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Sample records for fertility rates explained

  1. 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...... 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...... 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...

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

    NARCIS (Netherlands)

    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 s

  3. Fertility Clinic Success Rates

    Science.gov (United States)

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

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

    Science.gov (United States)

    Bengtson, Per; Ehtesham, Emad

    2015-04-01

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

  5. Temporal Trends in Fertility Rates

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  6. Air pollution and human fertility rates

    NARCIS (Netherlands)

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

    2014-01-01

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

  7. Air pollution and human fertility rates

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    Science.gov (United States)

    Henley, David

    2006-11-01

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

  9. Air pollution and human fertility rates.

    Science.gov (United States)

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

    2014-09-01

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

  10. 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 R

  11. Irrigation timing and fertilizer rate in peppers

    Science.gov (United States)

    Excessive rain fall might leach nutrients from the soil or cause producers to not supply irrigation to pepper (Capsicum sp.). Fertilizer at 150 or 300 lb/acre of triple 17 NPK, the lower rate is the recommended rate, was supplied to either bell, cv. Jupiter, or non-pungent jalapeno, cv. Pace 105, pe...

  12. Explaining fertility transition of a developing country: an analysis of quantum and tempo effect.

    Science.gov (United States)

    Fazle Rabbi, Ahbab Mohammad; Kabir, Mohammad

    2015-01-01

    The Total Fertility Rate (TFR) is defined as the average number of births a woman would have if she were to live throughout the reproductive span and bear children at each age at the rates observed in a particular year or period. The current demographic explanation for decline in TFR is primarily attributed to an increase in postponement in pregnancy. Being cross-sectional, fertility measures can be confounded by changes in the timing of births across women's lifetimes (tempo) and by changes in the numbers of children that they have by the time they end their childbearing (quantum). After a sharp fall in the last two decades, TFR of Bangladesh is now 2.3; whereas the TFR was greater than 3 in the last decade. However, mean age at childbearing showed decreasing trend in the last decade. This is a secondary analysis of data from the three consecutive Bangladesh Demographic Health Surveys; BDHS-2004, 2007 and 2011. The method of Bongaarts and Feeney has been applied to estimate the tempo of fertility. Life Table analyses were applied on birth intervals to explain the tempo effect. There was a sustained decline of the fertility quantum (the number of births per woman) as estimated by the conventional TFR; due to tempo effects during the last three BDHS surveys. Mean age at childbearing also showed decreasing trend in the last decade. The current study shows the presence of a significant tempo effect with variability of timing in having first or higher order births. If this trend continues, Bangladesh will be able to achieve below replacement level of fertility soon.

  13. China's fertility drop lowers world growth rate.

    Science.gov (United States)

    Haub, C

    1993-06-01

    China practices a stringent and compulsory program of family planning and population control. This approach has, however, served to increase the number of domestic IUD insertions and sterilizations. Contraceptive prevalence has reached 83% and total fertility (TFR) is estimated to be 1.9. This Chinese accomplishment has helped reduce TFR for all East Asia to 1.8, which is lower than that for northern Europe, and bring the world population growth rate down from the 1992 level of 1.68% to 1.63%. This latter rate is reported in the 1993 Population Reference Bureau's (PRB) World Population Data Sheet and is the lowest world population growth rate since PRB's first annual edition in 1962. Despite these reductions, world population still grows by 90 million annually. No one can say for sure whether or not observed fertility decline in China is permanent. China's birth rate rose twice in the 1980s and it could certainly rebound once again. A popular backlash to population policy or a relaxing of policy due to international pressure to reduce the level of compulsion in the program are 2 factors which might increase overall fertility and population growth. Fertility is also declining in subSaharan Africa, but not universally. Birth rates are rapidly declining in eastern Europe and the former USSR as economic conditions and outlooks pale. The populations of Estonia, Latvia, Ukraine, and possible Russia are even declining, while only mixed data are available from Yugoslavia. New statistical publications reflect changing borders. Finally, while Slovakia is the only country added to this year's sheet, Eritrea and the Channel Islands will likely be included in next year's.

  14. Fertility rates and future population trends: will Europe's birth rate recover or continue to decline?

    Science.gov (United States)

    Lutz, Wolfgang

    2006-02-01

    Europe has long completed its demographic transition from high birth and death rates to low birth and death rates. But the demographic transition paradigm that has been very useful for explaining global demographic trends during the 20th century and that still has strong predictive power when it comes to projecting future trends in countries that still have high fertility, has nothing to say about the future of fertility in Europe. The currently popular notion of a 'second demographic transition' is a useful way to describe a bundle of behavioural and normative changes that recently happened in Europe, but it has no predictive power. The social sciences have not yet come up with a useful theory to predict the future fertility level of post-demographic transition societies. We even do not know whether the trend will be up or down. Given the lack of a predictive theory, this paper will try to do two things: (i) Summarize different substantive arguments that would either suggest the assumption of a recovery of fertility rates in Europe or alternatively, imply further declines. (ii) Convert this discussion of the uncertainty of future fertility trends into probabilistic population projections for Europe, thus highlighting the implications of alternative fertility levels over the coming years. We will also discuss trade-offs between fertility and immigration, and the phenomenon that Europe now has entered a period of negative momentum of population growth.

  15. 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....

  16. Local gamete competition explains sex allocation and fertilization strategies in the sea.

    Science.gov (United States)

    Henshaw, Jonathan M; Marshall, Dustin J; Jennions, Michael D; Kokko, Hanna

    2014-08-01

    Within and across taxa, there is much variation in the mode of fertilization, that is, whether eggs and/or sperm are released or kept inside or on the surface of the parent's body. Although the evolutionary consequences of fertilization mode are far-reaching, transitions in the fertilization mode itself have largely escaped theoretical attention. Here we develop the first evolutionary model of egg retention and release, which also considers transitions between hermaphroditism and dioecy as well as egg size evolution. We provide a unifying explanation for reported associations between small body size, hermaphroditism, and egg retention in marine invertebrates that have puzzled researchers for more than 3 decades. Our model, by including sperm limitation, shows that all these patterns can arise as an evolutionary response to local competition between eggs for fertilization. This can provide a general explanation for three empirical patterns: sperm casters tend to be smaller than related broadcast spawners, hermaphroditism is disproportionately common in sperm casters, and offspring of sperm casters are larger. Local gamete competition also explains a universal sexual asymmetry: females of some species retain their gametes while males release theirs, but the opposite ("egg casting") lacks evolutionary stability and is apparently not found in nature.

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

    Science.gov (United States)

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

    2010-12-01

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

  18. 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

  19. Using Discrete-time Event History Fertility Models to Simulate Total Fertility Rates and Other Fertility Measures.

    Science.gov (United States)

    Van Hook, Jennifer; Altman, Claire E

    2013-08-01

    Event history models, also known as hazard models, are commonly used in analyses of fertility. One drawback of event history models is that the conditional probabilities (hazards) estimated by event history models do not readily translate into summary measures, particularly for models of repeatable events, like childbirth. In this paper, we describe how to translate the results of discrete-time event history models of all births into well-known summary fertility measures: simulated age- and parity-specific fertility rates, parity progression ratios (PPRs), and the total fertility rate (TFR). The method incorporates all birth intervals, but permits the hazard functions to vary across parities. It also can simulate values for groups defined by both fixed and time-varying covariates, such as marital or employment life histories. We demonstrate the method using an example from the National Survey of Family Growth (NSFG) and provide an accompanying data file and Stata program.

  20. Aneuploidy does not explain the difference in outcomes observed between Asian and Caucasian patients undergoingin vitro fertilization

    Institute of Scientific and Technical Information of China (English)

    Jonathan Kort; David Smotrich; Michelle Gaona; XiaWang; BarryBehr

    2015-01-01

    Objective:To understand whether reduced pregnancy and live birth rates for Asian patients undergoing in vitro fertilization (IVF) could be explained by discrepant rates of aneuploid embryos.Methods:A retrospective cohort study of all autologous and donor IVF cycles utilizing pre-implantation genetic screening (PGS) at a single infertility clinic from January 2012 to December 2013.Results:After controlling for maternal age, there was no difference in aneuploidy rates of Caucasian patients compared to Asian patients’. A trend was discerned that embryos of Caucasians form blastocysts more frequently than those of Asian patients, reaching significance for patients aged 25 to 30 and 40 to 45, but there was no difference in the likelihood of having at least one euploid blastocyst to transfer in any age group. Conclusion:While there may be a slight difference in blastocyst formation rates, there is no difference in aneuploidy or euploid blastocyst transfer rates between Asian and Caucasian patients that would explain the discrepancy in IVF outcomes observed between these patient populations. Possible ethnicity specific differences in non-ploidy related embryo viability and endometrial receptivity should be investigated as potential etiologies for this observation.

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

    Science.gov (United States)

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

    2006-01-01

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

  2. Probabilistic Projections of the Total Fertility Rate for All Countries

    Science.gov (United States)

    Raftery, Adrian E.; Gerland, Patrick; Clark, Samuel J.; Pelletier, François; Buettner, Thomas; Heilig, Gerhard K.

    2012-01-01

    We describe a Bayesian projection model to produce country-specific projections of the total fertility rate (TFR) for all countries. The model decomposes the evolution of TFR into three phases: pre-transition high fertility, the fertility transition, and post-transition low fertility. The model for the fertility decline builds on the United Nations Population Division’s current deterministic projection methodology, which assumes that fertility will eventually fall below replacement level. It models the decline in TFR as the sum of two logistic functions that depend on the current TFR level, and a random term. A Bayesian hierarchical model is used to project future TFR based on both the country’s TFR history and the pattern of all countries. It is estimated from United Nations estimates of past TFR in all countries using a Markov chain Monte Carlo algorithm. The post-transition low fertility phase is modeled using an autoregressive model, in which long-term TFR projections converge toward and oscillate around replacement level. The method is evaluated using out-of-sample projections for the period since 1980 and the period since 1995, and is found to be well calibrated. PMID:21748544

  3. Explaining differences in remuneration rates of nursing homes in Germany.

    Science.gov (United States)

    Mennicken, Roman; Augurzky, Boris; Rothgang, Heinz; Wasem, Jürgen

    2014-05-01

    Remuneration rates of German nursing homes are prospectively negotiated between long-term care insurance (LTCI) and social assistance on the one side and nursing homes on the other. They differ considerably across regions while there is no evidence for substantial differences in care provision. This article explains the differences in the remuneration rates by observable characteristics of the nursing home, its residents and its region with a special focus on the largest federal state of North Rhine Westphalia, in which the most expensive nursing homes are located. We use data from the German Federal Statistical Office for 2005 on all nursing homes that offer full-time residential care for the elderly. We find that differences in remuneration rates can partly be explained by exogenous factors. Controls for residents, nursing homes and district characteristics explain roughly 30 % of the price difference; 40 % can be ascribed to a regionally different kind of negotiation between nursing homes and LTCI. Thirty percent of the raw price difference remains unexplained by observable characteristics.

  4. 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

  5. What explains between-school differences in rates of smoking?

    Directory of Open Access Journals (Sweden)

    Wight Daniel

    2008-06-01

    Full Text Available Abstract Background Schools have the potential to influence their pupils' behaviour through the school's social organisation and culture (non-formal school characteristics, as well as through the formal curriculum. This paper examines whether these school characteristics (which include a measure of quality of social relationships can account for school differences in smoking rates. Methods This study uses a longitudinal survey involving 5,092 pupils in 24 Scottish schools. Pupils' smoking (at age 15/16, cognitive measures, attitude to school and pupils' rating of teacher pupil relationships (at age 13/14 were linked to school level data comprising teacher assessed quality of pupil-staff relationships, school level deprivation, staying on rates and attendance. Analysis involved multi-level modelling. Results Overall, 25% of males and 39% of females reported smoking, with rates by school ranging from 8% to 33% for males and from 28% to 49% for females. When individual socio-economic and socio-cultural factors were controlled for there was still a large school effect for males and a smaller (but correlated school effect for females at 15/16 years. For girls their school effect was explained by their rating of teacher-pupil relationships and attitude to school. These variables were also significant in predicting smoking among boys. However, the school effect for boys was most radically attenuated and became insignificant when the interaction between poor quality of teacher – pupil relationships and school level affluence was fitted, explaining 82% of the variance between schools. In addition, researchers' rating of the schools' focus on caring and inclusiveness was also significantly associated with both male and female smoking rates. Conclusion School-level characteristics have an impact on male and female pupils' rates of smoking up to 15/16 years of age. The size of the school effect is greater for males at this age. The social environment of

  6. CERTAINTY EQUIVALENCE FOR DETERMINATION OF OPTIMAL FERTILIZER APPLICATION RATES WITH CARRY-OVER

    OpenAIRE

    Taylor, C. Robert

    1983-01-01

    This note demonstrates that a certain class of stochastic problems for determination of optimal fertilizer application rates in the presence of fertilizer carry-over can be simplified to static, certainly equivalent problems. Conditions required for certainty equivalence to hold are: (1) fertilizer carry-over is agronomically equivalent to applied fertilizer; and (2) some addition of fertilizer is optimal in every decision period.

  7. Population Development Programme. Reduction of fertility rate a major goal.

    Science.gov (United States)

    1992-07-01

    South Africa's development program has aimed to reduce total fertility to 2 children per woman by the year 2010. Since the program's inception, fertility declined from 4.6 to 4.1. White fertility over the last 4 years decreased from 2.1 to 1.7; Asian fertility declined from 2.8 to 2.3; Black fertility declined from 4.2 to 3.7. Black fertility was very low in the PWV area (2.6) and in metropolitan areas (3.2). High fertility was reflected in TBVC countries and self-governing areas (5.3). Teenage births among Whites have declined from 7.2% to 5.9%, and among Coloreds from 16% to 12.8%. Asian teenage childbearing declined from 10.9% to 8.2%, and Black teenage childbearing increased from 11.4% to 16.5%. The infant mortality rate declined for all races, and Blacks remained with the highest rate of 50/1000 live births. Literacy rates improved for Coloreds from 60% to 66% and for Blacks from 48% to 54%. Contraceptive usage was 65% among Whites, 59.2% among Coloreds, 60.2% among Asians, and 43.8% among Blacks. Awareness of population growth problems was 68% in rural and 82% in urban areas. The business sector will gain from becoming involved in development through a better trained work force, improved job satisfaction and less unrest, reduced absenteeism rates, improved trust between employer and employee, and more favorable socioeconomic conditions for business. Public health and reduction in sexually transmitted diseases would also improve. The business community has the opportunity to invest in a variety of development activities: to promote technical education through scholarships, public campaigns to promote the image of technical careers, and exchange of information with educators about business needs. Business might also provide employee training, women's training, employee involvement in decision making, and employee benefits such as preventive health services. Family planning could be integrated into training courses for employees and emphasize the small family

  8. Application of computer-assisted semen analysis to explain variations in pig fertility.

    NARCIS (Netherlands)

    Broekhuijse, M.L.W.J.; Sostaric, E.; Feitsma, H.; Gadella, B.M.

    2012-01-01

    Sperm quality is often evaluated through computer-assisted semen analysis (CASA) and is an indicator of boar fertility. The aim of this research was to study the relationship between CASA motility parameters and fertility results in pigs. Insemination records and semen parameters from a total of 45,

  9. Explaining Below-Replacement Fertility and Increasing Childlessness in Wealthy Countries: Legacy Drive and the “Transmission Competition” Hypothesis

    OpenAIRE

    Aarssen, Lonnie W; Stephanie Tzipporah Altman

    2006-01-01

    We propose a novel evolutionary perspective for explaining why, in most wealthy countries, female fertility has recently dropped below replacement level, with an increasing incidence of childlessness. Our hypothesis is based on the proposition that throughout human evolution, behaviors that promoted gene transmission (offspring production), and hence fitness, have involved not just those associated with a strong “sex drive,” but also those associated with a strong “legacy drive”—the desire to...

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

    Science.gov (United States)

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

    2013-10-01

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

  11. High ratings of satisfaction with fertility treatment are common

    DEFF Research Database (Denmark)

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

    2003-01-01

    attending five fertility clinics. The response rate at the 12 month follow-up was 87.7% and included a total of 1934 patients. RESULTS: During the follow-up period about two-thirds had achieved a pregnancy and about a third became parents. The participants were satisfied with both the medical and patient......-centred (psychosocial) services. There were no sex differences in the evaluation of treatment except that women were more satisfied than men with how the staff had performed their medical examinations. Satisfaction with medical and patient-centred services was positively associated with a treatment-related pregnancy...

  12. Fertilization rate and its determinants in intracytoplasmic sperm injection

    Science.gov (United States)

    Jawed, Shireen; Rehman, Rehana; Ali, Mohammad Ashfaq; Abdullah, Umme Hani; Gul, Hina

    2016-01-01

    Objective: To identify predictors of fertilization rate in patients of unexplained infertility after intracytoplasmic sperm injection (ICSI). Methods: Retrospective analysis of females (282) enrolled in quasi experimental design for ICSI at “Islamabad Clinic Serving Infertile Couples” was carried out from July 2013 till June 2014. Females with unexplained infertility were included, whereas well defined male and female causes of infertility were excluded. Fertilization rate (FR) was calculated as percentage transformation of micro injected oocytes into two pronuclei. Categorical variable of FR defined on the basis of 50% FR grouped females; Group I with FR ≤50% and Group II with FR >50%. The groups were compared in terms of demographic variables, base line hormones and oocyte parameters. Univariate logistic regression was executed to obtain odds ratio with 95% confidence interval to quantify the association of predictors like age, duration of infertility, oocytes parameters, hormones; Estradiol, progesterone, follicle stimulating hormone (FSH), luteinizing hormone, prolactin and cytokines interleukin-Iβ (IL-Iβ) with the FR. Results: In our study out of 282 females, 19 (6.73%) were in group I and 263 (93.26%) comprised of Group II. Females with high FR(group II) had low Progesterone and FSH (p=0.04, p=0.02) respectively. Mature oocytes (OR: 0.35; 95% CI 1 – 2.56) and IL-Iβ in follicular phase (OR: 1.04; 95% CI: 0.000- 1.20) were significant positive predictors of FR while peak progesterone and FSH had significant negative effect on it Conclusion: Fertilization of oocytes in females of unexplained infertility depended on maturity of oocytes and optimal amounts of ILI- β released by developing follicles in the follicular phase of stimulation cycles of ICSI. PMID:27022334

  13. Functional- and abundance-based mechanisms explain diversity loss due to N fertilization

    OpenAIRE

    Suding, Katharine N.; Collins, Scott L.; Gough, Laura; Clark, Christopher; Cleland, Elsa E.; Gross, Katherine L.; Milchunas, Daniel G.; Pennings, Steven

    2005-01-01

    Human activities have increased N availability dramatically in terrestrial and aquatic ecosystems. Extensive research demonstrates that local plant species diversity generally declines in response to nutrient enrichment, yet the mechanisms for this decline remain unclear. Based on an analysis of >900 species responses from 34 N-fertilization experiments across nine terrestrial ecosystems in North America, we show that both trait-neutral and trait-based mechanisms operate simultaneously to inf...

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

    DEFF Research Database (Denmark)

    Priskorn, Lærke; Holmboe, Stine; Jørgensen, Niels

    2012-01-01

    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......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...... 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....

  15. Do expert ratings or economic models explain champagne prices?

    DEFF Research Database (Denmark)

    Bentzen, Jan Børsen; Smith, Valdemar

    2008-01-01

    Champagne is bought with low frequency and many consumers most likely do not have or seek full information on the quality of champagne. Some consumers may rely on the reputation of particular brands, e.g. "Les Grandes Marques", some consumers choose to gain information from sensory ratings...... of champagne. The aim of this paper is to analyse the champagne prices on the Scandinavian markets by applying a hedonic price function in a comparative framework with minimal models using sensory ratings....

  16. 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.

  17. 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.

  18. Fabrication and evaluation of variable rate fertilizer system

    OpenAIRE

    A Damirchi; M.H Aghkhani; M Khojastehpour; J Baradaran Motie

    2015-01-01

    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 bei...

  19. A microphysical model explains rate-and-state friction

    Science.gov (United States)

    Chen, Jianye; Spiers, Christopher J.

    2015-04-01

    The rate-and-state friction (RSF) laws were originally developed as a phenomenological description of the frictional behavior observed in lab experiments. In previous studies, the empirical RSF laws have been extensively and quite successfully applied to fault mechanisms. However, these laws can not readily be envisioned in terms of the underlying physics. There are several critical discrepancies between seismological constraints on RSF behavior associated with earthquakes and lab-derived RSF parameters, in particular regarding the static stress drop and characteristic slip distance associated with seismic events. Moreover, lab friction studies can address only limited fault topographies, displacements, experimental durations and P-T conditions, which means that scale issues, and especially processes like dilatation and fluid-rock interaction, cannot be fully taken into account. Without a physical basis accounting for such effects, extrapolation of lab-derived RSF data to nature involves significant, often unknown uncertainties. In order to more reliably apply experimental results to natural fault zones, and notably to extrapolate lab data beyond laboratory pressure, temperature and velocity conditions, an understanding of the microphysical mechanisms governing fault frictional behavior is required. Here, following some pioneering efforts (e.g. Niemeijer and Spiers, 2007; Den Hartog and Spiers, 2014), a mechanism-based microphysical model is developed for describing the frictional behavior of carbonate fault gouge, assuming that the frictional behavior seen in lab experiments is controlled by competing processes of intergranular slip versus contact creep by pressure solution. The model basically consists of two governing equations derived from energy/entropy balance considerations and the kinematic relations that apply to a granular fault gouge undergoing shear and dilation/compaction. These two equations can be written as ˙τ/K = Vimp- Lt[λ˙γsbps +(1-

  20. Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer

    Institute of Scientific and Technical Information of China (English)

    Zhang Ying-zi; Chen Hai-tao; Hou Shou-yin; Ji Wen-yi; Ouyang Bin-lin; Dun Guo-qiang; Zhang Ji-cheng

    2015-01-01

    In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  2. Explaining Below-Replacement Fertility and Increasing Childlessness in Wealthy Countries: Legacy Drive and the “Transmission Competition” Hypothesis

    Directory of Open Access Journals (Sweden)

    Lonnie W. Aarssen

    2006-01-01

    Full Text Available We propose a novel evolutionary perspective for explaining why, in most wealthy countries, female fertility has recently dropped below replacement level, with an increasing incidence of childlessness. Our hypothesis is based on the proposition that throughout human evolution, behaviors that promoted gene transmission (offspring production, and hence fitness, have involved not just those associated with a strong “sex drive,” but also those associated with a strong “legacy drive”—the desire to “leave something of oneself for the future. Because of this intrinsic legacy drive, we argue, humans (and males, in particular have been inherently vulnerable for “side-tracking” into other activities that promote “meme transmission” — i.e., activities perceived as providing a lasting legacy of “self through investment in career development, accumulation of wealth and status, and several other activities that have potential to impact on the thoughts and actions of others in both current and future generations. Humans engage in meme transmission, therefore, at the potential expense of time, energy, and resources for investing in gene transmission. Based on evolutionary arguments, we discuss why realized competition between gene transmission and meme transmission has emerged significantly only in recent human history, why meme transmission is presently winning out in wealthy countries — thus accounting for below-replacement fertility and increasing childlessness — and why natural selection can be expected in the near future to generate a significant shift in the fertility-promoting behaviors of humans.

  3. Evaluation of phosphorus fertilizer rates for maize and sources for ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... characteristics that affect yield responses. Experiments were conducted ... Phosphorus fertilization enhanced height and grain yield compared with no P. To .... into 500 ml of water to spray the plants. This was done four times.

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

    Science.gov (United States)

    Calot, G

    1977-01-01

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

  5. Lifetime models of female labor supply, wage rates, and fertility.

    Science.gov (United States)

    Carliner, G; Robinson, C; Tomes, N

    1984-01-01

    A simple 1 period lifetime model is specified in which schooling is part of the lifetime period. This implies that an adding-up constraint is imposed on the uses of time in the lifetime including schooling, which may induce a negative correlation between years of schooling and years in the market, while producing a positive correlation between years of schooling and the fraction of the postschool lifetime spent in the market. The model is used to interpret empirical analyses based on alternative measures of lifetime labor supply and on alternative specifications of which variables may be treated as exogenous. In the empirical analysis the retrospective and longitudinal aspects of the newly available National Longitudinal Survey of Women is used to construct a measure of the fraction of the lifetime supplied to the market and measures of the lifetime wage rates of both the husband and the wife. The empirical results take the lifetime model of labor supply seriously in that the empirical measures of labor supply and wage rates bear a much closer resemblance to the theoretical concepts than measures typically employed in the literature. The estimates indicate that the "plausible assumptions" required for the true coefficient on fertility in a labor supply equation to be zero are fulfilled. These estimates are compared with those obtained using current measures as proxies for lifetime variables. Based on these estimates, an explanation is offered for the apparent contradiction between the findings of studies using a simultaneous equations approach that report no effect of fertility on female labor supply and the strong depressing effect of children on (current) labor supply obtained from research that treats children as exogenous. Current female hours appear more responsive to husbands' current earnings and female education than is the case with the lifetime variables. There are marked differences in the effects of race. The lifetime hours of white women are only some

  6. 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.

  7. Effect of Nitrogen Fertilizer on Photosynthetic Rate of Leymus chinensis in Grassland of Different Degrading Degrees

    Institute of Scientific and Technical Information of China (English)

    Mingming WANG; Yajing BAO; Zhenghai LI; Shaohuan YANG; Jingping JIAO; Yanyu GUO

    2012-01-01

    [Objective] This study aimed to investigate the effect of nitrogen fertilizer on photosynthetic rate of Leymus chinensis in the grasslands of different degrading degrees. [Method] With the L. chinensis in Inner Mongolia Baiyinxile Ranch as the research object, different rations of nitrogen fertilizer were applied to the grassland (0, 30, 50, 80 g/m^2). The effect of different gradients of nitrogen fertilizer on photo- synthetic rate of Leymus chinensis, and the effect on grasslands of different degrading degrees were analyzed. [Result] The photosynthetic rate of L. chinensis in- creased with the increase of nitrogen gradients; in the grassland communities with different degrading degrees, the responses of the photosynthetic rate of L. chinensis to nitrogen fertilizer were different, and the response in the grassland with severe degradation was the best. [Conclusion] Nitrogen fertilizer played an important role in enhancing the restoration degree of grassland.

  8. 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.

  9. 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

  10. 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

  11. A Stata module for computing fertility rates and TFRs from birth histories: tfr2

    Directory of Open Access Journals (Sweden)

    Bruno Schoumaker

    2013-05-01

    Full Text Available BACKGROUND Since the 1970s, birth history data have become widely available, thanks to the World Fertility survey and the Demographic and Health Surveys programs. Despite their wide availability, these data remain under-exploited. Computation, even of simple indicators (fertility rates, total fertility rates, mean age at childbearing and their standard errors, is not direct with such data, and other types of analysis (fertility differentials, reconstruction of fertility trends et cetera may also involve reorganization of data sets and statistical modeling that present a barrier to the use of birth history data. OBJECTIVE This paper presents a Stata software module (tfr2 that was prepared to analyze birth history data in a user-friendly and flexible way. It is designed to be used primarily with DHS data, but can also be used easily with birth histories from other sources. Three types of analysis are performed by tfr2: (1 the computation of age-specific fertility rates and TFRs, as well as their standard errors, (2 the reconstruction of fertility trends, and (3 the estimation of fertility differentials (rate ratios. METHODS The tfr2 module is composed of two parts: (1 a Stata command to transform birth history data into a table of births and exposure (tabexp, and (2 a Poisson regression model to compute fertility rates, fertility trends and fertility differentials from a table of births and exposure (produced by tabexp. COMMENTS One can obtain tfr2 free of charge. It will work with Stata 10 and more recent versions of Stata.

  12. The Effects of Different Amounts of Controlled Release Fertilizer on the Root Growth and the Filling Rate in Winter Wheat

    Directory of Open Access Journals (Sweden)

    Meng Li

    2014-03-01

    Full Text Available In order to increase the fertilizer use efficiency and yield in winter wheat, the effects of controlled release fertilizer on the root growth and the filling rate in winter wheat by applying different amounts of controlled release fertilizer had been studied in open field. The results indicated that conventional complex fertilizer and controlled release fertilizer could cause corresponding changes of the wheat root activity, dry root weight, root-shoot ratio and filling rate, but the fertilizer of conventional fertilizer performed in the pre-stage significantly, controlled release fertilizer performed in the middle and late stage gradually. So mixing conventional fertilizer with controlled release fertilizer can ensure the nutrient supply of whole growth and development of wheat to explore the most appropriate collocation dosage. This will make fertilizer and economic benefits achieve the best.

  13. Dropout rates in couples undergoing in vitro fertilization and intrauterine insemination

    NARCIS (Netherlands)

    Bensdorp, Alexandra J.; Tjon-Kon-Fat, Raissa; Verhoeve, Harold; Koks, Carolien; Hompes, Peter; Hoek, Annemieke; de Bruin, Jan Peter; Cohlen, Ben; Hoozemans, Diederik; Broekmans, Frank; van Bomme, Peter; Smeenk, Jesper; Mol, Ben W. J.; van der Veen, Fulco; van Wely, Madelon

    2016-01-01

    Objective: To compare dropout rates in couples undergoing conventional in vitro fertilization with single embryo transfer (IVF-SET), in vitro fertilization in a modified natural cycle (IVF-MNC) or intrauterine insemination with ovarian stimulation (IUI-OS). Study design: Secondary analysis of a mult

  14. The Effects of Different Amounts of Controlled Release Fertilizer on the Root Growth and the Filling Rate in Winter Wheat

    OpenAIRE

    Meng Li; Jingtian Yang; Liyuan Yan; Yan Shi

    2014-01-01

    In order to increase the fertilizer use efficiency and yield in winter wheat, the effects of controlled release fertilizer on the root growth and the filling rate in winter wheat by applying different amounts of controlled release fertilizer had been studied in open field. The results indicated that conventional complex fertilizer and controlled release fertilizer could cause corresponding changes of the wheat root activity, dry root weight, root-shoot ratio and filling rate, but the fertiliz...

  15. The Effects of Different Amounts of Controlled Release Fertilizer on the Root Growth and the Filling Rate in Winter Wheat

    OpenAIRE

    Meng Li; Jingtian Yang; Liyuan Yan; Yan Shi

    2014-01-01

    In order to increase the fertilizer use efficiency and yield in winter wheat, the effects of controlled release fertilizer on the root growth and the filling rate in winter wheat by applying different amounts of controlled release fertilizer had been studied in open field. The results indicated that conventional complex fertilizer and controlled release fertilizer could cause corresponding changes of the wheat root activity, dry root weight, root-shoot ratio and filling rate, but the fertiliz...

  16. Influence of slow disintegrating fertilizer rates on quality of gazania (Gazania rigens L. seedlings

    Directory of Open Access Journals (Sweden)

    Vujošević Ana

    2007-01-01

    Full Text Available The work has examined the influence of slow disintegrating fertilizer rates of Scotts (Osmocote Exact formulation 15:9:9:MgO + Me on quality of Gazania rigens L. seedlings. The seedlings of Gazania rigens L. was produced in polystyrene containers (speedling system and polypropylene pots (pot system. During the production of seedlings the fertilizer has been applied in rates (0, 1, 2, 3, and 4g/l. The results show that the fertilizer rate of substrata 4g/l influences the qualitative properties of Gazania rigens L. seedlings.

  17. 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.

  18. Changes in fertility rates and family size in response to changes in age at marriage, the trend away from arranged marriages, and increasing urbanization.

    Science.gov (United States)

    Mitchell, R E

    1971-11-01

    Abstract Demographers have proposed a long list of factors that help explain why population growth and fertility rates respond to rising levels of urbanization, economic growth and national development.(2) Two of the many suggested influences will be investigated in the present paper with regard to urban Hong Kong.

  19. Explaining Changing Suicide Rates in Norway 1948-2004: The Role of Social Integration

    Science.gov (United States)

    Barstad, Anders

    2008-01-01

    Using Norway 1948-2004 as a case, I test whether changes in variables related to social integration can explain changes in suicide rates. The method is the Box-Jenkins approach to time-series analysis. Different aspects of family integration contribute significantly to the explanation of Norwegian suicide rates in this period. The estimated effect…

  20. Explaining Changing Suicide Rates in Norway 1948-2004: The Role of Social Integration

    Science.gov (United States)

    Barstad, Anders

    2008-01-01

    Using Norway 1948-2004 as a case, I test whether changes in variables related to social integration can explain changes in suicide rates. The method is the Box-Jenkins approach to time-series analysis. Different aspects of family integration contribute significantly to the explanation of Norwegian suicide rates in this period. The estimated effect…

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

    Science.gov (United States)

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

    2012-02-01

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

  2. Evaluation of Biofertilizers in Irrigated Rice: Effects on Grain Yield at Different Fertilizer Rates

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Badayos

    2012-03-01

    Full Text Available Biofertilizers are becoming increasingly popular in many countries and for many crops, but very few studies on their effect on grain yield have been conducted in rice. Therefore, we evaluated three different biofertilizers (based on Azospirillum, Trichoderma, or unidentified rhizobacteria in the Philippines during four cropping seasons between 2009 and 2011, using four different fertilizer rates (100% of the recommended rate [RR], 50% RR, 25% RR, and no fertilizer as Control. The experiments were conducted under fully irrigated conditions in a typical lowland rice environment. Significant yield increases due to biofertilizer use were observed in all experimental seasons with the exception of the 2008/09 DS. However, the effect on rice grain yield varied between biofertilizers, seasons, and fertilizer treatments. In relative terms, the seasonal yield increase across fertilizer treatments was between 5% and 18% for the best biofertilizer (Azospirillum-based, but went up to 24% in individual treatments. Absolute grain yield increases due to biofertilizer were usually below 0.5 t·ha−1, corresponding to an estimated additional N uptake of less than 7.5 kg N ha−1. The biofertilizer effect on yield did not significantly interact with the inorganic fertilizer rate used but the best effects on grain yield were achieved at low to medium fertilizer rates. Nevertheless, positive effects of the biofertilizers even occurred at grain yields up to 5 t·ha−1. However, the trends in our results seem to indicate that biofertilizers might be most helpful in rainfed environments with limited inorganic fertilizer input. However, for use in these target environments, biofertilizers need to be evaluated under conditions with abiotic stresses typical of such systems such as drought, soil acidity, or low soil fertility.

  3. Fertility waves, aggregate savings and the rate of interest.

    Science.gov (United States)

    Blomquist, N S; Wijkander, H

    1994-02-01

    "During the last fifty years there have in many countries been large movements in the growth of labor productivity, real wage rates, the rate of interest, and the household savings ratio. In this paper we use an overlapping generations model to study if demographic shocks, like the baby boom, can generate the kind of movements observed. Simulations show this is indeed the case. We also study the interactions between a pay-as-you-go pension system and demographic disturbances.... We present some stylized facts of the historical development in Sweden for the rate of interest, the aggregate household saving ratio, growth of labor productivity and the birth rate."

  4. 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.

  5. [Effects of nitrogen fertilization rate and harvest time on summer maize grain yield and its quality].

    Science.gov (United States)

    Zhang, Xue-lin; Wang, Qun; Zhao, Ya-li; Yang, Qing-hua; Li, Chao-hai

    2010-10-01

    In order to approach the optimal nitrogen fertilization rate and suitable harvest time for the high grain yield and quality of summer maize in Huanghe-Haihe Area, a field experiment with five nitrogen fertilization rates (0, 113, 181, 249, and 375 kg N x hm(-2)) and two harvest time (S1: September 23, conventional harvest time for local farmers, and S2: September 29, 6 days delayed) was conducted. The results showed that the kernel number, grain yield, and 1000-grain mass increased with nitrogen fertilization rate, but the differences were not significant. With increasing nitrogen fertilization rate, the protein and lysine contents of the grains increased, while the starch content decreased. After 6 days delayed for harvest, the grain yield, 1000-grain mass, and the starch and lysine contents of the grains increased, but the protein and crude fat contents decreased. Based on the yield level, the optimal nitrogen fertilization rate for the summer maize in Huanghe-Haihe Area was 113-180 kg N x hm(-2), and the suitable harvest time was from September 29 to October 5.

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

    Directory of Open Access Journals (Sweden)

    Martin Blomberg Jensen

    Full Text Available 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.

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

    Science.gov (United States)

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

    2014-07-15

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

  8. Explaining the Variation in Adoption Rates of the Information Content of Environmental Disclosure

    DEFF Research Database (Denmark)

    Fallan, Even

    2015-01-01

    , to information content (individual content categories). Perceived attributes of the information content itself and innovation adoption theory are used for the first time to explain reason for the reporting practice, and are considered fruitful tools to predict consistent variations in adoption rates among...

  9. Reflections on fertility dynamics in Romania.

    Science.gov (United States)

    Bratu, Eugenia Claudia; Minca, Dana Galieta

    2012-01-01

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

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

    Science.gov (United States)

    Attia, S; Katila, T; Andersson, M

    2016-02-01

    Good-quality semen is a prerequisite for successful and profitable artificial insemination (AI) of modern dairy cattle. Fertility of the bulls is evaluated with andrological examinations and semen analyses, such as morphology. However, little attention has been paid to the inheritance of bull fertility. In this study, we correlated sperm morphology, birth year and station of 695 AI bulls with calving rate (CR). Sperm morphology was clearly associated with CR underlining the usefulness of morphological examination in the assessment of fertility. The correlation between the proportion of normal spermatozoa and CR was significant (p bulls with the CR of their 27 sires to study the inheritance of fertility. Sire's CR did not correlate with the CR of the sons (p = 0.218). This result indicates that at least when sires of acceptable CR are used to produce sons for use in AI the inheritance of CR is not significantly correlated.

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

    Science.gov (United States)

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

    2012-06-28

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

  12. 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.

  13. 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...

  14. Filtering fens: Mechanisms explaining phosphorus-limited hotspots of biodiversity in wetlands adjacent to heavily fertilized areas

    NARCIS (Netherlands)

    Cusell, C.; Kooijman, A.; Fernandez, F.; van Wirdum, G.; Geurts, J.J.M.; van Loon, E.E.; Kalbitz, K.; Lamers, L.P.M.

    2014-01-01

    The conservation of biodiverse wetland vegetation, including that of rich fens, has a high priority at a global scale. Although P-eutrophication may strongly decrease biodiversity in rich fens, some well-developed habitats do still survive in highly fertilized regions due to nutrient filtering

  15. 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

    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...... 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...

  16. Fertility decline in Paraguay.

    Science.gov (United States)

    Ishida, Kanako; Stupp, Paul; Melian, Mercedes

    2009-09-01

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

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Science.gov (United States)

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

    2011-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Kaya Abdullah

    2008-02-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  1. [Responses of Scutellaria baicalensis Georgi yield and root baicalin content to the fertilization rates of nitrogen, phosphorus, and potassium].

    Science.gov (United States)

    Cao, Xian-Yan; Xu, Fu-Li; Wang, Wei-Ling; Wang, Jing; Huang, Shu-Hua; Zhang, Xiao-Hu

    2012-08-01

    A field experiment with three-factor (N, P, and K) and quadratic saturation D-optimal design was conducted to evaluate the effects of the fertilization rates of N, P, and K on the yield and root baicalin content of Scutellaria baicalensis Georgi at harvesting time. A ternary quadratic polynomial mathematical model was built, in which, the N, P, and K fertilization rates were independent variables, and the yield and root baicalin content were the target functions. Through the analysis of the model, the optimum fertilization pattern was obtained. The results showed that the fertilization rates of N and P had significant effects on the yield of S. baicalensis. Under low fertilization level, the yield increased with increasing N and P fertilization rates; after exceeding definite fertilization range, no obvious effects were observed. N, P, and K fertilization all had significant effects on the root baicalin content. With increasing fertilization rates of N and K, the root baicalin content rates decreased after an initial increase. Under low fertilization level, the root baicalin content increased with increasing P fertilization rate first, and kept stable then. There existed interactive effects between the fertilization rates of N and P, N and K, and P and K on the yield and root baicalin content of S. baicalensis. Under our experimental conditions, the optimum fertilization model for obtaining over 4000 kg x hm(-2) of S. baicalensis yield and > 14% of root baicalin content was 90.5-104.7 kg x hm(-2) of N, 163.9-199.9 kg x hm(-2) of P2O5, and 84.1-140.8 kg x hm(-2) of K2O, with an N:P2O5:K2O ratio of approximately 1:1.86:1.15.

  2. Decoupling of soil carbon and nitrogen turnover partly explains increased net ecosystem production in response to nitrogen fertilization

    Science.gov (United States)

    Ehtesham, Emad; Bengtson, Per

    2017-04-01

    During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially ‘prime’ the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration of soil organic matter that coincided with a substantial increase in gross nitrogen mineralization. An estimate of the magnitude of the effect demonstrates that the decoupling could potentially result in an increase in net ecosystem production by up to 51 kg C ha-1 day-1 in nitrogen fertilized stands during peak summer. Even if the effect is several times lower on an annual basis, the results still suggest that nitrogen fertilization can have a much stronger influence on net ecosystem production than can be expected from a direct stimulation of primary production alone.

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

    Science.gov (United States)

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

    2016-06-01

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

  4. 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.

  5. Age at first reproduction explains rate variation in the strepsirrhine molecular clock.

    Science.gov (United States)

    Tsantes, C; Steiper, M E

    2009-10-27

    Although the molecular clock hypothesis posits that the rate of molecular change is constant over time, there is evidence that rates vary among lineages. Some of the strongest evidence for variable molecular rates comes from the primates; e.g., the "hominoid slowdown." These rate differences are hypothesized to correlate with certain species attributes, such as generation time and body size. Here, we examine rates of molecular change in the strepsirrhine suborder of primates and test whether body size or age at first reproduction (a proxy for generation time) explains patterns of rate variation better than a null model where the molecular clock is independent of these factors. To examine these models, we analyzed DNA sequences from four pairs of recently diverged strepsirrhine sister taxa to estimate molecular rates by using sign tests, likelihood ratio tests, and regression analyses. Our analysis does not support a model where body weight or age at first reproduction strongly influences rates of molecular evolution across mitochondrial and nuclear sites. Instead, our analysis supports a model where age at first reproduction influences neutral evolution in the nuclear genome. This study supports the generation time hypothesis for rate variation in the nuclear molecular clock. Molecular clock variation due to generation time may help to resolve the discordance between molecular and paleontological estimates for divergence date estimates in primate evolution.

  6. Abundance and Community Composition of Ammonia-Oxidizers in Paddy Soil at Different Nitrogen Fertilizer Rates

    Institute of Scientific and Technical Information of China (English)

    SONG Ya-na; LIN Zhi-min

    2014-01-01

    Ammonia oxidation, the ifrst and rate-limiting step of nitriifcation, is carried out by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). However, the relative importance of AOB and AOA to nitriifcation in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm (root layer soil) and 0-5 cm (surface soil) depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 (75 kg N ha-1 yr-1), N2 (150 kg N ha-1 yr-1), N3 (225 kg N ha-1 yr-1) and CK (without fertilizers) in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis (DGGE) based on amoA (the unit A of ammonia monooxygenase) gene. Archaeal amoA copies in N3 and N2 were signiifcantly (P<0.05) higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3--N content increased but soil NH4+-N content didn’t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher (P<0.05) than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the ifeld among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia

  7. Effects of Sperm Acrosomal Integrity and Protamine Deficiency on In Vitro Fertilization and Pregnancy Rate

    Directory of Open Access Journals (Sweden)

    Marziyeh Tavalaee

    2007-01-01

    Full Text Available Background: The objective of this study was to evaluate the relationship between protaminedeficiency, and acrosomal integrity with fertilization and pregnancy rate in patients undergone in vitrofertilization (IVF.Material &Methods: Semen samples from 70 infertile couples undergoing IVF at Isfahan Fertility andInfertility center were assessed in this study. Semen analysis was carried out according to WHO criteria.Protamine deficiency, Sperm morphology and acrosin activity were assessed by Chromomycin A3(CMA3, Papanicolaou staining and Gelatinolysis tests, respectively. Coefficients of correlation andstudent t-test were carried out using the Statistical Package for the Social Studies (SPSS 11.5 and Pvaluelower than 0.05 was considered as significant.Results: Fertilization rate, percentage of halo formation, mean halo diameter and abnormalmorphology show a significant correlation with percentage of CMA3 positivity. CMA3 positivity,percentage of halo, mean halo and sperm morphology showed a significant correlation with fertilizationrate. Among the aforementioned parameters percentage of halo had the highest correlation. In thepresent study patients were divided into two groups according to pregnancy status. None of the studiedparameters were significantly different between pregnant and non-pregnant patients. However,percentage of halo formation showed a slightly significant difference (r=0.306; P=0.058.Conclusion: The results of this study revealed that, even though sperm morphology, sperm protaminecontent and acrosome formation are events related to spermiogenesis, sperm acrosomal integrityassessed by percentage of halo formation has more profound effect on fertilization rate and pregnancyoutcome during IVF procedure.

  8. 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

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

    Science.gov (United States)

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

    2011-05-01

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

  10. Interactions between rate processes with different timescales explain counterintuitive foraging patterns of arctic wintering eiders.

    Science.gov (United States)

    Heath, Joel P; Gilchrist, H Grant; Ydenberg, Ronald C

    2010-10-22

    To maximize fitness, animals must respond to a variety of processes that operate at different rates or timescales. Appropriate decisions could therefore involve complex interactions among these processes. For example, eiders wintering in the arctic sea ice must consider locomotion and physiology of diving for benthic invertebrates, digestive processing rate and a nonlinear decrease in profitability of diving as currents increase over the tidal cycle. Using a multi-scale dynamic modelling approach and continuous field observations of individuals, we demonstrate that the strategy that maximizes long-term energy gain involves resting during the most profitable foraging period (slack currents). These counterintuitive foraging patterns are an adaptive trade-off between multiple overlapping rate processes and cannot be explained by classical rate-maximizing optimization theory, which only considers a single timescale and predicts a constant rate of foraging. By reducing foraging and instead digesting during slack currents, eiders structure their activity in order to maximize long-term energetic gain over an entire tide cycle. This study reveals how counterintuitive patterns and a complex functional response can result from a simple trade-off among several overlapping rate processes, emphasizing the necessity of a multi-scale approach for understanding adaptive routines in the wild and evaluating mechanisms in ecological time series.

  11. Operational nitrogen fertilizer management in dairy farming systems: identification of criteria and derivation of fertilizer application rates

    NARCIS (Netherlands)

    Vellinga, T.V.; Andre, G.; Schils, R.L.M.; Oenema, O.

    2004-01-01

    Fertilizer-nitrogen (N) management is a decisive factor in grass-based, intensive dairy farming, as it strongly influences economic and environmental performance but little attention has been paid to providing guidance on N-fertilizer management at an operational level to meet these criteria of perf

  12. Influences of nitrogen fertilizer application rates on radish yield, nutrition quality, and nitrogen recovery efficiency

    Institute of Scientific and Technical Information of China (English)

    Yulin LIAO; Xiangmin RONG; Shengxian ZHENG; Qiang LIU; Meirong FAN; Jianwei PENG; Guixian XIE

    2009-01-01

    Radishes (Raphanus sativus L.) were grown in plastic pots in a screenhouse to investigate the influences of nitrogen fertilizer application rates (NFAR) on yield, nitrate content, nitrate reductase activity (NR), nutrition quality, and nitrogen recovery efficiency (NRE) at commercial mature stage. Five N-rate treatments, 0.644, 0.819, 0.995, 1.170, and 1.346 g·por-1, were set up in the screenhouse pot experiments, and nitrogen fertilizer (unlabeled N and l5N-labeled fertilizer) was applied as basal dressing and topdressing, respectively. The results indicated that the fresh and dry weight yields of radish increased with the increase of NFAR at the range of 0.099 to 0.180g N-kg-1 soil, decreased at 0.207 g N-kg-1 soil, and accordingly there was a significant quadratic relationship between the fresh and dry weight yields of radish and the NFAR. At the high addition of urea-N fertilizer, the nitrate content accumulated in the fleshy roots and leaves due to the decline in NR activity. From 0.644 to 0.819 g N-por1 NR increased most rapidly, the highest NR activity occurred at 0.819 g N-por-1, and the lowest NR activity happened at 1.346 g N-por-1. Soluble sugar and ascorbic acid initially increased to the highest value and then decreased, and, contrarily, crude fiber rapidly decreased with the increase of NFAR. Total N uptake (TNU), N derived from fertilizer (Ndff), and N derived from soil (Ndfs) in radish increased, except that Ndfs relatively and slightly decreased at the rate of 0.207 g N-kg'soil. The ratio of Ndff to TNU increased, but the ratio of Ndfs to TNU as well as NRE of N fertilizer decreased with the increase of NFAR. Therefore, the appropriate NFAR should be preferably recommended for improving the yields and nutrition qualities of radish and NRE of N fertilizer.

  13. What explains between-school differences in rates of sexual experience?

    Directory of Open Access Journals (Sweden)

    Williamson Lisa

    2008-02-01

    Full Text Available Abstract Background Schools have the potential to influence their pupils' behaviour through the school's social organisation and culture, as well as through the formal curriculum. This paper provides the first attempt to explain the differences between schools in rates of reported heterosexual sexual experience amongst 15 and 16 year olds. It first examined whether variations in rates of sexual experience remained after controlling for the known predictors of sexual activity. It then examined whether these residuals, or 'school effects', were attributable to processes within the school, or were more likely to reflect characteristics of the neighbourhood. Methods Longitudinal survey data from 4,926 pupils in 24 Scottish schools were linked to qualitative and quantitative data on school processes including quality of relationships (staff-pupil, etc, classroom discipline, organisation of Personal and Social Education, school appearance and pupil morale. Multi-level modelling was used to test a range of models and the resulting 'school effects' were then interpreted using the process data. Results Overall, 42% of girls and 33% of boys reported experience of sexual intercourse, with rates by school ranging from 23% to 61%. When individual socio-economic and socio-cultural factors were taken into account the school variation dropped sharply, though pupils' attitudes and aspirations had little effect. There was very little correlation between boys' and girls' rates of sexual experience by school, after controlling for known predictors of sexual activity. Girls were more influenced by individual socio-economic factors than boys. School-level socio-economic factors were predictive even after taking account of individual socio-cultural factors, suggesting that the wider socio-economic environment further influenced young people's sexual experience. Conclusion Importantly, school processes did not explain the variation between schools in sexual experience

  14. 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.

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

    Science.gov (United States)

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

    2009-12-01

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

  16. 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.

  17. Carbohydrates Concentration in leaves of potato plants affected by nitrogen fertilization rates

    Directory of Open Access Journals (Sweden)

    Heder Braun

    2016-04-01

    Full Text Available ABSTRACT At poor conditions of nitrogen (N in the soil, potato plants may accumulate starch in leaves and be indicative of N nutritional stress. The objective of this work was to determine the effects of N rates (0, 50, 100, 200 and 300 kg ha-1 of N on the concentrations of carbohydrates (total soluble sugars-TSS, reducing sugars-RS, non-reducing sugars-NRS and starch in the fourth leaf (FL of two potato cultivars (Asterix and Atlantic and their critical levels (CL associated to the N fertilization rate necessary to obtain the maximum physical (MPE and economic (MEE efficiency of tubers. A randomized block design with four replications was used in both experiments. On day 21 after plant emergence, four FL were collected from four plants. Potatoes plants fertilized with low rates of N accumulated less TSS in leaves than those properly fertilized. The opposite occurred with content of starch. The cultivars showed similar responses to five doses of N in relation to contents of starch and TSS. However, the response to the increase in doses of N for RS, NRS and Starch/NRS is cultivar-specific. The correlations between contents of RS, NRS and Starch/NRS with the starch and TSS were dependent on the potato cultivar.

  18. 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.

  19. Migration distance rather than migration rate explains genetic diversity in human patrilocal groups.

    Science.gov (United States)

    Marks, Sarah J; Levy, Hila; Martinez-Cadenas, Conrado; Montinaro, Francesco; Capelli, Cristian

    2012-10-01

    In patrilocal groups, females preferentially move to join their mate's paternal relatives. The gender-biased gene flow generated by this cultural practice is expected to affect genetic diversity across human populations. Greater female than male migration is predicted to result in a larger decrease in between-group differentiation for mitochondrial DNA (mtDNA) than for the non-recombining part of the Y chromosome (NRY). We address the question of how patrilocality affects the distribution of genetic variation in human populations controlling for confounding factors such as ethno-linguistic heterogeneity and geographic distance which possibly explain the contradictory results observed in previous studies. By combining genetic and bio-demographic data from Lesotho and Spain, we show that preferential female migration over short distances appears to minimize the impact of a generally higher female migration rate in patrilocal communities, suggesting patrilocality might influence genetic variation only at short ranges.

  20. In vitro fertility rate of 129 strain is improved by Buserelin (GnRH) administration prior to superovulation

    OpenAIRE

    Vasudevan, K; Sztein, J M

    2012-01-01

    The 129 mice are well recognized for their low fertility and it is speculated that this lack of fertility may be due to oocyte condition. In this study we investigated superovulation regimens for 129S1/SvImJ mouse strain to improve the oocyte quality and fertility rate of in vitro fertilization (IVF). Female mice were divided into four groups based on hormone and timing of injection. Group 1 received pregnant mare serum gonatotropin (PMSG) and 48 hours later human chorionic gonadotropin (hCG)...

  1. Explaining variation in GP referral rates for x-rays for back pain

    Directory of Open Access Journals (Sweden)

    Bond Senga

    2006-08-01

    Full Text Available Abstract Background Despite the availability of clinical guidelines for the management of low back pain (LBP, there continues to be wide variation in general practitioners' (GPs' referral rates for lumbar spine x-ray (LSX. This study aims to explain variation in GPs' referral rates for LSX from their accounts of the management of patients with low back pain. Methods Qualitative, semi-structured interviews with 29 GPs with high and low referral rates for LSX in North East England. Thematic analysis used constant comparative techniques. Results Common and divergent themes were identified among high- and low-users of LSX. Themes that were similar in both groups included an awareness of current guidelines for the use of LSX for patients with LBP and the pressure from patients and institutional factors to order a LSX. Differentiating themes for the high-user group included: a belief that LSX provides reassurance to patients that can outweigh risks, pessimism about the management options for LBP, and a belief that denying LSX would adversely affect doctor-patient relationships. Two specific differentiating themes are considered in more depth: GPs' awareness of their use of lumbar spine radiology relative to others, and the perceived risks associated with LSX radiation. Conclusion Several key factors differentiate the accounts of GPs who have high and low rates of referral for LSX, even though they are aware of clinical guideline recommendations. Intervention studies that aim to increase adherence to guideline recommendations on the use of LSX by changing the ordering behaviour of practitioners in primary care should focus on these factors.

  2. Filtering fens: mechanisms explaining phosphorus-limited hotspots of biodiversity in wetlands adjacent to heavily fertilized areas.

    Science.gov (United States)

    Cusell, Casper; Kooijman, Annemieke; Fernandez, Filippo; van Wirdum, Geert; Geurts, Jeroen J M; van Loon, E Emiel; Kalbitz, Karsten; Lamers, Leon P M

    2014-05-15

    The conservation of biodiverse wetland vegetation, including that of rich fens, has a high priority at a global scale. Although P-eutrophication may strongly decrease biodiversity in rich fens, some well-developed habitats do still survive in highly fertilized regions due to nutrient filtering services of large wetlands. The occurrence of such nutrient gradients is well-known, but the biogeochemical mechanisms that determine these patterns are often unclear. We therefore analyzed chemical speciation and binding of relevant nutrients and minerals in surface waters, soils and plants along such gradients in the large Ramsar nature reserve Weerribben-Wieden in the Netherlands. P-availability was lowest in relatively isolated floating rich fens, where plant N:P ratios indicated P-limitation. P-limitation can persist here despite high P-concentrations in surface waters near the peripheral entry locations, because only a small part of the P-input reaches the more isolated waters and fens. This pattern in P-availability appears to be primarily due to precipitation of Fe-phosphates, which mainly occurs close to entry locations as indicated by decreasing concentrations of Fe- and Al-bound P in the sub-aquatic sediments along this gradient. A further decrease of P-availability is caused by biological sequestration, which occurs throughout the wetland as indicated by equal concentrations of organic P in all sub-aquatic sediments. Our results clearly show that the periphery of large wetlands does indeed act as an efficient P-filter, sustaining the necessary P-limitation in more isolated parts. However, this filtering function does harm the ecological quality of the peripheral parts of the reserve. The filtering mechanisms, such as precipitation of Fe-phosphates and biological uptake of P, are crucial for the conservation and restoration of biodiverse rich fens in wetlands that receive eutrophic water from their surroundings. This seems to implicate that biodiverse wetland

  3. Purging deleterious mutations under self fertilization: paradoxical recovery in fitness with increasing mutation rate in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Levi T Morran

    Full Text Available BACKGROUND: The accumulation of deleterious mutations can drastically reduce population mean fitness. Self-fertilization is thought to be an effective means of purging deleterious mutations. However, widespread linkage disequilibrium generated and maintained by self-fertilization is predicted to reduce the efficacy of purging when mutations are present at multiple loci. METHODOLOGY/PRINCIPAL FINDINGS: We tested the ability of self-fertilizing populations to purge deleterious mutations at multiple loci by exposing obligately self-fertilizing populations of Caenorhabditis elegans to a range of elevated mutation rates and found that mutations accumulated, as evidenced by a reduction in mean fitness, in each population. Therefore, purging in obligate selfing populations is overwhelmed by an increase in mutation rate. Surprisingly, we also found that obligate and predominantly self-fertilizing populations exposed to very high mutation rates exhibited consistently greater fitness than those subject to lesser increases in mutation rate, which contradicts the assumption that increases in mutation rate are negatively correlated with fitness. The high levels of genetic linkage inherent in self-fertilization could drive this fitness increase. CONCLUSIONS: Compensatory mutations can be more frequent under high mutation rates and may alleviate a portion of the fitness lost due to the accumulation of deleterious mutations through epistatic interactions with deleterious mutations. The prolonged maintenance of tightly linked compensatory and deleterious mutations facilitated by self-fertilization may be responsible for the fitness increase as linkage disequilibrium between the compensatory and deleterious mutations preserves their epistatic interaction.

  4. BIOMETRIC AND PHYSIOLOGICAL CHARACTERISTICS OF CHRYSANTHEMUM (CHRYSANTHEMUM INDICUM L. PLANTS GROWN AT DIFFERENT RATES OF NITROGEN FERTILIZATION

    Directory of Open Access Journals (Sweden)

    V IVANOVA

    2003-07-01

    Full Text Available A trial with large the flowered chrysanthemum cultivar Dark Westland was carried out in an unheated greenhouse. Three rates of nitrogen fertilization were studied: 0, 100 and 140 kgN/ha, as well as two modes of plant formation – single- and two-stemmed plants. Parameters of the biometric characteristics, leaf gasexchange and leaf pigment content were determined. The best results about growth and decorative behaviour were achieved at nitrogen fertilization level of 100 kgN/ha. It was established that nitrogen fertilization in rates of 100 and 140 kgN/ha enhances photosynthetic rate in both modes of plant formation.

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

    Science.gov (United States)

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

    2016-05-01

    Novel candidates for biomarkers of a high-fertilization rate were identified here through global transcriptional profiling of ovarian follicles. Some other differentially expressed candidate genes were first noted to influence animal reproduction in our previous cDNA microarray analysis and are now recognized as markers for marker-assisted selection. In the present study, we compared gene expression in ovarian follicles from animals with high- and low-fertilization rates using an oligonucleotide array. On the basis of a fold change of greater than 1.2 and less than -1.2, a difference of >100 Affymetrix arbitrary units between the two groups, and a P value of less than 0.05, 47 genes were found to be associated with fertilization rate. GOEAST and MetaCore software were further used to identify the functional categories of genes that were differentially expressed. Then, we focused on three interesting genes associated with a high-fertilization rate: one of these genes was discovered to participate in signaling pathways of fertilization, and two genes take roles in lipid metabolism. An oligonucleotide array showed that the levels of orthodenticle homeobox 2 (OTX2) and lecithin:cholesterol acyltransferase (LCAT) gene expression were 1.62-fold and 1.95-fold higher in the high-fertilization rate group than in the low-fertilization rate group, respectively (P fertilization rate group, with a difference of 2.31-fold (P fertilization rates in ovarian follicles. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. The role of income differences in explaining social inequalities in self rated health in Sweden and Britain

    DEFF Research Database (Denmark)

    Yngwe, M A; Diderichsen, F; Whitehead, M

    2001-01-01

    STUDY OBJECTIVE: To analyse to what extent differences in income, using two distinct measures-as distribution across quintiles and poverty-explain social inequalities in self rated health, for men and women, in Sweden and Britain. DESIGN: Series of cross sectional surveys, the Swedish Survey...... 15 766 people in the Swedish dataset and 49 604 people in the British dataset. MAIN RESULTS: The magnitude of social inequalities in less than good self rated health was similar in Sweden and in Britain, but adjusting for income differences explained a greater part of these in Britain than in Sweden....... In Britain the distribution across income quintiles explained 47% of the social inequalities in self rated health among women and 31% among men, while in Sweden it explained, for women 13% and for men 20%. Poverty explained 22% for British women and 8% for British men of the social inequalities in self rated...

  7. Are the High Hip Fracture Rates Among Norwegian Women Explained by Impaired Bone Material Properties?

    Science.gov (United States)

    Duarte Sosa, Daysi; Vilaplana, Laila; Güerri, Roberto; Nogués, Xavier; Wang-Fagerland, Morten; Diez-Perez, Adolfo; F Eriksen, Erik

    2015-10-01

    Hip fracture rates in Norway rank among the highest in the world, more than double that of Spanish women. Previous studies were unable to demonstrate significant differences between the two populations with respect to bone mass or calcium metabolism. In order to test whether the difference in fracture propensity between both populations could be explained by differences in bone material quality we assessed bone material strength using microindentation in 42 Norwegian and 46 Spanish women with normal BMD values, without clinical or morphometric vertebral fractures, no clinical or laboratory signs of secondary osteoporosis, and without use of drugs with known influence on bone metabolism. Bone material properties were assessed by microindentation of the thick cortex of the mid tibia following local anesthesia of the area using the Osteoprobe device (Active Life Scientific, Santa Barbara, CA, USA). Indentation distance was standardized against a calibration phantom of methylmethacrylate and results, as percentage of this reference value, expressed as bone material strength index units (BMSi). We found that the bone material properties reflected in the BMSi value of Norwegian women was significantly inferior when compared to Spanish women (77 ± 7.1 versus 80.7 ± 7.8, p hip BMD was significantly higher in Norwegian women (1.218 g/cm(2) versus 0.938 g/cm(2) , p fracture after such falls. These ethnic differences in bone material properties may partly explain the higher propensity for fracture in Norwegian women. © 2015 American Society for Bone and Mineral Research.

  8. What explains usage of mobile physician-rating apps? Results from a web-based questionnaire.

    Science.gov (United States)

    Bidmon, Sonja; Terlutter, Ralf; Röttl, Johanna

    2014-06-11

    Consumers are increasingly accessing health-related information via mobile devices. Recently, several apps to rate and locate physicians have been released in the United States and Germany. However, knowledge about what kinds of variables explain usage of mobile physician-rating apps is still lacking. This study analyzes factors influencing the adoption of and willingness to pay for mobile physician-rating apps. A structural equation model was developed based on the Technology Acceptance Model and the literature on health-related information searches and usage of mobile apps. Relationships in the model were analyzed for moderating effects of physician-rating website (PRW) usage. A total of 1006 randomly selected German patients who had visited a general practitioner at least once in the 3 months before the beginning of the survey were randomly selected and surveyed. A total of 958 usable questionnaires were analyzed by partial least squares path modeling and moderator analyses. The suggested model yielded a high model fit. We found that perceived ease of use (PEOU) of the Internet to gain health-related information, the sociodemographic variables age and gender, and the psychographic variables digital literacy, feelings about the Internet and other Web-based applications in general, patients' value of health-related knowledgeability, as well as the information-seeking behavior variables regarding the amount of daily private Internet use for health-related information, frequency of using apps for health-related information in the past, and attitude toward PRWs significantly affected the adoption of mobile physician-rating apps. The sociodemographic variable age, but not gender, and the psychographic variables feelings about the Internet and other Web-based applications in general and patients' value of health-related knowledgeability, but not digital literacy, were significant predictors of willingness to pay. Frequency of using apps for health-related information

  9. 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

  10. In vitro fertility rate of 129 strain is improved by Buserelin (GnRH) administration prior to superovulation

    Science.gov (United States)

    Vasudevan, K; Sztein, J M

    2012-01-01

    The 129 mice are well recognized for their low fertility and it is speculated that this lack of fertility may be due to oocyte condition. In this study we investigated superovulation regimens for 129S1/SvImJ mouse strain to improve the oocyte quality and fertility rate of in vitro fertilization (IVF). Female mice were divided into four groups based on hormone and timing of injection. Group 1 received pregnant mare serum gonatotropin (PMSG) and 48 hours later human chorionic gonadotropin (hCG); using the same dose, group 2 received hCG 52 hours post PMSG and group 3, 55 hours post PMSG. Group 4 received Buserelin (gonadotropin releasing hormone agonist [GnRH]) followed 24 hours later by PMSG and then hCG 55 hours post PMSG. IVF was performed using 129S1/SvImJ oocytes and sperm; C57BL/6J sperm with 129S1/SvImJ oocytes was used as fertility control. The IVF fertility rate was 1% (Groups 1 & 2), 17% (Group 3) and 55% (Group 4) for 129 oocytes fertilized with 129 sperm. For 129 oocytes fertilized with C57BL/6J sperm, the fertility rate was 5% (Group 1) 10% (Group 2) 40% (Group 3) and 59% (Group 4).-These results suggest that extending the interval time between PMSG and hCG and giving GnRH in addition to the standard PMSG and hCG treatment can improve IVF fertility rate of 129S1/SvImJ strain mice significantly. PMID:23097563

  11. In vitro fertility rate of 129 strain is improved by buserelin (gonadotropin-releasing hormone) administration prior to superovulation.

    Science.gov (United States)

    Vasudevan, K; Sztein, J M

    2012-10-01

    The 129 mice are well recognized for their low fertility and it is speculated that this lack of fertility may be due to the oocyte condition. In this study we investigated superovulation regimens for the 129S1/SvImJ mouse strain to improve the oocyte quality and fertility rate of in vitro fertilization (IVF). Female mice were divided into four groups based on hormone and timing of injection. Group 1 received pregnant mare serum gonadotropin (PMSG) and 48 h later human chorionic gonadotropin (hCG); using the same dose, group 2 received hCG 52 h post-PMSG and group 3, 55 h post-PMSG. Group 4 received buserelin (gonadotropin-releasing hormone agonist [GnRH]) followed 24 h later by PMSG and then hCG 55 h post-PMSG. IVF was performed using 129S1/SvImJ oocytes and sperm; C57BL/6J sperm with 129S1/SvImJ oocytes was used as fertility control. The IVF fertility rate was 1% (Groups 1 and 2), 17% (Group 3) and 55% (Group 4) for 129 oocytes fertilized with 129 sperm. For 129 oocytes fertilized with C57BL/6J sperm, the fertility rate was 5% (Group 1), 10% (Group 2), 40% (Group 3) and 59% (Group 4). These results suggest that extending the interval time between PMSG and hCG and giving GnRH in addition to the standard PMSG and hCG treatments can improve IVF fertility rate of 129S1/SvImJ mouse strains significantly.

  12. Nitrogen-fertilization rate and soil nitrate distribution for microirrigated sugarcane

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, C.D. (Univ. of Florida, Bradenton (USA)); Green, R.E.; Khan, M.A. (Univ. of Hawaii, Honolulu (USA)); Santo, L.T. (Hawaiian Sugar Planters' Association, Honolulu (USA))

    Concern continues to grow over the fate of chemicals used in agricultural production and the associated potential for groundwater contamination. management practices can directly influence the efficiency of inorganic fertilizer use by crops, and can effect the amount that moves away from the root zone. A field study was conducted to investigate the effect of three N-fertilization rates (17.8, 9.1, and 6.0 kg ha{sup {minus}1} wk{sup {minus}1}) on NO{sub 3} distribution and movement for the first 24 wk of growth of microirrigated sugarcane (Saccharum officinarum L.) grown on a Wahiawa silty clay (clayey, kaolinitic, isohyperthermic Tropeptic Eutrustox). One uncropped treatment receiving 9.1 kg ha{sup {minus}1} wk{sup {minus}1} was included for evaluation without crop uptake. The plots received irrigation daily, with N being applied once weekly. Clusters of soil-solution extraction tubes were installed at depths of 15, 45, and 75 cm from the soil surface and 0, 30.5, 61, 91.5, and 122 cm away from microirrigation emitters to determine NO{sub 3} distribution patterns on a weekly basis. Soil water potential was monitored with tensiometers placed at similar locations. Results showed that all N levels were applied excessively early in the season and exhibited NO{sub 3} leaching beyond the root zone. Data collected at 22 wk after planting showed that the 6.0 kg ha{sup {minus}1} wk{sup {minus}1} rate had low NO{sub 3} concentrations through the soil profile, indicating a N-rate closer to crop requirements. Daily irrigation applications were probably excessive and may have contributed to loss of NO{sub 3} from the root zone for all treatments. This study demonstrated that a dynamic approach to fertilization and irrigation needs to be developed to minimize water and nutrient losses from the crop root zone.

  13. Nitrogen and Phosphorus Runoff Losses from Orchard Soils in South China as Affected by Fertilization Depths and Rates

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effects of different fertilization treatments on total N and P concentrations of surface runoff in a Chinese chestnut(Castanea mollissima Blume)orchard in Dongyuan County,Guangdong Province,China.In such orchards,fertilizer was typically applied in two short furrows or pits on either side of each tree.Treatments included three application depths(surface,10 era and 20 cm),and three application rates(low,median and high).Results showed that 90.5% of the runoff water samples had a total N concentration higher than 0.35 mg L-1 and 54.2% had a total P concentration higher than 0.1 mg L-1.Fertilizer application at all depths and at all but the lowest rate significantly increased total N and P concentrations in runoff water.Fertilization with chemical compound fertilizer at a soil depth of 20 cm prodiuced significantly lower(P<0.05)total N concentration in runoff than both surface and 10-cm depth fertilization,and significantly lower(P<0.05)total P concentration in runoff than surface fertilization.Total N and P concentrations in runoff significantly increased with the application rate of organic fertilizers.With the exception of total P concentrations,which were not significantly different between the control and fertilization at a rate of 119 kg P ha-1 in organic form,all the other fertilization treatments produced significantly higher total N and total P concentrations in runoff than the control.A fertilization depth ≥ 20 cm and an application rate ≤ 72 kg N ha-1 or 119 kg P ha-1 for compound organic fertilizer was suggested to substantially reduce N and P runoff losses from hillslope orchards and to protect receiving waters in South China.

  14. 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.

  15. The functional transfer of genes from the mitochondria to the nucleus: the effects of selection, mutation, population size and rate of self-fertilization.

    Science.gov (United States)

    Brandvain, Yaniv; Wade, Michael J

    2009-08-01

    The transfer of mitochondrial genes to the nucleus is a recurrent and consistent feature of eukaryotic genome evolution. Although many theories have been proposed to explain such transfers, little relevant data exist. The observation that clonal and self-fertilizing plants transfer more mitochondrial genes to their nuclei than do outcrossing plants contradicts predictions of major theories based on nuclear recombination and leaves a gap in our conceptual understanding how the observed pattern of gene transfer could arise. Here, with a series of deterministic and stochastic simulations, we show how epistatic selection and relative mutation rates of mitochondrial and nuclear genes influence mitochondrial-to-nuclear gene transfer. Specifically, we show that when there is a benefit to having a mitochondrial gene present in the nucleus, but absent in the mitochondria, self-fertilization dramatically increases both the rate and the probability of gene transfer. However, absent such a benefit, when mitochondrial mutation rates exceed those of the nucleus, self-fertilization decreases the rate and probability of transfer. This latter effect, however, is much weaker than the former. Our results are relevant to understanding the probabilities of fixation when loci in different genomes interact.

  16. 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.

  17. The Effect of Bio-Fertilizers on Plant Growth and Growth Rate of Grafted Avocado (Persea americana Mill.

    Directory of Open Access Journals (Sweden)

    Lazarus Agus Sukamto

    2014-01-01

    Full Text Available Avocado (Persea americana Mill. is considered the most nutritious of all fruits. Avocado fruit contain high unsaturated fat, protein, and energy. It could be eaten fresh for food, drinks, cooking, and cosmetics. Recently, it has become a significant commodity in international trade. Indonesia is the 2nd avocado producing country, but only little quantity of avocado fruits could be exported. The farmers usually grow avocado plants from the seeds, without proper fertilizers in their backyards or small gardens. The problems could be solved by using grafted plants, proper fertilizers, and growing in a large scale of areas. This research was conducted to find out the effect of two liquid bio-fertilizers namely Mega Rhizo and Beyonic StarTmik on the plant growth and growth rate of grafted avocado plants. Some plant growths and growth rates of grafted avocado were influenced significantly by genotype accession, kind of bio-fertilizer, and weather (temperature.  Plant growth and growth rate of most avocado accessions were not significant differences to bio-fertilizer applications, but some avocado accessions on certain months were significant differently. Growth rate ranks of plant height based on accession were no. 10, 28, 13, 1, 5, 2, and 14 consecutively. Those of canopy width were no. 28, 10, 1, 2, 14, 5, and 13 consecutively. Those of trunk diameters were no. 28, 10, 2, 5, 1, 13, and 14 consecutively. All growth rate ranks based on bio-fertilizer were Mega Rhizo, Beyonic StarTmik, and control consecutively.

  18. Higher abnormal fertilization, higher cleavage rate, and higher arrested embryos rate were found in conventional IVF than in intracytoplasmic sperm injection.

    Science.gov (United States)

    Ming, Li; Yuan, Chen; Ping, Liu; Jie, Qiao

    2015-01-01

    The aim of this study was to investigate whether performing different fertilization technologies (intracytoplasmic sperm injection [ICSI] and in vitro fertilization [IVF]) may affect the result of fertilization in the normal fertilization cycles. The authors performed a retrospective analysis of 164 cycles using sibling oocytes in combined IVF/ICSI with achieved a normal fertilization ( ≥ 25%) both conventional IVF and ICSI in this infertility centre. It was found that there were no differences in 2PN rate (70.25% vs 70.60%), but higher cleavage rate in ICSI than IVF insemination (98.99% vs 96.81%), higher arrested embryos rate in IVF than ICSI in 2PN group (20.00% vs 13.95%), and higher abnormal fertilization IPN (3.87% vs 1.92%) and 3PN (3.63 vs 0.854%) in IVF than ICSI. There were some differences fertilization outcomes between ICSI and IVF, which may be related to different procedures between two techniques.

  19. Recombinant fetuin-B protein maintains high fertilization rate in cumulus cell-free mouse oocytes.

    Science.gov (United States)

    Dietzel, E; Floehr, J; Van de Leur, E; Weiskirchen, R; Jahnen-Dechent, W

    2017-01-01

    Does fetuin-B inhibit premature zona pellucida (ZP) hardening in mouse oocytes in vitro and thus increase IVF rate? Supplementation of oocyte in vitro maturation (IVM) media with recombinant mouse fetuin-B (rmFetuB) increased fertilization rate without affecting mouse embryo development into blastocysts. Mice deficient in fetuin-B are infertile owing to premature ZP hardening. Premature ZP hardening also occurs during oocyte IVM leading to decreased fertilization rate. We fertilized batches of 20-30 mouse metaphase II (Mll) stage oocytes from C57BL/6 mice with fresh sperm, and studied early embryo development until blastocyst hatching. Oocytes were maintained with or without rmFetuB during IVM and IVF. Exogenous rmFetuB was added to media prior to oocyte isolation. ZP hardening was quantified by chymotrypsin digestion timing and by counting attached sperm. In the absence of cumulus cells, rmFetuB dose-dependently inhibited ZP hardening and increased IVF rate (P = 0.039). Fetuin-B at ≥0.03 mg/ml also inhibited physiological, fertilization-triggered ZP hardening (indicated by increased sperm binding, P = 0.0002), without increasing embryo death. Exogenous rmFetuB increased IVF rate for up to 5 hours of IVM (P = 0.02 at 1 hour, P = 0.01 at 5 hours of IVM). Mll stage oocytes in this study were isolated from the ampullae of fetuin-B expressing mice. Thus, oocytes were protected against premature ZP hardening by endogenous fetuin-B. In humans and livestock, oocytes are usually isolated by follicle puncture before ovulation. In this situation, the deprivation of endogenous fetuin-B would occur earlier and the effect of exogenous fetuin-B in the IVF medium may be even more pronounced. Fertilization-triggered ZP hardening is essential for embryo development but in this study the effect of fetuin-B supplementation was only studied to blastocyst stage. Any influence of added fetuin-B on later embryo development after transplantation remains to be determined. The astacin

  20. Explaining the entrepreneurial activity rate of women: a macro-level perspective

    NARCIS (Netherlands)

    A.R. Thurik (Roy); I. Verheul (Ingrid)

    2003-01-01

    textabstractThe present study aims at explaining female entrepreneurship from a country perspective. Explanatory variables are derived from three streams of literature, including the literature on the determinants of entrepreneurship in general, on female labor force participation, and on

  1. Effects of types and application rates of nitrogen fertilizer on the development and nitrogen utilization of summer maize

    Institute of Scientific and Technical Information of China (English)

    Zhenxie YI; Pu WANG; Hongbin TAO; Hongfang ZHANG; Lixia SHEN

    2008-01-01

    To reduce nitrogen fertilizer (NF) loss and improve nitrogen use efficiency (NUE) in summer maize, the effects of the different application rates of three types of NF (urea, coated urea and compound fertilizer) on the growth and development and NUE of summer maize (cultivars: Zhengdan958 and Nongda108) were studied in 2004. The main findings of this study were: (1) The yields of the two cultivars increased significantly with each The increase in the yield of summer maize treated with compound fertilizer was greater than the yield of those treated with either of the other two fertilizers at the same application rate, while the differences among the three types of NF were not significant. (2) Grain number per ear of the two cultivars rose in relation to the increase in N application rate, while its relationship with the type of NF was very weak. The type of NF had a greater impact on 1000-grain weight, and a difference between cultivars was observed. (3) Leaf area index (LAI), dry matter weight and leaf chlorophyll content grew in relation to the increase in N application rate, and were improved more sharply by compound fertilizer or coated urea than by urea alone. (4) Compared to the results achieved with urea, the NUEs of summer maize treated with coated urea and compound fertilizer were higher but the nitrogen harvest index was not improved. In addition, the NUEs of three types of NF exhibited a genotype difference from summer maize.

  2. Investigate of Rates and Time of Applying Micronutrients Fertilizer on Traits Quality and Quantity of Safflower (Carthamus tinctorius L.

    Directory of Open Access Journals (Sweden)

    heshmat omidi

    2014-09-01

    Full Text Available Safflower (Carthamus tinctorius L. is one of the oilseed crops adaption on a wide range circumstance of Iran edaphic, which deficiency of micronutrients cause in its quality and quantity yield. To assign the effect of amount and utility period of micronutrients fertilizer on grain yield, yield components and characters of oil quality of safflower var Mexi141 an experiment by factorial base Randomized Completely Block Design (RCBD with three replications was carried out. The factors were including foliar spraying of micronutrients fertilizer at four levels (1-Without consuming of micronutrients fertilizer or Control (F1, apply 2.5 (F2, apply 3 (F3 and 4.5 (F4 Kg.ha-1, and time of utilization (T1= 3, T2=4 and T3=5 weeks fertilizer after silique formation arranged to plots. Results showed that the traits of start and end flowering, flowering period, the height of first reproductive branch (silique, number of lateral branch, number of grain per siliqe, siliqe diameter, grain yield, oil content and unsaturated fatty acids profile of oil were affected under rates and time of foliar spraying micronutrients fertilizer and its interaction. With rising consume of rates micronutrients fertilizer, the grain yield increased and the uppermost of its (1792.1 kg ha-1 achieved in foliar spraying of 3 kg ha-1 micronutrients fertilizer during four weeks after siliqe formation. Rate of fertilizer on unsaturated fatty acids content of oil had effect, in which the greatest amount of mono band fatty acid of oleic acid (18:1 (15.92 % were gets without using of micronutrients or foliar spraying of at least of micronutrients fertilizer., also the highest amount (75.97 % of diband fatty acid of linoleic acid (18:2 with using 4.5 kg.ha-1 of micronutrients, and the most of multiple band fatty acid (0.29 % of linolenic acid (18:3 was obtained with consuming 3 kg.ha-1 of micronutrients fertilizer. Interaction effect of micronutrients fertilizer and time application of

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

    Science.gov (United States)

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

    2011-06-01

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

  4. High Rates of Self-Fertilization in a Marine Ribbon Worm (Nemertea).

    Science.gov (United States)

    Caplins, Serena A; Turbeville, James M

    2015-12-01

    Organisms capable of self-fertilization ("selfing") typically exhibit two evolutionary syndromes: uniting high inbreeding depression with low levels of selfing, or low inbreeding depression with high levels of selfing. We examined the effect of inbreeding on fecundity and time to first reproduction in an apparently self-compatible, simultaneously hermaphroditic marine nemertean worm Prosorhochmus americanus. Adult and juvenile worms were raised in isolation or in pairs. Isolated worms produced significantly more offspring than paired worms (in the adult experiment), and did not exhibit inbreeding avoidance (in the juvenile experiment). The selfing rate of six natural populations was evaluated using 17 species-specific, microsatellite markers, and was consistent with preferential selfing (mean: 0.843, SD: 0.027). Our results showed that P. americanus exhibited an interesting suite of life-history traits, uniting high colonization potential through self-fertilization and high fecundity, with no dispersive larval stage, and with moderate levels of gene flow. We believe that P. americanus is an ideal model system for studies of mating system evolution, inbreeding, and sex allocation. © 2015 Marine Biological Laboratory.

  5. 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.

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

    Science.gov (United States)

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

    2015-06-01

    A field experiment was conducted to investigate the effects of fertilization methods, i.e., drip (DF) and furrow fertilization (GF), and nitrogen (N) application rates (25, 50, 75 g N · plant(-1) · time(-1)) on the dynamics of soil N vertical migration in a Populus x euramericana cv. 'Guariento' plantation. The results showed that soil NH4(+)-N and NO3(-)-N contents decreased with the increasing soil depth under different fertilization methods and N application rates. In the DF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-40 cm soil layer, and their contents ascended firstly and then descended, reaching their maximum values at the 5th day (211.1 mg · kg(-1)) and 10th day (128.8 mg · kg(-1)) after fertilization, respectively. In the GF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-20 cm layer, and the content of soil NO3(-)-N rose gradually and reached its maximum at the 20th day (175.7 mg · kg(-1)) after fertilization, while the NH4(+)-N content did not change significantly after fertilization. Overall, N fertilizer had an effect within 20 days in the DF treatment, and more than 20 days in the GF treatment. In the DF treatment, the content and migration depth of soil NH4(+)-N and NO3(-)-N increased with the N application rate. In the GF treatment, the NO3(-)-N content increased with the N application rate, but the NH4(+)-N content was not influenced. Under the DF treatment, the hydrolysis rate, nitrification rate and migration depth of urea were higher or larger than that under the GF treatment, and more N accumulated in deep soil as the N application rate increased. Considering the distribution characteristics of fine roots and soil N, DF would be a better fertilization method in P. xeuramericana cv. 'Guariento' plantation, since it could supply N to larger distribution area of fine roots. When the N application rate was 50 g · tree(-1) each time, nitrogen mainly distributed in the zone of fine roots and

  7. 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.

  8. 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; pprematuros (OR:1,1; IC:1,08-1,13; pprematuro (OR:1,1; IC:1,08-1,13; p<0,001), bebé con peso bajo al nacer (OR:1,1; IC:1,10-1,15; p<0,001) y puntuación de Apgar baja a los 5 minutes (OR:1,4; IC:1,34-1,45; p<0,001) fue superior para madres entre 15 y 19 años en comparación con madres ≥20 años, con mayores chances de resultados negativos para aquellas entre 10 y 14 años de edad. este estudio evidencia que las tasas de fertilidad entre las adolescentes siguen superiores en regiones de pobreza 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.

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

    Science.gov (United States)

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

    2014-07-01

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

  10. 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

  11. 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, live-birth rate for the first 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

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

    Science.gov (United States)

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

    2003-11-01

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

  13. 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

  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. Exchange Rates: Predictable but not Explainable? Data Mining with Leading Indicators and Technical Trading Rules

    OpenAIRE

    Brandl, Bernd

    2005-01-01

    This paper presents a data mining approach to forecasting exchange rates. It is assumed that exchange rates are determined by both fundamental and technical factors. The balance of fundamental and technical factors varies for each exchange rate and frequency. It is difficult for forecasters to establish the relative relevance of different kinds of factors given this mixture; therefore the utilization of data mining algorithms is advantageous. The approach applied uses a genetic...

  16. Explaining the Variation in Adoption Rates of the Information Content of Environmental Disclosure

    DEFF Research Database (Denmark)

    Fallan, Even

    2015-01-01

    of content. The absolute level of adoption rates is affected by company size and environmental risk. However, those content categories that have either relatively high or low adoption rates are consistent among the subsamples, regardless of these corporate characteristics. This consistent variation...

  17. Explaining the Variation in Adoption Rates of the Information Content of Environmental Disclosure

    DEFF Research Database (Denmark)

    Fallan, Even

    2015-01-01

    Purpose: - Corporate management decides what types of environmental information content to disclose/adopt. It is explored whether internal context - decision-makers’ perception of characteristics of the information content - might predict the variation in adoption rates of different types...... of content, and whether innovation adoption theory might represent important factors of this decision-making process. Design/methodology/approach: - Actual adoption rates of 13 information content categories are computed using content analysis of annual reports for 62 listed companies. Each content category...... is seen as an innovation the company decides to adopt or not. Interviews with management in several companies illustrate the decision process of disclosure, and help predict adoption rates. Predicted and actual adoption rates are compared. Findings: - Adoption rates vary considerably among the 13 types...

  18. Putative extremely high rate of proteome innovation in lancelets might be explained by high rate of gene prediction errors.

    Science.gov (United States)

    Bányai, László; Patthy, László

    2016-08-01

    A recent analysis of the genomes of Chinese and Florida lancelets has concluded that the rate of creation of novel protein domain combinations is orders of magnitude greater in lancelets than in other metazoa and it was suggested that continuous activity of transposable elements in lancelets is responsible for this increased rate of protein innovation. Since morphologically Chinese and Florida lancelets are highly conserved, this finding would contradict the observation that high rates of protein innovation are usually associated with major evolutionary innovations. Here we show that the conclusion that the rate of proteome innovation is exceptionally high in lancelets may be unjustified: the differences observed in domain architectures of orthologous proteins of different amphioxus species probably reflect high rates of gene prediction errors rather than true innovation.

  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. Decreasing trends in malnutrition prevalence rates explained by regular audits and feedback.

    Science.gov (United States)

    Meijers, Judith M M; Candel, Math J M M; Schols, Jos M G A; van Bokhorst-de van der Schueren, Marian A E; Halfens, Ruud J G

    2009-07-01

    To our knowledge, no studies have analyzed the influence of annual audit and feedback on the prevalence rates of malnutrition. This study analyzes the trend of malnutrition prevalence rates between 2004 and 2007 and the effects of previous audits and feedback from the annual Dutch National Prevalence Measurement of Care Problems (LPZ) and the effect of the participation in Dutch national improvement programs. From 2004 to 2007, an annual multicenter study was performed in Dutch hospitals, nursing homes, and home care organizations using a standardized questionnaire involving measurements at institutional, ward, and patient levels. The data were analyzed by logistic multilevel analysis. Nutritional status was assessed by BMI, undesired weight loss, and nutritional intake. In total, 80 hospitals, 141 nursing homes, and 48 home care organizations participated. The prevalence of malnutrition tended to decrease in hospitals and home care over the years. In nursing homes, prevalence rates were stable. Furthermore, the more often hospitals and home care organizations participated in the annual LPZ audits, the lower the prevalence rate of malnutrition (P malnutrition prevalence rates have decreased over the last 4 y in hospitals and home care in The Netherlands. Participation in the LPZ and involvement in national improvement programs positively influenced these malnutrition prevalence rates, possibly indicating that increasing awareness and actively working toward improvement could be important in lowering these rates.

  1. The value of microscopic semen motility assessment at collection for a commercial artificial insemination center, a retrospective study on factors explaining variation in pig fertility.

    NARCIS (Netherlands)

    Broekhuijse, M.L.W.J.; Sostaric, E.; Feitsma, H.; Gadella, B.M.

    2012-01-01

    This study was conducted to evaluate the relationship between boar and semen related parameters and the variation in field fertility results. In 8 years time semen insemination doses from 110 186 ejaculates of 7429 boars were merged to fertility parameters of inseminations of 165 000 sows and these

  2. Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and lts lnfluences on Cotton Yield in the Yangtze River Valley

    Institute of Scientific and Technical Information of China (English)

    Naiyin XU; Jian Ll

    2014-01-01

    Objective] The historical evolution pattern of nitrogen (N), phosphorus (P) and potassium (K) fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

  3. Self-rated literacy level does not explain educational differences in health and disease

    DEFF Research Database (Denmark)

    Fransen, Mirjam P; Rowlands, Gillian; Leenaars, Karlijn Ef;

    2014-01-01

    BACKGROUND: Although literacy is increasingly considered to play a role in socioeconomic inequalities in health, its contribution to the explanation of educational differences in health has remained unexplored. The aim of this study was to investigate the contribution of self-rated literacy...... to educational differences in health. METHODS: Data was collected from the Healthy Foundation and Lifestyle Segmentation Dataset (n = 4257). Self-rated literacy was estimated by individuals' self-reported confidence in reading written English. We used logistic regression analyses to assess the association...... between educational level and health (long term conditions and self-rated health). Self-rated literacy and other potential explanatory variables were separately added to each model. For each added variable we calculated the percentage change in odds ratio to assess the contribution to the explanation...

  4. Exercise training bradycardia is largely explained by reduced intrinsic heart rate.

    Science.gov (United States)

    Bahrainy, Samira; Levy, Wayne C; Busey, Janet M; Caldwell, James H; Stratton, John R

    2016-11-01

    Resting heart rate (RHR) declines with exercise training. Possible mechanisms include: 1) increased parasympathetic tone, 2) decreased responsiveness to beta-adrenergic stimulation, 3) decreased intrinsic heart rate or 4) combination of these factors. To determine whether an increase in resting parasympathetic tone or decrease in response to beta-adrenergic stimulation contributes to the decrease in RHR with training. 51 screened healthy subjects aged 18-32 (n=20, mean age 26, 11 female) or 65-80 (n=31, mean age 69, 16 female) were tested before and after 6months of supervised exercise training. Heart rate response to parasympathetic withdrawal was assessed using atropine and beta-adrenergic responsiveness during parasympathetic withdrawal using isoproterenol. Training increased VO2 max by 17% (28.7±7.7 to 33.6±9.20ml/kg/min, Pincrease in heart rate in response to parasympathetic withdrawal was unchanged after training (+37.3±12.8 pre vs. +36.4±12.2 beats per min post, P=0.41). There was no change in the heart rate response to isoproterenol after parasympathetic blockade with training (+31.9±10.9 pre vs. +31.0±12.0 post beats per min, P=0.56). The findings were similar in all four subgroups. We did not find evidence that an increase in parasympathetic tone or a decrease in responsiveness to beta-adrenergic activity accounts for the reduction in resting heart rate with exercise training. We suggest that a decline in heart rate with training is most likely due to decrease in the intrinsic heart rate. Published by Elsevier Ireland Ltd.

  5. The combined effects of reactant kinetics and enzyme stability explain the temperature dependence of metabolic rates.

    Science.gov (United States)

    DeLong, J P; Gibert, J P; Luhring, T M; Bachman, G; Reed, B; Neyer, A; Montooth, K L

    2017-06-01

    A mechanistic understanding of the response of metabolic rate to temperature is essential for understanding thermal ecology and metabolic adaptation. Although the Arrhenius equation has been used to describe the effects of temperature on reaction rates and metabolic traits, it does not adequately describe two aspects of the thermal performance curve (TPC) for metabolic rate-that metabolic rate is a unimodal function of temperature often with maximal values in the biologically relevant temperature range and that activation energies are temperature dependent. We show that the temperature dependence of metabolic rate in ectotherms is well described by an enzyme-assisted Arrhenius (EAAR) model that accounts for the temperature-dependent contribution of enzymes to decreasing the activation energy required for reactions to occur. The model is mechanistically derived using the thermodynamic rules that govern protein stability. We contrast our model with other unimodal functions that also can be used to describe the temperature dependence of metabolic rate to show how the EAAR model provides an important advance over previous work. We fit the EAAR model to metabolic rate data for a variety of taxa to demonstrate the model's utility in describing metabolic rate TPCs while revealing significant differences in thermodynamic properties across species and acclimation temperatures. Our model advances our ability to understand the metabolic and ecological consequences of increases in the mean and variance of temperature associated with global climate change. In addition, the model suggests avenues by which organisms can acclimate and adapt to changing thermal environments. Furthermore, the parameters in the EAAR model generate links between organismal level performance and underlying molecular processes that can be tested for in future work.

  6. Paternal Age Explains a Major Portion of De Novo Germline Mutation Rate Variability in Healthy Individuals

    Science.gov (United States)

    Bourassa, Cynthia V.; Lemieux Perreault, Louis-Philippe; Legault, Marc-André; Barhdadi, Amina; Ambalavanan, Amirthagowri; Brendgen, Mara; Vitaro, Frank; Noreau, Anne; Dionne, Ginette; Tremblay, Richard E.; Dion, Patrick A.; Boivin, Michel; Dubé, Marie-Pierre; Rouleau, Guy A.

    2016-01-01

    De novo mutations (DNM) are an important source of rare variants and are increasingly being linked to the development of many diseases. Recently, the paternal age effect has been the focus of a number of studies that attempt to explain the observation that increasing paternal age increases the risk for a number of diseases. Using disease-free familial quartets we show that there is a strong positive correlation between paternal age and germline DNM in healthy subjects. We also observed that germline CNVs do not follow the same trend, suggesting a different mechanism. Finally, we observed that DNM were not evenly distributed across the genome, which adds support to the existence of DNM hotspots. PMID:27723766

  7. The Influence of Form and Rate on the Efficacy of Matrix-Based Fertilizers to Reduce Nutrient Leaching

    Directory of Open Access Journals (Sweden)

    James A. Entry

    2009-01-01

    Full Text Available We tested the efficacy of matrix-based fertilizers (MBFs to reduce NO3, NH4, and total phosphorus (TP leaching compared to Osmocote 14-14-14, a commercial slow release fertilizer (SRF in greenhouse column studies. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF4 and more tightly bound compounds (MBF5 with A12(SO43⋅18H2O and/or Fe2(SO43⋅3H2O and with high ionic exchange compounds starch, chitosan, and lignin. When N and P are released, the chemicals containing these nutrients in the MBF bind N and P to an Al2(SO43⋅18H2O and/or Fe2(SO43⋅3H2O starch- chitosan- lignin matrix. SRF leachate contained a greater amount of NO3, NH4, DRP, and TP than leachate from MBF4 and MBF5 regardless of whether fertilizers were pellets, banded or broadcast, or fertilizer rate. St Augustine grass growing in soils receiving MBF4 and MBF5 had decreased shoot biomass by 49% to 56% and decreased total biomass by 33% to 46% respectively as grass receiving SRF. Although further greenhouse and field testing are necessary, results of this initial investigation are promising and with further development, testing, and rate calibration should be competitive with commercial fertilizers in environmentally sensitive markets.

  8. Interactions between rate processes with different timescales explain counterintuitive foraging patterns of arctic wintering eiders

    NARCIS (Netherlands)

    Heath, J.P.; Gilchrist, H.G.; Ydenberg, R.C.

    2010-01-01

    To maximize fitness, animals must respond to a variety of processes that operate at different rates or timescales. Appropriate decisions could therefore involve complex interactions among these processes. For example, eiders wintering in the arctic sea ice must consider locomotion and physiology of

  9. Interactions between rate processes with different timescales explain counterintuitive foraging patterns of arctic wintering eiders

    NARCIS (Netherlands)

    Heath, J.P.; Gilchrist, H.G.; Ydenberg, R.C.

    2010-01-01

    To maximize fitness, animals must respond to a variety of processes that operate at different rates or timescales. Appropriate decisions could therefore involve complex interactions among these processes. For example, eiders wintering in the arctic sea ice must consider locomotion and physiology of

  10. Effects of a mindfulness-based intervention on fertility quality of life and pregnancy rates among women subjected to first in vitro fertilization treatment.

    Science.gov (United States)

    Li, Jing; Long, Ling; Liu, Yu; He, Wei; Li, Min

    2016-02-01

    Generally, undergoing an in vitro fertilization (IVF) treatment is an emotional and physical burden for the infertile woman, which may negatively influence the treatment outcome. We conducted a study to investigate the effectiveness of a mindfulness-based intervention (MBI) among women subjected to first IVF treatment at a fertility medical center in China. Among infertile women registered for their first IVF treatment, 58 completed the intervention, and 50 were assigned to a control group using a non-randomized controlled study. Standardized measures of mindfulness, self-compassion, emotion regulation difficulties, infertility-related coping strategies and fertility quality of life (FertiQoL) were endorsed pre- and post-MBI, and measure of pregnancy rates at the sixth months after the intervention. Both groups were shown to be equivalent at baseline. By the end of the intervention, women who attended the intervention revealed a significant increase in mindfulness, self-compassion, meaning-based coping strategies and all FertiQoL domains. Inversely, they presented a significant decrease in emotion regulation difficulties, active- and passive-avoidance coping strategies. Women in the control group did not present significant changes in any of the psychological measures. Moreover, there were statistically significant differences between participants in the pregnancy rates, the experiment group higher than the control group. Being fully aware of the present moment without the lens of judgment, seems to help women relate to their infertility and IVF treatment in new ways. This is beneficial for promoting their self-compassion, adaptive emotion regulation and infertility-related coping strategies, which, in turn, may influence the FertiQoL and pregnancy rates. The brief and nonpharmaceutical nature of this intervention makes it a promising candidate for women' use during first IVF treatment.

  11. Explaining the recent decrease in US infant mortality rate, 2007-2013.

    Science.gov (United States)

    Callaghan, William M; MacDorman, Marian F; Shapiro-Mendoza, Carrie K; Barfield, Wanda D

    2017-01-01

    The US infant mortality rate has been steadily decreasing in recent years as has the preterm birth rate; preterm birth is a major factor associated with death during the first year of life. The degree to which changes in gestational age-specific mortality and changes in the distribution of births by gestational age have contributed to the decrease in the infant mortality rate requires clarification. The objective of the study was to better understand the major contributors to the 2007-2013 infant mortality decline for the total population and for infants born to non-Hispanic black, non-Hispanic white, and Hispanic women. We identified births and infant deaths from 2007 and 2013 Centers for Disease Control and Prevention National Vital Statistics System's period linked birth and infant death files. We included all deaths and births for which there was a reported gestational age at birth on the birth certificate of 22 weeks or greater. The decrease in the infant mortality rate was disaggregated such that all of the change could be attributed to improvements in gestational age-specific infant mortality rates and changes in the distribution of gestational age, by week of gestation, using the Kitagawa method. Sensitivity analyses were performed to account for records in which the obstetric estimate of gestational age was missing and for deaths and births less than 22 weeks' gestation. Maternal race and ethnicity information was obtained from the birth certificate. The infant mortality rates after exclusions were 5.72 and 4.92 per 1000 live births for 2007 and 2013, respectively, with an absolute difference of -0.80 (14% decrease). Infant mortality rates declined by 11% for non-Hispanic whites, by 19% for non-Hispanic blacks, and by 14% for Hispanics during the period. Compared with 2007, the proportion of births in each gestational age category was lower in 2013 with the exception of 39 weeks during which there was an increase in the proportion of births from 30.1% in

  12. Disciplinary discourses: rates of cesarean section explained by medicine, midwifery, and feminism.

    Science.gov (United States)

    Lee, Amy Su May; Kirkman, Maggie

    2008-05-01

    In the context of international concern about increasing rates of cesarean sections, we used discourse analysis to examine explanations arising from feminism and the disciplines of medicine and midwifery, and found that each was positioned differently in relation to the rising rates. Medical discourses asserted that doctors are authorities on birth and that, although cesareans are sometimes medically necessary, women recklessly choose unnecessary cesareans against medical advice. Midwifery discourses portrayed medicine as paternalistic toward both women and midwifery, and feminist discourses situated birth and women's bodies in the context of a patriarchally structured society. The findings illustrate the complex ways in which this intervention in birth is discursively constructed, and demonstrate its significance as a site of disciplinary conflict.

  13. Trust and the demand for autonomy may explain the low rates of immunizations among nurses

    OpenAIRE

    2012-01-01

    Rates of vaccinations of healthcare workers with recommended vaccines are generally low in the developed countries. Our goals were to identify attitudes associated with self-reported vaccinations against pertussis and seasonal influenza among Israeli nurses in Mother and Child Healthcare Centers (MCHC) in the Haifa District. Over 100 nurses answered a self-administered questionnaire. Forty two percent of the nurses reported receiving the pertussis vaccine in the last five years and 44% report...

  14. A high power impulse magnetron sputtering model to explain high deposition rate magnetic field configurations

    Science.gov (United States)

    Raman, Priya; Weberski, Justin; Cheng, Matthew; Shchelkanov, Ivan; Ruzic, David N.

    2016-10-01

    High Power Impulse Magnetron Sputtering (HiPIMS) is one of the recent developments in the field of magnetron sputtering technology that is capable of producing high performance, high quality thin films. Commercial implementation of HiPIMS technology has been a huge challenge due to its lower deposition rates compared to direct current Magnetron Sputtering. The cylindrically symmetric "TriPack" magnet pack for a 10 cm sputter magnetron that was developed at the Center for Plasma Material Interactions was able to produce higher deposition rates in HiPIMS compared to conventional pack HiPIMS for the same average power. The "TriPack" magnet pack in HiPIMS produces superior substrate uniformity without the need of substrate rotation in addition to producing higher metal ion fraction to the substrate when compared to the conventional pack HiPIMS [Raman et al., Surf. Coat. Technol. 293, 10 (2016)]. The films that are deposited using the "TriPack" magnet pack have much smaller grains compared to conventional pack DC and HiPIMS films. In this paper, the reasons behind the observed increase in HiPIMS deposition rates from the TriPack magnet pack along with a modified particle flux model is discussed.

  15. Muscle-tendon mechanics explain unexpected effects of exoskeleton assistance on metabolic rate during walking.

    Science.gov (United States)

    Jackson, Rachel W; Dembia, Christopher L; Delp, Scott L; Collins, Steven H

    2017-06-01

    The goal of this study was to gain insight into how ankle exoskeletons affect the behavior of the plantarflexor muscles during walking. Using data from previous experiments, we performed electromyography-driven simulations of musculoskeletal dynamics to explore how changes in exoskeleton assistance affected plantarflexor muscle-tendon mechanics, particularly for the soleus. We used a model of muscle energy consumption to estimate individual muscle metabolic rate. As average exoskeleton torque was increased, while no net exoskeleton work was provided, a reduction in tendon recoil led to an increase in positive mechanical work performed by the soleus muscle fibers. As net exoskeleton work was increased, both soleus muscle fiber force and positive mechanical work decreased. Trends in the sum of the metabolic rates of the simulated muscles correlated well with trends in experimentally observed whole-body metabolic rate (R(2)=0.9), providing confidence in our model estimates. Our simulation results suggest that different exoskeleton behaviors can alter the functioning of the muscles and tendons acting at the assisted joint. Furthermore, our results support the idea that the series tendon helps reduce positive work done by the muscle fibers by storing and returning energy elastically. We expect the results from this study to promote the use of electromyography-driven simulations to gain insight into the operation of muscle-tendon units and to guide the design and control of assistive devices. © 2017. Published by The Company of Biologists Ltd.

  16. 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.

  17. 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)

  18. Net energy yield and carbon footprint of summer corn under different N fertilizer rates in the North China Plain

    Institute of Scientific and Technical Information of China (English)

    WANG Zhan-biao; WEN Xin-ya; ZHANG Hai-lin; LU Xiao-hong; CHEN Fu

    2015-01-01

    Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon (C) emissions. This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn (Zea mays L.). A ifeld experiment, including 0 (N0), 75 (N75), 150 (N150), 225 (N225), and 300 (N300) kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain (NCP). The results showed that grain yield, input energy, greenhouse gas (GHG) emissions, and carbon footprint (CF) were al increased with the increase of N rate, except net energy yield (NEY). The treatment of N225 had the highest grain yield (10 364.7 kg ha–1) and NEY (6.8%), but the CF (0.25) was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP. Comparing GHG emision compontents, N fertilizer (0–51.1%) was the highest and fol owed by electricity for irrigation (19.73–49.35%). We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efifciency and decrease GHG emissions in corn production.

  19. [Effects of drought stress and nitrogen fertilization rate on the accumulation of osmolytes in Jatropha curcas seedlings].

    Science.gov (United States)

    Yin, Li; Liu, Yong-An; Xie, Cai-Yong; Jiang, Xue; Wang, Yong-Jie; Li, Yin-Hua; Yan, Zhen; Hu, Ting-Xing

    2012-03-01

    A pot experiment with controlled water supply was conducted to study the effects of different drought stress degree (80% FC, 60% FC, 40% FC, and 20% FC) and nitrogen fertilization rate (0 g x pot(-1), 1.2 g x pot(-1), 3.6 g x pot(-1), and 6.0 g x pot(-1)) on the accumulation of osmolytes in different organs of Jatropha curcas seedlings. Under drought stress, the soluble protei and free proline in seedling shoots and roots and the soluble sugar in seedling shoots had a great accumulation, and the free proline content in seedling leaves had a great increase with increasing drought stress degree. Also under drought stress, the Na+, Ca2+, and Mg2+ all highly accumulated in seedling various organs, while K only accumulated greatly in shoots but slightly in leaves and roots. The effects of nitrogen fertilization on the accumulation of osmolytes in seedlings depended on drought stress degree and nitrogen fertilization rate. At 80% FC and 60% FC, increasing nitrogen fertilization rate could markedly promote the accumulation of osmolytes in the organs of J. curcas seedlings; at 40% FC, applying 6.0 g x pot(-1) weakened the promotion effect on the osmolytes accumulation; whereas at 20%, applying 1.2 g x pot(-1) made the plants have a higher capability in osmoregulation, but applying 3.6 g x pot(-1) and 6.0 g x pot(-1) had less promotion effect, and even, inhibited osmolytes accumulation.

  20. Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents

    Science.gov (United States)

    Martin, Thomas E.; Oteyza, Juan C.; Mitchell, Adam E.; Potticary, Ahva L.; Lloyd, P.

    2016-01-01

    Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.

  1. Heterogeneous Rates of Molecular Evolution and Diversification Could Explain the Triassic Age Estimate for Angiosperms.

    Science.gov (United States)

    Beaulieu, Jeremy M; O'Meara, Brian C; Crane, Peter; Donoghue, Michael J

    2015-09-01

    Dating analyses based on molecular data imply that crown angiosperms existed in the Triassic, long before their undisputed appearance in the fossil record in the Early Cretaceous. Following a re-analysis of the age of angiosperms using updated sequences and fossil calibrations, we use a series of simulations to explore the possibility that the older age estimates are a consequence of (i) major shifts in the rate of sequence evolution near the base of the angiosperms and/or (ii) the representative taxon sampling strategy employed in such studies. We show that both of these factors do tend to yield substantially older age estimates. These analyses do not prove that younger age estimates based on the fossil record are correct, but they do suggest caution in accepting the older age estimates obtained using current relaxed-clock methods. Although we have focused here on the angiosperms, we suspect that these results will shed light on dating discrepancies in other major clades. ©The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Tactile perception: do distinct subpopulations explain differences in mislocalization rates of stimuli across fingertips?

    Science.gov (United States)

    Warren, Jay P; Tillery, Stephen I Helms

    2011-11-07

    In a previous study we were able to demonstrate that the Cutaneous Rabbit Effect (CRE) could be induced across fingertips using a form of the reduced rabbit paradigm and electrotactile stimuli. The CRE, as used here, is an illusory phenomenon where two stimuli are rapidly at a site and then a stimulus is presented to a nearby site. The perception of the second of the stimuli is not at its presented location but at a site between the first and last stimuli. In this experiment, though the overall population did perceive the mislocalized stimuli as the CRE would predict, some subjects were very infrequently observed to mislocalize stimuli due to the CRE or other effects. Here we further examine this phenomena, attempting to identify whether a subpopulation exists that rarely mislocalizes stimuli on their fingertips. To test for this subpopulation, we reexamined the collected data from the previously published experiment and other unpublished data relating to that study. By examining these data for rates of mislocalization utilizing our previous metric we identified that there is a perceptual subpopulation that very infrequently misidentifies the location of a fingertip stimulus.

  3. Two Mechanisms: The Role of Social Capital and Industrial Pollution Exposure in Explaining Racial Disparities in Self-Rated Health.

    Science.gov (United States)

    Ard, Kerry; Colen, Cynthia; Becerra, Marisol; Velez, Thelma

    2016-10-19

    This study provides an empirical test of two mechanisms (social capital and exposure to air pollution) that are theorized to mediate the effect of neighborhood on health and contribute to racial disparities in health outcomes. To this end, we utilize the Social Capital Benchmark Study, a national survey of individuals nested within communities in the United States, to estimate how multiple dimensions of social capital and exposure to air pollution, explain racial disparities in self-rated health. Our main findings show that when controlling for individual-confounders, and nesting within communities, our indicator of cognitive bridging, generalized trust, decreases the gap in self-rated health between African Americans and Whites by 84%, and the gap between Hispanics and Whites by 54%. Our other indicator of cognitive social capital, cognitive linking as represented by engagement in politics, decreases the gap in health between Hispanics and Whites by 32%, but has little impact on African Americans. We also assessed whether the gap in health was explained by respondents' estimated exposure to toxicity-weighted air pollutants from large industrial facilities over the previous year. Our results show that accounting for exposure to these toxins has no effect on the racial gap in self-rated health in these data. This paper contributes to the neighborhood effects literature by examining the impact that estimated annual industrial air pollution, and multiple measures of social capital, have on explaining the racial gap in health in a sample of individuals nested within communities across the United States.

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

    Science.gov (United States)

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

  5. 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.

  6. [Values of the sperm deformity index, acrosome abnormity rate, and sperm DNA fragmentation index of optimized sperm in predicting IVF fertilization failure].

    Science.gov (United States)

    Jiang, Wei-jie; Jin, Fan; Zhou, Li-ming

    2016-02-01

    To investigate the values of the sperm deformity index (SDI), acrosome abnormity rate (AAR), and DNA fragmentation index (DFI) of optimized sperm in the prediction of fertilization failure (fertilization rate fertilization (IVF). We selected 695 cycles of conventional IVF for pure oviductal infertility in this study, including 603 cycles of normal fertilization and 92 cycles of fertilization failure. On the day of oocyte retrieval, we examined sperm morphology, acrosome morphology, and DNA fragmentation using the Diff-Quik, PSA-FITC and SCD methods. We established the joint predictor (JP) by logistic equation and analyzed the values of different parameters in predicting fertilization failure with the receiver operating characteristic (ROC) curve. The fertilization rate was negatively correlated with SDI (r = - 0.07; P = 0.03), AAR (r = -0.49; P fertilization group were 1.24 ± 0.20, (7.75 ± 2.28)%, and (7.87 ± 3.15)%, and those in the fertilization failure group were 1.42 ± 0.15, (12.02 ± 3.06)%, and (13.32 ± 4.13)%, respectively, all with statistically significant differences between the two groups (P fertilization failure ( OR = 2.68, 14.11, and 3.85; P = 0.01, fertilization failure were approximately 1.45, 10%, and 12%. The SDI, AAR and DFI of optimized sperm are closely associated with the fertilization rate, and all have the value for predicting fertilization failure in IVF. The AAR is more valuable than the other single predictors, but JP is more effective than the AAR.

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

    Science.gov (United States)

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

    2016-05-01

    Maharashtra is one of the states in India that has witnessed one of the highest rates of farmer suicides as proportion of total number of suicides. Most of the farmer suicides in Maharashtra are from semi-arid divisions such as Marathwada where cotton has been historically grown. Other dominant crops produced include cereals, pulses, oilseeds and sugarcane. Cotton (fibers), oilseeds and sugarcane providing highest value addition per unit cultivated area and cereals and pulses the least. Hence it is not surprising that smallholders take risks growing high value crops without "visualising" the risks it entails such as those corresponding to price and weather shocks.We deploy recently developed smallholder socio-hydrology modelling framework to understand the underlying dynamics of the crisis. It couples the dynamics of six main variables that are most relevant at the scale of a smallholder: water storage capacity (root zone storage and other ways of water storage), capital, livestock, soil fertility and fodder biomass. The hydroclimatic variability is accounted for at sub-annual scale and influences the socio-hydrology at annual scale. The model incorporates rule-based adaptation mechanisms (e.g., adjusting expenditures on food and fertilizers, selling livestocks) of smallholders when they face adverse conditions, such as high variability in rainfall or in agricultural prices. The model is applied to two adjoining divisions of Maharashtra: Marathwada and Desh. The former is the division with relatively higher farmer suicide rates than the latter. Diverse spatial data sets of precipitation, potential evaporation, soil, agricultural census based farm inputs, cropping pattern and prices are used to understand the dynamics of small farmers in these divisions, and to attribute farmer distress rates to soil types, hydroclimatic variability and crops grown.Comparative socio-hydrologic assessment across the two regions confirms existing narratives: low (soil) water storage

  8. Reduced spin-down rate of PSR J0738-4042 explained as due to an asteroid disruption event

    Science.gov (United States)

    Yu, Yong-Bo; Huang, Yong-Feng

    2016-05-01

    Long term observations by Brook et al. reveal that the derivative of rotational frequency of PSR J0738-4042 changed abruptly in 2005. Originally, the spin-down rate was relatively stable, with the rotational frequency derivative being -1.14×10-14 s-2. After September 2005, the derivative began to rise. About 1000 days later, it arrived at another relatively stable value of about -0.98 × 10-14 s-2, indicating that the pulsar is spinning-down relatively slowly. To explain the observed change in spin-down rate, we resort to an asteroid disrupted by PSR J0738-4042. In our model, the orbital angular momentum of the asteroid is assumed to be parallel to that of the rotating pulsar, so that the pronounced reduction in the spin-down rate can be naturally explained as due to the transfer of angular momentum from the disrupted material to the central pulsar. The derived magnetospheric radius is about 7.0 × 109 cm, which is smaller than the tidal disruption radius (8.7 × 1010 cm). Our model is self-consistent. It is shown that the variability in the spin-down rate of PSR J0738-4042 can be quantitatively accounted for by accretion from the asteroid disrupted by the central pulsar.

  9. Top-dressing nitrogen fertilizer rate contributes to decrease culm physical strength by reducing structural carbohydrate content in japonica rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wu-jun; WANG Shao-hua; WU Long-mei; DING Yan-feng; WENG Fei; WU Xiao-ran; LI Gang-hua; LIU Zheng-hui; TANG She; DING Cheng-qiang

    2016-01-01

    Lodging is an important factor limiting rice yield and quality by bending or breaking stem injaponica rice (Oryza sativaL.) production. The objectives of this study were to determine the mechanism of lodging resistance injaponica rice as affected by carbohydrate components, especialy its related arrangement in culm tissue and response to top-dressing nitrogen (N) fertilizer. Field experiments were conducted in Danyang County, Jiangsu Province, China, by using twojaponica rice vari-eties Wuyunjing 23 (lodging-resistance variety) and W3668 (lodging-susceptible variety) with three top-dressing N fertilizer rates (0, 135 and 270 kg N ha–1) in 2013 and 2014. Lodging related physical parameters, morphological characteristics and stem carbohydrate components were investigated at 30 d after ful heading stage. Results showed that with increasing N fertilizer rates, the lodging rate and lodging index increased rapidly primarily due to signiifcant reduction of breaking strength in twojaponica rice varieties. Correlation analysis revealed that breaking strength was signiifcantly and positively correlated with bending stress, but negatively correlated with section modulus, except for signiifcant correlation at W3668 in 2014. Higher stem plumpness status and structural carbohydrate contents signiifcantly enhanced stem stiffness, despite of lower non-structural carbohydrate. With higher N fertilizer rate, the culm wal thickness was almost identical, and culm diameter increased slightly. The structural carbohydrates, especialy for lignin content in culm, reduced signiifcantly under high N rate. Further histochemical staining analysis revealed that high N treatments decreased the lignin deposition rapidly in the sclerenchyma cels of mechanical tissue, large vascular bundle and smal vascular bundle region, which were consistent with reduction of bending stress, especialy for W3668 and thus, resulted in poor stem strength and higher lodging index. These results suggested that

  10. 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.

  11. Correlation and Regressive Model Between Spikelet Fertilized Rate and Temperature in Inter-Subspecific Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To study the sensitivity of inter-subspecific hybrid rice to climatic conditions, the spikelet fertilized rate (SFR) of four types of rice including indica-japonica hybrid, intermediate hybrid, indica and japonica were analyzed during 2000-2004. The inter-subspecific hybrids showed lower SFR, and much higher fluctuation under various climatic conditions than indica and japonica rice, showing the inter-subspecific hybrids were sensitive to ecological conditions. Among 12 climatic factors, the key factor affecting rice SFR was temperature, with the most significant factor being the average temperature of the seven days around panicle flowering (T7). A regressive equation of SFR-temperature by T7, and a comprehensive synthetic model by four important temperature indices were put forward. The optimum temperature for inter-subspecific hybrids was estimated to be 26.1-26.6 ℃, and lower limit of safe temperature to be 22.5-23.3 ℃ for panicle flowering, showing higher by averagely 0.5℃ and 1.7℃, respectively, to be compared with indica and japonica rice. This suggested that inter-subspecific hybrids require proper climatic conditions. During panicle flowering, the suitable daily average temperature was 23.3-29.0 ℃, with the fittest one at 26.1-26.6 ℃. For an application example, optimum heading season for inter-subspecific hybrids in key rice growing areas in China was as same as common pure lines, while inferior limit for safe date of heading was about a ten-day period earlier than those of common pure lines.

  12. 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.

  13. 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...

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

    Science.gov (United States)

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

    2015-08-01

    Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs and explore how pre-incubation of eggs in freshwater for 0min, 0.5min, 1min, and 10min interacts with different sperm ratios. Fertilization success ranged from 29.7% at 430:1 to 84.2% at 430,000:1. Pre-incubation time had no effect on fertilization success at 430,000:1 and 43,000:1 sperm to egg ratios, while it was significant at the 4300:1 and 430:1 ratios. The use of adequate experimental suboptimal sperm to egg ratio revealed a positive effect of pre-incubation time, such that at the 430:1 ratio, 0.5min pre-incubation increased the fertilization rate than 10min. At 0min pre-incubation the proportion of fertilized eggs increased at the 430,000:1 ratio, while at 1min fertilization increased at the 4300:1 ratio. At the 10min pre-incubation time, fertilization increased at the 43,000:1 ratio. Moreover, at the 0.5min pre-incubation time, the 43,000:1 ratio increased the fertilization rate than the 430:1 ratio. Generally, for 430:1 ratio, the fertilization rate is lower than in control. Transmission electron microscopy showed that pre-incubation of eggs in water for fertilization can enhance fertilization rate of sterlet. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Influence of Bacillus subtilis on the physiological state of wheat and the microbial community of the soil under different rates of nitrogen fertilizers

    Science.gov (United States)

    Pishchik, V. N.; Vorobyev, N. I.; Moiseev, K. G.; Sviridova, O. V.; Surin, V. G.

    2015-01-01

    The effects of inoculation with bacteria Bacillus subtilis strain No. 2 (hereinafter, B. subtilis 2) and of the physical properties of the soil on the physiological state of wheat ( Triticum aestivum L.) plants and the soil microbial community under different rates of nitrogen fertilizers are studied. In the field, the physiological state of wheat was evaluated using the optical vegetation index. It was found that (1) the impact of B. subtilis 2 on plants decreases with an increase in the rate of fertilizers and soil bulk density, (2) the inoculation of wheat with bacteria enhances the resistance of the plant-microbial system to the adverse impact of high rates of nitrogen fertilizers due to the rearrangement of bacteria in rhizosphere ecological niches, and (3) the highest agronomic efficiency of nitrogen fertilizers is observed in wheat inoculation with B. subtilis 2 at the rate of nitrogen fertilization of 120 kg/ha.

  16. Effect of Rate and Split Application of Nitrogen Fertilizer on Yield and Yield Components in (Bahar Hybrid Rice Cultivar

    Directory of Open Access Journals (Sweden)

    M Nahvi

    2011-02-01

    Full Text Available Abstract In order to determinate the optimum nitrogen rate and time for split N application based on phonological stages of Bahar hybrid rice, an experiment was conducted over two years (2007-2008 using a randomized complete block design with three replications at Rice Research Institute of Iran (RRII farm, Rasht. Factorial arrangement of the following factors was used: three N rates (90, 120 and 150 kg pure N in hectare and six different phonological stages (T1: using leaf color chart with number 4; T2; 1/3 base fertilizer, 1/3 in rise primary bud stage, 1/3 in booting stage; T3; 1/3 base fertilizer, 1/3 in tillering stage, 1/3 in rise primary bud stage; T4: 1/2 base fertilizer, 1/4 in tillering stage, 1/4 in booting stage; T5: 1/3base fertilizer, 1/3in tillering stage, 1/3 in booting stage; T6; 2/3 base fertilizer, 1/3 in rise primary bud stage with a control plot in each replication. After sowing in bed nursery the twenty days old seedlings were transplanted in the experimental plots. Results of analysis of variance clearly showed significant differences between different phonological stages on many characteristics. Means differences were highly significant for grain yield. The T6 treatment produced the highest yield of 8.373 and 7.920 t ha-1 in two years, respectively. However, 120 kg N ha-1 when applied as T5, produced the highest yield (8.760 t ha-1. Combined analysis of variance showed that yield and yield components.were affected by time of N application. Combined comparison of means also showed that the T5 treatment and 120 kg N ha-1 produced the highest yield of 7.925 and 7.514 t ha-1 in the first and second year, respectively. According to the results, it can be recommended that for Bahar hybrid rice maximum yield could be achieved by application of 120 kg N ha-1 when split as defined in T5 (1/3 based fertilizer + 1/3 first tillering stage + 1/3 booting stage. Keywords: Hybrid rice, Leaf Color Chart (LCC, Nitrogen fertilizer

  17. Migrant fertility differentials in Ecuador.

    Science.gov (United States)

    Rundquist, F; Brown, L A

    1989-01-01

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

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

    Science.gov (United States)

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

    2012-12-01

    interrow resulting in total direct emissions of about 1.5 to 2.3 kg N ha-1 yr-1 (area weighted average of row and interrow). Compared with the IPCC approach (EF = 0.01) these values are rather low which can be explained by high rates of simulated and measured nitrate leaching across all N treatments (row: 214 - 240 kg N ha-1 yr-1; interrow: 259 - 263 kg N ha-1 yr-1). Seasonal dynamic and magnitude of measured and simulated NO3 concentrations in soil water in different soil depths agreed well which give further evidence for the simulated nitrate leaching. Using the IPCC EF of 0.0075, nitrate leaching results in indirect N2O emissions of additionally 1.8 kg N ha-1 yr-1. Only slight increase of measured and simulated yields (4 to 5.2 t DW ha-1) with higher rates of N fertilization indicate that actual farmer practices can be improved and optimizing agricultural management considering the specific climatic and soil conditions has a high potential to reduce environmental impacts of crop cultivations in the study area of the Haean catchment.

  19. Live birth rates following in vitro fertilization in women with thyroid autoimmunity and/or subclinical hypothyroidism.

    Science.gov (United States)

    Chai, Joyce; Yeung, Wing-Yee T; Lee, Chi-Yan V; Li, Hang-Wun R; Ho, Pak-Chung; Ng, Hung-Yu E

    2014-01-01

    To investigate whether the live birth rate following in vitro fertilization (IVF) is affected by thyroid autoimmunity (TAI) and/or subclinical hypothyroidism in subfertile women. Retrospective study in a university infertility clinic. A total of 627 women without past or current history of thyroid disorder undergoing their first IVF cycle. Pre-IVF archived blood serum samples were tested for TAI and thyroid function tests. Live birth rate. The clinical pregnancy rate, live birth rate and miscarriage rate were similar among women with or without TAI and/or subclinical hypothyroidism using a TSH threshold 4·5 mIU/l. Thyroid autoantibody level did not affect these IVF outcomes. The live birth rate and miscarriage rate of women with TAI and/or subclinical hypothyroidism following IVF were not impaired. © 2013 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

  1. Differences in prevalence rates of PTSD in various European countries explained by war exposure, other trauma and cultural value orientation.

    Science.gov (United States)

    Burri, Andrea; Maercker, Andreas

    2014-06-28

    Guided by previous explorations of historical and cultural influences on the occurrence of PTSD, the aim of the present study was to investigate the contributions of war victimisation (in particular, World War II) and other civil trauma on the prevalence of PTSD, as mediated by cultural value orientation. Secondary data analysis was performed for 12 European countries using data, including PTSD prevalence and number of war victims, crime victims, and natural disaster victims, from different sources. Ten single value orientations, as well as value aggregates for traditional and modern factors, were investigated. Whilst differences in PTSD prevalence were strongly associated with war victim rates, associations, albeit weaker, were also found between crime victims and PTSD. When cultural value orientations, such as stimulation and conformity as representatives of modern and traditional values, were included in the multivariate predictions of PTSD prevalence, an average of approximately 80% of PTSD variance could be explained by the model, independent of the type of trauma exposure. The results suggest that the aftermath of war contributes to current PTSD prevalence, which may be explained by the high proportion of the older population who directly or indirectly experienced traumatic war experiences. Additional findings for other types of civil trauma point towards an interaction between value orientation and country-specific trauma rates. Particularly, being personally oriented towards stimulation appears to interact with differences in trauma prevalence. Thus, cultural value orientation might be viewed not only as an individual intrinsic process but also as a compensatory strategy after trauma exposure.

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

    Science.gov (United States)

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

    2016-08-01

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

  3. 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.

  4. Effect of season and mating system in Awassi ewes superovulated with FSH on fertilization rate and embryo recovery

    Directory of Open Access Journals (Sweden)

    M. K. M. A. Al-Mola

    2010-01-01

    Full Text Available The aim of the present study was to evaluate the contribution of laparoscopic intrauterine insemination to the improvement of fertilization and embryo recovery in Awassi ewes superovulated with FSH in breeding and non-breeding season. Twelve nonpregnant and cycling Awassi ewes of 3-4 years of age were randomly allocated in equal numbers (n = 6 to two groups. Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. All ewes were superovulated with FSH in eight reducing doses for four days in the morning and evening from two days prior to sponge withdrawal. Ewes of group 1 were mated naturally at least two times with Awassi rams of proven fertility. Ewes of group 2 had intrauterine insemination and were conducted 44-46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of semen in the distal portion of each uterine horn. Ovarian response was assessed by determining number of corpora lutea by laparoscopy on day 6 after mating. Embryo recovery was performed by hand assisted laparoscopy and by flushing both uterine horns. Ovarian response of the ewes superovulated with FSH was decreased to half in the non-breeding season. High number of unfertilized ova (P<0.05 was observed in ewes superovulated with FSH in the non-breeding season when naturally inseminated compared to ewes inseminated intrauterine using laparoscopic technique. Higher rates of embryo recovery (P<0.05 were achieved in superovulated ewes in the breeding season when ewes were inseminated by laparoscopic intrauterine insemination. The fertilization rates in ewes inseminated intrauterine using laparoscopic techniques in breeding season and non-breeding season were 88.1% and 37.98%, respectively. It could be concluded from the results of the present study that the use of FSH to induce superovulation in Awassi ewes combined with laparoscopic intrauterine insemination can increase the fertilization rate in the breeding

  5. The Effect of a Two-Hour, Room Temperature Incubation of Human Spermatozoa in TEST-Yolk Buffer on the Rate of Fertilization in Vitro

    OpenAIRE

    Jensen, Julie R.; Walker, John H.; Milki, Amin A.; Westphal, Lynn; Behr, Barry

    2004-01-01

    Patients: To reassess the use of TEST-yolk buffer (TYB) in an in vitro fertilization (IVF) program by comparing fertilization rates achieved in a glucose-free cleavage medium by the standard IVF preparation of sperm versus a 2-h, room temperature incubation of sperm in TYB.

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

    Science.gov (United States)

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

    2012-10-01

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

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

    Science.gov (United States)

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

    2005-08-01

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

  8. Optimum fertilizer rate for kangkong (Ipomoea reptans L.) production in ultisol Jasinga

    OpenAIRE

    Anas D Susila; T. Prasetyo; Kartika, J.G.

    2008-01-01

    Proper fertilization of a crop is knowing the crop nutrient requirement for production of maximum yield and the potential level of nutrient availability from the soil. In addition to yield obtained, quality of the commodity is an important factor of profit and shelf-life for high-value crops. Nitrogen, phosphor, and potassium availability are the most limiting factors for maximum growth and yield. Kangkong (Ipomoea reptans L.) are important traditional leafy vegetables crops cultivated in Ind...

  9. 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.

  10. The contagious nature of imprisonment: an agent-based model to explain racial disparities in incarceration rates.

    Science.gov (United States)

    Lum, Kristian; Swarup, Samarth; Eubank, Stephen; Hawdon, James

    2014-09-01

    We build an agent-based model of incarceration based on the susceptible-infected-suspectible (SIS) model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates between Black and White Americans can be explained as the result of differential sentencing between the two demographic groups. We demonstrate that if incarceration can be spread through a social influence network, then even relatively small differences in sentencing can result in large disparities in incarceration rates. Controlling for effects of transmissibility, susceptibility and influence network structure, our model reproduces the observed large disparities in incarceration rates given the differences in sentence lengths for White and Black drug offenders in the USA without extensive parameter tuning. We further establish the suitability of the SIS model as applied to incarceration by demonstrating that the observed structural patterns of recidivism are an emergent property of the model. In fact, our model shows a remarkably close correspondence with California incarceration data. This work advances efforts to combine the theories and methods of epidemiology and criminology.

  11. 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 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...

  12. Explaining variations in state foster care maintenance rates and the implications for implementing new evidence-based programs

    Science.gov (United States)

    Goldhaber-Fiebert, Jeremy D.; Babiarz, Kimberly S.; Garfield, Rachel L.; Wulczyn, Fred; Landsverk, John; Horwitz, Sarah M.

    2013-01-01

    declined $40 if a state's governorship and legislature became Republican, though significance was marginal. In analyses also examining state revenue, federal funding, and legal challenges, maintenance rates increased as the federal share of maximum TANF payments increased. However, >50% of variation in foster care maintenance rates was explained by unobserved state-level factors as measured by state fixed effects. These factors did not appear to be strongly related to 2008 Child Welfare outcomes like foster care placement stability and maltreatment which were also not correlated with foster care maintenance rates. Conclusions Despite being part of a social safety net, foster care maintenance rates have declined in real terms since 1991 in many states, and there is no strong evidence that they increase in response to harsher economic climates or to federal programs or legal reviews. State variation in maintenance rates was not related to Child Welfare outcomes, though further analysis of this important relationship is needed. Variability in state foster care maintenance rates appears highly idiosyncratic, an important contextual factor to consider when designing and disseminating evidence-based services. PMID:24659842

  13. Effect of Nitrogen Fertilizer Rates on Morphological Traits, Yield and Yield Components of Three Cultivars of Rice

    Directory of Open Access Journals (Sweden)

    S. Gh Moosavi

    2015-07-01

    Full Text Available In order to study the effect of N fertilizer rates on morphological traits, yield and yield components of rice cultivars, a study was carried out in Rice Research Institute of Rasht, Iran during 2009. It was a two-variable factorial experiment based on a randomized complete block design with three replications. The first factor was nitrogen fertilization at four rates of 0, 30, 60 and 90 kg N ha-1 and the second factor was rice cultivar at three levels of Hashemi, Ali-Kazemi and Khazar. The results of analysis of variance showed that N fertilizer rates did not significantly affect on panicle length, grain number per panicle, 1000- grain weight and harvest index but significantly affected plant height, tiller number per m2, panicle number per m2, grain yield and biological yield. Means comparison showed that as N rate was increased from 0 to 90 kg ha-1, plant height, tiller number per m2, panicle number per m2, grain yield and biological yield increased by 12.7, 27.6, 32.6, 84.5 and 61.6%, respectively. The cultivar significantly affected morphological traits, panicle number per m2, grain number per panicle, 1000-grain weight, grain yield and biological yield. The results indicated that cultivar of Khazar had the highest potential of grain yield (3424.5 kg ha-1. In total, application of 90 kg N ha-1 and cultivar of Khazar treatment was better for having the maximum production under the conditions of the current study.

  14. Dry matter and primary macroelements on the foliar biomass of sugarcane with different fertilizer rates of phosphorus

    Directory of Open Access Journals (Sweden)

    Juan Alejandro Villazón Gómez

    2016-07-01

    Full Text Available With the objective of determining the quantities of dry matter and primary macroelements on the foliar biomass of the sugar cane fertilized with different phosphorus rates was carried out a in an experiment in blocks at random (8 treatments x 6 replications on a Chromic Vertisol. Five plants per plot at the 3rd replication and crop cycle were cut before harvesting. To the sugarcane top of the samples were determined the percentages of dry matter, nitrogen, phosphorus and potassium; was carried out a count of sugarcane stalk in each plot to express the percentages in magnitudes of mass.An Analysis of Variance of simple classification and the test of multiple status of Duncan to 95 % of probability was executed. The yearly fertilizations with 50 and 25 kg ha-1 of phosphorus from the 1rst cycle and the application at the start of a cycle of 125 kg ha-1 showed the bigger dry matter contents and the second ratoons had the biggest influence in the matter production. It was appreciated that the influence of the crop cycle was bigger than that rates of phosphorus on the dry matter content. The rate of phosphorus and the crop cycle with bigger content of primary macroelements were those where the dry matter was in bigger quantities. In the interaction rates of phosphorus-crop cycle the bigger contents of phosphorus and potassium was obtained on the 2nd ratoon with yearly and to the start of crop cycle applications of phosphorus.

  15. Can jurisdictional uncertainty and capital controls explain the high level of real interest rates in Brazil? Evidence from panel data

    Directory of Open Access Journals (Sweden)

    Fernando M. Gonçalves

    2007-03-01

    Full Text Available This paper tests the assertion, popularized by Arida et al. (2005, that risks associated with the jurisdiction and currency inconvertibility are relevant determinants of the high level of short-term real interest rates in Brazil. The results are by and large unfavorable not only to their conjecture, but also to variants of their argument. The results further indicate that traditional monetary and fiscal factors are far more relevant to explain the level of short-term real interest rates than the binomial jurisdictional uncertainty/ currency inconvertibility is.Esse paper testa a hipütese, popularizada por Arida et al. (2005, de que riscos associados à incerteza jurisdicional e incoversibilidade da moeda nacional são importantes determinantes dos altos níveis da taxa básica de juros no Brasil. Os resultados dos testes são bastante desfavoráveis não apenas a essa hipotese, mas também a variantes dela. Os resultados também indicam que fatores tradicionais fiscais e monetários são bem mais relevantes para explicar o nível da taxa básica de juros, em comparação ao par incerteza jurisdicional/incoversibilidade da moeda.

  16. Decreased Rate of Plasma Arginine Appearance in Murine Malaria May Explain Hypoargininemia in Children With Cerebral Malaria.

    Science.gov (United States)

    Alkaitis, Matthew S; Wang, Honghui; Ikeda, Allison K; Rowley, Carol A; MacCormick, Ian J C; Chertow, Jessica H; Billker, Oliver; Suffredini, Anthony F; Roberts, David J; Taylor, Terrie E; Seydel, Karl B; Ackerman, Hans C

    2016-12-15

     Plasmodium infection depletes arginine, the substrate for nitric oxide synthesis, and impairs endothelium-dependent vasodilation. Increased conversion of arginine to ornithine by parasites or host arginase is a proposed mechanism of arginine depletion.  We used high-performance liquid chromatography to measure plasma arginine, ornithine, and citrulline levels in Malawian children with cerebral malaria and in mice infected with Plasmodium berghei ANKA with or without the arginase gene. Heavy isotope-labeled tracers measured by quadrupole time-of-flight liquid chromatography-mass spectrometry were used to quantify the in vivo rate of appearance and interconversion of plasma arginine, ornithine, and citrulline in infected mice.  Children with cerebral malaria and P. berghei-infected mice demonstrated depletion of plasma arginine, ornithine, and citrulline. Knock out of Plasmodium arginase did not alter arginine depletion in infected mice. Metabolic tracer analysis demonstrated that plasma arginase flux was unchanged by P. berghei infection. Instead, infected mice exhibited decreased rates of plasma arginine, ornithine, and citrulline appearance and decreased conversion of plasma citrulline to arginine. Notably, plasma arginine use by nitric oxide synthase was decreased in infected mice.  Simultaneous arginine and ornithine depletion in malaria parasite-infected children cannot be fully explained by plasma arginase activity. Our mouse model studies suggest that plasma arginine depletion is driven primarily by a decreased rate of appearance. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

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

    Science.gov (United States)

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

    2014-01-01

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

  18. 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.

  19. Selected Macronutrient Uptake by Sweet Corn under Different Rates of Liquid Organic Fertilizer in Closed Agriculture System

    Directory of Open Access Journals (Sweden)

    Zainal Muktamar

    2016-04-01

    Full Text Available In the last few years, soil deterioration due to excessive application of synthetic agrochemical has become growing concern. Use of organic fertilizer is believed to be able to enhance soil quality. The objective of this experiment was to determine nitrogen, phosphorus, and potassium uptakes by sweet corn as affected by local based liquid organic fertilizer (LOF under closed agriculture system. The experiment was conducted in Closed Agriculture Production System (CAPS Research Station in Air Duku Village, Bengkulu, Indonesia from March to June 2015, employing Randomized Completely Block Design with 2 factors. The first factor was 3 sweet corn genotypes, i.e. Talenta, Jambore, and Asian Honey and the second factor was 5 rates of LOF, i.e. 0, 25, 50, 75, and 100 mg l-1, respectively. Each treatment combination was replicated 3 times. Foliar application of LOF was carried out every week at 2-8 weeks after planting (WAP with total volume of 600 ml per plant. Sweet corn leaves were sampled at the beginning of tassel emergence. The experiment revealed that sweet corn genotype significantly influenced the uptake of nitrogen, but not phosphorus and potassium. It was observed that Asian Honey genotype absorbed highest nitrogen as compared to other genotypes. In addition, increase in rates of LOF significantly raised nitrogen uptake by sweet corn, but not phosphorus and potassium.

  20. 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

  1. 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.

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

    Science.gov (United States)

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

    2015-02-01

    Probable involvement of avidin and avidin-related protein-2 (AVR2) in sperm viability in the sperm storage tubules of turkeys has been suggested. The high affinity of biotin to avidin and its analogs is also well documented. The present study aimed to determine the effect of oral biotin on reproductive performance and oviductal mRNA expression of avidin and AVR2 in 2 broiler hen lines with different fertility rates. Low-fertility (line B) and high-fertility (line D) hens (n=144) were randomly allotted to receive 0 (T0), 0.30 (T1), or 0.45 (T2) mg/L biotin in drinking water from 30 through 33 wk of age. The reproductive performance of the hens was evaluated using artificial insemination. At the end of the treatment period, 24 hens per line were killed to assay the expression of avidin and AVR2 in the uterovaginal junction. Supplementary biotin increased egg production from 73.5% for T0 to 87.8% for T2. Hens administered with biotin in line B, but not in line D, showed an increase (8.4%) in fertility rate. Hatchability, chick quality, and overall embryonic mortality were not different among the experimental groups. Real-time PCR data showed that both avidin (P=0.0013) and AVR2 (Pavidin and AVR2 mRNA expression, although biotin did not affect these traits in line D hens. Control hens in line D had a dramatically higher AVR2 expression record (7.4-fold) compared with the control hens in line B. The correlation coefficients of fertility rate and avidin expression were 0.73 and 0.66 in lines B and D, respectively. However, the correlation of fertility and AVR2 (r=0.65) was significant for line D hens only. Overall, fertility rate and oviductal expression of avidin and AVR2 were dichotomously affected by oral biotin in low- and high-fertility line hens, where only low-fertility birds showed improvements in these attributes. © 2015 Poultry Science Association Inc.

  3. Maize response to elevated plant density combined with lowered N-fertilizer rate is genotype-dependent

    Institute of Scientific and Technical Information of China (English)

    Ahmed; Medhat; M.Al-Naggar; Reda; A.Shabana; Mohamed; M.M.Atta; Tarek; H.Al-Khalil

    2015-01-01

    Increasing plant density and improving N fertilizer rate along with the use of high density-tolerant genotypes would lead to maximizing maize(Zea mays L.) grain productivity per unit land area. The objective of this investigation was to match the functions of optimum plant density and adequate nitrogen fertilizer application to produce the highest possible yields per unit area with the greatest maize genotype efficiency. Six maize inbred lines differing in tolerance to low N and high density(D) [three tolerant(T); L-17, L-18, L-53,and three sensitive(S); L-29, L-54, L-55] were chosen for diallel crosses. Parents and crosses were evaluated in the 2012 and 2013 seasons under three plant densities: low(47,600),medium(71,400), and high(95,200) plants ha-1and three N fertilization rates: low(no N addition), medium(285 kg N ha-1) and high(570 kg N ha-1). The T × T crosses were superior to the S × S and T × S crosses under the low N–high D environment in most studied traits across seasons. The relationships between the nine environments and grain yield per hectare(GYPH) showed near-linear regression functions for inbreds L54, L29, and L55 and hybrids L18 × L53 and L18 × L55 with the highest GYPH at a density of47,600 plants ha-1and N rate of 570 kg N ha-1and a curvilinear relationship for inbreds L17, L18, and L53 and the rest of the hybrids with the highest GYPH at a density of95,200 plants ha-1combined with an N rate of 570 kg N ha-1. Cross L17 × L54 gave the highest grain yield in this study under both high N–high-D(19.9 t ha-1) and medium N–high-D environments(17.6 t ha-1).

  4. 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

    2017-03-01

    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

  5. Can postoperative process of care utilization or complication rates explain the volume-cost relationship for cancer surgery?

    Science.gov (United States)

    Ho, Vivian; Short, Marah N; Aloia, Thomas A

    2017-08-01

    Past studies identify an association between provider volume and outcomes, but less is known about the volume-cost relationship for cancer surgery. We analyze the volume-cost relationship for 6 cancer operations and explore whether it is influenced by the occurrence of complications and/or utilization of processes of care. Medicare hospital and inpatient claims for the years 2005 through 2009 were analyzed for 6 cancer resections: colectomy, rectal resection, pulmonary lobectomy, pneumonectomy, esophagectomy, and pancreatic resection. Regressions were first estimated to quantify the association of provider volume with costs, excluding measures of complications and processes of care as explanatory variables. Next, these variables were added to the regressions to test whether they weakened any previously observed volume-cost relationship. Higher hospital volume is associated with lower patient costs for esophagectomy but not for other operations. Higher surgeon volume reduces costs for most procedures, but this result weakens when processes of care are added to the regressions. Processes of care that are frequently implemented in response to adverse events are associated with 14% to 34% higher costs. Utilization of these processes is more prevalent among low-volume versus high-volume surgeons. Processes of care implemented when complications occur explain much of the surgeon volume-cost relationship. Given that surgeon volume is readily observed, better outcomes and lower costs may be achieved by referring patients to high-volume surgeons. Increasing patient access to surgeons with lower rates of complications may be the most effective strategy for avoiding costly processes of care, controlling expenditure growth. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Seismicity and Deformation of Krafla Volcano, Iceland. Intervals of Low Seismicity Rate during Rapid Inflation Explained By the Kaiser Effect.

    Science.gov (United States)

    Heimisson, E. R.; Einarsson, P.; Sigmundsson, F.; Brandsdottir, B.

    2014-12-01

    The Krafla central volcano in NE-Iceland produced about 20 dike intrusions during a rifting episode 1975-1984. These intrusions were always preceded by inflation of the caldera. Once a dike started propagating rapid deflation was observed. The first deflation event began in December 1975 with a dike traveling laterally from the magma chamber. Leveling measurements revealed subsidence of 2 m close to the deflation center. In February 1976 a stage of inflation began and at the same time the seismicity rate in the caldera rose in good correlation with the inflation. A small intrusion started propagating in late September 1976 which was accompanied by maximum subsidence of about 14 cm. However in the next 3 inflation and deflation cycles the inflation periods were almost aseismic until the inflation level of previous cycle was exceeded. At that point a sharp increase in the caldera earthquake count was observed. This phenomenon was observed until late April 1977 when a fissure eruption occurred inside the caldera. By inverting leveling data from 87 stations for a Mogi source and regarding the volume change of the source as a measure of stress we suggest that this phenomenon can be explained by the Kaiser effect. The Kaiser effect is well known from rock mechanics where under cyclic loading and unloading rocks, and other materials, induce dramatic increase in acoustic emissions when the load exceeds that of previous cycles. Krafla demonstrated the same effect while the external stress field was not significantly changed during the aforementioned 3 inflation/deflation cycles. This condition was disturbed when eruption occurred inside the caldera. The state of stress in the vicinity of the magma chamber was changed and subsequent inflation periods were not accompanied by significant seismicity. These results indicate that the Kaiser effect is an important part of understanding the relationship between deformation and seismicity in active volcanoes. The importance of

  7. Effect of Different Application Rate of Nitrogen Fertilizer Under Straw Return on Maize Yield and Inorganic Nitrogen Accumulation

    Directory of Open Access Journals (Sweden)

    ZHANG Xin

    2014-06-01

    Full Text Available We investigated the influences of different nitrogen fertilizer rate on maize production, nitrogen use efficiency and soil nitrate nitrogen at straw return farmland for two years. The results showed that maize production increased with the increment of nitrogen fertilizer. The maize production was the highest at 216 kg·hm -2(N216of nitrogen use and began to decrease when the amount of nitrogen use was beyond 216 kg· hm -2. There were significant interannual differences on maize production in the same treatment. The maize production in 2010 increased 0.69%~4.75% compared with that in 2009. Nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen harvest index improved with the year of straw return. The highest nitrate nitrogen accumulation was found in the treatment of 240 kg· hm -2(N240in 0~100 cm soil layer. Soil nitrate content increased with the depth of soil. This may potentially increased the risk of nitrate pollution on shallow groundwater. Compared with N240, the nitrate nitrogen accumulation of N168(168 kg·hm -2 , N192(192 kg·hm -2 and N216(216 kg·hm -2 were equally reduced by respectively 39.87%, 35.84% and 29.38% in 0~100 cm soil layer. Considering the maize production, nitrogen use efficiency and ecological environmental benefits, the optimum amount of nitrogen use should be 200 kg·hm -2.

  8. Endometriosis, Ovarian Reserve and Live Birth Rate Following In Vitro Fertilization/Intracytoplasmic Sperm Injection.

    Science.gov (United States)

    Coelho Neto, Marcela Alencar; Martins, Wellington de Paula; Luz, Caroline Mantovani da; Jianini, Bruna Talita Gazeto Melo; Ferriani, Rui Alberto; Navarro, Paula Andrea

    2016-05-01

    Purpose To evaluate whether women with endometriosis have different ovarian reserves and reproductive outcomes when compared with women without this diagnosis undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), and to compare the reproductive outcomes between women with and without the diagnosis considering the ovarian reserve assessed by antral follicle count (AFC). Methods This retrospective cohort study evaluated all women who underwent IVF/ICSI in a university hospital in Brazil between January 2011 and December 2012. All patients were followed up until a negative pregnancy test or until the end of the pregnancy. The primary outcomes assessed were number of retrieved oocytes and live birth. Women were divided into two groups according to the diagnosis of endometriosis, and each group was divided again into a group that had AFC ≤ 6 (poor ovarian reserve) and another that had AFC ≥ 7 (normal ovarian reserve). Continuous variables with normal distribution were compared using unpaired t-test, and those without normal distribution, using Mann-Whitney test. Binary data were compared using either Fisher's exact test or Chi-square (χ(2)) test. The significance level was set as p live birth was similar between women with the diagnosis of endometriosis and those without it (19.1 versus 22.5%), and also when considering only women with a poor ovarian reserve (9.4 versus 8.9%) and only those with a normal ovarian reserve (25.5 versus 26.5%). Conclusions Women diagnosed with endometriosis are more likely to have a poor ovarian reserve; however, their chance of conceiving by IVF/ICSI is similar to the one observed in patients without endometriosis and with a comparable ovarian reserve. Thieme Publicações Ltda Rio de Janeiro, Brazil.

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

    Science.gov (United States)

    Soulé, Peter T; Knapp, Paul A

    2006-01-01

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

  10. Finance and fertility: the effects of heavy taxation on the birth rate.

    Science.gov (United States)

    Dique, J C

    1976-05-15

    Increasing taxation since World War II has been a factor in reducing the marriage rate and consequently the birth rate in Australia, as a result of raising the cost of living indicated by the retail price index. Taxation has increased enormously though the population has not.

  11. Effects of nitrogen rate and ratio of base fertilizer and topdressing on uptake,translocation of nitrogen and yield in wheat

    Institute of Scientific and Technical Information of China (English)

    SHI Yu; YU Zhenwen; WANG Dong; LI Yanqi; WANG Xue

    2007-01-01

    Application of nitrogen (N) fertilizer is one of the most important measures to increase grain yield and protein content in winter wheat (Triticum aestivum L.) production.However,misuse of N fertilizer will not only affect grain yield and quality,but also cause the decline of economic benefits and related negative environmental effects.It is essential to study reasonable N application regimes for profitable yields,efficient N utilization and reduction in possible environmental pollution.The objective of this study was to determine the N uptake and translocation in wheat plants by using 15N isotope tracers in PVC cylinders (2.05 m long,0.2 m,without bottom) in seven treatments:without N fertilizer application (NO);N application rate of 168 kg/hm2(0.527 g/pot),with ratios of base fertilizer to topdressing of 1:1 (N1),1:2 (N2) and 0:1 (N3);N application rate of 240 kg/hm2 (0.753 g/pot),with ratios of base fertilizer to topdressing of 1:1 (N4),1:2 (N5) and 0:1 (N6),The 15N tracer experiment showed that the main basal N absorbed by plant from sowing to jointing stage accounted for 78.04%-89.67%;fertilizer N use efficiency (FNUE,N fertilizer accumulation in plant/N supplied) of topdressing was significantly higherthan that of basal N;reducing basal N amount and increasing topdressing N amount could appropriately promote the plant's absorption of more N fertilizer and enhance FNUE,of which treatment N2 had the highest values.Under the high-yield condition,when N fertilizer rate was increased from 168 to 240 kg/hm2,there were no significant differences in the amount of N accumulation in plants and in grains between treatments with the same ratio of base fertilizer to topdressing;by reducing basal N amount and increasing topdressing N amount accordingly,the translocation efficiency (TE,accumulation amount from vegetative organs to grain/N accumulation in vegetative organs during anthesis) increased,and the amount of N assimilation to grains after anthesis and its

  12. Decreased rates of terpene emissions in Ornithopus compressus L. and Trifolium striatum L. by ozone exposure and nitrogen fertilization.

    Science.gov (United States)

    Llusia, Joan; Bermejo-Bermejo, Victoria; Calvete-Sogo, Héctor; Peñuelas, Josep

    2014-11-01

    Increasing tropospheric ozone (O3) and nitrogen soil availability (N) are two of the main drivers of global change. They both may affect gas exchange, including plant emission of volatiles such as terpenes. We conducted an experiment using open-top chambers to analyze these possible effects on two leguminous species of Mediterranean pastures that are known to have different O3 sensitivity, Ornithopus compressus and Trifolium striatum. O3 exposure and N fertilization did not affect the photosynthetic rates of O. compressus and T. striatum, although O3 tended to induce an increase in the stomatal conductance of both species, especially T. striatum, the most sensitive species. O3 and N soil availability reduced the emission of terpenes in O. compressus and T. striatum. If these responses are confirmed as a general pattern, O3 could affect the competitiveness of these species.

  13. 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.

  14. Effect of cryoprotectants and cooling rates on fertility potential of sperm in the giant freshwater prawn, Macrobrachium rosenbergii (De Man).

    Science.gov (United States)

    Valentina Claudet, P; Narasimman, Selvakumar; Natesan, Munuswamy

    2016-08-01

    This study evaluates freezing protocol with suitable cryoprotectants and their effects on the fertility potential of sperm in the cryopreserved spermatophores of Macrobrachium rosenbergii. Spermatophores, collected using electroejaculation, were suspended in dimethyl sulfoxide (DMSO), propylene glycol (PG), methanol, glycerol and ethylene glycol (EG) at different concentrations (10, 15 & 20% v/v), prepared in sterile-filtered pond water. Based on the cryoprotectant toxicity assay, DMSO and PG were used individually as well as in combination with three freezing protocols (i.e. -1.5, -3 and -5°C/min and to final temperature of -39°C) and plunged into liquid nitrogen at -196°C. After 90 days of storage (-196°C) thawing was done at 35°C in a water bath for 1min. Results showed that fresh and cryopreserved spermatophores held for 90 days registered sperm viability of 91.4±2.9% and 50.4±1.9% respectively. Further, fertility potential of sperm was assessed based on acrosome reactivity using calcium ionophore (A23187). Observations indicated that cryopreserved sperm registered 28.3±2.2% of acrosome reactivity compared to freshly collected spermatophores (85.3±2.5%). Thus, one-step slow cooling rate of -1.5°C/min between 27°C and -39°C stored in liquid nitrogen at -196°C with DMSO (10%)+PG (10%) seems to be amenable for cryopreservation of spermatophores, compared to other cooling rates.

  15. Impact of estrogen-to-oocyte ratio on live birth rate in women undergoing in vitro fertilization and embryo transfer.

    Science.gov (United States)

    Bu, Zhiqin; Wang, Keyan; Guo, Yihong; Su, Yingchun; Zhai, Jun; Sun, Yingpu

    2015-01-01

    In order to evaluate whether the ratio of serum estrogen level on the day of human chorionic gonadotrophin (hCG) administration to number of oocyte retrieved has any impact on live birth rate in women undergoing in vitro fertilization (IVF), we retrospectively analyzed the clinical data from 7,112 women treated with GnRH-a long protocol in our center. Cycles were firstly divided into 6 groups according to the E2/oocyte ratio (Live birth rate (39.4%) in women with E2/oocyte ratio ≥ 750 pg/ml was the lowest compared with that in other groups. We further divided the top 10% of patients into high estrogen group (E2/oocyte ≥ 740 pg/ml; n = 713). Compared with controls, those with high E2/oocyte ratio had significantly higher peak E2 level (6711.85 pg/ml versus 4670.89 pg/ml; P = 0.000) on the day of hCG administration; however, the live birth rate (39.27% versus 45.67%; P = 0.001) was significantly lower for women with high estrogen level. Thus, we conclude that high E2/oocyte ratio adversely affects live birth rate in women undergoing IVF treated with GnRH-a long protocol.

  16. 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.

  17. Impact of sperms on fertilization rate after in-vitro fertilization and embryo transfer%精子因素对体外受精-胚胎移植术中受精率的影响

    Institute of Scientific and Technical Information of China (English)

    马兰; 刘洋; 镡颖; 陈静思; 杨晓玲

    2016-01-01

    Objective To explore the related factors of fertilization failure after in-vitro fertilization and embryo transfer. Methods 150 patients were divided into total fertilization failure (TFF) group, low fertilization (LFR) group, and control (NFR) group according to fertilization rate. Semen was collected from the male pa-tients; the number, concentration, shape, and progressive motility of sperms were measured. Level of gACE was detected by Western blot. Logistic regression was used to explore the factors affecting fertilization rate. Results The fertilization rate and the concentration , progressive motility , and shape of sperms in were lower TFF group than in LFR group and NFR group (P < 0.05). Western blot proved that level of gACE group was higher in TFF than in LFR group and NFR group (P < 0.05). Logistic regression showed that the fertilization rate, the concen-tration , progressive motility , shape of sperms , and the level of gACE were all the independent risk factors for fertilization failure. Conclusions The concentration, progressive motility, and shape of sperms have impact on IVF. A lower expression of gACE in patients with lower fertilization rate can be used as a potential biomarker for predicting fertilization failure.%目的:探究体外受精-胚胎移植术(IVF-ET)中受精失败的相关因素。方法:选取接受IVF治疗的患者150例,按照受精率分为完全受精失败组(TFF组,n =50)、低受精率组(LFR组,n =50)和正常对照组(NFR组,n =50)。男性患者采集精子后,观察计数,计算精子浓度、向前精子活动率及正常形态率。Western blot 检测精子中生死源性血管紧张素 I 转换酶(gACE)的表达水平,Logistic 回归检测影响受精率的因素。结果:TFF组的受精率、精子浓度、向前精子活动力和精子正常形态率均低于LFR组和NFR组(P <0.05)。Western blot 结果显示,TFF 组、LFR 组和 NFR3组患者 gACE 的表

  18. 配施木霉微生物肥对连作黄瓜的影响%Effect ofTrichoderma Biofertilizer on Continuous Cropping Cucumber Cultivation with Reduced Rates of Chemical Fertilizer Application

    Institute of Scientific and Technical Information of China (English)

    顾小龙; 陈巍; 蔡枫; 庞冠; 李瑞霞

    2016-01-01

    by>21% of yield compared to the OF treatment. This result was consistent across in our previous field experiments,which also indicates that only biofertilizer could be a viable supplementary strategy of fertilizer for maintaining or increasing cucumber yield. Reduced chemical fertilization,both of the BF and OF treatments,resulted in a higher Vitamin C(2%~23% and 35%~54%,respectively)contents in the BF and OF treatments but a lower(32%~46%)accumulation of NO3- in the cucumber fruits compared than those of the control(CF),suggesting that replacing 25% of the chemical fertilizer rates with(bio)organic fertilizer could significantly increase cucumber fruit quality. The application of SQR-T037 biofertilizer(BF)significantly(p<0.05)increased cucumber rhizospheric nutrient availability. Specifically,the highest contents of available P were more frequently observed in the BF treatment. Moreover,the BF treatment maintained at a higher level of available K compared with that of the CF and OF treatments. Also,the BF treatment significantly increased the population of soil microflora, including bacteria andTrichoderma,maintaining the population of actinomycetes,but with the reduced abundance of fungi,compared with the CF treatment. Based on the explanations known in other researches, the relationship between soil nutrients and microflora in this study may be explained as follows:plant growth might initially be improved by enhanced root growth,which occurs in response to a powerful plant-growth-promoting fungus,T.harzianumSQR-T037,as reported in our previous study. Then,better root growth influences soil microbes via the supply of additional root exudates or rhizodeposition,and soil microbes, in turn,alter plant performance through higher microbial abundance and more frequent interactions resulting in more available nutrients. This process continues in a cycle. More bio-available nutrients promote better root growth,which facilitates more microbial colonization in the

  19. Effect of applying different rates of slow - disintegrating fertilizer on the quality of marigold (Tagetes patula L. and scarlet sage seedlings (Salvia splendens L.

    Directory of Open Access Journals (Sweden)

    Vujošević Ana

    2007-01-01

    Full Text Available The paper investigates the effect of applying different rate of slow disintegrating fertilizer Scotts (Osmocot Exact with the formula 15:9:9:MgO+Me to the quality of seedlings of marigold and scarlet sage. The marigold and scarlet sage seedlings were grown in poly-propylene containers (speedling system and poly-propylene pots (pot system. Slow disintegrating fertilizer rate have been applied to the seedlings in the course of their growing (0, 1, 2, 3, i 4 g/l. The obtained data show that the 4g/l substrate rate of slow disintegrating fertilizer has significant effects on the studied parameters of seedlings quality of studied species.

  20. On the fertility transition in Africa

    DEFF Research Database (Denmark)

    Mveyange, Anthony Francis

    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...... of the unified growth theory....

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

    Science.gov (United States)

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

  2. 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.

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

    Science.gov (United States)

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

    2015-05-01

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

  4. 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.

  5. Dry matter and primary macroelements on the foliar biomass of sugarcane with different fertilizer rates of phosphorus

    Directory of Open Access Journals (Sweden)

    Juan Alejandro Villazón Gómez

    2016-01-01

    Full Text Available The research consisted of determining the quantities of dry matter and primary macroelements on the foliar biomass that contributes to the soil the sugarcane fertilized with different fertilizer rates of potassium in an experiment with a design in complete blocks at random (8 treatments x 6 repetitions on a Chromic Vertisol. Five plants were cut in the furrows 2 and 3 of the plots of the 3rd repetition before the harvest of each one of the four ratoons. To the sugarcane top of the samples were determined the percentages of dry matter, nitrogen, phosphorus and potassium; was carried out a count of sugarcane stalk in each plot to express the percentages in magnitudes of mass. An analysis of variance of simple classification was executed and means were compared by Duncan test at 95 % of confidence. The treatment V was the one of bigger dry matter content, with 11.04 t ha-1. The 2nd ratoon showed the bigger dry matter content in the sugarcane tops, with 11.13 t ha-1. In the interactions the bigger influence of the sugarcane stubble phase on the dry matter can be appreciated. The treatment V was the one of bigger nutrient content, with 83, 16 and 197 kg of NPK, respectively. In the case of nitrogen the best interaction was the treatment V in the 3rd ratoon, in the phosphorus also the treatment V in the 2nd and 3rd ratoons and the treatment IV in the 4th ratoon, in potassium the interaction of the treatment V in the 2nd ratoon.

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

    Directory of Open Access Journals (Sweden)

    Yuki Fujita

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

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

    Science.gov (United States)

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

    2013-01-01

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

  8. Effect of the primary cooling rate on the motility and fertility of frozen-thawed rabbit spermatozoa

    Directory of Open Access Journals (Sweden)

    Tatsuhiro Maeda

    2012-07-01

    Full Text Available In the present study, we examined the effect of primary cooling rates on the motility and fertility of frozen-thawed rabbit spermatozoa. Rabbit semen diluted with an egg-yolk acetamide extender was cooled from room temperature to 5°C at four different rates (-0.1, -0.2, -0.4, -0.8°C/min as a primary cooling step, then semen was frozen in liquid nitrogen vapour. After thawing, sperm cooled at -0.1°C/min showed the highest motility (40.7 ± 7.3%; there were no significant differences between the motilities of the -0.1, -0.2, and -0.4°C/min groups. The motility of frozen-thawed sperm cooled at -0.8°C/min (29.2 ± 6.8% was significantly lower than that of sperm cooled at -0.1 and -0.2°C/min. The viability (-0.1°C/min, 38.1 ± 4.0%; -0.8°C/min, 24.3 ± 7.3% of frozen-thawed sperm was closely related to its motility (-0.1°C/min, 36.7 ± 7.2%; -0.8°C/min, 22.3 ± 4.7%. Quality of post-thaw motile sperm cooled at different rates was estimated by comparing the fertilisation ability of the -0.1 and -0.8°C/min groups following artificial insemination. There were no significant differences in pregnancy rates and mean litter sizes. These data suggest that cooling rabbit semen at rates ranging from -0.1 to -0.8°C/min affects the viability but not the fertilisation capacity of motile spermatozoa after thawing.

  9. Family systems and fertility

    NARCIS (Netherlands)

    Moenkediek, Bastian

    2016-01-01

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

  10. Effect of N fertilization rate on soil alkali-hydrolyzable N, subtending leaf N concentration, fiber yield, and quality of cotton

    Directory of Open Access Journals (Sweden)

    Binglin Chen

    2016-08-01

    Full Text Available Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai (120°19″ E, 32°52″ N, Jiangsu, China in 2009 and Dafeng (120°28″ E, 33°12″ N, Jiangsu province, China in 2010. Six nitrogen rates (0, 150, 300, 375, 450, and 600 kg ha− 1 were used to study the effect of N fertilization rate on soil alkali-hydrolyzable nitrogen content (SAHNC, subtending leaf nitrogen concentration (SLNC, yield, and fiber quality. In both Dongtai and Dafeng experiment station, the highest yield (1709 kg ha− 1, best quality (fiber length 30.6 mm, fiber strength 31.6 cN tex− 1, micronaire 4.82, and highest N agronomic efficiency (2.03 kg kg− 1 were achieved at the nitrogen fertilization rate of 375 kg ha− 1. The dynamics of SAHNC and SLNC could be simulated with a cubic and an exponential function, respectively. The changes in SAHNC were consistent with the changes in SLNC. Optimal average rate (0.276 mg day− 1 and duration (51.8 days of SAHNC rapid decline were similar to the values obtained at the nitrogen rate of 375 kg ha− 1 at which cotton showed highest fiber yield, quality, and N agronomic efficiency. Thus, the levels and strategies of nitrogen fertilization can affect SAHNC dynamics. The N fertilization rate that optimizes soil alkali-hydrolyzable nitrogen content would optimize the subtending leaf nitrogen concentration and thereby increase the yield and quality of the cotton fiber.

  11. Effects of phosphorus fertilizer rate and Pseudomonas fluorescens strain on field pea (Pisum sativum subsp. arvense (L. Asch. growth and yield

    Directory of Open Access Journals (Sweden)

    Bahram SALEHI

    2015-11-01

    Full Text Available A field experiment was conducted at Rezvanshahr, Guilan province, Iran, to evaluate the effects of phosphorus fertilizer rate and Pseudomonas fluorescens strains on growth and yield of field pea (Pisum sativum L.. The experimental design was a randomized complete block in a factorial arrangement with three replicates. Factors were phosphorus fertilizer rates (0, 25, 50, 75, and 100 kg P2O5 ha-1 as triple superphosphate, and seed inoculation with P. florescens strains [control (non-inoculated, inoculated with strain R41, and strain R187. Analysis of variance showed that plant height, seed yield, pod number per m2, 100-seed weight, biological yield, harvest index, and leaf P concentration were significantly influenced by phosphorus fertilizer rate and P. florescens strain. At the same time, phosphorus fertilizer rate × P. fluorescens strain interaction was significant only for 100-seed weight. On the other hand, seed number per pod was significantly affected neither by phosphorus fertilizer rate nor by pseudomonas strains. Result showed that seed yield was significantly increased from 1099 ± 67 to 1898 ± 118 kg ha-1 as P2O5 application rate increased from 0 to 75 kg ha-1, and thereafter relatively remained constant. There was no significant difference in seed yield between plants raised from inoculated seeds with P. fluorescens, strain R187 (1664 ± 97 kg ha-1 and those raised from inoculated seeds with P. fluorescens, strain R41 (1669 ± 104 kg ha-1. At the same time, plants raised from inoculated seeds with P. fluorescens (both strains produced greater grain yield compared to those raised from uninoculated seeds (1370 ± 80 kg ha-1. Based on the results of this study, P2O5 application at the rate of 75 kg ha-1 and inoculation with pseudomonas bacteria are recommended for obtaining the greatest seed yield in field pea.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2011-07-01

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

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

    Science.gov (United States)

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

  15. 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...

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

    NARCIS (Netherlands)

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

    2015-01-01

    Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (pr

  17. 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

    /delivery and the report of marital benefits resulting from the infertility experience. Lower social class was a significant predictor for satisfaction. CONCLUSIONS: Both men and women in fertility treatment had high ratings on medical and patient-centred care. It seemed that satisfaction with the psychosocial services...

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

    Science.gov (United States)

    Lesoine, Bernd

    2016-01-01

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

  19. 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.

  20. France: High and stable fertility

    Directory of Open Access Journals (Sweden)

    Clémentine Rossier

    2008-07-01

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

  1. Application of the compensated Arrhenius formalism to explain the dielectric constant dependence of rates for Menschutkin reactions.

    Science.gov (United States)

    Petrowsky, Matt; Glatzhofer, Daniel T; Frech, Roger

    2013-11-21

    The dependence of the reaction rate on solvent dielectric constant is examined for the reaction of trihexylamine with 1-bromohexane in a series of 2-ketones over the temperature range 25-80 °C. The rate constant data are analyzed using the compensated Arrhenius formalism (CAF), where the rate constant assumes an Arrhenius-like equation that also contains a dielectric constant dependence in the exponential prefactor. The CAF activation energies are substantially higher than those obtained using the simple Arrhenius equation. A master curve of the data is observed by plotting the prefactors against the solvent dielectric constant. The master curve shows that the reaction rate has a weak dependence on dielectric constant for values approximately less than 10 and increases more rapidly for dielectric constant values greater than 10.

  2. Effects of nitrogen fertilizer rates and ratios of base and topdressing on wheat yield,soil nitrate content and nitrogen balance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Application of nitrogen (N) fertilizer is one of the most important measures that increases grain yield and improves grain quality in winter wheat (Triticum aestivum L.) production.Presently,there is a large number of investigations (experiments) in the field on different nitrogen fertilizer application regimes.However,there still exists a serious problem of low nitrogen use efficiency,especially in winter wheat high yield conditions:unsuitable nitrogen fertilizer,which often leads to lower yield and large accumulation of nitrate in the soil,bringing a potential risk to the environment.In order to explore the optimal regime of nitrogen fertilizer application suitable for environment and economy,a field experiment on the different rate and ratio of base and topdressing of nitrogen fertilizer at the different growth periods of winter wheat was conducted.The field experiment was undertaken from the fall of 2003 to the summer of 2004 in the village of Zhongcun in Longkou city,in the Shandong Province of China.The field experiment with three repeats for each treatment was designed in a split-plot.The major plot was applied with urea at a nitrogen fertilizer rate of three levels,namely,0 kg·hm-2 (CK),168 kg·hm-2 (A),and 240 kg·hm-2 (B).In the sub-plot,the ratios of base and topdressing nitrogen fertilizer at the different development periods of wheat were 1/2:1/2 (A1 and B1),1/3:2/3 (A2 and B2) and 0:1 (A3 and B3).Treatment B1 was under a regime used now in the local region.It was found that the amount of N accumulation in plants had no significant difference between treatments applied with nitrogen fertilizer.The grain yield and grain protein content were all elevated remarkably by applying nitrogen fertilizer compared with those of treatment CK.There was no significant difference in the grain yield and grain protein content between A2 and B2 and B3.However,when compared with those of B2 and B3,in A2 there was an increase in nitrogen use efficiency and residual soil

  3. 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.

  4. Sympathetic vasomotor control does not explain the change in femoral artery shear rate pattern during arm-crank exercise.

    Science.gov (United States)

    Thijssen, Dick H J; Green, Daniel J; Steendijk, Sjoerd; Hopman, Maria T E

    2009-01-01

    During lower limb exercise, blood flow through the resting upper limbs exhibits a change characterized by increased anterograde flow during systole, but also large increases in retrograde diastolic flow. One explanation for the retrograde flow is that increased sympathetic nervous system (SNS) tone and concomitant increased peripheral resistance generate a rebound during diastole. To examine whether the SNS contributes to retrograde flow patterns, we measured femoral artery blood flow during arm-crank exercise in 10 healthy men (31 +/- 4 yr) and 10 spinal cord-injured (SCI) subjects who lack sympathetic innervation in the legs (33 +/- 5 yr). Before, and every 5 min during 25-min arm-crank exercise at 50% maximal capacity, femoral artery blood flow and peak anterograde and retrograde shear rate were assessed using echo Doppler sonography. Femoral artery baseline blood flow was significantly lower in SCI compared with controls. Exercise increased femoral artery blood flow in both groups (ANOVA, P change during exercise in either group. Mean shear rate was lower in SCI than in controls (P rate was higher in SCI than in controls (P rate did not differ between groups. Arm-crank exercise induced an increase in peak anterograde and retrograde shear rate in the femoral artery in controls and SCI subjects (P change the flow pattern in inactive regions during exercise. Local mechanisms may play a role in the arm-crank exercise-induced changes in flow pattern in the femoral artery.

  5. Seroepidemiology of Rubella in Mozambique, 2006-2014: Implications for Rubella Immunization in Settings With High Fertility Rates.

    Science.gov (United States)

    Amade, Nádia Alves; Sultane, Thebora; Augusto, Orvalho; Ali, Sádia; Jani, Ilesh V; Gudo, Eduardo Samo

    2016-10-01

    Rubella and congenital rubella syndrome are highly underreported and neglected in most sub-Saharan countries and vaccination has not yet been incorporated into their national immunization schedules. In this study, we investigated the frequency of immunoglobulin M antibodies against rubella and examined correlations with fertility rates during the period from 2006 to 2014 in Mozambique. We conducted a retrospective analysis of data collected through the routine case-based surveillance system for measles in Mozambique. A total of 7312 serum samples from suspected cases of measles were tested between 2006 and 2014. The median age was 4 years (interquartile range: 1-8 years). Of these, 1331 (18.2%) were positive for immunoglobulin M anti-rubella. The highest frequency of rubella was observed within the 5-9-year-old age group (32.6%). The frequency in the age groups Mozambique. Considering that early pregnancy is common in Mozambique, this suggests that, in settings such as ours, the introduction of routine rubella vaccination in children should be accompanied by repeated vaccination campaigns targeting older children and adolescents.

  6. The Association between Neuroticism and Heart Rate Variability Is Not Fully Explained by Cardiovascular Disease and Depression.

    Science.gov (United States)

    Čukić, Iva; Bates, Timothy C

    2015-01-01

    Neuroticism is associated with cardiovascular disease, autonomic reactivity, and depression. Here we address the extent to which neuroticism accounts for the excess heart disease risk associated with depression and test whether cardiac autonomic tone plays a role as mediator. Subjects were derived from a nationally representative sample (n = 1,255: mean age 54.5, SD = 11.5). Higher neuroticism was associated with reduced heart rate variability equally under rest and stress. The baseline structural equation model revealed significant paths from neuroticism to heart rate variability, cardiovascular disease and depression, and between depression and cardiovascular disease, controlling for age, sex, height, weight, and BMI. Dropping both the neuroticism to heart rate variability, and neuroticism to heart disease paths significantly reduced the model fit (p neuroticism has independent associations with both autonomic reactivity and cardiovascular disease, over and above its associations with depression and other related variables.

  7. Compulsory Education Laws or Incentives from Conditional Cash Transfer Programs? Explaining the Rise in Secondary School Attendance Rate in Argentina

    Science.gov (United States)

    Edo, María; Marchionni, Mariana; Garganta, Santiago

    2017-01-01

    Argentina has traditionally stood out in terms of educational outcomes among its Latin American counterparts. Schooling of older children, however, still shows room for improvement especially among the more vulnerable. Fortunately, during the last years a sizeable improvement in attendance rates for children aged 15 through 17 took place. This…

  8. A germ-line-selective advantage rather than an increased mutation rate can explain some unexpectedly common human disease mutations.

    Science.gov (United States)

    Choi, Soo-Kyung; Yoon, Song-Ro; Calabrese, Peter; Arnheim, Norman

    2008-07-22

    Two nucleotide substitutions in the human FGFR2 gene (C755G or C758G) are responsible for virtually all sporadic cases of Apert syndrome. This condition is 100-1,000 times more common than genomic mutation frequency data predict. Here, we report on the C758G de novo Apert syndrome mutation. Using data on older donors, we show that spontaneous mutations are not uniformly distributed throughout normal testes. Instead, we find foci where C758G mutation frequencies are 3-4 orders of magnitude greater than the remaining tissue. We conclude this nucleotide site is not a mutation hot spot even after accounting for possible Luria-Delbruck "mutation jackpots." An alternative explanation for such foci involving positive selection acting on adult self-renewing Ap spermatogonia experiencing the rare mutation could not be rejected. Further, the two youngest individuals studied (19 and 23 years old) had lower mutation frequencies and smaller foci at both mutation sites compared with the older individuals. This implies that the mutation frequency of foci increases as adults age, and thus selection could explain the paternal age effect for Apert syndrome and other genetic conditions. Our results, now including the analysis of two mutations in the same set of testes, suggest that positive selection can increase the relative frequency of premeiotic germ cells carrying such mutations, although individuals who inherit them have reduced fitness. In addition, we compared the anatomical distribution of C758G mutation foci with both new and old data on the C755G mutation in the same testis and found their positions were not correlated with one another.

  9. Proximate determinants of fertility in peninsular Malaysia.

    Science.gov (United States)

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

    2012-05-01

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

  10. Male and female differential reproductive rate could explain parental transmission asymmetry of mutation origin in Hirschsprung disease.

    Science.gov (United States)

    Jannot, Anne-Sophie; Amiel, Jeanne; Pelet, Anna; Lantieri, Francesca; Fernandez, Raquel M; Verheij, Joke B G M; Garcia-Barcelo, Merce; Arnold, Stacey; Ceccherini, Isabella; Borrego, Salud; Hofstra, Robert M W; Tam, Paul K H; Munnich, Arnold; Chakravarti, Aravinda; Clerget-Darpoux, Françoise; Lyonnet, Stanislas

    2012-09-01

    Hirschsprung disease (HSCR, aganglionic megacolon) is a complex and heterogeneous disease with an incidence of 1 in 5000 live births. Despite the multifactorial determination of HSCR in the vast majority of cases, there is a monogenic subgroup for which private rare RET coding sequence mutations with high penetrance are found (45% of HSCR familial cases). An asymmetrical parental origin is observed for RET coding sequence mutations with a higher maternal inheritance. A parent-of-origin effect is usually assumed. Here we show that a differential reproductive rate for males and females also leads to an asymmetrical parental origin, which was never considered as a possible explanation till now. In the case of HSCR, we show a positive association between penetrance of the mutation and parental transmission asymmetry: no parental transmission asymmetry is observed in sporadic RET CDS mutation carrier cases for which penetrance of the mutation is low, whereas a parental transmission asymmetry is observed in affected sib-pairs for which penetrance of the mutation is higher. This allows us to conclude that the explanation for this parental asymmetry is that more severe mutations have resulted in a differential reproductive rate between male and female carriers.

  11. How can family policies reconcile fertility and women’s employment? Comparisons between South Korea and Sweden

    OpenAIRE

    Lee, Soomi; Duvander, Ann-Zofie; Zarit, Steven H.

    2016-01-01

    South Korea has extremely low rates of fertility and labor force participation by women during their childbearing years, whereas Sweden has high rates for both. Variations in family policy models may explain differences in fertility and women’s employment between the two countries. Drawing upon literature that examines the effects of family policies on fertility and women’s employment, this paper compares childcare support for very young children and parental leave policies in South Korea and...

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

    Directory of Open Access Journals (Sweden)

    Giulia eConversa

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-10-01

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

  14. [Effects of nitrogen fertilization rate and planting density on cotton biomass and nitrogen accumulation in extremely early mature cotton region of Northeast China].

    Science.gov (United States)

    Wang, Zi-Sheng; Xu, Min; Zhang, Guo-Wei; Jin, Lu-Lu; Shan, Ying; Wu, Xiao-Dong; Zhou, Zhi-Guo

    2011-12-01

    Taking two cotton cultivars Liaomian 19 and NuCOTN 33B with different growth periods as test materials, a field experiment was conducted to study the effects of different nitrogen fertilization rates (0, 240 and 480 kg N x hm(-2)) and different planting densities (75000, 97500 and 120000 plants x hm(-2)) on the cotton biomass, nitrogen accumulation, and accumulative nitrogen utilization in the planting region of extremely early mature cotton in Northeast China. The dynamics of cotton biomass and nitrogen accumulation of the two cultivars with their growth process followed Logistic model. Both nitrogen fertilization rate and planting density had significant effects on the cotton nitrogen accumulation dynamics and the cotton yield and quality. In all treatments, the beginning time of rapid accumulation of nitrogen was about 13 d earlier than that of biomass. In treatment plant density 97500 plants x hm(-2) and nitrogen fertilization rate 240 kg x hm(-2), the eigenvalues of the dynamic accumulation models of nitrogen and biomass for the two cultivars were most harmonious, lint yield was the highest, fiber quality was the best, and accumulative nitrogen utilization efficiency was the highest. In the study region, the earlier beginning time of rapid accumulation of nitrogen and biomass and their higher accumulation rates were benefit to the formation of higher cotton yield.

  15. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

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

    OpenAIRE

    Thomson Dana R; Hadley Michael B; Greenough P; Castro Marcia C

    2012-01-01

    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 rep...

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

    OpenAIRE

    Dana R Thomson; Hadley, Michael B; Greenough, P Gregg; Castro, Marcia C

    2012-01-01

    Background: Idjwi, an island of approximately 220,000 people, is located in eastern DRC and functions semi-autonomously under the governance of two kings (mwamis). At more than 8 live births per woman, Idjwi has one of the highest total fertility rates (TFRs) in the world. Rapid population growth has led to widespread environmental degradation and food insecurity. Meanwhile family planning services are largely unavailable.\\ud \\ud Methods: At the invitation of local leaders, we conducted a rep...

  18. 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%.

  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.

  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 3

  1. Vitamin E Supplementation to Sows and Effects on Fertility Rate and Subsequent Body Development of their Weanling Piglets

    Directory of Open Access Journals (Sweden)

    D. O. Umesiobi

    2009-10-01

    Full Text Available The aim of this study was to evaluate the effects of dietary supplementation of vitamin E to sows on sow fertility and serum α-tocopherol, growth and physiological state of their weanling pigs. A total of 60 Large White gilts were randomly allotted to three groups (20 gilts per group from coitus to lactation phases over a two-parity period to evaluate the effects of dietary vitamin E on fecundity rates and litter size of sows. Each of the three dietary vitamin E treatment combinations involved 0, 40 or 70 IU/kg of dl- α-tocopheryl acetate/kg of diet, and parity 1 and 2. Sow serum α-tocopherol and Selenium (Se were collected at 30 day post coitum, 99 day of gestation and 21 day lactation. Serum α-tocopherol and Se were collected from piglets at 1 day post natum and on day 21 (weaning age. Data relating to sow fecundity and litter size were also recorded. Results indicate that body weights and body weight gains of sows and their litters increased significantly (P < 0.01 by parity, increasing more from parities 1 to 2, mostly when dietary vitamin E was increased from 40 to 70 IU/kg diet. The highest number of total piglets and number of piglets born alive (12 ± 8.9 vs. 11 ± 0.1 were obtained at parity 2 when dietary vitamin E was increased to 70 IU/kg diet. There was an increase in weights of the piglets when dietary vitamin E was increased in sow’s diet. There was a dramatic increase in serum α-tocopherol and Se concentrations following 40 and 70 IU/kg of vitamin E supplementation during the 30 and 99 day gestation and 21 day lactation periods as parity increased. Se concentrations were about 3 fold higher in the 70 IU/kg vitamin E supplemented group in parity 2 compared to the other groups. In both parities, female piglets had higher serum α-tocopherol and Se concentrations at both 2 day post natum and on day 21 (weaning compared to the male piglets. Results from this study suggest that supplementing 70 IU/kg α-tocopheryl acetate in

  2. WOMEN’S EMPOYMENT ON THE BACKGROUND OF THEIR EDU-CATION AND FERTILITY RATES IN POLAND AND IN SELECTED COUNTRIES OF THE EUROPEAN UNION IN YEARS 2001-2013

    Directory of Open Access Journals (Sweden)

    Katarzyna Martens

    2016-12-01

    Full Text Available This publication considers effects of education and fertility on women’s employment in Poland and in selected countries of the European Union. Econometric models of trend and autoregression are built. It is shown that in Poland - higher education and fertility rates have little effect on the presence of women on the labor market. In the European Union both education and fertility have a significant impact on increasing job opportuni-ties. In Germany an important determinant is education and in France - fertility.

  3. A demographic explanation for the recent rise in European fertility.

    Science.gov (United States)

    Bongaarts, John; Sobotka, Tomáš

    2012-01-01

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

  4. Intracytoplasmic Sperm Injection Fertilization Rate Does Not-Depend on the Proportion of Round-headed Sperm, Small acrosomal Sperm, or Morphologically Normal Sperm in Patients with Partial Globozoospermia

    Institute of Scientific and Technical Information of China (English)

    Ling-Ying Jiang; Ling-Yun Yang; Xiao-Mei Tong; Hai-Yan Zhu; Ya-Mei Xue; Wen-Zhi Xu; Yang Yang

    2015-01-01

    Background:Generally,intracytoplasmic sperm injection (ICSI) may be the preferable method to treat partial globozoospermia,but whether there exist some correlations between ICSI fertilization rate and the proportion of round-headed sperm or morphologically normal sperm remains open.This study was to explore the correlation between ICSI fertilization rate and the sperm morphology in patients with partial globozoospermia.Methods:Thirty-four patients diagnosed with partial globozoospermia accepted the following assisted fertilization treatments-2 cases accepted in-vitro fertilization (IvF) alone,26 cases accepted ICSI alone,and 6 accepted split IVF/ICSI.Detailed morphological characteristics were described using Diff-Quik rapid staining.Sixty cases accepting IVF or ICSI treatment in our reproductive center were considered as the control group after being matched by relevant criteria.Fertilization rate,embryo quality,embryo implantation rate and clinical pregnancy rate were calculated.Results:Besides very high proportion of round-headed sperm,partial globozoospermia also showed very high proportion of small-acrosomal sperm and very low proportion of morphologically normal sperm.Fertilization rate of IVF (IVF alone plus split IVF) was very low in partial globozoospermia (25.4% ± 17.4%),but ICSI (ICSI alone plus split ICSI) achieved satisfying fertilization rate compared with the control group (66.2% ± 22.5% vs.68.8% ± 29.4%,P > 0.05).In patients with partial globozoospermia,there were no correlations between ICSI fertilization rate and the proportion of round-headed sperm,small-acrosomal sperm,or morphologically normal sperm.Conclusions:There was high proportion of small-acrosomal sperm in partial globozoospermia.For patients with partial globozoospermia,ICSI is more preferable than IVF.ICSI fertilization rate does not depend on the proportion of round-headed sperm,small-acrosomal sperm,or morphologically normal sperm.

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

    Science.gov (United States)

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

    2016-01-01

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

  6. 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.

  7. 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.

  8. Fertilization Rate and Number of Embryos on Day 2 after Intrauterine and Deep Intrauterine Insemination Using Frozen-Thawed Boar Semen in Multiparous Sows

    Directory of Open Access Journals (Sweden)

    Kakanang Buranaamnuay

    2011-01-01

    Full Text Available The present study determines fertilization rate and number of embryos on Day 2 after intrauterine insemination (IUI and deep intrauterine insemination (DIUI using frozen-thawed (FT boar semen in multiparous sows. Twelve crossbred Landrace × Yorkshire multiparous sows were included. The sows were inseminated at 24 h after oestrus detection and reinseminated every 12 h until ovulation took place. The inseminations were conducted using IUI with 2×109 FT sperm per dose (n=6 and DIUI with 1×109 FT sperm per dose (n=6. The sows were slaughtered at 45.1±7.2 h after ovulation. Embryos and unfertilized oocytes were flushed from the oviducts. IUI yielded a better fertilization rate than DIUI (66.0% versus 31.0%, P<.001. The number of embryos was 13.5±2.7 and 6.6±3.2 embryos/sow in IUI and DIUI groups, respectively (P=.08. The proportion of sows having unilateral fertilization was higher in the DIUI (3/5 than the IUI group (1/6. In conclusion, IUI with at least 2×109 total number of FT boar spermatozoa is recommended.

  9. Improved fertilization and implantation rates after non-touch zona pellucida microdrilling of mouse oocytes with a 1.48 microm diode laser beam.

    Science.gov (United States)

    Germond, M; Nocera, D; Senn, A; Rink, K; Delacretaz, G; Pedrazzini, T; Hornung, J P

    1996-05-01

    The safety of microdrilling the zona pellucida of mouse oocytes with a 1.48 microm diode laser has been investigated by determining the ability of mouse oocytes to fertilize in vitro and develop in vivo. Mice born after transfer of control and zona pellucida-microdrilled embryos into foster mothers were submitted to anatomical and immunohistochemical investigations, and their aptitude to breed was assessed in two subsequent generations. Decoronization of the oocytes with hyaluronidase induced a reduction of the fertilization and implantation rates, which was attributed to a zona hardening phenomenon. After laser zona pellucida microdrilling, these rates were restored to those obtained with embryos derived from untreated oocyte-cumulus complexes. Pups derived from zona pellucida microdrilled embryos were comparable with those obtained from control embryos, confirming the lack of deleterious effects of the laser treatment. In conclusion, the 1.48 microm diode laser allows safe microdrilling of the zona pellucida of mouse oocytes after decoronization with hyaluronidase. Based on the health of the F2 generation and the lack of neuroanatomical and neurochemical differences, we concluded that this technology may be investigated in the human, particularly when the zona pellucida represents the main impediment for fertilization or embryo hatching.

  10. The political economy of farmers' suicides in India: indebted cash-crop farmers with marginal landholdings explain state-level variation in suicide rates.

    Science.gov (United States)

    Kennedy, Jonathan; King, Lawrence

    2014-03-26

    A recent Lancet article reported the first reliable estimates of suicide rates in India. National-level suicide rates are among the highest in the world, but suicide rates vary sharply between states and the causes of these differences are disputed. We test whether differences in the structure of agricultural production explain inter-state variation in suicides rates. This hypothesis is supported by a large number of qualitative studies, which argue that the liberalization of the agricultural sector in the early-1990s led to an agrarian crisis and that consequently farmers with certain socioeconomic characteristics-cash crops cultivators, with marginal landholdings, and debts-are at particular risk of committing suicide. The recent Lancet study, however, contends that there is no evidence to support this hypothesis. We report scatter diagrams and linear regression models that combine the new state-level suicide rate estimates and the proportion of marginal farmers, cash crop cultivation, and indebted farmers. When we include all variables in the regression equation there is a significant positive relationship between the percentage of marginal farmers, cash crop production, and indebted farmers, and suicide rates. This model accounts for almost 75% of inter-state variation in suicide rates. If the proportion of marginal farmers, cash crops, or indebted farmers were reduced by 1%, the suicide rate--suicides per 100,000 per year--would fall by 0 · 437, 0 · 518 or 0 · 549 respectively, when all other variables are held constant. Even if the Indian state is unable to enact land reforms due to the power of local elites, interventions to stabilize the price of cash crops and relieve indebted farmers may be effective at reducing suicide rates.

  11. Current evolutionary adaptiveness of psychiatric disorders: Fertility rates, parent-child relationship quality, and psychiatric disorders across the lifespan.

    Science.gov (United States)

    Jacobson, Nicholas C

    2016-08-01

    This study sought to evaluate the current evolutionary adaptiveness of psychopathology by examining whether these disorders impact the quantity of offspring or the quality of the parent-child relationship across the life span. Using the National Comorbidity Survey, this study examined whether DSM-III-R anxiety, posttraumatic stress, depressive, bipolar, substance use, antisocial, and psychosis disorders predicted later fertility and the quality of parent-child relationships across the life span in a national sample (N = 8,098). Using latent variable and varying coefficient models, the results suggested that anxiety in males and bipolar pathology in males and females were associated with increased fertility at younger ages. The results suggested almost all other psychopathology was associated with decreased fertility in middle to late adulthood. The results further suggested that all types of psychopathology had negative impacts on the parent-child relationship quality (except for antisocial pathology in males). Nevertheless, for all disorders, the impact of psychopathology on both fertility and the parent-child relationship quality was affected by the age of the participant. The results also showed that anxiety pathology is associated with a high-quantity, low-quality parenting strategy followed by a low-quantity, low-quality parenting strategy. Further, the results suggest that bipolar pathology is associated with an early high-quantity and a continued low-quality parenting strategy. Posttraumatic stress, depression, substance use, antisocial personality, and psychosis pathology are each associated with a low-quantity, low-quality parenting strategy, particularly in mid to late adulthood. These findings suggest that the evolutionary impact of psychopathology depends on the developmental context. (PsycINFO Database Record

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

    Science.gov (United States)

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

    2015-09-15

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

  13. ENSO, nest predation risk, food abundance, and male status fail to explain annual variations in the apparent survival rate of a migratory songbird.

    Directory of Open Access Journals (Sweden)

    Alizée Vernouillet

    Full Text Available Adult mortality can be a major driver of population decline in species whose productivity is relatively low. Yet, little is known about the factors influencing adult survival rates in migratory bird species, nor do we know much about the longer-term effects of habitat disturbance on the fitness of individuals. The Ovenbird (Seiurus aurocapilla is one of the vertebrate species most sensitive to forest management, yet it is still common and widespread. We monitored the fate of 330 colour-banded Ovenbird males in four pairs of 25-ha plots during 9 successive breeding seasons. One plot of each pair was treated through selection harvesting (30-40% basal area removed during the first winter. We tested the following hypotheses: (1 higher physiological costs in harvested plots as a result of lower food abundance will reduce apparent survival rate (ASR relative to controls; (2 lower ASR following years with low nest survival and higher probability of renesting; (3 fluctuations in ASR reflecting El Niño Southern Oscillation (ENSO; and (4 higher ASR in returning males than in recruits (unbanded immigrants owing to greater site familiarity in the former. We tested the relative importance of these hypotheses, or combinations thereof, by generating 23 models explaining variation in ASR. The year-dependent model received the most support, showing a 41% decrease in ASR from 2007 to 2014. The important year-to-year variation we observed in ASR (Σw(i = 0.99 was not explained by variation in nest predation risk nor by ENSO. There was also little evidence for an effect of selection harvesting on ASR of Ovenbird males, despite a slight reduction in lifespan relative to males from control plots (2.7 vs 2.9 years. An avenue worth exploring to explain this intriguing pattern would be to determine whether conditions at migratory stopover sites or in the wintering area of our focal population have gradually worsened over the past decade.

  14. Explaining socioeconomic inequalities in self-rated health: a systematic review of the relative contribution of material, psychosocial and behavioural factors.

    Science.gov (United States)

    Moor, Irene; Spallek, Jacob; Richter, Matthias

    2017-06-01

    Material, psychosocial and behavioural factors are important explanatory pathways for socioeconomic inequalities in health. The aim of this systematic review was to summarise the available evidence on empirical studies and to analyse the relative contribution of these factors for explaining inequalities in self-rated health. The study was performed in compliance with PRISMA guidelines. The literature search was conducted in the electronic databases PubMed and Web of Science (1996-2016) as well as by screening of reference lists of obtained articles. Two reviewers performed the search and critical appraisal of the studies. All studies that focus on explaining socioeconomic inequalities in self-rated health, including at least 2 of the 3 main pathways and analysing the relative contribution of these approaches in separate and joint models, were included. Eleven publications were included. Separate analyses showed that material, psychosocial and behavioural factors contribute to the explanation of socioeconomic inequalities in self-rated health. However, the combined analyses revealed that material factors contributed most to differences in self-rated health because of their higher independent (direct) effect and additional shared (indirect) effect (through psychosocial and behavioural factors). These results were largely independent of age, gender and indicator of socioeconomic status. The evidence presented might be used for policymakers to identify and to justify prioritisation in terms of prevention and health promotion. The findings show that multiple factors are important for tackling social inequalities in health. Strategies for reducing these inequalities should focus on material/structural living conditions as they shape conditions of psychosocial resources and health behaviour. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  15. MEDIA CONCERN AND TRENDS OF FERTILITY IN BANGLADESH

    Directory of Open Access Journals (Sweden)

    Mohammad Morad

    2014-05-01

    Full Text Available This paper analyses how the media interprets Bangladeshian fertility trends by analyzing 11 online available articles from two Bangladeshi leading dailies, The Daily Star and the Prothom Alo. The exploration of the newspaper articles reveals that print media in Bangladesh has shown concern notably on the present scenario of the country’s declining fertility trend. It has been observed from the newspaper clippings that both population growth rate and fertility rate are gradually declining in Bangladesh which they explain as a matter of great satisfaction. Drawing on examples from South Asia, the articles explain that Bangladesh has a remarkable achievement in fertility reduction compared to India and Pakistan. However, almost all of the articles have expressed concern over the population bomb of Bangladesh. The newspapers also report that though fertility is declining at the national level, significant variation exists at the regional level and among different socio economic groups. The fertility rate is reported to be very high in the urban shanties and poverty-stricken rural areas. In this regard, the clippings have often criticized the government activities, especially governmental population control programme.

  16. 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

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

    Science.gov (United States)

    2009-01-01

    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 osteopontin slightly

  18. SPSS explained

    CERN Document Server

    Hinton, Perry R; Brownlow, Charlotte

    2014-01-01

    SPSS Explained provides the student with all that they need to undertake statistical analysis using SPSS. It combines a step-by-step approach to each procedure with easy to follow screenshots at each stage of the process. A number of other helpful features are provided: regular advice boxes with tips specific to each test explanations divided into 'essential' and 'advanced' sections to suit readers at different levels frequently asked questions at the end of each chapter. The first edition of this popular book has been fully updated for IBM SPSS version 21 and also includes: chapters that expl

  19. Effect of feeding guanidinoacetic acid and L-arginine on the fertility rate and sperm penetration in the perivitelline layer of aged broiler breeder hens.

    Science.gov (United States)

    Sharideh, H; Esmaeile Neia, L; Zaghari, M; Zhandi, M; Akhlaghi, A; Lotfi, L

    2016-04-01

    Two experiments were conducted to evaluate the effects of feeding guanidinoacetic acid (GAA) and L-arginine (ARG) on fertility and sperm penetration (SP) rate of broiler breeder hens. In the first experiment, a total of 200 broiler breeder hens (Ross 308) aged 53 weeks were randomly allotted to four dietary treatments (0, 0.6, 1.2 and 1.8 g GAA/kg diet) with five replicates of 10 birds each. In the second experiment, 320 broiler breeder hens (Ross 308) were used from 53 to 62 weeks of age in a 2 × 4 factorial arrangement (0 or 1.2 g GAA/kg diet along with 0, 3, 6 or 9 g ARG/kg diet). The hens received a diet containing 2800 kcal ME/kg and 14% CP. Sixteen sexually mature Ross 308 breeder roosters (34 weeks old) were used to artificially inseminate the hens. Fertility of the hens was determined in 61 and 62 weeks of age. The sperm penetration holes in the inner perivitelline layer (IPL) overlying the germinal disc were enumerated on days 3 and 7 following each insemination. Adding GAA to the breeder diet increased the number of SPs in the IPL and fertility in both experiments (p hens at the later phase of the egg production period.

  20. Falling fertility and increase in use of contraception in Zimbabwe.

    Science.gov (United States)

    Mturi, Akim; Joshua, Kembo

    2011-06-01

    Zimbabwe does not feature much on the current debate of fertility transition in sub-Saharan Africa. This article is trying to fill this gap by analysing the ZDHS data. The total fertility rate of Zimbabwe was close to 7 births during independence in 1980. However, it has declined to 3.8 in 2006. This does not only show that fertility in Zimbabwe has been declining over the years, but it is one of the lowest in the region. The fertility trend observed is mainly explained by use of contraception. The contraceptive prevalence rate was 60 percent in 2006. It is noted that the contraceptive uptake has continued to increase even during the years when Zimbabwe was going through serious political, economic, social and health challenges. This is because the groundwork done on the family planning programme soon after independence put a solid foundation in motivating women to use contraception.

  1. Effect of Partial Incision of the Zona Pellucida by Piezo-Micromanipulator for In Vitro Fertilization Using Frozen-Thawed Mouse Spermatozoa on the Developmental Rate of Embryos Transferred at the 2-Cell Stage

    National Research Council Canada - National Science Library

    Yosuke Kawase; Takamitsu Iwata; Otoya Ueda; Nobuo Kamada; Takanori Tachibe; Yukari Aoki; Kou-ichi Jishage; Hiroshi Suzuki

    2002-01-01

    .... The C57BL/6 mouse strain is a very widely used for establishment of transgenic mice, but the fertilization rate associated with the use of cryopreserved C57BL/6 spermatozoa is very low compared...

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

    Science.gov (United States)

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

    2016-01-01

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

  3. 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

    2016-01-01

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

  4. Fertility Awareness

    Science.gov (United States)

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

  5. 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.

  6. 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.

  7. Can contact allergy to p-phenylenediamine explain the high rates of terpene hydroperoxide allergy? - An epidemiological study based on consecutive patch test results

    DEFF Research Database (Denmark)

    Bennike, Niels Højsager; Lepoittevin, Jean-Pierre; Johansen, Jeanne D

    2017-01-01

    on proteins in mechanistic studies. OBJECTIVES: To test the hypothesis that patients sensitized to PPD are at increased risk of concomitant reactivity to either of the terpene hydroperoxides, owing to a 'common pathway' of skin protein oxidation. METHODS: A database study of consecutively patch tested eczema...... patients (n = 3843) from 2012 to 2015, tested concomitantly with PPD, Lim-OOHs and Lin-OOHs, was performed. Associations were examined by level of concordance and odds ratios (ORs) adjusted for age, sex, and contact allergy to fragrance mix I and fragrance mix II. RESULTS: Concomitant reactions to PPD were...... increased risk (OR 2.11, 95%CI:0.92-4.80) of a positive patch test reaction to Lin-OOHs. CONCLUSIONS: PPD sensitization cannot explain the high rates of sensitization to Lin-OOHs and/or Lim-OOHs. Contact allergy to oxidized linalool is more strongly associated with fragrance allergy than with PPD allergy....

  8. Blastocyst transfer ameliorates live birth rate compared with cleavage-stage embryos transfer in fresh in vitro fertilization or intracytoplasmic sperm injection cycles: reviews and meta-analysis.

    Science.gov (United States)

    Wang, Shan-Shan; Sun, Hai-Xiang

    2014-05-01

    Blastocyst transfer has been recommended to raise the implantation rate without affecting the pregnancy rate. The objective of this meta-analysis is to systematically evaluate whether the live birth rate and other pregnancy outcomes can be improved by blastocyst transfer compared with cleavage-stage embryos transfer. EMBASE and MEDLINE databases were searched for papers published between March 2004 and March 2013. An extensive range of the electronic databases yielded initially 317 studies from which seven trials met the inclusion criteria for further analysis. Our outcome measures were the live birth rate, clinical pregnancy rate, implantation rate, ongoing pregnancy rate, multiple pregnancy rate, first trimester miscarriage rate and ectopic pregnancy rate. Fixed effects models were chosen to calculate the odds ratio (OR). Seven trials (n=1446 cases) were finally analyzed. Compared with cleavage-stage embryos transfer, the blastocyst transfer was statistically significantly associated with an increase in clinical pregnancy rate [OR 1.43; 95% confidence interval (CI), 1.15-1.78], implantation rate (OR 1.38; 95% CI, 1.09-1.74) and ongoing pregnancy rate (OR 2.15; 95% CI, 1.57-2.94), and also a reduction in the probability of first trimester miscarriage rate (OR 0.51; 95% CI, 0.30-0.87). The improvement in the live birth rate was also observed (OR 1.77; 95% CI, 1.32-2.37). Moreover, there was no evidence of difference in multiple pregnancy and ectopic pregnancy rates. The available evidences suggest that live birth and other pregnancy outcomes after fresh in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) are significantly improved following blastocyst transfer as compared to cleavage-stage embryo transfer.

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

    Science.gov (United States)

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

    2017-01-01

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

  10. Natural fertility in the Philippines.

    Science.gov (United States)

    Aquino, E G

    1982-01-01

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

  11. 体外受精中受精低下周期的促排卵方案及妊娠结局观察%Analysis of ovarian stimulation protocols and pregnancy outcomes of in vitro fertilization cycles with low fertilization rate

    Institute of Scientific and Technical Information of China (English)

    金仁桃; 童先宏; 吴丽敏; 骆丽华; 周桂香; 栾红兵; 刘雨生

    2011-01-01

    目的 分析体外受精(IVF)周期受精低下的原因及妊娠结局.方法 观察IVF受精低下83周期(受精低下组),以同期受精正常的1,717个IVF周期为对照组,比较两组的卵裂率、优质胚胎率、种植率、临床妊娠率、流产率;同时观察不同促排方案对受精低下的影响.结果 两组不同促排方案的受精低下比率无显著差异(P>0.05);卵裂率、优质胚胎率、种植率、临床妊娠率、流产率也均无显著差异(P>0.05).结论 促排卵方案不是影响受精低下的因素,受精低下周期中获得的胚胎质量及发育潜能没有影响.%Objective: To analyze the possible reason and pregnancy outcomes of low fertilization rate cycle of in vitro fertilization (IVF) treatment. Methods: Eighty-three IVF cycles with low fertilization rate were retrospectively studied, with 1,717 cycles with normal fertilization rate during the same period as control. Cleavage rate, good embryo rate, clinical pregnancy rate, implantation rate and abortion rate were analyzed. The possible association of different ovarian stimulation protocols with low fertilization cycles was studied. Results: There was no significant difference in the incidence of low-fertilization-rate cycle between different stimulation protocols (P>0.05). The rates of cleavage, good embryo, implantation, clinical pregnancy or abortion were not significantly different between low-fertilization-rate cycles and normal control cycles (P>0.05). Conclusions: Ovarian stimulation protocol was not an influencing factor of low fertilization rate, and low fertilization rate did not have much impact on embryo quality and development potential.

  12. [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.

  13. [Effects of nitrogen fertilization rate and planting density on cotton boll biomass and nitrogen accumulation in extremely early maturing cotton region of Northeast China].

    Science.gov (United States)

    Wang, Zi-Sheng; Wu, Xiao-Dong; Gao, Xiang-Bin; Xu, Min; Shen, Dan; Jin, Lu-Lu; Zhou, Zhi-Guo

    2012-02-01

    Taking cotton cultivars Liaomian 19 and NuCoTN 33B as test materials, a field experiment was conducted to study the effects of nitrogen fertilization rate (0, 240 and 480 kg x hm(-2)) and planting density (75000, 97500 and 120000 plants x hm(-2)) on the boll biomass and nitrogen accumulation in the extremely early maturing cotton region of Northeast China. With the growth and development of cotton, the biomass and nitrogen accumulation of cotton boll, cotton seed, and cotton fiber varied in 'S' shape. Both nitrogen fertilization rate and planting density had significant effects on the dynamic characteristics of boll biomass and nitrogen accumulation, and on the fiber yield and quality. In treatment 240 kg x hm(-2) and 97500 plants x hm(-2), the biomass of single boll, cotton seed and cotton fiber was the maximum, the starting time and ending time of the rapid accumulation period of the biomass and nitrogen were earlier but the duration of the accumulation was shorter, the rapid accumulation speed of the biomass was the maximum, and the distribution indices of the biomass and nitrogen were the lowest in boll shell but the highest in cotton seed and cotton fiber.

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

    Science.gov (United States)

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

    2011-07-01

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

  15. The Effect of Seeding Rates and Nitrogen fertilizer on Yield and Yield Components of Wheat Cultivars in Corn residue (No Tillage

    Directory of Open Access Journals (Sweden)

    D Omidi Nasab

    2016-02-01

    Full Text Available Introduction Lots of studies have been conducted for increasing the wheat yield per unit area through sustainable agriculture, which is included low tillage and no tillage farming systems. Furthermore, nitrogen is the important element which is used to increase crop yield. On the other hand, if all the required conditions especially cultivar and fertilizer are at optimum level, but density is not appropriate, the maximum yield per unit area will not be achieved. Therefore, this study was conducted to evaluate the effect of seeding rates and nitrogen fertilizer on yield and yield components of wheat cultivars in corn residue. Materials and Methods An split factorial experiment in a randomized complete block design with four replications and three factors including cultivar at 2 levels, (Chamran (V1 and Behrang (V2, seed density at 5 levels (50 (D1, 100 (D2, 150 (D3, 200 (D4, 250 (D5 kg ha-1 and nitrogen fertilizers from urea source at 6 levels (0 (N1, 50 (N2, 100 (N3, 150 (N4, 200 (N5, 250 (N6 carried out in fall of 2011 – 2012 at Agricultural Farm located south of Dezful. Results and Discussion The results indicated that with increasing plant density, the number of spike and biological yield increased, however the number of grain in each spike and thousand seed weight decreased. Moreover, increasing nitrogen application resulted in increasing the number of spike, the number of grain in each cluster, thousand seed weight, biological yield and grain yield. seed consumption over than 100 (kg ha-1 decreased grain yield . In addition, applied nitrogen to 150 (kg ha-1 significantly increased grain yield. The effects of plant density on grain yield illustrated that the highest grain yield was obtained using 100 kg seeds per hectare. Furthermore, there were not any significant differences among 150, 200 and 250 kg seeds per hectare and they were at a lower level of grain yield. In addition, Chamran cultivar, with 413.70 (kg ha-1 average grain yield

  16. 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.

  17. Improvement in in vitro fertilization rate, decrease in reactive oxygen species and spermatozoa death incidence in rams by dietary fish oil.

    Science.gov (United States)

    Matini Behzad, A; Ebrahimi, B; Alizadeh, A R; Esmaeili, V; Dalman, A; Rashki, L; Shahverdi, A H

    2014-08-01

    Our aim was to evaluate the effects of fish oil feeding on sperm classical parameters, level of reactive oxygen spices (ROS), spermatozoa death incidence and in vitro fertilization (IVF) rate in rams. We randomly assigned nine rams, into two experimental groups (isoenergetic and isonitrogenous rations with constant level of vitamin E supplement): control (CTR; n = 5) and fish oil (FO; n = 4, 35 g/day/ram). Diets were fed for 70 days during the physiological breeding season. After a 21-day dietary adaptation period, semen was collected weekly from each ram by an artificial vagina. Sperm classical parameters were determined by the computer-assisted sperm analyzer system (CASA), and it was prepared for IVF process by swim-up technique. These evaluations were performed during the first and last weeks of sampling. Intracellular ROS level and spermatozoa death incidence were detected by flow cytometry on a weekly basis after adaptation. Data were analysed with SPSS 15. The volume, concentration (3.6 and 2.7 × 10(9) /ml) and sperm progressive motility (60 and 48%) were significantly improved in the FO group compared with the CTR (p < 0.05). A comparison of two-cell stage embryos following IVF in the two groups showed a significantly higher fertilization rate in the FO group (56%) compared with the CTR (49%). Superoxide anion (O2 (-) ) rate was significantly lower (p < 0.05) at the third week of sampling in the FO. Although the H2 O2 rate was numerically lower in the FO group compared with the CTR, this difference was not significant. In addition, apoptosis showed a significant difference in the third week of sampling (15 and 30% for FO and CTR, respectively; p < 0.05). Overall, adding fish oil to the ram diet not only improved sperm quality and IVF results, it also could reduce oxygen-free radicals and the incidence of spermatozoa death.

  18. Aqueous and gaseous nitrogen losses induced by fertilizer application

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-15

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

  19. The Role of Antioxidant Enzymes in Adaptive Responses to Sheath Blight Infestation under Different Fertilization Rates and Hill Densities

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2014-01-01

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

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

    Science.gov (United States)

    Thiex, Nancy

    2016-01-01

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

  1. The fertility decline in Kenya.

    Science.gov (United States)

    Robinson, W C; Harbison, S F

    1995-01-01

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

  2. 生育率最优路径、劳动力供给转型与经济增长%Fertility Rate Optimal Path,Labor Supply Transition and Economic Growth

    Institute of Scientific and Technical Information of China (English)

    陈仲常; 马红旗

    2011-01-01

    In this paper,through endogenous labor and human capital,based on Becker's Q-Q theory,according to fertility rate in the joint relations of labor supply and human capital accumulation and the transformation law of labor supply,and use of dynamic optimal control theory,it explains developing countries increased and then decreased in the country's population reproduction process and economic effects since the colonial liberation.The results showed: the optimal path of fertility rate inverted "U" type;this path exists two saddle points equilibrium,and only when human capital accumulation strides over a certain "threshold",the first saddle point equilibrium transits to another saddle point equilibrium;equilibrium level of output is proportional to the labor depreciation rate,and inversely proportional to human capital depreciation rate.%通过内生化劳动力和人力资本,以Q-Q理论为基础,根据生育率在劳动力供给和人力资本积累中的联动关系以及劳动力供给转型规律,利用动态最优控制原理,解释了殖民解放以来发展中国家先上升后下降的人口再生产过程及经济效应。结果表明:生育率的最优路径呈倒"U"型;整个路径存在两个鞍点均衡,只有当人力资本积累跨越某个"门槛值"时,第一个鞍点均衡才能过渡到另一个鞍点均衡;均衡的产出水平与劳动力折旧率成正比,与人力资本折旧率成反比。

  3. Design and Experiment on Control System of Self-Propelled Variable-Rate Fertilizer%液压变量施肥控制系统设计与试验

    Institute of Scientific and Technical Information of China (English)

    陈书法; 赵真; 封成龙; 杨进

    2012-01-01

    为解决现有水田撒肥机械存在肥量调节控制技术落后、不能适应变量作业工作要求等问题,设计了一种变量撒肥控制系统.通过分析国内外变量施肥技术研究情况,概述了变量撒肥机总体结构和工作原理,研究了控制内容和控制策略,确定了以AT89C51单片机作为主控制核心元件的计算机控制系统,进行软硬件设计和系统集成.通过场地和田间撒肥试验表明,撒肥机作业效率达到6 hm2/h,施肥量偏差小于5%,排肥量稳定性变异系数仅为6.2%,撒肥机工作性能和控制系统设计满足水田变量撒肥工作要求.%In order to solve the problem, of backward manure regulation control technology which was not suitable for variable -rate fertilization needs of paddy fertilizing machine,a variable -rate fertilization control system was designed.Based on the domestic and foreign research situations of the variable—rate fertilizing technology, the overall structure and working mechanism of the variable-rate fertilizing machine were described,and control content and strategy were studied, AT89C51single chip was used as a core control element in the control system, hardware and software were designed, and control system was integrated. The variable—rate fertilizing experiment in space and paddy field shows that the working efficiency is up to 6hm2/h, the fertilizing error is less than 5%, and the fertilizing stability variation coefficient is only 6.2%, so the working performance and control system design of the fertilizer is suitable for spreading the fertilizer invariable rate widely and efficiently in paddy field.

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

    Science.gov (United States)

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

    2010-02-01

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

  5. 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

  6. Serum progesterone elevation adversely affects cumulative live birth rate in different ovarian responders during in vitro fertilization and embryo transfer: a large retrospective study.

    Science.gov (United States)

    Bu, Zhiqin; Zhao, Feifei; Wang, Keyan; Guo, Yihong; Su, Yingchun; Zhai, Jun; Sun, Yingpu

    2014-01-01

    In order to explore the relationship between serum progesterone (P) level on the day of human chorionic gonadotrophin (HCG) administration and cumulative live birth rate in patients with different ovarian response during in vitro fertilization (IVF), we carried out this retrospective cohort study including a total of 4,651 patients undergoing their first IVF cycles from January 2011 to December 2012. All patients with a final live birth outcome (4,332 patients) were divided into three groups according to ovarian response: poor ovarian responder (≤5 oocytes, 785 patients), intermediate ovarian responder (6-19 oocytes, 3065 patients) and high ovarian responder (≥20 oocytes, 482 patients). The thresholds for serum P elevation were 1.60 ng/ml, 2.24 ng/ml, and 2.50 ng/ml for poor, intermediate, and high ovarian responders, respectively. Cumulative live birth rate per oocyte retrieval cycle was calculated in each group. The relationship between serum P level and cumulative live birth rate was evaluated by both univariate and multivariate logistic regression analysis. Cumulative live birth rate per oocyte retrieval cycle was inversely associated with serum P level in patients with different ovarian response. For all responders, patients with elevated P level had significantly higher number of oocytes retrieved, but lower high quality embryo rate, and lower cumulative live birth rate compared with patients with normal serum P level. In addition, serum P level adversely affected cumulative live birth rate by both univariate and multivariate logistic regression analysis, independent of ovarian response. Serum P elevation on the day of HCG administration adversely affects cumulative live birth rate per oocyte retrieval cycle in patients with different ovarian response.

  7. Cryopreservation of mammalian oocytes by using sugars: Intra- and extracellular raffinose with small amounts of dimethylsulfoxide yields high cryosurvival, fertilization, and development rates.

    Science.gov (United States)

    Eroglu, Ali

    2010-07-01

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

  8. Inconsistencies in the relationship between contraceptive use and fertility in Bangladesh.

    Science.gov (United States)

    Saha, Unnati Rani; Bairagi, Radheshyam

    2007-03-01

    Contraceptive prevalence increased by nine percentage points from 1993 to 2000 in Bangladesh, but there was almost no decline in the total fertility rate. Data from the 1999-2000 Bangladesh Demographic and Health Survey and from the Matlab Demographic Surveillance System area collected between 1978 and 2001 were analyzed to explain the lack of change in fertility and to examine relationships among contraceptive prevalence, the abortion ratio, desired fertility and total fertility. After a maternal and child health and family planning program was initiated in part of Matlab in 1977, the total fertility rate in the intervention area declined from 4.8 in 1979 to 2.9 in 2000, while fertility in the comparison area dropped from 6.3 to 3.5. Over this period, contraceptive prevalence rose from 30% to 70% and from 16% to 50% in the two areas, respectively; meanwhile, the abortion ratio fell from 4.3 to 3.6 in the intervention area, but rose from around two to 8.2 in the comparison area. Trends in desired fertility in each area were similar, declining from about 4.0 children per woman in 1979 to about 2.5 children in 2000. Among women at each level of parity, fertility generally decreased as the number of sons increased, and fertility was highest for women without sons. Preference for male children and parental concern over infant and child mortality may partially explain the difference between desired family size and fertility. A reduction in breast-feeding and an increase in use of less-effective contraceptive methods might be responsible for the inconsistency in the relationship between contraceptive use and fertility.

  9. Effect on Rate of Unclosed Spikelets of Hybrid Rice Seed Production by Applying Formula Micronutrient Fertilizer%施用配方微肥对杂交水稻制种种子裂颖率的影响

    Institute of Scientific and Technical Information of China (English)

    林生游; 陈兴总

    2014-01-01

    This study designed two treatment groups of fertilization formula micronutrient fertilizer and habits, surveyed application formula micronutrient fertilizer effect of unclosed rate of hybrid rice seed. The results showed that rate of brown rice grain decreased by 75%, unclosed rate decreased by 35.1%, seed germination rate increased by 8.9%, compared with habits fertilization. The formula micronutrient fertilizer could improve the economic benefit, expanded the demonstration.%设计施用配方微肥和习惯施肥2个处理,调查施用配方微肥对杂交水稻制种种子裂颖率的影响。结果表明:施用配方微肥比习惯施肥水稻种子糙米粒率降低75%,裂颖率降低35.1%,种子发芽率提高8.9%,可提高经济效益,扩大示范。

  10. Associations between Individual and Combined Polymorphisms of the TNF and VEGF Genes and the Embryo Implantation Rate in Patients Undergoing In Vitro Fertilization (IVF Programs.

    Directory of Open Access Journals (Sweden)

    Radia Boudjenah

    Full Text Available A multiple pregnancy is now considered to be the most common adverse outcome associated with in vitro fertilization (IVF. As a consequence, the identification of women with the best chances of embryo implantation is a challenge in IVF program, in which the objective is to offer elective single-embryo transfer (eSET without decreasing the pregnancy rate. To date, a range of hormonal and clinical parameters have been used to optimize eSET but none have significant predictive value. This variability could be due to genetic predispositions related to single-nucleotide polymorphisms (SNPs. Here, we assessed the individual and combined impacts of thirteen SNPs that reportedly influence the outcome of in vitro fertilisation (IVF on the embryo implantation rate for patients undergoing intracytoplasmic sperm injection program (ICSI.A 13 gene polymorphisms: FSHR(Asn680Ser, p53(Arg72Pro, AMH(Ile49Ser, ESR2(+1730G>A, ESR1(-397T>C, BMP15(-9C>G, MTHFR1(677C>T, MTHFR2(1298A>C, HLA-G(-725C>G, VEGF(+405G>C, TNFα(-308A>G, AMHR(-482A>G, PAI-1(4G/5G, multiplex PCR assay was designed to genotype women undergoing ICSI program. We analyzed the total patients population (n = 428 and a subgroup with homogeneous characteristics (n = 112.Only the VEGF(+405G>C and TNFα(-308A>G polymorphisms impacted fertilization, embryo implantation and pregnancy rates. Moreover, the combined VEGF+405.GG and TNFα-308.AG or AA genotype occurred significantly more frequently in women with high implantation potential. In contrast, the VEGF+405.CC and TNFα-308.GG combination was associated with a low implantation rate.We identified associations between VEGF(+405G>C and TNFα(-308A>G polymorphisms (when considered singly or as combinations and the embryo implantation rate. These associations may be predictive of embryo implantation and could help to define populations in which elective single-embryo transfer should be recommended (or, conversely, ruled out. However, the mechanism

  11. Does prolonged pituitary down-regulation with gonadotropin-releasing hormone agonist improve the live-birth rate in in vitro fertilization treatment?

    Science.gov (United States)

    Ren, Jianzhi; Sha, Aiguo; Han, Dongmei; Li, Ping; Geng, Jie; Ma, Chaihui

    2014-07-01

    To evaluate the effects of a prolonged duration of gonadotropin-releasing hormone agonist (GnRH-a) in pituitary down-regulation for controlled ovarian hyperstimulation (COH) on the live-birth rate in nonendometriotic women undergoing in vitro fertilization and embryo transfer (IVF-ET). Retrospective cohort study. University-affiliated hospital. Normogonadotropic women undergoing IVF. Three hundred seventy-eight patients receiving a prolonged pituitary down-regulation with GnRH-a before ovarian stimulation and 422 patients receiving a GnRH-a long protocol. Live-birth rate per fresh ET. In comparison with the long protocol, the prolonged down-regulation protocol required a higher total dose of gonadotropins. A lower serum luteinizing hormone (LH) level on the starting day of gonadotropin and the day of human chorionic gonadotropin (hCG) and a fewer number of oocytes and embryos were observed in the prolonged down-regulation protocol. However, the duration of stimulation and number of high-quality embryos were comparable between the two groups. A statistically significantly higher implantation rate (50.27% vs. 39.69%), clinical pregnancy rate (64.02% vs. 56.87%) and live-birth rate per fresh transfer cycle (55.56% vs. 45.73%) were observed in the prolonged protocol. Prolonged down-regulation in a GnRH-a protocol might increase the live-birth rates in normogonadotropic women. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Low body mass index compromises live birth rate in fresh transfer in vitro fertilization cycles: a retrospective study in a Chinese population.

    Science.gov (United States)

    Cai, Jiali; Liu, Lanlan; Zhang, Junwen; Qiu, Huiling; Jiang, Xiaoming; Li, Ping; Sha, Aiguo; Ren, Jianzhi

    2017-02-01

    To evaluate the effects of low body mass index (BMI) on in vitro fertilization (IVF) outcomes in fresh transfer cycles. Retrospective cohort study. University-affiliated hospital. A total of 4,798 cycles with conventional stimulation and fresh transfer in a single IVF center during the period 2013-2014. Low BMI (Live birth rate per fresh embryo transfer. Low BMI was associated with reduced live birth rates and increased miscarriage rates compared with normal weight, controlling for important covariates known to influence IVF outcomes. Patient age was the most potent confounder, causing a 10.5% reduction in the odds ratio (OR) for live birth between the groups compared. When an interaction term (age × BMI) was introduced, the OR for live birth was reduced in cycles of those aged ≥35 years compared with cycles of those aged 28-34 years, whereas the change in OR between cycles in those aged <28 and cycles in those aged 28-34 years was insignificant. Low BMI is associated with negative outcomes in fresh transfer cycles, especially for women of advanced age. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Aditi Kotdawala

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Riikka Shemeikka

    2006-01-01

    Full Text Available The aim of this study was to estimate the development of fertility in North-Central Namibia, former Ovamboland, from 1960 to 2001. Special attention was given to the onset of fertility decline and to the impact of the HIV epidemic on fertility. An additional aim was to introduce parish registers as a source of data for fertility research in Africa.  Data used consisted of parish registers from Evangelical Lutheran congregations, the 1991 and 2001 Population and Housing Censuses, the 1992 and 2000 Namibia Demographic and Health Surveys, and the HIV sentinel surveillances of 1992-2004. Both period and cohort fertility were analysed. The P/F ratio method was used when analysing census data. The impact of HIV infection on fertility was estimated indirectly by comparing the fertility histories of women who died at an age of less than 50 years with the fertility of other women. The impact of the HIV epidemic on fertility was assessed both among infected women and in the general population.  Fertility in the study population began to decline in 1980. The decline was rapid during the 1980s, levelled off in the early 1990s at the end of war of independence and then continued to decline until the end of the study period. According to parish registers, total fertility was 6.4 in the 1960s and 6.5 in the 1970s, and declined to 5.1 in the 1980s and 4.2 in the 1990s. Adjustment of these total fertility rates to correspond to levels of fertility based on data from the 1991 and 2001 censuses resulted in total fertility declining from 7.6 in 1960-79 to 6.0 in 1980-89, and to 4.9 in 1990-99. The decline was associated with increased age at first marriage, declining marital fertility and increasing premarital fertility. Fertility among adolescents increased, whereas the fertility of women in all other age groups declined.  During the 1980s, the war of independence contributed to declining fertility through spousal separation and delayed marriages. Contraception

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

    African Journals Online (AJOL)

    Osondu

    2012-05-29

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

  16. Adolescent fertility: worldwide concerns.

    Science.gov (United States)

    Senderowitz, J; Paxman, J M

    1985-04-01

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

  17. 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

    Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs...

  18. 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

  19. Follicular fluid insulin like growth factor-1 (FF IGF-1 is a biochemical marker of embryo quality and implantation rates in in vitro fertilization cycles

    Directory of Open Access Journals (Sweden)

    Bindu N Mehta

    2013-01-01

    Full Text Available Context: Insulin-like growth factor-1 (IGF-1 has been reported to play a role in human follicular and embryonic development. However, earlier studies carried out mostly in animal models or in culture mediums supplemented with IGF-1 have been unable to directly link IGF-1 with embryo quality. Results correlating IGF-1 with pregnancy outcome have also been ambiguous so far. Aim: The aim of this study is to find if in situ follicular-fluid level of IGF-1 is predictive of embryo quality and implantation rates in in vitro fertilization (IVF cycles. Settings and Design: Prospective study involving 120 cycles of conventional IVF-embryo transfer in infertile women. Subjects and Methods: IGF-1 concentrations were estimated in pooled follicular-fluid on the day of oocyte-pickup. Embryo quality was assessed daily at different developmental stages. Cycles were sorted into low and high follicular fluid insulin-like growth factor-1 (FF IGF-1 groups according to the median value of measurement. Embryo quality, clinical pregnancy and implantation rate were the main outcome measures. Statistical Analysis: Graph-pad Prism 5 statistical package. Results: FF IGF-1 correlates with embryo quality (Pearson r = 0.3894, r2 = 0.1516, P 58.50 ng/mg protein (receiver operating characteristics AUC : 0.85 ± 0.03, 95% CI: 0.78-0.91. Conclusion: FF IGF-1 is a plausible biochemical marker of embryo quality and implantation rate and correlates with clinical pregnancy rates in conventional IVF cycles.

  20. 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

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

    Science.gov (United States)

    Smith, Caroline A; de Lacey, Sheryl; Chapman, Michael; Ratcliffe, Julie; Norman, Robert J; Johnson, Neil; Sacks, Gavin; Lyttleton, Jane; Boothroyd, Clare

    2012-05-18

    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. 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). There remains a need for

  2. Differences in minor amputation rate in diabetic foot disease throughout Europe are in part explained by differences in disease severity at presentation

    DEFF Research Database (Denmark)

    van Battum, P; Schaper, N; Prompers, L

    2011-01-01

    The incidence of minor amputation may vary significantly, and determinants of minor amputation have not been studied systematically. We evaluated minor amputation rate, the determinants of minor amputation and differences in amputation rate between European centres....

  3. 低渗溶液浓度对黄颡鱼精子活力和受精率的影响%Effects of hypotonic solution on the sperm motility and fertilization rate in Yellow catfish

    Institute of Scientific and Technical Information of China (English)

    王德忠; 吴一春; 徐汉连; 陈荣国; 李平

    2013-01-01

    In order to improve the stability of artificial fertilization of Yellow catfish (Pelteobagrus fulvidraco) , sperm motility , fertilization rate and hatching rate were evaluated in the experiment of artificial fertilization in 6 levels ( ranged from 0% to 0. 5% ) of hypotonic solution by the methods of synchronous activation of eggs and sperm and pre activation of sperm respectively. The results showed that, hypotonic solution concentration was closely related to sperm motility, sperm activating rate and fertilization rate. In the same concentration of hypotonic solution, fertilization rate by using pre activation of sperm was significantly higher than that by using synchronous activation of eggs and sperm ( P < 0. 05 ) , fertilization rate increased by 7. 7% ~ 14. 5% accordingly. Hypotonic solution concentration and method of artificial fertilization had no significant impact on hatching rate. The results indicated that pre activation of sperm in 0. 3% hypotonic solution had the best effect.%为提高黄颡鱼(Pelteobagrus fulvidraco)人工授精的稳定性,分别用卵子和精子同步激活法以及预激活精子法,在6个梯度浓度(0%~0.5%)范围的低渗溶液中进行人工授精试验,比较精子活力、受精率和孵化率.结果显示:低渗溶液浓度与精子活力、精子激活率和受精率密切相关,在相同浓度的低渗溶液组中采用预激活精子法的受精率显著高于卵子和精子同步激活法(P<0.05),受精率相对应提高了7.7% ~14.5%;低渗溶液的浓度和人工授精方式对孵化率无显著影响.结果表明在浓度0.3%的低渗溶液中采用预激活精子法的效果最好.

  4. The effect of caffeine consumption on the success rate of pregnancy as well various performance parameters of in-vitro fertilization treatment.

    Science.gov (United States)

    Al-Saleh, Iman; El-Doush, Inaam; Grisellhi, Bellido; Coskun, Serdar

    2010-12-01

    This study evaluated the effect of caffeine consumption on the success rate of pregnancy and various in vitro fertilization (IVF) performance parameters. Serum and follicular fluid samples were collected from 619 women undergoing IVF treatment (2002-2003). Caffeine assessment was based on measuring the levels of caffeine in serum and follicular fluid and on the number of coffee or tea or caffeinated drinks consumed per day. A total of 97.3% of participants reported the consumption of caffeinated drinks such as coffee, tea and soft drinks. Their average caffeine consumption was 455.82 mg/day (range: 3.71-3561 mg/day). Coffee was the primary source of caffeine intake. The average caffeine levels in serum (0.913 µg/ml) were significantly higher than in follicular fluid (0.701 µg/ml). After controlling for various potential confounding variables, no association was found between coffee or tea consumption and the success rate of pregnancy. Looking at the effect of caffeine consumption on the IVF performance parameters, we found that the number of eggs decreased as the caffeine serum levels increased (P=0.011). An increase in coffee consumption was positively associated with the number of aborted pregnancy (P=0.007), while the number of good embryo decreased with high tea consumption (P=0.015). Though no association was seen between coffee or tea consumption and pregnancy rate, this study is the first to report that caffeine can reach the follicular fluid and there is a suggestive evidence of its possible harmful role on the consequences of reproductive process. This clearly warrants further investigation.

  5. Does lower dose of long-acting triptorelin maintain pituitary suppression and produce good live birth rate in long down-regulation protocol for in-vitro fertilization?

    Science.gov (United States)

    Chen, Xin; Feng, Shu-xian; Guo, Ping-ping; He, Yu-xia; Liu, Yu-dong; Ye, De-sheng; Chen, Shi-ling

    2016-04-01

    The effects of pituitary suppression with one-third depot of long-acting gonadotropin-releasing hormone (GnRH) agonist in GnRH agonist long protocol for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) were investigated. A retrospective cohort study was performed on 3186 cycles undergoing IVF/ICSI with GnRH agonist long protocol in a university-affiliated infertility center. The pituitary was suppressed with depot triptorelin of 1.25 mg or 1.875 mg. There was no significant difference in live birth rate between 1.25 mg triptorelin group and 1.875 mg triptorelin group (41.2% vs. 43.7%). The mean luteinizing hormone (LH) level on follicle-stimulating hormone (FSH) starting day was significantly higher in 1.25 mg triptorelin group. The mean LH level on the day of human chorionic gonadotrophin (hCG) administration was slightly but statistically higher in 1.25 mg triptorelin group. There was no significant difference in the total FSH dose between the two groups. The number of retrieved oocytes was slightly but statistically less in 1.25 mg triptorelin group than in 1.875 mg triptorelin group (12.90±5.82 vs. 13.52±6.97). There was no significant difference in clinical pregnancy rate between the two groups (50.5% vs. 54.5%). It was suggested that one-third depot triptorelin can achieve satisfactory pituitary suppression and produce good live birth rates in a long protocol for IVF/ICSI.

  6. Basal metabolic rate of endotherms can be modeled using heat-transfer principles and physiological concepts: reply to "can the basal metabolic rate of endotherms be explained by biophysical modeling?".

    Science.gov (United States)

    Roberts, Michael F; Lightfoot, Edwin N; Porter, Warren P

    2011-01-01

    Our recent article (Roberts et al. 2010 ) proposes a mechanistic model for the relation between basal metabolic rate (BMR) and body mass (M) in mammals. The model is based on heat-transfer principles in the form of an equation for distributed heat generation within the body. The model can also be written in the form of the allometric equation BMR = aM(b), in which a is the coefficient of the mass term and b is the allometric exponent. The model generates two interesting results: it predicts that b takes the value 2/3, indicating that BMR is proportional to surface area in endotherms. It also provides an explanation of the physiological components that make up a, that is, respiratory heat loss, core-skin thermal conductance, and core-skin thermal gradient. Some of the ideas in our article have been questioned (Seymour and White 2011 ), and this is our response to those questions. We specifically address the following points: whether a heat-transfer model can explain the level of BMR in mammals, whether our test of the model is inadequate because it uses the same literature data that generated the values of the physiological variables, and whether geometry and empirical values combine to make a "coincidence" that makes the model only appear to conform to real processes.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. The historical decline of fertility in Eastern Europe.

    Science.gov (United States)

    Leasure, J W

    1992-01-01

    Quantitative data from the Princeton European Fertility Project were used to explain the determinants of change in attitudes which lead to use of birth control within marriage and fertility decline in terms of the growth of autonomy over one's political, personal, religious, economic, and reproductive life. The following countries, which are arranged by their chronological order of marital fertility decline, were used in the primarily quantitative analysis: Hungary, Czechoslovakia, Greece, Yugoslavia, Poland, Romania, Bulgaria, and Albania. Prior research had identified an association between a decline in the birth rate and the presence of revolutions nationalist independence movements, or democratic reform movements. The connection is that once control over one's political and economic destiny is made, there is an extension into one's reproductive behavior. Further refinement has occurred. Autonomy is grounded in reason, the natural rights of individuals, and independence of thought. Reflective of this autonomous spirit were affiliations with Congregational, Presbyterian, Quaker, Unitarian, and Universalist religions. The present analysis is historical and describes the events surrounding the decline in marital fertility. These events might have preceded, been concurrent with, or followed the decline, but the thesis remains that the growth in autonomy contributes to political changes and fertility decline. The primary measure of fertility is Ig developed by Coale, and sustained decline maps of Coale and Watkins. Crude birth rate and total fertility rate were also used. the provincial analysis was impeded by lack of long time series for some countries and boundary changes. The hypothesis is generally supported, except in the case of Yugoslavia which varies too much. Support for the thesis was stronger in some countries than in others. Sustained decline occurred by each country in different periods, e.g., in Hungary it began between 1850-60 while in Albania it began

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

    Directory of Open Access Journals (Sweden)

    McNees P

    2012-04-01

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

  10. Effect of fertilization rate difference after IVF on the clinical outcome of half-ICSI%half-ICSI中IVF受精率的差异对临床结局的影响

    Institute of Scientific and Technical Information of China (English)

    杜红姿; 刘寒艳; 龙晓林; 孙筱放; 张伟良

    2011-01-01

    目的:比较行half-ICSI治疗中IVF受精率的差异对half-ICSI治疗结局的影响.方法:回顾性分析配偶精液分析处于临界状态,无法排除受精失败可能的患者,以及前次IVF受精失败的患者,采用half-ICSI治疗,并根据ICF部分的受精情况进行分组,其中IVF受精失败(定义为IVF受精率≤25%)的half-ICSI组为研究组,包括IVF受精率为0的完全受精失败half-ICSI组24个周期及IVF受精率低下的half-ICSI组19个周期;而IVF正常受精(定义为IVF受精率>65%)的half-ICSI组19个周期作为对照组.结果:IVF完全受精失败的half-ICSI组中ICSI的受精率、卵裂率、优质胚胎率、植入率、妊娠率、分娩率、流产率分别为68.94%、95.50%、53.77%、19.23%、33.33%、33.33%、0%,IVF受精率低下的half-ICSI组ICSI的受精率、卵裂率、优质胚胎率、植入率、妊娠率、分娩率、流产率分别为71.43%、94.4%、52.54%、18.75%、36.84%、31.58%、14.29%,与对照组即IVF正常受精的half-ICSI组(分别为81.34%、97.25%、55.66%、21.74%、36.84%、36.84%、0%)相比,除受精率研究组与对照组有显著差异外(P0.05).3组精液分析也无统计学差异.结论:half-ICSI中IVF受精失败将影响ICSI的受精率,但是对胚胎发育及妊娠结局并无显著影响.%Objective: To compare the clinical outcome among half-ICSI with different fertilization rates after in vitro fertilization (IVF).Methods: Patients with semen analysis of spouses which were in bordline so that it cannot explusive the possibility of fertilization failure for IVF, as well as patients with previous fertilization failure for IVF were treated with half-ICSI.To analyse retrospectively the data from half-ICSI cycles to separate them into two groups according to the fertilization result after IVF.The study group was consisted of 24 cycles with total fertilization failure (defined as zero fertilization) after IVF and 19 cycles with low fertilization (defined as < 25

  11. Fertility transition and adverse child sex ratio in districts of India.

    Science.gov (United States)

    Mohanty, Sanjay K; Rajbhar, Mamta

    2014-11-01

    Demographic research in India over the last two decades has focused extensively on fertility change and gender bias at the micro-level, and less has been done at the district level. Using data from the Census of India 1991-2011 and other sources, this paper shows the broad pattern of fertility transition and trends in the child sex ratio in India, and examines the determinants of the child sex ratio at the district level. During 1991-2011, while the Total Fertility Rate (TFR) declined by 1.2 children per woman, the child sex ratio fell by 30 points in the districts of India. However, the reduction in fertility was slower in the high-fertility compared with the low-fertility districts. The gender differential in under-five mortality increased in many districts of India over the study period. The decline in the child sex ratio was higher in the transitional compared with the low-fertility districts. The transitional districts are at higher risk of a low child sex ratio due to an increased gender differential in mortality and increase in the practice of sex-selective abortions. The sex ratio at birth and gender differential in mortality explains one-third of the variation, while region alone explains a quarter of the variation in the child sex ratio in the districts of India.

  12. Do differences in maternal age, parity and multiple births explain variations in fetal and neonatal mortality rates in Europe? - Results from the EURO-PERISTAT project

    NARCIS (Netherlands)

    Anthony, S.; Jacobusse, G.W.; Pal-De Bruin, K.M. van der; Buitendijk, S.; Zeitlin, J.

    2009-01-01

    Perinatal mortality rates differ markedly between countries in Europe. If population characteristics, such as maternal age, parity or multiple births, contribute to these differences, standardised rates may be useful for international comparisons of health status and especially quality of care. This

  13. Explaining Disproportionately High Rates of Adverse Birth Outcomes among African Americans: The Impact of Stress, Racism, and Related Factors in Pregnancy

    Science.gov (United States)

    Giscombe, Cheryl L.; Lobel, Marci

    2005-01-01

    Compared with European Americans, African American infants experience disproportionately high rates of low birth weight and preterm delivery and are more than twice as likely to die during their 1st year of life. The authors examine 5 explanations for these differences in rates of adverse birth outcomes: (a) ethnic differences in health behaviors…

  14. How can family policies reconcile fertility and women's employment? Comparisons between South Korea and Sweden.

    Science.gov (United States)

    Lee, Soomi; Duvander, Ann-Zofie; Zarit, Steven H

    2016-01-01

    South Korea has extremely low rates of fertility and labor force participation by women during their childbearing years, whereas Sweden has high rates for both. Variations in family policy models may explain differences in fertility and women's employment between the two countries. Drawing upon literature that examines the effects of family policies on fertility and women's employment, this paper compares childcare support for very young children and parental leave policies in South Korea and Sweden. Thereafter, we discuss the importance of providing stronger support for dual-earner rather than single-earner families to reconcile the two objectives of increasing fertility and women's workforce participation. Specifically, it is critical to: (a) enhance the quantity and quality of childcare services for very young children, (b) achieve gender equality in parental leave policies, and (c) reduce gaps in the accessibility and utilization of family benefits by working parents from different social classes.

  15. Contribution of exposure, risk of crash and fatality to explain age- and sex-related differences in traffic-related cyclist mortality rates.

    Science.gov (United States)

    Martínez-Ruiz, Virginia; Jiménez-Mejías, Eladio; Amezcua-Prieto, Carmen; Olmedo-Requena, Rocío; Luna-del-Castillo, Juan de Dios; Lardelli-Claret, Pablo

    2015-03-01

    This study was designed to quantify the percent contribution of exposure, risk of collision and fatality rate to the association of age and sex with the mortality rates among cyclists in Spain, and to track the changes in these contributions with time. Data were analyzed for 50,042 cyclists involved in road crashes in Spain from 1993 to 2011, and also for a subset of 13,119 non-infractor cyclists involved in collisions with a vehicle whose driver committed an infraction (used as a proxy sample of all cyclists on the road). We used decomposition and quasi-induced exposure methods to obtain the percent contributions of these three components to the mortality rate ratios for each age and sex group compared to males aged 25-34 years. Death rates increased with age, and the main component of this increase was fatality (around 70%). Among younger cyclists, however, the main component of increased death rates was risk of a collision. Males had higher death rates than females in every age group: this rate increased from 6.4 in the 5-14 year old group to 18.8 in the 65-79 year old group. Exposure, the main component of this increase, ranged between 70% and 90% in all age categories, although the fatality component also contributed to this increase. The contributions of exposure, risk of crash and fatality to cyclist death rates were strongly associated with age and sex. Young male cyclists were a high-risk group because all three components tended to increase their mortality rate.

  16. A prolongation of the postspike afterhyperpolarization following spike trains can partly explain the lower firing rates at derecruitment than those at recruitment

    DEFF Research Database (Denmark)

    Wienecke, Jacob; Zhang, Mengliang; Hultborn, Hans

    2009-01-01

    rates at derecruitment correlated with a change in the postspike afterhyperpolarization (AHP) after preceding spike trains? This question was investigated by intracellular recordings from cat motor neurons in both unanesthetized and anesthetized preparations. The firing frequencies at recruitment...... for the lower frequencies at derecruitment. This was independent of whether the current injection had activated persistent inward current (PIC; plateau potentials, secondary range firing). It was found that a preceding spike train could prolong the AHP duration following a subsequent spike. The lower rate...

  17. Urban versus rural: fertility decline in the cities and rural districts of Prussia, 1875 to 1910.

    Science.gov (United States)

    Galloway, P R; Lee, R D; Hammel, E A

    1998-09-01

    This study examined the level and pace of fertility decline in 54 large cities in Prussia during 1875-1910. Data were obtained from census records for 1875, 1880, 1885, 1890, 1895, 1900, 1905, and 1910. Analysis was based on pooled cross sectional time series methods and theories that structural socioeconomic change was a key factor in the decline of fertility in Prussian cities. During 1875-1910, city population grew from 3.8 to 9.6 million. The general marital fertility rate (GMFR) in the 54 cities declined from 281 to 164 during 1875-1910. Catholicism, female labor force participation (FLFP), manufacturing, mining, banking, and communication were statistically positively related to urban fertility level. Pace of decline was related significantly to language, education, FLFP, income, communications, insurance, population size, infant mortality, and married sex ratio. Population size was related to pace but not level. Education and banking had a stronger impact in rural areas. In the city equation, the variables plus dummies accounted for 90% of the variance. A very important variable explaining change in fertility level in Prussia was Catholicism. The most important variables for explaining fertility change in Prussia were infant mortality rate and insurance. Infant mortality, communications, insurance, and income increased in importance over time. FLFP declined over time, but contributed the most to predicted change in GMFR throughout the period, especially in nontraditional occupations. The analysis explained both rapid and slow urban fertility declines and closely approximated predicted fertility. Prussia differs from present developing country contexts in that the population was largely agrarian but literate.

  18. Teen fertility in transition: recent and historic trends in the United States.

    Science.gov (United States)

    Santelli, John S; Melnikas, Andrea J

    2010-01-01

    After considerable declines in teen birth and pregnancy rates between 1991 and 2005, teen birth rates rose unexpectedly in 2006 and 2007. To understand these recent trends, we examined historical changes in fertility, trends in sexual behaviors, social forces, and public policies that may influence teen fertility. Although social forces such as poverty are critical in shaping adolescent reproductive choices, these do not explain rapid change in teen pregnancy risk since 1991. These recent changes, including increases in teen births since 2005, follow closely changes in teen contraceptive use. Likewise, contraceptive use is critical in explaining differences between U.S. and European fertility patterns. Public policies related to HIV prevention and sexuality education may have played a critical role in influencing teen pregnancy risk.

  19. 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

  20. Europe's fertility transition: new evidence and lessons for today's developing world.

    Science.gov (United States)

    Van De Walle, E; Knodel, J

    1980-02-01

    Statistics of population dynamics in pre-fertility transition Europe, especially Western Europe, are diagrammed, tabulated, and graphed. A description of new sources of information, refined concepts on Europe's fertility transition, and ways of measuring the actual practice of family limitation are explained. New findings in the field indicate that the past was largely characterized by natural fertility. Factors such as the period of lactation and seasonal migration influenced total fertility differences. The transition from high to low fertility and mortality represented a shift from natural fertility to family limitation. Differences in the start and speed of the fertility decline are determined more by cultural than by socioeconomic conditions. This process began in Western Europe, under varying socioeconomic conditions, during the 1880-1910 period and was irreversible once it started. It is generally agreed that many areas of the developing world are currently undergoing a fertility transition. Both birth and death rates in these countries are higher than levels ever were in pre-transition Europe. However, the new findings relating to the transition in Europe lead experts to believe that this curent transition will follow the same courese. A certain level of socioeconomic development is not a precondition. Family planning programs, even in underdeveloped areas, can be effective.

  1. Social mobility and fertility

    Directory of Open Access Journals (Sweden)

    Gianpiero Dalla Zuanna

    2007-12-01

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

  2. Species-specific Response of Photosynthesis to Burning and Nitrogen Fertilization

    Institute of Scientific and Technical Information of China (English)

    Yanfang Zhang; Shuli Niu; Wenhua Xu; Yi Han

    2008-01-01

    The present study was conducted to examine photosynthetic characteristics of three dominant grass species (Agropyron cristatum, Leymus chinensis, and Cleistogenes squarrosa) and their responses to burning and nitrogen fertilization in a semiarid grassland in northern China. Photosynthetic rate (Pn), stomatal conductance (gs), and water use efficiency (WUE) showed strong temporal variability over the growing season. C. squarrosa showed a significantly higher Pn and WUE than A. cristatum and L. chinensis. Burning stimulated Pn of A. cristatum and L. chinensis by 24-59% (P<0.05) in the early growing season, but not during other time periods. Light-saturated photosynthetic rate (φmax) in A. cristatum C. squarrosa. The burning-induced changes in soil moisture could explain 51% (P=0.01) of the burning-induced changes The stimulation of Pn under N fertilization was mainly observed in the early growing season when the soil extractable N content was significantly higher in the fertilized plots. The N fertilization-induced changes in soil extractable N content could explain 66% (P=0.001) of the changes in Pn, under N fertilization. The photosynthetic responses of the three species indicate that burning and N fertilization will potentially change the community structure and ecosystem productivity in the semiarid grasslands of northern China.

  3. The Effect of the Different Proportion of Basal Fertilizer, Tiller Fertilizer and Panicle Fertilizer on Yield in Cold Area%寒地水稻不同基蘖穗肥比例对产量的影响

    Institute of Scientific and Technical Information of China (English)

    高世伟; 聂守军; 刘晴

    2012-01-01

    The effect of nitrogen fertilisers on yield were studied by researching the effect of the different proportion of basal fertilizer,tiller fertilizer,panicle fertilizer and nitrogen rate.The result indicated that the high yield of 8589.0 kg/ hm2 can be achieved under the condition of nitrogen amount was 120 kg/hm2 and the ratio of basal fertilizer to panicle fertilizer is 6:4,it explained the fertilizer amount and fertilization ratio were suitably.%通过对水稻不同基蘖穗肥比例及施氮量的研究,探讨了施用氮肥对水稻产量的影响。试验结果表明:在施氮量为120 kg/hm2,基蘖穗肥比例为6∶4时,产量高达8 589.0 kg/hm2,说明在该施肥量和施肥比例下比较合理。

  4. 常规体外授精中正常受精率患者的精液参数分析%Analysis of semen parameters of patients with normal fertilization rate in conventional IVF-ET cycles

    Institute of Scientific and Technical Information of China (English)

    王凤英; 屈宗银; 李玉艳; 何畏; 俞炽阳; 龙玲

    2009-01-01

    目的 了解常规体外授精(in.vitro fertilization,IVF)中正常受精率患者处理前后精液的参数范围及其对受精结果 的影响.方法 回顾性分析在本生殖医学中心接受常规IVF治疗且获得正常受精及移植胚胎的408个周期的精液参数及其与受精结果 的关系.结果 精子密度正常者399人次(97.79%),而活力正常者仅21人次(5.15%).处理前精液量0.2~8 ml,精子密度(3~400)×10~6个/ml,活率10%~85%,前向运动精子比率(progressive motile sperm,PMS%)2%~40%,前向运动精子总数(total progressive motile sperm count,TPMSC)2~597×10~6.处理后的精子活率、PMS%及精子总数与处理前精子密度、活率、PMS%以及A+B级精子总数均呈显著的正相关(P<0.05).处理后的精子活率与受精率明显相关(r=0.132,P=0.008).结论 常规IVF正常受精者精液参数波动范围大,轻、中度的弱精或少精可能不影响正常受精,但处理后的精子活率可影响受精率.%Objective To investigate the semen relative parameters and their effects on fertilization out-comes. Methods Totally 408 semen samples with normal fertilization rates in conventional in vitro fertilization and embryo transfer (IVF-ET) cycles in our department from January 2006 to July 2008 were collected. The relationship of the semen parameters and fertilized outcomes were retrospectively analyzed. Results Among 408 samples, there were 399 samples (about 97.79%) had normal sperm density, but only 21 samples (5.15%) had normal motility. The sperm density was 3 to 400 10~6/ml, its motility 10% to 85% , percentage of progressive motile sperm (PMS%) 2% to 40% , and total progressive motile sperm count (TPMSC) was 2 to 597 × 10~6. The motility, PMS% and total sperm count after sperm separation were positively correlated with the density, motility, PMS% and TPMSC before separation (P <0.05). There was a positive correlation between the fertilization rate and separated sperm motility (r =0

  5. 冬种马铃薯黑膜夹层覆盖栽培氮肥和钾肥不同用量和组配对植株及产量的影响%Effects of Application Rate and Proportion of Nitrogen Fertilizer and Potassium Fertilizer on Plants and Yield of Winter Potato Cultivated by Black Film Interlayer Covering

    Institute of Scientific and Technical Information of China (English)

    陆昆典; 李春光; 韦小贞

    2013-01-01

    Taking Holland 15 as the test material, we studied the effects of different application rates and proportions of nitrogen fertilizer and potassium fertilizer on the plant growth characteristics and yield of winter potato which was cultivated by black film interlayer covering. The results showed that different application rates and proportions of nitrogen fertilizer and potassium fertilizer had no effects on seedling emergence speed, eventual seedling rate, and total number of leaves. However, the plant height increased with the increase of nitrogen fertilizer application rate, while decreased with the increase of K2O application rate. When the application rate of K2O increased, the diameter of main stem showed a rising trend. When the application rate of nitrogen was below 225 kg/hm , the yield of potato increased with the increase of potassium fertilizer application rate. When the application rate of nitrogen reached 300 kg/hm2, the yield of potato decreased with the increase of potassium fertilizer application rate. These results showed that the fertilization quantity should not be higher than N 300 kg/hm2 + K2O 150 kg/hm2. The highest yield was obtained when N 225 kg/hm2 +K2O 450 kg/hm2 were applied.%以荷兰15为试材,研究了3个氮肥施用水平和3个钾肥施用水平及相互组配,对冬种马铃薯黑地膜夹层覆盖栽培植株生长特性及产量的影响,结果表明:氮钾肥的施用量以及不同配比,对黑地膜夹层覆盖栽培冬马铃薯的出苗快慢和最终成苗率和叶片总数没有明显影响,但株高呈现出随着N施用量的增加而增加、随着K2O施用量的增加而降低的趋势,对植株主茎茎粗呈现出随着K2O施用量的增加而增粗的趋势.N施用量在225 kg/hm2以下时,马铃薯的产量随着钾肥施用量的增大而提高,N施用量达到300 kg/hm2时,马铃薯的产量反而随着钾肥施用量增大而降低,这说明施肥量不宜高于N 300 kg/hm2+ K2O 150 kg/hm2;施N 225 kg/hm2、K2O

  6. Fertilizer and Lime: Why They Are Used.

    Science.gov (United States)

    McCaslin, Judith Strand

    This unit teaching guide is designed to help teachers explain the principles of fertilizer and lime use. The first of four major sections is a teaching outline keyed to transparency masters and student handouts. Thirteen major areas are covered in the teaching outline: (1) plant needs; (2) uses of fertilizer; (3) nutrients for plant growth; (4)…

  7. 15N Isotope Techniques for Estimating Effects of Urea-N Fertilizer Application Rate on Yieids and Nutrient Contents of Pakchoi Cabbage and Asparagus Lettuce and Nitrogen Utilization Efficiency

    Institute of Scientific and Technical Information of China (English)

    LIAO Yu-Iin; ZHENG Sheng-xian; RONG Xiang-min; LIU Qiang; FAN Mei-rong

    2010-01-01

    A pot experiment combined with15 N isotope techniques was conducted to evaluate effects of the varying rates of urea.N fertilizer application on yields,quailty,and nitrogen use efficiency(NUE)of pakchoi cabbage(Brassica chinensis L.)and asparagus lettuce(Lactuca saiva L.).15 N-labbled urea(5.35 15 N atom%)was added to pots with 6.5kg soil of 0.14,0.18,0.21,0.25,and 0.29 g N/kg soil.and applied in two splits:60 percenl as basel dressing in the mixture and 40 percent as toodressing.The fresh yields of two vegetable species increased with the increasing input of urea-N,but there was a significant quadratic relationship between the dose of urea-N fertilizer application and the fresh yields.Whan the dosage of urea-N fertilizer reached a certain value,nitrate readily accumulated in the two kinds of plants due to the decrease in NR activity;furthermore,there was a linear nagative correlation between nitrate content and NR activity.With the increasing input of urea-N.ascorbic acid and soluble sugar initially increased,declined after a while,and crude fiber rapidly decreased too.Total absorbed N(TAN).N derived from fertilizer(Ndff),and N derived from soil(Ndfs)increased,and the ratio of Ndff and TAN also increased.but the ratio of Ndfs and TAN as well as NUE of urea-N fertilizer decreased with the increasing input of urea-N.These results suggested that the increasing application of labeled N fertilizer led lo the increase in unlabeled N(namely,Ndfs)presumably due to"added nitrogen interaction"(ANI),the decease in NUE of urea-N fertilizer may be due to excess fertilization beyond the levels of plant requirements and the ANI.and the decrease jn the two vege table yields with the increasing addition of urea-N possibly because the excess accumulation of nitrate reached a toxic level.

  8. 不同聚合机理的聚合反应速率串讲%Explain of Polymerization Reaction Rate of Different Polymerization Mechanism

    Institute of Scientific and Technical Information of China (English)

    赵文杰; 张会轩

    2013-01-01

    In the polymerization reaction engineering course,the polymerization reaction rate directly influences average polymerization degree of the polymerization products,and has the important position in the teaching material.The polymerization rate of different polymerization mechanisms is different,but they have high correlation.In this paper,The polymerization rate in the course of “polymerization reaction engineering” was detailed based on the clue of different mechanism of free radical polymerization,ion polymerization,coordination polymerization and the condensation polymerization.The similarities and differences among different polymerization rate were pointed out,aimed at improving students to understand and grasp the definition of the polymerizationrate.%在《聚合反应工程》课程中,聚合反应速率直接影响聚合产物的平均聚合度,是课程的一个核心内容,在教材中占有重要地位.不同聚合反应机理所对应的聚合反应速率不同,但它们具有很强的关联性.文中以自由基聚合、离子聚合、配位聚合以及缩聚的聚合机理为主线,把不同聚合机理中的聚合反应速率这一重要知识点做了串讲;指出了不同聚合反应速率之间的相同之处和不同之处.旨在使学生对聚合反应速率能有一个系统的认识和把握.

  9. Lineage-specific sequence evolution and exon edge conservation partially explain the relationship between evolutionary rate and expression level in A. thaliana

    OpenAIRE

    Bush, Stephen J; Kover, Paula X.; Urrutia, Araxi O.

    2015-01-01

    Rapidly evolving proteins can aid the identification of genes underlying phenotypic adaptation across taxa, but functional and structural elements of genes can also affect evolutionary rates. In plants, the 'edges' of exons, flanking intron junctions, are known to contain splice enhancers and to have a higher degree of conservation compared to the remainder of the coding region. However, the extent to which these regions may be masking indicators of positive selection or account for the relat...

  10. Socio-economic fertility theories and their relevance to population policy.

    Science.gov (United States)

    Leibenstein, H

    1974-01-01

    A theory of fertility is necessary to assess the justification for family planning and to understand the effectiveness of the programs. 3 possibilities for uses of a theory of fertility are discussed: 1) assessment of population projections, 2) indications of what can be expected from family planning, and 3) assessment of population control projects. Birthrates are high, but fertility rates in developing countries are between 40% and 60% below the maximum possible. Social and cultural elements and economic incentives and constraints play a role in keeping the birthrates high. Economic development is frequently accompanied by a drop in fertility, but economic development implies other simultaneous changes which influence fertility rates. Gary Becker's fertility theory holds that with higher income people would purchase more children, the people behaving as they would in purchasing consumer durables. However, higher income groups frequently have fewer children. Becker says that higher income families want high-quality children who are more expensive. A pure economic theory does not explain all of the fertility variations; it is necessary to take account of the socioeconomic processes that result from economic development. Family planning policies that influence people's motivations should be developed.

  11. 大鲵胚胎早期发育特征和受精率计算方法%The chardcteristics of early embryonic development and the method for calculating fertility rate of Andrias davidianus

    Institute of Scientific and Technical Information of China (English)

    孟彦; 肖汉兵; 田海峰

    2014-01-01

    探讨了大鲵( Andrias davidianus)胚胎发育过程中受精率的评判标准和计算受精率的最佳时间。对大鲵胚胎发育观察表明:发育到二细胞的胚胎均能发育到神经胚期,因此可以将二细胞胚胎期作为受精的标志;孵化温度在17~20℃时,温度对大鲵的孵化率没有影响;胚胎发育经过24 h后,有90%~95%的受精卵可发育到二细胞期。因此可以以受精后24 h的二细胞分裂数作为计算大鲵胚胎受精率的基础数据。研究结果有利于对大鲵人工繁育效果提前判断和对孵化条件及时调控处理。%The relational fertilization tests of Chinese Andrias davidianus were carried out in order to analyze and evaluate the artificial insemination in early stage .During continuous observation of embryo development at early stages , the results proved that embryo at the two cell stage had the ability to develop dynamically to gastrula stage and neurula stage .Compar-ative analysis the time that fertility rate reached 90%and 95%revealed that 24 h after fertilized can be used as the optimal time.Combined the results , the embryo development at two cell stage and 24 h post-fertilization can serve as the judgment standard of fertility rate .The results served the important guidance for captive breeding in Chinese giant salamander .

  12. Women's education and fertility behaviour.

    Science.gov (United States)

    1993-12-01

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

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

    Science.gov (United States)

    Tuiran, R

    1991-01-01

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

  14. Structural and functional analysis of a FeoB A143S G5 loop mutant explains the accelerated GDP release rate.

    Science.gov (United States)

    Guilfoyle, Amy P; Deshpande, Chandrika N; Vincent, Kimberley; Pedroso, Marcelo M; Schenk, Gerhard; Maher, Megan J; Jormakka, Mika

    2014-05-01

    GTPases (G proteins) hydrolyze the conversion of GTP to GDP and free phosphate, comprising an integral part of prokaryotic and eukaryotic signaling, protein biosynthesis and cell division, as well as membrane transport processes. The G protein cycle is brought to a halt after GTP hydrolysis, and requires the release of GDP before a new cycle can be initiated. For eukaryotic heterotrimeric Gαβγ proteins, the interaction with a membrane-bound G protein-coupled receptor catalyzes the release of GDP from the Gα subunit. Structural and functional studies have implicated one of the nucleotide binding sequence motifs, the G5 motif, as playing an integral part in this release mechanism. Indeed, a Gαs G5 mutant (A366S) was shown to have an accelerated GDP release rate, mimicking a G protein-coupled receptor catalyzed release state. In the present study, we investigate the role of the equivalent residue in the G5 motif (residue A143) in the prokaryotic membrane protein FeoB from Streptococcus thermophilus, which includes an N-terminal soluble G protein domain. The structure of this domain has previously been determined in the apo and GDP-bound states and in the presence of a transition state analogue, revealing conformational changes in the G5 motif. The A143 residue was mutated to a serine and analyzed with respect to changes in GTPase activity, nucleotide release rate, GDP affinity and structural alterations. We conclude that the identity of the residue at this position in the G5 loop plays a key role in the nucleotide release rate by allowing the correct positioning and hydrogen bonding of the nucleotide base. © 2014 FEBS.

  15. 链条输送式变量施肥抛撒机的设计与试验%Design and experiment of variable rate fertilizer spreader with conveyor chain

    Institute of Scientific and Technical Information of China (English)

    张睿; 王秀; 赵春江; 白由路; 孟志军; 陈立平

    2012-01-01

    针对国内变量施肥机作业幅宽小,变量施肥抛撒机缺乏的问题,该文应用变量施肥技术,设计了一种基于处方图的链条输送式变量施肥抛撒机.通过分析肥料颗粒在撒肥盘上的运动和受力,建立了肥料颗粒在脱离撒肥机圆盘过程中的运动方程,设计并确定了变量抛撒控制系统、肥箱、肥门自动开启装置等关键部件的结构及参数.并进行了不同施肥量和抛撒均匀性的试验,结果表明:链条输送式变量施肥抛撒机变量效果较好,且具有较好的抛撒均匀性,在拖拉机速度1.5 m/s,实际施肥量与预置施肥量相对误差最大值为7.53%;拖拉机速度2m/s,目标施肥量225 kg/hm2,抛撒幅宽设定30m,有效幅宽抛撒变异系数为14.90%,能够较好的满足实际生产要求.%To solve the problem of lacking suitable variable rate fertilizer spreader in China, a variable rate fertilizer spreader with conveyor chain based on prescription map was designed. A motional equation of fertilizer granular at the moment of thrown from disc border was established through analyzing force and motion of fertilizer granular at spreader disc, and then the system of key components was designed and the corresponding machinery parameters were confirmed, such as variable rate control system, fertilizer box, the auto-opening device of gate etc. The experiments on different fertilizer amount and uniformity were conducted with a variable rate fertilizer spreader. Results showed that the spreader's effect of variable rate fertilization and uniformity of the spreader was better. When the speed of tractor was 1.5 m/s, relative error between actual application amount and pre-setting amount was less than 7.53%. When the speed of tractor was 2 m/s, the coefficient of variance was 14.90%, fertilization amount was 225 kg/hm2 and the spreader breadth was 30 m, which indicates the spreader can meet the need of practical production.

  16. Proton accumulation accelerated by heavy chemical nitrogen fertilization and its long-term impact on acidifying rate in a typical arable soil in the Huang-Huai-Hai Plain

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; ZHANG Jia-bao; XIN Xiu-li; ZHU An-ning; ZHANG Cong-zhi; MA Dong-hao; ZHU Qiang-gen; YANG Shan; WU Sheng-jun

    2015-01-01

    Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal N input. With decades’ intensive agricultural cultivation and heavy chemical N input in the Huang-Huai-Hai Plain, the impact extent of induced proton input on soil pH in the long term was not yet clear. In this study, acidiifcation rates of different soil layers in the soil proifle (0–120 cm) were calculated by pH buffer capacity (pHBC) and net input of protons due to chemical N incorporation. Topsoil (0–20 cm) pH changes of a long-term fertilization ifeld (from 1989) were determined to validate the predicted values. The results showed that the acid and alkali buffer capacities varied signiifcantly in the soil proifle, averaged 692 and 39.8 mmolc kg–1 pH–1, respectively. A signiifcant (P<0.05) correlation was found between pHBC and the content of calcium carbonate. Based on the commonly used application rate of urea (500 kg N ha–1 yr–1), the induced proton input in this region was predicted to be 16.1 kmol ha–1 yr–1, and nitriifcation and plant uptake of nitrate were the most important mechanisms for proton producing and consuming, respectively. The acidiifcation rate of topsoil (0–20 cm) was estimated to be 0.01 unit pH yr–1 at the assumed N fertilization level. From 1989 to 2009, topsoil pH (0–20 cm) of the long-term fertilization ifeld decreased from 8.65 to 8.50 for the PK (phosphorus, 150 kg P2O5 ha–1 yr–1;potassium, 300 kg K2O ha–1 yr–1; without N fertilization), and 8.30 for NPK (nitrogen, 300 kg N ha–1 yr–1; phosphorus, 150 kg P2O5 ha–1 yr–1; potassium, 300 kg K2O ha–1 yr–1), respectively. Therefore, the apparent soil acidiifcation rate induced by N fertilization equaled to 0.01 unit pH yr–1, which can be a reference to the estimated result, considering the effect of atmospheric N deposition, crop biomass, ifeld management and plant uptake of other

  17. Fretting and Corrosion Between a Metal Shell and Metal Liner May Explain the High Rate of Failure of R3 Modular Metal-on-Metal Hips.

    Science.gov (United States)

    Ilo, Kevin C; Derby, Emma J; Whittaker, Robert K; Blunn, Gordon W; Skinner, John A; Hart, Alister J

    2017-05-01

    The R3 acetabular system used with its metal liner has higher revision rates when compared to its ceramic and polyethylene liner. In June 2012, the medical and healthcare products regulatory agency issued an alert regarding the metal liner of the R3 acetabular system. Six retrieved R3 acetabular systems with metal liners underwent detailed visual analysis using macroscopic and microscopic techniques. Visual analysis discovered corrosion on the backside of the metal liners. There was a distinct border to the areas of corrosion that conformed to antirotation tab insertions on the inner surface of the acetabular shell, which are for the polyethylene liner. Scanning electron microscopy indicated evidence of crevice corrosion, and energy-dispersive X-ray analysis confirmed corrosion debris rich in titanium. The high failure rate of the metal liner option of the R3 acetabular system may be attributed to corrosion on the backside of the liner which appear to result from geometry and design characteristics of the acetabular shell. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. 不同控释氮肥对玉米产量和氮肥利用率的影响%Effects of Different Controlled-release Nitrogen Fertilizer on Yield and Nitrogen Utilization Rate of Maize

    Institute of Scientific and Technical Information of China (English)

    袁嫚嫚; 叶舒娅; 刘枫; 李敏; 吴学忠

    2011-01-01

    [目的]为控释氮肥在玉米上的广泛应用提供理论依据.[方法]通过田间小区试验,比较了不同控释氮肥对玉米产量和氮肥利用率的影响.[结果]3种控释氮肥中树脂包膜氮肥增产和提高玉米氮肥利用率的效果均最好.相比普通氮肥,不同控释氮肥显著提高了玉米氮肥利用率,增幅达4.99~14.54个百分点.[结论]控释氮肥可以提高玉米氮肥利用率,树脂包膜氮肥在玉米上的应用效果最佳.%[ Objective] The aim was to provide a theoretical fouhdation for wide utilization of controlled-release nitrogen fertilizer in maize field.[ Method ] Field plot experiment was conducted to compare the different controlled-release nitrogen fertilizers on yield and nitrogen utilization rate of maize. [ Result] The highest yield and nitrogen utilization rate of maize was applied of controlled-release polyolefin-coated urea. Nitrogen utilization rate was increased signifieantly by 4.99% to 14.54% by the applying of controlled-release nitrogen fertilizer. [ Conclusion] Controlled-release nitrogen fertilizer could increase nitrogen utilization rate of maize significantly, controlled-release polyolefin-coated urea had a best effect on maize.

  19. Modeling Strategic Interventions in a Population With a Total Fertility Rate of 8.3: A Cross-Sectional Study of Idjwi Island, DRC - With Appendix Detailing Patterns of Poverty and Disease Among the Bany'Idjwi People

    OpenAIRE

    Hadley, Michael B

    2015-01-01

    Idjwi Island, DRC, has a total fertility rate of 8.3, one of the highest in the world. Rapid population growth has led to widespread environmental degradation and food insecurity. Meanwhile family planning services are largely unavailable. We conducted a representative survey of 2,078 households measuring standard reproductive health indicators. We also interviewed local women, community leaders, and clinicians about access to reproductive services. In the survey, over half of all women repor...

  20. 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

  1. To what extent do financial strain and labour force status explain social class inequalities in self-rated health? Analysis of 20 countries in the European Social Survey.

    Directory of Open Access Journals (Sweden)

    Richard J Shaw

    Full Text Available Nordic countries do not have the smallest health inequalities despite egalitarian social policies. A possible explanation for this is that drivers of class differences in health such as financial strain and labour force status remain socially patterned in Nordic countries.Our analyses used data for working age (25-59 men (n = 48,249 and women (n = 52,654 for 20 countries from five rounds (2002-2010 of the European Social Survey. The outcome was self-rated health in 5 categories. Stratified by gender we used fixed effects linear regression models and marginal standardisation to instigate how countries varied in the degree to which class inequalities were attenuated by financial strain and labour force status.Before adjustment, Nordic countries had large inequalities in self-rated health relative to other European countries. For example the regression coefficient for the difference in health between working class and professional men living in Norway was 0.34 (95% CI 0.26 to 0.42, while the comparable figure for Spain was 0.15 (95% CI 0.08 to 0.22. Adjusting for financial strain and labour force status led to attenuation of health inequalities in all countries. However, unlike some countries such as Spain, where after adjustment the regression coefficient for working class men was only 0.02 (95% CI -0.05 to 0.10, health inequalities persisted after adjustment for Nordic countries. For Norway the adjusted coefficient was 0.17 (95% CI 0.10 to 0.25. Results for women and men were similar. However, in comparison to men, class inequalities tended to be stronger for women and more persistent after adjustment.Adjusting for financial security and labour force status attenuates a high proportion of health inequalities in some counties, particularly Southern European countries, but attenuation in Nordic countries was modest and did not improve their relative position.

  2. Piperine’s mitigation of obesity and diabetes can be explained by its up-regulation of the metabolic rate of resting muscle

    Science.gov (United States)

    Naber, Nariman; Pate, Edward; Canton, Marcella; Reggiani, Carlo; Cooke, Roger

    2016-01-01

    We identify a target for treating obesity and type 2 diabetes, the consumption of calories by an increase in the metabolic rate of resting skeletal muscle. The metabolic rate of skeletal muscle can be increased by shifting myosin heads from the super-relaxed state (SRX), with a low ATPase activity, to a disordered relaxed state (DRX), with a higher ATPase activity. The shift of myosin heads was detected by a change in fluorescent intensity of a probe attached to the myosin regulatory light chain in skinned skeletal fibers, allowing us to perform a high-throughput screen of 2,128 compounds. The screen identified one compound, which destabilized the super-relaxed state, piperine (the main alkaloid component of black pepper). Destabilization of the SRX by piperine was confirmed by single-nucleotide turnover measurements. The effect was only observed in fast twitch skeletal fibers and not in slow twitch fibers or cardiac tissues. Piperine increased ATPase activity of skinned relaxed fibers by 66 ± 15%. The Kd was ∼2 µM. Piperine had little effect on the mechanics of either fully active or resting muscle fibers. Previous work has shown that piperine can mitigate both obesity and type 2 diabetes in rodent models of these conditions. We propose that the increase in resting muscle metabolism contributes to these positive effects. The results described here show that up-regulation of resting muscle metabolism could treat obesity and type 2 diabetes and that piperine would provide a useful lead compound for the development of these therapies. PMID:27799519

  3. Optimization Design for Virtual Prototype of Variable Rate Fertilization Based on Embedded Communication System%基于嵌入式通信系统的变量施肥虚拟样机优化设计

    Institute of Scientific and Technical Information of China (English)

    葛蓁; 熊琼; 邓明华; 汪小志; 鲍秀兰

    2016-01-01

    and the amount of fertilizer , the fertilizer before and after optimization accuracy and effi-ciency are compared , found that the fertilizing machine using the PLC embedded system optimized by comparison , the accuracy of fertilization got obvious improvement , and fertilizer efficiency is high ,which provides the theory reference for the research on variable rate fertilization control .

  4. Effects of Different Fertilizer Rates, Planting Density and Plant Growth Regulators on Yield of Soybean Cultivar Tiedou 68%肥密化控对铁豆68号产量的影响

    Institute of Scientific and Technical Information of China (English)

    董友魁; 刘德恒; 韩艳红

    2015-01-01

    采用正交试验对影响铁豆68号产量的密度、施肥量、叶面喷肥、化控次数4因素进行研究,结果表明,对大豆新品种铁豆68号产量影响的顺序是:施肥量、密度、叶面喷肥、化控次数;铁豆68号最理想的栽培技术模式是密度1.1万株/667m2,施肥量为20 kg/667m2,叶面喷肥1次,化控次数1次。%In order to examine the effects of planting density, fertilization rates, foliar application and times of plant growth regulator application during the growing period of soybean cultivar Tiedou 68, the orthogonal experimental design was used to carry out data analysis. The result indicated that the order of cultivation practices on soybean new variety Tiedou 68 was: fertilization rate, planting density, foliar application and times of plant growth regulator application. The ideal cultural pattern of cultivar Tiedou 68 was planting density of 11 000/667m2, fertilization rate of 20 kg/667m2, and one time of foliar and plant growth regulator application.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

  7. Age-specific fertility by educational level in the Finnish male cohort born 1940‒1950

    Directory of Open Access Journals (Sweden)

    Jessica Nisén

    2014-07-01

    Full Text Available Background: Education is positively associated with completed fertility rate (CFR among men in Nordic countries, but the age patterns of fertility by educational level are poorly documented. Moreover, it is not known what parities contribute to the higher CFR among more highly educated men. Objective: To describe men's fertility by age, parity, and education in Finland. Methods: The study is based on register data covering the male cohort born in 1940‒1950 (N=38,838. Education was measured at ages 30‒34 and classified as basic, lower secondary, upper secondary, and tertiary. Fertility was measured until ages 59‒69. We calculated completed and age-specific fertility rates, and decomposed the educational gradient in CFR into parity-specific contributions. Results: The more highly educated men had more children (CFR: basic 1.71 and tertiary 2.06, had them later (mean age at having the first child: basic 26.1 and tertiary 28.1, and had them within a shorter interval (interquartile range of age at having the first child: basic 5.8 and tertiary 5.2. The educational gradient in the cumulative fertility rate was negative at young ages but turned positive by the early thirties. High levels of childlessness among those with a basic education explained three-quarters of the CFR difference between the lowest and highest educational groups. Fertility at ages above 45 was low and did not widen the educational gradient in CFR. Conclusions: The fact that highly educated men have more children than their counterparts with less education is largely attributable to higher fertility levels at older ages and the lower probability of remaining childless. Variation in fertility timing and quantity is wider among men with a low level of education.

  8. 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

    Directory of Open Access Journals (Sweden)

    Gaurav Majumdar

    2016-01-01

    Full Text Available 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.

  9. 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.

  10. Fertility, Migration, and Altruism

    OpenAIRE

    2000-01-01

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

  11. Perbandingan Angka Fertilitas dan Hambatan Perkembangan Embrio Mencit yang Dikultur dalam Medium M16 dan Human Tubal Fluid (THE COMPARISON OF MICE FERTILITY RATE AND EMBRYONIC DEVELOPMENT CELL BLOCK WHEN CULTURED IN M16 AND HUMAN TUBAL FLUID MEDIA

    Directory of Open Access Journals (Sweden)

    Widjiati .

    2013-07-01

    Full Text Available The aim of this research was to compare the fertility rate and embryonic development cell block ofmice when cultured in M16 and Human Tubal Fluid (HTF media, respectively. Two months old femaleBalbC mice were super ovulated using Pregnant Mare Serum Gonadotrophin (PMSG and Human ChorionicGonadotrophin (HCG prior to mating with vasectomies mice. At 17 hours post mating the mice wassacrificed for the collections of egg cells and spermatozoa. Egg cells were collected by tearing the fertilizationsac, while the sperm were collected from caudal epididymis. After the collection, both the egg cells andsperm were put in Petri dish containing M16 and HTF media and kept in 5% CO2 incubator at 370C for onehour prior to the in vitro fertilization (IVF was performed. In vitro fertilization was performed in 5% CO2 incubator at 370C and kept for 24 hours in M16 and in HTF culture media. The results showed thatfertilization rate was 98.09% and 99.57%; cell block embryonic development was 85.09% and 83.36%when cultured in M16 and HTF media, respectively. In conclusion, HTF media can be used for culturingmouse embryo.

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

    OpenAIRE

    Sam Hyun Yoo

    2014-01-01

    Background: While there has been a considerable amount of research on the association between women's education and fertility rates, few of these studies have examined the pattern of fertility differentials over the course of the fertility transition. As a country that has experienced a rapid decline in fertility and marked improvements in women's educational attainment over the last several decades, South Korea represents an ideal case for studying this dynamic association. Objective: The...

  13. Using /sup 15/N tracer technique to determine the nitrogen effect of slurry fractions in pot experiments with Festuca pratensis. 2. Nitrogen effect of slurry solid matter at rising mineral fertilizer rates

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, P. (Akademie der Landwirtschaftswissenschaften der DDR, Leipzig-Potsdam. Inst. fuer Duengungsforschung)

    1983-01-01

    A combination of organic manuring and mineral fertilization had positive effects on crop yields, first of all on sandy soils, particularly after high nitrogen applications (up to a maximum of 4 g N/pot). These effects correlate with a higher utilization of the mineral nitrogen. Rising mineral fertilizer rates, soil substrate, and parameters of slurry solid matter, especially their C:N ratio, influence the mobility of soil nitrogen as well as the uptake of organic manure nitrogen. The solid matter nitrogen of pig slurry was more easily available to plants on sandy and loess soils. Slurry solid matter applied in addition to mineral nitrogen had positive effects on the quality of the harvested products.

  14. Design and experiment of self-propelled high-ground- clearance spreader for paddy variable-rate fertilization%水田高地隙自走式变量撒肥机设计与试验

    Institute of Scientific and Technical Information of China (English)

    陈书法; 张石平; 孙星钊; 李耀明

    2012-01-01

    为解决现有水田撒肥机械地隙低、撒肥量调节技术落后、工作效率低等问题,设计了一种水田高地隙自走式变量撒肥机,介绍了整机结构与工作原理,研究设计了高地隙专用底盘、撒肥盘及排肥口调节装置,并确定了关键结构和参数,对以AT89C51单片机为核心的控制系统进行软硬件设计与系统集成.场地和水稻田间撒肥试验结果显示,推肥板推肥角度-20°~40°可调,机器最小转弯半径1.8 m,撒肥盘离地高度可达1100 mm,撤肥幅宽达14m,作业效率达到6hm2/h,试验结果表明撒肥机适合在水田里自主行走,整机与控制系统设计满足水田宽幅高效变量撒肥工作要求.%In order to solve the problems of low ground clearance, backward manure regulation technology and low working efficiency present in paddy fertilizing machine, a self-propelled high-ground-clearance spreader was designed for paddy variable-rate fertilization, the whole structure and working mechanism of the machine were introduced, the special chassis with high ground clearance, the fertilization disc and regulation device for fertilizing orifice were designed, the structures and parameters of main components of the machine were given, the software and hardware integrated control system which mainly consists of AT89C51 single-chip microcomputer (SCM) was designed, The fertilizing experiments in grounds and paddy fields showed that the angle for pushing fertilizer board was at -20°-40°, the minimum turning radius of the machine was less than 1.8 m, the height of fertilization disc from the ground was 1100 mm, the fertilizing width of machine achieved 14 m, working efficiency was up to 6 hm2/h, the experimental results indicate that the machine is suitable for self-propelled walking in paddy fields, and the design for the machine and its control system meets variable-rate fertilization requirements of widespread distribution and high efficiency in paddy fields.

  15. The fertility of internal migrants to Kinshasa.

    Science.gov (United States)

    Anglewicz, Philip; Corker, Jamaica; Kayembe, Patrick

    2017-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  17. How can family policies reconcile fertility and women’s employment? Comparisons between South Korea and Sweden

    Science.gov (United States)

    LEE, Soomi; DUVANDER, Ann-Zofie; ZARIT, Steven H.

    2017-01-01

    South Korea has extremely low rates of fertility and labor force participation by women during their childbearing years, whereas Sweden has high rates for both. Variations in family policy models may explain differences in fertility and women’s employment between the two countries. Drawing upon literature that examines the effects of family policies on fertility and women’s employment, this paper compares childcare support for very young children and parental leave policies in South Korea and Sweden. Thereafter, we discuss the importance of providing stronger support for dual-earner rather than single-earner families to reconcile the two objectives of increasing fertility and women’s workforce participation. Specifically, it is critical to: (a) enhance the quantity and quality of childcare services for very young children, (b) achieve gender equality in parental leave policies, and (c) reduce gaps in the accessibility and utilization of family benefits by working parents from different social classes. PMID:28163567

  18. Effects of Different Sources and Rates of Potassium Fertilizer on Potato Yield and Quality%不同钾肥品种及用量对马铃薯产量和品质的影响

    Institute of Scientific and Technical Information of China (English)

    周芳; 张振洲; 贾景丽; 刘兆财; 贾立君; 杜江

    2013-01-01

      以‘荷兰15’为试验品种,采用随机区组设计进行田间试验,研究不同钾肥品种(氯化钾和硫酸钾)及其用量对马铃薯产量和品质的影响,以期指导马铃薯钾肥的施用。结果表明,不同钾肥品种均提高了马铃薯的产量,降低了还原糖含量。与施用硫酸钾相比,施用氯化钾后,单薯重提高,产量增加幅度较大。若施用氯化钾,用量以18 kg/667m2(K2O)为佳;若施用硫酸钾,用量以21 kg/667m2(K2O)为佳。以优质为目的,钾肥用量低时,氯化钾为优,钾肥用量高时,硫酸钾为优。%A field experiment in Randomized Complete Block Design was conducted to study the effects of different sources (potassium chloride and potassium sulfate) and rates of potassium fertilizer on potato yield and quality in order to guide the application of potassium fertilizer on potato, using 'Helan 15' as experimental material. The results indicated that potato yield was improved, and reducing sugar content was reduced by using different sources of potassium fertilizer. Tuber weight and yield were increased more by potassium chloride than potassium sulfate. 18 kg/667m2 (K2O) was the best when the potassium chloride was used, while 21 kg/667m2 (K2O) was the best when the potassium sulfate was used. In order to get high quality of potato, potassium chloride was superior to potassium sulfate when low rate of potassium fertilizer was used; however, potassium sulfate was superior to potassium chloride when high rate of potassium fertilizer was applied.

  19. 百色烟区烤烟合理种植密度及施肥量研究%Studies on Planting Density and Fertilizer Application Rate of Flue-cured Tobacco in Baise

    Institute of Scientific and Technical Information of China (English)

    周文亮; 赖洪敏; 黄瑾; 林北森; 高华军

    2012-01-01

    [目的]为了掌握百色烟区合理的种植密度及施肥量,为烤烟生产提供科学指导和应用依据.[方法]研究了不同种植密度和施肥水平对烟株生长、烟叶产量和质量的影响.[结果]烤烟生育前期受种植密度和施肥量影响不大,但腰叶、顶叶成熟的时间随着施氮量的增大而变晚.不同种植密度和施肥量对烤烟农艺性状的影响较大,在种植密度相同时,随施肥量的增加,烟株株高、茎围、节距、有效叶片数和叶片长度呈递增趋势;减小种植密度有利于顶叶的开片生长及有效叶片数的增加.综合各经济性状及烟叶主要内在化学成分和评吸质量,A2B3处理(行株距120 cm×50 cm,施氮量112.5 kg/hm2,氮、磷、钾比例1∶1∶3)能够得到较好的经济效益和烟叶质量.[结论]在百色特定的气候、中等土壤肥力条件下,烤烟种植密度以行距120 cm,株距50 cm,纯氮用量112.5 kg/hm2(氮、磷、钾比例1∶1∶3)为宜.%[Objective] To explore the suitable planting density and fertilizer application rate of flue-cured tobacco and to provide the scientific basis and reference applications for guiding its production in Baise. [Method] The effects of different planting density and fertilizer application rate on the growth of tobacco plants, the yield and quality of tobacco leaves were studied. [ Result ] Planting density and fertilizer application rate had a little effects on the growth period of tobacco plants at early growth stage, but the mature stage of central and top leaves delayed with the increasing of fertilizer application rate. Different planting density and fertilizer application rate had significant effect on the agronomic characters, with the increasing fertilizer application rate, the plant height, stem diameter, node distance, effecttive number of leaves and length of leaf increased at the same planting density; when planting density was decreased, top leaves advantageous to growing and

  20. The Fertility Transition Around the World - 1950-2005

    OpenAIRE

    Strulik, Holger; Vollmer, Sebastian

    2010-01-01

    In this paper we analyze the distribution of fertility rates across the world using parametric mixture models. We demonstrate the existence of twin peaks and the division of the world's countries in two distinct components: a high-fertility regime and a low fertility regime. Whereas the significance of twin peaks vanishes over time, the two fertility regimes continue to exists over the whole observation period. In 1950 about two thirds of the world's countries belonged to the high-fertility r...

  1. Spacial distribution of fertility rate in Shandong Province and its influencing factors%山东省生育率空间分布及其影响因素

    Institute of Scientific and Technical Information of China (English)

    李琦; 孙一鑫; 李怡雪; 张翠琴; 吴荣山; 薛付忠

    2014-01-01

    Objective To analyze the spatial distribution of fertility rate in Shandong Province and its influencing factors. Methods Spatial analysis software GIS and GeoDA were used to build the spatial database of fertility rate of 139 counties in Shandong Province,and spatial autocorrelation analysis and global spatial regression model analysis were conducted. Results The global spatial autocorrelation analysis showed Morans I=0.46,P<0.01.In the spatial error model analy-sis,marriage rate,dependency ratio,sex ratio,high education rate and divorce rate showed statistical significance (P<0.05 ),in which only the regression coefficient of the divorce rate was less than zero.Conclusion There is a certain spa-tial correlation and clustering in fertility rate among counties in Shandong Province.Weihai,Yantai and surrounding areas have lower aggregation in fertility rate,while Linyi and surrounding areas have higher aggregation in fertility rate.Fertili-ty rate is positively related to the marriae rate,dependency ratio and sex ratio,and negatively related to divorce rate.%目的:分析山东省生育率的空间分布及其影响因素。方法利用空间分析软件GIS和GeoDA构建山东省139个县区人口生育率的空间数据库,并进行空间自相关和全局空间回归模型分析。结果全局空间自相关分析结果显示,Morans I=0.46,P<0.01。空间误差模型分析结果显示,影响因素中已婚率、抚养比、性别比、高学历率、离婚率差异有统计学意义,P<0.05,其中只有离婚率回归系数小于零。结论山东省各县区的生育率具有一定的空间相关性与聚集性。生育率聚集度较低的区域为威海、烟台等地及其周边,聚集度较高区域为临沂等地及其周边,存在明显地区差异。已婚率、抚养比、性别比与生育率空间分布呈正相关,离婚率与生育率空间分布呈负相关。

  2. A model comparison approach shows stronger support for economic models of fertility decline.

    Science.gov (United States)

    Shenk, Mary K; Towner, Mary C; Kress, Howard C; Alam, Nurul

    2013-05-14

    The demographic transition is an ongoing global phenomenon in which high fertility and mortality rates are replaced by low fertility and mortality. Despite intense interest in the causes of the transition, especially with respect to decreasing fertility rates, the underlying mechanisms motivating it are still subject to much debate. The literature is crowded with competing theories, including causal models that emphasize (i) mortality and extrinsic risk, (ii) the economic costs and benefits of investing in self and children, and (iii) the cultural transmission of low-fertility social norms. Distinguishing between models, however, requires more comprehensive, better-controlled studies than have been published to date. We use detailed demographic data from recent fieldwork to determine which models produce the most robust explanation of the rapid, recent demographic transition in rural Bangladesh. To rigorously compare models, we use an evidence-based statistical approach using model selection techniques derived from likelihood theory. This approach allows us to quantify the relative evidence the data give to alternative models, even when model predictions are not mutually exclusive. Results indicate that fertility, measured as either total fertility or surviving children, is best explained by models emphasizing economic factors and related motivations for parental investment. Our results also suggest important synergies between models, implicating multiple causal pathways in the rapidity and degree of recent demographic transitions.

  3. Psychosocial aspects of fertility behavior: an overview.

    Science.gov (United States)

    David, H P

    1981-06-01

    Selected aspects of decision making in fertility behavior are reviewed. Attention is directed to assessing motivational determinants, the value of children, the concept of "wantedness," delayed childbearing, and adolescent fertility. A woman's decision to use or not to use a birth control method is heavily influenced by partner interaction. The perception of the partner's attitudes and degree of control in the couple relationship are likely to affect the type of method used, the consistency of contraceptive practice, and the resolution of eventual pregnancies. The present generation in many countries is the 1st to be involved in the conscious process of deciding when and how many children to have and to discontinue contraception. The psychosocial model of fertility behaviour emphasizes the subjective assessment of the environment by the individual and the importance of the 2 partners in a couple influencing each other's perceptions and choice behavior. A key feature of successful couple planning behavior is their joint ability to anticipate future outcomes, plan ahead, and develop contingency alternatives. The history of attempts to explain and delineate motivational determinants of fertility behavior is long and filled with testimonials regarding the complexity of the task. It has been well documented in cross-national studies and commentaries that the pleasures which parents experience in raising their children are highly valued. The gradual transition in the perceived economic value of children probably reflects changing parental attitudes accompanying the secular decline in fertility rates. Reducing the number of unwanted pregnancies has been and continues to be one of the major objectives of international planned parenthood and responsible parenthood movements. No published evidence exists, however, that the unexpected, unplanned, or even unwanted pregnancy is always "bad" or that a planned pregnancy more often produces a psychologically healthy child. To date

  4. Fertilization of SRC willow. II

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  5. [The impact of obesity on fertility].

    Science.gov (United States)

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

    2010-03-31

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

  6. 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.

  7. Effects of different organic manure application rate on mango fruit quality and soil fertility%不同用量有机肥对芒果果实品质及土壤肥力的影响

    Institute of Scientific and Technical Information of China (English)

    臧小平; 周兆禧; 林兴娥; 戴敏洁; 葛宇; 刘永霞; 马蔚红

    2016-01-01

    通过田间小区试验,研究了不同用量有机肥处理对芒果果实品质及果园土壤肥力的影响,旨在为生产上芒果科学施肥提供技术支持。结果表明:与不施有机肥处理( CK)比较,增施有机肥处理使果实可溶性固形物含量提高10.1%~21.6%、 Vc含量提高3.1%~38.4%、可滴定酸含量下降6.6%~16.0%、固酸比提高17.9%~44.9%。增施有机肥提高了土壤有机质、全N、有效P、速效K、交换性Ca、交换性Mg、电导率及pH值,促进土壤肥力水平的提升。综合比较,以T2处理(有机肥7.5 kg/株+尿素400 g/株+高钾复合肥1.25 kg/株)对改善果实品质和改良土壤性状效果最好。%Abatract: A field plot experiment was carried out to study the effects of different organic manure application rate on mango fruit quality and soil fertility. The result showed that compared with chemical fertilizer (CK), the applications of organic manure increased the fruit total soluble solid, Vc, ratio of tss and acid, by 10. 1% ~21. 6%, 3. 1% ~38. 4%, 17. 9% ~44. 9%, total titration acid decreased by 6. 6% ~16. 0%. Meanwhile, different organic manure application rates increased soil organic matter, total nitrogen, available phosphorus, available potassium, exchangeable calcium, exchangeable mag-nesium, electrical conductivity and pH, then soil fertility was improved significantly. Applying 7. 5 kg organic manure with 400 g urea and 1. 25 kg high potassium compound fertilizer to each plant was the best, which improved the fruit quality and soil fertility effectively.

  8. Proximate determinants of fertility in Taiwan area.

    Science.gov (United States)

    Lo, S R; Chen, C H

    1987-06-01

    To establish base line data and to evaluate the impacts of induced abortion on fertility in Taiwan before and after legalization, and induced abortion prevalence survey was conducted. 12,516 samples of married women age 15-49 were covered to represent all of Taiwan. Bongaarts' model of proximate determinants of fertility is applied to the survey data to analyze the relationships among total fertility rate, total fecundity, and the indices of the proximate determinants on nonmarriage, contraception, induced abortion, and lacatation. The index of contraception appears to have the greatest (47%) effect on the recent decline of total fertility rate (TFR). Contraception also has the greatest effect on fertility decline among different urbanization areas: 45% for large cities; 46% for urbantownships; and 50% for rural areas. The effects of the proportion of married on the fertility of the 3 areas are 45%, 40%, and 40%, respectively. For induced abortion, the effect is 13% in urban townships and 11% in large cities.

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

    Science.gov (United States)

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

    2011-09-01

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

  10. 心理护理对体外授精-胚胎移植成功率的影响观察%Analysis of the Effect of Psychological Nursing on in Vitro Fertilization Embryo Transplantation Success Rate

    Institute of Scientific and Technical Information of China (English)

    陈辉莲

    2014-01-01

    目的:观察分析体外授精-胚胎移植过程中实施心理护理对成功率的影响。方法回顾性分析98例体外授精-胚胎移植患者临床资料,按护理方法分为研究组(49例)和对照组(49例),两组患者均实施常规护理,研究组在此基础上实施心理护理,对比观察两组患者护理效果。结果经相应护理后,研究组妊娠率、流产率均优于对照组,差异有统计学意义(P<0.05)。结论在常规护理基础上,对体外授精-胚胎移植患者实施心理护理,能有效提高体外授精-胚胎移植成功率,效果优于单一实施常规护理。%Objective To observe in the process of in vitro fertilization and embryo transplantation impact on the success rate of psychological nursing. Methods A retrospective analysis of clinical data of 98 cases with in vitro fertilization and embryo transplantation patients, according to the nursing methods are divided into research group (49 cases) and control group (49 cases), two groups of patients, routine nursing group on the basis of the implementation of psychological care, compared two groups of patient care ef ect. Results After the cor esponding nursing team pregnancy rate, miscar iage rate were superior to control group, the dif erence was statistical y significant ( < 0.05). Conclusion On the basis of conventional nursing, psychological nursing in patients with in vitro fertilization and embryo transplantation, can ef ectively improve the success rate of in vitro fertilization and embryo transplantation, the ef ect is bet er than that of single conventional nursing.

  11. Before normal form to the total number of sperm movement and in vitro fertilization fertility rate analysis of the relationship%正常形态前向运动精子总数对体外受精受精率的影响

    Institute of Scientific and Technical Information of China (English)

    高彩凤; 余相; 陈志云; 刘利敏; 李敦高

    2015-01-01

    目的:探讨正常形态前向运动精子总数对体外受精( IVF)受精率的影响。方法选取第1次进行常规体外受精-胚胎移植周期治疗的108对不孕夫妇分为A组、B组和C组。 A组为正常形态前向运动精子总数0~0.4×106/mL,B组为正常形态前向运动精子总数0.4~1.8×106/mL,C组为正常形态前向运动精子总数>1.8×106/mL。对取卵前半年内的平均正常形态前向运动精子总数和体外受精受精率的数据进行回顾性统计分析,分析正常形态前向运动精子总数和体外受精受精率之间的关系。结果 C组的体外受精受精率为91.02%显著高于A组60.38%和 B 组76.06%的体外受精受精率,差异有统计学意义(P<0.01)。结论正常形态前向运动精子总数大于0.4×106时,可获得稳定的体外受精率。%Objective To investigate the impact of total number of nor-mal forward and progressive motility sperm ( TNNPS) on the rate of in vitro fertilization ( IVF).Methods A total of 108 infertile patients who had operations for in vitro fertilization-embryo transfer treatment firstly was divided into group A, group B and group C.Group A was total num-ber of normal form and progressive motility sperm ( TNNPS) 0-0.4 × 106/mL.Group B was TNNPS 0.4 -1.8 ×106/mL. Group C was TNNPS >1.8 ×106/mL.The mean TNNPS and IVF fertilization rate at 6 months before treatment were obtained.The relation of TNNPS and IVF fertilization rate were analyzed.Results The IVF fertilization rate of group C was 91.02% and it was significantly higher than 60.38% in group A and 76.06%in group B(P<0.01).Conclusion TNNPS was one of most important impaction in IVF fertilization.It could be an indi-cator for evaluation of sperm quality and it showed a tendency towards choose for clinical treatment programs.

  12. Constraint or choice? Disentangling fertility determinants by switching regressions

    Directory of Open Access Journals (Sweden)

    Christoph Sax

    2011-11-01

    Full Text Available In 1953, many poor countries had not yet approached the demographic transition. Accordingly, income generally had a positive impact on fertility in poor countries, while it has a negative impact today. Easterlin's supply-demand framework offers an explanation for this nonlinearity by attributing the positive relationship to Malthusian (or "supply" factors and the negative relationship to "demand" factors. This paper estimates Easterlin's supply-demand framework by switching regressions in a panel data set of 152 countries from 1953 to 1998. The technique allows identifying several factors affecting the Malthusian constraint and the demand for children, such as income, the source of income, urbanization, religion and the medical environment. It is found that a combination of higher GDP per capita, a decrease in the infant death rate and an increase in education explain a substantial part of the reversal of the relationship between income and net fertility over the sample period.

  13. 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...

  14. Double fertilization in Helianthus

    Directory of Open Access Journals (Sweden)

    J. Telżyńska

    2015-01-01

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

  15. Fertilization and oversowing on natural grassland: effects on pasture characteristics and yearling steers performance

    Directory of Open Access Journals (Sweden)

    Eduardo Tonet Ferreira

    2011-09-01

    Full Text Available The objective of this study was to evaluate the vegetal and animal production of a natural pasture on a Mollisol soil in the region of Campanha, in RS. The experimental design consisted of complete randomized blocks with three replicates, which enables the comparison between natural unfertilized pastures with fertilized pastures and pastures fertilized and overseeded with Lolium multiflorum, Lotus corniculatus cv. São Gabriel and Trifolium repens cv. Lucero (NPO. Data were submitted to the analyses of variance considering seasons of the year as time repeated measurements. Aberddeen Angus calves of about nine months of age were used in continuous stocking with variable stocking rate in order to maintain forage offer at 13% of live weight. Data were collected between July 7th (2007 and May 3rd (2008, totaling 302 days. Fertilized and oversown pastures showed higher green forage mass mainly in the spring, as result of higher dry matter (DM accumulation rate. Average daily live-weight gain for fertilized pasture (0.581 kg/day was higher than for natural pasture (0.473 kg/day. Higher live-weight gains were obtained in the fall (0.869 kg/day. Stocking rate showed interaction with the seasons of the year, with higher stocking rates obtained in oversown pasture (701 kg of LW/ha and fertilized pasture (667 kg of LW/ha during the spring. Live-weight gain per hectare from natural pasture (224 kg LW/ha was lower than on fertilized (310 kg LW/ha and over-sown pasture (287 kg LW/ha. Forage mass, dry matter content, forage allowance and pasture height explained 61% of the average live weight gain. Despite the good performance of native grasslands in this region in its natural condition, the utilization of different inputs as fertilization and oversowing of winter cultivated species promoted positive differences in forage production and its distribution along the year and in animal yield.

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

    Science.gov (United States)

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

    1985-10-01

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

  17. Fertility in the context of Mexican migration to the United States: A case for incorporating the pre-migration fertility of immigrants

    Directory of Open Access Journals (Sweden)

    Kate Choi

    2014-03-01

    Full Text Available Background: Mexican-American fertility is poorly understood because data limitations prevent researchers from accurately estimating the fertility levels of members of this group and from determining how their fertility changes within and across generations. Objective: Using binational data and an innovative methodological addressing key methodological limitations, I (1 estimate the fertility of Mexican Americans, (2 describe how selective Mexican migration to the United States is in terms of fertility, (3 document how Mexican-American fertility changes within and across generations, and (4 assess how educational selectivity and assimilation contribute to levels of fertility and fertility changes within and across generations. Results: My findings show that migration from Mexico to the United States is positively selective with respect to fertility. Among the migrants studied, there was a disruption in fertility in anticipation of migration, but a resumption of pre-migration fertility patterns and partial compensation for the earlier fertility loss after migration. Fertility levels among Mexican-Americans appear to be decreasing within and across generations, as immigrants deviate from their pre-migration fertility patterns and increasingly adopt those of whites. Nonetheless, Mexican-American fertility has not yet fully converged with white fertility. Educational assimilation explains a considerable portion of this fertility decline within and across generations. Comments: These findings highlight the importance of empirically observing the pre-migration fertility of immigrants.

  18. Effects of different fertilization treatments on winter survival rate of bent grass%不同施肥处理对匍匐翦股颖越冬性能的影响

    Institute of Scientific and Technical Information of China (English)

    王亚静; 孙吉雄; 张香运; 刘文序

    2011-01-01

    试验研究了诺维信生物复合肥分别与雷力果岭肥、尿素、富利禾鸡粪肥以不同比例配合施用对匍匐翦股颖(Agrostis stolonifera)绿期、地下生物量、密度及越冬率指标的影响,以期为高尔夫球场果岭秋季施肥提供参考。结果表明:各施肥处理均能促进草坪草初期生长,延长草坪绿期,诺维信:雷力(2:1)配合使用全年绿期最长为303d,且与诺维信:鸡粪肥(2:1)的绿期和越冬率显著高于其他处理(P〈0.05);地下生物量诺维信:雷力(1:2)显著高于其他处理(P〈0.05);秋季诺维信生物复合肥与尿素按不同比例配合施用草坪密度大,显著高于其他处理(P〈0.05),导致草坪徒长,枯草层增厚,延迟返青。综合各个指标,诺维信生物复合肥与雷力果岭专用肥配合施用,匍匐翦股颖越冬效果较好。%This experiment was studied the effects of the different mixture proportion between Novozymes Biological Fertilizer and other fertilizers(Lei Li Special Fertilizer, Urea and poultry fertilizer)on green period, underground biomass,density and winter survival rate of bent grass in order to provide some references for fertilizer management on putting green in autumn. The results showed that all the fertilization treatments promoted growth of the bent grass at early stage, and prolong its green period as well. The mixing proportion of Novozymes:Lei Li with 2 : 1 could prolong green period to 300 days. The proportion of Novozymes:Poultry Fertilizer with 2 : 1 had significant effect on green period and winter survival rate than other treatments(P〈0.05). The underground biomass under the proportion of Novozymes:Lei Li with 1 : 2 was higher than other treatments(P〈0.05). The treatment of Novozymes combined with Urea in autumn significantly improved density of putting green(P〈0.05)but it led to grass overgrowing and thick

  19. Plagiarism explainer for students

    OpenAIRE

    Barba, Lorena A

    2016-01-01

    A slide deck to serve as an explainer of plagiarism in academic settings, with a personal viewpoint. For my students.Also on SpeakerDeck:https://speakerdeck.com/labarba/plagiarism-explainer-for-students(The slide viewer on SpeakerDeck is much nicer.)

  20. 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.

  1. 心理干预对体外受精-胚胎移植临床妊娠率影响的Meta分析%Influence of psychological intervention on pregnancy rate of in vitro fertilization-embryo transfer

    Institute of Scientific and Technical Information of China (English)

    苏霞; 丛云凤

    2013-01-01

    Objective To evaluate the influence of psychological intervention on pregnancy rate of in vitro fertilization-embryo transfer.Methods Using the key words,including in vitro fertilization-embryo transfer and psychological,the data were retrieved from CNKI,CBM,VIP,Wanfang and PubMed.The quality of eligible studies was evaluated by two reviews independently and Meta-analysis was conducted on studies.Results Totally thirteen Chinese studies and three foreign studies were included.Conclusions Psychological intervention using in the process of in vitro fertilization-embryo transfer can improve the pregnancy rate,which is worthy of clinical application.%目的 评价心理干预对体外受精-胚胎移植临床妊娠率的影响.方法 通过计算机检索中文文献数据库,包括中国知网(CNKI)、中国生物医学文献数据库(CBM)、维普、万方等,关键词为心理护理、体外受精;外文数据库Pubmed,关键词包括in vitro fertilization-embryo transfer、psychological.获取文献之后按照入选标准要求筛选相关文献,选择合适文献纳入进行相关数据的Meta分析,探讨心理干预对体外受精-胚胎移植临床妊娠率的影响.结果 共有13篇中文文献,3篇外文文献纳入,进行Meta分析.结论 心理干预应贯穿于体外受精-胚胎移植的过程之中,可以提高体外受精-胚胎移植患者的妊娠成功率,是值得推广应用的护理措施.

  2. Alteration of ERβ gene RsaI polymorph ism may contribute to reduced fertilization rate and embryonic developmental competence%ERβ基因RsaI多态性可能降低精子受精力及胚胎的发育潜能

    Institute of Scientific and Technical Information of China (English)

    Qiu-Fang Zhang; Huai-Liang Feng; Lan Zhao; Ping Liu; Li Li; Jie Yan; Jie Qiao

    2011-01-01

    This paper aims to determine the possible role of estrogen receptor-β(ERβ)gene Rsal polymorphism on sperm fertility and early embryonic development in humans. Three groups of Chinese men were recruited: in vitro fertilization (IVF) group, including 374 couples who underwent conventional IVF; intracytoplasmic sperm injection (ICSI) group, including 294 couples who underwent an ICSI procedure using ejaculated sperm; and azoospermic group, consisting of 197 couples who underwent ICSI using either testis or epididymis sperm. Rsal polymorphism in the ERβ gene was detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism technique; fertilization and high-quality embryo rates were evaluated for each group. In each group, no significant differences were found in the overall rates of fertilization and high-quality embryos among GG, AG and AA genotypes. However, the proportion of cycles possessing a satisfactory high-quality embryo rate with the AA genotype was significantly lower than that in the wild-type GG genotype from each group. These results demonstrated that sperm possessing the ERp Rsal A genotype may have reduced fertilization ability and decreased early embryonic developmental potential, which could directly or indirectly contribute to the low fertilization rate and early embryonic developmental arrest in some cases.

  3. Soil NH+4 Fixation and Fertilizer N Recovery as Affected by Soil Moisture and Fertilizer Application Methods

    Institute of Scientific and Technical Information of China (English)

    TONG Yah-An; O.EMTERYD; H.GRIP; LU Dian-Qing

    2004-01-01

    Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.

  4. The Cost of Raising Fertility

    DEFF Research Database (Denmark)

    Kurjanska, Malgorzata; Lyngsie, Jacob

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

  5. 成熟卵泡获卵率对体外受精结局的影响%The influence of retrieved oocyte rate of mature follicles on the outcomes during in vitro fertilization & embryo transfer procedure

    Institute of Scientific and Technical Information of China (English)

    马黔红; 黄仲英; 樊伟

    2011-01-01

    Objective To investigate the influence of retrieved oocyte rate on clinical and laboratory results during in vitro fertilization and embryo transfer or intracytoplasmic sperm injection procedure. Methods 746 IVF/ ICSI cycles (693 patients) were analysed retrospectively in West China Second University Hospital of Sichuan University from May to December in 2010. Based on retrieved oocyte rate, all these cycles were divided into four groups: group A, retrieved oocyte rate ≥80%; group B, retrieved oocyte rate 50 %~79%; group C, retrieved o-ocyte rate 30%~49%; group D, retrieved oocyte rate 0. 05). The cases from group D obtained the lowest number of retrieved oocytes in the four groups, and there were significantly lower in group D than in group A and B in maturation rate of oocytes, fertilization rate, cleavage rate and embryo formation rate that could be transferred (P< 0. 05) , which resulting to the lower clinical pregnancy rate, implantation rate and cumulative pregnancy rate in group D than in group A and B (P<0. 05). Also, there were significantly lower in fertilization rate, cleavage rate, embryo formation rate that could be transferred in group C than in group A (P<0. 05), but cumulative pregnancy rate in group C was similar to group A and B. Conclusions Decreased retrieved oocyte rate may cause decreased oocyte maturation rate, fertilization rate, cleavage rate and good quality embryo rate, so as to lessen the clinical pregnancy rate.%目的 比较在体外受精-胚胎移植/卵细胞浆内单精子注射(IVF- ET/ICSI)过程中,控制性超促排卵(COH)后成熟卵泡获卵率对IVF- ET/ICSI的实验室和临床结局的影响.方法 回顾性分析2010年5月至2010年12月四川大学华西第二医院行IVF- ET/ICSI治疗的693例患者,共746个周期,根据获卵率将患者分为A组:获卵率≥80%;B组:获卵率50%~79%;C组:获卵率30%~49%;D组:获卵率<30%.比较4组患者的临床和实验室结局.结果 A、B组卵子成

  6. How does the inclusion of twins conceived via fertility treatments influence the results of twin studies?

    Science.gov (United States)

    Burt, S Alexandra; Klump, Kelly L

    2012-12-01

    Rates of twinning have risen dramatically over the last 30 years, from 1 in 53 births in 1980 to 1 in 30 births in 2009 (Martin et al. (January 2012). Three decades of twin births in the United States, 1980-2009. Atlanta, GA: Centers for Disease Control and Prevention, National Center for Health Statistics). This increase is largely attributable to increases in the use of fertility treatments (i.e., ovulation induction and in vitro fertilization) combined with delays in parenthood. Although this increase means that more twins are available for recruitment into twin studies, it also has potential consequences for the heritability estimates obtained in these studies. This study sought to evaluate this possibility, making use of the ongoing Michigan Twins Project (N = 7,261 families with twins aged 3-17 years), an arm of the Michigan State University Twin Registry. Results revealed that, on average, twins conceived via fertility treatments had lower rates of behavior problems than those conceived naturally, although these behavioral differences could be explained largely by demographic and socio-economic differences across the two types of twin families. Twin similarity did not meaningfully differ across fertility treatment status. We thus conclude that estimates of genetic and environmental influences obtained from twin studies over the last 10-15 years are more or less unaffected by the inclusion of twins conceived via fertility treatments in their samples.

  7. Cancer and fertility : strategies to preserve fertility

    NARCIS (Netherlands)

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

    2011-01-01

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

  8. Cancer and fertility : strategies to preserve fertility

    NARCIS (Netherlands)

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

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

  9. Impact of alleles at the Yellow Burley (Yb) loci and nitrogen fertilization rate on nitrogen utilization efficiency and tobacco-specific nitrosamine (TSNA) formation in air-cured tobacco.

    Science.gov (United States)

    Lewis, Ramsey S; Parker, Robert G; Danehower, David A; Andres, Karen; Jack, Anne M; Whitley, D Scott; Bush, Lowell P

    2012-06-27

    Tobacco-specific nitrosamine (TSNA) formation in tobacco is influenced by alkaloid levels and the availability of nitrosating agents. Tobacco types differ in their potential for TSNA accumulation due to genetic, agronomic, and curing factors. Highest TSNA concentrations are typically measured in burley tobaccos. One of the main genetic differences between burley and all other tobacco types is that this tobacco type is homozygous for recessive mutant alleles at the Yellow Burley 1 (Yb(1)) and Yellow Burley 2 (Yb(2)) loci. In addition, burley tobacco is typically fertilized at higher nitrogen (N) rates than most other tobacco types. This study utilized nearly isogenic lines (NILs) differing for the presence of dominant or recessive alleles at the Yb(1) and Yb(2) loci to investigate the potential influence of genes at these loci on TSNA accumulation. Three pairs of NILs were evaluated at three different nitrogen fertilization rates for alkaloid levels, nitrogen physiology measures, and TSNA accumulation after air-curing. As previously observed by others, positive correlations were observed between N application rates and TSNA accumulation. Recessive alleles at Yb(1) and Yb(2) were associated with increased alkaloid levels, reduced nitrogen use efficiency, reduced nitrogen utilization efficiency, and increased leaf nitrate nitrogen (NO(3)-N). Acting together, these factors contributed to significantly greater TSNA levels in genotypes possessing the recessive alleles at these two loci relative to those carrying the dominant alleles. The chlorophyll-deficient phenotype conferred by the recessive yb(1) and yb(2) alleles probably contributes in a substantial way to increase available NO(3)-N during curing and, consequently, increased potential for TSNA formation.

  10. Transition cow: interaction with fertility.

    Science.gov (United States)

    Formigoni, A; Trevisi, E

    2003-09-01

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

  11. 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.

  12. Age and Fertility

    Science.gov (United States)

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

  13. Plant fertilizer poisoning

    Science.gov (United States)

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

  14. In vitro fertilization (IVF)

    Science.gov (United States)

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

  15. Toward replacement fertility in Egypt and Tunisia.

    Science.gov (United States)

    Eltigani, Eltigani E

    2009-09-01

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

  16. Multiscale Regional Formula Fertilization Considering Environment Information Incompleteness

    Institute of Scientific and Technical Information of China (English)

    Qianqian ZHANG; Yan LIANG

    2015-01-01

    Conventional formula fertilization tends to calculate regional rate of fertilizer application by means of analyzing spatial distribution of regional cultivated land productivity combined with experiment data. However,as environment information of cultivated land is incomplete due to limitation of traditional cultivated land management technology and data acquisition,uncertainty of rate of fertilizer makes it hard to define the interval of formula fertilization and support the regional fertilization task. With the technique of spatial analysis and multiscale uncertainty theory,conventional fertilization can be optimized. Four steps are involved to calculate regional formula fertilization interval based on conventional formula fertilization:( i) To simulate cultivated land productivity according to EGLSN Model,and make it crop target field;( ii) To determine rate of fertilizer according to target field to define cultivated land productivity fertilizer interval and mid-value;( iii) To define region fertilizer interval length and value of region varying with scales as environment information becomes complete gradually;( iv) To apply block fertilizer combined with conventional formula by soil testing. Multiscale optimizing formula fertilization system has been established by using the Arc Engine as a platform to integrate the methods,which is applied in Xinjiang County,Shanxi Province,in order to optimize the existing fertilization formula in study area. It showed that the optimized formula fertilization had more spatial details of productivity than the original one.And the new method is available to support formula fertilization in any region or the block with uncertain environment information. It is therefore concluded that the proposed method has the potential for popularity,which provides a multiscale,multiple-factor and standardized formula fertilization method.

  17. A comparative study between cleavage stage embryo transfer at day 3 and blastocyst stage transfer at day 5 in in-vitro fertilization/intra-cytoplasmic sperm injection on clinical pregnancy rates.

    Science.gov (United States)

    Kaur, Prabhleen; Swarankar, M L; Maheshwari, Manju; Acharya, Veena

    2014-07-01

    To evaluate the efficacy of blastocyst transfer in comparison with cleavage stage transfer. A randomized, prospective study was conducted in Infertility clinic, Department of Obstetrics and Gynecology, Mahatma Gandhi Hospital, Jaipur on 300 patients aged 25-40 years undergoing in-vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) cycle from May 2010-April 2011. When three or more Grade-I embryos were observed on day 2 of culture, patients were divided randomly into two study groups, cleavage stage transfer and blastocyst transfer group having 150 patients each. Primary outcomes evaluated were, Clinical pregnancy rate and Implantation rate. The results were analyzed using proportions, standard deviation and Chi-square test. Both the groups were similar for age, indication and number of embryos transferred. Clinical pregnancies after blastocyst transfer were significantly higher 66 (44.0%) compared to cleavage stage embryo transfer 44 (29.33%) (P < 0.01). Implantation rate for blastocyst transfer group was also significantly higher (P < 0.001). Blastocyst transfer having higher implantation rate and clinical pregnancy rate lead to reduction in multiple pregnancies.

  18. A comparative study between cleavage stage embryo transfer at day 3 and blastocyst stage transfer at day 5 in in-vitro fertilization/intra-cytoplasmic sperm injection on clinical pregnancy rates

    Directory of Open Access Journals (Sweden)

    Prabhleen Kaur

    2014-01-01

    Full Text Available Objective: To evaluate the efficacy of blastocyst transfer in comparison with cleavage stage transfer. Study Design: A randomized, prospective study was conducted in Infertility clinic, Department of Obstetrics and Gynecology, Mahatma Gandhi Hospital, Jaipur on 300 patients aged 25-40 years undergoing in-vitro fertilization (IVF/intra-cytoplasmic sperm injection (ICSI cycle from May 2010-April 2011. When three or more Grade-I embryos were observed on day 2 of culture, patients were divided randomly into two study groups, cleavage stage transfer and blastocyst transfer group having 150 patients each. Primary outcomes evaluated were, Clinical pregnancy rate and Implantation rate. The results were analyzed using proportions, standard deviation and Chi-square test. Results: Both the groups were similar for age, indication and number of embryos transferred. Clinical pregnancies after blastocyst transfer were significantly higher 66 (44.0% compared to cleavage stage embryo transfer 44 (29.33% (P < 0.01.Implantation rate for blastocyst transfer group was also significantly higher (P < 0.001. Conclusion: Blastocyst transfer having higher implantation rate and clinical pregnancy rate lead to reduction in multiple pregnancies.

  19. Effects of Nitrogen Fertilizer Rate on Nitrogen and Dry Matter Accumulation in Summer Peanut%施氮水平对夏播花生氮素及干物质积累的影响

    Institute of Scientific and Technical Information of China (English)

    王小龙; 孟强; 谢永乐; 赵晓娜; 王巧平

    2015-01-01

    Summer peanut nitrogen accumulation dynamics and its relationship with peanut pro-ductivity were studied through plot nitrogen fertilizer rate experiment with 2 summer peanut varieties (YH15 and BS101 6) in the Yellow River Basin in China.The results showed: nitrogen accumulation of peanut was found as the “S” type curve.While nitrogen fertilizer application amount was less than 120 kg /ha, the peanut plant nitrogen accumulation, leaf area index, dry matter and the leaf nitrogen concentration increased with the increase of nitrogen fertilizer rate, but they showed stagflationary when the nitrogen rate reached over 120 kg /ha.At each level of nitrogen application, the leaf nitrogen concentration decreased with the increasing of the growth process, but decreased gradually with the increase of nitrogen application rate.The LAID dynamic curve could distinguish the peanut growth differences under different nitrogen fertilizer rate.The curves showed that the LAID complied with exponential curve when RGDD≤0.5 and linear growth when RGDD>0.5.%基于黄河流域夏播花生种植区两个类型花生品种(豫花15和白沙1016)不同施氮水平进行田间试验,研究夏播花生氮素积累动态,及与花生生产力的关系。结果表明,各施氮水平下,氮素积累动态呈近“S”型曲线;施氮量在120 kg /hm2以下,花生植株氮积累量、叶面积指数、叶面积指数持续期、干物质积累量和各生育时期叶片氮浓度均随着施氮量增加而增加,但当施氮量达到和超过120 kg /hm2时均出现滞涨;每个施氮水平下,整个叶层平均氮浓度随着生育进程推进均呈下降趋势,但随着施氮量增加氮浓度下降速度趋缓。本研究用叶面积指数持续期拟合的动态曲线较好地区分了不同施氮水平间的差异,该曲线显示,在苗后10℃以上积温归一化值 RGDD≤0.5时,夏播花生的叶面积指数持续期呈指数曲线增长;当 RGDD>0.5时,呈线性增长。

  20. Computer jargon explained

    CERN Document Server

    Enticknap, Nicholas

    2014-01-01

    Computer Jargon Explained is a feature in Computer Weekly publications that discusses 68 of the most commonly used technical computing terms. The book explains what the terms mean and why the terms are important to computer professionals. The text also discusses how the terms relate to the trends and developments that are driving the information technology industry. Computer jargon irritates non-computer people and in turn causes problems for computer people. The technology and the industry are changing so rapidly; it is very hard even for professionals to keep updated. Computer people do not

  1. Impact of long-term different fertilization on yellow brownish paddy soil carbon sequestration rate and organic carbon fractions%长期施肥对黄棕壤固碳速率及有机碳组分影响

    Institute of Scientific and Technical Information of China (English)

    陈云峰; 韩雪梅; 胡诚; 李双来; 乔艳; 刘东海

    2013-01-01

    Impact of long-term application of chemical fertilizer (NPK), manure (M), chemical fertilizer plus manure (MNPK) on yellow brownish paddy soil carbon sequestration rate (CSR) and organic carbon chemical fractions were explored based on a 31 years long-term experiment station. The plot of no fertilizer input was regard as the control (CK). CSR was estimated from data collected in 1985, 2002 and 2010. Organic carbon fractions that includes total organic carbon (TOC), microbial biomass carbon (MBC), labile carbon (LC) and recalcitrant carbon (RC) were measured in the wheat/middle-rice rotation season of 2010 and 2011. Moreover, recalcitrant index (RI) and microbial quotient (MQ) were used to evaluate stability of organic carbon. The results showed that the CSR among the three period of 1985—2002, 2002—2010, 1985—2010 were different irrespective of fertilization treatments. The CSR of MNPK in the three period were 512, 1 132, 711 kg·hm-2·a-1, respectively. Correspondingly, the CSR of M were 627, 528, 595 kg·hm-2·a-1, NPK were 141, -50, 80 kg·hm-2·a-1. Fertilization improved TOC, RC, LC and MBC with the rank of MNPK>M>NPK>CK and occasionally MNPK>M>NPK>CK. Fertilization decreased RI and the RI of MNPK was the lowest among the three fertilization treatments. The mean RI of four sampling times of MNPK was lower 7.3% than that of CK. M and MNPK significantly increased the MQ compared to that of CK. In conclusion, fertilization increased the capacity of carbon sequestration and the stability of organic carbon as well as the contribution of labile carbon to total organic carbon. Of the three fertilization treatments, MNPK had the best positive effects on soil carbon sequestration and organic stabilization, followed by M, and NPK.%  依托长江中下游黄棕壤稻麦轮作区31年长期定位试验,以不施肥为对照(CK),研究施用化肥(NPK)、有机肥(M)及有机肥—化肥(MNPK)对土壤固碳速率、总有机碳及其组成(难降

  2. Reproductive Responses to Economic Uncertainty : Fertility Decline in Post-Soviet Ust'-Avam, Siberia.

    Science.gov (United States)

    Nolin, David A; Ziker, John P

    2016-12-01

    In the face of economic and political changes following the end of the Soviet Union, total fertility rates fell significantly across the post-Soviet world. In this study we examine the dramatic fertility transition in one community in which the total fertility rate fell from approximately five children per woman before 1993 to just over one child per woman a decade later. We apply hypotheses derived from evolutionary ecology and demography to the question of fertility transition in the post-Soviet period, focusing on an indigenous community (Ust'-Avam) in the Taimyr Region, northern Russia. We employ a mixed parametric accelerated failure-time model that allows comparison of age at first birth, interbirth interval, and reproductive postponement or cessation prior to and following 1993. We find that short-term reproductive delay alone does not explain the dramatic drop in fertility in Ust'-Avam. Age at first birth remains constant. Interbirth intervals increase moderately. The estimated fraction of women who have ceased or indefinitely postponed reproducing doubles (for parities 2 through 4) or triples (for nulliparous women). We caution against assuming that environmental harshness necessarily leads to earlier and more rapid reproduction. An evolutionary theory of fertility responses to acute environmental shocks remains relatively undeveloped. In such contexts it is possible that selection favors a conservative reproductive strategy while more information is learned about the new environment. When investigating fertility responses to environmental stressors we suggest researchers examine postponement and stopping behavior in addition to changes in age at first birth and interbirth interval.

  3. 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.

  4. 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.

  5. The wireless internet explained

    CERN Document Server

    Rhoton, John

    2001-01-01

    The Wireless Internet Explained covers the full spectrum of wireless technologies from a wide range of vendors, including initiatives by Microsoft and Compaq. The Wireless Internet Explained takes a practical look at wireless technology. Rhoton explains the concepts behind the physics, and provides an overview that clarifies the convoluted set of standards heaped together under the umbrella of wireless. It then expands on these technical foundations to give a panorama of the increasingly crowded landscape of wireless product offerings. When it comes to actual implementation the book gives abundant down-to-earth advice on topics ranging from the selection and deployment of mobile devices to the extremely sensitive subject of security.Written by an expert on Internet messaging, the author of Digital Press''s successful Programmer''s Guide to Internet Mail and X.400 and SMTP: Battle of the E-mail Protocols, The Wireless Internet Explained describes and evaluates the current state of the fast-growing and crucial...

  6. Fertility in Advanced Societies : A Review of Research

    NARCIS (Netherlands)

    Balbo, Nicoletta; Billari, Francesco C.; Mills, Melinda; Bilari, F.C.

    2013-01-01

    This paper provides a review of fertility research in advanced societies, societies in which birth control is the default option. The central aim is to provide a comprehensive review that summarizes how contemporary research has explained ongoing and expected fertility changes across time and space

  7. Soil fertility controls the size-specific distribution of eukaryotes.

    Science.gov (United States)

    Mulder, Christian

    2010-05-01

    The large range of body-mass values of soil organisms provides a tool to assess the organization of soil ecological communities. Relationships between log-transformed body mass M and log-transformed numerical abundance N of all eukaryotes occurring under organic pastures, mature grasslands, and seminatural heathlands in the Netherlands were investigated. The observed allometry of (M,N) assemblages of below-ground communities strongly reflects the availability of primary macronutrients and essential micronutrients. This log-linear model describes the continuous variation in the allometric slope of animals and fungi along an increasing soil fertility gradient. The aggregate contribution of small invertebrates (M soil explains 72% of these shifts but the nitrogen concentration explains only 36%, with copper and zinc as intermediate predictors (59% and 49%, respectively). Empirical evidence supports common responses of invertebrates to the rates of resource supply and, possibly, to the above-ground primary production of ecosystems.

  8. 移栽密度与施氮量对油菜生长发育和产量的影响%Effects of Different Transplanting Densities and Nitrogen Fertilizer Rates on Growth and Yield of Rape

    Institute of Scientific and Technical Information of China (English)

    聂泽民; 唐海明; 聂丽群; 高建彬; 汤文光; 杨光立; 肖小平

    2012-01-01

    以华杂油9号为材料,研究了不同移栽密度与施氮量对油菜生长发育、植株生物学特性、产量构成因素和产量的影响.研究结果表明:在15~45万株/hm2的移栽密度下,移栽密度对油菜生育期无明显影响,前期施用氮肥能促进油菜苗期的生长发育.在相同的施氮条件,各处理油菜植株的单株叶干重、茎干重、叶面积均随着种植密度的增加而降低.各处理油菜产量均显著高于对照,其产量大小顺序为T4>T5>T6>T3>T1>T2,分别比对照增加175.90%、168.83%、180.97%、222.55%、220.54%和203.29%.试验条件下油菜获得高产的适宜施氮量为180.0 kg/hm2、移栽密度15万株/hm2.%The effects of different transplanting densities and nitrogen fertilizer rates on growth, biological characteristics, yield components and yield of Huazayou 9 were studied. The results showed that with the transplanting density of 15~45×l04 shoots/hm2, ihe growth period of rape was not affected by transplanting density, and application of nitrogen fertilizer in early period can promote the growth of rape in seedling stage; with the same nitrogen fertilizer rate, dry weight of leaf, dry weight of stem and leaf area per rape plant in each treatment all decreased with increasing transplanting density; the yield of rape in each treatment was all obviously higher than that in control, and the yield in each treatment ordered as T4 >T5 >T6 >T3 >T1 >T2, which respectively increased by 175.90%, 168.83%, 180.97%, 222.55%, 220.54% and 203.29% than control; when nitrogen fertilizer rate was 180.0 kg/hm2 and transplanting density was 15xlO4 shoots/hm2, the rape can achieve high yield.

  9. 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.

  10. 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 elec

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

    Science.gov (United States)

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

    2016-04-01

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

  12. Religiosity, nationalism and fertility in Israel.

    Science.gov (United States)

    Anson, J; Meir, A

    1996-03-01

    It is suggested that Israel's high fertility can be explained by a collective national conscience rather than the traditional interpretation of Jewish religiosity. It is suggested that religiosity is a proxy for a national consciousness and daily living standards. It is argued that normative orientations or cultural explanations of the value of children are intervening variables according to the framework established by Davis and Blake. The collective conscience reflects Israel's special position in the Middle East and within the world economy. The nationalist feelings reflect a range in political views. The author disputes the ethnic and religious explanations for high fertility. Fertility increased since the 1960s even among low fertility European-American born women. During the early 1980s fertility was 2.75, which was high compared to European levels at the same standard of living. Reference is made to the literature on the association between high fertility and survival strategies in insecure or discriminatory settings. This study's analysis is based on a macro- rather than individual-level approach to understanding behavior. The theoretical framework is based on the theories of Durkheim and Gane. The analysis uses data from the 1983 census on Jewish fertility in urban statistical areas and Jewish voting patterns in national elections in 1984. Correspondence analysis is used to identify voting patterns by area. The four political postures are identified as religious and conciliatory (71 areas), religious and nationalist (142 areas), nonreligious and nationalist, and nonreligious and conciliatory. Women in nationalist areas had 35% more children than women in conciliatory areas. Although both religiosity and nationalism were positively correlated with high fertility, nationalist commitment was a better predictor. The model including religiosity, nationalism, and income showed no independent effect of religiosity on fertility.

  13. Is Wildlife Fertility Control Always Humane?

    Directory of Open Access Journals (Sweden)

    Jordan O. Hampton

    2015-10-01

    Full Text Available Investigation of fertility control techniques to reduce reproductive rates in wildlife populations has been the source of much research. Techniques targeting wildlife fertility have been diverse. Most research into fertility control methods has focused upon efficacy, with few studies rigorously assessing animal welfare beyond opportunistic anecdote. However, fertility control techniques represent several very different mechanisms of action (modalities, each with their own different animal welfare risks. We provide a review of the mechanisms of action for fertility control methods, and consider the role of manipulation of reproductive hormones (“endocrine suppression” for the long-term ability of animals to behave normally. We consider the potential welfare costs of animal manipulation techniques that are required to administer fertility treatments, including capture, restraint, surgery and drug delivery, and the requirement for repeated administration within the lifetime of an animal. We challenge the assumption that fertility control modalities generate similar and desirable animal welfare outcomes, and we argue that knowledge of reproductive physiology and behaviour should be more adeptly applied to wild animal management decisions. We encourage wildlife managers to carefully assess long-term behavioural risks, associated animal handling techniques, and the importance of positive welfare states when selecting fertility control methods as a means of population control.

  14. Effects of Decreasing Controlled- release Fertilizer Application Rate on Yield and Quality of Potato, and Soil Nitrate Nitrogen Content%控释肥减量施用对马铃薯产量、品质及土壤硝态氮含量的影响

    Institute of Scientific and Technical Information of China (English)

    董亮; 张玉凤; 刘苹; 于淑芳; 杨力; 杨鹏

    2012-01-01

    The effects of decreasing the application rate of controlled - release coated urea on the yield and quality of potato, and soil nitrate nitrogen content were studied through field experiments. The results indicated that the controlled - release fertilizer treatment increased the first grade rate of potato tube as compared with the traditional fertilization, enhanced potato yield by 8. 00% -25.59% , and the best yield - increasing effect was obtained in the treatment of applying 100% controlled - release fertilizer. Decreasing the application rate of controlled - release fertilizer improved potato quality, increased the utilization rate of nitrogen fertilizer by 10.53% ~22.69% , and the utilization rate of nitrogen fertilizer was the highest in the treatment of decreasing 40% nitrogen of controlled - release fertilizer. The controlled - release fertilizer treatment reduced soil nitrate nitrogen accumulation in each soil layer, and decreasing 30% ~ 40% nitrogen of controlled - release fertilizer achieved the least soil nitrate nitrogen accumulation.%通过田间试验,研究了包膜尿素减量化施用对马铃薯产量、品质及土壤硝态氮含量的影响.结果表明,与习惯施肥处理相比,花用控释肥可以提高马铃薯的一级品率,并且能较好地保证马铃薯产量,马铃薯产量增加8.00%~25.59%,以100%控释肥增产效果最好.马铃薯品质方面,减氮控释肥处理能提高马铃薯品质.施用控释肥可以提高氮肥利用率10.53%~22.69%,其中,以减氮40%控释肥的氮肥利用率最高.在马铃薯土壤硝态氮含量方面,施用控释肥能降低硝态氮在各个土层的累积,其中减氮30%~40%控释肥处理土壤硝态氮的累积量最低.

  15. Association of number of retrieved oocytes with live birth rate and birth weight: an analysis of 231,815 cycles of in vitro fertilization.

    Science.gov (United States)

    Baker, Valerie L; Brown, Morton B; Luke, Barbara; Conrad, Kirk P

    2015-04-01

    To determine if number of retrieved oocytes correlates with live birth rate and incidence of low birth weight (LBW). Retrospective cohort. Not applicable. Women undergoing fresh embryo transfer with the use of either autologous (n = 194,627) or donor (n = 37,188) oocytes whose cycles were reported to the Society for Assisted Reproductive Technology in the years 2004-2010. None. Live birth rate, birth weight, birth weight z-score, LBW. For both autologous and donor oocyte cycles, increasing number of retrieved oocytes paralleled live birth rate and embryos available for cryopreservation in most analyses, with all models adjusted for age and previous births. For cycles achieving singleton pregnancy with the use of autologous oocytes via transfer of two embryos, a higher number of retrieved oocytes was associated with lower mean birth weight, lower birth weight z-score, and greater incidence of LBW. In contrast, for cycles using donor oocytes, there was no association of number of retrieved oocytes with measures of birth weight. A higher number of retrieved oocytes was associated with an increased incidence of LBW in autologous singleton pregnancies resulting from transfer of two embryos, but not in donor oocyte cycles. Although the effect of high oocyte number on the incidence of LBW in autologous cycles was of modest magnitude, further study is warranted to determine if a subgroup of women may be particularly vulnerable. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  16. Effects of breed and progestin source on estrus synchronization and rates of fertility and fecundity in Iranian Sanjabi and Lori ewes.

    Science.gov (United States)

    Moeini, M M; Moghaddam, A A; Bahirale, A; Hajarian, H

    2007-11-01

    A trial was conducted to evaluate the effects of FGA (Fluorogestone acetate) and CIDR (Controlled internal drug release) on the induction of estrus and pregnancy and fecundity rates of the Sanjabi and Lori sheep. A total of 360 Sanjabi and Lori sheep were randomly grouped into two treatments with intravaginal devices inserted for 13 days: Group FGA (40 mg FGA, n = 180) and Group CIDR (n = 180). All ewes received an i.m. injection of 400 IU eCG (equine chorionic gonadotrophin) at devices removal. Estrous was assessed by exposing all ewes to vasectomized rams at 12 h intervals. Cervical artificial insemination was performed 12 h after estrus onset. The overall estrus response was 72.5%. The source of progestin did not influence the efficiency of estrus response but a significant difference (psheep that received either CIDR or FGA, estrus response was significantly (psheep breed did not influence the pregnancy and fecundity rates. The sheep breed influences the estrous response rate while the source of progestin did not affect the estrous response.

  17. Effects of seeding rate and fertilizer on photosynthetic characteristics and yield of spring Fagopyrum esculentum%播种量和施肥水平对春播甜荞光合特性及产量的影响

    Institute of Scientific and Technical Information of China (English)

    汪灿; 王诗雪; 李曼; 杨浩; 胡丹; 阮仁武; 袁晓辉; 易泽林

    2014-01-01

    [Objectives]Fagopyrum esculentum originated in China,and has the higher nutritional, medicinal and health care quality, and has been one of the most popular green functional foods in the 21th century. At present, Fagopyrum esculentum having lower yields is relatively scarce both in the domestic market and abroad exportation market. Thus, the objective of this study is to provide the best cultivation measures for Fagopyrum esculentum by investigating the effects of seeding rate and fertilizer on net photosynthetic rate, chlorophyll content and yield of a Fagopyrum esculentum cultivar, Xidahuaqiao, which is usually planted in spring. [Methods]Xidahuaqiao was used to investigate the effects of seeding rate and fertilizer on net photosynthetic rate, chlorophyll content and yield by using the quadratic general rotary unitized design, and the seeding rate, nitrogen fertilizer, phosphate fertilizer and potash were defined as experimental factors. The field experiments were respectively conducted from March to June in 2012 and in 2013 at the Xiema experimental station of Southwest University located at Beibei city, Chongqing municipality, China. The field experiments were the randomized block design with three replications, and the individual plot had 10 m2 area with 2 m width × 5 m length, and included 6 rows by spacing 33 cm, and surrounded by 3 guard rows. The reciprocal third functional leaf of three plants in the middle stripe was randomly selected to measure the net photosynthetic rate and chlorophyll content ( SPAD) between am 9:30 and 11:30 at a sunny day of full-bloom stage by using photosynthetic apparatus LI-6400 XT and chlorophyll meter SPAD 502 , respectively. Grain in each plot was harvested separately at the stage with 70%-80% mature grain, and then threshing, air drying and calculating yield. Data of each indicator were analyzed separately using Microsoft Excell2003 and SPSS 19 , and the contour map of interaction of two factors was drawn by Surfer 8

  18. Explaining the Allocation of Regional Structural Funds

    DEFF Research Database (Denmark)

    Charron, Nicholas

    2016-01-01

    What regional factors can explain the heterogeneity in Structural Funds distribution to European Union regions? Past studies have shown that aside from the level of economic development and rates of unemployment, other political, and economic factors systematically explain why certain European...

  19. Linear Algebra Thoroughly Explained

    CERN Document Server

    Vujičić, Milan

    2008-01-01

    Linear Algebra Thoroughly Explained provides a comprehensive introduction to the subject suitable for adoption as a self-contained text for courses at undergraduate and postgraduate level. The clear and comprehensive presentation of the basic theory is illustrated throughout with an abundance of worked examples. The book is written for teachers and students of linear algebra at all levels and across mathematics and the applied sciences, particularly physics and engineering. It will also be an invaluable addition to research libraries as a comprehensive resource book for the subject.

  20. Mid-luteal phase injection of subcutaneous leuprolide acetate improves live delivered pregnancy and implantation rates in younger women undergoing in vitro fertilization-embryo transfer (IVF-ET).

    Science.gov (United States)

    Check, J H; Wilson, C; Cohen, R; Choe, J K; Corley, D

    2015-01-01

    To see if the single injection of one mg of the gonadotropin releasing hormone agonist (GnRHa) leuprolide acetate given in the mid-luteal phase can increase live delivered pregnancy and implantation rates. Furthermore the purpose was to determine if improvement was found, did the mechanism involve increased secretion of human chorionic gonadotropin (hCG). A prospective study was conducted in women aged 35 who were undergoing in vitro fertilization-embryo transfer (IVF-ET). They were advised of data from Tesarik et al. and a previous pilot study conducted in the present IVF center showing improved pregnancy rates with the injection of a GnRHa three days after embryo transfer. They were offered the option of returning for a one-mg injection s.c. of leuprolide acetate or not. Clinical and live delivered pregnancy rates were compared according to those taking or not the leuprolide acetate one-mg injection. Chi-square analysis was used for statistical comparisons. Serum beta-hCG levels were compared between those conceiving with or without the extra injection of leuprolide. There was a non-significant trend for higher live delivered pregnancy rates in those taking leuprolide (47.8%, 64/134) vs. those not taking it (38.6%, 76/197). For those pregnant there was no difference in hCG levels according to taking the GnRHa or not. The 25% increased live delivered pregnancy rate per transfer was insufficiently powered to detect a significant difference. The results do justify continuing the study. Perhaps the difference could be wider using a slightly older age group whose embryos are frequently less hearty.

  1. Explaining immigrants’ moves into homeownership

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    , employment and family situation, and actual changes, but the importance of these factors differ from Danes. Different immigrant groups have a somewhat lower propensity to move into homeownership than Danes, which only to some extent can be explained by differences in income, education and employment. Living...... in social housing and in multi-ethnic neighbourhoods reduces the probability of moving into homeownership. But there are still some unexplained reasons for lower homeownership rate among immigrants. A probable hypothesis is that immigrants are more uncertain about their future employment and income. Some...

  2. The Role of Contemporary Childbearing Postponement and Recuperation in Shaping Period Fertility Trends

    Directory of Open Access Journals (Sweden)

    Tomas Frejka

    2012-09-01

    3. These TPFR increases were predominantly the consequence of changes in cohort childbearing age patterns, i.e. changes in the timing of fertility. They were not generated by fertility quantum increases. During this period in almost all the low-fertility countries TPFRs were rising while corresponding total cohort fertility rates were declining.

  3. 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

  4. Fertilization in northern forests

    DEFF Research Database (Denmark)

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

    2014-01-01

    resources into food, health and industrial products and energy. Fertilization in Sweden and Finland is currently practiced by extensive fertilization regimens where nitrogen fertilizers are applied once, or up to three times, during a rotation period, mainly in mature forest. This type of fertilization......Forests of northern ecosystems respond slowly to management activities and the possibilities to increase the growth in a short-term perspective and meet swift increases in society's demand for biomass are small. An exception among the silvicultural measures is fertilization which can be applied...... in combination with present management systems and, almost instantly, enhances forest productivity. There may, however, be both economic and environmental constraints to large-scale applications of fertilizers in forest. Here we review the literature concerning biomass production of forests under different...

  5. Fertility Preservation for Female

    Institute of Scientific and Technical Information of China (English)

    Jack Huang; Seang Lin Tan; Ri-Cheng Chian

    2006-01-01

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

  6. Explaining embodied cognition results.

    Science.gov (United States)

    Lakoff, George

    2012-10-01

    From the late 1950s until 1975, cognition was understood mainly as disembodied symbol manipulation in cognitive psychology, linguistics, artificial intelligence, and the nascent field of Cognitive Science. The idea of embodied cognition entered the field of Cognitive Linguistics at its beginning in 1975. Since then, cognitive linguists, working with neuroscientists, computer scientists, and experimental psychologists, have been developing a neural theory of thought and language (NTTL). Central to NTTL are the following ideas: (a) we think with our brains, that is, thought is physical and is carried out by functional neural circuitry; (b) what makes thought meaningful are the ways those neural circuits are connected to the body and characterize embodied experience; (c) so-called abstract ideas are embodied in this way as well, as is language. Experimental results in embodied cognition are seen not only as confirming NTTL but also explained via NTTL, mostly via the neural theory of conceptual metaphor. Left behind more than three decades ago is the old idea that cognition uses the abstract manipulation of disembodied symbols that are meaningless in themselves but that somehow constitute internal "representations of external reality" without serious mediation by the body and brain. This article uniquely explains the connections between embodied cognition results since that time and results from cognitive linguistics, experimental psychology, computational modeling, and neuroscience.

  7. Human Capital, Fertility and Growth

    OpenAIRE

    Galor, Oded

    2006-01-01

    The demographic transition that swept the world in the past 140 years has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed. The rise in the demand for human capital in the second phase of industrialization brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to c...

  8. A decrease in serum estradiol levels after human chorionic gonadotrophin administration predicts significantly lower clinical pregnancy and live birth rates in in vitro fertilization cycles.

    Science.gov (United States)

    Kondapalli, L A; Molinaro, T A; Sammel, M D; Dokras, A

    2012-09-01

    Although close observation of serum estradiol (E2) levels remains a mainstay of assessing clinical response to controlled ovarian stimulation, the prognostic value of any change in E2 levels after administration of hCG remains unclear. The objective of this study is to evaluate the relationship between serum E2 response after hCG administration and the clinical pregnancy and live birth rates in fresh IVF cycles. We conducted a retrospective cohort study of women aged 21-45 years undergoing their first IVF cycle from 1999 to 2008 at a single practice. We compared the post-hCG serum E2 level with values on the day of hCG trigger. IVF cycles were stratified by post-hCG E2 response and appropriate parametric and non-parametric statistics were performed. Clinical intrauterine pregnancy and live births were the primary outcomes of interest. Multivariable logistic regression models were created to identify predictive factors associated with outcomes while adjusting for potential confounders. Among the 1712 IVF cycles, 1065 exhibited a >10% increase (Group A), 525 had a plateau (± 10%, Group B) and 122 showed a >10% decrease (Group C) in post-hCG E2 levels. While the E2 levels on the day of hCG were similar across groups, Group C had more patients with diminished ovarian reserve, required higher gonadotrophin doses and had the lowest implantation rates. After adjusting for age, total gonadotrophin dose, infertility diagnosis, number of oocytes and number of transferred embryos, the associations between post-hCG E2 decline (Group C) and clinical pregnancy [adjusted odds ratio (aOR): 0.53; 95% confidence interval (CI): 0.33-0.84, P= 0.007] and live birth (aOR: 0.40; 95% CI: 0.22-0.71, P= 0.002) were significant. We also found significant associations between E2 plateau (Group B) and clinical pregnancy (aOR: 0.73; 95% CI: 0.57-0.94, P= 0.013) and live birth (aOR: 0.74; 95% CI: 0.56-0.97, P= 0.032) when adjusting for the same factors. In our study, >10% decrease in E2 levels

  9. Effect of Different Fertilization Practices on Yield of a Wheat-Maize Rotation and Soil Fertility

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK>MNP>MN>NPK>NP>M>N>the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N>P>K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.

  10. Fertilization in echinoderms.

    Science.gov (United States)

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

    2012-08-31

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

  11. Effects of seeding rate and nitrogen fertilization rate on physiological traits of winter wheat after anthesis in a field with plastic mulched rides and unmulched furrows%播种量和施氮量对垄沟覆膜栽培冬小麦花后生理性状的影响

    Institute of Scientific and Technical Information of China (English)

    师日鹏; 上官宇先; 李娜; 周芳; 韩坤; 王林权

    2012-01-01

    Taking winter wheat cultivar Xiaoyan 22 as test material, a field experiment with central composite rotatable design was conducted to investigate the effects of seeding rate and nitrogen (N) fertilization rate on the physiological traits of the cultivar after anthesis under ridge-furrow cultivation with plastic film mulching, aimed to harmonize the relationships between winter wheat population and its individuals and to fully use the advantages of ridge-furrow cultivation in dry land areas. With increasing N fertilization rate, the leaf area index and the flag leaf chlorophyll content and net photosynthesis rate after anthesis increased; with increasing seeding rate, the leaf area index increased first and was stable then at early and middle milking stages but decreased at later milking stage, the flag leaf chlorophyll content and net photosynthesis rate decreased, and the grain yield per plant increased after an initial decrease. Appropriate seeding rate could optimize the relationships between winter wheat population and its individuals, and optimal N fertilization rate benefited the improvement of winter wheat physiological traits after anthesis and the enhancement of winter wheat yield. Under our experimental condition, seeding rate 112. 5 kg · hm-2 plus N fertilization rate 180-222 kg N · hm-2 is a scheme beneficial to optimize the relationships between winter wheat population and its individuals and to establish a good winter wheat community structure with a reasonable leaf area index after anthesis, higher flag leaf chlorophyll content and net photosynthesis rate, higher grain yield per plant, and high yield per unit area.%为协调冬小麦个体与群体间的关系,充分发挥旱作条件下垄沟栽培优势,以冬小麦品种小偃22为材料,采用二元二次正交旋转组合设计,通过田间试验研究了垄下集中施肥、垄上覆膜、膜际种植模式下播种量和施氮量对冬小麦花后生理性状的影响.结果表明:花后叶

  12. Hindu-Muslim differentials in fertility and population growth in India: role of proximate variables.

    Science.gov (United States)

    Balasubramanian, K

    1984-09-01

    In India, Hindu and Muslim differentials in fertility were examined using census data and the findings of 11 surveys. An explanation of the fertility differences was offered. The proportion of Muslims in the population increased and the proportion of Hindus decreased, both before and after partition of the country. After partition, and between 1951-71, the proportion of Muslims increased from 9.9%-11.2% while the proportion of Hindus decreased from 84.9%-82.7%. An examination of mortality and migration data suggests that these proportional changes cannot be attributed to differences in migration or mortality; therefore, they must be due to differences in fertility. Census and survey data provide considerable evidence that fertility is higher among Muslims than among Hindus. According to the 1971 census data, the total marital fertility rate for Muslim women was 11% higher in urban areas and 20% higher in rural areas than the rate for Hindus. Even when education was controlled, the Muslim rate remained higher. The findings of 11 demographic surveys consistently revealed higher fertility rates for Muslims compared to Hindus. Several studies demonstrated that these differences narrowed but remained significant when education and socioeconomic factors were controlled. Investigators generally offer 1 of 3 hypotheses to explain the differences. The 1st hypothesis attributes the fertility differences to differences in the background or socioeconomic characteristics of the 2 populations. This explanation is not supported by studies which have introduced socioeconomic controls. The 2nd hypothesis states that minority status itself is a sufficient cause of high fertility. There is considerable evidence with which to refute this hypothesis. For example, in predominantly Muslim countries, Hindu minorities tend to have lower fertility than Muslims. The 3rd hypothesis attributed the fertility differences to religious beliefs concerning reproduction. Both Islam and Hinduism are

  13. FERTILITY AND ITS DETERMINANTS IN ROMANIA AFTER 1995

    Directory of Open Access Journals (Sweden)

    DĂNUT-VASILE JEMNA

    2012-05-01

    Full Text Available This article provides an overall survey on fertility and its determinants in Romania after 1995. The empirical evidence presented in this paper supports the view that after the fall of the communism we register only five years of decline in fertility. After 1995 follows a very weak variation in fertility on the national level, but with significant differences between regions. Using a descriptive statistical analysis we emphasize the differences for fertility in these regions and we assume that the variation in fertility can be explained by demographic and economic variables. The results of the econometric model identify the principal determinants of the fertility variation in time and between Romanian regions after 1995.

  14. Matlab for engineers explained

    CERN Document Server

    Gustafsson, Fredrik

    2003-01-01

    This book is written for students at bachelor and master programs and has four different purposes, which split the book into four parts: 1. To teach first or early year undergraduate engineering students basic knowledge in technical computations and programming using MATLAB. The first part starts from first principles and is therefore well suited both for readers with prior exposure to MATLAB but lacking a solid foundational knowledge of the capabilities of the system and readers not having any previous experience with MATLAB. The foundational knowledge gained from these interactive guided tours of the system will hopefully be sufficient for an effective utilization of MATLAB in the engineering profession, in education and in research. 2. To explain the foundations of more advanced use of MATLAB using the facilities added the last couple of years, such as extended data structures, object orientation and advanced graphics. 3. To give an introduction to the use of MATLAB in typical undergraduate courses in elec...

  15. Explaining wartime rape.

    Science.gov (United States)

    Gottschall, Jonathan

    2004-05-01

    In the years since the first reports of mass rapes in the Yugoslavian wars of secession and the genocidal massacres in Rwanda, feminist activists and scholars, human rights organizations, journalists, and social scientists have dedicated unprecedented efforts to document, explain, and seek solutions for the phenomenon of wartime rape. While contributors to this literature agree on much, there is no consensus on causal factors. This paper provides a brief overview of the literature on wartime rape in historical and ethnographical societies and a critical analysis of the four leading explanations for its root causes: the feminist theory, the cultural pathology theory, the strategic rape theory, and the biosocial theory. The paper concludes that the biosocial theory is the only one capable of bringing all the phenomena associated with wartime rape into a single explanatory context.

  16. Explaining moral religions.

    Science.gov (United States)

    Baumard, Nicolas; Boyer, Pascal

    2013-06-01

    Moralizing religions, unlike religions with morally indifferent gods or spirits, appeared only recently in some (but not all) large-scale human societies. A crucial feature of these new religions is their emphasis on proportionality (between deeds and supernatural rewards, between sins and penance, and in the formulation of the Golden Rule, according to which one should treat others as one would like others to treat oneself). Cognitive science models that account for many properties of religion can be extended to these religions. Recent models of evolved dispositions for fairness in cooperation suggest that proportionality-based morality is highly intuitive to human beings. The cultural success of moralizing movements, secular or religious, could be explained based on proportionality.

  17. Effects of fertilization and drought on substrate decomposition and inorganic nitrogen concentration in a managed loblolly pine forest

    Science.gov (United States)

    Zhang, Y.; West, J. B.; Will, R. E.; Vogel, J. G.

    2013-12-01

    The productivity of managed pine forests in the southeastern US has been improved in part through nutrient management over the past 50 years. Although significant uncertainty exists, climate change may drive a reduction of rainfall of 10%-30% by 2080 for the region. This reduced precipitation may interact with fertilization to affect forest productivity and carbon balance. In this study, we analyzed the decomposition of southern pine wood and the accumulation of soil NH4+ and NO3- under a factorial combination of two treatments: soil moisture (30% throughfall removal) and nitrogen addition (386 lbs. /ac N fertilizer). We also studied the relationship between the distance from the trees and wood substrate decomposition. Our results showed that after 6 months the substrate decomposition rate (mass loss) under throughfall removal, irrespective of fertilization treatment, was lower compared to the decomposition rate under control (1.64% versus 2.35%). Although reduced precipitation did lower decomposition rates, local spatial pattern was also important, as the substrate in the middle location of a row of trees (regardless of throughfall treatment; 2.62%) decomposed faster than those near the tree (2.13%) and far from the tree (1.86%), likely reflecting small-scale variation in soil moisture. The effect of increased fertilization on inorganic soil N pools depended strongly on precipitation. While N pools increased as a result of fertilization, the relative increase was greater under throughfall removal for both NH4+ and NO3-. The possible mechanisms to explain this effect of precipitation include 1) reduced plant uptake of inorganic nitrogen due to soil moisture limitation; 2) drought reduced the activity of soil nitrifying and denitrifying microorganisms; and 3) less NO3- leaching after fertilization under drought. Our results indicate that future drought may cause slower substrate decomposition and will interact with fertilization to affect forest N dynamics.

  18. Fertilizer Use and Water Quality.

    Science.gov (United States)

    Reneau, Fred; And Others

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

  19. Fertilizer Use and Water Quality.

    Science.gov (United States)

    Reneau, Fred; And Others

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

  20. Explaining errors in children's questions.

    Science.gov (United States)

    Rowland, Caroline F

    2007-07-01

    The ability to explain the occurrence of errors in children's speech is an essential component of successful theories of language acquisition. The present study tested some generativist and constructivist predictions about error on the questions produced by ten English-learning children between 2 and 5 years of age. The analyses demonstrated that, as predicted by some generativist theories [e.g. Santelmann, L., Berk, S., Austin, J., Somashekar, S. & Lust. B. (2002). Continuity and development in the acquisition of inversion in yes/no questions: dissociating movement and inflection, Journal of Child Language, 29, 813-842], questions with auxiliary DO attracted higher error rates than those with modal auxiliaries. However, in wh-questions, questions with modals and DO attracted equally high error rates, and these findings could not be explained in terms of problems forming questions with why or negated auxiliaries. It was concluded that the data might be better explained in terms of a constructivist account that suggests that entrenched item-based constructions may be protected from error in children's speech, and that errors occur when children resort to other operations to produce questions [e.g. Dabrowska, E. (2000). From formula to schema: the acquisition of English questions. Cognitive Liguistics, 11, 83-102; Rowland, C. F. & Pine, J. M. (2000). Subject-auxiliary inversion errors and wh-question acquisition: What children do know? Journal of Child Language, 27, 157-181; Tomasello, M. (2003). Constructing a language: A usage-based theory of language acquisition. Cambridge, MA: Harvard University Press]. However, further work on constructivist theory development is required to allow researchers to make predictions about the nature of these operations.