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Sample records for age-specific fertility rates

  1. Structural modeling of age specific fertility curves in Peninsular Malaysia: An approach of Lee Carter method

    NASA Astrophysics Data System (ADS)

    Hanafiah, Hazlenah; Jemain, Abdul Aziz

    2013-11-01

    In recent years, the study of fertility has been getting a lot of attention among research abroad following fear of deterioration of fertility led by the rapid economy development. Hence, this study examines the feasibility of developing fertility forecasts based on age structure. Lee Carter model (1992) is applied in this study as it is an established and widely used model in analysing demographic aspects. A singular value decomposition approach is incorporated with an ARIMA model to estimate age specific fertility rates in Peninsular Malaysia over the period 1958-2007. Residual plots is used to measure the goodness of fit of the model. Fertility index forecast using random walk drift is then utilised to predict the future age specific fertility. Results indicate that the proposed model provides a relatively good and reasonable data fitting. In addition, there is an apparent and continuous decline in age specific fertility curves in the next 10 years, particularly among mothers' in their early 20's and 40's. The study on the fertility is vital in order to maintain a balance between the population growth and the provision of facilities related resources.

  2. The Application of Age-Specific Rates to Divorce

    ERIC Educational Resources Information Center

    England, J. Lynn; Kunz, Phillip R.

    1975-01-01

    Age-Specific divorce rates and weighted divorce rates are evaluated in comparison with several traditional rates. The analysis reversals of the ranking of some states in comparison with rankings based on other divorce rates, and the age-specific rates for young married couples is lower than expected. (Author)

  3. A stochastic version of the brass PF ratio adjustment of age-specific fertility schedules.

    PubMed

    Baker, Jack; Alcantara, Adélamar; Ruan, Xiaomin

    2011-01-01

    Estimates of age-specific fertility rates based on survey data are known to suffer down-bias associated with incomplete reporting. Previously, William Brass (1964, 1965, 1968) proposed a series of adjustments of such data to reflect more appropriate levels of fertility through comparison with data on children-ever-born by age, a measure of cohort-specific cumulative fertility. His now widely-used Parity/Fertility or PF ratio method makes a number of strong assumptions, which have been the focus of an extended discussion in the literature on indirect estimation. However, while it is clear that the measures used in making adjusted age-specific fertility estimates with this method are captured with statistical uncertainty, little discussion of the nature of this uncertainty around PF-ratio based estimates of fertility has been entertained in the literature. Since both age-specific risk of childbearing and cumulative parity (children ever born) are measured with statistical uncertainty, an unknown credibility interval must surround every PF ratio-based estimate. Using the standard approach, this is unknown, limiting the ability to make statistical comparisons of fertility between groups or to understand stochasticity in population dynamics. This paper makes use of approaches applied to similar problems in engineering, the natural sciences, and decision analysis--often discussed under the title of uncertainty analysis or stochastic modeling--to characterize this uncertainty and to present a new method for making PF ratio-based fertility estimates with 95 percent uncertainty intervals. The implications for demographic analysis, between-group comparisons of fertility, and the field of statistical demography are explored.

  4. Fertility Clinic Success Rates

    MedlinePlus

    ... Birth Defects ART and Autism 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook ... RSS ABOUT About CDC Jobs Funding LEGAL Policies Privacy FOIA No Fear Act OIG 1600 Clifton Road ...

  5. Age-Specific Morbidity and Mortality Rates Among U.S. Navy Enlisted Divers and Controls

    DTIC Science & Technology

    1984-07-01

    The purpose of this study was to compare age-specific hospitalization, disability, and mortality rates for diving-related and stress- induced...actions for stress-related disorders were observed among controls than divers. For both groups, medical board, physical evaluation board, and mortality ... rates increased with age as did hospitalization for musculoskeletal disorders, stress-related disorders, and circulatory diseases. Subsequent research

  6. Method for projecting age-specific mortality rates for certain causes of death

    SciTech Connect

    Leggett, R.W.; Crawford, D.J.

    1981-01-01

    A method is presented for projecting mortality rates for certain causes on the basis of observed rates during past years. This method arose from a study of trends in age-specific mortality rates for respiratory cancers, and for heuristic purposes it is shown how the method can be developed from certain theories of cancer induction. However, the method is applicable in the more common situation in which the underlying physical processes cannot be modeled with any confidence but the mortality rates are approximable over short time intervals by functions of the form a exp(bt), where b may vary in a continuous, predictable fashion as the time interval is varied. It appears from applications to historical data that this projection method is in some cases a substantial improvement over conventional curve-fitting methods and often uncovers trends which are not apparent from observed data.

  7. A method for projecting age-specific mortality rates for certain causes of death

    SciTech Connect

    Leggett, R.W.; Crawford, D.J.

    1981-09-01

    A method is presented for projecting mortality rates for certain causes on the basis of observed rates during past years. This method arose from a study of trends in age-specific mortality rates for respiratory cancers, and for heuristic purposes it is shown how the method can be developed from certain theories of cancer induction. However, the method is applicable in the more common situation in which the underlying physical processes cannot be modeled with any confidence but the mortality rates are approximable over short time intervals by functions of the form a exp(bt), where b may vary in a continuous, predictable fashion as the time interval is varied. It appears from applications to historical data that this projection method is in some cases a substantial improvement over conventional curve-fitting methods and often uncovers trends which are not from observed data.

  8. Age-specificity of black-capped chickadee survival rates: Analysis of capture-recapture data

    USGS Publications Warehouse

    Loery, G.; Pollock, K.H.; Nichols, J.D.; Hines, J.E.

    1987-01-01

    The ornithological literature indicates a widespread belief in two generalizations about the age-specificity of avian survival rates: (1) survival rates of young birds for some period following fledging are lower than those of adults, and (2) after reaching adulthood survival rates are constant for birds of all ages. There is a growing body of evidence in support of the first generalization, although little is known about how long the survival difference between young and adults lasts. This latter question can be addressed with capture-recapture or band recovery studies based on birds marked in the winter, but the inability to determine age in many species during winter has prevented the use of standard methods. There is very little evidence supporting the second generalization, and we are in need of methods and actual analyses that address this question. In the present paper we restate the two generalizations as hypotheses and test them using data from a wintering Black-capped Chickadee (Parus atricapillus) population in Connecticut, which has been studied by Loery for 26 yr. We use a cohort-based Jolly-Seber approach, which should be useful in other investigations of this nature. We found strong evidence of lower survival rates in 1st-yr birds than in adults, but could not determine whether this was the result of higher mortality rates, higher emigration rates, or a combination of the two. We also found evidence that survival rates of adult birds were not constant with age but decreased at a rate of ? 3.5%/yr. As adult birds are very faithful to their wintering areas, we believe that almost all this decrease can be attributed to an increase in mortality with age. Simulation results suggest that heterogeneity of capture probabilities could not explain the magnitude of the decrease in survival with age. Age-dependent tag loss is also discussed as an alternative explanation, but is dismissed as very unlikely in this situation. This analysis thus provides some of the

  9. Age-Specific Variation in Adult Mortality Rates in Developed Countries

    PubMed Central

    Zheng, Hui; Yang, Y. Claire; Land, Kenneth C.

    2016-01-01

    This paper investigates historical changes in both single-year-of-age adult mortality rates and variation of the single-year mortality rates around expected values within age intervals over the past two centuries in 15 developed countries. We apply an integrated Hierarchical Age-Period-Cohort—Variance Function Regression Model to data from the Human Mortality Database. We find increasing variation of the single-year rates within broader age intervals over the life course for all countries, but the increasing variation slows down at age 90 and then increases again after age 100 for some countries; the variation significantly declined across cohorts born after the early 20th century; and the variation continuously declined over much of the last two centuries but has substantially increased since 1980. Our further analysis finds the recent increases in mortality variation are not due to increasing proportions of older adults in the population, trends in mortality rates, or disproportionate delays in deaths from degenerative and man-made diseases, but rather due to increasing variations in young and middle-age adults. PMID:28133402

  10. Age-Specific Incidence Rates for Norovirus in the Community and Presenting to Primary Healthcare Facilities in the United Kingdom

    PubMed Central

    O'Brien, Sarah J.; Donaldson, Anna L.; Iturriza-Gomara, Miren; Tam, Clarence C.

    2016-01-01

    In a prospective, population-based cohort study and a study of primary-healthcare consultations, we had a rare opportunity to estimate age-specific rates of norovirus-associated infectious intestinal disease in the United Kingdom. Rates in children aged <5 years were significantly higher than those for other age groups in the community (142.6 cases per 1000 person-years [95% confidence interval {CI}, 99.8–203.9] vs 37.6 [95% CI, 31.5–44.7]) and those for individuals presenting to primary healthcare (14.4 cases per 1000 person-years [95% CI, 8.5–24.5] vs 1.4 [95% CI, .9–2.0]). Robust incidence estimates are crucial for vaccination policy makers. This study emphasises the impact of norovirus-associated infectious intestinal disease, especially in children aged <5 years. PMID:26744427

  11. Age-specific vibrissae growth rates: a tool for determining the timing of ecologically important events in Steller sea lions

    USGS Publications Warehouse

    Rea, L.D.; Christ, A.M.; Hayden, A.B.; Stegall, V.K.; Farley, S.D.; Stricker, Craig A.; Mellish, J.E.; Maniscalco, John M.; Waite, J.N.; Burkanov, V.N.; Pitcher, K.W.

    2015-01-01

    Steller sea lions (SSL; Eumetopias jubatus) grow their vibrissae continually, providing a multiyear record suitable for ecological and physiological studies based on stable isotopes. An accurate age-specific vibrissae growth rate is essential for registering a chronology along the length of the record, and for interpreting the timing of ecologically important events. We utilized four methods to estimate the growth rate of vibrissae in fetal, rookery pup, young-of-the-year (YOY), yearling, subadult, and adult SSL. The majority of vibrissae were collected from SSL live-captured in Alaska and Russia between 2000 and 2013 (n = 1,115), however, vibrissae were also collected from six adult SSL found dead on haul-outs and rookeries during field excursions to increase the sample size of this underrepresented age group. Growth rates of vibrissae were generally slower in adult (0.44 ± 0.15 cm/mo) and subadult (0.61 ± 0.10 cm/mo) SSL than in YOY (0.87 ± 0.28 cm/mo) and fetal (0.73 ± 0.05 cm/mo) animals, but there was high individual variability in these growth rates within each age group. Some variability in vibrissae growth rates was attributed to the somatic growth rate of YOY sea lions between capture events (P = 0.014, r2 = 0.206, n = 29).

  12. Courtship rate signals fertility in an externally fertilizing fish

    PubMed Central

    Weir, Laura K.; Grant, James W. A.

    2010-01-01

    Sperm limitation is widespread across many animal species. Several mechanisms of sperm allocation have been proposed, including optimal allocation according to clutch size and equal allocation across females. However, considerably less effort has been directed at investigating the behavioural signals associated with sperm limitation in males, which may include mating rate and the intensity of courtship. We investigated whether multiple successive spawnings affect individual male fertilization success, mating rates and courtship rates in Japanese medaka (Oryzias latipes). Across an average of 17 spawning events per male, fertilization success decreased from 83.7 per cent for the first spawning to 40 per cent for the last spawning while courtship rate decreased from 3.4 to 1.5 min−1. Females appeared to respond to male sperm depletion by reducing clutch size. Our results suggest that male Japanese medaka are sperm-limited, and that courtship rate may be an honest indication of fertilization ability. PMID:20410031

  13. Effects of Maternal Age and Age-Specific Preterm Birth Rates on Overall Preterm Birth Rates - United States, 2007 and 2014.

    PubMed

    Ferré, Cynthia; Callaghan, William; Olson, Christine; Sharma, Andrea; Barfield, Wanda

    2016-11-04

    Reductions in births to teens and preterm birth rates are two recent public health successes in the United States (1,2). From 2007 to 2014, the birth rate for females aged 15-19 years declined 42%, from 41.5 to 24.2 per 1,000 females. The preterm birth rate decreased 8.4%, from 10.41% to 9.54% of live births (1). Rates of preterm births vary by maternal age, being higher among the youngest and oldest mothers. It is unknown how changes in the maternal age distribution in the United States have affected preterm birth rates. CDC used birth data to assess the relative contributions of changes in the maternal age distribution and in age-specific preterm birth rates to the overall decrease in preterm birth rates. The preterm birth rate declined in all age groups. The effects of age distribution changes on the preterm birth rate decrease were different in younger and older mothers. The decrease in the proportion of births to mothers aged ≤19 and 20-24 years and reductions in age-specific preterm rates in all age groups contributed to the overall decline in the preterm birth rate. The increase in births to mothers aged ≥30 years had no effect on the overall preterm birth rate decrease. The decline in preterm births from 2007 to 2014 is related, in part, to teen pregnancy prevention and the changing maternal age distribution. Effective public health strategies for further reducing preterm birth rates need to be tailored to different age groups.

  14. Irrigation timing and fertilizer rate in peppers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Maternal Age-Specific Rates for Trisomy 21 and Common Autosomal Trisomies in Fetuses from a Single Diagnostic Center in Thailand

    PubMed Central

    Jaruthamsophon, Kanoot; Sriplung, Hutcha; Charalsawadi, Chariyawan

    2016-01-01

    To provide maternal age-specific rates for trisomy 21 (T21) and common autosomal trisomies (including trisomies 21, 18 and 13) in fetuses. We retrospectively reviewed prenatal cytogenetic results obtained between 1990 and 2009 in Songklanagarind Hospital, a university teaching hospital, in southern Thailand. Maternal age-specific rates of T21 and common autosomal trisomies were established using different regression models, from which only the fittest models were used for the study. A total of 17,819 records were included in the statistical analysis. The fittest models for predicting rates of T21 and common autosomal trisomies were regression models with 2 parameters (Age and Age2). The rate of T21 ranged between 2.67 per 1,000 fetuses at the age of 34 and 71.06 per 1,000 at the age of 48. The rate of common autosomal trisomies ranged between 4.54 per 1,000 and 99.65 per 1,000 at the same ages. This report provides the first maternal age-specific rates for T21 and common autosomal trisomies fetuses in a Southeast Asian population and the largest case number of fetuses have ever been reported in Asians. PMID:27812158

  16. Avian growth and development rates and age-specific mortality: the roles of nest predation and adult mortality.

    PubMed

    Remes, V

    2007-01-01

    Previous studies have shown that avian growth and development covary with juvenile mortality. Juveniles of birds under strong nest predation pressure grow rapidly, have short incubation and nestling periods, and leave the nest at low body mass. Life-history theory predicts that parental investment increases with adult mortality rate. Thus, developmental traits that depend on the parental effort exerted (pre- and postnatal growth rate) should scale positively with adult mortality, in contrast to those that do not have a direct relationship with parental investment (timing of developmental events, e.g. nest leaving). I tested this prediction on a sample of 84 North American songbirds. Nestling growth rate scaled positively and incubation period duration negatively with annual adult mortality rates even when controlled for nest predation and other covariates, including phylogeny. On the contrary, neither the duration of the nestling period nor body mass at fledging showed any relationship. Proximate mechanisms generating the relationship of pre- and postnatal growth rates to adult mortality may include increased feeding, nest attentiveness during incubation and/or allocation of hormones, and deserve further attention.

  17. Age specific survival rates of Steller sea lions at rookeries with divergent population trends in the Russian Far East.

    PubMed

    Altukhov, Alexey V; Andrews, Russel D; Calkins, Donald G; Gelatt, Thomas S; Gurarie, Eliezer D; Loughlin, Thomas R; Mamaev, Evgeny G; Nikulin, Victor S; Permyakov, Peter A; Ryazanov, Sergey D; Vertyankin, Vladimir V; Burkanov, Vladimir N

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas.

  18. Age Specific Survival Rates of Steller Sea Lions at Rookeries with Divergent Population Trends in the Russian Far East

    PubMed Central

    Altukhov, Alexey V.; Andrews, Russel D.; Calkins, Donald G.; Gelatt, Thomas S.; Gurarie, Eliezer D.; Loughlin, Thomas R.; Mamaev, Evgeny G.; Nikulin, Victor S.; Permyakov, Peter A.; Ryazanov, Sergey D.; Vertyankin, Vladimir V.; Burkanov, Vladimir N.

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas. PMID:26016772

  19. Age-specific and age-standardised incidence rates for intraoral squamous cell carcinoma in blacks on the Witwatersrand, South Africa.

    PubMed

    Altini, M; Kola, A H

    1985-12-01

    All new cases of intraoral squamous cell carcinoma which occurred in Blacks resident on the Witwatersrand during the 10-yr period 1971-80 were traced by examining the records of all the hospital pathology departments in this area. The population at risk at the mid-point of the study (1975) was calculated from the National Population Censuses of 1970 and 1980, and consisted of 1125960 men and 880269 women. Age-specific incidence rates and age-standardised incidence rates were calculated for each intraoral site for men and women. In the latter calculation a standard World population was used. All rates are expressed as average number of cases per 100000 population per annum. The age-specific incidence rates and age-standardised incidence rates (in brackets) for men and women respectively are: tongue, 1.43 and 0.26 (2.69 and 0.41); gingiva and alveolar ridge, 0.04 and 0.01 (0.07 and 0.01); floor of mouth, 0.87 and 0.22 (1.64 and 0.38); buccal mucosa, 0.05 and 0.04 (0.13 and 0.05); hard and soft palate, 0.34 and 0.05 (0.63 and 0.08). There appears to have been an increase in the incidence of intraoral cancer in Black South Africans since the first survey in 1953-55, which can probably be ascribed to the urbanization process. In Europe, North America and in other population groups in South Africa, the palate is least frequently affected. In contrast, in Black South Africans lesions of the palate are much more common, being less frequent only than tongue and floor of mouth lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Fertility rates in women with asthma, eczema, and hay fever: a general population-based cohort study.

    PubMed

    Tata, L J; Hubbard, R B; McKeever, T M; Smith, C J P; Doyle, P; Smeeth, L; West, J; Lewis, S A

    2007-05-01

    The protective association between having older siblings and the risk of subsequent allergic disease may be due to decreased fertility among women with allergic disease. In this study, the authors compared fertility rates among women with asthma, eczema, or hay fever with those in the general female population. Computerized primary-care data from the United Kingdom were used to conduct a cohort analysis of 491,516 women. General fertility rates and age-specific fertility rates for 1994-2004 were estimated. Using Poisson regression, the authors compared fertility rates among women with asthma, eczema, or hay fever with rates in women without these diagnoses. Fertility rates were 53.0 and 52.3 livebirths per 1,000 person-years in women with and without asthma, respectively. The fertility rate ratio for women with asthma compared with women without asthma was 1.02 (95% confidence interval (CI): 1.00, 1.04) after adjustment for age, smoking, body mass index, and socioeconomic status. Equivalent fertility rate ratios for eczema and hay fever were 1.15 (95% CI: 1.13, 1.17) and 1.08 (95% CI: 1.06, 1.10), respectively. The authors found no evidence that the fertility rates of women with asthma, eczema, or hay fever are lower than those of women in the general population.

  1. Sex- and age- specific relations between economic development, economic inequality and homicide rates in people aged 0-24 years: a cross-sectional analysis.

    PubMed Central

    Butchart, Alexander; Engström, Karin

    2002-01-01

    OBJECTIVE: To test whether relations between economic development, economic inequality, and child and youth homicide rates are sex- and age-specific, and whether a country's wealth modifies the impact of economic inequality on homicide rates. METHODS: Outcome variables were homicide rates around 1994 in males and females in the age ranges 0-4, 5-9, 10-14, 15-19 and 20-24 years from 61 countries. Predictor variables were per capita gross domestic product (GDP), GINI coefficient, percentage change in per capita gross national product (GNP) and female economic activity as a percentage of male economic activity. Relations were analysed by ordinary least squares regression. FINDINGS: All predictors explained significant variances in homicide rates in those aged 15-24. Associations were stronger for males than females and weak for children aged 0-9. Models that included female economic inequality and percentage change in GNP increased the effect in children aged 0-9 and the explained variance in females aged 20-24. For children aged 0-4, country clustering by income increased the explained variance for both sexes. For males aged 15-24, the association with economic inequality was strong in countries with low incomes and weak in those with high incomes. CONCLUSION: Relations between economic factors and child and youth homicide rates varied with age and sex. Interventions to target economic factors would have the strongest impact on rates of homicide in young adults and late adolescent males. In societies with high economic inequality, redistributing wealth without increasing per capita GDP would reduce homicide rates less than redistributions linked with overall economic development. PMID:12471400

  2. Multidimensional Life Table Estimation of the Total Fertility Rate and Its Components

    PubMed Central

    Retherford, Robert D.; Eini-Zinab, Hassan; Choe, Minja Kim; Ogawa, Naohiro; Matsukura, Rikiya

    2013-01-01

    Using discrete-time survival models of parity progression and illustrative data from the Philippines, this article develops a multivariate multidimensional life table of nuptiality and fertility, the dimensions of which are age, parity, and duration in parity. The measures calculated from this life table include total fertility rate (TRF), total marital fertility rate (TMFR), parity progression ratios (PPR), age-specific fertility rates, mean and median ages at first marriage, mean and median closed birth intervals, and mean and median ages at childbearing by child’s birth order and for all birth orders combined. These measures are referred to collectively as “TFR and its components.” Because the multidimensional life table is multivariate, all measures derived from it are also multivariate in the sense that they can be tabulated by categories or selected values of one socioeconomic variable while controlling for other socioeconomic variables. The methodology is applied to birth history data, in the form of actual birth histories from a fertility survey or reconstructed birth histories derived from a census or household survey. The methodology yields period estimates as well as cohort estimates of the aforementioned measures. PMID:23264037

  3. Sire conception rate: New national AI bull fertility evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bull fertility evaluations called Estimated Relative Conception Rate (ERCR) were provided to the industry by Dairy Records Management Systems (DRMS) from 1986 to November 2005. In May 2006, AIPL assumed responsibility for evaluation of U.S. bull fertility. As an initial step, AIPL implemented the ER...

  4. The Impact of Soil Sampling Errors on Variable Rate Fertilization

    SciTech Connect

    R. L. Hoskinson; R C. Rope; L G. Blackwood; R D. Lee; R K. Fink

    2004-07-01

    Variable rate fertilization of an agricultural field is done taking into account spatial variability in the soil’s characteristics. Most often, spatial variability in the soil’s fertility is the primary characteristic used to determine the differences in fertilizers applied from one point to the next. For several years the Idaho National Engineering and Environmental Laboratory (INEEL) has been developing a Decision Support System for Agriculture (DSS4Ag) to determine the economically optimum recipe of various fertilizers to apply at each site in a field, based on existing soil fertility at the site, predicted yield of the crop that would result (and a predicted harvest-time market price), and the current costs and compositions of the fertilizers to be applied. Typically, soil is sampled at selected points within a field, the soil samples are analyzed in a lab, and the lab-measured soil fertility of the point samples is used for spatial interpolation, in some statistical manner, to determine the soil fertility at all other points in the field. Then a decision tool determines the fertilizers to apply at each point. Our research was conducted to measure the impact on the variable rate fertilization recipe caused by variability in the measurement of the soil’s fertility at the sampling points. The variability could be laboratory analytical errors or errors from variation in the sample collection method. The results show that for many of the fertility parameters, laboratory measurement error variance exceeds the estimated variability of the fertility measure across grid locations. These errors resulted in DSS4Ag fertilizer recipe recommended application rates that differed by up to 138 pounds of urea per acre, with half the field differing by more than 57 pounds of urea per acre. For potash the difference in application rate was up to 895 pounds per acre and over half the field differed by more than 242 pounds of potash per acre. Urea and potash differences

  5. 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…

  6. Age-Specific Morbidity among Navy Pilots

    DTIC Science & Technology

    1983-10-01

    categories. Younger pilots have the highest rates for disorders of tooth development and eruption and accidental ...rates among aviation officers for accidental injuries were attributed prim.arily to athletic or sports activities. Comparisons of hospitalizations...important age-specific health problems (i.e., accidental injuries among young pilots and cardiovascular conditions among older pilots). In order for

  7. Age-specific bone tumour incidence rates are governed by stem cell exhaustion influencing the supply and demand of progenitor cells.

    PubMed

    Richardson, Richard B

    2014-07-01

    Knudson's carcinogenic model, which simulates incidence rates for retinoblastoma, provides compelling evidence for a two-stage mutational process. However, for more complex cancers, existing multistage models are less convincing. To fill this gap, I hypothesize that neoplasms preferentially arise when stem cell exhaustion creates a short supply of progenitor cells at ages of high proliferative demand. To test this hypothesis, published datasets were employed to model the age distribution of osteochondroma, a benign lesion, and osteosarcoma, a malignant one. The supply of chondrogenic stem-like cells in femur growth plates of children and adolescents was evaluated and compared with the progenitor cell demand of longitudinal bone growth. Similarly, the supply of osteoprogenitor cells from birth to old age was compared with the demands of bone formation. Results show that progenitor cell demand-to-supply ratios are a good risk indicator, exhibiting similar trends to the unimodal and bimodal age distributions of osteochondroma and osteosarcoma, respectively. The hypothesis also helps explain Peto's paradox and the finding that taller individuals are more prone to cancers and have shorter lifespans. The hypothesis was tested, in the manner of Knudson, by its ability to convincingly explain and demonstrate, for the first time, a bone tumour's bimodal age-incidence curve.

  8. The utility of age-specific cut-offs for visual rating of medial temporal atrophy in classifying Alzheimer's disease, MCI and cognitively normal elderly subjects

    PubMed Central

    Duara, Ranjan; Loewenstein, David A.; Shen, Qian; Barker, Warren; Varon, Daniel; Greig, Maria T.; Curiel, Rosie; Agron, Joscelyn; Santos, Isael; Potter, Huntington

    2013-01-01

    Background: New research criteria for diagnosing Alzheimer's disease (AD) in the mild cognitive impairment stage (MCI-AD) incorporate biomarkers to assign a level of certainty to the diagnosis. Structural MRI is widely available but greatly under-utilized for assessing atrophy of structures affected in early AD, such as the hippocampus (HP), because the quantification of HP volumes (HP-v) requires special expertise, and normative values have not been established. Methods: Elderly subjects (n =273) from the Florida ADRC were classified as having no cognitive impairment (cognitively normal, CN), amnestic mild cognitive impairment (aMCI) or AD. Volumes for the hippocampus (HP-v) were measured on structural MRI scans. A validated visual rating system for measuring medial temporal atrophy (VRS-MTA), including hippocampal, entorhinal cortex and perirhinal cortex atrophy was employed. The participants were subdivided into younger (less than or equal to 75 years of age) and older (greater than 75 years of age) subgroups. Results: Volumetric and VRS-MTA measures were equivalent in predicting classification of CN vs. aMCI for older (area under the receiver operator curves [aROC]: 0.652 vs. 0.723) and younger subjects (aROC: 0.764 vs. 0.736). However, for younger AD subjects, aROC values were significantly higher for VRS-MTA measures (0.920) than for volumetric measures (0.847). Relative to HP-v, VRS-MTA score was significantly more correlated to impairment on a range of memory tests and was more associated with progression of aMCI to AD than HP-v. Conclusion: Structural MRI with VRS-MTA assessment can serve as a biomarker for supporting the diagnosis of MCI-AD. Age-adjusted VRS-MTA scores are at least as effective as HP-v for distinguishing aMCI and AD from CN and for predicting progression from aMCI to AD. VRS-MTA is convenient for use in the clinic as well as for clinical trials and can readily be incorporated into a standardized radiological report. PMID:24065917

  9. [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.

  10. Age-specific breeding in Emperor Geese

    USGS Publications Warehouse

    Schmutz, J.A.

    2000-01-01

    I studied the frequency with which Emperor Geese (Chen canagica) of known age were observed breeding on the Yukon-Kuskokwim Delta, Alaska. No one- or two-year old geese were observed on nests. Three-year old geese bred at a lower rate than four-year old geese. These data suggest that patterns of age-specific breeding in Emperor Geese are similar to other sympatrically nesting, large bodied geese [Greater White-fronted Geese (Anser albifrons)] but delayed relative to smaller bodied geese [Cackling Canada Geese (Branta canadensis minima) and Pacific Black Brant (B. bernicla nigricans)].

  11. Stable aggregate fertility in a time of family change: a decomposition of trends in American fertility, 1970-1999.

    PubMed

    Hayford, Sarah R

    2005-01-01

    Population-level birth rates in the United States were largely stable between 1970 and 1999. This stability contrasts with rapid change in marriage rates and fertility timing during the same period. In this article, I use decomposition techniques to analyze this seeming paradox. I decompose the general fertility rate into four components: age distribution, marital status, age-specific nonmarital fertility, and age-specific marital fertility. Absent other changes, declining time spent married would have led to substantial decline in fertility. Several factors combined to counterbalance these changes in marital behavior. Among white women in the 1970s and 1980s, marital fertility rates increased at older ages, consistent with a scenario in which women postponed both marriage and childbearing; increased nonmarital birth rates during this period were not a driving factor in overall fertility trends. Increased nonmarital fertility was more important in compensating for declining time spent married among African American women and among white women in the 1990s.

  12. 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.

  13. Influence of sperm dilution and gamete contact time on the fertilization rate of scleractinian corals

    NASA Astrophysics Data System (ADS)

    Nozawa, Yoko; Isomura, Naoko; Fukami, Hironobu

    2015-12-01

    This study presents new information on the influence of sperm dilution on the fertilization rates of eight broadcast-spawning scleractinian coral species [three Acropora species and five merulinid species (three genera)]. The presented information nearly doubled the existing information, now totaling 17 species comprising eight acroporid species and nine merulinid species. No obvious differences in the fertilization rates were observed at the family and genus levels; furthermore, the fertilization curve estimated uniquely for Favites pentagona exhibited a strong sigmoid shape, indicating the existence of species-specific variation. In addition, a general fertilization response against sperm dilution was observed for the first time in broadcast-spawning scleractinian corals. The fertilization rate peaked (>75 %) at a sperm concentration of approximately 106 sperm mL-1 (optimal concentration) and rapidly declined to <50 % at a concentration of 104 sperm mL-1. The influence of gamete contact time (10, 30, and 60 min) on fertilization rates was also examined in two Acropora and four merulinid species, at the optimal sperm concentration. No influence of gamete contact time on fertilization rates was observed in two of the examined species ( Acropora papillare and Platygyra ryukyuensis), whereas reduced fertilization rates occurred mostly in the 10-min treatment for the other species. These results suggested that broadcast-spawning scleractinian corals can rapidly fertilize, indicating that these corals have a fair chance of achieving high fertilization success in the field under optimal conditions. The sperm concentration values (e.g., 104 sperm mL-1, indicating <50 % fertilization rates) may be useful in estimating the success of in situ fertilization of broadcast-spawning scleractinian corals, particularly in degraded, low-density populations where the degree of fertilization success is of management concern. Information on the fertilization ecology of scleractinian

  14. 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.

  15. Low rates of multiple fertilization in parous Anopheles albimanus.

    PubMed

    Villarreal, C; Fuentes-Maldonado, G; Rodriguez, M H; Yuval, B

    1994-03-01

    We determined how frequently parous female Anopheles albimanus fertilize their eggs with sperm from more than one male. To establish paternity we relied on 2 phenotypically distinct laboratory strains. Nulliparous females were allowed to mate freely with males from one strain, and after oviposition they were offered a 2nd mating with males of the other strain. Fertilization patterns were determined by the phenotypes of offspring. Only 0.6% of females ovipositing for a 2nd time (n = 312) used sperm from the 2nd male, as did 4% of females completing a 3rd gonotrophic cycle (n = 25). In this species receptivity is not routinely renewed following oviposition.

  16. 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.

  17. 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…

  18. 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.

  19. Ejaculate and type of freezing extender affect rates of fertilization of horse oocytes in vitro.

    PubMed

    Roasa, L M; Choi, Y H; Love, C C; Romo, S; Varner, D D; Hinrichs, K

    2007-09-01

    In vitro fertilization (IVF) was performed on in vitro-matured equine oocytes in three experiments. Frozen-thawed sperm were prepared using swim-up separation and heparin treatment. In Experiment 1, fertilization was achieved with sperm from only one frozen ejaculate of four obtained from the same stallion. Within this ejaculate, fertilization rates were higher with fresh media, as compared to media held for 6-8 days before use (39.6% versus 7.3%, respectively; P<0.001). The type of bovine serum albumin used affected fertilization rates (4% versus 39.6%; P<0.001). To determine if IVF rates were influenced by factors associated with the freezing process (Experiment 2), a single ejaculate from a second stallion was frozen using eight variations in timing of steps in the freezing protocol. There were no differences among treatments in fertilization rates (range, 0-3%). In Experiment 3, fertilization rates of semen frozen in an extender containing 21.5% egg yolk were lower than fertilization rates of semen from the same ejaculate but frozen with a 3% egg-yolk extender (0% versus 15%, respectively; P<0.01). We inferred that rates of equine IVF with frozen-thawed sperm were influenced by ejaculate, the composition and age of the media used, and freezing extender. To our knowledge, this is the first report of ejaculate or extender differences affecting in vitro fertilization in this species. These factors may help to explain the great variability in fertilization rates reported with equine IVF, both among and within laboratories.

  20. 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.

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

    PubMed Central

    Kim, Yujin; Raley, R. Kelly

    2015-01-01

    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. PMID:26504257

  2. [Effects of organic fertilizer application rate on leaf photosynthetic characteristics and grain yield of dryland maize].

    PubMed

    Wang, Xiao-Juan; Jia, Zhi-Kuan; Liang, Lian-You; Ding, Rui-Xia; Wang, Min; Li, Han

    2012-02-01

    A 4-year field experiment was conducted at the Heyang Research Station in Weibei dryland to study the effects of organic fertilizer application rate on the leaf photosynthetic characteristics and grain yield of dryland maize. Comparing with applying chemical fertilizer, applying organic fertilizer increased the leaf photosynthetic rate and stomatal conductance, but decreased the leaf intercellular CO2 concentration at each growth stage of maize significantly. With the increasing application rate of organic fertilizer, the leaf photosynthetic rate and stomatal conductance at each growth stage of maize had a gradual increase, while the leaf intercellular CO2 concentration had a gradual decrease. The leaf photosynthesis of maize at each growth stage was controlled by non-stomatal factors, and the application of organic fertilizer reduced the non-stomatal limitation on the photosynthesis performance significantly. The 4-year application of organic fertilizer improved soil nutrient status, and soil nutrients were no longer the main factors limiting the leaf photosynthetic rate and grain yield of maize.

  3. 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.

  4. Environmental and economic benefits of variable rate nitrogen fertilization in a nitrate vulnerable zone.

    PubMed

    Basso, Bruno; Dumont, Benjamin; Cammarano, Davide; Pezzuolo, Andrea; Marinello, Francesco; Sartori, Luigi

    2016-03-01

    Agronomic input and management practices have traditionally been applied uniformly on agricultural fields despite the presence of spatial variability of soil properties and landscape position. When spatial variability is ignored, uniform agronomic management can be both economically and environmentally inefficient. The objectives of this study were to: i) identify optimal N fertilizer rates using an integrated spatio-temporal analysis of yield and site-specific N rate response; ii) test the sensitivity of site specific N management to nitrate leaching in response to different N rates; and iii) demonstrate the environmental benefits of variable rate N fertilizer in a Nitrate Vulnerable Zone. This study was carried out on a 13.6 ha field near the Venice Lagoon, northeast Italy over four years (2005-2008). We utilized a validated crop simulation model to evaluate crop response to different N rates at specific zones in the field based on localized soil and landscape properties under rainfed conditions. The simulated rates were: 50 kg N ha(-1) applied at sowing for the entire study area and increasing fractions, ranging from 150 to 350 kg N ha(-1) applied at V6 stage. Based on the analysis of yield maps from previous harvests and soil electrical resistivity data, three management zones were defined. Two N rates were applied in each of these zones, one suggested by our simulation analysis and the other with uniform N fertilization as normally applied by the producer. N leaching was lower and net revenue was higher in the zones where variable rates of N were applied when compared to uniform N fertilization. This demonstrates the efficacy of using crop models to determine variable rates of N fertilization within a field and the application of variable rate N fertilizer to achieve higher profit and reduce nitrate leaching.

  5. Italy's fertility rate falls as women reject childbearing.

    PubMed

    Evans, L

    1996-03-02

    Italy's 1991 census indicated that the size of the family fell from 3.4 members in 1971 to 2.8 members in 1991, with most families having only one child or none. This phenomenon has put the country on the path for zero population growth. In the decade before the census was taken the population grew by just 221,000. In 1991 the population was 57,500,000. By 1991 children under 6 years constituted only 5.8% of the population, while people over 65 years old made up 15.3%. There was only one grandchild for every three grandparents. The decline in fertility started in the 1960s and accelerated in the 1970s for various reasons that are debated by experts. One factor is that families are stable, with very few births outside marriage and little cohabitation. Young people continue to live with their parents until they get married. Furthermore, young Italians choose not to marry or marry late because of career considerations and education. This is a more pronounced phenomenon in Italy than in other European countries. Catholic leaders have imputed this to material and comfort considerations and to being unwilling to have several children. On the other hand, an anthropologist advanced a more controversial view, to wit, that Italian women do not want to be mothers because society does not offer much help to mothers and maternity destroys the chance for career development and advancement. Working hours lack flexibility and part-time jobs are almost nonexistent. Reentry into the labor force three or four years after childbirth is also unfeasible for a woman in medium or high level employment.

  6. Effect of contaminated preprocessed semen on fertilization rate and embryo quality in assisted reproductive techniques.

    PubMed

    Krissi, H; Orvieto, R; Ashkenazi, J; Gilboa, Y; Shalev, J; Moscovitch, I; Bar-Hava, I

    2004-02-01

    We aimed to identify the sources and prevalence of semen contamination from mastrubation and determine the effect of bacterospermia on fertilization rate and embryo quality in standard in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). This was a prospective controlled study, in an IVF unit of a university teaching hospital, of 93 consecutive couples undergoing IVF-embryo transfer cycles. We evaluated handwashing; semen collection and processing; and assisted reproductive technology using semen provided by masturbation. The main outcome measures were presence and type of micro-organisms in the semen samples and embryo culture medium; the effect of hand washing on rate of contamination; and the effect of semen contamination on fertilization rate and embryo quality. The first consecutive 52 men of the 93 couples were not instructed to wash their hands before masturbation, and the remainder were so instructed. Forty-nine semen cultures (94.2%) in the first group were contaminated compared to only 16 (39%) in the second (p < 0.016); 27 of the 65 positive cultures (41.5%) were contaminated by more than one organism. The most common contaminators were bacteria usually found on the skin. All but four embryo medium cultures were negative. There was no significant difference in fertilization rate and embryo quality by culture findings in either the IVF or the ICSI procedures. We found that a high percentage of manually obtained semen for standard IVF or ICSI procedures was contaminated, but this had no effect on fertilization rate and embryo quality.

  7. Comparison of broiler litter and commercial fertilizer at equivalent N rates on soil quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3-year study was conducted to determine the effects of variable rates of broiler litter relative to inorganic fertilizer at equivalent N rates on soil nutrient content and quality in an upland Granada silt loam (fine-silty, mixed, active, Thermic, Fraglossudalfs) soil. Treatments included annual b...

  8. Validation of a heterologous fertilization assay and comparison of fertilization rates of equine oocytes using in vitro fertilization, perivitelline, and intracytoplasmic sperm injections.

    PubMed

    Sessions-Bresnahan, D R; Graham, J K; Carnevale, E M

    2014-07-15

    IVF in horses is rarely successful. One reason for this could be the failure of sperm to fully capacitate or exhibit hyperactive motility. We hypothesized that the zona pellucida (ZP) of equine oocytes prevents fertilization in vitro, and bypassing the ZP would increase fertilization rates. Limited availability of equine oocytes for research has necessitated the use of heterologous oocyte binding assays using bovine oocytes. We sought to validate an assay using bovine oocytes and equine sperm and then to demonstrate that bypassing the ZP using perivitelline sperm injections (PVIs) with equine sperm capacitated with dilauroyl phosphatidylcholine would result in higher fertilization rates than standard IVF in bovine and equine oocytes. In experiment 1, bovine oocytes were used for (1) IVF with bovine sperm, (2) IVF with equine sperm, and (3) intracytoplasmic sperm injections (ICSIs) with equine sperm. Presumptive zygotes were either stained with 4',6-diamidino-2-phenylindole from 18 to 26 hours at 2-hour intervals or evaluated for cleavage at 56 hours after addition of sperm. Equine sperm fertilized bovine oocytes; however, pronuclei formation was delayed compared with bovine sperm after IVF. The delayed pronuclear formation was not seen after ICSI. In experiment 2, bovine oocytes were assigned to the following five groups: (1) cumulus oocyte complexes (COCs) coincubated with bovine sperm; (2) COC exposed to sucrose then coincubated with bovine sperm; (3) COC coincubated with equine sperm; (4) COC exposed to sucrose, and coincubated with equine sperm; and (5) oocytes exposed to sucrose, and 10 to 15 equine sperm injected into the perivitelline (PV) space. Equine sperm tended (P = 0.08) to fertilize more bovine oocytes when injected into the PV space than after IVF. In experiment 3, oocytes were assigned to the following four groups: (1) IVF, equine, and bovine COC coincubated with equine sperm; (2) PVI of equine and bovine oocytes; (3) PVI with equine oocytes

  9. 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.

  10. Corn nitrogen fertilization rate tools compared over eight midwest states

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail both when N is over-applied and result in excess N being lost to the environment, or when N is under-applied and the result in decreased yield and economic returns...

  11. Corn nitrogen fertilization rate tools compared over eight Midwest states

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. Perfo...

  12. Sperm cryopreservation of the Indian major carp, Labeo calbasu: effects of cryoprotectants, cooling rates and thawing rates on egg fertilization.

    PubMed

    Nahiduzzaman, Md; Hassan, Md Mahbubul; Roy, Pankoz Kumar; Hossain, Md Akhtar; Hossain, Mostafa Ali Reza; Tiersch, Terrence R

    2012-12-01

    A sperm cryopreservation protocol for the Indian major carp, Labeo calbasu, was developed for long-term preservation and artificial fertilization. Milt collected from mature male fish were placed in Alsever's solution (296mOsmolkg(-1)) to immobilize the sperm. Cryoprotectant toxicity was evaluated by motility assessment with dimethyl sulfoxide (DMSO) and methanol at 5, 10 and 15% concentrations. DMSO was more toxic at higher concentrations than methanol, and consequently 15% DMSO was excluded from further study. A one-step cooling protocol (from 5 to 80°C) with two cooling rates (5 and 10°C/min) was carried out in a computer-controlled freezer (FREEZE CONTROL(®) CL-3300; Australia). Based on post-thaw motility, the 10°C/min cooling rate with either 10% DMSO or 10% methanol yielded significantly higher (P=0.011) post-thaw motility than the other rate and cryoprotectant concentrations. Sperm thawed at 40°C for 15s and fresh sperm were used to fertilize freshly collected L. calbasu eggs and significant differences were observed (P=0.001) in percent fertilization between cryopreserved and fresh sperm as well as among different sperm-to-egg ratios (P=0.001). The highest fertilization and hatching rates were observed for thawed sperm at a sperm-to-egg ratio of 4.1×10(5):1. The cryopreservation protocol developed can facilitate hatchery operations and long-term conservation of genetic resources of L. calbasu.

  13. [Effects of irrigation amount and nitrogen fertilization rate on wheat yield and soil nitrate content].

    PubMed

    Jiang, Dong-Yan; Yu, Zhen-Wen; Xu, Zhen-Zhu

    2011-02-01

    A field experiment was conducted to study the effects of irrigation amount and nitrogen fertilization rate on wheat yield and soil nitrate content. With the increase of irrigation amount, the soil nitrate content in 0-200 cm layer at the same nitrogen fertilization rates had a trend of decrease -increase-decrease. Under irrigation, the soil nitrate content was significantly lower in 0-80 cm layer while significantly higher in 80-200 cm layer, compared with the control. As the irrigation amount increased, the translocation of soil nitrate nitrogen to deeper layers accelerated dramatically, with the content decreased in 0-80 cm layer, increased in 120-200 cm layer, and peaked in 120-140 cm layer. When the nitrogen fertilization rate increased from 210 kg x hm(-2) to 300 kg x hm(-2) the soil nitrate content at the same irrigation amounts increased significantly through anthesis, filling, and maturity stages. With the increase of irrigation amount, the grain yield decreased after an initial increase, being the highest when the irrigation amount in whole growth period was 60 mm. The grain yield, grain protein content, and grain protein yield all increased significantly with increasing nitrogen fertilization rate. Under the conditions of the present experiment, the treatment with nitrogen fertilization rate 210 kg N x hm(-2) and irrigation amount 60 mm (split into two times) had the highest grain yield, grain protein content, grain protein yield, and harvest index but the least NO3(-)-N leaching, being the more available irrigation and nitrogen fertilization mode for wheat production in the study area.

  14. Age-Specific Correlates of Child Growth.

    PubMed

    Rieger, Matthias; Trommlerová, Sofia Karina

    2016-02-01

    Growth faltering describes a widespread phenomenon that height- and weight-for-age of children in developing countries collapse rapidly in the first two years of life. We study age-specific correlates of child nutrition using Demographic and Health Surveys from 56 developing countries to shed light on the potential drivers of growth faltering. Applying nonparametric techniques and exploiting within-mother variation, we find that maternal and household factors predict best the observed shifts and bends in child nutrition age curves. The documented interaction between age and maternal characteristics further underlines the need not only to provide nutritional support during the first years of life but also to improve maternal conditions.

  15. Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility

    PubMed Central

    Peddinti, Divyaswetha; Nanduri, Bindu; Kaya, Abdullah; Feugang, Jean M; Burgess, Shane C; Memili, Erdogan

    2008-01-01

    Background Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder. Results Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G2/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa. Conclusion This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype. PMID:18294385

  16. 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.

  17. 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

  18. On the relationship between income, fertility rates and the state of democracy in society

    NASA Astrophysics Data System (ADS)

    Hutzler, S.; Sommer, C.; Richmond, P.

    2016-06-01

    Empirical data for 145 countries shows a strong correlation between the gross national income per capita and the political form of their governance, as specified by the so-called democracy index. We interpret this relationship in analogy to phase transitions between different states of matter, using concepts of statistical physics. Fertility rates play the role of binding energy in solid state physics.

  19. Nitrogen fertilizer rate affects root exudation, the rhizosphere microbiome and nitrogen-use-efficiency of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The composition and function of microbial communities present in the rhizosphere of crops has been linked to edaphic factors and root exudate composition. In this paper, we examined the effect of N fertilizer rate on maize root exudation, the associated rhizosphere community, and nitrogen-use-effici...

  20. The effect of medical clowning on pregnancy rates after in vitro fertilization and embryo transfer.

    PubMed

    Friedler, Shevach; Glasser, Saralee; Azani, Liat; Freedman, Laurence S; Raziel, Arie; Strassburger, Dvora; Ron-El, Raphael; Lerner-Geva, Liat

    2011-05-01

    This experimental prospective quasi-randomized study examining the impact of a medical clowning encounter after embryo transfer (ET) after in vitro fertilization (IVF) found that the pregnancy rate in the intervention group was 36.4%, compared with 20.2% in the control group (adjusted odds ratio, 2.67; 95% confidence interval, 1.36-5.24). Medical clowning as an adjunct to IVF-ET may have a beneficial effect on pregnancy rates and deserves further investigation.

  1. 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

  2. Mitochondrial permeability transition pore (MPTP) desensitization increases sea urchin spermatozoa fertilization rate.

    PubMed

    Torrezan-Nitao, Elis; Boni, Raianna; Marques-Santos, Luis Fernando

    2016-10-01

    Mitochondrial permeability transition pore (MPTP) is a protein complex whose opening promotes an abrupt increase in mitochondrial inner membrane permeability. Calcium signaling pathways are described in gametes and are involved in the fertilization process. Although mitochondria may act as Ca(2+) store and have a fast calcium-releasing mechanism through MPTP, its contribution to fertilization remains unclear. The work aimed to investigate the MPTP phenomenon in sea urchin spermatozoa and its role on the fertilization. Several pharmacological tools were used to evaluate the MPTP's physiology. Our results demonstrated that MPTP occurs in male gametes in a Ca(2+) - and voltage-dependent manner and it is sensitive to cyclosporine A. Additionally, our data show that MPTP opening does not alter ROS generation in sperm cells. Inhibition of MPTP in spermatozoa strongly improved the fertilization rate, which may involve mechanisms that increase the spermatozoa lifespan. The present work is the first report of the presence of a voltage- and Ca(2+) -dependent MPTP in gametes of invertebrates and indicates MPTP opening as another evolutionary feature shared by sea urchins and mammals. Studies about MPTP in sea urchin male gametes may contribute to the elucidation of several mechanisms involved in sperm infertility.

  3. Effects of mechanical stresses on sperm function and fertilization rate in mice.

    PubMed

    Shi, Xiao; Wang, Ting; Qiu, Zhuo Lin; Li, Ke; Li, Liu; Chan, Carol Pui Shan; Chan, Si Mei; Li, Tian-Chiu; Quan, Song

    2016-01-01

    In this study, we investigated whether any of the observed changes in mouse sperm function tests secondary to mechanical stresses (centrifugation and pipetting) correlate with sperm fertilization ability. Chinese Kunming mice were used as sperm and oocyte donors. Sperm samples were allocated evenly into centrifugation, pipette, and control groups. Sperm plasma membrane integrity (PMI), mitochondrial membrane permeability (MMP), baseline and stimulated intracellular ROS, and sperm fertilization ability were measured by hypo-osmotic swelling, flow cytometry, and fertilization tests. Parallel studies were conducted and all tests were repeated six times. Our results showed that after centrifugation, the progressive motility, average path velocity, and overall sperm motility and PMI decreased significantly (p < 0.05). In addition, the MMP level decreased significantly in viable sperm when the centrifugation condition reached 1,400 g × 15 minutes (p < 0.05). When pipetting was performed two or more times, progressive motility, average path velocity, and overall sperm motility decreased significantly (p < 0.05); when it was performed four or more times, sperm membrane integrity and intracellular basal ROS level of viable sperm was also significantly decreased (p < 0.05). In conclusion, various mechanical stresses seem to affect sperm function, however this does not appear to alter fertilization rate. Laboratory handling steps should be minimized to avoid unnecessary mechanical stresses being applied to sperm samples.

  4. The Effect of Sperm Morphology and Sire Fertility on Calving Rate of Finnish Ayrshire AI Bulls.

    PubMed

    Attia, S; Katila, T; Andersson, M

    2016-02-01

    Good-quality semen is a prerequisite for successful and profitable artificial insemination (AI) of modern dairy cattle. Fertility of the bulls is evaluated with andrological examinations and semen analyses, such as morphology. However, little attention has been paid to the inheritance of bull fertility. In this study, we correlated sperm morphology, birth year and station of 695 AI bulls with calving rate (CR). Sperm morphology was clearly associated with CR underlining the usefulness of morphological examination in the assessment of fertility. The correlation between the proportion of normal spermatozoa and CR was significant (p < 0.001). No significant differences were detected between stations or birth years. We also compared the CR of 695 AI bulls with the CR of their 27 sires to study the inheritance of fertility. Sire's CR did not correlate with the CR of the sons (p = 0.218). This result indicates that at least when sires of acceptable CR are used to produce sons for use in AI the inheritance of CR is not significantly correlated.

  5. Addition of L-arginine to the fertilization medium enhances subsequent bovine embryo development rates.

    PubMed

    Santana, Priscila P B; da Silva, Bruno B; Silva, Thiago V G; Costa, Nathalia N; Cordeiro, Marcela S; Santos, Simone S D; Ohashi, Otávio M; Miranda, Moysés S

    2016-04-01

    Although L-Arginine (ARG) has been reported as a promising bovine sperm capacitation agent, its effects on embryo development are still poorly understood. Herein, we compared the effects of ARG and/or heparin (HEP) addition to the fertilization medium for bovine oocytes on sperm capacitation and embryo development. We chose 10 mM ARG based on blastocyst development rates in a titration experiment. Addition of ARG and/or HEP to the fertilization medium resulted in similar rates of blastocyst development (P > 0.05). However, when ARG, but not HEP, was combined with a nitric oxide (NO) synthase inhibitor (N-Nitro-L-ARG-methyl ester, 10 mM) blastocyst development was decreased (P < 0.05). To assess the effects on capacitation, bovine sperm were incubated for 0, 3, and 6 hours in fertilization medium containing ARG and/or HEP and/or N-Nitro-L-ARG-methyl esterand acrosomal exocytosis rates were evaluated using fluorescein isothiocyanate conjugated Pisum sativum lectin (FITC-PSA) staining and flow cytometry. With HEP, acrosomal exocytosis rates were highest by 3 hours of incubation; however, by 6 hours, rates were similar for HEP and/or ARG (P > 0.05) and higher than those in control media (P < 0.05). Although both ARG and HEP increased sperm NO production (P < 0.05), combination with L-NAME only precluded acrosomal exocytosis when ARG added alone in the medium (P > 0.05). These results suggest that although both ARG and HEP supported sperm capacitation, only the effects of the former were driven via NO production. Moreover, ARG was also as effective as HEP at improving blastocyst development rates. Therefore, ARG may be used as a low-cost alternative sperm capacitation agent for bovine in vitro embryo production.

  6. Inter-provincial migration in Spain: temporal trends and age-specific patterns.

    PubMed

    Garcia Coll, A; Stillwell, J

    1999-01-01

    "This paper provides interpretation of the changing patterns of internal migration in Spain at the inter-provincial scale, and new analysis of age-specific migration during the 1980s using a 10% sample of anonymised records from the 1991 census. Schedules of age-specific gross migration rates are constructed and classified according to their shape and level relative to the national schedule, and the relationships between in-migration and out-migration rates are examined for four selected age groups to demonstrate how aggregate patterns of inter-provincial migration conceal a wide diversity of age specific experience."

  7. bayesTFR: An R Package for Probabilistic Projections of the Total Fertility Rate.

    PubMed

    Ševčíková, Hana; Alkema, Leontine; Raftery, Adrian E

    2011-07-01

    The bayesTFR package for R provides a set of functions to produce probabilistic projections of the total fertility rate (TFR) for all countries. In the model, a random walk with drift is used to project the TFR during the fertility transition, using a Bayesian hierarchical model to estimate the parameters of the drift term. The TFR is modeled with a first order autoregressive process during the post-transition phase. The computationally intensive part of the projection model is a Markov chain Monte Carlo algorithm for estimating the parameters of the drift term. This article summarizes the projection model and describes the basic steps to generate probabilistic projections, as well as other functionalities such as projecting aggregate outcomes and dealing with missing values.

  8. From Prediction to Prescription: Intelligent Decision Support for Variable Rate Fertilization

    SciTech Connect

    Fink, Raymond Keith; Hoskinson, Reed Louis; Hess, John Richard

    2001-07-01

    We describe the use of machine learning methods in the analysis of spatial soil fertility, soil physical characteristics, and yield data, with a particular objective of determining local (field- to farm-scale) crop response patterns. For effective prescriptive use, the output of these tools is augmented with economic data and operational constraints, and recast as a rulebased decision support tool to maximize economic return in variable rate fertilization systems. We describe some of the practical issues addressed in development of one such system, including data preparation, adaptation of regression tree output for use in a rule-based expert system, and incorporation of real-world limits on system recommendations. Results from various field trials of this system are summarized.

  9. Global transcriptional expression in ovarian follicles from Tsaiya ducks (Anas platyrhynchos) with a high-fertilization rate.

    PubMed

    Wu, Shyh-Jong; Cheng, Yu-Shin; Liu, Hsiao-Lung; Wang, Hsing-He; Huang, Hsiu-Lin

    2016-05-01

    Novel candidates for biomarkers of a high-fertilization rate were identified here through global transcriptional profiling of ovarian follicles. Some other differentially expressed candidate genes were first noted to influence animal reproduction in our previous cDNA microarray analysis and are now recognized as markers for marker-assisted selection. In the present study, we compared gene expression in ovarian follicles from animals with high- and low-fertilization rates using an oligonucleotide array. On the basis of a fold change of greater than 1.2 and less than -1.2, a difference of >100 Affymetrix arbitrary units between the two groups, and a P value of less than 0.05, 47 genes were found to be associated with fertilization rate. GOEAST and MetaCore software were further used to identify the functional categories of genes that were differentially expressed. Then, we focused on three interesting genes associated with a high-fertilization rate: one of these genes was discovered to participate in signaling pathways of fertilization, and two genes take roles in lipid metabolism. An oligonucleotide array showed that the levels of orthodenticle homeobox 2 (OTX2) and lecithin:cholesterol acyltransferase (LCAT) gene expression were 1.62-fold and 1.95-fold higher in the high-fertilization rate group than in the low-fertilization rate group, respectively (P < 0.05). The level of apolipoprotein A-I (APOA1) gene expression was also higher in the high-fertilization rate group, with a difference of 2.31-fold (P < 0.05). The data were validated through quantitative polymerase chain reaction analysis. These results confirm the usefulness of the array technique and data mining methods in the discovery of new biomarkers and add knowledge to our understanding of the factors affecting fertilization rates in ovarian follicles.

  10. Age-Specific Morbidity Among Naval Aviators.

    DTIC Science & Technology

    1983-01-01

    health problems (i.e., accidental injuries among young pilots and cardiovascular conditions among older pilots). In order for the Navy’s medical de...conditions. With increasing age, differences in rates for most categories narrowed substantially across groups although rates for accidental injuries...order to ensure the pilot’s and aircrew member’s total concentration during flight. The higher rates among aviation officers for accidental injuries

  11. Precision of farmer-based fertility ratings and soil organic carbon for crop production on a Ferralsol

    NASA Astrophysics Data System (ADS)

    Musinguzi, P.; Ebanyat, P.; Tenywa, J. S.; Basamba, T. A.; Tenywa, M. M.; Mubiru, D.

    2015-09-01

    Simple and affordable soil fertility ratings are essential, particularly for the resource-constrained farmers in sub-Saharan Africa (SSA), in planning and implementing prudent interventions. A study was conducted on Ferralsols in Uganda to evaluate farmer-based soil fertility assessment techniques, hereafter referred to as farmers' field experiences (FFE), for ease of use and precision, against more formal scientific quantitative ratings using soil organic carbon (SQR-SOC). A total of 30 fields were investigated and rated using both techniques, as low, medium and high in terms of soil fertility - with maize as the test crop. Both soil fertility rating techniques were fairly precise in delineating soil fertility classes, though the FFE was inefficient in distinguishing fields > 1.2 % SOC with medium and high fertility. Soil organic carbon, silt and clay were exceptionally influential, accounting for the highest percentage in grain yield of 50 % in the topsoil (0-15 cm) and 67 % for the mean concentrations from 0 to 15 and 15 to 30 cm. Each unit increase in SOC concentration resulted in 966 to 1223 kg ha-1 yield gain. The FFE technique was effective in identifying low-fertility fields, and this was coherent with the fields categorized as low (SOC < 1.2 %). Beyond this level, its precision can be remarkably increased when supplemented with the SQR-SOC technique.

  12. Effect of chromosomal polymorphisms of different genders on fertilization rate of fresh IVF-ICSI embryo transfer cycles.

    PubMed

    Liang, Ji; Zhang, Yongsheng; Yu, Yang; Sun, Wentao; Jing, Jili; Liu, Ruizhi

    2014-10-01

    To explore whether chromosomal polymorphisms of different genders affect outcomes of fresh IVF and intracytoplasmic sperm injection (ICSI) embryo transfer cycles differently, 37 couples with chromosomal polymorphisms were identified out of 614 infertile couples undergoing IVF-ICSI treatments. Group 1 included 20 couples in which only the male carried chromosomal polymorphisms; group 2 included 17 couples with female carriers only; group 3 included 19 infertile couples with normal karyotypes randomly selected as controls. A significantly lower fertilization rate was found in group 1 compared with groups 2 and 3 (56.68% in Group 1, 78.02% in group 2 and 71.74% in group 3; group 1 versus group 2, P < 0.001; group 1 versus group 3, P = 0.001; respectively). When stratified according to fertilization method, the fertilization rate in IVF cycles of group 1 was significantly lower than group 3 (50.00% in Group 1, 73.89% in Group 3, P < 0.001). Fertilization rates in ICSI cycles between groups 1 and 3 were not significantly different. This study suggests that male chromosomal polymorphisms adversely influence fertilization rates of IVF cycles. The use of ICSI may improve the success of infertility treatment by increasing the fertilization rate for men with chromosomal polymorphisms.

  13. Effects of growth medium and fertilizer rate on the yield response of soybeans exposed to chronic doses of ozone

    SciTech Connect

    Heagle, A.S.; Letchworth, M.B.; Mitchell, C.A.

    1983-01-01

    The objectives were to determine whether wide variation in fertilizer rates or type of growth medium would affect the response of soybeans, Glycine max 'Davis' exposed to chronic doses of ozone (O/sub 3/) in open-top field chambers. Responses to O/sub 3/ were compared for plants grown in the ground or in pots containing an artificial growth medium. In 1977, the yield of plants grown in pots containing soil, sand, and a mixture of perlite, peat moss, and vermiculite was greater than that of plants grown in the ground; in 1978, the reverse was true. However, the percentage yeild loss caused by O/sub 3/ was not affected by the growth medium either year. Separate tests were made for potted plants that received different levels of fertilizer. At moderate fertilizer rates, the yield response to different doses of O/sub 3/ was not significantly affected by fertilizer rate for either year. In 1978, plants with no fertilizer added were severely stunted and even relatively high doses of O/sub 3/ did not further decrease yield. The results suggest that plant response to O/sub 3/ will be fairly uniform over a range of substrate types and fertilizer rates when edaphic conditions are adequate to insure normal plant growth. 17 references, 5 figures, 2 tables.

  14. 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.

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

    PubMed Central

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

    2015-01-01

    Background: 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. Materials and Methods: 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. Results: 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). Conclusions: 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. PMID:25878707

  16. Effects of fertilizer and low rates of imidacloprid on Adelges tsugae (Hemiptera: Adelgidae).

    PubMed

    Joseph, S V; Hanula, J L; Braman, S K; Byrne, F J

    2011-06-01

    Healthy hemlock trees, Tsuga canadensis (L.) Carrière, and hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), populations should favor retention and population growth of adelgid predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae (Sasaji & McClure) (Coleoptera: Coccinellidae). Eastern hemlock trees between 15 and 38 cm diameter at breast height (dbh) were treated with 0, 10, or 25% of 1.5 g imidacloprid (Merit 75 WP) per 2.5 cm dbh and were either fertilized or not, in a 3 by 2 factorial design. After 2 yr, imidacloprid reduced the numbers of ovisacs and eggs found on trees in a dosage-dependent manner, while enhancing tree growth parameters such as new shoots or needles and the length of new shoots. Fertilized trees had greater adelgid fecundity, which was positively correlated with total foliar N in both winter generations. In February 2009 (27 mo after imidacloprid treatment), higher imidacloprid dosages to unfertilized trees resulted in reduced adelgid fecundity. Concentrations of N, P, and K were higher in the foliage of trees treated with insecticide, whereas foliar aluminum concentrations were consistently lower in trees with higher insecticide dosages. Trees treated with low rates of imidacloprid were healthier than untreated trees, but only trees treated with the 0.1 x dosage had sufficient adelgids to possibly sustain predators over extended periods.

  17. Cold Tolerance of Container-Grown Green Ash Nursery Trees is Influenced by Nitrogen Fertilizer Type and Rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to determine whether nitrogen (N) application rate and fertilizer form is related to cold tolerance of buds and stems of nursery-grown green ash (Fraxinus pennsylvanica ‘Summit’) trees. Trees were grown with different rates of N from either urea formaldehyde (UF) or a controlle...

  18. Cryopreservation of human embryos and its contribution to in vitro fertilization success rates.

    PubMed

    Wong, Kai Mee; Mastenbroek, Sebastiaan; Repping, Sjoerd

    2014-07-01

    Cryopreservation of human embryos is now a routine procedure in assisted reproductive technologies laboratories. There is no consensus on the superiority of any protocol, and substantial differences exist among centers in day of embryo cryopreservation, freezing method, selection criteria for which embryos to freeze, method of embryo thawing, and endometrial preparation for transfer of frozen-thawed embryos. In the past decade, the number of frozen-thawed embryo transfer cycles per started in vitro fertilization (IVF) cycle increased steadily, and at the same time the percentage of frozen-thawed embryo transfers that resulted in live births increased. Currently, cryopreservation of human embryos is more important than ever for the cumulative pregnancy rate after IVF. Interestingly, success rates after frozen-thawed embryo transfer are now nearing the success rates of fresh embryo transfer. This supports the hypothesis of so called freeze-all strategies in IVF, in which all embryos are frozen and no fresh transfer is conducted, to optimize success rates. High-quality randomized controlled trials should be pursued to find out which cryopreservation protocol is best and whether the time has come to completely abandon fresh transfers.

  19. Declining fertility in Nepal.

    PubMed

    Das Dangol, B; Retherford, R D; Thapa, S

    1997-03-01

    This article relies on data from the 1991 Nepal Fertility, Family Planning, and Health Survey (NFFPHS) and the 1996 Nepal Living Standards Survey (NLSS) to assess trends in fertility in Nepal. The NFFPHS shows heaping at ages 5, 8, 10, and 12 years and a larger proportion of infants. The NLSS shows a different pattern of misreporting of youth and a stronger but similar pattern of age heaping as the NFFPHS for adults. Children ever born by maternal age indicates a degree of completeness and the deletion by older women of deceased children and married children living outside the household. Findings suggest less complete reporting in the NLSS. Age-specific fertility rates are calculated based on birth histories (BH) and the own-children (OC) method based on life tables. Findings indicate that BH and OC estimates of the cumulative fertility rate (CFR) derived from the NLSS and the NFFPHS were comparable for estimating trends in the total fertility rate (TFR). The trends from the two data sets overlapped fairly well during 1983-89. Fertility trends by single years of age showed considerably annual fluctuations due to age misreporting. The CFR and TFR for aggregated time periods showed little or no decline for the earlier 5-year period, a steeper decline in the second period, and variations in trends by data set for the third period from 1983 to 1989. One curve showed no decline and the other showed fertility decline. Fitting a straight line to the trend for 1977-91 shows that CFR declined by 1.61 children from 5.29 children in 1977 to 3.68 children in 1991. TFR declined by 1.90 children from 6.68 children in 1977 to 4.78 children in 1991. The author cautions that the point of fertility decline was not determined exactly, but data suggest that decline occurred around 1980, and the rate was fast thereafter. TFR declined by 2.70 children in urban areas and 1.83 children in rural areas.

  20. 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

  1. [Effects of soil fertility and nitrogen application rate on nitrogen absorption and translocation, grain yield, and grain protein content of wheat].

    PubMed

    Wang, Yuefu; Yu, Zhenwen; Li, Xiangxia; Yu, Songlie

    2003-11-01

    The results of this study showed that nitrogen application improved the nitrogen uptake by wheat, especially during its late growth stage. Although a higher nitrogen application rate could increase the amount of absorbed nitrogen, an excess of nitrogen would remain in vegetative organs at the stage after flowering, owing to the low translocation rate of nitrogen from these organs to the grain, and hence, the nitrogen use efficiency and nitrogen harvest index were decreased. Compared with that on high fertility soil, the ratio of nitrogen absorbed from fertilizer to total absorbed nitrogen was higher when the wheat was grown on low fertility soil. On high fertility soil, wheat plant absorbed more nitrogen from top-dressed fertilizer than from basis fertilizer, and top-dressed fertilizer contributed more nitrogen to the grain. It was reversed on low fertility soil.

  2. Fertilizer trends

    SciTech Connect

    Donaldson, R.

    1992-01-01

    This fourteenth edition of Fertilizer Trends presents historical fertilizer market data to aid industry, government, and financial market analysis and planners in their study of fertilizer and agricultural market cycles, market planning, and investment decisions. A 27-year summary of the US fertilizer market is presented in graphic and tabular form. Production, use, and trade data are included for each plant nutrient and sulfur. Canadian statistics have been included because of the important role of the Canadian fertilizer industry in the US fertilizer market. World production and consumption of nitrogen, phosphate, and potash are included because of the strong influence of world markets on the domestic market. Planted acreage and plant nutrient application rates for the major crops have been included to illustrate their effect on fertilizer use. Retail prices of the leading US fertilizer materials also are given.

  3. Fertilizer trends

    SciTech Connect

    Donaldson, R.

    1992-12-31

    This fourteenth edition of Fertilizer Trends presents historical fertilizer market data to aid industry, government, and financial market analysis and planners in their study of fertilizer and agricultural market cycles, market planning, and investment decisions. A 27-year summary of the US fertilizer market is presented in graphic and tabular form. Production, use, and trade data are included for each plant nutrient and sulfur. Canadian statistics have been included because of the important role of the Canadian fertilizer industry in the US fertilizer market. World production and consumption of nitrogen, phosphate, and potash are included because of the strong influence of world markets on the domestic market. Planted acreage and plant nutrient application rates for the major crops have been included to illustrate their effect on fertilizer use. Retail prices of the leading US fertilizer materials also are given.

  4. Sperm chromatin structure assay results after swim-up are related only to embryo quality but not to fertilization and pregnancy rates following IVF.

    PubMed

    Niu, Zhi-Hong; Shi, Hui-Juan; Zhang, Hui-Qin; Zhang, Ai-Jun; Sun, Yi-Juan; Feng, Yun

    2011-11-01

    The aim of this study was to investigate whether the sperm chromatin structure assay (SCSA) results after swim-up are related to fertilization rates, embryo quality and pregnancy rates following in vitro fertilization (IVF). A total of 223 couples undergoing IVF in our hospital from October 2008 to September 2009 were included in this study. Data on the IVF process and sperm chromatin structure assay results were collected. Fertilization rate, embryo quality and IVF success rates of different DNA fragmentation index (DFI) subgroups and high DNA stainability (HDS) subgroups were compared. There were no significant differences in fertilization rate, clinical pregnancy or delivery rates between the DFI and HDS subgroups. However, the group with abnormal DFI had a lower good embryo rate. So, we concluded that the SCSA variables, either DFI or HDS after swim-up preparation, were not valuable in predicting fertilization failure or pregnancy rate, but an abnormal DFI meant a lower good embryo rate following IVF.

  5. Evaluation of Physical Strength of Wheat Straw Under Different Fertilizer Treatments and Rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Application of nitrogen (N) fertilizer as urea ammonium nitrate and N plus sulfur fertilizer as ammonium thiosulfate as a mist on crop residue to stimulate microbial activity and subsequent decomposition of the residue is often debated, particularly for its potential to solve stand establishment iss...

  6. Long-term analysis of survival, fertility, and population growth rate of black bears in North Carolina

    USGS Publications Warehouse

    Brongo, L.L.; Mitchell, M.S.; Grand, J.B.

    2005-01-01

    We estimated survival, fertility, and realized and asymptotic population growth rates from 1981 to 2002 for a protected population of black bears (Ursus americanus) in the southern Appalachian Mountains. We used Akaike's information criterion to assess the time interval for averaging observations that was best for estimating vital rates for our study, given our yearly sample sizes. The temporal symmetry approach allowed us to directly assess population growth and to address all losses and gains to the population by using only capture data, offering an alternative to the logistically intensive collection of reproductive data. Models that averaged survival and fertility across 5- and 7-year time intervals were best supported by our data. Studies of black bear populations with annual sample sizes similar to ours should be of at least 5 years in duration to estimate vital rates reliably, and at least 10 years in duration to evaluate changes in population growth rate (??). We also hypothesized that survival would not track changes in ?? because ?? is influenced by both survival and fertility. The 5-year model supported our hypothesis, but the 7-year model did not. Where long-term dynamics of large, relatively stable bear populations are of interest, monitoring survival is likely to be sufficient for evaluating trends in ??. For rapidly changing, small populations, however, failure to incorporate fertility into assessments of ?? could be misleading. ?? 2005 American Society of Mammalogists.

  7. Epigenetic regulation of sex ratios may explain natural variation in self-fertilization rates

    PubMed Central

    Ellison, Amy; Rodríguez López, Carlos Marcelino; Moran, Paloma; Breen, James; Swain, Martin; Megias, Manuel; Hegarty, Matthew; Wilkinson, Mike; Pawluk, Rebecca; Consuegra, Sofia

    2015-01-01

    Self-fertilization (selfing) favours reproductive success when mate availability is low, but renders populations more vulnerable to environmental change by reducing genetic variability. A mixed-breeding strategy (alternating selfing and outcrossing) may allow species to balance these needs, but requires a system for regulating sexual identity. We explored the role of DNA methylation as a regulatory system for sex-ratio modulation in the mixed-mating fish Kryptolebias marmoratus. We found a significant interaction between sexual identity (male or hermaphrodite), temperature and methylation patterns when two selfing lines were exposed to different temperatures during development. We also identified several genes differentially methylated in males and hermaphrodites that represent candidates for the temperature-mediated sex regulation in K. marmoratus. We conclude that an epigenetic mechanism regulated by temperature modulates sexual identity in this selfing species, providing a potentially widespread mechanism by which environmental change may influence selfing rates. We also suggest that K. marmoratus, with naturally inbred populations, represents a good vertebrate model for epigenetic studies. PMID:26559950

  8. Stabilized nitrogen fertilizers and application rate influence nitrogen losses under rainfed spring wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) losses associated with fertilizer application have negative economic and environmental consequences, but urease and nitrification inhibitors have potential to reduce N losses. The effectiveness of these inhibitors has been studied extensively in irrigated but not rainfed systems. Theref...

  9. Basis for the ICRP`s age-specific biokinetic model for uranium

    SciTech Connect

    Leggett, R.W.

    1994-12-01

    In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP`s age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: (1) measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; (2) postmortem measurements of uranium in tissues of some of those subjects; (3) postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; (4) data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and (5) consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. 82 refs., 17 figs., 8 tabs.

  10. 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.

  11. Increased Fertilization Rates after In Vitro Culture of Frozen-Thawed Testicular Immotile Sperm in Nonobstructive Azoospermic Patients

    PubMed Central

    Nuñez-Calonge, R.; Cortes, S.; Gago, M.; López, P.; Caballero-Peregrin, P.

    2012-01-01

    Objective. To optimise the use of freeze/thaw testicular immotile spermatozoa from nonobstructive azoospermia patients and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. Methods. Testicular specimens were retrieved and cryopreserved from forty patients with nonobstructive azoospermia and underwent one cycle with thawed spermatozoa (Group I) that led to pregnancy in sixteen cases. Twenty-four patients of group I underwent treatment with the same batch of thawed spermatozoa (Group II). For the first ICSI attempt, injection was performed when motile spermatozoa were found. In group II, injection was performed when maximum motility was reached. We compared mean of fertilization rate, embryo quality, clinical pregnancy rate and embryo implantation rate. Results. The mean percentage of motility was significantly higher in the group II than in the group I (18, 6 versus 8, 2). Group I showed a significant decrease in fertilization rates when compared with cryopreserved testicular spermatozoa in group II (54% versus 72%, P < 0.05). No difference was noted between the cleavage rate, embryo quality, clinical pregnancy rates and implantation rates among group II and I. Conclusion. Fecundation rate can be significantly improved after in-vitro culture and sperm selection of frozen-thawed immotile testicular spermatozoa in patients with nonobstructive azoospermia. PMID:22567413

  12. Influence of a 50 hz extra low frequency electromagnetic field on spermatozoa motility and fertilization rates in rabbits.

    PubMed

    Roychoudhury, Shubhadeep; Jedlicka, Jaroslav; Parkanyi, Vladimir; Rafay, Jan; Ondruska, Lubomir; Massanyi, Peter; Bulla, Jozef

    2009-08-01

    Effects of a 50 Hz extra-low frequency electromagnetic field (ELF EMF) on in vitro rabbit spermatozoa motility were analyzed, as well as the effect on fertilization rates after insemination. Pooled semen samples and a control were exposed to 50 Hz ELF EMF. The difference of the samples of the test groups G1 and G2 with the control group CG (75.56%) for spermatozoa motility were found to be significant (P < 0.01). Differences were significant (P < 0.01) for curvilinear velocity (VCL) between the test group G3 (122.38 microm/s) and the control group CG (112.02 microm/s). Hormonally stimulated adult (9-12 months) females (n = 140) were inseminated with semen samples from G1, G2, G3 and CG (0.88 x 109 spermatozoa/0.5 mL average insemination portion) immediately after ELF EMF exposure and fertilization (kindling) rates were calculated. For the G2 it was 54.28% data indicate 50 Hz ELF EMF induced alterations of spermatozoa motility and kindling rate in rabbits, therefore influencing fertility.

  13. Cold Hardiness of Green Ash Nursery Trees is Influenced by Nitrogen Fertilizer Type and Rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tip dieback and bud death in the spring can decrease salability and growth of nursery trees of green ash (Fraxinus pennsylvanica ‘Summit’). For some species, tip dieback in the spring is correlated with low nitrogen (N) reserves in trees; however, application of nitrogen (N) fertilizers late in the ...

  14. Soybean seed protein, oil, fatty acids, and isoflavones altered by potassium fertilizer rates in the midsouth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has shown that the effect of potassium fertilizer on soybean ([Glycine max (L.) Merr.] seed composition (protein, oil, fatty acids, and isoflavones) is still largely unknown. Therefore, the objective of this research was to investigate the effects of potassium application on seed p...

  15. Derivation of a Variable Rate Nitrogen Application Model for In-Season Fertilization of Corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen fertilizers used in crop production contribute to pollution of groundwater by nitrate and occurrence of hypoxia in the Gulf of Mexico. Economic and environmental pressures are forcing producers to improve nitrogen use efficiency. The objective of this study was to develop a production-based...

  16. Effect of manure under different nitrogen application rates on winter wheat production and soil fertility in dryland

    NASA Astrophysics Data System (ADS)

    Zhang, H. Q.; Yu, X. Y.; Zhai, B. N.; Jin, Z. Y.; Wang, Z. H.

    2016-08-01

    Exploring an effective fertilization practice is crucial for achieving a sustainable dryland winter wheat cropping system. Following a split-plot design, this study was conducted to investigate the combined effect of manure (-M or +M; main plot) and various rates of nitrogen (N) fertilizer (0, 75, 150, 225, and 300 kg N ha-1; sub plot) on grain yield, water and N use efficiencies of winter wheat, and soil nutrients. The results showed that the treatments with manure improved the grain yield by 8%, and WUE by 10% relative to that without manure throughout the study years. The highest winter wheat yield and WUE were both recorded in the M+N225 treatment, which were not significantly different from those for M+N75 and M+N150 treatment. In contrast, high levels of N fertilizer (> 150 kg N ha-1) combined with manure not only caused a reduction in the N use efficiency (NUE), but it also caused an increase in the soil residual nitrate-N (from 43.7 to 188.9 kg ha-1) relative to without manure. After three years of continuous cropping, the treatment combining manure with 150 kg N ha-1 fertilizer had the highest SOM, available P and available K, which was 24%, 379% and 102% higher than that for unfertilized treatment (CK), and 10%, 267%, and 55% higher than that for without manure, respectively. Thus, the combination of manure (17.5 t ha-1 poultry or 30 t ha-1 pig manure) with 75-150 kg N ha-1 N fertilizer is recommended for improving winter wheat yield, water and N use efficiencies, and reducing soil nitrate-N residue as well.

  17. The effects of income level, income distribution, education and urbanization on fertility rates among 28 administrative regions of China.

    PubMed

    Lee, B S

    1990-07-01

    Conflicting empirical evidence on the role of income distribution on fertility rates is the impetus for this 1982 study of providence-specific Chinese Census data, excluding Tibet. The findings support the prior thesis of Repetto but utilize the micromethods and per household income measures of the competing findings of Boulier. It is cautioned that in the Chinese analysis equal income distribution depresses fertility, but China may not reflect world wide patterns. China did not have until recently a market incentive system, and there are income measurement problems. The data are per capita economic output not per capita income, and those high output areas which did not produce low fertility may actually have had households with low incomes. The importance of this research is in establishing that cross-province data are a useful tool in understanding the influence of income distribution on fertility. As with most developing countries, women's education, for instance, at least junior high education explained the largest variation of fertility differences among the 28 provinces. The urbanization variable when controlling for income was positive, unlike the other developing countries. The 1949 Chinese government's spatial industrial policy encouraged urbanization and industrialization in rural areas and family planning programs such that highly urbanized provinces have low population density. A variety of variables on income level, income distribution, education, and urbanization are discussed. OLSQ regressions were generated utilizing such independent variables as output per capita in yuan (YOUTHPC80), the square of YOUTHPC80 (YOUTHPC802), YOUTHPC80 multiplied by the average family size in each province (YOUTHPH80), and the squared value of YOUTHPH80.

  18. Possible natural hybridization of two morphologically distinct species of Acropora (Cnidaria, Scleractinia) in the Pacific: fertilization and larval survival rates.

    PubMed

    Isomura, Naoko; Iwao, Kenji; Fukami, Hironobu

    2013-01-01

    Natural hybridization of corals in the Indo-Pacific has been considered rather rare. However, field studies have observed many corals with intermediate interspecific or unusual morphologies. Given that the existence of F1 hybrids with intermediate interspecific morphologies has been proven in the Caribbean, hybrids may also inhabit the Indo-Pacific and occur more frequently than expected. In this study, we focused on two morphologically different species, Acropora florida and A. intermedia, and performed crossing experiments at Akajima Island, Japan. Results showed that these species could hybridize in both directions via eggs and sperm, but that fertilization rates significantly differed according to which species provided eggs. These results are similar to those reported from the Caribbean. Although all embryos developed normally to the planular larval stage, the developmental processes of some hybrid embryos were delayed by approximately 1 h compared with conspecific embryos, suggesting that fertilization occurred 1 h later in interspecific crosses than in intraspecific crosses. More successful hybridization could occur under conditions with low numbers of conspecific colonies. Additionally, a comparison of survival rates between hybrid and intraspecific larvae revealed that intra- and interspecific larvae produced from eggs of A. florida survived for significantly longer than those produced from eggs of A. intermedia. Considering these data, under specific conditions, hybrids can be expected to be produced and survive in nature in the Pacific. Furthermore, we identified one colony with intermediate morphology between A. florida and A. intermedia in the field. This colony was fertilized only by eggs of A. florida, with high fertilization rates, suggesting that this colony would be a hybrid of these two species and might be backcrossed.

  19. [Effects of irrigation mode and N application rate on cotton field fertilizer N use efficiency and N losses].

    PubMed

    Wang, Xiao-Juan; Wei, Chang-Zhou; Zhang, Jun; Dong, Peng; Wang, Juan; Zhu, Qi-Chao; Wang, Jin-Xin

    2012-10-01

    A field experiment was conducted to study the effects of different irrigation modes (drip irrigation and furrow irrigation) and different N application rates (0, 240, 360 and 480 kg N x hm(-2)) on the fertilizer N use efficiency and N losses in a cotton field in Xinjiang, Northwest China. The main N cycling pathways, such as the N uptake by cotton plant, NO3(-)-N residual in soil, NH3 volatilization, NO3(-)-N leaching, and nitrification-denitrification, were quantitatively monitored. Compared with furrow irrigation, drip irrigation increased the seed cotton yield, plant N uptake, and fertilizer N use efficiency significantly. The NO3(-)-N residual in soil was significantly greater under furrow irrigation than under drip irrigation. With the application of fertilizer N, the N loss from NH3 volatilization under drip irrigation occupied 0.06% -0.14% of applied N, and was significantly greater than that under furrow irrigation. The N loss from NO3(-)-N leaching under drip irrigation and furrow irrigation was 4.4% and 8.8% of the applied N, respectively. Compared with furrow irrigation, drip irrigation could significantly decrease the NO3(-)-N leakage rate in leakage water. The nitrification-dinetrification loss under drip irrigation and furrow irrigation was 17.9% and 16.8% of the applied N, respectively. It was suggested that NO3(-)-N leaching and nitrification-denitrification were the main N losses in the cotton fields of Xinjiang.

  20. Growth response of Douglas-fir seedlings to nitrogen fertilization: importance of Rubisco activation state and respiration rates.

    PubMed

    Manter, Daniel K; Kavanagh, Kathleen L; Rose, Cathy L

    2005-08-01

    High foliar nitrogen concentration ([N]) is associated with high rates of photosynthesis and thus high tree productivity; however, at excessive [N], tree productivity is reduced. Reports of excessive [N] in the Douglas-fir forests of the Oregon Coast Range prompted this investigation of growth and needle physiological responses to increasing foliar N concentrations in 1-year-old Douglas-fir seedlings. After 1 year of N fertilization, total seedling biomass increased with each successive increase in N fertilizer concentration, except in the highest N fertilization treatment. Of the many physiological responses that were analyzed, only photosynthetic capacity (i.e., Vcmax), respiration rates and leaf specific conductance (KL) differed significantly between N treatments. Photosynthetic capacity showed a curvilinear relationship with foliar [N], reaching an apparent maximum rate when needle N concentrations exceeded about 12 mg g(-1). In vitro measurements of ribulose-1,5-bisphosphate carboxylase (Rubisco) activity suggested that photosynthetic capacity was best related to activated, not total, Rubisco content. Rubisco activation state declined as foliar [N] increased, and based on its significant correlation (r2= 0.63) with foliar Mn:Mg ratios, it may be related to Mn inactivation of Rubisco. Respiration rates increased linearly as foliar N concentration increased (r2= 0.84). The value of K(L) also increased as foliar [N] increased, reaching a maximum when foliar [N] exceeded about 10 mg g(-1). Changes in K(L) were unrelated to changes in leaf area or sapwood area because leaf area to sapwood area ratios remained constant. Cumulative effects of the observed physiological responses to N fertilization were analyzed by modeling annual net CO2 assimilation (Anet) based on treatment specific values of Vcmax, dark respiration (Rdark) and KL. Estimates of Anet were highly correlated with measured total seedling biomass (r2= 0.992), suggesting that long-term, cumulative

  1. The Effect of Extremely Low Frequency Pulsed Electromagnetic Field on In Vitro Fertilization Success Rate in N MRI Mice

    PubMed Central

    Hafizi, Leili; Sazgarnia, Ameneh; Mousavifar, Nezhat; Karimi, Mohammad; Ghorbani, Saleh; Kazemi, Mohammad Reza; Emami Meibodi, Neda; Hosseini, Golkoo; Mostafavi Toroghi, Hesam

    2014-01-01

    Objective: The effects of exposure to electromagnetic fields (EMF) on reproduction systems have been widely debated. In this study, we aimed to investigate whether low frequency EMF could ameliorate the in vitro fertilization success rate in Naval medical research institute (NMRI) Mice. Materials and Methods: In this randomized comparative animal study, ten NMRI mice were randomly divided into 2 equal groups (control and experimental). 10 IU of human chorionic gonadotropin (hCG) was injected intraperitoneally to both groups in order to stimulate ovulating, and ovums were then aspirated and kept in KSOM (modified version of sequential simplex optimization medium with a higher K+ concentration) culture medium. Metaphase II ovums were separated, and sperms obtained by "swim out" method were added to metaphase II ovums in the culture medium. The experimental group was exposed to 1.3 millitesla pulsed electromagnetic field at 4 kilohertz frequency for 5 hours. To assess the efficacy, we considered the identification of two-pronuclear zygote (2PN) under microscope as fertilizing criterion. Results: Total number of collected ovums in the control and experimental groups was 191 and 173, respectively, from which 58 (30.05%) and 52 (30.36%) ovums were collected from metaphase II, respectively. In vitro fertilization (IVF) success rate was 77% in extremely low frequency- pulsed electromagnetic field (ELFPEMF) for exposed group (experimental), whereas the rate was 68% for control group. Conclusion: Despite increased percentile of IVF success rate in exposed group, there was no statistically significant difference between 2 groups, but this hypothesis has still been stated as a question. Further studies with larger sample sizes and different EMF designs are suggested. PMID:24381855

  2. Age-specific MRI templates for pediatric neuroimaging

    PubMed Central

    Sanchez, Carmen E.; Richards, John E.; Almli, C. Robert

    2012-01-01

    This study created a database of pediatric age-specific MRI brain templates for normalization and segmentation. Participants included children from 4.5 through 19.5 years, totaling 823 scans from 494 subjects. Open-source processing programs (FSL, SPM, ANTS) constructed head, brain and segmentation templates in 6 month intervals. The tissue classification (WM, GM, CSF) showed changes over age similar to previous reports. A volumetric analysis of age-related changes in WM and GM based on these templates showed expected increase/decrease pattern in GM and an increase in WM over the sampled ages. This database is available for use for neuroimaging studies (blindedforreview). PMID:22799759

  3. [Effects of different application rates of humic acid compound fertilizer on pepper and its mechanism of anti-senility and incremental yield].

    PubMed

    Sun, Zhimei; Xue, Shichuan; Liang, Wenju; Liu, Yuzhu

    2004-01-01

    The effects of different application rates of humic acid compound fertilizer (HA) on the yield and physiological characteristics of pepper (Capsicum frutescens L.) were studied in this paper. The results showed that different application rates of (HA) could affect the physiological activities and yield of pepper. The nitrate reductase activity (NRA) and peroxidase (POD) activity were improved with increasing application rate, but the change rate of NRA was reduced gradually. POD activity in inorganic compound fertilizer treatment was improved significantly when the application rate of fertilizer was higher than 0.3 g.kg-1, but that in HA treatment changed smoothly. Superoxide dismutase (SOD) activity was improved significantly when the application rate of fertilizer was lower than 0.2 g.kg-1, and decreased gradually when the application rate was higher than 0.2 g.kg-1. The change of transpiration rate was consistent with that of SOD activity. The relationship between the application rate of fertilizer and the yield of pepper could be described with quadratic curve regression model. According to the equation, the highest application rate of HA should be 0.27 g.kg-1, and the highest yield of pepper could reach 165.22 g per pot.

  4. Body growth considerations in age-specific dosimetry. Final report

    SciTech Connect

    Eckerman, K.F.

    1993-09-30

    This report describes the manner in which the age-specific dosimetric calculations of the International Commission on Radiological Protection (ICRP) addressed changes in organ size that occur with age. The approach involves an interpolation of dosimetric information derived for six reference individuals using the inverse of the total body mass as the interpolation variable. An alternative formulation is investigated that employs a functional representation of the organ mass as a function of age in conjunction with an explicit formulation of the dosimetric factors in terms of organ mass. Using an exponential-logistic growth function as suggested by Walker, this report demonstrates, through application to the dosimetry of radioiodines in the thyroid, that the alternative formulation can be formulated and implemented. Although either approach provides a workable basis for age-specific dosimetry, it is clear that the functional representation of organ growth has some attractive features. However, without question, the major difficulty is the quality and quantity of data available to address the age- and gender-specific parameters in the dosimetric formulations.

  5. Changing pattern of age-specific breast cancer incidence in the Swiss canton of Geneva.

    PubMed

    Bouchardy, Christine; Usel, Massimo; Verkooijen, Helena M; Fioretta, Gérald; Benhamou, Simone; Neyroud-Caspar, Isabelle; Schaffar, Robin; Vlastos, Georges; Wespi, Yves; Schäfer, Peter; Rapiti, Elisabetta

    2010-04-01

    Hormone replacement therapy (HRT) use declined sharply after mid-2002, when the Women's Health Initiative trial reported an association between breast cancer occurrence and HRT. Hypothesized mechanism behind this association is that HRT promotes growth of pre-existing small tumors, leading to earlier tumor detection. We evaluated the impact of the sudden decline in HRT use on age distribution of breast cancer in Geneva. We included all incident breast cancer cases recorded from 1975 to 2006 at the Geneva cancer registry. We calculated mean annual incidence rates per 100,000 for 2 year periods for three age groups and assessed temporal changes by joinpoint regression. We compared age-specific incidence curves for different periods, reflecting different prevalence rates of HRT use. After increasing constantly between 1986 and 2002 among women aged 50-69 years [annual percent change (APC): +4.4, P < 0.0001], rates declined sharply after 2003 (APC: -6.0; P = 0.0264). Age-specific breast cancer rates changed dramatically with changes in prevalence of HRT use. During low HRT prevalence, breast cancer incidence increased progressively with age, when HRT prevalence was reaching its maximum (1995-2002), higher rates were seen in 60- to 64-year-old women, with a concomitant decrease in risk among elderly. After the sudden decline in HRT use, the incidence peak diminished significantly and incidence increased again with age. Following the abrupt decline in HRT use in Geneva, breast cancer incidence rates among post-menopausal women decreased considerably with striking changes in age-specific incidence rates before, during and after the peak in HRT prevalence.

  6. 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

  7. In Vitro Fertilization Pregnancy Rates in Levothyroxine-Treated Women With Hypothyroidism Compared to Women Without Thyroid Dysfunction Disorders

    PubMed Central

    Demir, Habibe; Kang, Yuna; Fierro, Michelle A.; Winston, Nicola J.

    2012-01-01

    Background Untreated hypothyroidism can lead to ovulatory dysfunction resulting in oligo-amenorrhea. Treatment with levothyroxine can reverse such dysfunction and thus should improve fertility. The purpose of this retrospective study was to assess whether in vitro fertilization (IVF) pregnancy rates differ in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction/disorders. Methods Treated hypothyroid and euthyroid women undergoing IVF at an academic IVF center were studied after Institutional Review Board approval. Women with hypothyroidism were treated with levothyroxine 0.025–0.15 mg/day for at least 3 months to maintain baseline thyrotropin (TSH) levels of 0.35–4.0 μU/mL prior to commencing IVF treatment (HYPO-Rx group). Causes of infertility were similar in both groups with the exception of male factor, which was more common in the HYPO-Rx group. The main outcomes studied were implantation rate, clinical pregnancy rate, clinical miscarriage rate, and live birth rate. Results We reviewed the first IVF retrieval cycle performed on 240 women aged 37 years or less during the period January 2003 to December 2007. Women with treated hypothyroidism (n=21) had significantly less implantation, clinical pregnancy, and live birth rates than euthyroid women (n=219). Conclusions We conclude that, despite levothyroxine treatment, women with hypothyroidism have a significantly decreased chance of achieving a pregnancy following IVF compared to euthyroid patients. A larger prospective study is necessary to assess confounding variables, confirm these findings, and determine the optimal level of TSH prior to and during controlled ovarian hyperstimulation for IVF. PMID:22540326

  8. Oocytes with a dark zona pellucida demonstrate lower fertilization, implantation and clinical pregnancy rates in IVF/ICSI cycles.

    PubMed

    Shi, Wei; Xu, Bo; Wu, Li-Min; Jin, Ren-Tao; Luan, Hong-Bing; Luo, Li-Hua; Zhu, Qing; Johansson, Lars; Liu, Yu-Sheng; Tong, Xian-Hong

    2014-01-01

    The morphological assessment of oocytes is important for embryologists to identify and select MII oocytes in IVF/ICSI cycles. Dysmorphism of oocytes decreases viability and the developmental potential of oocytes as well as the clinical pregnancy rate. Several reports have suggested that oocytes with a dark zona pellucida (DZP) correlate with the outcome of IVF treatment. However, the effect of DZP on oocyte quality, fertilization, implantation, and pregnancy outcome were not investigated in detail. In this study, a retrospective analysis was performed in 268 infertile patients with fallopian tube obstruction and/or male factor infertility. In 204 of these patients, all oocytes were surrounded by a normal zona pellucida (NZP, control group), whereas 46 patients were found to have part of their retrieved oocytes enclosed by NZP and the other by DZP (Group A). In addition, all oocytes enclosed by DZP were retrieved from 18 patients (Group B). No differences were detected between the control and group A. Compared to the control group, the rates of fertilization, good quality embryos, implantation and clinical pregnancy were significantly decreased in group B. Furthermore, mitochondria in oocytes with a DZP in both of the two study groups (A and B) were severely damaged with several ultrastructural alterations, which were associated with an increased density of the zona pellucida and vacuolization. Briefly, oocytes with a DZP affected the clinical outcome in IVF/ICSI cycles and appeared to contain more ultrastructural alterations. Thus, DZP could be used as a potential selective marker for embryologists during daily laboratory work.

  9. Reduction of centrifugation force in discontinuous percoll gradients increases in vitro fertilization rates without reducing bovine sperm recovery.

    PubMed

    Guimarães, A C G; Leivas, F G; Santos, F W; Schwengber, E B; Giotto, A B; Machado, C I U; Gonçalves, C G M; Folchini, N P; Brum, D S

    2014-05-01

    The objective of this study was to determine the effect of different centrifugation forces in bovine sperm separation by discontinuous Percoll gradients for in vitro fertilization IVF. The semen samples from each bull were pooled or each bull were centrifuged separately and centrifuged in discontinuous Percoll gradients (30, 60 and 90%) at different forces: F1 (9000×g), F2 (6500×g), F3 (4500×g) and F4 (2200×g), according experiment. The sperm samples were evaluated to determine the concentration, motility, vigor, morphology, reactive oxygen species (ROS), integrity of the plasma membrane, lipid peroxidation, antioxidants and embryo development were also evaluated. No difference was observed in the concentration of sperm submitted to different centrifugation forces. The total percentage of motile sperm was increased after centrifugation at F3 and F4, and the ROS production at F1 was greater than the other forces. When the bulls semen were processed individually, no significant differences were observed for the sperm quality parameters between F1 and F4, including lipid peroxidation, antioxidants, cleavage rate and average time to the first cleavage. This work demonstrated for the first time that centrifugation at 2200×g enhanced the sperm penetration and fertilization rates without reducing sperm recovery compared to the typical centrifugation force (9000×g) currently used by the commercial bovine IVF industry.

  10. Country- and age-specific optimal allocation of dengue vaccines.

    PubMed

    Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P

    2014-02-07

    Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.

  11. Uncertainty in age-specific harvest estimates and consequences for white-tailed deer management

    USGS Publications Warehouse

    Collier, B.A.; Krementz, D.G.

    2007-01-01

    Age structure proportions (proportion of harvested individuals within each age class) are commonly used as support for regulatory restrictions and input for deer population models. Such use requires critical evaluation when harvest regulations force hunters to selectively harvest specific age classes, due to impact on the underlying population age structure. We used a stochastic population simulation model to evaluate the impact of using harvest proportions to evaluate changes in population age structure under a selective harvest management program at two scales. Using harvest proportions to parameterize the age-specific harvest segment of the model for the local scale showed that predictions of post-harvest age structure did not vary dependent upon whether selective harvest criteria were in use or not. At the county scale, yearling frequency in the post-harvest population increased, but model predictions indicated that post-harvest population size of 2.5 years old males would decline below levels found before implementation of the antler restriction, reducing the number of individuals recruited into older age classes. Across the range of age-specific harvest rates modeled, our simulation predicted that underestimation of age-specific harvest rates has considerable influence on predictions of post-harvest population age structure. We found that the consequence of uncertainty in harvest rates corresponds to uncertainty in predictions of residual population structure, and this correspondence is proportional to scale. Our simulations also indicate that regardless of use of harvest proportions or harvest rates, at either the local or county scale the modeled SHC had a high probability (>0.60 and >0.75, respectively) of eliminating recruitment into >2.5 years old age classes. Although frequently used to increase population age structure, our modeling indicated that selective harvest criteria can decrease or eliminate the number of white-tailed deer recruited into older

  12. Age-specific nomograms for follicle stimulating hormone and anti-Mullerian hormone: A pilot study in Ile-Ife, Nigeria

    PubMed Central

    Okunola, Omoladun Temitope; Ajenifuja, Olusegun Kayode; Loto, Morebise Olabisi; Salawu, Afolabi; Omitinde, Oluseyi Stephen; Akande, Joel; Oke, Elizabeth

    2016-01-01

    Background: Assessment of ovarian reserve is one of the steps in the management of infertile couples. Follicle Stimulating hormone (FSH) and anti-Müllerian hormone (AMH) are commonly used ovarian reserve markers in Africa. However, there is paucity of age-specific reference values for FSH and AMH among the African population. Objective: This study aimed at conducting a pilot study for generation of age-specific nomograms for FSH and AMH among fertile women in Ile-Ife, Nigeria. Materials and Methods: A pilot cross-sectional study that involved 65 fertile women within the age range of 18-45 yr were prospectively and consecutively recruited from November 2014 to January 2015. Peripheral blood samples were taken for basal serum FSH and random serum AMH. The samples were processed using enzyme linked immunosorbent (ELISA) assays. Results: Age-specific FSH nomogram showed a gradual increase which became steeper at age 35 yr with an average yearly increase of 0.2 IU/L in basal serum FSH, while age-specific AMH nomogram showed a peak at 25 yr and then; an average yearly decrease of 0.11 ng/ml in random serum AMH from 25 yr. Conclusion: The age-specific nomograms generated by this pilot study suggest that AMH may be an earlier marker of reduced ovarian reserve; which if validated by future multicenter population based studies may facilitate counseling of women on their reproductive potentials. PMID:28066837

  13. 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.

  14. Modeling age-specific cancer incidences using logistic growth equations: implications for data collection.

    PubMed

    Shen, Xing-Rong; Feng, Rui; Chai, Jing; Cheng, Jing; Wang, De-Bin

    2014-01-01

    Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical modeling of cancer incidence and mortality rates. Most contemporary models in this regard use time series and APC (age-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research models age-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and modeled the age-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of modeling, namely full age-span by fitting, multiple 5-year- segment fitting and single-segment fitting. Measurement of model performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both model simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For models built upon full age-span data, predicted age-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth model derived using observed data from urban residents was greater than or at least equal to that of the same model built on data from rural people. For models based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For models using a fixed length single-segment of observed data, the older the age covered by the corresponding

  15. Effects of ovulation rate and fetal number on fertility in twin-producing cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of ovulation rate and of fetal number and distribution within the uterus on pregnancy rate and fetal survival were evaluated in nulliparous (n = 1,331) and parous (n = 3,517) cattle selected for twinning. Cattle were divided into a spring (70 d) and fall (60 d) breeding season and bred by a ...

  16. Age-specific response of a migratory bird to an experimental alteration of its habitat.

    PubMed

    Haché, Samuel; Villard, Marc-André

    2010-07-01

    1. Recruitment, i.e. the influx of new breeding individuals into a population, is an important demographic parameter, especially in species with a short life span. Few studies have measured this parameter in solitary-breeding animal populations even though it may yield critical information on habitat suitability and functional connectivity. 2. Using a before-after, control-impact pairs (BACIP) experimental design, we measured: (i) the return rate and apparent survival rate of individually marked territorial males of a neotropical migrant bird species, the Ovenbird Seiurus aurocapilla Linnaeus and (ii) the age-specific recruitment rate. Study plots (n = 10) were paired: one was treated through single-tree selection harvesting (30-40% basal area removal) and the other acted as a control. We hypothesized that experienced males would out-compete inexperienced ones and tend to avoid settling in lower-quality, treated stands. 3. In the first year post-harvest, the mean density of territorial males was significantly lower in treated plots (-41%) than in controls and the difference remained relatively stable thereafter. This lower density mainly reflected a lower recruitment rate compared to controls (17.9 vs. 49.0% of males present), itself driven by a lower recruitment rate of experienced males (2.8 vs. 22.8%). Return rate was similar between controls and treated plots in the first year post-harvest (59 vs. 55%, respectively) but it decreased in treated plots during the second (-15.8% relative to controls) and third (-12.7%) year post-harvest. The trend was even stronger when considering only experienced males. The treatment was followed by a major expansion in mean territory size in treated plots (+49% relative to controls, 3rd year post-treatment). 4. Neither apparent survival rate nor recruitment rate varied as predicted. There was a strong year effect but no treatment effect on apparent survival rate, whereas male recruitment patterns were both year- and age-specific

  17. Fertility after young onset colorectal cancer: a study of subjects with Lynch syndrome

    PubMed Central

    Stupart, Douglas; Win, Aung Ko; Jenkins, Mark; Winship, Ingrid M.

    2016-01-01

    Aim Infertility is a concern for young colorectal cancer (CRC) survivors, but this risk is not well quantified. Mismatch repair (MMR) mutation carriers are a useful cohort for studying fertility after CRC as they commonly develop CRC when young, and unaffected family members provide demographically similar controls. The aim of this study was to determine the effect of CRC on fertility in a large cohort of MMR mutation carriers. Method MMR mutation carriers identified from the Australasian Colorectal Cancer Family Registry were included. For each year of life within the fertile age range (15 to 49), the number of living individuals and the number of children born to them were determined. Individuals were grouped by whether or not they had had a diagnosis of CRC by that age. Age-specific and total fertility rates were calculated. Results 1068 subjects (611 women and 457 men) were identified, of whom 467 were diagnosed with CRC. There were 1,192 births during 18674 person- years of follow up of the women and 814 births during 14013 person- years of follow up to the men. The total fertility rate was decreased in women after a diagnosis of CRC compared who did not have CRC (1.3 vs. 2.2 P=0.0011), but age- specific fertility was only reduced in the 20–24 year age group. In men TFR was similar for both groups (2.0 vs. 1.8) P = 0.27). Conclusion Age- specific fertility was decreased in female CRC survivors with Lynch syndrome aged 20–24, but not in older women or in men. PMID:25754680

  18. The effect of serum and follicular fluid anti-Mullerian hormone level on the number of oocytes retrieved and rate of fertilization and clinical pregnancy

    PubMed Central

    Bolat, Seda Eymen; Ozdemirci, Safak; Kasapoglu, Taner; Duran, Bulent; Goktas, Levent; Karahanoglu, Ertugrul

    2016-01-01

    OBJECTIVE: The objective of this study was to evaluate the relationship between oocyte yield, fertilization, and clinical pregnancy (CP), and anti-Mullerian hormone (AMH) level in serum and follicular fluid during in vitro fertilization treatment. METHODS: Forty-four infertile women who underwent IVF treatment using multiagonist protocol were included in this study. Baseline level of AMH in serum and follicular fluid was measured on third day of menstrual cycle. AMH level in serum and follicular fluid was then measured again on day of oocyte pick-up. Pearson correlation and binary regression tests were used for statistical analysis. For Type 1 error, p=5% was selected as cut-off value for statistical significance. RESULTS: Serum AMH level was positively correlated with total number of oocytes retrieved and rate of fertilization and CP (r=0.397, p=0.008; r=0.401, p=0.007; and r=0.382, p=0.011, respectively). There was significantly negative correlation between serum level of follicle-stimulating hormone (FSH) and fertilization rate (r=-0.320; p=0.034), as well as serum FSH level and CP rate (r=-0.308; p=0.042). There were no significant correlations between AMH level in follicular fluid and IVF treatment outcomes. CONCLUSION: Serum AMH levels may be more reliable for prediction of total number of oocytes retrieved and rate of fertilization and CP than AMH levels in follicular fluid. PMID:28058394

  19. Can the anaerobic potentially mineralizable nitrogen test improve predictions of fertilizer nitrogen rates in the Cornbelt?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Correctly estimating the amount of mineralizable nitrogen (N) can enhance nitrogen use efficiency. The anaerobic potentially mineralizable nitrogen (PMNAn) test is a tool that may help improve predictions of N uptake, grain yield, and the economical optimum nitrogen rate (EONR) of corn (Zea mays L...

  20. Fertilizer summary data 1990

    SciTech Connect

    Berry, J.T.; Hargett, N.L.

    1991-05-01

    Fertilizer Summary Data, published biennially by the National Fertilizer and Environmental Research Center (NFERC), combines fertilizer application and consumption statistics, crop acreage, and farm income/expense data by state and region for the period 1970 through 1990. This sixteenth edition contains statistics on commercial fertilizers sold for farm and nonfarm use, fertilizer distribution by class, and the leading fertilizer grades. Fertilizers are classified as single- or multiple-nutrient materials. Single-nutrient fertilizers, such as anhydrous ammonia (82-0-0), contain only one primary plant nutrient. Multiple-nutrient fertilizers contain two or more plant nutrients and include the ammonium phosphates and grades manufactured by dry or fluid mixing or chemical processing. In some cases, States report materials used in blending multiple-nutrient fertilizers as single-nutrient ingredients lather than the final manufactured product. Fertilizer consumption statistics for 1970 through 1980 are from US Department of Agriculture annual reports. Annual consumption data for 1985 through 1990 are based on the tabulation of individual state fertilizer tonnage reports submitted annually to TVA for inclusion in the National record of fertilizer consumption, Commercial Fertilizers. Crop statistics, fertilizer application rates, and farm income and expense data are supplied by the National Agricultural Statistics Service and the Economic Research Service, USDA.

  1. Fertility Rates in Young Korean Breast Cancer Patients Treated with Gonadotropin-Releasing Hormone and Chemotherapy

    PubMed Central

    Kim, Isaac; Ryu, Jai Min; Paik, Hyun-June; Park, Sungmin; Bae, Soo Youn; Lee, Se Kyung; Yu, Jonghan; Kim, Seok Won; Nam, Seok Jin

    2017-01-01

    Purpose Gonadotropin-releasing hormone (GnRH) agonists have been used with adjuvant chemotherapy to protect ovarian function. However, there are no data on the actual pregnancy rates among young breast cancer patients receiving GnRH agonists and concurrent chemotherapy in Korea. Methods Among patients who underwent surgery from January 2002 to April 2012, premenopausal patients aged between 20 and 40 years were included in the analysis. We retrospectively reviewed clinicopathologic features (e.g., age, obstetric and menstruation history), recurrence, and survival status. The rate of resumption of menstruation was calculated in all patients. In the married group, pregnancy and delivery rates were also recorded. Results Among 101 patients, 19 were lost to follow-up and 82 were eligible for the analysis. Among them, 31 were married, 10 of 51 got married, and 41 remained unmarried through the follow-up period. Among the married patients, 15 became pregnant and gave birth to 19 babies, whereas 26 did not become pregnant. The pregnancy rate in the married group was 50.0% (15/30). Three of 15 pregnancies (20.0%) were multiparous. Most of the delivered babies were healthy and 80.0% of patients had no problems breastfeeding (12/15). More than half the patients in all groups recovered menstrual status within 12 months. Conclusion Fifty percent of young breast cancer patients who attempted pregnancy succeeded in pregnancy after adjuvant chemotherapy and GnRH agonists. Further studies that include control groups are required to confirm whether the use of GnRH agonists improves pregnancy. PMID:28382099

  2. Effect of nitrogen fertilization rate and regrowth interval of grass herbage on methane emission of zero-grazing lactating dairy cows.

    PubMed

    Warner, D; Podesta, S C; Hatew, B; Klop, G; van Laar, H; Bannink, A; Dijkstra, J

    2015-05-01

    Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (predominantly ryegrass) on CH4 emission from lactating dairy cows. In a randomized block design, 28 lactating Holstein-Friesian dairy cows received a basal diet of GH and compound feed [85:15; dry matter (DM) basis]. Treatments consisted of GH cut after 3 or 5 weeks of regrowth, after receiving either a low (20kg of N/ha) or a high (90kg of N/ha) fertilization rate after initial cut. Feed intake, digestibility, milk production and composition, N and energy balance, and CH4 emission were measured during a 5-d period in climate respiration chambers after an adaptation to the diet for 12d. Cows were restricted-fed during measurements and mean DM intake was 15.0±0.16kg/d. Herbage crude protein content varied between 76 and 161g/kg of DM, and sugar content between 186 and 303g/kg of DM. Fat- and protein-corrected milk (FPCM) and feed digestibility increased with increased N fertilization rates and a shorter regrowth interval. Increasing the N fertilization rate increased daily CH4 emission per cow (+10%) and per unit of DM intake (+9%), tended to increase the fraction of gross energy intake emitted as CH4 (+7%), and (partly because of the low crude protein content for the low fertilized GH) only numerically reduced CH4 per unit of FPCM. The longer regrowth interval increased CH4 emission per unit of FPCM (+14%) compared with the shorter regrowth interval, but did not affect CH4 emission expressed in any other unit. With increasing N fertilization CH4 emission decreased per unit of digestible neutral detergent fiber intake (-13%) but not per unit of digestible organic matter intake. There was no interaction of the effect of N fertilization rate and regrowth interval on CH4

  3. Pupillary Response as an Age-Specific Measure of Sexual Interest.

    PubMed

    Attard-Johnson, Janice; Bindemann, Markus; Ó Ciardha, Caoilte

    2016-05-01

    In the visual processing of sexual content, pupil dilation is an indicator of arousal that has been linked to observers' sexual orientation. This study investigated whether this measure can be extended to determine age-specific sexual interest. In two experiments, the pupillary responses of heterosexual adults to images of males and females of different ages were related to self-reported sexual interest, sexual appeal to the stimuli, and a child molestation proclivity scale. In both experiments, the pupils of male observers dilated to photographs of women but not men, children, or neutral stimuli. These pupillary responses corresponded with observer's self-reported sexual interests and their sexual appeal ratings of the stimuli. Female observers showed pupil dilation to photographs of men and women but not children. In women, pupillary responses also correlated poorly with sexual appeal ratings of the stimuli. These experiments provide initial evidence that eye-tracking could be used as a measure of sex-specific interest in male observers, and as an age-specific index in male and female observers.

  4. Growth hormone treatment of breeding bulls used for artificial insemination improves fertilization rates.

    PubMed

    Sauerwein, H; Breier, B H; Gallaher, B W; Götz, C; Küfner, G; Montag, T; Vickers, M; Schallenberger, E

    2000-01-01

    To evaluate new therapeutical concepts for male subfertility, we tested the effects of exogenous recombinant bovine growth hormone (rbGH) on various endocrine and metabolic parameters both in blood and in seminal plasma of bulls. Sperm quality was assessed morphometrically and by monitoring the number of successful artificial inseminations (AIs) defined as non-return rates (NRR). Aliquots of 450 semen samples were used from each bull and each experimental period (4 wk before, 14 weeks during and 6 wk after treatment). Six out of ten sires (average age 8.4 years) were treated every two weeks with 640-mg depot formulated rbGH (Eli Lilly). Four bulls received vehicle only. Blood plasma bGH, IGF-I, insulin and glucose concentrations were increased with rbGH treatment. In seminal plasma there was no effect of rbGH treatment on fructose and citrate or on testosterone concentrations. With one exception, rbGH-treated bulls had greater IGFBP-3 concentrations in seminal plasma. Motility of spermatozoa after freezing and thawing was increased compared with pretreatment rates. Most interestingly, the number of successful AIs was increased by an average of 6.0% NRR when ejaculates from rbGH-treated bulls were used.

  5. Fertility decline and differences in less-developed countries: an anthropological microstudy of some communities of West Bengal, India and Upper Khumbu, Nepal.

    PubMed

    Basu, A; Bharati, P; Mukhopadhyay, B; Gupta, R

    1981-01-01

    The role of socioeconomic and other cultural factors as determinants of fertility change has been widely discussed, with some scholars emphasising an inverse relation between socioeconomic development and fertility, others suggesting that no such relation necessarily exists, and yet others indicating that by using data from various sources it is possible to "prove" that a given country's crude birth rate has declined, remained unchanged or increased. Demographic data are presented on age-sex structure, completed and total fertility rates, and age specific fertility rates by age cohorts of women, from several small, anthropological population units of West Bengal, India and Upper Khumbu, Nepal, exposed to various physical and cultural environmental stresses. The data show that fertility has declined in most of the populations/subpopulations studied and that the decline may, deductively, be attributed to economic development via greater family planning practices.

  6. 47,XXY Klinefelter syndrome: clinical characteristics and age-specific recommendations for medical management.

    PubMed

    Aksglaede, Lise; Link, Katarina; Giwercman, Aleksander; Jørgensen, Niels; Skakkebaek, Niels E; Juul, Anders

    2013-02-15

    47,XXY (Klinefelter syndrome) is the most frequent sex chromosomal disorder and affects approximately one in 660 newborn boys. The syndrome is characterized by varying degrees of cognitive, social, behavioral, and learning difficulties and in adulthood additionally primary testicular failure with small testes, hypergonadotropic hypogonadism, tall stature, and eunuchoid body proportions. The phenotype is variable ranging from "near-normal" to a significantly affected individual. In addition, newborns with Klinefelter syndrome generally present with a normal male phenotype and the only consistent clinical finding in KS is small testes, that are most often not identified until after puberty. Decreased awareness of this syndrome among health professionals and a general perception that all patients with 47,XXY exhibit the classic textbook phenotype results in a highly under-diagnosed condition with up to 75% of the patients left undetected. Typically, diagnosis is delayed with the majority of patients identified during fertility workup in adulthood, and only 10% of patients diagnosed prior to puberty. Early detection of this syndrome is recommended in order to offer treatment and intervention at the appropriate ages and stages of development for the purpose of preventing osteopenia/osteoporosis, metabolic syndrome, and other medical conditions related to hypogonadism and to the XXY as well as minimizing potential learning and psychosocial problems. The aim of this review is to present the clinical aspects of XXY and the age-specific recommendations for medical management. © 2013 Wiley Periodicals, Inc.

  7. Pregnancy rates with recombinant versus urinary human chorionic gonadotropin in in vitro fertilization: an observational study.

    PubMed

    Zeke, József; Kanyó, Katalin; Zeke, Helga; Cseh, Aron; Vásárhelyi, Barna; Szilágyi, András; Konc, János

    2011-01-01

    Randomized clinical trials (RCTs) demonstrated the equal efficacy of urinary human chorionic gonadotropin (uhCG) and recombinant hCG (rhCG) products in in vitro fertilisation (IVF). However, limitations inherent with RCTs necessitate the reinforcement of RCT results in real-life. We retrospectively analyzed pregnancies after treatment with rhCG and uhCG products (n = 391, and 96, resp.). We found that laboratory-verified pregnancy occurred more frequently in rhCG patients than in those on uhCG (43% versus 30%, P = 0.02). The association remains significant (P = 0.002) after its adjustment for clinical characteristics. The prevalence of laboratory-verified pregnancies was higher with GnRH agonist use (P = 0.012) and BMI under 30 kg/m(2) (P = 0.053) while decreased the age (P = 0.014) and the number of previous failed attempts (P = 0.08). Similar (but not significant) trends were observed with rates of pregnancy filled the 24th week. These results reinforce RCTs supporting the notion that rhCG is more efficient as uhCG during IVF.

  8. [Nitrogen uptake rate and use efficiency by rice under different levels of the controlled-release N fertilizers (CRF) in the Nansi Lake basin].

    PubMed

    Zhang, Qing-Wen; Du, Chun-Xiang; Li, Xiao-Wei; Li, Gui-Chun; Wang, Ming

    2011-07-01

    The nitrogen (N) fertilizers overused or misused are the main contributors for water eutrophication of the Nansi Lake in eastern China. A field experiment with different application levels of controlled-release N fertilizer (CRF) was carried out at a rice field in the Nansi lake basin to provide information on the nitrogen uptake rate and use efficiency by rice with CRF application at different growth stages of rice. The fertilization levels for the controlled fertilizer in this study were 0, 300, 337.5 and 375 kg/hm2, respectively, and 375 kg/hm2 for conventional urea (CU). We estimated the N uptake rate in different growing season and apparent recovery of fertilizer in root, stover and grain of rice. The result showed that grain yield increased by higher N rate. However, the N uptake rate did not increase linearly with the nitrogen application amount. The highest N uptake rate was 22.48 mg/(plant x d) under the fertilization amount of 337.5 kg/hm2 during the young panicle differentiation stage. Apparent N recovery efficiency for CU with traditional application amount of 375 kg/hm2 was 21.86%. Apparent N recovery efficiency for CRF with application amount of 337.5 kg/hm2 was highest with 37.17%. Based on the statistical data, with CU of traditional urea application amount of 375 kg/hm2, nitrogen loss and soil N residue at one growing season are 130.07 x 10(3) t for Jining city and 11.4 x 10(3) t for Yutai county of the Nansi Lake basin. If using CRF with the optimized application amount of 337.5 kg/hm2, nitrogen loss and soil residual at one growing season is 10.46 x 10(4) t for Jining city. It could reduce losses of 2.55 x 10(4) t N for Jining city and 2 235.26 t N for Yutai county per year. Because of releasing patterns more closely matched to crop N uptake patterns, controlled release N fertilizer could be a good way to prevent water eutrophication due to nitrogen fertilizer overused or misused in the Nansi Lake.

  9. WholeTree Substrate and Fertilizer Rate in Production of Greenhouse Grown Petunia (Petunia*hybrida Vilm) and marigold (Tagetes patula L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A substrate component (WholeTree) made from loblolly pine (Pinus taeda L.) was evaluated along with starter fertilizer rate in the production of greenhouse-grown petunia (Petunia 'hybrida Vilm. ‘Dreams Purple’) and marigold (Tagetes patula L. ‘Hero Spry’). Loblolly pine from a 12 year old plantation...

  10. Effects of irrigation frequency and nitrogen fertilizer rate on water stress, nitrogen uptake, and plant growth of container-grown Rhododendron

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of irrigation frequency (same amount of water per day given at different times) and nitrogen (N) fertilizer rate on water stress (stomatal conductance, gs), N uptake, and growth (biomass) of container-grown evergreen Rhododendron ‘P.J.M. Compact’ and ‘English Roseum’ and deciduous Rhod...

  11. Prospective Randomized Study on the Influence of Myoinositol in PCOS Women Undergoing IVF in the Improvement of Oocyte Quality, Fertilization Rate, and Embryo Quality

    PubMed Central

    Lesoine, Bernd

    2016-01-01

    Polycystic ovarian syndrome (PCOS) is one of the pathological factors involved in the failure of in vitro fertilization (IvF). The aim of the present study was to investigate if the combination of myoinositol + folic acid was able to improve the oocyte quality, the ratio between follicles and retrieved oocytes, the fertilization rate, and the embryo quality in PCOS patients undergoing IvF treatments. 29 patients with PCOS underwent IvF protocols for infertility treatment and were randomized prospectively into two groups. Group A (placebo) with 15 patients and group B (4000 mg myoinositol + 400 μg folic acid per day) with 14 patients. The patients of group B used for two months myoinositol + folic acid before starting the IvF protocol and data were obtained concerning number of follicles, number of oocytes, quality of oocytes, fertilization rates, and embryo quality in both groups. The ratio follicle/retrieved oocyte was better in the myoinositol group (= group B). Out of the 233 oocytes collected in the myoinositol group 136 were fertilized, whereas only 128 out of 300 oocytes in the placebo group were fertilized. More metaphase II and I oocytes were retrieved in relation to the total amount of oocytes in the myoinositol. More embryos of grade I quality were obtained in the myoinositol. The duration of stimulation was 9,7 days (±3,3) in the myoinositol group and 11,2 (±1,8) days in the placebo group and the number of used FSH units was lower in the myoinositol group: 1750 FSH units (mean) versus 1850 units (mean). Our evidence suggests that myoinositol therapy in women with PCOS results in better fertilization rates and a clear trend to a better embryo quality. As the number of retrieved oocytes was smaller in the myoinositol group, the risk of hyper stimulation syndrome can be reduced in these patients. PMID:27635136

  12. Increased site fertility and litter decomposition rate in high-pollution sites in the San Bernardino Mountains

    SciTech Connect

    Fenn, M. )

    1991-09-01

    Some possible factors causing enhanced litter decomposition in high-pollution sites in the San Bernardino Mountains of southern California were investigated. Nitrogen concentration of soil, as well as foliage and litter of ponderosa pine (Pinus ponderosa Laws.) and Jeffrey pine (Pinus jeffreyi Grev, and Balf.) were greater in high-pollution plots than in moderate- or low-pollution plots. Nitrogen concentration of soil, foliage, and litter of ponderosa pine (ozone-sensitive), and of the ozone-tolerant species, sugar pine (Pinus lambertiana Dougl.) and incense cedar (Calocedrus decurrens (Torr.) Florin.), were all higher at a higher pollution site than at a moderate-pollution site. The rate of litter decomposition for all three species was also greater at the high-pollution site. Results suggest than the primary factor causing enhanced decomposition of L-layer litter in high-pollution plots is greater site fertility, leading to the production of foliage and litter that is higher in N than litter from moderate- or low-pollution plots.

  13. Runoff, nitrogen (N) and phosphorus (P) losses from purple slope cropland soil under rating fertilization in Three Gorges Region.

    PubMed

    Bouraima, Abdel-Kabirou; He, Binghui; Tian, Taiqiang

    2016-03-01

    Soil erosion along with soil particles and nutrients losses is detrimental to crop production. We carried out a 5-year (2010 to 2014) study to characterize the soil erosion and nitrogen and phosphorus losses caused by rainfall under different fertilizer application levels in order to provide a theoretical evidence for the agricultural production and coordinate land management to improve ecological environment. The experiment took place under rotation cropping, winter wheat-summer maize, on a 15° slope purple soil in Chongqing (China) within the Three Gorges Region (TGR). Four treatments, control (CK) without fertilizer, combined manure with chemical fertilizer (T1), chemical fertilization (T2), and chemical fertilizer with increasing fertilization (T3), were designed on experimental runoff plots for a long-term observation aiming to study their effects on soil erosion and nutrients losses. The results showed that fertilization reduced surface runoff and nutrient losses as compared to CK. T1, T2, and T3, compared to CK, reduced runoff volume by 35.7, 29.6, and 16.8 %, respectively and sediment yield by 40.5, 20.9, and 49.6 %, respectively. Regression analysis results indicated that there were significant relationships between soil loss and runoff volume in all treatments. The combined manure with chemical fertilizer (T1) treatment highly reduced total nitrogen and total phosphorus losses by 41.2 and 33.33 %, respectively as compared with CK. Through this 5-year experiment, we can conclude that, on the sloping purple soil, the combined application of manure with fertilizer is beneficial for controlling runoff sediments losses and preventing soil erosion.

  14. Transcriptome analysis of bull semen with extreme nonreturn rate: use of suppression-subtractive hybridization to identify functional markers for fertility.

    PubMed

    Lalancette, C; Thibault, C; Bachand, I; Caron, N; Bissonnette, N

    2008-04-01

    Spermatozoa are terminally differentiated cells produced during the complex process of spermatogenesis. Although the role of their residual RNA content is still being debated, this transcriptome may represent a fingerprint of spermatogenesis quality. In the present study, we undertook differential transcript profiling of spermatozoa from fertile bulls with extreme nonreturn rates (NRRs): a low-fertile group, and a high-fertile group. Using the suppression-subtractive hybridization technique in combination with macroarray analysis, we also identified novel genes. Both extreme NRR index groups retained redundant identity, such as ribosomal and mitochondrial sequences, at a statistically significant level. An elevated number of 12S, 18S, and Large Chain R rRNA gene copies were found in low-fertile bulls and validated in spermatozoa by quantitative RT-PCR for a small cohort of bulls with known fertility index. Whereas the high-NRR library exhibited a large proportion (29%) of transcripts associated with known functions (e.g., metabolism, signal transduction, translation, glycosylation, and protein degradation), only 10% of the low-NRR sequences did. This difference is also conveyed by two other categories: 17% Bovine Genome and 48% unknown in the high-NRR library, compared with 3% and 80%, respectively, in the low-NRR library. Some of the unknown transcripts are similar to expressed sequence tags detected in the male reproductive organ of certain plants and retain homology to a putative human protein. Whereas the individual transcriptome profiles may be useful in fertility assessment, these findings also suggest cross-species conservation, could contribute to a better understanding of spermatogenesis, and provide new insights regarding idiopathic infertility.

  15. Influence of biochar, mycorrhizal inoculation, and fertilizer rate on growth and flowering of Pelargonium (Pelargonium zonale L.) plants

    PubMed Central

    Conversa, Giulia; Bonasia, Anna; Lazzizera, Corrado; Elia, Antonio

    2015-01-01

    Peat is the most common substrate used in nurseries despite being a very expensive and a non-renewable material. Peat replacement with biochar could be a sound environmental practice, as it is produced from waste biomass, but evaluation of biochar as a potting substrate is needed. Ratios of peat:biochar of 100:0, 70:30, 30:70 (BC0, BC30, and BC70, respectively), two fertilizer rates (FERT1, FERT2), and arbuscular mycorrhizal fungi (AMF) inoculation were tested on potted Pelargonium plants. Plant growth, flowering, bio-physiological and nutritional responses, and root mycorrhization were evaluated. The BC30 mixture did not affect plant growth compared with pure peat. However, BC30 in combination with FERT2 treatment was more effective in enhancing nitrogen (N) and chlorophyll (CHL) leaf concentrations, and leaf and flower numbers. The BC70 mixture depressed plant growth, flowering traits, and root mycorrhization. Leaf N concentration was below the sufficiency range reported for Pelargonium growth. Leaf concentration of phosphorous (P) was adequate in pure peat and in BC30 but it dropped close to sub-optimal values in BC70. The pH value of the mixtures lowered P availability, though in BC30 the mycorrhizal activity could have allowed adequate P plant uptake. In BC70 plants, the deficiency of both N and P might be a reason for the observed growth reduction. The inoculation of the substrate with selected AMF improved plant growth (higher dry biomass, greater floral clusters, larger and more abundant leaves) and quality resulting in unstressed (lower electrolyte leakage and higher relative water content values) and greener leaves (low L∗ and C∗, high CHL content) and in more intensely colored flowers. We conclude that biochar can be applied in nursery/potted plant production provided that the proportion in the peat mixture does not exceed 30%. Furthermore, AMF inoculation contributed to achieving the best plant performance in 30% biochar amended medium. PMID

  16. Decrease in fertilization and cleavage rates, but not in clinical outcomes for infertile men with AZF microdeletion of the Y chromosome.

    PubMed

    Zhu, Yuan-Chang; Wu, Tong-Hua; Li, Guan-Gui; Yin, Biao; Liu, Hong-Jie; Song, Cheng; Mo, Mei-Lan; Zeng, Yong

    2015-10-01

    This study aimed to explore whether the presence of a Y chromosome azoospermia factor (AZF) microdeletion confers any adverse effect on embryonic development and clinical outcomes after intracytoplasmic sperm injection (ICSI) treatment. Fifty-seven patients with AZF microdeletion were included in the present study and 114 oligozoospermia and azoospermia patients without AZF microdeletion were recruited as controls. Both AZF and control groups were further divided into subgroups based upon the methods of semen collection: the AZF-testicular sperm extraction subgroup (AZF-TESE, n = 14), the AZF-ejaculation subgroup (AZF-EJA, n = 43), the control-TESE subgroup (n = 28) and the control-EJA subgroup (n = 86). Clinical data were analyzed in the two groups and four subgroups respectively. A retrospective case-control study was performed. A significantly lower fertilization rate (69.27 versus 75.70%, P = 0.000) and cleavage rate (89.55 versus 94.39%, P = 0.000) was found in AZF group compared with the control group. Furthermore, in AZF-TESE subgroup, the fertilization rate (67.54 versus 74.25%, P = 0.037) and cleavage rate (88.96 versus 94.79%, P = 0.022) were significantly lower than in the control-TESE subgroup; similarly, the fertilization rate (69.85 versus 75.85%, P = 0.004) and cleavage rate (89.36 versus 94.26%, P = 0.002) in AZF-EJA subgroup were significantly lower than in the control-EJA subgroup; however, the fertilization rate and cleavage rate in AZF-TESE (control-TESE) subgroup was similar to that in the AZF-EJA (control-EJA) subgroup. The other clinical outcomes were comparable between four subgroups (P > 0.05). Therefore, sperm from patients with AZF microdeletion, obtained either by ejaculation or TESE, may have lower fertilization and cleavage rates, but seem to have comparable clinical outcomes to those from patients without AZF microdeletion.

  17. [Fertility and contraception in the rural areas. Important changes in contraception].

    PubMed

    Zuniga Herrera, E

    1990-01-01

    National fertility surveys conducted in Mexico since 1969 indicate that fertility in rural areas (localities with under 2500 inhabitants) is declining. The total fertility rate of rural women in union aged 20-44 years declined from 8.2 in 1968 to 5.8 in 1985. The beginning of the steep decline in rural fertility apparently occurred between 1973-75, at a time when official family planing programs were just starting, especially those accessible to rural women. Knowledge of contraception spread rapidly between 1969-76. The number of women in union who had ever used contraception doubled between 1976-81 to 40.2%. Important rural health programs developed in the late 1970s may have influenced contraceptive usage. Fertility continued to decline between 1980-85. The proportion of women who had ever used contraception in 1985 increased by only 3.5% in comparison to the 1981 level, but by 1987 the use of traditional methods such as rhythm and withdrawal was almost nil, and the use of IUDs, injectables, and sterilization had expanded. The age specific fertility rates suggest that the fertility reduction between 1980 and 1985 resulted in large part from the behavior of women over 34.

  18. [Fertility decline in Spain].

    PubMed

    Arango, J

    1987-01-01

    The historical processes of secular fertility decline in Spain and Portugal are not well understood. Very few microdemographic studies of small geographic regions or particular social strata have been done. A contribution by David Reher to the First Spanish-Portuguese-Italian Historical Demography Conference on the fertility decline in the interior province of Cuenca, Spain, uses the own-children method to analyze changes in marital fertility in the 19th and 20th centuries. Reher discovered a slight fertility decline of perhaps 15% which occurred between the end of the 18th century and 1860-75. The fertility decline did not resume until after the Spanish Civil War, and then it was a very gradual and continuous process. When instead of the total female population, women aged 35-39 were studied, unequivocal signs of fertility control appeared. Conscious fertility control thus appears to have begun among older women limiting rather than spacing births. Reher's analysis by social groups demonstrates that fertility declined first and more rapidly in the nonagricultural and urban populations and among the higher income groups. The fertility decline in Cuenca was certainly not identical to that in most of Spain, but may have been fairly typical of a large part of the interior. Another contribution to the Historical Demography Conference, by Anna Cabre and Isabel Pujadas, analyzes fertility trends and cyclical fluctuations in 20th century Cataluna, arguing that they must be placed in historical perspective if recent changes are to be understood and plausible projections made. Their work demonstrates the value of selecting a relatively homogeneous geographic unit for analysis. The contribution of Margarita Delgado to the conference analyzed interregional fertility differences in contemporary Spain. The high legitimate fertility of the south of Spain is accentuated by high nuptiality rates. In central Spain, the combination of high legitimate fertility rates and low

  19. Fertility transition in the Islamic Republic of Iran: 1976-1996.

    PubMed

    Aghajanian, A; Mehryar, A H

    1999-03-01

    This article examines the fertility transition pattern and related demographic, social, economic, and political factors in the Islamic Republic of Iran over the period 1976-96. Data on fertility rates were obtained from the Survey of Population Growth of Iran (1976) and the post-census enumeration survey (1996). During the period 1976-86, the rate of population growth accelerated dramatically (3.4% annually). This increase, depending mainly on an increase in the crude birth rate, constituted a reversal of the trend during the previous 10-year interval. However, during the period 1986-96 the census revealed a sharp decline in the population growth rate and crude birth rate. This declining trend accelerated between 1991 and 1996. Demographic factors affecting fertility change were the increase in the average age of marriage, the decrease in the proportion of the population that was married, and the increase in age-specific fertility rates for women aged 25 years. There was a potential fertility decline among the rural population. An estimated 12 million women will be added to the 15-49 age group during the period 1996-2006. This demographic fact alone is justification for the government to continue providing strong support for family planning services and to expand the budget for improving family planning services and reducing the contraceptive failure rate.

  20. Do age-specific survival patterns of wild boar fit current evolutionary theories of senescence?

    PubMed

    Gamelon, Marlène; Focardi, Stefano; Gaillard, Jean-Michel; Gimenez, Olivier; Bonenfant, Christophe; Franzetti, Barbara; Choquet, Rémi; Ronchi, Francesca; Baubet, Eric; Lemaître, Jean-François

    2014-12-01

    Actuarial senescence is widespread in age-structured populations. In growing populations, the progressive decline of Hamiltonian forces of selection with age leads to decreasing survival. As actuarial senescence is overcompensated by a high fertility, actuarial senescence should be more intense in species with high reproductive effort, a theoretical prediction that has not been yet explicitly tested across species. Wild boar (Sus scrofa) females have an unusual life-history strategy among large mammals by associating both early and high reproductive effort with potentially long lifespan. Therefore, wild boar females should show stronger actuarial senescence than similar-sized related mammals. Moreover, being polygynous and much larger than females, males should display higher senescence rates than females. Using a long-term monitoring (18 years) of a wild boar population, we tested these predictions. We provided clear evidence of actuarial senescence in both sexes. Wild boar females had earlier but not stronger actuarial senescence than similar-sized ungulates. Both sexes displayed similar senescence rates. Our study indicates that the timing of senescence, not the rate, is associated with the magnitude of fertility in ungulates. This demonstrates the importance of including the timing of senescence in addition to its rate to understand variation in senescence patterns in wild populations.

  1. Evaluating the impacts of landscape positions and nitrogen fertilizer rates on dissolved organic carbon on switchgrass land seeded on marginally yielding cropland.

    PubMed

    Lai, Liming; Kumar, Sandeep; Mbonimpa, Eric G; Hong, Chang Oh; Owens, Vance N; Neupane, Ram P

    2016-04-15

    Dissolved organic carbon (DOC) through leaching into the soils is another mechanism of net C loss. It plays an important role in impacting the environment and impacted by soil and crop management practices. However, little is known about the impacts of landscape positions and nitrogen (N) fertilizer rates on DOC leaching in switchgrass (Panicum virgatum L.). This experimental design included three N fertilizer rates [0 (low); 56 (medium); 112 (high) kg N ha(-1)] and three landscape positions (shoulder, backslope and footslope). Daily average DOC contents at backslope were significantly lower than that at shoulder and footslope. The DOC contents from the plots that received medium N rate were also significantly lower than the plots that received low N rates. The interactions of landscape and N rates on DOC contents were different in every year from 2009 to 2014, however, no significant consistent trend of DOC contents was observed over time. Annual average DOC contents from the plots managed with low N rate were higher than those with high N rate. These contents at the footslope were higher than that at the shoulder position. Data show that there is a moderate positive relationship between the total average DOC contents and the total average switchgrass biomass yields. Overall, the DOC contents from leachate in the switchgrass land were significantly influenced by landscape positions and N rates. The N fertilization reduced DOC leaching contents in switchgrass field. The switchgrass could retain soil and environment sustainability to some extent. These findings will assist in understanding the mechanism of changes in DOC contents with various parameters in the natural environment and crop management systems. However, use of long-term data might help to better assess the effects of above factors on DOC leaching contents and loss in the switchgrass field in the future.

  2. Age-specific patterns of genetic variance in Drosophila melanogaster. I. Mortality

    SciTech Connect

    Promislow, D.E.L.; Tatar, M.; Curtsinger, J.W.

    1996-06-01

    Peter Medawar proposed that senescence arises from an age-related decline in the force of selection, which allows late-acting deleterious mutations to accumulate. Subsequent workers have suggested that mutation accumulation could produce an age-related increase in additive genetic variance (V{sub A}) for fitness traits, as recently found in Drosophila melanogaster. Here we report results from a genetic analysis of mortality in 65,134 D. melanogaster. Additive genetic variance for female mortality rates increases from 0.007 in the first week of life to 0.325 by the third week, and then declines to 0.002 by the seventh week. Males show a similar pattern, though total variance is lower than in females. In contrast to a predicted divergence in mortality curves, mortality curves of different genotypes are roughly parallel. Using a three-parameter model, we find significant V{sub A} for the slope and constant term of the curve describing age-specific mortality rates, and also for the rate at which mortality decelerates late in life. These results fail to support a prediction derived from Medawar`s {open_quotes}mutation accumulation{close_quotes} theory for the evolution of senescence. However, our results could be consistent with alternative interpretations of evolutionary models of aging. 65 refs., 2 figs., 2 tabs.

  3. Genotypic variation in spike fertility traits and ovary size as determinants of floret and grain survival rate in wheat

    PubMed Central

    Guo, Zifeng; Slafer, Gustavo A; Schnurbusch, Thorsten

    2016-01-01

    Spike fertility traits are critical attributes for grain yield in wheat (Triticum aestivum L.). Here, we examine the genotypic variation in three important traits: maximum number of floret primordia, number of fertile florets, and number of grains. We determine their relationship in determining spike fertility in 30 genotypes grown under two contrasting conditions: field and greenhouse. The maximum number of floret primordia per spikelet (MFS), fertile florets per spikelet (FFS), and number of grains per spikelet (GS) not only exhibited large genotypic variation in both growth conditions and across all spikelet positions studied, but also displayed moderate levels of heritability. FFS was closely associated with floret survival and only weakly related to MFS. We also found that the post-anthesis process of grain set/abortion was important in determining genotypic variation in GS; an increase in GS was mainly associated with improved grain survival. Ovary size at anthesis was associated with both floret survival (pre-anthesis) and grain survival (post-anthesis), and was thus believed to ‘connect’ the two traits. In this work, proximal florets (i.e. the first three florets from the base of a spikelet: F1, F2, and F3) produced fertile florets and set grains in most cases. The ovary size of more distal florets (F4 and beyond) seemed to act as a decisive factor for grain setting and effectively reflected pre-anthesis floret development. In both growth conditions, GS positively correlated with ovary size of florets in the distal position (F4), suggesting that assimilates allocated to distal florets may play a critical role in regulating grain set. PMID:27279276

  4. [Utilization rate of fertilizer N and dynamic changes of soil NO3(-)-N in summer maize field in semi-humid area of Northwest China].

    PubMed

    Fan, Ya-ning; Li, Shi-qing; Li, Sheng-xiu

    2008-04-01

    A field experiment on manual loessial soil was conducted to study the dynamic changes of NO3(-)-N in soil profile, utilization rate of fertilizer N, and relationships between N application rate and soil residual N accumulation during the growth period of summer maize under different N application rates (0, 45, 90, 135, and 180 kg hm(-2)). The results showed that in the whole growth period of summer maize, the NO3(-)-N concentration in the soil profile was the highest in 0-20 cm layer, and increased with increasing N application rate. The NO3(-)-N concentration in 0-60 cm soil layer changed significantly, but no significant change was observed in 60-100 cm soil layer. In the growth season of summer maize, soil NO3(-)-N accumulation presented a fluctuated decreasing trend due to the N uptake by crop and the precipitation. The N utilization rate (NUR) increased with increasing N application rate when the application rate was less than 135 kg hm(-2), but tended to decrease when the application rate exceeded 135 kg hm(-2). With the increase of N application rate, the N agronomy efficiency (NAE) decreased but the N physiology efficiency (NPE) increased. There was a significant positive correlation between soil residual N accumulation and N application rate (R2 = 0.957**, n = 5). The grain yield under N application was significantly higher than that without N application (P <0.05), and there existed a significant positive correlation between grain yield and N application rate (R2 = 0.934**, n = 5). In our experiment, the optimal application rate of fertilizer N was 135 kg hm(-2), which could harmonize the relationship between economic benefits and environment.

  5. Enhancing rock phosphate integration rate for fast bio-transformation of cow-dung waste-paper mixtures to organic fertilizer.

    PubMed

    Unuofin, F O; Siswana, M; Cishe, E N

    2016-01-01

    Rock phosphate (RP) addition in cow-dung waste-paper mixtures at rates above 2% P has been reported to increase the rate of bio-transformation and humification of organic waste mixtures during vermicomposting to produce organic fertilizer for organic farming. However, the optimization of RP for vermicomposting was not established. The objective of this study was to determine the optimal amount of RP integration rates for effective bio-transformation of cow-dung waste-paper mixtures. Arrays of RP integration degrees (0, 0.5, 1, 1.5, 2, and 4% P as RP) were thoroughly mixed with cow- dung waste-paper mixtures to achieve an optimized C:N ratio of 30 and allowed to vermidegrade following the introduction of earthworms at a stocking mass of 12.5 g-worms kg(-1). The bio-transformation of the waste mixtures was examined by measuring C:N ratios and humification index (HI) and per cent ash and volatile solids. Application of 1% P as RP resulted in fast bio-transformation and maturation of cow-dung waste-paper mixtures. A scanning electron microscopy (SEM) was used to evaluate the morphological properties of the different vermicomposts affected by rates of RP showing the degree of degradation of initial compacted aggregates of cellulose and protein fibres in the mixtures at maturity. A germination test was used to further determine phytotoxicity of the final composts and microbial biomass assessment. The final vermicompost (organic fertilizer) had a C:N ratio of 7, MBC of 900 mg kg(-1) and HI of 27.1%. The RP incorporation rate of 1% P of RP investigated is therefore, recommended for efficient vermidegradation and humification of cow-dung waste-paper mixtures. However, higher rates of RP incorporation should be considered where greater P enrichment of the final vermicompost (organic fertilizer) is desired.

  6. Decoupling of soil C and N mineralization by labile C inputs explain high C sequestration rates in response to N fertilization

    NASA Astrophysics Data System (ADS)

    Bengtson, Per; Ehtesham, Emad

    2015-04-01

    During the last decade there have been an ongoing controversy regarding the extent to which N fertilization can increase C sequestration in forest ecosystems by stimulating primary production. There is also evidence that N fertilization commonly results in reduced soil respiration rates that cannot be fully explained by lower root respiration. Several hypotheses aimed at explaining the phenomenon have been proposed, but the mechanism remains elusive. The aim of this study was to examine if decreased decomposition and respiration of soil organic matter (SOM) in response to N fertilization can be explained by diminishing priming effects, and to determine to which extent priming of SOM decomposition is manifested as C or N mineralization under different loadings of labile C and N. We also aimed at determining if any changes that occur in response to N fertilization are long-term effects dependent on a shift in e.g. microbial community composition, or an immediate effect caused by increased N availability and decreased N mining. To achieve these aims we designed an experiment where the potential priming of microbial C and N mineralization was studied in a Norway spruce forest. SOM derived respiration, gross N mineralization and 13C-incorporation into microbial biomarker lipids (PLFA's) were measured 4 and 24 hours after addition of 13C-enriched glucose. Field treatments included control, N fertilization, and two levels of tree density. We also included a treatment where the control soil received inorganic N, at the same level as in the field N fertilization treatment, in addition to glucose. Glucose additions in most cases caused a significant reduction in microbial respiration of SOM, resulting in what is commonly referred to as "negative priming". In contrast, gross N mineralization rates generally increased in response to the glucose additions. Glucose additions, therefore, appeared to result in a decoupling of microbial respiration of SOM and gross N mineralization

  7. Age-specific incidence of neutralization antibodies of Herpes simplex virus.

    PubMed Central

    Terzin, A. L.; Masic, M. G.

    1976-01-01

    Sera of 1255 individuals from Novi Sad, varying in age from less than 1 month to 69 years, have been tested for neutralization antibodies to Herpes implex virus type 1. The eight newborns tested and 97% of the 507 adults were positive, with titres ranging from 1/4 to 1/256. The titres in newborns were significantly lower than the titres in adults. After birth the maternal antibodies declined rapidly and 94% of infants at the age of greater than 6 months and less than 2 years were negative. After the first year infants in Novi Sad start to acquire herpes-neutralizing antibodies actively, reaching a 50% incidence of positives between the 2nd and 3rd year of age. Age-specific incidence rates of herpes positives found in Novi Sad have been compared with those reported from Edinburgh, Freiburg i. Br. and Louisiana. Possible influences of several circumstances upon the incidence rate of positives detected by the neutralization test are discussed. PMID:185287

  8. Effects of N loading rate on CH4 and N2O emissions during cultivation and fallow periods from forage rice fields fertilized with liquid cattle waste.

    PubMed

    Riya, S; Zhou, S; Kobara, Y; Sagehashi, M; Terada, A; Hosomi, M

    2015-09-15

    The use of liquid cattle waste (LCW) as a fertilizer for forage rice is important for material recycling because it can promote biomass production, and reduce the use of chemical fertilizer. Meanwhile, increase in emission of greenhouse gases (GHGs), especially CH4 and N2O would be concerned. We conducted a field study to determine the optimum loading rate of LCW as N to promote forage rice growth with lower GHG emissions. The LCW was applied to forage rice fields, N100, N250, N500, and N750, at four different N loading rates of 107, 258, 522, and 786 kg N ha(-1), respectively, including 50 kg N ha(-1) of basal chemical fertilizer. The above-ground biomass yields increased 14.6-18.5 t ha(-1) with increases in N loading rates. During the cultivation period, both the CH4 and N2O fluxes increased with increases in LCW loading rates. In the treatments of N100, N250, N500, and N750, the cumulative CH4 emissions during the entire period, including cultivation and fallow period were 29.6, 18.1, 54.4, and 67.5 kg C ha(-1), respectively, whereas those of N2O were -0.15, -0.02, 1.49, and 5.82 kg N ha(-1), respectively. Considering the greenhouse gas emissions and above-ground biomass, the yield-scaled CO2-equivalents (CO2-eqs) were 66.3, 35.9, 161, and 272 kg CO2 t(-1) for N100, N250, N500, and N750, respectively. These results suggest that N250 is the most appropriate LCW loading rate for promoting forage rice production with lower GHG emissions.

  9. A 3-year continuous record on the influence of daytime, season, and fertilizer treatment on methane emission rates from an Italian rice paddy

    SciTech Connect

    Schuetz, H.; Holzapfel-Pschorn, A.; Conrad, R.; Rennenberg, H.; Seiler, W. )

    1989-11-20

    CH{sub 4} emission rates have been measured in an Italian rice paddy between 1984 and 1986, covering three vegetation periods. For these measurements a fully automated, computerized sampling and analyzing system was developed which allowed the simultaneous determination of CH{sub 4} emission rates at 16 different field plots. CH{sub 4} emission rates showed strong diurnal and seasonal variations. Diurnal changes correlated with changes in soil temperature. During the season, CH{sub 4} emission rates showed a first maximum in May--June before tillering and a second maximum in July during the reproductive stage of the rice plants. In 1985 and 1986 two maxima were observed during summer in addition to the first maximum in the rate of CH{sub 4} emission during spring. Application of mineral and/or organic fertilizer application. Thus the rates decreased by at most 40% and 60% after fertilization by deep incorporation with 200 kg N/ha urea and 200 kg N/ha ammonium sulfate, respectively. Application of 200 kg N/ha calcium cyanamide led to a reduction of the first maximum of CH{sub 4} emission but caused the second maximum to increase, the overall result being that the seasonally averaged CH{sub 4} emission rate was comparable to that observed in unfertilized fields. Application of rice straw at a rate of 12t/ha enhanced the rate of CH{sub 4} emission by a factor of 2 compared with the control. Higher application rates of rice straw did not cause a further increase in CH{sub 4} emission.

  10. Decreased Sperm Motility Retarded ICSI Fertilization Rate in Severe Oligozoospermia but Good-Quality Embryo Transfer Had Achieved the Prospective Clinical Outcomes

    PubMed Central

    Zheng, Jufeng; Lu, Yongning; Qu, Xianqin; Wang, Peng; Zhao, Luiwen; Gao, Minzhi; Shi, Huijuan; Jin, Xingliang

    2016-01-01

    Introduction Spermatozoa motility is the critical parameter to affect the treatment outcomes during assisted reproductive technologies (ART), but its reproductive capability remains a little informed in condition of severe male factor infertility. This retrospective cohort study aimed to evaluate the effects of reduced sperm motility on the embryological and clinical outcomes in intra-cytoplasmic sperm injection (ICSI) treatment of severe oligozoospermia. Patients and Methods 966 cycles (812 couples) of severe oligozoospermia diagnosed by spermatozoa count ≤ 5 × 106/mL and motile spermatozoa ≤ 2 × 106/mL were divided into four groups in according to the number of motile spermatozoa in one ejaculate on the day of oocyte retrieval (Group B—E). The control (Group A) was 188 cycles of moderate oligozoospermia with spermatozoa count > 5 × 106/mL and motile spermatozoa > 2 × 106/mL. All female partners were younger than 35 years of age. Logistic regression analyzed embryological outcomes (the rates of fertilization, cleavage and good-quality embryo) and clinical outcomes (the rates of pregnancy, implantation, early miscarriage and live birth). Quality of embryo transfer (ET) was divided into three classes as continuous factor to test the effects of embryo quality on clinical outcomes. Results The reduction in the number of motile sperm in four groups of severe oligozoospermia gave rise to comparable inability of the fertilization (p < 0.001) and a decreased rate of good-quality embryo at Day 3 (p < 0.001) by compared to the control. The cleavage rate of the derived zygotes was similar to the control. ET classes significantly affected the clinical outcomes (p < 0.001). Class I ET gave rise to similar rates of clinical outcomes between five groups, but Class II and Class III ET retarded the rates of pregnancy, implantation and live birth and this particularly occurred in Group C, D and E. The rate of early miscarriage was not comparably different between groups

  11. Modeling the effects of different N fertilizer rates on N2O emissions and nitrate leaching from arable soils in Korea

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Berger, S.; Tenhunen, J. D.; Gebauer, G.; Kiese, R.

    2012-12-01

    Process-based biogeochemical models can be used to predict the impact of various agricultural management practices on plant nitrogen use efficiency and nitrogen losses to the environment such as greenhouse gas emissions and nitrate leaching by analyzing the interactions between management practices, primary drivers such as climate, soil properties, crop types, etc., and biogeochemical reactions. In this study we applied the Landscape-DNDC model, which combines and uniforms functions of the agricultural-DNDC and the Forest-DNDC for simulation of C and N turnover, GHG emissions, nitrate leaching, and plant growth for a Korean arable field cultivated with radish (Raphanus sativus L.). The annual average temperature is app. 8.5°C and the annual precipitation is app. 1,500 mm. According to farmers practice the study field received a basal fertilizer application of app. 200 kg N ha-1 before setting up four fertilizer treatments i.e. additionally 50, 150, 250 and 350 kg N ha-1. All N treatment plots were tilled a week after application of specific N fertilizer in order to make row and interrow. Just before radish seeding rows were covered with black plastic mulch which was removed after harvest. In spite the widespread usage of black mulch in Korea or even Asia; so far biogeochemical models do not consider impacts of mulch on soil environmental conditions and soil biogeochemistry. Based on field measurements we adjusted input information and used only half of the annual precipitation and the maximum temperature for simulation of row conditions, whereas the actual weather data were used for the interrow simulations. Simulated N2O emissions agreed well with measurements; however peak emissions after fertilization were slightly underestimated in row and interrow. Annual N2O emissions of the fertilizer treatments increased with increasing fertilization rates from around 1.5 to 3 kg N ha-1 in the row and lower emissions of app. 1.5 kg N ha-1 (for all N treatments) in the

  12. Depolarization of sperm membrane potential is a common feature of men with subfertility and is associated with low fertilization rate at IVF

    PubMed Central

    Brown, Sean G.; Publicover, Stephen J.; Mansell, Steven A.; Lishko, Polina V.; Williams, Hannah L.; Ramalingam, Mythili; Wilson, Stuart M.; Barratt, Christopher L.R.; Sutton, Keith A.; Da Silva, Sarah Martins

    2016-01-01

    STUDY QUESTION Are significant abnormalities in outward (K+) conductance and resting membrane potential (Vm) present in the spermatozoa of patients undertaking IVF and ICSI and if so, what is their functional effect on fertilization success? SUMMARY ANSWER Negligible outward conductance (≈5% of patients) or an enhanced inward conductance (≈4% of patients), both of which caused depolarization of Vm, were associated with a low rate of fertilization following IVF. WHAT IS KNOWN ALREADY Sperm-specific potassium channel knockout mice are infertile with defects in sperm function, suggesting that these channels are essential for fertility. These observations suggest that malfunction of K+ channels in human spermatozoa might contribute significantly to the occurrence of subfertility in men. However, remarkably little is known of the nature of K+ channels in human spermatozoa or the incidence and functional consequences of K+ channel defects. STUDY DESIGN, SIZE AND DURATION Spermatozoa were obtained from healthy volunteer research donors and subfertile IVF and ICSI patients attending a hospital assisted reproductive techniques clinic between May 2013 and December 2015. In total, 40 IVF patients, 41 ICSI patients and 26 normozoospermic donors took part in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS Samples were examined using electrophysiology (whole-cell patch clamping). Where abnormal electrophysiological characteristics were identified, spermatozoa were further examined for Ca2+ influx induced by progesterone and penetration into viscous media if sufficient sample was available. Full exome sequencing was performed to specifically evaluate potassium calcium-activated channel subfamily M α 1 (KCNMA1), potassium calcium-activated channel subfamily U member 1 (KCNU1) and leucine-rich repeat containing 52 (LRRC52) genes and others associated with K+ signalling. In IVF patients, comparison with fertilization rates was done to assess the functional significance of

  13. Age-specific patterns of genetic variance in Drosophila melanogaster. II. Fecundity and its genetic covariance with age-specific mortality

    SciTech Connect

    Tatar, M.; Promislow, D.E.L.; Khazaeli, A.A.; Curtsinger, J.W.

    1996-06-01

    Under the mutation accumulation model of senescence, it was predicted that the additive genetic variance (V{sub A}) for fitness traits will increase with age. We measured age-specific mortality and fecundity from 65,134 Drosophila melanogaster and estimated genetic variance components, based on reciprocal crosses of extracted second chromosome lines. Elsewhere we report the results for mortality. Here, for fecundity, we report a biomodal pattern for V{sub A} with peaks at 3 days and at 17-31 days. Under the antagonistic pleiotropy model of senescence, it was predicted that negative correlations will exist between early and late life history traits. For fecundity itself we find positive genetic correlations among age classes >3 days but negative nonsignificant correlations between fecundity at 3 days and at older age classes. For fecundity vs. age-specific mortality, we find positive fitness correlations (negative genetic correlations) among the traits at all ages >3 days but a negative fitness correlation between fecundity at 3 days and mortality at the oldest ages (positive genetic correlations). For age-specific mortality itself we find overwhelmingly positive genetic correlations among all age classes. The data suggest that mutation accumulation may be a major source of standing genetic variance for senescence. 75 refs., 4 figs., 1 tab.

  14. 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.

  15. Age-specific mortality among advanced-age Chinese citizens and its difference between the two genders.

    PubMed

    Gan, J; Zheng, Z; Li, G

    1998-01-01

    This study describes the patterns of age-specific mortality among the elderly in China. Data were obtained from the 1990 census. The age groups ending in zero were validated with the Weber Index and found to be of good quality among those aged under 97 years. Differences were found between censuses and genders. The data for the aged were adjusted with 2-year moving averages in order to smooth the data. The end age of interval mortality is used. Tables provide single years of age between 60 years and 104 years by sex for the actual number and the adjusted number of each census year: 1953, 1964, 1982, and 1990. The pattern of change in age specific mortality rates (ASMRs) was similar in all census years. Mortality rates were highest among infants aged under 1 year, declined with increased age, and were lowest among 10 year olds. Mortality rose gradually after 10 years and sharply after 40-50 years. ASMRs were "U" shaped. Age-specific interval mortality rates among the elderly show that mortality increased drastically as it approached 90 years of age and then grew more slowly or declined. The Gompers rule about exponential increases among the extremely old (over 90 years) does not apply. Male mortality was higher than female mortality until the very old ages, which showed lower male mortality. The ratio declined with rising age until the two genders were equal. Mortality rose to a point and then declined to a lesser extent. The peak was 93 years in 1953, with a sex ratio (SR) of 32.48; 90 years in 1964, with an SR of 35.22; 93 years in 1982, with an SR of 35.96; and 95 years in 1990, with an SR of 32.94.

  16. Hepatitis A virus age-specific sero-prevalence and risk factors among Jordanian children.

    PubMed

    Hayajneh, Wail A; Balbeesi, Adel; Faouri, Samir

    2015-04-01

    Hepatitis A Virus (HAV) has been a significant cause of infections among the children and adolescents of Jordan. Availability of safe vaccines made it necessary to identify the ill-defined temporal immunity trends for HAV and possible age-specific prevalence transitions. This community-based cross sectional study was conducted during the period July-August 2008 on 3,066 recruited subjects from the 12 governorates of Jordan, with pre-defined criteria. Several households were chosen at random within each selected block to enroll the subjects. They were interviewed and data were collected. Their sera were tested for total antibodies against HAV. A multivariate model was then performed to identify the possible risk factors. The HAV sero-prevalence rates among the age categories-second year, 2-4 years, 5-9 years, 10-14 years, 15-19 years, and those above 20 years were 26%, 32%, 44%, 63%, 78%, and 94%, respectively. The model revealed the association of several risk factors for higher HAV sero-prevalence rates: (i) older age groups; (ii) lower maternal education levels; (iii) residing in certain governorates; (iv) using public net drinking water; and (v) avoiding use of public net sewage system. This study provided strong evidence for continuous transition of HAV epidemiology towards intermediate endemicity in Jordan, with more susceptible adolescents and adults. Following the World Health Organization (WHO) recommendations for countries with intermediate endemicity, large-scale hepatitis A vaccination is recommended for children in Jordan. This is strengthened by the availability of effective and safe HAV vaccines, improving the socio-economic status of the Jordanians, and increasing life expectancy among Jordanians.

  17. A theory of the cancer age-specific incidence data based on extreme value distributions

    NASA Astrophysics Data System (ADS)

    Soto-Ortiz, Luis; Brody, James P.

    2012-03-01

    The incidence of cancers varies with age, if normalized this is called the age-specific incidence. A mathematical model that describes this variation should provide a better understanding of how cancers develop. We suggest that the age-specific incidence should follow an extreme value distribution, based on three widely accepted assumptions: (1) a tumor develops from a single cell, (2) many potential tumor progenitor cells exist in a tissue, and (3) cancer is diagnosed when the first of these many potential tumor cells develops into a tumor. We tested this by comparing the predicted distribution to the age-specific incidence data for colon and prostate carcinomas collected by the Surveillance, Epidemiology and End Results network of 17 cancer registries. We found that colon carcinoma age-specific incidence data is consistent with an extreme value distribution, while prostate carcinomas age-specific incidence data generally follows the distribution. This model indicates that both colon and prostate carcinomas only occur in a subset of the population (22% for prostate and 13.5% for colon.) Because of their very general nature, extreme value distributions might be applicable to understanding other chronic human diseases.

  18. Programmatic implementation of blastocyst transfer in a university-based in vitro fertilization clinic: maximizing pregnancy rates and minimizing triplet rates.

    PubMed

    Grifo, James A; Flisser, Eric; Adler, Alexis; McCaffrey, Caroline; Krey, Lewis C; Licciardi, Frederick; Noyes, Nicole; Kump, Lisa M; Berkeley, Alan S

    2007-08-01

    To assess whether the use of extended embryo culture can reduce the incidence of high-order multiple gestations, a retrospective analysis of 7,418 fresh ETs performed in a university-based IVF clinic from 1997-2003 was conducted, comparing program results before and after institution of a protocol to select patients for extended culture of in vitro fertilized embryos. The incidence of triplet pregnancies was significantly reduced in patients at highest risk for high-order multiple gestations, i.e., those at <35 years of age (16.8% versus 6.8%), those at 35-37 years of age (13.0% versus 5.6%), and recipients of donated oocytes (11.2% versus 4.5%).

  19. [Observation for CH4 and N2O emissions under different rates of nitrogen and phosphate fertilization in double rice fields].

    PubMed

    Shi, Sheng-Wei; Li, Yu-E; Wan, Yun-Fan; Qin, Xiao-Bo; Gao, Qing-Zhu

    2011-07-01

    . Therefore, the mitigation options should focus on how to reduce CH4 emission in local area. The result indicates that BF is a recommended fertilization method for early rice production, and a optimum fertilization for late season can increase rates of nitrogen and phosphate fertilizers on the basis of BF treatment slightly by considering total global warming potential and grain yield. The rates of BF treatment were 150-90-90 kg x hm(-2) N-P2O5-K2O for early rice, and 180-90-135 kg x hm(-2) N-P2O5-K2O for late rice, respectively.

  20. Age-Specific Frequencies and Characteristics of Ovarian Cysts in Children and Adolescents

    PubMed Central

    Emeksiz, Hamdi Cihan; Derinöz, Okşan; Akkoyun, Esra Betül; Güçlü Pınarlı, Faruk; Bideci, Aysun

    2017-01-01

    Objective: The aim of the present study was to document ovarian cyst frequency and characteristics as well as distribution of these parameters with respect to age in children and adolescents. Methods: We retrospectively analyzed the medical records of 1009 girls between the ages of 5-18 years who presented to our pediatric emergency department (PED) with pelvic pain and therefore underwent pelvic ultrasound examination between June 2011 and May 2014. Results: In total, 132 of 1009 girls (13.1%) were identified as having ovarian cysts ≥1 cm in diameter. The frequency of ovarian cysts was found to be 1.8% (6/337) in children aged 5-9 years and 18.8% (126/672) in those aged 10-18 years. All the cysts detected in children aged 5-9 years were small (<3 cm) and simple with age-specific frequencies ranging between 1.5-2.7%. With the onset of adolescence, ovarian cyst frequency started to increase with age and ranged between 3.8-31.3% throughout adolescence. Age of peak ovarian cyst frequency was 15 years with a rate of 31.3%. Large ovarian cysts (>5 cm) were identified in 19 adolescents (15.1%) with most occurring during middle adolescence. Of the 19 adolescents, five were found to have cyst-related significant ovarian pathologies including cystadenoma (n=3) and ovarian torsion (n=2). Conclusion: In children aged 5-9 years, ovarian cysts were infrequent and small (<3 cm). Peak ovarian cyst frequency was detected at the age of 15 years. All patients diagnosed with cyst-related significant ovarian pathologies were adolescents having a cyst >5 cm in diameter with a complex appearance in most. PMID:28044991

  1. Basis and implications of the CAP88 age-specific dose coefficients

    SciTech Connect

    Leggett, Richard Wayne; Scofield, Patricia A; Eckerman, Keith F

    2013-01-01

    Recent versions of CAP88 incorporate age-specific dose coefficients based on biokinetic and dosimetric models applied in Federal Guidance Report 13, Cancer Risk Coefficients for Environmental Exposure to Radionuclides (EPA 1999). With a few exceptions the models are those recommended in a series of reports by the International Commission on Radiological Protection (ICRP) on estimation of doses to the public from environmental radionuclides. This paper describes the basis for the ICRP s age-specific biokinetic and dosimetric models and examines differences with age in the derived dose coefficients and in estimates of dose per unit exposure based on those coefficients.

  2. Deriving age-specific incidence from prevalence with an ordinary differential equation.

    PubMed

    Brinks, Ralph; Landwehr, Sandra; Icks, Andrea; Koch, Michael; Giani, Guido

    2013-05-30

    This article describes new relationships between the age-specific incidence of, the prevalence of and mortality from a chronic disease. We express these relationships in terms of an ordinary differential equation and form the methodological basis for a novel approach to estimating incidences from age-specific prevalence data. We examine practical aspects of the relationships and a comparison with a known stochastic method in a simulation study. Finally, we apply the novel method to a data set of renal replacement therapy recorded from patients with chronic kidney failure in a region of Germany with approximately 310,000 inhabitants from 2002 to 2010.

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

    PubMed Central

    2012-01-01

    Background Idjwi, an island of approximately 220,000 people, is located in eastern DRC and functions semi-autonomously under the governance of two kings (mwamis). At more than 8 live births per woman, Idjwi has one of the highest total fertility rates (TFRs) in the world. Rapid population growth has led to widespread environmental degradation and food insecurity. Meanwhile family planning services are largely unavailable. Methods At the invitation of local leaders, we conducted a representative survey of 2,078 households in accordance with MEASURE DHS protocols, and performed ethnographic interviews and focus groups with key informants and vulnerable subpopulations. Modelling proximate determinates of fertility, we evaluated how the introduction of contraceptives and/or extended periods of breastfeeding could reduce the TFR. Results Over half of all women reported an unmet need for spacing or limiting births, and nearly 70% named a specific modern method of contraception they would prefer to use; pills (25.4%) and injectables (26.5%) were most desired. We predicted that an increased length of breastfeeding (from 10 to 21 months) or an increase in contraceptive prevalence (from 1% to 30%), or a combination of both could reduce TFR on Idjwi to 6, the average desired number of children. Increasing contraceptive prevalence to 15% could reduce unmet need for contraception by 8%. Conclusions To meet women’s need and desire for fertility control, we recommend adding family planning services at health centers with NGO support, pursuing a community health worker program, promoting extended breastfeeding, and implementing programs to end sexual- and gender-based violence toward women. PMID:23137304

  4. The role of antioxidant enzymes in adaptive responses to sheath blight infestation under different fertilization rates and hill densities.

    PubMed

    Wu, Wei; Wan, Xuejie; Shah, Farooq; Fahad, Shah; Huang, Jianliang

    2014-01-01

    Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and malondialdehyde content (MDA) responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method) were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development.

  5. Determination of Nitrogen, Phosphorus, and Potassium Release Rates of Slow- and Controlled-Release Fertilizers: Single-Laboratory Validation, First Action 2015.15.

    PubMed

    Thiex, Nancy

    2016-01-01

    A previously validated method for the determination of nitrogen release patterns of slow- and controlled-release fertilizers (SRFs and CRFs, respectively) was submitted to the Expert Review Panel (ERP) for Fertilizers for consideration of First Action Official Method(SM) status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. The 180 day soil incubation-column leaching technique was demonstrated to be a robust and reliable method for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and the results were only slightly affected by variations in environmental factors such as microbial activity, soil moisture, temperature, and texture. The release of P and K were also studied, but at fewer replications than for N. Optimization experiments on the accelerated 74 h extraction method indicated that temperature was the only factor found to substantially influence nutrient-release rates from the materials studied, and an optimized extraction profile was established as follows: 2 h at 25°C, 2 h at 50°C, 20 h at 55°C, and 50 h at 60°C.

  6. Premature Progesterone Rise Positively Correlates with Clinical Pregnancy Rate in In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) Patients with good Ovarian Response.

    PubMed

    Cui, Na; Zhang, Jie; Xu, Yueming; Jiang, Lei; Yang, Aimin; Hao, Guimin

    2017-03-28

    Infertility affects millions of couples worldwide resulting in distress and depression. In the past several decades, in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) have been developed with high efficiency and success rate. The possible effects of gonadotropin administration on follicular metabolism have been discussed but the outcomes remain controversial. The aim of this study was to identify whether serum progesterone on the day of human chorionic gonadotropin (hCG) administration and the ratio of serum progesterone and the number of oocyte retrieved (P/O) had a predictive role for the outcomes of IVF/ICSI. Eight hundred and twenty-five patients were enrolled between January 2012 and December 2012. A positive correlation between progesterone and IVF/ICSI outcomes were found in patients with good ovarian response using receiver operating characteristic (ROC) curve. We found that when progesterone level was higher than 1.04 ng/ml in good ovarian responses, the implantation rate and clinical pregnancy rate were both reduced compared to the rates in patients exhibiting lower progesterone level (progesterone≤1.04 ng/ml). Moreover, the rise of serum progesterone on the day of hCG was negatively correlated with luteinizing hormone (LH) level. This study used 1.04 ng/ml as a definition of progesterone elevation and an adverse effect of serum progesterone rise was observed on clinical pregnancy rate.

  7. Senescence and age-specific trade-offs between reproduction and survival in female Asian elephants.

    PubMed

    Robinson, Matthew R; Mar, Khyne U; Lummaa, Virpi

    2012-03-01

    Although studies on laboratory species and natural populations of vertebrates have shown reproduction to impair later performance, little is known of the age-specific associations between reproduction and survival, and how such findings apply to the ageing of large, long-lived species. Herein we develop a framework to examine population-level patterns of reproduction and survival across lifespan in long-lived organisms, and decompose those changes into individual-level effects, and the effects of age-specific trade-offs between fitness components. We apply this to an extensive longitudinal dataset on female semi-captive Asian timber elephants (Elephas maximus) and report the first evidence of age-specific fitness declines that are driven by age-specific associations between fitness components in a long-lived mammal. Associations between reproduction and survival are positive in early life, but negative in later life with up to 71% of later-life survival declines associated with investing in the production of offspring within this population of this critically endangered species.

  8. The Age Specific Incidence Anomaly Suggests that Cancers Originate During Development

    NASA Astrophysics Data System (ADS)

    Brody, James P.

    The accumulation of genetic alterations causes cancers. Since this accumulation takes time, the incidence of most cancers is thought to increase exponentially with age. However, careful measurements of the age-specific incidence show that the specific incidence for many forms of cancer rises with age to a maximum, and then decreases. This decrease in the age-specific incidence with age is an anomaly. Understanding this anomaly should lead to a better understanding of how tumors develop and grow. Here we derive the shape of the age-specific incidence, showing that it should follow the shape of a Weibull distribution. Measurements indicate that the age-specific incidence for colon cancer does indeed follow a Weibull distribution. This analysis leads to the interpretation that for colon cancer two subpopulations exist in the general population: a susceptible population and an immune population. Colon tumors will only occur in the susceptible population. This analysis is consistent with the developmental origins of disease hypothesis and generalizable to many other common forms of cancer.

  9. Relationship between the length of the uterine cavity and clinical pregnancy rates after in vitro fertilization or intracytoplasmic sperm injection.

    PubMed

    Chun, Sang Sik; Chung, Min Ji; Chong, Gun Oh; Park, Kee Sang; Lee, Taek Hoo

    2010-02-01

    In this prospective clinical study involving 354 IVF-intracytoplasmic sperm injection cycles, we determined the influence of the length of the uterine cavity on clinical pregnancy rates. Our data showed that clinical pregnancy and implantation rates are associated positively with an increased length of the uterine cavity.

  10. Medical innovation and age-specific trends in health care utilization: findings and implications.

    PubMed

    Wong, Albert; Wouterse, Bram; Slobbe, Laurentius C J; Boshuizen, Hendriek C; Polder, Johan J

    2012-01-01

    Health care utilization is expected to rise in the coming decades. Not only will the aggregate need for health care grow by changing demographics, so too will per capita utilization. It has been suggested that trends in health care utilization may be age-specific. In this paper, age-specific trends in health care utilization are presented for different health care sectors in the Netherlands, for the period 1981-2009. For the hospital sector we also explore the link between these trends and the state of medical technology. Using aggregated data from a Dutch health survey and a nationwide hospital register, regression analysis was used to examine age-specific trends in the probability of utilizing health care. To determine the influence of medical technology, the growth in age-specific probabilities of hospital care was regressed on the number of medical patents while adjusting for confounders related to demographics, health status, supply and institutional factors. The findings suggest that for most health care sectors, the trend in the probability of health care utilization is highest for ages 65 and up. Larger advances in medical technology are found to be significantly associated with a higher growth of hospitalization probability, particularly for the higher ages. Age-specific trends will raise questions on the sustainability of intergenerational solidarity in health care, as solidarity will not only be strained by the ageing population, but also might find itself under additional pressure as the gap in health care utilization between elderly and non-elderly grows over time. For hospital care utilization, this process might well be accelerated by advances in medical technology.

  11. 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

  12. Cryopreservation of Mammalian Oocytes by Using Sugars: Intra- and extracellular raffinose with small amounts of dimethylsulfoxide yields high cryosurvival, fertilization, and development rates

    PubMed Central

    Eroglu, Ali

    2009-01-01

    Accumulation of intra- and extracellular sugars such as trehalose, glucose, and raffinose is central to survival strategies of a variety of organisms coping with extreme conditions including freezing and almost complete drying. The objective of the present study was to investigate the potential application of intra- and extracellular raffinose in combination with low concentrations of dimethylsulfoxide (Me2SO) to mammalian oocyte cryopreservation. To this end, the fertilization and embryonic development of cryopreserved metaphase II (M II) mouse oocytes were studied in comparison to unfrozen controls. For cryopreservation, M II oocytes were microinjected with 0.1 M raffinose, and then cooled to -196°C in the presence of either 0.3 M raffinose and 0.5 M Me2SO (cryopreservation group 1) or 0.3 M raffinose and 1.0 M Me2SO (cryopreservation group 2). The control groups included untreated oocytes (untreated control) and oocytes microinjected with raffinose, but not frozen (injection control). The post-thaw survival rates were 83.9% and 80.6% for the cryopreservation group 1 and 2, respectively. The fertilization and blastocyst rates in the cryopreservation group 1 (90.0% and 77.8%, respectively) and 2 (94.6% and 72.5%, respectively) were also high and similar to the ones of the injection controls (97.8% and 78.5%, respectively) and untreated controls (98.8% and 83.6%, respectively). These results are consistent with the findings of our earlier studies and support the use of sugars as intra- and extracellular cryoprotectants. Furthermore, the results of the present study indicate that the presence of intra- and extracellular sugars alleviates high concentrations of conventional penetrating cryoprotectants, and thus minimizes their toxicity. PMID:19596315

  13. Fertilization rates and in vitro embryo production using sexed or non-sexed semen selected with a silane-coated silica colloid or Percoll.

    PubMed

    Rodríguez Villamil, P; Wei, H; Moreira, G; Caccia, M; Fernandez Taranco, M; Bó, G A

    2012-07-01

    The aim of this study was to evaluate sperm fertilization rates and in vitro embryo development rates for sexed and non-sexed semen selected using a silane-coated silica colloid method (Isolate) or Percoll. Frozen/thawed, sexed and unsexed semen samples from four Holstein bulls were randomly allocated to one of two different density gradient selection methods. Sperm quality (motility, concentration, morphology and membrane integrity) were evaluated and compared before and after sperm selection. Sperm motility and morphology improved (P < 0.005) after the sperm selection process with no differences between the two methods. For non-sexed semen, Percoll gradient increased the mean (± SEM) percentage of sperm recovered (57.3 ± 2.8) compared to Isolate (46.0 ± 1.8; P < 0.01). However, membrane integrity was higher after Isolate than Percoll (sexed semen: 41.0 ± 0.6 vs. 38.8 ± 0.8 and non-sexed semen 60.8 ± 1.6 vs. 58.8 ± 0.5; P < 0.05). The percentage of blastocysts produced was higher when either sexed or non-sexed semen was selected by Isolate (14.0 ± 1.0; 22.0 ± 1.1) than by Percoll (10.5 ± 1.5; 17.0 ± 2.1, respectively; P < 0.05). In summary, Isolate was a more effective method for the recovery of high quality sperm for in vitro fertilization embryo production.

  14. Age-Specific Anti-Hepatitis A Virus Seroepidemiology in Italian Travelers: Indications for Anti-Hepatitis A Vaccination.

    PubMed

    Castelli; Carosi; Tebaldi; Pizzocolo; Pisani; Rossitto; Boffelli; Crevatin; Pettoello; Fausti; Messino; Brunelli; Costa; Ronca

    1996-12-01

    Background: Hepatitis A virus (HAV) circulation in the environment is decreasing in most industrialized Western countries. This decrease has lead to low seroprevalence rates in adults. As a consequence, many nonimmune unprotected travelers from areas of low prevalence are considered at risk of acquiring HAV infection when traveling to high HAV endemic areas in developing countries. The recent HAV inactivated vaccine has proved safe and effective, and its use in different geographic areas should be guided by local age-specific HAV seroprevalence rates. The aim of this paper is to describe the age-specific sero-epidemiology of HAV infection in travelers from a highly industrialized region in Northern Italy (Lombardy). Methods: Seven hundred and forty-four consecutive travelers aged from 20 to 59 years, subdivided in 10-year age groups, gave blood samples in the collaborative Health Centers in the Lombardy region and sera were tested for HAV IgG antibodies. A questionnaire was given to travelers that investigated alimentary habits and a history of previous travel. Results: Anti-HAV seroprevalence was 18.0%, 58.0%, 75.8%, and 89.5% in the 20-29, 30-39, 40-49, and 50-59 age groups, respectively. Age was the single most important determinant of anti-HAV seroprevalence. The influence of previous travels, eating shellfish, or ingestion of self-cultivated vegetables was ruled out by multivariate analysis. Conclusions: In the Lombardy region (Northern Italy), age specific anti-HAV seroprevalence rates are much higher than those reported in other Western European countries. The cost-benefit analysis suggested that travelers born after 1960 do not need serologic screening before vaccination. Whenever possible, however, HAV serologic screening is advisable for travelers born before 1960. However, the severity of the disease in older subjects, and the proved safety of HAV vaccination in immune subjects, may advise d'emblée HAV vaccination without prior screening, when serologic

  15. Controlling Fertility.

    ERIC Educational Resources Information Center

    Donnay, France

    1991-01-01

    Recent developments in fertility control are presented in relation to the global demographic situation. Discussion focuses on changes in scientific knowledge and concepts that have shifted the focus from birth control to planned parenthood to the notion of controlled fertility. The place of family planning programs, including their socioeconomic…

  16. 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

  17. Growing Fixed With Age: Lay Theories of Malleability Are Target Age-Specific.

    PubMed

    Neel, Rebecca; Lassetter, Bethany

    2015-11-01

    Beliefs about whether people can change ("lay theories" of malleability) are known to have wide-ranging effects on social motivation, cognition, and judgment. Yet rather than holding an overarching belief that people can or cannot change, perceivers may hold independent beliefs about whether different people are malleable-that is, lay theories may be target-specific. Seven studies demonstrate that lay theories are target-specific with respect to age: Perceivers hold distinct, uncorrelated lay theories of people at different ages, and younger targets are considered to be more malleable than older targets. Both forms of target-specificity are consequential, as target age-specific lay theories predict policy support for learning-based senior services and the rehabilitation of old and young drug users. The implications of target age-specific lay theories for a number of psychological processes, the social psychology of aging, and theoretical frameworks of malleability beliefs are discussed.

  18. Automated tissue classification of pediatric brains from magnetic resonance images using age-specific atlases

    NASA Astrophysics Data System (ADS)

    Metzger, Andrew; Benavides, Amanda; Nopoulos, Peg; Magnotta, Vincent

    2016-03-01

    The goal of this project was to develop two age appropriate atlases (neonatal and one year old) that account for the rapid growth and maturational changes that occur during early development. Tissue maps from this age group were initially created by manually correcting the resulting tissue maps after applying an expectation maximization (EM) algorithm and an adult atlas to pediatric subjects. The EM algorithm classified each voxel into one of ten possible tissue types including several subcortical structures. This was followed by a novel level set segmentation designed to improve differentiation between distal cortical gray matter and white matter. To minimize the req uired manual corrections, the adult atlas was registered to the pediatric scans using high -dimensional, symmetric image normalization (SyN) registration. The subject images were then mapped to an age specific atlas space, again using SyN registration, and the resulting transformation applied to the manually corrected tissue maps. The individual maps were averaged in the age specific atlas space and blurred to generate the age appropriate anatomical priors. The resulting anatomical priors were then used by the EM algorithm to re-segment the initial training set as well as an independent testing set. The results from the adult and age-specific anatomical priors were compared to the manually corrected results. The age appropriate atlas provided superior results as compared to the adult atlas. The image analysis pipeline used in this work was built using the open source software package BRAINSTools.

  19. Aneuploidy screening by array comparative genomic hybridization improves success rates of in vitro fertilization: A multicenter Indian study

    PubMed Central

    Kotdawala, Aditi; Patel, Deven; Herrero, Javier; Khajuria, Rajni; Mahajan, Nalini; Banker, Manish

    2016-01-01

    OBJECTIVE: To evaluate the usefulness of preimplantation genetic screening (PGS) using array comparative genomic hybridization (aCGH) in the Indian population. MATERIALS AND METHODS: This is a retrospective, multicenter study including 235 PGS cycles following intracytoplasmic sperm injection performed at six different infertility centers from September 2013 to June 2015. Patients were divided as per maternal age in several groups (<35, 35–36, 37–38, 39–40, and >40 years) and as per indication for undergoing PGS. Indications for performing PGS were recurrent miscarriage, repetitive implantation failure, severe male factor, previous trisomic pregnancy, and advanced maternal age (≥35). Day 3 embryo biopsy was performed and analyzed by aCGH followed by day 5 embryo transfer in the same cycle or the following cycle. Outcomes such as pregnancy rates (PRs)/transfer, implantation rates, miscarriage rates, percentage of abnormal embryos, and number of embryos with more than one aneuploidy and chaotic patterns were recorded for all the treated subjects based on different age and indication groups. RESULTS: aCGH helped in identifying aneuploid embryos, thus leading to consistent implantation (range: 33.3%–42.9%) and PRs per transfer (range: 31.8%–54.9%) that were obtained for all the indications in all the age groups, after performing PGS. CONCLUSION: Aneuploidy is one of the major factors which affect embryo implantation. aCGH can be successfully employed for screening of aneuploid embryos. When euploid embryos are transferred, an increase in PRs can be achieved irrespective of the age or the indication. PMID:28216909

  20. Gender and age-specific seroprevalence of human papillomavirus 16 and 18 in general population in Tehran, Iran.

    PubMed

    Aghakhani, Arezoo; Mamishi, Setareh; Sabeti, Shahram; Bidari-Zerehpoosh, Farahnaz; Banifazl, Mohammad; Bavand, Anahita; Ramezani, Amitis

    2017-04-01

    The assessment of the gender and age-specific seroprevalence of human papillomavirus (HPV) is essential for planning of HPV vaccine implementation into the preventive programs. In this study, we aimed to determine the age-specific seroprevalence of HPV-16 and 18 in both males and females in Tehran, Iran. Three hundred and seventy-eight women (10-35 years) and 162 men (10-25 years) from Tehran, Iran, were enrolled. Anti-HPV IgG antibodies against HPV-16 and HPV-18 were detected by ELISA using papillomavirus type 16 and 18 L1-capsids as antigen. HPV-16 antibody was detected in 15.6 and 13.6% of women and men, respectively. Antibody against HPV-18 was found positive in 12.7 and 8% of women and men, respectively. The highest seroprevalence of HPV-16 and 18 were seen in women aged 26-30 years (22.2 and 19.4%, respectively), and the lowest HPV-16 and 18 seropositivity rates were seen in males and females aged 10-15 years (9.3 and 1.9%, respectively). In our cohort of study, in males, both anti-HPV-16 and 18 increased after age 15 years, peaking in men aged 21-25 years. In women, both HPV-16 and 18 seropositivity increased after 15 years, declined at 21-25 years, peaked in women aged 26-30 years and again decreased after 30 years. Our data showed increasing exposure rate to high-risk HPV vaccine types in our studied population over 15 years of age. In order to prevent the HPV-related cancers, implementation of HPV vaccine into the national immunization program in Iran and vaccination of females and males less than 15 years of age are suggested.

  1. Effects of Fertile Mantle Compositional Variation and Spreading Rate Variation on the Working of Global Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Niu, Y.; O'Hara, M. J.

    2014-12-01

    Mantle temperature variation, plate spreading rate variation and mantle compositional variation have been considered to be the three fundamental variables that govern the working of global ocean ridges [1]. An analysis demonstrates that mantle compositional variation exerts the primary control on ocean ridge processes; it determines (1) variation in both composition and mode of mantle mineralogy, (2) variation of mantle density, (3) variation of ridge axial depth, (4) source-inherited MORB compositional variation, (4) density-controlled variation in the amplitude of mantle upwelling, (5) apparent variation in the extent of melting, and (6) the correlated variation of MORB chemistry with ridge axial depth [2]. The above interpretations are reinforced by the updated MORB database [3]. The new database also confirms spreading rate control on the extent of melting as shown previously [4]. Mantle temperature variation could play a part, but its overstated role [3,5] results from a basic error (1) in treating ridge axial depth variation as evidence of mantle temperature variation by ignoring the intrinsic control of mantle composition, (2) in treating "mantle plume" influenced ridges (e.g., Iceland) as normal ridges of plate spreading origin, and (3) in treating low Vs at greater depths (> 300 km vs. < 200 km beneath ridges) beneath these "mantle plume" influenced ridges as evidence for hot ridge mantle. In order to understand the working of global ocean ridges, we must avoid plume-influenced ridges (e.g., in the vicinity of Iceland) and remove/average out data from such ridges. As a result, the correlations (e.g., between ridge axial depth, mantle low Vs anomaly, and some geochemical parameters) required for the interpretation of mantle temperature control all disappear. There is thus no evidence for large mantle temperature variation away from ridges influenced by "mantle plumes". References: [1] Niu et al., 2001, Earth Planet Sci. Lett., 186, 383-399; [2] Niu & O

  2. Fertility Awareness

    MedlinePlus

    ... when ovulation happens. Couples use a calendar, a thermometer to measure body temperature, the thickness of cervical ... fertility awareness — such as ovulation detection kits and thermometers, for example — are available in drugstores. But they ...

  3. Predicting fertility.

    PubMed

    Maheshwari, Abha; Bhattacharya, Siladitya; Johnson, Neil P

    2008-06-01

    Various predictors of fertility have been described, suggesting that none are ideal. The literature on tests of ovarian reserve is largely limited to women undergoing in vitro fertilization, and is reliant on the use of surrogate markers, such as cycle cancellation and number of oocytes retrieved, as reference standards. Currently available prediction models are far from ideal; most are applicable only to subfertile women seeking assisted reproduction, and lack external validation. Systematic reviews and meta-analyses of predictors of fertility are limited by their heterogeneity in terms of the population sampled, predictors tested and reference standards used. There is an urgent need for consensus in the design of these studies, definition of abnormal tests, and, above all, a need to use robust outcomes such as live birth as the reference standard. There are no reliable predictors of fertility that can guide women as to how long childbearing can be deferred.

  4. Fertility Awareness

    MedlinePlus

    ... time the couple using only fertility awareness for birth control who does not want to get pregnant should ... period. In general, how well each type of birth control method works depends on a lot of things. ...

  5. Adolescent fertility: worldwide concerns.

    PubMed

    Senderowitz, J; Paxman, J M

    1985-04-01

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

  6. The age-specific force of natural selection and biodemographic walls of death

    PubMed Central

    Wachter, Kenneth W.; Evans, Steven N.; Steinsaltz, David

    2013-01-01

    W. D. Hamilton’s celebrated formula for the age-specific force of natural selection furnishes predictions for senescent mortality due to mutation accumulation, at the price of reliance on a linear approximation. Applying to Hamilton’s setting the full nonlinear demographic model for mutation accumulation recently developed by Evans, Steinsaltz, and Wachter, we find surprising differences. Nonlinear interactions cause the collapse of Hamilton-style predictions in the most commonly studied case, refine predictions in other cases, and allow walls of death at ages before the end of reproduction. Haldane’s principle for genetic load has an exact but unfamiliar generalization. PMID:23657010

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

    PubMed Central

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

    2016-01-01

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

  8. Developmentally Sensitive Markers of Personality Functioning in Adolescents: Age-Specific and Age-Neutral Expressions.

    PubMed

    Debast, Inge; Rossi, Gina; Feenstra, Dineke; Hutsebaut, Joost

    2016-05-23

    Criterion D of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association [APA], 2013) refers to a possible onset of personality disorders (PDs) in adolescence and in Section II the development/course in adolescence is described by some typical characteristics for several PDs. Yet, age-specific expressions of PDs are lacking in Section III. We urgently need a developmentally sensitive assessment instrument that differentiates developmental and contextual changes on the one hand from expressions of personality pathology on the other hand. Therefore we investigated which items of the Severity Indices for Personality Problems-118 (SIPP-118) were developmentally sensitive throughout adolescence and adulthood and which could be considered more age-specific markers requiring other content or thresholds over age groups. Applying item response theory (IRT) we detected differential item functioning (DIF) in 36% of the items in matched samples of 639 adolescents versus 639 adults. The DIF across age groups mainly reflected a different degree of symptom expressions for the same underlying level of functioning. The threshold for exhibiting symptoms given a certain degree of personality dysfunction was lower in adolescence for areas of personality functioning related to the Self and Interpersonal domains. Some items also measured a latent construct of personality functioning differently across adolescents and adults. This suggests that several facets of the SIPP-118 do not solely measure aspects of personality pathology in adolescents, but likely include more developmental issues. (PsycINFO Database Record

  9. Age-specific measles mortality during the late 19th-early 20th centuries.

    PubMed

    Shanks, G D; Waller, M; Briem, H; Gottfredsson, M

    2015-12-01

    Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14-15% of measles deaths as opposed to 8-9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

  10. Experimental evidence of environmental effects on age-specific reproductive success: the importance of resource quality.

    PubMed Central

    Pärt, T.

    2001-01-01

    Age-specific access to high-quality resources (e.g. territory or nest site) might be an important determinant for improved reproductive performance with increasing age. I experimentally investigated the effects of territory quality versus other age-related improvements in breeding competence (e.g. foraging skills, breeding experience and local knowledge) on age-specific reproductive success. Territory quality (i.e. territory field layer height) was manipulated in year 2 of northern wheatears (Oenanthe oenanthe) that were breeding in the same territory in two consecutive years. Changing territory quality by changing field layer height had a strong effect on within-individual change in the reproductive success of wheatears. This effect was mainly due to a corresponding change in nest predation risk. When territory quality was kept constant (i.e. no between-year change in territory field layer height), within-individual reproductive success did not change between subsequent years. Thus, age-related improvements in foraging skills, breeding experience and local familiarity had no significant effect on within-individual changes in reproductive success. Increased reproductive success with increased age in northern wheatears is therefore mainly explained by an improved access to high-quality territories with increasing age. I conclude that age-dependent access to high-quality breeding resources might be a widespread phenomenon in nature. PMID:11674875

  11. Determinants of fertility in Guatemala.

    PubMed

    Anderson, J E; Morris, L; Pineda, A; Santiso, R

    1980-01-01

    The 1978 Contraceptive Prevalence Survey for Guatemala provides an opportunity to examine fertility levels and a number of determinants of fertility for three broad segments of the country: the Department of Guatemala and, in the remainder of the country, the Ladino and Indian populations. While Ladinos had a much higher rate of contraceptive use than did Indians, the two groups had similar birth rates. The lack of difference in fertility appears to be due to the pattern of prolonged breastfeeding among Indians and perhaps to differences in the rate of conception due to nutrition, coital frequency, or other factors.

  12. Adjuvant-induced Human Monocyte Secretome Profiles Reveal Adjuvant- and Age-specific Protein Signatures*

    PubMed Central

    Oh, Djin-Ye; Dowling, David J.; Ahmed, Saima; Choi, Hyungwon; Brightman, Spencer; Bergelson, Ilana; Berger, Sebastian T.; Sauld, John F.; Pettengill, Matthew; Kho, Alvin T.; Pollack, Henry J.; Steen, Hanno; Levy, Ofer

    2016-01-01

    Adjuvants boost vaccine responses, enhancing protective immunity against infections that are most common among the very young. Many adjuvants activate innate immunity, some via Toll-Like Receptors (TLRs), whose activities varies with age. Accordingly, characterization of age-specific adjuvant-induced immune responses may inform rational adjuvant design targeting vulnerable populations. In this study, we employed proteomics to characterize the adjuvant-induced changes of secretomes from human newborn and adult monocytes in response to Alum, the most commonly used adjuvant in licensed vaccines; Monophosphoryl Lipid A (MPLA), a TLR4-activating adjuvant component of a licensed Human Papilloma Virus vaccine; and R848 an imidazoquinoline TLR7/8 agonist that is a candidate adjuvant for early life vaccines. Monocytes were incubated in vitro for 24 h with vehicle, Alum, MPLA, or R848 and supernatants collected for proteomic analysis employing liquid chromatography-mass spectrometry (LC-MS) (data available via ProteomeXchange, ID PXD003534). 1894 non-redundant proteins were identified, of which ∼30 - 40% were common to all treatment conditions and ∼5% were treatment-specific. Adjuvant-stimulated secretome profiles, as identified by cluster analyses of over-represented proteins, varied with age and adjuvant type. Adjuvants, especially Alum, activated multiple innate immune pathways as assessed by functional enrichment analyses. Release of lactoferrin, pentraxin 3, and matrix metalloproteinase-9 was confirmed in newborn and adult whole blood and blood monocytes stimulated with adjuvants alone or adjuvanted licensed vaccines with distinct clinical reactogenicity profiles. MPLA-induced adult monocyte secretome profiles correlated in silico with transcriptome profiles induced in adults immunized with the MPLA-adjuvanted RTS,S malaria vaccine (Mosquirix™). Overall, adjuvants such as Alum, MPLA and R848 give rise to distinct and age-specific monocyte secretome profiles

  13. Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: analysis of reproductive tracts

    USGS Publications Warehouse

    Bodkin, James L.; Mulcahy, Daniel M.; Lensink, Calvin J.

    1993-01-01

    We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, Primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oil spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% at age 2 to 78% at age 5 and remained relatively stable (75-88%) through to age 15. the sex ratio (female:male) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than 8 tended to produce more female fetuses, while older mothers did not. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similiar to those reported in the literature based on in situ observations of marked individuals.

  14. 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.

  15. Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration.

    PubMed

    Elabd, Christian; Cousin, Wendy; Upadhyayula, Pavan; Chen, Robert Y; Chooljian, Marc S; Li, Ju; Kung, Sunny; Jiang, Kevin P; Conboy, Irina M

    2014-06-10

    The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation; however, systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin--a hormone best known for its role in lactation, parturition and social behaviours--is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signalling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation through activation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle but instead leads to premature sarcopenia. Considering that oxytocin is an FDA-approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle ageing.

  16. [Age-specific effects at the beginning of in-/out-/day patient welfare measures].

    PubMed

    Rücker, Stefan; Büttner, Peter; Petermann, Ulrike; Petermann, Franz

    2014-01-01

    The study presented examines age-specific differences in emotional and behaviour problems as well as resources at the beginning of in-, out- and day-patient youth welfare measures. Additionally, parenting-skills were investigated. A sample of N = 126 was divided by the median (10.1 years) thus leading to two groups: ages six to ten (version for parents) versus eleven to sixteen (self-completion). Children and adolescents were evaluated with the SDQ, parenting skills with the DEAPQ-EL-GS. Values of both groups were compared cross-sectionally with multivariate, one-factorial variance analysis. Parents of younger children achieve significantly better results for parenting-skills. Compared to the older ones, younger children show significantly greater behaviour problems. Younger children belong to the group especially affected in youth welfare measures. Therefore, measures should be specifically adapted for this group to reduce symptoms.

  17. Experimental evidence that age-specific reproductive success is independent of environmental effects

    PubMed Central

    Daunt, F.; Wanless, S.; Harris, M. P.; Monaghan, P.

    1999-01-01

    An age-specific improvement in reproductive performance has been reported in many iteroparous breeders. However, whether this is a consequence of intrinsic differences in competence amongst age classes or extrinsic differences in the environment they experience is unclear since the timing of breeding within a season generally also differs with age. To disentangle these effects, we experimentally manipulated the timing of breeding in shags, Phalacrocorax aristotelis. Old and young individuals thus reared their chicks at the same time both early and late in the breeding season. When breeding in the same environmental conditions, old pairs performed consistently better than young pairs. These data clearly demonstrate that the age-related differences in reproductive performance are not a result of environmental effects, but rather a consequence of intrinsic differences in brood rearing capacity.

  18. [The age-specific features of palm dermatoglyphics in the adults subjects].

    PubMed

    Teplov, K V; Bozhchenko, A P; Tolmachev, I A; Moiseenko, S A

    2016-01-01

    This article was designed to consider the congenital age-specific features of palm dermatoglyphics in the adults subjects (including the type of the papillary patterns, axial tri-radii, the termini of palmar main lines, the rudiments of palmar lines, the dermatoglyphic ridge count between the stable anatomical structures). The objective of the study was to look for the new diagnostic markers of the biological age. It included the identification of the palm prints obtained from 180 Caucasoid men and 120 women at the age varying from 16 to 80 years. The results of the mathematical and statistical analysis provided the basis for drawing up the list of 18 attributes of palm dermatoglyphics significantly (p<0.05) differing in the frequency of occurrence between the representatives of individual age groups. The methods are proposed allowing to use these findings for the expert evaluation of the age of unknown subjects.

  19. Age-specific inhalation radiation dose commitment factors for selected radionuclides

    SciTech Connect

    Strenge, D.L.; Peloquin, R.A.; Baker, D.A.

    1982-08-01

    Inhalation dose commitment factors are presented for selected radionuclides for exposure of individuals in four age groups: infant, child, teen and adult. Radionuclides considered are /sup 35/S, /sup 36/Cl, /sup 45/Ca, /sup 67/Ga, /sup 75/Se, /sup 85/Sr, /sup 109/Cd, /sup 113/Sn, /sup 125/I, /sup 133/Ba, /sup 170/Tm, /sup 169/Yb, /sup 182/Ta, /sup 192/Ir, /sup 198/Au, /sup 201/Tl, /sup 204/Tl, and /sup 236/Pu. The calculational method is based on the human metabolic model of ICRP as defined in Publication 2 (ICRP 1959) and as used in previous age-specific dose factor calculations by Hoenes and Soldat (1977). Dose commitment factors are presented for the following organs of reference: total body, bone, liver, kidney, thyroid, lung and lower large intestine.

  20. Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration

    PubMed Central

    Upadhyayula, Pavan; Chen, Robert Y.; Chooljian, Marc S.; Li, Ju; Kung, Sunny; Jiang, Kevin P.; Conboy, Irina M.

    2014-01-01

    The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation, but systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin- a hormone best known for its role in lactation, parturition, and social behaviors - is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signaling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation throughactivation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle, but instead leads to premature sarcopenia. Considering that oxytocin is an FDA approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle aging. PMID:24915299

  1. Age-specific occurrence of HPV16- and HPV18-related cervical cancer

    PubMed Central

    Quint, Wim G. V.; Hunt, William C.; Joste, Nancy E.; Alemany, Laia; Bosch, F. Xavier; Myers, Evan R.; Castle, Philip E.

    2014-01-01

    The age-specific of occurrence of cervical cancer related to human papillomavirus genotypes HPV16 and HPV18, the two targeted by current HPV vaccines, is not well described. We therefore used data from two large, tissue-based HPV genotyping studies of cervical cancer, one conducted in New Mexico (USA) (n = 744) and an international study restricted to cancers (n = 1,729) from Europe, North America, and Australia to represent those regions with widely available cervical cancer screening facilities. HPV results were categorized as HPV16 or HPV18 positive (HPV16/18) versus other HPV genotype. We observed a decreasing proportion of HPV16/18-positive cancers with increasing age in the international study (ptrend < 0.001) and New Mexico study (ptrend < 0.001). There was no heterogeneity in the relationship between age of diagnosis and the proportion of HPV16/18-positive cancers between studies (p = 0.8). Combining results from the two studies (n = 2,473), the percentages of HPV16/18-positive cases were 77.0% (95%CI: 75.1%-78.9%) for women less than 65 years old and 62.7% (95%CI: 58.4%-66.9%) for women aged 65 and older (p < 0.001). In women who are under the age of 25 and have been vaccinated before becoming sexually active, the cervical cancer incidence is expected to be approximately 3.5 per million by 2020. HPV vaccination against HPV16/18 may have a greater impact on cervical cancers in women under 65 than in women aged 65 and older. These data will inform the age-specific impact of HPV vaccination and its integration with cervical cancer screening activities. PMID:23632816

  2. An Atypical Age-Specific Pattern of Hepatocellular Carcinoma in Peru: A Threat for Andean Populations

    PubMed Central

    Loli, Sebastian; Moura, Julien; Zimic, Mirko; Deharo, Eric; Ruiz, Eloy

    2013-01-01

    Background In South America, the highest incidence of primary liver cancer is observed in Peru. However, national estimations on hepatocellular carcinoma incidence and mortality are approximated using aggregated data from surrounding countries. Thus, there is a lack of tangible information from Peru that impairs an accurate description of the local incidence, presentation, and outcomes of hepatocellular carcinoma. The present study attempts to fill this gap and assesses the clinical epidemiology of hepatocellular carcinoma in this country. Methods A retrospective cohort study was conducted by analysing the medical charts of 1,541 patients with hepatocellular carcinoma admitted between 1997 and 2010 at the Peruvian national institute for cancer. The medical records including liver function, serologic status, and tumor pathology and stage were monitored. Statistical analyses were performed in order to characterize tumor presentation according to demographic features, risk factors, and regional origin. Results Surprisingly, the age distribution of the patient population displayed bimodality corresponding to two distinct age-based subpopulations. While an older group was in keeping with the age range observed for hepatocellular carcinoma around the world, a younger population displayed an abnormally juvenile mean age of 25.5 years old. In addition, each subpopulation displayed age-specific pathophysiological and clinical characteristics. Conclusions The analysis suggests two different age-specific natural histories of hepatocellular carcinoma in the Peruvian patient population. This otherwise unusual tumor process that is ongoing in younger patients leads to the hypothesis that there may be a Peru-endemic risk factor driving hepatocarcinogenesis in the local population. PMID:23840771

  3. Superovulation in red deer (Cervus elaphus) and Père David's deer (Elaphurus davidianus), and fertilization rates following artificial insemination with Père David's deer semen.

    PubMed

    Argo, C M; Jabbour, H N; Goddard, P J; Webb, R; Loudon, A S

    1994-03-01

    Two comparative studies were undertaken using adult, female red and Père David's deer to examine the ovulatory response of these animals to a superovulation regimen and fertilization rates following inter- and intraspecific laparoscopic insemination. In Expt 1 six Père David's deer and 12 red deer hinds were treated during the breeding season with an intravaginal progesterone-impregnated controlled internal drug release device (CIDR) for 14 days, with 200 iu pregnant mares' serum gonadotrophin (PMSG) administered 72 h before the device was withdrawn and eight injections of ovine FSH given at 12 h intervals starting at the time of PMSG administration. Oestrous behaviour began one day after CIDR device withdrawal (Père David's deer: 24.00 +/- 2.32 h; red deer: 24.60 +/- 2.23 h). The duration of oestrus was greater in Père David's deer than in red deer (17.50 +/- 1.43 h and 8.25 +/- 3.25 h, respectively, P < 0.001). The peak LH surge of Père David's deer was 68.65 +/- 4.74 ng ml-1 occurring 29.00 +/- 2.41 h after removal of the CIDR devices. In comparison, the peak LH surge in red deer was 17.09 +/- 3.64 ng ml-1 (P < 0.001), occurring 24.00 +/- 0.00 h after CIDR device withdrawal. Pre-surge concentrations of LH were also greater (P < 0.001) in Père David's deer (1.37 +/- 0.11 ng ml-1) than in red deer hinds (0.41 +/- 0.02 ng ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Age-specific survival and philopatry in three species of European ducks: a long-term study

    USGS Publications Warehouse

    Blums, P.; Mednis, A.; Bauga, I.; Nichols, J.D.; Hines, J.E.

    1996-01-01

    Capture-recapture and band recovery models were used to estimate age-specific survival probabilities for female Northern Shovelers (Anas clypeata), Common Pochards (Aythya ferina), and Tufted Ducks (Aythya.fuligula) at Engure Marsh, Latvia, in 1964-1993. We banded more than 65,100 day-old ducklings of both sexes and captured 10,211 incubating females (3,713 new bandings and 6,498 recaptures). We developed a set of 3-age capture-recapture models to estimate annual survival rates for female ducklings, yearlings (SY), and adults (ASY) using programs SURGE and SURVIV and selected parsimonious models using a method developed bv Akaike (1973). Survival rates of SY and ASY females were highest-for Tufted Ducks intermediate for Common Pochards, and lowest for Northern Shovelers. Survival rates of SY and ASY females varied in parallel for shovelers and pochards. We believe that much of the difference in survival estimates between SY and ASY birds was caused by mortality rather than permanent emigration. Estimates of day-old duckling survival, reflecting both mortality and permanent emigration, were 0.12 for shoveler, 0.06 for pochard, and 0.03 for Tufted Duck. For all species, duckling survival varied over years, but the pattern of variation was not similar to that of the other age classes. Estimates of survival using band recovery data for SY + ASY female pochards and Tufted Ducks were similar to the capture-recapturee stimates, suggestingt hat surviving females returned to the breeding marsh with probabilities approaching 1.

  5. An age-specific kinetic model of lead metabolism in humans.

    PubMed Central

    Leggett, R W

    1993-01-01

    Although considerable progress has been made in recent years in reducing human exposures to lead, the potential for high intake of this contaminant still exists in millions of homes and in many occupational settings. Moreover, there is growing evidence that levels of lead intake considered inconsequential just a few years ago can result in subtle, adverse health effects, particularly in children. Consequently, there have been increased efforts by health protection agencies to develop credible, versatile methods for relating levels of lead in environmental media to levels in blood and tissues of exposed humans of all ages. In a parallel effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age-specific biokinetic models for calculating radiation doses from environmentally important radionuclides, including radioisotopes of lead. This paper describes a new age-specific biokinetic model for lead originally developed for the ICRP but expanded to include additional features that are useful for consideration of lead as a chemical toxin. The model is developed within a generic, physiologically motivated framework designed to address a class of calciumlike elements. This framework provides a useful setting in which to synthesize experimental, occupational, and environmental data on lead and exploit common physiological properties of lead and the alkaline earth elements. The modular design is intended to allow researchers to modify specific parameter values or model components to address special problems in lead toxicology or to incorporate new information. Transport of lead between compartments is assumed to follow linear, first-order kinetics provided the concentration in red blood cells remains below a nonlinear threshold level, but a nonlinear relation between plasma lead and red blood cell lead is modeled for concentrations above that level. The model is shown to be consistent

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrification inhibitors have potential to reduce N2O emissions from maize fields. A new micro-encapsulated formulation of nitrapyrin, optimized to be used with liquid fertilizers became available to US farmers in 2010. Our objectives were to: i) 15assess the impacts of urea-ammonium nitrate (UAN) m...

  7. Statistical correlation of the soil incubation and the accelerated laboratory extraction methods to estimate nitrogen release rates of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry; Obreza, Thomas; Leary, Emily; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of enhanced-efficiency fertilizers (EEFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize nutrient release of slow-release fertilizer (SRF) and controlled-release fertilizer (CRF) materials, no official method exists to assess their nutrient release patterns. However, the increased production and distribution of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. Nonlinear regression was used to establish a correlation between the data generated from a 180-day soil incubation-column leaching procedure and 74 h accelerated lab extraction method, and to develop a model that can predict the 180-day nitrogen (N) release curve for a specific SRF and CRF product based on the data from the accelerated laboratory extraction method. Based on the R2 > 0.90 obtained for most materials, results indicated that the data generated from the 74 h accelerated lab extraction method could be used to predict N release from the selected materials during 180 days, including those fertilizers that require biological activity for N release.

  8. The response of soil carbon cycling in managed loblolly pine forests to fertilization and the planting of families with differing growth rates

    NASA Astrophysics Data System (ADS)

    Vogel, J. G.; Schuur, E. A.; Gill, C.; Bracho, R.; Jokela, E.

    2010-12-01

    Forest management practices in the southern United States have made the pine forests of the region some of the most productive in the world. This remarkable productivity makes the region attractive for offsetting anthropogenic emissions of CO2 through increased biomass capture, or through the biomass-to-fuel approach. In other agricultural systems, however, increased plant productivity from management has often corresponded to a decrease in soil carbon. Over half of a forest ecosystem’s carbon is found in the soil; therefore a decrease in soil carbon could counteract a considerable amount of the reduction in atmospheric CO2 that results from enhanced tree growth. We have examined two forestry practices, fertilization with nitrogen and phosphorus and the genetic control of planted seedlings, in terms of how these practices affect key controls on soil carbon cycling. Root biomass dynamics, soil CO2 efflux, and microbial respiration were contrasted for a “fast” and a “slow” growing family of loblolly pine receiving two different levels of fertilization at two sites in north central Florida. Our overarching hypothesis was that greater aboveground growth would correspond to increased inputs of carbon to the soil as root biomass, and a greater efflux of CO2 from roots and soil microbes. At both sites, the faster growing families supported significantly (p<0.05) more fine root biomass (<1 mm diameter) under low fertilization than did the slow growing families. However under higher levels of fertilization, the fast and the slow growing families had similar levels of fine root biomass and soil CO2 efflux. Results from this study suggest that greater aboveground growth due to genetic selection only related to greater inputs of carbon to the soil when fertilization levels were low. Radiocarbon measurements of microbial respiration indicated no differences in soil organic matter turnover among families or fertilization treatments. These results suggest that the

  9. Exposure-Specific and Age-Specific Attack Rates for Ebola Virus Disease in Ebola-Affected Households, Sierra Leone

    PubMed Central

    Bower, Hilary; Johnson, Sembia; Bangura, Mohamed S.; Kamara, Alie Joshua; Kamara, Osman; Mansaray, Saidu H.; Sesay, Daniel; Turay, Cecilia; Checchi, Francesco

    2016-01-01

    Using histories of household members of Ebola virus disease (EVD) survivors in Sierra Leone, we calculated risk of EVD by age and exposure level, adjusting for confounding and clustering, and estimated relative risks. Of 937 household members in 94 households, 448 (48%) had had EVD. Highly correlated with exposure, EVD risk ranged from 83% for touching a corpse to 8% for minimal contact and varied by age group: 43% for children <2 years of age; 30% for those 5–14 years of age; and >60% for adults >30 years of age. Compared with risk for persons 20–29 years of age, exposure-adjusted relative risks were lower for those 5–9 (0.70), 10–14 (0.64), and 15–19 (0.71) years of age but not for children <2 (0.92) or 2–4 (0.97) years of age. Lower risk for 5–19-year-olds, after adjustment for exposure, suggests decreased susceptibility in this group. PMID:27144428

  10. Age-specific toxicity of copper to larval topsmelt Atherinops affinis

    SciTech Connect

    McNulty, H.R.; Anderson, B.S.; Hunt, J.W.; Turpen, S.L.; Singer, M.M. . Inst. of Marine Sciences)

    1994-03-01

    The age-specific sensitivity of topsmelt (Atherinops affinis) larvae to copper was assessed. A series of 7-d growth and survival experiments were conducted using cohorts of larval fish isolated into different age groups of 0, 1, 3, 5, 7, 9, 11, 15, and 20 d post-hatch. Fish aged 0, 3, and 5 d were less sensitive to copper chloride than fish [>=] 7 d old. The median lethal concentration (LC50) for copper ranged from 365 [mu]g L[sup [minus]1] in 0-d larvae, to 137 [mu]g L[sup [minus]1] in 20-d larvae. NOECs remained relatively constant for all ages: 180 [mu]g L[sup [minus]1] for 1- and 3-d-old fish, 100 [mu]g L[sup [minus]1] for all other cohorts. Regression analysis indicated a significant negative correlation between LC50 and gill surface area and cutaneous surface area. Although these correlations were expected because both morphometrics increase with age, the relationships between increasing respiratory surface area and LC50 may indicate that the increase in sensitivity with larval age is related to an increase in copper uptake, either cutaneously or branchially. GSA increased more than seven fold between hatch and 20 d, whereas CSA increased only threefold throughout the same period.

  11. Age-specific survival of reintroduced swift fox in Badlands National Park and surrounding lands

    USGS Publications Warehouse

    Sasmal, Indrani; Klaver, Robert W.; Jenks, Jonathan A.; Schroeder, Greg M.

    2016-01-01

    In 2003, a reintroduction program was initiated at Badlands National Park (BNP), South Dakota, USA, with swift foxes (Vulpes velox) translocated from Colorado and Wyoming, USA, as part of a restoration effort to recover declining swift fox populations throughout its historical range. Estimates of age-specific survival are necessary to evaluate the potential for population growth of reintroduced populations. We used 7 years (2003–2009) of capture–recapture data of 243 pups, 29 yearlings, and 69 adult swift foxes at BNP and the surrounding area to construct Cormack–Jolly–Seber model estimates of apparent survival within a capture–mark–recapture framework using Program MARK. The best model for estimating recapture probabilities included no differences among age classes, greater recapture probabilities during early years of the monitoring effort than later years, and variation among spring, winter, and summer. Our top ranked survival model indicated pup survival differed from that of yearlings and adults and varied by month and year. The apparent annual survival probability of pups (0.47, SE = 0.10) in our study area was greater than the apparent annual survival probability of yearlings and adults (0.27, SE = 0.08). Our results indicate low survival probabilities for a reintroduced population of swift foxes in the BNP and surrounding areas. Management of reintroduced populations and future reintroductions of swift foxes should consider the effects of relative low annual survival on population demography.

  12. Handling Age Specification in the SNOMED CT to ICD-10-CM Cross-map

    PubMed Central

    Xu, Junchuan; Fung, Kin Wah

    2012-01-01

    A SNOMED CT-encoded problem list will be required to satisfy the Certification Criteria for Stage 2 “Meaningful Use” of the EHR incentive program. ICD-10-CM will be replacing ICD-9-CM as the reimbursement code set in the near future. Having a cross-map from SNOMED CT to ICD-10-CM will promote the use of SNOMED CT as the primary problem list terminology, while easing the transition to ICD-10-CM. This rule-based map will support semi-automatic generation of ICD-10-CM codes from SNOMED CT-encoded data. Among the different types of rules, the age rule is used to handle age-specific code assignment in ICD-10-CM. To supplement the manual process of creation of age rules, a special QA process was implemented to flag maps that were potentially missing age rules. The QA flagged 342 concepts for review (out of 7,277), of which 172 concepts (50.3%) were true positives. Without the special QA, many of the age rules would have been missed. PMID:23304377

  13. Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations.

    PubMed

    Yamauchi-Kawaura, C; Fujii, K; Akahane, K; Yamauchi, M; Narai, K; Aoyama, T; Katsu, T; Obara, S; Imai, K; Ikeda, M

    2015-02-01

    In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations.

  14. Age-specific survival and reproductive probabilities: evidence for senescence in male fallow deer (Dama dama).

    PubMed Central

    McElligott, Alan G; Altwegg, Res; Hayden, Thomas J

    2002-01-01

    Survival and reproduction are key features in the evolution of life-history strategies. In this study, we use capture-mark-resighting and multi-state models to examine survival senescence and reproductive senescence in six successive cohorts of fallow bucks that were studied for 16 years. We found that the overall age-specific survival probabilities of males were highly variable and the best-fitting model revealed that fallow bucks have four life-history stages: yearling, pre-reproductive, prime-age and senescent. Pre-reproductive males (2 and 3 years old) had the highest survival. Survival declined sharply after the age of 9 years, indicating that senescence had begun. When we considered reproducing and non-reproducing males separately, there was no evidence of senescence in the former, and steadily decreasing survival after the onset of social maturity in the latter. Reproduction probability also declined in older males, and thus we provide very strong evidence of senescence. Reproducers had a greater chance of reproducing again in the following year than non-reproducers. Furthermore, there were differences in the survival probabilities, with reproducers consistently surviving better than non-reproducers. In our study population, reproducers allocate more to the effort to reproduce than non-reproducers. Therefore our results indicate the generally higher phenotypic quality of reproducing males. These results, along with earlier studies on the same population, could indicate positive relationships between fitness correlates. PMID:12061956

  15. Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River

    PubMed Central

    Murzina, Svetlana A.; Nefedova, Zinaida A.; Pekkoeva, Svetlana N.; Veselov, Alexey E.; Efremov, Denis A.; Nemova, Nina N.

    2016-01-01

    The age-specific lipid and fatty acid profiles of juvenile Atlantic salmon at different ages (0+, 1+, and 2+ years) after hatching from nests located in the mainstream of a large Arctic River, the Varzuga River, and resettling to the favorable Sobachji shoal in autumn before overwinter are herein presented. The contemporary methods of the lipid analysis were used: thin layer chromatography and gas chromatography. The results show that the stability of the regulation of important functions in developing organisms is maintained through structural alterations in lipids. These alterations can be considered as a sequence of the modifications and changes in the ratios of certain lipid classes and fatty acids constituents. In general, changes in the lipids and fatty acids (FAs) maintained the physiological limits and controls through the adaptive systems of the organism. The mechanisms of juvenile fish biochemical adaptation to the environmental conditions in the studied biotope include the modification of the energy metabolism and anabolism, and here belongs to the energy characteristics of metabolic processes. PMID:27376274

  16. Gender- and Age-Specific REE and REE/FFM Distributions in Healthy Chinese Adults

    PubMed Central

    Cheng, Yu; Yang, Xue; Na, Li-Xin; Li, Ying; Sun, Chang-Hao

    2016-01-01

    Basic data on the resting energy expenditure (REE) of healthy populations are currently rare, especially for developing countries. The aims of the present study were to describe gender- and age-specific REE distributions and to evaluate the relationships among glycolipid metabolism, eating behaviors, and REE in healthy Chinese adults. This cross-sectional survey included 540 subjects (343 women and 197 men, 20–79 years old). REE was measured by indirect calorimetry and expressed as kcal/day/kg total body weight. The data were presented as the means and percentiles for REE and the REE to fat-free mass (FFM) ratio; differences were described by gender and age. Partial correlation analysis was used to analyze the correlations between REE, tertiles of REE/FFM, and glycolipid metabolism and eating behaviors. In this study, we confirmed a decline in REE with age in women (p = 0.000) and men (p = 0.000), and we found that men have a higher REE (p = 0.000) and lower REE/FFM (p = 0.021) than women. Furthermore, we observed no associations among glycolipid metabolism, eating behaviors, and REE in healthy Chinese adults. In conclusion, the results presented here may be useful to clinicians and nutritionists for comparing healthy and ill subjects and identifying changes in REE that are related to aging, malnutrition, and chronic diseases. PMID:27598192

  17. Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River.

    PubMed

    Murzina, Svetlana A; Nefedova, Zinaida A; Pekkoeva, Svetlana N; Veselov, Alexey E; Efremov, Denis A; Nemova, Nina N

    2016-06-30

    The age-specific lipid and fatty acid profiles of juvenile Atlantic salmon at different ages (0+, 1+, and 2+ years) after hatching from nests located in the mainstream of a large Arctic River, the Varzuga River, and resettling to the favorable Sobachji shoal in autumn before overwinter are herein presented. The contemporary methods of the lipid analysis were used: thin layer chromatography and gas chromatography. The results show that the stability of the regulation of important functions in developing organisms is maintained through structural alterations in lipids. These alterations can be considered as a sequence of the modifications and changes in the ratios of certain lipid classes and fatty acids constituents. In general, changes in the lipids and fatty acids (FAs) maintained the physiological limits and controls through the adaptive systems of the organism. The mechanisms of juvenile fish biochemical adaptation to the environmental conditions in the studied biotope include the modification of the energy metabolism and anabolism, and here belongs to the energy characteristics of metabolic processes.

  18. Age-specific variation in immune response in Drosophila melanogaster has a genetic basis.

    PubMed

    Felix, Tashauna M; Hughes, Kimberly A; Stone, Eric A; Drnevich, Jenny M; Leips, Jeff

    2012-07-01

    Immunosenescence, the age-related decline in immune system function, is a general hallmark of aging. While much is known about the cellular and physiological changes that accompany immunosenescence, we know little about the genetic influences on this phenomenon. In this study we combined age-specific measurements of bacterial clearance ability following infection with whole-genome measurements of the transcriptional response to infection and wounding to identify genes that contribute to the natural variation in immunosenescence, using Drosophila melanogaster as a model system. Twenty inbred lines derived from nature were measured for their ability to clear an Escherichia coli infection at 1 and 4 weeks of age. We used microarrays to simultaneously determine genome-wide expression profiles in infected and wounded flies at each age for 12 of these lines. Lines exhibited significant genetically based variation in bacterial clearance at both ages; however, the genetic basis of this variation changed dramatically with age. Variation in gene expression was significantly correlated with bacterial clearance ability only in the older age group. At 4 weeks of age variation in the expression of 247 genes following infection was associated with genetic variation in bacterial clearance. Functional annotation analyses implicate genes involved in energy metabolism including those in the insulin signaling/TOR pathway as having significant associations with bacterial clearance in older individuals. Given the evolutionary conservation of the genes involved in energy metabolism, our results could have important implications for understanding immunosenescence in other organisms, including humans.

  19. Preliminary inferences on the age-specific seriousness of human disease caused by avian influenza A(H7N9) infections in China, March to April 2013

    PubMed Central

    Wong, JY; Wu, P; Liao, Q; Lau, EH; Wu, JT; Fielding, R; Leung, GM

    2013-01-01

    Between 31 March and 21 April 2013, 102 laboratory-confirmed influenza A(H7N9) infections have been reported in six provinces of China. Using survey data on age-specific rates of exposure to live poultry in China, we estimated that risk of serious illness after infection is 5.1 times higher in persons 65 years and older versus younger ages. Our results suggest that many unidentified mild influenza A(H7N9) infections may have occurred, with a lower bound of 210–550 infections to date. PMID:23725807

  20. Age-specific mortality trends in France and Italy since 1900: period and cohort effects.

    PubMed

    Caselli, G; Vallin, J; Vaupel, J W; Yashin, A

    1987-11-01

    The age/sex-specific mortality trends of France and Italy were studied over the 1899-1979 period in as much detail as possible in an effort to distinguish between cohort effects and those related to period changes. Complete series of mortality data by individual years of age and calendar years were available from 1869 to 1979 for Italy and from 1899 to 1982 for France. For both countries, these data include the military and civil deaths not registered in vital statistics during the war periods. They cover each national territory as defined by its present boundaries. The graphical representation method of mortality surfaces, elaborated by Vaupel, Gambill, and Yashin (1985), was adopted. The age/sex-specific mortality patterns of France and Italy have not followed the same trends, and the differences observed today are not those of 100 years ago. The mean death probabilities for the 1975-79 period were used to illustrate the age-specific patterns of mortality. Although infant mortality was higher in Italy than in France, the death probabilities at ages 1-15 for both sexes were roughly the same for both countries. At ages 15-23, they were much higher in France than in Italy, and they remained considerably higher in France up to age 55. From then on, the sexes differ: for males, the 2 countries showed similar patterns, whereas for females the probabilities were noticeably higher for France. The situation was very different for both countries at the beginning of the century. For both sexes, higher mortality was observed in Italy not only during infancy but throughout childhood and the adolescent years up to age 15. The 2 countries showed similar patterns from 15-25. Above age 25, the 2 countries had similar patterns for females, whereas male mortality was higher in France right up to the old age groups. Such differences in the age-specific mortality trends depend in part on a different development of health and social conditions but also may be due to factors concerning

  1. Age-specific absolute and relative organ weight distributions for Fischer 344 rats.

    PubMed

    Marino, Dale J

    2012-01-01

    The Fischer 344 (F344) rat has been the standard rat strain used in toxicology studies conducted by the National Cancer Institute (NCI) and the National Toxicology Program (NTP). However, the numerous reports published to date on growth, survival, and tumor incidence have not included an overall compilation of organ weight data. Notably, dose-related organ weight effects are endpoints used by regulatory agencies to develop toxicity reference values (TRVs) for use in human health risk assessments. In addition, physiologically-based pharmacokinetic (PBPK) models, which utilize relative organ weights, are increasingly being used to develop TRVs. Because a compilation of organ weights for F344 rats could prove beneficial for TRV development and PBPK modeling, all available absolute and relative organ weight data for untreated control F344 rats were collected from NCI/NTP feed, drinking-water, and inhalation studies in order to develop age-specific distributions. Results showed that organ weights were collected more frequently at 2-wk (59 studies), 3-mo (148 studies), and 15-mo (38 studies) intervals than at other intervals and more frequently from feeding and inhalation than from drinking-water studies. Liver, right kidney, lung, heart, thymus, and brain weights were most frequently collected. From the collected data, the mean and standard deviation for absolute and relative organ weights were calculated. Findings showed age-related increases in absolute weights and decreases in relative weights for brain, liver, right kidney, lung, heart, thyroid, and right testis. The results suggest a general variability trend in absolute organ weights of brain < right testis < heart < right kidney < liver < lung < thymus < thyroid.

  2. Spatially adapted augmentation of age-specific atlas-based segmentation using patch-based priors

    NASA Astrophysics Data System (ADS)

    Liu, Mengyuan; Seshamani, Sharmishtaa; Harrylock, Lisa; Kitsch, Averi; Miller, Steven; Chau, Van; Poskitt, Kenneth; Rousseau, Francois; Studholme, Colin

    2014-03-01

    One of the most common approaches to MRI brain tissue segmentation is to employ an atlas prior to initialize an Expectation- Maximization (EM) image labeling scheme using a statistical model of MRI intensities. This prior is commonly derived from a set of manually segmented training data from the population of interest. However, in cases where subject anatomy varies significantly from the prior anatomical average model (for example in the case where extreme developmental abnormalities or brain injuries occur), the prior tissue map does not provide adequate information about the observed MRI intensities to ensure the EM algorithm converges to an anatomically accurate labeling of the MRI. In this paper, we present a novel approach for automatic segmentation of such cases. This approach augments the atlas-based EM segmentation by exploring methods to build a hybrid tissue segmentation scheme that seeks to learn where an atlas prior fails (due to inadequate representation of anatomical variation in the statistical atlas) and utilize an alternative prior derived from a patch driven search of the atlas data. We describe a framework for incorporating this patch-based augmentation of EM (PBAEM) into a 4D age-specific atlas-based segmentation of developing brain anatomy. The proposed approach was evaluated on a set of MRI brain scans of premature neonates with ages ranging from 27.29 to 46.43 gestational weeks (GWs). Results indicated superior performance compared to the conventional atlas-based segmentation method, providing improved segmentation accuracy for gray matter, white matter, ventricles and sulcal CSF regions.

  3. Age-Specific Epigenetic Drift in Late-Onset Alzheimer's Disease

    PubMed Central

    Wang, Sun-Chong; Oelze, Beatrice; Schumacher, Axel

    2008-01-01

    Despite an enormous research effort, most cases of late-onset Alzheimer's disease (LOAD) still remain unexplained and the current biomedical science is still a long way from the ultimate goal of revealing clear risk factors that can help in the diagnosis, prevention and treatment of the disease. Current theories about the development of LOAD hinge on the premise that Alzheimer's arises mainly from heritable causes. Yet, the complex, non-Mendelian disease etiology suggests that an epigenetic component could be involved. Using MALDI-TOF mass spectrometry in post-mortem brain samples and lymphocytes, we have performed an analysis of DNA methylation across 12 potential Alzheimer's susceptibility loci. In the LOAD brain samples we identified a notably age-specific epigenetic drift, supporting a potential role of epigenetic effects in the development of the disease. Additionally, we found that some genes that participate in amyloid-β processing (PSEN1, APOE) and methylation homeostasis (MTHFR, DNMT1) show a significant interindividual epigenetic variability, which may contribute to LOAD predisposition. The APOE gene was found to be of bimodal structure, with a hypomethylated CpG-poor promoter and a fully methylated 3′-CpG-island, that contains the sequences for the ε4-haplotype, which is the only undisputed genetic risk factor for LOAD. Aberrant epigenetic control in this CpG-island may contribute to LOAD pathology. We propose that epigenetic drift is likely to be a substantial mechanism predisposing individuals to LOAD and contributing to the course of disease. PMID:18628954

  4. [STUDY OF THE INFLUENCE OF MINERAL FERTILIZERS ON THE NEONATAL MORBIDITY RATE IN INFANTS WITH CONGENITAL MALFORMATIONS (CM) IN THE BELGOROD REGION].

    PubMed

    Verzilina, I N; Chumosov, M I; Evdokimov, V I

    2015-01-01

    Results of the performed study showed that the use of mineral fertilizers for crops increases the risk of morbidity in neonates with congenital malformations (CM). P-elevated levels of relative environmental risk is established for: anomalies of the musculoskeletal system, multiple congenital malformations, the CM as a whole. Maximum environmental risk in the conditions of high load offertilizers on farmland is established for congenital abnormalities of the development of reproductive system in newborn infants (RR = 2,76).

  5. Fertility and the family.

    PubMed

    Kono, S

    1991-09-01

    The developed countries of Asia include Japan and the newly industrialized economies of Hong Kong, Taiwan, Republic of Korea, and Singapore. These 5 societies share various similarities that have helped in their socioeconomic development. The 1st includes a significant and quite rapid socioeconomic development (per capita gross national product, urbanization, demographic transition, educational attainment, and industrialization). The 2nd similarity is the extremely high levels of education. Indeed those 5 societies boast the most highly educated populations in Asia. 3rd, they have achieved below replacement fertility. In fact, they never really had very high birth rates anyhow. 4th, extended families are the norm despite rapid transformation of their societies. Confucianism, the 5th similarity, advocates multigenerational families. Children understand that it is their duty to always take care of their parents. Parents know that they have a right to ask for their children's help at any time. In 1981, a demographer hypothesized that 1 of the leading signs of fertility decline is the nucleation of the family. yet in these 5 societies nucleation did not appear before fertility decline. In fact, in Japan, fertility is higher in those homes where the grandmother watches her grandchildren while the daughter or daughter-in-law is at work. Some have compared the role of Confucianism in socioeconomic development with that of Protestantism in the industrialization of Europe. Both stress hard work, simplicity, frugality, discipline, and regularity in daily life. Yet Confucianism sees women as bearers of children and servants to men. Women in these societies protest this mindset by postponing marriage and having few children. If these societies wish to increase fertility, they need to restructure their male oriented societies.

  6. The feasibility of age-specific travel restrictions during influenza pandemics

    PubMed Central

    2011-01-01

    Background Epidemiological studies have shown that imposing travel restrictions to prevent or delay an influenza pandemic may not be feasible. To delay an epidemic substantially, an extremely high proportion of trips (~99%) would have to be restricted in a homogeneously mixing population. Influenza is, however, strongly influenced by age-dependent transmission dynamics, and the effectiveness of age-specific travel restrictions, such as the selective restriction of travel by children, has yet to be examined. Methods A simple stochastic model was developed to describe the importation of infectious cases into a population and to model local chains of transmission seeded by imported cases. The probability of a local epidemic, and the time period until a major epidemic takes off, were used as outcome measures, and travel restriction policies in which children or adults were preferentially restricted were compared to age-blind restriction policies using an age-dependent next generation matrix parameterized for influenza H1N1-2009. Results Restricting children from travelling would yield greater reductions to the short-term risk of the epidemic being established locally than other policy options considered, and potentially could delay an epidemic for a few weeks. However, given a scenario with a total of 500 imported cases over a period of a few months, a substantial reduction in the probability of an epidemic in this time period is possible only if the transmission potential were low and assortativity (i.e. the proportion of contacts within-group) were unrealistically high. In all other scenarios considered, age-structured travel restrictions would not prevent an epidemic and would not delay the epidemic for longer than a few weeks. Conclusions Selectively restricting children from traveling overseas during a pandemic may potentially delay its arrival for a few weeks, depending on the characteristics of the pandemic strain, but could have less of an impact on the economy

  7. Bayes plus Brass: estimating total fertility for many small areas from sparse census data.

    PubMed

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

    2013-01-01

    Estimates of fertility in small areas 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. In these circumstances 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 procedure for estimating total fertility in such circumstances and illustrate it by applying the method to data from the 2000 Brazilian Census for over 5,000 municipalities. Our proposed procedure 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 to conditions of rapid fertility decline. Supplementary material at the project website ( http://schmert.net/BayesBrass ) will allow readers to replicate all the authors' results in this paper using their data and programs.

  8. Hispanic Assimilation and Fertility in New Destinations

    PubMed Central

    Lichter, Daniel T.; Johnson, Kenneth M.; Turner, Richard N.; Churilla, Allison

    2012-01-01

    This paper evaluates comparative patterns of fertility in new Hispanic destinations and established gateways using pooled cross-sectional data from the 2005–2009 microdata files of the American Community Survey. Changing Hispanic fertility provides a useful indicator of cultural incorporation. Analyses show that high fertility among Hispanics has been driven in part by the Mexican-origin and other new immigrant populations (e.g., noncitizens, those with poor English language skills, etc.). However, high fertility rates among Hispanics – and Mexican-origin Hispanics in particular – cannot be explained entirely by socio-demographic characteristics that place them at higher risk of fertility. For 2005–2009, Hispanic fertility rates were 48 percent higher than fertility among whites; they were roughly 25 percent higher after accounting for differences in key social characteristics, such as age, nativity, county of origin, and education. Contrary to most previous findings of spatial assimilation among in-migrants, fertility rates among Hispanics in new destinations exceeded fertility in established gateways by 18 percent. In the multivariate analyses, Hispanics in new destinations were roughly 10 percent more likely to have had a child in the past year than those living in established gateways. Results are consistent with sub-cultural explanations of Hispanic fertility and raise new questions about the spatial patterning of assimilation and the formation of ethnic enclaves outside traditional settlement areas. PMID:23325987

  9. TCRC Fertility Page

    MedlinePlus

    The Testicular Cancer Resource Center The TCRC Fertility Page Testicular Cancer and fertility are interrelated in numerous ways. TC usually ... Orchiectomy: As I mentioned, many men who have testicular cancer also already have fertility problems. In some, the ...

  10. A Cohort Model of Fertility Postponement

    PubMed Central

    Goldstein, Joshua R.; Cassidy, Thomas

    2015-01-01

    We introduce a new formal model in which demographic behavior such as fertility is postponed by differing amounts depending only on cohort membership. The cohort-based model shows the effects of cohort shifts on period fertility measures and provides an accompanying tempo adjustment to determine the period fertility that would have occurred without postponement. Cohort-based postponement spans multiple periods and produces “fertility momentum,” with implications for future fertility rates. We illustrate several methods for model estimation and apply the model to fertility in several countries. We also compare the fit of period-based and cohort-based shift models to the recent Dutch fertility surface, showing how cohort- and period-based postponement can occur simultaneously. PMID:25233957

  11. Age-specific reference values for serum FSH and estradiol levels throughout the reproductive period.

    PubMed

    Grisendi, Valentina; Spada, Elena; Argento, Cindy; Plebani, Maddalena; Milani, Silvano; Seracchioli, Renato; Volpe, Annibale; La Marca, Antonio

    2014-06-01

    High serum day 3 FSH levels are associated with poor ovarian reserve and reduced fertility, but the interpretation of FSH values according to age is still not univocal. The purpose of this study was to determine age-dependent reference values in women with regular menstrual cycles and FSH as a guide for specialists. The study was performed at the Department of Mother-Infant of a University-based tertiary care centre. One-hundred ninety-two healthy normal menstruating women were recruited for the study. All patients attended the department on menstrual cycle day 3 for a blood sample for FSH and estradiol determination. A linear relationship between FSH or estradiol serum levels and age was observed. The FSH level increased by 0.11 IU for every year of age (1 IU for every 9 years of age). The values of FSH and estradiol corresponding to the 5th, 25th, 50th, 75th, 95th centiles for any specific age have been calculated. Serum FSH levels need to be interpreted according to age-dependent reference values. Serum FSH levels on 95th centile for any age may represent a warning sign for reduced ovarian reserve.

  12. A Method to Teach Age-Specific Demography with Field Grown Rapid Cycling "Brassica rapa" (Wisconsin Fast Plants)

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

    In this paper, we demonstrate that rapid cycling "Brassica rapa" (Wisconsin Fast Plants) can be used in inquiry-based, student ecological fieldwork. We are the first to describe age-specific survival for field-grown Fast Plants and identify life history traits associated with individual survival. This experiment can be adapted by educators as a…

  13. A simple and fast method for assessment of the nitrogen-phosphorus-potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; da Silva, Ricardo Moutinho; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta

    2014-11-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500-5000 mg L- 1 N (r = 0.9994), 100-2000 mg L- 1 P (r = 0.9946), and 100-2500 mg L- 1 K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97-105% (NO3--N), 95-103% (NH4+-N), 93-103% (urea-N), 99-108% (P), and 99-102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively.

  14. [Determinants of fertility in Costa Rica].

    PubMed

    Rosero, L

    1983-08-01

    An attempt to systematize variables or factors traditionally associated with fertility, this study is not intended as a theoretical framework. 2 periods in Costa Rican fertility are recognized: one before 1960 and one after 1960. Within these periods 4 stages, each with different "key" determinants, are recognized. Until 1960, high fertility rates prevailed, with more than 6 children as total. Fluctuations were due to voluntary factors such as nuptiality and breastfeeding, and involuntary factors such as demand for less children during economic recession. Between 1960 and 1975 fertility declined. It is believed that the "key" factors in this fertility decline were on the contraceptive "offert" side rather than on the children demand side. The participation of peasants and low socioeconomic groups in the fertility decline and governmental health and family planning services are also recognized as important factors. Since the mid 70's a new stage of relative stability has been reached with an apparent convergence towards a total fertility of 3 children. How close this level is reached in the near future will depend on the control of unwanted fertility. The possibility of a 2nd fertility decline in Costa Rica depends mainly on factors which determine why couples have a 3rd child. Consequently, investigation of these factors is suggested to anticipate the future course of Costa Rican fertility. Basic fertility data are given in tables and an appendix.

  15. The forms and fitness cost of senescence: age-specific recapture, survival, reproduction, and reproductive value in a wild bird population.

    PubMed

    Bouwhuis, Sandra; Choquet, Rémi; Sheldon, Ben C; Verhulst, Simon

    2012-01-01

    Longitudinal studies of senescence accumulate rapidly from natural populations. However, it is largely unknown whether different fitness components senesce in parallel, how reproductive and survival senescence contribute to declines in reproductive value, and how large the fitness cost of senescence is (the difference between the observed reproductive value and the hypothetical reproductive value, if senescence would not occur). We analyzed age-specific survival in great tits Parus major and combined our results with analyses of reproductive senescence to address these issues. Recapture probability of breeding females declined with age, suggesting age-specific increases in skipped or failed breeding and highlighting an important bias that studies of senescence in wild populations should incorporate. Survival probability also declined with age and in parallel with recruit production. Reproductive value decreased 87% between age 1 and age 9 but at a fitness cost of only 4%; the proportion of the contribution of reproductive senescence versus survival senescence to this cost was 0.7. For 11 other species, we estimated fitness costs of senescence of 6%-63% (average: birds, 9%; mammals, 42%), with relative contributions of reproductive senescence of 0.0-0.7 (average: birds, 0.4; mammals, 0.3). We suggest that understanding when and why reproductive and survival senescence differ will help in the identification of proximate mechanisms underlying variation in rates of senescence and its evolution.

  16. Age-specific survival estimates of King Eiders derived from satellite telemetry

    USGS Publications Warehouse

    Oppel, Steffen; Powell, Abby N.

    2010-01-01

    Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fiedging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48–0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86–0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n = 9) returned to their natal area at the age of 2 years, none of the 2-year old males (n = 3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark—recapture methods.

  17. Improved pregnancy rate in human in vitro fertilization with the use of a medium based on the composition of human tubal fluid.

    PubMed

    Quinn, P; Kerin, J F; Warnes, G M

    1985-10-01

    Significantly more mouse zygotes developed to blastocysts in culture in a medium formulated on the composition of human tubal fluid (HTF) than in modified Tyrode's medium (T6). In a randomized 2 X 2 factorial trial of human in vitro fertilization that compared the two media and culture under oil versus culture in loosely capped tubes, significantly more clinical pregnancies (30% of 60 transfers) were obtained with HTF medium than with T6 medium (11% of 53 transfers). Decreasing the K+ content of HTF medium to that present in T6 medium significantly decreased the number of mouse zygotes that developed in culture. Modifying Ca++ levels had no effect. It is therefore likely that the higher K+ content in HTF medium is primarily responsible for the superiority of HTF medium over T6 medium, but other differences in the composition of the two media could contribute to the results observed.

  18. 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.

  19. 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.

  20. [Estimation of mortality from census survival rates and consequent estimates of birth and death rates: 1975-1980 in Korea case].

    PubMed

    Kwon, H Y; Kim, K S

    1982-07-01

    The rate of natural increase in population between the census in 1975 and 1980 is calculated with total population by sex. An abridged life table, based on the Coale and Demeny life table model, is used. The number of deaths from this life table is calculated by using age specific death rate. According to this number, each crude death rate for both sexes is calculated. The crude birth rate calculation is the difference between the rate of natural increase in population and the crude death rate. Each computed rate is as follows: natural increase rate: 1.98% (male), 1.83% (female), 1.91% (total); crude death rate: .547% (male), .546% (female), .547% (total); crude birth rate: 2.535% (male), 2.340% (female), 2.448% (total). In evaluating the crude death rate and crude birth rate result, the crude death rate is lower than expected. Crude death rate from the whole country fertility survey taken in 1974 is 7/1000 people. According to the whole country fertility survey data taken in 1976, the infant mortality rate in 1974 and 1975 are at 26% and 27.5% respectively, which is considered low. This low death rate in recent times is due to the decrease in the infant mortality rate and the decrease in death of the aged population. Calculated crude birth rate is 25.6/1000 persons for males, and 24/1000 for females. After the whole country fertility survey conducted in 1976, the crude birth rate is estimated at 24/1000 persons and crude birth rate in 1980 was estimated at 23.4 persons. Results are in line with the calculations of the Third Social Economic Development 5-year plan which was drafted by working staff in the population sector including the population professionals in the Bureau of Statistics of the Economic Planning Board.

  1. The impact of women's education, workforce experience, and the One Child Policy on fertility in China: a census study in Guangdong, China.

    PubMed

    Lan, Manyu; Kuang, Yaoqiu

    2016-01-01

    The impact of women's education on fertility is of interest to researchers, particularly in China. However, few studies have provided well-founded assessments of how women's education, workforce experience, and birth control policy jointly affect fertility in China. This study, conducted in Guangdong Province, aimed to analyze how these three factors influenced the timing of births and affected women at different stages of their reproductive lives. We used census data for Guangdong Province (1990, 2000, and 2010) to make cross-sectional age-specific comparisons to examine the effects of women's education and workforce participation on fertility outcomes under China's One Child Policy. We found that: (1) under circumstances of low fertility, women tend to have more children with greater educational attainment; (2) the impact of women's education and workforce experience on fertility varied across age groups, with the effect of education showing a bimodal curve peaking at 25-29 years and 40-44 years, and a workforce experience effect at 25-34 years; and (3) the fertility time-squeeze effect by educational attainment was relatively small, the effect by workforce participation was larger, and the most important effect was birth control policy and its implementation. These results suggest that educational attainment and workforce experience have a substantial effect on women's fertility, and a tradeoff between them is unavoidable. China's 2015 birth control policy adjustment should be considered in planning future services to accommodate anticipated increases in the birth rate. More attention should be directed to the causal mechanism (women's preference and selection effects) behind the factors analyzed in this study.

  2. Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011.

    PubMed

    Tao, Lichan; Pu, Cunying; Shen, Shutong; Fang, Hongyi; Wang, Xiuzhi; Xuan, Qinkao; Xiao, Junjie; Li, Xinli

    2015-01-01

    Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension.

  3. Trends in age-specific cerebrovascular disease in the European Union

    PubMed Central

    Wang, Hui; Sun, Wei; Ji, Yue; Shi, Jing; Xuan, Qinkao; Wang, Xiuzhi; Xiao, Junjie; Kong, Xiangqing

    2014-01-01

    Although the mortality of cerebrovascular disease (CVD) has been steadily declined in the European Union (EU), CVD remains among the major causes of death in EU. As risk factors such asobesity and diabetes mellitus are increasing, the trends of European CVD mortality remains unknown. To understand the variation in CVD mortality of different EU countries, we studied the trends in CVD mortality in EU countries over the last three decades between males and females. Age- and sex-specific mortality rates between 1980 and 2011 were calculated by data from the WHO mortality database. Joinpoint software was used to calculate annual percentage changes and to characterize trends in mortality rates over time. Our study showed that between 1980 and 2011, CVD mortality significantly decreased in both men and women across all age groups. The specific mortality trends varied largely between EU countries. The plateau trend was observed in little regions at different age groups, however, the EU as a whole displayed declined trend CVD mortality. During the last three decades, CVD mortality decreased substantially in the entire population of EU. However, despite this overall decline in CVD mortality, several areas were identified as having no change in their CVD mortality rates at different period. The whole EU needs to establish strict prevention measures toreduce the incidence of CVD risk factors. PMID:25550927

  4. Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011

    PubMed Central

    Tao, Lichan; Pu, Cunying; Shen, Shutong; Fang, Hongyi; Wang, Xiuzhi; Xuan, Qinkao; Xiao, Junjie; Li, Xinli

    2015-01-01

    Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension. PMID:25932090

  5. TENORM: Fertilizer and Fertilizer Production Wastes

    EPA Pesticide Factsheets

    Phosphate rock is used in the production of phosphate fertilizers. Due to its chemical properties, phosphate rock may contain significant quantities of naturally occurring radioactive materials (NORM).

  6. Decomposing variation in male reproductive success: age-specific variances and covariances through extra-pair and within-pair reproduction.

    PubMed

    Lebigre, Christophe; Arcese, Peter; Reid, Jane M

    2013-07-01

    Age-specific variances and covariances in reproductive success shape the total variance in lifetime reproductive success (LRS), age-specific opportunities for selection, and population demographic variance and effective size. Age-specific (co)variances in reproductive success achieved through different reproductive routes must therefore be quantified to predict population, phenotypic and evolutionary dynamics in age-structured populations. While numerous studies have quantified age-specific variation in mean reproductive success, age-specific variances and covariances in reproductive success, and the contributions of different reproductive routes to these (co)variances, have not been comprehensively quantified in natural populations. We applied 'additive' and 'independent' methods of variance decomposition to complete data describing apparent (social) and realised (genetic) age-specific reproductive success across 11 cohorts of socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia). We thereby quantified age-specific (co)variances in male within-pair and extra-pair reproductive success (WPRS and EPRS) and the contributions of these (co)variances to the total variances in age-specific reproductive success and LRS. 'Additive' decomposition showed that within-age and among-age (co)variances in WPRS across males aged 2-4 years contributed most to the total variance in LRS. Age-specific (co)variances in EPRS contributed relatively little. However, extra-pair reproduction altered age-specific variances in reproductive success relative to the social mating system, and hence altered the relative contributions of age-specific reproductive success to the total variance in LRS. 'Independent' decomposition showed that the (co)variances in age-specific WPRS, EPRS and total reproductive success, and the resulting opportunities for selection, varied substantially across males that survived to each age. Furthermore, extra-pair reproduction increased

  7. Ethnic fertility differentials in Peninsular Malaysia and Singapore.

    PubMed

    Saw, S H

    1990-01-01

    Differences in fertility between the three major ethnic groups (Malays, Chinese and Indians) in Peninsular Malaysia and Singapore have existed since before the onset of fertility decline in the late 1950s and remain today, although the relative positions and the actual differences have changed due to the varying rates of decline. By 1987, the Malays experienced the highest fertility and the Chinese the lowest in both countries but in Singapore the Malay fertility was lower than the Chinese fertility in Peninsular Malaysia. The fertility differentials will lead to changes in the ethnic composition in both countries but more so in Peninsular Malaysia.

  8. Age-specific reproduction in female sea otters (`enhydra lutris`) from southcentral Alaska: Analysis of reproductive tracts. Marine mammal study 6-4. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Bodkin, J.L.; Mulcahy, D.M.; Lensink, C.J.

    1996-06-01

    We estimated age of sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from southcentral Alaska, primarily western Prince William Sound, following the T/V Exxon Valdez oil spill in 1989. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similar to those in the literature based on in situ observations of marked individuals.

  9. The role of age-specific learning and experience for turtles navigating a changing landscape.

    PubMed

    Roth, Timothy C; Krochmal, Aaron R

    2015-02-02

    The severity of the environment often influences animal cognition [1-6], as does the rate of change within that environment [7-10]. Rapid alteration of habitat places limitations on basic resources such as energy, water, nesting sites, and refugia [8, 10]. How animals respond to these situations provides insight into the mechanisms of cognition and the role of behavior in adaptation [11-13]. We tested the hypothesis that learning plays a role in the navigation of the painted turtle (Chrysemys picta) within a model of environmental change. We radiotracked experienced and naive turtles at different developmental stages from two different populations as they sought out new habitats when their pond was destroyed. Our data suggest that the ability of turtles to navigate is facilitated in part by experience during a critical period. Resident adults repeatedly used specific routes with exceptional precision, while translocated adults failed to find water. Naive juveniles (1-3 years old) from both populations used the same paths taken by resident adults; the ability to follow paths was lost by age 4. We also used laboratory behavioral assays to examine the possible cues facilitating this precise navigation. Turtles responded to manipulation of the local ultraviolet environment, but not the olfactory environment. This is the first evidence to suggest that learning during a critical period may be important for how animals respond to changing environments. Our work emphasizes the need for the examination of learning in navigation and the breadth of critical learning periods across vertebrates.

  10. Patterns and Trends in Age-Specific Black-White Differences in Breast Cancer Incidence and Mortality - United States, 1999-2014.

    PubMed

    Richardson, Lisa C; Henley, S Jane; Miller, Jacqueline W; Massetti, Greta; Thomas, Cheryll C

    2016-10-14

    Breast cancer continues to be the most commonly diagnosed cancer and the second leading cause of cancer deaths among U.S. women (1). Compared with white women, black women historically have had lower rates of breast cancer incidence and, beginning in the 1980s, higher death rates (1). This report examines age-specific black-white disparities in breast cancer incidence during 1999-2013 and mortality during 2000-2014 in the United States using data from United States Cancer Statistics (USCS) (2). Overall rates of breast cancer incidence were similar, but death rates remained higher for black women compared with white women. During 1999-2013, breast cancer incidence decreased among white women but increased slightly among black women resulting in a similar average incidence at the end of the period. Breast cancer incidence trends differed by race and age, particularly from 1999 to 2004-2005, when rates decreased only among white women aged ≥50 years. Breast cancer death rates decreased significantly during 2000-2014, regardless of age with patterns varying by race. For women aged ≥50 years, death rates declined significantly faster among white women compared with black women; among women aged <50 years, breast cancer death rates decreased at the same rate among black and white women. Although some of molecular factors that lead to more aggressive breast cancer are known, a fuller understanding of the exact mechanisms might lead to more tailored interventions that could decrease mortality disparities. When combined with population-based approaches to increase knowledge of family history of cancer, increase physical activity, promote a healthy diet to maintain a healthy bodyweight, and increase screening for breast cancer, targeted treatment interventions could reduce racial disparities in breast cancer.

  11. Fertility preservation in Turner syndrome.

    PubMed

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

    2016-01-01

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

  12. Age-specific survival of tundra swans on the lower Alaska Peninsula

    USGS Publications Warehouse

    Meixell, Brandt W.; Lindberg, Mark S.; Conn, Paul B.; Dau, Christian P.; Sarvis, John E.; Sowl, Kristine M.

    2013-01-01

    The population of Tundra Swans (Cygnus columbianus columbianus) breeding on the lower Alaska Peninsula represents the southern extremity of the species' range and is uniquely nonmigratory. We used data on recaptures, resightings, and recoveries of neck-collared Tundra Swans on the lower Alaska Peninsula to estimate collar loss, annual apparent survival, and other demographic parameters for the years 1978–1989. Annual collar loss was greater for adult males fitted with either the thinner collar type (0.34) or the thicker collar type (0.15) than for other age/sex classes (thinner: 0.10, thicker: 0.04). The apparent mean probability of survival of adults (0.61) was higher than that of immatures (0.41) and for both age classes varied considerably by year (adult range: 0.44–0.95, immature range: 0.25–0.90). To assess effects of permanent emigration by age and breeding class, we analyzed post hoc the encounter histories of swans known to breed in our study area. The apparent mean survival of known breeders (0.65) was generally higher than that of the entire marked sample but still varied considerably by year (range 0.26–1.00) and indicated that permanent emigration of breeding swans was likely. We suggest that reductions in apparent survival probability were influenced primarily by high and variable rates of permanent emigration and that immigration by swans from elsewhere may be important in sustaining a breeding population at and near Izembek National Wildlife Refuge.

  13. Toward replacement fertility in Egypt and Tunisia.

    PubMed

    Eltigani, Eltigani E

    2009-09-01

    Egypt and Tunisia began their fertility transition at almost identical fertility levels and at roughly the same time period, yet the difference in the pace of decline has been such that the total fertility rate (TFR) in Tunisia reached replacement level by the year 2001, whereas the TFR in Egypt remains above three live births per woman. This article draws on the secondary literature and on several nationally representative surveys from the two countries between 1978 and 2005 to provide empirical evidence of the difference in the pace of fertility decline and to analyze the determinants of the differential. Findings include (a) variation across the two countries in the consistency of fertility decline among the segments of the population leading the transition; (b) that the success of each country's family planning program was influenced by the role of political leaders and the extent of the program's integration within socioeconomic development objectives; (c) that the impact of contraception on TFR decline became an important factor in the mid-1980s; and (d) that the greatest determinant of the discrepancy in the pace of fertility decline is the disparity in age at marriage, which rose more significantly in Tunisia than in Egypt. The latter finding indicates that reaching replacement fertility in Egypt hinges primarily on further declines in marital fertility, resulting from reduction of wanted fertility and from an expansion of family planning program coverage and improved efficiency of service delivery and use.

  14. Plant fertilizer poisoning

    MedlinePlus

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

  15. What Is Fertility Preservation?

    MedlinePlus

    ... cancer.net/navigating-cancer-care/dating-sex-and-reproduction/fertility-concerns-and-preservation-men [top] ASCO. (2016). ... cancer.net/navigating-cancer-care/dating-sex-and-reproduction/fertility-concerns-and-preservation-women [top] National Cancer ...

  16. Poly-LacNAc as an Age-Specific Ligand for Rotavirus P[11] in Neonates and Infants

    PubMed Central

    Liu, Yang; Huang, Pengwei; Jiang, Baoming; Tan, Ming; Morrow, Ardythe L.; Jiang, Xi

    2013-01-01

    Rotavirus (RV) P[11] is an unique genotype that infects neonates. The mechanism of such age-specific host restriction remains unknown. In this study, we explored host mucosal glycans as a potential age-specific factor for attachment of P[11] RVs. Using in vitro binding assays, we demonstrated that VP8* of a P[11] RV (N155) could bind saliva of infants (60.3%, N = 151) but not of adults (0%, N = 48), with a significantly negative correlation between binding of VP8* and ages of infants (P<0.01). Recognition to the infant saliva did not correlate with the ABO, secretor and Lewis histo-blood group antigens (HBGAs) but with the binding of the lectin Lycopersicon esculentum (LEA) that is known to recognize the oligomers of N-acetyllactosamine (LacNAc), a precursor of human HBGAs. Direct evidence of LacNAc involvement in P[11] binding was obtained from specific binding of VP8* with homopolymers of LacNAc in variable lengths through a glycan array analysis of 611 glycans. These results were confirmed by strong binding of VP8* to the Lec2 cell line that expresses LacNAc oligomers but not to the Lec8 cell line lacking the LacNAc. In addition, N155 VP8* and authentic P[11] RVs (human 116E and bovine B223) hemagglutinated human red blood cells that are known to express poly-LacNAc. The potential role of poly-LacNAc in host attachment and infection of RVs has been obtained by abrogation of 116E replication by the PAA-conjugated poly-LacNAc, human milk, and LEA positive infant saliva. Overall, our results suggested that the poly-LacNAc could serve as an age-specific receptor for P[11] RVs and well explained the epidemiology that P[11] RVs mainly infect neonates and young children. PMID:24244290

  17. Polygamy and fertility in Somalia.

    PubMed

    Johnson, N E; Elmi, A M

    1989-04-01

    The 1983 Somali Family Health Survey showed that polygamy and monogamy selected women with different social characteristics. Wives in polygamous unions were prone to be younger at first martial cohabitation and to have previous marital disruptions. Since a young age at first cohabitation and number of previous marriages have opposite effects on the cumulative fertility rate of women, the difference in this rate between wives in polygamous and monogamous unions vanished when both factors were controlled in a multivariate analysis.

  18. Income, education, and fertility.

    PubMed

    1978-01-01

    A study based on data from the National Impact Survey (1968-69) delineates the impact of family planning programs on the demography of Pakistan. Son preference was found to be a strong factor in deciding the desire for an additional child. Raising the status of women would decrease the fertility rate. In the rural areas higher income had a positive effect on fertility; in the urban areas it had a negative effect. Policies explicitly directed at actual distribution of income would have a positive effect. The educational level of the family, especially the wife, was related to lower family size. Families with at least one child in school had a lower completed family size. Couples who married later in life did not tend to have smaller families but smaller intervals between births. Rural nuclear families have more children than non-nuclear families or kinship groups, presumably because they need children for labor and old age security. Incentives and disincentives to motivate couples to limit family size should be offered by the Pakistan government.

  19. Effects of greenhouse warming and N-fertilization on carbon accumulation rates in a nutrient-poor boreal mire: decadal effects assessed using 210Pb

    NASA Astrophysics Data System (ADS)

    Olid, Carolina; Nilsson, Mats B.; Eriksson, Tobias; Klaminder, Jonatan

    2013-04-01

    Boreal peatlands represent a major long-term reservoir of atmospheric carbon (C) and play an important role in the global C cycle. How C accumulation in these peatlands responds to changing temperature and nutrient conditions is under debate. In this study, we assessed how peat and C accumulation rates have responded to increased annual nitrogen additions (30 kg ha-1 yr-1) and increased air temperatures (+3.6°C) in the longest ongoing boreal mire manipulation experiment. Accumulation rates for the uppermost 40 cm of peat in nitrogen and temperature treated plots (n=11) were assessed by 210Pb dating covering the last ~100yrs. A reference surface, installed in 1995 was used as independent validation of the dating model. An empirically based model of organic matter accumulation/degradation was applied to evaluate changes in both peat inputs and organic matter decay rates in response to the treatments. A significant increase in C-accumulation (15 g C m-2 yr-1) was observed in peat subjected to nitrogen additions, while greenhouse warming did not seem to significantly affect C-accumulation or decay rates. Based on our findings we argue that C-accumulation in nutrient poor boreal mires is mainly altered in near-surface peat layers (~15 cm) in response to nitrogen additions and that the uppermost peat layers (<40 cm) in nutrient poor boreal peatlands will continue to function as net C-sinks during the first decades of global warming.

  20. Cancer and fertility: strategies to preserve fertility.

    PubMed

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

    2011-03-01

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

  1. Using auditory pre-information to solve the cocktail-party problem: electrophysiological evidence for age-specific differences.

    PubMed

    Getzmann, Stephan; Lewald, Jörg; Falkenstein, Michael

    2014-01-01

    Speech understanding in complex and dynamic listening environments requires (a) auditory scene analysis, namely auditory object formation and segregation, and (b) allocation of the attentional focus to the talker of interest. There is evidence that pre-information is actively used to facilitate these two aspects of the so-called "cocktail-party" problem. Here, a simulated multi-talker scenario was combined with electroencephalography to study scene analysis and allocation of attention in young and middle-aged adults. Sequences of short words (combinations of brief company names and stock-price values) from four talkers at different locations were simultaneously presented, and the detection of target names and the discrimination between critical target values were assessed. Immediately prior to speech sequences, auditory pre-information was provided via cues that either prepared auditory scene analysis or attentional focusing, or non-specific pre-information was given. While performance was generally better in younger than older participants, both age groups benefited from auditory pre-information. The analysis of the cue-related event-related potentials revealed age-specific differences in the use of pre-cues: Younger adults showed a pronounced N2 component, suggesting early inhibition of concurrent speech stimuli; older adults exhibited a stronger late P3 component, suggesting increased resource allocation to process the pre-information. In sum, the results argue for an age-specific utilization of auditory pre-information to improve listening in complex dynamic auditory environments.

  2. Using auditory pre-information to solve the cocktail-party problem: electrophysiological evidence for age-specific differences

    PubMed Central

    Getzmann, Stephan; Lewald, Jörg; Falkenstein, Michael

    2014-01-01

    Speech understanding in complex and dynamic listening environments requires (a) auditory scene analysis, namely auditory object formation and segregation, and (b) allocation of the attentional focus to the talker of interest. There is evidence that pre-information is actively used to facilitate these two aspects of the so-called “cocktail-party” problem. Here, a simulated multi-talker scenario was combined with electroencephalography to study scene analysis and allocation of attention in young and middle-aged adults. Sequences of short words (combinations of brief company names and stock-price values) from four talkers at different locations were simultaneously presented, and the detection of target names and the discrimination between critical target values were assessed. Immediately prior to speech sequences, auditory pre-information was provided via cues that either prepared auditory scene analysis or attentional focusing, or non-specific pre-information was given. While performance was generally better in younger than older participants, both age groups benefited from auditory pre-information. The analysis of the cue-related event-related potentials revealed age-specific differences in the use of pre-cues: Younger adults showed a pronounced N2 component, suggesting early inhibition of concurrent speech stimuli; older adults exhibited a stronger late P3 component, suggesting increased resource allocation to process the pre-information. In sum, the results argue for an age-specific utilization of auditory pre-information to improve listening in complex dynamic auditory environments. PMID:25540608

  3. The effects of acupuncture on rates of clinical pregnancy among women undergoing in vitro fertilization: a systematic review and meta-analysis

    PubMed Central

    Manheimer, Eric; van der Windt, Daniëlle; Cheng, Ke; Stafford, Kristen; Liu, Jianping; Tierney, Jayne; Lao, Lixing; Berman, Brian M.; Langenberg, Patricia; Bouter, Lex M.

    2013-01-01

    BACKGROUND Recent systematic reviews of adjuvant acupuncture for IVF have pooled heterogeneous trials, without examining variables that might explain the heterogeneity. The aims of our meta-analysis were to quantify the overall pooled effects of adjuvant acupuncture on IVF clinical pregnancy success rates, and evaluate whether study design-, treatment- and population-related factors influence effect estimates. METHODS We included randomized controlled trials that compared needle acupuncture administered within 1 day of embryo transfer, versus sham acupuncture or no adjuvant treatment. Our primary outcome was clinical pregnancy rates. We obtained from all investigators additional methodological details and outcome data not included in their original publications. We analysed sham-controlled and no adjuvant treatment-controlled trials separately, but since there were no large or significant differences between these two subsets, we pooled all trials for subgroup analyses. We prespecified 11 subgroup variables (5 clinical and 6 methodological) to investigate sources of heterogeneity, using single covariate meta-regressions. RESULTS Sixteen trials (4021 participants) were included in the meta-analyses. There was no statistically significant difference between acupuncture and controls when combining all trials [risk ratio (RR) 1.12, 95% confidence interval (CI), 0.96–1.31; I2 = 68%; 16 trials; 4021 participants], or when restricting to sham-controlled (RR 1.02, 0.83–1.26; I2 = 66%; 7 trials; 2044 participants) or no adjuvant treatment-controlled trials (RR 1.22, 0.97–1.52; I2 = 67%; 9 trials; 1977 participants). The type of control used did not significantly explain the statistical heterogeneity (interaction P = 0.27). Baseline pregnancy rate, measured as the observed rate of clinical pregnancy in the control group of each trial, was a statistically significant effect modifier (interaction P < 0.001), and this covariate explained most of the heterogeneity of the

  4. Effects of sex-sorting and sperm dosage on conception rates of Holstein heifers: is comparable fertility of sex-sorted and conventional semen plausible?

    PubMed

    Dejarnette, J M; Leach, M A; Nebel, R L; Marshall, C E; McCleary, C R; Moreno, J F

    2011-07-01

    The conception rates of Holstein heifers after AI with 2.1 or 10 × 10(6) sperm dosages of sex-sorted or conventionally processed sperm were compared. Ejaculates collected by artificial vagina from 8 Holstein sires were cryopreserved at either 2.1 or 10 × 10(6) sperm per dose with or without sorting to 90% purity for X-chromosome-bearing spermatozoa using flow cytometry. All treatments were processed in an egg-yolk (20%), TRIS, glycerol (7%) extender and packaged in color-coded 0.25-mL French straws. Straws (n=350 straws/treatment per sire) were packaged and distributed in aliquots of 12 (3 straws of each treatment) to 51 herds of Holstein heifers. Straw color was recorded in the on-farm record keeping system at the time of AI and retrieved by electronic download. In total, 9,172 services were recovered, providing a mean sample size of 287±3.5 services/sperm dose per semen type within sire (range: 248 to 318). Conception rates were influenced by the main effects of herd, sire, semen type, sperm dosage, and service number. The herd by sperm dosage interaction was the only interaction determined to be significant and implies that some herds (technicians) are more proficient than others at maintaining high levels of conception with decreased sperm dosages. Across herds and sires, the conception rates of each semen type by sperm dosage combination were as follows: 2.1 × 10(6) sex-sorted, 38%, n=2,319; 10 × 10(6) sex-sorted, 44%, n=2,279; 2.1 × 10(6) conventional, 55%, n=2,282; and 10 × 10(6) conventional, 60%, n=2,292. The observation that conception rates of sex-sorted semen were improved by the 10 × 10(6) sperm dosage is encouraging toward the prospectus of development of a commercially available sex-sorted product with improved conception potential over existing technology. However, the failure of the 10 × 10(6) sex-sorted sperm dosage to achieve conception rates comparable to either dosage of conventional semen is somewhat discouraging toward the

  5. Mitigation of Water Stress on Apple Trees under Rotational Irrigation Conditions by Increasing the Application Rate of Organic Fertilizers to Sandy Soils

    NASA Astrophysics Data System (ADS)

    Hamed, Lamy Mamdoh Mohamed; Ramadan Eid, Abdelraouf; Mohsmed Rabie Abdellatif Abdelaziz, Adel; Fathy Abdelsalam Essa, El-Sayed

    2016-04-01

    Egypt, as part of Mediterranean regions, is characterized by irregular and low rainfall amount which varies between (30-150 mm.year-1), and characterized also by high temperature which increase the rate of evapotranspiration from the cultivated soil. On the other hand, New reclaimed soils are mostly occupies around 84 % of total area of Egypt, which is mainly sandy soils. These soils generally characterized by low water capacity holding, soil organic matter, and weak in nutrients retention. Under these conditions which have a great influence on crop production, there is a great needing to increase the crop water use efficiency and increasing of nutrient retention in sandy soils. In this context, two field experiments were carried out on sand soil located in north Cairo-Egypt at the experimental farm of National Research Center, El-NUBARIA, (latitude 30° 30' N, and longitude 30° 19' E). The effect of compost rates on soil hydraulic characteristics, fruit yields, quality traits, and water use efficiency and productivity of apple tree (Apple Anna Cultivar), was studied under deficit irrigation conditions. Four rates of compost [I1: control, I2: 12 ton.ha-1., I3: 24 ton.ha-1., I4: 36 ton.ha-1. and I5:48 ton.ha-1.] were applied under irrigation frequencies of (IF1 :once per week; IF2 :twice per week, IF3 :three times per week). The obtained results indicated that by increasing the application rate of compost, the available water capacity and saturated water content of sandy soil have been enhanced. In the same time, the fruit yield, quality traits and water productivity were increased by increasing the application rate of compost. It is worthy to mention that the I5IF3 treatment gave the highest values of fruit yield, quality traits and water productivity, whereas I1IF1 treatment gave the lowest values of all the above mentioned variables. As result, for apple cultivation in El-NUBARIA region, the recommended rate of compost is 48 ton.ha-1 and irrigation frequency

  6. Birth delays skew developing world's fertility figures.

    PubMed

    1999-09-01

    This article explains that birth delays skew developing world's fertility figures. When successive groups of women who have delayed childbearing start having children, the rapid fertility decline stalls. Such change in the timing of childbearing skews the total fertility rate (TFR). Analysis of the tempo component of TFR trends in Taiwan suggests that tempo effects reduced its TFR by about 10% in the late 1970s and early 1990s and by about 19% in the late 1980s. In Colombia, on the basis of increasing mean maternal age at childbirth between the 1970s and the late 1980s, tempo distortions of the TFR during the most of the 1980s seem likely. Moreover, many developing countries are now experiencing rapid fertility declines that are in part attributable to tempo changes. These changes have accelerated past fertility transitions, but they also make these countries vulnerable to future stalls in fertility when the delays in childbearing end. Since fertility reductions caused by tempo effects lead to real declines in birth rates and hence in population growth, countries that wish to reduce birth rates can take actions that encourage women to delay marriage and the onset of childbearing.

  7. Obesity and fertility.

    PubMed

    Best, Damian; Bhattacharya, Siladitya

    2015-10-01

    The prevalence of overweight and obesity in women of reproductive age has increased over the past 30 years. Infertility affects 1 in 7 couples, and female obesity is associated with anovulation. The mechanisms by which excessive fat delays time to pregnancy (TTP) appear rooted in ovulatory problems and direct effects on oocytes, causing poorer embryo development, as well as in effects on the endometrium. Weight loss in women has been shown to improve conception, but not necessarily live birth rates following fertility treatment, and further research in this area is needed. The obesity epidemic has been accompanied by a potential rise in male infertility, which has been attributed to hormonal disturbances and compromised semen parameters.

  8. Growth, root formation, and nutrient value of triticale plants fertilized with biosolids.

    PubMed

    Rauw, Wendy Mercedes; Teglas, Michael Bela; Chandra, Sudeep; Forister, Matthew Lewis

    2012-01-01

    Biosolids are utilized as nutrient rich fertilizer. Little material is available on benefits to forage crops resulting from fertilization with biosolids. This paper aimed to compare the effects of fertilization with biosolids versus commercial nitrogen fertilizer on growth, root formation, and nutrient value of triticale plants in a greenhouse experiment. Per treatment, five pots were seeded with five triticale seeds each. Treatments included a nonfertilized control, fertilization with 100, 200, 300, 400, and 500 ml biosolids per pot, and fertilization with a commercial nitrogen fertilizer at the recommended application rate and at double that rate. Biomass production, root length, root diameter, nitrogen, phosphorus, and potassium concentration were analyzed at harvest. Fertilization with biosolids increased triticale production (P < 0.001); production was similar for the 100 to 400 mL treatments. Root length, nitrogen, and phosphorus concentration increased, and potassium concentration decreased linearly with application rate. At the recommended rate, biomass production was similar between fertilization with biosolids and commercial fertilizer. However, plants fertilized with commercial fertilizer had considerably longer roots (P < 0.001), higher nitrogen concentration (P < 0.05), and lower potassium concentration (P < 0.01) than those fertilized with biosolids. Our results indicate that at the recommended application rate, biomass production was similar between fertilization with biosolids and with commercial nitrogen fertilizer, indicating the value of biosolids fertilization as a potential alternative.

  9. Growth, Root Formation, and Nutrient Value of Triticale Plants Fertilized with Biosolids

    PubMed Central

    Rauw, Wendy Mercedes; Teglas, Michael Bela; Chandra, Sudeep; Forister, Matthew Lewis

    2012-01-01

    Biosolids are utilized as nutrient rich fertilizer. Little material is available on benefits to forage crops resulting from fertilization with biosolids. This paper aimed to compare the effects of fertilization with biosolids versus commercial nitrogen fertilizer on growth, root formation, and nutrient value of triticale plants in a greenhouse experiment. Per treatment, five pots were seeded with five triticale seeds each. Treatments included a nonfertilized control, fertilization with 100, 200, 300, 400, and 500 ml biosolids per pot, and fertilization with a commercial nitrogen fertilizer at the recommended application rate and at double that rate. Biomass production, root length, root diameter, nitrogen, phosphorus, and potassium concentration were analyzed at harvest. Fertilization with biosolids increased triticale production (P < 0.001); production was similar for the 100 to 400 mL treatments. Root length, nitrogen, and phosphorus concentration increased, and potassium concentration decreased linearly with application rate. At the recommended rate, biomass production was similar between fertilization with biosolids and commercial fertilizer. However, plants fertilized with commercial fertilizer had considerably longer roots (P < 0.001), higher nitrogen concentration (P < 0.05), and lower potassium concentration (P < 0.01) than those fertilized with biosolids. Our results indicate that at the recommended application rate, biomass production was similar between fertilization with biosolids and with commercial nitrogen fertilizer, indicating the value of biosolids fertilization as a potential alternative. PMID:22593686

  10. Fertility Herbs: Do They Enhance Fertility?

    MedlinePlus

    ... pregnant. I've seen many ads for fertility herbs and supplements. Do they work? Answers from Jani ... it's not surprising that some people look to herbs and supplements as a possible alternative treatment to ...

  11. Two years monitoring of soil N_{2}O emissions on durum wheat in a Mediterranean area: the effect of tillage intensity and N-fertilizer rate.

    NASA Astrophysics Data System (ADS)

    Volpi, Iride; Bosco, Simona; Triana, Federico; Di Nasso, Nicoletta Nassi o.; Laville, Patricia; Virgili, Giorgio; Bonari, Enrico

    2016-04-01

    Evaluating the magnitude and the key factors affecting N2O emissions from agriculture has a scientific and practical relevance, in fact emissions from agricultural and natural soils account for 56-70% of all global N2O sources (Syakila and Kroeze, 2011). Moreover, the necessity to increase the food production rate minimizing greenhouse gas emissions require a deeper understanding of the effect of the agricultural practices on direct soil emissions. Therefore, the aim of this work is to assess the effect of tillage intensity and nitrogen rate on soil N2O emissions on durum wheat. A two years monitoring campaign was carried out using a high-sensibility transportable instrument developed within the LIFE+ "Improved flux Prototypes for N2O emission from Agriculture" IPNOA project (Bosco et al., 2015; Laville et al., 2015). The project aims at improving the measurement technique of N2O flux directly in field using the flow-through non-steady state chamber technique. The monitoring campaign on durum wheat lasted for two growing seasons and two fallow periods (2013-14 and 2014-15). Treatment on the main plot was tillage intensity with two levels, ploughing and minimum tillage, and three different nitrogen rates were distributed to the subplots (N0: 0 kg ha-1, N1: 110 kg ha-1, N2: 170 kg ha-1). Ancillary measurements concerned meteorological data, soil temperature and moisture, NO3-, NH4+ soil concentration. Main results of the two years highlighted N rate as the main driver for both N2O daily flux and cumulative emissions during the growing season, while in the fallow period treatments did not affect the emission magnitude. Tillage intensity was not a key factor for N2O emissions. N2O emissions were significantly different in the two years. In particular, cumulative emissions of 2013-14 were about five times higher than in 2014-15, respectively on average 2885±260 g N-N2O ha-1 and 534±53 g N-N2O ha-1 for a similar monitoring period of about 300 days. Differences could be

  12. An age adjustment of very young children of India, 1981 and reappraisal of fertility and mortality rates--A model approach.

    PubMed

    Mukhopadhyay, B K

    1986-01-01

    Several approaches were made by actuaries and demographers to correct and smooth the Indian age distribution with special emphasis on population in age group 0-4 at different points of time. The present analysis conceives the life table stationary population (using the West Model) as 'reference standard'. 2 parameters were estimated from a regression equation using the proportion of population in age groups 5-14 and 60-plus as independent variables and that in 0-4 as the dependent variable. The corrected census proportions in age group 0-4 obtained from the regression model under certain assumptions for the 14 major states and India seem to be consistent and to have slightly lower values than those of the 1971 adjusted data. Moreover, unadjusted and adjusted proportions in 5-14 and 60 plus do not show any significant difference between the predicted values. Using the corrected population aged 0-4 years, the average annual birth and death rates during the 5 year period preceeding the 1981 census have been estimated for those 14 states and India as well. The estimated birth rates so obtained were further adjusted using an appropriate factor from the West Model and Indian life table survival ratios. The final estimates seem to be consistent, except for a few, and to have slightly higher values than those of earlier estimates. As the present analysis is based on a 5% sample and confined to only 14 states, it is proposed to study the same for all the states and India in greater detail using full count data on age distribution and actul life tables as and when available.

  13. Age-Specific Dynamics of Corpus Callosum Development in Children and its Peculiarities in Infantile Cerebral Palsy.

    PubMed

    Krasnoshchekova, E I; Zykin, P A; Tkachenko, L A; Aleksandrov, T A; Sereda, V M; Yalfimov, A N

    2016-10-01

    The age dynamics of corpus callosum development was studied on magnetic resonance images of the brain in children aged 2-11 years without neurological abnormalities and with infantile cerebral palsy. The areas of the total corpus callosum and its segments are compared in the midsagittal images. Analysis is carried out with the use of an original formula: proportion of areas of the anterior (genu, CC2; and anterior part, CC3) and posterior (isthmus, CC6 and splenium, CC7) segments: kCC=(CC2+CC3)×CC6/CC7. The results characterize age-specific dynamics of the corpus callosum development and can be used for differentiation, with high confidence, of the brain of children without neurological abnormalities from the brain patients with infantile cerebral palsy.

  14. Race/ethnicity-, gender- and age-specific differences in micronutrient intakes of US adults with and without diabetes.

    PubMed

    Vaccaro, Joan A; Huffman, Fatma G

    2013-03-01

    Race/ethnicity-, gender- and age-specific differences in dietary micronutrient intakes of US adults ≥  21 years were assessed from National Health and Nutrition Examination Survey, 2007-2008. The participants included Black non-Hispanics, Mexican-American and White non-Hispanics who signed an informed consent form for the interview and who completed the in-person 24-h recall. Micronutrient intakes were based on the Institute of Medicines' classifications of recommended dietary allowances specific for age and gender. Likelihood of many micronutrient insufficiencies was associated with being female, over 65 years, having diabetes and minority status. Younger and female adults had a greater likelihood of iron insufficiency than male and older adults. These findings demonstrate the importance of considering the intersection of age, gender and race in setting policies for micronutrient deficiency screening, particularly in young female adults and minorities.

  15. 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.

  16. Age-specific and sex-specific incidence of systemic lupus erythematosus: an estimate from cross-sectional claims data of 2.3 million people in the German statutory health insurance 2002

    PubMed Central

    Brinks, Ralph; Hoyer, Annika; Weber, Sergej; Fischer-Betz, Rebecca; Sander, Oliver; Richter, Jutta G; Chehab, Gamal; Schneider, Matthias

    2016-01-01

    Objective To provide an estimate of age-specific incidence rate of physician-diagnosed systemic lupus erythematosus (SLE) for German men and women. Methods The age-specific and sex-specific prevalence of diagnosed SLE in claims data is used to estimate the incidence in the German male and female population. The claims data set stems from a representative sample of the statutory health insurance in 2002 and comprises 2.3 million people. The statutory health insurance covers >85% of the German population. Results The estimated incidence rates are 0.9 (95% CI 0.7 to 1.1) per 100 000 person-years for men and 1.9 (95% CI 1.7 to 2.2) per 100 000 person-years for women. The age-specific incidence rate of SLE in the male population has a maximum of 2.2 (95% CI 1.0 to 3.4) per 100 000 person-years at the age of 65–70 years. In women, the incidence is peaking at the rate of 3.6 (95% CI 2.9 to 4.3) cases per 100 000 person-years at the age of 20–25 years, but has a second local maximum (2.6, 95% CI 1.5 to 3.8) at menopausal age. Conclusions For the first time, representative data on the incidence of SLE in Germany are provided. The estimated incidence rates of SLE for men and women in Germany are at the lower end of other estimates from comparable European countries. PMID:27933200

  17. Reduction of phosphorus concentration in mineral supplement on fertility rate, maternal ability and costs of beef cows reared in pastures of Urochloa decumbens.

    PubMed

    Costa, Rogério Magnoli; Ponsano, Elisa Helena Giglio; de Souza, Vinícius Carneiro; Malafaia, Pedro

    2016-02-01

    Manufacturing and marketing of mineral mixtures with less than 40 g kg(-1) phosphorus (P) is prohibited under Brazilian regulations, although scientific evidence rejects this recommendation. Considering the hypothesis that P levels in commercial mineral supplements can be reduced without affecting animal performance and health, the objective of this experiment was to evaluate the effects of reducing the concentration of P in the mineral supplement (from 40 to 18 g kg(-1)) of a herd of beef cows grazing tropical pastures of signal grass (Urochloa decumbens). The experiment was carried out in the savanna region of Mato Grosso do Sul, Brazil, during the years 2011 to 2013. Variables analyzed included pregnancy rate, calving interval, weight of calves at weaning, and cost of mineral supplementation. There were no changes in the reproductive parameters of the herd and the weight at weaning of the calves. However, the cost of mineral supplementation was significantly lower when the herd was supplemented with the mineral mix containing only 18 g kg(-1) P. Phosphorus concentration of the forage was analyzed monthly during 1 year and averaged 1.9 ± 0.45 g kg(-1) DM. Thus, it appears possible to reduce P content and cost of mineral supplementation without any adverse effects on the health and productivity of beef cattle herds in the State of Mato Grosso do Sul. However, the final decision should be made based on the clinical-nutritional examination and by constant technical assistance to the farm.

  18. Fertilization in echinoderms.

    PubMed

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

    2012-08-31

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

  19. Fertilizer Use and Water Quality.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

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

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

    USGS Publications Warehouse

    Ransom, J.I.

    2012-01-01

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

  1. 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.

  2. Inconceivable? Deducting the costs of fertility treatment.

    PubMed

    Pratt, Katherine T

    2004-07-01

    This Article considers whether infertile taxpayers can deduct their fertility treatment costs as medical expenses under Internal Revenue Code section 213 and whether they should be able to deduct them. Internal Revenue Code section 213 defines medical expenses as "amounts paid-for the diagnosis, cure, mitigation, treatment, or prevention of disease, or for the purpose of affecting any structure or function of the body." This definition is interpreted by reference to a baseline of normal biological functioning, which includes reproductive functioning. Most people conceive and bear children without having to incur expenses for fertility treatment. Expenses incurred to approximate the baseline of normal reproductive health are deductible, even if the taxpayer winds up better off, with a child, after the fertility treatment. The medical profession recognizes that infertility is a disease or condition. Infertility is a loss, just as a broken leg is a loss. Fertility treatment costs are thus medical expenses under section 213. In addition, given the existence of the medical expense deduction, taxpayers should be able to deduct the cost of fertility treatments, including IVF, egg donor, and surrogate procedures, under either an "ability-to-pay" or consequentialist normative approach. Reproduction is extremely important to most people. In addition, allowing taxpayers to deduct the costs of fertility treatment will encourage infertile taxpayers to elect the most effective treatment option and reduce the rate of risky multifetal pregnancies. This Article concludes that fertility treatment costs are deductible as medical expenses under current law and should be deductible as medical expenses.

  3. Fertility Treatments for Females

    MedlinePlus

    ... are some causes of infertility?​​​ What is fertility preservation? When should I consult a health care provider?​ ... are some causes of infertility?​​​ What is fertility preservation? When should I consult a health care provider?​ ...

  4. Infertility and Fertility

    MedlinePlus

    ... are some causes of infertility?​​​ What is fertility preservation? When should I consult a health care provider?​ ... are some causes of infertility?​​​ What is fertility preservation? When should I consult a health care provider?​ ...

  5. Precision fertilization of Wyoming sugar beets: A case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field Studies were conducted on a farm in northwest Wyoming to compare variable-rate fertilization (VRF) with uniform-rate fertilization (URF) of sugar beets. Results from this study failed to show an economic advantage from VRF compared to URF, implying producers should be very cautious to adopt VR...

  6. 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…

  7. [Socioeconomic variables and fertility].

    PubMed

    Arguello, O

    1980-08-01

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

  8. Fertilizer use and price statistics, 1960-1991. Statistical bulletin

    SciTech Connect

    Vroomen, H.; Taylor, H.

    1992-11-01

    Fertilizer consumption grew rapidly throughout the 1960's and 1970's and peaked at 23.7 million nutrient tons in 1981. After falling to 18.1 million tons in 1983, use has remained relatively stable, ranging from 19.1 million to 21.8 million tons in 1984-91. Use declined from its peak level because of fewer planted acres and stabilizing rates of application. Retail fertilizer prices, while stable or declining during the 1960's, have varied widely since 1973. The bulletin includes quarterly or semiannual time series for retail fertilizer prices, annual retail and wholesale fertilizer price indexes, fertilizer consumption by plant nutrient and major selected products, consumption of mixed fertilizers and secondary and micronutrients, and statistics on fertilizer use per acre by nutrient in the major producing States for corn, cotton, soybeans, and wheat.

  9. Age-specific absolute and relative organ weight distributions for B6C3F1 mice.

    PubMed

    Marino, Dale J

    2012-01-01

    The B6C3F1 mouse is the standard mouse strain used in toxicology studies conducted by the National Cancer Institute (NCI) and the National Toxicology Program (NTP). While numerous reports have been published on growth, survival, and tumor incidence, no overall compilation of organ weight data is available. Importantly, organ weight change is an endpoint used by regulatory agencies to develop toxicity reference values (TRVs) for use in human health risk assessments. Furthermore, physiologically based pharmacokinetic (PBPK) models, which utilize relative organ weights, are increasingly being used to develop TRVs. Therefore, all available absolute and relative organ weight data for untreated control B6C3F1 mice were collected from NCI/NTP studies in order to develop age-specific distributions. Results show that organ weights were collected more frequently in NCI/NTP studies at 2-wk (60 studies), 3-mo (147 studies), and 15-mo (40 studies) intervals than at other intervals, and more frequently from feeding and inhalation than drinking water studies. Liver, right kidney, lung, heart, thymus, and brain weights were most frequently collected. From the collected data, the mean and standard deviation for absolute and relative organ weights were calculated. Results show age-related increases in absolute liver, right kidney, lung, and heart weights and relatively stable brain and right testis weights. The results suggest a general variability trend in absolute organ weights of brain < right testis < right kidney < heart < liver < lung < spleen < thymus. This report describes the results of this effort.

  10. Estimating Age-Specific Immunity and Force of Infection of Varicella Zoster Virus in Norway Using Mixture Models

    PubMed Central

    Rimseliene, Grazina; Flem, Elmira; Freiesleben de Blasio, Birgitte; Scalia Tomba, Gianpaolo; Manfredi, Piero

    2016-01-01

    This study applies mixture modelling to examine age-specific immunity to varicella zoster virus (VZV) infection in Norway based on the first large-scale serological study in the general population. We estimated the seropositive proportions at different ages and calculated the underlying force of infection by using a sample of 2103 residual sera obtained from patients seeking primary and hospital care. A rapid increase in the VZV-associated immunity is observed in the first years of life with 63% of children being immune by age 5. The increase in the immunity levels slows down thereafter, with a large proportion of adults still susceptible by age 20 (around 14.5%), thus at risk of serious sequelae of varicella infection. The corresponding force of infection peaks during the preschool period, subsequently declines to a minimum between ages 10 and 20 years, and afterwards moderately increases to reach a plateau lasting throughout the childbearing period. In comparison with the traditional cut-off approach, mixture modelling used the whole data without producing any inconclusive cases, led to an unbiased classification of individuals between susceptible and immune, and provided a smoother immune profile by age. These findings represent an important step towards any decision about the introduction of varicella vaccination in Norway, as they are a primary input for mathematical transmission models aimed at evaluating potential vaccination scenarios. PMID:27689800

  11. Haploinsufficiency in the PPAR{alpha} and LDL receptor genes leads to gender- and age-specific obesity and hyperinsulinemia

    SciTech Connect

    Sugiyama, Eiko . E-mail: eikoyoko@nagano-kentan.ac.jp; Tanaka, Naoki; Nakajima, Tamie; Kamijo, Yuji; Yokoyama, Shin; Li Yufeng; Gonzalez, Frank J.; Aoyama, Toshifumi

    2006-11-17

    When preparing peroxisome proliferator-activated receptor (PPAR){alpha}:low-density lipoprotein receptor (LDLR) (-/-) double knockout mice, we unexpectedly found a unique gender- and age-specific obesity in the F1 generation, PPAR{alpha} (+/-):LDLR (+/-), even in mice fed standard chow. Body weights of the male heterozygous mice increased up to about 60 g at 75 weeks of age, then decreased by about 30 g at 100 weeks of age. More than 95% of the heterozygous mice between 35- and 75-week-olds were overweight. Of interest, the obese heterozygous mice also exhibited hyperinsulinemia correlating with moderate insulin resistance. Hepatic gene expression of LDLR was lower than expected in the heterozygous mice, particularly at 50 and 75 weeks of age. In contrast, the hepatic expression of PPAR{alpha} was higher than expected in obese heterozygous mice, but decreased in non-obese older heterozygous mice. Modulated expression of these genes may be partially associated with the onset of the hyperinsulinemia.

  12. Standardization of age-adjusted mortality rates

    SciTech Connect

    Selvin, S.; Sacks, S.T.; Merrill, D.W.

    1980-02-01

    Because age is a significant variable in the occurrence and frequency of human disease, any comparison of disease or mortality rates, to be useful, must be age-specific or age-adjusted. Age-specific comparisons are not always appropriate or possible, however. A common method of eliminating the influence of age in comparing mortality rates from one community to another is to employ statistical methods of age-adjustment. While a variety of methods will accomplish this task, most are weighted averages of the age-specific rates. Two widely used adjustment procedures are direct and indirect age-adjustment.

  13. Is Wildlife Fertility Control Always Humane?

    PubMed Central

    Hampton, Jordan O.; Hyndman, Timothy H.; Barnes, Anne; Collins, Teresa

    2015-01-01

    Simple Summary There are various fertility control methods (modalities) currently available that aim to reduce the abundance of problematic free-ranging mammalian wildlife. Here, we propose that dissimilarities in the mechanism of action indicate these methods produce great variation in animal welfare outcomes. We present a framework to assist managers in minimising animal welfare risks. Abstract Investigation of fertility control techniques to reduce reproductive rates in wildlife populations has been the source of much research. Techniques targeting wildlife fertility have been diverse. Most research into fertility control methods has focused upon efficacy, with few studies rigorously assessing animal welfare beyond opportunistic anecdote. However, fertility control techniques represent several very different mechanisms of action (modalities), each with their own different animal welfare risks. We provide a review of the mechanisms of action for fertility control methods, and consider the role of manipulation of reproductive hormones (“endocrine suppression”) for the long-term ability of animals to behave normally. We consider the potential welfare costs of animal manipulation techniques that are required to administer fertility treatments, including capture, restraint, surgery and drug delivery, and the requirement for repeated administration within the lifetime of an animal. We challenge the assumption that fertility control modalities generate similar and desirable animal welfare outcomes, and we argue that knowledge of reproductive physiology and behaviour should be more adeptly applied to wild animal management decisions. We encourage wildlife managers to carefully assess long-term behavioural risks, associated animal handling techniques, and the importance of positive welfare states when selecting fertility control methods as a means of population control. PMID:26506395

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

    NASA Astrophysics Data System (ADS)

    Vyborova, Oxana

    2010-05-01

    physical, physicochemical properties of soils, its air, water and thermal rate. Humic acids with mineral and organomineral particles of soil form the soil absorbent complex. The inclusion of humic fertilizers promotes the process when humic substances form a very valuable water-stable clumpy-granular structure, which improves water-carrying and water-holding capacity, its air permeability by agglutination of mineral particles with each other. The soils, where humic fertilizers are carried in soils regularly, are more stable for influence of chemical polluting substances (for example, radioactive nuclides, heavy metals, pesticides) than poor soils. The inclusion of humic fertilizers is very important in period of urbanization and cropping on the plough-lands not far from a big industrial area. The lignitic materials tie together the detrimental compounds formed the insoluble complex in soil solution. The detrimental compounds don't go into plants, subsoil waters and atmosphere. The lignitic watering of soils (in concentration from 0.1 to 0.01%) increases biological activity of soil in a man-caused zones and it promotes to stability of plants to detrimental emission of enterprises. Today the problem of processing of sugar-beet industry is very important. In the result of storing sugar-beet wastes the pollution of environment is occurred, examples of this pollution are gassing, salinization of soils and ground waters by filtrational sediments. One of these wastes is defecation sludge. The defecation sludge consists of CaCO3, organic matter, nitrogen, phosphorus, potassium and microelements. The technology of receiving N-Ca fertilizer based on defecate was developed because of impossibility of using this waste in pure form. For available data, using of these fertilizers improves the soil fertility and degree of pollution by heavy metals don't exceed an acceptance limits.

  15. Biplot models applied to cancer mortality rates.

    PubMed

    Osmond, C

    1985-01-01

    "A graphical method developed by Gabriel to display the rows and columns of a matrix is applied to tables of age- and period-specific cancer mortality rates. It is particularly useful when the pattern of age-specific rates changes with time. Trends in age-specific rates and changes in the age distribution are identified as projections. Three examples [from England and Wales] are given."

  16. Wuchereria bancrofti filariasis in French Polynesia: age-specific patterns of microfilaremia, circulating antigen, and specific IgG and IgG4 responses according to transmission level.

    PubMed

    Chanteau, S; Glaziou, P; Plichart, C; Luquiaud, P; Moulia-Pelat, J P; N'Guyen, L; Cartel, J L

    1995-01-01

    The age-specific patterns of microfilaremia, Og4C3 antigenemia, anti-Brugia malayi IgG and IgG4 were assessed in 3 villages of low, medium and high transmission level for Wuchereria bancrofti filariasis. The prevalence rates for each of the 4 markers were clearly age dependent and their patterns strongly associated with the transmission level. The antigenemia prevalence rate was consistently higher than the microfilaremia prevalence rate, in all age groups. The prevalences of anti-B. malayi IgG and IgG4 responses were very similar and much higher than those of microfilaremia or antigenemia. Antibody responses reached the plateau at an earlier age and at a higher prevalence with increased intensity of transmission. For all the markers, the prevalence rates were significantly higher in males than in females.

  17. Fertilizer nitrogen isotope signatures.

    PubMed

    Bateman, Alison S; Kelly, Simon D

    2007-09-01

    There has been considerable recent interest in the potential application of nitrogen isotope analysis in discriminating between organically and conventionally grown crops. A prerequisite of this approach is that there is a difference in the nitrogen isotope compositions of the fertilizers used in organic and conventional agriculture. We report new measurements of delta15N values for synthetic nitrogen fertilizers and present a compilation of the new data with existing literature nitrogen isotope data. Nitrogen isotope values for fertilizers that may be permitted in organic cultivation systems are also reported (manures, composts, bloodmeal, bonemeal, hoof and horn, fishmeal and seaweed based fertilizers). The delta15N values of the synthetic fertilizers in the compiled dataset fall within a narrow range close to 0 per thousand with 80% of samples lying between-2 and 2 per thousand and 98.5% of the data having delta15N values of less than 4 per thousand (mean=0.2 per thousand n=153). The fertilizers that may be permitted in organic systems have a higher mean delta15N value of 8.5 per thousand and exhibit a broader range in delta15N values from 0.6 to 36.7 per thousand (n=83). The possible application of the nitrogen isotope approach in discriminating between organically and conventionally grown crops is discussed in light of the fertilizer data presented here and with regard to other factors that are also important in determining crop nitrogen isotope values.

  18. [Effects of different fertilization modes on vegetable growth, fertilizer nitrogen utilization, and nitrogen loss from vegetable field].

    PubMed

    Huang, Dong-feng; Wang, Guo; Li, Wei-hua; Qiu, Xiao-xuan

    2009-03-01

    A field experiment with Chinese cabbage, water spinach, and three-colored amaranth cropped three times in one year was conducted to study the effects of seven fertilization modes, i.e., none fertilization, basal application of chemical fertilizers, 1/2 basal application and 1/2 top-dressing of chemical fertilizers, basal application of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure, and basal application of organic manure, on the plant height, yield, nitrogen accumulation, and fertilizer nitrogen utilization of the vegetables, and the loss of NO3- -N and NH4+ -N from vegetable field under natural rainfall condition. The results showed that comparing with none fertilization, the fertilization modes '1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure' and 'basal application of chemical fertilizers and dicyandiamide' improved the agronomic properties of test vegetables, increased their yields by 103%-219% and 93%-226%, and nitrogen accumulation by 153% -216% and 231%-320%, respectively, and enhanced fertilizer nitrogen utilization rate. They also decreased the surface runoff loss of NO3- -N and NH4+ -N by 48.1% and 46.5%, respectively, compared with the mode 'basal application of chemical fertilizers', and hence, reduced the risk of agricultural non-point pollution. Therefore, these two fertilization modes could be popularized in vegetable production.

  19. From non school-based, co-payment to school-based, free Human Papillomavirus vaccination in Flanders (Belgium): a retrospective cohort study describing vaccination coverage, age-specific coverage and socio-economic inequalities.

    PubMed

    Lefevere, Eva; Theeten, Heidi; Hens, Niel; De Smet, Frank; Top, Geert; Van Damme, Pierre

    2015-09-22

    School-based, free HPV vaccination for girls in the first year of secondary school was introduced in Flanders (Belgium) in 2010. Before that, non school-based, co-payment vaccination for girls aged 12-18 was in place. We compared vaccination coverage, age-specific coverage and socio-economic inequalities in coverage - 3 important parameters contributing to the effectiveness of the vaccination programs - under both vaccination systems. We used retrospective administrative data from different sources. Our sample consisted of all female members of the National Alliance of Christian Mutualities born in 1995, 1996, 1998 or 1999 (N=66,664). For each vaccination system we described the cumulative proportion HPV vaccination initiation and completion over time. We used life table analysis to calculate age-specific rates of HPV vaccination initiation and completion. Analyses were done separately for higher income and low income groups. Under non school-based, co-payment vaccination the proportions HPV vaccination initiation and completion slowly rose over time. By age 17, the proportion HPV vaccination initiation/completion was 0.75 (95% CI 0.74-076)/0.66 (95% CI 0.65-0.67). The median age at vaccination initiation/completion was 14.4 years (95% CI 14.4-14.5)/15.4 years (95% CI 15.3-15.4). Socio-economic inequalities in coverage widened over time and with age. Under school-based, free vaccination rates of HPV vaccination initiation were substantially higher. By age 14,the proportion HPV vaccination initiation/completion was 0.90 (95% CI 0.90-0.90)/0.87 (95% CI 0.87-0.88). The median age at vaccination initiation/completion was 12.7 years (95% CI 12.7-12.7)/13.3 years (95% CI 13.3-13.3). Socio-economic inequalities in coverage and in age-specific coverage were substantially smaller.

  20. 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

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

    PubMed

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

    2011-09-01

    A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P < 0.01). However, when the N application rate exceeded 200 kg x hm(-2), its yield-increasing effect was not significant (P > 0.05). The N translocation rate after anthesis and the N fertilizer use efficiency decreased with increasing N application rate. Applying fertilizer additive further improved the rice yield, accumulative absorbed N, N translocation rate after anthesis, and N fertilizer use efficiency, and this effect was more evident when the N application rate was equal to or greater than 200 kg x hm(-2). Relatively high rice yield and N use efficiency were achieved when applying 150 kg x hm(-2) of N fertilizer without the application of fertilizer additive.

  2. H3N2v and other influenza epidemic risk based on age-specific estimates of sero-protection and contact network interactions.

    PubMed

    Skowronski, Danuta M; Moser, Flavia S; Janjua, Naveed Z; Davoudi, Bahman; English, Krista M; Purych, Dale; Petric, Martin; Pourbohloul, Babak

    2013-01-01

    Cases of a novel swine-origin influenza A(H3N2) variant (H3N2v) have recently been identified in the US, primarily among children. We estimated potential epidemic attack rates (ARs) based on age-specific estimates of sero-susceptibility and social interactions. A contact network model previously established for the Greater Vancouver Area (GVA), Canada was used to estimate average epidemic (infection) ARs for the emerging H3N2v and comparator viruses (H1N1pdm09 and an extinguished H3N2 seasonal strain) based on typical influenza characteristics, basic reproduction number (R(0)), and effective contacts taking into account age-specific sero-protection rates (SPRs). SPRs were assessed in sera collected from the GVA in 2009 or earlier (pre-H1N1pdm09) and fall 2010 (post-H1N1pdm09, seasonal A/Brisbane/10/2007(H3N2), and H3N2v) by hemagglutination inhibition (HI) assay. SPR was assigned per convention based on proportion with HI antibody titre ≥40 (SPR40). Recognizing that the HI titre ≥40 was established as the 50%sero-protective threshold we also explored for ½SPR40, SPR80 and a blended gradient defined as: ¼SPR20, ½SPR40, ¾SPR80, SPR160. Base case analysis assumed R(0) = 1.40, but we also explored R(0) as high as 1.80. With R(0) = 1.40 and SPR40, simulated ARs were well aligned with field observations for H1N1pdm09 incidence (AR: 32%), sporadic detections without a third epidemic wave post-H1N1pdm09 (negligible AR<0.1%) as well as A/Brisbane/10/2007(H3N2) seasonal strain extinction and antigenic drift replacement (negligible AR<0.1%). Simulated AR for the novel swine-origin H3N2v was 6%, highest in children 6-11years (16%). However, with modification to SPR thresholds per above, H3N2v AR ≥20% became possible. At SPR40, H3N2v AR ≥10%, ≥15% or ≥30%, occur if R(0)≥1.48, ≥1.56 or ≥1.86, respectively. Based on conventional assumptions, the novel swine-origin H3N2v does not currently pose a substantial pandemic threat. If H3N2v epidemics do

  3. Chapter VII. Predicting Fertility

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Optimizing Natural Fertility

    MedlinePlus

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

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

    PubMed

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

    2010-07-01

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

  6. Fertility Preservation for Cancer Patients: A Review

    PubMed Central

    Ajala, Tosin; Rafi, Junaid; Larsen-Disney, Peter; Howell, Richard

    2010-01-01

    Infertility can arise as a consequence of treatment of oncological conditions. The parallel and continued improvement in both the management of oncology and fertility cases in recent times has brought to the fore-front the potential for fertility preservation in patients being treated for cancer. Oncologists must be aware of situations where their treatment will affect fertility in patients who are being treated for cancer and they must also be aware of the pathways available for procedures such as cryopreservation of gametes and/or embryos. Improved cancer care associated with increased cure rates and long term survival, coupled with advances in fertility treatment means that it is now imperative that fertility preservation is considered as part of the care offered to these patients. This can only be approached within a multidisciplinary setting. There are obvious challenges that still remain to be resolved, especially in the area of fertility preservation in prepubertal patients. These include ethical issues, such as valid consent and research in the area of tissue retrieval, cryopreservation, and transplantation. PMID:20379357

  7. Characterization of Smoc-1 uncovers two transcript variants showing differential tissue and age specific expression in Bubalus bubalis

    PubMed Central

    Srivastava, Jyoti; Premi, Sanjay; Kumar, Sudhir; Parwez, Iqbal; Ali, Sher

    2007-01-01

    Background Secreted modular calcium binding protein-1 (Smoc-1) belongs to the BM-40 family which has been implicated with tissue remodeling, angiogenesis and bone mineralization. Besides its anticipated role in embryogenesis, Smoc-1 has been characterized only in a few mammalian species. We made use of the consensus sequence (5' CACCTCTCCACCTGCC 3') of 33.15 repeat loci to explore the buffalo transcriptome and uncovered the Smoc-1 transcript tagged with this repeat. The main objective of this study was to gain an insight into its structural and functional organization, and expressional status of Smoc-1 in water buffalo, Bubalus bubalis. Results We cloned and characterized the buffalo Smoc-1, including its copy number status, in-vitro protein expression, tissue & age specific transcription/translation, chromosomal mapping and localization to the basement membrane zone. Buffalo Smoc-1 was found to encode a secreted matricellular glycoprotein containing two EF-hand calcium binding motifs homologous to that of BM-40/SPARC family. In buffalo, this single copy gene consisted of 12 exons and was mapped onto the acrocentric chromosome 11. Though this gene was found to be evolutionarily conserved, the buffalo Smoc-1 showed conspicuous nucleotide/amino acid changes altering its secondary structure compared to that in other mammals. In silico analysis of the Smoc-1 proposed its glycoprotein nature with a calcium dependent conformation. Further, we unveiled two transcript variants of this gene, varying in their 3'UTR lengths but both coding for identical protein(s). Smoc-1 evinced highest expression of both the variants in liver and modest to negligible in other tissues. The relative expression of variant-02 was markedly higher compared to that of variant-01 in all the tissues examined. Moreover, expression of Smoc-1, though modest during the early ages, was conspicuously enhanced after 1 year and remained consistently higher during the entire life span of buffalo with gradual

  8. Integration of environmental, agronomic, and economic aspects of fertilizer management

    PubMed

    Matson; Naylor; Ortiz-Monasterio

    1998-04-03

    Nitrogen fertilization is a substantial source of nitrogen-containing trace gases that have both regional and global consequences. In the intensive wheat systems of Mexico, typical fertilization practices lead to extremely high fluxes of nitrous oxide (N2O) and nitric oxide (NO). In experiments, lower rates of nitrogen fertilizer, applied later in the crop cycle, reduced the loss of nitrogen without affecting yield and grain quality. Economic analyses projected this alternative practice to save 12 to 17 percent of after-tax profits. A knowledge-intensive approach to fertilizer management can substitute for higher levels of inputs, saving farmers money and reducing environmental costs.

  9. Age-Specific Serum Anti-Mullerian Hormone and Follicle Stimulating Hormone Concentrations in Infertile Iranian Women

    PubMed Central

    Raeissi, Alireza; Torki, Alireza; Moradi, Ali; Mousavipoor, Seyed Mehdi; Pirani, Masoud Doosti

    2015-01-01

    Background Anti-Müllerian hormone (AMH) is secreted by the granulosa cells of growing follicles during the primary to large antral follicle stages. Abnormal levels of AMH and follicle stimulating hormone (FSH) may indicate a woman’s diminished ability or inability to conceive. Our aim is to investigate the changes in serum AMH and FSH concentrations at different age groups and its correlation with ovarian reserves in infertile women. Materials and Methods This cross-sectional study analyzed serum AMH and FSH levels from 197 infertile women and 176 healthy controls, whose mean ages were 19-47 years. Sample collection was performed by random sampling and analyzed with SPSS version 16 software. Results There were significantly lower mean serum AMH levels among infertile women compared to the control group. The mean AMH serum levels from different ages of infertile and control group (fertile women) decreased with increasing age. However, this reduction was greater in the infertile group. The mean FSH serum levels of infertile women were significantly higher than the control group. Mean serum FSH levels consistently increased with increasing age in infertile women; however mean luteinizing hormone (LH) levels were not consistent. Conclusion We have observed increased FSH levels and decreased AMH levels with increasing age in women from 19 to 47 years of age. Assessments of AMH and FSH levels in combination with female age can help in predicting ovarian reserve in infertile women. PMID:25918589

  10. Fertilizer intensification and its impacts in China's HHH Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accomplishment of China’s food security by application of high rates of fertilizers has generated several controversies regarding the quality of soil and water resources. Thus, the objective of this article is to assess the effects and causes of the fertilizer intensification in the Huang Huai ...

  11. Sensor-based precision fertilization for field crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From the development of the first viable variable-rate fertilizer systems in the upper Midwest USA, precision agriculture is now approaching three decades old. Early precision fertilization practice relied on laboratory analysis of soil samples collected on a spatial pattern to define the nutrient-s...

  12. Are Difficulties Balancing Work and Family Associated with Subsequent Fertility?

    ERIC Educational Resources Information Center

    Liu, Siwei; Hynes, Kathryn

    2012-01-01

    Despite considerable interest in the causes and consequences of work-family conflict, and the frequent suggestion in fertility research that difficulty in balancing work and family is one of the factors leading to low fertility rates in several developed countries, little research uses longitudinal data to examine whether women who report…

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

    PubMed Central

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

    2014-01-01

    STUDY QUESTION Is it possible to construct an age curve denoting the ages above which women are biologically too old to reproduce? SUMMARY ANSWER We constructed a curve based on the distribution of female age at last birth in natural fertility populations reflecting the ages above which women have become biologically too old to have children. WHAT IS KNOWN ALREADY The median age at last birth (ALB) for females is ∼40–41 years of age across a range of natural fertility populations. This suggests that there is a fairly universal pattern of age-related fertility decline. However, little is known about the distribution of female ALB and in the present era of modern birth control, it is impossible to assess the age-specific distribution of ALB. Reliable information is lacking that could benefit couples who envisage delaying childbearing. STUDY DESIGN, SIZE, DURATION This study is a review of high-quality historical data sets of natural fertility populations in which the distributions of female age at last birth were analysed. The studies selected used a retrospective cohort design where women were followed as they age through their reproductive years. PARTICIPANTS/MATERIALS, SETTING, METHODS Using a common set of eligibility criteria, large data files of natural fertility populations were prepared such that the analysis could be performed in parallel across all populations. Data on the ALB and confounding variables are presented as box and whisker plots denoting the 5th, 25th, 50th, 75th and 95th percentile distribution of the age at last birth for each population. The analysis includes the estimation of Kaplan–Meier curves for age at last birth of each population. The hazard curve for ALB was obtained by plotting the smoothed hazard curve of each population and taking the lowest hazard within a time period of at least 5 years. This lowest hazard curve was then transformed into a cumulative distribution function representing the composite curve of the end of

  14. Use of polysulfone in controlled-release NPK fertilizer formulations.

    PubMed

    Tomaszewska, Maria; Jarosiewicz, Anna

    2002-07-31

    Encapsulation of fertilizers in polymeric coatings is a method used to reduce fertilizer losses and to minimize environmental pollution. Polysulfone was used for a coating preparation for soluble NPK granular fertilizer in controlled-release fertilizer formulations. The coatings were formed by the phase inversion technique (wet method). The influence of the polymer concentration in the film-forming solution on the physical properties of the coatings was examined. The coating structure controls the diffusion of the elements from the interior of the fertilizer granule. It was experimentally confirmed that the use of polysulfone as a coating for a soluble fertilizer decreases the release rate of components. Moreover, the release rate of nutrients from coated granules decreases with the decrease of the coating porosity. In the case of coating with 38.5% porosity, prepared from 13.5% polymer solution after 5 h of test, 100% of NH(4)(+) was released, whereas only 19.0% of NH(4)(+) was released after 5 h for the coating with 11% porosity. In addition, coating of fertilizers leads to improvement of handling properties, and the crushing strength of all coated fertilizers was an average 40% higher than that for uncoated NPK fertilizer.

  15. Effects of salinity on the transcriptome of growing maize leaf cells point at cell-age specificity in the involvement of the antioxidative response in cell growth restriction

    PubMed Central

    2013-01-01

    . Conclusions The results demonstrate a cell-age specificity in the salinity response of growing cells, and point at involvement of the antioxidative response in cell growth restriction. Processes involved in reactive oxygen species (ROS) scavenging are more pronounced in the young cells, while the higher growth sensitivity of older cells is suggested to involve effects on cell-wall rigidity and lower protein protection. PMID:23324477

  16. [Effect of straw return to field and fertilization in autumn on dryland corn growth and on water and fertilizer efficiency].

    PubMed

    Zhou, Huaiping; Yang, Zhiping; Li, Hongmei; Guan, Chunlin

    2004-07-01

    A ten years location experiment of various kinds straw return to field and deep fertilization in autumn was conducted in Shouyang dryland experimental area of Shanxi Province to study their effect on the growth and yield of dryland corn, the use efficency of soil water and fertilizer, and the changes of soil fertility. The results showed that this kind of experimental method could better solve the contradiction of deep fertilization with maintaining soil moisture and keeping a full stand of seedlings in spring, and the competition of water and fertilizer between the degradation of crop remains and the seedlings. What is more, the abundant resources of crop remains were used more sufficiently, the activity of soil microorganisms was more active, and soil fertility was obviously improved, which was proved by the complete and strong seedlings and developed roots, the photosynthesis and transpiration rates were enhanced, the water use efficiency (WUE) was increased by 3.26 - 3.51 kg x hm(-2) x mm(-1), and the accumulated water consumption was decreased by 8.1 - 264.5 mm. During plant growth period, the utilization rate of fertilizer N and P could increase 3.9% - 13.9% and 3.0% - 9.1%, respectively, and the use efficiency of water and fertilizer was higher. The ten years accumulated yield increased 12.10 - 17.27 t x hm(-2), a rise of 25.6% - 36.5%, and in the meantime, higher soil fertility and productivity were maintained.

  17. A novel test of the phenotype-linked fertility hypothesis reveals independent components of fertility.

    PubMed Central

    Pizzari, Tommaso; Jensen, Per; Cornwallis, Charles K.

    2004-01-01

    The phenotype-linked fertility hypothesis predicts that male sexual ornaments signal fertilizing efficiency and that the coevolution of male ornaments and female preference for such ornaments is driven by female pursuit of fertility benefits. In addition, directional testicular asymmetry frequently observed in birds has been suggested to reflect fertilizing efficiency and to covary with ornament expression. However, the idea of a phenotypic relationship between male ornaments and fertilizing efficiency is often tested in populations where environmental effects mask the underlying genetic associations between ornaments and fertilizing efficiency implied by this idea. Here, we adopt a novel design, which increases genetic diversity through the crossing of two divergent populations while controlling for environmental effects, to test: (i) the phenotypic relationship between male ornaments and both, gonadal (testicular mass) and gametic (sperm quality) components of fertilizing efficiency; and (ii) the extent to which these components are phenotypically integrated in the fowl, Gallus gallus. We show that consistent with theory, the testosterone-dependent expression of a male ornament, the comb, predicted testicular mass. However, despite their functional inter-dependence, testicular mass and sperm quality were not phenotypically integrated. Consistent with this result, males of one parental population invested more in testicular and comb mass, whereas males of the other parental population had higher sperm quality. We found no evidence that directional testicular asymmetry covaried with ornament expression. These results shed new light on the evolutionary relationship between male fertilizing efficiency and ornaments. Although testosterone-dependent ornaments may covary with testicular mass and thus reflect sperm production rate, the lack of phenotypic integration between gonadal and gametic traits reveals that the expression of an ornament is unlikely to reflect the

  18. Trust and Fertility Dynamics

    PubMed Central

    Billari, Francesco C.; Pessin, Léa

    2016-01-01

    We argue that the divergence in fertility trends in advanced societies is influenced by the interaction of long-standing differences in generalized trust with the increase in women’s educational attainment. Our argument builds on the idea that trust enhances individuals’ and couples’ willingness to outsource childcare to outside their extended family. This becomes critically important as women’s increased education enhances the demand for combining work and family life. We test our hypothesis using data from the World Values Survey and European Values Study on 36 industrialized countries between the years 1981 and 2009. Multilevel statistical analyses reveal that the interaction between national-level generalized trust and cohort-level women’s education is positively associated with completed fertility. As education among women expands, high levels of generalized trust moderate fertility decline. PMID:28003707

  19. 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.

  20. Fertility incentives and disincentives.

    PubMed

    Financioglu, N

    1984-06-01

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

  1. Determinants of aggregate fertility in Pakistan.

    PubMed

    Soomro, G Y

    1986-01-01

    Data were obtained from the government of Pakistan's Census Organization and the Population Welfare Division to investigate and identify policy-relevant factors which influence fertility at an aggregate level by examining the supply, demand, and cost factors of fertility regulation. Information on fertility, mortality, nuptiality, and other socioeconomic variables was gathered for the 63 districts of Pakistan. The 3 districts of Karachi division were taken together as there appeared to be no appreciable variation among those districts. The unit of analysis was a district, which, as an administrative unit, ranks in importance after a province and a division. The dependent variable of an aggregate fertility measure is Total Fertility Rate (TFR). The TFR was measured indirectly from the age structure through the application of the stable population model. Only 2 variables appeared significant in their effect on fertility, i.e., enrollment ratio and marriage age, which tended to show a negative effect on fertility when controlled for other socioeconomic development variables. The effect of urbanization, although insignificant, showed a positive association with fertility; it was expected to have a negative association. The mean age at marriage was dropped from the equation in Table 2 because of its association with infant mortality. Only enrollment appeared to be a significant variable. In Table 3, only 3 variables, including urbanization, were controlled to rank individual variables in regard to their effect on their fertility. The results did not show any change from those of the 1st equation. In the 4th equation (Table 4), electrification substituted for the variable of urbanization; the results did not differ from those of the previous equation. In the 5th equation (Table 5), the composite variable was controlled with the family planning clinics variable. The effect of family planning clinics was insignificant. The enrollment variable appeared to be the most

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

    PubMed Central

    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

    2015-01-01

    Objective To explore the relationship between urinary paraben concentrations and IVF outcomes among women attending an academic fertility center. Design Prospective cohort study. Setting Fertility clinic in a hospital setting. Patient(s) A total of 245 women contributing 356 IVF cycles. Intervention(s) 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. Main Outcome Measure(s) Total and mature oocyte counts, proportion of high quality embryos, fertilization rates, and rates of implantation, clinical pregnancy and live births. Results The geometric mean of the urinary concentrations of methyl (MP), propyl (PP) and butyl paraben (BP) 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 MP, PP and BP 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. Conclusion(s) Urinary paraben concentrations were not associated with IVF outcomes among women undergoing infertility treatments. PMID:26654974

  3. Kisspeptin and fertility.

    PubMed

    Hameed, Saira; Jayasena, Channa N; Dhillo, Waljit S

    2011-02-01

    The kisspeptins are a family of peptide hormones, which in recent years have been shown to play a critical role in the regulation of the hypothalamic-pituitary-gonadal axis, thus in turn influencing fertility and reproduction. This review examines the physiological role of kisspeptin and the kisspeptin receptor in the control of gonadotrophin and gonadal steroid hormone secretion and the implications of these findings with respect to fertility. In addition, the potential therapeutic use of kisspeptin in the treatment of reproductive disorders will be examined.

  4. Soil microbes and plant fertilization.

    PubMed

    Miransari, Mohammad

    2011-12-01

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

  5. Associations of adiponectin and fertility estimates in Holstein bulls.

    PubMed

    Kasimanickam, Vanmathy R; Kasimanickam, Ramanathan K; Kastelic, John P; Stevenson, Jeffrey S

    2013-03-15

    Adiponectin is a pleiotropic regulator of numerous biological functions, including gonadal steroidogenesis and might play a role in sperm structures and functions. The objectives were to: (1) determine associations among serum concentrations of adiponectin, testosterone, and prolactin, and the sperm DNA fragmentation index; (2) associate sperm adiponectin mRNA abundance with estimates of fertility (sire conception rate); and (3) determine sperm protein expression of adiponectin and its receptor in pre- and postcapacitated sperm from Holstein bulls. In experiment 1, biweekly serum concentrations of adiponectin, prolactin, and testosterone were greater (P < 0.05) for high fertility bulls compared with average and low fertility bulls. Furthermore, sperm DNA fragmentation index was greater (P < 0.05) for low fertility compared with both average and high fertility bulls. In experiment 2, samples of sperm from a single collection from commercial Holstein bulls (N = 34) were used to evaluate relative sperm mRNA expression of adiponectin and its receptors, AdipoR1 and AdipoR2, and protein levels of adiponectin and its receptors, AdipoR1 and AdipoR2, in pre- and postcapacitation sperm. The mRNA abundance of adiponectin and its receptors, AdipoR1 and AdipoR2, were greater for high fertility bulls (>2 to ≤4 sire conception rate) compared with average (≥2 to ≤2) and low (>-2 to ≤-4) fertility bulls. Based on the sperm capacitation assay, average fertility bulls had a greater percentage of acrosome-reacted sperm at 5 hours than high and low fertility bulls, whereas high fertility bulls had a greater percentage of acrosome-reacted sperm than low fertility bulls. After capacitation, levels of adiponectin protein were lower in average fertility bulls, AdipoR1 was lower in all fertility groups, and AdipoR2 was lower in average and high fertility bulls. In conclusion, adiponectin and its receptors had vital roles in sperm structural and functional traits and consequently

  6. The Effectiveness of Age-Specific Isolation Policies on Epidemics of Influenza A (H1N1) in a Large City in Central South China

    PubMed Central

    Zhang, Xixing; Chen, Faming; Chen, Shuilian; Zhao, Jin

    2015-01-01

    During the early stage of a pandemic, isolation is the most effective means of controlling transmission. However, the effectiveness of age-specific isolation policies is not clear; especially little information is available concerning their effectiveness in China. Epidemiological and serological survey data in the city of Changsha were employed to estimate key model parameters. The average infectious period (date of recovery – date of symptom onset) of influenza A (H1N1) was 5.2 days. Of all infected persons, 45.93% were asymptomatic. The basic reproduction number of the influenza A (H1N1) pandemic was 1.82. Based on the natural history of influenza A (H1N1), we built an extended susceptible-exposed-infectious/asymptomatic-removed model, taking age groups: 0–5, 6–14, 15–24, 25–59, and ≥60 years into consideration for isolation. Without interventions, the total attack rates (TARs) in each age group were 42.73%, 41.95%, 20.51%, 45.03%, and 37.49%, respectively. Although the isolation of 25–59 years-old persons was the most effective, the TAR of individuals of aged 0–5 and 6–14 could not be reduced. Paradoxically, isolating individuals ≥60 year olds was not predicted to be an effective way of reducing the TAR in this group but isolating the age-group 25–59 did, which implies inter-age-group transmission from the latter to the former is significant. Isolating multiple age groups increased effectiveness. The most effective combined isolation target groups were of 6–14 + 25–59 year olds, 6–14 + 15–24 + 25–59 year olds, and 0–5 + 6–14 + 25–59 + ≥60 year olds. The last of these isolation schemas reduced the TAR of the total population from 39.64% to 0.006%, which was exceptionally close to the effectiveness of isolating all five age groups (TAR = 0.004%). PMID:26161740

  7. Age-specific discrimination of blood plasma samples of healthy and ovarian cancer prone mice using laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Melikechi, Noureddine; Markushin, Yuri; Connolly, Denise C.; Lasue, Jeremie; Ewusi-Annan, Ebo; Makrogiannis, Sokratis

    2016-09-01

    Epithelial ovarian cancer (EOC) mortality rates are strongly correlated with the stage at which it is diagnosed. Detection of EOC prior to its dissemination from the site of origin is known to significantly improve the patient outcome. However, there are currently no effective methods for early detection of the most common and lethal subtype of EOC. We sought to determine whether laser-induced breakdown spectroscopy (LIBS) and classification techniques such as linear discriminant analysis (LDA) and random forest (RF) could classify and differentiate blood plasma specimens from transgenic mice with ovarian carcinoma and wild type control mice. Herein we report results using this approach to distinguish blood plasma samples obtained from serially bled (at 8, 12, and 16 weeks) tumor-bearing TgMISIIR-TAg transgenic and wild type cancer-free littermate control mice. We have calculated the age-specific accuracy of classification using 18,000 laser-induced breakdown spectra of the blood plasma samples from tumor-bearing mice and wild type controls. When the analysis is performed in the spectral range 250 nm to 680 nm using LDA, these are 76.7 (± 2.6)%, 71.2 (± 1.3)%, and 73.1 (± 1.4)%, for the 8, 12 and 16 weeks. When the RF classifier is used, we obtain values of 78.5 (± 2.3)%, 76.9 (± 2.1)% and 75.4 (± 2.0)% in the spectral range of 250 nm to 680 nm, and 81.0 (± 1.8)%, 80.4 (± 2.1)% and 79.6 (± 3.5)% in 220 nm to 850 nm. In addition, we report, the positive and negative predictive values of the classification of the two classes of blood plasma samples. The approach used in this study is rapid, requires only 5 μL of blood plasma, and is based on the use of unsupervised and widely accepted multivariate analysis algorithms. These findings suggest that LIBS and multivariate analysis may be a novel approach for detecting EOC.

  8. Fertility management for women with cancer.

    PubMed

    Agarwal, Sanjay K; Chang, R Jeffrey

    2007-01-01

    With time, great strides are being made in the care of cancer sufferers. The longevity and quality of life of these unfortunate individuals continues to improve and the word "cure" is more commonly being heard. In a similar manner, there is also much reason for optimism regarding the future fertility options for patients with cancer as well as for those with other diseases that have a high likelihood of rendering a female infertile prior to completing her family. Figure 2.4 outlines the various cryopreservation technologies currently available. While IVF and embryo freezing remain the gold standard at the present, refinements in in vitro maturation of oocytes and cryopreservation of oocytes and ovarian cortex will lead to improved results and availability of these technologies. Counseling patients of child-bearing age or their parents regarding future fertility when faced with a life-threatening cancer diagnosis is difficult but extremely important. With modern approaches to cancer care, survival rates have improved significantly. Therefore, the health care team has a responsibility to provide screening to identify these patients, provide education so that an informed decision can be made as rapidly as possible, and have a team ready to preserve fertility once a decision has been made. With the improvements in fertility outcomes for these patients, appropriate education of key communities, including cancer sufferers and their health care providers, will be necessary to ensure that the issue of fertility after cancer is at least discussed and offered to those in whom it is appropriate.

  9. The role of SPRASA in female fertility.

    PubMed

    Wagner, Angela; Holland, Olivia J; Tong, Mancy; Shelling, Andrew N; Chamley, Lawrence W

    2015-04-01

    Fertility is a complex process and infertility can have many causes. Sperm protein reactive with antisperm antibody (SPRASA)/sperm lysozyme-like protein 1 is a protein discovered as the target of autoantibodies in infertile men and previously thought to be expressed only in sperm. Using a bovine in vitro fertilization model, we have shown that SPRASA antiserum reduced sperm binding to zona-free oocytes and the development of embryos to morulae but did not affect the postfertilization cleavage rate to 2 cells or sperm motility. We demonstrated that SPRASA was expressed in ovarian follicles, corpora lutea, and oocytes by a combination of reverse transcription-polymerase chain reaction and immunohistochemistry. Female mice immunized with SPRASA had profound infertility following timed matings and those mice that did become pregnant had reduced fetal viability. The levels of antibodies reactive with SPRASA in 204 fertile and 202 infertile couples were elevated in 3 infertile but no fertile women. Together, these results indicate that SPRASA has a role in female fertility.

  10. Negative effects of fertilization on plant nutrient resorption.

    PubMed

    Yuan, Z Y; Chen, Han Y H

    2015-02-01

    Plants in infertile habitats are thought to have a high rate of nutrient resorption to enable them reuse nutrients more efficiently than those in fertile habitats. However, there is still much debate on how plant nutrient resorption responds to nutrient availability. Here we used a meta-analysis from a global data set of 9703 observations at 306 sites from 508 published articles to examine the effects of nitrogen (N) and phosphorus (P) fertilization on plant foliar N and P concentrations and resorption efficiency. We found that N fertilization enhanced N concentration in green leaves by 27% and P fertilization enhanced green-leaf P by 73% on average. The N and P concentrations in senesced leaves also increased with respective nutrient fertilization. Resorption efficiencies (percentage of nutrient recovered from senescing leaves) of both N and P declined in response to respective nutrient fertilization. Combined N and P fertilization also had negative effects on both N and P resorption efficiencies. Whether nutrient resorption efficiency differs among plant growth types and among ecosystems, however, remains uncertain due to the limited sample sizes when analyzed by plant growth types or ecosystem types. Our analysis indicates that fertilization decreases plant nutrient resorption and the view that nutrient resorption is a critical nutrient conservation strategy for plants in nutrient-poor environments cannot be abandoned. The response values to fertilization presented in our analysis can help improve biogeochemical models.

  11. Fertility and Infertility.

    ERIC Educational Resources Information Center

    Orgebin-Crist, Marie-Claire; And Others

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

  12. Genetics, genomics and fertility

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Nutrition and fertility.

    PubMed

    Pinelli, G; Tagliabue, A

    2007-12-01

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

  14. Sex and Fertility After SCI

    MedlinePlus

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

  15. Agriculture: Nutrient Management and Fertilizer

    EPA Pesticide Factsheets

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

  16. Dune Grass Fertilization and Maintenance

    DTIC Science & Technology

    1982-12-01

    plants often suffer, thereafter, from neglect. PURPOSE: To recommend a fertilization and maintenance program to sustain healthy dune grasses in coastal...TYPE 3. DATES COVERED 00-00-1982 to 00-00-1982 4. TITLE AND SUBTITLE Dune Grass Fertilization and Maintenance 5a. CONTRACT NUMBER 5b. GRANT...TO APPLY: Apply a granular or pelletized agricultural type fertilizer . It need not be a costly, slow- release material. A.t\\!OUNT OF FERTILIZER TO

  17. Development and test of sets of 3D printed age-specific thyroid phantoms for 131I measurements.

    PubMed

    Beaumont, Tiffany Mélanie; Caldeira Ideias, Pedro; Rimlinger, Maeva; Broggio, David; Franck, Didier

    2017-03-07

    In the case of a nuclear reactor accident the release contains a high proportion of iodine-131 that can be inhaled or ingested by members of the public. Iodine-131 is naturally retained in the thyroid and increases the thyroid cancer risk. Since the radiation induced thyroid cancer risk is greater for children than for adults, the thyroid dose to children should be assessed as accurately as possible. For that purpose direct measurements should be carried out with age-specific calibration factors but, currently, there is no age-specific thyroid phantoms allowing a robust measurement protocol. A set of age-specific thyroid phantoms for 5, 10, 15 years old children and for the adult has been designed and 3D printed. A realistic thyroid shape has been selected and material properties taken into account to simulate the attenuation of biological tissues. The thyroid volumes follow ICRP recommendations and the phantoms also include the trachea and a spine model. Several versions, with or without spine, with our without trachea, with or without age-specific neck have been manufactured, in order to study the influence of these elements on calibration factors. The calibration factor obtained with the adult phantom and a reference phantom are in reasonable agreement. In vivo calibration experiments with germanium detectors have shown that the difference in counting efficiency, the inverse of the calibration factor, between the 5-years and adult phantoms is 25% for measurement at contact. It is also experimentally evidenced that the inverse of the calibration factor varies linearly with the thyroid volume. The influence of scattering elements like the neck or spine is not evidenced by experimental measurements.

  18. Using clinically acquired MRI to construct age-specific ADC atlases: Quantifying spatiotemporal ADC changes from birth to 6-year old.

    PubMed

    Ou, Yangming; Zöllei, Lilla; Retzepi, Kallirroi; Castro, Victor; Bates, Sara V; Pieper, Steve; Andriole, Katherine P; Murphy, Shawn N; Gollub, Randy L; Grant, Patricia Ellen

    2017-03-31

    Diffusion imaging is critical for detecting acute brain injury. However, normal apparent diffusion coefficient (ADC) maps change rapidly in early childhood, making abnormality detection difficult. In this article, we explored clinical PACS and electronic healthcare records (EHR) to create age-specific ADC atlases for clinical radiology reference. Using the EHR and three rounds of multiexpert reviews, we found ADC maps from 201 children 0-6 years of age scanned between 2006 and 2013 who had brain MRIs with no reported abnormalities and normal clinical evaluations 2+ years later. These images were grouped in 10 age bins, densely sampling the first 1 year of life (5 bins, including neonates and 4 quarters) and representing the 1-6 year age range (an age bin per year). Unbiased group-wise registration was used to construct ADC atlases for 10 age bins. We used the atlases to quantify (a) cross-sectional normative ADC variations; (b) spatiotemporal heterogeneous ADC changes; and (c) spatiotemporal heterogeneous volumetric changes. The quantified age-specific whole-brain and region-wise ADC values were compared to those from age-matched individual subjects in our study and in multiple existing independent studies. The significance of this study is that we have shown that clinically acquired images can be used to construct normative age-specific atlases. These first of their kind age-specific normative ADC atlases quantitatively characterize changes of myelination-related water diffusion in the first 6 years of life. The quantified voxel-wise spatiotemporal ADC variations provide standard references to assist radiologists toward more objective interpretation of abnormalities in clinical images. Our atlases are available at https://www.nitrc.org/projects/mgh_adcatlases. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc.

  19. Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy.

    PubMed

    Kim, Hye Sung; Kim, Byoung Jae; Oh, Sohee; Lee, Da Young; Hwang, Kyu Ri; Jeon, Hye Won; Lee, Seung Mi

    2015-09-01

    During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

  20. 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.

  1. Age-specific responses to spring temperature in a migratory songbird: older females attempt more broods in warmer springs

    PubMed Central

    Bulluck, L; Huber, S; Viverette, C; Blem, C

    2013-01-01

    Increasing global temperature has led to an interest in plasticity in the timing of annual events; however, little is known about the demographic consequences of changing phenology. Annual reproductive success varies significantly among individuals within a population, and some of that variation has to do with the number of broods attempted by reproducing adults. In birds, female age and the timing of reproduction are often predictors of multiple breeding. We hypothesize that double brooding rates may be affected by spring temperature and that the response may vary with female age. We used a long-term reproductive data set for a migratory songbird, the prothonotary warbler (Protonotaria citrea) to assess which factors influence (a) an individual female's probability of double brooding and (b) the annual variation in population-level double brooding rates. We found that older and earlier nesting birds are more likely to double brood, and that there is no evidence for senescence with regard to this trait such that the oldest females were most likely to double brood. Previous experience with double brooding (i.e., whether the female double brooded in the previous year) significantly increased the probability of doing so again. When assessing annual variation in the double brooding rate, we found an interaction between spring temperature and the proportion of older females in the population. Specifically, older females are more likely to double brood in years with warmer springs, but this relationship was not seen for younger females. Previous studies have shown that warmer temperatures lead to earlier and narrower peaks in resources and we hypothesize that these peaks are more available to older and earlier arriving females, enabling them to successfully raise more than one brood in a season. Understanding how different age classes respond to changing environmental conditions will be imperative to managing declining species. PMID:24223269

  2. Age-Specific Sex-Related Differences in Infections: A Statistical Analysis of National Surveillance Data in Japan

    PubMed Central

    Eshima, Nobuoki; Tokumaru, Osamu; Hara, Shohei; Bacal, Kira; Korematsu, Seigo; Karukaya, Shigeru; Uruma, Kiyo; Okabe, Nobuhiko; Matsuishi, Toyojiro

    2012-01-01

    Background To prevent and control infectious diseases, it is important to understand how sex and age influence morbidity rates, but consistent clear descriptions of differences in the reported incidence of infectious diseases in terms of sex and age are sparse. Methods and Findings Data from the Japanese surveillance system for infectious diseases from 2000 to 2009 were used in the analysis of seven viral and four bacterial infectious diseases with relatively large impact on the Japanese community. The male-to-female morbidity (MFM) ratios in different age groups were estimated to compare incidence rates of symptomatic reported infection between the sexes at different ages. MFM ratios were >1 for five viral infections out of seven in childhood, i.e. male children were more frequently reported as infected than females with pharyngoconjunctival fever, herpangina, hand-foot-and-mouth disease, mumps, and varicella. More males were also reported to be infected with erythema infectiosum and exanthema subitum, but only in children 1 year of age. By contrast, in adulthood the MFM ratios decreased to <1 for all of the viral infections above except varicella, i.e. adult women were more frequently reported to be infected than men. Sex- and age-related differences in reported morbidity were also documented for bacterial infections. Reported morbidity for enterohemorrhagic Escherichia coli infection was higher in adult females and females were reportedly more infected with mycoplasma pneumonia than males in all age groups up to 70 years. Conclusions Sex-related differences in reported morbidity for viral and bacterial infections were documented among different age groups. Changes in MFM ratios with age may reflect differences between the sexes in underlying development processes, including those affecting the immune, endocrine, and reproductive systems, or differences in reporting rates. PMID:22848753

  3. 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.

  4. How well are lesbians treated in UK fertility clinics?

    PubMed

    Priddle, Helen

    2015-09-01

    Legislation regulating fertility treatment in the United Kingdom originally discouraged treatment without a father, resulting in many clinics denying access to lesbian couples. Lesbians now enjoy rights to legal union, dual parenthood and protection against discrimination. Consequently, increasing numbers seek fertility treatment. This is a growing stakeholder group, but it is unknown whether UK licensed centres are serving them adequately. Data from the Human Fertilisation and Embryology Authority suggests live birth rates after in vitro fertilisation for lesbians is comparable to estimates for natural attempt at pregnancy for heterosexuals, whereas success rates with donor insemination are lower. Unsurprisingly, live birth rates for lesbians after in vitro fertilisation are higher compared with heterosexual couples (the latter attending with fertility issues). However, outcomes for lesbians after donor insemination are slightly lower, potentially due to increased female age. Rather than adopting a one-heterosexual-size-fits-all approach, lesbian couples may benefit from new treatment pathways. They also have a different experience of fertility treatment, some reporting a wish to be presumed fertile rather than medicalised, and others encountering heterosexism by fertility professionals. Additionally, some lesbians with known fertility issues have needed to resort to legal action to obtain the publicly funded treatment they are entitled to.

  5. Low Fertility, Socioeconomic Development, and Gender Equity1

    PubMed Central

    Anderson, Thomas; Kohler, Hans-Peter

    2015-01-01

    While new empirical findings and theoretical frameworks provide insight into the interrelations between socioeconomic development, gender equity, and low fertility, puzzling exceptions and outliers in these findings call for a more all-encompassing framework to understand the interplay between these processes. We argue that the pace and onset of development are two important factors to be considered when analyzing gender equity and fertility. Within the developed world, “first-wave developers”—or countries that began socioeconomic development in the 19th/early 20th century – currently have much higher fertility levels than “late developers”. We lay out a novel theoretical approach to explain why this is the case and provide empirical evidence to support our argument. Our approach not only explains historical periods of low fertility but also sheds light on why there exists such large variance in fertility rates among today’s developed countries. PMID:26526031

  6. Slow-Release Fertilizer

    NASA Technical Reports Server (NTRS)

    1998-01-01

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

  7. 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

  8. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  9. Memoir of fertility preservation.

    PubMed

    Gosden, Roger G

    2013-01-01

    Fertility preservation has been practiced for at least 50 years using semen banking, pelvic surgery, and radiation shields, but in the past 20 years it has emerged as a rapidly growing subspecialty of reproductive medicine. A dramatic rise in survivorship of young cancer patients and the widespread postponement of family building to the later years of the female reproductive lifespan have been major driving forces. Throughout the history of fertility preservation, low temperature banking has played a pivotal role, first for gametes and later for embryos and immature germ cells, while ovarian transplantation recently began to contribute and spermatogonial stem cell transfer holds future promise for men and prepubertal boys. But there are significant risks with some diseases from reimplanting residual disease, which hopefully can be eliminated by new methods for purging the tissue and germ cell culture. Since all technologies are interim, cryopreservation as a mainstay in this field will likely be swept aside eventually by a stream of progress aimed at managing fertility preservation in vivo.

  10. Environmental friendly nitrogen fertilization.

    PubMed

    Shaviv, Avi

    2005-09-01

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

  11. Melanin-based coloration covaries with ovary size in an age-specific manner in the barn owl

    NASA Astrophysics Data System (ADS)

    Roulin, Alexandre

    2009-10-01

    While the adaptive function of black eumelanin-based coloration is relatively well known, the function of reddish-brown pheomelanin-based coloration is still unclear. Only a few studies have shown or suggested that the degree of reddish-brownness is associated with predator-prey relationships, reproductive parameters, growth rate and immunity. To gain insight into the physiological correlates of melanin-based coloration, I collected barn owl ( Tyto alba) cadavers and examined the covariation between this colour trait and ovary size, an organ that increases in size before reproduction. A relationship is expected because melanin-based coloration often covaries with sexual activity. The results showed that reddish-brown juveniles had larger ovaries than whiter juveniles particularly in individuals in poor condition and outside the breeding season, while in birds older than 2 years lightly coloured females had larger ovaries than reddish-brown conspecifics. As barn owls become less reddish-brown between the first and second year of age, the present study suggests that reddish-brown pheomelanic and whitish colorations are associated with juvenile- and adult-specific adaptations, respectively.

  12. Melanin-based coloration covaries with ovary size in an age-specific manner in the barn owl.

    PubMed

    Roulin, Alexandre

    2009-10-01

    While the adaptive function of black eumelanin-based coloration is relatively well known, the function of reddish-brown pheomelanin-based coloration is still unclear. Only a few studies have shown or suggested that the degree of reddish-brownness is associated with predator-prey relationships, reproductive parameters, growth rate and immunity. To gain insight into the physiological correlates of melanin-based coloration, I collected barn owl (Tyto alba) cadavers and examined the covariation between this colour trait and ovary size, an organ that increases in size before reproduction. A relationship is expected because melanin-based coloration often co-varies with sexual activity. The results showed that reddish-brown juveniles had larger ovaries than whiter juveniles particularly in individuals in poor condition and outside the breeding season, while in birds older than 2 years lightly coloured females had larger ovaries than reddish-brown conspecifics. As barn owls become less reddish-brown between the first and second year of age, the present study suggests that reddish-brown pheomelanic and whitish colorations are associated with juvenile- and adult-specific adaptations, respectively.

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

    PubMed

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

    2013-01-01

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

  14. Age-specific survival of male golden-cheeked warblers on the Fort Hood Military Reservation, Texas

    USGS Publications Warehouse

    Duarte, Adam; Hines, James E.; Nichols, James D.; Hatfield, Jeffrey S.; Weckerly, Floyd W.

    2014-01-01

    Population models are essential components of large-scale conservation and management plans for the federally endangered Golden-cheeked Warbler (Setophaga chrysoparia; hereafter GCWA). However, existing models are based on vital rate estimates calculated using relatively small data sets that are now more than a decade old. We estimated more current, precise adult and juvenile apparent survival (Φ) probabilities and their associated variances for male GCWAs. In addition to providing estimates for use in population modeling, we tested hypotheses about spatial and temporal variation in Φ. We assessed whether a linear trend in Φ or a change in the overall mean Φ corresponded to an observed increase in GCWA abundance during 1992-2000 and if Φ varied among study plots. To accomplish these objectives, we analyzed long-term GCWA capture-resight data from 1992 through 2011, collected across seven study plots on the Fort Hood Military Reservation using a Cormack-Jolly-Seber model structure within program MARK. We also estimated Φ process and sampling variances using a variance-components approach. Our results did not provide evidence of site-specific variation in adult Φ on the installation. Because of a lack of data, we could not assess whether juvenile Φ varied spatially. We did not detect a strong temporal association between GCWA abundance and Φ. Mean estimates of Φ for adult and juvenile male GCWAs for all years analyzed were 0.47 with a process variance of 0.0120 and a sampling variance of 0.0113 and 0.28 with a process variance of 0.0076 and a sampling variance of 0.0149, respectively. Although juvenile Φ did not differ greatly from previous estimates, our adult Φ estimate suggests previous GCWA population models were overly optimistic with respect to adult survival. These updated Φ probabilities and their associated variances will be incorporated into new population models to assist with GCWA conservation decision making.

  15. Aqueous and gaseous nitrogen losses induced by fertilizer application

    SciTech Connect

    Gu, C.; Maggi, F.; Riley, W.J.; Hornberger, G.M.; Xu, T.; Oldenburg, C.M.; Spycher, N.; Miller, N.L.; Venterea, R.T.; Steefel, C.

    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 and 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.

  16. General aspects of fertility and infertility.

    PubMed

    Damario, Mark A

    2014-01-01

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

  17. 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.

  18. Jointly determined saving and fertility behaviour: theory, and estimates for Germany, Italy, UK and USA.

    PubMed

    Cigno, A; Rosati, F C

    1996-11-01

    This study uses new theories of capital accumulation and fertility in a comparative framework to test predictions with time-series data for Germany, Italy, the UK, and the US. The exogenous-fertility model is based on models of Barro and Becker. The endogenous-fertility models are based on models of Veall and Nishimura and Zhang. It is assumed that life cycle periods are youth, middle age, and old age. Several theoretical frameworks are tested with endogenous and exogenous fertility and altruism and nonaltruism. Data are obtained during 1950-90. Dependent variables are the total lifetime fertility rate and real per capita household savings. Explanatory variables include social security, the real social security deficit per capita, the real rate of interest, the real per capita disposable income, the average male real wage rate, the average female real wage rate, and the real child benefit rate. The explanatory variables are individually graphed to show differences by country over time. Findings suggest that fertility is endogenous in a nonaltruistic model. The only model not rejected by the data was the model in which fertility and intergenerational transfers were explained by nonaltruistic concerns. Fertility was positively affected by the male wage rate in all countries. Fertility was negatively affected by the female wage rate in all countries. Disposable income was insignificant in the UK and Germany and positive and significant in Italy and the US. The interest rate was significant in only 1 model. Child benefits had a positive and significant effect on fertility in the UK. In savings models, disposable income was significant and positive, and child benefits and wage rates were insignificant. Social security coverage had a negative effect on fertility and a positive effect on savings, except in Germany. Findings indicate that saving and fertility are jointly determined.

  19. 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

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

    PubMed

    Currie, Janet; Schwandt, Hannes

    2014-10-14

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

  1. Theoretical explanations of the rapid fertility decline in China.

    PubMed

    Wu, C

    1986-07-01

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

  2. Getting a piece of the pie? The economic boom of the 1990s and declining teen birth rates in the United States.

    PubMed

    Colen, Cynthia G; Geronimus, Arline T; Phipps, Maureen G

    2006-09-01

    In the United States, the 1990s was a decade of dramatic economic growth as well as a period characterized by substantial declines in teenage childbearing. This study examines whether falling teen fertility rates during the 1990s were responsive to expanding employment opportunities and whether the implementation of the Personal Responsibility and Work Opportunities Act (PRWORA), increasing rates of incarceration, or restrictive abortion policies may have affected this association. Fixed-effects Poisson regression models were estimated to assess the relationship between age-specific birth rates and state-specific unemployment rates from 1990 to 1999 for Black and White females aged 10-29. Falling unemployment rates in the 1990s were associated with decreased childbearing among African-American women aged 15-24, but were largely unrelated to declines in fertility for Whites. For 18-19 year-old African-Americans, the group for whom teen childbearing is most normative, our model accounted for 85% of the decrease in rates of first births. Young Black women, especially older teens, may have adjusted their reproductive behavior to take advantage of expanded labor market opportunities.

  3. [Obesity and male fertility].

    PubMed

    Martini, Ana C; Molina, Rosa I; Ruiz, Rubén D; Fiol de Cuneo, Marta

    2012-01-01

    Obesity and male infertility have increased in the last decades; therefore, a possible association between these pathologies has been explored. Studies inform that obesity may affect fertility through different mechanisms, which alltogether could exert erectile dysfunction and/or sperm quality impairment. These include: 1) hypothalamic-pituitary-testicular (HPG) axis malfunction: obese hormonal profile is characterized by reduction of testosterone, gonadotrophins, SHBG and/or inhibin B concentrations (marker of Sertoli cells function) and hyperestrogenemy (consequence of aromatase overactivity ascribed to adipose tissue increase); 2) increased release of adipose-derived hormones: leptin increase could be responsible for some of the alterations on the HPG axis and could also exert direct deleterious effects on Leydig cells physiology, spermatogenesis and sperm function; 3) proinflammatory adipokines augmentation, higher scrotal temperature (due to fat accumulation in areas surrounding testes) and endocrine disruptors accumulation in adiposites, all of these responsible for the increase in testes oxidative stress and 4) sleep apnea, frequent in obese patients, suppresses the nocturnal testosterone rise needed for normal spermatogenesis. Finally, although controversial, all the above mentioned factors could comprise gametes quality; i.e. decrease sperm density and motility and increase DNA fragmentation, probably disturbing spermatogenesis and/or epididymal function. In summary, although obesity may impair male fertility by some/all of the described mechanisms, the fact is that only a small proportion of obese men are infertile, probably those genetically predisposed or morbidly obese. Nevertheless, it is likely that because the incidence of obesity is growing, the number of men with reduced fertility will increase as well.

  4. [Using compost of agricultural solid waste to produce organic-inorganic compound fertilizer].

    PubMed

    Yang, Bo-jing; Wang, Hong-tao

    2006-07-01

    Techniques of compound fertilizer production from solid waste compost were studied. Different ratio of water moisture, proportion between organic and inorganic and infection of different granularity to the effect of granulation is separately determined through experiments at the pilot scale in the field. The optimal parameters of the techniques are determined. The moisture content is 35%-40%; the rate of organic matter is 80%-90%; granularity is 20 mu. According the data of the organism's concentration, height and weight in crop, the crop was fertilized compound fertilizer is batter than chemical fertilizer. And the ability of increasing the production of the compound fertilizer was testified.

  5. SEOM Clinical Guideline of fertility preservation and reproduction in cancer patients (2016).

    PubMed

    Muñoz, M; Santaballa, A; Seguí, M A; Beato, C; de la Cruz, S; Espinosa, J; Fonseca, P J; Perez, J; Quintanar, T; Blasco, A

    2016-12-01

    Chemotherapy and radiotherapy often result in reduced fertility in cancer patients. With increasing survival rates, fertility is an important quality-of-life concern for many young cancer patients. Around 70-75% of young cancer survivors are interested in parenthood but the numbers of patients who access fertility preservation techniques prior to treatment are significantly lower. Moreover, despite existing guidelines, healthcare professionals do not address fertility preservation issues adequately. There is a critical need for improvements in clinical care to ensure patients are well informed about infertility risks and fertility preservation options and to support them in their reproductive decision-making prior to cancer treatment.

  6. Use of isotopically labeled fertilizer to trace nitrogen fertilizer contributions to surface, soil, and ground water

    USGS Publications Warehouse

    Wilkison, D.H.; Blevins, D.W.; Silva, S.R.

    2000-01-01

    The fate and transport of a single N fertilizer application through plants, soil, runoff, and the unsaturated and saturated zones was determined for four years at a field site under continuous corn (Zea mays L.) management. Claypan soils, which underlie the site, were hypothesized to restrict the movement of agrichemicals from the soil surface to ground water. However, N fertilizer moved rapidly through preferential flow paths in the soil and into the underlying glacial till aquifer. Most N transport occurred during the fall and winter when crops were not available to use excess N. Forty months after application, 33 percent of the fertilizer had been removed by grain harvests, 30 percent had been transpired to the atmosphere, and 33 percent had migrated to ground water. Although runoff volumes were 50 percent greater than infiltration, less than 2 percent of the fertilizer was lost to runoff. Small measured denitrification rates and large measured dissolved oxygen concentrations in ground water favor the long-term stability of NO3-1 in ground water. Successive fertilizer applications, in areas that lack the ability to moderate N concentrations through consumptive N reactions, risk the potential of N-saturated ecosystems.

  7. HLA and fertility

    SciTech Connect

    Ober, C.

    1995-11-01

    The recent paper by Jin et al., reporting that class 11 region major histocompatibility complex genes may influence embryonic loss in outbred couples supports previous results of our studies of HLA and fertility in the Hutterites. However, the authors have incorrectly cited our work and have omitted the reference that is most relevant to their results. The paper by Kostyu et al. is incorrectly referred to in the introduction as providing evidence for HLA sharing being associated with recurrent spontaneous abortion. The Kostyu et al. paper does not include any data on fertility or reproduction but reports frequencies of individuals who are homozygous at the HLA-A, -C, -B, -DR, and -DQ loci in the Hutterite population. In fact, recurrent spontaneous abortion has not been observed in any of the couples in our sample of >500 Hutterite couples. References more appropriate to the association between HLA sharing and recurrent miscarriage are those by Komlos et al., Schacter et al., Gerencer and Kastelan, and Beer et al. It might also be worth pointing out that many studies of recurrent miscarriage in outbred couples have not found an association with HLA sharing; examples include the studies of Ergolu et al., Oksenberg et al., and Christiansen et al., among others. 11 refs.

  8. Is the mouse a clinically relevant model for human fertilization failures?

    PubMed

    Neuber, E; Powers, R D

    2000-01-01

    This study compares failed fertilization oocytes from patients participating in an in-vitro fertilization (IVF) programme with failed fertilization oocytes from B6SJLF(1)/J mice, in order to characterize and describe the distribution of DNA in oocytes that do not undergo normal fertilization. Our goal is to evaluate the mouse IVF system as a model to gain insight into reasons for human fertilization failures. All oocytes were stained with the vital fluorescent dye, Hoechst 33342, which rapidly stains double-stranded DNA. Of the 237 human oocytes that had been scored as failed fertilization by brightfield microscopy, 61 (25.7%) showed the presence of at least one spermatozoon within the oocyte cytoplasm. In contrast, out of 69 failed fertilization mouse oocytes, only one oocyte showed the presence of a spermatozoon within its cytoplasm. Mouse failed fertilization oocytes exhibited a significantly lower internal sperm rate (P < 0.0001) than human failed fertilization oocytes. Human failed fertilization oocytes show a higher incidence of sperm penetration, but the cytoplasm fails to support pronuclear development, whereas, at least in this strain, mouse failed fertilization oocytes arise from an inability of the spermatozoa to penetrate the oocyte. This study suggests that the mouse is not a clinically relevant model for human fertilization failures.

  9. Fertility preservation and breast cancer: a review

    PubMed Central

    de Pedro, María; Otero, Borja; Martín, Belén

    2015-01-01

    Breast cancer is the most common malignancy in women, and its incidence increases with age, with the majority of patients diagnosed after menopause. However, in 15–25% of cases, patients are premenopausal at the time of diagnosis, and about 7% of them are below the age of 40. Therefore, a considerable amount of young women are diagnosed with breast cancer during their reproductive life. Within this group, most cancer cases require cytotoxic chemotherapy and/or hormone therapy, which are responsible for a decrease in the patients’ reproductive function, along with their age. The efficacy of such treatments, among other factors, has led to a high five-year-survival rate, which results in an increasing number of young women who survive breast cancer before having fulfilled their reproductive wishes, especially considering the current trend to delay pregnancy until the late 30s or early 40s in developed countries. The combination of these factors justifies the importance of fertility preservation and reproductive counselling at the time of breast cancer diagnosis in young women. A wide range of fertility preservation techniques has been developed, such as ovarian suppression, oocyte and embryo cryopreservation, immature oocyte retrieval and in vitro maturation, and ovarian tissue cryopreservation. Early counselling and referral of these patients to fertility specialists are fundamental factors in order to maximise their chances of pregnancy. This review aims to update the knowledge about the influence of breast cancer in fertility, the influence of pregnancy and fertility preservation techniques in breast cancer patients and assessment of ovarian reserve for a better treatment choice. A special section dedicated to BRCA-mutation carriers has been included because of their specific features. A comprehensive literature search has been conducted, including publications from the last five years. PMID:25729416

  10. Prospects and programs for fertility reduction, 1990-2015.

    PubMed

    Mauldin, W P; Ross, J A

    1994-01-01

    What is the likelihood that each of the 37 developing countries with populations of 15 million or more in 1990 will reach replacement fertility by the year 2015? These countries have a combined population of 3.9 billion, 91 percent of the population of all developing countries. For this article, a composite index was used as the basis for predicting future levels of total fertility. The index was constructed from socioeconomic variables (life expectancy at birth, infant mortality rates, percent adult literacy, ratio of children enrolled in primary or secondary school, percent of the labor force in nonagricultural occupations, gross national product per capita, and percent of the population living in urban areas), total fertility rates for the years 1985-90, total fertility rate decline from 1960-65 to 1985-90, family planning program effort scores in 1989, and the level of contraceptive prevalence in 1990. Eight countries are classified as certain to reach replacement fertility by 2015, and an additional thirteen probably will also. Five countries are classified as possibly reaching replacement fertility, and eleven as unlikely to do so.

  11. Fertility of American women: June 1983.

    PubMed

    Rogers, C C

    1983-11-01

    This report examines current fertility patterns, delayed childbearing and birth expectations, supplemented by detailed tables and charts. The birth expectations and fertility data are based on the June 1983 supplement to the Current Population Survey (CPS) which obtained information from women about their childbearing to date as well as their anticipated childbearing. Among women who had a child in the year preceding the 1983 survey, 43% were in the labor force, compared with only 31% in 1976. A continuing increase in childlessness is noted among ever-married women 25 to 29 years old, implying a greater tendency to postpone motherhood; only 16% of these women in 1970 were childless, compared with 27% in 1983. American women 18 to 34 years old in 1983 expected to have an average of 2.1 births in their lifetimes, only slightly below the 2.2 births expected/woman in 1976. 9% of currently married women 18 to 34 years old in 1983 reported uncertainty in future childbearing plans. This represents a slight decline from 12% reported by women in 1976. The 1983 fertility rate for the US was an estimated 73.2 births/1000 women 18 to 44 years. About 38% of the births to women 18 to 44 years old were 1st births, resulting in a 1st birth rate of 27.6/1000. Women 18 to 24 years old recorded a higher 1st birth rate (52.6). Fertility differences by race are still evident, with a higher rate among Black women (85.4) than among White women (71.4). The fertility rate in 1983 for married women with husbands present was 101.5/1000, significantly higher than that recorded for married women with husbands absent (75.5), single women (30.5), or widowed or divorced women (31.3). An examination of the changes in labor force participation of women with young children indicates the potential demand for maternal and child social service programs. There are numerous reasons for delayed childbearing, including changes in women's attitudes in the 1970s toward marriage and the family, improvements

  12. Nitrogen fertilization challenges the climate benefit of cellulosic biofuels

    NASA Astrophysics Data System (ADS)

    Ruan, Leilei; Bhardwaj, Ajay K.; Hamilton, Stephen K.; Robertson, G. Philip

    2016-06-01

    Cellulosic biofuels are intended to improve future energy and climate security. Nitrogen (N) fertilizer is commonly recommended to stimulate yields but can increase losses of the greenhouse gas nitrous oxide (N2O) and other forms of reactive N, including nitrate. We measured soil N2O emissions and nitrate leaching along a switchgrass (Panicum virgatum) high resolution N-fertilizer gradient for three years post-establishment. Results revealed an exponential increase in annual N2O emissions that each year became stronger (R 2 > 0.9, P < 0.001) and deviated further from the fixed percentage assumed for IPCC Tier 1 emission factors. Concomitantly, switchgrass yields became less responsive each year to N fertilizer. Nitrate leaching (and calculated indirect N2O emissions) also increased exponentially in response to N inputs, but neither methane (CH4) uptake nor soil organic carbon changed detectably. Overall, N fertilizer inputs at rates greater than crop need curtailed the climate benefit of ethanol production almost two-fold, from a maximum mitigation capacity of -5.71 ± 0.22 Mg CO2e ha-1 yr-1 in switchgrass fertilized at 56 kg N ha-1 to only -2.97 ± 0.18 Mg CO2e ha-1 yr-1 in switchgrass fertilized at 196 kg N ha-1. Minimizing N fertilizer use will be an important strategy for fully realizing the climate benefits of cellulosic biofuel production.

  13. Nitrogen fertilization challenges the climate benefit of cellulosic biofuels

    DOE PAGES

    Ruan, Leilei; Bhardwaj, Ajay K.; Hamilton, Stephen K.; ...

    2016-06-01

    Cellulosic biofuels are intended to improve future energy and climate security. Nitrogen (N) fertilizer is commonly recommended to stimulate yields but can increase losses of the greenhouse gas nitrous oxide (N2O) and other forms of reactive N, including nitrate. We measured soil N2O emissions and nitrate leaching along a switchgrass (Panicum virgatum) high resolution N-fertilizer gradient for three years post-establishment. Results revealed an exponential increase in annual N2O emissions that each year became stronger (R2 > 0.9, P < 0.001) and deviated further from the fixed percentage assumed for IPCC Tier 1 emission factors. Concomitantly, switchgrass yields became less responsivemore » each year to N fertilizer. Nitrate leaching (and calculated indirect N2O emissions) also increased exponentially in response to N inputs, but neither methane (CH4) uptake nor soil organic carbon changed detectably. Overall, N fertilizer inputs at rates greater than crop need curtailed the climate benefit of ethanol production almost two-fold, from a maximum mitigation capacity of–5.71 ± 0.22 Mg CO2e ha–1 yr–1 in switchgrass fertilized at 56 kgNha–1 to only –2.97 ± 0.18 MgCO2e ha–1 yr–1 in switchgrass fertilized at 196 kgNha–1. In conclusion, minimizing N fertilizer use will be an important strategy for fully realizing the climate benefits of cellulosic biofuel production.« less

  14. 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

  15. Nitrogen fertilizer influence on aflatoxin contamination of corn in Louisiana.

    PubMed

    Tubajika, K M; Mascagni, H J; Damann, K E; Russin, J S

    1999-12-01

    Studies were conducted in 1997 and 1998 on a Gigger silt loam at the Macon Ridge Research Station at Winnsboro, LA, to determine the influence of nitrogen (N) rate, timing, and starter nitrogen fertilizer on aflatoxin contamination in corn. Fertilizer N (0, 50, 100, 150, 200, and 250 lb of N/acre), two timings (at planting and six-leaf stage), and starter N fertilizer (a control and 10 lb of N/acre applied in furrow) were evaluated. Application of starter, N rates, and the interaction of starter with N timing and N rates significantly affected aflatoxin levels. Rates of 50-250 lb of N/acre were 34-43% lower in aflatoxin contamination than plots receiving no N. The application of 10 lb of N/acre starter reduced the aflatoxin levels by 20% compared to the no-starter control.

  16. ASSESSMENT OF PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

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

  17. Relationships between applied nitrogen fertilizer and postharvest storage properties of sugarbeet roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the impact of nitrogen fertilizer rate on changes in processing quality of sugarbeet (Beta vulgaris L.) during postharvest storage. Based upon averages over three environments, seven fertilizer rates, and two storage intervals (30 and 90 days), each additional 43.2 kg ha-1 of nit...

  18. [Analysis of the temporal and regional development of fertility, 1970-1978, for projecting the population in forecasts].

    PubMed

    Schawo, F A

    1981-01-01

    This study attempts to use empirically based appraisals of regional fertility patterns in West Germany as a basis for forecasts of future fertility. Nondemographic fertility determinants must be stressed in such an investigation: about 90% of the fertility decline in Berlin between 1970-77 was due to changes in reproductive behavior rather than in age structures. The analysis seeks to quantify the nondemographic influences on fertility and to use the resulting measure as a basis for forecasts of future development of fertility in the different regions. The crude birth rate, general fertility rate, total fertility rate, net reproduction rate, and standardized fertility rate are defined and explained, and some comparisons presented for the years 1970, 1974, and 1977 for different regions defined on the basis of density and settlement structure. A typology of 5 regional types is constructed on the basis of changes in the standardized fertility rate between 1970-1977 and between 1974-77. Necessary assumptions for forecasting future fertility on this basis and a suggested procedure for making such predictions are supplied. An example of application of the procedure is included.

  19. Internal fertilization in an oviparous frog.

    PubMed

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

    1981-04-24

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

  20. Reduced Environmental Impact of Fertilizers Using PGPR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of fertilizers is becoming a threat to sustainability in agriculture. Inorganic fertilizer is linked to nitrate contamination of groundwater and phosphorus runoff. Even with organic fertilizers, such as poultry litter, high phosphorus bioavailability, nitrogen accumulation, and leaching may ...

  1. Children Procedures and Treatment (Fertility Issues)

    MedlinePlus Videos and Cool Tools

    ... do to protect her fertility? What can a boy's cancer doctor do to protect his fertility? How ... families? What are the legal issues for young boys undergoing fertility preservation? What are the legal issues ...

  2. 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.

  3. Determinants of fertility in Athoor block, Tamil Nadu, India.

    PubMed

    Dutt, P R; Rajaretnam, T; Sasty, K R; Ramanujam, C

    1988-09-01

    Data from at least 10 surveys of thousands of households over the period 1960-86 indicate a decline in crude birth rate (CBR) between 1959-85 from 43.1 to 25.6 in the Athoor community development block. The adjacent community development block of Batlagundu, with a higher literacy rate and level of socioeconomic development, was used as control while identifying the proximate determinants of fertility in the study areas. Socioeconomic, institutional, and programmatic factors influencing these proximate determinants were also considered. Declines in the marital fertility rate, due in large part to high age of marriage and a decline in the incidence of young widows, contributed more than other factors to the decline in overall fertility rate. Greater use of contraceptive methods from 0 to 34.2% by 1986, further stemmed fertility. These effects were tempered, however, by a shortened postpartum amenorrhea from 14 to 10 months. Beyond identifying principal proximate determinants, 2 phenomena were explored. While there was an overall decline in CBR over the period, 25.6 is not the lowers level achieved during 1959-85. CBR reached a low of 23.7 in 1980, then climbed over the next few years to its 1985 level. A strong contributing factor to this reversal in a declining trend is a decrease of family planning activities from the level experienced in the 1960s. The 2nd phenomenon is the higher fertility level, desire for larger families, and greater fertility level variation over socioeconomic groups seen in the higher socioeconomic level control block. The authors concluded that high program efficiency must be maintained in the early stages of demographic transition to stabilize against fluctuations in birth rates and contraception prevalence. Additionally, modernizing influences may also affect proximate determinants in opposing manners. Education on child spacing and motivational campaigns targeted especially to young couples should be developed to afford maximum declines

  4. Statistically tested comparisons of the accuracy of forecasting methods for age-specific and sex-specific mortality and life expectancy.

    PubMed

    Shang, Han Lin

    2015-01-01

    Although there are continuing developments in the methods for forecasting mortality, there are few comparisons of the accuracy of the forecasts. The subject of the statistical validity of these comparisons, which is essential to demographic forecasting, has all but been ignored. We introduce Friedman's test statistics to examine whether the differences in point and interval forecast accuracies are statistically significant between methods. We introduce the Nemenyi test statistic to identify which methods give results that are statistically significantly different from others. Using sex-specific and age-specific data from 20 countries, we apply these two test statistics to examine the forecast accuracy obtained from several principal component methods, which can be categorized into coherent and non-coherent forecasting methods.

  5. Fertilization in the sea: are the hazards of broadcast spawning avoided when free-spawned sperm fertilize retained eggs?

    PubMed Central

    Bishop, J. D. D.

    1998-01-01

    problem in this species and comparable taxa, a conclusion with potential significance for expected patterns of mating, sex allocation and gamete attributes in sessile aquatic invertebrates. Variance in reproductive success between individuals due to differences in fertilization rate may be much lower than in broadcast spawners exhibiting external fertilization.

  6. Long-term fate of nitrate fertilizer in agricultural soils

    PubMed Central

    Sebilo, Mathieu; Mayer, Bernhard; Nicolardot, Bernard; Pinay, Gilles; Mariotti, André

    2013-01-01

    Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere–hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three–decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61–65% of the applied fertilizers N were taken up by plants, whereas 12–15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8–12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of 15N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils. PMID:24145428

  7. Fertility transition and socio-economic change in western Kenya.

    PubMed

    Uitto, J I

    1992-12-01

    Kenya's national survey data have shown patterns of fertility decline in the more socioeconomically advantaged regions. In the central areas, where urbanization and economic development is the highest, fertility has begun to decline rapidly. The lowest fertility was in Nairobi capital region; the Coast Province also experienced recent fertility decline. Fertility has remained high in the Western Province and in Nyanza, Rift Valley, and Eastern Provinces. The case study of Kisii district in Nyanza Province was used to illustrate the preconditions of high fertility. The district is an agriculturally rich region that includes rounded, steep-sided hills and narrow valleys. The district is a primary producer of cash crops such as coffee, tea, and pyrethrum, and other food crops including high-yielding varieties of maize. Farm size varies between 0.11 and 2.2 hectares and farms are owner occupied. All cultivable land is in use with traditional farming methods. Tractors are used in flat areas by 11.6% of farmers. 69.3% of farmers use fertilizers, but only 32% use insecticides and pesticides. Population density is 395 persons per square kilometer. The total fertility rate is 8.2 compared to 7.7 for the nation. 6% currently used contraception, and 23% have ever used. Fertility preferences of women under 25 years old is 6.9 children. Most farm labor, even among the wealthy farmers, is family labor organized by age and gender. Women are responsible for planting, weeding, harvesting and household chores. Male off-farm employment increases the agricultural production responsibilities of women. Only mothers of sons can control property and gain prestige. Modernization and land shortages have pressured families to increase nonfarm employment.

  8. Long-term fate of nitrate fertilizer in agricultural soils.

    PubMed

    Sebilo, Mathieu; Mayer, Bernhard; Nicolardot, Bernard; Pinay, Gilles; Mariotti, André

    2013-11-05

    Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere-hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three-decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61-65% of the applied fertilizers N were taken up by plants, whereas 12-15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8-12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of (15)N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils.

  9. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. X. Age-specific dynamics of adult epicuticular hydrocarbon expression in response to different host plants.

    PubMed

    Etges, William J; de Oliveira, Cassia C

    2014-06-01

    Analysis of sexual selection and sexual isolation in Drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. Here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (CHCs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. Flies were never exposed to laboratory food and showed significant reductions in average CHC amounts consistent with CHCs of wild-caught flies. Overall, total hydrocarbon amounts increased from eclosion to 14-18 days, well past age at sexual maturity, and then declined in older flies. Most flies did not survive past 4 weeks. Baja California and mainland populations showed significantly different age-specific CHC profiles where Baja adults showed far less age-specific changes in CHC expression. Adults from populations reared on the host cactus typically used in nature expressed more CHCs than on the alternate host. MANCOVA with age as the covariate for the first six CHC principal components showed extensive differences in CHC composition due to age, population, cactus, sex, and age × population, age × sex, and age × cactus interactions. Thus, understanding variation in CHC composition as adult D. mojavensis age requires information about population and host plant differences, with potential influences on patterns of mate choice, sexual selection, and sexual isolation, and ultimately how these pheromones are expressed in natural populations. Studies of drosophilid aging in the wild are badly needed.

  10. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. X. Age-specific dynamics of adult epicuticular hydrocarbon expression in response to different host plants

    PubMed Central

    Etges, William J; de Oliveira, Cassia C

    2014-01-01

    Analysis of sexual selection and sexual isolation in Drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. Here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (CHCs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. Flies were never exposed to laboratory food and showed significant reductions in average CHC amounts consistent with CHCs of wild-caught flies. Overall, total hydrocarbon amounts increased from eclosion to 14–18 days, well past age at sexual maturity, and then declined in older flies. Most flies did not survive past 4 weeks. Baja California and mainland populations showed significantly different age-specific CHC profiles where Baja adults showed far less age-specific changes in CHC expression. Adults from populations reared on the host cactus typically used in nature expressed more CHCs than on the alternate host. MANCOVA with age as the covariate for the first six CHC principal components showed extensive differences in CHC composition due to age, population, cactus, sex, and age × population, age × sex, and age × cactus interactions. Thus, understanding variation in CHC composition as adult D. mojavensis age requires information about population and host plant differences, with potential influences on patterns of mate choice, sexual selection, and sexual isolation, and ultimately how these pheromones are expressed in natural populations. Studies of drosophilid aging in the wild are badly needed. PMID:25360246

  11. Greenhouse Gas Emissions from Solid and Liquid Organic Fertilizers Applied to Lettuce.

    PubMed

    Toonsiri, Phasita; Del Grosso, Stephen J; Sukor, Arina; Davis, Jessica G

    2016-11-01

    Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (NO) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha) on NO emissions and to track CO emissions from a lettuce field ( L.). The study was conducted in 2013 and 2014 and compared preplant-applied solid fertilizers (feather meal and blood meal) and multiple applications of liquid fertilizers (fish emulsion and cyano-fertilizer). Three days a week, NO and CO emissions were measured twice per day in 2013 and once per day in 2014 using a closed-static chamber, and gas samples were analyzed by gas chromatography. Preplant-applied solid fertilizers significantly increased cumulative NO emissions as compared with control, but multiple applications of liquid fertilizers did not. Emission factors for NO ranged from 0 to 0.1% for multiple applications of liquid fertilizers and 0.6 to 11% for preplant-applied solid fertilizers, which could be overestimated due to chamber placement over fertilizer bands. In 2014, solid fertilizers with higher C/N ratios (3.3-3.5) resulted in higher CO emissions than liquid fertilizers (C/N ratio, 0.9-1.5). Therefore, organic farmers should consider the use of multiple applications of liquid fertilizers as a means to reduce soil greenhouse gas emissions while maintaining high yields.

  12. Female Fertility: Is it Safe to “Freeze?”

    PubMed Central

    Zhang, Lu; Yan, Li-Ying; Zhi, Xu; Yan, Jie; Qiao, Jie

    2015-01-01

    Objective: To evaluate the safety and risk of cryopreservation in female fertility preservation. Data sources: The data analyzed in this review were the English articles from 1980 to 2013 from journal databases, primarily PubMed and Google scholar. The criteria used in the literature search show as following: (1) human; embryo; cryopreservation/freezing/vitrification, (2) human; oocyte/immature oocyte; cryopreservation/ freezing/vitrification, (3) human; ovarian tissue transplantation; cryopreservation/freezing/vitrification, (4) human; aneuploidy/DNA damage/epigenetic; cryopreservation/freezing/vitrification, and (5) human; fertility preservation; maternal age. Study selection: The risk ratios based on survival rate, maturation rate, fertilization rate, cleavage rate, implantation rate, pregnancy rate, and clinical risk rate were acquired from relevant meta-analysis studies. These studies included randomized controlled trials or studies with one of the primary outcome measures covering cryopreservation of human mature oocytes, embryos, and ovarian tissues within the last 7 years (from 2006 to 2013, since the pregnancy rates of oocyte vitrification were significantly increased due to the improved techniques). The data involving immature oocyte cryopreservation obtained from individual studies was also reviewed by the authors. Results: Vitrifications of mature oocytes and embryos obtained better clinical outcomes and did not increase the risks of DNA damage, spindle configuration, embryonic aneuploidy, and genomic imprinting as compared with fresh and slow-freezing procedures, respectively. Conclusions: Both embryo and oocyte vitrifications are safe applications in female fertility preservation. PMID:25635437

  13. [Fertility and contraception in Maghreb].

    PubMed

    Lacoste-dujardin, C

    1987-01-01

    In analyzing the historical and cultural factors defining the specific situation of women in Maghreb, it is shown that economic, political, and structural changes are occurring in the countries of Maghreb (Morocco, Algeria, Tunisia and Libya), but that the traditional patriarchal conception of life is even more conservative in reaction to these changes. In the patriarchal lineage structure, where the power of a family depends on the number of its males, the role of women is essentially reproductive. A woman has a social value once she becomes the mother of several sons. This was, and still is, the only way out of the lowest position in the social hierarchy for women. This situation has been leading to an intensive fertility (The birth rate was 50% in Morocco, in 1975; it was 46% in Algeria, in 1981; 32% in Tunisia, in 1983; and 47% in Libya, in 1981). It also has led to a high rate of maternal mortality, and morbidity, as well as puerperal psychosis. The sexual discrimination in favour of men in this reproductive context, has been immobilizing the relation between the sexes. The only affective relation between woman and man has been the relation between mother and son. The perpetuation of this conception in people's mind, by the weight of habits and of religius ideology, has been the strongest obstacle to demographic transition and to the necessary decline of the birth rate in these countries. Nevertheless, the possibility of changes in mentality has been growing through the slow development of women's education, and through State demographic policies favoring birth limitation.

  14. [Marriage patterns and fertility of the world population].

    PubMed

    Shao, N

    1983-09-29

    Marriage patterns of the world population may be divided into two major categories; i.e., the traditional marriage pattern, and the European marriage pattern. Characteristics of the traditional marriage pattern are: early marriage, a high percentage of married people, and a low percentage of people who remain single during their lifetime. Characteristics of the European marriage pattern include: late marriage and a higher percentage of females who do not marry in their lifetime. In most parts of Asia and Africa and some Latin American countries, the traditional marriage pattern is dominant, and the birth rate in these countries has remained very high. Most countries in Europe show the characteristics of the European marriage pattern, and the fertility rate in these countries is comparatively low. Some other countries, such as Sri Lanka, are in a process of transformation in their marriage pattern, and their fertility level also shows a transition from a high fertility rate to a lower fertility rate. There is a close relationship between marriage patterns and the level of fertility.

  15. Development and agronomical validation of new fertilizer compositions of high bioavailability and reduced potential nutrient losses.

    PubMed

    Erro, Javier; Urrutia, Oscar; San Francisco, Sara; Garcia-Mina, Jose M

    2007-09-19

    To optimize the economical cost of each unit of fertilizer applied and to reduce the environmental contamination caused by nutrient losses, the development of highly efficient granulated fertilizers is of great importance. This study proposes a strategy that consists of developing specific fertilizers having nutrient release patterns that are dependent on plant activity in the rhizosphere. This type of fertilizer is named "rhizosphere-controlled fertilizer" (RCF fertilizer). This fertilizer is based on the introduction of an organomineral matrix composed of metal [Mg (Ca is also possible), Zn (Fe and other metals are also possible)]-humic phosphates. The presence of this matrix modifies the nutrient release pattern of the fertilizer. In this way there are two main nutrient fractions: (i) a water-soluble fraction or "starter" fraction and (ii) a "rhizosphere-controlled" fraction insoluble in water but soluble by the action of the rhizospheric acids released by plants and microorganisms. This study shows the chemical and structural characterization of the organomineral matrix, as well as its efficiency in slowing the nutrient release rate of the RCF fertilizer, principally with respect to P and N. It is demonstrated how these properties of the matrix were also reflected in the significant reduction in both ammonia volatilization and N leaching in a pot system consisting of wheat plants cultivated in a calcareous soil and fertilized with a RCF fertilizer.

  16. 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.

  17. Ocean Fertilization and Ocean Acidification

    NASA Astrophysics Data System (ADS)

    Cao, L.; Caldeira, K.

    2008-12-01

    It has been suggested that ocean fertilization could help diminish ocean acidification. Here, we quantitatively evaluate this suggestion. Ocean fertilization is one of several ocean methods proposed to mitigate atmospheric CO2 concentrations. The basic idea of this method is to enhance the biological uptake of atmospheric CO2 by stimulating net phytoplankton growth through the addition of iron to the surface ocean. Concern has been expressed that ocean fertilization may not be very effective at reducing atmospheric CO2 concentrations and may produce unintended environmental consequences. The rationale for thinking that ocean fertilization might help diminish ocean acidification is that dissolved inorganic carbon concentrations in the near-surface equilibrate with the atmosphere in about a year. If ocean fertilization could reduce atmospheric CO2 concentrations, it would also reduce surface ocean dissolved inorganic carbon concentrations, and thus diminish the degree of ocean acidification. To evaluate this line of thinking, we use a global ocean carbon cycle model with a simple representation of marine biology and investigate the maximum potential effect of ocean fertilization on ocean carbonate chemistry. We find that the effect of ocean fertilization on ocean acidification depends, in part, on the context in which ocean fertilization is performed. With fixed emissions of CO2 to the atmosphere, ocean fertilization moderately mitigates changes in ocean carbonate chemistry near the ocean surface, but at the expense of further acidifying the deep ocean. Under the SRES A2 CO2 emission scenario, by year 2100 simulated atmospheric CO2, global mean surface pH, and saturation state of aragonite is 965 ppm, 7.74, and 1.55 for the scenario without fertilization and 833 ppm, 7.80, and 1.71 for the scenario with 100-year (between 2000 and 2100) continuous fertilization for the global ocean (For comparison, pre-industrial global mean surface pH and saturation state of

  18. Semen collection and fertility in naturally fertile sandhill cranes

    USGS Publications Warehouse

    Chen, G.; Gee, G.F.; Nicolich, Jane M.; Taylor, J.A.; Urbanek, R.P.; Stahlecker, D.W.

    1997-01-01

    Aviculturists often ask if semen collection will interfere with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had produced fertile eggs in previous years and were in out-of-doors pens scattered throughout different pen complexes, within auditory range but physically isolated. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection did not affect semen quality or quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm live, sperm number per collection, and male response to semen collection exhibited significant daily variation (P < 0.05). Although semen collection began 13 days before the first egg in the experimental group, we observed no differences in the date of first egg laid or in fertility between experimental and control groups. Also, we observed no differences in the interval between clutches or in the percentage of broken eggs between experimental and control groups. Sires consistently producing better semen samples produced fewer fertile eggs than sires producing poorer semen samples (r = 0.60).

  19. Preservation of female fertility: an essential progress.

    PubMed

    Tulandi, Togas; Huang, Jack Y J; Tan, Seang Lin

    2008-11-01

    Chemotherapy and radiation treatment for malignancies or other conditions such as hematologic and autoimmune disorders, have resulted in improved survival rates but may lead to sterility. Women who postpone conception until late reproductive years are also at increased risk to become infertile. The purpose of our review is to evaluate advances and techniques for fertility preservation. We performed a literature search using the keywords fertility preservation, vitrification, oocytes, embryo, ovarian cryopreservation, and ovarian suspension and conducted the search in MEDLINE, EMBASE, and the Cochrane Database of systematic reviews. The results show that today, it is possible to cryopreserve oocytes, embryos, or ovarian tissue. The most commonly used technique remains embryo cryopreservation. Another improvement is the development of vitrification or rapid freezing technique. For women undergoing local pelvic radiation, one should consider ovarian suspension. Medical professionals, patients, and their families should be aware that in some conditions, the reproductive function can be preserved. Although one cannot guarantee future fertility, a realistic hope for women at risk of having premature ovarian failure can now be offered.

  20. Fertility targets and policy options in Asia.

    PubMed

    Bulatao, R A

    1984-11-01

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

  1. The Impact of Adenomyosis on Women's Fertility

    PubMed Central

    Harada, Tasuku; Khine, Yin Mon; Kaponis, Apostolos; Nikellis, Theocharis; Decavalas, George; Taniguchi, Fuminori

    2016-01-01

    Until recently, adenomyosis has been associated with multiparity, not impaired fertility. Currently, adenomyosis is diagnosed with increasing frequency in infertile patients since women delay their first pregnancy until their late 30s or early 40s. Although an association between adenomyosis and infertility has not been fully established, based on the available information, recent studies suggested that adenomyosis has a negative impact on female fertility. Several uncontrolled studies with limited data also suggested that treatment of adenomyosis may improve fertility. This article discusses (i) the hypothesis and epidemiology of adenomyosis, (ii) diagnostic techniques, (iii) clinical evidence of correlation between adenomyosis and infertility, (iv) proposed mechanism of infertility in women with adenomyosis, (v) different treatment strategies and reproductive outcomes, and (vi) assisted reproductive technology outcome in women with adenomyosis. Target Audience Obstetricians and gynecologists, family physicians. Learning Objectives After completing this activity, the learner should be better able to: Recall the hypothesis and epidemiology of adenomyosis; Evaluate the important findings on improved imaging techniques to diagnose adenomyosis; Understand that the presence of adenomyosis may impair the reproductive outcomes in women with adenomyosis; Explain the proposed mechanism of infertility in women with adenomyosis; Give the most appropriate treatment for better reproductive outcomes in women with adenomyosis; and Advise patients that surgery could be effective in women with adenomyosis with a history of IVF failure although latter finding could be partly attributed to the higher rate of early miscarriage. PMID:27640610

  2. Fertility after abdominal myomectomy.

    PubMed

    Connolly, G; Doyle, M; Barrett, T; Byrne, P; De Mello, M; Harrison, R F

    2000-07-01

    This study aimed to evaluate the morbidity and pregnancy outcome of myomectomy in infertile women with uterine fibroids. This was a cross-sectional study. Records were reviewed for 100 consecutive women in the Rotunda Hospital who underwent myomectomy in the years 1995-1996. A questionnaire regarding subsequent fertility was sent. The study was carried out in the infertility unit at the Rotunda Hospital, Dublin, Ireland. Seventy-five women responded. Multiple myomectomy was performed in 52 (70%). Mean fibroid size was 6.8 cm (range 2-14.5 cm). Nine women (12%) developed complications; five had menstrual problems, two had wound discomfort and two had abdominal discomfort. Twenty-five women (33%) became pregnant. Seven (28%) were IVF pregnancies. Overall six (24%) miscarried. In 19 of 25, pregnancy occurred where fibroids were the only identifiable cause of infertility. We conclude that abdominal myomectomy is associated with a favourable outcome in infertile women particularly if no other confounding variable is present.

  3. Glucocorticoids, Stress, and Fertility

    PubMed Central

    Whirledge, Shannon; Cidlowski, John A.

    2012-01-01

    Modifications of the hypothalamo-pituitary-adrenal axis and associated changes in circulating levels of glucocorticoids form a key component of the response of an organism to stressful challenges. Increased levels of glucocorticoids promote gluconeogenesis, mobilization of amino acids, and stimulation of fat breakdown to maintain circulating levels of glucose necessary to mount a stress response. In addition to profound changes in the physiology and function of multiple tissues, stress and elevated glucocorticoids can also inhibit reproduction, a logical effect for the survival of self. Precise levels of glucocorticoids are required for proper gonadal function; where the balance is disrupted, so is fertility. Glucocorticoids affect gonadal function at multiple levels in hypothalamo-pituitary-gonadal axis: 1) the hypothalamus (to decrease the synthesis and release of GnRH); 2) the pituitary gland (to inhibit the synthesis and release of LH and FSH); 3) the testis/ovary (to modulate steroidogenesis and/or gametogenesis directly). Furthermore, maternal exposure to prenatal stress or exogenous glucocorticoids can lead to permanent modification of hypothalamo-pituitary-adrenal function and stress-related behaviors in offspring. Glucocorticoids are vital to many aspects of normal brain development, but fetal exposure to superabundant glucocorticoids can result in life-long effects on neuroendocrine function. This review focuses on the molecular mechanisms believed to mediate glucocorticoid inhibition of reproductive functions and the anatomical sites at which these effects take place. PMID:20595939

  4. Physiological responses to fertilization recorded in tree rings: isotopic lessons from a long-term fertilization trial.

    PubMed

    Brooks, J Renée; Coulombe, Rob

    2009-06-01

    Nitrogen fertilizer applications are common land use management tools, but details on physiological responses to these applications are often lacking, particularly for long-term responses over decades of forest management. We used tree ring growth patterns and stable isotopes to understand long-term physiological responses to fertilization using a controlled fertilization experiment begun in 1964 in Washington State (USA), in which three levels of nitrogen fertilizer were applied: 157, 314; and 471 kg/ha. Basal area increment (BAI) increased more than fourfold in the highest treatment to twofold in the lowest, and a significant increase in BAI was observed for 20 years. Latewood delta 13C sharply decreased by 1.4 per thousand after fertilization and was significantly lower than controls for four years, but no differences existed between fertilization levels, and the effect disappeared after four years, indicating that intrinsic water use efficiency (A/gs) increased in response to fertilization. Earlywood delta 13C showed similar trends but was more variable. Latewood delta 18O increased significantly above controls by approximately 2 per thousand in all treatments, but the duration differed with treatment level, with the effect being longer for higher levels of fertilization and lasting as long as nine years after fertilization. Because source water and relative humidity were the same between experimental plots, we interpreted the delta 18O increase with treatment as a decrease in leaf-level transpiration. Earlywood delta 18O did not show any treatment effects. Because the Pacific Northwest has a mediterranean climate with dry summers, we speculated that fertilization caused a substantial increase in leaf area, causing the trees to transpire themselves into drought stress during the late summer. We estimate from the delta 18O data that stomatal conductance (gs) was reduced by approximately 30%. Using the delta 13C data to estimate assimilation rates (A), A during

  5. UN projections assume fertility decline, mortality increase.

    PubMed

    Haub, C

    1998-12-01

    This article summarizes the latest findings from the UN Population Division's 1998 review of World Population Estimates and Projections. The revisions reflect lower future population size and faster rates of fertility and mortality decline. The medium variant of population projection for 2050 indicates 8.9 billion, which is 458 million lower than projected in 1996 and 924 million lower than projected in 1994. The changes are due to changes in developing countries. Africa's changes accounted for over 50% of the change. The UN medium projection assumes that the desire for fewer children and effective contraceptive practice will continue and that the availability of family planning services will increase. The revisions are also attributed to the widespread prevalence of AIDS in sub-Saharan Africa and greater chances for lower fertility in developing countries. AIDS mortality may decrease average life expectancy in 29 African countries by 7 years. The UN medium projection assumes a decline in fertility from 2.7 children/woman during 1995-2000 to 2.0 children/woman by 2050. The UN high variant is 10.7 billion by 2050; the low variant is 7.3 billion. It is concluded that efforts of national governments and international agencies have contributed to increased access to reproductive health services and subsequent fertility decline. Future declines will depend on accessibility issues. Despite declines, world population is still growing by 78 million annually. Even countries such as Botswana, with 25% of the population infected with HIV/AIDS, will double in size by 2050.

  6. The influence of reduced glutathione in fertilization medium on the fertility of in vitro-matured C57BL/6 mouse oocytes.

    PubMed

    Ishizuka, Y; Nishimura, M; Matsumoto, K; Miyashita, M; Takeo, T; Nakagata, N; Hosoi, Y; Anzai, M

    2013-09-15

    It is well known that IVM oocytes show a decreased potential for fertility and development compared with in vivo-matured oocytes. In this study, we added reduced glutathione (GSH) to the fertilization medium during IVF to investigate its effect on the fertility and early embryo development of IVM oocytes. The fertilization rate for IVM oocytes and fresh sperm increased with the addition of GSH (0, 1.0, and 2.0 mM: 51%, 76%, and 70%). Moreover, the addition of GSH to the fertilization medium also improved the developmental potential compared with the control sample (0 mM). In addition, we performed IVF using IVM oocytes and frozen/thawed sperm that had been cryopreserved in a mouse bank. Results indicated a marked increase in the fertilization rate when 1.0 mM GSH was added to the fertilization medium compared with when no GSM was used (0.0 mM GSH: 2% (3/195); 1.0 mM GSH: 33% (156/468)). Furthermore, the fertilization rate improved dramatically via zona drilling using laser equipment (52%: 267/516), whereas normal offspring were obtainsed after transferring embryos created via IVF using IVM oocytes and frozen/thawed sperm. This is the first report in which offspring have been obtained via IVF using IVM oocytes and frozen/thawed sperm.

  7. Global fertility and population trends.

    PubMed

    Bongaarts, John

    2015-01-01

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

  8. IVF-In Vitro Fertilization.

    ERIC Educational Resources Information Center

    Kieffer, George H.

    1980-01-01

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

  9. Food security: Fertilizing hidden hunger

    NASA Astrophysics Data System (ADS)

    Müller, Christoph; Elliott, Joshua; Levermann, Anders

    2014-07-01

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

  10. Healthy Sperm: Improving Your Fertility

    MedlinePlus

    Healthy Lifestyle Getting pregnant Healthy sperm aren't always a given. Understand how lifestyle factors can affect your ... as a laptop, might enhance sperm quality. Adopting healthy lifestyle practices to promote your fertility — and avoiding things ...

  11. Liquid N and S fertilizer solutions effects on the mass, chemical, and shear strength properties of winter wheat (Triticum aestuvum) residue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To improve stand establishment in high crop residue situations, the utility of fertilizer to stimulate microbial decomposition of residue has been debated. Field experiments assessed winter wheat (Triticum aestivum) straw decomposition under different fertilizer rates and application timings at thre...

  12. [Fertility decline in Colombia: expression of a profound social change].

    PubMed

    De Llinas, H M

    1983-01-01

    Demographers have identified 3 phases in the evolution of human population growth: 1) high mortality and high fertility resulting in very slow growth, 2) declining mortality and high fertility, resulting in rapid growth, and 3) declining mortality and fertility, resulting in slower growth. From the beginning of the century until the 1930s, Colombia was in the 1st phase, while the greatest mortality declines were registered from 1930-60. Fertility did not decline commensurately, and from 1951-64 the rate of population increase was 3.14%. The National Fertility Survey in 1969 and the 1973 census indicated that the country had at last begun its fertility decline. The 1969 survey showed that the total fertility rate (TFR) had dropped from 7.0 in the early 1960s to 6.0 in 1967-68, with fertility declining in both rural and urban areas. The 1973 census showed a rate of growth of 2.8% and an average number of children/woman of 4.7, showing that the fertility decline was structural and reflected profound changes in the values, norms, and attitudes regarding children of the Colombian population. Urbanization, the increased educational level and labor force participation of women, and the influence of the mass media in propagating the values of a consumer society are factors in the reduction of family size. Fertility differentials by region and social group have been declining progressively. The TFR in 1960-64 was 7.0 overall, 6.1 in urban areas, and 7.9 in rural areas, while in 1980 it was 3.6 overall, 3.0 in urban areas, and 5.1 in rural areas. In 1968-69, the TFR was 7.8 in the Atlantic region, 7.9 in the Oriental, 6.8 in the Central, 5.9 in the Pacific, and 4.5 in Bogota, while in 1980 it was 4.1 in the Atlantic, 4.0 in the Oriental, 3.5 in the Central, 3.3 in the Pacific, and 2.8 in Bogota. The number of women using family planning programs increased from 83 in 1965 to 1,790,484 in 1980. The proportion using contraception increased from 53% in 1976 to 55% in 1980. The

  13. Use-effectiveness of fertility awareness among the urban poor.

    PubMed

    Dorairaj, K

    1984-01-01

    -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.

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

    PubMed Central

    Allouche, Lynda; Madani, Toufik; Mechmeche, Mohamed; Clement, Laetitia; Bouchemal, Allaoua

    2017-01-01

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

  15. Age-Specific Gene Expression Signatures for Breast Tumors and Cross-Species Conserved Potential Cancer Progression Markers in Young Women

    PubMed Central

    Colak, Dilek; Nofal, Asmaa; AlBakheet, AlBandary; Nirmal, Maimoona; Jeprel, Hatim; Eldali, Abdelmoneim; AL-Tweigeri, Taher; Tulbah, Asma; Ajarim, Dahish; Malik, Osama Al; Kaya, Namik; Park, Ben H.; Bin Amer, Suad M.

    2013-01-01

    Breast cancer in young women is more aggressive with a poorer prognosis and overall survival compared to older women diagnosed with the disease. Despite recent research, the underlying biology and molecular alterations that drive the aggressive nature of breast tumors associated with breast cancer in young women have yet to be elucidated. In this study, we performed transcriptomic profile and network analyses of breast tumors arising in Middle Eastern women to identify age-specific gene signatures. Moreover, we studied molecular alterations associated with cancer progression in young women using cross-species comparative genomics approach coupled with copy number alterations (CNA) associated with breast cancers from independent studies. We identified 63 genes specific to tumors in young women that showed alterations distinct from two age cohorts of older women. The network analyses revealed potential critical regulatory roles for Myc, PI3K/Akt, NF-κB, and IL-1 in disease characteristics of breast tumors arising in young women. Cross-species comparative genomics analysis of progression from pre-invasive ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) revealed 16 genes with concomitant genomic alterations, CCNB2, UBE2C, TOP2A, CEP55, TPX2, BIRC5, KIAA0101, SHCBP1, UBE2T, PTTG1, NUSAP1, DEPDC1, HELLS, CCNB1, KIF4A, and RRM2, that may be involved in tumorigenesis and in the processes of invasion and progression of disease. Array findings were validated using qRT-PCR, immunohistochemistry, and extensive in silico analyses of independently performed microarray datasets. To our knowledge, this study provides the first comprehensive genomic analysis of breast cancer in Middle Eastern women in age-specific cohorts and potential markers for cancer progression in young women. Our data demonstrate that cancer appearing in young women contain distinct biological characteristics and deregulated signaling pathways. Moreover, our integrative genomic and cross

  16. Fertility preservation options for children and adolescents with cancer

    PubMed Central

    Romao, Rodrigo L.P.; Lorenzo, Armando J.

    2017-01-01

    Introduction: Cancer in children and adolescents has seen a stark rise in survival rates in the last decades; overall survival in excess of 80% can be reasonably expected for many newly diagnosed patients with malignancies in this age group. Survivorship has unfolded several specific issues faced by these patients, including fertility concerns. Hence, fertility preservation efforts have been discussed and undertaken with increased frequency. Methods: In this article, the authors provide a broad overview of the current recommendations surrounding fertility preservation in this patient population. Reasons to offer fertility preservation, target groups for interventions, and methods available based on age group and gender are discussed in detail. Results: The medical literature and patient advocates strongly support a discussion about fertility preservation at the time of diagnosis; the risk of infertility is real and parents and families wish to be informed about it. In postpubertal males, sperm-banking is relatively straightforward and should be attempted by most newly diagnosed patients, ideally before commencement of treatment. Cryopreservation of testicular tissue in higher-risk prepubertal males is feasible, but still experimental. Female fertility preservation is more complex, requires more invasive procedures, and can delay initiation of treatment due to the requirement for hormone stimulation of follicles prior to harvesting. Conclusions: Oncofertility initiatives in children and youth are still in their early days and will continue to expand; urologists should be prepared to offer counselling and interventions when appropriate to this growing vulnerable population. PMID:28265333

  17. 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

  18. 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.

  19. Recent fertility declines in China and India: a comparative view.

    PubMed

    Kulkarni, P M; Rani, S

    1995-12-01

    This paper compares fertility transitions in China and parts of India. It is argued that China experienced a more rapid and more "impressive" decline than that of India. Socioeconomic conditions in China were more conducive to fertility decline. Kerala State in India experienced a similar decline as China but at a slower pace. The birth control campaign in China is credited with an important role in speeding the transition. It is posited that the political and administrative system and economic conditions in India are not compatible with the Chinese style program strategies. Both countries had similar fertility levels in the immediate post-revolutionary period. The most rapid decline occurred during the 1970s in China. The fertility transition was almost completed by 1981. In India, the total fertility rate (TFR) declined by only 1 point between the 1950s and 1981. In China TFR declined over 3 points during 1970-81. 76.7% of the decline in China during 1970-81 is attributed to a marked decline in marital fertility in all age groups, with the exception of ages 15-19 years. The decline in India is attributed to the decline in marital fertility. Female age at marriage rose in India, but less "impressively." In 1981 the mean age at marriage in India was 18.4 years, but it was 22.8 years in China. Marital fertility among women aged older than 30 years was considerably lower in China. Both countries experienced an increase in literacy, but in China the level of literacy was much greater. Both countries faced food shortages, but China improved food availability and calorie consumption per capita. Health services also improved in both countries, but the Chinese system of "barefoot" doctors brought services with easier reach of rural populations. Political structures differed in their dominance and organization. Family planning programs were introduced earlier in India, but prevalence was 64.4% in China in 1981 and about 22% in India.

  20. 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

  1. 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

  2. [Present situation of rice fertilization in qin-ba mountainous area of Southern Shaanxi, China].

    PubMed

    Wang, Xiao-Ying; Liu, Fen; Tong, Yan-An; Zhao, Zuo-Ping

    2013-11-01

    In order to understand the present situation of rice fertilization and the existing problems in the farmers' nutrient resources input in the Qin-Ba mountainous area of southern Shaanxi, the survey data from 2854 households in 11 counties of this area in the project "soil testing and formulated fertilization in 2006-2009" were analyzed and evaluated, and the countermeasures for the existing problems in the farmers' nutrient resources input were proposed. In the study area, the average rice yield was 7822 kg x hm(-2) per year, and the ratio of the households obtained the medium level yield was up to 50.9%. The input of the total fertilizers N, P2O5, K2O was 169, 68, and 54 kg x hm(-2), and the chemical fertilizer rate was 159, 62, and 45 kg x hm(-2), with the partial factor productivity (PFP) of the N, P2O5, and K2O being 51.52, 135.69, and 158.26 kg x kg(-1), respectively. According to the nutrient fertilization level, the proportion of the households fertilized with rational level of chemical N, P2O5, and K2O occupied 48.0%, 42.4%, and 7.2%, that of the households fertilized with excessive level was 22.6%, 11.2%, and 0.6%, and the proportion of the households fertilized with insufficient level occupied 29.4%, 46.5%, and 92.2%, respectively. The rice yield in the Qin-Ba mountainous area could be increased by 77 thousand tons if the households fertilizing with insufficient level of chemical NPK fertilizers increased the fertilization rate to a rational level. The existing problems in the farmers' nutrient resources input were mainly the coexistence of excessive and insufficient application of nitrogen and phosphate fertilizers and the insufficient input of potassium fertilizer and organic manure. In the rice fertilization in this area, the focus would be the balanced application of nitrogen and phosphate fertilizers, the increase of the fertilization rates of potassium fertilizer and organic manure, and the increase of top dressing, especially potassium.

  3. Does Fluoride Affect Serum Testosterone and Androgen Binding Protein with Age-Specificity? A Population-Based Cross-Sectional Study in Chinese Male Farmers.

    PubMed

    Duan, Leizhen; Zhu, Jingyuan; Wang, Keyan; Zhou, Guoyu; Yang, Yuejin; Cui, Liuxin; Huang, Hui; Cheng, Xuemin; Ba, Yue

    2016-12-01

    Many studies have demonstrated that exposure to excess fluoride was associated with a variety of diseases. Little is known about the variation of testosterone (T) levels caused by fluoride exposure. The aim of this study is to explore the association of fluoride exposure and age with serum T and androgen-binding protein (ABP) levels in male farmers. A cross-sectional study was conducted in a county of Henan Province, China, including high fluoride exposure from drinking water villages and control villages. Male farmers aged 18-55 years old who lived in these villages were recruited by cluster sampling and divided into a higher fluoride exposure group (HFG) and a lower fluoride exposure group (LFG) according to the level of urinary fluoride. Levels of T and ABP in serum were measured using chemiluminescence immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) respectively. Markedly lower T levels were observed in male farmers from the HFG than in those from the LFG (t = 2.496, P < 0.05). Furthermore, younger farmers, 18-29 and 30-39 years old, may be the most likely to have lower T levels when exposed to fluoride (P < 0.05). No significant differences were observed in serum ABP levels in all male farmers between the two groups with different fluoride exposure. These results supported that excess fluoride exposure decreased serum T levels of male farmers with age-specificity.

  4. Screening of Undiagnosed Hypothyroidism in Elderly Persons with Diabetes according to Age-Specific Reference Intervals for Serum Thyroid Stimulating Hormone and the Impact of Antidiabetes Drugs

    PubMed Central

    Teixeira, Patricia de Fatima dos Santos; Vaisman, Mario

    2016-01-01

    Background. Studies have suggested that hypothyroidism is more frequent in the elderly with diabetes mellitus. However, an adaptation of TSH levels to age should be considered in this assessment. Some antidiabetes drugs reportedly interfere with TSH levels. The objectives of this study were to evaluate the prevalence of undiagnosed hypothyroidism in patients with diabetes and the influence of antidiabetes drugs. Material and Methods. 1160 subjects, 60 years and older (751 with diabetes), were studied; results were compared according to diabetes treatment and with persons without diabetes. TSH, FT4, antithyroperoxidase, fasting glucose, and HbA1c were measured. Results and Discussion. 6.4% of patients with diabetes had hypothyroidism, a higher prevalence compared with persons without diabetes (5.1%), but lower than observed in many studies. The use of age-specific TSH reference interval (RI) could explain this difference. Patients taking metformin (MTF) had TSH (showed in medians) slightly lower (2.8 mU/L) than those not on MTF (3.3 mU/L), p < 0.05. MTF doses influenced TSH levels. Conclusions. The use of specific TSH RI could avoid the misdiagnosis of hypothyroidism in elderly with diabetes. Patients in use of MTF as single drug had lower TSH than those using other medications and persons without diabetes. PMID:27403442

  5. Organic fertilization leads to increased peach root production and lifespan.

    PubMed

    Baldi, E; Toselli, M; Eissenstat, D M; Marangoni, B

    2010-11-01

    We evaluated the effects of mineral and organic fertilizers on peach root dynamics in the growing season from 2003 to 2006 in a nectarine (Prunus persica L.) orchard, planted in 2001 and located in the Po valley, northeastern Italy. Very few studies have conducted long-term investigations of root dynamics of fruit crops. Our main objective was to determine whether organic fertilizers affect root dynamics differently than mineral fertilizers. The experiment was a completely randomized block design with four replicates of three treatments: unfertilized, mineral fertilized and composted with municipal waste. Mineral fertilizers included P (100 kg ha(-1) year(-1)) and K (200 kg ha(-1) year(-1)) applied only at planting and N (70-130 kg ha(-1) year(-1)) split into two applications, one at 40 days after full bloom (60%) and the other in September (40%) each year. The compost fertilization represented a yearly rate of 10 metric tons (t) dry weight ha(-1), which approximates (in kg ha(-1) year(-1)) 240 N, 100 P and 200 K, split similarly to that described for the mineral fertilization of N. Both root growth and survival were evaluated at 20-day intervals during the growing season by the minirhizotron technique. Compost increased the production of new roots compared with the other treatments (P < 0.01). Roots were mainly produced at a depth of 41-80 cm and from March to May and in late summer. An analysis of covariance indicated no significant effect of soil nitrate on root production (P = 0.47). The root lifespan was longer in compost-treated trees than in mineral-fertilized or unfertilized trees (P < 0.01) and it was strongly affected by time of birth; roots born later in the summer lived longer than those born in the spring. Across years and treatments, the average root lifespan was positively correlated with soil nitrate (r = 0.60; P < 0.001). Variation in root lifespan with method of fertilization could be accounted for by variation in soil

  6. Phosphorus content in long-term fertilized soils

    NASA Astrophysics Data System (ADS)

    Pizzeghello, D.; Morari, F.; Berti, A.; Nardi, S.; Giardini, L.

    2009-04-01

    Phosphorous (P) is often considered a limiting nutrient in crop production. However, particularly in intensive livestock and pig farming areas large surplus of P inputs associated with manure application to agricultural soils may result in an excessive P accumulation and a consequent gradual saturation of the soil P-sorption capacity. This event must be discouraged in order to contain possible eutrophication. In this study we investigated the impact of a long-term fertilization experiment on the accumulation in soil of different form of P. The experiment has been underway since 1964 on the University of Padova Experimental farm. The treatments derived from the factorial combination of 3 types of soil (clay, sandy and peaty) with 3 types of mineral, organic or mixed fertilization, organized in two randomized blocks. A total of 36 lysimeters (surface of 4 m2 and 80 cm deep) were cultivated. Fertilization rates were as follows: 0, no fertilization; F1 manure (20 t ha-1 y-1); M1, mineral fertilization (100 kg ha-1 y-1 N); F1M1, manure (20 t ha-1 y-1) + mineral fertilization (100 kg ha-1 y-1 N); F2 manure (40 t ha-1 y-1); M2, mineral fertilization (200 kg ha-1 y-1 N - 100 P2O5 - 280 K2O). Soil samples were taken using a 2-cm diameter auger from 0 to 100 cm depth, every 10 cm. P was analysed in term of total, organic and available (Olsen) phosphorus. Only treatments 0, M2 and F2 were subjected to soil sampling and chemical analyses. Results showed as the variables were affected by all the factors considered (treatment, soil and depth). Both farmyard manure and mineral fertilization increased the P content in function of soil types. In particular, as concerning the interaction between fertilization and depth, manure as well as mineral fertilization influenced the available P along soil profiles. The long-term fertilizer applications increased the P content at a level which resulted potentially hazardous for the environment.

  7. The Relationship of Socio-Demographic Factors, Fertility Behavior and Child’s Perceived Value with Fertility

    PubMed Central

    Azmoude, Elham; Behnam, Haniye; Barati-Far, Saeede; Kabirian, Maryam

    2017-01-01

    ABSTRACT Background: Fertility intention is one of the strongest predictors of couple’s fertility behavior that is affected by many variables. This study aimed to identify the relationship of socio-demographic factors, fertility behavior, and child’s perceived value with fertility intention of women in a region in the east Iran Methods: In this descriptive cross-sectional study, 241 married women aged between 15 and 49 years of Torbat Heydariyeh City in 2015, were studied. The data collection scales included a demographic information form, fertility information questionnaire and Trommsdorff’s child value questionnaire. Data were analyzed using SPSS 16 by Chi-square, Kruskal-Wallis, t-independent test and logistic regression. The significance level of P<0.05 was considered. Results: Most of the subjects (52.7%) had no fertility intention. Independent-samples test and Kruskal-Wallis revealed significant differences in fertility intention with the subject’s age, mate’s age, number of children and costs of children (P=0.001). In addition, in subjects with children of both sexes, intention for childbearing was significantly lower when compared to subjects with only one sex in children (P=0.001). However, when the logistic regression test was performed, being housewife, number of children, having children of both sexes, benefit and costs of children showed statistical significance (P<0.05). Conclusion: The results indicate that being housewife, number of current children, having children of both sexes, and perceived childbearing costs are important in determining the odds that a woman will intend to have a child. These findings can contribute to the realization of new population programs towards higher fertility rate in the country.

  8. Methods for Improving In Vitro and In Vivo Boar Sperm Fertility.

    PubMed

    Funahashi, H

    2015-07-01

    Fertility of boar spermatozoa is changed after ejaculation in vivo and in vitro. During processing for in vitro fertilization (IVF), although spermatozoa are induced capacitation, resulting in a high penetration rate, persistent obstacle of polyspermic penetration is still observed with a high incidence. For artificial insemination (AI), we still need a large number of spermatozoa and lose a majority of those in the female reproductive tract. Fertility of cryopreserved boar spermatozoa is still injured through freezing and thawing process. In the present brief review, factors affecting fertility of boar sperm during IVF, AI and cryopreservation are discussed in the context of discovering methodologies to improve it.

  9. Inorganic fertilizers after broiler litter amendment reduce surplus nutrients in orchardgrass soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The common producer practice to dispose of broiler litter at high rates to forage crops allow excessive accumulation of soil nutrients. A remediation study was developed to examine if inorganic fertilizer application over the residual fertility of broiler litter would reduce surplus soil nutrients i...

  10. Can leguminous cover crops partially replace nitrogen fertilization in Mississippi delta cotton production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Petroleum prices impacts cotton (Gossypium hirsutum L.) N fertilization cost. A 3-year field study was conducted on a Dundee silt loam to assess the interactions of leguminous cover crops [none, Austrian winter field pea (Pisum sativum L.) or hairy vetch (Vicia villosa Roth] and N fertilization rate...

  11. Biologically based fertilizer recommendations to meet yield expectations and preserve water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn is one of the most demanding crops for N and therefore often requires a high rate of N fertilizer to achieve high productivity. Cost of N fertilizer has risen dramatically during the past decade. Our goal was to develop a biologically based tool to improve N management in high N demanding cer...

  12. Nutrient management of blueberry – Assessing plant nutrient needs and designing good fertilizer programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this article and presentation, we will address recommended soil nutrient levels for making pre-planting decisions, starting rates of key nutrients to apply, how to assess plant nutrient status to modify fertilizer programs, timing and source of fertilizer to apply, and fertigation. Key questions ...

  13. Novel slow release nanocomposite nitrogen fertilizers: the impact of polymers on nanocomposite properties and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficient use of fertilizers, especially nitrogen, is essential and strategic to agricultural production. Among the technologies that can contribute to efficient use of fertilizers are slow or controlled release products. This paper describes the impact on structure, urea release rate and function i...

  14. A Rapid Test for Prediction of Nutrient Release from Controlled Release Fertilizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient release from soluble granular fertilizers can be modified by polymer coating. The coating technology can be fine-tuned to change the duration (3 to 9 months) and rate of nutrient release, hence these products are termed as controlled release fertilizers (CRF). There is a need to develop a r...

  15. Variable Rate Irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systems are available to producers with the ability to make variable-rate applications of defoliants, fertilizer, lime, pesticides, plant growth regulators, and seed. These systems could potentially offer a producer great cost savings; however, the full potential of these benefits and savings cannot...

  16. Variable rate irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systems are available to producers to make variable-rate applications of defoliants, fertilizer, lime, pesticides, plant growth regulators, and seed. These systems could potentially offer cost savings to a producer; however, the full potential of the benefits and savings cannot be realized if water ...

  17. Education Fever and the East Asian Fertility Puzzle: A case study of low fertility in South Korea

    PubMed Central

    Anderson, Thomas; Kohler, Hans-Peter

    2014-01-01

    Fertility throughout East Asia has fallen rapidly over the last five decades and is now below the replacement rate of 2.1 in every country in the region. Using South Korea as a case study, we argue that East Asia's ultra-low fertility rates can be partially explained by the steadfast parental drive to have competitive and successful children. Parents throughout the region invest large amounts of time and money to ensure that their children are able to enter prestigious universities and obtain top jobs. Accordingly, childrearing has become so expensive that the average couple cannot afford to have more than just one or two children. The trend of high parental investment in child education, also known as ‘education fever’, exemplifies the notion of ‘quality over quantity’ and is an important contributing factor to understanding low-fertility in East Asia. PMID:24883076

  18. The economics of fertility.

    PubMed

    Loraine, J A

    1982-01-01

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

  19. Improvement of natural pastures using liquid organic fertilizers

    NASA Astrophysics Data System (ADS)

    Ghambashidze, Giorgi; Gabedava, Giorgi; Abuladze, Paata

    2016-04-01

    Nowadays natural pastures remains the main source to supply livestock with fresh feed material in Georgia. Due to that common pasturelands are under continues grazing pressure and normally no measures are taken in order to improve pasture productivity and to protect soil from erosion. Unregulated stocking rate leads to overutilization of natural pastures causing reduction in productivity and soil fertility. It is especially evident in arid regions, where bare soil after removal of vegetation dries out and is subject to wind erosion. In many areas even with regulated stocking rate plant available soil nutrient pool is already diminished and vegetation cannot be recovered easily after grazing. Therefore it is essential to improve soil fertility, which provide adequate amount of nutrients to plants to regenerate. Ongoing study aims to compare effect of different types of organic fertilizers on natural pastures in combination with pasture rotation scheme in order to maintain soil fertility and prepare the basis for its gradual improvement. Initial results shows positive impact of liquid organic fertilizers which increased aboveground biomass production by 200-300 kg per hectare.

  20. Impact of air pollution on fertility: a systematic review.

    PubMed

    Frutos, Víctor; González-Comadrán, Mireia; Solà, Ivan; Jacquemin, Benedicte; Carreras, Ramón; Checa Vizcaíno, Miguel A

    2015-01-01

    Air pollution has gained considerable interest because of the multiple adverse effects reported on human health, although its impact on fertility remains unclear. A systematic search was performed to evaluate the impact of air pollutants on fertility. Controlled trials and observational studies assessing animal model and epidemiological model were included. Occupational exposure and semen quality studies were not considered. Outcomes of interest included live birth, miscarriage, clinical pregnancy, implantation, and embryo quality. Ten studies were included and divided into two groups: animal studies and human epidemiological studies including the general population as well as women undergoing in vitro fertilization and embryo transfer (IVF/ET). Results from this systematic review suggest a significant impact of air pollution on miscarriage and clinical pregnancy rates in the general population, whereas among subfertile patients certain air pollutants seem to exert a greater impact on fertility outcomes, including miscarriage and live birth rates. Besides, studies in mammals observed a clear detrimental effect on fertility outcomes associated to air pollutants at high concentration. The lack of prospective studies evaluating the effect of air pollution exposure in terms of live birth constitutes an important limitation in this review. Thus, further studies are needed to confirm these findings.

  1. Sperm head phenotype and male fertility in ram semen.

    PubMed

    Maroto-Morales, A; Ramón, M; García-Álvarez, O; Montoro, V; Soler, A J; Fernández-Santos, M R; Roldan, E R S; Pérez-Guzmán, M D; Garde, J J

    2015-12-01

    Although there is ample evidence for the effects of sperm head shape on sperm function, its impact on fertility has not been explored in detail at the intraspecific level in mammals. Here, we assess the relationship between sperm head shape and male fertility in a large-scale study in Manchega sheep (Ovis aries), which have not undergone any selection for fertility. Semen was collected from 83 mature rams, and before insemination, head shapes were measured for five parameters: area, perimeter, length, width, and p2a (perimeter(2)/2×π×area) using a computer-assisted sperm morphometric analysis. In addition, a cluster analysis using sperm head length and p2a factor was performed to determine sperm subpopulations (SPs) structure. Our results show the existence of four sperm SPs, which present different sperm head phenotype: SP1 (large and round), SP2 (short and elongated), SP3 (shortest and round), and SP4 (large and the most elongated). No relationships were found between males' fertility rates and average values of sperm head dimensions. However, differences in fertility rates between rams were strongly associated to the proportion of spermatozoa in an ejaculate SP with short and elongated heads (P < 0.001). These findings show how the heterogeneity in sperm head shape of the ejaculate has an effect on reproductive success, and highlight the important role of modulation of the ejaculate at the intraspecific level.

  2. The core root microbiome of sugarcanes cultivated under varying nitrogen fertilizer application.

    PubMed

    Yeoh, Yun Kit; Paungfoo-Lonhienne, Chanyarat; Dennis, Paul G; Robinson, Nicole; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2016-05-01

    Diazotrophic bacteria potentially supply substantial amounts of biologically fixed nitrogen to crops, but their occurrence may be suppressed by high nitrogen fertilizer application. Here, we explored the impact of high nitrogen fertilizer rates on the presence of diazotrophs in field-grown sugarcane with industry-standard or reduced nitrogen fertilizer application. Despite large differences in soil microbial communities between test sites, a core sugarcane root microbiome was identified. The sugarcane root-enriched core taxa overlap with those of Arabidopsis thaliana raising the possibility that certain bacterial families have had long association with plants. Reduced nitrogen fertilizer application had remarkably little effect on the core root microbiome and did not increase the relative abundance of root-associated diazotrophs or nif gene counts. Correspondingly, low nitrogen fertilizer crops had lower biomass and nitrogen content, reflecting a lack of major input of biologically fixed nitrogen, indicating that manipulating nitrogen fertilizer rates does not improve sugarcane yields by enriching diazotrophic populations under the test conditions. Standard nitrogen fertilizer crops had improved biomass and nitrogen content, and corresponding soils had higher abundances of nitrification and denitrification genes. These findings highlight that achieving a balance in maximizing crop yields and minimizing nutrient pollution associated with nitrogen fertilizer application requires understanding of how microbial communities respond to fertilizer use.

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

    PubMed Central

    Han, Shery; Rekret, Phil; Rentschler, Christine S.; Heath, Katy D.; Stinchcombe, John R.

    2015-01-01

    Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia), a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community, either directly

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

    PubMed

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

    2015-01-01

    Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia), a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community, either directly

  5. Fertilization and early seed formation.

    PubMed

    Dumas, Christian; Rogowsky, Peter

    2008-10-01

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

  6. [Fertility in testicular cancer patients].

    PubMed

    Shin, Takeshi; Miyata, Akane; Arai, Gaku; Okada, Hiroshi

    2015-03-01

    Testicular cancer(TC)is the most common and curable cancer affecting men of reproductive age. Successful treatment approaches have resulted in longer life expectancy in TC survivors. The most frequently used treatment for TC is a combination of inguinal orchiectomy, and either radiotherapy or cisplatin-based chemotherapy. In many TC patients, sperm quality is already abnormal and there may even be a lack of viable spermatozoa at the time of diagnosis. Therefore, the effect of cancer treatment on fertility is a potentially significant issue. Fertility preservation in these men has become essential and needs to be discussed prior to the start of cancer treatment. The only currently established fertility preservation method is the cryopreservation of sperm before therapy. For most patients seeking cryopreservation, the semen sample is collected via masturbation. If the patient is unable to ejaculate for any reason, other techniques such as vibratory stimulation and electroejaculation can be performed. In azoospermic or severely oligozoospermic patients, testicular sperm extraction at the time of the inguinal orchiectomy is a useful technique for obtaining spermatozoa before cytotoxic therapy. We herein present an overview of the current topics on fertility in TC patients, including the effects of surgery, chemotherapy, and radiation therapy. We also describe the strategy for fertility preservation in these patients.

  7. Influence of fertilization on the Colorado potato beetle, Leptinotarsa decemlineata, in organic potato production.

    PubMed

    Boiteau, G; Lynch, D H; Martin, R C

    2008-04-01

    The abundance of the Colorado potato beetle, Leptinotarsa decemlineata (Say), in organically grown potato did not change significantly in response to increasing rates of dehydrated poultry manure. However, peaks of abundance of larvae were shifted forward in time in response to the high rate of organic fertilizer. Tests using excised foliage showed that the shift was not caused by differential larval mortality or longer developmental times. Time allocation to resting, walking, and feeding by adults was similar regardless of fertilizer rate. Adult foliage consumption was unaffected by organic fertilizer rates in no choice tests and significantly affected in few choice tests. A 22% longer larval development time on plants treated with low fertilizer rate than on plants with high rate was the most significant effect. Even though maximum plant height, canopy, biomass, and yield were significantly smaller in the organic than in conventional plots, the suitability of the plants was not affected except for reduced feeding by summer beetles. Summer adults spent less time feeding and consumed two to five times less foliage on organic potato than on inorganically fertilized and conventionally produced plants. The overall influence of fertilizer on Colorado potato beetle populations was limited and therefore can only play a secondary role in management strategies for organic potato. Avoidance of excessive organic fertilizer that promotes short larval development time and extension of the period over which large Colorado potato beetle larvae are present should be recommended.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27713476

  9. 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.

  10. Sex- and Age-Specific Incidence of Healthcare-Register-Recorded Eating Disorders in the Complete Swedish 1979–2001 Birth Cohort

    PubMed Central

    Javaras, Kristin N.; Runfola, Cristin D.; Thornton, Laura M.; Agerbo, Esben; Birgegård, Andreas; Norring, Claes; Yao, Shuyang; Råstam, Maria; Larsson, Henrik; Lichtenstein, Paul; Bulik, Cynthia M.

    2016-01-01

    Objective To investigate the sex- and age-specific incidence of healthcare-register-recorded anorexia nervosa (AN) and other eating disorders (OED) in a complete birth cohort, and assess whether incidence varies by diagnostic period and (sub-) birth cohort. Method We used the actuarial method and Poisson models to examine the incidence of AN and OED from 1987–2009 (when individuals were 8–30 years) for a cohort of 2.3 million individuals (48.7% female) born from 1979–2001 in Sweden, identified using Swedish registers. Results For both sexes, incidences of AN and OED increased considerably for diagnostic periods after 2000, but differed little by birth cohort. In 2009, AN incidence in the peak age category was 205.9 cases/100,000 persons (95% CI: 178.2, 233.5) for females (14–15 years), versus 12.8 cases/100,000 (95% CI: 5.6, 20.1) for males (12–13 years). OED incidence in the peak age category was 372.1 cases/100,000 (95% CI: 336.4, 407.9) for females (16–17 years), versus 22.2 cases/100,000 (95% CI: 13.3, 31.1) for males (14–15 years). Discussion Our finding of an increase in healthcare register-recorded eating disorders for diagnostic periods after 2000 likely reflects improved detection and expanded register coverage in Sweden. The peak of eating disorder incidence in adolescence, which began unexpectedly early for AN in males, suggests the importance of vigilance for signs of AN in young boys and early primary prevention efforts. Waiting until later could miss critical windows for intervention that could prevent disorders from taking root. PMID:26769444

  11. Improving fertility of dairy cattle using translational genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection for higher milk production in United States dairy cattle has been very successful during the past 50 years, however today’s lactating dairy cows exhibit a high incidence of subfertility and infertility with a national pregnancy rate of only 15%. An integrated approach to improve fertility ...

  12. 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.

  13. In vitro fertilization experiments using sockeye salmon reveal that bigger eggs are more fertilizable under sperm limitation.

    PubMed

    Macfarlane, Christopher P; Hoysak, Drew J; Liley, N Robin; Gage, Matthew J G

    2009-07-07

    Although theory and widespread evidence show that the evolution of egg size is driven primarily by offspring and maternal fitness demands, an additional explanation invokes sperm limitation as a selective force that could also influence egg size optima. Levitan proposed that constraints from gamete encounter in external fertilization environments could select for enlargement of ova to increase the physical size of the fertilization target. We test this theory using in vitro fertilization experiments in an externally fertilizing fish. Sockeye salmon (Onchorhyncus nerka) females show considerable between-individual variation in ovum size, and we explored the consequences of this natural variation for the fertilization success of individual eggs under conditions of sperm limitation. By engineering consistent conditions where in vitro fertilization rate was always intermediate, we were able to compare the sizes of fertilized and unfertilized eggs across 20 fertilization replicates. After controlling for any changes in volume through incubation, results showed that successfully fertilized eggs were significantly larger than the eggs that failed to achieve fertilization. Under conditions without sperm limitation, fertility was unaffected by egg size. Our findings therefore support Levitan's theory, demonstrating empirically that some element of egg size variation could be selected by fertilization demands under sperm limitation. However, further research on sperm limitation in natural spawnings is required to assess the selective importance of these results.

  14. Crystallographic properties of fertilizer compounds

    SciTech Connect

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

    1991-02-01

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

  15. Has East Germany overtaken West Germany? Recent trends in order-specific fertility.

    PubMed

    Goldstein, Joshua R; Kreyenfeld, Michaela

    2011-01-01

    Some 20 years after reunification, the contrast between East and West Germany offers a natural experiment for studying the degree of persistence of Communist-era family patterns, the effects of economic change, and fertility postponement. After reunification, period fertility rates plummeted in the former East Germany to record low levels. Since the mid-1990s, however, period fertility rates have been rising in East Germany, in contrast to the nearly constant rates seen in the West. By 2008, the TFR of East Germany had overtaken that of the West. We explore why fertility in East Germany is higher than in West Germany, despite unfavorable economic circumstances in the East. We address this and related questions by (a) presenting an account of the persisting East/West differences in attitudes toward and constraints on childbearing, (b) conducting an order-specific fertility analysis of recent fertility trends, and (c) projecting completed fertility for the recent East and west German cohorts. In addition to using the Human Fertility Database, perinatal statistics allow us to calculate a tempo-corrected TFR for East and West Germany.

  16. Potential fertility and averted births.

    PubMed

    Barrett, J C

    1981-01-01

    The natural fertility of a group of contraceptive acceptors is the fertility they would have experienced in the absence of any sort of birth control. Their net potential fertility is what their fertility would be in the absence of a defined family planning program. In this work it is assumed that there was no birth control prior to acceptance of contraception in a defined family planning strategy. Thus, reference is to natural potential fertility and to the gross births averted as the difference from the subsequent actual fertility of the group in question, e.g., contraceptive acceptors. A Monte Carlo microsimulation model is used to estimate the selection for natural fecundability that has taken place in a synthetic group of contraceptive acceptors. In this microanalytic simulation, events are represented individually so that parameters may vary between women (or couples) and can be made to depend on their ages or any other variables. The reproductive histories of a cohort of women are simulated from the marriage (at a fixed age of 25 in the present runs) to the end of the reproductive span. Events occur only at intervals of 1 "lunar" month (1/13th year), so all fecundabilities should be multiplied by 13/12 if risks per calendar month are wanted. The natural fecundability p varies between women and declines with age. Each woman's history is simulated through a series of states in turn. Induced abortion, voluntary sterilization, divorce, and death (of the child or the parent) are not represented in the present runs. A formula is derived for the births subsequently averted by contraception. The result is compared with the potential fertility found from further simulation runs, with various desired family sizes, by permitting contraceptive acceptors (limiters) to revert to nonuser status at defined durations of marriage. The distribution of naturally sterile women is also analyzed by their contraceptive status. It is argued that both variations in and selection for

  17. [Fertility treatment in Denmark--development and challenges].

    PubMed

    Ingerslev, Hans Jakob; Humaidan, Peter; Andersen, Anders Nyboe

    2012-10-08

    In Denmark, a total of 31,000 assisted reproductive technology (ART) and intrauterine insemination treatments yearly results in the delivery of around 6,300 children, which represents 9% of the Danish birth cohort. The delivery rate following ART (in vitro fertilization/intracytoplasmatic sperm injection, frozen embryo replacement and oocyte donation) has been stable around 20% per cycle initiated during the last decade, despite the transfer of fewer embryos. The future challenges are the increasing age of women seeking fertility treatment, the development of biomarkers of embryonic implantation potential as well as the improvement of embryo culture, and embryo freezing techniques.

  18. CD9 Expression by Human Granulosa Cells and Platelets as a Predictor of Fertilization Success during IVF.

    PubMed

    Jaslow, Carolyn R; Patterson, Kyle S; Cholera, Shila; Jennings, Lisa K; Ke, Raymond W; Kutteh, William H

    2010-01-01

    Objective. To determine whether CD9 expression on human granulosa cells (GCs) and platelets could predict the success of conventional fertilization of human oocytes during in vitro fertilization (IVF). Methods. Thirty women undergoing IVF for nonmale factor infertility participated. Platelets from venous blood and GCs separated from retrieved oocytes were prepared for immunofluorescence. Flow cytometry quantified the percent of GCs expressing CD9, and CD9 surface density on GCs and platelets. Fertilization rate was determined for the total number of oocytes, and the number of mature oocytes per patient. Correlations tested for significant relationships (P < .05) between fertilization rates and CD9 expression. Results. CD9 surface density on human GCs is inversely correlated with fertilization rate of oocytes (P = .04), but the relationship was weak. Conclusion. More studies are needed to determine if CD9 expression on GCs would be useful for predicting conventional fertilization success during IVF.

  19. Nitrogen fertilization challenges the climate benefit of cellulosic biofuels

    SciTech Connect

    Ruan, Leilei; Bhardwaj, Ajay K.; Hamilton, Stephen K.; Robertson, G. Philip

    2016-06-01

    Cellulosic biofuels are intended to improve future energy and climate security. Nitrogen (N) fertilizer is commonly recommended to stimulate yields but can increase losses of the greenhouse gas nitrous oxide (N2O) and other forms of reactive N, including nitrate. We measured soil N2O emissions and nitrate leaching along a switchgrass (Panicum virgatum) high resolution N-fertilizer gradient for three years post-establishment. Results revealed an exponential increase in annual N2O emissions that each year became stronger (R2 > 0.9, P < 0.001) and deviated further from the fixed percentage assumed for IPCC Tier 1 emission factors. Concomitantly, switchgrass yields became less responsive each year to N fertilizer. Nitrate leaching (and calculated indirect N2O emissions) also increased exponentially in response to N inputs, but neither methane (CH4) uptake nor soil organic carbon changed detectably. Overall, N fertilizer inputs at rates greater than crop need curtailed the climate benefit of ethanol production almost two-fold, from a maximum mitigation capacity of–5.71 ± 0.22 Mg CO2e ha–1 yr–1 in switchgrass fertilized at 56 kgNha–1 to only –2.97 ± 0.18 MgCO2e ha–1 yr–1 in switchgrass fertilized at 196 kgNha–1. In conclusion, minimizing N fertilizer use will be an important strategy for fully realizing the climate benefits of cellulosic biofuel production.

  20. 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.

  1. [Studying the fertility peak in Beijing].

    PubMed

    Zhong, L

    1989-07-01

    Beijing, China, is experiencing a baby boom in response to 2 periods of large population increase in the mid-1950s and early 1960s. The average number of annual births was 220,000 in the first period and 269,000 in the second period. The causes of the large increase in the population in the first period were an improvement of health conditions which led to a reduction in mortality, immigration flow, and an erroneous population policy. The causes in the second period were recuperative fertility after three years of natural calamity and increased fertility among immigrants. Net migration had an important role in population growth these two periods; it also will have an important impact in future population changes. According to population projections, another baby boom is expected to occur before the end of the end of the century. During the up-coming baby boom period, 1.54 million births are expected, 190,000 per annum. The average increase in population size is expected to 127,000 per year. In the peak year, it may be around 200,000. Thanks to the family planning (FP) program the occurrence of the third baby boom in Beijing has been postponed and the duration will be shortened. From 1972 to 1982, 2.57 million births was averted due to FP, which drastically reduced pressure on the demand for resources and on the momentum of the next baby boom. Another baby booms is not expected during the early half of the 21st century, although an elevated birth rate within the range of normal fluctuation is predicted. The projection was based on the assumption of restricted migration and the enforcement of the FP program. The realization of the projected population will depend on deferred marriage, deferred child-bearing, prolonged birth spacing, the prevention of high parity fertility, the maintenance of the current population policy, and control over the reproductive behavior of the new migrant population.

  2. The insults of illicit drug use on male fertility.

    PubMed

    Fronczak, Carolyn M; Kim, Edward D; Barqawi, Al B

    2012-01-01

    One-third of infertile couples may have a male factor present. Illicit drug use can be an important cause of male factor infertility and includes use of anabolic-androgenic steroids, marijuana, opioid narcotics, cocaine, and methamphetamines. The use of these illicit drugs is common in the United States, with a yearly prevalence rate for any drug consistently higher in males compared with females. We aim to provide a review of recent literature on the prevalence and effects of illicit drug use on male fertility and to aid health professionals when counseling infertile men whose social history suggests illicit drug use. Anabolic-androgenic steroids, marijuana, cocaine, methamphetamines, and opioid narcotics all negatively impact male fertility, and adverse effects have been reported on the hypothalamic-pituitary-testicular axis, sperm function, and testicular structure. The use of illicit drugs is prevalent in our society and likely adversely impacting the fertility of men who abuse drugs.

  3. World fertilizer nutrient reserves: a view to the future.

    PubMed

    Fixen, Paul E; Johnston, Adrian M

    2012-03-30

    The increasing need for food production in subtropical regions likely translates to a need for additional plant nutrients. As a consequence, knowledge of world fertilizer nutrient reserves is of particular relevance to sustainable agriculture in the subtropics. The stewardship responsibilities of agriculture include the wise use of the raw materials from which commercial fertilizers are produced. Development and implementation of fertilizer best management practices with focus on the 4Rs-right source, right rate, right time, right place-are timely not only for short-term economic and environmental reasons, but also for the wise stewardship of the non-renewable nutrient resources upon which food, feed, fiber, and fuel production depend.

  4. Environmental contaminants, fertility, and multioocytic follicles: a lesson from wildlife?

    PubMed

    Guillette, Louis J; Moore, Brandon C

    2006-07-01

    The overall contribution of environmental exposures to infertility is unknown, but a growing scientific database suggests that exposure to various environmental factors, both in utero and neonatally, could dramatically affect adult fertility. Studies of various contaminant-exposed wildlife populations suggest that multiple mechanisms contribute to changes in gonadal development, maturation of germ cells, fertilization, and pregnancy; specifically, the endocrine processes supporting these events. Although great debate and extensive research has occurred during the last decade surrounding fertility, fecundity, and semen quality, much less work has focused on environmental alterations in oocyte development and maturation. Exposure of the developing ovary to estrogens, whether of pharmaceutical (e.g., diethylstilbesterol) or environmental (e.g., phytoestrogens, pesticides with estrogenic action) origin, can disrupt early oogenesis and folliculogenesis leading to a pathology termed the multioocytic follicle (polyovular follicle), which in rodents reduces fertilization and embryonic survival rates. The mechanism underlying this pathology is hypothesized to involve a disruption in the gonadotropin-estrogen-inhibin/activin signaling pathway. Given the conserved nature of vertebrate oogenesis and folliculogenesis, we suggest that perturbations of these phenomena in humans, caused by environmental contaminant exposure, could lead to altered fertility, as has been reported in wildlife and laboratory rodent models.

  5. Changes in contraceptive use and fertility: Panama, 1976 to 1984.

    PubMed

    Warren, C W; Oberle, M W; Morris, L; Medica, W

    1988-01-01

    From 1976 to 1984 important demographic changes occurred in Panama. The total fertility rate declined from 4.5 to 3.7, and contraceptive use among married women 20-44 years of age increased from 55% to 63%. However, using data from 3 national level reproductive health surveys which were conducted in Panama in 1976, 1979, and 1984, we found that most of the changes took place between 1976 and 1979. Since 1979, overall contraceptive use and fertility have remained virtually unchanged, although there has been an important method-mix shift toward an increase in the use of contraceptive sterilization and IUD's, with an accompanying decline in the use of oral contraceptives. Although the singulate mean age at marriage remained relatively constant, the average duration of breastfeeding rose 23% during the period. Further gains in contraceptive prevalence and reduction in unplanned fertility in Panama will largely depend on enhanced program efforts 1st begun in the early 1970's by the Panama Ministry of Health. Future program efforts especially should be directed toward encouraging young couples to space their children more effectively by using temporary methods of contraception. The surveys used for this analysis were the 1976 Panama National Fertility Survey of the World Fertility Survey program, the 1979 Panama Contraceptive Prevalence Survey (Westinghouse), and the 1984 Panama Maternal-Child Health/Family Planning Survey.

  6. Wetting mechanisms of gel-based controlled-release fertilizers.

    PubMed

    Shavit, U; Reiss, M; Shaviv, A

    2003-02-14

    The release mechanism of gel-based controlled release fertilizers (CRFs) involves water penetration into dry mixtures of fertilizers and gel forming polymers. Water penetration provides an upper limit to the whole release process. Where wetting prediction is often based on models that describe the flow of the liquid phase, vapor motion may become significant when a sharp wetting front exists. In this study we examine the role of vapor and fluid flows in the wetting process of CRFs consisting of urea or KNO(3) mixed with polyacrylamide (PAM). Vapor adsorption isotherms were obtained for typical fertilizer-PAM mixtures. Wetting and release experiments were conducted by dividing the CRFs into regions alternately filled with a pure fertilizer and mixtures of PAM and fertilizer. The experiments were designed in such a way that when the wetting front reaches a mixtures interface, its motion depends on the gradient imposed by the difference in osmotic potential (OP). The coupled equations of vapor and liquid flow in initially dry conditions were solved numerically to demonstrate the conceptual understanding gained by the experiments. The results show that wetting front motion is affected by transport and adsorption of vapor. It was also shown that the release rate is different when wetting is governed by vapor flow or by liquid flow. The release pattern from a multi-regions device was consistent with the wetting pattern, demonstrating the possibility to tailor the release according to periods of peak demand.

  7. Mercury Speciation, Retention and Genomics in Fertilized Salt Marsh Sediments

    NASA Astrophysics Data System (ADS)

    Collins, C. W.; Lamborg, C. H.; Whalen, K.; Mincer, T.; Buchanan, W.; Huber, J. A.; Swarr, G.; Ganguli, P. M.; Bernhard, A.

    2014-12-01

    Recent studies have demonstrated that increased nutrient loading and eutrophication can impact the production of monomethylmercury (MMHg) in marine systems. Experimental plots in Great Sippewisset Marsh (GSM), Falmouth, Massachusetts USA, have been chronically treated with a mixed fertilizer during the growing season since 1971, providing nutrients and other elements, including mercury (Hg) to the salt marsh. To assess the retention, release and methylation of Hg in these marsh sediments in response to fertilization, we collected cores from control, low, high, and extra high fertilization plots across low and high marsh settings. We determined total mercury (HgT) and MMHg concentration and accumulation rates and compared them to those of atmospheric deposition and the loading from the mixed fertilizer. Environmental DNA was extracted from the core sub-samples and polymerase chain reaction (PCR) was used to detect three genes of interest: merA (Hg(II) reducing), hgcA (Hg(II) methylating) and dsrAB (dissimilatory sulfite reduction). Quantitative PCR (qPCR) will be performed in order to overlay the abundance and diversity of the three genes to the Hg profiles and speciation metadata. By comparing the genomic data to the geochemical patterns within the treatment plots we can develop a greater sense of how Hg cycling has changed as a result of fertilization and the overall response of GSM to long-term nutrient loading.

  8. Greenhouse evaluation and environmental impact assessment of different urine-derived struvite fertilizers as phosphorus sources for plants.

    PubMed

    Antonini, Samantha; Arias, Maria Alejandra; Eichert, Thomas; Clemens, Joachim

    2012-11-01

    A selection of six urine-derived struvite fertilizers generated by innovative precipitation technologies was assessed for their quality and their effectiveness as phosphorus sources for crops. Struvite purity was influenced by drying techniques and magnesium dosage. In a greenhouse experiment, the urine fertilizers led to biomass yields and phosphorus uptakes comparable to or higher than those induced by a commercial mineral fertilizer. Heavy metal concentrations of the different struvite fertilizers were below the threshold limits specified by the German Fertilizer and Sewage Sludge Regulations. The computed loading rates of heavy metals to agricultural land were also below the threshold limits decreed by the Federal Soil Protection Act. Urine-derived struvite contributed less to heavy metal inputs to farmland than other recycling products or commercial mineral and organic fertilizers. When combined with other soil conditioners, urine-derived struvite is an efficient fertilizer which covers the magnesium and more than half of the phosphorus demand of crops.

  9. [Variation characteristics of soil carbon sequestration under long-term different fertilization in red paddy soil].

    PubMed

    Huang, Jing; Zhang, Yang-zhu; Gao, Ju-sheng; Zhang, Wen-ju; Liu, Shu-jun

    2015-11-01

    The objective of this study was to clarify the changes of soil organic carbon (SOC) content, the saturation capacity of soil carbon sequestration and its cooperation with carbon input (crop source and organic fertilizer source carbon) under long-term (1982-2012) different fertilization in red paddy soil. The results showed that fertilization could increase SOC content. The SOC content of all the fertilization treatments demonstrated a trend of stabilization after applying fertilizer for 30 years. The SOC content in the treatments applying organic manure with mineral fertilizers was between 21.02 and 21.24 g · kg(-1), and the increase rate ranged from 0.41 to 0.59 g · kg(-1) · a(-1). The SOC content in the treatments applying mineral fertilizers only was 15.48 g · kg(-1). The average soil carbon sequestration in the treatments that applied organic manure with mineral fertilizers ranged from 43.61 to 48.43 t C · hm(-2), and the average SOC storage over the years in these treatments was significantly greater than those applying mineral fertilizers only. There was an exponentially positive correlation between C sequestration efficiency and annual average organic C input. It must input exogenous organic carbon at least at 0. 12 t C · hm(-2) · a(-1) to maintain the balance of soil organic carbon under the experimental conditions.

  10. Temporal and spatial relations between age specific mortality and ambient air quality in the United States: regression results for counties, 1960–97

    PubMed Central

    Lipfert, F; Morris, S

    2002-01-01

    Objective: To investigate longitudinal and spatial relations between air pollution and age specific mortality for United States counties (except Alaska) from 1960 to the end of 1997. Methods: Cross sectional regressions for five specific periods using published data on mortality, air quality, demography, climate, socioeconomic status, lifestyle, and diet. Outcome measures are statistical relations between air quality and county mortalities by age group for all causes of death, other than AIDS and trauma. Results: A specific regression model was developed for each period and age group, using variables that were significant (p<0.05), not substantially collinear (variance inflation factor <2), and had the expected algebraic sign. Models were initially developed without the air pollution variables, which varied in spatial coverage. Residuals were then regressed in turn against current and previous air quality, and dose-response plots were constructed. The validity of this two stage procedure was shown by comparing a subset of results with those obtained with single stage models that included air quality (correlation=0.88). On the basis of attributable risks computed for overall mean concentrations, the strongest associations were found in the earlier periods, with attributable risks usually less than 5%. Stronger relations were found when mortality and air quality were measured in the same period and when the locations considered were limited to those of previous cohort studies (for PM2.5 and SO42-). Thresholds were suggested at 100–130 µg/m3 for mean total suspended particulate (TSP), 7–10 µg/m3 for mean sulfate, 10–15 ppm for peak (95th percentile) CO, 20–40 ppb for mean SO2. Contrary to expectations, associations were often stronger for the younger age groups (<65 y). Responses to PM, CO, and SO2 declined over time; responses in elderly people to peak O3 increased over time as did responses to NO2 for the younger age groups. These results generally agreed

  11. Variance in age-specific sex composition of Pacific halibut catches, and comparison of statistical and genetic methods for reconstructing sex ratios

    NASA Astrophysics Data System (ADS)

    Loher, Timothy; Woods, Monica A.; Jimenez-Hidalgo, Isadora; Hauser, Lorenz

    2016-01-01

    Declines in size at age of Pacific halibut Hippoglossus stenolepis, in concert with sexually-dimorphic growth and a constant minimum commercial size limit, have led to the expectation that the sex composition of commercial catches should be increasingly female-biased. Sensitivity analyses suggest that variance in sex composition of landings may be the most influential source of uncertainty affecting current understanding of spawning stock biomass. However, there is no reliable way to determine sex at landing because all halibut are eviscerated at sea. In 2014, a statistical method based on survey data was developed to estimate the probability that fish of any given length at age (LAA) would be female, derived from the fundamental observation that large, young fish are likely female whereas small, old fish have a high probability of being male. Here, we examine variability in age-specific sex composition using at-sea commercial and closed-season survey catches, and compare the accuracy of the survey-based LAA technique to genetic markers for reconstructing the sex composition of catches. Sexing by LAA performed best for summer-collected samples, consistent with the hypothesis that the ability to characterize catches can be influenced by seasonal demographic shifts. Additionally, differences between survey and commercial selectivity that allow fishers to harvest larger fish within cohorts may generate important mismatch between survey and commercial datasets. Length-at-age-based estimates ranged from 4.7% underestimation of female proportion to 12.0% overestimation, with mean error of 5.8 ± 1.5%. Ratios determined by genetics were closer to true sample proportions and displayed less variability; estimation to within < 1% of true ratios was limited to genetics. Genetic estimation of female proportions ranged from 4.9% underestimation to 2.5% overestimation, with a mean absolute error of 1.2 ± 1.2%. Males were generally more difficult to assign than females: 6.7% of

  12. The marginal valuation of fertility

    PubMed Central

    Jones, James Holland; Bird, Rebecca Bliege

    2014-01-01

    Substantial theoretical and empirical evidence demonstrates that fertility entails economic, physiological, and demographic trade-offs. The existence of trade-offs suggests that fitness should be maximized by an intermediate level of fertility, but this hypothesis has not had much support in the human life-history literature. We suggest that the difficulty of finding intermediate optima may be a function of the way fitness is calculated. Evolutionary analyses of human behavior typically use lifetime reproductive success as their fitness criterion. This fitness measure implicitly assumes that women are indifferent to the timing of reproduction and that they are risk-neutral in their reproductive decision-making. In this paper, we offer an alternative, easily-calculated fitness measure that accounts for differences in reproductive timing and yields clear preferences in the face of risky reproductive decision-making. Using historical demographic data from a genealogically-detailed dataset from 19th century Utah, we show that this measure is highly concave with respect to reproductive effort. This result has three major implications: (1) if births are properly timed, a lower-fertility reproductive strategy can have the same fitness as a high-fertility strategy, (2) intermediate optima are far more likely using fitness measures that are strongly concave with respect to effort, (3) we expect mothers to have strong investment preferences with respect to the risk inherent in reproduction. PMID:24778546

  13. Fertility options in transgender people.

    PubMed

    De Roo, Chloë; Tilleman, Kelly; T'Sjoen, Guy; De Sutter, Petra

    2016-01-01

    Hormonal and surgical treatments for transgender people have a devastating effect on the possibility for these patients to reproduce. Additionally, transgender people tend to start sex reassignment treatment at a young age, when reproductive wishes are not yet clearly defined nor fulfilled. The most recent Standards of Care of the World Professional Association for Transgender Health recommend clearly informing patients regarding their future reproductive options prior to initiation of treatment. This review gives an overview of the current knowledge and state-of-the-art techniques in the field of fertility preservation for transgender people. Where genital reconstructive surgery definitely results in sterility, hormone therapy on the other hand also has an important, but partially reversible impact on fertility. The current fertility preservation options for trans men are embryo cryopreservation, oocyte cryopreservation and ovarian tissue cryopreservation. For trans women, sperm cryopreservation, surgical sperm extraction and testicular tissue cryopreservation are possible. Although certain fertility preservation techniques could be applicable in a standardized manner based on clear biological criteria, the technique that eventually will be performed should be the prefe