WorldWideScience

Sample records for varying fertility rates

  1. Male chimpanzees' grooming rates vary by female age, parity, and fertility status

    DEFF Research Database (Denmark)

    Proctor, Darby P; Lambeth, Susan P; Schapiro, Steve

    2011-01-01

    , should show little or no preference when choosing mating partners (e.g. should mate indiscriminately). To determine if the preferences indicated by copulations appear in other contexts as well as how they interact, we examined how male chimpanzees' grooming patterns varied amongst females. We found...... that males' preferences were based on interactions among females' fertility status, age, and parity. First, grooming increased with increasing female parity. We further found an effect of the estrous cycle on grooming; when females were at the lowest point of their cycle, males preferentially groomed parous...... females at peak reproductive age, but during maximal tumescence, males preferred the oldest multiparous females. Nulliparous females received relatively little grooming regardless of age or fertility. Thus, male chimpanzees apparently chose grooming partners based on both female's experience and fertility...

  2. Male chimpanzees' grooming rates vary by female age, parity, and fertility status.

    Science.gov (United States)

    Proctor, Darby P; Lambeth, Susan P; Schapiro, Steven J; Brosnan, Sarah F

    2011-10-01

    Copulation preferences in our closest living relative, the chimpanzee, suggest that males prefer older females who have had previous offspring. However, this finding is counter to some behavioral models, which predict that chimpanzee males, as promiscuous breeders with minimal costs to mating, should show little or no preference when choosing mating partners (e.g. should mate indiscriminately). To determine if the preferences indicated by copulations appear in other contexts as well as how they interact, we examined how male chimpanzees' grooming patterns varied amongst females. We found that males' preferences were based on interactions among females' fertility status, age, and parity. First, grooming increased with increasing female parity. We further found an effect of the estrous cycle on grooming; when females were at the lowest point of their cycle, males preferentially groomed parous females at peak reproductive age, but during maximal tumescence, males preferred the oldest multiparous females. Nulliparous females received relatively little grooming regardless of age or fertility. Thus, male chimpanzees apparently chose grooming partners based on both female's experience and fertility, possibly indicating a two-pronged social investment strategy. Male selectivity seems to have evolved to effectively distribute costly social resources in a pattern which may increase their overall reproductive success. © 2011 Wiley-Liss, Inc.

  3. Fertility Clinic Success Rates

    Science.gov (United States)

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

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

    DEFF Research Database (Denmark)

    Siddique, Mohammad Abdul Momin; Butts, Ian; Psěnička, Martin

    2015-01-01

    , 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, 0.5. min pre-incubation increased the fertilization rate than 10. min. At 0. min pre......-incubation the proportion of fertilized eggs increased at the 430,000:1 ratio, while at 1. min fertilization increased at the 4300:1 ratio. At the 10. min pre-incubation time, fertilization increased at the 43,000:1 ratio. Moreover, at the 0.5. min 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

  5. Temporal Trends in Fertility Rates

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    Nitrification inhibitors have the potential to reduce N 2 O emissions from maize fields, but optimal results may depend on deployment of integrated N fertilizer management systems that increase yields achieved per unit of N 2 O 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 N 2 O fluxes and (ii) identify UAN treatment combinations that both reduce N 2 O 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 N 2 O–N emissions (Q 10 corrected) were 0.81, 1.83 and 3.52 kg N 2 O–N ha −1 for the rates of 0, 90 and 180 kg N ha −1 , respectively; 1.80 and 2.31 kg N 2 O–N ha −1 for pre-emergence and side-dress timings, respectively; and 1.77 versus 2.34 kg N 2 O–N ha −1 for with and without nitrapyrin, respectively. Yield-scaled N 2 O–N emissions increased with N rates as anticipated (averaging 167, 204 and 328 g N 2 O–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 N 2 O–N emissions were 22% lower with nitrapyrin than without the inhibitor, but these did not interact with N rate or timing. (letter)

  8. URBANIZATION AND FERTILITY RATES IN ETHIOPIA1

    African Journals Online (AJOL)

    Eyerusalem

    Survey (2010) data suggest that Ethiopia not only has one of the largest fertility rates .... Asian countries where the rural-urban fertility differentials were smaller and more ...... Sibanda, A., Z. Woubalem, D. P. Hogan, and D. P. Lindstrom. 2003.

  9. Test procedure for variable rate fertilizer on coffee = Método para avaliação de aplicação de fertilizantes em taxa variável em café

    Directory of Open Access Journals (Sweden)

    Gustavo Di Chiacchio Faulin

    2010-10-01

    Full Text Available The objective was to develop and test a procedure for applying variable rates of fertilizers and evaluate yield response in coffee (Coffea arabica L. with regard to the application of phosphorus and potassium. The work was conducted during the 2004 season in a 6.4 ha field located in central São Paulo state. Two treatments were applied with alternating strips of fixed and variable rates during the whole season: one following the fertilizing procedures recommended locally, and the other based on a grid soil sampling. A prototype pneumatic fertilizer applicator was used, carrying two conveyor belts, one foreach row. Harvesting was done with a commercial harvester equipped with a customized volumetric yield monitor, separating the two treatments. Data were analyzed based on geostatistics, correlations and regressions. The procedure showed to be feasible and effective. The area that received fertilizer applications at a variable rate showed a 34% yield increase compared to the area that received a fixed rate. The variable rate fertilizer resulted in a savings of 23% in phosphate fertilizer and a 13% increase in potassium fertilizer, when compared to fixed rate fertilizer. Yield in 2005, the year after the variable rate treatments, still presented residual effect from treatments carried out during the previous cycle.O objetivo foi desenvolver um procedimento para avaliar a resposta daprodutividade de café (Coffea arabica L., a partir da aplicação de fósforo e potássio. O trabalho foi conduzido durante o ciclo produtivo do ano de 2004 em um talhão de 6,4 ha localizado na região central do Estado de São Paulo. Foram aplicados dois tratamentos emlinhas alternadas de plantas com doses fixas e variadas, um seguindo procedimentos e recomendações locais e o outro com base na amostragem de solo em grade. Para a aplicação dos fertilizantes, foi utilizado o protótipo de uma adubadora com duas esteiras independentes, uma para cada linha de plantas

  10. Influence of Human Chorionic Gonadotropin on the Fertility Rate in ...

    African Journals Online (AJOL)

    An experiment was carried out on the influence of human chorionic gonadotropin hormone (hCG) on the fertility rate of rabbit does under artificial insemination. The rabbit does (7-8 months old) were used for the trial. The hCG was administered to the rabbit does at varying doses: 0, 50, 100 and 150 I.U representing ...

  11. Management strategy 3: fixed rate fertilizer applications

    Science.gov (United States)

    Previous chapters outlined management strategies for pond fertilization that take into account specific individual pond nutrient needs. Those methods would most likely be more ecologically efficient than a pre-determined fixed-rate nutrient addition strategy. However, the vast majority of available ...

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

    African Journals Online (AJOL)

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

  13. TIME-VARYING DYNAMICAL STAR FORMATION RATE

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chang, Philip; Murray, Norman, E-mail: evelee@berkeley.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)

    2015-02-10

    We present numerical evidence of dynamic star formation in which the accreted stellar mass grows superlinearly with time, roughly as t {sup 2}. We perform simulations of star formation in self-gravitating hydrodynamic and magnetohydrodynamic turbulence that is continuously driven. By turning the self-gravity of the gas in the simulations on or off, we demonstrate that self-gravity is the dominant physical effect setting the mass accretion rate at early times before feedback effects take over, contrary to theories of turbulence-regulated star formation. We find that gravitational collapse steepens the density profile around stars, generating the power-law tail on what is otherwise a lognormal density probability distribution function. Furthermore, we find turbulent velocity profiles to flatten inside collapsing regions, altering the size-line width relation. This local flattening reflects enhancements of turbulent velocity on small scales, as verified by changes to the velocity power spectra. Our results indicate that gas self-gravity dynamically alters both density and velocity structures in clouds, giving rise to a time-varying star formation rate. We find that a substantial fraction of the gas that forms stars arrives via low-density flows, as opposed to accreting through high-density filaments.

  14. Confinement lowers fertility rate of helmeted guinea fowl ( Numida ...

    African Journals Online (AJOL)

    ... common game bird in Africa and there have been efforts to domesticate it for use as a source of human food. An important obstacle in successful domestication of guinea fowl is their low fertility rate.We studied the effects of semi-confinement on the fertility rates of helmeted guinea fowl by comparing egg fertility, hatch rate ...

  15. The effect of juvenile hormone on Polistes wasp fertility varies with cooperative behavior.

    Science.gov (United States)

    Tibbetts, Elizabeth A; Sheehan, Michael J

    2012-04-01

    Social insects provide good models for studying how and why the mechanisms that underlie reproduction vary, as there is dramatic reproductive plasticity within and between species. Here, we test how the effect of juvenile hormone (JH) on fertility covaries with cooperative behavior in workers and nest-founding queens in the primitively eusocial wasp Polistes metricus. P. metricus foundresses and workers appear morphologically similar and both are capable of reproduction, though there is variation in the extent of social cooperation and the probability of reproduction across castes. Do the endocrine mechanisms that mediate reproduction co-vary with cooperative behavior? We found dramatic differences in the effect of JH on fertility across castes. In non-cooperative nest-founding queens, all individuals responded to JH by increasing their fertility. However, in cooperative workers, the effect of JH on fertility varies with body weight; large workers increase their fertility in response to JH while small workers do not. The variation in JH response may be an adaptation to facilitate resource allocation based on the probability of independent reproduction. This work contrasts with previous studies in closely related Polistes dominulus paper wasps, in which both foundresses and workers form cooperative associations and both castes show similar, condition-dependent JH response. The variation in JH responsiveness within and between species suggests that endocrine responsiveness and the factors influencing caste differentiation are surprisingly evolutionarily labile. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Effect of weed management methods and nitrogen fertilizer rates on ...

    African Journals Online (AJOL)

    Inefficient weed management practices and the use of inappropriate nitrogen fertilizer rates are the major causes of low yield of wheat in Ethiopia. Therefore, field experiments were conducted at Bobicho and Faate in southern Ethiopia to determine the effect of weed management practices and N fertilizer rates on grain yield ...

  17. Effects of varying feeding times on fertility and hatchability of broiler ...

    African Journals Online (AJOL)

    Effects of varying feeding times on fertility and hatchability of broiler chicken breeders in a tropical environment. ... Journal Home > Vol 65, No 4 (2017) > ... Prior to the eighth week data collection, the birds were allowed to get accustomed to ...

  18. NCHS - Births and General Fertility Rates: United States

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset includes crude birth rates and general fertility rates in the United States since 1909. The number of states in the reporting area differ historically....

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Fabrication and evaluation of variable rate fertilizer system

    Directory of Open Access Journals (Sweden)

    A Damirchi

    2015-09-01

    Full Text Available Introduction: In conventional farming, the soil and crop are considered uniform in different locations of the farm and the fertilizers are applied according to the average of soil needs with an additional percentage for safety (Loghavi, 2003. Non-essential chemical fertilizers in the field have harmful effects and social, economic and environmental concerns will increase. Many fertilizers go into the surface waters and ground waters and cause poisoning and environmental pollution without being absorbed by the plants. In variable rate technology, the soil fertilizer needs a map of all parts of the farm which is prepared with the GIS system. This map is uploaded on the computer before variable rate fertilizer machine starts. The computer continually controls the fertilizing rate for each part of the farm using a fertilizing map and global positioning system. The purpose of this study is to construct and evaluate a map-based variable rate fertilizer system that can be installed on a common fertilizer in Iran to be used as a variable rate system. Materials and methods: In common variable rate fertilizers, the rotational speed change of the distributor shaft is used to apply fertilizers. In this way, a DC motor is assembled on the main shaft of all distributors, which reduces the fertilizing accuracy. The reason for this is that there is no separation for units along the width of the fertilizer. Therefore, we used one DC motor for each distributor and another motor to rotate the agitator in the tank. System Set up: To design and select a suitable engine, the required torque for the rotation distributor shaft was measured by a torque meter and the amount of 2.1 Nm was acquired for that. With regard to the maximum rate of nitrogen fertilizer for land and tractor speed at the time of fertilizing, the order of 350 kg per hectare and 8 km per hour, the maximum distributor shaft speed and power required to rotate distributor shaft were calculated to be 55

  1. Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Francesco Basso

    2011-02-01

    Full Text Available Yield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009. After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management.

  2. Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Bruno Basso

    Full Text Available Yield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009. After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management.

  3. Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Bruno Basso

    2009-12-01

    Full Text Available Yield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009. After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management.

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

    Science.gov (United States)

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

    2006-01-01

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

  5. Entropy Rate of Time-Varying Wireless Networks

    DEFF Research Database (Denmark)

    Cika, Arta; Badiu, Mihai Alin; Coon, Justin P.

    2018-01-01

    In this paper, we present a detailed framework to analyze the evolution of the random topology of a time-varying wireless network via the information theoretic notion of entropy rate. We consider a propagation channel varying over time with random node positions in a closed space and Rayleigh...... fading affecting the connections between nodes. The existence of an edge between two nodes at given locations is modeled by a Markov chain, enabling memory effects in network dynamics. We then derive a lower and an upper bound on the entropy rate of the spatiotemporal network. The entropy rate measures...

  6. Natural conception rates in subfertile couples following fertility awareness training.

    Science.gov (United States)

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

    2017-04-01

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

  7. Adenoma detection rate varies greatly during colonoscopy training

    NARCIS (Netherlands)

    van Doorn, Sascha C.; Klanderman, Robert B.; Hazewinkel, Yark; Fockens, Paul; Dekker, Evelien

    2015-01-01

    The adenoma detection rate (ADR) is considered the most important quality indicator for colonoscopy and varies widely among colonoscopists. It is unknown whether the ADR of gastroenterology consultants can already be predicted during their colonoscopy training. To evaluate the ADR of fellows in

  8. Epidemic spread in coupled populations with seasonally varying migration rates

    Science.gov (United States)

    Muzyczyn, Adam; Shaw, Leah B.

    2009-03-01

    The H5N1 strain of avian influenza has spread worldwide, and this spread may be due to seasonal migration of birds and mixing of birds from different regions in the wintering grounds. We studied a multipatch model for avian influenza with seasonally varying migration rates. The bird population was divided into two spatially distinct patches, or subpopulations. Within each patch, the disease followed the SIR (susceptible-infected-recovered) model for epidemic spread. Migration rates were varied periodically, with a net flux toward the breeding grounds during the spring and towards the wintering grounds during the fall. The case of two symmetric patches reduced to single-patch SIR dynamics. However, asymmetry in the birth and contact rates in the breeding grounds and wintering grounds led to bifurcations to longer period orbits and chaotic dynamics. We studied the bifurcation structure of the model and the phase relationships between outbreaks in the two patches.

  9. Warming and nitrogen fertilization effects on winter wheat yields in northern China varied between four years

    DEFF Research Database (Denmark)

    Liu, Liting; Hu, Chunsheng; Olesen, Jørgen E

    2013-01-01

    per m2. This suggests that the wheat yield loss may be related to reduction of spike number, which was affected by decreased soil water content under warming. Warming tended to give larger yield reductions at higher nitrogen fertilizer rates, and this may be related to larger water consumption...... with both higher nitrogen and temperature leading to water shortages. These effects indicate that wheat yield loss from warming was primarily associated with more severe water shortage from greater evapotranspiration under warming. The large crop canopy in the fertilized plot may further have enhanced......). The volumetric water content decreased significantly before heading by 9.3, 3.9, 2.4 and 1.2 vol% in the soil depth of 0.10, 0.20, 0.40, 0.60 m in N2 and by 5.9, 1.4, 1.3 and 1.2 vol% in N1 from heating compared with no heating. The duration of the entire growth period was shortened by on average 7 days...

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

    Directory of Open Access Journals (Sweden)

    Ladiyani Retno Widowati

    2009-09-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Sex differences in obesity associated with total fertility rate.

    Directory of Open Access Journals (Sweden)

    Robert Brooks

    Full Text Available The identification of biological and ecological factors that contribute to obesity may help in combating the spreading obesity crisis. Sex differences in obesity rates are particularly poorly understood. Here we show that the strong female bias in obesity in many countries is associated with high total fertility rate, which is well known to be correlated with factors such as low average income, infant mortality and female education. We also document effects of reduced access to contraception and increased inequality of income among households on obesity rates. These results are consistent with studies that implicate reproduction as a risk factor for obesity in women and that suggest the effects of reproduction interact with socioeconomic and educational factors. We discuss our results in the light of recent research in dietary ecology and the suggestion that insulin resistance during pregnancy is due to historic adaptation to protect the developing foetus during famine. Increased access to contraception and education in countries with high total fertility rate might have the additional benefit of reducing the rates of obesity in women.

  13. Does the endometrial gene expression of fertile women vary within and between cycles?

    Science.gov (United States)

    Evans, Gloria E; Phillipson, Gregory T M; Sykes, Peter H; McNoe, Les A; Print, Cristin G; Evans, John J

    2018-01-23

    Does gene expression of putative endometrial implantation markers vary in expression between menstrual cycles? In fertile women the expression of certain genes exhibits a pattern of stable regulation.which is not affected even when sampled twice in one cycle. Successful implantation occurs in a minority of IVF embryo transfers. In contrast to knowledge regarding the ovulatory process, there is a sparse understanding of endometrial genes critical to implantation. This lack of knowledge hinders progress in this field. Endometrial pipelle samples were collected based on blood endocrinological markers at 2 and 7 days post initial LH surge. Five samples were collected over four cycles where the interval between collections ranged from sequential months to three years. Six fertile women attending an IVF clinic for male factor infertility, had samples collected. Global gene expression profiles were obtained from laser-microdissected, endometrial glands and stroma. Nineteen potential proliferation, cytokine and adhesion markers based on previous validated reports were studied. There was a significant modification between LH+2 and LH+7 of expression for 23 genes-11 in 8 in glands and stroma, 4 in stroma only and 3 in glands only suggesting stable, controlled regulation. Nevertheless, genes exhibited individual characteristics, e.g MKI67 exhibited lower expression at LH+7 than LH+2 and CCL4 higher, whereas TRO expressed limited difference in both cell types. Stability between cycles was demonstrated for gene expression at both LH+2-more than 60% of genes had cycles for each participant permitted the aim of obtaining information on intercycle and intracycle variability to be achieved. Our results support the feasibility of a clinical means of identification of a functional receptive endometrium. The robustness of data from individual women suggests that samples from one cycle can generally be applied to subsequent cycles. Funding was granted from the Tertiary Education

  14. Short-term carbon partitioning fertilizer responses vary among two full-sib loblolly pine clones

    Science.gov (United States)

    Jeremy P. Stovall; John R. Seiler; Thomas R. Fox

    2012-01-01

    We investigated the effects of fertilizer application on the partitioning of gross primary productivity (GPP) between contrasting full-sib clones of Pinus taeda (L.). Our objective was to determine if fertilizer growth responses resulted from similar short-term changes to partitioning. A modeling approach incorporating respiratory carbon (C) fluxes,...

  15. Home visits: why do rates vary so much?

    LENUS (Irish Health Repository)

    Stewart, P

    2012-03-01

    Data including information on patient age, gender, who initiated the visit and call classification was collected during office hours from 12 G.P. rural teaching practices with a combined GMS patient population of 24,720, over a 2 month period. There were a total of 603 home visits, giving an annual visiting rate of 143\\/1000. Visiting rates varied between practices from 45 to 305\\/1000 per year. When high visiting practices (>210\\/1000\\/year) were compared to low visiting rate practices (>90\\/1000\\/year), patients tended to be older (79.7 v. 74.5 years) and calls were 12 times more likely to be doctor initiated (16.6% v. 1.4%) or classified as routine( 50.7% v. 44.9%). The variation between practices was related in part to patient age but appears largely due to differences in doctor home visiting behaviour. There are no recent figures on home visiting in Ireland.

  16. Monitoring of German fertility: Estimation of monthly and yearly total fertility rates on the basis of preliminary monthly data

    NARCIS (Netherlands)

    G. Doblhammer (Gabriele); Milewski, N. (Nadja); F. Peters (Frederick)

    2010-01-01

    textabstractThis paper introduces a set of methods for estimating fertility indicators in the absence of recent and short-term birth statistics. For Germany, we propose a set of straightforward methods that allow for the computation of monthly and yearly total fertility rates (mTFR) on the basis of

  17. Historical nitrogen fertilizer use in agricultural ecosystems of the contiguous United States during 1850-2015: application rate, timing, and fertilizer types

    Science.gov (United States)

    Cao, Peiyu; Lu, Chaoqun; Yu, Zhen

    2018-06-01

    A tremendous amount of anthropogenic nitrogen (N) fertilizer has been applied to agricultural lands to promote crop production in the US since the 1850s. However, inappropriate N management practices have caused numerous ecological and environmental problems which are difficult to quantify due to the paucity of spatially explicit time-series fertilizer use maps. Understanding and assessing N fertilizer management history could provide important implications for enhancing N use efficiency and reducing N loss. In this study, we therefore developed long-term gridded maps to depict crop-specific N fertilizer use rates, application timing, and the fractions of ammonium N (NH4+-N) and nitrate N (NO3--N) used across the contiguous US at a resolution of 5 km × 5 km during the period from 1850 to 2015. We found that N use rates in the US increased from 0.22 g N m-2 yr-1 in 1940 to 9.04 g N m-2 yr-1 in 2015. Geospatial analysis revealed that hotspots for N fertilizer use have shifted from the southeastern and eastern US to the Midwest, the Great Plains, and the Northwest over the past century. Specifically, corn in the Corn Belt region received the most intensive N input in spring, followed by the application of a large amount of N in fall, implying a high N loss risk in this region. Moreover, spatial-temporal fraction of NH4+-N and NO3--N varied largely among regions. Generally, farmers have increasingly favored ammonia N fertilizers over nitrate N fertilizers since the 1940s. The N fertilizer use data developed in this study could serve as an essential input for modeling communities to fully assess N addition impacts, and improve N management to alleviate environmental problems. Datasets used in this study are available at https://doi.org/10.1594/PANGAEA.883585" target="_blank">https://doi.org/10.1594/PANGAEA.883585.

  18. Adverse trends in male reproductive health and decreasing fertility rates

    DEFF Research Database (Denmark)

    Priskorn, Lærke; Holmboe, Stine; Jørgensen, Niels

    2012-01-01

    Healthy men produce an enormous number of sperms, far more than necessary for conception. However, several studies suggest that semen samples where the concentration of sperms is below 40 mill/mL may be associated with longer time to pregnancy or even subfertility, and specimens where the concent...... are now so low that we may be close to the crucial tipping point of 40 mill/mL spermatozoa. Consequently, we must face the possibility of more infertile couples and lower fertility rates in the future....... that the first decline in average sperm number of 20-40 mill/mL might not have had much effect on pregnancy rates, as the majority of men would still have had counts far above the threshold value. However, due to the assumed decline in semen quality, the sperm counts of the majority of 20 year old European men...

  19. Fertility rate oF epileptic women at Kenyatta national Hospital

    African Journals Online (AJOL)

    2008-07-07

    Jul 7, 2008 ... multifaceted, and both epilepsy and antiepileptic drug (aeDs) use may alter fertility and pregnancy ... Conclusion: Fertility rate in epileptic women is decreased by two thirds ..... The effect of this bias on our primary aim was.

  20. Psychotherapeutic counseling and pregnancy rates in in vitro fertilization.

    Science.gov (United States)

    Poehl, M; Bichler, K; Wicke, V; Dörner, V; Feichtinger, W

    1999-07-01

    Since the Austrian propagation bill of July 1, 1992, was passed into law, Austrian physicians are committed to offer psychological counseling to women before performing assisted reproductive techniques, unless refused by the patient. The acceptance of psychotherapeutic counseling (PSITCO) and its influence on pregnancy rate were carefully reviewed. The study comprised 1156 consecutive patients (mean age, 33.3 years) and 1736 in vitro fertilization (IVF) cycles. In a consent form for follicle puncture, the patients were interviewed about PSITCO as follows. Several methods of psychological support during IVF-embryo transfer treatment were offered to patients especially psychotherapy, hypnotherapy, and relaxation and physical perception exercises. Forty-two and three-tenths percent of patients rejected PSITCO, 17.8% had already received PSITCO, and 10.4% were willing to undergo PSITCO. The acceptance of PSITCO had no relevance on pregnancy rate. The cumulative calculation of pregnancy rates showed that up to 56.4% of women who had undergone PSITCO conceived. In patients who were planning to undergo PSITCO, the pregnancy rate was 41.9%. Concerning the cumulative pregnancy rate, this study showed that patients who accepted or underwent PSITCO had a higher pregnancy rate than those who did not avail themselves of this possibility. These results should encourage sterility specialists to consider psychological therapy as an essential aspect of IVF. Solely a written declaration of the patient stating his/her awareness of the possibility to undergo PSITCO is, in our opinion, insufficient.

  1. Hatching rate and growth rate of Nothobranchius guentheri fertilized eggs after space flight

    International Nuclear Information System (INIS)

    Guo Mingzhong; Zheng Leyun; Lin Guangji; Zhong Jianxing; Yang Huosheng; Zheng Yangfu

    2012-01-01

    Hatching, abnormal, growth and survival rate of the fertilized eggs of Nothobranchius guentheri were carried by Shenzhou 7 spacecraft were studied. The results indicated that the hatching and abnormal rate were no significant difference between the spaceflight group (99.3% and 16.8%) and ground group (97.2% and 10.4%); but the growth rate of male fish from spaceflight group was significant higher (0.094 g/d) than that of ground group (0.059 g/d), leading to the significant bigger of the male fish from spaceflight group. The survival rate of spaceflight group (66.7%) was higher than the ground group (47.9%). It was concluded that there was a higher growth and survival rate of Nothobranchius guentheri fertilized eggs after space flight. (authors)

  2. The Influence of Seed Rate and Fertilizer Type on Growth of Tridax procumbens in Subhumid Nigeria

    Directory of Open Access Journals (Sweden)

    Onifade, OS.

    2001-01-01

    Full Text Available Forage production of Tridax procumbens was examined from three seed rates (20, 40 and 60 kg/ha, four types of fertilizer [(unfertilized control, single superphosphate (SSP, 18 % P, NPK (20 : 10 : 10, and calcium ammonium nitrate (CAN, 25 % N] and four harvest stages (6, 9, 12 and 15 weeks post sowing, WPS. Fertilizer rates used were 20 kg/ha P for (SSP and 50 kg/ha N for each of NPK and CAN. Plant height (cm, density (plants/m2 and spread (cm were measured at 3, 6, 9, 12 and 15 WPS. Sampling for yield estimation in each plot was done at 6, 9, 12 and 15 WPS. Mean plant height with respect to seed rate, fertilizer type and growth stage significantly (P 2000 kg DM/ha. Application of SSP, NPK and CAN gave more total DM yields than the unfertilized control plot respectively by about 69, 75 and 75 %. Total DM yield varied from 1024 kg DM/ha when T. procumbens was harvested at an earlier stage (6 WPS to 2130 kg DM/ha at a later harvest (12 WPS. The main CP of leaf was significantly (P <0.05 affected by ail the treatments imposed.

  3. Effect of nitrificide in temporally varied /sup 15/N-labelled slurry fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Peschke, H. (Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Pflanzenproduktion)

    1983-01-01

    The fertilizing effect of /sup 15/N-labelled semi-liquid cattle manure (application in August, November and March) with nitrification inhibitor 'N-Serve' added in amounts of 1 and 3 percent of the fertilizer N on perennial ryegrass with feed oats as follow-up seed was tested in an open-air pot experiment using sand of a sandy-rusty soil. A combination of semi-liquid manure and straw and winter rape-seed, respectively, as green manure (August) and ammonium sulfate with and without 1 per cent N-Serve (November and March) were used as comparative variants. Manuring in August had no effect on the yield, the 3 per cent N-Serve application in November and of 1 and 3 percent in March resulted in an increase of the perennial ryegrass yield. By analogy, the N utilization of the fertilizers was increased with later fertilizing dates and the amount of the nitrificide applied. In the case of semi-liquid manure application, N-Serve promoted the mineralization of the nitrogen in the soil.

  4. Nitrogen Cycling in the Mycorrhizosphere: Multipartite Interactions and Plant Nitrogen Uptake Vary with Fertilization Legacy

    Science.gov (United States)

    Hestrin, R.; Lehmann, J.

    2017-12-01

    Soil microbes play an important role in rhizosphere nutrient cycling and plant productivity. In this study, the contributions of soil microbes to organic matter mineralization and plant nitrogen uptake were investigated using incubation and microcosm experiments. Microbial inocula included arbuscular mycorrhizal fungi and microbial communities sampled across a long-term gradient of nitrogen fertilization. Stable isotopes, nanoSIMS imaging, and phospholipid fatty acid analysis were used to track carbon and nitrogen movement from organic matter into microbes, mycorrhizal fungi, and plants. Results show that multipartite relationships between plants and microbes increased plant growth and access to nitrogen from organic matter, and that nitrogen fertilization history had a lasting effect on microbial contributions to fungal and plant nitrogen uptake. This research links rhizosphere ecology and land management with terrestrial biogeochemistry.

  5. Are low Danish fertility rates explained by changes in timing of births?

    DEFF Research Database (Denmark)

    Hvidtfeldt, Ulla A; Gerster, Mette; Knudsen, Lisbeth B

    2010-01-01

    AIMS: The most commonly used indicator of fertility, the period total fertility rate (TFR(p)), tends to underestimate actual fertility when women delay childbearing. The objective of this study was to examine to which extent fluctuations in Danish fertility rates result from changes in timing...... from the Danish Fertility of Women and Couples Dataset, 1980-2001. We evaluated fluctuations in period fertility rates by the tempo-adjusted TFR(') - a proposed variant of the conventional TFR(p) taking period changes in timing of births into account. Tempo-effects were given by the difference between...... of births and, thus, whether the conventional TFR(p) is a distorted indicator of fertility quantum. In addition, we investigated whether such changes in timing explained the observed regional differences in the TFR(p) in Denmark. METHODS: The study applied age-, period-, county-, and parity-specific data...

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

    OpenAIRE

    Fulda, B.

    2015-01-01

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

  7. Determining Optimum Rates of Mineral Fertilizers for Economic Rice ...

    African Journals Online (AJOL)

    komla

    Rice may benefit from the use of fertilizer to compensate exported nutrients. It is estimated ... Each replicate was then divided (use of smaller bunds) ..... In Ghana, a similar case may arise as both P and K fertilization are given less attention.

  8. Peanut canopy temperature and NDVI response to varying irrigation rates

    Science.gov (United States)

    Variable rate irrigation (VRI) systems have the potential to conserve water by spatially allocating limited water resources. In this study, peanut was grown under a VRI system to evaluate the impact of differential irrigation rates on peanut yield. Additionally, we evaluated the impact of differenti...

  9. Dressed to Present: Ratings of Classroom Presentations Vary with Attire

    Science.gov (United States)

    Gurung, Regan A. R.; Kempen, Laura; Klemm, Kayla; Senn, Rebecca; Wysocki, Rosie

    2014-01-01

    This study investigates the effects of formality of dress on ratings of classroom presentations. Participants (N = 65, 66% women) from a Midwestern university in the United States rated three female students giving a presentation designed for a health psychology class in one of four outfits: casual, party, business casual, or business formal.…

  10. Determination of varying consumption rates from radiotracer data

    International Nuclear Information System (INIS)

    Cadwell, L.L.; Schreckhise, R.G.

    1976-01-01

    Data obtained on the uptake and elimination of phosphorus-32 by foraging grasshoppers were utilized to estimate consumption rates of blue grama grass (Bouteloua gracilis). Grasshoppers were caged in field enclosures containing blue grama grass labeled with 32 P. Periodic measurements were made to determine the body burdens of the grasshoppers and concentration of 32 P in the grass. This information, along with a two-component exponential function which was observed to best mathematically describe the retention of acutely ingested phosphorus, provided the basis for a convolution integral of the consumption rate. The consumption rate was estimated by dividing the observed body burden of the grasshopper by the convolution integral of the input (grass concentration) and impulse (retention curve) function over each observation period. Successive calculations of the consumption rates were made at various points in time as the body burden changed from continued feeding on labeled forage

  11. Mater certa est, pater numquam: What can Facebook Advertising Data Tell Us about Male Fertility Rates?

    OpenAIRE

    Rampazzo, Francesco; Zagheni, Emilio; Weber, Ingmar; Testa, Maria Rita; Billari, Francesco

    2018-01-01

    In many developing countries, timely and accurate information about birth rates and other demographic indicators is still lacking, especially for male fertility rates. Using anonymous and aggregate data from Facebook's Advertising Platform, we produce global estimates of the Mean Age at Childbearing (MAC), a key indicator of fertility postponement. Our analysis indicates that fertility measures based on Facebook data are highly correlated with conventional indicators based on traditional data...

  12. Monitoring of German Fertility: Estimation of Monthly and Yearly Total Fertility Rates on the Basis of Preliminary Monthly Data

    Directory of Open Access Journals (Sweden)

    Gabriele Doblhammer

    2011-02-01

    Full Text Available This paper introduces a set of methods for estimating fertility indicators in the absence of recent and short-term birth statistics. For Germany, we propose a set of straightforward methods that allow for the computation of monthly and yearly total fertility rates (mTFR on the basis of preliminary monthly data, including a confidence interval. The method for estimating most current fertility rates can be applied when no information on the age structure and the number of women exposed to childbearing is available. The methods introduced in this study are useful for calculating monthly birth indicators, with minimal requirements for data quality and statistical effort. In addition, we suggest an approach for projecting the yearly TFR based on preliminary monthly information up to June.

  13. THE IMPLICATIONS OF VARYING EXCHANGE RATES FOR THE INTERNATIONAL TRADE

    Directory of Open Access Journals (Sweden)

    Sandu Carmen

    2011-07-01

    Full Text Available The benefit of international trade is a more efficient employment of the productive forces of the world. (John Stuart Mill The exchange rate is a primary factor that influences economy. This instrument is used by some countries in order to improve the lack of balance caused as a result of the financial crisis felt in many countries considered by then infallible. The negative effects of the financial crisis can also be found in the decreased volume of commodities involved in international trade exchanges, as a consequence of modified prices and decreased offer. The globalizing trend leads to a constant expansion of exchanges between countries and to the consolidation of international cooperation. Except that economic interdependence generates an increased risk under the influence of economic, financial, monetary or political factors. The currency risk can generate either a gain or loss during foreign trade operations. The long period of RON depreciation made possible the entry of Romanian products on the international markets due to their prices. Sheltered by the gain generated by the evolution of the exchange rate, most of the exporters were not concerned by the increase of product competitiveness or by avoiding the currency risk. The fact that, for many years, the evolution of the exchange rate generated substantial losses for the exporters shows that risk coverage in Romania is, in most cases, a purely theoretical concept.

  14. Nitrogen Fertilizer Source, Rates, and Timing for a Cover Crop and Subsequent Cotton Crop

    Science.gov (United States)

    The objectives were to compare N fertilizer sources, rates, and time of application for a rye winter cover crop to determine optimal biomass production for conservation tillage production, compare recommended and no additional N fertilizer rates across different biomass levels for cotton, and determ...

  15. Study the rate of fertility and risk factors of schizophrenia in Najaf, Iraq

    African Journals Online (AJOL)

    This study is designed to investigate the main risk factors, which increased the incidence of schizophrenia and the rate of fertility in patients measuring sex hormones (testosterone and estrogen) and prolactin hormone. The aim of study was to evaluate the fertility rate and risk factors of schizophrenia. Blood samples were ...

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

    Science.gov (United States)

    Child Trends, 2016

    2016-01-01

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

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

    Science.gov (United States)

    2018-01-01

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

  18. Optical crop sensor for variable-rate nitrogen fertilization in corn: II - indices of fertilizer efficiency and corn yield

    Directory of Open Access Journals (Sweden)

    Jardes Bragagnolo

    2013-10-01

    Full Text Available Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF, based on optical spectrometry crop sensors, could increase the N use efficiency (NUE. The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF. With this purpose, three experiments with no-tillage corn were carried out in the 2008/09 and 2010/11 growing seasons on a Hapludox in South Brazil, in a completely randomized design, at three different sites that were analyzed separately. The following crop properties were evaluated: aboveground dry matter production and quantity of N uptake at corn flowering, grain yield, and vegetation index determined by an N-Sensor® ALS optical sensor. Across the sites, the corn N fertilizer had a positive effect on corn N uptake, resulting in increased corn dry matter and grain yield. However, N fertilization induced lower increases of corn grain yield at site 2, where there was a severe drought during the growing period. The VRF defined by the optical crop sensor increased the apparent N recovery (NRE and agronomic efficiency of N (NAE compared to the traditional fertilizer strategy. In the average of sites 1 and 3, which were not affected by drought, VRF promoted an increase of 28.0 and 41.3 % in NAE and NRE, respectively. Despite these results, no increases in corn grain yield were observed by the use of VRF compared to TSF.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    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.

  1. Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application

    Directory of Open Access Journals (Sweden)

    Saeed FIROUZI

    2015-11-01

    Full Text Available To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1 and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria. Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1. Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain

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

    Science.gov (United States)

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

    2015-05-01

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

  3. Effect of long-term fertilization with different norms and rates of nutrients on slightly lashed chernozem fertility

    International Nuclear Information System (INIS)

    Nankova, M.; Kirchev, C.; Penchev, E.

    1999-01-01

    As a result from a 30-year fertilization with nitrogen, phosphorus and potassium applied with different norms and rates, the nutrition regime of slightly leached chernozems was considerably altered. A significant increase of mineral nitrogen, especially of its nitrate form, was observed down the profile (140-200 cm) when applying nitrogen norms of 120 and 180 kg/ha. A high correlation between yield and nitrate nitrogen content was registered under these conditions. During the period of fertilization mentioned above, phosphorus available in soil changed from low to moderate to good and very good depending to the phosphorus fertilization norm. A considerable enrichment of the root-deep layer with available phosphorus was established. A similar tendency was registered for water-soluble and available potassium content in the surface layer in accordance with the potassium dressing. The correlation and path-coefficients calculated for the period of study show a strong relation between yield and the autumn-winter moisture reserve, rainfalls in May and in April-June; these are considered to guarantee the efficiency of mineral fertilization on yield. Refs. 4 (author)

  4. Phosphate fertilizers with varying water-solubility applied to Amazonian soils: II. Soil P extraction methods

    International Nuclear Information System (INIS)

    Muraoka, T.; Brasil, E.C.; Scivittaro, W.B.

    2002-01-01

    A pot experiment was carried out under greenhouse conditions at the Centro de Energia Nuclear na Agricultura, Piracicaba (SP, Brazil), to evaluate the phosphorus availability of different phosphate sources in five Amazonian soils. The soils utilized were: medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic. Four phosphate sources were applied: triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin termo-phosphate and North Carolina phosphate rock at P rates of 0, 40, 80 and 120 mg kg -1 soil. The dry matter yield and the amount of P taken up by cowpea and rice were correlated with the extractable P by anionic exchangeable resin, Mehlich-1, Mehlich-3 and Bray-I. The results showed that the extractable P by Mehlich-1 was higher in the soils amended with North Carolina rock phosphate. Irrespective of the phosphorus sources used, the Mehlich-3 extractant showed close correlation with plant response. The Mehlich-3 and Bray-I extractants were more sensitive to soil variations. The Mehlich-3 extractant was more suitable in predicting the P availability to plants in the different soils and phosphorus sources studied. (author)

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

    Science.gov (United States)

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

    2016-05-01

    With improved cancer survival rates and the current trend of delaying parenthood, fertility is a growing issue among cancer patients. The purpose of this study was to evaluate the incidence of fertility counseling and sperm banking in reproductive-age male cancer patients and to assess factors that influence counseling and banking. Male patients ages 13 to 50 years who received a new cancer diagnosis from January 1, 2013, to May 1, 2015, and planned to initiate curative chemotherapy at our center were identified. Documentation of fertility counseling and sperm cryopreservation was abstracted from the medical record. Univariable and multivariable logistic regression modeling was used to examine variables associated with fertility counseling and sperm banking. Of 201 patients who fit the study criteria, 59 (29%) received fertility counseling and 23 (11%) attempted sperm banking. All patients who banked sperm had documentation of fertility counseling. Younger patients were significantly more likely to be counseled, with mean ages of 27.4 and 40.4 years for counseled and noncounseled patients, respectively (P year odds ratio, 0.61; P fertility counseling and referral for sperm banking in young men with cancer receiving chemotherapy. Further work is needed to develop interventions to improve fertility counseling rates and opportunities for sperm banking. Copyright © 2016 by American Society of Clinical Oncology.

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

    Science.gov (United States)

    Kim, Yujin; Raley, R Kelly

    2015-02-01

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

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

    Science.gov (United States)

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

    2018-06-13

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

  8. The Correlation of Human Development Index on Fertility and Mortality Rate: a Global Ecological Study

    Directory of Open Access Journals (Sweden)

    Amir Almasi-Hashiani

    2016-12-01

    Full Text Available BackgroundSeveral studies have examined the relationship between Human Development Index (HDI and various health outcomes. The aim of this study was to investigate the relationship between HDI, and infant mortality rate, mortality rate of children under one year and under 5 years, maternal mortality rate, and total fertility rate.Materials and MethodsIn this ecologic study, data on HDI, total fertility rate (TFR, maternal mortality rate (MMR, neonatal mortality rate (NMR, infant mortality rate (IMR and mortality rate in children under 5 years of age (< 5MR, were extracted from 188 countries in 2014 in the world. The data required in this study was obtained from the World Bank. Data analysis was performed using Pearson correlation in Stata version 12.0 software. ResultsIn this study, a negative significant correlation was observed between HDI and IMR (r = -0.878, P = 0.001, NMR (r = -0.870, 95% CI: -0.902, -0.828, P = 0.001, ConclusionIMR, children under one year old and under 5 years, and MMR mostly occur in developing countries. There was a correlation between HDI and its components, and the neonatal, infants, children under 5 years, maternal mortality rate and total fertility. The average annual percentage change of HDI also had a correlation with neonatal, infants, children under 5- year mortality rate, total fertility and maternal deaths.

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

    Science.gov (United States)

    Sutton, Paul D; Mathews, T J

    2006-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Ondřej Šimpach

    2015-03-01

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

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

    Science.gov (United States)

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

    2015-01-01

    Increasing age at first childbirth has been suggested to increase the risk for infertility. Our objective is to determine whether women above thirty years of age historically have been able to sustain fertility rates above replacement level. A descriptive nationwide Danish study using birth registries from 1901-2014. Information on women's age at childbirth was obtained by using records from primary, secondary and tertiary institutions. Mothers to 8,024,969 live births. Mothers were stratified according to age at childbirth to determine total and age specific fertility rates. Total fertility rate (TFR) decreased from 4.1 to 1.8 children per woman and age specific fertility also decreased from 1901 to 2014. Women aged 30-34, 35-39 or 40-44 years in the first decade of the 20th century had higher fertility rates than the corresponding five year younger age groups (25-29, 30-34 and 35-39, respectively) have had for the last 65 years. On average, women gave birth to two children after the age of 30 and one or more child after 35 years of age in the beginning of the 1900s. Furthermore, women more than 40 years of age accounted for 10% of TFR in 1901 compared with 4% in 2014 despite usage of assisted reproduction. This nationwide study shows that women above 30 years of age historically have been able to sustain fertility rates above replacement level. This implies that other factors besides age are strong determinants of fertility in women above 30 years of age.

  12. The Effect of Varying Speed Release of Nutrients from Fertilizers on Growth-production Process of Turf

    Directory of Open Access Journals (Sweden)

    Peter Hric

    2016-01-01

    Full Text Available The aim of this experiment was to compare the influence of fertilizers with different speed of nutrients release on growth–production indicators of turf under non–irrigated conditions. The experiment was carried in warm and dry conditions in area Nitra (Slovak Republic. In the experiment were followed 5 treatments (1. without fertilization, 2. Nitre with dolomite, Superphosphate, Potassium salt, 3. Turf fertilizer Travcerit®, 4. Slow release fertilizer SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S, 5. Controlled release fertilizer Duslocote® NPK (S 13–9–18 (+6S. The highest gain of height reached variant fertilized by fertilizer SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S. Comparison of the individual treatments for the whole period showed significantly lower average daily gains of height on control treatment compared to fertilizing treatments Nitre with dolomite, Superphosphate, Potassium salt, SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S and Duslocote® NPK (S 13–9–18 (+6S. During the reported period the highest gain of weight reached treatment by application fertilizer Duslocote® NPK (S 13– 9–18 (+ 6S. Comparison of the individual treatments for the whole period, were found significantly lower average daily production of phytomass on control treatment in comparison with fertilization turfs by Travcerit® and Duslocote® NPK (S 13–9–18 (+6S.

  13. Does a Teacher's Classroom Observation Rating Vary across Multiple Classrooms?

    Science.gov (United States)

    Lei, Xiaoxuan; Li, Hongli; Leroux, Audrey J.

    2018-01-01

    Classroom observations have been increasingly used for teacher evaluations, and it is important to examine the measurement quality and the use of observation ratings. When a teacher is observed in multiple classrooms, his or her observation ratings may vary across classrooms. In that case, using ratings from one classroom per teacher may not be…

  14. Psychotherapeutic Counseling and Pregnancy Rates in In Vitro Fertilization

    OpenAIRE

    Poehl, Michaela; Bichler, Katherina; Wicke, Veronika; Dörner, Veronika; Feichtinger, Wilfried

    1999-01-01

    Purpose:Since the Austrian propagation bill of July 1, 1992, was passed into law, Austrian physicians are committed to offer psychological counseling to women before performing assisted reproductive techniques, unless refused by the patient. The acceptance of psychotherapeutic counseling (PSITCO) and its influence on pregnancy rate were carefully reviewed.

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

    Science.gov (United States)

    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...

  16. Phosphate fertilizers with varying water-solubilities applied to Amazonian soils: I. agronomic efficiency of P sources

    International Nuclear Information System (INIS)

    Brasil, E.C.; Muraoka, T.; Boaretto, A.E.; Scivittaro, W.B.

    2002-01-01

    The relative agronomic efficiency of four phosphate sources (triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin thermophosphate and North Carolina phosphate rock) were evaluated, in a pot experiment carried out under greenhouse conditions, using five soils (medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic) from Para State, Brazil. The soils received three rates of phosphorus (40, 80 and 120 mg P/kg of soil) plus the control (0P) treatment. A randomized block design with three replicates was used. Two consecutive crops (cowpea and rice) were used as test plants. The results showed that the best dry matter yield and P uptake for cowpea were obtained in soils fertilized with triple superphosphate. The agronomic efficiency index of ordinary Yoorin was superior to the coarse Yoorin and North Carolina phosphate rock for the cowpea grown as first crop. The indices were similar for all phosphate sources for the subsequent rice crop. The best residual effect was obtained with North Carolina phosphate rock and coarse Yoorin. The larger particle size of coarse thermophosphate resulted in a decreased P efficiency. (author)

  17. Should Unemployment Insurance Vary with the Unemployment Rate? Theory and Evidence

    OpenAIRE

    Kroft, Kory; Notowidigdo, Matthew J.

    2012-01-01

    We study how optimal unemployment insurance (UI) benefits vary over the business cycle by estimating how the moral hazard cost and the consumption smoothing benefit of UI vary with the unemployment rate. We find that the moral hazard cost is procyclical, greater when the unemployment rate is relatively low. By contrast, our evidence suggests that the consumption smoothing benefit of UI is acyclical. Using these estimates to calibrate our job search model, we find that a one standard deviation...

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

    OpenAIRE

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2002-06-01

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

  1. Effect of different rates of nitrogen fertilizer on durum wheat (Triticum ...

    African Journals Online (AJOL)

    Dr Asefa

    2012-05-03

    May 3, 2012 ... The result showed that nitrogen rates and cultivars had significant effect on yield, yield related traits, nitrogen uptake ... cooking quality [8]. Durum wheat grain protein functionality can be influenced by N fertilization, particularly in the varieties of relatively with less gluten strength [9]. Information on the quality ...

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

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes de Souza

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

  3. Effect of N-fertilizer rates on Dry Matter Yield (DMY) and quality of ...

    African Journals Online (AJOL)

    Effect of N-fertilizer rates on Dry Matter Yield (DMY) and quality of pinapple propagules (Ananas comosus) in the acid sands of cross river. W Ubi, M W Ubi, VE Osedeke. Abstract. No Abstract. Global Journal of Pure and Applied Physics Vol. 14 (1) 2008 pp. 1-4. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD ...

  4. Nitrogen Balance During Sweet Sorghum Cropping Cycle as Affected by Irrigation and Fertilization Rate

    Directory of Open Access Journals (Sweden)

    Stella Lovelli

    Full Text Available A two-year trial was carried out on sweet sorghum, grown in semi-arid environments of southern Europe. The trial was aimed to monitor the main components of the crop N-balance under different irrigation regimes and nitrogen fertilization rates, in factorial combination. A rainfed condition (only one watering soon after sowing was compared with a deficit irrigation regime and a full irrigation treatment (50 and 100% restoration of total crop water consumption, respectively. Crop nitrogen uptake always showed to be the highest N-balance components and was included in the range of 125-194 kg ha-1 during 1997-1998, with respect to the total shoot biomass, according to the nitrogen fertilization rate; consequently, it significantly reduced both nitrogen concentration in the soil solution and the total nitrogen loss due to drainage. Nitrogen concentration in the drainage water didn’t result to be strictly dependent on the rate of fertiliser applied but on the actual soil nitrogen content; the maximum registered value of total nitrogen lost by leaching was 1.9 kg ha-1. Differently, total nitrogen loss due to volatilisation was proportional to the amount of fertilizer applied; irrigation favourably reduced this kind of loss. The limited amount of Nvolatilisation loss was probably due to the neutral pH soil conditions; as an order of magnitude, referring to the highest fertilized but rainfed treatment, the utmost N-volatilisation loss was equal to 5.5 Kg ha-1, as an average over the three years, that is to say less than the 5% of the fertilization rate. A fertilisation rate of 120 Kg ha-1 of nitrogen, together with water application, generally produced a balance between crop N-uptake and total N-loss due to volatilisation and drainage (only the stalk biomass was considered in this calculation. Lower rates of fertilizing nitrogen, indeed, determined a depletion in the soil nitrogen content because of the high crop biomass and the strong N-uptake by the

  5. Nitrogen Balance During Sweet Sorghum Cropping Cycle as Affected by Irrigation and Fertilization Rate

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    2011-02-01

    Full Text Available A two-year trial was carried out on sweet sorghum, grown in semi-arid environments of southern Europe. The trial was aimed to monitor the main components of the crop N-balance under different irrigation regimes and nitrogen fertilization rates, in factorial combination. A rainfed condition (only one watering soon after sowing was compared with a deficit irrigation regime and a full irrigation treatment (50 and 100% restoration of total crop water consumption, respectively. Crop nitrogen uptake always showed to be the highest N-balance components and was included in the range of 125-194 kg ha-1 during 1997-1998, with respect to the total shoot biomass, according to the nitrogen fertilization rate; consequently, it significantly reduced both nitrogen concentration in the soil solution and the total nitrogen loss due to drainage. Nitrogen concentration in the drainage water didn’t result to be strictly dependent on the rate of fertiliser applied but on the actual soil nitrogen content; the maximum registered value of total nitrogen lost by leaching was 1.9 kg ha-1. Differently, total nitrogen loss due to volatilisation was proportional to the amount of fertilizer applied; irrigation favourably reduced this kind of loss. The limited amount of Nvolatilisation loss was probably due to the neutral pH soil conditions; as an order of magnitude, referring to the highest fertilized but rainfed treatment, the utmost N-volatilisation loss was equal to 5.5 Kg ha-1, as an average over the three years, that is to say less than the 5% of the fertilization rate. A fertilisation rate of 120 Kg ha-1 of nitrogen, together with water application, generally produced a balance between crop N-uptake and total N-loss due to volatilisation and drainage (only the stalk biomass was considered in this calculation. Lower rates of fertilizing nitrogen, indeed, determined a depletion in the soil nitrogen content because of the high crop biomass and the strong N-uptake by the

  6. Field effect of P fertilization on N$_{2}$ fixation rate of Ulex europaeus

    OpenAIRE

    Cavard , Xavier; Augusto , Laurent; Saur , Etienne; Trichet , Pierre

    2007-01-01

    European gorse (Ulex europaeus L.) N-2 fixation rate (% Ndfa) was studied in a maritime pine (Pinus pinaster Ait.) oligotrophic forest. Fertilization field trials were carried out on 5 sites with various inputs of phosphorus (0-240 kg P2O5. ha(-1)). Seven to ten years after pine planting, gorse were sampled to evaluate the effect of P fertilization on gorse % Ndfa, determined using the N-15 natural abundance method. One of the prerequisites of this method is the existence of a significant dif...

  7. Prediction of pregnancy success rate through in vitro fertilization based on maternal age

    Directory of Open Access Journals (Sweden)

    Soegiharto Soebijanto

    2009-12-01

    Full Text Available Aim To evaluate the correlation between the success of pregnancy through in vitro fertilization and maternal age. Methods Assessment of pregnancy was performed in eight in vitro fertilization centers in Indonesia: Harapan Kita Pediatric and Obstetric Hospital from 1997 to 2001, and seven in vitro fertilization centers in Indonesia. Follicular induction was performed through the long protocol, short protocol and natural cycle. Insemination was performed through ICSI (intra cytoplasmic sperm injection on petri dish. Spermatozoa were obtained through masturbation, testicular biopsy and epididimical biopsy. A successful pregnancy was indicated chemically, with the presence of fetal heart beat and the birth of a baby (take home baby. Results There was a 34% pregnancy rate for the age group below 30 years, 33.75% for those between 31 and 35 years olds, and 26% for the age group 36 to 40 years old, and 8% for the age group above 40 years. Conclusion The higher the maternal age, the lower pregnancy rate. In other words, the higher the maternal age, the higher the rate of miscarriage. (Med J Indones 2009; 18: 244-8Keywords: pregnancy, in vitro fertilization

  8. Explaining Dutch fertility Rates in a Comparative European perspective: The role of economy, social policy and culture

    OpenAIRE

    Rijken, Arieke J.; Knijn, Trudie

    2008-01-01

    This article contributes to the search for explanations of the cross-national variation in fertility rates by studying the influence of social policy, economic and cultural factors on fertility in the former EU15, while giving special attention to one case: The Netherlands. This country lacks good social policy for supporting parents to combine work and care and nevertheless has a relatively high fertility rate. This article addresses the backgrounds of that phenomenon, using comparative macr...

  9. Hydrodynamic mean-field solutions of 1D exclusion processes with spatially varying hopping rates

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, Greg; O' Brien, John; Chou, Tom [Department of Biomathematics and Institute for Pure and Applied Mathematics, UCLA, Los Angeles, CA 90095 (United States)

    2006-03-10

    We analyse the open boundary partially asymmetric exclusion process with smoothly varying internal hopping rates in the infinite-size, mean-field limit. The mean-field equations for particle densities are written in terms of Ricatti equations with the steady-state current J as a parameter. These equations are solved both analytically and numerically. Upon imposing the boundary conditions set by the injection and extraction rates, the currents J are found self-consistently. We find a number of cases where analytic solutions can be found exactly or approximated. Results for J from asymptotic analyses for slowly varying hopping rates agree extremely well with those from extensive Monte Carlo simulations, suggesting that mean-field currents asymptotically approach the exact currents in the hydrodynamic limit, as the hopping rates vary slowly over the lattice. If the forward hopping rate is greater than or less than the backward hopping rate throughout the entire chain, the three standard steady-state phases are preserved. Our analysis reveals the sensitivity of the current to the relative phase between the forward and backward hopping rate functions.

  10. Hydrodynamic mean-field solutions of 1D exclusion processes with spatially varying hopping rates

    International Nuclear Information System (INIS)

    Lakatos, Greg; O'Brien, John; Chou, Tom

    2006-01-01

    We analyse the open boundary partially asymmetric exclusion process with smoothly varying internal hopping rates in the infinite-size, mean-field limit. The mean-field equations for particle densities are written in terms of Ricatti equations with the steady-state current J as a parameter. These equations are solved both analytically and numerically. Upon imposing the boundary conditions set by the injection and extraction rates, the currents J are found self-consistently. We find a number of cases where analytic solutions can be found exactly or approximated. Results for J from asymptotic analyses for slowly varying hopping rates agree extremely well with those from extensive Monte Carlo simulations, suggesting that mean-field currents asymptotically approach the exact currents in the hydrodynamic limit, as the hopping rates vary slowly over the lattice. If the forward hopping rate is greater than or less than the backward hopping rate throughout the entire chain, the three standard steady-state phases are preserved. Our analysis reveals the sensitivity of the current to the relative phase between the forward and backward hopping rate functions

  11. Seed Yield of Long Fiber Flax (Linum usitatissimum L. Plants Depending on Rates of Sawing of Seed and Mineral Fertilization

    Directory of Open Access Journals (Sweden)

    М. Ф. Рибак

    2010-10-01

    Full Text Available Impact of rates of sawing of seed and fertilization on seed productivity of Kameniar and Irma Long Fiber Flax in the conditions of Ukrainian Woodlands are highlighted. A trustworthy proportion is established of factors influence, in particular, of the sawing and fertilization rates, on Long Fiber Flax yield formation.

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

    Science.gov (United States)

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

    2014-12-01

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

  13. Sojourn time asymptotics in Processor Sharing queues with varying service rate

    NARCIS (Netherlands)

    Egorova, R.; Mandjes, M.R.H.; Zwart, B.

    2007-01-01

    Abstract This paper addresses the sojourn time asymptotics for a GI/GI/⋅ queue operating under the Processor Sharing (PS) discipline with stochastically varying service rate. Our focus is on the logarithmic estimates of the tail of sojourn-time distribution, under the assumption that the job-size

  14. Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity

    Science.gov (United States)

    2010-12-10

    Armen Babikyan, Nathaniel M. Jones, Thomas H. Shake, and Andrew P. Worthen MIT Lincoln Laboratory 244 Wood Street Lexington, MA 02420 DDRE, 1777...delay U U U U SAR 11 Zach Sweet 781-981-5997 1 Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity Brooke Shrader, Armen

  15. Energy productivity, fertilization rate and profitability of wheat production after various predecessors II.Profitability of wheat production

    Directory of Open Access Journals (Sweden)

    Z. Uhr

    2016-03-01

    Full Text Available Abstract. In the course of our study on the adaptation of modern genotypes common winter wheat (Triticum aestivum to the requirements of sustainable agriculture data were received concerning the influence of the predecessor and nitrogen fertilizer rate on energy efficiency and recyclable nitrogen fertilization and profitability of productivity.We share these data with the scientific community, as they are up-to-date and informative in both theoretical and practical aspects. The analyses are based on data from field experiments fertilizer derived after predecessor cereals – regular crop of sorghum, millet, maize and legumes after predecessor - separate sowing of chickpeas. Energy efficiency of nitrogen fertilization was calculated as the ratio between the energy supplied in the additional grain yield and energy input in the form of fertilizers. Refundable efficiency of nitrogen fertilization is the additional amount of nitrogen accumulated in the grain, with respect to the applied nitrogen fertilization. Economic profitability of production is evaluated by coefficient R = P/Ra (ratio of benefits/costs. The results show that energy efficiency and recyclable nitrogen fertilization are on average five times higher after cereal than after legumes predecessor, and decreased with increasing the fertilizer rate, the decrease was statistically significant only for the first item (exponent. Profitability ratio of production after the introduction of legumes predecessor in crop rotation increases by an average of 42% and retains maximum values of fertilization levels 0.06, 0.12 and 0.18 t/ha nitrogen. Profitability of wheat production using pre-legumes crop is not determined by the parameters nitrogen fertilizer rate and energy efficiency of nitrogen fertilization and refundable efficiency of nitrogen fertilization.

  16. Europe-wide fertility trends since the 1990s: Turning the corner from declining first birth rates

    Directory of Open Access Journals (Sweden)

    Marion Burkimsher

    2015-03-01

    Full Text Available Background: In the period 1995-2002 there was a change in trajectory from decline to rise in first birth fertility rates across Europe. Objective: A number of previous studies have looked at the demographic causes of the transition. This study evaluates their conclusions by analysing a comprehensive set of indicators for fifteen countries with data in the Human Fertility Database. Methods: Comparisons are made between the four years before and after the fertility trough, to discover what changed between these two periods. Results: In the period before the trough, peak age-specific fertility rates were falling; these tended to stabilise after the year of minimum fertility. The width of the fertility curve, however, was already widening in the 1990s, and this trend continued. The transition from fall to rise in TFR1 occurred when the increase in the width of the curve more than compensated for any further falls in peak rates; this explanation is valid for countries in both Eastern and Western Europe. The increasing width of the fertility curve was caused by two factors: the decline in young (pre-modal fertility slowed, whilst the rise in older (post-modal fertility accelerated. For some countries, a rise in underlying cohort rates also contributed to the rise in period rates. The likelihood of childless women entering motherhood also rose in some but not all countries. Conclusions: During the 1990s, women were postponing first births across Europe. A rebound took place for several reasons, with the overarching driver being the strong rise in late fertility. Comments: In some countries the steep rise in late fertility had an unexpected and paradoxical effect on postponement rates (defined as the year-on-year increase in mean age at first birth. Recuperation at post-modal ages of postponed first births caused an acceleration in 'postponement' rates, as defined by this metric.

  17. Accumulation of N and P in the Legume Lespedeza davurica in Controlled Mixtures with the Grass Bothriochloa ischaemum under Varying Water and Fertilization Conditions.

    Science.gov (United States)

    Xu, Bingcheng; Xu, Weizhou; Wang, Zhi; Chen, Zhifei; Palta, Jairo A; Chen, Yinglong

    2018-01-01

    Water and fertilizers affect the nitrogen (N) and phosphorus (P) acquisition and allocation among organs in dominant species in natural vegetation on the semiarid Loess Plateau. This study aimed to clarify the N and P accumulation and N:P ratio at organ and plant level of a local legume species mixed with a grass species under varying water and fertilizer supplies, and thus to fully understand the requirements and balance of nutrient elements in response to growth conditions change of native species. The N and P concentration in the organ (leaf, stem, and root) and plant level of Lespedeza davurica (C 3 legume), were examined when intercropped with Bothriochloa ischaemum (C 4 grass). The two species were grown outdoors in pots under 80, 60, and 40% of soil water field capacity (FC), -NP, +N, +P, and +NP supply and the grass:legume mixture ratios of 2:10, 4:8, 6:6, 8:4, 10:2, and 12:0. The three set of treatments were under a randomized complete block design. Intercropping with B. ischaemum did not affect N concentrations in leaf, stem and root of L. davurica , but reduced P concentration in each organ under P fertilization. Only leaf N concentration in L. davurica showed decreasing trend as soil water content decreased under all fertilization and mixture proportion treatments. Stems had the lowest, while roots had the highest N and P concentration. As the mixture proportion of L. davurica decreased under P fertilization, P concentration in leaf and root also decreased. The N concentration in L. davurica at the whole plant level was 11.1-17.2%. P fertilization improved P concentration, while decreased N:P ratio in L. davurica . The N:P ratios were less than 14.0 under +P and +NP treatments. Our results implied that exogenous N and P fertilizer application may change the N:P stoichiometry and influence the balance between nutrients and organs of native dominant species in natural grassland, and P element should be paid more attention when considering rehabilitating

  18. Effect of cotton leaf-curl virus on the yield-components and fibre properties of cotton genotypes under varying plant spacing and nitrogen fertilizer

    International Nuclear Information System (INIS)

    Ahmad, S.; Hayat, K.; Ashraf, F.; Sadiq, M.A.

    2008-01-01

    Cotton leaf-curl virus (CLCu VB. Wala strain) is one of the major biotic constraints of cotton production in Punjab. Development of resistant cotton genotype is the most feasible, economical and effective method to combat this hazardous problem, but so far no resistant genotype has been reported. Therefore, the objective of this study was to compare yield and yield-components and fiber traits of different genotypes/varieties under different plant spacing and nitrogen fertilizer as a management strategy to cope with this viral disease. Field experiment was conducted during 2006-07 to evaluate the effect of genotype, plant spacing and nitrogen fertilizer on cotton. Five genotypes (MNH-786, MNH-789, MNH- 6070, CIM- 496, and BH-160), three plant-spacings (15, 30 and 45 cm) and three nitrogen fertilizer-levels (6.5, 8.6 and 11 bags Urea / ha) were studied. Results showed that significant differences exist for plant height, no. of bolls/m/sup -2/, seed-cotton yield (kg/ha) due to genotype, interaction of genotype with plant spacing and nitrogen fertilizer level. Whereas boll weight, ginning out-turn, staple length and fiber fineness were not affected significantly by the plant spacing and nitrogen fertilizer, the effect due to genotype was significant for these traits. CLCuV infestation varied significantly with genotypes, while all other factors, i.e., plant spacing and nitrogen fertilizers, have non-significant effect. As the major objective of cotton cultivation is production of lint for the country and seed- cotton yield for the farmers, it is noted that genotypes grown in narrow plant-spacing (15 cm) and higher nitrogen fertilizer level (11.0 bags of urea/ha) produced maximum seed-cotton yield under higher CLCu V infestation in case of CIM-496, MNH-789 and BH-I60, while the new strain MNH-6070 gave maximum yield under 30cm plant-spacing and 8.6 bags of urea/ha has the 2.3% CLCu V infestation was observed in this variety. From the present study, it is concluded that

  19. Accumulation of N and P in the Legume Lespedeza davurica in Controlled Mixtures with the Grass Bothriochloa ischaemum under Varying Water and Fertilization Conditions

    Directory of Open Access Journals (Sweden)

    Bingcheng Xu

    2018-02-01

    Full Text Available Water and fertilizers affect the nitrogen (N and phosphorus (P acquisition and allocation among organs in dominant species in natural vegetation on the semiarid Loess Plateau. This study aimed to clarify the N and P accumulation and N:P ratio at organ and plant level of a local legume species mixed with a grass species under varying water and fertilizer supplies, and thus to fully understand the requirements and balance of nutrient elements in response to growth conditions change of native species. The N and P concentration in the organ (leaf, stem, and root and plant level of Lespedeza davurica (C3 legume, were examined when intercropped with Bothriochloa ischaemum (C4 grass. The two species were grown outdoors in pots under 80, 60, and 40% of soil water field capacity (FC, -NP, +N, +P, and +NP supply and the grass:legume mixture ratios of 2:10, 4:8, 6:6, 8:4, 10:2, and 12:0. The three set of treatments were under a randomized complete block design. Intercropping with B. ischaemum did not affect N concentrations in leaf, stem and root of L. davurica, but reduced P concentration in each organ under P fertilization. Only leaf N concentration in L. davurica showed decreasing trend as soil water content decreased under all fertilization and mixture proportion treatments. Stems had the lowest, while roots had the highest N and P concentration. As the mixture proportion of L. davurica decreased under P fertilization, P concentration in leaf and root also decreased. The N concentration in L. davurica at the whole plant level was 11.1–17.2%. P fertilization improved P concentration, while decreased N:P ratio in L. davurica. The N:P ratios were less than 14.0 under +P and +NP treatments. Our results implied that exogenous N and P fertilizer application may change the N:P stoichiometry and influence the balance between nutrients and organs of native dominant species in natural grassland, and P element should be paid more attention when considering

  20. Cesarean Delivery Rates Vary 10-Fold Among US Hospitals; Reducing Variation May Address Quality, Cost Issues

    Science.gov (United States)

    Kozhimannil, Katy Backes; Law, Michael R.; Virnig, Beth A.

    2013-01-01

    Cesarean delivery is the most commonly performed surgical procedure in the United States, and cesarean rates are increasing. Working with 2009 data from 593 US hospitals nationwide, we found that cesarean rates varied tenfold across hospitals, from 7.1 percent to 69.9 percent. Even for women with lower-risk pregnancies, in which more limited variation might be expected, cesarean rates varied fifteen-fold, from 2.4 percent to 36.5 percent. Thus, vast differences in practice patterns are likely to be driving the costly overuse of cesarean delivery in many US hospitals. Because Medicaid pays for nearly half of US births, government efforts to decrease variation are warranted. We focus on four promising directions for reducing these variations, including better coordination of maternity care, more data collection and measurement, tying Medicaid payment to quality improvement, and enhancing patient-centered decision making through public reporting. PMID:23459732

  1. Effect of Different Silicon Sources on Yield and Silicon Uptake of Rice Grown under Varying Phosphorus Rates

    Directory of Open Access Journals (Sweden)

    Flavia B. Agostinho

    2017-08-01

    Full Text Available A series of pot experiments were conducted to: (1 evaluate the effects of different Si sources (soil- and foliar-applied on grain yield and Si accumulation of rice supplied with varying P rates, and (2 evaluate Si absorption of rice using foliar- and soil-applied Si fertilizers. Three P rates, (0, 112, and 224 kg ha−1 combined with five Si treatments (wollastonite and slag applied at 4.5 ton ha−1 and one foliar Si solution applied at 20, 40 and 80 mg Si L−1 and a check were arranged in a randomized complete block design with four replications. The presence of P and Si in the soil created a synergistic effect on soil Al, Mn, and As (P < 0.01, but not on rice growth and P uptake. Wollastonite and slag application were most effective in raising rice Si content than foliar applied Si (P < 0.001. While there was an improvement in biomass (42% and tiller production (25% for rice receiving foliar Si, no supporting evidence was obtained in these experiments to verify leaf surface Si absorption. The application of Si-rich materials to soil still remains the most effective method for enhancing Si uptake by plants.

  2. Effect of Different Silicon Sources on Yield and Silicon Uptake of Rice Grown under Varying Phosphorus Rates.

    Science.gov (United States)

    Agostinho, Flavia B; Tubana, Brenda S; Martins, Murilo S; Datnoff, Lawrence E

    2017-08-29

    A series of pot experiments were conducted to: (1) evaluate the effects of different Si sources (soil- and foliar-applied) on grain yield and Si accumulation of rice supplied with varying P rates, and (2) evaluate Si absorption of rice using foliar- and soil-applied Si fertilizers. Three P rates, (0, 112, and 224 kg ha -1 ) combined with five Si treatments (wollastonite and slag applied at 4.5 ton ha -1 and one foliar Si solution applied at 20, 40 and 80 mg Si L -1 ) and a check were arranged in a randomized complete block design with four replications. The presence of P and Si in the soil created a synergistic effect on soil Al, Mn, and As ( P rice growth and P uptake. Wollastonite and slag application were most effective in raising rice Si content than foliar applied Si ( P production (25%) for rice receiving foliar Si, no supporting evidence was obtained in these experiments to verify leaf surface Si absorption. The application of Si-rich materials to soil still remains the most effective method for enhancing Si uptake by plants.

  3. Time-varying exchange rate pass-through: experiences of some industrial countries

    OpenAIRE

    Toshitaka Sekine

    2006-01-01

    This paper estimates exchange rate pass-through of six major industrial countries using a time-varying parameter with stochastic volatility model. Exchange rate pass-through is divided into impacts of exchange rate fluctuations to import prices (first-stage pass-through) and those of import price movements to consumer prices (second-stage pass-through). The paper finds that both stages of pass-through have declined over time for all the sample countries. The decline in second-stage pass-throu...

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

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Carlsen, Elisabeth; Jørgensen, Niels

    2002-01-01

    may not be attributable to social factors, changes in conception practices or diminished sexual activity alone. It seems reasonable also to consider widespread poor semen quality among men as a potential contributing factor to low fertility rates among teenagers. Due to the concern caused by the low...... sperm count among younger Danish men, the Danish Ministries of Health and Environment have launched a surveillance programme which includes an annual examination of the semen quality in 600 young Danes from the general population. We propose that researchers in other countries with low and falling...... fertility rates among young women should consider the possibility that semen quality of their younger male cohorts may also have deteriorated....

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

    Science.gov (United States)

    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. © 2016 International Federation for Cell Biology.

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

    OpenAIRE

    Blomberg Jensen, Martin; Priskorn, L?rke; Jensen, Tina Kold; Juul, Anders; Skakkebaek, Niels Erik

    2015-01-01

    Objective Increasing age at first childbirth has been suggested to increase the risk for infertility. Our objective is to determine whether women above thirty years of age historically have been able to sustain fertility rates above replacement level. Design A descriptive nationwide Danish study using birth registries from 1901?2014. Setting Information on women?s age at childbirth was obtained by using records from primary, secondary and tertiary institutions. Participants Mothers to 8,024,9...

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

    OpenAIRE

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

    2015-01-01

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

  8. A cross-over in Mexican and Mexican-American fertility rates: Evidence and explanations for an emerging paradox

    Directory of Open Access Journals (Sweden)

    Patrick Heuveline

    2005-03-01

    Full Text Available Against a backdrop of two new developments in the fertility behavior of the Mexican- Origin population in the U.S., the present discussion will update contemporary Mexican-Origin fertility patterns and address several theoretical weaknesses in the current approach to minority group fertility. Data come from six national surveys (three from Mexico and three from the U.S. that cover a twenty-five year period (1975-2000. The findings demonstrate dramatic decreases in the fertility rates in Mexico at the same time that continuous increases have been documented in the fertility rates of third-or-later generation Mexican-Americans in the U.S., particularly at younger ages. These changes necessitate a reexamination of the ubiquitous theory that Mexican pronatalist values are responsible for the high fertility rates found within the Mexican-Origin population in the U.S. Instead, they point to the increasing relevance of framing the fertility behavior of the Mexican-Origin population within a racial stratification perspective that stresses the influence of U.S. social context on fertility behavior. As a step in this direction, the analysis examines fertility patterns within the Mexican-Origin population in the U.S. Special attention is given to the role of nativity/generational status in contributing to within group differences.

  9. [Association between the decline in global fertility rate and the incorporation of women to the workforce].

    Science.gov (United States)

    Stefanelli, María de Los Ángeles; Valenzuela, María Teresa; Cárcamo, Marcela; Urquidi, Cinthya; Cavada, Gabriel; San Martín P, Pamela

    2016-05-01

    The global fertility rate (GFR) is defined as the mean number of children that a woman could have in a hypothetical cohort, not exposed to death during the fertile period. GFR has fallen from 3.4 to 1.9 children per women in the period 1970-2010. To explore the relationship between the fall in GFR and the incorporation of women to work in the period 1960-2011. Data from the National Statistics Institute was used. GRF was calculated using specific fertility rates for each year considering women aged 15 to 49 years. Work rates were obtained from yearly vital statistics reports. Between 1960 and 2011, GRF decreased from 5.5 to 1.9 in Chile. The first inflection occurred in 1970. In the same period, female workforce increased from 22.4 to 40.2%. To motivate the participation of female work-force without decrease the GRF allowing population replacement, it is suggested the need to create new public policies with benefits and support from the state.

  10. Modeling the time--varying subjective quality of HTTP video streams with rate adaptations.

    Science.gov (United States)

    Chen, Chao; Choi, Lark Kwon; de Veciana, Gustavo; Caramanis, Constantine; Heath, Robert W; Bovik, Alan C

    2014-05-01

    Newly developed hypertext transfer protocol (HTTP)-based video streaming technologies enable flexible rate-adaptation under varying channel conditions. Accurately predicting the users' quality of experience (QoE) for rate-adaptive HTTP video streams is thus critical to achieve efficiency. An important aspect of understanding and modeling QoE is predicting the up-to-the-moment subjective quality of a video as it is played, which is difficult due to hysteresis effects and nonlinearities in human behavioral responses. This paper presents a Hammerstein-Wiener model for predicting the time-varying subjective quality (TVSQ) of rate-adaptive videos. To collect data for model parameterization and validation, a database of longer duration videos with time-varying distortions was built and the TVSQs of the videos were measured in a large-scale subjective study. The proposed method is able to reliably predict the TVSQ of rate adaptive videos. Since the Hammerstein-Wiener model has a very simple structure, the proposed method is suitable for online TVSQ prediction in HTTP-based streaming.

  11. Effect of exogenous glutathione in medium fertilization to improve blastocyst rates of bovine embryos

    Directory of Open Access Journals (Sweden)

    E Triwulaninngsih

    2002-06-01

    Full Text Available Glutathione (C10H17N3O6S is a tripeptide (γ-Glu-Cys-Gly widespread in living organism. Glutathione (GSH at the 5 mM concentration increased the motility and fertility of frozen-thawed sperm. Intracellulair glutathione improved the cleavage rate and embryo development to the blastocyst rate. Research on in vitro embryos production through the implementation of GSH during IVF (in vitro fertilization on embryo development has been conducted at the Laboratorium Reproductive of Physiology, Research Institute for Animal Production. Ovaries of beef cattle as source of oocytes were collected from the slaughterhouse in a thermo flask with 350C PBS as medium and transported to the laboratory. The oocytes were fertilized in vitro with selected motile sperm using Percoll gradient (90 and 45%. Ten COCs (cumulus oocytes complexes were transfered to 44 μl of fertilization medium (mTALP was performed with either 0; 0.25; 0.50; 0.75 and 1.00 mM of glutathione as treatment A, B, C, D and E respectively, and inseminated with 2 μl of capacitated sperm and added 2 μl of heparin and 2 μl of PHE (consisting of 20 μM penicillamine, 10 μM hypotaurine, 1 μM epinephrine. Incubation between sperm and oocytes in the 5% CO2 incubator and RH 90% in fertilization media (TALP for 20 hours. All zygotes were cultured in modification of CR1aa medium up to blastocyst and were fed serum 5 μl/50μl medium on day 6. Results of this experiment showed that the effect of concentration of glutathione (0, 0.25; 0.50; 0.75 and 1.00 mM on fertilization medium to the percentage of cleavage rates were 69.35 + 29.40; 79.07 + 13.17; 67.88 + 10.65; 98.10 + 3.30 and 82.62 + 24.19% not significant different (P>0.05 among treatments A, B, C, D dan E respectively.The precentages of morula and blastocyst for treatment D were 50.45 + 42.64% and 31.28 + 24.28%; while 36.55 + 24.13% and 17.74 + 17.86% for treatment E respectively.

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

    Science.gov (United States)

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

    1993-09-01

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

  13. Mind the information gap: fertility rate and use of cesarean delivery and tocolytic hospitalizations in Taiwan.

    Science.gov (United States)

    Ma, Ke-Zong M; Norton, Edward C; Lee, Shoou-Yih D

    2011-12-12

    Physician-induced demand (PID) is an important theory to test given the longstanding controversy surrounding it. Empirical health economists have been challenged to find natural experiments to test the theory because PID is tantamount to strong income effects. The data requirements are both a strong exogenous change in income and two types of treatment that are substitutes but have different net revenues. The theory implies that an exogenous fall in income would lead physicians to recoup their income by substituting a more expensive treatment for a less expensive treatment. This study takes advantages of the dramatic decline in the Taiwanese fertility rate to examine whether an exogenous and negative income shock to obstetricians and gynecologists (ob/gyns) affected the use of c-sections, which has a higher reimbursement rate than vaginal delivery under Taiwan's National Health Insurance system during the study period, and tocolytic hospitalizations. The primary data were obtained from the 1996 to 2004 National Health Insurance Research Database in Taiwan. We hypothesized that a negative income shock to ob/gyns would cause them to provide more c-sections and tocolytic hospitalizations to less medically-informed pregnant women. Multinomial probit and probit models were estimated and the marginal effects of the interaction term were conducted to estimate the impacts of ob/gyn to birth ratio and the information gap. Our results showed that a decline in fertility did not lead ob/gyns to supply more c-sections to less medically-informed pregnant women, and that during fertility decline ob/gyns may supply more tocolytic hospitalizations to compensate their income loss, regardless of pregnant women's access to health information. The exogenous decline in the Taiwanese fertility rate and the use of detailed medical information and demographic attributes of pregnant women allowed us to avoid the endogeneity problem that threatened the validity of prior research. They also

  14. Efficient kinetic Monte Carlo method for reaction-diffusion problems with spatially varying annihilation rates

    Science.gov (United States)

    Schwarz, Karsten; Rieger, Heiko

    2013-03-01

    We present an efficient Monte Carlo method to simulate reaction-diffusion processes with spatially varying particle annihilation or transformation rates as it occurs for instance in the context of motor-driven intracellular transport. Like Green's function reaction dynamics and first-passage time methods, our algorithm avoids small diffusive hops by propagating sufficiently distant particles in large hops to the boundaries of protective domains. Since for spatially varying annihilation or transformation rates the single particle diffusion propagator is not known analytically, we present an algorithm that generates efficiently either particle displacements or annihilations with the correct statistics, as we prove rigorously. The numerical efficiency of the algorithm is demonstrated with an illustrative example.

  15. Estimation of exponential convergence rate and exponential stability for neural networks with time-varying delay

    International Nuclear Information System (INIS)

    Tu Fenghua; Liao Xiaofeng

    2005-01-01

    We study the problem of estimating the exponential convergence rate and exponential stability for neural networks with time-varying delay. Some criteria for exponential stability are derived by using the linear matrix inequality (LMI) approach. They are less conservative than the existing ones. Some analytical methods are employed to investigate the bounds on the interconnection matrix and activation functions so that the systems are exponentially stable

  16. Reduced rates of controlled-release fertilizer lower potential nitrogen leaching from a Wisconsin bare-root tree nursery

    Science.gov (United States)

    Ryosuke Fujinuma; Nick J. Balster; Hyung-Kyung. Lee

    2011-01-01

    Controlled-release fertilizer (CRF) typically increases nitrogen (N) fertilizer uptake and lowers N lost from the rooting zone via leaching. However, questions remain as to whether lower rates of CRF could further increase this efficiency, especially in sandy bare-root nurseries in Wisconsin. We hypothesized that: 1) a reduced CRF application at 60 percent of the...

  17. Structure/property relations of aluminum under varying rates and stress states

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, Matthew T [Los Alamos National Laboratory; Horstemeyer, Mark F [MISSISSIPPI STATE UNIV; Whittington, Wilburn R [MISSISSIPPI STATE UNIV; Solanki, Kiran N [MISSISSIPPI STATE UNIV.

    2010-11-19

    In this work we analyze the plasticity, damage, and fracture characteristics of three different processed aluminum alloys (rolled 5083-H13, cast A356-T6, and extruded 6061-T6) under varying stress states (tension, compression, and torsion) and strain rates (0.001/, 1/s., and 1000/s). The stress state difference had more of a flow stress effect than the applied strain rates for those given in this study (0.001/sec up to 1000/sec). The stress state and strain rate also had a profound effect on the damage evolution of each aluminum alloy. Tension and torsional straining gave much greater damage nucleation rates than compression. Although the damage of all three alloys was found to be void nucleation dominated, the A356-T6 and 5083-H131 aluminum alloys incurred void damage via micron scale particles where the 6061-T6 aluminum alloy incurred void damage from two scales, micron-scale particles and nanoscale precipitates. Having two length scales of particles that participated in the damage evolution made the 6061-T6 incur a strain rate sensitive damage rate that was different than the other two aluminum alloys. Under tension, as the strain rate increased, the 6061-T6 aluminum alloy's void nucleation rate decreased, but the A356-T6 and 5083-H131 aluminum alloys void nucleation rate increased.

  18. Rate of solidification of aluminium casting in varying wall thickness of cylindrical metallic moulds

    Directory of Open Access Journals (Sweden)

    Katsina Christopher BALA

    2014-02-01

    Full Text Available The quality of final casting mainly depends on the rate of solidification as rapid solidification produces fine grains structures with better mechanical properties. The analysis of heat transfer during the casting and solidification of aluminium alloy as well as the experimental investigation of the rate of solidification in varying thicknesses of cylindrical metallic mould was carried out. The temperature variation with time of the casting was recorded from which cooling curves were obtained for the determination of solidification time of the cast. The results showed that as the cylindrical mould thickness increases the solidification time decreases due to the chilling effect of the mould.

  19. Big bang nucleosynthesis with a varying fine structure constant and nonstandard expansion rate

    International Nuclear Information System (INIS)

    Ichikawa, Kazuhide; Kawasaki, Masahiro

    2004-01-01

    We calculate the primordial abundances of light elements produced during big bang nucleosynthesis when the fine structure constant and/or the cosmic expansion rate take nonstandard values. We compare them with the recent values of observed D, 4 He, and 7 Li abundances, which show a slight inconsistency among themselves in the standard big bang nucleosynthesis scenario. This inconsistency is not solved by considering either a varying fine structure constant or a nonstandard expansion rate separately but solutions are found by their simultaneous existence

  20. Effect of Irrigation Methods, Nitrogen and Phosphorus Fertilizer Rates on Sugar Beet Yield and Quality

    International Nuclear Information System (INIS)

    Janat, M.; Abudlkareem, J.

    2007-01-01

    The experiment was conducted at a research station near Adlib. Two irrigation methods, sprinkler irrigation and drip fertigation, two phosphorus rates and four nitrogen rates 0, 70, 140 and 210 kg N/ha were tested. All N fertilizers were injected for drip irrigation or broadcasted for the sprinkler-irrigated treatments in six equally split applications. Neutron probe Results revealed that the introduction of drip fertigation was not proved to be a water saving relative to sprinkler irrigation. Dry matter production was slightly increased for the drip-fertigated treatments relative to sprinkler irrigated treatments. Nitrogen use efficiency was not improved under drip fertigation relative to that of sprinkler irrigation. Application of phosphorus fertilizer improved sugar beet yield as well as N uptake. No significant differences in sugar beet yield were observed due to the application of N fertilizer under drip fertigation. On the other hand, there was a trend toward increasing sugar beet yield grown under sprinkler irrigation. Drip fertigation had no negative effects on sugar content and other related properties, furthermore some of those properties were enhanced due to the employment of drip fertigation. Field water-use efficiency followed a similar trend and was increased under sprinkler irrigation relative to drip-fertigation for sugar beet yield parameter.

  1. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory

    OpenAIRE

    John A. D. Appleby

    2010-01-01

    We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. ...

  2. Changing maternity leave policy: short-term effects on fertility rates and demographic variables in Germany.

    Science.gov (United States)

    Thyrian, Jochen René; Fendrich, Konstanze; Lange, Anja; Haas, Johannes-Peter; Zygmunt, Marek; Hoffmann, Wolfgang

    2010-08-01

    Changes in reproductive behaviour and decreasing fertility rates have recently led to policy actions that attempt to counteract these developments. Evidence on the efficacy of such policy interventions, however, is limited. The present analysis examines fertility rates and demographic variables of a population in Germany in response to new maternity leave regulations, which were introduced in January 2007. As part of a population-based survey of neonates in Pomerania (SNiP), all births in the study region from the period 23 months prior to January 1st, 2007 until 23 months afterwards were examined. Crude Birth Rates (CBR) per month, General Fertility Rates (GFR) per month, parity and sociodemographic variables were compared using bivariate techniques. Logistic regression analysis was performed. No statistically significant difference in the CBR or GFR after Jan. 1st, 2007 was found. There were statistically significant differences in other demographic variables, however. The proportion of mothers who (a) were employed full-time before pregnancy; (b) came from a higher socioeconomic status; and (c) had higher income levels all increased after January 1st, 2007. The magnitude of these effects was higher in multigravid women. Forward stepwise logistic regression found an odds ratio of 1.79 for women with a family income of more than 3000 euro to give birth after the new law was introduced. This is the first analysis of population-based data that examines fertility rates and sociodemographic variables in response to new legal regulations. No short-term effects on birth rates were detected, but there was a differential effect on the subgroup of multigravidae. The focus of this policy was to provide financial support, which is certainly important, but the complexity of having a child suggests that attitudinal and motivational aspects also need to be taken into account. Furthermore, these analyses were only able to evaluate the short-term consequences of the policy

  3. Inequality in fertility rate and modern contraceptive use among Ghanaian women from 1988–2008

    Science.gov (United States)

    2013-01-01

    Background In most resource poor countries, particularly sub-Saharan Africa, modern contraceptive use and prevalence is unusually low and fertility is very high resulting in rapid population growth and high maternal mortality and morbidity. Current evidence shows slow progress in expanding the use of contraceptives by women of low socioeconomic status and insufficient financial commitment to family planning programs. We examined gaps and trends in modern contraceptive use and fertility within different socio-demographic subgroups in Ghana between 1988 and 2008. Methods We constructed a database using the Women’s Questionnaire from the Ghana Demographic and Health Survey (GDHS) 1988, 1993, 1998, 2003 and 2008. We applied regression-based Total Attributable Fraction (TAF); we also calculated the Relative and Slope Indices of Inequality (RII and SII) to complement the TAF in our investigation. Results Equality in use of modern contraceptives increased from 1988 to 2008. In contrast, inequality in fertility rate increased from 1988 to 2008. It was also found that rural–urban residence gap in the use of modern contraceptive methods had almost disappeared in 2008, while education and income related inequalities remained. Conclusions One obvious observation is that the discrepancy between equality in use of contraceptives and equality in fertility must be addressed in a future revision of policies related to family planning. Otherwise this could be a major obstacle for attaining further progress in achieving the Millennium Development Goal (MDG) 5. More research into the causes of the unfortunate discrepancy is urgently needed. There still exist significant education and income related inequalities in both parameters that need appropriate action. PMID:23718745

  4. Inequality in fertility rate and modern contraceptive use among Ghanaian women from 1988-2008.

    Science.gov (United States)

    Asamoah, Benedict O; Agardh, Anette; Ostergren, Per-Östergren

    2013-05-29

    In most resource poor countries, particularly sub-Saharan Africa, modern contraceptive use and prevalence is unusually low and fertility is very high resulting in rapid population growth and high maternal mortality and morbidity. Current evidence shows slow progress in expanding the use of contraceptives by women of low socioeconomic status and insufficient financial commitment to family planning programs. We examined gaps and trends in modern contraceptive use and fertility within different socio-demographic subgroups in Ghana between 1988 and 2008. We constructed a database using the Women's Questionnaire from the Ghana Demographic and Health Survey (GDHS) 1988, 1993, 1998, 2003 and 2008. We applied regression-based Total Attributable Fraction (TAF); we also calculated the Relative and Slope Indices of Inequality (RII and SII) to complement the TAF in our investigation. Equality in use of modern contraceptives increased from 1988 to 2008. In contrast, inequality in fertility rate increased from 1988 to 2008. It was also found that rural-urban residence gap in the use of modern contraceptive methods had almost disappeared in 2008, while education and income related inequalities remained. One obvious observation is that the discrepancy between equality in use of contraceptives and equality in fertility must be addressed in a future revision of policies related to family planning. Otherwise this could be a major obstacle for attaining further progress in achieving the Millennium Development Goal (MDG) 5. More research into the causes of the unfortunate discrepancy is urgently needed. There still exist significant education and income related inequalities in both parameters that need appropriate action.

  5. Methods for innovation : the varying role of industrial research in DSM's nitrogen fertilizer business, 1925-1970

    NARCIS (Netherlands)

    Rooij, van J.W.

    2007-01-01

    In this article the varying methods firms use to innovate are central in an attempt to balance our understanding of innovation processes. Often, research-driven innovation attracts the most attention, obscuring the contributions of other company functions and of external technology. In this article,

  6. Short communication. Estimation of cross-fertilization rate in safflower (Carthamus tinctorius L.)

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, L.; Fischer, M.; Fernandez-Martinez, J. M.

    2012-11-01

    Safflower is a promising oilseed crop for the production of specialty oils in the Mediterranean area. Oil quality traits such as high oleic acid content, high linoleic acid content, high saturated fatty acid content, or high gamma-tocopherol content have been developed in this crop. The traits are controlled by the genotype of the developing embryo and therefore they are influenced by the presence of foreign pollen. The objective of this research was to study the rate of cross-fertilization in safflower using the high oleic acid trait as a biochemical marker. An experiment in which each high oleic plant was surrounded by 24 low oleic acid plants was conducted over three environments in the same location at Cordoba, Spain. The average rate of cross-fertilization in the three environments was 5.7, 12.1, and 13.2%, though higher frequencies up to 35.9% were detected at the single-plant level and up to 58.3% at the single-head level. The low average out crossing frequencies identified in this research indicate no need for large isolation distances between conventional cultivars and cultivars with special oil characteristics. However, the occurrence of a significant out crossing rate should be taken into consideration if transgenic safflower is to be cultivated close to conventional safflower or in areas of distribution of wild Carthamus species. (Author) 21 refs.

  7. On the link between oil price and exchange rate: A time-varying VAR parameter approach

    International Nuclear Information System (INIS)

    Bremond, Vincent; Razafindrabe, Tovonony; Hache, Emmanuel

    2015-07-01

    The aim of this paper is to study the relationship between the effective exchange rate of the dollar and the oil price dynamics from 1976 to 2013. In this context, we propose to explore the economic literature dedicated to financial channels factors (exchange rate, monetary policy, and international liquidity) that could affect the oil price dynamics. In addition to oil prices and the effective exchange rate of the dollar, we use the dry cargo index as a proxy for the real economic activity and prices for precious and industrial raw materials. Using a Bayesian time-varying parameter vector auto-regressive estimation, our main results show that the US Dollar effective exchange rate elasticity of the crude oil prices is not constant across the time and remains negative from 1989. It then highlights that a depreciation of the effective exchange rate of the dollar leads to an increase of the crude oil prices. Our paper also demonstrates the growing influence of financial and commodities markets development upon the global economy. (authors)

  8. Hybrid Structure White Organic Light Emitting Diode for Enhanced Efficiency by Varied Doping Rate.

    Science.gov (United States)

    Kim, Dong-Eun; Kang, Min-Jae; Park, Gwang-Ryeol; Kim, Nam-Kyu; Lee, Burm-Jong; Kwon, Young-Soo; Shin, Hoon-Kyu

    2016-03-01

    Novel materials based on Zn(HPB)2 and Ir-complexes were synthesized as blue or red emitters, respectively. White organic light emitting diodes were fabricated using the Zn(HPB)2 as a blue emitting layer, Ir-complexes as a red emitting layer and Alq3 as a green emitting layer. The obtained experimental results, were based on white OLEDs fabricated using double emission layers of Zn(HPB)2 and Alq3:Ir-complexes. The doping rate of the Ir-complexes was varied at 0.4%, 0.6%, 0.8% and 1.0%. When the doping rate of the Alq3:Ir-complexes was 0.6%, a white emission was achieved. The Commission Internationale de l'Eclairage coordinates of the device's white emission were (0.316, 0.331) at an applied voltage of 10.75 V.

  9. Complication rates of ostomy surgery are high and vary significantly between hospitals.

    Science.gov (United States)

    Sheetz, Kyle H; Waits, Seth A; Krell, Robert W; Morris, Arden M; Englesbe, Michael J; Mullard, Andrew; Campbell, Darrell A; Hendren, Samantha

    2014-05-01

    Ostomy surgery is common and has traditionally been associated with high rates of morbidity and mortality, suggesting an important target for quality improvement. The purpose of this work was to evaluate the variation in outcomes after ostomy creation surgery within Michigan to identify targets for quality improvement. This was a retrospective cohort study. The study took place within the 34-hospital Michigan Surgical Quality Collaborative. Patients included were those undergoing ostomy creation surgery between 2006 and 2011. We evaluated hospital morbidity and mortality rates after risk adjustment (age, comorbidities, emergency vs elective, and procedure type). A total of 4250 patients underwent ostomy creation surgery; 3866 procedures (91.0%) were open and 384 (9.0%) were laparoscopic. Unadjusted morbidity and mortality rates were 43.9% and 10.7%. Unadjusted morbidity rates for specific procedures ranged from 32.7% for ostomy-creation-only procedures to 47.8% for Hartmann procedures. Risk-adjusted morbidity rates varied significantly between hospitals, ranging from 31.2% (95% CI, 18.4-43.9) to 60.8% (95% CI, 48.9-72.6). There were 5 statistically significant high-outlier hospitals and 3 statistically significant low-outlier hospitals for risk-adjusted morbidity. The pattern of complication types was similar between high- and low-outlier hospitals. Case volume, operative duration, and use of laparoscopic surgery did not explain the variation in morbidity rates across hospitals. This work was limited by its retrospective study design, by unmeasured variation in case severity, and by our inability to differentiate between colostomies and ileostomies because of the use of Current Procedural Terminology codes. Morbidity and mortality rates for modern ostomy surgery are high. Although this type of surgery has received little attention in healthcare policy, these data reveal that it is both common and uncommonly morbid. Variation in hospital performance provides an

  10. Efficacy of Standardized Nursing Fertility Counseling on Sperm Banking Rates in Cancer Patients.

    Science.gov (United States)

    Rotker, Katherine; Vigneswaran, Hari; Omil-Lima, Danly; Sigman, Mark; Hwang, Kathleen

    2017-06-01

    To examine the effect of brief nurse counseling on sperm banking rates among patients prior to initiating chemotherapy. A retrospective chart review was performed for men aged 18-50 with newly diagnosed cancer, from 1998 to 2003, prior to initiation of chemotherapy. A standardized nursing education session including brief fertility counseling was implemented at one institution in 2008 (Institution A). Rates of sperm banking among patients who received counseling were compared to those without counseling at institution A and to those at institution B where a counseling program was never initiated. A total of 766 male patients, 402 treated at institution A and 364 at institution B, were included. At institution A, sperm banking rates prior to 2008 were 6.4% and 8.3% after 2008 for those who did not receive counseling. The rate of sperm banking for those patients who did receive counseling was significantly higher at 17.6% (P = .002). The odds of banking increased 2.9 times for those who received counseling compared to those who did not (P = .003). At institution B, where counseling was never initiated, rates of banking remained low before and after 2008. Additional analysis revealed that younger patients and those patients who did not have children were more likely to perform sperm banking. The rates of sperm banking among cancer patients increased with the receipt of a brief, formalized nurse counseling session prior to initiation of chemotherapy. These findings may validate the use of a formalized fertility counseling prior to initiation of chemotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Meta-analytic methods for pooling rates when follow-up duration varies: a case study

    Directory of Open Access Journals (Sweden)

    Wolf Fredric M

    2004-07-01

    Full Text Available Abstract Background Meta-analysis can be used to pool rate measures across studies, but challenges arise when follow-up duration varies. Our objective was to compare different statistical approaches for pooling count data of varying follow-up times in terms of estimates of effect, precision, and clinical interpretability. Methods We examined data from a published Cochrane Review of asthma self-management education in children. We selected two rate measures with the largest number of contributing studies: school absences and emergency room (ER visits. We estimated fixed- and random-effects standardized weighted mean differences (SMD, stratified incidence rate differences (IRD, and stratified incidence rate ratios (IRR. We also fit Poisson regression models, which allowed for further adjustment for clustering by study. Results For both outcomes, all methods gave qualitatively similar estimates of effect in favor of the intervention. For school absences, SMD showed modest results in favor of the intervention (SMD -0.14, 95% CI -0.23 to -0.04. IRD implied that the intervention reduced school absences by 1.8 days per year (IRD -0.15 days/child-month, 95% CI -0.19 to -0.11, while IRR suggested a 14% reduction in absences (IRR 0.86, 95% CI 0.83 to 0.90. For ER visits, SMD showed a modest benefit in favor of the intervention (SMD -0.27, 95% CI: -0.45 to -0.09. IRD implied that the intervention reduced ER visits by 1 visit every 2 years (IRD -0.04 visits/child-month, 95% CI: -0.05 to -0.03, while IRR suggested a 34% reduction in ER visits (IRR 0.66, 95% CI 0.59 to 0.74. In Poisson models, adjustment for clustering lowered the precision of the estimates relative to stratified IRR results. For ER visits but not school absences, failure to incorporate study indicators resulted in a different estimate of effect (unadjusted IRR 0.77, 95% CI 0.59 to 0.99. Conclusions Choice of method among the ones presented had little effect on inference but affected the

  12. Meta-analytic methods for pooling rates when follow-up duration varies: a case study.

    Science.gov (United States)

    Guevara, James P; Berlin, Jesse A; Wolf, Fredric M

    2004-07-12

    Meta-analysis can be used to pool rate measures across studies, but challenges arise when follow-up duration varies. Our objective was to compare different statistical approaches for pooling count data of varying follow-up times in terms of estimates of effect, precision, and clinical interpretability. We examined data from a published Cochrane Review of asthma self-management education in children. We selected two rate measures with the largest number of contributing studies: school absences and emergency room (ER) visits. We estimated fixed- and random-effects standardized weighted mean differences (SMD), stratified incidence rate differences (IRD), and stratified incidence rate ratios (IRR). We also fit Poisson regression models, which allowed for further adjustment for clustering by study. For both outcomes, all methods gave qualitatively similar estimates of effect in favor of the intervention. For school absences, SMD showed modest results in favor of the intervention (SMD -0.14, 95% CI -0.23 to -0.04). IRD implied that the intervention reduced school absences by 1.8 days per year (IRD -0.15 days/child-month, 95% CI -0.19 to -0.11), while IRR suggested a 14% reduction in absences (IRR 0.86, 95% CI 0.83 to 0.90). For ER visits, SMD showed a modest benefit in favor of the intervention (SMD -0.27, 95% CI: -0.45 to -0.09). IRD implied that the intervention reduced ER visits by 1 visit every 2 years (IRD -0.04 visits/child-month, 95% CI: -0.05 to -0.03), while IRR suggested a 34% reduction in ER visits (IRR 0.66, 95% CI 0.59 to 0.74). In Poisson models, adjustment for clustering lowered the precision of the estimates relative to stratified IRR results. For ER visits but not school absences, failure to incorporate study indicators resulted in a different estimate of effect (unadjusted IRR 0.77, 95% CI 0.59 to 0.99). Choice of method among the ones presented had little effect on inference but affected the clinical interpretability of the findings. Incidence rate

  13. Women, Demography, and Politics: How Lower Fertility Rates Lead to Democracy.

    Science.gov (United States)

    Sommer, Udi

    2018-04-01

    Where connections between demography and politics are examined in the literature, it is largely in the context of the effects of male aspects of demography on phenomena such as political violence. This project aims to place the study of demographic variables' influence on politics, particularly on democracy, squarely within the scope of political and social sciences, and to focus on the effects of woman-related demographics-namely, fertility rate. I test the hypothesis that demographic variables-female-related predictors, in particular-have an independent effect on political structure. Comparing countries over time, this study finds a growth in democracy when fertility rates decline. In the theoretical framework developed, it is family structure as well as the economic and political status of women that account for this change at the macro and micro levels. Findings based on data for more than 140 countries over three decades are robust when controlling not only for alternative effects but also for reverse causality and data limitations.

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

    Science.gov (United States)

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

    2017-04-06

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

  15. Precision for Smallholder Farmers: A Small-Scale-Tailored Variable Rate Fertilizer Application Kit

    Directory of Open Access Journals (Sweden)

    Jelle Van Loon

    2018-03-01

    Full Text Available Precision agriculture technology at the hands of smallholder farmers in the developing world is often deemed far-fetched. Low-resource farmers, however, are the most susceptible to negative changes in the environment. Providing these farmers with the right tools to mitigate adversity and to gain greater control of the production process could unlock their potential and support rural communities to meet the increasing global food demand. In this study, a real-time variable rate fertilizer application system was developed and tested as an add-on kit to conventional farm machinery. In the context of low investment costs for smallholder farmers, high user-friendliness and easy installment were the main concerns for the system to be viable. The system used nitrogen (N-sensors to assess the plant nutrient status on the spot and subsequently adjust the amount of fertilizer deposited according to the plant’s needs. Test bench trials showed that the add-on kit performed well with basic operations, but more precision is required. Variability between N-sensors and metering systems, combined with power fluctuations, created inaccuracies in the resulting application rate. Nevertheless, this work is a stepping stone towards catalyzing the elaboration of more cutting-edge precision solutions to support small-scale farmers to become successful, high producing agro-entrepreneurs.

  16. Effect of Bio-fertilizers in Combination with Different Rates of Chemical Fertilizers on the Growth Characters and Sepals Yield of Roselle (Hibiscus sabdariffa L.

    Directory of Open Access Journals (Sweden)

    roghayeh mohammadpour vashvaei

    2017-10-01

    Full Text Available Roselle or Maki tea (Hibiscus sabdariffa L. is a subtropical medicinal and aromatic plant belongs to the family Malvaceae that sepals of it's due to its medicinal properties and culinary uses. To evaluate the effect of bio-fertilizers in combination with different rates of chemical fertilizers on the growth characters, sepals yield and yield components of roselle, an experiment was conducted in randomized coplete block design with three replications, at the Research Station in Zabol University, during 2012 and 2013. Experimental treatments were plant nutrition with NPK, biophosphate, biophosphate+25% NPK, biophosphate+50% NPK, biophosphate+ 100% NPK, nitroxin, nitroxin+25%NPK, nitroxin+50%NPK, nitroxin+100%NPK, nitroxin+biophosphate, nitroxin+ biophosphate+25% NPK, nitroxin+biophosphate+50% NPK, nitroxin+biophosphate+100% NPK and control (non-use of any fertilizer. Plant traits such as plant height, no. of branches.plant-1, fresh and dry weight of vegetative, roots fresh and dry weight, calyx no.plant-1, sepal dry weight, sepals yield of roselle were measured. The results of combined analysis of variance showed that the effect of fertilizer were significant (P≤0.01 for all studied traits. Calyx no.plant-1 was the most important component in determining the sepals yield. The highest of all studied triates belong to nitroxin+biophosphate+100% NPK treatment that its difference with nitroxin+ biophosphate+50% NPK treatment was not significant. Thus, with respect to the production of medicinal plants in cropping systems and attention to the cultivation of these plants in low input systems, to improve plant growth and increase the sepals yield of roselle, 50% of the recommended dose of fertilizers with bio-fertilizers is recommended.

  17. Association of high fetuin-B concentrations in serum with fertilization rate in IVF: a cross-sectional pilot study.

    Science.gov (United States)

    Floehr, Julia; Dietzel, Eileen; Neulen, Josef; Rösing, Benjamin; Weissenborn, Ute; Jahnen-Dechent, Willi

    2016-03-01

    Is serum fetuin-B associated with the fertilization rate in in vitro fertilization (IVF)? Serum fetuin-B increased during IVF cycles when oocytes could be fertilized while remained unchanged in fertilization failure. Fetuin-B deficiency in mice causes premature zona pellucida hardening mediated by the zona protease ovastacin. Thus fetuin-B deficiency renders females infertile. We determined the human serum fetuin-B reference range, studying longitudinally, over the course of one month, five male and seven female volunteers without hormone treatment and four female volunteers on varying hormonal contraception. We sampled blood and determined serum fetuin-B, luteinizing hormone (LH), estradiol (E2) and progesterone (P4). In addition, we determined serum fetuin-B and estradiol in eight women undergoing intracytoplasmatic sperm injection (ICSI, nine ICSI cycles) and 19 women undergoing IVF (21 IVF cycles) after ovarian stimulation with recombinant human follicular stimulating hormone (rFSH) and/or a combined medication of FSH and LH. At least three blood samples were analyzed in each cycle. We compared serum fetuin-B and follicular fluid fetuin-B in nine patients by measuring follicular fetuin-B in pooled follicular fluid, and in fluid obtained from individual follicles. Samples were drawn from January 2012 to March 2014. All volunteers and patients gave informed consent. Fetuin-B was measured employing a commercial sandwich enzyme-linked immunosorbent assay. Serum fetuin-B was determined as duplicates in 5 male (34 ± 14.6 years) and 11 female volunteers (29.4 ± 4.1 years) as well as in female volunteers on hormonal contraception (30.0 ± 6.5 years). The duplicate standard deviation was 4.0 ± 2.3%. The contraceptive drugs were mono or combined preparations containing 0-0.03 mg ethinyl estradiol, and 0.15-3.0 mg of various progestins. In addition, serum fetuin-B was determined as triplicates in 27 female patients undergoing conventional IVF (19) or ICSI (8). The

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

    Science.gov (United States)

    Avellaneda, Claudia N.; Dávalos, Eleonora

    2017-01-01

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

  19. Robust and Optimal Control of Magnetic Microparticles inside Fluidic Channels with Time-Varying Flow Rates

    Directory of Open Access Journals (Sweden)

    Islam S.M. Khalil

    2016-06-01

    Full Text Available Targeted therapy using magnetic microparticles and nanoparticles has the potential to mitigate the negative side-effects associated with conventional medical treatment. Major technological challenges still need to be addressed in order to translate these particles into in vivo applications. For example, magnetic particles need to be navigated controllably in vessels against flowing streams of body fluid. This paper describes the motion control of paramagnetic microparticles in the flowing streams of fluidic channels with time-varying flow rates (maximum flow is 35 ml.hr−1. This control is designed using a magnetic-based proportional-derivative (PD control system to compensate for the time-varying flow inside the channels (with width and depth of 2 mm and 1.5 mm, respectively. First, we achieve point-to-point motion control against and along flow rates of 4 ml.hr−1, 6 ml.hr−1, 17 ml.hr−1, and 35 ml.hr−1. The average speeds of single microparticle (with average diameter of 100 μm against flow rates of 6 ml.hr−1 and 30 ml.hr−1 are calculated to be 45 μm.s−1 and 15 μm.s−1, respectively. Second, we implement PD control with disturbance estimation and compensation. This control decreases the steady-state error by 50%, 70%, 73%, and 78% at flow rates of 4 ml.hr−1, 6 ml.hr−1, 17 ml.hr−1, and 35 ml.hr−1, respectively. Finally, we consider the problem of finding the optimal path (minimal kinetic energy between two points using calculus of variation, against the mentioned flow rates. Not only do we find that an optimal path between two collinear points with the direction of maximum flow (middle of the fluidic channel decreases the rise time of the microparticles, but we also decrease the input current that is supplied to the electromagnetic coils by minimizing the kinetic energy of the microparticles, compared to a PD control with disturbance compensation.

  20. Spatially varying predictors of teenage birth rates among counties in the United States

    Directory of Open Access Journals (Sweden)

    Carla Shoff

    2012-09-01

    Full Text Available BACKGROUND Limited information is available about teenage pregnancy and childbearing in rural areas, even though approximately 20 percent of the nation's youth live in rural areas. Identifying whether there are differences in the teenage birth rate (TBR across metropolitan and nonmetropolitan areas is important because these differences may reflect modifiable ecological-level influences such as education, employment, laws, healthcare infrastructure, and policies that could potentially reduce the TBR. OBJECTIVE The goals of this study are to investigate whether there are spatially varying relationships between the TBR and the independent variables, and if so, whether these associations differ between metropolitan and nonmetropolitan counties. METHODS We explore the heterogeneity within metropolitan/nonmetropolitan county groups separately using geographically weighted regression (GWR, and investigate the difference between metropolitan/nonmetropolitan counties using spatial regime models with spatial errors. These analyses were applied to county-level data from the National Center for Health Statistics and the US Census Bureau. RESULTS GWR results suggested that non-stationarity exists in the associations between TBR and determinants within metropolitan/nonmetropolitan groups. The spatial regime analysis indicated that the effect of socioeconomic disadvantage on TBR significantly varied by the metropolitan status of counties. CONCLUSIONS While the spatially varying relationships between the TBR and independent variables were found within each metropolitan status of counties, only the magnitude of the impact of the socioeconomic disadvantage index is significantly stronger among metropolitan counties than nonmetropolitan counties. Our findings suggested that place-specific policies for the disadvantaged groups in a county could be implemented to reduce TBR in the US.

  1. Probing background ionization: positive streamers with varying pulse repetition rate and with a radioactive admixture

    International Nuclear Information System (INIS)

    Nijdam, S; Van Veldhuizen, E M; Ebert, U; Wormeester, G

    2011-01-01

    Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive 85 Kr. We find that the general morphology of a positive streamer discharge in high-purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding 85 Kr, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.

  2. Estimation of time-varying growth, uptake and excretion rates from dynamic metabolomics data.

    Science.gov (United States)

    Cinquemani, Eugenio; Laroute, Valérie; Cocaign-Bousquet, Muriel; de Jong, Hidde; Ropers, Delphine

    2017-07-15

    Technological advances in metabolomics have made it possible to monitor the concentration of extracellular metabolites over time. From these data, it is possible to compute the rates of uptake and excretion of the metabolites by a growing cell population, providing precious information on the functioning of intracellular metabolism. The computation of the rate of these exchange reactions, however, is difficult to achieve in practice for a number of reasons, notably noisy measurements, correlations between the concentration profiles of the different extracellular metabolites, and discontinuties in the profiles due to sudden changes in metabolic regime. We present a method for precisely estimating time-varying uptake and excretion rates from time-series measurements of extracellular metabolite concentrations, specifically addressing all of the above issues. The estimation problem is formulated in a regularized Bayesian framework and solved by a combination of extended Kalman filtering and smoothing. The method is shown to improve upon methods based on spline smoothing of the data. Moreover, when applied to two actual datasets, the method recovers known features of overflow metabolism in Escherichia coli and Lactococcus lactis , and provides evidence for acetate uptake by L. lactis after glucose exhaustion. The results raise interesting perspectives for further work on rate estimation from measurements of intracellular metabolites. The Matlab code for the estimation method is available for download at https://team.inria.fr/ibis/rate-estimation-software/ , together with the datasets. eugenio.cinquemani@inria.fr. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  3. Impact of nitrogen rates on growth, yield and radiation use efficiency of maize under varying environments

    International Nuclear Information System (INIS)

    Khaliq, T.; Ahmad, A.; Hussain, A.

    2008-01-01

    Growth, yield and radiation use efficiency (RUE) of hybrid maize, in response to different nitrogen rates (150, 200, 250, 300, 350 kg ha/sub -1/ were analyzed for three different locations (Faisalabad, Sargodha and Sahiwal) in Punjab, Pakistan during 2004 and 2005. The results depicted a large yearly variations mainly attributed to more rainfall and incidence of solar radiation in 2005. Maize hybrids respond differently for all variable under study, at all sites except IPAR and radiation use efficiency 919 at different locations. Similar types of differences were noted in GGR and Final TOM. Increasing nitrogen rates had significant effects on CGR, final TOM and grain yield and RUE. The intercepted PAR, RUE/sub TDM/ and RUE/sub Gy/ were significantly affected by hybrid potential and nitrogen application rates. On an average RUE/sub TDM/ varied from 2.45 to 2.73 g MJ/sup -1/ at different locations, while RUE/sub Gy/ was recorded 1.12, 1.14 and 1.03 for Faisalabad, Sargodha and Sahiwal, respectively. Total dry matter and grain yield of different treatments was linearly related to IPAR at all location and the common regression (R/sup 2/) accounted for 94, 68, and 80 % for TDM and 64, 34, and 95% for grain yield at the Faisalabad, Sargodha and sahiwal, respectively. It was concluded that planting of hybrid Bemasal-202 with 300 kg N ha/sup -1/ is the best recommendation for semi-arid areas of Pakistan. (author)

  4. Family size preference and factors affecting the fertility rate in Hyogo, Japan.

    Science.gov (United States)

    Matsumoto, Yasuyo; Yamabe, Shingo

    2013-01-30

    Japan has consistently shown a low fertility rate, which has been lower than the replacement level since 1974, and represents one of the least fertile countries in the world. This study was designed to determine the family size preference of and its effect on Japanese women. We conducted a questionnaire survey among women who visited the obstetrics and gynecology department of 18 hospitals and clinics in the Hyogo Prefecture, Japan, between October 2011 and February 2012. All the women were categorized according to age group and area of residence, and the survey results were statistically analyzed using a t test. A total of 1616 women were included in this study. There was no significant difference between the mean desired and actual marital ages (26.70 and 26.67 years, respectively). The mean desired number of children was 2.55, which was significantly more than the mean actual number of children (1.77) in all generations. The mean desired and actual numbers of children were more in the rural areas (2.73 and 2.09, respectively) than in the urban (2.54 and 1.70, respectively) and semi-urban areas (2.49 and 1.60, respectively). The mean number of family members was significantly greater in the rural areas (3.84) than in the urban (3.25) and semi-urban areas (3.05).The most important concern among women who had never delivered a baby was childbearing itself, followed by the expenses related to pregnancy and childbearing. The family size preference of the women in our study was higher than the actual numbers of children. The fertility intentions were low among the younger women but high among those living in rural areas with larger families.

  5. On-line statistical processing of radiation detector pulse trains with time-varying count rates

    International Nuclear Information System (INIS)

    Apostolopoulos, G.

    2008-01-01

    Statistical analysis is of primary importance for the correct interpretation of nuclear measurements, due to the inherent random nature of radioactive decay processes. This paper discusses the application of statistical signal processing techniques to the random pulse trains generated by radiation detectors. The aims of the presented algorithms are: (i) continuous, on-line estimation of the underlying time-varying count rate θ(t) and its first-order derivative dθ/dt; (ii) detection of abrupt changes in both of these quantities and estimation of their new value after the change point. Maximum-likelihood techniques, based on the Poisson probability distribution, are employed for the on-line estimation of θ and dθ/dt. Detection of abrupt changes is achieved on the basis of the generalized likelihood ratio statistical test. The properties of the proposed algorithms are evaluated by extensive simulations and possible applications for on-line radiation monitoring are discussed

  6. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory

    Directory of Open Access Journals (Sweden)

    Appleby JohnAD

    2010-01-01

    Full Text Available We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. The result is considered both for a linear Volterra integrodifferential equation as well as for the delay logistic equation from population biology.

  7. Decomposition rate of organic fertilizers: effect on yield, nitrogen availability and nitrogen stock in the soil

    NARCIS (Netherlands)

    Opheusden, van A.H.M.; Burgt, van der G.J.H.M.; Rietberg, P.I.

    2012-01-01

    The nitrogen of organic fertilizers does not fully mineralize within a season, and hence will partly become available in later years. This effect is taken into account for the first year but generally not in later fertilizer applications. If it would be taken into account, fertilizer use could be

  8. Garlic essential oil increases rates of eggs fertilization and hatching of Rhamdia quelen larvae in an artificial incubation system

    Directory of Open Access Journals (Sweden)

    Nilton Garcia Marengoni

    Full Text Available ABSTRACT: The objective of this study was to evaluate the effects of garlic (Allium sativum essential oil on the rates of eggs fertilization and hatching and on the normal development of larvae of artificially incubated silver catfish (Rhamdia quelen. The experiment was carried out using a completely randomized experimental design with four treatments and five replicates. The treatments consisted of introducing garlic essential oil into the incubators, which used a closed system of water recirculation, at concentrations of 0, 1, 3, and 5mg L-1. Rates of eggs fertilization and larval hatching were determined at 10 and 24h after the beginning of eggs hydration. Morphology of larvae was assessed with the aid of a stereo microscope to determine the rate of normal development. The concentration of 5mg L-1 promoted better rates of eggs fertilization and larval hatching. Concentrations of garlic essential oil had a linear effect on eggs fertilization rates and larval hatching. Garlic oil did not influence the morphology of the larvae (P>0.05. It is recommended to use 5mg L-1 of garlic essential oil to promote better rates of eggs fertilization and larval hatching of artificially incubated silver catfish.

  9. Maize dry matter production and macronutrient extraction model as a new approach for fertilizer rate estimation

    Directory of Open Access Journals (Sweden)

    KARLA V. MARTINS

    Full Text Available ABSTRACT Decision support for nutrient application remains an enigma if based on soil nutrient analysis. If the crop could be used as an auxiliary indicator, the plant nutrient status during different growth stages could complement the soil test, improving the fertilizer recommendation. Nutrient absorption and partitioning in the plant are here studied and described with mathematical models. The objective of this study considers the temporal variation of the nutrient uptake rate, which should define crop needs as compared to the critical content in soil solution. A uniform maize crop was grown to observe dry matter accumulation and nutrient content in the plant. The dry matter accumulation followed a sigmoidal model and the macronutrient content a power model. The maximum nutrient absorption occurred at the R4 growth stage, for which the sap concentration was successfully calculated. It is hoped that this new approach of evaluating nutrient sap concentration will help to develop more rational ways to estimate crop fertilizer needs. This new approach has great potential for on-the-go crop sensor-based nutrient application methods and its sensitivity to soil tillage and management systems need to be examined in following studies. If mathematical model reflects management impact adequately, resources for experiments can be saved.

  10. Indoor measurement of photovoltaic device characteristics at varying irradiance, temperature and spectrum for energy rating

    International Nuclear Information System (INIS)

    Bliss, M; Betts, T R; Gottschalg, R

    2010-01-01

    The first three-dimensional performance matrix for use in photovoltaic (PV) energy rating is reported utilizing a novel energy rating solar simulator based on LEDs. Device characteristics are measured indoors at varying irradiance (G), temperature (T) and spectrum (E). This opens the possibility for a more accurate measurement system for energy yield prediction of PV devices, especially for devices with high spectral dependence such as wide bandgap solar cells as they take into account spectral changes in the light. The main aspects of the LED-based solar simulator used are briefly described. A measurement method is developed and detailed in the paper, which takes into account the current imperfections in the achievable spectrum. Measurement results for a crystalline silicon solar cell are used to demonstrate the measurement approach. An uncertainty analysis of the measurement system is given, resulting in an overall absolute uncertainty of 4.3% (coverage factor k = 2) in maximum power measurements at 765 W m −2 irradiance with scope for further improvements

  11. Soil Fertility and Electrical Conductivity Affected by Organic Waste Rates and Nutrient Inputs

    Directory of Open Access Journals (Sweden)

    Davi Lopes do Carmo

    2016-01-01

    Full Text Available ABSTRACT The composition of organic waste (OW and its effect on soil processes may change soil fertility and electrical conductivity (EC. The side effects of waste use in crop fertilization are poorly understood for Brazilian soils. This study examined the effect of the addition of 15 different organic wastes to Oxisols and a Neosol on pH, base saturation, EC, cation exchange capacity (CEC at pH 7, and the availability of Al, macro (P, K, Ca2+, Mg2+ and S and micronutrients (B, Fe2+, Mn2+, Cu2+ and Zn2+. Soil samples (150 g were treated with chicken, pig, horse, cattle, and quail manures, sewage sludge 1 and 2, eucalyptus sawdust, plant substrate, coconut fiber, pine bark, coffee husk, peat, limed compost, and biochar. Wastes were added considering a fixed amount of C (2 g kg-1, which resulted in waste rates ranging from 2.5 to 25.6 Mg ha-1. The soil-waste mixtures were incubated for 330 days in laboratory conditions. The waste liming or acidification values were soil-dependent. The use of some manures and compost increased the pH to levels above of those considered adequate for plant growth. The soil EC was slightly increased in the Neosol and in the medium textured Oxisol, but it was sharply changed (from 195 to 394 µS cm-1 by the addition of organic wastes in the clayey Oxisol, although the EC values were below the range considered safe for plant growth. Changes in the soil availability of P, K+, Ca2+ and Zn2+ were highly related to the inputs of these nutrients by the wastes, and other factors in soil changed due to waste use. Organic waste use simultaneously affects different soil fertility attributes; thus, in addition to the target nutrient added to the soil, the soil acidity buffering capacity and the waste liming and agronomic value must be taken into account in the waste rate definition.

  12. Efficiency of ammonium nitrate phosphates of varying water-soluble phosphorus content for rice and succeeding maize crop on contrasting soil types. [/sup 32/P-labelled fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Bhujbal, B M; Mistry, K B [Bhabha Atomic Research Centre, Bombay (India). Biology and Agriculture Div.; Chapke, V G; Mutatkar, V K [Fertilizer Corp. of India Ltd., Bombay

    1977-09-01

    Efficiency of ammonium nitrate phosphates (ANP) containing 30 and 50 percent of water-soluble phosphorus (W.S.P.) vis-a-vis that of entirely water-soluble monoammonium orthophosphate (MAP) for rice and succeeding maize crop on phosphate responsive laterite, red sandy loam (Chalka) and calcareous black soils was examined in greenhouse experiments. Data on dry matter yield, uptake of phosphorus, utilization of applied fertilizer, 'Effective Rate of Application' and 'Relative Efficiency percent' at flowering stage of rice indicated no significant differences between ammonium nitrate phosphate (30 percent and 50 percent water-soluble ohosphorus) and monoammonium orthophosphate (MAP) on laterits and natural red sandy loam soils. MAP was significantly superior to the two ANP fertilizers on calcareous black soil; no significant differences were observed between ANP (30 percent W.S.P.) and ANP (50 percent W.S.P.) on this soil. The succeeding maize crop grown up to flowering in the same pots indicated that the residual value of ANP (30 percent W.S.P.) was equal or superior to that of MAP on the laterits as well as calcareous black soil. No significant differences were detected between the residual values of the two water-solubility grades of ANP. Incubation under submerged conditions for periods upto 60 days showed that 0.5 M NaHCO/sub 3/ (pH 8.5) extractable phosphorus (plant-available phosphate) in the ANP (30 percent W.S.P.) treatment was, in general, equal to those in the MAP treatments in the laterite and red sandy loam but was significantly lower in the calcareous black soil. No marked differences were observed between the effects of the two ANP fertilizers.

  13. Response of winter rape (Brassica napus L. ssp. oleifera Metzg., Sinsk to foliar fertilization and different seeding rates

    Directory of Open Access Journals (Sweden)

    Cezary A. Kwiatkowski

    2012-12-01

    Full Text Available A field experiment in growing winter rape was carried out during the period 2009-2011 in a family farm (owned by Mr. M. Bednarczyk located in Jaroszewice (Lublin region, on podzolic soil. Plant biometric features as well as yield and seed qualitative parameters (oil, protein and glucosinolate content were evaluated depending on the following rates of soil NPK fertilizers and on foliar fertilization (autumn spraying with the fertilizer solution: 100% and 75% of NPK as well as urea + nickel chelate + MgSO4H2O; 100% and 75% of NPK as well as urea + Plonvit R + MgSO4H2O. Plots without foliar fertilization (only 100% of NPK were the control treatment. The other experimental factor was the seeding rate (2.5 kg×ha-1 – 30 cm row spacing; 4 kg×ha-1 – 18 cm row spacing. Foliar spraying was done once in the autumn in the second decade of October. Tillage as well as mechanical and chemical control of agricultural pests in the plantation were typical for this plant species and consistent with the recommendations for winter rape protection. A hypothesis was made that the application of foliar fertilizers would have a beneficial effect on winter rape productivity, at the same time maintaining the high quality of raw material. It was also assumed that a reduction in the seeding rate of winter oilseed rape would result in reduced plant lodging and an increased number of siliques per plant; as a consequence, seed and oil productivity would be at a level not lower than that obtained at the higher seeding rate. The present study has proved that foliar fertilization of winter oilseed rape in the autumn period contributes to improved plant winter hardiness and increased productivity. The application of foliar fertilizers also enables the rates of basic mineral NPK fertilizers to be reduced by 25% without detriment to seed yield. Foliar fertilizers have been found to have a weaker effect on changing the chemical composition of rapeseed. The study has shown that

  14. Soil water erosion under different cultivation systems and different fertilization rates and forms over 10 years

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2014-12-01

    Full Text Available The action of rain and surface runoff together are the active agents of water erosion, and further influences are the soil type, terrain, soil cover, soil management, and conservation practices. Soil water erosion is low in the no-tillage management system, being influenced by the amount and form of lime and fertilizer application to the soil, among other factors. The aim was to evaluate the effect of the form of liming, the quantity and management of fertilizer application on the soil and water losses by erosion under natural rainfall. The study was carried out between 2003 and 2013 on a Humic Dystrupept soil, with the following treatments: T1 - cultivation with liming and corrective fertilizer incorporated into the soil in the first year, and with 100 % annual maintenance fertilization of P and K; T2 - surface liming and corrective fertilization distributed over five years, and with 75 % annual maintenance fertilization of P and K; T3 - surface liming and corrective fertilization distributed over three years, and with 50 % annual maintenance fertilization of P and K; T4 - surface liming and corrective fertilization distributed over two years, and with 25 % annual maintenance fertilization of P and K; T5 - fallow soil, without liming or fertilization. In the rotation the crops black oat (Avena strigosa , soybean (Glycine max , common vetch (Vicia sativa , maize (Zea mays , fodder radish (Raphanus sativus , and black beans (Phaseolus vulgaris . The split application of lime and mineral fertilizer to the soil surface in a no-tillage system over three and five years, results in better control of soil losses than when split in two years. The increase in the amount of fertilizer applied to the soil surface under no-tillage cultivation increases phytomass production and reduces soil loss by water erosion. Water losses in treatments under no-tillage cultivation were low in all crop cycles, with a similar behavior as soil losses.

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

    Science.gov (United States)

    Meier, Elizabeth A; Thorburn, Peter J

    2016-01-01

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

  16. Long term sugarcane crop residue retention offers limited potential to reduce nitrogen fertilizer rates in Australian wet tropical environments

    Directory of Open Access Journals (Sweden)

    Elizabeth Anne Meier

    2016-07-01

    Full Text Available 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 yr after trash blanketing commenced. After this period, there was potential to

  17. Contrast and autoshaping in multiple schedules varying reinforcer rate and duration.

    Science.gov (United States)

    Hamilton, B E; Silberberg, A

    1978-07-01

    Thirteen master pigeons were exposed to multiple schedules in which reinforcement frequency (Experiment I) or duration (Experiment II) was varied. In Phases 1 and 3 of Experiment I, the values of the first and second components' random-interval schedules were 33 and 99 seconds, respectively. In Phase 2, these values were 99 seconds for both components. In Experiment II, a random-interval 33-second schedule was associated with each component. During Phases 1 and 3, the first and second components had hopper durations of 7.5 and 2.5 seconds respectively. During Phase 2, both components' hopper durations were 2.5 seconds. In each experiment, positive contrast obtained for about half the master subjects. The rest showed a rate increase in both components (positive induction). Each master subject's key colors and reinforcers were synchronously presented on a response-independent basis to a yoked control. Richer component key-pecking occurred during each experiment's Phases 1 and 3 among half these subjects. However, none responded during the contrast condition (unchanged component of each experiment's Phase 2). From this it is inferred that autoshaping did not contribute to the contrast and induction findings among master birds. Little evidence of local contrast (highest rate at beginning of richer component) was found in any subject. These data show that (a) contrast can occur independently from autoshaping, (b) contrast assays during equal-valued components may produce induction, (c) local contrast in multiple schedules often does not occur, and (d) differential hopper durations can produce autoshaping and contrast.

  18. Live-Birth Rate Associated With Repeat In Vitro Fertilization Treatment Cycles.

    Science.gov (United States)

    Smith, Andrew D A C; Tilling, Kate; Nelson, Scott M; Lawlor, Debbie A

    The likelihood of achieving a live birth with repeat in vitro fertilization (IVF) is unclear, yet treatment is commonly limited to 3 or 4 embryo transfers. To determine the live-birth rate per initiated ovarian stimulation IVF cycle and with repeated cycles. Prospective study of 156,947 UK women who received 257,398 IVF ovarian stimulation cycles between 2003 and 2010 and were followed up until June 2012. In vitro fertilization, with a cycle defined as an episode of ovarian stimulation and all subsequent separate fresh and frozen embryo transfers. Live-birth rate per IVF cycle and the cumulative live-birth rates across all cycles in all women and by age and treatment type. Optimal, prognosis-adjusted, and conservative cumulative live-birth rates were estimated, reflecting 0%, 30%, and 100%, respectively, of women who discontinued due to poor prognosis and having a live-birth rate of 0 had they continued. Among the 156,947 women, the median age at start of treatment was 35 years (interquartile range, 32-38; range, 18-55), and the median duration of infertility for all 257,398 cycles was 4 years (interquartile range, 2-6; range, cycle was 29.5% (95% CI, 29.3%-29.7%). This remained above 20% up to and including the fourth cycle. The cumulative prognosis-adjusted live-birth rate across all cycles continued to increase up to the ninth cycle, with 65.3% (95% CI, 64.8%-65.8%) of women achieving a live birth by the sixth cycle. In women younger than 40 years using their own oocytes, the live-birth rate for the first cycle was 32.3% (95% CI, 32.0%-32.5%) and remained above 20% up to and including the fourth cycle. Six cycles achieved a cumulative prognosis-adjusted live-birth rate of 68.4% (95% CI, 67.8%-68.9%). For women aged 40 to 42 years, the live-birth rate for the first cycle was 12.3% (95% CI, 11.8%-12.8%), with 6 cycles achieving a cumulative prognosis-adjusted live-birth rate of 31.5% (95% CI, 29.7%-33.3%). For women older than 42 years, all rates within each cycle

  19. Effectiveness of psychiatric and counseling interventions On fertility rate in infertile couples

    Directory of Open Access Journals (Sweden)

    Ramezanzadeh F.

    2007-10-01

    Full Text Available Background: Considering the psycho-social model of diseases, the aim of this study was to evaluate the effect of psychiatric intervention on the pregnancy rate of infertile couples.Methods: In a randomized clinical trial, 638 infertile patients referred to a university infertility clinic were evaluated. Among them, 140 couples with different levels of depression in at least one of the spouses were included in this substudy. These couples were divided randomly into two groups. The patients in the case group received 6-8 sessions of psychotherapy before starting infertility treatment and were given fluoxetine 20-60 mg per day during the same period. The control group did not receive any intervention. Three questionnaires including the Beck Depression Inventory (BDI, Holmes-Rahe stress scale and a socio-demographic questionnaire were applied for all patients. The clinical pregnancy rates of the two groups, based on sonographic detection of the gestational sac six weeks after LMP, were compared. The data were analyzed by paired-T test, T-test, χ2 and the logistic regression method. Results: The pregnancy rate was 47.1% in the case group and 7.1% in the control group. The pregnancy rate was significantly related to the duration and cause of infertility and the level of stress in both groups (p< 0.001. The pregnancy rate was shown to be higher in couples in which the male has a secondary level of education (p< 0.001.Conclusions: Psychiatric interventions greatly improve pregnancy rates, and it is therefore crucial to mandate psychiatric counseling in all fertility centers in order to diagnose and treat infertile patients with psychiatric disorders and help couples deal with stress.

  20. Increased pregnancy rate with use of the Clearblue Easy Fertility Monitor.

    Science.gov (United States)

    Robinson, Janet E; Wakelin, Melanie; Ellis, Jayne E

    2007-02-01

    To determine the effect on pregnancy rates through use of the Clearblue Easy Fertility Monitor (CEFM) in women trying to conceive. Prospective study, in which volunteers were randomly assigned either to use or not to use the CEFM. All participants could also use other aids to conception. Data were self-reported by volunteers using daily diaries, supplied and collected by mail. Home use, under conditions normally experienced by over-the-counter purchasers of the marketed device. Women who were trying to conceive; 653 (CEFM 305, control 348) provided evaluable information. CEFM was used for two cycles. Cumulative pregnancy rates over two cycles of use. The cumulative pregnancy rate for 2 cycles was significantly higher in the CEFM group (22.7%) compared with the control group (14.4%). More women who had been trying to conceive for conceive for >6 months (odds ratio: 2.67). Previous pregnancy and younger age of partners were also significant prognostic factors, but use of other aids to conception was not. After adjustment for other factors, CEFM use remained a significant factor affecting the chance of conceiving within two cycles (odds ratio: 1.89). CEFM users found the device to be easy/very easy to use (90%) and convenient/very convenient (80%). Use of the CEFM increases the likelihood of getting pregnant during the first two cycles of use compared with its nonuse, in women who had been trying to conceive for up to 2 years.

  1. [Fertility transition in Peru].

    Science.gov (United States)

    Ferrando, D; Aramburu, C E

    1992-12-01

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

  2. Establishment of Alleycropped Hybrid Aspen “Crandon” in Central Iowa, USA: Effects of Topographic Position and Fertilizer Rate on Aboveground Biomass Production and Allocation

    Directory of Open Access Journals (Sweden)

    Richard B. Hall

    2013-07-01

    Full Text Available Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC in the Midwest USA, and the hybrid aspen “Crandon” (Populus alba L. × P. grandidenta Michx. has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic returns early in the rotation. Alleycropping has the potential to address this issue, especially when paired with crops such as winter triticale which complete their growth cycle early in the summer and therefore are expected to exert minimal competition on establishing trees. In addition, well-placed fertilizer in low rates at planting has the potential to improve tree establishment and shorten the rotation, which is also economically desirable. To test the potential productivity of “Crandon” alleycropped with winter triticale, plots were established on five topographic positions with four different rates of fertilizer placed in the planting hole. Trees were then harvested from the plots after each of the first three growing seasons. Fertilization resulted in significant increases in branch, stem, and total aboveground biomass across all years, whereas the effects of topographic position varied by year. Allocation between branches and stems was found to be primarily a function of total aboveground biomass.

  3. Effect of endometrial cavity fluid on pregnancy rate of fresh versus frozen In Vitro fertilization cycle

    Directory of Open Access Journals (Sweden)

    Nitika Gupta

    2017-01-01

    Full Text Available Objective: This study aims to study the difference in etiology and outcome in terms of implantation rate and abortion rate in fresh (self-stimulated versus frozen (oocyte donation cycle in vitro fertilization (IVF and in transient versus persistent fluid. Material and Methods: This retrospective study was conducted in the Department of Reproductive Medicine of tertiary care center from January 2012 to November 2015. Data were collected retrospectively from the departmental files. Twenty-four patients from fresh IVF-stimulated cycles and 24 from frozen oocyte donation cycle with their endometrium prepared by hormone replacement treatment were included in the study. All patients selected in the study had grade-A embryo transfer of day 3–4 with maximum three embryo transferred. Pregnancy was defined by rising serum beta-human chorionic gonadotrophin levels performed after 14 days of embryo transfer and further confirmed by ultrasonographic visualization of gestational sac at 6 weeks. All biochemical pregnancies were included in implantation failure. All pregnant patients were followed till the termination of pregnancy and further noted as live birth or abortion. Results: Clinical pregnancy rate was seen more in self-stimulated cycle (62.5% with live birth rate of 50% than hormone replacement treatment cycle, in which clinical pregnancy rate was 45.83% with live birth rate of 33.33%. Clinical pregnancy rate was highest in group with very less fluid in cavity (1–2 mm 63% and with live birth of 52.63%. Clinical pregnancy was seen only in two patients of group B with anterior and posterior (AP diameter of fluid in cavity of 2–3 mm with live birth of only one, whereas in group C, with AP diameter of 3–5 mm, none of the patient conceived. This difference was statistically significant. Clinical pregnancy rate was 65.62% in transient fluid accumulation with live birth rate of 53.25%, which was significantly higher than persistent fluid accumulation

  4. An ICSI rate of 90% minimizes complete failed fertilization and provides satisfactory implantation rates without elevating fetal abnormalities.

    Science.gov (United States)

    Yovich, John L; Conceicao, Jason L; Marjanovich, Nicole; Ye, Yun; Hinchliffe, Peter M; Dhaliwal, Satvinder S; Keane, Kevin N

    2018-05-22

    IVF cycles utilizing the ICSI technique for fertilization have been rising over the 25 years since its introduction, with indications now extending beyond male factor infertility. We have performed ICSI for 87% of cases compared with the ANZARD average of 67%. This retrospective study reports on the outcomes of 1547 autologous ART treatments undertaken over a recent 3-year period. Based on various indications, cases were managed within 3 groupings - IVF Only, ICSI Only or IVF-ICSI Split insemination where oocytes were randomly allocated. Overall 567 pregnancies arose from mostly single embryo transfer procedures up to December 2016, with 402 live births, comprising 415 infants and a low fetal abnormality rate (1.9%) was recorded. When the data was adjusted for confounders such as maternal age, measures of ovarian reserve and sperm quality, it appeared that IVF-generated and ICSI-generated embryos had a similar chance of both pregnancy and live birth. In the IVF-ICSI Split model, significantly more ICSI-generated embryos were utilised (2.5 vs 1.8; p < 0.003) with productivity rates of 67.8% for pregnancy and 43.4% for livebirths per OPU for this group. We conclude that ART clinics should apply the insemination method which will maximize embryo numbers and the first treatment for unexplained infertility should be undertaken within the IVF-ICSI Split model. Whilst ICSI-generated pregnancies are reported to have a higher rate of fetal abnormalities, our data is consistent with the view that the finding is not due to the ICSI technique per se. Copyright © 2018 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  6. Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

    International Nuclear Information System (INIS)

    Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

    2004-01-01

    A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

  7. Impacts of long-term nitrogen fertilization on acid buffering rates and mechanisms of a slightly calcareous clay soil

    NARCIS (Netherlands)

    Zhang, Yuting; Vries, de Wim; Thomas, Ben W.; Hao, Xiying; Shi, Xiaojun

    2017-01-01

    Acidification of cropland soils is a serious problem in China that may cause long term pH decline, which threatens the sustainability of soil fertility and crop yields. The objective of this research was to investigate those rates and mechanisms for a slightly calcareous soil. The field data were

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

    Science.gov (United States)

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

    2015-01-01

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

  9. The effect of different nitrogen fertilization rates on yield and quality of marigold (Calendula officinalis L. 'Tokaj' raw material

    Directory of Open Access Journals (Sweden)

    Beata Król

    2012-12-01

    Full Text Available Pot marigold (Calendula officinalis L. is an annual ornamental plant which is also grown for herbal raw material (flower heads used in the pharmaceutical and cosmetic industries. A field experiment was carried out in the years 2006-2008 in the Experimental Farm of the University of Life Sciences in Lublin. The study was conducted on loess soil with the granulometric composition of silt loam. The aim of the experiment was to determine the effect of different nitrogen rates (0, 40, 80, 120, 160 kg N × ha-1 on some morphological features of flower heads as well as on yield and quality of pot marigold raw material. Flowering of pot marigold was shortest in the control treatment (32 days and longest (43 days in the plot where nitrogen fertilization had been applied at the highest rate (160 kg N × ha-1. Nitrogen fertilization had a significant influence on the number of flower heads per plant, but no significant difference was found in diameter as well as in ligulate flowers and tubular flowers in the flower head. It was found to increase significantly raw material yield after the application of 80 kg N × ha-1, compared to the control treatment. Yield of flower heads did not differ markedly for fertilization rates from 80 to 160 kg N × ha-1. Nitrogen fertilization modified slightly essential oil content (this content increased with increasing nitrogen rates, but at the same time it decreased the percentage of flavonoid compounds.

  10. Fertile assembly for a fast neutron nuclear reactor cooled by liquid sodium, with regulation of the cooling rate

    International Nuclear Information System (INIS)

    Pradal, L.; Berte, M.; Chiarelli, C.

    1985-01-01

    The assembly has a casing in which are arranged the fertile elements, the liquid sodium flowing through the casing along these elements. It includes several apertured diaphragms transverse to the rods to regulate the liquid sodium flow rate. At least one diaphragm, in its central part around its aperture, of a material soluble in liquid sodium, such as copper. The invention applies, more particularly, to fast neutron nuclear reactor having a heterogeneous core. The coolant flow can increase with time to match the increased power generated by the fertile assembly along its life [fr

  11. Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

    International Nuclear Information System (INIS)

    Guo Ruiying; Li Xiaolin; Christie, Peter; Chen Qing; Zhang Fusuo

    2008-01-01

    Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate. - Nitrogen inputs can be reduced to minimize N losses to the environment while maintaining yields but N recommendations must reflect seasonal temperature effects

  12. Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

    Energy Technology Data Exchange (ETDEWEB)

    Guo Ruiying; Li Xiaolin [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China); Christie, Peter [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Chen Qing [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China)], E-mail: qchen@cau.edu.cn; Zhang Fusuo [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China)

    2008-02-15

    Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate. - Nitrogen inputs can be reduced to minimize N losses to the environment while maintaining yields but N recommendations must reflect seasonal temperature effects.

  13. Estimates of the Tempo-adjusted Total Fertility Rate in Western and Eastern Germany, 1955-2008

    Directory of Open Access Journals (Sweden)

    Marc Luy

    2011-09-01

    Full Text Available In this article we present estimates of the tempo-adjusted total fertility rate in Western and Eastern Germany from 1955 to 2008. Tempo adjustment of the total fertility rate (TFR requires data on the annual number of births by parity and age of the mother. Since official statistics do not provide such data for West Germany as well as Eastern Germany from 1990 on we used alternative data sources which include these specific characteristics. The combined picture of conventional TFR and tempo-adjusted TFR* provides interesting information about the trends in period fertility in Western and Eastern Germany, above all with regard to the differences between the two regions and the enormous extent of tempo effects in Eastern Germany during the 1990s. Compared to corresponding data for populations from other countries, our estimates of the tempo-adjusted TFR* for Eastern and Western Germany show plausible trends. Nevertheless, it is important to note that the estimates of the tempo-adjusted total fertility rate presented in this paper should not be seen as being on the level of or equivalent to official statistics since they are based on different kinds of data with different degrees of quality.

  14. Energy assessment of nitrogen variable rate fertilization on wheat; Analise energetica da aplicacao de nitrogenio em taxa variavel em trigo

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, A.F.; Karam, E.H.; Romanelli, T.L.; Molin, J.P. [Escola Superior de Agricultura Luiz Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Engenharia de Biossistemas], Email: andrecolaco@usp.br; Povh, F.P. [Fundacao ABC Pesquisa e Desenvolvimento Agropecuario, Castro, PR (Brazil)

    2011-07-01

    Precision Agriculture (PA) is a technique that can reduce the inputs utilization in agriculture production, including the nitrogen fertilizer consume. Great importance is given to this fertilizer, due to its contribution on energy input in agriculture. Methodologies based on the calculation of energy flow of agriculture systems are capable to identify management practices that use energy more efficiently. So, this study's objective is to evaluate the variable-rate nitrogen fertilization on wheat, using energy assessment. This study was carried on in two wheat fields, in which the fertilization was done adopting strips alternated by conventional method (single nitrogen dose) and by nitrogen variable-rate technology. Thus, the input and output energy in the system, energy balance, energy return on investment (EROI) and incorporated energy were determined for each geo-referenced point within the fields. Results showed that less energy was demanded when using variable-rate technology, due to the nitrogen saving, providing greater energy balance, EROI and lower incorporated energy on the areas managed using PA. The energy assessment showed to be an important tool to evaluate systems that use PA, because it is capable of monitoring crops energy potential. (author)

  15. Impact of The Endometrioma on Ovarian Response and Pregnancy Rate in In Vitro Fertilization Cycles

    Directory of Open Access Journals (Sweden)

    Mahnaz Ashrafi

    2014-03-01

    Full Text Available Background: Our objective was to evaluate the effect of ovarian endometrioma on ovarian stimulation outcomes in in vitro fertilization cycles (IVF. Materials and Methods: In this prospective cohort study, we followed 103 patients who underwent intra-cytoplasmic sperm injection (ICSI procedures over a 24-months period. The study group consisted of 47 infertile women with either unilateral or bilateral ovarian endometrial cysts of less than 3 cm. The control group consisting of 57 patients with mild male factor infertility was candidate for ICSI treatment during the same time period as the study groups. Both groups were compared for number of oocytes retrieved, grades of oocytes, as well as embryo quantity and quality. Results: Our results showed similar follicle numbers, good embryo grades (A or B and pregnancy rates in the compared groups. However, patients with endometrioma had higher gonadotropin consumption than the control group. The mean number of retrieved oocytes in patients with endometrioma was significantly lower than control group (6.6 ± 3.74 vs. 10.4 ± 5.25 (p<0.001. In addition, patients with endometrioma had significantly lower numbers of metaphase II (MII oocytes (5 ± 3.21 than controls (8.2 ± 5.4 (p<0.001. In patients with unilateral endometrioma, there were no significant differences in main outcome measures between normal and involved ovaries in the patients with endometrioma. Conclusion: Patients with ovarian endometrioma had poor outcome. They showed poor ovarian response with lower total numbers of retrieved oocytes and lower MII oocytes during the stimulation phase; however, it does not affect the total number of embryos transferred per patient, quality of embryos, and pregnancy rate per patient.

  16. 70-79 Effects of Crop Rotation and NP Fertilizer Rate on Grain Yield a

    African Journals Online (AJOL)

    amendment enabled maize yields and soil fertility to be maintained at a higher level. Multiple ... Higher grain yield and high net return of maize were realized following Niger seed, ...... Generation, Transfer and Gap Analysis Workshop. Nekemt ...

  17. Effects of the rate and methods of placement of K-fertilizer in

    Directory of Open Access Journals (Sweden)

    mehrdad mahloji

    2009-06-01

    Full Text Available In order to study the effects of potassium amounts and methods of potassium application in different systems of tillaging on barley cultivar of Karoon*Kavir grain yield in salinity stress conditions, a farm trail was conducted in a split block arrangement in three replications with a Randomized Complete Block Design at Roodasht salinity and drainage research station (Esfahan province in 2003-5. Experimental treatments were soil tillage systems, potassium fertilizer amounts and its, placement methods. The main plots were soil till systems (conventional, minimum and no tillage.The horizontal treatments were recommended (300 kg/ha potassium sulfate, 33% lower and 33% higher than recommended amounts of potassium fertilizer. The vertical treatments in main plots were fertilizer placement methods (spreading and strip replacement of fertilizer 5 centimeter under the seeds. The water salinity of irrigation after spring growth stage was 12 ds/m. The conventional irrigation before spring growth stage is river water supply. The ANOVA results showed that: In the first year of study, the different soil till systems effected significantly(p = 0.01 plant height, number of spike per square meter, the concentration of minerals in leaf, grain yield, biological yield and harvest index. The fertilizer applications and its, placement effects on above-mentioned traits were not significant. The highest grain yield (3213 Kg/ha obtained in conventional till. In the second year of experiment: soil tillage systems, the potassium fertilizer amounts and fertilizer placements had no significant effect on grain and biological yields of barley cultivar. The two-year study results showed that: The conventional till system is a suitable method for planting barley in soils with clay loam texture. In spite of higher amounts of potassium fertilizer application and higher amount of absorbable K+ in the soil, there were no significant effect on grain yield and its components.

  18. Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping, E-mail: jpyang@zju.edu.cn; 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, 375 kg N/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O) 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 CH{sub 4} mainly appeared at the vegetative phase, and emission peaks of CO{sub 2}, and N{sub 2}O mainly appeared at reproductive phase of rice growth. The CO{sub 2} flux was significantly correlated with soil temperature, while the CH{sub 4} flux was influenced by logging water remaining period and N{sub 2}O flux was significantly associated with nitrogen application rates. This study showed that 225 kg N/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 CO{sub 2}-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89 t/ha in paddy fields. - Highlights: • Exploiting co-benefits of rice yield and reduction of greenhouse gas emission. • Global warming potential and rice yield increased with nitrogen fertilizer rate up. • Emission peaks of CH{sub 4,} CO{sub 2} and N{sub 2}O appeared at vegetative and reproductive phase. • 225 kg N/ha rate benefits both rice yields and GWP reduction.

  19. Integrated system for recommending fertilization rates in pineapple (Ananas comosus (L. Merr. crop

    Directory of Open Access Journals (Sweden)

    Sergio Salgado García

    2017-10-01

    Full Text Available In recent years much attention has focused on the impacts of agriculture on climate change, due to this stage specialists in plant nutrition and soil fertility have achieved the task of generating adequate fertilization doses for pineapple to reduce effects on environment. A methodology for Integrated System for Recommending Fertilizer Dose (ISRFD was used. As a result, seven Thiessen polygons of the average annual rainfall, where rainfall ranged from 1640 to 2841 mm was correlated. Therefore, three major soil groups were defined and classified as subunit level. Likewise, eight doses of fertilizers were generated as follows: N, P2O5 and K2O, with a fertilizer dose, a map is generated according to the cultivar: 230-138-300 for Creole pineapple in Acrisol Cutanic (Chromic, Ferric; 460-161-480 for Cayenne and MD2 in Acrisol Cutanic (Endoclayic, Ferric; 345-161-450 for Cayenne and MD2, 253-138-450 for Creole in Acrisol Cutanic (Endoclayic, Hyperdystric, Ferric; 391-161-450 for Cayenne and MD2 in Acrisol Umbric Cutanic (Endoclayic, Hyperdystric and Acrisol Umbric Cutanic (Endoclayic, Hyperdystric, Ferric; 207-138-300 for Creole in Acrisol Umbric Cutanic (Endoclayic, Hyperdystric; 253-138-300 for Creole in Acrisol Umbric Cutanic (Endoclayic,Hyperdystric, Ferric; 253-138-360 for Creole in Acrisol Umbric Gleyic (Hyperdystric, Ferric; and 391-161-360 in Cambisol Endogleyic (Clayic, Eutric. These fertilizer doses were supplemented with micronutrients to obtain the expected results.

  20. The impact of monetary policy and exchange rate shocks in Poland: evidence from a time-varying VAR

    OpenAIRE

    Arratibel, Olga; Michaelis, Henrike

    2014-01-01

    This paper follows the Bayesian time-varying VAR approach with stochastic volatility developed by Primiceri (2005), to analyse whether the reaction of output and prices to interest rate and exchange rate shocks has changed across time (1996-2012) in the Polish economy. The empirical findings show that: (1) output appears more responsive to an interest rate shock at the beginning of our sample. Since 2000, absorbing this shock has become less costly in terms of output, notwithstanding some rev...

  1. Fertility and Population Policy

    OpenAIRE

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

    2018-01-01

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

  2. Survival, Fertilization and Developmental Rates of Cryotop-Vitrified Oocyte and Embryo Using Low Concentrated Cryoprotectants

    Directory of Open Access Journals (Sweden)

    A Roozbehi

    2012-10-01

    Full Text Available Background & Aim: The preserving embryos, the risk of multiple pregnancies, the existence of factors in stimulated uterine cycle, are important forces in perfecting embryo cryopreservation. The aim of current study was to assess Survival, Fertilization and Developmental Rates (SRs, FRs, DRs of the mouse oocytes and embryos using cryotop and low concentrated cryoprotectants solutions. Methods: Mouse C57BL/6 oocytes and embryos were collected. Oocytes SRs, FRs, DRs were recorded after cryotop-vitrification/ warming. As well as comparing fresh oocytes and embryos, the data obtained from experimental groups (exp. applying 1.25, 1.0, and 0.75 Molar (M CPAs were analyzed in comparison to those of exp. adopting 1.5 M CPAs (largely-used concentration of EthylenGlycol (EG and Dimethylsulphoxide (DMSO. Results: The data of oocytes exposed to 1.25 M CPAs were in consistency with those exposed to 1.5 M and control group in terms of SR, FR and DR. As fewer concentrations were applied, the more decreased SRs, FRs and DRs were obtained from other experimental groups. The results of embryos were exposed to 1.25 M and 1.0 M was close to those vitrified with 1.5 M and fresh embryos. The results of 0.75 M concentrated CPAs solutions were significantly lower than those of control, 1.5 M and 1.0 M treated groups. Conclusion: CPAs limited reduction to 1.25 M and 1.0 M instead of using 1.5 M, for oocyte and embryo cryotop-vitrification procedure may be a slight adjustment.

  3. Controllable deterioration rate for time-dependent demand and time-varying holding cost

    Directory of Open Access Journals (Sweden)

    Mishra Vinod Kumar

    2014-01-01

    Full Text Available In this paper, we develop an inventory model for non-instantaneous deteriorating items under the consideration of the facts: deterioration rate can be controlled by using the preservation technology (PT during deteriorating period, and holding cost and demand rate both are linear function of time, which was treated as constant in most of the deteriorating inventory models. So in this paper, we developed a deterministic inventory model for non-instantaneous deteriorating items in which both demand rate and holding cost are a linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged. The model is solved analytically by minimizing the total cost of the inventory system. The model can be applied to optimizing the total inventory cost of non-instantaneous deteriorating items inventory for the business enterprises, where the preservation technology is used to control the deterioration rate, and demand & holding cost both are a linear function of time.

  4. Optical crop sensor for variable-rate nitrogen fertilization in corn: i - plant nutrition and dry matter production

    Directory of Open Access Journals (Sweden)

    Jardes Bragagnolo

    2013-10-01

    Full Text Available Variable-rate nitrogen fertilization (VRF based on optical spectrometry sensors of crops is a technological innovation capable of improving the nutrient use efficiency (NUE and mitigate environmental impacts. However, studies addressing fertilization based on crop sensors are still scarce in Brazilian agriculture. This study aims to evaluate the efficiency of an optical crop sensor to assess the nutritional status of corn and compare VRF with the standard strategy of traditional single-rate N fertilization (TSF used by farmers. With this purpose, three experiments were conducted at different locations in Southern Brazil, in the growing seasons 2008/09 and 2010/11. The following crop properties were evaluated: above-ground dry matter production, nitrogen (N content, N uptake, relative chlorophyll content (SPAD reading, and a vegetation index measured by the optical sensor N-Sensor® ALS. The plants were evaluated in the stages V4, V6, V8, V10, V12 and at corn flowering. The experiments had a completely randomized design at three different sites that were analyzed separately. The vegetation index was directly related to above-ground dry matter production (R² = 0.91; p<0.0001, total N uptake (R² = 0.87; p<0.0001 and SPAD reading (R² = 0.63; p<0.0001 and inversely related to plant N content (R² = 0.53; p<0.0001. The efficiency of VRF for plant nutrition was influenced by the specific climatic conditions of each site. Therefore, the efficiency of the VRF strategy was similar to that of the standard farmer fertilizer strategy at sites 1 and 2. However, at site 3 where the climatic conditions were favorable for corn growth, the use of optical sensors to determine VRF resulted in a 12 % increase in N plant uptake in relation to the standard fertilization, indicating the potential of this technology to improve NUE.

  5. Optimal harvesting of fish stocks under a time-varying discount rate.

    Science.gov (United States)

    Duncan, Stephen; Hepburn, Cameron; Papachristodoulou, Antonis

    2011-01-21

    Optimal control theory has been extensively used to determine the optimal harvesting policy for renewable resources such as fish stocks. In such optimisations, it is common to maximise the discounted utility of harvesting over time, employing a constant time discount rate. However, evidence from human and animal behaviour suggests that we have evolved to employ discount rates which fall over time, often referred to as "hyperbolic discounting". This increases the weight on benefits in the distant future, which may appear to provide greater protection of resources for future generations, but also creates challenges of time-inconsistent plans. This paper examines harvesting plans when the discount rate declines over time. With a declining discount rate, the planner reduces stock levels in the early stages (when the discount rate is high) and intends to compensate by allowing the stock level to recover later (when the discount rate will be lower). Such a plan may be feasible and optimal, provided that the planner remains committed throughout. However, in practice there is a danger that such plans will be re-optimized and adjusted in the future. It is shown that repeatedly restarting the optimization can drive the stock level down to the point where the optimal policy is to harvest the stock to extinction. In short, a key contribution of this paper is to identify the surprising severity of the consequences flowing from incorporating a rather trivial, and widely prevalent, "non-rational" aspect of human behaviour into renewable resource management models. These ideas are related to the collapse of the Peruvian anchovy fishery in the 1970's. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Pulse pile-up in nuclear particle detection systems with rapidly varying counting rates

    International Nuclear Information System (INIS)

    Datlowe, D.W.

    1977-01-01

    Pulse pile-up in nuclear particle detection systems is the distortion of the measured pulse height distribution which occurs when there is a significant probability that more than one particle will arrive within the detector resolving time. This paper treats the problem in cases where the probability of pile-up varies on a time scale comparable to the rise time of the detector system electronics. These variations introduce structure into the pulse height distributions which cannot occur for a time-independent pile-up probability. Three classes of problems which exemplify these effects are as follows: 1) Pile-up rejection circuits. 2) Cascaded nuclear decays, in which the lifetime for emission of a second X-ray is comparable to the detector rise time. 3) Bursts of particles where the intensity is modulated on a time scale comparable to the detector rise time. These problems are solved computationally by an extension of a numerical technique previously developed. (Auth.)

  7. Analyzing the term structure of interest rates using the dynamic Nelson-Siegel model with time-varying parameters

    NARCIS (Netherlands)

    Koopman, S.J.; Mallee, M.I.P.; van der Wel, M.

    2010-01-01

    In this article we introduce time-varying parameters in the dynamic Nelson-Siegel yield curve model for the simultaneous analysis and forecasting of interest rates of different maturities. The Nelson-Siegel model has been recently reformulated as a dynamic factor model with vector autoregressive

  8. Seed rate and nitrogen fertilizer effects on wild mustard (Sinapis arvensis L. and winter wheat (Triticum aestivum L. competition

    Directory of Open Access Journals (Sweden)

    karim moosavi

    2009-06-01

    Full Text Available In order to evaluate wild mustard competitive effect on winter wheat, an additive series experiment was conducted in 2000-2001 at Agricultural Research Station of Mashhad University.The experiment had 3 factor: wheat seed rate (175 , 215 and 255 kg/ha, nitrogen rate (150 and 225 kg/ha, and a range of wild mustard densities. Hyperbolic functions was used to describe yield-weed density relationship. Increasing wild mustard density had a negative , asymptotic – type effect on wheat biomass and grain yield. By increasing wheat seed rate , in optimum nitrogen rate , maximum wheat biomas loss has reduced about 51 %. Maximum yield loss has increased from 42.1 % to 50.4 %, as nitrogen rate incrased from optimum to upper optimum rate of wheat. By increasing of wheat seed rate from 175 to 255 kg/ha, maximum tiller number reduction due to high densities of wild mustard, has decreased by 54 %. Reduction of fertile tiller number was mostly occurred at presence of high nitrogen level, thus, reduction of fertile tiller number compared to control in N1 was 18% , while in N2 has increased to 30%. Wild mustard competition has reduced wheat seed number per ear 30% in compare to weed free control. Results show that wheat 1000 seed weight was more affected by nitrogen rate than plant densities. Apparently, in competition with wheat, wild mustard was better able to utilize the added nitrogen and thus gained a competitive adventage over the wheat.

  9. Morphological Evolution of Gyroid-Forming Block Copolymer Thin Films with Varying Solvent Evaporation Rate.

    Science.gov (United States)

    Wu, Yi-Hsiu; Lo, Ting-Ya; She, Ming-Shiuan; Ho, Rong-Ming

    2015-08-05

    In this study, we aim to examine the morphological evolution of block copolymer (BCP) nanostructured thin films through solvent evaporation at different rates for solvent swollen polystyrene-block-poly(l-lactide) (PS-PLLA). Interesting phase transitions from disorder to perpendicular cylinder and then gyroid can be found while using a partially selective solvent for PS to swell PS-PLLA thin film followed by solvent evaporation. During the transitions, gyroid-forming BCP thin film with characteristic crystallographic planes of (111)G, (110)G, and (211)G parallel to air surface can be observed, and will gradually transform into coexisting (110)G and (211)G planes, and finally transforms to (211)G plane due to the preferential segregation of constituted block to the surface (i.e., the thermodynamic origin for self-assembly) that affects the relative amount of each component at the air surface. With the decrease on the evaporation rate, the disorder phase will transform to parallel cylinder and then directly to (211)G without transition to perpendicular cylinder phase. Most importantly, the morphological evolution of PS-PLLA thin films is strongly dependent upon the solvent removal rate only in the initial stage of the evaporation process due to the anisotropy of cylinder structure. Once the morphology is transformed back to the isotropic gyroid structure after long evaporation, the morphological evolution will only relate to the variation of the surface composition. Similar phase transitions at the substrate can also be obtained by controlling the ratio of PLLA-OH to PS-OH homopolymers to functionalize the substrate. As a result, the fabrication of well-defined nanostructured thin films with controlled orientation can be achieved by simple swelling and deswelling with controlled evaporation rate.

  10. Occurrence and fertility rates of hydatid cysts in sheep and goats ...

    African Journals Online (AJOL)

    In Ethiopia very limited studies were conducted in small ruminant hydatidosis compared to cattle. A cross-sectional study was conducted at Modjo Luna Export Slaughter House from December 2009 to February 2010 to determine the prevalence and fertility of hydatid cysts. A total of 325 sheep and 440 goats were examined ...

  11. 70-79 Effects of Crop Rotation and NP Fertilizer Rate on Grain Yield a

    African Journals Online (AJOL)

    Primary nutrient (N, P and K) composition of the ... Crop rotation with fertilizer amendment improved the pH of the soil. Crop rotation and ..... Soil organic carbon contents declined regardless of inputs application for continuously cultivated land (Kapkiyai, 1996). Higher. Organic carbon content next to before planting (1.98 %).

  12. Yield and nutritional efficiency of corn in response to rates and splits of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Telmo Jorge Carneiro Amado

    Full Text Available ABSTRACT Despite its relevance, nitrogen is poorly utilized by the plants when improperly applied. Thus, the objective of this study was to evaluate the yield and nitrogen use efficiency (NUE in corn in response to doses and split application of nitrogen fertilization. The experimental design was a randomized block design, with three replications. Doses of nitrogen of 0, 30, 60 and 180 kg ha-1 were applied at sowing in order to create different nutritional status of corn plants and to obtain different values of Normalized Difference Vegetation Index (NDVI measured with “Greenseeker®” optical sensor. The subplots with nitrogen doses in topdressing of 0, 30, 60 and 90 kg ha-1 at V8 and a dose of 60 kg ha-1 at V12 were placed in experimental plots with doses of 0, 30, 60 and 180 kg ha-1 of nitrogen at sowing. Moreover, NUE was calculated in the experiment using agronomic indexes determined by applications of nitrogen in late topdressing (V8 and V12 and contrasted to the possible combinations at doses of 60, 90 and 120 kg ha-1 of total N applied. The results showed the occurrence of a linear relationship between nitrogen fertilizer dose and NDVI at V8 as well as at V12 stages. Late topdressing fertilizations (V12 did not cause a decrease in grain yield when combined with nitrogen fertilization at sowing, moreover resulted in higher NUE. Split the nitrogen dose showed better NUE than the combinations where nitrogen was not applied at sowing or in topdressing. The delay of nitrogen topdressing can be an alternative for the planning of the moment of the N fertilization according to the climate forecast in each region.

  13. Effects of Biosolids at Varying Rates on Earthworms (Eisenia fetida and Springtails (Folsomia candida

    Directory of Open Access Journals (Sweden)

    N. Artuso

    2011-01-01

    Full Text Available Land spreading is a major option internationally for the disposal/use of treated sewage sludge (biosolids, but effects of this practice on soil organisms are largely unknown. This study investigated the effects of biosolids on two soil invertebrate species, earthworms (Eisenia fetida and Collembola (Folsomia candida, in laboratory tests. Five biosolids from different sewage works were assessed at rates equivalent to 0, 2, 5, 10, and 20 t ha−1. Biosolids applied at 2 and 5 t ha−1 did not cause mortality of adult earthworms but did at 10 and 20 t ha−1. At 5, 10 and 20 t ha−1, all biosolids had significantly fewer juvenile worms relative to controls. Increasing the rates from 2 to 10 t ha−1 did not impact on the number of adult Collembola, but at 20 t ha−1 there were significantly fewer adults. There were significantly fewer juvenile Collembola recorded for biosolids applied at the 2 t ha−1 when compared with controls, and also when biosolids were applied at 5, 10, and 20 t ha−1 relative to 2 t ha−1. Some significant difference between biosolids were observed, but generally, negative effects were not related to heavy metal concentrations in biosolids. It is recommended that possible detrimental mechanisms (e.g., ammonia production, lack of oxygen be investigated in future work. It is concluded that biosolids, applied at legal, low rates (about 2 t ha−1 are unlikely to be detrimental to earthworms or adult Collembola but can be detrimental to Collembola reproduction.

  14. Varying Definitions for Periprocedural Myocardial Infarction Alter Event Rates and Prognostic Implications

    Science.gov (United States)

    Idris, Hanan; Lo, Sidney; Shugman, Ibrahim M.; Saad, Yousef; Hopkins, Andrew P.; Mussap, Christian; Leung, Dominic; Thomas, Liza; Juergens, Craig P.; French, John K.

    2014-01-01

    Background Periprocedural myocardial infarction (PMI) has had several definitions in the last decade, including the Society for Cardiovascular Angiography and Interventions (SCAI) definition, that requires marked biomarker elevations congruent with surgical PMI criteria. Methods and Results The aim of this study was to examine the definition‐based frequencies of PMI and whether they influenced the reported association between PMI and increased rates of late death/ myocardial infarction (MI). We studied 742 patients; 492 (66%) had normal troponin T (TnT) levels and 250 (34%) had elevated, but stable or falling, TnT levels. PMI, using the 2007 and the 2012 universal definition, occurred in 172 (23.2%) and in 99 (13.3%) patients, respectively, whereas 19 (2.6%) met the SCAI PMI definition (PPMI using the 2012 definition, occlusion of a side branch ≤1 mm occurred in 48 patients (48.5%) and was the most common angiographic finding for PMI. The rates of death/MI at 2 years in patients with, compared to those without, PMI was 14.7% versus 10.1% (P=0.087) based on the 2007 definition, 16.9% versus 10.3% (P=0.059) based on the 2012 definition, and 29.4% versus 10.7% (P=0.015) based on the SCAI definition. Conclusion In this study, PMI, according to the SCAI definition, was associated with more‐frequent late death/MI, with ≈20% of all patients, who had PMI using the 2007 universal MI definition, not having SCAI‐defined PMI. Categorizing these latter patients as SCAI‐defined no PMI did not alter the rate of death/MI among no‐PMI patients. PMID:25359403

  15. Irradiation embrittlement of some 15Kh2MFA pressure vessel steels under varying neutron fluence rates

    Energy Technology Data Exchange (ETDEWEB)

    Valo, M; Bars, B [Technical Research Centre of Finland, Espoo (Finland); Ahlstrand, A [Imatran Voima Oy (IVO), Helsinki (Finland)

    1994-12-31

    Irradiation sensitivity of two forging materials was measured with Charpy-V and fracture mechanic tests, and with different fluence, fluence rate and irradiation time values. Irradiation sensitivity of the materials was found to be less or equal to the current Russian standard, and appears to be well described by the fluence parameter only. A slight additional effect on embrittlement from a long term low fluence irradiation is noticed, but it stays within the total scatter band of data. 7 refs., 17 figs., 4 tabs.

  16. MACRONUTRIENT CONCENTRATION AND CONTENT IN PASSION FRUIT LEAVES UNDER SAMPLING METHODS AND N-K FERTILIZATION RATES

    Directory of Open Access Journals (Sweden)

    RODINEI FACCO PEGORARO

    2017-12-01

    Full Text Available ABSTRACT Nitrogen and potassium fertilization and assessment of adequate nutritional status are essential for increasing fruit production of passion fruit. However, studies related to characterization of the leaf nutrient concentration and content in passion fruit with different production capacities are scarce in the literature in Brazil. The objective of this study was to evaluate macronutrient leaf concentration and content in different parts of the reproductive shoot of yellow passion fruit subjected to different ratios of N and K fertilization. The study was conducted in a randomized block design, with three replications, following a 4 x 6 factorial arrangement consisting of four cultivars of yellow passion fruit (BRS Gigante Amarelo, IAC 275, BRS Ouro Vermelho, and BRS Sol do Cerrado and six application rates of N-K2O fertilizer (0-0, 50-125, 100-250, 150-375, 200-500, and 250-625 kg ha-1 year-1. Two leaf sampling methods were adopted (leaf located at a position adjacent to the fruit, and leaf located at the end of the reproductive branch for nutritional assessment. The leaf located at the adjacent position had lower N, P, K, Mg, and S concentration and higher Ca concentration than the concentrations observed in the standard leaf. However, the higher leaf dry matter in adjacent leaves resulted in increased macronutrient concentration/content. The increase in N-K fertilizations inhibited Ca and Mg content in the leaves adjacent to the fruit of the Gigante Amarelo, IAC, and Ouro Vermelho passion fruit cultivars, but did not affect Ca and Mg content in the standard leaf. The passion fruit cultivars showed different leaf nutrient contents after N-K fertilization, indicating variable nutritional demands and the need for specific diagnostic methods for each cultivar.

  17. Long-term influence of tillage and fertilization on net carbon dioxide exchange rate on two soils with different textures.

    Science.gov (United States)

    Feiziene, Dalia; Feiza, Virginijus; Slepetiene, Alvyra; Liaudanskiene, Inga; Kadziene, Grazina; Deveikyte, Irena; Vaideliene, Asta

    2011-01-01

    The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO exchange rate (NCER) and environmental factors (SOC, soil temperature [T], and water content [W]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Essential oil and composition of anise (pimpinella anisum l.) with varying seed rates and row spacing

    International Nuclear Information System (INIS)

    Ullah, H.

    2014-01-01

    Two year study was carried out to explore the effect of seed rate and row spacing on the fruit yield, essential oil yield and composition of aniseed. The study factors included seed rate (6 g, 12 g, 24 g/10 m2) and row spacing (15 cm, 25 cm, 37.5 cm. A significantly higher fruit yield was produced at narrow row spacing of 15 cm among treatments. Wider row spacing produced markedly higher essential oil than narrow row spacing. Essential oil accumulation decreased as planting densities increased. The major constituent of anise oil was trans-anethole (82.1%) followed by himachalene (7.0%). The quality parameters including estragol, himachalene and trans-anethole were significantly affected by different row spacing. Plant grown at 37.5 cm row spacing accumulated the highest estragol and trans-anethole concentration among the row spacing treatments. It can be concluded that higher plant density and wider row spacing increased the disease infestation and lodging cultivar Enza Zaden in current study exhibited high concentration trans-anethole in essential oil composition therefore is a good quality chemotype. (author)

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

    Directory of Open Access Journals (Sweden)

    Naoko Isomura

    Full Text Available 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.

  20. Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

    Science.gov (United States)

    Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

    2012-04-01

    Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (pcaffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Yield and nutritional efficiency of corn in response to rates and splits of nitrogen fertilization

    OpenAIRE

    Amado, Telmo Jorge Carneiro; Villalba, Enrique Oswin Hahn; Bortolotto, Rafael Pivotto; Nora, Douglas Dalla; Bragagnolo, Jardes; León, Enrique Asterio Benítez

    2017-01-01

    ABSTRACT Despite its relevance, nitrogen is poorly utilized by the plants when improperly applied. Thus, the objective of this study was to evaluate the yield and nitrogen use efficiency (NUE) in corn in response to doses and split application of nitrogen fertilization. The experimental design was a randomized block design, with three replications. Doses of nitrogen of 0, 30, 60 and 180 kg ha-1 were applied at sowing in order to create different nutritional status of corn plants and to obtain...

  2. What causes EBRI retirement readiness ratings to vary: results from the 2014 Retirement Security Projection Model.

    Science.gov (United States)

    VanDerhei, Jack

    2014-02-01

    RETIREMENT INCOME ADEQUACY IMPROVED SLIGHTLY IN 2013: Due to the increase in financial market and housing values during 2013, the probability that Baby Boomers and Generation Xers would NOT run short of money in retirement increases between 0.5 and 1.6 percentage points, based on the Employee Benefit Research Institute (EBRI) Retirement Readiness Ratings (RRRs). ELIGIBILITY FOR PARTICIPATION IN AN EMPLOYER-SPONSORED DEFINED CONTRIBUTION PLAN REMAINS ONE OF THE MOST IMPORTANT FACTORS FOR RETIREMENT INCOME ADEQUACY: RRR values double for Gen Xers in the lowest-income quartile when comparing those with 20 or more years of future eligibility with those with no years of future eligibility, while those in the middle income quartiles experience increases in RRR values by 27.1-30.3 percentage points. FUTURE SOCIAL SECURITY BENEFITS MAKE A HUGE DIFFERENCE FOR THE RETIREMENT INCOME ADEQUACY OF SOME HOUSEHOLDS, ESPECIALLY GEN XERS IN THE LOWEST-INCOME QUARTILE: If Social Security benefits are subject to proportionate decreases beginning in 2033 (according to the values in Figure 8), the RRR values for those households will drop by more than 50 percent: from 20.9 percent to 10.3 percent. LONGEVITY RISK AND STOCHASTIC HEALTH CARE RISK ARE ASSOCIATED WITH HUGE VARIATIONS IN RETIREMENT INCOME ADEQUACY: For both of these factors, a comparison between the most "risky" quartile with the least risky quartile shows a spread of approximately 30 percentage points for the lowest income range, approximately 25 to 40 percentage points for the highest income range, and even larger spreads for those in the middle income ranges. A GREAT DEAL OF THE VARIABILITY IN RETIREMENT INCOME ADEQUACY COULD BE MITIGATED BY APPROPRIATE RISK-MANAGEMENT TECHNIQUES AT OR NEAR RETIREMENT AGE: For example, the annuitization of a portion of the defined contribution and IRA balances may substantially increase the probability of not running short of money in retirement. Moreover, a well-functioning market in long

  3. Fertility desires and fertility outcomes.

    Science.gov (United States)

    Bracher, M; Santow, G

    1991-05-01

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

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

    Science.gov (United States)

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

    2007-10-01

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

  5. Fertility and productivity index rating of some soils conditioned by climate and topography

    International Nuclear Information System (INIS)

    Okae-Anti, Daniel; Imoro, Abukari Z.

    2004-10-01

    In the humid tropics, well-drained soils with abundant loose iron concretions, soils with very little weatherable minerals left and of poor chemical status due to the abundance of low activity clays, pose serious limitations to agricultural productivity. Accurate and reliable soil productivity information is needed in the form of crop yield estimates and productivity indices. We investigated the productive potential of some acrisols and plinthosols by computing productivity indices (PI) and estimating yields of four test crops, namely cowpea, groundnut, maize and soybean. PI was based on physico-chemical parameters expected to regulate air-water relations, have a role in determining the mechanical resistance to crop roots and the volume of soil, and, contribute to the fertility status of the soils. Very low Pls in the order 7.2x10 - 5, 9.6x10 - 5 and 8.32x10 - 4 were observed for Nyankpala, Changnayili and Kpelesawgu series respectively. Based on the inherently low fertility status of these soils, maize, planted as a sole crop or in rotation with groundnut is the sustainable cropping system for the soils. A return of crop residue to the soil is envisaged as a long term practice to maintain adequate levels of organic matter. (author)

  6. Reduced fertilization rates in older men when cervical mucus is suboptimal.

    Science.gov (United States)

    Dunson, David B; Bigelow, Jamie L; Colombo, Bernardo

    2005-04-01

    Cervical mucus is vital in the regulation of sperm survival and transport through the reproductive tract. The goal of this study is to assess whether the lowered fertility for men in their late 30s and early 40s is related to the nature of cervical mucus on the day of intercourse. In a prospective study of 7 European family planning centers, 782 couples not using birth control recorded daily observations of intercourse and the nature of cervical mucus. Using data from 1,459 menstrual cycles, 342 ending in pregnancy, we estimate day-specific conception probabilities in relation to mucus and male and female age. On days where cervical mucus was not evident, intercourse for men in their late 30s and early 40s was 50% less likely to result in a clinical pregnancy, adjusting for intercourse timing and female age. As secretions become more conducive to sperm transport, the effect of male age diminishes steadily from 21% on days with damp secretions, to 11% on days with thick mucus, to only 4% on days with most fertile-type mucus. The effect of male age on fecundability can be minimized by timing intercourse on days with optimal secretions. II-2.

  7. Effect of different phosphorus fertilizer rates on N-uptake, N-efficiency and zea maize yield in irrigated soils

    International Nuclear Information System (INIS)

    Khalifa, Kh.

    1993-01-01

    Effect of different rates of P fertilizer on N-uptake, N-efficiency and zea mays (C.V.Lg 11) were studied by use of 15 N technique. The main objectives of this study were to study effect of different level of P on N-utilization and determine the interaction between P and N on zea mays yield, and the efficiency of N-fertilizer during different stages of plant growth. The field experiment was conducted for two years 1985 and 1986. The treatments were 0, 80, 160 Kg N, as urea Co( 15 NH 2 ) 2 and 0, 40, 80, 160 Kg P 2 O 5 as triplsuperphophate. The experiment design was randomized block of four replicates for each treatment. Yield (grain and dry matter), utilization of urea, N-uptake, total N, N-yield, Ndff%, NDF% and A-values were determined. All results indicate that zea mays responds to the addition of nitrogen and the yield increases with the increase of added nitrogen. The highest yield was for N 2 (160 Kg) level during two seasons. Also zea mays responds clearly to phosphorus especially at stages 1 and 2, where dry matter yield increases with the increase of phosphorus rate. The highest yield was for P 3 (160 Kg) rate. While in grain stage the response was for rate P 1 (40 Kg) and P 2 (80 Kg) in comparison with control. However P 1 , rate was dominant over P 2 and P 3 . The effect of P 2 rate on grain yield was very little in comparison with P 1 , while P 3 decreases the grain yield during two seasons in comparison with control. There is an effect of N and P when added both or separately. There is also effect for interaction between them on the yield (grain and dry matter). Generally, from the previous data we can conclude that the rate 160 Kg N/ha and 40 Kg P 2 O 5 /ha were optimum rate for zea mays fertilization in Deir-Ezzor (Syria) and similar areas for grain yield. (author). 17 refs., 6 tabs

  8. The Effects of the Incubation of Hyaluronidase Applicated Oocytes Before ICSI on Fertilization, Embryo Development and Pregnancy Rates

    Directory of Open Access Journals (Sweden)

    Zeynep Coskun

    2007-03-01

    Full Text Available OBJECTIVE: Intracytoplasmic sperm injection (ICSI is one of the most important techniques used for the treatment of male infertility. Before ICSI oocytes have to be denuded from cumulus and corona cells using a combination of enzymatic and mechanical methods. In this study 40 IU/ml hyaluronidase has been used to denude the oocytes. The aim of this study is to investigate the effects of the incubation of hyaluronidase applicated oocytes before ICSI on fertilization, embryo development and pregnancy rates.\tMATERIALS-METHODS: Patients were randomly selected according to the days of the week. In 114 patient ( Group I oocytes were incubated in 37 C, %5 CO2 and %5 O2 for 30-60 minutes before ICSI. In 136 patient ( Group II ICSI is performed immediately after denudation. RESULTS: There was no statistical difference on fertilization rates and number of grade I embryo that were transferred between\ttwo groups. Although implantation rates were higher in group II that no incubation had been performed, there was no statistical difference between two groups.\tDISCUSSION: ICSI can be performed immediately after denudation with hyaluronidase.

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

    Science.gov (United States)

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

    2015-02-01

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

  10. Evaluation of sources, rates and methods of zinc fertilizer applications in flooded rice

    International Nuclear Information System (INIS)

    Sarkar, A.K.; Deb, D.L.

    1981-01-01

    A pot experiment was conducted using 65 Zn as tracer to evaluate the different sources, levels and methods of zinc fertilization in flooded rice. Results indicated that zinc sulphate was either at par or slightly superior to zincated urea from the point of view of yield and total zinc uptake by rice. The Zndff percent was found to be the highest with zincated urea and the lowest was observed with zinc oxide. 5 and 10 kg/ha levels of zinc were statistically at par in this regard. Among the different methods, surface application and thorough mixing with soil were comparable. Root dipping in 1 percent zinc oxide suspension and application of zinc in irrigation water also indicated high zinc absorption by the rice plant. (author)

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

    Science.gov (United States)

    Wu, C; Mu, G

    1996-01-01

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

  12. Cryopreservation of Boer goat spermatozoa: Comparison of two freezing extenders based on post-thaw sperm quality and fertility rates

    Directory of Open Access Journals (Sweden)

    Fitra Aji Pamungkas

    2014-06-01

    Full Text Available Boer goat have recently been popularly used for cross breeding with local goats. However, it is currently considered a breed at very limited number with relatively high prices . In this context, the cryopreservation of spermatozoa is important because it could be conserved for a very long period of time. Egg yolk extenders are most commonly used for cryopreservation of goat sperm. The aim of this study was to compare the ability of two extenders to maintain sperm viability after cryopreservation. Semen from three male Boer goat aged about 2-3 years old was collected using artificial vagina and frozen with Tris and Triladyl extender. The results showed that percentage of motility, viability and membrane integrity of spermatozoa with Tris and Triladyl extenders at every stage of cryopreservation showed not significantly difference (P>0.05, except the percentage of sperm motility post thawing of Triladyl was higher than Tris extender (52.00±4.47% vs 47.50±2.74%, P<0.05. Cryopreserved semen in Tris extender provided the same fertility rates after cervical insemination compared to Triladyl (62.50% vs 60.00%. In conclusion, the Tris extender has the same capabilities to Triladyl in cryopreservation of Boer goat spermatozoa as to maintain sperm quality and fertility rates.

  13. Evaluation of competitive and economic indices in canola and pea intercropping at different rates of nitrogen fertilizer

    Directory of Open Access Journals (Sweden)

    Seyfollah fallah

    2016-05-01

    Full Text Available The experiment was conducted in order to evaluate of competitive and economic indices in canola and pea intercropping at different rates of nitrogen fertilizer at Shahrekord University research farm during 1390 - 1391. Intercropping and sole cropping treatments (100% canola; 66% canola + 33% pea, 50% canola + 50% pea; 33% canola + 66% pea; 100% pea were evaluated as the first factor and nitrogen rates (100% need; 75% need and 50% need as the second factor in a randomized complete block design with three replications. The calculated competitive indices were included land equivalent ratio (LER, relative crowding coefficient (K, aggressively (A, the system production index (SPI, actual yield loss (AYL, competitive ratio (CR and economy indices included monetary advantage index (MAI, and the intercropping advantage (IA. Results showed that all the competitive and economic indices had the highest amount in 50 and 75% of nitrogen requirement. The amounts of AYLt and SPI and economic indices (MAI and IA were positive for all intercropping ratios. Also, LERt and Kt for all intercropping ratio were greater than one, that indicating the superiority of intercropping over sole cropping any of the two plants. The positive values aggressively index and the greater than one values competitive ratio for canola, indicated canola was superior competitor in compared to pea. In conclusion, the evaluation of competitive and economic indices appropriately describes intercropping advantage of canola with pea in reduced nitrogen fertilizer conditions.

  14. Effect of seed inoculation with Azospirillum brasilense and nitrogen fertilization rates on maize plant yield and silage quality

    Directory of Open Access Journals (Sweden)

    Fernando Reimann Skonieski

    Full Text Available ABSTRACT The objective of this study was to determine the effect of Azospirillum brasilense inoculation and different nitrogen (N rates applied as topdressing on the productivity of a maize crop and the nutritional value of maize silage. Two experiments were conducted in the 2012/2013 and 2013/2014 harvests. Treatments were distributed in a randomized block design in a factorial arrangement, which consisted of two maize hybrids (AS 1572 and Defender coupled with nitrogen rates (0, 60, 120, 240, and 480 kg ha-1, inoculated or uninoculated with A. brasilense. Inoculated seeds were treated with the A. brasilense strains Ab-V5 and Ab-V6. Inoculation with A. brasilense showed interaction with the hybrids, agricultural years, and nitrogen rates for the maize plant yield. In the 2012/2013 agricultural year, inoculation increased the AS 1572 hybrid silage yield by 6.16% and, in the 2013/2014 harvest, A. brasilense inoculation produced an increase of 16.15% for the Defender hybrid. Nitrogen fertilization applied at 0, 60, and 120 kg ha-1 N benefited the plants inoculated with A. brasilense. The statistical equations revealed that N rates between 0 and 184 kg ha-1 in A. brasilense inoculated plants raised the plant productivity for silage when compared with the control plants. Regarding the nutritional value of the silage, inoculation with A. brasilense increased the ether extract levels and total digestible nutrients and reduced the amount of acid detergent fiber. For all this, positive results with inoculation for silage yield are dependent on nitrogen fertilization rate. Inoculation with A. brasilense can promote changes in the maize silage quality, but with obtained results it is not possible to definitely conclude upon nutritive value of maize silage.

  15. Evaluating the Role of First Polar Body Morphology on Rates of Fertilization and Embryo Development in ICSI Cycles

    Directory of Open Access Journals (Sweden)

    Iman Halvaei

    2011-01-01

    Full Text Available Background: Recent studies have demonstrated that morphology of the first polar body (1st PBis related to oocyte viability, which can be used as a prognostic tool to predict oocyte performanceand pregnancy outcomes in an intracytoplasmic sperm injection (ICSI program. According to somestudies, there is a correlation between oocyte performance and 1st PB morphology, while others havenot reported any correlation. The objective of this study is to evaluate the role of 1st PB morphologyon rates of fertilization and embryo development in ICSI cases.Materials and Methods: In this prospective study morphological characteristics of 470 metaphaseII (MII oocytes were assessed in 80 ICSI cycles. The women were ages 21-42 years (mean 32.6 ±0.2. Their oocytes were retrieved after a hyperstimulation protocol. After denudation, all oocyteswere evaluated for 1st PB morphology. The oocytes were divided into two groups of A (normal 1stPB and B (abnormal fragmented 1st PB. In addition, other abnormalities, such as refractile bodies(RF, wide previtelline space (wPVS, central and general granulation, bull’s eye, vacuole, smoothendoplasmic reticulum cluster (SERc, debris in PVS, shape and dark oocyte were checked. Forverifying of fertilization, about 18-19 hours post-ICSI, oocytes were checked for two-pronuclear.Assessments of embryo quality, development and embryo transfer were done at day two. Chisquare,Fisher’s exact and independent sample t tests were chosen for statistical analysis.Results: Twenty-seven percent of oocytes had fragmented 1st PB, while the remainder was associatedwith other morphological abnormalities. A total of 46.1% and 26.9% of oocytes showed double andmultiple defects, respectively. RF was the most common abnormality observed in group B. Nosignificant differences in women’s’ ages between groups A and B were noted (p=0.3. A total of 179and 107 oocytes (61.5% vs. 59.8% were fertilized in groups A and B, respectively (p=0.7. Therates of

  16. Nitrogen Fertilizer Rate and Crop Management Effects on Nitrate Leaching from an Agricultural Field in Central Pennsylvania

    Directory of Open Access Journals (Sweden)

    Richard H. Fox

    2001-01-01

    Full Text Available Eighteen pan lysimeters were installed at a depth of 1.2 m in a Hagerstown silt loam soil in a corn field in central Pennsylvania in 1988. In 1995, wick lysimeters were also installed at 1.2 m depth in the same access pits. Treatments have included N fertilizer rates, use of manure, crop rotation (continuous corn, corn-soybean, alfalfa-corn, and tillage (chisel plow-disk, no-till. The leachate data were used to evaluate a number of nitrate leaching models. Some of the highlights of the 11 years of results include the following: 1 growing corn without organic N inputs at the economic optimum N rate (EON resulted in NO3–-N concentrations of 15 to 20 mg l-1 in leachate; 2 use of manure or previous alfalfa crop as partial source of N also resulted in 15 to 20 mg l-1 of NO3–-N in leachate below corn at EON; 3 NO3–-N concentration in leachate below alfalfa was approximately 4 mg l-1; 4 NO3–-N concentration in leachate below soybeans following corn was influenced by fertilizer N rate applied to corn; 5 the mass of NO3–-N leached below corn at the EON rate averaged 90 kg N ha-1 (approx. 40% of fertilizer N applied at EON; 6 wick lysimeters collected approximately 100% of leachate vs. 40–50% collected by pan lysimeters. Coefficients of variation of the collected leachate volumes for both lysimeter types were similar; 7 tillage did not markedly affect nitrate leaching losses; 8 tested leaching models could accurately predict leachate volumes and could be calibrated to match nitrate leaching losses in calibration years, but only one model (SOILN accurately predicted nitrate leaching losses in the majority of validation treatment years. Apparent problems with tested models: there was difficulty estimating sizes of organic N pools and their transformation rates, and the models either did not include a macropore flow component or did not handle macropore flow well.

  17. An Ecological Study on the Spatially Varying Relationship between County-Level Suicide Rates and Altitude in the United States

    Directory of Open Access Journals (Sweden)

    Hoehun Ha

    2018-04-01

    Full Text Available Suicide is a serious but preventable public health issue. Several previous studies have revealed a positive association between altitude and suicide rates at the county level in the contiguous United States. We assessed the association between suicide rates and altitude using a cross-county ecological study design. Data on suicide rates were obtained from a Web-based Injury Statistics Query and Reporting System (WISQARS, maintained by the U.S. National Center for Injury Prevention and Control (NCIPC. Altitude data were collected from the United States Geological Survey (USGS. We employed an ordinary least square (OLS regression to model the association between altitude and suicide rates in 3064 counties in the contiguous U.S. We conducted a geographically weighted regression (GWR to examine the spatially varying relationship between suicide rates and altitude after controlling for several well-established covariates. A significant positive association between altitude and suicide rates (average county rates between 2008 and 2014 was found in the dataset in the OLS model (R2 = 0.483, p < 0.001. Our GWR model fitted the data better, as indicated by an improved R2 (average: 0.62; range: 0.21–0.64 and a lower Akaike Information Criteria (AIC value (13,593.68 vs. 14,432.14 in the OLS model. The GWR model also significantly reduced the spatial autocorrelation, as indicated by Moran’s I test statistic (Moran’s I = 0.171; z = 33.656; p < 0.001 vs. Moran’s I = 0.323; z = 63.526; p < 0.001 in the OLS model. In addition, a stronger positive relationship was detected in areas of the northern regions, northern plain regions, and southeastern regions in the U.S. Our study confirmed a varying overall positive relationship between altitude and suicide. Future research may consider controlling more predictor variables in regression models, such as firearm ownership, religion, and access to mental health services.

  18. The Effect of Crop Residue and Different NPK Fertilizer Rates on yield Components and Yield of Wheat

    Directory of Open Access Journals (Sweden)

    fatemeh khamadi

    2017-08-01

    Full Text Available Introduction Integrated nutrient management involving crop residue/green manures and chemical fertilizer is potential alternative to provide a balanced supply of nutrients, enhance soil quality and thereby sustain higher productivity. The present experiment was undertaken to evaluate the effect of different crop residue management practices and NPK levels on yield components and yield of wheat. Materials and methods Field experiments were conducted during 2012-2014 at department of agronomy, Chamran University. Experiment was laid out in a randomized block designs in split plot arrangement. With three replications. Crop residues were assigned to main plot consistent CR1: wheat residue; CR2: rape residue; CR3: barley residue; CR4: barley residue + vetch; CR5: wheat straw + mungbean; CR6: vetch residue; CR7: mungbean residue; CR8: No residue incorporation as main plot and three NPK fertilizer rates: F1: (180N-120P-100K kg.ha-1; F2: (140N-90P-80K kg.ha-1; F3: (90N-60P-40K kg.ha-1 as sub plots. Twelve hills were collected at physiological maturity for measuring yield components from surrounding area of grain yield harvest area. Yield components, viz. number of spike per m2, seed per spike, 1000- grain weight, plant height were measured. Grain and straw yields were recorded from the central 5 m2 grain yield harvest area of each treatment and harvest index was calculated. Data were subjected to analysis by SAS and mean companions were performed using the Duncan multiple range test producer. Also, graphs were drawn in Excel software. Results and discussion The result of analysis variance showed significant difference between crop residues for evaluated traits. The result indicated that the highest biological and grain yield was obtained when wheat treated with CR5: wheat straw + mungbean (green manure and CR4: barley straw + vetch (green manure. Biological and grain yield increased 31 and 26% respectively by CR5 comparing with control. The highest

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

    Directory of Open Access Journals (Sweden)

    Krystof Zeman

    2018-02-01

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

  20. NPK, protein content and yield of broccoli as affected by gamma rays seeds irradiation and phosphorus fertilizer rates

    International Nuclear Information System (INIS)

    El-Desoki, S.A.; Abdallah, A.A.G.; Awad, S.M.; Aboel-Kheir, O.H.

    2005-01-01

    Two field experiments were carried out during 1999/2000 and 2000/2001 winter growing seasons at the experimental farm of Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt. The experiments were conducted to study the effect of pre sowing-seeds irradiation with different doses of gamma rays (0, 2, 3 and 4 Gy) and different phosphorus fertilizer application rates, 0, 30, 60 and 90 k P 2 O 5 /fed) on NPK content of leaves and spear, and protein content in spears at maturity, spear diameter, main spear fresh and dry weight per plant, total spear fresh weight per plant and total spear yield. In general, exposing broccoli seeds to different gamma ray doses up to 4 Gy prior to sowing increased the above mentioned parameters with different magnitudes comparing with the non-irradiated control plants. The highest percentage of increase was obtained by exposing broccoli seeds to 3 Gy. There were non-significant differences between 3 and 4 Gy treatments during the two growing seasons. With respect to the effect of phosphorus fertilizer application rates on the studied parameters, increasing phosphorus application rates up to 90 kg P 2 O 5 /fed increased the above mentioned parameters. The highest percentage of increase was obtained by applying 90 kg P 2 O 5 /fed. The interaction, gamma ray and P level showed phosphorus there were significant differences in main spear fresh and dry weight per plant, total spear yield and spear diameter in first season. The highest value was obtained by 3 Gy and 90 kg P 2 O 5 /fed. Also there were significant effects on NPK content in broccoli leaves at 90 days after transplanting (DAT) except P in second season and nonsignificant values of broccoli spear at harvest except N, K in first season. The highest protein content of broccoli spears at harvest was obtained with 2 Gy and 30 kg P 25 /fed

  1. Benthic Uptake Rate due to Hyporheic Exchange: The Effects of Streambed Morphology for Constant and Sinusoidally Varying Nutrient Loads

    Directory of Open Access Journals (Sweden)

    Daniele Tonina

    2015-01-01

    Full Text Available Hyporheic exchange carries reactive solutes, which may include biological oxygen demand (BOD, dissolved oxygen (DO and reactive dissolved inorganic nitrogen (Nr, into the sediment, where biochemical reactions consume DO. Here, we study the impact of streambed morphology, stream-reactive solute loads and their diel oscillations on the DO benthic uptake rate (BUR due to hyporheic processes. Our model solves the hyporheic flow field and the solute transport equations analytically, within a Lagrangian framework, considering advection, longitudinal diffusion and reactions modeled as first order kinetics. The application of the model to DO field measurements over a gravel bar-pool sequence shows a good match with measured DO concentrations with an overall agreement of 58% and a kappa index of 0.46. We apply the model to investigate the effects of daily constant and sinusoidally time varying stream BOD, DO and Nr loads and of the morphodynamic parameters on BUR. Our modeling results show that BUR varies as a function of bedform size and of nutrient loads and that the hyporheic zone may consume up to 0.06% of the stream DO at the pool-riffle bedform scale. Daily oscillations of stream BOD and DO loads have small effects on BUR, but may have an important influence on local hyporheic processes and organisms’ distribution.

  2. Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

    International Nuclear Information System (INIS)

    Winterle, Bret

    2001-01-01

    Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

  3. Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

    Energy Technology Data Exchange (ETDEWEB)

    Winterle, Bret

    2001-07-01

    Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

  4. Impacts of low dose rate irradiation on the fertility, fecundity and hatchling survival of Japanese rice fish (medaka, Oryzias latipes)

    International Nuclear Information System (INIS)

    Hinton, T.G.; Coughlin, D.P.; Marsh, L.C.; Yi, Yi; Winn, R.

    2004-01-01

    A renewed international interest in the effects on biota from low dose rate irradiation has recently occurred. Much of that interest is centered on the relevance of previously accepted dose rate guidelines (e.g. 10 mGy d -1 for aquatic biota) suggested by the ICRP and IAEA. All parties concerned seem to agree that additional data are needed on population level impacts from chronic low-level exposures to radionuclides. Using a Low Dose Rate Irradiation Facility (LoDIF), we conducted an experiment on the fecundity, fertility and hatchling survival of Japanese Rice Fish (medaka, Oryzias latipes). Fish were exposed externally to 137 Cs from juvenile through adulthood at mean dose rates of 3.5, 35 and 350 mGy d -1 . Fish were bred at maturity and the following endpoints were examined: 1) the number of eggs produced; 2) the percent of eggs that hatched; and 3) the survival of hatchlings 20-days post hatch. The influence of gender was examined by breeding irradiated males with control females; control males with irradiated females; irradiated males with irradiated females; and control males with control females. The data contribute to our understanding the impacts of low dose rate irradiation. (author)

  5. Parental attitudes toward fertility preservation in boys with cancer: context of different risk levels of infertility and success rates of fertility restoration

    NARCIS (Netherlands)

    Sadri-Ardekani, Hooman; Akhondi, Mohammad-Mehdi; Vossough, Parvaneh; Maleki, Haleh; Sedighnejad, Shirin; Kamali, Koorosh; Ghorbani, Behzad; van Wely, Madelon; van der Veen, Fulco; Repping, Sjoerd

    2013-01-01

    To measure the parental attitudes toward fertility preservation in boys with cancer. Retrospective cohort study. Questionnaire survey via regular mail. A total of 465 families whose sons were already treated for cancer. The questionnaire was designed for two groups based on child's age at the time

  6. Comparison of Technical and Economical Effect of Different Planters using Varied Seed Rates on Canola Yield in Moghan Region

    Directory of Open Access Journals (Sweden)

    J Taghinazhad

    2017-10-01

    Full Text Available Introduction One of the most important agricultural crops is rape seed oil as its special features can play an important role in the agricultural region. Due to the presence of more than 40% oil and 25% protein in the grain can play an important role in the supply of edible oil. After determining of various factors such as uniformity of planting depth, evenness between shrub, plant height and grain yield concluded that Nordsten drill along the seeding density of 75 cm for mechanized planting is acceptable yield. Afzali nia et al. (1999 in one study aimed to assess the performance of common grain drills in Iran in Zarghan area in Fars Province showed that differences between treatments in terms of seed distribution uniformity factor, plant population per unit area and yield product is not significant. The purpose of this study was to evaluate and select the most suitable types of canola planter and variable seed rate planting density and aims to increase the canola cultivated area by the highest yield. Materials and Methods Moghan Plain, located in the north areas of Ardebil province, is considered as an important areas of canola planting in Iran. This study was performed in the agricultural research center of Ardabil Province (Moghan (39°39´N; 48°88´E; 78 m a.s.l. in Northwest of Iran. To evaluate different planters with varied seed rates on canola yield. The experimental design was carried out in a randomized complete block design with strip splits (varied seed rates 6, 8 and10 kg per hectare and different drills consist of B1: Barzagar Hamadani drill (conventional method B2: Amazon drill pals teeth harrow, B3: Gaspardo drill pals teeth harrow and B4: Agromaster drill and four replications. To investigatethe different treatments in the experiment, various parameters such as percent germination, seeding uniformity of width and depth intervals, plant establishment, effective field capacity, fuel consumption rate andgrain yield were measured

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

    Directory of Open Access Journals (Sweden)

    Wei Shi

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Gülüm Kosova

    2010-06-01

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

  9. Effect of Gutai Decoction (固胎汤) on the Abortion Rate of in vitro Fertilization and Embryo Transfer

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; WU Jing-zhi

    2006-01-01

    Objective: To study the effect of Chinese herbal medicine Gutai Decoction (固胎汤, GTD) on the abortion rate of in vitro fertilization and embryo transfer (IVF-ET). Methods: Observed were two hundred and forty-seven women having received IVF-ET and with β-human chorionic gonadotropin (β-HCG) > 25 IU/L on the 14th day after transferring. All were treated conventionally with progesterone 20-80 mg per day after transferring and if necessary the treatment was supplemented with Progynova 2 - 4 mg per day, with the medication withdrawn gradually from the 9th week of pregnancy till stopped completely. Among them 131 cases received GTD medication additionally, for 109 cases of whom the medication started from the 2nd day of transferring (taken as Group A) and for the other 22 cases from the 14th day after transferring (taken as Group B), the other 116 cases with no additional GTD treatment given were taken as the control group, with the medication lasting to the 12th week. The abortion rate in them was observed. Results: The abortion rate in Group A, Group B and the control group was 12.84%, 13.64% and 23.28%, respectively, the difference between the GTD treated groups and the control group was significant (P<0.05). Conclusion: Chinese medicine GTD could reduce abortion rate in women receiving IVF-ET.

  10. Time-varying surrogate data to assess nonlinearity in nonstationary time series: application to heart rate variability.

    Science.gov (United States)

    Faes, Luca; Zhao, He; Chon, Ki H; Nollo, Giandomenico

    2009-03-01

    We propose a method to extend to time-varying (TV) systems the procedure for generating typical surrogate time series, in order to test the presence of nonlinear dynamics in potentially nonstationary signals. The method is based on fitting a TV autoregressive (AR) model to the original series and then regressing the model coefficients with random replacements of the model residuals to generate TV AR surrogate series. The proposed surrogate series were used in combination with a TV sample entropy (SE) discriminating statistic to assess nonlinearity in both simulated and experimental time series, in comparison with traditional time-invariant (TIV) surrogates combined with the TIV SE discriminating statistic. Analysis of simulated time series showed that using TIV surrogates, linear nonstationary time series may be erroneously regarded as nonlinear and weak TV nonlinearities may remain unrevealed, while the use of TV AR surrogates markedly increases the probability of a correct interpretation. Application to short (500 beats) heart rate variability (HRV) time series recorded at rest (R), after head-up tilt (T), and during paced breathing (PB) showed: 1) modifications of the SE statistic that were well interpretable with the known cardiovascular physiology; 2) significant contribution of nonlinear dynamics to HRV in all conditions, with significant increase during PB at 0.2 Hz respiration rate; and 3) a disagreement between TV AR surrogates and TIV surrogates in about a quarter of the series, suggesting that nonstationarity may affect HRV recordings and bias the outcome of the traditional surrogate-based nonlinearity test.

  11. Evaluation of varying ductile fracture criteria for 42CrMo steel by compressions at different temperatures and strain rates.

    Science.gov (United States)

    Quan, Guo-zheng; Luo, Gui-chang; Mao, An; Liang, Jian-ting; Wu, Dong-sen

    2014-01-01

    Fracturing by ductile damage occurs quite naturally in metal forming processes, and ductile fracture of strain-softening alloy, here 42CrMo steel, cannot be evaluated through simple procedures such as tension testing. Under these circumstances, it is very significant and economical to find a way to evaluate the ductile fracture criteria (DFC) and identify the relationships between damage evolution and deformation conditions. Under the guidance of the Cockcroft-Latham fracture criteria, an innovative approach involving hot compression tests, numerical simulations, and mathematic computations provides mutual support to evaluate ductile damage cumulating process and DFC diagram along with deformation conditions, which has not been expounded by Cockcroft and Latham. The results show that the maximum damage value appears in the region of upsetting drum, while the minimal value appears in the middle region. Furthermore, DFC of 42CrMo steel at temperature range of 1123~1348 K and strain rate of 0.01~10 s(-1) are not constant but change in a range of 0.160~0.226; thus, they have been defined as varying ductile fracture criteria (VDFC) and characterized by a function of temperature and strain rate. In bulk forming operations, VDFC help technicians to choose suitable process parameters and avoid the occurrence of fracture.

  12. Evaluation of Varying Ductile Fracture Criteria for 42CrMo Steel by Compressions at Different Temperatures and Strain Rates

    Directory of Open Access Journals (Sweden)

    Guo-zheng Quan

    2014-01-01

    Full Text Available Fracturing by ductile damage occurs quite naturally in metal forming processes, and ductile fracture of strain-softening alloy, here 42CrMo steel, cannot be evaluated through simple procedures such as tension testing. Under these circumstances, it is very significant and economical to find a way to evaluate the ductile fracture criteria (DFC and identify the relationships between damage evolution and deformation conditions. Under the guidance of the Cockcroft-Latham fracture criteria, an innovative approach involving hot compression tests, numerical simulations, and mathematic computations provides mutual support to evaluate ductile damage cumulating process and DFC diagram along with deformation conditions, which has not been expounded by Cockcroft and Latham. The results show that the maximum damage value appears in the region of upsetting drum, while the minimal value appears in the middle region. Furthermore, DFC of 42CrMo steel at temperature range of 1123~1348 K and strain rate of 0.01~10 s-1 are not constant but change in a range of 0.160~0.226; thus, they have been defined as varying ductile fracture criteria (VDFC and characterized by a function of temperature and strain rate. In bulk forming operations, VDFC help technicians to choose suitable process parameters and avoid the occurrence of fracture.

  13. Sensitivity of CO2 storage performance to varying rates and dynamic injectivity in the Bunter Sandstone, UK

    Science.gov (United States)

    Kolster, C.; Mac Dowell, N.; Krevor, S. C.; Agada, S.

    2016-12-01

    Carbon capture and storage (CCS) is needed for meeting legally binding greenhouse gas emissions targets in the UK (ECCC 2016). Energy systems models have been key to identifying the importance of CCS but they tend to impose few constraints on the availability and use of geologic CO2 storage reservoirs. Our aim is to develop simple models that use dynamic representations of limits on CO2 storage resources. This will allow for a first order representation of the storage reservoir for use in systems models with CCS. We use the ECLIPSE reservoir simulator and a model of the Southern North Sea Bunter Sandstone saline aquifer. We analyse reservoir performance sensitivities to scenarios of varying CO2 injection demand for a future UK low carbon energy market. With 12 injection sites, we compare the impact of injecting at a constant 2MtCO2/year per site and varying this rate by a factor of 1.8 and 0.2 cyclically every 5 and 2.5 years over 50 years of injection. The results show a maximum difference in average reservoir pressure of 3% amongst each case and a similar variation in plume migration extent. This suggests that simplified models can maintain accuracy by using average rates of injection over similar time periods. Meanwhile, by initiating injection at rates limited by pressurization at the wellhead we find that injectivity steadily increases. As a result, dynamic capacity increases. We find that instead of injecting into sites on a need basis, we can strategically inject the CO2 into 6 of the deepest sites increasing injectivity for the first 15 years by 13%. Our results show injectivity as highly dependent on reservoir heterogeneity near the injection site. Injecting 1MTCO2/year into a shallow, low permeability and porosity site instead of into a deep injection site with high permeability and porosity reduces injectivity in the first 5 years by 52%. ECCC. 2016. Future of Carbon Capture and Storage in the UK. UK Parliament House of Commons, Energy and Climate Change

  14. Fertility Rates of Ewes Treated with Medroxyprogesterone and Injected with Equine Chorionic Gonadotropin plus Human Chorionic Gonadotropin in Anoestrous Season

    Directory of Open Access Journals (Sweden)

    I. W. Santos

    2010-01-01

    Full Text Available The aim of the present paper was to investigate the efficiency of the equine chorionic gonadotropin (eCG plus human chorionic gonadotropin (hCG associated with medroxyprogesterone acetate (MAP to estrous ewes synchronization. Ninety Texel ewes were investigated during seasonal anoestrous. The ewes received intravaginal sponges containing MAP (60 mg for nine days. At the time of sponges' withdrawal, the ewes were divided into three groups (G: (1 receiving 2 mL of saline i.m. (n=30, (2 receiving eCG 400 IU i.m. (n=30, and (3 receiving eCG 400 IU plus hCG 200 IU i.m. (n=30. Twelve h after sponges' removal, teaser rams were used to estrus check and remained with the ewes for 96 h. The artificial insemination was made with fresh semen 10 h after estrus detection. The effect of the treatment was not significant for the estrous rates among the groups: 73%, 90%, and 86%, respectively. The main effect was observed in the pregnancy and lambing rates among the groups: 70%, 86%, 56%, and 80%, 120%, 56%, respectively. Based on these results from our study, the use of the MAP—eCG is the best choice to improve the fertility rate on ewes.

  15. Impact of the Z potential technique on reducing the sperm DNA fragmentation index, fertilization rate and embryo development.

    Science.gov (United States)

    Duarte, Carlos; Núñez, Víctor; Wong, Yat; Vivar, Carlos; Benites, Elder; Rodriguez, Urso; Vergara, Carlos; Ponce, Jorge

    2017-12-01

    In assisted reproduction procedures, we need to develop and enhance new protocols to optimize sperm selection. The aim of this study is to evaluate the ability of the Z potential technique to select sperm with intact DNA in non-normospermic patients and evaluate the impact of this selection on embryonic development. We analyzed a total of 174 human seminal samples with at least one altered parameter. We measured basal, post density gradients, and post density gradients + Z potential DNA fragmentation index. To evaluate the impact of this technique on embryo development, 54 cases were selected. The embryo development parameters evaluated were fertilization rate, cleavage rate, top quality embryos at the third day and blastocysts rate. We found significant differences in the study groups when we compared the sperm fragmentation index by adding the Z potential technique to density gradient selection vs. density gradients alone. Furthermore, there was no significant difference in the embryo development parameters between the low sperm fragmentation index group vs. the moderate and high sperm fragmentation index groups, when selecting sperms with this new technique. The Z potential technique is a very useful tool for sperm selection; it significantly reduces the DNA fragmentation index and improves the parameters of embryo development. This technique could be considered routine for its simplicity and low cost.

  16. Fertilizer N application rate impacts plant-soil feedback in a sanqi production system.

    Science.gov (United States)

    Wei, Wei; Yang, Min; Liu, Yixiang; Huang, Huichuan; Ye, Chen; Zheng, Jianfen; Guo, Cunwu; Hao, Minwen; He, Xiahong; Zhu, Shusheng

    2018-08-15

    Replant failure caused by negative plant-soil feedback (NPFS) in agricultural ecosystems is a critical factor restricting the development of sustainable agriculture. Soil nutrient availability has the capacity to affect plant-soil feedback. Here, we used sanqi (Panax notoginseng), which is severely threatened by NPSF, as a model plant to decipher the overall effects of nitrogen (N) rates on NPSF and the underlying mechanism. We found that a high rate of N at 450kgNha -1 (450N) aggravated the NPSF through the accumulation of pathogens in the soil compared with the optimal 250N. The increased N rates resulted in a significant increase in the soil electrical conductivity and available nitrogen but a decrease in the soil pH and C/N ratio. GeoChip 5.0 data demonstrated that these changed soil properties caused the soil to undergo stress (acidification, salinization and carbon starvation), as indicated by the enriched soil microbial gene abundances related to stress response and nutrition cycling (N, C and S). Accordingly, increased N rates reduced the richness and diversity of soil fungi and bacteria and eventually caused a shift in soil microbes from a bacterial-dominant community to a fungal-dominant community. In particular, the high 450N treatment significantly suppressed the abundance of copiotrophic bacteria, including beneficial genera Bacillus and Pseudomonas, thus weakening the antagonistic activity of these bacteria against fungal pathogens. Moreover, 450N application significantly enriched the abundance of pathogen pathogenicity-related genes. Once sanqi plants were grown in this N-stressed soil, their host-specific fungal pathogen Fusarium oxysporum significantly accumulated, which aggravated the process of NPSF. This study suggested that over-application of nitrogen is not beneficial for disease management or the reduction of fungicide application in agricultural production. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Photosynthesis rate, chlorophyll content and initial development of physic nut without micronutrient fertilization

    Directory of Open Access Journals (Sweden)

    Elcio Ferreira dos Santos

    2013-10-01

    Full Text Available Few studies in Brazil have addressed the need for micronutrients of physic nut focusing on physiological responses, especially in terms of photosynthesis. The objective of this study was to evaluate the effects of omission of boron (B, copper (Cu, iron (Fe, manganese (Mn and zinc (Zn on Jatropha curcas L.. The experimental design was a randomized block with four replications. The treatments were complete solution (control and solution without B, Cu, Fe, Mn, and Zn. We evaluated the chlorophyll content (SPAD units, photosynthetic rate, dry matter production and accumulation of micronutrients in plants, resulting from different treatments. The first signs of deficiency were observed for Fe and B, followed by Mn and Zn, while no symptoms were observed for Cu deficiency. The micronutrient omission reduced the dry matter yield, chlorophyll content and photosynthetic rate of the plants differently for each omitted nutrient. It was, however, the omission of Fe that most affected the development of this species in all parameters evaluated. The treatments negatively affected the chlorophyll content, evaluated in SPAD units, and the photosynthetic rate, except for the omission of B. However this result was probably due to the concentration effect, since there was a significant reduction in the dry matter production of B-deficient plants.

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

    Science.gov (United States)

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

    2016-01-01

    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. 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. 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%). 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.

  19. The magnitude and rate of reduction in strength, dexterity and sensation in the human hand vary with ageing.

    Science.gov (United States)

    Bowden, Jocelyn L; McNulty, Penelope A

    2013-08-01

    Cutaneous sensation and motor performance of the hand decline with age. It is not known if motor performance declines are influenced by reductions in cutaneous sensation, or if motor performance deteriorates at a consistent rate across motor tasks. Handgrip strength, finger-tapping frequency and grooved-pegboard performance were assessed for both hands of 70 subjects (20-88 years), 10 per decade. Motor declines were compared to reductions in perceptual cutaneous sensation tested at 10 hand sites using calibrated von Frey filaments. Motor performance decreased with age for all motor tasks (psensation also decreased with age, measured as increased von Frey thresholds of 0.04 g [0.02-0.07] to 0.16 g [0.04-0.4] (psensation varied with sex, side-tested and site. Reductions in grip-based tasks were associated with sensory declines in the palm, but elsewhere there was little correlation among motor tasks and cutaneous sensation in the hand. Grooved-pegboard performance was the best predictor of age-related declines in motor performance regardless of sex or side-tested. Our results suggest age-related declines in motor function cannot be inferred from, or provide information about, changes in cutaneous sensation. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. NPK, protein content and yield of broccoli as affected by gamma rays seeds irradiation and phosphorus fertilizer rates

    Energy Technology Data Exchange (ETDEWEB)

    El-Desoki, S A [Botany Department, Faculty of Agriculture, Moshtohor, Zagazig University (Egypt); Abdallah, A A.G.; Awad, S M; Aboel-Kheir, O H [Plant Research Department, Nuclear Research Center, Cairo (Egypt)

    2005-07-01

    Two field experiments were carried out during 1999/2000 and 2000/2001 winter growing seasons at the experimental farm of Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt. The experiments were conducted to study the effect of pre sowing-seeds irradiation with different doses of gamma rays (0, 2, 3 and 4 Gy) and different phosphorus fertilizer application rates, 0, 30, 60 and 90 k P{sub 2}O{sub 5} /fed) on NPK content of leaves and spear, and protein content in spears at maturity, spear diameter, main spear fresh and dry weight per plant, total spear fresh weight per plant and total spear yield. In general, exposing broccoli seeds to different gamma ray doses up to 4 Gy prior to sowing increased the above mentioned parameters with different magnitudes comparing with the non-irradiated control plants. The highest percentage of increase was obtained by exposing broccoli seeds to 3 Gy. There were non-significant differences between 3 and 4 Gy treatments during the two growing seasons. With respect to the effect of phosphorus fertilizer application rates on the studied parameters, increasing phosphorus application rates up to 90 kg P{sub 2}O{sub 5}/fed increased the above mentioned parameters. The highest percentage of increase was obtained by applying 90 kg P{sub 2}O{sub 5}/fed. The interaction, gamma ray and P level showed phosphorus there were significant differences in main spear fresh and dry weight per plant, total spear yield and spear diameter in first season. The highest value was obtained by 3 Gy and 90 kg P{sub 2}O{sub 5}/fed. Also there were significant effects on NPK content in broccoli leaves at 90 days after transplanting (DAT) except P in second season and nonsignificant values of broccoli spear at harvest except N, K in first season. The highest protein content of broccoli spears at harvest was obtained with 2 Gy and 30 kg P{sub 25}/fed.

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

    Directory of Open Access Journals (Sweden)

    Bernd Lesoine

    2016-01-01

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Kadušić Alma

    2015-01-01

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

  3. Influence of the form and rate of 15N-labelled nitrogen fertilizers on nitrogen uptake by maize grown on two different soils

    International Nuclear Information System (INIS)

    Balabanova-Georgieva, R.; Ikonomova, E.

    1996-01-01

    The influence of 15 N-labelled urea and ammonium sulfate on the yield and uptake of fertilizer nitrogen and soil nitrogen by maize was studied under the conditions of pot experiments on calcareous black earth and leached black earth. The nitrogen fertilizers were applied in rates: N 1 =250 mg, N 2 =500 mg, N 3 =750 mg and N 4 =1000 mg/1 kg of soil, on phosphorus(P)-potassium(K) background (P=200 and K=600 mg/kg soil). When treating with N 3 and N 4 , the application of the whole nitrogen rate was compared with its split application. It was found that the form of the nitrogen fertilizer played no important role for the formation of the yield of biomass and the uptake of nitrogen with the yield when it is applied in low nitrogen rates and maize was grown on calcareous black earth. The yield of biomass and the uptake of nitrogen with the yield of maize reach their maximum under the conditions of calcareous black earth and high nitrogen rates applied as urea depressed the plants which proves the statement that in case of calcareous black earth application of ammonium sulfate should be preferred rather that urea, fertilization with which should be avoided. No depression of plants was observed under the conditions of leached black earth and application of high urea rates. The amount of nitrogen taken up is growing with the increasing of the nitrogen rate (excluding the N-treatment). The split application of high nitrogen rates increased notably the yield of maize-vegetation mass which proved the great ability of this crop for effective utilization of the nitrogen fertilizers when applied in portions and at suitable phases of plant vegetation. The role of the fertilizer nitrogen on the formation of the plant mass yield is much greater compared to that of the soil nitrogen; in the split application of urea the soil nitrogen plays a much bigger role than in its single application. The additional mobilization of the soil nitrogen under the influence of the applied nitrogen

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

    Science.gov (United States)

    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.

  5. Fertility in female reindeer: the effects of nutrition and growth

    OpenAIRE

    N. J.C. Tyler

    1987-01-01

    Pregnancy rates in juvenile reindeer (Rangifer tarandus) vary considerably both within and between flocks. This potentially has considerable economic significance for reindeer husbandry. This paper discusses the influence of nutrition and growth on fertility in female reindeer using examples taken from the literature. Fertility in reindeer is related to body weight, like in many other mammals, but the relationship is not invariant. Weight-specific pregnancy rates appear to be density dependen...

  6. [Milk yield and environmental factors: Multiple regression analysis of the association between milk yield and udder health, fertility data and replacement rate].

    Science.gov (United States)

    Fölsche, C; Staufenbiel, R

    2014-01-01

    The relationship between milk yield and both fertility and general animal health in dairy herds is discussed from opposing viewpoints. The hypothesis (1) that raising the herd milk yield would decrease fertility results, the number of milk cells as an indicator for udder health and the replacement rate as a global indicator for animal health as well as increasing the occurrence of specific diseases as a herd problem was compared to the opposing hypotheses that there is no relationship (2) or that there is a differentiated and changing relationship (3). A total of 743 herd examinations, considered independent, were performed in 489 herds between 1995 and 2010. The milk yield, fertility rate, milk cell count, replacement rate, categorized herd problems and management information were recorded. The relationship between the milk yield and both the fertility data and animal health was evaluated using simple and multiple regression analyses. The period between calving and the first service displayed no significant relationship to the herd milk yield. Simple regression analysis showed that the period between calving and gestation, the calving interval and the insemination number were significantly positively associated with the herd milk yield. This positive correlation was lost in multiple regression analysis. The milk cell count and replacement rate using both the simple and multiple regression analyses displayed a significant negative relationship to the milk yield. The alternative hypothesis (3) was confirmed. A higher milk yield has no negative influence on the milk cell count and the replacement rate in terms of the udder and general health. When parameterizing the fertility, the herd milk yield should be considered. Extending the resting time may increase the milk yield while preventing a decline in the insemination index.

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

    Science.gov (United States)

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

    2012-08-01

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

  8. Genetic and environmental factors influencing first service conception rate and late embryonic/foetal mortality in low fertility dairy herds.

    Science.gov (United States)

    Grimard, B; Freret, S; Chevallier, A; Pinto, A; Ponsart, C; Humblot, P

    2006-01-01

    The objective of this study was to identify factors affecting variation in conception rate to first artificial inseminations (AI) (CR: number of pregnant cows on D80-100/inseminated cows) and the incidence of embryonic/foetal loss (LEM) between 21 and 80 days of pregnancy (number of cows non-pregnant on D80-100/pregnant on D21) in 44 low fertility dairy herds of the west-central region of France. Reproductive status was assessed using progesterone milk concentration on D0 = Day of AI and D21-24, plasma PSPB concentration on D30-35, rectal palpation on D80-100 and observed return to oestrous. The final data set contained 1285 Prim'Holstein cows, 5.0% (64/1285) were inseminated in the luteal phase (progesterone > or = 3 ng/ml on D0), 61.3% (787/1285) were pregnant on D21-24 (progesterone or = 5 ng/ml on D21-24), 15.4% lost their embryo/foetus between D21-24 and D80-100 (198/1285) and 45.8% (589/1285) were pregnant on D80-100. The incidence of late embryonic/foetal loss (LEM) was 25.2% (198/787). Multivariate logistic regression models including the random herd effect were used to analyse the relationship between AI centre, AI sire, cow's sire, parity, interval between calving and AI, milk production, milk protein content, body condition score (BCS) on D0, season of calving, season of AI, estimated genetic index on CR and LEM incidence. CR was significantly related to parity (p or = 70 days versus > or = 90 days, but the overall effect of the interval was not significant (p = 0.11). LEM incidence was affected by period of AI (p < 0.05), milk production (p < 0.05) and BCS (p < 0.05), but was not related to estimated genetic index. In conclusion, in these low fertility herds, the incidence of LEM was high and 25% of the cows lost their embryo after 21 days of pregnancy. LEM was affected by specific factors (season, BCS), which were not related to CR. The absence of a relationship between estimated genetic index and LEM in spite of its effect on CR indicates that

  9. Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

    International Nuclear Information System (INIS)

    Saravanan, N.; Nagarajan, G.

    2010-01-01

    Automobiles are one of the major sources of air pollution in the environment. In addition CO 2 emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 o crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 o CA before gas exchange top dead centre (BGTDC) with injection duration of 30 o CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO X emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO 2 ) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of hydrogen

  10. Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, N. [ERC Engines, Tata Motors, Pimpri, Pune (India); Nagarajan, G. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai (India)

    2010-07-15

    Automobiles are one of the major sources of air pollution in the environment. In addition CO{sub 2} emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 CA before gas exchange top dead centre (BGTDC) with injection duration of 30 CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO{sub X} emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO{sub 2}) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of

  11. Accelerated Rates of Nitrogen Cycling and N2O Production in Salt Marsh Sediments due to Long-Term Fertilization

    Science.gov (United States)

    Peng, X.; Ji, Q.; Angell, J.; Kearns, P.; Bowen, J. L.; Ward, B. B.

    2014-12-01

    Intensified sedimentary production of nitrous oxide (N2O), one of the most potent greenhouse gases, is one of the many possible environmental consequences of elevated nitrogen (N) loading into estuarine ecosystems. This study investigates the response to over 40 years of fertilization of nitrogen removal processes in the sediments of the Great Sippewissett Marsh in Falmouth, MA. Sediment slurries were incubated (1.5 hr) with trace amounts (fertilized sediments (0.89 nmol hr-1 g-1 wet weight) was 30-fold higher than in unfertilized sediments. The ratio of N2O to N2 production was also significantly higher in fertilized sediments (2.9%) than in unfertilized sediments (1.2%). This highlights the disproportionally large effect of long-term fertilization on N2O production in salt marsh sediments. The reduced oxygen level and higher ammonium concentrations in situ probably contributed to the significant rise in N2O production as a result of long-term fertilization. When detected, anammox and coupled nitrification-denitrification accounted for 10% and 14% of the total N2 production in fertilized sediments (30.5 nmol hr-1 g-1 wet weight), respectively, whereas neither was detected in unfertilized sediments. Thus these experiments indicate that N loading has important effects on multiple N cycle processes that result in N loss and N2O production.

  12. The effects of varying injection rates in Osage County, Oklahoma, on the 2016 Mw5.8 Pawnee earthquake

    Science.gov (United States)

    Barbour, Andrew J.; Norbeck, Jack H.; Rubinstein, Justin L.

    2017-01-01

    The 2016 Mw 5.8 Pawnee earthquake occurred in a region with active wastewater injection into a basal formation group. Prior to the earthquake, fluid injection rates at most wells were relatively steady, but newly collected data show significant increases in injection rate in the years leading up to earthquake. For the same time period, the total volumes of injected wastewater were roughly equivalent between variable‐rate and constant‐rate wells. To understand the possible influence of these changes in injection, we simulate the variable‐rate injection history and its constant‐rate equivalent in a layered poroelastic half‐space to explore the interplay between pore‐pressure effects and poroelastic effects on the fault leading up to the mainshock. In both cases, poroelastic stresses contribute a significant proportion of Coulomb failure stresses on the fault compared to pore‐pressure increases alone, but the resulting changes in seismicity rate, calculated using a rate‐and‐state frictional model, are many times larger when poroelastic effects are included, owing to enhanced stressing rates. In particular, the variable‐rate simulation predicts more than an order of magnitude increase in seismicity rate above background rates compared to the constant‐rate simulation with equivalent volume. The observed cumulative density of earthquakes prior to the mainshock within 10 km of the injection source exhibits remarkable agreement with seismicity predicted by the variable‐rate injection case.

  13. Decreasing fertility rate correlates with the chronological increase and geographical variation in incidence of Kawasaki disease in Japan.

    Directory of Open Access Journals (Sweden)

    Yoshiro Nagao

    Full Text Available BACKGROUND: Kawasaki disease (KD is a common cause of acquired paediatric heart disease in developed countries. KD was first identified in the 1960s in Japan, and has been steadily increasing since it was first reported. The aetiology of KD has not been defined, but is assumed to be infection-related. The present study sought to identify the factor(s that mediate the geographical variation and chronological increase of KD in Japan. METHODS AND FINDINGS: Based upon data reported between 1979 and 2010 from all 47 prefectures in Japan, the incidence and mean patient age at the onset of KD were estimated. Using spatial and time-series analyses, incidence and mean age were regressed against climatic/socioeconomic variables. Both incidence and mean age of KD were inversely correlated with the total fertility rate (TFR; i.e., the number of children that would be born to one woman. The extrapolation of a time-series regressive model suggested that KD emerged in the 1960s because of a dramatic decrease in TFR in the 1940s through the 1950s. CONCLUSIONS: Mean patient age is an inverse surrogate for the hazard of contracting the aetiologic agent. Therefore, the observed negative correlation between mean patient age and TFR suggests that a higher TFR is associated with KD transmission. This relationship may be because a higher TFR facilitates sibling-to-sibling transmission. Additionally, the observed inverse correlation between incidence and TFR implies a paradoxical "negative" correlation between the incidence and the hazard of contracting the aetiologic agent. It was hypothesized that a decreasing TFR resulted in a reduced hazard of contracting the agent for KD, thereby increasing KD incidence.

  14. Effect of different rates of potassium fertilizer and soil moisture on nitrogen and potassium use efficiencies and tomato yield using an 15N isotopic dilution technique

    International Nuclear Information System (INIS)

    Khalifa, Kh.; Al-Ain, F.; Al-Chamma'a, M.

    2005-03-01

    A pot experiment was conducted to evaluate the response of tomato to 4 potassium rates (0, 90, 120, 150 kg K 2 O/ha), one rate of N (150 kg/ha) and two irrigation regimes 65 % and 85 % of field capacity (FC) on yield and the efficient use of N and K fertilizers. Results showed that dry matter yield was positively correlated with the rate of K fertilizer applied under the two irrigation regimes. However the increase in production of fruits and dry matter was higher at the 85% FC. The K-uptake in fruit and whole plant increased with increasing K application levels and was higher at the 85 % but the opposite was observed in shoots and roots. Potassium use efficiency increased with increasing K levels at the two irrigation regimes and the values were higher at the 85 %. The nitrogen use efficiency in shoots, roots , fruits and the whole plant increased with increasing K levels and was highest at the 85 % FC and 150 kg K 2 O/ ha fertilizer rate. (Authors)

  15. Fertility and reproductive rate of Varroa mite, Varroa destructor, in native and exotic honeybee, Apis mellifera L., colonies under Saudi Arabia conditions

    Directory of Open Access Journals (Sweden)

    Yehya Alattal

    2017-07-01

    Full Text Available Varroa mite is the most destructive pest to bee colonies worldwide. In Saudi Arabia, preliminary data indicated high infestation levels in the exotic honeybee colonies; such as Apis mellifera carnica and Apis mellifera ligustica, compared to native honeybee subspecies Apis mellifera jemenitica, which may imply higher tolerance to Varroasis. In this study, fertility and reproductive rate of Varroa mite, Varroa destructor, in capped brood cells of the native honeybee subspecies were investigated and compared with an exotic honeybee subspecies, A. m. carnica. Mite fertility was almost alike (87.5% and 89.4% in the native and craniolan colonies respectively. Similarly, results did not show significant differences in reproduction rate between both subspecies (F = 0.66, Pr > F = 0.42. Number of adult Varroa daughters per fertile mother mite was 2.0 and 2.1 for native and craniolan honeybee subspecies respectively. This may indicate that mechanisms of keeping low infestation rates in the native honeybee colonies are not associated with Varroa reproduction. Therefore, potential factors of keeping lower Varroa infestation rates in native honey bee subspecies should be further investigated.

  16. Microsatellite frequencies vary with body mass and body temperature in mammals, suggesting correlated variation in mutation rate

    Directory of Open Access Journals (Sweden)

    William Amos

    2014-11-01

    Full Text Available Substitution rate is often found to correlate with life history traits such as body mass, a predictor of population size and longevity, and body temperature. The underlying mechanism is unclear but most models invoke either natural selection or factors such as generation length that change the number of mutation opportunities per unit time. Here we use published genome sequences from 69 mammals to ask whether life history traits impact another form of genetic mutation, the high rates of predominantly neutral slippage in microsatellites. We find that the length-frequency distributions of three common dinucleotide motifs differ greatly between even closely related species. These frequency differences correlate with body mass and body temperature and can be used to predict the phenotype of an unknown species. Importantly, different length microsatellites show complicated patterns of excess and deficit that cannot be explained by a simple model where species with short generation lengths have experienced more mutations. Instead, the patterns probably require changes in mutation rate that impact alleles of different length to different extents. Body temperature plausibly influences mutation rate by modulating the propensity for slippage. Existing hypotheses struggle to account for a link between body mass and mutation rate. However, body mass correlates inversely with population size, which in turn predicts heterozygosity. We suggest that heterozygote instability, HI, the idea that heterozygous sites show increased mutability, could provide a plausible link between body mass and mutation rate.

  17. Growth and Survival Rate of Tilapia (Oreochromis niloticus Larvae Fed by Daphnia magna Cultured With Organic Fertilizer Resulted From Probiotic Bacteria Fermentation

    Directory of Open Access Journals (Sweden)

    Vivi Endar Herawati

    2015-10-01

    Full Text Available Daphnia magna is a potential feed for fish. The aim of this research was to find the best treatment and effect of D. magna culture addition from fermented organic fertilizer, to growth and survival rate of Oreochromis niloticus larvae. There were five treatments, each with three repetitions used in the study. All treatments used chicken dung, and different combinations of rice bran, coconut oilcake waste and tilapia larvae. Feeding on tilapia was given by ad libitum method for five times a day until 14 days. Water quality during the research was maintained at temperature 28–29°C, DO 0.3 ppm and pH 8.1–8.2. Observed variables include relative growth rate, survival rate, food consumption rate and water quality. Our results showed that D. magna cultured by fermented organic fertilizer for tilapia larvae (O. niloticus had high significant effect (p < 0.01 on the relative growth rate and survival rate. Treatment of D. magna cultured by 1.2 g/L chicken manure, 0.9 g/L rice bran and 0.3 g/L coconut oilcake showed the highest value on the relative growth rate (10.86%; survival rate (98.46% and food consumption at first week (106.43% and second week (152.76%.

  18. Economic recession and fertility in the developed world.

    Science.gov (United States)

    Sobotka, Tomáš; Skirbekk, Vegard; Philipov, Dimiter

    2011-01-01

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

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Tomato nitrogen accumulation and fertilizer use efficiency on a sandy soil, as affected by nitrogen rate and irrigation scheduling

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Munoz-Carpena, R.; Icerman, J.

    2009-01-01

    Tomato production systems in Florida are typically intensively managed with high inputs of fertilizer and irrigation and on sandy soils with low inherent water and nutrient retention capacities; potential nutrient leaching losses undermine the sustainability of such systems. The objectives of this

  1. A Simulation of the Effects of Varying Repetition Rate and Pulse Width of Nanosecond Discharges on Premixed Lean Methane-Air Combustion

    Directory of Open Access Journals (Sweden)

    Moon Soo Bak

    2012-01-01

    Full Text Available Two-dimensional kinetic simulation has been carried out to investigate the effects of repetition rate and pulse width of nanosecond repetitively pulsed discharges on stabilizing premixed lean methane-air combustion. The repetition rate and pulse width are varied from 10 kHz to 50 kHz and from 9 ns to 2 ns while the total power is kept constant. The lower repetition rates provide larger amounts of radicals such as O, H, and OH. However, the effect on stabilization is found to be the same for all of the tested repetition rates. The shorter pulse width is found to favor the production of species in higher electronic states, but the varying effects on stabilization are also found to be small. Our results indicate that the total deposited power is the critical element that determines the extent of stabilization over this range of discharge properties studied.

  2. Consumption-leisure tradeoffs in pigeons: Effects of changing marginal wage rates by varying amount of reinforcement.

    Science.gov (United States)

    Green, L; Kagel, J H; Battalio, R C

    1987-01-01

    Pigeons' rates of responding and food reinforcement under simple random-ratio schedules were compared with those obtained under comparable ratio schedules in which free food deliveries were added, but the duration of each food delivery was halved. These ratio-with-free-food schedules were constructed so that, were the pigeon to maintain the same rate of responding as it had under the simple ratio schedule, total food obtained (earned plus free) would remain unchanged. However, any reduction in responding would reduce total food consumption below that under the simple ratio schedule. These "compensated wage decreases" led to decreases in responding and decreases in food consumption, as predicted by an economic model of labor supply. Moreover, the reductions in responding increased as the ratio value increased (i.e., as wage rates decreased). Pigeons, therefore, substituted leisure for consumption. The relationship between these procedures and negative-income-tax programs is noted.

  3. Mycelial growth rate and toxin production in the seed pathogen Pyrenophora semeniperda: Resource trade-offs and temporally varying selection

    Science.gov (United States)

    S. E. Meyer; M. Masi; S. Clement; T. L. Davis; J. Beckstead

    2015-01-01

    Pyrenophora semeniperda, an important pathogen in Bromus tectorum seed banks in semi-arid western North America, exhibits >4-fold variation in mycelial growth rate. Host seeds exhibit seasonal changes in dormancy that affect the risk of pathogen-caused mortality. The hypothesis tested is that contrasting seed dormancy phenotypes select for contrasting strategies...

  4. Effect of different rates of potassium fertilizer on nitrogen use efficiency and cotton yield using an 15N isotopic dilution technique

    International Nuclear Information System (INIS)

    Khalifa, Kh.; Al-Chamma'a, M.; Al-Ain, F.

    2005-03-01

    A field study was carried out during the 2003 growing season on a loamy to sandy clay loamy soil, located at the Lower Euphrate's Valley, 15 km southeast of Deir - Ezzor city to evaluate the effect of K fertilizer on nitrogen , potassium use efficiency and cotton yield. Three nitrogen ( N1 =120, N2 =180, and N3 = 240 kg N / ha ) and four potassium application rates ( K0 = 0 , K1 = 50, K2 = 100, K3 = 150 kg K2O / ha ) were employed. The cotton variety was Deir 22 sown on April 2003 at a spacing of 70 cm between rows and 20 cm between pits with 5 seeds per pit. The plants were thinned to 2 plants per pit 4 weeks after planting. Representative samples of aboveground portions of cotton plants were harvested from labeled subplots at 108 and 161 days after planting . Dry matter weight , N uptake, N fertilizer yield, N use efficiency, K use efficiency, seed cotton yield, earliness, leaf area, number of bolls / plant, and number of branches / plant were evaluated. The results showed that seed cotton yield increased with increasing K levels applied under each rate of N ( except N120 ). The highest seed cotton yield was obtained with the combined treatment N3K1 ( 6442 kg/ha ). This treatment gave also the optimum potassium use efficiency ( 42 % ). Nitrogen use efficiency (at 180 days of harvest ) increased with the increasing K application rate. Nitrogen use efficiency (NUE) was decreased with increasing N rates . Increasing K application rate ( KUE ) decreased potassium use efficiency. A maximum N use efficiency ( 98% ) was obtained for combined treatment N2 K3. Also the results indicated that dry matter weight and N uptake increased with increasing K rates applied. Nitrogen derived from fertilizer (Ndff ) was higher in combined treatments than the control treatments (K0 ). (Authors)

  5. Potential of VIS-NIR-SWIR Spectroscopy from the Chinese Soil Spectral Library for Assessment of Nitrogen Fertilization Rates in the Paddy-Rice Region, China

    Directory of Open Access Journals (Sweden)

    Shuo Li

    2015-05-01

    Full Text Available To meet growing food demand with limited land and reduced environmental impact, soil testing and formulated fertilization methods have been widely adopted around the world. However, conventional technology for investigating nitrogen fertilization rates (NFR is time consuming and expensive. Here, we evaluated the use of visible near-infrared shortwave-infrared (VIS-NIR-SWIR: 400–2500 nm spectroscopy for the assessment of NFR to provide necessary information for fast, cost-effective and precise fertilization rating. Over 2000 samples were collected from paddy-rice fields in 10 Chinese provinces; samples were added to the Chinese Soil Spectral Library (CSSL. Two kinds of modeling strategies for NFR, quantitative estimation of soil N prior to classification and qualitative by classification, were employed using partial least squares regression (PLSR, locally weighted regression (LWR, and support vector machine discriminant analogy (SVMDA. Overall, both LWR and SVMDA had moderate accuracies with Cohen’s kappa coefficients of 0.47 and 0.48, respectively, while PLSR had fair accuracy (0.37. We conclude that VIS-NIR-SWIR spectroscopy coupled with the CSSL appears to be a viable, rapid means for the assessment of NFR in paddy-rice soil. Based on qualitative classification of soil spectral data only, it is recommended that the SVMDA be adopted for rapid implementation.

  6. Female fertility preservation in the pediatric and adolescent cancer patient population.

    Science.gov (United States)

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

    2018-04-01

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

  7. Estimation of the potential fertility based upon non-return rates of bulls: using polyacrylamide gel instead of cervical mucus in the sperm penetration test.

    Science.gov (United States)

    Taş, M; Bacinoglu, S; Cirit, U; Ozgümüş, S; Kaşgöz, H; Pabuccuoğlu, S

    2007-10-15

    In the present study, we aimed to develop a polyacrylamide gel that could be used instead of bovine cervical mucus in the cervical mucus penetration test (CMPT) to obtain coherent and replicable results in bulls. The frozen semen samples of six Holstein bulls, which were divided into two fertility groups as low and high according to their non-return rate (NRR), were used. In this study, the modified CMPT (mCMPT) was carried out within 0.25 mL transparent plastic straws with an inner diameter 1.7 mm. The penetration ability of spermatozoa to bovine cervical mucus and to polyacrylamide gels swollen with two different solutions [NaCl (G1) and PBS (G2)] was compared. For the penetration test, the straws filled with cervical mucus and both gels were dipped into thawed semen samples and incubated at 37 degrees C for 15 min. After the incubation, straws were frozen in liquid nitrogen vapour and stored at -20 degrees C. On the evaluation day, the frozen straws were cut at 1.5-1.75 cm (penetration distance range=PDR1), 3.25-3.5 cm (PDR2) and 5.0-5.25 cm (PDR3), beginning from open-end of the straws. The separated frozen parts were then immediately transferred onto special counting slides by pushing with a mandrel and left to thaw. Thawed samples were covered with cover glass and penetrated spermatozoa in these parts were counted. The relation between the results and fertility of bulls was determined. In the tests performed using mucus, the number of spermatozoa determined in the high fertility group was found to be higher at PDR3 (p<0.0001) compared to the low fertility group, while in G1 spermatozoa number was significantly higher at PDR1 and PDR3 (p<0.0001). However, in G2 medium, no significant difference was observed between either of the fertility groups with respect to spermatozoa number determined at all distance ranges. In the study, we have determined that the gel swollen with NaCl produces better results and this gel can be used instead of bovine cervical mucus

  8. The Effects of Source and Rate of Nitrogen Fertilizer and Irrigation on Nitrogen Uptake of Silage Corn and Residual Soil Nitrate

    Directory of Open Access Journals (Sweden)

    M. A. Khodshenas

    2016-09-01

    Full Text Available Introduction: Growing irrigation demand for corn production, along side with draws of ground water from stressed water sources, should be limited due to scarce resources and environmental protection aspects. Nitrogen fertilizer applied at rates higher than the optimum requirement for crop production may cause an increase in nitrate accumulation below the root zone and pose a risk of nitrate leaching. Improving nitrogen management for corn production has a close relation with soil water content. In this study, we investigated the effects of source and rate of nitrogen fertilizer and irrigation on silage corn production and nitrogen concentration, nitrogen uptake and residual soil nitrate in two depths. Materials and Methods: This experiment carried out as split spli- plot in a Randomized Complete Block design (RCBD with three replications, in Arak station (Agricultural research center of markazi province, 34.12 N, 49.7 E; 1715 m above mean sea level during three years. The soil on the site was classified as a Calcaric Regosols (loamy skeletal over fragmental, carbonatic, thermic, calcixerollic xerochrepts. Main plots were irrigation treatments based on 70, 100 and 130 mm cumulative evaporation from A class Pan. Sub plots were two kinds of nitrogen fertilizers (Urea and Ammonium nitrate and sub sub-plots were five levels of nitrogen rates (0, 100, 200, 300 and 400 kgN.ha-1. Nitrogen fertilizer rates were split into three applications: 1/3 was applied at planting, 1/3 at 7-9 leaf stage and 1/3 remainder was applied before tasseling as a banding method. Phosphorus was applied at a rate of 150 kg.ha-1in each season and potassium at a rate of 30kg.ha-1 (only in first growth season based on soil testing as triple super phosphate and potassium sulfate, respectively. The corn variety of single cross 704 was planted at 20 m2 plots. The plants were sampled at dough stage from the two rows and weighted in each plot. Plant samples were dried in a forced air

  9. The secretions of oviduct epithelial cells increase the equine in vitro fertilization rate: are osteopontin, atrial natriuretic peptide A and oviductin involved?

    Directory of Open Access Journals (Sweden)

    Canepa Sylvie

    2009-11-01

    Full Text Available Abstract Background Oviduct epithelial cells (OEC co-culture promotes in vitro fertilization (IVF in human, bovine and porcine species, but no data are available from equine species. Yet, despite numerous attempts, equine IVF rates remain low. Our first aim was to verify a beneficial effect of the OEC on equine IVF. In mammals, oviductal proteins have been shown to interact with gametes and play a role in fertilization. Thus, our second aim was to identify the proteins involved in fertilization in the horse. Methods & results In the first experiment, we co-incubated fresh equine spermatozoa treated with calcium ionophore and in vitro matured equine oocytes with or without porcine OEC. We showed that the presence of OEC increases the IVF rates. In the subsequent experiments, we co-incubated equine gametes with OEC and we showed that the IVF rates were not significantly different between 1 gametes co-incubated with equine vs porcine OEC, 2 intact cumulus-oocyte complexes vs denuded oocytes, 3 OEC previously stimulated with human Chorionic Gonadotropin, Luteinizing Hormone and/or oestradiol vs non stimulated OEC, 4 in vivo vs in vitro matured oocytes. In order to identify the proteins responsible for the positive effect of OEC, we first searched for the presence of the genes encoding oviductin, osteopontin and atrial natriuretic peptide A (ANP A in the equine genome. We showed that the genes coding for osteopontin and ANP A are present. But the one for oviductin either has become a pseudogene during evolution of horse genome or has been not well annotated in horse genome sequence. We then showed that osteopontin and ANP A proteins are present in the equine oviduct using a surface plasmon resonance biosensor, and we analyzed their expression during oestrus cycle by Western blot. Finally, we co-incubated equine gametes with or without purified osteopontin or synthesized ANP A. No significant effect of osteopontin or ANP A was observed, though

  10. Investigation of surface roughness and tool wear length with varying combination of depth of cut and feed rate of Aluminium alloy and P20 steel machining

    International Nuclear Information System (INIS)

    Varmma Suparmaniam, Madan; Yusoff, Ahmad Razlan

    2016-01-01

    High-speed milling technique is often used in many industries to boost productivity of the manufacturing of high-technology components. The occurrence of wear highly limits the efficiency and accuracy of high- speed milling operations. In this paper, analysis of high-speed milling process parameters such as material removal rate, cutting speed, feed rate and depth of cut carried out by implemented to conventional milling. This experiment investigate the effects of varying combination of depth of cut and feed rate to tool wear rate length using metallurgical microscope and surface roughness using portable surface roughness tester after end milling of Aluminium and P20 steel. Results showed that feed rate significantly influences the surface roughness value while depth of cut does not as the surface roughness value keep increasing with the increase of feed rate and decreasing depth of cut. Whereas, tool wear rate almost remain unchanged indicates that material removal rate strongly contribute the wear rate. It believe that with no significant tool wear rate the results of this experiment are useful by showing that HSM technique is possible to be applied in conventional machine with extra benefits of high productivity, eliminating semi-finishing operation and reducing tool load for finishing. (paper)

  11. Determination of Fertility Rating (FR in the 3-PG Model for Loblolly Pine Plantations in the Southeastern United States Based on Site Index

    Directory of Open Access Journals (Sweden)

    Santosh Subedi

    2015-08-01

    Full Text Available Soil fertility is an important component of forest ecosystems, yet evaluating soil fertility remains one of the least understood aspects of forest science. We hypothesized that the fertility rating (FR used in the model 3-PG could be predicted from site index (SI for loblolly pine in the southeastern US and then developed a method to predict FR from SI to test this hypothesis. Our results indicate that FR values derived from SI when used in 3-PG explain 89% of the variation in loblolly pine yield. The USDA SSURGO dataset contains SI values for loblolly pine for the major soil series in most of the counties in the southeastern US. The potential of using SI from SSURGO data to predict regional productivity of loblolly pine was assessed by comparing SI values from SSURGO with field inventory data in the study sites. When the 3-PG model was used with FR values derived using SI values from SSURGO database to predict loblolly pine productivity across the broader regions, the model provided realistic outputs of loblolly pine productivity. The results of this study show that FR values can be estimated from SI and used in 3-PG to predict loblolly pine productivity in the southeastern US.

  12. Comparative study of enriched and depleted sup(15)N to determine the efficiency of nitrogenous fertilizers utilization

    International Nuclear Information System (INIS)

    Kliemann, H.J.; Victoria, R.L.

    1989-01-01

    With the objective of estimating the fertilizer use efficiency and A value, an experiment was performed under greenhouse conditions, using a Red Yellow Podzol (Serie Sertaozinho, Piracicaba-SP) and millet Setaria italica, L.) as a test plant. Ammonium sulfate was used at the rates of 0, 52, 104 and 208 mg of N per pot (2.5 kg of air dried soil). Two levels of sub(15)N enrichment were used: 2.281 Atoms % (enriched) and 0.045 Atoms % (depleted), with three replicates per treatment. Nitrogen use efficiency varied significantly with the fertilizer rates applied; values estimated with depleted fertilizer were always lower than those estimated with the enriched one. A value did not vary significantly with fertilizer rates. A values estimated with the enriched tracer were higher than those estimated with the depleted tracer for the lower and higher fertilizer rates. The values were equivalent for the intermediary rate. (author)

  13. In Vitro Fertilization Using Luteinizing Hormone-Releasing Hormone Injections Resulted in Healthy Triplets without Increased Attack Rates in a Hereditary Angioedema Case

    Directory of Open Access Journals (Sweden)

    Ceyda Tunakan Dalgıç

    2018-01-01

    Full Text Available Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE is a rare, autosomal dominant disorder. The management of pregnant patients with C1-INH-HAE is a challenge for the physician. Intravenous plasma-derived nanofiltered C1-INH (pdC1INH is the only recommended option throughout pregnancy, postpartum, and breastfeeding period. In order to increase pregnancy rates, physicians use fertilization therapies increasing endogen levels of estrogens. Therefore, these techniques can provoke an increase in the number and severity of edema attacks in C1-INH-HAE. Our patient is a 32-year-old female, diagnosed with C1-INH-HAE type 1 since 2004. She had been taking danazol 50–200 mg/day for 9 years. Due to her pregnancy plans in 2013, danazol was discontinued. PdC1INH was prescribed regularly for prophylactic purpose. Triplet pregnancy occurred by in vitro fertilization using luteinizing hormone-releasing hormone (LHRH injections. In our patient, LHRH injections were done four times without causing any severe attack during in vitro fertilization. Angioedema did not worsen during pregnancy and delivery due to the prophylactic use of intravenous pdC1INH in our patient. According to the attack frequency and severity, there was no difference between the three pregnancy trimesters. To our knowledge, this is the first published case of C1-INH-HAE receiving in vitro fertilization therapies without any angioedema attacks during pregnancy and delivery and eventually having healthy triplets with the prophylactic use of intravenous pdC1INH.

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

    Science.gov (United States)

    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

    2016-06-01

    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? 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. 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. 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. Samples were examined using electrophysiology (whole-cell patch clamping). Where abnormal electrophysiological characteristics were identified, spermatozoa were further examined for Ca(2+) 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 the electrophysiological abnormalities. Patch clamp electrophysiology was used to assess outward (K

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

    OpenAIRE

    Rajesh Kumar; Vishal Dogra; Khushbu Rani; Kanti Sahu

    2017-01-01

    Background: District level determinants of total fertility rate in Empowered Action Group states of India can help in ongoing population stabilization programs in India. Objective: Present study intends to assess the role of district level determinants in predicting total fertility rate among districts of the Empowered Action Group states of India. Material and Methods: Data from Annual Health Survey (2011-12) was analysed using STATA and R software packages. Multiple linear regression models...

  16. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    Key, Jane; Best, Nicky; Joffe, Michael

    2009-01-01

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

  18. Effect of music therapy on the anxiety levels and pregnancy rate of women undergoing in vitro fertilization-embryo transfer: A randomized controlled trial.

    Science.gov (United States)

    Aba, Yilda Arzu; Avci, Dilek; Guzel, Yilmaz; Ozcelik, Semanur Kumral; Gurtekin, Basak

    2017-08-01

    The aim of this study was to determine the effect of music therapy on the anxiety levels and pregnancy rates of women who underwent in vitro fertilization-embryo transfer. This prospective randomized controlled trial was conducted with 186 infertile women who presented to the In Vitro Fertilization Unit at the American Hospital in Turkey between April 2015 and April 2016. The infertile women who met the inclusion criteria were assigned to the music therapy group or the standard therapy group through block randomization. The study data were collected using the Personal Information Form, and State-Trait Anxiety Inventory. Early treatment success was determined by serum beta human chorionic gonadotrophin levels seven or ten days after the luteal day zero. For the analysis, descriptive statistics, chi-square test, Fisher's exact test, independent sample t-test were used. After the embryo transfer, the mean state anxiety scores decreased in both groups, and the mean trait anxiety score decreased in the music therapy group; however, the difference was not statistically significant (p>0.05). Clinical pregnancy rates did not differ between the music (48.3%) and standard (46.4%) therapy groups. After the two sessions of music therapy, state and trait anxiety levels decreased and pregnancy rates increased, but the difference was not significant. Therefore, larger sample sizes and more sessions are needed to evaluate whether music therapy has an effect on clinical outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Different places, different stories: A study of the spatial heterogeneity of county-level fertility in China

    Directory of Open Access Journals (Sweden)

    Donghui Wang

    2017-08-01

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

  20. Development of a nonlocal convective mixing scheme with varying upward mixing rates for use in air quality and chemical transport models.

    Science.gov (United States)

    Mihailović, Dragutin T; Alapaty, Kiran; Sakradzija, Mirjana

    2008-06-01

    Asymmetrical convective non-local scheme (CON) with varying upward mixing rates is developed for simulation of vertical turbulent mixing in the convective boundary layer in air quality and chemical transport models. The upward mixing rate form the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. This scheme provides a less rapid mass transport out of surface layer into other layers than other asymmetrical convective mixing schemes. In this paper, we studied the performance of a nonlocal convective mixing scheme with varying upward mixing in the atmospheric boundary layer and its impact on the concentration of pollutants calculated with chemical and air-quality models. This scheme was additionally compared versus a local eddy-diffusivity scheme (KSC). Simulated concentrations of NO(2) and the nitrate wet deposition by the CON scheme are closer to the observations when compared to those obtained from using the KSC scheme. Concentrations calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme (of the order of 15-20%). Nitrate wet deposition calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme. To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO(2)) and nitrate wet deposition was compared for the year 2002. The comparison was made for the whole domain used in simulations performed by the chemical European Monitoring and Evaluation Programme Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

  1. Fertilization in northern forests

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  3. Effect of Plant Density, Rate and Split Application of Nitrogen Fertilizer on Quality Characteristics and Nitrogen Use Efficiency of Safflower under Weed Competition

    Directory of Open Access Journals (Sweden)

    M Fuladvand

    2015-09-01

    Full Text Available In order to evaluation of plant density, rate and method of nitrogen fertilizer split application on quality characteristics and nitrogen use efficiency of safflower (Sofeh variety under weed competition a field experiment was carried out in field research Yasouj University in 2013. This experiment was a factorial based on randomized complete block design with three replications. First factor was a two levels plant density (20 and 40 plants m-2 and second factor was nitrogen rate application on nine levels. That included; non nitrogen application and 75 and 150 kgN ha-1 nitrogen application that both used with four split method. Split methods were included; S1 (%50 in pre planting stage - %50 in stem elongation stage, S2 (%25 in pre planting stage - %75 in stem elongation stage, S3 (%25 in pre planting stage - %50 in stem elongation stage -%25 in flowering stage and S4 (%25 in pre planting stage - %25 in stem elongation stage - %25 in flowering stage. Also in this experiment, weed did not control. Results showed that whit increasing crop density, oil yield and protein grain yield increased by 20 percent and nitrogen utilization efficiency increased by 10 percent. The highest oil yield (50.25 g m-2 was obtained from 75 kg ha-1 nitrogen with three-stage split application (S4. Finally, results showed that increasing nitrogen fertilizer application decreased nitrogen utilization efficiency but three-stage split method application increased this trait.

  4. Nano Fertilizers

    Directory of Open Access Journals (Sweden)

    Hatice DAĞHAN

    2017-06-01

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

  5. Components of Particle Emissions from Light-Duty Spark-Ignition Vehicles with Varying Aromatic Content and Octane Rating in Gasoline.

    Science.gov (United States)

    Short, Daniel Z; Vu, Diep; Durbin, Thomas D; Karavalakis, Georgios; Asa-Awuku, Akua

    2015-09-01

    Typical gasoline consists of varying concentrations of aromatic hydrocarbons and octane ratings. However, their impacts on particulate matter (PM) such as black carbon (BC) and water-soluble and insoluble particle compositions are not well-defined. This study tests seven 2012 model year vehicles, which include one port fuel injection (PFI) configured hybrid vehicle, one PFI vehicle, and six gasoline direct injection (GDI) vehicles. Each vehicle was driven on the Unified transient testing cycle (UC) using four different fuels. Three fuels had a constant octane rating of 87 with varied aromatic concentrations at 15%, 25%, and 35%. A fourth fuel with higher octane rating, 91, contained 35% aromatics. BC, PM mass, surface tension, and water-soluble organic mass (WSOM) fractions were measured. The water-insoluble mass (WIM) fraction of the vehicle emissions was estimated. Increasing fuel aromatic content increases BC emission factors (EFs) of transient cycles. BC concentrations were higher for the GDI vehicles than the PFI and hybrid vehicles, suggesting a potential climate impact for increased GDI vehicle production. Vehicle steady-state testing showed that the hygroscopicity of PM emissions at high speeds (70 mph; κ > 1) are much larger than emissions at low speeds (30 mph; κ < 0.1). Iso-paraffin content in the fuels was correlated to the decrease in WSOM emissions. Both aromatic content and vehicle speed increase the amount of hygroscopic material found in particle emissions.

  6. Conference considers low fertility.

    Science.gov (United States)

    1997-01-01

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

  7. The effect of bedload transport rates on bedform and planform morphological development in a laboratory meandering stream under varying flow conditions

    Science.gov (United States)

    Sullivan, C.; Good, R. G. R.; Binns, A. D.

    2017-12-01

    Sediment transport processes in streams provides valuable insight into the temporal evolution of planform and bedform geometry. The majority of previous experimental research in the literature has focused on bedload transport and corresponding bedform development in rectangular, confined channels, which does not consider planform adjustment processes in streams. In contrast, research conducted with laboratory streams having movable banks can investigate planform development in addition to bedform development, which is more representative of natural streams. The goal of this research is to explore the relationship between bedload transport rates and the morphological adjustments in meandering streams. To accomplish this, a series of experimental runs were conducted in a 5.6 m by 1.9 m river basin flume at the University of Guelph to analyze the bedload impacts on bed formations and planform adjustments in response to varying flow conditions. In total, three experimental runs were conducted: two runs using steady state conditions and one run using unsteady flow conditions in the form of a symmetrical hydrograph implementing quasi steady state flow. The runs were performed in a series of time-steps in order to monitor the evolution of the stream morphology and the bedload transport rates. Structure from motion (SfM) was utilized to capture the channel morphology after each time-step, and Agisoft PhotoScan software was used to produce digital elevation models to analyze the morphological evolution of the channel with time. Bedload transport rates were quantified using a sediment catch at the end of the flume. Although total flow volumes were similar for each run, the morphological evolution and bedload transport rates in each run varied. The observed bedload transport rates from the flume are compared with existing bedload transport formulas to assess their accuracy with respect to sediment transport in unconfined meandering channels. The measured sediment transport

  8. Use of complementary and alternative medicines associated with a 30% lower ongoing pregnancy/live birth rate during 12 months of fertility treatment

    DEFF Research Database (Denmark)

    Boivin, J; Schmidt, L

    2009-01-01

    BACKGROUND There seems to be little discussion between patient and physician about the use of complementary and alternative medicines (CAMs), perhaps because they are not perceived to have adverse effects on fertility. We therefore compared ongoing pregnancy and live birth rate in spontaneous users......, years infertile). CONCLUSIONS Concurrent use of CAM during treatment with ART was associated with a 30% lower pregnancy rate that could not be explained by poor prognosis or life style factors. The mechanisms that could account for this association were discussed. Concurrent CAM use should be monitored...... women about to have ART for the first time completed self-report assessments prior to treatment (Time 1, T1) and at 12-month follow-up (Time 2, T2). Data from treatment records were also available for n = 590. RESULTS About 30.6% (n = 223) of women used CAMs during the observation period. At T2...

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

    Directory of Open Access Journals (Sweden)

    Thomson Dana R

    2012-11-01

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

  10. Rate and time of nitrogen fertilizer application on the growth, nitrogen remobilization and yield of soyabean (Glycine max(L) Merrill)

    International Nuclear Information System (INIS)

    Bebeley, J. F.; Sarkodie-Addo; Duku, S.

    2015-01-01

    Two field experiments were conducted in 2012 at the plantation Crop section of the Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, to investigate the effect N availability on nodulation, nitrogen fixation, N remobilization and grain yield of soybean. The design used in both studies was a 3 x 4 factorial arranged in randomized complete block design. Each treatment was replicated three times. The factors studied were rate and time of N fertilizer application. The N rate were 0, 20, 40 and 60kg N/ha and the time of application were early vegetative and early flowering phases. Anidaso, an improved soybean variety of 110 days maturity was used. Following land preparation, seeds were planted at the beginning of the rains at a spacing of 50 x 5cm. All required cultural practices were observed. Data collected were nodule number per plant and nodule dry weight, number of pods per plant, number of seeds per pod, 100 seeds weight, total nitrogen fixed, harvest index, grain yield and remobilized N. The total nitrogen difference method was used in determining the amount of N 2 fixed by the soybean and the micro kjeldahl method was used in determining the total plant N. The results indicated that nodulation was not significantly (p>0.05) affected by N rate and time of N application. However Nitrogen fixation was significantly (p<0.05 in affected time of N application in the minor season. Harvest index was significantly affected time of N application in the major season. Grain yield was also significantly affected by time of N application in both seasons. The results indicate that if farmers would apply N fertilizer to soybean at the vegetative growth phase, there would be increase in yield. The study also demonstrate that N remobilization occurs in soybean during grain filling although rate and time of application used did not significantly (p>0.05) affect N remobilization. (au)

  11. Determination of fertility rating (FR) in the 3-PG model for loblolly pine (Pinus taeda L.) plantations in the southeastern United States

    OpenAIRE

    Subedi, Santosh

    2015-01-01

    Soil fertility is an important component of forest ecosystem, yet evaluating soil fertility remains one of the least understood aspects of forest science. Phytocentric and geocenctric approaches were used to assess soil fertility in loblolly pine plantations throughout their geographic range in the United States. The model to assess soil fertility using a phytocentric approach was constructed using the relationship between site index and aboveground productivity. Geocentric models used physic...

  12. Behavior of a PCM at Varying Heating Rates: Experimental and Theoretical Study with an Aim at Temperature Moderation in Radionuclide Concrete Encasements

    Science.gov (United States)

    Medved', Igor; Trník, Anton

    2018-07-01

    Phase-change materials (PCMs) can store/release thermal energy within a small temperature range. This is of interest in various industrial applications, for example, in civil engineering (heating/cooling of buildings) or cold storage applications. Another application may be the moderation of temperature increases in concrete encasements of radionuclides during their decay. The phase-change behavior of a material is determined by its heat capacity and the peak it exhibits near a phase change. We analyze the behavior of such peaks for a selected PCM at heating rates varying between 0.1°C\\cdot min^{-1} and 1°C\\cdot min^{-1}, corresponding in real situations to different decay rates of radionuclides. We show that experimentally measured peaks can be plausibly described by an equilibrium theory that enables us to calculate the latent heat and phase-change temperature from experimental data.

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

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  16. Identification of soil P fractions that are associated with P loss from surface runoff under various cropping systems and fertilizer rates on sloped farmland.

    Directory of Open Access Journals (Sweden)

    Xinghua Li

    Full Text Available Soil phosphorus (P fractions and runoff P concentration were measured to understand the fate of soil P entering surface runoff water during summer cropping season of different double cropping systems under two fertilizer regimes. The dominant form of runoff P was particulate P (PP. Runoff total P (TP was higher at the vegetative growth stage and lower at the crop reproductive stage. TP and PP were derived mainly from soil Olsen-P, Al-P and Fe-P and amounts increased with sediment content in runoff water. Runoff P discharge was closely related to the changes in soil P forms. Soil Olsen-P, mainly consisting of some Ca2-P and Al-P, was increased by elevating fertilizer rate. Along with crop growth, there were active interconversions among Olsen-P, Org-P, Fe-P and O-Al-P in the soil, and some available P converted into Ca10-P, with O-Fe-P possibly being a transitional form for this conversion. The oilseed rape/corn system had less runoff TP at the early stage, and wheat/sweet potato system had a lower runoff P at the late stage. Intercropping corn with sweet potato in the field with oilseed rape as a previous crop may be helpful for alleviating runoff P load during the summer in this region.

  17. Identification of soil P fractions that are associated with P loss from surface runoff under various cropping systems and fertilizer rates on sloped farmland.

    Science.gov (United States)

    Li, Xinghua; Wang, Baona; Yang, Tewu; Zhu, Duanwei; Nie, Zhongnan; Xu, Junchi

    2017-01-01

    Soil phosphorus (P) fractions and runoff P concentration were measured to understand the fate of soil P entering surface runoff water during summer cropping season of different double cropping systems under two fertilizer regimes. The dominant form of runoff P was particulate P (PP). Runoff total P (TP) was higher at the vegetative growth stage and lower at the crop reproductive stage. TP and PP were derived mainly from soil Olsen-P, Al-P and Fe-P and amounts increased with sediment content in runoff water. Runoff P discharge was closely related to the changes in soil P forms. Soil Olsen-P, mainly consisting of some Ca2-P and Al-P, was increased by elevating fertilizer rate. Along with crop growth, there were active interconversions among Olsen-P, Org-P, Fe-P and O-Al-P in the soil, and some available P converted into Ca10-P, with O-Fe-P possibly being a transitional form for this conversion. The oilseed rape/corn system had less runoff TP at the early stage, and wheat/sweet potato system had a lower runoff P at the late stage. Intercropping corn with sweet potato in the field with oilseed rape as a previous crop may be helpful for alleviating runoff P load during the summer in this region.

  18. The fertility decline in Kenya.

    Science.gov (United States)

    Robinson, W C; Harbison, S F

    1995-01-01

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

  19. Estimation of time-varying pollutant emission rates in a ventilated enclosure: inversion of a reduced model obtained by experimental application of the modal identification method

    International Nuclear Information System (INIS)

    Girault, M; Maillet, D; Bonthoux, F; Galland, B; Martin, P; Braconnier, R; Fontaine, J R

    2008-01-01

    A method is proposed for the estimation of time-varying emission rates of pollutant sources in a ventilated enclosure, through the resolution of an inverse forced convection problem. Unsteady transport–diffusion of the pollutant is considered, with the assumption of a stationary velocity field remaining unchanged during emission (passive contaminant). The pollutant transport equation is therefore linear with respect to concentration. The source's location is also supposed to be known. As the first step, a reduced model (RM) linking concentrations at a set of control points to emission rates of sources is identified from experimental data by using the modal identification method (MIM). This parameter estimation problem uses transient contaminant concentration measurements made at control points inside the ventilated enclosure, corresponding to increasing and decreasing steps of emission rates. Such experimental modelling allows us to avoid dealing with a CFD code involving turbulence modelling and to get rid of uncertainties about sensors position. In a second step, the identified RM is used to solve an inverse forced convection problem: from contaminant concentration measured at the same control points, rates of sources emitting simultaneously are estimated with a sequential in time algorithm using future time steps

  20. The Effectiveness of Experimental Diet with Varying Levels of Papain on The Growth Performance, Survival Rate and Feed Utilization of Keureling Fish (Tor tambra

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Muchlisin

    2016-09-01

    Full Text Available The objective of present study was to determine the optimum level of papain in the diet of keureling fish (Tor tambra. The complete random design was utilized in this study. Six levels of papain dosage were tested in triplicates, i.e. 0 (control; 17.5 mg kg-1,  20.0 mg kg-1, 22.5 mg kg-1, 25.0 mg kg-1 and 27.5 mg kg-1 of feed. The experimental fish were fed the experimental diet two times a day at 8 AM and 5 PM at feeding level of 5% body weight for 90 days. The Anova test result showed that papain enzyme  gave a significant effect on the weight gain, daily growth rate, specific growth rate, survival rate, feed conversion ratio and feed efficiency (P<0.05. The Duncan multi-rage test result showed that the higher values for all measured parameters were obtained at the dosage of 27.5 mg kg-1. Therefore, it is concluded that the optimum dosage of papain enzyme for keureling fish was 27.5 mg kg-1 of feed.How to CiteMuchlisin, Z. A., Afrido, F., Murda, T., Fadli, N., Muhammadar, A. A., Jalil, Z., & Yulvizar, C. (2016. The Effectiveness of Experimental Diet with Varying Levels of Papain on The Growth Performance, Survival Rate and Feed Utilization of Keureling Fish (Tor tambra. Biosaintifika: Journal of Biology & Biology Education, 8(2, 172-177.

  1. Patients with endometriosis have aneuploidy rates equivalent to their age-matched peers in the in vitro fertilization population.

    Science.gov (United States)

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

    2017-08-01

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

  2. A multi-group path analysis of the relationship between perceived racial discrimination and self-rated stress: how does it vary across racial/ethnic groups?

    Science.gov (United States)

    Yang, Tse-Chuan; Chen, Danhong

    2018-04-01

    The objective of this study was to answer three questions: (1) Is perceived discrimination adversely related to self-rated stress via the social capital and health care system distrust pathways? (2) Does the relationship between perceived discrimination and self-rated stress vary across race/ethnicity groups? and (3) Do the two pathways differ by one's race/ethnicity background? Using the Philadelphia Health Management Corporation's Southeastern Pennsylvania Household Survey, we classified 9831 respondents into 4 race/ethnicity groups: non-Hispanic White (n = 6621), non-Hispanic Black (n = 2359), Hispanic (n = 505), and non-Hispanic other races (n = 346). Structural equation modeling was employed to simultaneously estimate five sets of equations, including the confirmatory factor analysis for both social capital and health care distrust and both direct and indirect effects from perceived discrimination to self-rated stress. The key findings drawn from the analysis include the following: (1) in general, people who experienced racial discrimination have higher distrust and weaker social capital than those without perceived discrimination and both distrust and social capital are ultimately related to self-rated stress. (2) The direct relationship between perceived discrimination and self-rated stress is found for all race/ethnicity groups (except non-Hispanic other races) and it does not vary across groups. (3) The two pathways can be applied to non-Hispanic White and Black, but for Hispanic and non-Hispanic other races, we found little evidence for the social capital pathway. For non-Hispanic White, non-Hispanic Black, and Hispanic, perceived discrimination is negatively related to self-rated stress. This finding highlights the importance of reducing interpersonal discriminatory behavior even for non-Hispanic White. The health care system distrust pathway can be used to address the racial health disparity in stress as it holds true for all four race

  3. Prediction of bull fertility.

    Science.gov (United States)

    Utt, Matthew D

    2016-06-01

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

  4. Europe the continent with the lowest fertility

    NARCIS (Netherlands)

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

    2010-01-01

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

  5. Improving usability and pregnancy rates of a fertility monitor by an additional mobile application: results of a retrospective efficacy study of Daysy and DaysyView app.

    Science.gov (United States)

    Koch, Martin C; Lermann, Johannes; van de Roemer, Niels; Renner, Simone K; Burghaus, Stefanie; Hackl, Janina; Dittrich, Ralf; Kehl, Sven; Oppelt, Patricia G; Hildebrandt, Thomas; Hack, Caroline C; Pöhls, Uwe G; Renner, Stefan P; Thiel, Falk C

    2018-03-02

    Daysy is a fertility monitor that uses the fertility awareness method by tracking and analyzing the individual menstrual cycle. In addition, Daysy can be connected to the application DaysyView to transfer stored personal data from Daysy to a smartphone or tablet (IOS, Android). This combination is interesting because as it is shown in various studies, the use of apps is increasing patients´ focus on their disease or their health behavior. The aim of this study was to investigate if by the additional use of an App and thereby improved usability of the medical device, it is possible to enhance the typical-use related as well as the method-related pregnancy rates. In the resultant group of 125 women (2076 cycles in total), 2 women indicated that they had been unintentionally pregnant during the use of the device, giving a typical-use related Pearl-Index of 1.3. Counting only the pregnancies which occurred as a result of unprotected intercourse during the infertile (green) phase, we found 1 pregnancy, giving a method-related Pearl-Index of 0.6. Calculating the pregnancy rate resulting from continuous use and unprotected intercourse exclusively on green days, gives a perfect-use Pearl-Index of 0.8. It seems that combining a specific biosensor-embedded device (Daysy), which gives the method a very high repeatable accuracy, and a mobile application (DaysyView) which leads to higher user engagement, results in higher overall usability of the method.

  6. Reduced ovulation rate, failure to be mated and fertilization failure/embryo loss are the underlying causes of poor reproductive performance in juvenile ewes.

    Science.gov (United States)

    Edwards, Sara J; Smaill, Bronwyn; O'Connell, Anne R; Johnstone, Peter D; Stevens, David R; Quirke, Laurel D; Farquhar, Philip A; Juengel, Jennifer L

    2016-04-01

    A ewe that is mated as a juvenile (producing a lamb at 1 year of age) will produce an average of only 0.6 lambs to weaning, compared to an average of 1.2 lambs in adult ewes. Understanding the underlying causes of this low reproductive efficiency and designing methods to improve or mitigate these effects could potentially increase adoption of mating juvenile ewes. In Experiment 1, 2 Cohorts of ewes, born a year apart, were mated in order to lamb at 1 and 2 years of age and the performance of the ewes at each age was compared. Onset of puberty, mating by the fertile ram, ovulation rate, early pregnancy (day 30-35) litter size, number of lambs born and number of lambs weaned were measured. In juvenile ewes, by day 35 of pregnancy, 43% of ova had failed to become a viable embryo and this early loss was the largest contributor to the poor reproductive performance observed. Compared with young adult ewes, ovulation rate was lower (pewes with a greater ovulation rate (pewes, failure to mate with the ram, lower ovulation rate and increased fertilisation failure/embryo loss underlie their poor reproductive performance. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2005-01-01

    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...

  8. Isotope technology as applied to studies of soil fertility, nutrient availability and fertilizer use on flooded rice soils

    International Nuclear Information System (INIS)

    Patnaik, S.; Mohanty, S.K.; Dash, R.N.

    1979-01-01

    Research is reviewed on soil fertility and nutrient availability in relation to fertilizer efficiency, especially o stimulated the mineralization of soil N. Losses of added N from oxidation, leaching, denitrification and volatilization could be minimized through placement of N fertilizer in the reduced zone or by the addition of rice straw for rapid immobilization of added N. Fe-P and, to some extent, Al-P provided P to the rice plants, particularly in P-deficient soils. Added phosphates were converted to these forms which, under waterlogged soil conditions, released more P into the soil solution through reductive solubilization of Fe-P and hydrolytic dissolution of Al-P. The rice plants generally absorbed fertilizer N during the vegetative growth period and N mineralized from soil organic matter during the reproductive growth period. 15 N studies indicated higher grain yield and utilization of applied N through fractional application of 70-80% during the vegetative growth period, and the remaining 20-30% top-dressed at the panicle initiation stage. Ammonia-containing and -forming (urea) fertilizers were superior to the nitrate form of N. In field tests, however, the crop recovery of applied N was relatively low. Phosphatic fertilizers were best applied at puddling. In general, water-soluble phosphates were superior to citrate-soluble or insoluble phosphates. The latter could be made as efficient as the water-soluble phosphate, at comparable low rates, by applying to the moist aerobic acid soil 2-3 weeks before flooding and transplanting rice. Tracer studies have been used to evaluate the nutrient-supplying capacity of the soil from the 'A' value concept. 'A' values varied with varying conditions of soil, rate, time and form of fertilizer application. Zn nutrition of the rice plant and fertilizer use with 65 Zn have been studied relatively little. Some lines of future work are suggested

  9. Tradeoffs between impact loading rate, vertical impulse and effective mass for walkers and heel strike runners wearing footwear of varying stiffness.

    Science.gov (United States)

    Addison, Brian J; Lieberman, Daniel E

    2015-05-01

    Humans experience repetitive impact forces beneath the heel during walking and heel strike running that cause impact peaks characterized by high rates and magnitudes of loading. Impact peaks are caused by the exchange of momentum between the ground and a portion of the body that comes to a full stop (the effective mass) during the period of the impact peak. A number of factors can influence this exchange of momentum, including footwear stiffness. This study presents and tests an impulse-momentum model of impact mechanics which predicts that effective mass and vertical impulse is greater in walkers and heel strike runners wearing less stiff footwear. The model also predicts a tradeoff between impact loading rate and effective mass, and between impact loading rate and vertical impulse among individuals wearing footwear of varying stiffness. We tested this model using 19 human subjects walking and running in minimal footwear and in two experimental footpads. Subjects walked and ran on an instrumented treadmill and 3D kinematic data were collected. As predicted, both vertical impulse (walking: F(2,54)=52.0, p=2.6E-13; running: F(2,54)=25.2, p=1.8E-8) and effective mass (walking: F(2,54)=12.1, p=4.6E-5; running: F(2,54)=15.5, p=4.7E-6) increase in less stiff footwear. In addition, there is a significant inverse relationship between impact loading rate and vertical impulse (walking: r=-0.88, pfootwear heels influence injury risk during human walking and running. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Order-Specific Fertility Rates for Germany
    Estimates from Perinatal Statistics for the Period 2001-2008

    OpenAIRE

    Michaela Kreyenfeld; Rembrandt Scholz; Frederik Peters; Ines Wlosnewski

    2011-01-01

    Until 2008, Germany’s vital statistics did not include information on the biological order of each birth. This resulted in a dearth of important demographic indicators, such as the mean age at first birth and the level of childlessness. Researchers have tried to fill this gap by generating order-specific birth rates from survey data, and by combining survey data with vital statistics. This paper takes a different approach by using Perinatal Statistics to generate birth order-specific fertilit...

  11. [Fertility and health in Mexico].

    Science.gov (United States)

    Urbina-Fuentes, M; Echánove-Fernández, E

    1989-01-01

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

  12. Organic Biochar Based Fertilization

    Science.gov (United States)

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

    2017-04-01

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

  13. Acupuncture to improve live birth rates for women undergoing in vitro fertilization: a protocol for a randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background IVF is a costly treatment option for women, their partners, and the public. Therefore new therapies that improve reproductive and health outcomes are highly desirable. There is a growing body of research evaluating the effect of acupuncture administered during IVF, and specifically on the day of embryo transfer (ET). Many trials are heterogeneous and results inconsistent. There remains insufficient evidence to determine if acupuncture can enhance live birth rates when used as an adjunct to IVF treatment. The study will determine the clinical effectiveness of acupuncture with improving the proportion of women undergoing IVF having live births. Other objectives include: determination of the cost effectiveness of IVF with acupuncture; and examination of the personal and social context of acupuncture in IVF patients, and examining the reasons why the acupuncture may or may not have worked. Methods We will conduct a randomized controlled trial of acupuncture compared to placebo acupuncture. Inclusion criteria include: women aged less than 43 years; undergoing a fresh IVF or ICSI cycle; and restricted to women with the potential for a lower live birth rate defined as two or more previous unsuccessful ETs; and unsuccessful clinical pregnancies of quality embryos deemed by the embryologist to have been suitable for freezing by standard criteria. Women will be randomized to acupuncture or placebo acupuncture. Treatment is administered on days 6 to 8 of the stimulated cycle and two treatments on the day of ET. A non-randomized cohort of women not using acupuncture will be recruited to the study. The primary study outcome is the proportion of women reporting a live birth. Secondary outcomes include the proportion of women reporting a clinical pregnancy miscarriage prior to 12 weeks, quality of life, and self-efficacy. The sample size of the study is 1,168 women, with the aim of detecting a 7% difference in live births between groups (P = 0.05, 80% power

  14. Acupuncture to improve live birth rates for women undergoing in vitro fertilization: a protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Smith Caroline A

    2012-05-01

    Full Text Available Abstract Background IVF is a costly treatment option for women, their partners, and the public. Therefore new therapies that improve reproductive and health outcomes are highly desirable. There is a growing body of research evaluating the effect of acupuncture administered during IVF, and specifically on the day of embryo transfer (ET. Many trials are heterogeneous and results inconsistent. There remains insufficient evidence to determine if acupuncture can enhance live birth rates when used as an adjunct to IVF treatment. The study will determine the clinical effectiveness of acupuncture with improving the proportion of women undergoing IVF having live births. Other objectives include: determination of the cost effectiveness of IVF with acupuncture; and examination of the personal and social context of acupuncture in IVF patients, and examining the reasons why the acupuncture may or may not have worked. Methods We will conduct a randomized controlled trial of acupuncture compared to placebo acupuncture. Inclusion criteria include: women aged less than 43 years; undergoing a fresh IVF or ICSI cycle; and restricted to women with the potential for a lower live birth rate defined as two or more previous unsuccessful ETs; and unsuccessful clinical pregnancies of quality embryos deemed by the embryologist to have been suitable for freezing by standard criteria. Women will be randomized to acupuncture or placebo acupuncture. Treatment is administered on days 6 to 8 of the stimulated cycle and two treatments on the day of ET. A non-randomized cohort of women not using acupuncture will be recruited to the study. The primary study outcome is the proportion of women reporting a live birth. Secondary outcomes include the proportion of women reporting a clinical pregnancy miscarriage prior to 12 weeks, quality of life, and self-efficacy. The sample size of the study is 1,168 women, with the aim of detecting a 7% difference in live births between groups (P

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

    Directory of Open Access Journals (Sweden)

    Christopher Concha

    2011-07-01

    Full Text Available El incremento de la frecuencia de malformaciones y la reducción de la viabilidad y fecundidad suelen ser las primeras manifestaciones de la depresión por consanguinidad en animales. El ostión del norte, Argopectenpurpuratus (Lamarck, 1819, es una especie hermnafrodita funcional con autofecundación parcial y durante la reproducción artificial puede presentar altos grados de autofecundación. En este trabajo se analizó la asociación de la tasa de autofecundación con la frecuencia de larvas malformadas y la supervivencia larval. Se desovaron adultos maduros y se recogieron separadamente los gametos femeninos del 5° pulso de liberación en adelante y los masculinos. Los ovocitos fueron fecundados con espermatozoides de otro individuo, formando familias de hermanos completos. La tasa de autofecundación se verificó por la proporción de ovocitos que entra en división en una muestra de ellos sin fecundar. La tasa de autofecundación varió entre familias de 0 a 100%, con distribución de frecuencias normal. La proporción de larvas malformadas se distribuyó al azar entre las familias analizadas, pero se correlacionó negativamente, en forma moderada pero significativa, con la tasa de autofecundación y la temperatura media del cultivo. Los datos sugieren que la autofecundación en las familias de ostiones puede favorecer una mayor homeostasis del desarrollo larval.Increased frequencies of malformations and the reduction of viability and fecundity are some of the first manifestations of inbreeding depression in animals. The northern scallop, Argopecten purpuratus (Lamarck, 1819, is a functional hermaphrodite species with partial self-fertilization. During artificial reproduction, this species may present high degrees of self-fertilization. In this work, the association between the selfing rate and the frequency of larval malformations and survival were analyzed. Mature adults were spawned, and female and male gametes were collected

  16. Low-dose metformin improves pregnancy rate in in vitro fertilization repeaters without polycystic ovary syndrome: prediction of effectiveness by multiple parameters related to insulin resistance.

    Science.gov (United States)

    Jinno, Masao; Kondou, Kenichi; Teruya, Koji

    2010-01-01

    Insulin resistance is associated with aging and stress, both common among patients repeatedly failing to conceive with in vitro fertilization (IVF repeaters). In the present study we examined whether low-dose metformin could improve the outcome in IVF repeaters without polycystic ovary syndrome (PCOS). Study I was a preliminary clinical trial aiming at defining indications for therapy; study II was a prospective randomized study. The studies involved a university hospital and a private infertility clinic. We studied 232 women without PCOS who had failed at least twice to conceive by previous IVF. Metformin (500 mg/ day) was administered for 8 to 12 weeks before and during ovarian stimulation (metformin IVF). In study I, IVF outcomes with metformin (n = 33) were compared to outcomes without metformin of previous IVF in the same subjects. A discriminant score (DS) was determined from nine parameters assessed before metformin administration to predict achievement of ongoing pregnancy by metformin IVF. In study II (n = 199), ongoing pregnancy rates were compared prospectively between groups with/without metformin and with DS above/below 0.6647. Study I. Ongoing pregnancy rate improved significantly with metformin compared with previous IVF, and pregnancy correlated significantly with a DS at an optimal threshold of 0.6647 (sensitivity, 0.90; specificity, 0.91). Study II. Ongoing pregnancy and implantation rates were significantly higher in women with a DS above 0.6647 who received metformin (56% and 33%) compared with those having a DS below 0.6647 with metformin (14% and 11%) and those having a DS above/below 0.6647 without metformin (20% and 7.1%/15% and 11%, respectively). Low-dose metformin improved pregnancy rate in IVF repeaters without PCOS, probably by decreasing insulin resistance. Indication can be determined from insulin-resistance-related multiple parameters assessed before metformin administration.

  17. Chinese culture and fertility decline.

    Science.gov (United States)

    Wu, C; Jia, S

    1992-01-01

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

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

    African Journals Online (AJOL)

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

  19. Herbicides effect on the nitrogen fertilizer assimilation by sensitive plants

    International Nuclear Information System (INIS)

    Ladonin, V.F.; Samojlov, L.N.

    1976-01-01

    It has been established in studying the effect of herbicides on pea plants that the penetration of the preparations into the tissues of leaves and stems results in a slight increase of the rate of formation of dry substance in the leaves of the treated plants within 24 hours after treatment as compared with control, whereas in the last period of the analysis the herbicides strongly inhibit the formation of dry substance in leaves. The applied herbicide doses have resulted in drastic changes of the distribution of the plant-assimilated nitrogen between the protein and non-protein fractions in the leaves and stems of pea. When affected by the studied herbicides, the fertilizer nitrogen supply to the pea plants changes and the rate of the fertilizer nitrogen assimilation by the plants varies noticeably. The regularities of the fertilizer nitrogen inclusion in the protein and non-protein nitrogen compounds of the above-ground pea organs have been studied

  20. Radiological impact of phosphate fertilizers on the agricultural areas in Iran

    International Nuclear Information System (INIS)

    Fathivand, A.A.; Kashian, S.; Moradi, M.

    2014-01-01

    It is common practice to use phosphate fertilizers in the soil to raise crop yield. Natural radionuclides present in fertilizers are sources of external and internal radiation exposure. External radiation exposure is caused by gamma radiation originating from radionuclides in situ. Internal radiation exposure, mainly affecting the respiratory tract, is due to short-lived daughter products of radon which are exhaled from fertilizers. This paper describes the results of gamma spectrometric measurement of the concentration of the natural radionuclides namely 226 Ra, thorium-232 and potassium-40 in the soil samples from the fields using phosphate fertilizers. The radon concentration and exhalation rate have also been discussed. The values of outdoor annual effective dose are found to vary from 0.07 to 0.09 mSv/year in soil samples containing fertilizers, whereas the outdoor annual effective dose is 0.06 mSv/year in barren soil samples. (author)

  1. Maize Response to Fertilizer Dosing at Three Sites in the Central Rift Valley of Ethiopia

    Directory of Open Access Journals (Sweden)

    Getachew Sime

    2014-09-01

    Full Text Available This study examines the agronomic response, efficiency and profitability of fertilizer microdosing in maize. An experiment with the following treatments was conducted: control without fertilizer, microdosing treatments, with the rate of 27 + 27, 53 + 53 and 80 + 80 kg ha−1, and banding of fertilizer with 100 + 100 kg ha−1 of di ammonium phosphate (DAP + urea, applied at planting and jointing, respectively. The treatments were arranged in a randomized complete block design with four replications. The experiment was conducted during the 2011/2012 and 2012/2013 cropping seasons at Ziway, Melkassa and Hawassa in the semiarid central rift valley region of Ethiopia. Compared to the control, the fertilizer treatments had higher yield and fertilizer use efficiency (FUE profitably. The 27 + 27 kg ha−1 fertilizer rate increased the grain yield by 19, 45 and 46% at Hawassa, Ziway and Melkassa, respectively, and it was equivalent to the higher rates. The value cost ratio (VCR was highest with the lowest fertilizer rate, varying between seven and 11 in the treatment with 27 + 27 kg ha−1, but two and three in the banding treatment. Similarly, FUE was highest with the lowest fertilizer rate, varying between 23 and 34 kg kg−1 but 7 and 8 kg kg−1 in the banding treatment. The improved yield, FUE, VCR and gross margin in maize with microdosing at the 27 + 27 kg ha−1 of DAP + urea rate makes it low cost, low risk, high yielding and profitable. Therefore, application of this particular rate in maize may be an option for the marginal farmers in the region with similar socioeconomic and agroecological conditions.

  2. Radioactivity in Chemical Fertilizers

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. Therapeutic analysis of high-dose-rate {sup 192}Ir vaginal cuff brachytherapy for endometrial cancer using a cylindrical target volume model and varied cancer cell distributions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hualin, E-mail: hualin.zhang@northwestern.edu; Donnelly, Eric D.; Strauss, Jonathan B. [Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, Illinois 60611 (United States); Qi, Yujin [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2016-01-15

    Purpose: To evaluate high-dose-rate (HDR) vaginal cuff brachytherapy (VCBT) in the treatment of endometrial cancer in a cylindrical target volume with either a varied or a constant cancer cell distributions using the linear quadratic (LQ) model. Methods: A Monte Carlo (MC) technique was used to calculate the 3D dose distribution of HDR VCBT over a variety of cylinder diameters and treatment lengths. A treatment planning system (TPS) was used to make plans for the various cylinder diameters, treatment lengths, and prescriptions using the clinical protocol. The dwell times obtained from the TPS were fed into MC. The LQ model was used to evaluate the therapeutic outcome of two brachytherapy regimens prescribed either at 0.5 cm depth (5.5 Gy × 4 fractions) or at the vaginal mucosal surface (8.8 Gy × 4 fractions) for the treatment of endometrial cancer. An experimentally determined endometrial cancer cell distribution, which showed a varied and resembled a half-Gaussian distribution, was used in radiobiology modeling. The equivalent uniform dose (EUD) to cancer cells was calculated for each treatment scenario. The therapeutic ratio (TR) was defined by comparing VCBT with a uniform dose radiotherapy plan in term of normal cell survival at the same level of cancer cell killing. Calculations of clinical impact were run twice assuming two different types of cancer cell density distributions in the cylindrical target volume: (1) a half-Gaussian or (2) a uniform distribution. Results: EUDs were weakly dependent on cylinder size, treatment length, and the prescription depth, but strongly dependent on the cancer cell distribution. TRs were strongly dependent on the cylinder size, treatment length, types of the cancer cell distributions, and the sensitivity of normal tissue. With a half-Gaussian distribution of cancer cells which populated at the vaginal mucosa the most, the EUDs were between 6.9 Gy × 4 and 7.8 Gy × 4, the TRs were in the range from (5.0){sup 4} to (13

  4. Agricultural growth, the status of women, and fertility.

    Science.gov (United States)

    Whittington, L A; Stapleton, D C

    1995-08-01

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

  5. Including climate variability in determination of the optimum rate of N fertilizer application using a crop model: A case study for rainfed corn in eastern Canada

    Science.gov (United States)

    Mesbah, M.; Pattey, E.; Jégo, G.; Geng, X.; Tremblay, N.; Didier, A.

    2017-12-01

    N rates for the region and soil. For instance, the probability to achieve a yield of 9.2 t ha-1 at 15% grain moisture on a loamy soil varied from 0 to 73% along the ecozone. For this level of expected yield, the recommended N rates ranged from 64 to 155 kg ha-1, which are relatively less than current provincial recommendations in Ontario and Quebec (120-170 kg ha-1).

  6. Efficiency of nitrogen fertilizer applied at corn sowing in contrasting growing seasons in Paraguay

    Directory of Open Access Journals (Sweden)

    Telmo Jorge Carneiro Amado

    2013-12-01

    Full Text Available In order to select soil management practices that increase the nitrogen-use efficiency (NUE in agro-ecosystems, the different indices of agronomic fertilizer efficiency must be evaluated under varied weather conditions. This study assessed the NUE indices in no-till corn in southern Paraguay. Nitrogen fertilizer rates from 0 to 180 kg ha-1 were applied in a single application at corn sowing and the crop response investigated in two growing seasons (2010 and 2011. The experimental design was a randomized block with three replications. Based on the data of grain yield, dry matter, and N uptake, the following fertilizer indices were assessed: agronomic N-use efficiency (ANE, apparent N recovery efficiency (NRE, N physiological efficiency (NPE, partial factor productivity (PFP, and partial nutrient balance (PNB. The weather conditions varied largely during the experimental period; the rainfall distribution was favorable for crop growth in the first season and unfavorable in the second. The PFP and ANE indices, as expected, decreased with increasing N fertilizer rates. A general analysis of the N fertilizer indices in the first season showed that the maximum rate (180 kg ha-1 obtained the highest corn yield and also optimized the efficiency of NPE, NRE and ANE. In the second season, under water stress, the most efficient N fertilizer rate (60 kg ha-1 was three times lower than in the first season, indicating a strong influence of weather conditions on NUE. Considering that weather instability is typical for southern Paraguay, anticipated full N fertilization at corn sowing is not recommended due the temporal variability of the optimum N fertilizer rate needed to achieve high ANE.

  7. Measurement of fertilizers induced radioactivity in tobacco plants and elemental analysis using ICAP–AES

    International Nuclear Information System (INIS)

    Chauhan, Pooja; Chauhan, R.P.

    2014-01-01

    It is widely accepted that tobacco smoke is the leading cause of lung cancer worldwide. The alpha radioactive content present in tobacco smoke and increasing number of lung cancer cases explain the importance of investigation. The use of different fertilizers may cause alteration in the metabolism of plants causing different response towards uptake of different element and radionuclides. In the present study, the estimation of alpha radioactivity induced by use of different fertilizers in tobacco leaves was made using solid state nuclear track detector (LR-115) to identify the relative presence of radionuclides in the plants. The radon exhalation rates from the tobacco plant were carried out to confirm the presence of radium or emission of radon from plant. The elemental analysis of tobacco plant by inductively coupled argon plasma atomic emission spectrometry provides a way to understand the difference occurred in metabolism caused by the use of fertilizers. The alpha track densities were found to vary with nature of fertilizers added to the soil and an increase was also observed with time. The radon mass exhalation rates in various tobacco plants were found to vary with type of fertilizers used. - Highlights: • The study is related to alpha radioactivity measurements in tobacco plants. • The radon mass exhalation rates in various tobacco plants were also measured. • Study is related to analysis of chemical elements in different fertilized tobacco samples

  8. Studies on the abnormality of embryo sac and pollen fertility in aurotetraploid rice during different growing seasons

    International Nuclear Information System (INIS)

    Shahid, M.; Jilanfan, S.; Changmin, W.; Peng, Z.; Xiang-dong, X.

    2010-01-01

    Auto tetraploid rice has a great genetic potential but low seed setting rate is the major encumbrance in its use. Embryo sac fertility and pollen fertility are the most important factors which affect the seed setting rate in auto tetraploid rice. Whole mount eosin B-staining confocal laser scanning microscopy (WE-CLSM) was used to study the fertility and abnormalities in embryo sacs of diploid and auto tetraploid rice during different seasons. The results indicated that the embryo sac fertility (64.5%) was much low in auto tetraploid than that in diploid rice (86%), and five main types of abnormal embryo sac were found in all 10 auto tetraploid rice. Moreover, some other type abnormal embryo sacs were also observed in auto tetraploid rice. Embryo sac without female germ unit and embryo sac degeneration were the most frequent types of abnormalities in auto tetraploid rice. Embryo sac fertility ranged from 49.3% to 79.3%, pollen fertility ranged from 56.2 to 85.9%, and seed setting rate varied from 12.5 to 69.01% in various genotypes of auto tetraploid rice. Embryo sac and pollen fertility were found to have a significant correlation with seed setting rate. Seasons have significant effect on pollen and embryo sac fertility in both type of rice. All the auto tetraploid lines exhibited different types of embryo sac abnormalities which indicated that these might be related to different genotypes. (author)

  9. Plant Mating Systems Often Vary Widely Among Populations

    Directory of Open Access Journals (Sweden)

    Michael R. Whitehead

    2018-04-01

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

  10. Ninety-five orthotopic transplantations in 74 women of ovarian tissue after cytotoxic treatment in a fertility preservation network: tissue activity, pregnancy and delivery rates.

    Science.gov (United States)

    Van der Ven, H; Liebenthron, J; Beckmann, M; Toth, B; Korell, M; Krüssel, J; Frambach, T; Kupka, M; Hohl, M K; Winkler-Crepaz, K; Seitz, S; Dogan, A; Griesinger, G; Häberlin, F; Henes, M; Schwab, R; Sütterlin, M; von Wolff, M; Dittrich, R

    2016-09-01

    -one pregnancies and 17 deliveries were recorded. In Subgroup 1, tissue was cryopreserved at the age of 30 ± 5.6 and transplanted at 34 ± 4.9 years. Ovaries remained active 1 year after transplantation in 67% of cases (n = 33/49), the pregnancy rate was 33% (n = 16/49) and the delivery rate was 25% (n = 12/49). In Subgroup 5, tissue was cryopreserved at the age 30 ± 5.9 years and transplanted at 34 ± 5.2 years. Ovaries remained active 1 year after transplantation in 63% of cases (n = 25/40), the pregnancy rate was 28% (n = 11/40) and the delivery rate was 23% (n = 9/40). The success rates were age dependant with higher success in women who cryopreserved at a younger age. In Subgroup 5, tissue was exclusively transplanted into the ovary in 10% (n = 4/40) of women and into a peritoneal pocket in 75% (n = 30/40), resulting in spontaneous conceptions in 91% of patients (n = 10/11). The data were drawn from a retrospective analysis. The cryopreservation and transplantation techniques used have changed during the study period. The tissue was stored in many tissue banks and many surgeons were involved, leading to heterogeneity of the procedures. However, this does reflect the realistic situation in many countries. Although patients with POI were evaluated before transplantation to allow specific analysis of the transplanted tissue itself, the possibility cannot be excluded that residual ovarian tissue was also reactivated. This is the largest case series worldwide to date and it confirms that cryopreservation and transplantation of ovarian tissue can be a successful option for preserving fertility. Persistent tissue activity 12 months after transplantation suggests that the pregnancy and delivery rates may increase further in the future. As transplantation into the peritoneum results in a high success rate, this approach may be an alternative to transplantation into the ovary. However, in order to establish the best transplantation site, a randomized study is required. This study was

  11. Researches with the 'Fertexpert' model concerning the relationships between the efficiency indexes of the fertilizers usage in optimal economic rates and the agrochemical indexes of the soil and expected yields

    International Nuclear Information System (INIS)

    Budoi, G.; Berca, M.; Borlan, Z.; Gavriluta, I.; Soare, M.; Danuso, F.; Bireescu, L.

    1999-01-01

    The 'Fertexpert' model allows undertaking researches concerning the variation of efficiency indexes for fertilizers usage in the case of many crops depending on the content of available soil nutrients (the values of soil agrochemical indexes - IA) and on the expected yield, R s , when fertilization are applied in optimal economic rates, DOE. The physical efficiency indexes calculated and researched are the following: the total physical yield increase, SFR (kg/ha), the specific average yield increase, SSp (kg/kg N, P 2 O 5 or K 2 O), the specific consumption of active substance (a.s.) from fertilizer, CSp (kg a.s./1 kg average yield increase). The economic efficiency indexes computed are: the total profit, in monetary units/ha, the specific profit, in monetary units/l monetary unit spent with fertilization, PSp, and in monetary units/kg a.s., PSpsa. The model also allows the study of DOE variation depending on R s and IA. Starting from the made calculations, there can be drown up specific graphics that can then be used in practice and for research purposes to. Refs. 6 (author)

  12. High ratings of satisfaction with fertility treatment are common: findings from the Copenhagen Multi-centre Psychosocial Infertility (COMPI) Research Programme

    DEFF Research Database (Denmark)

    Schmidt, L; Holstein, B E; Boivin, J

    2003-01-01

    BACKGROUND: The aims were: (i). to identify gender differences in evaluation of medical and patient-centred (psychosocial) care in fertility clinics and (ii). to identify predictors of satisfaction. METHODS: An epidemiological prospective study based on questionnaire responses among all new coupl...

  13. Education Differences in Intended and Unintended Fertility

    Science.gov (United States)

    Musick, Kelly; England, Paula; Edgington, Sarah; Kangas, Nicole

    2009-01-01

    Using a hazards framework and panel data from the National Longitudinal Survey of Youth (1979-2004), we analyze the fertility patterns of a recent cohort of white and black women in the United States. We examine how completed fertility varies by women's education, differentiating between intended and unintended births. We find that the education…

  14. Fertility in midlife women.

    Science.gov (United States)

    Yoldemir, T

    2016-06-01

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

  15. Preimplantation genetic screening for all 24 chromosomes by microarray comparative genomic hybridization significantly increases implantation rates and clinical pregnancy rates in patients undergoing in vitro fertilization with poor prognosis

    Science.gov (United States)

    Majumdar, Gaurav; Majumdar, Abha; Lall, Meena; Verma, Ishwar C.; Upadhyaya, Kailash C.

    2016-01-01

    CONTEXT: A majority of human embryos produced in vitro are aneuploid, especially in couples undergoing in vitro fertilization (IVF) with poor prognosis. Preimplantation genetic screening (PGS) for all 24 chromosomes has the potential to select the most euploid embryos for transfer in such cases. AIM: To study the efficacy of PGS for all 24 chromosomes by microarray comparative genomic hybridization (array CGH) in Indian couples undergoing IVF cycles with poor prognosis. SETTINGS AND DESIGN: A retrospective, case–control study was undertaken in an institution-based tertiary care IVF center to compare the clinical outcomes of twenty patients, who underwent 21 PGS cycles with poor prognosis, with 128 non-PGS patients in the control group, with the same inclusion criterion as for the PGS group. MATERIALS AND METHODS: Single cells were obtained by laser-assisted embryo biopsy from day 3 embryos and subsequently analyzed by array CGH for all 24 chromosomes. Once the array CGH results were available on the morning of day 5, only chromosomally normal embryos that had progressed to blastocyst stage were transferred. RESULTS: The implantation rate and clinical pregnancy rate (PR) per transfer were found to be significantly higher in the PGS group than in the control group (63.2% vs. 26.2%, P = 0.001 and 73.3% vs. 36.7%, P = 0.006, respectively), while the multiple PRs sharply declined from 31.9% to 9.1% in the PGS group. CONCLUSIONS: In this pilot study, we have shown that PGS by array CGH can improve the clinical outcome in patients undergoing IVF with poor prognosis. PMID:27382234

  16. Estimating pesticide sampling rates by the polar organic chemical integrative sampler (POCIS) in the presence of natural organic matter and varying hydrodynamic conditions

    International Nuclear Information System (INIS)

    Charlestra, Lucner; Amirbahman, Aria; Courtemanch, David L.; Alvarez, David A.; Patterson, Howard

    2012-01-01

    The polar organic chemical integrative sampler (POCIS) was calibrated to monitor pesticides in water under controlled laboratory conditions. The effect of natural organic matter (NOM) on the sampling rates (R s ) was evaluated in microcosms containing −1 of total organic carbon (TOC). The effect of hydrodynamics was studied by comparing R s values measured in stirred (SBE) and quiescent (QBE) batch experiments and a flow-through system (FTS). The level of NOM in the water used in these experiments had no effect on the magnitude of the pesticide sampling rates (p > 0.05). However, flow velocity and turbulence significantly increased the sampling rates of the pesticides in the FTS and SBE compared to the QBE (p < 0.001). The calibration data generated can be used to derive pesticide concentrations in water from POCIS deployed in stagnant and turbulent environmental systems without correction for NOM. - Highlights: ► We assessed the effect of TOC and stirring on pesticide sampling rates by POCIS. ► Total organic carbon (TOC) had no effect on the sampling rates. ► Water flow and stirring significantly increased the magnitude of the sampling rates. ► The sampling rates generated are directly applicable to field conditions. - This study provides POCIS sampling rates data that can be used to estimate freely dissolved concentrations of toxic pesticides in natural waters.

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta, E-mail: anchieta@iq.unesp.br

    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{sup −1} N (r = 0.9994), 100–2000 mg L{sup −1} P (r = 0.9946), and 100–2500 mg L{sup −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% (NO{sub 3}{sup −}-N), 95–103% (NH{sub 4}{sup +}-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. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H{sub 2}O{sub 2} allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time.

  18. 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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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% (NO 3 − -N), 95–103% (NH 4 + -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. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H 2 O 2 allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time

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

    Directory of Open Access Journals (Sweden)

    Sam Hyun Yoo

    2014-05-01

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

  20. Study on the placement of phosphorus fertilizer to improve fertilizer utilization by lowland rice

    International Nuclear Information System (INIS)

    Sisworo, W.H.; Riswantoro; Mardjo, M.

    1976-01-01

    An experiment for studying the placement of phosphorus fertilizer was carried out in the glass house by using 32 P-labelled superphosphate. The specific activity of the labelled fertilizer used was 0,25 mCi/g P 2 O 5 . Three placement methods were studied: (1) Hill placement: Fertilizer was burried at a distance of 5cm from the plants at the depth of 5 cm, (2) Surface placement: Fertilizer was spread on the surface, and (3) Soil mixed application: Fertilizer was mixed with the soil at the depth of 5 cm. Superphosphate was applied at the rates of 0, 30, 60, 90, and 120 kg P 25 /ha. Results obtained from the experiment showed that the dry matter production was significantly affected by the methods of placement of phosphorus fertilizer. Soil mixed placement gave the lowest yield of dry plant material. It differed significantly from the two other methods of placement. However, there was no significant difference between hill and surface placement. The placement of phosphorus fertilizer significantly affected the total uptake of phosphorus nutrient, uptake fertilizer phosphorus, and the percentage of fertilizer utilization. Surface placement gave the highest utilization of fertilizer when supplied at rates higher than 60 kg P 2 O 5 /ha. At low rate applications, hill placement was the best, but, at rates higher than 60 kg P 2 O 5 /ha the percentage of fertilizer utilization decreased. Soil mixed application was the least efficient fertilizer utilization. (author)

  1. Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Butts, Ian; Munk, Peter

    2016-01-01

    sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic...... and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30–40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion...

  2. Crackle pitch and rate do not vary significantly during a single automated-auscultation session in patients with pneumonia, congestive heart failure, or interstitial pulmonary fibrosis.

    Science.gov (United States)

    Vyshedskiy, Andrey; Ishikawa, Sadamu; Murphy, Raymond L H

    2011-06-01

    To determine the variability of crackle pitch and crackle rate during a single automated-auscultation session with a computerized 16-channel lung-sound analyzer. Forty-nine patients with pneumonia, 52 with congestive heart failure (CHF), and 18 with interstitial pulmonary fibrosis (IPF) performed breathing maneuvers in the following sequence: normal breathing, deep breathing, cough several times; deep breathing, vital-capacity maneuver, and deep breathing. From the auscultation recordings we measured the crackle pitch and crackle rate. Crackle pitch variability, expressed as a percentage of the average crackle pitch, was small in all patients and in all maneuvers: pneumonia 11%, CHF 11%, pulmonary fibrosis 7%. Crackle rate variability was also small: pneumonia 31%, CHF 32%, IPF 24%. Compared to the first deep-breathing maneuver (100%), the average crackle pitch did not significantly change following coughing (pneumonia 100%, CHF 103%, IPF 100%), the vital-capacity maneuver (pneumonia 100%, CHF 92%, IPF 104%), or during quiet breathing (pneumonia 97%, CHF 100%, IPF 104%). Similarly, the average crackle rate did not change significantly following coughing (pneumonia 105%, CHF 110%, IPF 90%) or the vital-capacity maneuver (pneumonia 102%, CHF 101%, IPF 99%). However, during normal breathing the crackle rate was significantly lower in the patients with pneumonia (74%, P auscultation session suggests that crackle rate can be used to follow the course of cardiopulmonary illnesses such as pneumonia, IPF, and CHF.

  3. Model-supported estimation of mortality rates in Baltic cod (Gadus morhua callarias L. larvae: the varying impact of 'critical periods'

    Directory of Open Access Journals (Sweden)

    Hinrichsen Hans-Harald

    2001-11-01

    Full Text Available Abstract Background Changes in the survival-rate during the larval phase may strongly influence the recruitment level in marine fish species. During the larval phase different 'critical periods' are discussed, e.g. the hatching period and the first-feeding period. No such information was available for the Baltic cod stock, a commercially important stock showing reproduction failure during the last years. We calculated field-based mortality rates for larval Baltic cod during these phases using basin-wide abundance estimates from two consecutive surveys. Survey information was corrected by three dimensional hydrodynamic model runs. Results The corrections applied for transport were of variable impact, depending on the prevailing circulation patterns. Especially at high wind forcing scenarios, abundance estimates have the potential to be biased without accounting for transport processes. In May 1988 mortality between hatch and first feeding amounted to approximately 20% per day. Mortality rates during the onset of feeding were considerably lower with only 7% per day. In August 1991 the situation was vice versa: Extremely low mortality rates of 0.08% per day were calculated between hatch and first feeding, while the period between the onset of feeding to the state of an established feeder was more critical with mortality rates of 22% per day. Conclusions Mortality rates during the different proposed 'critical periods' were found to be highly variable. Survival rates of Baltic cod are not only influenced by a single 'critical period', but can be limited at different points during the larval phase, depending on several biotic and abiotic factors.

  4. Estimating pesticide sampling rates by the polar organic chemical integrative sampler (POCIS) in the presence of natural organic matter and varying hydrodynamic conditions

    Science.gov (United States)

    Charlestra, Lucner; Amirbahman, Aria; Courtemanch, David L.; Alvarez, David A.; Patterson, Howard

    2012-01-01

    The polar organic chemical integrative sampler (POCIS) was calibrated to monitor pesticides in water under controlled laboratory conditions. The effect of natural organic matter (NOM) on the sampling rates (Rs) was evaluated in microcosms containing -1 of total organic carbon (TOC). The effect of hydrodynamics was studied by comparing Rs values measured in stirred (SBE) and quiescent (QBE) batch experiments and a flow-through system (FTS). The level of NOM in the water used in these experiments had no effect on the magnitude of the pesticide sampling rates (p > 0.05). However, flow velocity and turbulence significantly increased the sampling rates of the pesticides in the FTS and SBE compared to the QBE (p < 0.001). The calibration data generated can be used to derive pesticide concentrations in water from POCIS deployed in stagnant and turbulent environmental systems without correction for NOM.

  5. Cost-effectiveness of a potential future Helicobacter pylori vaccine in the Netherlands: the impact of varying the discount rate for health.

    Science.gov (United States)

    de Vries, Robin; Klok, Rogier M; Brouwers, Jacobus R B J; Postma, Maarten J

    2009-02-05

    To estimate the cost-effectiveness of a potential Helicobacter pylori (HP) vaccine for the Dutch situation, we developed a Markov model. Several HP prevalence scenarios were assessed. Additionally, we assessed the impact of the discount rate for health on the outcomes, as this influence can be profound for vaccines. When applying the current discount rate of 1.5% for health, the expected cost-effectiveness of HP vaccination is estimated below the informal Dutch threshold of euro 20,000/LYG when the HP prevalence is assumed > or =20% in the Dutch population. In conclusion, we showed that HP vaccination could possibly be a cost-effective intervention. However, this depends to a large extend on the prevalence of HP in the population. Furthermore, we showed the large impact of the discount rate for health on the cost-effectiveness of a HP vaccination program, illustrative for other vaccination programs.

  6. The Dynamics of Nitrous Oxide Emission from the Use of Mineral Fertilizers in Russia

    Directory of Open Access Journals (Sweden)

    A AA. Romanovskaya

    2001-01-01

    Full Text Available The intensity of nitrous oxide (N2O emission was considered based on literature data on the single input of mineral N (nitrogen fertilizers into different agricultural soil types in Russia. Ambient environmental factors exert a combined effect on the process of gaseous nitrogen formation from fertilizers applied. To reduce the uncertainty of estimates as much as possible, only experimental results obtained under conditions similar to natural were selected for the assessments. Mineral nitric fertilizers were applied to soil at a rate of 40 to 75 kg/ha and the N2O emissions were measured for approximately 140 days. Daily average emission values varied from 0.08 to 0.45% of fertilizer nitrogen. Correspondingly, 1.26 and 2.38% of fertilizer nitrogen were emitted as N2O from chernozems and soddy podzols. In 1990, the use of fertilizers in Russian agricultural practices for 53 Gg N2O-N, which equates to approximately 6.1% of global nitrous oxide emissions from nitric fertilizers. Later, the emission dropped because of a decrease in the input of nitric fertilizers to agricultural crops, and in 1998, it constituted just 20.5% of the 1990 level. In the period from 2008 to 2012, the nitrous oxide emission is expected to vary from 0.5 to 65.0 Gg N2O-N due to possible changes in national agricultural development. In the most likely scenario, the use of mineral fertilizers in Russia will account for approximately 34 to 40 Gg N2O-N emissions annually from 2008�2012.

  7. Variáveis biométricas da cana-de-açúcar fertilizada com resíduos orgânico e industrial e irrigada com água servida e potável Biometric variable of sugar cane fertilized with organic and industrial residues irrigated with potable and wastewater

    Directory of Open Access Journals (Sweden)

    Fabio O. de Nobile

    2011-02-01

    Full Text Available O uso agrícola de resíduos orgânicos e industriais é uma alternativa de aproveitamento como fertilizante e fonte de matéria orgânica ao solo. Neste sentido, o objetivo deste trabalho foi avaliar o uso do composto de lixo e biofertilizante como fonte de nutrientes, e o resíduo do processamento da bauxita como corretivo da acidez do solo, para a cultura da cana-de-açúcar (cana-planta, irrigada com água potável e servida. Para tanto foi conduzido experimento em vaso, utilizando-se de solo Argissolo Vermelho-Amarelo distrófico, cultivado com a variedade RB855536. Foram avaliadas variáveis biométricas da planta, tais como: altura de plantas, diâmetro do colmo, perfilhamento, número de folhas, matéria seca de raiz e parte aérea. Os dados obtidos evidenciaram que a qualidade da água de irrigação, potável ou servida, não influenciou as variáveis avaliadas. A aplicação de composto de lixo e de biofertilizante constituiu-se numa fonte eficiente de nutrientes para as plantas de cana-de-açúcar, mas é necessária a aplicação adicional de fertilizantes para a obtenção de produção de colmos, similar ao do tratamento com adubação mineral convencional. Já o resíduo do processamento da bauxita mostrou-se eficiente na correção da acidez, apresentando as variáveis físicas semelhantes ao tratamento com adubação mineral, com exceção da matéria seca de raiz.The agricultural use of organic and industrial residues is an alternative of exploitation with fertilization and source of organic matter to the soil. In this direction, the objective of this research was to evaluate the use of the urban solid waste and biofertilizer as nutrient source, and residue of the bauxite processing as agricultural liming materials of the soil for sugar cane (cane plant and culture yields, irrigated with potable water and wastewater. For in such an experiment in vase was lead, under Alfisol soil, cultivated with the variety RB855536. It had

  8. Cost-effectiveness of a potential future Helicobacter pylori vaccine in the Netherlands : The impact of varying the discount rate for health

    NARCIS (Netherlands)

    de Vries, Robin; Klok, Rogier M.; Brouwers, Jacobus R. B. J.; Postma, Maarten J.

    2009-01-01

    To estimate the cost-effectiveness of a potential Helicobacter pylori (HP) vaccine for the Dutch situation, we developed a Markov model. Several HP prevalence scenarios were assessed. Additionally, we assessed the impact of the discount rate for health on the outcomes, as this influence can be

  9. Standardized laryngeal videostroboscopic rating : Differences between untrained and trained male and female subjects, and effects of varying sound intensity, fundamental frequency, and age

    NARCIS (Netherlands)

    Sulter, AM; Schutte, HK; Miller, DG

    To determine the influence of the factors gender, vocal training, sound intensity, pitch, and aging on vocal function, videolaryngostroboscopic images of 214 subjects, subdivided according to gender and status of vocal training, were evaluated by three judges with standardized rating scales,

  10. Will sex selection reduce fertility?

    Science.gov (United States)

    Leung, S F

    1994-01-01

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

  11. Varied Rates of Implementation of Patient-Centered Medical Home Features and Residents' Perceptions of Their Importance Based on Practice Experience.

    Science.gov (United States)

    Eiff, M Patrice; Green, Larry A; Jones, Geoff; Devlaeminck, Alex Verdieck; Waller, Elaine; Dexter, Eve; Marino, Miguel; Carney, Patricia A

    2017-03-01

    Little is known about how the patient-centered medical home (PCMH) is being implemented in residency practices. We describe both the trends in implementation of PCMH features and the influence that working with PCMH features has on resident attitudes toward their importance in 14 family medicine residencies associated with the P4 Project. We assessed 24 residency continuity clinics annually between 2007-2011 on presence or absence of PCMH features. Annual resident surveys (n=690) assessed perceptions of importance of PCMH features using a 4-point scale (not at all important to very important). We used generalized estimating equations logistic regression to assess trends and ordinal-response proportional odds regression models to determine if resident ratings of importance were associated with working with those features during training. Implementation of electronic health record (EHR) features increased significantly from 2007-2011, such as email communication with patients (33% to 67%), preventive services registries (23% to 64%), chronic disease registries (63% to 82%), and population-based quality assurance (46% to 79%). Team-based care was the only process of care feature to change significantly (54% to 93%). Residents with any exposure to EHR-based features had higher odds of rating the features more important compared to those with no exposure. We observed consistently lower odds of the resident rating process of care features as more important with any exposure compared to no exposure. Residencies engaged in educational transformation were more successful in implementing EHR-based PCMH features, and exposure during training appears to positively influence resident ratings of importance, while exposure to process of care features are slower to implement with less influence on importance ratings.

  12. Fertility preservation 2

    Science.gov (United States)

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

    2014-01-01

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

  13. Impact toughness and microstructure relationship in niobium- and vanadium-microalloyed steels processed with varied cooling rates to similar yield strength

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, S. [Center for Structural and Functional Materials and Department of Chemical Engineering, University of Louisiana at Lafayette, LA 70504-4130 (United States); Misra, R.D.K. [Center for Structural and Functional Materials and Department of Chemical Engineering, University of Louisiana at Lafayette, LA 70504-4130 (United States)]. E-mail: dmisra@louisiana.edu; Mannering, T. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Panda, D. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Jansto, S.G. [Reference Metals, 1000 Old Pond Road, Bridgeville, PA 15017 (United States)

    2006-11-15

    We describe here the relationship between microstructure and impact toughness behavior as a function of cooling rate for industrially processed Nb- and V-microalloyed steels of almost similar yield strength ({approx}60 ksi). Both Nb- and V-microalloyed steels exhibited increase in toughness with increase in cooling rates during processing. However, Nb-microalloyed steels were characterized by relatively higher toughness than the V-microalloyed steels under identical processing conditions. The microstructure of Nb- and V-microalloyed steels processed at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while Nb-microalloyed steels besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite. The microstructure of Nb- and V-microalloyed steels processed at relatively higher cooling rate contained degenerated pearlite and lath-type (acicular) ferrite in addition to the primary ferrite-pearlite constituents. The fraction of degenerated pearlite was higher in Nb-microalloyed steels than in the V-microalloyed steels. In both Nb- and V-microalloyed steels the precipitation characteristics were similar with precipitation occurring at grain boundaries, dislocations, and in the ferrite matrix. Fine-scale ({approx}5-10 nm) precipitation was observed in the ferrite matrix of both the steels. The selected area diffraction (SAD) pattern analysis revealed that these fine precipitates were MC type of niobium and vanadium carbides in the respective steels and followed Baker-Nutting orientation relationship with the ferrite matrix. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels is attributed to higher fraction of degenerated pearlite in the steel.

  14. Impact toughness and microstructure relationship in niobium- and vanadium-microalloyed steels processed with varied cooling rates to similar yield strength

    International Nuclear Information System (INIS)

    Shanmugam, S.; Misra, R.D.K.; Mannering, T.; Panda, D.; Jansto, S.G.

    2006-01-01

    We describe here the relationship between microstructure and impact toughness behavior as a function of cooling rate for industrially processed Nb- and V-microalloyed steels of almost similar yield strength (∼60 ksi). Both Nb- and V-microalloyed steels exhibited increase in toughness with increase in cooling rates during processing. However, Nb-microalloyed steels were characterized by relatively higher toughness than the V-microalloyed steels under identical processing conditions. The microstructure of Nb- and V-microalloyed steels processed at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while Nb-microalloyed steels besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite. The microstructure of Nb- and V-microalloyed steels processed at relatively higher cooling rate contained degenerated pearlite and lath-type (acicular) ferrite in addition to the primary ferrite-pearlite constituents. The fraction of degenerated pearlite was higher in Nb-microalloyed steels than in the V-microalloyed steels. In both Nb- and V-microalloyed steels the precipitation characteristics were similar with precipitation occurring at grain boundaries, dislocations, and in the ferrite matrix. Fine-scale (∼5-10 nm) precipitation was observed in the ferrite matrix of both the steels. The selected area diffraction (SAD) pattern analysis revealed that these fine precipitates were MC type of niobium and vanadium carbides in the respective steels and followed Baker-Nutting orientation relationship with the ferrite matrix. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels is attributed to higher fraction of degenerated pearlite in the steel

  15. Optimization of Ligninolytic Enzyme Activity and Production Rate with Ceriporiopsis subvermispora for Application in Bioremediation by Varying Submerged Media Composition and Growth Immobilization Support

    Directory of Open Access Journals (Sweden)

    Janja Babič

    2012-09-01

    Full Text Available Response surface methodology (central composite design of experiments was employed to simultaneously optimize enzyme production and productivities of two ligninolytic enzymes produced by Ceriporiopsis subvermispora. Concentrations of glucose, ammonium tartrate and Polysorbate 80 were varied to establish the optimal composition of liquid media (OLM, where the highest experimentally obtained activities and productivities were 41 U L−1 and 16 U L−1 day−1 for laccase (Lac, and 193 U L−1 and 80 U L−1 day−1 for manganese peroxidase (MnP. Considering culture growth in OLM on various types of immobilization support, the best results were obtained with 1 cm beech wood cubes (BWCM. Enzyme activities in culture filtrate were 152 U L−1 for Lac and 58 U L−1 for MnP, since the chemical composition of this immobilization material induced higher Lac activity. Lower enzyme activities were obtained with polyurethane foam. Culture filtrates of OLM and BWCM were applied for dye decolorization. Remazol Brilliant Blue R (RBBR was decolorized faster and more efficiently than Copper(IIphthalocyanine (CuP with BWCM (80% and 60%, since Lac played a crucial role. Decolorization of CuP was initially faster than that of RBBR, due to higher MnP activities in OLM. The extent of decolorization after 14 h was 60% for both dyes.

  16. Historical Agricultural Nitrogen Fertilizer Management in the Contiguous United States during 1850-2015.

    Science.gov (United States)

    Lu, C.; Cao, P.; Yu, Z.

    2017-12-01

    The United States has a century-long history of managing anthropogenic nitrogen (N) fertilizer to booster the crop production. Accurate characterization of N fertilizer use history could provide essential implications for N use efficiency (NUE) enhancement and N loss reduction. However, a spatially explicit time-series data remains lacking to describe how N fertilizer use varied among crop types, regions, and time periods. In this study, we therefore developed long-term gridded N management maps depicting N fertilizer application rate, timing, and ratio of fertilizer forms in nine major crops (i.e. corn, soybean, winter wheat, spring wheat, cotton, sorghum, rice, barley, and durum wheat) in the contiguous U.S. at a resolution of 1 km × 1 km during 1850-2015. We found that N application rates of the U.S. increased by approximately 34 times since 1940. Nonetheless, spatial analysis revealed that N-use hotspots have shifted from the West and Southeast to the Midwest and the Great Plains since 1900. Specifically, corn of the Corn Belt region received the most intensive N input in spring, followed by large N application amount in fall, implying a high N loss risk in this region. Moreover, spatiotemporal patterns of NH4+/NO3- ratio varied largely among regions. Generally, farmers have increasingly favored NH4+-form fertilizers over NO3- fertilizers since the 1940s. The N fertilizer use data developed in this study could serve as an essential input for modeling communities to fully assess the N addition impacts, and improve N management to alleviate environmental problems.

  17. Is fertility falling in Zimbabwe?

    Science.gov (United States)

    Udjo, E O

    1996-01-01

    With an unequalled contraceptive prevalence rate in sub-Saharan Africa, of 43% among currently married women in Zimbabwe, the Central Statistical Office (1989) observed that fertility has declined sharply in recent years. Using data from several surveys on Zimbabwe, especially the birth histories of the Zimbabwe Demographic and Health Survey, this study examines fertility trends in Zimbabwe. The results show that the fertility decline in Zimbabwe is modest and that the decline is concentrated among high order births. Multivariate analysis did not show a statistically significant effect of contraception on fertility, partly because a high proportion of Zimbabwean women in the reproductive age group never use contraception due to prevailing pronatalist attitudes in the country.

  18. Fertilizer value of urine in pumpkin (Cucurbita maxima L. cultivation

    Directory of Open Access Journals (Sweden)

    S.K. PRADHAN

    2008-12-01

    Full Text Available The fertilizer value of human urine was compared with mineral fertilizer in pumpkin (Cucurbita maxima cultivation at a dose of 113 kg N ha-1 with no-fertilization used as control. The growth of the vine was better in urine fertilized pumpkins than in mineral fertilized and non-fertilized pumpkins. Total fruit biomass was higher in mineral fertilized plants compared to urine fertilized and non-fertilized pumpkins. Urine fertilized pumpkins may have suffered from lower potassium or higher chloride, thus they produced fewer flowers and fruits. However, total fruit biomass and the number of fruits were slightly higher in urine fertilized plants than in their non-fertilized counterparts, i.e. 17.2 t ha-1 more pumpkin could be produced with urine fertilizer. The microbial hygiene quality as well as the contents of soluble sugars, protein and taste quality were similar in all treatments, but lower nitrate and higher chloride contents were recorded in urine fertilized pumpkins than other treatments. In conclusion, our study shows that the production rate of urine fertilized pumpkins was somewhat lower than mineral fertilized pumpkins but it was higher than non-fertilized pumpkins. The hygienic quality was equally good with all treatments.;

  19. The Effect of Different Rates of Municipal Compost and N Fertilizer on the Essential Oil and some Vegetative Characteristics of Summer Savoury (Satureja hortensis L.

    Directory of Open Access Journals (Sweden)

    Sh Zare

    2013-08-01

    Full Text Available To evaluate the effect of different levels of nitrogen fertilizer and municipal compost on the essential yeild of savory pot experiment in 2009 was carried out in the Darab region. Different doses of compost was in four levels, including: zero C0:, 10C1:, 20C2: and 30C3: tons per hectare and nitrogen fertilizer include: zero N0:, 30N1:, 60 N2: and 90N3: kg of pure nitrogen from urea per hectare. Analysis of variance showed that the consumption of different amounts of nitrogen, compost and interaction between them on dry matter yield and height, percentage and yield of essential oil of savory, is statistically significant. Comparison of mean showed that treatment 90 kg N/ha along with 30 tons of municipal compost consumption per hectare (N3C3 with an average 50/8 g dry weight in pot greatest and treatments without N and compost (N0C0 and non-N with 10 and 20 tons of compost ha (N0C1 and N0C2 were mean 23/69, 23/42 and 24/63 g dry weight, the lowest plant dry weight were allocated to pot. N fertilizer and compost on the number of lateral branches per plant and nitrogen application on mean stem diameter was significant. N3 with an average 24/75 lateral branches and C3 with a mean 22/19 lateral branches, were the highest number of lateral branches per plant. N2C3 with mean of 2/13 percent of most essential oil produced. The most essential yield of the combination treatment N3C3, respectively. Generally produce more essential oil percent and to have more dry matter level N2C3 be seems appropriate.

  20. Nanocomposites for controlled release of nitrogen fertilizer

    International Nuclear Information System (INIS)

    Silva, Viviane J.M. da; Visconte, Leila L.Y.; Nascimento, Regina Sandra V.

    2009-01-01

    The study aimed at the development of nano structured materials capable of reducing the rate of release of nitrogen in the soil from an agricultural nitrogen fertilizer. Four different systems of polymer composites were prepared: (1) montmorillonite clay/fertilizer, (2) montmorillonite clay/thermoplastic starch and fertilizer, (3) montmorillonite clay/fertilizer, thermoplastic starch and low-density polyethylene (LDPE) and also (4) montmorillonite clay/fertilizer, thermoplastic starch and polycaprolactone. It was confirmed the formation of nano structured materials by elemental analysis (CHN) and X-ray diffraction (XRD). The kinetics of nitrogen release was detected by enzymatic colorimetric analysis and spectroscopy in the ultraviolet/visible. The results showed that all materials evaluated were able to reduce the rate of release of nitrogen in the fertilizers. (author)

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

    Science.gov (United States)

    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 1 (maximum T, ET and rainfall on AI day, and ET and rainfall on day 15), and two variables presented OR 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.

  2. Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols treated with different phosphorus rates and sources for varied soil-source contact periods

    Directory of Open Access Journals (Sweden)

    Irio Fernando de Freitas

    2013-06-01

    Full Text Available Despite the large number of studies addressing the quantification of phosphorus (P availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR and Mixed Resin (MR, to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2 + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV, a sandy clay loam Red Yellow Latosol (LVA, and a sandy loam Yellow Latosol (LA, to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais at two P rates (75 and 150 mg dm-3, plus three control treatments (each soil without P application after four contact periods (15, 30, 60, and 120 days of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction. These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay and LVA (medium texture for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of

  3. Are Nitrogen Fertilizers Deleterious to Soil Health?

    Directory of Open Access Journals (Sweden)

    Bijay- Singh

    2018-04-01

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

  4. Evaluation of fertility traits of Friesian X Bunaji dairy cows ...

    African Journals Online (AJOL)

    Evaluation of fertility traits of Friesian X Bunaji dairy cows. ... days open (DO) , number of insemination per conception (NIC), and non- return rate 56 days ... Keywords: Fertility, Friesian x Bunaji cows, Parity, Body condition score, Season, Year ...

  5. Indirect Estimation of Selected Measures of Fertility and Marital ...

    African Journals Online (AJOL)

    DLHS6

    2018-01-09

    Jan 9, 2018 ... marital status distribution data of India especially of the 2011 census in deriving indirectly the fertility measures .... 2011 Census, Economic and Political weekly, EPW Vol. ... Indirect Estimates of Total Fertility Rate Using Child.

  6. Can simple trachelectomy or conization show comparable survival rate compared with radical trachelectomy in IA1 cervical cancer patients with lymphovascular space invasion who wish to save fertility? A systematic review and guideline recommendation.

    Science.gov (United States)

    Shim, Seung-Hyuk; Lim, Myong Cheol; Kim, Hyun Jung; Lee, Maria; Nam, Eun Ji; Lee, Jung Yun; Lee, Yoo-Young; Lee, Kwang Beom; Park, Jeong Yeol; Kim, Yun Hwan; Ki, Kyung Do; Song, Yong Jung; Chung, Hyun Hoon; Kim, Sunghoon; Lee, Jeong-Won; Kim, Jae-Weon; Bae, Duk-Soo; Lee, Jong-Min

    2018-01-01

    This study aims to analyze the published literatures on the effect of less radical fertility-preserving procedures, such as conization or simple trachelectomy, on oncological outcomes in IA1 cervical cancer patients with lymphovascular space invasion (LVSI) through a systematic-review. The EMBASE and MEDLINE databases and Cochrane Library were searched for published studies reporting the oncological outcomes of conization/simple trachelectomy in these patients, through April 2017. The endpoints were recurrence and mortality rates. Data were presented as per the Meta-analysis Of Observational Studies in Epidemiology checklist. Practice guidelines were generated via the Grading of Recommendation, Assessment, Development and Evaluation system. From 6,755 records, 94 full-texts articles were reviewed for eligibility, and five studies were included in this systematic review. All included studies were nonrandomized studies: two case-control studies comparing conization (n = 14) with hysterectomy (n = 24), and the other three were interrupted time series including conization (n = 20) and simple vaginal trachelectomy (n = 59). During the median follow-up duration of 43 months, no recurrence was reported in both conization and simple trachelectomy groups in IA1 patients with LVSI. From three studies reporting the fertility outcomes, the rates of pregnancy, live birth, preterm delivery, and second-trimester miscarriage were 73% (35/48), 64% (32/50), 10% (5/48), and 6% (3/48), respectively. Results suggest that simple trachelectomy or conization could be performed for IA1 cervical cancer patients with LVSI who want to preserve fertility, although these results are only based on a small number of nonrandomized studies (recommendation grade 2 = weak; evidence level D = very low). Further randomized trials with long-term study period are needed to address this issue.

  7. In vitro fertilization (IVF)

    Science.gov (United States)

    ... the vagina Blood in the urine Outlook (Prognosis) Statistics vary from one clinic to another and must be looked at carefully. Pregnancy rates reflect the number of women who became pregnant after IVF. But not all pregnancies result in a live birth. Live birth rates reflect the number of women ...

  8. On the fertility transition in Africa

    DEFF Research Database (Denmark)

    Mveyange, Anthony Francis

    A consensus among social scientists is that fertility rates in Africa are declining. What determines these declines? I present fresh evidence that shows education, especially for women, is an important determinant of the fertility transition in Africa. This finding is consistent with the predicti......A consensus among social scientists is that fertility rates in Africa are declining. What determines these declines? I present fresh evidence that shows education, especially for women, is an important determinant of the fertility transition in Africa. This finding is consistent...... with the predictions of the unified growth theory and sheds important insights in explaining the sustained income growth Africa has experienced since 1995. The paper also shows that the effects of income per capita and child mortality on fertility rates are non-robust and inconsistent with the predictions...

  9. Fertility trends in Singapore.

    Science.gov (United States)

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

    1988-10-01

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

  10. Male fertility in cystic fibrosis.

    LENUS (Irish Health Repository)

    Chotirmall, S H

    2011-04-05

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

  11. A physical theory on placement of fertilizers

    NARCIS (Netherlands)

    Wit, de C.T.

    1953-01-01

    A theory was developed enabling calculation of the effect of any placement method of fertilizer on yield if the effect of one method is known.

    This theory was based on the following established facts. The reactions between soil and fertilizer rate are the same for broadcasting and placement

  12. Global Fertilizer and Manure, Version 1: Nitrogen Fertilizer Application

    Data.gov (United States)

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

  13. Global Fertilizer and Manure, Version 1: Phosphorus Fertilizer Application

    Data.gov (United States)

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

  14. Ecological feedbacks can reduce population-level efficacy of wildlife fertility control

    Science.gov (United States)

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

    2014-01-01

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

  15. 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

    Directory of Open Access Journals (Sweden)

    Mayadhar Barik

    2016-01-01

    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.

  16. Fertilization of SRC willow. II

    DEFF Research Database (Denmark)

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

    2014-01-01

    impacts of different doses of mineral fertilizer, manure and sewage sludge in a commercially grown SRC willow stand. We examined macro nutrient and heavy metal leaching rates and calculated element balances to evaluate the environmental impact. Growth responses were reported in a former paper (Sevel et al...

  17. Fertility test of frozen boar semen.

    Science.gov (United States)

    Osinowa, O; Salamon, S

    1976-10-01

    The fertility results of two experiments are presented. In experiment 1, the semen was frozen in tris-fructose-EDTA or BF3 diluents at 0-25 X 10(9)/ml sperm concentration and extended after thawing with either seminal plasma (SP) or the freezing medium (FM) containing no cryoprotective agent. In the second experiment the semen was glycerolated by two methods, frozen at 1-0 X 10(9)/ml sperm concentration, and extended wtih FM before insemination. Fertility after double insemination within one oestrus with semen frozen in tris-fructose-EDTA or BF3 diluents varied depending on the medium used for extension of thawed semen. The farrowing rates for semen frozen in the former diluent with FM and SP post-thawing media were 4/8 and 1/8 respectively, and for semen frozen BF3 diluent with FM and SP post-thawing extenders 1/8 and 5/8. The mean farrowing for the 32 animals inseminasted was 34-4%. Pregnancies for semen frozen in tris-fructose-EDTA and glycerolated at 30 or 5 degrees C were 5/12 and 4/12 respectively, and for single and double inseminations 6/12 and 3/12 respectively. Of 24 animals inseminated 37-5% farrowed.

  18. Impact of mineral fertilizers on common winter barley (Hordeum vulgare L. agrophytocenosis development

    Directory of Open Access Journals (Sweden)

    Я. М. Мукан

    2014-04-01

    Full Text Available In 2011 to 2013 a study was completed for the impact of varying rates of fertilizing onto the indices of productivity for barley agrophytocenosis of Helios and Commandor, in particular, such its components as a number of productive stems, number of seeds per ear, potential biological activity of ear and photosynthetic apparatus. It is found that the level of spring barley agrophytocenosis productivity is subject both to varietal peculiarities and the rate of mineral fertilizer application. When applying N 60P 60K 60 і N 90P 90K 90 the highest potential and biological productivity of Helios and Commandor was recorder as compared against the control. Impact of varying application rates for fertilizers onto the components of ear biological productivity has been scrutinized. The qualitative composition of ear is a clear expression of variety phenotype and identifies the level of biological yield for spring barley. Application of N 60 P 60 K 60 і N 90 P 90 K 90 mineral fertilizers fairly increased the average leaf surface, photosynthetic lead capacity of varieties in 2 to 2.5 times, as well as FAR efficiency coefficient in 1.5 to 2.0 times as against control that thus contributed to the development of highest biological yield of Helios variety phytomass at the level of 14.9 to 15.0, grain – 7.8 to 8.0 ton per ha and, respectively, 12.7 and 7.5 tons per ha for Comandor variety.

  19. Mineralization of residual fertilizer nitrogen in soil after rice harvest

    International Nuclear Information System (INIS)

    Hazarika, S.; Sarkar, M.C.

    1994-01-01

    Remineralization of immobilized 15 N labelled urea N applied to rice crop at the rate of 180 kg N/ha was determined. Mineral N increased rapidly up to 14 days of incubation and thereafter remained more or less constant. The recovery of fertilizer as mineral N varied between 0.7 and 3.1 μg/g soil. The percent mineralization of labelled organic N ranged between 3.1 and 9.5. (author). 5 refs., 2 tabs., 1 fig

  20. Male Fertility Issues

    Science.gov (United States)

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

  1. Fertility effects of cancer treatment.

    Science.gov (United States)

    Marsden, Donald E; Hacker, Neville

    2003-01-01

    Cancer sufferers are a subfertile group, and most treatments have the potential to adversely affect gonadal function. As cancer treatment becomes more effective and survival rates improve there are more cancer survivors in the reproductive age group for whom parenting is an important consideration. This article outlines the effects on fertility of cancer treatments and techniques to minimise the risk of infertility. The overall prospects for younger cancer sufferers to either retain their fertility or have genetic offspring is now better than ever before, due to advances in assisted reproductive technology, the appropriate use of fertility sparing surgery and other techniques to reduce the toxicity of therapy on the reproductive organs. These advances raise new moral and ethical concerns that must be considered before advising cancer sufferers of the options for preserving reproductive capacity.

  2. Fertility preservation in Turner syndrome.

    Science.gov (United States)

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

    2016-01-01

    Premature ovarian insufficiency is a relatively rare condition that can appear early in life. In a non-negligible number of cases the ovarian dysfunction results from genetic diseases. Turner syndrome (TS), the most common sex chromosome abnormality in females, is associated with an inevitable premature exhaustion of the follicular stockpile. The possible or probable infertility is a major concern for TS patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The severely reduced follicle pool even during prepubertal life represents the major limit for fertility preservation and is the root of numerous questions regarding the competence of gametes or ovarian tissue crybanked. In addition, patients suffering from TS show higher than usual rates of spontaneous abortion, fetal anomaly, and maternal morbidity and mortality, which should be considered at the time of fertility preservation and before reutilization of the cryopreserved gametes. Apart from fulfillment of the desire of becoming genetic parents, TS patients may be potential candidates for egg donation, gestational surrogacy, and adoption. The present review discusses the different options for preserving female fertility in TS and the ethical questions raised by these approaches. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  3. Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Hansen, Jørgen Frederik; Kjellerup, Viggo K.

    1993-01-01

    ammonium nitrate (CAN) or animal slurry according to recommended rates (1N) or 50% above recommended rates (1.5N). Compared with unfertilized crops, leaching of nitrate increased only slightly when 1N (CAN) was added. Successive annual additions of 1.5N (CAN) or IN and 1.5N (animal slurry) caused...

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

    African Journals Online (AJOL)

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

  5. Fertilizer use efficiency by maize (Zea mays) and egusi- melon ...

    African Journals Online (AJOL)

    DBOY

    fertilizers by maize and egusi-melon in various ratios of mixtures in an ultisol in ... fertilizers replicated three timesfor two years as experiments 2009 and 2010, .... design. In 2011, the fertilizer rates were increased to six to further determine the ...

  6. Sperm dosage and site of insemination in relation to fertility in bovines

    Directory of Open Access Journals (Sweden)

    Tushar Kumar Mohanty

    2018-01-01

    Full Text Available Low sperm numbers in artificial insemination (AI-doses are being used widely to make the best use of high genetic value bulls as well as sex-sorted semen. Sperm concentration needed for AI to obtain reasonable fertility, taking genetic value of bull and numerous others components into consideration is one of the essential constituents for successful AI breeding program. However, low sperm concentrations in AI-doses lead to reducing post-thaw viability. The reduction in viability of low sperm doses may be affected by fresh semen volume, sperm number and seminal plasma level at final dilution. Reduction in quality and fertility of low sperm doses is one of the limitations for their use in successful AI programme. Sperm number per AI required to achieve optimum fertility is one of the main crucial things to AI industry, and numerous efforts have been made in this regard. Due to great variability among bulls, sperm number per AI could be a limiting factor in achieving acceptable fertility values. Fertility of low sperm doses may vary among bulls, and non-return rates (NRRs with low sperm doses may be determined by fertility level of bull. On the basis of individual bulls, sperm numbers in AI doses needed to be adjusted to reduce the variations in NRRs among bulls. Utilizing high fertile bulls for low sperm doses with acceptable non-return rates (NRRs may be a way to cover a large number of bovines under AI in countries like India. Deposition site within the uterine horn may alter non return rates following inseminations with low sperm doses. Following deep-uterine inseminations, acceptable pregnancies may be achieved with low sperm doses and even if ovulation side is unknown.

  7. Fertility preservation in young cancer patients

    Directory of Open Access Journals (Sweden)

    Ariel Revel

    2010-01-01

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

  8. Cancer and fertility: strategies to preserve fertility.

    Science.gov (United States)

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

    2011-03-01

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

  9. The effect of metformin use on pregnancy rates among polycystic ovary syndrome patients undergoing in vitro fertilization: A retrospective-cohort study

    Directory of Open Access Journals (Sweden)

    Yazed Sulaiman Al-Ruthia

    2017-09-01

    Conclusions: Metformin co-treatment during IVF may negatively affect pregnancy rates. Further well-designed, randomized, double-blind placebo-control clinical trials are needed to confirm the findings of this study.

  10. Genetic correlations between body condition scores and fertility in dairy cattle using bivariate random regression models.

    Science.gov (United States)

    De Haas, Y; Janss, L L G; Kadarmideen, H N

    2007-10-01

    Genetic correlations between body condition score (BCS) and fertility traits in dairy cattle were estimated using bivariate random regression models. BCS was recorded by the Swiss Holstein Association on 22,075 lactating heifers (primiparous cows) from 856 sires. Fertility data during first lactation were extracted for 40,736 cows. The fertility traits were days to first service (DFS), days between first and last insemination (DFLI), calving interval (CI), number of services per conception (NSPC) and conception rate to first insemination (CRFI). A bivariate model was used to estimate genetic correlations between BCS as a longitudinal trait by random regression components, and daughter's fertility at the sire level as a single lactation measurement. Heritability of BCS was 0.17, and heritabilities for fertility traits were low (0.01-0.08). Genetic correlations between BCS and fertility over the lactation varied from: -0.45 to -0.14 for DFS; -0.75 to 0.03 for DFLI; from -0.59 to -0.02 for CI; from -0.47 to 0.33 for NSPC and from 0.08 to 0.82 for CRFI. These results show (genetic) interactions between fat reserves and reproduction along the lactation trajectory of modern dairy cows, which can be useful in genetic selection as well as in management. Maximum genetic gain in fertility from indirect selection on BCS should be based on measurements taken in mid lactation when the genetic variance for BCS is largest, and the genetic correlations between BCS and fertility is strongest.

  11. Comparing the performance of 11 crop simulation models in predicting yield response to nitrogen fertilization

    OpenAIRE

    Salo , Tapio J.; Palosuo , Taru; Kersebaum , Kurt Christian; Nendel , Claas; Angulo , Carlos; Ewert , Frank; Bindi , Marco; Calanca , Pierluigi; Klein , Tommy; Moriondo , Marco; Ferrise , Roberto; Olesen , Jørgen Eivind; Patil , Rasmi H.; Ruget , Francoise; Takac , Jozef

    2016-01-01

    Eleven widely used crop simulation models (APSIM, CERES, CROPSYST, COUP, DAISY, EPIC, FASSET, HERMES, MONICA, STICS and WOFOST) were tested using spring barley (Hordeum vulgare L.) data set under varying nitrogen (N) fertilizer rates from three experimental years in the boreal climate of Jokioinen, Finland. This is the largest standardized crop model inter-comparison under different levels of N supply to date. The models were calibrated using data from 2002 and 2008, of which 2008 included si...

  12. Uptake rate of nitrogen from soil and fertilizer, and N derived from symbiotic fixation in cowpea (Vigna unguiculata (L.) Walp.) and common bean (Phaseolus vulgaris L.) determined using the 15N isotope

    International Nuclear Information System (INIS)

    Brito, Marciano de Medeiros Pereira; Muraoka, Takashi; Silva, Edson Cabral da

    2009-01-01

    Common bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata (L.) Walp.) are among the main sources of plant protein for a large part of the world population, mainly that of low income, and nitrogen is the main constituent of these proteins. The objectives of this study were to evaluate, through the 15 N-dilution technique and using rice and non-nodulating soybean as control plants, the relative contributions of nitrogen sources (symbiotically fixed N, soil native N and fertilizer N) on the growth of common bean and cowpea and to compare the isotopic technique (ID) with the difference methods (DM) for the evaluation of symbiotic N 2 fixation. The study was carried out in a greenhouse of the Center for Nuclear Energy in Agriculture - CENA/USP, Sao Paulo State, Brazil, using 5 kg pots with a Typic Haplustox (Dystrophic Red-Yellow Latosol). The experiment was arranged in completely randomized blocks, with 16 treatments and three replications, in an 8 x 2 factorial design. The treatments were eight sampling times: 7, 24, 31, 38, 47, 58, 68 and 78 days after sowing (DAS) and two crops: common bean and cowpea. An N rate of 10 mg kg -1 soil was used, as urea, enriched with an excess of 10 % of 15 N atoms. Symbiotic N fixation supplied the bean and cowpea plants with the greatest amount of accumulated N, followed, in decreasing order, by soil and fertilizer. The highest rate of N symbiotic fixation was observed at the pre-flowering growth stage of the bean and cowpea plants. After the initial growth stage, 24 DAS, rice and non nodulating soybean were appropriate control plants to evaluate symbiotic N fixation. There was a good agreement between ID and DM, except in the initial growth stage of the crops. (author)

  13. Female relative wages, household specialization and fertility

    OpenAIRE

    Siegel, Christian

    2017-01-01

    Falling fertility rates have often been linked to rising female wages. However, over the last 40 years the US total fertility rate has been rather stable while female wages have continued to grow. Over the same period, women's hours spent on housework have declined, but men's have increased. I propose a model in which households are not perfectly specialized, but both men and women contribute to home production. As the gender wage gap narrows, the time allocations of men and women converge, a...

  14. Physiology, phenology and yield of sunflower (autumn) as affected by NPK fertilizer and hybrids

    International Nuclear Information System (INIS)

    Bakht, J.; Shah, S.U.

    2010-01-01

    The present field studies investigate the effect of NPK fertilizer on the physiology, phenology and yield response of sunflower hybrids at National Agricultural Research Centre (NARC), Islamabad, Pakistan during autumn, 2000 and 2001. The response of sunflower hybrids (SF-187 and Parsun-1) were studied using low medium and high rate of NPK (0, 50, 100,150 kg ha/sup -1/) in factorial design with split plot arrangements. Days to R1 (button stage), R4 (inflorescence begins to open), R5.8 (80% anthesis) and R9 (physiological maturity) stages significantly (P<0.05) increased with an increase in fertilizer levels. Among the hybrids, Parsun-1 matured 4-5 days later than SF-187. Similarly, leaf area index (LAI), crop growth rate (CGR), and dry matter accumulation (DMA) also significantly (P<0.05) increased with an increase in fertilizer levels. Maximum LAI, CGR, DMA and seed yield was produced by fertilizer treatments of 150:100:100 kg ha/sup -1/ during both the seasons. Oil content also varied with different combinations of NPK fertilizers which ranged from 37 to 39% during both the seasons. (author)

  15. Societal foundations for explaining fertility: Gender equity

    Directory of Open Access Journals (Sweden)

    Peter McDonald

    2013-05-01

    Full Text Available BACKGROUND Gender equity theory in relation to fertility argues that very low fertility is the result of incoherence in the levels of gender equity in individually-oriented social institutions and family-oriented social institutions. The salience of gender to the fertility transition is strong in theory but not as strong in specification of testable hypotheses as has been pointed out in the literature. OBJECTIVE The paper aims to clarify the specification of gender equity theory through a discussion of the difference between equity and equality and to suggest methods that might be applied to test the theory. METHODS The theory is restated and further developed using literature from different disciplines. The method is described using a decomposition of fertility for women by human capital levels. RESULTS The clarification of the theory includes a reminder that the theory relates to differences in fertility between countries and not to differences in fertility between women in the same country. In comparisons between countries, higher gender equity leads to higher fertility. In comparisons of fertility across women in the same country, higher gender equity does not necessarily imply higher fertility. In relation to measurement, a specification is suggested that effectively compares women across countries controlling for their level of human capital. Simple graphics are used to indicate ways in which fertility between countries may vary. CONCLUSIONS The paper concludes that it is likely the gender equity theory can be tested more readily by examining the behaviour across countries of women with higher levels of human capital.

  16. Nitrogen Fixed by Pea Plant as Affected by Lead,Cadmium and Rates of N-Fertilizer Using 15N Tracer Technique

    International Nuclear Information System (INIS)

    Ismail, M.M.; El-Degwy, S.M.; Abdel-Aziz, H.A.; Elbaz, A.S.

    2012-01-01

    A pot experiment was carried out in greenhouse to investigate the effect Pb and Cd applied on growth, yield and the amount of fixed nitrogen by pea's plants. 15 N-labelled (5 % atom excess) ammonium nitrate was applied at three levels (0,20 and 40 mg N -1 kg soil). The legume pea seeds were inoculated with Rhizobium Leguminesarum. Lead was applied as lead sulfate at rates of 0, 50 and 200 mg Pb kg -1 soil, while the cadmium applied as cadmium sulfate at rates of 0, 5 and 10 mg Cd kg -1 soil. Results indicated that the highest values of Pb uptake were 540,11.55 and 552 mg -1 pot for pea shoot, pods and whole plant at the rate of 200 mg Pb kg -1 soil + 40 mg N kg -1 soil, respectively, While, the highest values of Cd-uptake were 13.90, 6.54 and 20 mg -1 pot at the rate of 10 mg Cd kg -1 + 20 mg N kg -1 soil for the same sequence. The values of Ndff and Ndfa were 43.74 and 278.2 while Ndfs recorded 164.1 mg pot -1 at rate of 5 mg Cd kg -1 soil + 40 mg N kg -1 soil compared to the control.

  17. Utilization and success rates of unstimulated in vitro fertilization in the United States: an analysis of the Society for Assisted Reproductive Technology database.

    Science.gov (United States)

    Gordon, John David; DiMattina, Michael; Reh, Andrea; Botes, Awie; Celia, Gerard; Payson, Mark

    2013-08-01

    To examine the utilization and outcomes of natural cycle (unstimulated) IVF as reported to the Society of Assisted Reproductive Technology (SART) in 2006 and 2007. Retrospective analysis. Dataset analysis from the SART Clinical Outcome Reporting System national database. All patients undergoing IVF as reported to SART in 2006 and 2007. None. Utilization of unstimulated IVF; description of patient demographics; and comparison of implantation and pregnancy rates between unstimulated and stimulated IVF cycles. During 2006 and 2007 a total of 795 unstimulated IVF cycles were initiated. Success rates were age dependent, with patients Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Preferences of subfertile women regarding elective single embryo transfer: additional in vitro fertilization cycles are acceptable, lower pregnancy rates are not

    NARCIS (Netherlands)

    Twisk, Moniek; van der Veen, Fulco; Repping, Sjoerd; Heineman, Maas-Jan; Korevaar, Johanna C.; Bossuyt, Patrick M. M.

    2007-01-01

    With identical pregnancy rates after elective single embryo transfer (ET) and double ET strategies consisting of three cycles of IVF or intracytoplasmic sperm injection (ICSI) plus transfers of thawed/frozen embryos if available, 46% of the women undergoing IVF/ICSI favor elective single ET. If

  19. Preferences of subfertile women regarding elective single embryo transfer : additional in vitro fertilization cycles are acceptable, lower pregnancy rates are not

    NARCIS (Netherlands)

    Twisk, Moniek; van der Veen, Fulco; Repping, Sjoerd; Heineman, Maas-Jan; Korevaar, Johanna C.; Bossuyt, Patrick M. M.

    2007-01-01

    With identical pregnancy rates after elective single embryo transfer (ET) and double ET strategies consisting of three cycles of IVF or intracytoplasmic sperm injection (ICSI) plus transfers of thawed/frozen embryos if available, 46% of the women undergoing IVF/ICSI favor elective single ET. If

  20. Wealth, intelligence, politics and global fertility differentials.

    Science.gov (United States)

    Meisenberg, Gerhard

    2009-07-01

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

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

    Science.gov (United States)

    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 acupuncture across all trials (adjusted R2 = 93%; I2 residual = 9

  2. Demographic and fertility characteristics of 4 squatter settlements.

    Science.gov (United States)

    Yusof, K; Zulkifli, S N

    1985-01-01

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

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

    Science.gov (United States)

    Kudesia, Rashmi; Chernyak, Elizabeth; McAvey, Beth

    2017-10-01

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

  4. Diverging patterns of fertility decline in Uruguay

    Directory of Open Access Journals (Sweden)

    Mathías Nathan

    2016-03-01

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

  5. 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.

    Science.gov (United States)

    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

  6. Fertility after uterine artery embolization: a review.

    Science.gov (United States)

    McLucas, Bruce; Voorhees, William D; Elliott, Stephanie

    2016-01-01

    Uterine artery embolization (UAE) research has largely been focused on women over 40 years, yet women of reproductive age undergo UAE without any increased morbidity. Some physicians refrain from recommending UAE to women in this age group because of some research findings showing a negative effect on fertility. This review presents a comprehensive discussion of the fertility potential of women undergoing UAE, in terms of pregnancy rates and complications as well as ovarian function and reserve. Findings indicate many benefits for women desiring fertility who undergo UAE over traditional myomectomy.

  7. Disruptive Events and Demographic Behaviour : Explaining the Shifts in Fertility in Rwanda

    NARCIS (Netherlands)

    Rutayisire, P.C.

    2015-01-01

    The fertility transition of Rwanda stagnated between 1992 and 2005 at a total fertility rate (TFR) of 6 children per woman. After 2005 the fertility decline resumed its course and the TFR dropped remarkably fast till 4.6. The period of the fertility stall coincided with a very disruptive period in

  8. Optimum size in grid soil sampling for variable rate application in site-specific management Tamanho ideal em grades de amostragem de solos para aplicação em taxa variável em manejo localizado

    Directory of Open Access Journals (Sweden)

    Marcos Rafael Nanni

    2011-06-01

    Full Text Available The importance of understanding spatial variability of soils is connected to crop management planning. This understanding makes it possible to treat soil not as a uniform, but a variable entity, and it enables site-specific management to increase production efficiency, which is the target of precision agriculture. Questions remain as the optimum soil sampling interval needed to make site-specific fertilizer recommendations in Brazil. The objectives of this study were: i to evaluate the spatial variability of the main attributes that influence fertilization recommendations, using georeferenced soil samples arranged in grid patterns of different resolutions; ii to compare the spatial maps generated with those obtained with the standard sampling of 1 sample ha-1, in order to verify the appropriateness of the spatial resolution. The attributes evaluated were phosphorus (P, potassium (K, organic matter (OM, base saturation (V% and clay. Soil samples were collected in a 100 × 100 m georeferenced grid. Thinning was performed in order to create a grid with one sample every 2.07, 2.88, 3.75 and 7.20 ha. Geostatistical techniques, such as semivariogram and interpolation using kriging, were used to analyze the attributes at the different grid resolutions. This analysis was performed with the Vesper software package. The maps created by this method were compared using the kappa statistics. Additionally, correlation graphs were drawn by plotting the observed values against the estimated values using cross-validation. P, K and V%, a finer sampling resolution than the one using 1 sample ha-1 is required, while for OM and clay coarser resolutions of one sample every two and three hectares, respectively, may be acceptable.A importância de compreender a variabilidade espacial do solo está conectada ao planejamento do manejo das culturas. Este entendimento faz com que seja possível tratar o solo não como uma entidade uniforme, mas variável, e permite o

  9. Estimation of natural radioactivity in different fertilizers

    International Nuclear Information System (INIS)

    Gupta, Monika; Chauhan, Pooja; Chauhan, R.P.; Sonkawade, R.G.; Kant, K.

    2011-01-01

    Fertilizers have become essential to the agricultural field all over the world. The natural radionuclides of fertilizers consist mainly of 226 Ra, 232 Th, isotopes with their decay products. The level of activity concentration of radionuclides in phosphate fertilizers provides useful information in the monitoring of environmental contamination. The concepts of natural radiation are essential for radiation protection purpose. Radionuclides present in fertilizers affect the common people and farmers immensely. They are produced and used worldwide in increasing quantities to replenish natural nutrients depleted from soils because of forming and erosion. However, the mining, processing and use of fertilizer materials in massive quantities redistribute radioactive trace elements throughout the environment, principally uranium, radium, radium decay products. The agricultural phosphate fertilizer industries use raw materials that consist of phosphate rocks, phosphoric acid, ammonium phosphate. The level of activity concentration of radionuclides in different fertilizers provides useful information in the monitoring of environmental contamination. Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. The concepts of natural radiation are essential for radiation protection purpose. This paper emphasis on the public risk assessment in an integrated manner assessing doses to members of the public via the atmospheric aquatic and secondary pathways. In the present study radioactivity in different fertilizer samples, which are widely used in Indian fields, was determined. The experimental work includes the measurements of 226 Ra, 232 Th and 40 K using gamma spectrometry and radon concentration and exhalation rates measurement using solid state nuclear track detectors to asses a

  10. Fertility and its relationship with sociocultural factors in Kuwaiti society.

    Science.gov (United States)

    Al-Kandari, Y Y

    2007-01-01

    The aim of this study was to examine the effect of some sociocultural variables on the fertility of Kuwaiti women. A questionnaire was administered to a sample of 7749 married women (aged 15-78 years) selected randomly from 10 primary health care clinics in Kuwait. The fertility rate was 3.58 live births per woman. Fertility was higher among Sunni Muslim women, those of Bedouin ethnicity, and those in a consanguineous marriage (P relationship between fertility and respondents' educational level, occupation, age at marriage, socioeconomic status and type of marriage (consanguineous or not). There was a positive relationship between fertility and the respondents' age and the family income.

  11. Numerical investigation on the combined effects of varying piston bowl geometries and ramp injection rate-shapes on the combustion characteristics of a kerosene-diesel fueled direct injection compression ignition engine

    International Nuclear Information System (INIS)

    Tay, Kun Lin; Yang, Wenming; Zhao, Feiyang; Yu, Wenbin; Mohan, Balaji

    2017-01-01

    Highlights: • Effect of injection rate-shaping on heat-release is significant with less turbulence. • Two peak heat-releases are seen for the shallow-depth re-entrant piston. • Significant combustion phasing occurs with kerosene usage and high turbulence. - Abstract: In this work, the combustion characteristics of a direct injection compression ignition (DICI) engine fueled with kerosene-diesel blends, using different piston bowl geometries together with varying injection rate-shapes were investigated. A total of three combustion bowl geometries, namely the omega combustion chamber (OCC), the shallow-depth combustion chamber (SCC) and the shallow-depth re-entrant combustion chamber (SRCC), were used together with six different ramp injection rate-shapes and pure diesel, kerosene-diesel and pure kerosene fuels. It is seen that the SRCC geometry, which has the shortest throat length, gives the highest turbulence kinetic energy (TKE) and this resulted in two peak heat-releases, with a primary peak heat-release during the premixed combustion phase and a secondary peak heat-release during the mixing-controlled combustion phase. In addition, the SCC geometry gives rather distinct premixed combustion and mixing-controlled combustion phases due to the fact that combustion is predominantly controlled by the injected fuel spray itself because of less turbulence. Also, when kerosene is used in place of diesel, the heat-release during the premixed combustion phase increases and diminishes during the mixing-controlled and late combustion phases. It is interesting to note that the effect of injection rate-shaping on the heat-release rate is more obvious for bowl geometries that generate less TKE. Moreover, bowl geometries that generate higher TKEs as well as fuels with lower viscosities generally give lower carbon monoxide (CO) emissions and higher nitrogen oxide (NO) emissions. More importantly, it is possible to achieve low NO and CO emissions simultaneously by using the

  12. Female age, serum antimüllerian hormone level, and number of oocytes affect the rate and number of euploid blastocysts in in vitro fertilization/intracytoplasmic sperm injection cycles.

    Science.gov (United States)

    La Marca, Antonio; Minasi, Maria Giulia; Sighinolfi, Giovanna; Greco, Pierfrancesco; Argento, Cindy; Grisendi, Valentina; Fiorentino, Francesco; Greco, Ermanno

    2017-11-01

    To study the relative role of female age and ovarian reserve, measured through serum antimüllerian hormone (AMH) in determining the rate and number of euploid blastocysts in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. Retrospective analysis of cycles performed in 2014-2015. Tertiary referral IVF center. A total of 578 infertile couples undergoing IVF/ICSI and preimplantation genetic screening (PGS) analysis. All embryos were cultured and biopsied at the blastocyst stage. The method involved whole-genome amplification followed by array comparative genome hybridization. Serum AMH was measured by means of the modified Beckman Coulter AMH Gen II assay. The rate and number of euploid blastocysts and their correlation with ovarian reserve and response to stimulation. The mean (±SD) age of patients was 37.6 ± 4.1 years, and the mean number of blastocysts per patient was 3.1 ± 2. The total number of blastocysts available to the analysis was 1,814, and 36% of them were euploid after PGS. Age and serum AMH were significantly and independently related to the rate of euploid blastocysts available for patients. As an effect of the cohort size, the number of mature oocytes positively affected the total number of euploid blastocysts per patient. A strong positive age-independent relationship between AMH level and the rate of euploid blastocysts was found. This confirms that the measurement of ovarian reserve by means of AMH has high relevance when counseling infertile patients. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Fertility transition: forecast for demography.

    Science.gov (United States)

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

    2008-08-01

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

  14. Research on the Fertility Of Bulgarian Women

    Directory of Open Access Journals (Sweden)

    T. KALOYANOV

    2011-03-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2017-07-01

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

  17. How does variance in fertility change over the demographic transition?

    Science.gov (United States)

    Hruschka, Daniel J; Burger, Oskar

    2016-04-19

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

  18. Fertility in patients treated for testicular cancer.

    Science.gov (United States)

    Matos, Erika; Skrbinc, Breda; Zakotnik, Branko

    2010-09-01

    Testicular cancer affects men mostly in their reproductive age with a cure rate over 90% and fertility is one of the main concerns of survivors. To further elucidate the question of fertility after treatment for testicular cancer, we performed a survey in patients treated in our institution. We sent a questionnaire to patients treated for testicular cancer at our institute from 1976 to 2002 (n = 490) of whom 297 (60.6%) responded. We considered the patients to have conserved fertility if they had children after treatment without assisted reproductive technologies. Before treatment 119/297 (40.1%) of patients and after treatment 150/297 (50.5%) of patients tried to have children (p = 0.019). Of 119 patients who tried to have children before treatment for testicular cancer 98 (82.4%) succeeded and 74/150 (49.3%) were successful after treatment (p years. The post-treatment fatherhood in patients treated with surgery only (orchidectomy +/- retroperitoneal lymphnode dissection-RPLND) was 59%, in those with additional radiotherapy 68%, and chemotherapy 50% (p = 0.233). Fertility rate in patients where a non nerve sparing RPLND was performed was only 37%, 62% in patients with nerve sapring RPLND, and 77% in patients where RPLND was not performed (p Fertility rate after treatment for testicular cancer is reduced. From our data, the most important treatment modality that influences fertility is non nerve sparing RPLND that should be avoided whenever possible in order improve the quality of life our patients.

  19. Protect Your Fertility

    Science.gov (United States)

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

  20. Evaluation of sources and rates of P fertilizers on the initial growth of corn/ Avaliação de fontes e doses de fósforo no crescimento inicial do milho

    Directory of Open Access Journals (Sweden)

    Toshio Sérgio Watanabe

    2007-07-01

    Full Text Available Phosphorus is an essential element for all living organisms and important also for agricultural production. The content of P in most agricultural soils in Brazil is low. In order to supply the plant needs and the soil fixation, application of P fertilizer is required. Among the various options of P fertilizers in the market, the totally acidified phosphates are usually commercialized. The evaluation of the efficiency of the reactive natural phosphates as P fertilizers is important due to the increase of the utilization of cheaper sources of natural P. The experiment was carried out in green house, using a Nitossolo. The experimental design used was complete randomized design, with the treatments in a 4x2 factorial arrangement, and four replications. The objective of the experiment was to evaluate the effects of sources and rates of P on the growth of corn. The production of dry matter and the content of P on the corn leave and stalks (above ground corn parts increased as rates of P increased, regardless the P sources tested. However, the Triple Super Phosphate was more efficient compared with Arad phosphate, providing better nutrition and initial growth of corn plants.O fósforo é componente vital para todos os seres vivos e é essencial para a produção agrícola. No Brasil, a maior parte dos solos agricultáveis tem baixos teores de fósforo disponível. Para atender as exigências das plantas e suprimento adequado de fósforo há a necessidade da aplicação de adubos fosfatados. Dentre as opções de fontes no mercado, os fosfatos totalmente acidulados são os usualmente comercializados. Com o aumento do uso dos fosfatos naturais reativos, a avaliação da eficiência da aplicação do fertilizante é importante no manejo da adubação fosfatada. O experimento foi realizado em casa de vegetação, utilizando um Nitossolo. O delineamento experimental empregado foi o inteiramente casualizado com os tratamentos arranjados em um fatorial 4 x 2

  1. Genetic parameters for body condition score, body weight, milk yield, and fertility estimated using random regression models.

    Science.gov (United States)

    Berry, D P; Buckley, F; Dillon, P; Evans, R D; Rath, M; Veerkamp, R F

    2003-11-01

    Genetic (co)variances between body condition score (BCS), body weight (BW), milk yield, and fertility were estimated using a random regression animal model extended to multivariate analysis. The data analyzed included 81,313 BCS observations, 91,937 BW observations, and 100,458 milk test-day yields from 8725 multiparous Holstein-Friesian cows. A cubic random regression was sufficient to model the changing genetic variances for BCS, BW, and milk across different days in milk. The genetic correlations between BCS and fertility changed little over the lactation; genetic correlations between BCS and interval to first service and between BCS and pregnancy rate to first service varied from -0.47 to -0.31, and from 0.15 to 0.38, respectively. This suggests that maximum genetic gain in fertility from indirect selection on BCS should be based on measurements taken in midlactation when the genetic variance for BCS is largest. Selection for increased BW resulted in shorter intervals to first service, but more services and poorer pregnancy rates; genetic correlations between BW and pregnancy rate to first service varied from -0.52 to -0.45. Genetic selection for higher lactation milk yield alone through selection on increased milk yield in early lactation is likely to have a more deleterious effect on genetic merit for fertility than selection on higher milk yield in late lactation.

  2. Kerala reaps low fertility dividends.

    Science.gov (United States)

    1992-01-01

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

  3. Perceived partner fertility desires and influence on contraceptive use.

    Science.gov (United States)

    Gibbs, Susannah E; Moreau, Caroline

    2017-08-01

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

  4. The Cost of Raising Fertility

    DEFF Research Database (Denmark)

    Kurjanska, Malgorzata; Lyngsie, Jacob

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

  5. [Fertility in rural and urban areas of Mexico].

    Science.gov (United States)

    Garcia Y Garma, I O

    1989-01-01

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

  6. Effects of Nitrogen and Phosphorus Fertilizer on Agro ...

    African Journals Online (AJOL)

    SH

    caraway plant (Carum carvi) grown from root tubers when phosphorus was applied at the rate of 40 kg/ ha. The significant reduction in the number of days to first flower appearance, number of days to 50% flower appearance and first fruit maturity with increasing rates of phosphorus fertilizer showed that well P-fertilized T.

  7. The 'Own Children' fertility estimation procedure: a reappraisal.

    Science.gov (United States)

    Avery, Christopher; St Clair, Travis; Levin, Michael; Hill, Kenneth

    2013-07-01

    The Full Birth History has become the dominant source of estimates of fertility levels and trends for countries lacking complete birth registration. An alternative, the 'Own Children' method, derives fertility estimates from household age distributions, but is now rarely used, partly because of concerns about its accuracy. We compared the estimates from these two procedures by applying them to 56 recent Demographic and Health Surveys. On average, 'Own Children' estimates of recent total fertility rates are 3 per cent lower than birth-history estimates. Much of this difference stems from selection bias in the collection of birth histories: women with more children are more likely to be interviewed. We conclude that full birth histories overestimate total fertility, and that the 'Own Children' method gives estimates of total fertility that may better reflect overall national fertility. We recommend the routine application of the 'Own Children' method to census and household survey data to estimate fertility levels and trends.

  8. Occurrence of priority organic pollutants in the fertilizers, China.

    Science.gov (United States)

    Mo, Ce-Hui; Cai, Quan-Ying; Li, Yun-Hui; Zeng, Qiao-Yun

    2008-04-15

    The use of large quantities of chemical fertilizers is usually associated with environmental problems. A lot of work has been done on the concentrations of heavy metals and radionuclides in chemical fertilizers, but little work has focused on the occurrence of semi-volatile organic compounds (SVOCs). In this study the occurrence of 43 SVOCs listed as priority pollutants in 22 widely used-fertilizers of China was determined by gas chromatography coupled with mass spectrometry. Twenty-six SVOCs were detected with different detection frequencies and concentrations. The most abundant compounds were phthalic acid esters (PAEs; ranging from 1.17 to 2795 microg kg(-1) dry weight, d.w.) and nitroaromatics (up to 9765 microg kg(-1) d.w.), followed by polycyclic aromatic hydrocarbons (PAHs; fertilizers, and the total concentrations of each class of contaminants varied widely, too. The highest levels of sum concentration for 16 PAHs, for 6 PAEs and for nitroaromatics were found in organic fertilizer containing pesticide and soil amendments. Concentrations of SVOCs in coated fertilizers (the controlled release fertilizer with coating) were considerably higher than those in the corresponding fertilizers without coating. The occurrence frequencies of SVOCs in the straight fertilizers (containing only one of the major plant nutrients) were lower than in the other fertilizers.

  9. Occurrence of priority organic pollutants in the fertilizers, China

    International Nuclear Information System (INIS)

    Mo Cehui; Cai Quanying; Li Yunhui; Zeng Qiaoyun

    2008-01-01

    The use of large quantities of chemical fertilizers is usually associated with environmental problems. A lot of work has been done on the concentrations of heavy metals and radionuclides in chemical fertilizers, but little work has focused on the occurrence of semi-volatile organic compounds (SVOCs). In this study the occurrence of 43 SVOCs listed as priority pollutants in 22 widely used-fertilizers of China was determined by gas chromatography coupled with mass spectrometry. Twenty-six SVOCs were detected with different detection frequencies and concentrations. The most abundant compounds were phthalic acid esters (PAEs; ranging from 1.17 to 2795 μg kg -1 dry weight, d.w.) and nitroaromatics (up to 9765 μg kg -1 d.w.), followed by polycyclic aromatic hydrocarbons (PAHs; -1 d.w.) and halogenated hydrocarbons ( -1 d.w.). Chlorobenzenes and haloethers occurred generally at low concentrations. There are large variations in concentrations of various compounds in different fertilizers, and the total concentrations of each class of contaminants varied widely, too. The highest levels of sum concentration for 16 PAHs, for 6 PAEs and for nitroaromatics were found in organic fertilizer containing pesticide and soil amendments. Concentrations of SVOCs in coated fertilizers (the controlled release fertilizer with coating) were considerably higher than those in the corresponding fertilizers without coating. The occurrence frequencies of SVOCs in the straight fertilizers (containing only one of the major plant nutrients) were lower than in the other fertilizers

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

    Science.gov (United States)

    Vyborova, Oxana

    2010-05-01

    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.

  11. Parental Infertility, Fertility Treatment, and Childhood Epilepsy

    DEFF Research Database (Denmark)

    Kettner, Laura O; Ramlau-Hansen, Cecilia Høst; Kesmodel, Ulrik S

    2016-01-01

    . RESULTS: A total of 60 440 pregnancies were included, and 0.8% of the children developed epilepsy.The primary analyses showed no association between parental infertility or fertility treatment, and the overall risk of childhood epilepsy (hazard rate ratios (HRs); 95% confidence intervals (CIs): 1.08 (0......BACKGROUND: A few studies have indicated an increased risk of epilepsy in children conceived by fertility treatment possibly due to characteristics of the infertile couple rather than the treatment. We therefore aimed to investigate the association between parental infertility, fertility treatment......, and epilepsy in the offspring, including the subtypes of epilepsy; idiopathic generalised epilepsy and focal epilepsy. METHODS: This cohort included all pregnancies resulting in liveborn singletons from the Aarhus Birth Cohort, Denmark (1995-2013). Information on time to pregnancy and fertility treatment...

  12. Comparing the performance of 11 crop simulation models in predicting yield response to nitrogen fertilization

    DEFF Research Database (Denmark)

    Salo, T J; Palosuo, T; Kersebaum, K C

    2016-01-01

    Eleven widely used crop simulation models (APSIM, CERES, CROPSYST, COUP, DAISY, EPIC, FASSET, HERMES, MONICA, STICS and WOFOST) were tested using spring barley (Hordeum vulgare L.) data set under varying nitrogen (N) fertilizer rates from three experimental years in the boreal climate of Jokioinen......, Finland. This is the largest standardized crop model inter-comparison under different levels of N supply to date. The models were calibrated using data from 2002 and 2008, of which 2008 included six N rates ranging from 0 to 150 kg N/ha. Calibration data consisted of weather, soil, phenology, leaf area...... ranged from 170 to 870 kg/ha. During the test year 2009, most models failed to accurately reproduce the observed low yield without N fertilizer as well as the steep yield response to N applications. The multi-model predictions were closer to observations than most single-model predictions, but multi...

  13. Fertilizer nitrogen leaching in relation to water regime and the fertilizer placement method

    International Nuclear Information System (INIS)

    Moustafa, A.T.A.; Khadr, M.S.

    1983-01-01

    A field experiment was conducted at the farm of Sids Experimental Station, Ministry of Agriculture, Middle Egypt, to evaluate the effect of the water regime and fertilizer placement method on the leaching of urea fertilizer under field conditions. Ordinary and heavy irrigations were the water regimes, while side-banding and surface broadcasting were the fertilizer placement methods. Wheat (Giza 158, local variety) was planted, and urea labelled with 15 N at the rate of 100 kg N/ha was added at planting. The data obtained showed that in general the leaching process of urea fertilizer, as evaluated from the amounts of fertilizer nitrogen residues, is not uniform even within replicates. This is despite the fact that the average total amount of fertilizer nitrogen residues in the soil profile to a depth of 125 cm is almost the same in the different treatments. Data also show that the bulk of fertilizer nitrogen residues is accumulated in the surface soil layers, especially at 0-25 cm. Only 10% of the fertilizer nitrogen is detected below 75 cm and up to 125 cm depth of the soil profile. It could be concluded that urea leaching (amount and depth) under these conditions is affected mainly by the soil characteristics, namely soil pores. This is in addition to some other factors that cause variable concentrations in the soil solution leaving the root zone. (author)

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

    Science.gov (United States)

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

    2017-07-01

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

  15. Effects of Different Fertilizing Formulae on Potato

    Directory of Open Access Journals (Sweden)

    Giovanna Cucci

    2007-09-01

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

  16. Female employment reduces fertility in rural Senegal.

    Science.gov (United States)

    Van den Broeck, Goedele; Maertens, Miet

    2015-01-01

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

  17. Female employment reduces fertility in rural Senegal.

    Directory of Open Access Journals (Sweden)

    Goedele Van den Broeck

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

  18. Content of nitrates in potato tubers depending on the organic matter, soil fertilizer, cultivation simplifications applied and storage

    Directory of Open Access Journals (Sweden)

    Jaroslaw Pobereżny

    2015-03-01

    Full Text Available Nitrates naturally occur in plant-based food. Nitrates content in consumable plant organs is small and should not raise concern provided that the recommended fertilization and harvest terms of the original plants are observed. The aim was to determine the effect of the application of various organic matter of soil fertilizer and simplifications in growing potato (Solanum tuberosum L. on the content of nitrates in the tubers of mid-early cultivar 'Satina' after harvest and after 6-mo of storage. Introducing cultivation simplification involves limiting mineral fertilization by 50% as well as chemical protection limitation. The soil fertilizer was used: 0.6 (autumn, 0.3 (spring, and 0.3 L ha-1 (during the vegetation period. The content of nitrates, was determined with the use of the ion-selective method (multi-purpose computer device CX-721, Elmetron. The lowest amount of nitrates was recorded in the tubers from the plots without the application of organic matter with a 50% rate of mineral fertilization with soil fertilizer (120.5 mg kg-1 FW. The use of varied organic matter resulted in a significant increase in the content of nitrates in tubers and the lowest effect on their accumulation was reported for straw. The soil fertilizer used significantly decreased the content of nitrates in tubers by 15% for 100% NPK and 10.4% for 50% NPK. After 6-mo storage, irrespective of the experiment factors, the content of nitrates decreased in the fertilization experiment by 26% and in the experiment with a limited protection - by 19.9%.

  19. Education as policy: the impact of education on marriage, contraception, and fertility in Colombia, Peru, and Bolivia.

    Science.gov (United States)

    Heaton, T B; Forste, R

    1998-01-01

    Using data from the World Fertility and Demographic and Health Surveys of Colombia, Peru, and Bolivia, we model the effects of education on three demographic outcomes: the timing of first sexual union, contraceptive use, and fertility. These effects are examined over time and across geographic areas using a multivariate framework. We find substantial improvements in female educational attainment over the last fifty years and a strong relationship between education and the demographic outcomes. Each successive increment in education is associated with declines in the marriage rate, increased contraceptive use, and lower fertility. Education accounts for some of the changes over time in the demographic outcomes, but the pattern varies by outcome, time period, and geographic area. In support of the social diffusion hypothesis, our results indicate that educational differences in reproductive behavior are reduced as the level of development increases and societies pass through their demographic transition.

  20. Fertility after breast cancer treatment.

    Science.gov (United States)

    Kasum, Miro; Beketić-Orešković, Lidija; Peddi, Parvin F; Orešković, Slavko; Johnson, Rebecca H

    2014-02-01

    In many countries of the developed world, there is an increasing trend toward delay in childbearing from 30 to 40 years of age for various reasons. This is unfortunately concordant with an increasing incidence of breast cancer in women who have not yet completed their family. The current choice for premenopausal women with breast cancer is adjuvant therapy which includes cytotoxic chemotherapy, ovarian ablation (by surgery, irradiation, or chemical ovarian suppression), anti-estrogen therapy, or any combination of these. Although the use of adjuvant therapies with cytotoxic drugs can significantly reduce mortality, it raises issues of the long-term toxicity, such as induction of an early menopause and fertility impairment. The risk of infertility is a potential hardship to be faced by the patients following treatment of breast cancer. The offspring of patients who became pregnant after completion of chemotherapy have shown no adverse effects and congenital anomalies from the treatment, but sometimes high rates of abortion (29%) and premature deliveries with low birth weight (40%) have been demonstrated. Therefore, the issue of recent cytotoxic treatment remains controversial and further research is required to define a "safety period" between cessation of treatment and pregnancy. Preservation of fertility in breast cancer survivors of reproductive age has become an important issue regarding the quality of life. Currently, there are several potential options, including all available assisted technologies, such as in vitro fertilization and embryo transfer, in vitro maturation, oocyte and embryo cryopreservation, and cryopreservation of ovarian tissue. Because increased estrogen levels are thought to be potentially risky in breast cancer patients, recently developed ovarian stimulation protocols with the aromatase inhibitor letrozole and tamoxifen appear to provide safe stimulation with endogenous estrogen. Embryo cryopreservation seems to be the most established

  1. Fertility among female hairdressers.

    Science.gov (United States)

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

    2006-02-01

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

  2. Perchlorate in Fertilizers

    National Research Council Canada - National Science Library

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

    1999-01-01

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

  3. Commercial Phosporus Fertilizer Purchased

    Data.gov (United States)

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

  4. Commercial Nitrogen Fertilizer Purchased

    Data.gov (United States)

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

  5. Cancer and fertility preservation

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  6. Queering the fertility clinic.

    Science.gov (United States)

    Mamo, Laura

    2013-06-01

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

  7. Sperm preparation for fertilization

    NARCIS (Netherlands)

    Gadella, B.M.

    2014-01-01

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

  8. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

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

  9. Immunosuppressive drugs and fertility

    OpenAIRE

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Milly Marston

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

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

    Science.gov (United States)

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

    2016-04-19

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

  12. Cryopreservation: a cold look at technology for fertility preservation.

    Science.gov (United States)

    Gosden, Roger

    2011-08-01

    To outline the history of cryopreservation technology and its contributions to reproductive medicine, including fertility preservation. A search of the relevant literature using Medline and other online tools. Research and laboratory protocol development. The biology of preserving cells at low temperatures is complex and still being unraveled. Principles were first established more than half a century ago, with progress being driven empirically and often by trial and error. The protocols vary widely, and practice is still heavily dependent on operator skill, accounting for wide differences in the success rates between centers. No single protocol fits all specimen types, and differential vulnerability to cryoinjury remains a major obstacle. Nevertheless, semen cryopreservation has long been established, embryo banking is now highly effective, and vitrification appears to overcome problems with oocytes. Protocols in the future, although specific to the cell type and tissue, are likely to evolve toward generally acknowledged standards. But heterogeneity between patients and even within samples implies that each cell may have its own peculiar optimum for minimizing cryoinjury; because protocols are therefore compromises, "perfect" preservation may be unattainable. Cryopreservation has become a mainstay in the assisted reproduction laboratory and underpins fertility preservation for patients with cancer and other conditions. The practice is currently evolving from slow freezing methods toward more vitrification, and future technology is likely to reduce dependence on operator skill, which should raise success rates to higher, more uniform levels. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Reverse survival method of fertility estimation: An evaluation

    Directory of Open Access Journals (Sweden)

    Thomas Spoorenberg

    2014-07-01

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

  14. Time-varying BRDFs.

    Science.gov (United States)

    Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K

    2007-01-01

    The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.

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

    Science.gov (United States)

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

    1988-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  17. Fertility patterns according to occupational grouping in Norway, 1989.

    Science.gov (United States)

    Strand, K; Wergeland, E; Bjerkedal, T

    1996-03-01

    In the early 1990s, most pregnant women in Norway were in gainful employment. This led to increased interest in the possible consequences for reproductive health, and a growing concern for the need to accommodate the pregnancy. We have therefore investigated how accurately general fertility rates predict the number of pregnancies in the workforce. Fertility rates (FR) among employed women and standardized fertility ratios (SFR) in occupational groups were estimated on the basis of information from the Labour Market Statistics and the national survey "Pregnancy and Work", Norway, 1989. The fertility rate among employed women was 17% higher than the general fertility rate. Two occupational groups had significantly different SFRs: technical/professional workers (SFR 118) and transport/communication workers (SFR 82). In addition, differences were found for parity-specific SFRs in administrative/executive work (SFR nullipara 80, SFR para 125) and service work (SFR nullipara 114, SFR para 80). We suggest that work status and occupation should be included among the variables registered in the Medical Birth Registry of Norway, in order to facilitate routine presentations of fertility rates and pregnancy outcomes for women in paid work. The results further indicate that work-specific conditions influence first-birth fertility. This should be explored in demographic studies of the relation between women's fertility and participation in paid work.

  18. Therapeutic analysis of high-dose-rate "1"9"2Ir vaginal cuff brachytherapy for endometrial cancer using a cylindrical target volume model and varied cancer cell distributions

    International Nuclear Information System (INIS)

    Zhang, Hualin; Donnelly, Eric D.; Strauss, Jonathan B.; Qi, Yujin

    2016-01-01

    Purpose: To evaluate high-dose-rate (HDR) vaginal cuff brachytherapy (VCBT) in the treatment of endometrial cancer in a cylindrical target volume with either a varied or a constant cancer cell distributions using the linear quadratic (LQ) model. Methods: A Monte Carlo (MC) technique was used to calculate the 3D dose distribution of HDR VCBT over a variety of cylinder diameters and treatment lengths. A treatment planning system (TPS) was used to make plans for the various cylinder diameters, treatment lengths, and prescriptions using the clinical protocol. The dwell times obtained from the TPS were fed into MC. The LQ model was used to evaluate the therapeutic outcome of two brachytherapy regimens prescribed either at 0.5 cm depth (5.5 Gy × 4 fractions) or at the vaginal mucosal surface (8.8 Gy × 4 fractions) for the treatment of endometrial cancer. An experimentally determined endometrial cancer cell distribution, which showed a varied and resembled a half-Gaussian distribution, was used in radiobiology modeling. The equivalent uniform dose (EUD) to cancer cells was calculated for each treatment scenario. The therapeutic ratio (TR) was defined by comparing VCBT with a uniform dose radiotherapy plan in term of normal cell survival at the same level of cancer cell killing. Calculations of clinical impact were run twice assuming two different types of cancer cell density distributions in the cylindrical target volume: (1) a half-Gaussian or (2) a uniform distribution. Results: EUDs were weakly dependent on cylinder size, treatment length, and the prescription depth, but strongly dependent on the cancer cell distribution. TRs were strongly dependent on the cylinder size, treatment length, types of the cancer cell distributions, and the sensitivity of normal tissue. With a half-Gaussian distribution of cancer cells which populated at the vaginal mucosa the most, the EUDs were between 6.9 Gy × 4 and 7.8 Gy × 4, the TRs were in the range from (5.0)"4 to (13.4)"4 for

  19. Sand-RAPG combination simulating fertile clayey soil (Part I to IV)

    International Nuclear Information System (INIS)

    Azzam, R.; El-Hady, O.A.; Lotfy, A.A.; Hegela, M.

    1983-01-01

    I. Radiation Preparation of RAPG. Sites of co-ordination and reinforcement are dominated in reclaimer ameliorator polymeric gel (RAPG). It is a modified acrylonitrile base multifunction polymer grafted upon a binder of worthless cellulosic agricultural discard. It varies chemically from non-ionic through anionic and cationic to ampholite. The hydroproperty of the gel is similarly controlled. Thus, RAPG can be tailored for any soil texture under various climatic conditions. II. Structure Stability and Maintenance. Sinai dune sand is treated with non-ionic and anionic RAPGs at rates varying from 0.05 to 0.2 wt.%. The stability increased with RAPG anionicity and application rate. The structure formed maintained three cycles of complete destruction and re-formation without significant changes in erosion index. The resistance of sand-RAPG combination to breakdown by tillage, as well as to wind and water erosion, is practically proved. This is in addition to the beneficial changes in bulk density, void ratio and microporosity, which were also achieved. III. Water Preservation. Inshas sandy soil treated by RAPG is compared with fertile clayey soil. The water-holding capacity and retention at different suctions are increased. The available water to plants in treated sand has reached 15 times that of the control, and even exceeded clay by 11%. Water losses by evaporation and leaching as well as deep percolation are all reduced to a minimum. IV. Plantation and Nutritional Status. Pepper seed germination, growth and dry matter are increased in the sand-RAPG combination relative to fertile clayey soil. The optimum rate and anionicity of RAPG are determined. This increases water-use efficiency to twice that of the fertile clayey soil. Macro- and micro-nutrient uptake have also increased. Thus, fertilizer use efficiency is increased by almost three times over that of clay. These factors lead convincingly to the conclusion that RAPG furnishes adequate conditions for sandy soil

  20. Tunisia: high fertility stalls development.

    Science.gov (United States)

    Barberis, M

    1985-01-01

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

  1. Declining world fertility: trends, causes, implications.

    Science.gov (United States)

    Tsui, A O; Bogue, D J

    1978-10-01

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

  2. Urbanization and fertility: an event-history analysis of coastal Ghana.

    Science.gov (United States)

    White, Michael J; Muhidin, Salut; Andrzejewski, Catherine; Tagoe, Eva; Knight, Rodney; Reed, Holly

    2008-11-01

    In this article, we undertake an event-history analysis of fertility in Ghana. We exploit detailed life history calendar data to conduct a more refined and definitive analysis of the relationship among personal traits, urban residence, and fertility. Although urbanization is generally associated with lower fertility in developing countries, inferences in most studies have been hampered by a lack of information about the timing of residence in relationship to childbearing. We find that the effect of urbanization itself is strong, evident, and complex, and persists after we control for the effects of age, cohort, union status, and education. Our discrete-time event-history analysis shows that urban women exhibit fertility rates that are, on average, 11% lower than those of rural women, but the effects vary by parity. Differences in urban population traits would augment the effects of urban adaptation itself Extensions of the analysis point to the operation of a selection effect in rural-to-urban mobility but provide limited evidence for disruption effects. The possibility of further selection of urbanward migrants on unmeasured traits remains. The analysis also demonstrates the utility of an annual life history calendar for collecting such data in the field.

  3. [The effect of contraception on fertility in the border region of Chiapas, Mexico].

    Science.gov (United States)

    Nazar-Beutelspacher, A; Halperin-Frisch, D; Salvatierra-Izaba, B

    1996-01-01

    To estimate the effect of contraception on fertility in the border region of Chiapas, Mexico. In 1994 an epidemiological cross-sectional study was carried out on a representative sample of 1,560 non-indigenous women between ages 15 and 49 in the border region of Chiapas. The prevalence of contraception practices and the total fertility rates (TFR) were obtained and stratified by rural, intermediate and urban communities. TFR were compared between women who had never used contraceptives and those who had used them. The estimated TFR was 3.67 and varied from 4.14 in rural areas to 3.36 in urban areas. There were no differences in the TFR (3.74 and 3.88) nor in the average live births (3.47 and 3.48) between women who had never used contraceptives and those who had used them. The major effect of contraception on fertility was observed in rural areas. Factors which influence the small impact of contraception on fertility include the late use of these methods and the early age of first union among users.

  4. Increased venous thrombosis incidence in pregnancies after in vitro fertilization

    DEFF Research Database (Denmark)

    Hansen, Anette Tarp; Kesmodel, U S; Juul, S

    2014-01-01

    STUDY QUESTION Is venous thrombosis risk increased in pregnancies after in vitro fertilization? SUMMARY ANSWER The venous thrombosis incidence was significantly increased in pregnancies after in vitro fertilization; especially in the first trimester and in the first 6 weeks post-partum. WHAT...... IS KNOWN ALREADY In vitro fertilization without pregnancy is not associated with increased venous thrombosis incidence. STUDY DESIGN, SIZE, DURATION This national register-based cohort study covered the period from 1995 to 2005. PARTICIPANTS/MATERIALS, SETTING, METHODS All Danish pregnancies conceived...... by in vitro fertilization (n = 18 787) were included. Venous thrombosis incidence rates in pregnancies after in vitro fertilization were compared with venous thrombosis incidence rates in reference pregnancies, by calculating incidence rate ratios. MAIN RESULTS AND THE ROLE OF CHANCE In total, 48 cases were...

  5. The effect of N fertilization on sugar beet production, root activity, and the efficent use of fertilizer N

    International Nuclear Information System (INIS)

    Charanek, Ahmad

    1990-10-01

    This study includes 2 field experiments using 15 N labelled fertilizer on sugarbeets. Five fertilization treatments with 6 replicates in Autumn and 3 with 5 replicates in Spring were carried out for three years (1985-1987), in the fields of the Faculty of Agriculture, University of Damascus. The aim of the Autumn sugarbeet experiment was to study the effects of nitrogen fertilizer on the production of sugarbeet, root activity and the efficeint use of N from the fertilizer. The purpose of the Spring sugarbeet experiment was to compare two methods of N-fertilizer applications (surface and banding) and their effects on the utilization of N-fertilizer. Nitrogen fertilizer was applied as ammonium sulphate (21%) in Autumn at rates of 60, 120, 180 and 240 KgN/ha and as urea (46%) at 120 KgN/ha in Spring. The fertilizer was applied in two equal amounts, the first at the emergence and the second at the beginning of the optimal leaves development. Treatment at 120 Kg was only given labelled 15 N fertilizer. The purpose of this research study was to find out the optimal amount of fertilizer that produces the highest yield and the best nitrogen utilization rate. It was concluded from these results that the optimal amount of fertilizer needed to achieve the highest sugar content was between 120-180 KgN/ha. The second application of fertilizer affected positivily root production. The utilization rate of nitrogen in banding was more efficient than surface method at harvest of the second application. (author). 14 refs., 14 figs., 43 tabs

  6. Plant-based fertilizers for organic vegetable production

    DEFF Research Database (Denmark)

    Sørensen, Jørn Nygaard; Thorup-Kristensen, Kristian

    2011-01-01

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

  7. Lixiviação de potássio no solo de acordo com suas doses aplicadas sobre palha de milheto Potassium leaching in soil as affected by potassium fertilizer rates applied over pearl millet straw

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2006-10-01

    distributed over the soil surface of 20 cm diameter PVC tubes at a rate of 8 t ha-1. Rates of 0, 40, 80, 120, and 160 kg ha-1 of K2O were applied over the straw and a 30 mm rain simulated. The straw was collected and analyzed for K contents. The soil was sampled at depths of 0-2, 2-4, 4-8, 8-12, and 12-20 cm and analyzed for exchangeable K contents. The 30 mm rain was necessary and sufficient to wash the K fertilizer applied over the straw down to the soil surface. K leaching intensity in the soil profile increased with K rates to a depth of 8-12 cm when there was no pearl millet straw on the soil surface. More K reached the soil in pots with straw on the surface, while K leaching decreased.

  8. Risk for borderline ovarian tumours after exposure to fertility drugs

    DEFF Research Database (Denmark)

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

    2015-01-01

    numbers. To obtain information on use of fertility drugs, hospital files and medical records of infertility-associated visits to all Danish fertility clinics were collected and supplemented with information from the Danish IVF register. We used case-cohort techniques to calculate rate ratios (RRs......STUDY QUESTION: Do fertility drugs increase the risk for borderline ovarian tumours, overall and according to histological subtype? SUMMARY ANSWER: The use of any fertility drug did not increase the overall risk for borderline ovarian tumours, but an increased risk for serous borderline ovarian...... tumours was observed after the use of progesterone. WHAT IS KNOWN ALREADY: Many epidemiological studies have addressed the connection between fertility drugs use and risk for ovarian cancer; most have found no strong association. Fewer studies have assessed the association between use of fertility drugs...

  9. Fertility, Mothers' Employment and Family Policy - what kind of relationship?

    DEFF Research Database (Denmark)

    Boje, Thomas P.; Ejrnæs, Anders

    The aim of this paper will be to explain the differences in birth rates among European countries by analysing how the level of fertility is related to a number of dimensions of importance for the work-life balance in the European households. The dimensions included in our analysis of fertility...

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

    African Journals Online (AJOL)

    Farouk-Fati

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

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

    Science.gov (United States)

    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…

  12. Using organic fertilizers in forest and native plant nurseries

    Science.gov (United States)

    Thomas D. Landis; R. Kasten Dumroese

    2012-01-01

    Since World War II, synthetic fertilizers have been used almost exclusively to grow forest and native plant nursery crops because they are quickly soluble and readily taken up by crops, producing the rapid growth rates that are necessary in nursery culture. In recent years, however, a wide variety of new organic fertilizers have become available. We divided these...

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

    African Journals Online (AJOL)

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

  14. Role of Conflict in shaping fertility preferences in Rwanda

    NARCIS (Netherlands)

    Rutayisire, P.-C.; Broekhuis, A.; Hooimeijer, P.

    2013-01-01

    Conflicts affect the social and economic conditions that could account for the stall in fertility decline in Sub-Saharan Africa. For Rwanda, the total fertility rate decreased very rapidly to 6.1 in the eighties but stalled at that level in the nineties. Part of the stall can be attributed to a lack

  15. Fate of phosphorus in Everglades agricultural soils after fertilizer application