influence of L-arginine during bovine in vitro fertilization.

PubMed

Silva, Thiago Velasco Guimarães; da Silva, Bruno Baraúna; de Sá, André Luiz Alves; da Costa, Nathalia Nogueira; Sampaio, Rafael Vilar; Cordeiro, Marcela da Silva; Santana, Priscila Di Paula Bessa; Adona, Paulo Roberto; Santos, Simone do Socorro Damasceno; Miranda, Moysés dos Santos; Ohashi, Otávio Mitio

2014-12-01

The objective of this work was to evaluate the effect of using L-arginine during in vitro fertilization (IVF) on in vitro embryonic development using Bos taurus and Bos indicus semen. Effect of different concentrations (0, 1, 10 and 50 mM) of L-arginine, added to the IVF medium, was evaluated on the fertilization rate at 18 h post-fertilization (hpf), NO3(-)/NO2(-) production during IVF by the Griess colorimetric method (30 hpf), cleavage and blastocyst rates (on Day 2 and Day 7 of culture, respectively) and total blastocyst cell number (Day 7 of culture). The results reveal that the addition of 50 mM L-arginine to IVF medium, with either Bos taurus or Bos indicus spermatozoa, decreased the cleavage rate and blastocyst rate compared to the control group. Other concentrations did not affect embryo production. However, 1 mM L-arginine with Bos indicus semen increased the proportion of hatched blastocysts. These results indicate that high L-arginine concentrations may exhibit toxic effects on bovine gametes during in vitro fertilization.

[Effects of fertilizer application on greenhouse vegetable yield: a case study of Shouguang].

PubMed

Liu, Ping; Li, Yan; Jiang, Li-Hua; Liu, Zhao-Hui; Gao, Xin-Hao; Lin, Hai-Tao; Zheng, Fu-Li; Shi, Jing

2014-06-01

Data collected from 51 representative greenhouses of Shouguang through questionnaire survey were analyzed to investigate the effect of chemical fertilizers on vegetable yield, relationship between application of organic manure and yield, and influence factors and evolution rule of fertilizer application rate. The results showed that averages of 3338 kg N x hm(-2), 1710 kg P2O5 x hm(-2) 3446 kg K2O x hm(-2) were applied to greenhouse vegetables annually in Shouguang, 6-14 times as that in the local wheat-maize rotation system. The application rates of chemical N, P, and K fertilizers accounted for about 35%, 49% and 42% of the total input. Increasing application of chemical fertilizers had no significant effect on vegetable yields, while organic manure input significantly increased the vegetable yields. With the increase of greenhouse cultivating time, no significant changes in the input of chemical N, P, and K fertilizers were observed in greenhouse vegetable production while organic manure input decreased significantly. Differences in vegetable species, planting pattern and cultivating time of greenhouses was one of the reasons for large variations in nutrient application rate. In recent more than ten years, organic manure nutrient input increased significantly, chemical N and P fertilizer input presented a downward trend, chemical K fertilizer input increased significantly, and the N/P/K ratio became more and more reasonable in greenhouse vegetable production in Shouguang.

Economic development and population policy in Bangladesh.

PubMed

Khan, M R

1984-09-01

This paper deals with Bangladesh's growth rate and the policy implications for its economy. Despite its obvious influence on the economy, population has never been integrated as an endogenous variable in any planning model. Development planning is mostly supported by donor agencies, involving little micro-level planning and practically no trickle-down effect. This paper examines the interaction of population and other development variables in the country's planning process. Much of the rural population consists of landless farmers share croppers, so that the land ownership pattern contributes to low productivity. Population increase is making the rural masses even poorer. This process is further compounded by increasing foreign aid dependence, adverse terms of trade in the international market, low savings and investments, and the rural sector's worsening terms of trade. During 1950-1970 real per capita gross domestic product (GDP) increased only at a rate of 1% per annum and during 1950-1970 real growth of GDP fell behind the population growth rate. A cost benefit analysis of fertility reduction is needed. The cost benefit ratio of most countries varies between 1:10 to 1:30; for Bangladesh it is 1:16. Macro-model studies indicate that the higher the fertility reduction and shorter the period of required decline, the higher will be the benefits in terms of gains in per capita income. There is, however, a contradiction between national and household interests. The latter's decision to have more children has a negative spillover effect, which nullifies the gains of the community. The national family planning program suffered a serious setback during and after the liberation of Bangladesh, mainly due to lack of administrative leadership and support. In order for the population growth rate to be checked and to increase the quality of life for the entire population, the family planning program must be revitalized by mobilizing the entire government machinery and involving the people at the grass roots level.

National trends and outcomes of autologous in vitro fertilization cycles among women ages 40 years and older.

PubMed

Hipp, Heather; Crawford, Sara; Kawwass, Jennifer F; Boulet, Sheree L; Grainger, David A; Kissin, Dmitry M; Jamieson, Denise

2017-07-01

The purpose of the study was to describe trends in and investigate variables associated with clinical pregnancy and live birth in autologous in vitro fertilization (IVF) cycles among women ≥40 years. We used autologous IVF cycle data from the National ART Surveillance System (NASS) for women ≥40 years at cycle start. We assessed trends in fresh and frozen cycles (n = 371,536) from 1996 to 2013. We reported perinatal outcomes and determined variables associated with clinical pregnancy and live birth in fresh cycles between 2007 and 2013. From 1996 to 2013, the total number of cycles in women ≥40 years increased from 8672 to 28,883 (p < 0.0001), with frozen cycles almost tripling in the last 8 years. Cycles in women ≥40 years accounted for 16.0% of all cycles in 1996 and 21.0% in 2013 (p < 0.0001). For fresh cycles from 2007 to 2013 (n = 157,890), the cancelation rate was 17.1%. Among cycles resulting in transfer (n = 112,414), the live birth rate was 16.1%. The following were associated with higher live birth rates: multiparity, fewer prior ART cycles, use of standard agonist or antagonist stimulation, lower gonadotropin dose, ovarian hyperstimulation syndrome, more oocytes retrieved, use of pre-implantation genetic screening/diagnosis, transferring more and/or blastocyst stage embryos, and cryopreserving more supernumerary embryos. Of the singleton infants born (n = 14,992), 86.9% were full term and 88.3% normal birth weight. The NASS allows for a comprehensive description of IVF cycles in women ≥40 years in the USA. Although live birth rate is less than 20%, identifying factors associated with IVF success can facilitate treatment option counseling.

Fertility of American Women: June 1988. Current Population Reports. Population Characteristics.

ERIC Educational Resources Information Center

Current Population Reports, 1989

1989-01-01

The fertility rate for the 12 months ending in June 1988 was an estimated 69.7 births per 1,000 women aged 18 to 44 years. Fertility rates during the 1980s have been stable. The statistics on childbearing and birth expectations of U.S. women contained in the detailed tables of this report are based on data collected in the June 1988 supplement to…

The impact of legal abortion on marital and nonmarital fertility in upstate New York.

PubMed

Tu, E J; Herzfeld, P M

1982-01-01

Nonmarital fertility rates declined rapidly immediately after the legalization of abortion in upstate New York, but began to rise again in the mid-1970s concomitant with an increase in nonmarital abortion rates. The downward pressure exerted by abortion on nonmarital fertility is thus more than offset by other factors, among which are possible increases in sexual activity and less use of effective contraception.

Increase of As release and phytotoxicity to rice seedlings in As-contaminated paddy soils by Si fertilizer application.

PubMed

Lee, Chia-Hsing; Huang, Hsuan-Han; Syu, Chien-Hui; Lin, Tzu-Huei; Lee, Dar-Yuan

2014-07-15

Silicon (Si) was shown to be able to reduce arsenic (As) uptake by rice in hydroponic culture or in low As soils using high Si application rates. However, the effect of Si application on As uptake of rice grown in As-contaminated soils using Si fertilizer recommendation rate has not been investigated. In this study, the effect of Si application using Si fertilizer recommendation rate on As release and phytotoxicity in soils with different properties and contents of As was examined. The results show that the concentrations of As in soil solutions increased after Si applications due to competitive adsorption between As and Si on soil solids and the Si concentrations in soil solutions were also elevated to beneficial levels for rice growth. The rice seedlings accumulated more As and its growth was inhibited by Si application in As contaminated/spiked soils. The results indicate that there is an initial aggravation in As toxicity before the beneficial effects of Si fertilizing to rice were revealed when Si application based on fertilizer recommendation rate to As-contaminated paddy soils. Therefore, for As-contaminated paddy soils with high levels of As, the application of Si fertilizer could result in increasing As phytotoxicity and uptake by rice. Copyright © 2014 Elsevier B.V. All rights reserved.

Modification of the 137Cs, 90Sr, and 60Co transfer to wheat plantlets by NH4+ fertilizers.

PubMed

Guillén, J; Muñoz-Muñoz, G; Baeza, A; Salas, A; Mocanu, N

2017-03-01

Inorganic fertilizers are used as agricultural countermeasures intended to inhibit the soil to plant transfer of radionuclides after a radioactive fallout. Two NH 4 + fertilizers, diammonium phosphate (DAP) and NPK, were applied to soil contaminated with a mixture of radionuclides to analyze whether they modify the transfer of 137 Cs, 90 Sr, and 60 Co and stable elements (K, Na, Ca, and Mg) to wheat plantlets grown under controlled laboratory conditions. DAP introduced NH 4 + in the soil, which can increase 137 Cs transfer, while NPK also introduced K + , which can decrease it. The application of DAP increased the accumulation of 137 Cs in wheat plantlets with increasing application rate, so did the 137 Cs/K in plantlets. Regarding the NPK application, the 137 Cs increased in all treatments, but at maximum rate, the available K introduced by the fertilizer was probably able to partially satisfy the nutritional requirements of the wheat plantlet and the 137 Cs decreased relative to the recommended rate. The 137 Cs/K ratio in plantlet decreased with increasing NPK rates. The transfer of 90 Sr increased with increasing DAP rate and only at the maximum NPK rate. The 60 Co transfer only increased at the maximum application rates for DAP and NPK. These modifications should be considered when using these fertilizers as agricultural countermeasures.

External validation of the endometriosis fertility index (EFI) staging system for predicting non-ART pregnancy after endometriosis surgery.

PubMed

Tomassetti, C; Geysenbergh, B; Meuleman, C; Timmerman, D; Fieuws, S; D'Hooghe, T

2013-05-01

Can the ability of the endometriosis fertility index (EFI) to predict non-assisted reproductive technology (ART) pregnancy after endometriosis surgery be confirmed by an external validation study? The significant relationship between the EFI score and the time to non-ART pregnancy observed in our study represents an external validation of this scoring system. The EFI was previously developed and tested prospectively in a single center, but up to now no external validation has been published. Our data provide validation of the EFI in an external fertility unit on a robust scientific basis, to identify couples with a good prognosis for spontaneous conception who can therefore defer ART treatment, regardless of their revised American Fertility Society (rAFS) endometriosis staging. Retrospective cohort study where the EFI was calculated based on history and detailed surgical findings, and related to pregnancy outcome in 233 women attempting non-ART conception immediately after surgery; all data used for EFI calculation and analysis of reproductive outcome had been collected prospectively as part of another study. The EFI score was calculated (score 0-10) for 233 women with all rAFS endometriosis stages (minimal-mild, n = 75; moderate-severe, n = 158) after endometriosis surgery (1 September 2006-30 September 2010) in a university hospital-based reproductive medicine unit with combined expertise in reproductive surgery and medically assisted reproduction. All participants attempted non-ART conception immediately after surgery by natural intercourse, ovulation induction with timed intercourse or intrauterine insemination (with or without ovulation induction or controlled ovarian stimulation). All analyses were performed for three different definitions of pregnancy [overall (any HCG >25 IU/l), clinical and ongoing >20 weeks]. Six groups were distinguished (EFI scores 1-3, 4, 5, 6, 7+8, 9+10), and Kaplan-Meier (K-M) estimates for cumulative pregnancy rate were calculated. Subjects were censored when they were lost to follow-up, had subsequent surgery for endometriosis, started ovarian suppression or underwent ART. As K-M estimates might overestimate the actual event rate, cumulative incidence estimates treating ART as competing event were also calculated. Cox regression analysis was used to assess the performance of EFI and constituting variables. Performance of the score (prediction, discrimination) was quantified with the following methods: mean squared error of prediction (Brier score), areas under the receiver-operating curve and global concordance index C(τ). There was a highly significant relationship between the EFI and the time to non-ART pregnancy (cumulative overall pregnancy rate, P = 0.0004), with the K-M estimate of cumulative overall pregnancy rate at 12 months after surgery equal to 45.5% [95% confidence interval (CI) 39.47-49.87]-ranging from 16.67% (95% CI 5.01-47.65) for EFI scores 0-3, to 62.55% (95% CI 55.18-69.94) for EFI scores 9-10. For each increase of 1 point in the EFI score, the relative risk of becoming pregnant increased by 31% (95% CI 16-47%; i.e. hazard ratio 1.31). The 'least function score'-which assesses the tubal/ovarian function at conclusion of surgery-was found to be the most important contributor to the total EFI score among all the other variables (age, duration of infertility, prior pregnancy, AFS endometriosis lesion and total score). The EFI score had a moderate performance in the prediction of the pregnancy rate. Indeed, the decrease in prediction error was rather small, as shown by the decrease in Brier score from 0.213 to 0.198, and low estimates for R² (13%) and C(τ) (0.629). As the EFI was validated externally in our own European population after initial testing by Adamson and Pasta (Endometriosis fertility index: the new, validated endometriosis staging system. Fertil Steril 2010;94:1609-1615) in an American population, it appears that the EFI can be used clinically to counsel infertile endometriosis patients receiving reproductive surgery in specialized centers about their post-operative conception options. This research was supported by funds obtained via the Clinical Research Fund of the University Hospitals Leuven, Belgium, via the Ferring Chair in Reproductive Medicine and Surgery, and the Serono Chair in Reproductive Medicine granted to the Leuven University Fertility Center. The authors have no conflicts of interest to declare.

Forage yield, weed suppression and fertilizer nitrogen replacement value (FNRV) of alfalfa-tall fescue mixtures

USDA-ARS?s Scientific Manuscript database

Adding plant diversity to forage systems may help growers deal with increasing fertilizer costs and a more variable climate. Maintaining highly diverse forage mixtures in forage-livestock production is difficult and may warrant a closer reexamination of simpler grass-legume mixtures to achieve simi...

Women's Schooling, Patterns of Fertility, and Child Survival.

ERIC Educational Resources Information Center

LeVine, Robert

1987-01-01

Expansion of women's schooling is associated with lower fertility and child mortality. This article provides demographic evidence and a framework for discovering how educational processes operate on maternal behavior. Findings from a study in Mexico focus on mother-infant interaction and social attitudes as important variables. Research needs are…

Optimization of the sperm:oocyte ratio and sperm economy in the artificial reproduction of Rhamdia quelen using fructose as a sperm motility modulator.

PubMed

Adames, Maurício Spagnolo; de Toledo, Cesar Pereira Rebechi; Neumann, Giovano; Buzzi, Alexandre Henrique; Buratto, Cíntia Nara; Piana, Pitágoras Augusto; Bombardelli, Robie Allan

2015-10-01

This research was conducted to evaluate the effects of fructose as a modulator of sperm motility and its effects on the reduction in number of sperm cells in IVF using cryopreserved Rhamdia quelen semen. Sperm activation occurred in solutions containing fructose (0.0, 0.9, 1.8, 2.7, 3.6 and 4.5%). The sperm motility rate, velocity and duration of sperm motility were assessed by polynomial regression analysis and grouped by the principal component analysis (PCA). Then, the oocytes were mixed with semen at proportions of 1×10(4), 3×10(4), 5×10(4), 7×10(4) and 9×10(4) for the sperm:oocyte ratio and fertilization was induced by the activation of gametes with the fructose-containing solutions. The fertilization, hatching and larval normality rate were evaluated by response surface protocol and were further grouped by PCA. All sperm variables were affected by the activating solutions, and the most desirable theoretical results for the rate of sperm motility were obtained when using a solution containing 2.85% fructose. In the IVF and incubation assays, there was an interactive effect between the motile sperm:oocyte ratio and the fructose concentration on the rates of oocyte fertilization, hatching and on the clustered index for reproductive success. The results suggest the possibility of reducing the sperm cells on IVF by 17.77% when using a solution containing 2.28% fructose. In conclusion, the use of solutions containing fructose at concentrations that maximize sperm movement allow the reduction of the motile sperm:oocyte ratio, thus promoting sperm metabolic efficiencies and contributing to the feasibility of using cryopreserved semen at a large-scale in IVF. Copyright © 2015 Elsevier B.V. All rights reserved.

[Reducing nutrients loss by plastic film covering chemical fertilizers].

PubMed

Chen, Huo-jun; Wei, Ze-bin; Wu, Qi-tang; Zeng, Shu-cai

2010-03-01

With the low utilization rate of fertilizers by crop and the growing amount of fertilizer usage,the agricultural non-point source pollution in China is becoming more and more serious. The field experiments planting corns were conducted, in which the applied chemical fertilizers were recovered with plastic film to realize the separation of fertilizers from rain water. In the experiments, the influences of different fertilizing treatments on the growing and production of sweet corn were observed. The fertilizer utilization rate and the nutrient contents in surface run-off water with and without the film covering were also determined. Results showed that, with only 70% of the normal amount of fertilizers,the sweet corn could already get high yield under the experimental soil conditions. Soil analysis after corn crops showed that the amounts of available N, P and K in the soil increased obviously with the film-covering, and the decreasing order was: 100% fertilizers with film-covering > 70% fertilizers with film-covering > 100% fertilizers, 70% fertilizers > no fertilizer. The average utilization coefficients of fertilizers by the crop were 42%-87%, 0%-3%, 5%-15% respectively for N, P and K. It was higher with film-covering than that without covering, especially for the high fertilization treatment. Analysis of water samples collected for eight run-off events showed that, without film-covering, N, P and K average concentrations in the runoff waters with fertilizations were 27.72, 2.70 and 7.07 mg x L(-1), respectively. And they were reduced respectively by 39.54%, 28.05%, 43.74% with the film-covering. This can give significant benefits to the decrease of agricultural non-point source pollution and water eutrophication.

Short- and long-term effects of unemployment on fertility

PubMed Central

Currie, Janet; Schwandt, Hannes

2014-01-01

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. PMID:25267622

[Rhizosphere effect of nutrients in different maize soils with different fertility levels].

PubMed

Wu, L; Zhang, S

2000-08-01

Maize plants and soil samples were collected from Jilin Province to study the nutrient dynamics in soil-maize plant rhizosphere and their relationship with plant uptake. The results showed that NH4(+)-N and NO3(-)-N were accumulated in rhizospheric soil, and mainly controlled by the application of chemical fertilizers. Soil available P was depleted in high fertility fields, especially in high seedling density, while accumulated in low fertility fields. Soil available K was accumulated in rhizospheric soil, and its accumulation rate was higher in high fertility than in low fertility fields. The nutrient absorption amount was N approximately K > P for maize plant shoots and roots, but was N > K > P for seeds. The contribution rate of chemical fertilizers to maize yield was only 1/5-1/3 in Jilin Province, and the rest was contributed by the application of organic manure, such as chicken feces or cow feces, and by the mineralization of soil organic matter.

Borderline ovarian tumors, fertility-sparing surgery and pregnancy outcome.

PubMed

Frega, A; Coluccia, A C; Di Martino, G; Catalano, A; Milazzo, G N; Assorgi, C; Manzara, F; Romeo, G D; Gentile, M; Marziani, R; Moscarini, M

2014-01-01

Borderline ovarian tumors (BOTs) represent a type of epithelial tumors having a biologic intermediate behavior between clearly malignant and straight benign tumors. Most of BOTs interest women during fertile age, for which it is necessary to consider a fertility sparing surgery. To evaluate the clinical aspects and pregnancy rate of women affected by borderline ovarian tumors who have undergone fertility sparing surgery. A study of 22 patients affected by BOTs who have been treated with a fertility sparing surgery was conducted between January 2005 and October 2011 at Sant'Andrea Hospital, "Sapienza" University of Rome. The patients' characteristics analyzed were: age, histological type, tumor size, adnexal surgery, pre-operative serum CA-125, diagnostic circumstances, number of patients who became pregnant and number of overall pregnancies. Among the 22 patients treated with a fertility sparing surgery, only sixteen wanted to get pregnant. Eleven patents out of 16 accomplished it. The pregnancy rate was 68.7%. Fertility sparing surgery can be considered a safe procedure for young women affected by borderline ovarian tumors.

Can human populations be stabilized?

NASA Astrophysics Data System (ADS)

Warren, Stephen G.

2015-02-01

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

[Knowledge and use of contraceptives: a comparative analysis with data from reports from Latin American countries].

PubMed

Taucher, E

1980-12-01

Objective of this paper is to compare data published in the general reports of countries participating in the World Fertility Survey. The major differences encountered were presented by the differences between the surveys of the different countries, in this case Colombia, Costa Rica, Peru, Panama, and the Dominican Republic, and the disparity of classification criteria of the variables considered. For example, age intervals varied in the different countries, as did distribution of women as to place of residence and educational status. Since such variables are strictly related to fertility rate and contraceptive usage, differences must be taken into consideration in the interpretation of results. In all countries considered the proportion of women knowing about contraception was very high; there were, however, great differences in contraceptive usage. Panama and Costa Rica, for example, had high levels of contraceptive use, while Colombia was in an intermediate position, and Peru and the Dominican Republic had low levels. In all countries contraceptive use was higher in urban residents, and in women with better education. Such differences were less noticeable in countries where contraceptive use was higher. Parity had a great influence on contraceptive use, since women with no children had lower levels of contraceptive use than women with higher parity.

Heat stress during in vitro fertilization decreases fertilization success by disrupting anti-polyspermy systems of the oocytes.

PubMed

Sakatani, Miki; Yamanaka, Kenichi; Balboula, Ahmed Z; Takenouchi, Naoki; Takahashi, Masashi

2015-01-01

Low pregnancy rates during the summer are due, in part, to reduced fertilization. Given that elevated temperature is associated with this season, we investigated the effect of heat stress during fertilization using an in vitro model. Three experiments were performed to determine the mechanism by which exposure to elevated temperature disrupts fertilization. Oocytes were fertilized for 6 hr at 38.5°C or 41.0°C or 40.0°C with non-pre-incubated sperm, or for 6 hr at 38.5°C with sperm that had been pre-incubated at 38.5°C or 41.0°C for 4 hr. In each experiment, zygotes were cultured at 38.5°C in 5% CO(2) and 5% O(2). Rates of cleavage and blasocyst formation were reduced when fertilization occurs at elevated temperatures. The percent of sperm classified as alive, using fluorescein diacetate labeling, was decreased by pre-incubation and fertilization at 40.0°C. Although no difference was observed in sperm penetration rate, polyspermy tended to be increased by heat stress during fertilization. The zona pellucidae of zygotes formed following fertilization at 40.0°C for 6 hr were more sensitive to digestion with pronase. Furthermore, these zygotes exhibited higher hydrogen peroxide levels, measured by 2,7-dihydrodichlorofluorescein diacetate staining, and showed increased transcript abundance for HSPA1A, a gene involved in the heat-shock response, but decreased transcript abundance for UCHL1, a gene involved in preventing polyspermy. Results indicate that heat stress during fertilization is lethal to sperm, and causes oxidative stress, altered transcript abundance, and a defective block to polyspermy in the zygote. Thus, an increase in polyspermy is likely one cause of the reduced competency of zygotes fertilized under elevated temperatures to develop to the blastocyst stage. © 2014 Wiley Periodicals, Inc.

Recent trends in fertility in Botswana.

PubMed

Diamond, I; Rutenberg, N

1995-01-01

The argument is made that fertility decline in rural Botswana during the 1980s could be a response to the extremely harsh economic conditions resulting from the sustained drought. The drought may have contributed to greater separation of spouses and increased the openness of the population to integrated maternal and child health (MCH) and family planning programs. Migration to urban areas was accompanied by housing shortages, which occurred because of a moratorium on construction to conserve water and crowding that could have reduced urban fertility. Supplementary feeding programs for children aged under five years were only available at MCH centers. The impact of the drought on men's resources may have reduced available resources for paying "bogadi" and thus delayed childbearing and marriage. Agricultural relief programs may have contributed to men's longer stays on arable land and thus delayed marriage. Women in female headed households, which are large in number in Botswana, and unmarried women may have chosen to adopt contraception due to limited resources for supporting children. Period declines in fertility are described. The total fertility rate is 4.9 children per woman, and cumulative fertility among women aged 45-49 is only 5.8, which suggests the presence of a fertility decline in Botswana. Knowledge and awareness of modern methods of contraception is high (95%), as is unmet need for contraception. 45% of women in union desired a delay or a stop to childbearing. Trends suggest a further decline in births to 4.5 within five years. High rates of teenage pregnancy and discontinued schooling are trends which suggest higher or sustained high fertility. Family life education in schools has not yet had an impact on fertility. High fertility may be maintained by the high proportion of visiting unions and a high ideal family size. Contraceptive use has increased, but discontinuation rates are also high. Reduced migration to South Africa could increase fertility due to the reuniting of couples. Future declines in fertility are considered to be dependent upon the success of the family planning program.

Nitrous oxide fluxes from upland soils in central Hokkaido, Japan.

PubMed

Mu, Zhijian; Kimura, Sonoko D; Toma, Yo; Hatano, Ryusuke

2008-01-01

Nitrous oxide (N2O) fluxes from soils were measured using the closed chamber method during the snow-free seasons (middle April to early November), for three years, in a total of 11 upland crop fields in central Hokkaido, Japan. The annual mean N2O fluxes ranged from 2.95 to 164.17 microgN/(m2 x h), with the lowest observed in a grassland and the highest in an onion field. The instantaneous N2O fluxes showed a large temporal variation with peak emissions generally occurring following fertilization and heavy rainfall events around harvesting in autumn. No clear common factor regulating instantaneous N2O fluxes was found at any of the study sites. Instead, instantaneous N2O fluxes at different sites were affected by different soil variables. The cumulative N2O emissions during the study period within each year varied from 0.15 to 7.05 kgN/hm2 for different sites, which accounted for 0.33% to 5.09% of the applied fertilizer N. No obvious relationship was observed between cumulative N2O emission and applied fertilizer N rate (P > 0.4). However, the cumulative N2O emission was significantly correlated with gross mineralized N as estimated by CO2 emissions from bare soils divided by C/N ratios of each soil, and with soil mineral N pool (i.e., the sum of gross mineralized N and fertilizer N) (P < 0.001).

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

PubMed

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

2002-06-01

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

Factors affecting the fertility of ewes after intrauterine insemination with frozen-thawed semen during the non-breeding season.

PubMed

Fukui, Yutaka; Kohno, Hirohide; Okabe, Kentaro; Katsuki, Sara; Yoshizawa, Masahiro; Togari, Tetsuro; Watanabe, Hiroyuki

2010-08-01

In this study, two successive field trials were conducted during the non-breeding season to investigate various factors affecting on fertility of Suffolk ewes after intrauterine insemination with frozen-thawed semen. In the first year (Experiment 1), three sperm numbers per insemination dose (0.25, 0.5 and 1 million sperm) and five sheep farms were used, and in the second year (Experiment 2), parity, age, body weight, body condition score (BCS) and postpartum days were investigated to compare pregnancy and lambing rates. High pregnancy and lambing rates (70.6 and 70.6%, respectively) were obtained with 0.25 million sperm per dose. There were no significant differences in the pregnancy and lambing rates among the five farms, but there was a tendency for one farm to have higher pregnancy (75.8%, P=0.065) and lambing (72.7%, P=0.077) rates than those (46.7-53.3% and 45.2-53.3% for the pregnancy and lambing rates, respectively) of the other farms. In Experiment 2, ewe age significantly affected both the pregnancy and lambing rates. Nulliparous ewes had a higher lambing rate (72.0%) than that (44.2%) of multiparous ewes, but a significant difference was not revealed. Regardless of body weight, BCS tended to be an important factor influencing on fertility of ewes. Body weight and the postpartum days did not affect the fertility of ewes. It was concluded from these results that the fertility of Suffolk ewes after intrauterine insemination with frozen semen was significantly influenced by sperm number per dose and ewe age. Nulliparous ewes at less than three years of age and with a BCS of more than 3.0 are expected to have higher fertility than other ewes.

Behavior differentiation between wild Japanese quail, domestic quail, and their first filial generation.

PubMed

Chang, G B; Liu, X P; Chang, H; Chen, G H; Zhao, W M; Ji, D J; Chen, R; Qin, Y R; Shi, X K; Hu, G S

2009-06-01

The number of wild quail has dramatically reduced in China and reached a state of endangerment with the deterioration of the environment in recent years. In this study, we examined the ecological behaviors of quails in the cage to determine the differentiation level between wild Japanese quail and domestic quail, to detect the relationship between quail behavior and evolutionary differentiation and to analyze the possibility of restoring effective size of wild population. With the on-the-spot observations and measurements, the behaviors of 3 categories of quail, namely wild Japanese quail from the Weishan Lake area in China, domestic quail, and their first filial generation (F(1)) were studied. Domestic quail differed from wild Japanese quail in morphological pattern and ecological behaviors, including some indexes of figure type and egg, vocalization, aggression and fighting, and mating, but wild Japanese quail and domestic quail could succeed in mating and reproducing fertile hybrid offspring. There were significant differences between domestic quail and wild Japanese quail in reproductive traits, involved mating times, fertility rate, hatching rate, and hatching rate of fertilized eggs (P < 0.05). The first filial generation presented significant difference from the wild Japanese quail in vocalization, aggression and fighting, mating, hatching rate, hatching rate of fertilized eggs, and some egg indexes (P < 0.05) and significantly differ from the domestic quail in vocalization, hatching rate, and hatching rate of fertilized eggs (P < 0.05). Evolutionary differentiation between wild quail and domestic quail was still at a relatively low level because no reproductive isolation existed. The advantages of the F(1) hybrids in reproductive capacity, fertilization, and hatching recommend that releasing hybrids instead of domestic quails to the wild would be a more effective way to restore the effective size of wild quail population if necessary.

A Survey on Oocyte Donation: Turkish Fertile and Infertile Women’s Opinions

PubMed Central

Akyuz, Aygul; Sever, Nese; Karasahin, Emre; Guvenc, Gulten; Cek, Suzan

2014-01-01

Background There are various treatment options for infertility, and new techniques are also being developed as it is an important healthcare problem affecting approximately 15-20% of married couples. The purpose of this study was to evaluate the level of infor- mation of fertile and infertile Turkish women on oocyte donation in order to understand their awareness of the legal, ethical, social and religious issues regarding this technique and to compare these two groups in terms of these variables. Materials and Methods This cross-sectional study included infertile women being treated at the assisted reproductive technologies (ART) program of a university hos- pital and women who had presented at the gynecology outpatients department of the same university for routine check-ups and who had no previous history of infertility. After consulting with specialists in the field and searching the related literature, a data collection form having 22 questions for infertile women and 18 questions for fertile women was prepared. Results The women were asked whether they would use the oocytes of another woman if necessary. The results showed that 67.6% of the fertile women said they would never want to use this method, while 63.9% of the infertile women stated they may accept to use this method under certain conditions (two distinct answers appeared in the answers, some women stated they would prefer donated oocytes from close relatives, while others stated they would prefer oocytes from total strangers), such as from a close relative or from someone they do not know at all. Conclusion Infertile women mentioned that they could use illegal routes if necessary to have a child at much higher rates than stated by fertile women. This shows that desire to have a child is a strong source of motivation in Turkey. PMID:25379158

Women's attitudes towards mechanisms of action of family planning methods: survey in primary health centres in Pamplona, Spain.

PubMed

de Irala, Jokin; Lopez del Burgo, Cristina; Lopez de Fez, Carmen M; Arredondo, Jorge; Mikolajczyk, Rafael T; Stanford, Joseph B

2007-06-27

Informed consent in family planning includes knowledge of mechanism of action. Some methods of family planning occasionally work after fertilization. Knowing about postfertilization effects may be important to some women before choosing a certain family planning method. The objective of this survey is to explore women's attitudes towards postfertilization effects of family planning methods, and beliefs and characteristics possibly associated with those attitudes. Cross-sectional survey in a sample of 755 potentially fertile women, aged 18-49, from Primary Care Health Centres in Pamplona, Spain. Participants were given a 30-item, self-administered, anonymous questionnaire about family planning methods and medical and surgical abortion. Logistic regression was used to identify variables associated with women's attitudes towards postfertilization effects. The response rate was 80%. The majority of women were married, held an academic degree and had no children. Forty percent of women would not consider using a method that may work after fertilization but before implantation and 57% would not consider using one that may work after implantation. While 35.3% of the sample would stop using a method if they learned that it sometimes works after fertilization, this percentage increased to 56.3% when referring to a method that sometimes works after implantation. Women who believe that human life begins at fertilization and those who consider it is important to distinguish between natural and induced embryo loss were less likely to consider the use of a method with postfertilization effects. Information about potential postfertilization effects of family planning methods may influence women's acceptance and choice of a particular family planning method. Additional studies in other populations are necessary to evaluate whether these beliefs are important to those populations.

Accessory sperm as an indication of fertilizing ability of rabbit spermatozoa frozen in egg yolk-acetamide with detergent.

PubMed

Arriola, J; Foote, R H

2001-01-01

Many factors besides initial semen quality affect fertilization rates as sperm interact with the environment of the female reproductive tract. One of these factors is sperm transport, which can be evaluated by accessory sperm counts. Dutch rabbits were used to test the effects on sperm transport, fertilization, and production of young when sodium and triethanolamine lauryl sulfate (STLS) detergent was added to a medium for sperm cryopreservation. When STLS was added in 10 concentrations ranging from 0% to 2.0% (vol/vol) to an egg yolk-acetamide semen extender, optimal post-thaw motility of rabbit sperm occurred when 0.2% to 0.7% STLS was included. However, when 0%, 0.2%, and 0.7% STLS was included to cryopreserve sperm used for insemination, the fertilization rates were 95%, 68%, and 75%, and the corresponding mean numbers of accessory sperm per embryo were 13.1, 1.7, and 0.4 (P < .05). In another experiment, increasing the acetamide concentration from 0.75 M to 1.25 M decreased fertilization rates from 66% to 35%, and was associated with 4.5 and 0.6 accessory sperm per embryo (P < .05). In the final experiment, 48 does inseminated with sperm cryopreserved with 0%, 0.35%, and 0.70% STLS were allowed to produce young. Corresponding pregnancy rates were 56%, 56%, and 31% (P < .05), and litter sizes were 5.6, 4.1, and 4.2 (P > .05). In these studies, low concentrations of STLS improved motility of frozen-thawed sperm, but fertilization and pregnancy rates were reduced. Sperm transport was correspondingly reduced, and the accessory sperm count provided a reliable measure of the effect of STLS on fertility in contrast to the assessment of the percentage of motile sperm.

Interactions between observer and stimuli fertility status: Endocrine and perceptual responses to intrasexual vocal fertility cues.

PubMed

Ostrander, Grant M; Pipitone, R Nathan; Shoup-Knox, Melanie L

2018-02-01

Both men and women find female voices more attractive at higher fertility times in the menstrual cycle, suggesting the voice is a cue to fertility and/or hormonal status. Preference for fertile females' voices provides males with an obvious reproduction advantage, however the advantage for female listeners is less clear. One possibility is that attention to the fertility status of potential rivals may enable women to enhance their own reproductive strategies through intrasexual competition. If so, the response to having high fertility voices should include hormonal changes that promote competitive behavior. Furthermore, attention and response to such cues should vary as a function of the observer's own fertility, which influences her ability to compete for mates. The current study monitored variation in cortisol and testosterone levels in response to evaluating the attractiveness of voices of other women. All 33 participants completed this task once during ovulation then again during the luteal phase. The voice stimuli were recorded from naturally cycling women at both high and low fertility, and from women using hormonal birth control. We found that listeners rated high fertility voices as more attractive compared to low fertility, with the effect being stronger when listeners were ovulating. Testosterone was elevated following voice ratings suggesting threat detection or the anticipation of competition, but no stress response was found. Copyright © 2017 Elsevier Inc. All rights reserved.

[Application of spontaneous acrosome reaction of sperm in prediction of outcome of in-vitro fertilization and embryo transfer].

PubMed

Xuan, X J; Xu, C; Zhao, Y R; Wu, K L; Chen, T; Zhang, H B; Li, X; Su, S Z; Ma, G; Tang, R; Sheng, Y; Ma, J L

2016-04-26

To investigate the clinical application of spontaneous acrosome reaction (AR) rate of sperm in predicting the outcome of in-vitro fertilization and embryo transfer (IVF-ET). The spontaneous AR rate of the sperm of patients who underwent IVF-ET treatment in our center during the period from November to December 2014 were studied. The cut-off value from 6% to 12% were set and analyzed its association between the IVF-ET outcomes (including fertility rates, normal fertilization rates and high-quality embryo rates). For those who underwent fresh embryo transplantation, the rates of chemical pregnancy and clinical pregnancy were calculated, and compared the spontaneous AR rates and quantity of acrosomal enzyme according to the pregnancy outcome. There were 202 patients in this study and the mean spontaneous AR rate was 5.99%±5.18%. For patients with the spontaneous AR rate ≥9% versus <9%, the fertility rate, normal fertilization rate and high-quality embryo rate were 81.33% vs 83.85%, 60.53% vs 60.99%, and 51.10% vs 59.67%, respectively, with statistically significant difference in the high-quality embryo rate (P=0.02). For patients who underwent fresh embryo transplantation, when comparison was made between those with spontaneous AR rate ≥8% and those <8%, the rate of chemical pregnancy and clinical pregnancy were 48.57% (17/35) vs 69.64% (78/112) and 37.14% (13/35) vs 63.39% (71/112), respectively, both with statistically significant difference (P=0.02 and P<0.01). The patients with clinical pregnancy had lower spontaneous AR rate than those without clinical pregnancy (5.41%±3.87% vs 7.40%±6.79%, P=0.04), while the quantity of acrosomal enzyme showed no significant difference [(131.79±68.50) vs (153.62±59.59) μU/10(6,) P=0.06]. Logistic regression analysis demonstrated association between spontaneous AR rates and clinical pregnancy (OR=0.93, 95%CI: 0.87-0.99, P=0.03). The spontaneous AR rate of sperm may have clinical significance in predicting the outcome of IVF-ET, as it is reversely correlated with IVF high-quality embryo rate and pregnancy rate. The quantity of acrosomal enzyme may not have significant predictive value for the outcome of IVF.

Handling of boar spermatozoa during and after flow cytometric sex-sorting process to improve their in vitro fertilizing ability.

PubMed

del Olmo, D; Parrilla, I; Gil, M A; Maside, C; Tarantini, T; Angel, M A; Roca, J; Martinez, E A; Vazquez, J M

2013-09-01

The objective of this study was to develop an adequate sperm handling protocol in order to obtain a sex-sorted sperm population with an optimal fertilizing ability. For this purpose, different aspects of the sorting procedure were examined. The effects of the high dilution rates (experiment 1), type of collection medium used (experiment 2), and sheath fluid composition (experiment 3) on sorted boar sperm quality and function were evaluated. Sperm quality was assessed by motility and viability tests, whereas sperm function was evaluated by an in vitro fertilization assay which determined the penetration and polyspermy rates as well as the mean number of sperm penetrating each oocyte. In experiment 1, the results obtained indicated that the high dilution rates did not cause a decrease either in the sperm quality parameters evaluated or the in vitro fertilization ability of spermatozoa. In experiment 2, although sperm quality was not affected, fertilizing ability was compromised after sorting, regardless of the collection medium that was used. In the experiment 3, all groups displayed adequate sperm quality values, but higher in vitro fertility parameters were obtained for spermatozoa sorted in presence of EDTA in the sheath fluid and egg yolk (EY) in the collection media when compared with those sorted in absence of these protective agents. No differences in penetration rates between unsorted highly diluted (control) and sorted sperm in the presence of EDTA and EY were observed. In conclusion, fertilizing ability was compromised in sex-sorted sperm. The addition of EDTA to sheath fluid and EY to collection medium improved boar sperm fertilizing ability, and both agents should be included as essential media components in future studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Determination of arsenic, cadmium, cobalt, chromium, lead, molybdenum, nickel, and selenium in fertilizers by microwave digestion and inductively coupled plasma-optical emission spectrometry detection: collaborative study.

PubMed

Kane, Peter F; Hall, William L

2006-01-01

There is increasing regulatory interest in the non-nutritive metals content of fertilizer materials, but at present there is no consensus analytical method for acid digestion and instrument detection of those elements in fertilizer matrixes. This lack of method standardization has resulted in unacceptable variability of results between fertilizer laboratories performing metals analysis. A method has been developed using microwave digestion with nitric acid at 200 degrees C, followed by inductively coupled plasma-optical emission spectrometry instrument detection, for the elements arsenic, cadmium, cobalt, chromium, molybdenum, nickel, lead, and selenium. The method has been collaboratively studied, and statistical results are here reported. Fourteen collaborators were sent 62 sample materials in a blind duplicate design. Materials represented a broad cross section of fertilizer types, including phosphate ore, manufactured phosphate products, N-P-K blends, organic fertilizers, and micro-nutrient materials. As much as possible within the limit of the number of samples, materials were selected from different regions of the United States and the world. Limit of detection (LOD) was determined using synthetic fertilizers consisting of reagent grade chemicals with near zero levels of the non-nutritive elements, analyzed blindly. Samples with high iron content caused the most variability between laboratories. Most samples reasonably above LOD gave HorRat values within the range 0.5 to 2.0, indicating acceptable method performance according to AOAC guidelines for analyses in the mg/kg range. The method is recommended for AOAC Official First Action status.

Effects of triploidy incidence on clinical outcomes for IVF-ET cycles in different ovarian stimulation protocols.

PubMed

Li, Mingzhao; Xue, Xia; Zhang, Silin; Li, Wei; Zhao, Xiaoli; Ren, Wenjuan; Shi, Juanzi

2015-10-01

To discuss the relationship between triploidy incidence and clinical outcomes of embryos derived from normally fertilized oocytes from the same cohort for in vitro fertilization-embryo transfer (IVF-ET) cycles in different ovarian stimulation protocol. This study included 2070 in vitro fertilization (IVF) cycles with long-term protocol, 802 IVF cycles with ultra short-term protocol and 508 IVF-D (in vitro fertilization by donor semen) cycles with long-term protocol from January 2013 to September 2014. According to the different 3PN rate, patients were divided into three groups as follows: Group 1 included patients with 0% 3PN zygotes, Group 2 included patients with 1-25% 3PN zygotes and Group 3 included patients with >25% 3PN zygotes. female age, no. of retrieved oocytes, normal fertilization rate, day-3 grade I + II embryos rate, day-3 grade I + II + III embryos rate, implantation rate, pregnancy rate and early abortion rate. Triploidy cycle incidence rate in IVF and IVF-D cycles with long-term protocol were significantly higher than in IVF cycles with ultra short-term protocol (p < 0.001). Triploidy fertilization rate found no significant difference between the three groups (p > 0.05). In three protocols, normal fertilization rate in 3PN = 0% and 3PN = 1-25% groups were significantly higher compared to 3PN > 25% group (p < 0.001). In IVF cycles with long-term protocol, the day-3 grade I + II embryos, implantation and pregnancy rate in 3PN > 25% group were significantly lower than other two groups (p < 0.05). The day-3 grade I + II + III embryos and early abortion rate found no significant difference between the three groups (p > 0.05). In IVF cycles with ultra short-term protocol, there were no significant differences found in day-3 grade I + II embryos, day-3 grade I + II + III embryos, implantation, pregnancy and early abortion rate (p > 0.05). In IVF-D cycles with long-term protocol, the day-3 grade I + II embryos, day-3 grade I + II + III embryos and implantation rate in 3PN > 25% group were significantly lower than other two groups (p < 0.05). The pregnancy and early abortion rates found no significant difference in the three groups (p > 0.05). We observed that high proportion of triploid zygotes made a negative effect on clinical outcomes for IVF-ET cycles with long-term protocol.

Genome-wide association study and gene network analysis of fertility, retained placenta, and metritis in US Holstein cattle

USDA-ARS?s Scientific Manuscript database

The objectives of this research were to identify genes, genomic regions, and gene networks associated with three measures of fertility (daughter pregnancy rate, DPR; heifer conception rate, HCR; and cow conception rate, CCR) and two measures of reproductive health (metritis, METR; and retained place...

Irrigation timing and fertilizer rate in peppers

USDA-ARS?s Scientific Manuscript database

Excessive rain fall might leach nutrients from the soil or cause producers to not supply irrigation to pepper (Capsicum sp.). Fertilizer at 150 or 300 lb/acre of triple 17 NPK, the lower rate is the recommended rate, was supplied to either bell, cv. Jupiter, or non-pungent jalapeno, cv. Pace 105, pe...

Inhibitors of serine proteases decrease sperm penetration during porcine fertilization in vitro by inhibiting sperm binding to the zona pellucida and acrosome reaction.

PubMed

Beek, J; Nauwynck, H; Appeltant, R; Maes, D; Van Soom, A

2015-11-01

Serine proteases are involved in mammalian fertilization. Inhibitors of serine proteases can be applied to investigate at which point these enzymes exert their action. We selected two serine protease inhibitors, 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF, 100 μM) and soybean trypsin inhibitor (STI, 5 μM) from Glycine max, via previous dose-response IVF experiments and sperm toxicity tests. In the present study, we evaluated how these inhibitors affect porcine fertilization in vitro as calculated on total fertilization rate, polyspermy rate, and the sperm number per fertilized oocyte of cumulus-intact, cumulus-free, and zona-free oocytes. In the control group (no inhibitor), these parameters were 86%, 49%, and 2.2 for cumulus-intact oocytes and 77%, 43%, and 2.2 for cumulus-free oocytes (6-hour gamete incubation period, 1.25 × 10(5) spermatozoa/mL). 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride and STI significantly reduced total fertilization and polyspermy rate in cumulus-intact and cumulus-free oocytes (P < 0.05). Total fertilization rates were respectively 65% and 53% (AEBSF) and 36% and 17% (STI). Inhibition rates were higher in cumulus-free oocytes than in cumulus-intact oocytes, indicating that inhibitors exerted their action after sperm passage through the cumulus. 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride but not STI reduced sperm binding to the ZP. The acrosome reaction was significantly inhibited by both inhibitors. Only 40.4% (AEBSF) and 11.4% (STI) of spermatozoa completed a calcium-induced acrosome reaction compared to 86.7% of spermatozoa in the control group. There was no effect on sperm binding or fertilization parameters in zona-free oocytes. In conclusion, sperm-zona binding and acrosome reaction were inhibited by serine protease inhibitors during porcine IVF. Copyright © 2015 Elsevier Inc. All rights reserved.

Interrelationships between mortality and fertility in Germany: rural and urban Prussia and modern Germany.

PubMed

Entorf, H; Zimmermann, K F

1990-01-01

"The paper investigates the interrelationship between fertility and infant mortality and its economic determinants by time-series methods for historical and modern Germany. It is studied whether the causal effects of infant mortality on fertility have to be considered as hoarding or replacement, and whether the costs of nutrition have an influence on family decision making about demographic variables. Results show that there are indications for replacement motives, and that economic factors matter." (SUMMARY IN FRE AND ITA) excerpt

Influence of Agricultural Management on Phytochemicals of Colored Corn Genotypes ( Zea mays L.). Part 1: Nitrogen Fertilization.

PubMed

Giordano, Debora; Beta, Trust; Vanara, Francesca; Blandino, Massimo

2018-05-02

In this study, the influence of nitrogen (N) fertilization (170 versus 300 kg of N/ha) on the content of bioactive compounds of whole-meal flour of 10 different colored corn genotypes was investigated. Considerable differences in antioxidant capacity and phytochemical concentrations were observed among genotypes. Higher N fertilization rates significantly ( p < 0.05) increased the content of both total cell-wall-bound phenolics and xanthophylls (lutein and zeaxanthin). Nevertheless, the main phenolic acids (ferulic, p-coumaric, and sinapic acids) as well as the antioxidant capacity and content of β-cryptoxanthin, β-carotene, and total anthocyanins did not show significant differences as far as the N fertilization rate is concerned. For corn cultivation, the application of high N fertilization rates, generally carried out to obtain higher grain yields, could positively influence the content of some bioactives particularly in years characterized by high rainfall levels responsible for N leaching from the soil.

Collection of gametes from live axolotl, Ambystoma mexicanum, and standardization of in vitro fertilization.

PubMed

Mansour, N; Lahnsteiner, F; Patzner, R A

2011-01-15

This study established the first protocol for collection of gametes from live axolotl, Ambystoma mexicanum, by gentle abdominal massage and in vitro fertilization. To stimulate spermiation and ovulation, human chorionic gonadotrophin (hCG) and Ovopel pellets, which are commercially used to stimulate spawning in fish, were tested. The hCG was more effective than Ovopel pellets and yielded a higher semen volume in the injected males and a shorter response time in the females. Collected semen by this method was already motile and fertile. Fertile eggs could be collected in 3-4 successive collection times after the female has started the typical spawning behaviour. The fertilization condition that yielded the highest hatching rate was mixing semen with eggs before the addition of a fertilization saline solution (20 mmol/l NaCl, 1 mmol/l KCl, 1 mmol/l Mg(2)SO(4), 1 mmol Ca(2)Cl, 3 mmol NaHCO(3), 10 mmol/l Tris, pH 8.5 - Osmolality = 65 mosmol/kg). When the pH of the fertilization solution was increased to ≥ 10, the hatching rate was significantly increased. The use of fertilization solutions with osmolalities of ≥ 150 and ≥ 182 were accompanied with a significant decrease in hatching rates and the appearance of deformed larvae, respectively. In conclusion, a reliable protocol for gamete collection from live axolotl is established as a laboratory model of in vitro fertilization for urodele amphibians. This protocol may be transferable to endangered urodeles. Copyright © 2011 Elsevier Inc. All rights reserved.

Unmanned Aerial Vehicle (UAV) data analysis for fertilization dose assessment

NASA Astrophysics Data System (ADS)

Kavvadias, Antonis; Psomiadis, Emmanouil; Chanioti, Maroulio; Tsitouras, Alexandros; Toulios, Leonidas; Dercas, Nicholas

2017-10-01

The growth rate monitoring of crops throughout their biological cycle is very important as it contributes to the achievement of a uniformly optimum production, a proper harvest planning, and reliable yield estimation. Fertilizer application often dramatically increases crop yields, but it is necessary to find out which is the ideal amount that has to be applied in the field. Remote sensing collects spatially dense information that may contribute to, or provide feedback about, fertilization management decisions. There is a potential goal to accurately predict the amount of fertilizer needed so as to attain an ideal crop yield without excessive use of fertilizers cause financial loss and negative environmental impacts. The comparison of the reflectance values at different wavelengths, utilizing suitable vegetation indices, is commonly used to determine plant vigor and growth. Unmanned Aerial Vehicles (UAVs) have several advantages; because they can be deployed quickly and repeatedly, they are flexible regarding flying height and timing of missions, and they can obtain very high-resolution imagery. In an experimental crop field in Eleftherio Larissa, Greece, different dose of pre-plant and in-season fertilization was applied in 27 plots. A total of 102 aerial photos in two flights were taken using an Unmanned Aerial Vehicle based on the scheduled fertilization. Α correlation of experimental fertilization with the change of vegetation indices values and with the increase of the vegetation cover rate during those days was made. The results of the analysis provide useful information regarding the vigor and crop growth rate performance of various doses of fertilization.

Fertilization of black spruce or poor site peatland in Minnesota.

Treesearch

David H. Alban; Richard F. Watt

1981-01-01

Fertilization of poor site black spruce on organic soil with various rates of nitrogen and phosphorus increased height and diameter growth from 2 to 4 times. The growth response declined with time but was still apparent 16 years after fertilization. Shrub biomass and coverage, and nutrient levels of spruce foliage were strongly affected by fertilization.

Effects of Combined Application of Biogas Slurry and Chemical Fertilizer on Soil Aggregation and C/N Distribution in an Ultisol.

PubMed

Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing

2017-01-01

Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate-associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical-stable aggregates (MSAs) formation and stability as well as MSAs-associated C/N concentration and storage were observed in different aggregate sizes (>5, 5-2, 2-1, 1.0-0.5, 0.50-0.25 and <0.25 mm). The proportion of MSAs >5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0-0.5 mm, MSAs 0.50-0.25 mm and MSAs <0.25 mm significantly decreased. Both mean weight diameter and geometric mean diameter were highest in T5, which improved soil aggregation stability as well as resulted in significantly higher SOC and TN concentrations and storage in MSAs >0.5 mm that constituted 72-82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2-1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco-friendly way to improve soil quality in an Ultisol.

[Influence of the high peak serum estradiol on the outcome of in vitro fertilization cycles].

PubMed

Carmona-Ruiz, Israel Obed; Galache-Vega, Pedro; Santos-Haliscak, Roberto; Díaz-Spíndola, Pablo; Batiza-Reséndiz, Víctor Alfonso; Hernández-Ayup, Samuel

2010-10-01

For the use of assisted reproductive technologies of high complexity (IVF-ET and ICSI) is essential to proper ovarian stimulation with recombinant FSH drugs menotropins, as well as the use of GnRH analogues. To correlate serum estradiol level on day 10th with the outcome of in vitro fertilization cycles. Retrospective study of 523 IVF cycles, selected and analyzed from 2005 to 2009. Patients underwent individualized stimulation protocols with gonadotropins and agonist (late luteal phase). The patients were divided into three groups according with the serum level of estradiol on day 10th of stimulation: Group I, patients with serum level of Estradiol below 1,000 pg/mL; Group II, with levels between 1,000-4,000 pg/mL; and Group III, with levels above 4,000 pg/mL. Peak serum estradiol levels, oocyte number, fertilization rates, implantation rates, and pregnancy rates were compared among groups. The fertilization rate was 62.8 in Group I; 60.6% in Group II, and 54.2% in Group III. The pregnancy rate in Group I was 29.8%; in Group II, 37.3%; and 24% for Group III. The implantation rates were 14, 22 and 14% for each group respectively (I, II and III). There is an inverse relationship between high peak serum estradiol levels and pregnancy rate; the implantation rate seems affected by the extreme levels of serum estradiol. The percent of total mature oocytes and fertilization rate improve with serum levels of estradiol at physiologic values.

Developmental competence of embryos derived from reciprocal in vitro fertilization between Yak (Bos grunniens) and cattle (Bos taurus).

PubMed

Zi, Xiang-Dong; Yin, Rong-Hua; Chen, Shao-Wei; Liang, Guan-Nan; Zhang, Da-Wei; Guo, Chun-Hua

2009-10-01

The purpose of this study was to investigate fertilization ability and embryo development to the blastocyst stage after reciprocal in vitro fertilization (IVF) between yak and cattle in an attempt to clarify the problem of low conception rate after mating yak females with cattle bulls. In vitro-matured (IVM) cattle and yak oocytes were inseminated with either Holstein or yak spermatozoa, and after an 18-h of coincubation period, a proportion of the oocytes was fixed and examined for sperm penetration, polyspermy and male pronuclear formation. The remaining oocytes were cultured in vitro and evaluated for cleavage and blastocyst formation rates. The percentage of IVM oocytes penetrated by spermatozoa ranged from 78.5 to 90.5%, and the formation of one or two pronuclei and the incidence of polyspermy did not differ among the different combinations. The cleavage and blastocyst rates were not affected by the species of the sperm, but they were affected by the species of the oocytes (P<0.05), with cattle oocytes having a higher (P<0.05) cleavage and blastocyst rates (69.9 and 31.3%) than yak oocytes (62.7 and 11.5%). The blastocyst formation rate was calculated from the cleaved zygotes. The interaction between sire and oocytes species (P<0.05) influenced blastocyst formation rate, with the highest blastocyst rate occurring in cattle oocytes fertilized with yak spermatozoa (36.5%) and the lowest rate occurring in yak oocytes fertilized with yak spermatozoa (9.4%). The effect of heterosis was apparent at the blastocyst stage, but there was a large reciprocal difference in blastocyst production between crosses. It was concluded that the low conception rate that results from crossing yaks with cattle is not due to either a species-specific block of fertilization or the developmental competence of the early stage embryo.

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

PubMed

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 (P<.0001 for all). Live birth rates were the highest when multiple third-party in vitro 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. All rights reserved.

Management strategy 3: fixed rate fertilizer applications

USDA-ARS?s Scientific Manuscript database

Previous chapters outlined management strategies for pond fertilization that take into account specific individual pond nutrient needs. Those methods would most likely be more ecologically efficient than a pre-determined fixed-rate nutrient addition strategy. However, the vast majority of available ...

In search of real autonomy for fertility patients.

PubMed

Johnston, Josephine; Gusmano, Michael K; Patrizio, Pasquale

2015-07-01

Nearly one in eight infants in the United States is born preterm. A variety of factors are associated with preterm birth, including multiplicity. In the United States fertility treatments are currently associated with high rates of multiplicity, but these rates could be reduced significantly if changes can be made to fertility treatment policy and practice. These include reducing the financial pressure on patients to prioritize pregnancy chances over safety by expanding insurance coverage and altering the way we calculate success rates and insurance benefits so that two consecutive single embryo transfers is equivalent to one double embryo transfer.

Application of Glomus sp. and Pseudomonas diminuta Reduce the Use of Chemical Fertilizers in Production of Potato Grown on Different Soil Types

NASA Astrophysics Data System (ADS)

Nurbaity, A.; Sofyan, E. T.; Hamdani, J. S.

2016-08-01

The use of high chemical fertilizer rates in potato production has been applied on the farm in Indonesia. Application of biofertilizer consists of arbuscular mycorrhizal fungi has been tested to reduce the use of NPK rates in production of potato and to determine whether different soil types will have different response to this biofertilizer. A greenhouse experiment was conducted using mixtures of spores of Glomus sp. and inoculant of mycorrhizal helper bacteria Pseudomonas diminuta, applied at different rates of NPK fertilizer (0, 25, 50, 75 and 100% of recommended rates) and different soil types (Andisols and Inceptisols). Results of experiment showed that application of Glomus sp. and P. diminuta reduced the use of NPK up to 50%, where the growth (plant height and tuber number), N,P,K uptake and tuber yields of potato had similar effect to the highest recommendation rate of NPK fertilizer. Inceptisols in general had better response to the biofertiliser compared to Andisols. Findings from this experiment confirmed the evidences that biofertilizer could reduce the use of chemical fertilizer, and the widely distributed soil in Indonesia such as Inceptisols, is potential to be used as a medium for potato production.

Response of soil organic carbon fractions, microbial community composition and carbon mineralization to high-input fertilizer practices under an intensive agricultural system

PubMed Central

Wu, Xueping; Gebremikael, Mesfin Tsegaye; Wu, Huijun; Cai, Dianxiong; Wang, Bisheng; Li, Baoguo; Zhang, Jiancheng; Li, Yongshan; Xi, Jilong

2018-01-01

Microbial mechanisms associated with soil organic carbon (SOC) decomposition are poorly understood. We aim to determine the effects of inorganic and organic fertilizers on soil labile carbon (C) pools, microbial community structure and C mineralization rate under an intensive wheat-maize double cropping system in Northern China. Soil samples in 0–10 cm layer were collected from a nine-year field trial involved four treatments: no fertilizer, CK; nitrogen (N) and phosphorus (P) fertilizers, NP; maize straw combined with NP fertilizers, NPS; and manure plus straw and NP fertilizers, NPSM. Soil samples were analyzed to determine labile C pools (including dissolved organic C, DOC; light free organic C, LFOC; and microbial biomass C, MBC), microbial community composition (using phospholipid fatty acid (PLFA) profiles) and SOC mineralization rate (from a 124-day incubation experiment). This study demonstrated that the application of chemical fertilizers (NP) alone did not alter labile C fractions, soil microbial communities and SOC mineralization rate from those observed in the CK treatment. Whereas the use of straw in conjunction with chemical fertilizers (NPS) became an additional labile substrate supply that decreased C limitation, stimulated growth of all PLFA-related microbial communities, and resulted in 53% higher cumulative mineralization of C compared to that of CK. The SOC and its labile fractions explained 78.7% of the variance of microbial community structure. Further addition of manure on the top of straw in the NPSM treatment did not significantly increase microbial community abundances, but it did alter microbial community structure by increasing G+/G- ratio compared to that of NPS. The cumulative mineralization of C was 85% higher under NPSM fertilization compared to that of CK. Particularly, the NPSM treatment increased the mineralization rate of the resistant pool. This has to be carefully taken into account when setting realistic and effective goals for long-term soil C stabilization. PMID:29668702

Response of soil organic carbon fractions, microbial community composition and carbon mineralization to high-input fertilizer practices under an intensive agricultural system.

PubMed

Li, Jing; Wu, Xueping; Gebremikael, Mesfin Tsegaye; Wu, Huijun; Cai, Dianxiong; Wang, Bisheng; Li, Baoguo; Zhang, Jiancheng; Li, Yongshan; Xi, Jilong

2018-01-01

Microbial mechanisms associated with soil organic carbon (SOC) decomposition are poorly understood. We aim to determine the effects of inorganic and organic fertilizers on soil labile carbon (C) pools, microbial community structure and C mineralization rate under an intensive wheat-maize double cropping system in Northern China. Soil samples in 0-10 cm layer were collected from a nine-year field trial involved four treatments: no fertilizer, CK; nitrogen (N) and phosphorus (P) fertilizers, NP; maize straw combined with NP fertilizers, NPS; and manure plus straw and NP fertilizers, NPSM. Soil samples were analyzed to determine labile C pools (including dissolved organic C, DOC; light free organic C, LFOC; and microbial biomass C, MBC), microbial community composition (using phospholipid fatty acid (PLFA) profiles) and SOC mineralization rate (from a 124-day incubation experiment). This study demonstrated that the application of chemical fertilizers (NP) alone did not alter labile C fractions, soil microbial communities and SOC mineralization rate from those observed in the CK treatment. Whereas the use of straw in conjunction with chemical fertilizers (NPS) became an additional labile substrate supply that decreased C limitation, stimulated growth of all PLFA-related microbial communities, and resulted in 53% higher cumulative mineralization of C compared to that of CK. The SOC and its labile fractions explained 78.7% of the variance of microbial community structure. Further addition of manure on the top of straw in the NPSM treatment did not significantly increase microbial community abundances, but it did alter microbial community structure by increasing G+/G- ratio compared to that of NPS. The cumulative mineralization of C was 85% higher under NPSM fertilization compared to that of CK. Particularly, the NPSM treatment increased the mineralization rate of the resistant pool. This has to be carefully taken into account when setting realistic and effective goals for long-term soil C stabilization.

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

PubMed

Noble, J; Potts, M

1996-04-01

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

Fertility Values: Why People Stop Having Children.

ERIC Educational Resources Information Center

Terhune, Kenneth W.

This methodological study investigated which fertility values are correlated with the variable of desired family size. Data was gathered from 310 Caucasian Protestant, Catholic, and Jewish women from the Buffalo metropolitan area. The subjects were between the ages of 15 and 44, lived with their husbands, and had either none, one, two, or four…

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed Central

Nivelle, Elodie; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate. PMID:28552945

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed

Nivelle, Elodie; Verzeaux, Julien; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate.

Fertility and Childlessness in the United States.

PubMed

Baudin, Thomas; de la Croix, David

2015-06-01

We develop a theory of fertility, distinguishing its intensive margin from its extensive margin. The deep parameters are identified using facts from the 1990 US Census: (i) fertility of mothers decreases with education; (ii) childlessness exhibits a U-shaped relationship with education; (iii) the relationship between marriage rates and education is hump-shaped for women and increasing for men. We estimate that 2.5 percent of women were childless because of poverty and 8.1 percent because of high opportunity cost of childrearing. Over time, historical trends in total factor productivity and in education led to a U-shaped response in childlessness rates while fertility of mothers decreased.

Feeling the ovaries prior to insemination. Clinical implications for improving the fertility of the dairy cow.

PubMed

López-Gatius, F

2011-07-01

During the periovulatory period in dairy cattle, the largest ovarian follicle can be felt by palpation per rectum as a firm/soft follicle (young preovulatory follicle), a very soft follicle separating it from the remainder of the ovary (mature preovulatory follicle), or an evacuated follicle (follicle associated with ovulation). Because any one of these three follicle types may be present at the time of artificial insemination, the objective of this study was to identify possible differences between the effects of a firm/soft, very soft, or evacuated ovarian follicle on fertility. Out of a study sample of 2365 inseminations, very soft, firm/soft, and evacuated follicles were recorded in 1689 (71%), 593 (25%), and 83 (3.5%) inseminations, respectively. Logistic regression analysis indicated no significant effects of largest follicle type, vaginal discharge, season, days in milk, parity, synchronized or natural estrus, and semen-providing bull on the pregnancy rate. The only variable included in the final logistic regression model was the interaction season-follicle type. This interaction determined that the likelihood of pregnancy decreased significantly by factors of 0.86 or 0.82 in cows with a firm/soft follicle inseminated during the cool or warm period, respectively, and by a factor of 0.09 in cows with evacuated follicles inseminated during the warm period, using as reference cows with a very soft follicle inseminated during the cool period (yielding the highest pregnancy rate). As an overall conclusion, the state of the periovulatory follicle at insemination was clearly related to fertility and masked the effects of factors commonly affecting fertility such as parity, days in milk at AI and inseminating bull. More importantly they suggest that by including ovarian follicle checks in artificial insemination routines, the success of this procedure could be improved. Copyright © 2011 Elsevier Inc. All rights reserved.

A new insight into male fertility preservation for patients with completely immotile spermatozoa.

PubMed

Chen, Huanhua; Feng, Guixue; Zhang, Bo; Zhou, Hong; Wang, Caizhu; Shu, Jinhui; Gan, Xianyou; Lin, Ruoyun; Huang, Dongmei; Huang, Yingqin

2017-09-18

Sperm cryopreservation is the most effective method to preserve male fertility but this is normally used for motile spermatozoa. Thus, only motile spermatozoa are used for cryopreservation in most reproductive medicine centers worldwide. The immotile spermatozoa from some problematic patients are usually discarded, resulting in a missed opportunity of sterility cryopreservation for future assisted reproductive treatments. Many studies have shown that successful fertilization can be obtained after selection of viable sperm from the completely immotile spermatozoa before ICSI. Whether the completely immotile spermatozoa are worth of freezing has not been realized The aim of this study is to explore the clinical value of cryopreservation of immotile spermatozoa. Completely immotile spermatozoa were collected and frozen, and subsequently viable but immotile frozen-thawed spermatozoa were selected by laser plus for ICSI. Main outcomes included spermatozoa survival index, fertilization rate and good quality embryo rate. After identification by laser, the fresh samples of spermatozoa presented with a mean survival rate of 54.86% and 26.05%, and this was reduced to 44.13% and 18.13% in frozen-thawed spermatozoa samples, which showed a frozen-thawed spermatozoa survival index of 0.80 and 0.70 in the testicular and ejaculate sperm, respectively. There were no statistically differences in fertilization rate (80% vs80.51%, 75.00% vs 81.48%), cleavage rate (95.45% vs 98.95%, 100.00% vs 95.45%) and good quality embryo rate (40.48% vs 52.13%, 33.33%vs38.10%) between the frozen-thawed immotile spermatozoa group and the routine fresh immotile spermatozoa ICSI group in both testicular and ejaculate sperm, respectively. The results of the study show that completely immotile spermatozoa can be frozen in order to preserve male fertility as long as viable spermatozoa are present. This procedure provides a further possibility for fertility preservation for patients with completely immotile spermatozoa.

Relationship between antithyroid antibody and pregnancy outcome following in vitro fertilization and embryo transfer.

PubMed

Zhong, Yi-ping; Ying, Ying; Wu, Hai-tao; Zhou, Can-quan; Xu, Yan-wen; Wang, Qiong; Li, Jie; Shen, Xiao-ting; Li, Jin

2012-01-01

To investigate the impact of antithyroid antibody on pregnancy outcome following the in vitro fertilization and embryo transfer (IVF-ET). A total of 90 patients (156 cycles) positive for antithyroid antibody (ATA+ group) and 676 infertile women (1062 cycles) negative for antithyroid antibody (ATA- group) undergoing IVF/ICSI from August 2009 to August 2010 were retrospectively analyzed. There was no significant difference in the days of ovarian stimulation, total gonadotropin dose, serum E2 level of HCG day and number of oocytes retrieved between the two groups. The fertilization rate, implantation rate and pregnancy rate following IVF-ET were significantly lower in women with antithyroid antibody than in control group (64.3% vs 74.6%, 17.8% vs 27.1% and 33.3% vs 46.7%, respectively), but the abortion rate was significantly higher in patients with antithyroid antibody (26.9% vs 11.8%). Patients with antithyroid antibody showed significantly lower fertilization rate, implantation rate and pregnancy rate and higher risk for abortion following IVF-ET when compared with those without antithyroid antibody. Thus, the presence of antithyroid antibody is detrimental for the pregnancy outcome following IVF-ET.

Relationship between Antithyroid Antibody and Pregnancy Outcome following in Vitro Fertilization and Embryo Transfer

PubMed Central

Zhong, Yi-ping; Ying, Ying; Wu, Hai-tao; Zhou, Can-quan; Xu, Yan-wen; Wang, Qiong; Li, Jie; Shen, Xiao-ting; Li, Jin

2012-01-01

Objective: To investigate the impact of antithyroid antibody on pregnancy outcome following the in vitro fertilization and embryo transfer (IVF-ET). Methods: A total of 90 patients (156 cycles) positive for antithyroid antibody (ATA+ group) and 676 infertile women (1062 cycles) negative for antithyroid antibody (ATA- group) undergoing IVF/ICSI from August 2009 to August 2010 were retrospectively analyzed. Results: There was no significant difference in the days of ovarian stimulation, total gonadotropin dose, serum E2 level of HCG day and number of oocytes retrieved between the two groups. The fertilization rate, implantation rate and pregnancy rate following IVF-ET were significantly lower in women with antithyroid antibody than in control group (64.3% vs 74.6%, 17.8% vs 27.1% and 33.3% vs 46.7%, respectively), but the abortion rate was significantly higher in patients with antithyroid antibody (26.9% vs 11.8%). Conclusion: Patients with antithyroid antibody showed significantly lower fertilization rate, implantation rate and pregnancy rate and higher risk for abortion following IVF-ET when compared with those without antithyroid antibody. Thus, the presence of antithyroid antibody is detrimental for the pregnancy outcome following IVF-ET. PMID:22253557

The ex-pat effect: presence of recent Western immigrants is associated with changes in age at first birth and birth rate in a Maya population from rural Guatemala.

PubMed

McKerracher, Luseadra; Collard, Mark; Altman, Rachel; Richards, Michael; Nepomnaschy, Pablo

2017-08-01

Economic transitions expose indigenous populations to a variety of ecological and cultural challenges, especially regarding diet and stress. These kinds of challenges are predicted by evolutionary ecological theory to have fitness consequences (differential reproduction) and, indeed, are often associated with changes in fertility dynamics. It is currently unclear whether international immigration might impact the nature of such an economic transition or its consequences for fertility. To examine measures of fertility, diet and stress in two economically transitioning Maya villages in Guatemala that have been differentially exposed to immigration by Westerners. This study compared Maya women's ages at first birth and birth rates between villages and investigated whether these fertility indicators changed through time. It also explored whether the villages differed in relation to diet and/or a proxy of stress. It was found that, in the village directly impacted by immigration, first births occurred earlier, but birth rate was slower. In both villages, over the sampled time window, age at first birth increased, while birth rate decreased. The villages do not differ significantly in dietary indicators, but the immigration-affected village scored higher on the stress proxy. Immigration can affect fertility in host communities. This relationship between immigration and fertility dynamics may be partly attributable to stress, but this possibility should be evaluated prospectively in future research.

Live birth after artificial oocyte activation using a ready-to-use ionophore: a prospective multicentre study.

PubMed

Ebner, Thomas; Montag, Markus; Montag, M; Van der Ven, K; Van der Ven, H; Ebner, T; Shebl, O; Oppelt, P; Hirchenhain, J; Krüssel, J; Maxrath, B; Gnoth, C; Friol, K; Tigges, J; Wünsch, E; Luckhaus, J; Beerkotte, A; Weiss, D; Grunwald, K; Struller, D; Etien, C

2015-04-01

Artificial oocyte activation has been proposed as a suitable means to overcome the problem of failed or impaired fertilization after intracytoplasmic sperm injection (ICSI). In a multicentre setting artificial oocyte activation was applied to 101 patients who were diagnosed with fertilization abnormalities (e.g. less than 50% fertilized oocytes) in a previous conventional ICSI cycle. Female gametes were activated for 15 min immediately after ICSI using a ready-to-use Ca(2+)-ionophore solution (A23187). Fertilization, pregnancy and live birth rates were compared with the preceding cycle without activation. The fertilization rate of 48% in the study cycles was significantly higher compared with the 25% in the control cycles (P < 0.001). Further splitting of the historical control group into failed (0%), low (1-30%) and moderate fertilization rate (31-50%) showed that all groups significantly benefitted (P < 0.001) in the ionophore cycle. Fewer patients had their embryo transfer cancelled compared with their previous treatments (1/101 versus 15/101). In total, 99% of the patients had an improved outcome with A23187 application resulting in a 28% live birth rate (35 babies). These data suggest that artificial oocyte activation using a ready-to-use compound is an efficient method. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Fertilization Is Not a New Beginning: The Relationship between Sperm Longevity and Offspring Performance

PubMed Central

Crean, Angela J.; Dwyer, John M.; Marshall, Dustin J.

2012-01-01

Sperm are the most diverse cell type known: varying not only among- and within- species, but also among- and within-ejaculates of a single male. Recently, the causes and consequences of variability in sperm phenotypes have received much attention, but the importance of within-ejaculate variability remains largely unknown. Correlative evidence suggests that reduced within-ejaculate variation in sperm phenotype increases a male’s fertilization success in competitive conditions; but the transgenerational consequences of within-ejaculate variation in sperm phenotype remain relatively unexplored. Here we examine the relationship between sperm longevity and offspring performance in a marine invertebrate with external fertilization, Styela plicata. Offspring sired by longer-lived sperm had higher performance compared to offspring sired by freshly-extracted sperm of the same ejaculate, both in the laboratory and the field. This indicates that within-ejaculate differences in sperm longevity can influence offspring fitness – a source of variability in offspring phenotypes that has not previously been considered. Links between sperm phenotype and offspring performance may constrain responses to selection on either sperm or offspring traits, with broad ecological and evolutionary implications. PMID:23155458

Effects of consanguineous marriage on reproductive behaviour, adverse pregnancy outcomes and offspring mortality in Oman.

PubMed

Islam, M Mazharul

2013-05-01

The long tradition of high prevalence of consanguineous marriages in Omani society may have ramifications for reproductive behaviour and health of offspring. To examine the relevance of consanguinity to reproductive behaviour, adverse pregnancy outcome and offspring mortality in Oman. The data analysed came from the 2000 Oman National Health Survey. Selected indicators that are related to reproductive behaviour, adverse pregnancy outcome and offspring mortality were considered as explanatory variables. Various statistical methods and tests were used for data analysis. Consanguineous marriage was found to be associated with lower age at first birth, higher preference for larger family size, lower level of husband-wife communication about use of family planning methods and lower rate of contraceptive use. Although bivariate analysis showed elevated fertility and childhood mortality among the women with consanguineous marriage, after controlling for relevant socio-demographic factors in multivariate analysis, fertility, childhood mortality and foetal loss showed no significant association with consanguinity in Oman. Consanguinity plays an important role in determining some of the aspects of reproduction and health of newborns, but did not show any detrimental effects on fertility and offspring mortality. The high level of consanguinity and its relevance to reproduction in Oman need to be considered in its public health strategy in a culturally acceptable manner.

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

PubMed

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

2011-07-01

The aim of this study was to investigate the reasons for differences in field fertility of bulls following insemination with frozen-thawed semen. The study was carried out in two separate parts over two years and comparisons were made between 5 high and 4 low fertility Holstein Friesian bulls as determined by their either 90 day non-return rate (Year 1) or calving rate (Year 2). Two high fertility Limousin bulls were included in Year 1 for comparative purposes. The ability of sperm from each bull to penetrate artificial mucus was assessed (Year 1 = 7 replicates; Year 2 = 5 replicates). Glass capillary tubes (2 per bull per replicate) were filled with artificial mucus and incubated with sperm stained in 1% Hoechst 33342 for 30 min at 37 °C. The number of sperm were subsequently counted at 10 mm intervals along the tube between 40 and 80 mm markers. Sperm mitochondrial activity of each bull was assessed by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay (4 replicates in each year). Sperm were incubated with MTT for 1 h at 37 °C following which the absorbance of formazan was read using a spectrophotometer. Sperm viability after thawing was assessed for each bull using a live/dead sperm viability kit (Year 1 = 3 replicates; Year 2 = 4 replicates). A minimum of 250 cells were assessed per bull in each replicate and classified as either live or dead. Finally, the ability of sperm to fertilize oocytes in vitro and their ability to develop to blastocyst stage embryos were assessed (5 replicates in each year involving 220 to 306 oocytes per bull). Data transformation to normalize residuals was required for mucus sperm penetration (square root) and IVF (cleavage and blastocyst rate) results (arcsin). The mean number of sperm counted at each 10 mm mark between 40 and 80 mm was higher in the high fertility (56.0; 95% CI 39.5 to 75.3) compared to the low fertility (42.9; 95% CI 29.3 to 59.1) Holstein Friesian bulls but the difference did not reach formal significance (P = 0.09). Fertility status had no effect on the ability of sperm to reduce MTT to formazan (mean absorbance 0.34 ± 0.051 and 0.30 ± 0.044) or on the percentage of live sperm per straw (mean 47.3 ± 5.47 and 32.4 ± 4.66) for high and low fertility Holstein Friesian bulls respectively. Oocyte cleavage rate following insemination with sperm from high fertility Holstein Friesian bulls was significantly higher than with sperm from low fertility Holstein Friesian bulls [76.7% (95% CI 60.9 to 89.4) and 55.3 (95% CI 40.4 to 69.7) respectively, P = 0.04]. There was no significant effect of bull fertility on blastocyst rate [34.7% (95% CI 21.1 to 49.6) and 24.2 % (95% CI 14.1 to 36.0) for the high and low fertility Holstein Friesian bulls, respectively; P = 0.2]. In conclusion, sperm from high fertility bulls tended to be more effective in penetrating artificial mucus and to have an increased ability to fertilize oocytes in vitro; however, once fertilization occurred subsequent embryo development was not significantly affected by fertility status. Copyright © 2011 Elsevier Inc. All rights reserved.

Optimization of IVF pregnancy outcomes with donor spermatozoa.

PubMed

Wang, Jeff G; Douglas, Nataki C; Prosser, Robert; Kort, Daniel; Choi, Janet M; Sauer, Mark V

2009-03-01

To identify risk factors for suboptimal IVF outcomes using insemination with donor spermatozoa and to define a lower threshold that may signal a conversion to fertilization by ICSI rather than insemination. Retrospective, age-matched, case-control study of women undergoing non-donor oocyte IVF cycles using either freshly ejaculated (N=138) or cryopreserved donor spermatozoa (N=69). Associations between method of fertilization, semen sample parameters, and pregnancy rates were analyzed. In vitro fertilization of oocytes with donor spermatozoa by insemination results in equivalent fertilization and pregnancy rates compared to those of freshly ejaculated spermatozoa from men with normal semen analyses when the post-processing motility is greater than or equal to 88%. IVF by insemination with donor spermatozoa when the post-processing motility is less than 88% is associated with a 5-fold reduction in pregnancy rates when compared to those of donor spermatozoa above this motility threshold. When the post-processing donor spermatozoa motility is low, fertilization by ICSI is associated with significantly higher pregnancy rates compared to those of insemination. While ICSI does not need to be categorically instituted when using donor spermatozoa in IVF, patients should be counseled that conversion from insemination to ICSI may be recommended based on low post-processing motility.

Extreme weather conditions reduce the CO2 fertilization effect in temperate C3 grasslands

NASA Astrophysics Data System (ADS)

Obermeier, Wolfgang; Lehnert, Lukas; Kammann, Claudia; Müller, Christoph; Grünhage, Ludger; Luterbacher, Jürg; Erbs, Martin; Yuan, Naiming; Bendix, Jörg

2016-04-01

The increase in atmospheric greenhouse gas concentrations from anthropogenic activities is the major driver of global climate change. The rising atmospheric carbon dioxide (CO2) concentrations may stimulate plant photosynthesis and, thus, cause a net sink effect in the global carbon cycle. As a consequence of an enhanced photosynthesis, an increase in the net primary productivity (NPP) of C3 plants (termed CO2 fertilization) is widely assumed. This process is associated with a reduced stomatal conductance of leaves as the carbon demand of photosynthesis is met earlier. This causes a higher water-use efficiency and, hence, may reduce water stress in plants exposed to elevated CO2 concentrations ([eCO2]). However, the magnitude and persistence of the CO2 fertilization effect under a future climate including more frequent weather extremes are controversial. To test the CO2 fertilization effect for Central European grasslands, a data set comprising 16 years of biomass samples and environmental variables such as local weather and soil conditions was analysed by means of a novel approach. The data set was recorded on a "Free Air Carbon dioxide Enrichment" (FACE) experimental site which allows to quantify the CO2 fertilization effect under naturally occurring climate variations. The results indicate that the CO2 fertilization effect on the aboveground biomass is strongest under local average environmental conditions. Such intermediate regimes were defined by the mean +/- 1 standard deviation of the long-term average in the respective variable three months before harvest. The observed CO2 fertilization effect was reduced or vanished under drier, wetter and hotter conditions when the respective variable exceeded the bounds of the intermediate regimes. Comparable conditions, characterized by a higher frequency of more extreme weather conditions, are predicted for the future by climate projections. Consequently, biogeochemical models may overestimate the future NPP sink capacity of temperate C3 grasslands. Because temperate grasslands represent an important part of the Earth's terrestrial surface and therefore the global carbon cycle, atmospheric CO2 concentrations [CO2] might increase faster than currently expected.

Continuing fertility transitions in a plural society: ethnic trends and differentials in Peninsular Malaysia.

PubMed

Lim, L L; Jones, G W; Hirschman, C

1987-10-01

Fertility in Peninsular Malaysia has declined continuously from the late 1950s, reaching a total fertility rate of 3735 in 1983. All ethnic groups in Malaysia have contributed to this modern demographic transition but the rate of change has been most rapid for Chinese and Indians, Malay fertility having reached a plateau in the early 1980s. The effect of age structure, marital patterns and marital fertility (by parity) on the fertility declines for each ethnic community are analyzed. There has been a tendency, in each ethnic group, for the age distribution within the group of reproductive-age women to grow younger, reflecting the entry into the younger reproductive ages of the large birth cohorts of the 1950s and early 1960s. The effect of this on crude birth rates is hard to determine, because rising age at marriage and increasing use of contraception meant that fertility was increasingly concentrated in the more central reproductive ages. By the 1990s, the earlier declines in fertility will bring about a decline in the proportion of the total population made up of females in the main reproductive ages. After that point, further declines in fertility will be reflected in a sharper decline in the crude birth rate and hence the rate of population increase. Between 1947 and 1980, the age at marriage changed dramatically for females of all ethnic groups. The transition to higher age at marriage for Chinese was completed earlier, and since 1970 has risen by only a year. For Malays and Indians, the rise began later, proceeded faster and continued right up to 1980 when the medium ages at 1st marriage were Malays 22, Indians 23, Chinese 24 years. In 1980, Malay women on average were marrying 5 years later, and Indian women 6 years later than had their mothers' generation in 1947. The proportion never-married among Malay and Indian women aged 20-24 rose from 1/10 to 1/2 over this period; relatively greater changes are evident at ages 25-29. Other factors are the almost complete shift from parent-arranged to self-arranged marriages. Family size desired has decreased for all groups and the decline in breastfeeding has been offset by the sharp increase in the practice of contraception. Continuation of these trends would lead to replacement-level fertility for Malaysian Chinese and Indians by the year 2000. Malay fertility is likely to continue to decline but at a more moderate pace.

Toxicity of pesticide and fertilizer mixtures simulating corn production to eggs of snapping turtles (Chelydra serpentina).

PubMed

de Solla, Shane Raymond; Martin, Pamela Anne; Mikoda, Paul

2011-09-15

Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed. Copyright © 2011. Published by Elsevier B.V.

Biodemographic Modeling of the Links Between Fertility Motivation and Fertility Outcomes in the NLSY79

PubMed Central

MILLER, WARREN B.; BARD, DAVID E.; PASTA, DAVID J.; RODGERS, JOSEPH LEE

2010-01-01

In spite of long-held beliefs that traits related to reproductive success tend to become fixed by evolution with little or no genetic variation, there is now considerable evidence that the natural variation of fertility within populations is genetically influenced and that a portion of that influence is related to the motivational precursors to fertility. We conduct a two-stage analysis to examine these inferences in a time-ordered multivariate context. First, using data from the National Longitudinal Survey of Youth, 1979, and LISREL analysis, we develop a structural equation model in which five hypothesized motivational precursors to fertility, measured in 1979–1982, predict both a child-timing and a child-number outcome, measured in 2002. Second, having chosen two time-ordered sequences of six variables from the SEM to represent our phenotypic models, we use Mx to conduct both univariate and multivariate behavioral genetic analyses with the selected variables. Our results indicate that one or more genes acting within a gene network have additive effects that operate through child-number desires to affect both the timing of the next child born and the final number of children born, that one or more genes acting through a separate network may have additive effects operating through gender role attitudes to produce downstream effects on the two fertility outcomes, and that no genetic variance is associated with either child-timing intentions or educational intentions. PMID:20608103

Hair mercury concentrations and in vitro fertilization (IVF) outcomes among women from a fertility clinic

PubMed Central

Ehrlich, Shelley; Smith, Kristen; Williams, Paige L.; Chavarro, Jorge E.; Batsis, Maria; Toth, Thomas L.; Hauser, Russ

2015-01-01

Total hair mercury (Hg) was measured among 205 women undergoing in vitro fertilization (IVF) treatment and the association with prospectively collected IVF outcomes (229 IVF cycles) was evaluated. Hair Hg levels (median=0.62 ppm, range: 0.03-5.66 ppm) correlated with fish intake (r=0.59), and exceeded the recommended EPA reference of 1ppm in 33% of women. Generalized linear mixed models with random intercepts accounting for within-woman correlations across treatment cycles were used to evaluate the association of hair Hg with IVF outcomes adjusted for age, body mass index, race, smoking status, infertility diagnosis, and protocol type. Hair Hg levels were not related to ovarian stimulation outcomes (peak estradiol levels, total and mature oocyte yields) or to fertilization rate, embryo quality, clinical pregnancy rate or live birth rate. PMID:25601638

Fertilizer responses of longleaf pine trees within a loblolly pine plantation: separating direct effects from competition effects

Treesearch

Peter H Anderson; Kurt H. Johnsen

2009-01-01

Evidence is mixed on how well longleaf pine (Pinus palustris Mill.) responds to increased soil nitrogen via fertilization. We examined growth and physiological responses of volunteer longleaf pine trees within an intensive loblolly pine (Pinus taeda L.) fertilization experiment. Fertilizer was applied annually following thinning at age 8 years (late 1992) at rates...

Limnology of nine small lakes, Matanuska-Susitna Borough, Alaska, and the survival and growth rates of rainbow trout

USGS Publications Warehouse

Woods, P.F.

1985-01-01

The survival and growth rates of rainbow trout (Salmo gairdnieri) were concurrently measured with selected limnological characteristics in nine small (surface area < 25 sq hectometers) lakes in the Matanuska-Susitna Borough. The project goal was to develop empirical models for predicting rainbow trout growth rates from the following variables: total phosphorus concentration, chlorophyll a concentration, Secchi disc transparency, or the morphoedaphic index--a means of characterizing potential biological productivity. No suitable model could be developed from the data collected during 1982 and 1983. The lack of significant correlation was attributed in part to the wide variation in survival of rainbow trout. Winterkills, caused by severe depletion of dissolved oxygen, were suspected in four of the lakes. Varied levels of fishing pressure and competition with threespine stickleback (Gasterosteus aculeatus) also influenced survival of rainbow trout but their effects were overshadowed by winterkill. Predictive capability was also reduced because of inconsistencies in rankings generated by each of the four limnological variables chosen as indicators of potential biological productivity. A lake ranked low in productivity by one variable was commonly ranked high in productivity by another variable. The survivability of rainbow trout stocked in lakes such as these nine may be a more important indicator of potential biomass production than are indicators of lake fertility. Assessments of a lake 's susceptibility to winterkill and the degree of competition with threespine stickleback are suggested as important topics for additional research. (Author 's abstract)

The influence of the Chinese zodiac on fertility in Hong Kong SAR.

PubMed

Yip, Paul S F; Lee, Joseph; Cheung, Y B

2002-11-01

The annual total of births in Hong Kong SAR fell substantially in the past 20 years; hence the total fertility rate (TFR) followed the downward trend and dropped to a low of 0.9 below replacement level in 2000. Despite the long-term downward trend, short-run increases in the annual total of births and the TFR were exhibited. Such temporary fertility increases are identified in the Dragon Years of 1988 and 2000. The phenomenon of fertility changes associated with zodiacal animal years is examined in this paper with a view to gaining some insight into whether Chinese cultural preferences and folklore beliefs might have influenced prospective parents' reproductive behaviour. The paper explains the underlying philosophy of the Chinese astrological tradition and discusses how zodiacal preferences affect fertility between 1976 and 2000. The paper also explores why zodiacal influences on Chinese fertility before 1976 did not exist. It is unquestionable that the Dragon Year preference exerts an influence on fertility of modern Chinese populations through zodiacal birth-timing motivations. Birth rate rise in the Dragon Year is due to changes in timing of births that will have little effect on cumulative fertility.

Wanted and unwanted fertility in Bolivia: does ethnicity matter?

PubMed

McNamee, Catherine B

2009-12-01

In Bolivia, the total fertility rate (TFR) among indigenous populations is higher than that among the nonindigenous population. It is important to investigate whether this difference is attributable to ethnic differences in wanted or unwanted fertility. Data from the 2003 Bolivian Demographic and Health Survey were used to estimate women's wanted and unwanted TFRs. Logistic regression analyses were conducted to examine whether women's, men's and couples' characteristics were associated with use of any contraceptive method and modern methods. The TFRs for indigenous and nonindigenous women were 1.5 and 1.7, [corrected] respectively. The wanted fertility rate for indigenous women was nearly the same as that for nonindigenous women (2.8 and 1.4, [corrected] respectively); virtually all of the ethnic difference in the TFRs was attributable to the ethnic difference in unwanted fertility. The proportion of women in need of contraception was greater among indigenous women than among nonindigenous women (26% vs. 19%). In logistic regression analyses, male fertility preferences explained only a small part of the ethnic difference in contraceptive use. Women's, men's and couples' preferences contribute only marginally to unwanted fertility, suggesting that structural factors act as obstacles to preventing unwanted fertility.

Human sperm devoid of germinal angiotensin-converting enzyme is responsible for total fertilization failure and lower fertilization rates by conventional in vitro fertilization.

PubMed

Li, Le-Jun; Zhang, Feng-Bin; Liu, Shu-Yuan; Tian, Yong-Hong; Le, Fang; Wang, Li-Ya; Lou, Hang-Ying; Xu, Xiang-Rong; Huang, He-Feng; Jin, Fan

2014-06-01

In conventional in vitro fertilization (IVF), complete failure of fertilization occurs in 5% to 15% of treatments. Although the causes may be unclear, sperm defects appear to be the major contributor. However, a convincing test is not yet available that can predict the risk of fertilization failure. In this study, we found that germinal angiotensin-converting enzyme (gACE) (also called testicular ACE) was undetectable in sperm from patients who had total fertilization failure (TFF) and lower fertilization rates (LFRs) by IVF based on Western blot and indirect immunofluorescence analyses. Additionally, almost all of the patients without gACE on sperm (23 of 25) manifested a TT genotype of the rs4316 single-nucleotide polymorphism of ACE. Overall, our results indicate that the absence of gACE expression is responsible for TFF and LFRs by IVF. The rs4316 polymorphism of ACE might be associated with infertility in those patients. We conclude that sperm lacking gACE may be recognized before commencing IVF and that the patients may be directed instead to consider intracytoplasmic sperm injection. © 2014 by the Society for the Study of Reproduction, Inc.

Is Low Fertility a Twenty-First-Century Demographic Crisis?*

PubMed Central

Morgan, S. Philip

2010-01-01

Nearly half of the world's population in 2000 lived in countries with fertility rates at or below replacement level, and nearly all countries will reach low fertility levels in the next two decades. Concerns about low fertility, fertility that is well below replacement, are widespread. But there are both persistent rationales for having children and institutional adjustments that can make the widespread intentions for two children attainable, even in increasingly individualistic and egalitarian societies. PMID:14686132

Do children make you happier? Sustained child-wish and mental health in women 11-17 years after fertility treatment.

PubMed

Gameiro, Sofia; van den Belt-Dusebout, Alexandra W; Bleiker, Eveline; Braat, Didi; van Leeuwen, Flora E; Verhaak, Christianne M

2014-10-10

Are fertility treatment-related factors, parenthood status and sustained child-wish associated with women's long-term mental health? Sustaining a child-wish is more strongly associated with women's long-term mental health than fertility treatment-related factors and parenthood status. About one-third of the couples starting fertility treatment do not achieve parenthood and have to adjust to an unfulfilled child-wish. In women, remaining childless after treatment is associated with less favourable mental health. It is unclear if this is only related to their childlessness or if adjustment after unsuccessful treatment is affected by other variables. These include diagnostic and treatment-related factors (cause of fertility problems, age at first consultation, type and number of treatments) and the psychological ability to come to terms with the unfulfilled child-wish. Differentiating the relative contribution of these factors to women's long-term mental health will provide useful knowledge to support patients adjusting to negative treatment outcomes. A cross-sectional study with a nationally representative sample of 7148 women who started fertility treatment at any of the 12 IVF hospitals in the Netherlands from 1995 through 2000. Of 16 482 women who were invited to participate, 7148 (43.4%) provided psychological data. The average age of women was 47 years and the average age at first fertility consultation was 30 years. Fifty-one per cent of women did IUI and 85% did IVF/ICSI. Ninety per cent of women were married/cohabiting, 20.9% remained childless and 5.9% had a child-wish. Women completed a questionnaire assessing diagnostic and treatment factors (retrospective data), parenthood status, sustained child-wish and mental health. A multiple regression analysis controlling for background variables showed that, first, male factor (P < 0.05) and/or idiopathic infertility (P < 0.001) were associated with better mental health. Secondly, starting fertility treatment at an older age was associated with better mental health (P < 0.01). Thirdly, the interaction between parenthood status and sustained child-wish was significant (P < 0.01). Having a child-wish was associated with worse mental health for women with (β = -0.058, P < 0.01) and without children (β =-0.136, P < 0.001), but associations were stronger for the latter. Predictive factors accounted for <5% of the variation in mental health status in the study population. The sample was large and nationally representative. Response rate was in line with other studies but women without psychological data were less likely to have biological children and 15.9% of non-responders considered the questionnaire to be too confronting or to elicit too emotional memories. This could reflect an underestimation of the proportion of women with a sustained child-wish. Sustaining a child-wish is a more important risk for long-term adjustment problems than parenthood status. Women adjust better when they start treatment at older ages and know they were not responsible for the cause of the fertility problem. Fertility staff can play an important role in preparing patients for the possibility of treatment failure and the associated grief process. They can also inform patients about the positive effect of refocusing their life goals. This study was supported by a grant from the Dutch Cancer Society (2006-3631). No competing interests exist. N/A. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed

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

2012-08-01

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

[Comparison of growth and field microclimate characteristics of broomcorn millet under different fertilization conditions].

PubMed

Zhang, Pan-pan; Zhou, Yu; Song, Hui; Qiao, Zhi-jun; Wang, Hai-gang; Zheng, Dian-feng; Feng, Bai-li

2015-02-01

A field experiment with two broomcorn millet varieties Longmi 8 (strong drought-resistant variety) and Jinmi 4 (drought-sensitive variety) was conducted to compare their differences in growth, field microclimate and photosynthetic capacity from anthesis to maturity under different fertility conditions. The results showed that, fertilization decreased canopy temperature, air temperature, soil temperature, illumination, but improved the relative humidity among broomcorn millet plants compared with the non-fertilization treatment. With an increase of the fertilizer level, the plant height, SPAD, LAI, net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration in broomcorn millet showed an increasing trend, which of the high fertilization treatment were 9.2%, 15.1%, 56.6%, 17.8%, 24.6%, 14.2%, 29.7% higher than those of non-fertilization treatment, respectively. Compared with Jinmi 4, Longmi 8 showed a cold wet characteristic, with lower canopy temperature, air temperature, soil temperature; illumination, and higher plant height, LAI, SPAD and relative humidity during grain filling. Moreover, each photosynthetic index of Longmi 8 slowly decreased and extended the period of leaf photosynthetic function so as to accumulate more photosynthetic products.

Irrigation frequency and timing influence pepper yields

USDA-ARS?s Scientific Manuscript database

Information on how fertilizer and irrigation affect production of vegetables can help growers improve resource use efficiency and profitability. Fertilizer was applied at the recommended rate and twice the recommended rate to bell and non-pungent jalapeno peppers, both Capsicum annuum L., in 2009 a...

Intercountry comparisons of labor force trends and of related developments: an overview.

PubMed

Mincer, J

1985-01-01

This paper is a survey of analyses of women's labor force growth in 12 industrialized countries, presented at a conference in Sussex, England in 1983. The main focus is on growth of the labor force of married women from 1960-1980; trends in fertility, wages, and family instability are discussed. In all countries, wages of women were lower than wages of men, although between 1960 and 1980 labor force rates of married women rose in most of the industrialized countries. 2 factors that are associated with this growth are declines in fertility and increases in divorce rates. The 12 countries studied are: 1) Australia, 2) Britain, 3) France, 4) Germany, 5) Israel, 6) Italy, 7) Japan, 8) Netherlands, 9) Spain, 10) Sweden, 11) US, and 12) USSR. The substitution variables (wages of women or their education) have strong positive effects on labor force participation in most cases, and in most cases the positive wage elasticities exceed the negative income elasticities by a sizable margin. A summary table estimating parameters of the P-function for each country, and their predictive performance in time series, are included. From 1960-1980 the average per country growth in participation of married women was 2.84% per year. Wages of working women, in this same period grew, on average, faster than wages of men in most countries, in part due to selectivity by education in labor force growth. While growth rates of real wages across countries have a weak relation with the differential growth rates of married women's labor force, the relation is strong when country parameters are taken into account. The dominance of the "discouraged" over the "added" workers in female labor force growth appears to be upheld internationally. On the average, total fertility rate dropped from 2.42 in 1970 to 1.85 in 1980. Both fertility declines and the growth of family instability appear to represent lagged effects of longer term developments in the labor force of women. Women's wages are lower than men's wages in all countries; wage differentials narrowed in all other countries over the past 2 decades. This narrowing was due both to women's educational attainment catching up with men's, and to a positive educational selectivity of women's labor force growth during this period. Ultimately, without labor market discrimination and with equal educational attainment, the wage gap can be eliminated only when sex differences in lifetime work experience vanish.

Inhibition of 19S proteasomal regulatory complex subunit PSMD8 increases polyspermy during porcine fertilization in vitro.

PubMed

Yi, Young-Joo; Manandhar, Gaurishankar; Sutovsky, Miriam; Jonáková, Vera; Park, Chang-Sik; Sutovsky, Peter

2010-03-01

The 26S proteoasome is a multi-subunit protease specific to ubiquitinated substrate proteins. It is composed of a 20S proteasomal core with substrate degradation activity, and a 19S regulatory complex that acts in substrate recognition, deubiquitination, priming and transport to the 20S core. Inhibition of proteolytic activities associated with the sperm acrosome-borne 20S core prevents fertilization in mammals, ascidians and echinoderms. Less is known about the function of the proteasomal 19S complex during fertilization. The present study examined the role of PSMD8, an essential non-ATPase subunit of the 19S complex, in sperm-ZP penetration during porcine fertilization in vitro (IVF). Immunofluorescence localized PSMD8 to the outer acrosomal membrane, acrosomal matrix and the inner acrosomal membrane. Colloidal gold transmission electron microscopy detected PSMD8 on the surface of vesicles in the acrosomal shroud, formed as a result of zona pellucida-induced acrosomal exocytosis. Contrary to the inhibition of fertilization by blocking of the 20S core activities, fertilization and polyspermy rates were increased by adding anti-PSMD8 antibody to fertilization medium. This observation is consistent with a possible role of PSMD8 in substrate deubiquitination, a process which when blocked, may actually accelerate substrate proteolysis by the 26S proteasome. Subunit PSMD8 co-immunoprecipitated with acrosomal surface-associated spermadhesin AQN1. This association indicates that the sperm acrosome-borne proteasomes become exposed onto the sperm surface following the acrosomal exocytosis. Since immunological blocking of subunit PSMD8 increases the rate of polyspermy during porcine fertilization, the activity of the 19S complex may be a rate-limiting factor contributing to anti-polyspermy defense during porcine fertilization. Copyright 2009. Published by Elsevier Ireland Ltd.

Effects of combined application of nitrogen fertilizer and biochar on the nitrification and ammonia oxidizers in an intensive vegetable soil.

PubMed

Bi, Qing-Fang; Chen, Qiu-Hui; Yang, Xiao-Ru; Li, Hu; Zheng, Bang-Xiao; Zhou, Wei-Wei; Liu, Xiao-Xia; Dai, Pei-Bin; Li, Ke-Jie; Lin, Xian-Yong

2017-11-07

Soil amended with single biochar or nitrogen (N) fertilizer has frequently been reported to alter soil nitrification process due to its impact on soil properties. However, little is known about the dynamic response of nitrification and ammonia-oxidizers to the combined application of biochar and N fertilizer in intensive vegetable soil. In this study, an incubation experiment was designed to evaluate the effects of biochar and N fertilizer application on soil nitrification, abundance and community shifts of ammonia-oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) in Hangzhou greenhouse vegetable soil. Results showed that single application of biochar had no significant effect on soil net nitrification rates and ammonia-oxidizers. Conversely, the application of only N fertilizer and N fertilizer + biochar significantly increased net nitrification rate and the abundance of AOB rather than AOA, and only AOB abundance was significantly correlated with soil net nitrification rate. Moreover, the combined application of N fertilizer and biochar had greater effect on AOB communities than that of the only N fertilizers, and the relative abundance of 156 bp T-RF (Nitrosospira cluster 3c) decreased but 60 bp T-RF (Nitrosospira cluster 3a and cluster 0) increased to become a single predominant group. Phylogenetic analysis indicated that all the AOB sequences were grouped into Nitrosospira cluster, and most of AOA sequences were clustered within group 1.1b. We concluded that soil nitrification was stimulated by the combined application of N fertilizer and biochar via enhancing the abundance and shifting the community composition of AOB rather than AOA in intensive vegetable soil.

Phosphorus runoff from turfgrass as affected by phosphorus fertilization and clipping management.

PubMed

Bierman, Peter M; Horgan, Brian P; Rosen, Carl J; Hollman, Andrew B; Pagliari, Paulo H

2010-01-01

Phosphorus enrichment of surface water is a concern in many urban watersheds. A 3-yr study on a silt loam soil with 5% slope and high soil test P (27 mg kg(-1) Bray P1) was conducted to evaluate P fertilization and clipping management effects on P runoff from turfgrass (Poa pratensis L.) under frozen and nonfrozen conditions. Four fertilizer treatments were compared: (i) no fertilizer, (ii) nitrogen (N)+potassium (K)+0xP, (iii) N+K+1xP, and (iv) N+K+3xP. Phosphorus rates were 21.3 and 63.9 kg ha(-1) yr(-1) the first year and 7.1 and 21.3 kg ha(-1) yr(-1) the following 2 yr. Each fertilizer treatment was evaluated with clippings removed or clippings recycled back to the turf. In the first year, P runoff increased with increasing P rate and P losses were greater in runoff from frozen than nonfrozen soil. In year 2, total P runoff from the no fertilizer treatment was greater than from treatments receiving fertilizer. This was because reduced turf quality resulted in greater runoff depth from the no fertilizer treatment. In year 3, total P runoff from frozen soil and cumulative total P runoff increased with increasing P rate. Clipping management was not an important factor in any year, indicating that returning clippings does not significantly increase P runoff from turf. In the presence of N and K, P fertilization did not improve turf growth or quality in any year. Phosphorus runoff can be reduced by not applying P to high testing soils and avoiding fall applications when P is needed.

[Association between the decline in global fertility rate and the incorporation of women to the workforce].

PubMed

Stefanelli, María de Los Ángeles; Valenzuela, María Teresa; Cárcamo, Marcela; Urquidi, Cinthya; Cavada, Gabriel; San Martín P, Pamela

2016-05-01

The global fertility rate (GFR) is defined as the mean number of children that a woman could have in a hypothetical cohort, not exposed to death during the fertile period. GFR has fallen from 3.4 to 1.9 children per women in the period 1970-2010. To explore the relationship between the fall in GFR and the incorporation of women to work in the period 1960-2011. Data from the National Statistics Institute was used. GRF was calculated using specific fertility rates for each year considering women aged 15 to 49 years. Work rates were obtained from yearly vital statistics reports. Between 1960 and 2011, GRF decreased from 5.5 to 1.9 in Chile. The first inflection occurred in 1970. In the same period, female workforce increased from 22.4 to 40.2%. To motivate the participation of female work-force without decrease the GRF allowing population replacement, it is suggested the need to create new public policies with benefits and support from the state.

Comparison of embryo development between intracytoplasmic and Piezo-assisted sperm injection after treating mouse sperms by Ca2+ ionophore.

PubMed

Shahverdi, Abdolhossein; Movahedin, Mansoureh; Rezazadeh Valojerdi, Mojtaba; Kazemi Ashtiani, Saeid

2007-10-01

The purpose of this study was to evaluate the efficiency of intracytoplasmic sperm injection (ICSI) and Piezo-assisted sperm injection after pretreatment with calcium ionophore (CaI) on the mouse embryo development. In this study, the conventional ICSI and Piezo-ICSI procedures were used. The efficacy of the methods was examined after mouse matured oocytes were fertilized with or without CaI-treated sperms. Piezo-ICSI demonstrated significantly more favorable results, with a fertilization rate of 64% (conventional ICSI: 42%, P<0.001) and a cleavage rate of 73% (conventional ICSI: 58%, P<0.05). When the Piezo-ICSI procedure was performed with CaI-pretreated sperms, the cleavage rate significantly increased (92% vs. 73%, P<0.05). However, the fertilization rate did not change significantly (64% vs. 56%). The Piezo-ICSI accompanies with CaI-treated sperms is more efficient than the conventional ICSI method for fertilizing and thus obtaining more mouse embryos.

The impact of CO2-driven ocean acidification on early development and calcification in the sea urchin Strongylocentrotus intermedius.

PubMed

Zhan, Yaoyao; Hu, Wanbin; Zhang, Weijie; Liu, Minbo; Duan, Lizhu; Huang, Xianya; Chang, Yaqing; Li, Cong

2016-11-15

The impact of CO 2 -driven ocean acidification(OA) on early development and calcification in the sea urchin Strongylocentrotus intermedius cultured in northern Yellow Sea was investigated by comparing fertilization success, early cleavage rate, hatching rate of blastulae, larvae survival rate at 70h post-fertilization, larval morphology and calcification under present natural seawater condition (pH=8.00±0.03) and three laboratory-controlled acidified conditions (OA 1 , △pH=-0.3units; OA 2 , △pH=-0.4units; OA 3 , △pH=-0.5units) projected by IPCC for 2100. Results showed that pH decline had no effect on the overall fertilization, however, with decreased pH, delayed early embryonic cleavage, reduced hatching rate of blastulae and four-armed larvae survival rate at 70h post-fertilization, impaired larval symmetry, shortened larval spicules, and corrosion spicule structure were observed in all OA-treated groups as compared to control, which indicated that CO 2 -driven OA affected early development and calcification in S. intermedius negatively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of corifollitropin alfa and daily recombinant follicle-stimulating hormone in poor responder patients undergoing in vitro fertilization cycles.

PubMed

Akarsu, Süleyman; Demir, Sibel; Gode, Funda; Işık, Ahmet Zeki

2017-12-01

The aim of this study was to compare the effect of corifollitropin alfa (CFA) and recombinant follicle-stimulating hormone (rFSH) in poor-responder patients undergoing antagonist cycles. The study was a retrospective analysis of the treatment results of 214 poor responder patients who had been admitted to the In Vitro Fertilization Unit of İzmir Medical Park Hospital between November 2014 and November 2016. Intracytoplasmic sperm injections were performed in 38 patients (group 1) with CFA, and the remaining 176 (group 2) with rFSH for controlled ovarian hyperstimulation. The age, body mass index, anti-müllerian hormone level, duration of infertility, duration of induction and antral follicle number were similar in the two groups. There was no difference in the total aspirated oocyte counts, mature oocyte ratio, fertilization rate, implantation rate, and clinical pregnancy rates between the two groups. The implantation rate was 9/38 (23.6%) in group 1 and 42/176 (23.8%) in group 2, whereas the clinical pregnancy rates were 16.3% and 17.2%, respectively. No difference was found in terms of oocyte count, fertilization rate, implantation rate, and clinical pregnancy rates of CFA or rFSH use in the antagonist cycles in poor-responder patients.

Integrated soil fertility management in sub-Saharan Africa: unravelling local adaptation

NASA Astrophysics Data System (ADS)

Vanlauwe, B.; Descheemaeker, K.; Giller, K. E.; Huising, J.; Merckx, R.; Nziguheba, G.; Wendt, J.; Zingore, S.

2014-12-01

Intensification of smallholder agriculture in sub-Saharan Africa is necessary to address rural poverty and natural resource degradation. Integrated Soil Fertility Management (ISFM) is a means to enhance crop productivity while maximizing the agronomic efficiency (AE) of applied inputs, and can thus contribute to sustainable intensification. ISFM consists of a set of best practices, preferably used in combination, including the use of appropriate germplasm, the appropriate use of fertilizer and of organic resources, and good agronomic practices. The large variability in soil fertility conditions within smallholder farms is also recognised within ISFM, including soils with constraints beyond those addressed by fertilizer and organic inputs. The variable biophysical environments that characterize smallholder farming systems have profound effects on crop productivity and AE and targeted application of limited agro-inputs and management practices is necessary to enhance AE. Further, management decisions depend on the farmer's resource endowments and production objectives. In this paper we discuss the "local adaptation" component of ISFM and how this can be conceptualized within an ISFM framework, backstopped by analysis of AE at plot and farm level. At plot level, a set of four constraints to maximum AE is discussed in relation to "local adaptation": soil acidity, secondary nutrient and micro-nutrient (SMN) deficiencies, physical constraints, and drought stress. In each of these cases, examples are presented whereby amendments and/or practices addressing these have a significantly positive impact on fertilizer AE, including mechanistic principles underlying these effects. While the impact of such amendments and/or practices is easily understood for some practices (e.g., the application of SMNs where these are limiting), for others, more complex interactions with fertilizer AE can be identified (e.g., water harvesting under varying rainfall conditions). At farm scale, adjusting fertilizer applications within-farm soil fertility gradients has the potential to increase AE compared with blanket recommendations, in particular where fertility gradients are strong. In the final section, "local adaption" is discussed in relation to scale issues and decision support tools are evaluated as a means to create a better understanding of complexity at farm level and to communicate best scenarios for allocating agro-inputs and management practices within heterogeneous farming environments.

Laminated root rot in a western Washington plantation: 8-year mortality and growth of Douglas-fir as related to infected stumps, tree density, and fertilization.

Treesearch

Richard E. Miller; Timothy B. Harrington; Walter G. Thies; Jeff. Madsen

2006-01-01

A 4-year-old Douglas-fir plantation in the western Washington Cascades was monitored for 8 years after fertilization with potassium (K), nitrogen (N), and K+N to determine fertilizer effects on rates of mortality from laminated root rot (LRR) and other causes relative to a nonfertilized control. Each element was applied at a rate of 300 lb/acre on and around 0.2-acre...

Transitions in fertility for Brazilian women: an analysis of impact factors.

PubMed

Madalozzo, Regina

2012-01-01

The labor participation of Brazilian women has increased during the last few decades. According to the World Bank, the percentage of Brazilian women participating in the labor market rose from 20% in the early 1970s to 65% (for women between 16 and 64 years of age) in 2009. The fertility profile has also changed, the fertility rate has decreased from 6.2 in 1960 to 1.9 in 2009, below the replacement rate, according to the World Bank. This paper will present Brazilian fertility trends during the previous (20(th)) and present (21(st)) centuries and, emphasize the importance of individual profiles for fertility decisions. This work uses Brazilian data from PNAD (Pesquisa Nacional de Amostra por Domicilios) to understand the cause of this relationship and to predict the consequences of these choices on women's economic development.

Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment.

PubMed

Huang, Min; Zhou, Xuefeng; Xie, Xiaobing; Zhao, Chunrong; Chen, Jiana; Cao, Fangbo; Zou, Yingbin

2016-01-01

The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot-1 (equivalent to the recommended field rate of 150 kg ha-1) to 0.44 g pot-1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.

Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment

PubMed Central

Huang, Min; Zhou, Xuefeng; Xie, Xiaobing; Zhao, Chunrong; Chen, Jiana; Cao, Fangbo; Zou, Yingbin

2016-01-01

The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot–1 (equivalent to the recommended field rate of 150 kg ha–1) to 0.44 g pot–1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk. PMID:27880837

Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

NASA Astrophysics Data System (ADS)

Gallagher, M. E.; Hockaday, W. C.; Snapp, S.; McSwiney, C.; Baldock, J.

2010-12-01

Corn grain biofuel crops produce the highest yields when the cropping ecosystem is not nitrogen (N)-limited, achieved by application of fertilizer. There are environmental consequences for excessive fertilizer application to crops, including greenhouse gas emissions, hypoxic “dead zones,” and health problems from N runoff into groundwater. The increase in corn acreage in response to demand for alternative fuels (i.e. ethanol) could exacerbate these problems, and divert food supplies to fuel production. A potential substitute for grain ethanol that could reduce some of these impacts is cellulosic ethanol. Cellulosic ethanol feedstocks include grasses (switchgrass), hardwoods, and crop residues (e.g. corn stover, wheat straw). It has been assumed that these feedstocks will require similar N fertilization rates to grain biofuel crops to maximize yields, but carbohydrate yield versus N application has not previously been monitored. We report the biochemical stocks (carbohydrate, protein, and lignin in Mg ha-1) of a corn ecosystem grown under varying N levels. We measured biochemical yield in Mg ha-1 within the grain, leaf and stem, and reproductive parts of corn plants grown at seven N fertilization rates (0-202 kg N ha-1), to evaluate the quantity and quality of these feedstocks across a N fertilization gradient. The N fertilization rate study was performed at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. Biochemical stocks were measured using 13C nuclear magnetic resonance spectroscopy (NMR), combined with a molecular mixing model (Baldock et al. 2004). Carbohydrate and lignin are the main biochemicals of interest in ethanol production since carbohydrate is the ethanol feedstock, and lignin hinders the carbohydrate to ethanol conversion process. We show that corn residue carbohydrate yields respond only weakly to N fertilization compared to grain. Grain carbohydrate yields plateau in response to fertilization at moderate levels (67 kg N ha-1). Increasing fertilizer application beyond the point of diminishing returns for grain (67 kg N ha-1) to double the regionally-recommended amount (202 kg N ha-1) resulted in only marginal increases (25%) in crop residue carbohydrate yield, while increasing lignin yields 41%. In the case of at least this ecosystem, high fertilization rates did not result in large carbohydrate yield increases in the crop residue, and instead produced a lower quality feedstock for cellulosic ethanol production.

Humus and energy balances and greenhouse gas emissions with compost fertilization in organic farming compared with mineral fertilization

NASA Astrophysics Data System (ADS)

Erhart, Eva; Schmid, Harald; Hülsbergen, Kurt-Jürgen; Hartl, Wilfried

2015-04-01

Humus and energy balances and greenhouse gas emissions with compost fertilization in organic farming compared with mineral fertilization E. Erhart, H. Schmid, K.-J. Hülsbergen, W. Hartl The positive effects of compost fertilization on soil humus with their associated benefits for soil quality are well-established. The aim of the present study was to assess the effect of compost fertilization on humus and energy balances and greenhouse gas emissions and to compare the results of the humus balances with the changes in soil organic carbon contents measured in the soil of the experimental field. In order to assess the effects of compost use in organic farming as compared to conventional farming practice using mineral fertilizers, the field experiment with compost fertilization 'STIKO' was set up in 1992 near Vienna, Austria, on a Molli-gleyic Fluvisol. It included three treatments with compost fertilization (C1, C2 and C3 with 8, 14 and 20 t ha-1 y-1 f. m. on average of 14 years), three treatments with mineral nitrogen fertilization (N1, N2 and N3 with 29, 46 and 63 kg N ha-1 y 1 on average) and an unfertilized control (0) in six replications in a latin rectangle design. In the field trial, biowaste compost from the composting plant of the City of Vienna was used. Data from the field experiment (from 14 experimental years) were fed into the model software REPRO to calculate humus and energy balances and greenhouse gas emissions. The model software REPRO (REPROduction of soil fertility) couples the balancing of C, N and energy fluxes. For the determination of the net greenhouse effect, REPRO performs calculations of C sequestration in the soil, CO2 emissions from the use of fossil energy and N2O emissions from the soil. Humus balances showed that compost fertilization at a rate of 8 t ha-1 y-1 (C1) resulted in a positive humus balance of +115 kg C ha-1 y-1. With 14 and 20 t ha-1 y-1 compost (C2 and C3), respectively, humus accumulated at rates of 558 and 1021 kg C ha-1 y-1. With mineral fertilization at rates of 29 - 63 kg N ha-1 y-1 (N1 - N3), balances were moderately negative ( 169 to -227 kg C ha-1 y-1), while a clear humus deficit of 457 kg C ha-1 y-1 showed in the unfertilized control. Compared with measured soil organic carbon data REPRO predicted soil organic carbon contents fairly well with the exception of the treatments with high compost rates. Here REPRO clearly overestimated soil organic carbon contents for this site. Energy efficiency, as described by the output/input ratio, was highest in the control, followed by C1. Mineral fertilization treatment N3 was most energy intensive. The greenhouse gas balance indicated net carbon sequestration already with medium compost rates (C2), and net carbon sequestration of 1700 kg CO2-eq ha-1 y-1 in C3. Mineral fertilization yielded net greenhouse gas emissions of around 2000 kg CO2-eq ha-1 y 1. The highest greenhouse gas emissions had the unfertilized control due to the degradation of soil organic matter and lowest organic matter input. These findings underline that compost fertilization holds a high potential for carbon sequestration and for the reduction of greenhouse gas emissions.

Present-day nearshore pH differentially depresses fertilization in congeneric sea urchins.

PubMed

Frieder, Christina A

2014-02-01

Ocean acidification impacts fertilization in some species of sea urchin, but whether sensitivity is great enough to be influenced by present-day pH variability has not been documented. In this study, fertilization in two congeneric sea urchins, Strongylocentrotus purpuratus and S. franciscanus, was found to be sensitive to reduced pH, <7.50, but only within a range of sperm-egg ratios that was species-specific. By further testing fertilization across a broad range of pH, pH-fertilization curves were generated and revealed that S. purpuratus was largely robust to pH, while fertilization in S. franciscanus was sensitive to even modest reductions in pH. Combining the pH-fertilization response curves with pH data collected from these species' habitat demonstrated that relative fertilization success remained high for S. purpuratus but could be as low as 79% for S. franciscanus during periods of naturally low pH. In order for S. franciscanus to maintain high fertilization success in the present and future, adequate adult densities, and thus sufficient sperm-egg ratios, will be required to negate the effects of low pH. In contrast, fertilization of S. purpuratus was robust to a broad range of pH, encompassing both present-day and future ocean acidification scenarios, even though the two congeners have similar habitats.

fusing regional and weather variability with site-specific canopy reflectance for improved in-season N fertilizer recommendation

USDA-ARS?s Scientific Manuscript database

Corn production across the U.S. Corn belt can be often limited by the loss of nitrogen (N) due to leaching, volatilization and denitrification. The use of canopy sensors for making in-season N fertilizer applications has been proven effective in matching plant N requirements with periods of rapid N ...

Fertilization increases diameter growth of birch-beech-maple trees in New Hampshire

Treesearch

L. O. Safford

1973-01-01

In a 60-year-old northern hardwood stand treated with lime plus NPK fertilizer, the following increases in average basal area growth rate over untreated trees were observed: sugar maple 128 percent, paper birch 69 percent, yellow birch 51 percent, and beech 20 percent. Magnitude of response was inversely related to relative growth rate of the species. Growth rate...

Impact of daylight savings time on spontaneous pregnancy loss in in vitro fertilization patients.

PubMed

Liu, Constance; Politch, Joseph A; Cullerton, Evan; Go, Kathryn; Pang, Samuel; Kuohung, Wendy

2017-01-01

Transition into daylight savings time (DST) has studied negative impacts on health, but little is known regarding impact on fertility. This retrospective cohort study evaluates DST impact on pregnancy and pregnancy loss rates in 1,654 autologous in vitro fertilization cycles (2009 to 2012). Study groups were identified based on the relationship of DST to embryo transfer. Pregnancy rates were similar in Spring and Fall (41.4%, 42.2%). Pregnancy loss rates were also comparable between Spring and Fall (15.5%, 17.1%), but rates of loss were significantly higher in Spring when DST occurred after embryo transfer (24.3%). Loss was marked in patients with a history of prior spontaneous pregnancy loss (60.5%).

Agents affecting health of mother and child in a rural area of Kenya. XVIII. Fertility, mortality and migration in 1975-1978.

PubMed

Van Ginneken, J K; Voorhoeve, A M; Omondi-Odhiambo; Muller, A S; Blok, P G; W'Oigo, H O

1980-06-01

The results reported here are based on age-specific rates and are, therefore, more sensitive and meaningful as indicators of fertility and mortality than the crude rates mentioned in the previous article. The results confirm that, compared to world standards, the study area is characterized by a high level of fertility and a fairly low level of mortality. Fertility and mortality are, however, lower in the study area in comparison to Kenya as a whole. Another characteristic is high population mobility which is of two types: temporary migration of absent members of the population, and permanent in- and out-migration.

Response of highbush blueberry to nitrogen fertilizer during field establishment. I. Accumulation and allocation of fertilizer nitrogen and biomass

USDA-ARS?s Scientific Manuscript database

The effects of N fertilizer rate on plant growth, N uptake, and biomass and N partitioning was studied in highbush blueberry during the first 2 years after planting. Plants were grown without N fertilizer or with either 50, 100, or 150 kg/ha N applied each year using 15N-depleted ammonium sulfate t...

Effects of Fertilizer Nitrogen on Tree Growth, Foliar Nitrogen, and Herbage in Eastern Cottonwood Plantations

Treesearch

B. G. Blackmon

1977-01-01

When five rates of nitrogen fertilizer (0 to 672 kg/ha) were tested in two eastern cottonwood (Populus deltoides Bartr.) plantations 7 and 10 years old in the Mississippi River floodplain , first season volume growth was more than doubled by fertilization . By the end of the third season, the direct effect of fertilization had apparently disappeared although a volume...

Effect of fertilizer applications and grazing exclusion on species composition and biomass in wet meadow restoration in eastern Washington.

Treesearch

John Beebe; Richard Everett; George Scherer; Carl. Davis

2002-01-01

Fertilizer applications and grazing exclusion were used as restoration strategies in degraded wet meadows in eastern Washington to grow biomass in the root systems where it could not be grazed. We used a split-block design to test vegetation responses to six fertilizer rates, eight fertilizer types, and three grazing treatments after three growing seasons. Little...

Estimating the agricultural fertilizer NH3 emission in China based on the bi-directional CMAQ model and an agro-ecosystem model

NASA Astrophysics Data System (ADS)

Wang, S.

2014-12-01

Atmospheric ammonia (NH3) plays an important role in fine particle formation. Accurate estimates of ammonia can reduce uncertainties in air quality modeling. China is one of the largest countries emitting ammonia with the majority of NH3 emissions coming from the agricultural practices, such as fertilizer applications and animal operations. The current ammonia emission estimates in China are mainly based on pre-defined emission factors. Thus, there are considerable uncertainties in estimating NH3 emissions, especially in time and space distribution. For example, fertilizer applications vary in the date of application and amount by geographical regions and crop types. In this study, the NH3 emission from the agricultural fertilizer use in China of 2011 was estimated online by an agricultural fertilizer modeling system coupling a regional air-quality model and an agro-ecosystem model, which contains three main components 1) the Environmental Policy Integrated Climate (EPIC) model, 2) the meso-scale meteorology Weather Research and Forecasting (WRF) model and 3) the CMAQ air quality model with bi-directional ammonia fluxes. The EPIC output information about daily fertilizer application and soil characteristics would be the input of the CMAQ model. In order to run EPIC model, much Chinese local information is collected and processed. For example, Crop land data are computed from the MODIS land use data at 500-m resolution and crop categories at Chinese county level; the fertilizer use rate for different fertilizer types, crops and provinces are obtained from Chinese statistic materials. The system takes into consideration many influencing factors on agriculture ammonia emission, including weather, the fertilizer application method, timing, amount, and rate for specific pastures and crops. The simulated fertilizer data is compared with the NH3 emissions and fertilizer application data from other sources. The results of CMAQ modeling are also discussed and analyzed with field measurements. The estimated agricultural fertilizer NH3 emission in this study is about 3Tg in 2011. The regions with the highest emission rates are located in the North China Plain. Monthly, the peak ammonia emissions occur in April to July.

Response of turf and quality of water runoff to manure and fertilizer.

PubMed

Gaudreau, J E; Vietor, D M; White, R H; Provin, T L; Munster, C L

2002-01-01

Manure applications can benefit turfgrass production and unused nutrients in manure residues can be exported through sod harvests. Yet, nutrients near the soil surface could be transported in surface runoff. Our research objective was to evaluate responses of bermudagrass [Cynodon dactylon (L.) Pers. var. Guymon] turf and volumes and P and N concentrations of surface runoff after fertilizer or composted manure applications. Three replications of five treatments were established on a Boonville fine sandy loam (fine, smectitic, thermic Vertic Albaqualf) that was excavated to create an 8.5% slope. Manure rates of 50 and 100 kg P ha(-1) at the start of two monitoring periods were compared with P fertilizer rates of 25 and 50 kg ha(-1) and an unfertilized control. Compared with initial soil tests, nitrate concentrations decreased and P concentrations increased after two manure or fertilizer applications and eight rain events over the two monitoring periods. The fertilizer sources of P and N produced 19% more dry weight and 21% larger N concentrations in grass clippings than manure sources. Yet, runoff volumes were similar between manure and fertilizer sources of P. Dissolved P concentration (30 mg L(-1)) in runoff during a rain event 3 d after application of 50 kg P ha(-1) was five times greater for fertilizer than for manure P. Observations during both monitoring periods indicated that total P and N losses in runoff were no greater for composted manure than for fertilizer sources of P at relatively large P rates on a steep slope of turfgrass.

[Effect of spermatozoa from different sources on normal fertilization of oocytes and embryo quality and development in intracytoplasmic sperm injection cycles].

PubMed

Xie, Duo; Qiu, Zhuolin; Luo, Chen; Chu, Qingjun; Quan, Song

2014-06-01

To evaluate the impact of spermatozoa from different sources on normal fertilization of oocytes, embryo quality and embryo developmental potential in intracytoplasmic sperm injection (ICSI) cycles. A retrospective analysis was conducted among 197 patients undergoing ICSI cycles in our center. The patients were classified into 3 groups according to the sources of semen, namely ejaculated spermatozoa group (n=102), percutaneous epididymal sperm aspiration (PESA) group (n=68), and testicular sperm aspiration (TESA) group (n=27). The ejaculated spermatozoa group was further classified into oligoasthenoteratozoospermia (n=67) and cryptozoospermia (n=35) subgroups. The normal fertilization, high-quality embryo, implantation and clinical pregnancy rates were compared among the groups; the rate of high-quality blastocyst formation in in-vitro culture of non-top quality embryos was also observed. The patients with PESA showed significantly higher normal fertilization rate (75.6%) than those in oligoasthenoteratozoospermia (64.8%), cryptozoospermia (62.1%), and TESA (61.6%) groups (P<0.05). No significant differences were found in the high-quality embryo, implantation, and clinical pregnancy rates among the groups (P>0.05). The rate of high-quality blastocyst formation in the in-vitro culture of non-top quality embryos was also comparable among the groups (P>0.05). Although spermatozoa obtained with by PESA is associated with a higher normal fertilization rate, the sources of spermatozoa do not significantly affect the embryonic quality and developmental potential in ICSI cycles.

Comparison of in vitro fertilization/intracytoplasmic sperm injection outcomes in male factor infertility patients with and without spinal cord injuries.

PubMed

Kathiresan, Anupama S Q; Ibrahim, Emad; Aballa, Teodoro C; Attia, George R; Ory, Steven J; Hoffman, David I; Maxson, Wayne S; Barrionuevo, Marcelo J; Lynne, Charles M; Brackett, Nancy L

2011-09-01

To determine if outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) using sperm from men with spinal cord injury (SCI group) differ from those of other etiologies of male factor infertility (non-SCI group). In men with SCI, to determine if IVF/ICSI outcomes differ with sperm obtained by penile vibratory stimulation (PVS group) versus electroejaculation (EEJ group). Retrospective analysis. University medical center and major infertility center. Couples with male factor infertility due to SCI versus other etiologies. PVS, EEJ, surgical sperm retrieval, and IVF/ICSI. Rates of fertilization, pregnancy, and live birth. A total of 31 couples in the SCI group underwent 48 cycles of IVF/ICSI, and a total of 297 couples in the non-SCI group underwent 443 cycles of IVF/ICSI. The SCI group had lower fertilization rates but similar pregnancy and live birth rates compared with the non-SCI group. These rates, however, did not differ significantly when the PVS group was compared with the EEJ group. IVF/ICSI of sperm from men with SCI yield lower fertilization rates but similar pregnancy and live birth outcomes as IVF/ICSI of sperm from men with other etiologies of male factor infertility. Sperm collected by PVS versus EEJ in men with SCI appear to result in similar IVF/ICSI success rates. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

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

PubMed Central

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

2015-01-01

China's total fertility rate fell below replacement level in the 1990s. From the 1970s the fertility rate declined dramatically, mainly as a consequence of the national population policy whose aim has been to limit birth numbers, control population growth and boost economic growth. Having achieved such a low fertility rate, how will China's population policy evolve in the future? This paper first reviews the history of China's population policy since 1970 in terms of three stages: 1970-1979; 1980-1999; and after 2000. We explore the impacts of China's population policy, including relief of pressure on China's environment and resources, fertility decline, the unexpectedly high male-biased sex ratio at birth (SRB), the coming shortage of labor force, and the rapid aging of the population. We also investigate ethical issues raised by the implementation of the policy and its results. Finally we introduce the controversy over potential adjustment of the policy, acknowledging the problems faced by western countries with low fertility and countermeasures they have taken. We offer some suggestions that might be appropriate in the Chinese context. PMID:26612983

Organ-preserving and reconstructive microsurgery of the fallopian tubes in tubal infertility: still an alternative to in vitro fertilization (IVF).

PubMed

Schippert, Cordula; Hille, Ursula; Bassler, Christina; Soergel, Philipp; Hollwitz, Bettina; Garcia-Rocha, Guillermo José

2010-07-01

Tubal infertility mostly results from infections. Conception only is possible through complex treatments (in vitro fertilization or surgery). Success cannot be guaranteed, even after repeated treatments. Unfortunately, many couples are not informed about the prospect for success of tubal reconstruction. Problems of in vitro fertilization are low pregnancy and birth rates of 28.4% and <20% respectively (Germany) and the high number of multiple pregnancies (21%). In this retrospective study 462 women with acquired tubal infertility and further 127 women after previous sterilization underwent microsurgical treatment (microsurgical adhesiolysis, anastomosis, fimbrioplasty, salpingostomy, and refertilization due to former sterilization). The main outcome measures are the pregnancy and birth rates following the microsurgical procedure. Pregnancy and birth rates of 43.4% and 29.2%, respectively, were higher than the outcomes post-single in vitro fertilization (abortion: 6.4%, extrauterine pregnancy: 7.9%). When reversal of sterilization was performed, pregnancy and birth rates were higher at 73% and 50.6%, respectively (abortion: 15.7%, extrauterine pregnancy: 6.7%). The advantages of reconstructive microsurgery over in vitro fertilization include the ideally permanent restoration of woman's ability to conceive naturally (repeated pregnancies are possible without further therapy), a high postoperative birth rate overall, and avoidance of multiple births. It is advisable to inform the patient about the objective possibility of reconstructive tubal surgery. Thieme Medical Publishers.

Constructing fertility tables for Soviet populations.

PubMed

Mazur, D P

1976-02-01

Because the 1970 Soviet Union census does not provide information on the age structure of men and women separately by sex and according to their ethnic affiliation, the 1959 USSR census data serve as the basis to infer knowledge about ethnic fertility. The model takes into account (1) the total number of births in 1960, estimated from the child-woman ratio in 1959, (2) the age structure of women in 1959, and (3) the assumed pattern of age-specific birth rates structured in terms of the modal age at childbearing and the length of the fertility age span. The results show that Ukrainians among the Slav populations ranked as the lowest with 2.07 children born per woman. Their total fertility contrasts with that of Kazakhs native to Central Asia, who reportedly according to Soviet sources had 7.46 children per woman in 1958-1959, and whose estimated rate is around 8.59 children. Extreme variations appear in the estimates of fertility among nationalities of the Caucasus region, Volga Basin, and to a lesser degree in Siberia. Official Soviet calculations of crude birth rates and age-specific rates for 15 Union Republics in 1967-1968 are transcribed and compared with the estimates for nationalities in 1959-1960. The same theoretical model used to generate the Soviet rates may be adapted under different assumptions to non-Soviet populations in other situations where the data are scanty or incomplete.

Estimation of Whole Plant Photosynthetic Rate of Irwin Mango under Artificial and Natural Lights Using a Three-Dimensional Plant Model and Ray-Tracing.

PubMed

Jung, Dae Ho; Lee, Joon Woo; Kang, Woo Hyun; Hwang, In Ha; Son, Jung Eek

2018-01-04

Photosynthesis is an important physiological response for determination of CO₂ fertilization in greenhouses and estimation of crop growth. In order to estimate the whole plant photosynthetic rate, it is necessary to investigate how light interception by crops changes with environmental and morphological factors. The objectives of this study were to analyze plant light interception using a three-dimensional (3D) plant model and ray-tracing, determine the spatial distribution of the photosynthetic rate, and estimate the whole plant photosynthetic rate of Irwin mango ( Mangifera indica L. cv. Irwin) grown in greenhouses. In the case of mangoes, it is difficult to measure actual light interception at the canopy level due to their vase shape. A two-year-old Irwin mango tree was used to measure the whole plant photosynthetic rate. Light interception and whole plant photosynthetic rate were measured under artificial and natural light conditions using a closed chamber (1 × 1 × 2 m). A 3D plant model was constructed and ray-tracing simulation was conducted for calculating the photosynthetic rate with a two-variable leaf photosynthetic rate model of the plant. Under artificial light, the estimated photosynthetic rate increased from 2.0 to 2.9 μmolCO₂·m -2 ·s -1 with increasing CO₂ concentration. On the other hand, under natural light, the photosynthetic rate increased from 0.2 μmolCO₂·m -2 ·s -1 at 06:00 to a maximum of 7.3 μmolCO₂·m -2 ·s -1 at 09:00, then gradually decreased to -1.0 μmolCO₂·m -2 ·s -1 at 18:00. In validation, simulation results showed good agreement with measured results with R ² = 0.79 and RMSE = 0.263. The results suggest that this method could accurately estimate the whole plant photosynthetic rate and be useful for pruning and adequate CO₂ fertilization.

Hair mercury concentrations and in vitro fertilization (IVF) outcomes among women from a fertility clinic.

PubMed

Wright, Diane L; Afeiche, Myriam C; Ehrlich, Shelley; Smith, Kristen; Williams, Paige L; Chavarro, Jorge E; Batsis, Maria; Toth, Thomas L; Hauser, Russ

2015-01-01

Total hair mercury (Hg) was measured among 205 women undergoing in vitro fertilization (IVF) treatment and the association with prospectively collected IVF outcomes (229 IVF cycles) was evaluated. Hair Hg levels (median=0.62ppm, range: 0.03-5.66ppm) correlated with fish intake (r=0.59), and exceeded the recommended EPA reference of 1ppm in 33% of women. Generalized linear mixed models with random intercepts accounting for within-woman correlations across treatment cycles were used to evaluate the association of hair Hg with IVF outcomes adjusted for age, body mass index, race, smoking status, infertility diagnosis, and protocol type. Hair Hg levels were not related to ovarian stimulation outcomes (peak estradiol levels, total and mature oocyte yields) or to fertilization rate, embryo quality, clinical pregnancy rate or live birth rate. Copyright © 2015 Elsevier Inc. All rights reserved.

Which factors are most predictive for live birth after in vitro fertilization and intracytoplasmic sperm injection (IVF/ICSI) treatments? Analysis of 100 prospectively recorded variables in 8,400 IVF/ICSI single-embryo transfers.

PubMed

Vaegter, Katarina Kebbon; Lakic, Tatevik Ghukasyan; Olovsson, Matts; Berglund, Lars; Brodin, Thomas; Holte, Jan

2017-03-01

To construct a prediction model for live birth after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment and single-embryo transfer (SET) after 2 days of embryo culture. Prospective observational cohort study. University-affiliated private infertility center. SET in 8,451 IVF/ICSI treatments in 5,699 unselected consecutive couples during 1999-2014. A total of 100 basal patient characteristics and treatment data were analyzed for associations with live birth after IVF/ICSI (adjusted for repeated treatments) and subsequently combined for prediction model construction. Live birth rate (LBR) and performance of live birth prediction model. Embryo score, treatment history, ovarian sensitivity index (OSI; number of oocytes/total dose of FSH administered), female age, infertility cause, endometrial thickness, and female height were all independent predictors of live birth. A prediction model (training data set; n = 5,722) based on these variables showed moderate discrimination, but predicted LBR with high accuracy in subgroups of patients, with LBR estimates ranging from <10% to >40%. Outcomes were similar in an internal validation data set (n = 2,460). Based on 100 variables prospectively recorded during a 15-year period, a model for live birth prediction after strict SET was constructed and showed excellent calibration in internal validation. For the first time, female height qualified as a predictor of live birth after IVF/ICSI. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Response of Penstemon Fruticosus to fertilization

Treesearch

G. O. Klock

1976-01-01

Bush penstemon (Penstemon fruticosus (Pursh) Greene), an attractive ground cover on east Cascade slopes, appears to survive under low fertility, xeric conditions. These plant characteristics are desirable for revegetating severely disturbed areas. Seedling response to fertilization was tested to find if growth rates could be increased to provide...

Effect of caffeine on motility and vitality of sperm and in vitro fertilization of outbreed mouse in T6 and M16 media.

PubMed

Nabavi, Narges; Todehdehghan, Fatemeh; Shiravi, Abdollhossein

2013-09-01

Caffeine increases the CAMP production that stimulates spermatozoa movement. Caffeine is also used for induction of in vitro acrosome reaction in mammalian spermatozoa, an important step in achieving fertilization. The aim of this study was to assess the effect of caffeine on sperm's motility, vitality and laboratory fertilization rates in mouse in two T6 and M16 media. Epididymal mouse sperms were collected and treated by caffine in T6 and M16 media and their motility and vitality rates were evaluated. The pretreated sperms were added to oocytes in T6 and M16 media with and without caffeine and fertilization rates were recorded after 24 hours incubation. Sperm's motility (81.7±1.67%) and vitality (88.7±1.33%) rates and percentage of fertilized oocytes (67.52±8.16%) in T6 medium plus caffeine compare to control group have increased and shown significant differences at p≤0.01. While the percentages of these parameters in M16 medium supplemented with caffeine were 68.3±6.01%, 78±6.11%, and 42.6±12.96 respectively and in comparison to control group (M16 without caffeine) have not shown significant differences. Addition of caffeine to T6 medium promotes the sperm's motility and vitality and enhances fertilization and early in vitro development of mouse embryos. This article extracted from M.Sc. thesis. (Narges Navabi).

Impact of ketorolac administration around ovarian stimulation on in vivo and in vitro fertilization and subsequent embryo development.

PubMed

Jee, Byung Chul; Youm, Hye Won; Lee, Jae Ho; Kim, Jee Hyun; Suh, Chang Suk; Kim, Seok Hyun

2013-05-01

We performed this study to investigate the effect of ketorolac (a non-steroidal anti-inflammatory drug) administration around ovarian stimulation on in vivo and in vitro fertilization process. Sixty-four female mice (ICR) were injected with ketorolac (0, 7.5, 15 and 30 µg/d) for 3 d starting from the day of eCG treatment. In experiment 1, 41 mice were triggered by hCG and then mated; two-cell embryos were obtained and in vitro development up to blastocyst was observed. In experiment 2, 23 mice were triggered by hCG and mature oocytes were collected; in vitro fertilization rate and subsequent embryo development up to blastocyst was recorded. In experiment 1, the blastocyst-forming rates per in vivo fertilized two-cell embryo showed an inverse relationship with a dosage of ketorolac (97.6%, 64.2%, 35.4% and 25.9%). In experiment 2, degenerated oocytes were frequently observed in a dose-dependent manner (4.3%, 22.9%, 22.4% and 75.0%). Lower fertilization rates were noted in all the three ketorolac-treating groups; blastocyst-forming rate was significantly lower in 30-µg-treating group when compared with the control group. Administration of ketorolac around ovarian stimulation significantly affects the development of in vivo fertilized embryo in a dose-dependent manner. High-dose ketorolac could result in a poor oocyte quality and decreased embryo developmental competence.