miRNAs involved in the development and differentiation of fertile and sterile flowers in Viburnum macrocephalum f. keteleeri.

PubMed

Li, Weixing; He, Zhichong; Zhang, Li; Lu, Zhaogeng; Xu, Jing; Cui, Jiawen; Wang, Li; Jin, Biao

2017-10-13

Sterile and fertile flowers are important evolutionary developmental phenotypes in angiosperm flowers. The development of floral organs, critical in angiosperm reproduction, is regulated by microRNAs (miRNAs). However, the mechanisms underpinning the miRNA regulation of the differentiation and development of sterile and fertile flowers remain unclear. Here, based on investigations of the morphological differences between fertile and sterile flowers, we used high-throughput sequencing to characterize the miRNAs in the differentiated floral organs of Viburnum macrocephalum f. keteleeri. We identified 49 known miRNAs and 67 novel miRNAs by small RNA (sRNA) sequencing and bioinformatics analysis, and 17 of these known and novel miRNA precursors were validated by polymerase chain reaction (PCR) and Sanger sequencing. Furthermore, by comparing the sequencing results of two sRNA libraries, we found that 30 known and 39 novel miRNA sequences were differentially expressed, and 35 were upregulated and 34 downregulated in sterile compared with fertile flowers. Combined with their predicted targets, the potential roles of miRNAs in V. macrocephalum f. keteleeri flowers include involvement in floral organogenesis, cell proliferation, hormonal pathways, and stress responses. miRNA precursors and targets were further validated by quantitative real-time PCR (qRT-PCR). Specifically, miR156a-5p, miR156g, and miR156j expression levels were significantly higher in fertile flowers than in sterile flowers, while SPL genes displayed the opposite expression pattern. Considering that the targets of miR156 are predicted to be SPL genes, we propose that miR156 may be involved in the regulation of stamen development in V. macrocephalum f. keteleeri. We identified miRNAs differentially expressed between fertile and sterile flowers in V. macrocephalum f. keteleeri and provided new insights into the important regulatory roles of miRNAs in the differentiation and development of fertile and sterile flowers.

Differential responses to guano fertilization among tropical tree species with varying functional traits.

PubMed

Young, Hillary S; McCauley, Douglas J; Dirzo, Rodolfo

2011-02-01

Seabirds often cause significant changes to soil properties, and seabird-dominated systems often host unique plant communities. This study experimentally (1) examined species-specific responses to seabird guano gradients, (2) considered the role that differential functional traits among species play in altering plant response to guano, and (3) investigated the implications of seabird guano on range-expanding species. Using a greenhouse fertilization experiment, we examined how guano fertilization affects the growth and functional traits of four tree species dominant in the Pacific Islands: Cocos nucifera, Pisonia grandis, Scaevola sericea, and Tournefortia argentea. In these systems, seabirds are frequently found in association with three of these four species; the remaining species, C. nucifera, is a recently proliferating species commonly found in the region but rarely associated with seabirds. We determined that responses to guano addition differed significantly between species in ways that were consistent with predictions based on differing functional traits among species. Notably, we demonstrated that C. nucifera showed no growth responses to guano additions, whereas all seabird-associated plants showed strong responses. These results provide experimental evidence of differential species response to guano additions, suggesting that differences in species functional traits may contribute to changes in plant communities in seabird-dominated areas, with seabird-associated species garnering performance advantages in these high-nutrient environments. Among these species, results also suggest that C. nucifera may have a competitive advantage in low-nutrient environments, providing an unusual example of how a range-expanding plant species can profit from low-nutrient environments.

Translatome analysis at the egg-to-embryo transition in sea urchin

PubMed Central

Chassé, Héloïse; Aubert, Julie; Boulben, Sandrine; Le Corguillé, Gildas; Corre, Erwan; Cormier, Patrick

2018-01-01

Abstract Early embryogenesis relies on the translational regulation of maternally stored mRNAs. In sea urchin, fertilization triggers a dramatic rise in translation activity, necessary for the onset of cell division. Here, the full spectrum of the mRNAs translated upon fertilization was investigated by polysome profiling and sequencing. The translatome of the early sea urchin embryo gave a complete picture of the polysomal recruitment dynamics following fertilization. Our results indicate that only a subset of maternal mRNAs were selectively recruited onto polysomes, with over-represented functional categories in the translated set. The increase in translation upon fertilization depends on the formation of translation initiation complexes following mTOR pathway activation. Surprisingly, mTOR pathway inhibition differentially affected polysomal recruitment of the newly translated mRNAs, which thus appeared either mTOR-dependent or mTOR-independent. Therefore, our data argue for an alternative to the classical cap-dependent model of translation in early development. The identification of the mRNAs translated following fertilization helped assign translational activation events to specific mRNAs. This translatome is the first step to a comprehensive analysis of the molecular mechanisms governing translation upon fertilization and the translational regulatory networks that control the egg-to-embryo transition as well as the early steps of embryogenesis. PMID:29660001

Translatome analysis at the egg-to-embryo transition in sea urchin.

PubMed

Chassé, Héloïse; Aubert, Julie; Boulben, Sandrine; Le Corguillé, Gildas; Corre, Erwan; Cormier, Patrick; Morales, Julia

2018-05-18

Early embryogenesis relies on the translational regulation of maternally stored mRNAs. In sea urchin, fertilization triggers a dramatic rise in translation activity, necessary for the onset of cell division. Here, the full spectrum of the mRNAs translated upon fertilization was investigated by polysome profiling and sequencing. The translatome of the early sea urchin embryo gave a complete picture of the polysomal recruitment dynamics following fertilization. Our results indicate that only a subset of maternal mRNAs were selectively recruited onto polysomes, with over-represented functional categories in the translated set. The increase in translation upon fertilization depends on the formation of translation initiation complexes following mTOR pathway activation. Surprisingly, mTOR pathway inhibition differentially affected polysomal recruitment of the newly translated mRNAs, which thus appeared either mTOR-dependent or mTOR-independent. Therefore, our data argue for an alternative to the classical cap-dependent model of translation in early development. The identification of the mRNAs translated following fertilization helped assign translational activation events to specific mRNAs. This translatome is the first step to a comprehensive analysis of the molecular mechanisms governing translation upon fertilization and the translational regulatory networks that control the egg-to-embryo transition as well as the early steps of embryogenesis.

Hispanic Familism Reconsidered: Ethnic Differences in Perceived Value of Children and Fertility Intentions

PubMed Central

Hartnett, Caroline Sten; Parrado, Emilio A.

2013-01-01

Familism has been described as a cultural trait that might explain why the fertility of Hispanic women remains higher than non-Hispanic White women. Still, few studies have analyzed group differences in childbearing attitudes. This paper focuses on two dimensions of childbearing orientation: social value of children and fertility intentions. Using the National Survey of Family Growth we find limited support for the idea that familism undergirds differentials in fertility between native-born Hispanics and Whites. However, for foreign-born Hispanics, there are some differences in the perceived value of children compared with Whites, and these differences could contribute to fertility differentials. PMID:24068847

Retinoic acid signaling is dispensable for somatic development and function in the mammalian ovary.

PubMed

Minkina, Anna; Lindeman, Robin E; Gearhart, Micah D; Chassot, Anne-Amandine; Chaboissier, Marie-Christine; Ghyselinck, Norbert B; Bardwell, Vivian J; Zarkower, David

2017-04-15

Retinoic acid (RA) is a potent inducer of cell differentiation and plays an essential role in sex-specific germ cell development in the mammalian gonad. RA is essential for male gametogenesis and hence fertility. However, RA can also disrupt sexual cell fate in somatic cells of the testis, promoting transdifferentiation of male Sertoli cells to female granulosa-like cells when the male sexual regulator Dmrt1 is absent. The feminizing ability of RA in the Dmrt1 mutant somatic testis suggests that RA might normally play a role in somatic cell differentiation or cell fate maintenance in the ovary. To test for this possibility we disrupted RA signaling in somatic cells of the early fetal ovary using three genetic strategies and one pharmaceutical approach. We found that deleting all three RA receptors (RARs) in the XX somatic gonad at the time of sex determination did not significantly affect ovarian differentiation, follicle development, or female fertility. Transcriptome analysis of adult triple mutant ovaries revealed remarkably little effect on gene expression in the absence of somatic RAR function. Likewise, deletion of three RA synthesis enzymes (Aldh1a1-3) at the time of sex determination did not masculinize the ovary. A dominant-negative RAR transgene altered granulosa cell proliferation, likely due to interference with a non-RA signaling pathway, but did not prevent granulosa cell specification and oogenesis or abolish fertility. Finally, culture of fetal XX gonads with an RAR antagonist blocked germ cell meiotic initiation but did not disrupt sex-biased gene expression. We conclude that RA signaling, although crucial in the ovary for meiotic initiation, is not required for granulosa cell specification, differentiation, or reproductive function. Copyright © 2017 Elsevier Inc. All rights reserved.

[Regional difference of NPK fertilizers application and environmental risk assessment in Jiangsu Province, China].

PubMed

Liu, Qin-pu

2015-05-01

It is of great importance to have a deep understanding of the spatial distribution of NPK fertilizers application and the potential threat to the ecological environment in Jiangsu Province, which is helpful for regulating the rational fertilization, strengthening the fertilizer use risk management and guidance, and preventing agricultural non-point pollution. Based on the environmental risk assessment model with consideration of different impacts of N, P, K fertilizers on environment, this paper researched the regional differentiation characteristic and environmental risk of intensity of NPK fertilizer usages in Jiangsu. Analystic hierarchy process ( AHP) was used to determine the weithts of N, P, K. The environmental safety thresholds of N, P, K were made according to the standard of 250 kg · hm(-2) for the construction of ecological counties sponsered by Chinese government and the proportion of 1:0.5:0.5 for N:P:K surposed by some developed countries. The results showed that the intensity of NPK fertilizer application currently presented a gradually increasing trend from south to north of Jiangsu, with the extremum ratio of 3.3, and the extremum ratios of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer were 3.3, 4.5 and 4.4, respectively. The average proportion of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of 13 cities in Jiangsu was 1:0.39:0.26. Their proportion was relatively in equilibrium in southern Jiangsu, but the nutrient structure disorder was serious in northern Jiangsu. In Jiangsu, the environmental risk index of fertilization averaged at 0.69 and in the middle-range of environmental risk. The environmental risk index of fertilizer application in southern and central Jiangsu was respectively at the low and moderate levels, while that of cities in northern Jiangsu was at the moderate, serious or severe level. In Jiangsu, the regional difference of fertilizer application and environmental risk assessment were affected by many factors, including physical and economic conditions, government policy, management system, technology, and management methods.

Focal adenomyosis (intramural endometriotic cyst) in a very young patient - differential diagnosis with uterine fibromatosis

PubMed Central

Manta, L; Suciu, N; Constantin, A; Toader, O; Popa, F

2016-01-01

Introduction. Adenomyosis is a widespread disease usually affecting the late reproductive years of the women’s life, which has a great impact on their fertility. The most common form is diffuse adenomyosis, while focal adenomyosis, a cystic variant, is very rare, particularly in patients younger than 30 years old. Materials and methods. We reported a rare case of a 20-year-old Caucasian woman with cystic adenomyosis who was admitted in our service with severe chronic pelvic pain, dysmenorrhea, and menorrhagia, who had received conservative surgical treatment to preserve fertility and improve her obstetrical prognosis. Results and Discussions. Although the necrobiosis of a uterine fibroid was suspected preoperatively, the extemporaneous histopathological exam revealed adenomyosis associated with fibroleiomyoma with hyaline dystrophy and multiple foci of endometriosis of cystic formation in the wall of a young woman without any risk factors. Conclusion. Although a rare lesion in young patients, cystic adenomyosis should be considered when chronic pelvic pain is exacerbated during menstruation and is associated with a uterine tumor. In young patients, the differential diagnosis should be made with uterine malformations (hematometra), necrobiosis of uterine fibroids, pelvic endometriosis. The surgical treatment should be conservative with the excision of the lesion, always taking into account fertility preservation in young patients. PMID:27453751

Ethnicity and fertility in Nigeria.

PubMed

Kollehlon, Konia T

2003-01-01

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

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray

PubMed Central

2010-01-01

Background As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Methods Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Results Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. Conclusions In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment. PMID:20409345

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray.

PubMed

Xie, Shuwu; Zhu, Yan; Ma, Li; Lu, Yingying; Zhou, Jieyun; Gui, Youlun; Cao, Lin

2010-04-22

As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment.

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

PubMed

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

2015-02-01

Probable involvement of avidin and avidin-related protein-2 (AVR2) in sperm viability in the sperm storage tubules of turkeys has been suggested. The high affinity of biotin to avidin and its analogs is also well documented. The present study aimed to determine the effect of oral biotin on reproductive performance and oviductal mRNA expression of avidin and AVR2 in 2 broiler hen lines with different fertility rates. Low-fertility (line B) and high-fertility (line D) hens (n=144) were randomly allotted to receive 0 (T0), 0.30 (T1), or 0.45 (T2) mg/L biotin in drinking water from 30 through 33 wk of age. The reproductive performance of the hens was evaluated using artificial insemination. At the end of the treatment period, 24 hens per line were killed to assay the expression of avidin and AVR2 in the uterovaginal junction. Supplementary biotin increased egg production from 73.5% for T0 to 87.8% for T2. Hens administered with biotin in line B, but not in line D, showed an increase (8.4%) in fertility rate. Hatchability, chick quality, and overall embryonic mortality were not different among the experimental groups. Real-time PCR data showed that both avidin (P=0.0013) and AVR2 (P<0.0001) expressions were influenced by a biotin×line interaction effect, where low-fertility line B hens receiving the high biotin level recorded respectively a 3.9 and 15.3% increase in avidin and AVR2 mRNA expression, although biotin did not affect these traits in line D hens. Control hens in line D had a dramatically higher AVR2 expression record (7.4-fold) compared with the control hens in line B. The correlation coefficients of fertility rate and avidin expression were 0.73 and 0.66 in lines B and D, respectively. However, the correlation of fertility and AVR2 (r=0.65) was significant for line D hens only. Overall, fertility rate and oviductal expression of avidin and AVR2 were dichotomously affected by oral biotin in low- and high-fertility line hens, where only low-fertility birds showed improvements in these attributes. © 2015 Poultry Science Association Inc.

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

PubMed

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.

Multiple deleterious effects of experimentally aged sperm in a monogamous bird

USGS Publications Warehouse

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

2008-01-01

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

A comparative analysis of fertility differentials in Ghana and Nigeria.

PubMed

Olatoregun, Oluwaseun; Fagbamigbe, Adeniyi Francis; Akinyemi, Odunayo Joshua; Yusuf, Oyindamola Bidemi; Bamgboye, Elijah Afolabi

2014-09-01

Nigeria and Ghana are the most densely populated countries in the West African sub-region with fertility levels above world average. Our study compared the two countries' fertility levels and their determinants as well as the differentials in the effect of these factors across the two countries. We carried out a retrospective analysis of data from the Nigeria and Ghana Demographic Health Surveys, 2008. The sample of 33,385 and 4,916 women aged 15-49 years obtained in Nigeria and Ghana respectively was stratified into low, medium and high fertility using reported children ever born. Data was summarized using appropriate descriptive statistics. Factors influencing fertility were identified using ordinal logistic regression at 5% significance level. While unemployment significantly lowers fertility in Nigeria, it wasn't significant in Ghana. In both countries, education, age at first marriage, marital status, urban-rural residence, wealth index and use of oral contraception were the main factors influencing high fertility levels.

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

PubMed

Yang, Yang; Morgan, S Philip

2003-01-01

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

Throughfall reduction and nutrient availability effects on carbon balance in loblolly pine plantations in the southeastern United States

NASA Astrophysics Data System (ADS)

Bracho, R. G.; Vogel, J.; Jokela, E. J.; Cucinella, J.; Noormets, A.; Laviner, M. A.; Gonzalez-Benecke, C. A.; Samuelson, L. J.; Markewitz, D.; Will, R.; Meek, C.; Seiler, J.; Strahm, B. D.; McElligott, K.; Martin, T.

2016-12-01

Planted loblolly pine covers over 11 million hectares in the southeastern United States. Occurring across a range of climatic conditions, these pine plantations are critical for the regional economy and offset a significant fraction of anthropogenic CO2 emissions. Loblolly pine productivity has been enhanced through genetic improvement and intensive silviculture. However, climate projections forecast higher air temperature and more variable precipitation patterns for the region. A critical question is how silvicultural practices will interact with projected climate change to affect loblolly pine carbon balance. A fertilization by throughfall reduction experiment was established in the spring of 2012 at four loblolly pine plantations at the margins of the natural range of the specie (Florida FL, Georgia GA, Oklahoma OK and Virginia VA). Net primary productivity (NPP) was estimated from repeated tree inventories and net ecosystem productivity (NEP) as the difference between NPP and heterotrophic respiration (RH). Soil respiration (RS) and RH were measured simultaneously several times during the experiment. Throughfall reduction significantly decreased surface soil water content at all sites. After four years of treatment, fertilization increased NPP at all sites and throughfall reduction had a negative effect on NPP at the GA and OK sites. The combination fertilization x throughfall reduction did not have a significant effect on NPP. RS and RH were, in general negatively affected by fertilization and throughfall reduction with differential responses between sites, leading to significant NEP increases under fertilization, while throughfall reduction increased NEP at FL and VA due to no effect on NPP and negative effect on RS. Fertilization offset the negative effect of throughfall reduction on NEP in the fertilization x throughfall reduction treatment. All sites were significant carbon sinks, accumulating from 3.5 to 24 Mg C ha-1 in a 3 year period under a range of climatic conditions, age and treatments.

[Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

PubMed

Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

2015-07-01

Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

Expression of granulosa cell microRNAs, AVEN and ATRX are associated with human blastocyst development.

PubMed

O'Doherty, Alan M; O'Brien, Yvonne M; Browne, John A; Wingfield, Mary; O'Shea, Lynne C

2018-04-25

A greater understanding of the key molecules associated with embryo development during human-assisted reproduction is imperative for the development of advanced diagnostics. Previous studies have shown that follicular microRNAs (miRNAs) are reliable markers of the polycystic ovarian syndrome (PCOS). Leveraging the utility of miRNAs in PCOS, the aim of this study was to identify miRNAs in human granulosa cells that may be indicative of blastocyst development. Granulosa cells and oocytes were collected from the first follicle aspirated from patients undergoing oocyte retrieval for in vitro fertilization or intracytoplasmic sperm injection. The development of isolated oocytes was recorded, and granulosa cell samples in this study were separated as follows. Group 1-BLAST: granulosa cells from follicles containing an oocyte that fertilized and developed into a blastocyst, and Group 2-FERT: granulosa cells from oocytes that fertilized but failed to reach blastocyst. A panel of 84 miRNAs, related to development and cellular differentiation, was assessed between the two groups using a miScript PCR array. Fourteen miRNAs and one snoRNA were differentially expressed between the groups. In addition, two downstream candidate protein biomarkers, ATRX and AVEN, were also found to be differentially expressed between the groups. The findings of this pilot study reveal follicular abnormalities on a molecular level, which may affect oocyte competence and its potential to develop successfully as an embryo. We encourage additional studies to confirm and expand on our findings and to determine the usefulness of granulosa-borne miRNAs, ATRX, and AVEN as biomarkers. © 2018 Wiley Periodicals, Inc.

Wealth, intelligence, politics and global fertility differentials.

PubMed

Meisenberg, Gerhard

2009-07-01

Demographic trends in today's world are dominated by large fertility differentials between nations, with 'less developed' nations having higher fertility than the more advanced nations. The present study investigates whether these fertility differences are related primarily to indicators of economic development, the intellectual level of the population, or political modernity in the form of liberal democracy. Results obtained with multiple regression, path models and latent variable models are compared. Both log-transformed GDP and measures of intelligence independently reduce fertility across all methods, whereas the effects of liberal democracy are weak and inconsistent. At present rates of fertility and mortality and in the absence of changes within countries, the average IQ of the young world population would decline by 1.34 points per decade and the average per capita income would decline by 0.79% per year.

Gestational Exposure to Bisphenol A Affects the Function and Proteome Profile of F1 Spermatozoa in Adult Mice.

PubMed

Rahman, Md Saidur; Kwon, Woo-Sung; Karmakar, Polash Chandra; Yoon, Sung-Jae; Ryu, Buom-Yong; Pang, Myung-Geol

2017-02-01

Maternal exposure to the endocrine disruptor bisphenol A (BPA) has been linked to offspring reproductive abnormalities. However, exactly how BPA affects offspring fertility remains poorly understood. The aim of the present study was to evaluate the effects of gestational BPA exposure on sperm function, fertility, and proteome profile of F1 spermatozoa in adult mice. Pregnant CD-1 mice (F0) were gavaged with BPA at three different doses (50 μg/kg bw/day, 5 mg/kg bw/day, and 50 mg/kg bw/day) on embryonic days 7 to 14. We investigated the function, fertility, and related processes of F1 spermatozoa at postnatal day 120. We also evaluated protein profiles of F1 spermatozoa to monitor their functional affiliation to disease. BPA inhibited sperm count, motility parameters, and intracellular ATP levels in a dose-dependent manner. These effects appeared to be caused by reduced numbers of stage VIII seminiferous epithelial cells in testis and decreased protein kinase A (PKA) activity and tyrosine phosphorylation in spermatozoa. We also found that BPA compromised average litter size. Proteins differentially expressed in spermatozoa from BPA treatment groups are known to play a critical role in ATP generation, oxidative stress response, fertility, and in the pathogenesis of several diseases. Our study provides mechanistic support for the hypothesis that gestational exposure to BPA alters sperm function and fertility via down-regulation of tyrosine phosphorylation through a PKA-dependent mechanism. In addition, we anticipate that the BPA-induced changes in the sperm proteome might be partly responsible for the observed effects in spermatozoa. Citation: Rahman MS, Kwon WS, Karmakar PC, Yoon SJ, Ryu BY, Pang MG. 2017. Gestational exposure to bisphenol-A affects the function and proteome profile of F1 spermatozoa in adult mice. Environ Health Perspect 125:238-245; http://dx.doi.org/10.1289/EHP378.

Gestational Exposure to Bisphenol A Affects the Function and Proteome Profile of F1 Spermatozoa in Adult Mice

PubMed Central

Rahman, Md Saidur; Kwon, Woo-Sung; Karmakar, Polash Chandra; Yoon, Sung-Jae; Ryu, Buom-Yong; Pang, Myung-Geol

2016-01-01

Background: Maternal exposure to the endocrine disruptor bisphenol A (BPA) has been linked to offspring reproductive abnormalities. However, exactly how BPA affects offspring fertility remains poorly understood. Objectives: The aim of the present study was to evaluate the effects of gestational BPA exposure on sperm function, fertility, and proteome profile of F1 spermatozoa in adult mice. Methods: Pregnant CD-1 mice (F0) were gavaged with BPA at three different doses (50 μg/kg bw/day, 5 mg/kg bw/day, and 50 mg/kg bw/day) on embryonic days 7 to 14. We investigated the function, fertility, and related processes of F1 spermatozoa at postnatal day 120. We also evaluated protein profiles of F1 spermatozoa to monitor their functional affiliation to disease. Results: BPA inhibited sperm count, motility parameters, and intracellular ATP levels in a dose-dependent manner. These effects appeared to be caused by reduced numbers of stage VIII seminiferous epithelial cells in testis and decreased protein kinase A (PKA) activity and tyrosine phosphorylation in spermatozoa. We also found that BPA compromised average litter size. Proteins differentially expressed in spermatozoa from BPA treatment groups are known to play a critical role in ATP generation, oxidative stress response, fertility, and in the pathogenesis of several diseases. Conclusions: Our study provides mechanistic support for the hypothesis that gestational exposure to BPA alters sperm function and fertility via down-regulation of tyrosine phosphorylation through a PKA-dependent mechanism. In addition, we anticipate that the BPA-induced changes in the sperm proteome might be partly responsible for the observed effects in spermatozoa. Citation: Rahman MS, Kwon WS, Karmakar PC, Yoon SJ, Ryu BY, Pang MG. 2017. Gestational exposure to bisphenol-A affects the function and proteome profile of F1 spermatozoa in adult mice. Environ Health Perspect 125:238–245; http://dx.doi.org/10.1289/EHP378 PMID:27384531

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-05-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm-egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm-egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm-egg interactions.

A nonsemen copulatory fluid influences the outcome of sperm competition in Japanese quail.

PubMed

Finseth, F R; Iacovelli, S R; Harrison, R G; Adkins-Regan, E K

2013-09-01

Sperm competition is a powerful and widespread evolutionary force that drives the divergence of behavioural, physiological and morphological traits. Elucidating the mechanisms governing differential fertilization success is a fundamental question of sperm competition. Both sperm and nonsperm ejaculate components can influence sperm competition outcomes. Here, we investigate the role of a nonsemen copulatory fluid in sperm competition. Male Japanese quail possess a gland that makes meringue-like foam. Males produce and store foam independent of sperm and seminal fluid, yet transfer foam to females during copulation. We tested whether foam influenced the outcome of sperm competition by varying foam state and mating order in competitive matings. We found that the presence of foam from one male decreased the relative fertilization success of a rival, and that foam from a given male increased the probability he obtained any fertilizations. Mating order also affected competitive success. Males mated first fertilized proportionally more eggs in a clutch and had more matings with any fertilizations than subsequent males. We conclude that the function of foam in sperm competition is mediated through the positive interaction of foam with a male's sperm, and we speculate whether the benefit is achieved through improving sperm storage, fertilizing efficiency or retention. Our results suggest males can evolve complex strategies to gain fertilizations at the expense of rivals as foam, a copulatory fluid not required for fertilization, nevertheless, has important effects on reproductive performance under competition. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Foods That Can Affect Fertility

MedlinePlus

... Reproduction Foods That Can Affect Fertility Print Email Foods That Can Affect Fertility By Caroline Kaufman, MS, ... to a registered dietitian nutritionist. Choose Iron-Rich Foods An diet rich in iron that comes from ...

Fertility desires and fertility outcomes.

PubMed

Bracher, M; Santow, G

1991-05-01

An Australian 1-in-1000 national probability sample conducted in 1986 yielded 2547 women aged 20-59 who provided detailed life histories on marital unions, childbearing, and contraception. Age specific fertility rates, desired family size, differentials in desired family size, desired fertility and achieved fertility, and sequential family building are examined. The results indicate that the desired family size at 1st marriage has declined only slightly over the past 30 years. 3 children are generally desired, and ver few desire 2. The constance of fertility desires in contrasted with the fertilitydecline to below replacement levels. Several reasons are suggested for the desired family size: the desire is for a family size within the family tradition and modified by the desire to have 1 of each sex, the desire reflects less on intentions but more on normative pressure to become a parent. Marrying is self selecting on the desire for a traditional family of at least 2 children. There is a rising age at marriage as well as a decline in marriages. Desired family size exceeds completed fertility. Period factors and personal circumstances affect fertility intentions. Future inquires should explore the multiple factors relating to fertility, rather than in comparing fertility desires and actual fertility. The data collected on age specific fertility were comparable to official estimates. The fertility decline was evidenced in all groups except teenagers. The decline was nearly 50% for those 20-24 years between the 1050's-80's, 33% for ages 25-29. Marriage patterns explain this decline in part. Between 1971-76, women aged 20-25 were married 37 months out of 60 months in 1971-76 versus 25 out of 60 months in 1981-86. Within the 25 year age group, marital fertility has declined and unmarried fertility, which is low, has risen, Women in a marital union of any kind has remained stable. Fertility within de facto unions, which is lower than within marriage, is higher than fertility outside a marital union, and highest in the teens. Distributions of desired children were strongly bimodel with concentrations of 2 and 4 children.

Effects of tributyltin on early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes).

PubMed

Horie, Yoshifumi; Yamagishi, Takahiro; Shintaku, Yoko; Iguchi, Taisen; Tatarazako, Norihisa

2018-07-01

Tributyltin, an organotin compound, was used worldwide as an antifouling agent in aquatic environments and there has been much concern about the toxicological and ecotoxicological properties of organotin compounds. Even though it has been prohibited worldwide, tributyltin is still detected at low concentrations in aquatic environments. Here we investigated the effects of tributyltin on the early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes). In adults, exposure to tributyltin at 3.82 μg/L suppressed fecundity and fertility and increased mortality. At 10.48 μg/L all medaka died by the sixth day of exposure. Exposure to tributyltin during early life-stages induced no significant differences in mortality or embryonic development, but growth was suppressed in groups exposed to 0.13 and 0.68 μg/L. Furthermore, there was no abnormal gonadal development in Japanese medaka exposed to tributyltin. These results provide evidence of the negative effects of tributyltin on reproduction in a teleost fish. Tributyltin did not affect gonadal sex differentiation in Japanese medaka, but fecundity and fertility were suppressed, although it is not clear whether this suppression resulted from the endocrine-disrupting action of tributyltin or its toxicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-01-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm–egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm–egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm–egg interactions. PMID:28051059

Fertilization and irrigation of Eucalyptus in southern California

Treesearch

Paul W. Moore

1983-01-01

An experiment to determine the interaction of three levels of irrigation, three levels of fertility and three densities of planting was started at the University of California Moreno Ranch in 1982. Differential irrigation and fertility treatments will begin in June of 1983. Some current practices of irrigation and fertilization by southern California growers are...

HINDU-MUSLIM FERTILITY DIFFERENTIAL IN INDIA: A COHORT APPROACH.

PubMed

Pasupuleti, Samba Siva Rao; Pathak, Prasanta; Jatrana, Santosh

2017-03-01

Hindus and Muslims together account for 94% of the population of India. The fertility differential between these two religious groups is a sensitive and hotly debated issue in political and academic circles. However, the debate is mostly based on a period approach to fertility change, and there have been some problems with the reliability of period fertility data. This study investigated cohort fertility patterns among Hindus and Muslims and the causes of the relatively higher level of fertility among Muslims. Data from the three National Family Health Surveys conducted in India since the early 1990s were analysed using a six-parameter special form of the Gompertz model and multiple linear regression models. The results show a gap of more than 1.3 children per woman between those Muslim and Hindu women who ended/will end their reproductive period in the calendar years 1993 to 2025. The socioeconomic and demographic characteristics of Muslims explain 31.2% of the gap in fertility between Muslims and Hindus, while the desire for more children among Muslims explains an additional 18.2% of the gap in fertility.

Functions of TAM RTKs in regulating spermatogenesis and male fertility in mice.

PubMed

Chen, Yongmei; Wang, Huizhen; Qi, Nan; Wu, Hui; Xiong, Weipeng; Ma, Jing; Lu, Qingxian; Han, Daishu

2009-10-01

Mice lacking TYRO3, AXL and MER (TAM) receptor tyrosine kinases (RTKs) are male sterile. The mechanism of TAM RTKs in regulating male fertility remains unknown. In this study, we analyzed in more detail the testicular phenotype of TAM triple mutant (TAM(-/-)) mice with an effort to understand the mechanism. We demonstrate that the three TAM RTKs cooperatively regulate male fertility, and MER appears to be more important than AXL and TYRO3. TAM(-/-) testes showed a progressive loss of germ cells from elongated spermatids to spermatogonia. Young adult TAM(-/-) mice exhibited oligo-astheno-teratozoospermia and various morphological malformations of sperm cells. As the mice aged, the germ cells were eventually depleted from the seminiferous tubules. Furthermore, we found that TAM(-/-) Sertoli cells have an impaired phagocytic activity and a large number of differentially expressed genes compared to wild-type controls. By contrast, the function of Leydig cells was not apparently affected by the mutation of TAM RTKs. Therefore, we conclude that the suboptimal function of Sertoli cells leads to the impaired spermatogenesis in TAM(-/-) mice. The results provide novel insight into the mechanism of TAM RTKs in regulating male fertility.

The impact of kin availability, parental religiosity, and nativity on fertility differentials in the late 19th-century United States

PubMed Central

Hacker, J. David; Roberts, Evan

2017-01-01

METHODS Most quantitative research on fertility decline in the United States ignores the potential impact of cultural and familial factors. We rely on new complete-count data from the 1880 U.S. census to construct couple-level measures of nativity/ethnicity, religiosity, and kin availability. We include these measures with a comprehensive set of demographic, economic, and contextual variables in Poisson regression models of net marital fertility to assess their relative importance. We construct models with and without area fixed effects to control for unobserved heterogeneity. CONTRIBUTION All else being equal, we find a strong impact of nativity on recent net marital fertility. Fertility differentials among second generation couples relative to the native-born white population of native parentage were in most cases less than half of the differential observed among first generation immigrants, suggesting greater assimilation to native-born American childbearing norms. Our measures of parental religiosity and familial propinquity indicated a more modest impact on marital fertility. Couples who chose biblical names for their children had approximately 3% more children than couples relying on secular names while the presence of a potential mother-in-law in a nearby households was associated with 2% more children. Overall, our results demonstrate the need for more inclusive models of fertility behavior that include cultural and familial covariates. PMID:29720893

The impact of kin availability, parental religiosity, and nativity on fertility differentials in the late 19th-century United States.

PubMed

Hacker, J David; Roberts, Evan

2017-12-01

Most quantitative research on fertility decline in the United States ignores the potential impact of cultural and familial factors. We rely on new complete-count data from the 1880 U.S. census to construct couple-level measures of nativity/ethnicity, religiosity, and kin availability. We include these measures with a comprehensive set of demographic, economic, and contextual variables in Poisson regression models of net marital fertility to assess their relative importance. We construct models with and without area fixed effects to control for unobserved heterogeneity. All else being equal, we find a strong impact of nativity on recent net marital fertility. Fertility differentials among second generation couples relative to the native-born white population of native parentage were in most cases less than half of the differential observed among first generation immigrants, suggesting greater assimilation to native-born American childbearing norms. Our measures of parental religiosity and familial propinquity indicated a more modest impact on marital fertility. Couples who chose biblical names for their children had approximately 3% more children than couples relying on secular names while the presence of a potential mother-in-law in a nearby households was associated with 2% more children. Overall, our results demonstrate the need for more inclusive models of fertility behavior that include cultural and familial covariates.

Principles and limitations of stable isotopes in differentiating organic and conventional foodstuffs: 1. Plant products.

PubMed

Inácio, Caio Teves; Chalk, Phillip Michael; Magalhães, Alberto M T

2015-01-01

Among the lighter elements having two or more stable isotopes (H, C, N, O, S), δ(15)N appears to be the most promising isotopic marker to differentiate plant products from conventional and organic farms. Organic plant products vary within a range of δ(15)N values of +0.3 to +14.6%, while conventional plant products range from negative to positive values, i.e. -4.0 to +8.7%. The main factors affecting δ(15)N signatures of plants are N fertilizers, biological N2 fixation, plant organs and plant age. Correlations between mode of production and δ(13)C (except greenhouse tomatoes warmed with natural gas) or δ(34)S signatures have not been established, and δ(2)H and δ(18)O are unsuitable markers due to the overriding effect of climate on the isotopic composition of plant-available water. Because there is potential overlap between the δ(15)N signatures of organic and conventionally produced plant products, δ(15)N has seldom been used successfully as the sole criterion for differentiation, but when combined with complementary analytical techniques and appropriate statistical tools, the probability of a correct identification increases. The use of organic fertilizers by conventional farmers or the marketing of organic produce as conventional due to market pressures are additional factors confounding correct identification. The robustness of using δ(15)N to differentiate mode of production will depend on the establishment of databases that have been verified for individual plant products.

[Feeding and adolescence].

PubMed

Dain, E

2012-09-01

Adolescence is a transition period during which young people face many changes. Their desire to assert and differentiate themselves is reflected even in their food choices. These choices may have impacts until their adult lives. Moreover the media affect them in contradictory ways from images of extreme thinnesses to enticing advertisements of calorie food. A lack of self-esteem may appear, and in case of fertile ground may cause either diet, either addiction, or eating disorder. A comforting family as well as empathetic physicians have a main role in the medical care.

Effects of fertilization of four hemlock species on Adelges tsugae (Hemiptera: Adelgidae) growth and feeding preference of predators.

Treesearch

S.V. Joseph; James Hanula

2011-01-01

Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera:Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to...

A decomposition analysis of recent fertility decline in Fiji.

PubMed

Gubhaju, B; Shahidullah, M

1990-12-01

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

Nitrite-Oxidizing Bacteria Community Composition and Diversity Are Influenced by Fertilizer Regimes, but Are Independent of the Soil Aggregate in Acidic Subtropical Red Soil.

PubMed

Han, Shun; Li, Xiang; Luo, Xuesong; Wen, Shilin; Chen, Wenli; Huang, Qiaoyun

2018-01-01

Nitrification is the two-step aerobic oxidation of ammonia to nitrate via nitrite in the nitrogen-cycle on earth. However, very limited information is available on how fertilizer regimes affect the distribution of nitrite oxidizers, which are involved in the second step of nitrification, across aggregate size classes in soil. In this study, the community compositions of nitrite oxidizers ( Nitrobacter and Nitrospira ) were characterized from a red soil amended with four types of fertilizer regimes over a 26-year fertilization experiment, including control without fertilizer (CK), swine manure (M), chemical fertilization (NPK), and chemical/organic combined fertilization (MNPK). Our results showed that the addition of M and NPK significantly decreased Nitrobacter Shannon and Chao1 index, while M and MNPK remarkably increased Nitrospira Shannon and Chao1 index, and NPK considerably decreased Nitrospira Shannon and Chao1 index, with the greatest diversity achieved in soils amended with MNPK. However, the soil aggregate fractions had no impact on that alpha-diversity of Nitrobacter and Nitrospira under the fertilizer treatment. Soil carbon, nitrogen and phosphorus in the soil had a significant correlation with Nitrospira Shannon and Chao1 diversity index, while total potassium only had a significant correlation with Nitrospira Shannon diversity index. However, all of them had no significant correlation with Nitrobacter Shannon and Chao1 diversity index. The resistance indices for alpha-diversity indexes (Shannon and Chao1) of Nitrobacter were higher than those of Nitrospira in response to the fertilization regimes. Manure fertilizer is important in enhancing the Nitrospira Shannon and Chao1 index resistance. Principal co-ordinate analysis revealed that Nitrobacter - and Nitrospira -like NOB communities under four fertilizer regimes were differentiated from each other, but soil aggregate fractions had less effect on the nitrite oxidizers community. Redundancy analysis and Mantel test indicated that soil nitrogen, carbon, phosphorus, and available potassium content were important environmental attributes that control the Nitrobacter - and Nitrospira -like NOB community structure across different fertilization treatments under aggregate levels in the red soil. In general, nitrite-oxidizing bacteria community composition and alpha-diversity are depending on fertilizer regimes, but independent of the soil aggregate.

Reducing fertilizer-derived N2O emission: Point injection vs. surface application of ammonium-N fertilizer at a loamy sand site

NASA Astrophysics Data System (ADS)

Deppe, Marianna; Well, Reinhard; Giesemann, Anette; Kücke, Martin; Flessa, Heinz

2013-04-01

N2O emitted from soil originates either from denitrification of nitrate and/or nitrification of ammonium. N fertilization can have an important impact on N2O emission rates. Injection of nitrate-free ammonium-N fertilizer, in Germany also known as CULTAN (Controlled Uptake Long-Term Ammonium Nutrition), results in fertilizer depots with ammonium concentrations of up to 10 mg N g-1 soil-1. High concentrations of ammonium are known to inhibit nitrification. However, it has not yet been clarified how N2O fluxes are affected by CULTAN. In a field experiment, two application methods of nitrogen fertilizer were used at a loamy sand site: Ammonium sulphate was applied either by point injection or by surface application. 15N-ammonium sulphate was used to distinguish between N2O originating from either fertilizer-N or soil-N. Unfertilized plots and plots fertilized with unlabeled ammonium sulphate served as control. N2O emissions were measured using static chambers, nitrate and ammonium concentrations were determined in soil extracts. Stable isotope analysis of 15N in N2O, nitrate and ammonium was used to calculate the contribution of fertilizer N to N2O emissions and the fertilizer turnover in soil. 15N analysis clearly indicated that fertilizer derived N2O fluxes were higher from surface application plots. For the period of the growing season, about 24% of the flux measured in surface application treatment and less than 10% from injection treatment plots originated from the fertilizer. In addition, a lab experiment was conducted to gain insight into processes leading to N2O emission from fertilizer depots. One aim was to examine whether the ratio of N2O to nitrate formation differs depending on the ammonium concentration. Loamy sand soil was incubated in microcosms continuously flushed with air under conditions favouring nitrification. 15N-labeled nitrate was used to differentiate between nitrification and denitrification. Stable isotope analyses of 15N were performed on N2O in the gas phase and on ammonium and nitrate extracted from soil samples.

Intergenerational effects of shifts in women's educational distribution in South Korea: Transmission, differential fertility, and assortative mating

PubMed Central

Kye, Bongoh; Mare, Robert D.

2014-01-01

This study examines the intergenerational effects of changes in women's education in South Korea. We define intergenerational effects as changes in the distribution of educational attainment in an offspring generation associated with the changes in a parental generation. Departing from the previous approach in research on social mobility that has focused on intergenerational association, we examine the changes in the distribution of educational attainment across generations. Using a simulation method based on Mare and Maralani's recursive population renewal model, we examine how intergenerational transmission, assortative mating, and differential fertility influence intergenerational effects. The results point to the following conclusions. First, we find a positive intergenerational effect: improvement in women's education leads to improvement in daughter's education. Second, we find that the magnitude of intergenerational effects substantially depends on assortative marriage and differential fertility: assortative mating amplifies and differential fertility dampens the intergenerational effects. Third, intergenerational effects become bigger for the less educated and smaller for the better educated over time, which is a consequence of educational expansion. We compare our results with Mare and Maralani's original Indonesian study to illustrate how the model of intergenerational effects works in different socioeconomic circumstances. PMID:23017970

Fertility Preservation in Klinefelter Syndrome Patients during the Transition Period.

PubMed

Rives, Nathalie; Rives, Aurélie; Rondanino, Christine; Castanet, Mireille; Cuny, Ariane; Sibert, Louis

2018-01-01

Spermatozoa have occasionally been identified in ejaculate of adult Klinefelter syndrome (KS) patients but very exceptionally in KS adolescents. Spermatozoa can also be retrieved in testicular tissue of KS adolescents. The testis may also harbor spermatogonia and noncompletely differentiated germ cells. Neither clinical features nor hormonal parameters could predict germ cell recovery in KS adults or adolescents. No predictive factors can actually demonstrate that early diagnosis of KS would allow increasing the chance of sperm retrieval even if it has been suggested that semen quality may decline with age in KS patients. Leydig cell dysfunction may also be another factor that might affect the spermatogenesis process in XXY adolescents. Fertility preservation might be preferentially proposed in KS adolescents when semen sampling is possible, when the patient is able to consider alternative options to become a father, and to accept germ cell retrieval failure. However, precocious diagnosis of KS has also to be considered because it might not solely improve the possibility of fertility preservation after the onset of puberty, but also the medical care and the quality of life of these patients. © 2018 S. Karger AG, Basel.

Differential Fertility, Intergenerational Educational Mobility, and Racial Inequality.

ERIC Educational Resources Information Center

Mare, Robert D.

Recent commentary has suggested that the relatively high fertility of poorly educated women tends to dampen the average intellectual qualifications of the population. To evaluate this claim requires a model of population growth that takes account of fertility differences among women with varying levels of educational attainment and patterns of…

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

PubMed

Chackiel, J

1982-04-01

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

Uranium in groundwater--Fertilizers versus geogenic sources.

PubMed

Liesch, Tanja; Hinrichsen, Sören; Goldscheider, Nico

2015-12-01

Due to its radiological and toxicological properties even at low concentration levels, uranium is increasingly recognized as relevant contaminant in drinking water from aquifers. Uranium originates from different sources, including natural or geogenic, mining and industrial activities, and fertilizers in agriculture. The goal of this study was to obtain insights into the origin of uranium in groundwater while differentiating between geogenic sources and fertilizers. A literature review concerning the sources and geochemical processes affecting the occurrence and distribution of uranium in the lithosphere, pedosphere and hydrosphere provided the background for the evaluation of data on uranium in groundwater at regional scale. The state of Baden-Württemberg, Germany, was selected for this study, because of its hydrogeological and land-use diversity, and for reasons of data availability. Uranium and other parameters from N=1935 groundwater monitoring sites were analyzed statistically and geospatially. Results show that (i) 1.6% of all water samples exceed the German legal limit for drinking water (10 μg/L); (ii) The range and spatial distribution of uranium and occasional peak values seem to be related to geogenic sources; (iii) There is a clear relation between agricultural land-use and low-level uranium concentrations, indicating that fertilizers generate a measurable but low background of uranium in groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of nutrient enrichment on growth, photosynthesis and hydraulic conductance of dwarf mangroves in Panamá

USGS Publications Warehouse

Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Engelbrecht, B.M.J.; Ball, M.C.

2004-01-01

1. Dwarf stands of the mangrove Rhizophora mangle L. are extensive in the Caribbean. We fertilized dwarf trees in Almirante Bay, Bocas del Toro Province, north-eastern Panama with nitrogen (N) and phosphorus (P) to determine (1) if growth limitations are due to nutrient deficiency; and (2) what morphological and/or physiological factors underlie nutrient limitations to growth. 2. Shoot growth was 10-fold when fertilized with P and twofold with N fertilization, indicating that stunted growth of these mangroves is partially due to nutrient deficiency. 3. Growth enhancements caused by N or P enrichment could not be attributed to increases in photosynthesis on a leaf area basis, although photosynthetic nutrient-use efficiency was improved. The most dramatic effect was on stem hydraulic conductance, which was increased sixfold by P and 2-5-fold with N enrichment. Fertilization with P enhanced leaf and stem P concentrations and reduced C:N ratio, but did not alter leaf damage by herbivores. 4. Our findings indicate that addition of N and P significantly alter tree growth and internal nutrient dynamics of mangroves at Bocas del Toro, but also that the magnitude, pattern and mechanisms of change will be differentially affected by each nutrient.

Sterilization Effects of Adult-targeted Baits Containing Insect Growth Regulators on Delia antiqua

PubMed Central

Zhou, Fangyuan; Zhu, Guodong; Zhao, Haipeng; Wang, Zheng; Xue, Ming; Li, Xianxian; Xu, Huaqiang; Ma, Xiaodan; Liu, Yanyan

2016-01-01

The onion maggot, Delia antiqua, is a devastating pest of liliaceous crops and current control measures fail to avert pesticide residues, threats to agroecosystem, and costly expenditures. Insect growth regulators (IGRs) are used as trypetid pest chemosterilants for their suppression on adult fertility and fecundity, but their effects on onion flies are unknown. Here, three IGRs (lufenuron, cyromazine, pyriproxyfen) were incorporated into baits to evaluate their effects on onion fly survival, fecundity, fertility, susceptibility of adults in different ages and offspring development. Lufenuron and cyromazine did not affect survival of new-emerged adults, but lufenuron inhibited adult fertility without affecting fecundity, and cyromazine reduced fertility and fecundity. Differently, pyriproxyfen enhanced fecundity within 10 days after treatment, while it reduced adult survival without affecting fertility. The fertility of younger adults was affected by lufenuron and cyromazine whereas the fecundity was affected with cyromazine and pyriproxyfen. For offspring of onion flies treated with lufenuron or cyromazine, most of larvae died within 5 days after hatch, but surviving larvae pupated and emerged normally. Pyriproxyfen did not affect offspring larval survival or pupation but affected pupal emergence. Thus, lufenuron and cyromazine could be potential chemosterilants for onion flies. PMID:27619006

Behavior differentiation between wild Japanese quail, domestic quail, and their first filial generation.

PubMed

Chang, G B; Liu, X P; Chang, H; Chen, G H; Zhao, W M; Ji, D J; Chen, R; Qin, Y R; Shi, X K; Hu, G S

2009-06-01

The number of wild quail has dramatically reduced in China and reached a state of endangerment with the deterioration of the environment in recent years. In this study, we examined the ecological behaviors of quails in the cage to determine the differentiation level between wild Japanese quail and domestic quail, to detect the relationship between quail behavior and evolutionary differentiation and to analyze the possibility of restoring effective size of wild population. With the on-the-spot observations and measurements, the behaviors of 3 categories of quail, namely wild Japanese quail from the Weishan Lake area in China, domestic quail, and their first filial generation (F(1)) were studied. Domestic quail differed from wild Japanese quail in morphological pattern and ecological behaviors, including some indexes of figure type and egg, vocalization, aggression and fighting, and mating, but wild Japanese quail and domestic quail could succeed in mating and reproducing fertile hybrid offspring. There were significant differences between domestic quail and wild Japanese quail in reproductive traits, involved mating times, fertility rate, hatching rate, and hatching rate of fertilized eggs (P < 0.05). The first filial generation presented significant difference from the wild Japanese quail in vocalization, aggression and fighting, mating, hatching rate, hatching rate of fertilized eggs, and some egg indexes (P < 0.05) and significantly differ from the domestic quail in vocalization, hatching rate, and hatching rate of fertilized eggs (P < 0.05). Evolutionary differentiation between wild quail and domestic quail was still at a relatively low level because no reproductive isolation existed. The advantages of the F(1) hybrids in reproductive capacity, fertilization, and hatching recommend that releasing hybrids instead of domestic quails to the wild would be a more effective way to restore the effective size of wild quail population if necessary.

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

PubMed

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

2015-05-01

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

Education Differences in Intended and Unintended Fertility

ERIC Educational Resources Information Center

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

2009-01-01

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

Fertility Behavior in a Tri-Racial, Low Income Rural County. Project Report.

ERIC Educational Resources Information Center

Davis, Adam Clarke; And Others

Child bearing is probably one of the most important functions of the family in American society today. This study identified and investigated the (1) reasons for the existing differentials in fertility behavior (preferences, contraceptive use and effectiveness, and actual fertility) of white, black, and American Indian groups in a low income…

Intergenerational effects of shifts in women's educational distribution in South Korea: Transmission, differential fertility, and assortative mating.

PubMed

Kye, Bongoh; Mare, Robert D

2012-11-01

This study examines the intergenerational effects of changes in women's education in South Korea. We define intergenerational effects as changes in the distribution of educational attainment in an offspring generation associated with the changes in a parental generation. Departing from the previous approach in research on social mobility that has focused on intergenerational association, we examine the changes in the distribution of educational attainment across generations. Using a simulation method based on Mare and Maralani's recursive population renewal model, we examine how intergenerational transmission, assortative mating, and differential fertility influence intergenerational effects. The results point to the following conclusions. First, we find a positive intergenerational effect: improvement in women's education leads to improvement in daughter's education. Second, we find that the magnitude of intergenerational effects substantially depends on assortative marriage and differential fertility: assortative mating amplifies and differential fertility dampens the intergenerational effects. Third, intergenerational effects become bigger for the less educated and smaller for the better educated over time, which is a consequence of educational expansion. We compare our results with Mare and Maralani's original Indonesian study to illustrate how the model of intergenerational effects works in different socioeconomic circumstances. Copyright © 2012 Elsevier Inc. All rights reserved.

Haploid parthenotes express differential response to in vitro exposure of ammonia compared to normally fertilized embryos.

PubMed

Nair, Ramya; Mutalik, Srinivas; Dasappa, Jagadeesh Prasad; Kalthur, Guruprasad; Adiga, Satish Kumar

2017-04-22

In the present study, we assessed whether absence of paternal genome imparts any differential response in embryos to chemical stress such as ammonia. Parthenogenesis was induced in MII stage oocytes using 10 mM SrCl 2 in M16 medium. Parthenotes and normally fertilized embryos at 2 cell stage were exposed to different concentrations of ammonia and cultured till blastocyst. Exposure of ammonia to normally fertilized embryos resulted in significant decrease in the developmental potential (p < 0.0001) and blastocyst quality (p < 0.001). Whereas, in parthenotes, even though lower concentrations of ammonia did not have any effect, at 200 μM concentration the blastocyst rate was two times higher than control. The baseline apoptotic index was higher in parthenotes compared to normally fertilized embryos, which further increased after ammonium exposure (p < 0.001). Unlike in normally fertilized embryos ammonia exposure altered the mitochondrial distribution pattern and lead to increased expression of Oct4, Nanog and Na + /K + ion exchange channel, while the cytochrome C expression was downregulated. This indicates that haploidy and/or absence of paternal factors in the embryo results in differential tolerance to stress induced by ammonia. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Polyzos, Aris; Schmid, Thomas Ernst; Pina-Guzman, Belem

Cigarette smoking in men has been associated with increased chromosomal abnormalities in sperm and with increased risks for spontaneous abortions, birth defects and neonatal death. Little is known, however, about the reproductive consequences of paternal exposure to second-hand smoke. We used a mouse model to investigate the effects of paternal exposure to sidestream (SS) smoke, the main constituent of second-hand smoke, on the genetic integrity and function of sperm, and to determine whether male germ cells were equally sensitive to mainstream (MS) and SS smoke. A series of sperm DNA quality and reproductive endpoints were investigated after exposing male micemore » for two weeks to MS or SS smoke. Our results indicated that: (i) only SS smoke significantly affected sperm motility; (ii) only MS smoke induced DNA strand breaks in sperm; (iii) both MS and SS smoke increased sperm chromatin structure abnormalities; and (iv) MS smoke affected both fertilization and the rate of early embryonic development, while SS smoke affected fertilization only. These results show that MS and SS smoke have differential effects on the genetic integrity and function of sperm and provide further evidence that male exposure to second-hand smoke, as well as direct cigarette smoke, may diminish a couple's chance for a successful pregnancy and the birth of a healthy baby.« less

Fertile offspring from sterile sex chromosome trisomic mice§

PubMed Central

Hirota, Takayuki; Ohta, Hiroshi; Powell, Benjamin E.; Mahadevaiah, Shantha K.; Ojarikre, Obah A.; Saitou, Mitinori; Turner, James M. A.

2017-01-01

Having the correct number of chromosomes is vital for normal development and health. Sex chromosome trisomy (SCT) affects 0.1% of the human population and is associated with infertility. We show that during reprogramming to induced pluripotent stem cells (iPSC), fibroblasts from sterile trisomic XXY and XYY mice lose the extra sex chromosome, by a phenomenon we term trisomy-biased chromosome loss (TCL). Resulting euploid XY iPSCs can be differentiated into the male germ cell lineage and functional sperm that can be used in intracytoplasmic sperm injection to produce chromosomally normal, fertile offspring. Sex chromosome loss is comparatively infrequent during mouse XX and XY iPSC generation. TCL also applies to other chromosomes, generating euploid iPSCs from cells of a Down syndrome mouse model. It can also create euploid iPSCs from human trisomic patient fibroblasts. The findings have relevance to overcoming infertility and other trisomic phenotypes. PMID:28818972

Fertility of the Puerto Rican Origin Population: Mainland United States Puerto Rico: 1970

ERIC Educational Resources Information Center

Jaffe, A. J.; Cullen, Ruth M.

1975-01-01

Presents findings from an analysis of the 1970 census on the differential fertility of Puerto Ricans in the U.S. and in Puerto Ricans with the stated purpose of demonstrating that the apparent higher fertility of Puerto Rican women is due to their age structure, as well as their socioeconomic status. (Author/JM)

Nitrite-Oxidizing Bacteria Community Composition and Diversity Are Influenced by Fertilizer Regimes, but Are Independent of the Soil Aggregate in Acidic Subtropical Red Soil

PubMed Central

Han, Shun; Li, Xiang; Luo, Xuesong; Wen, Shilin; Chen, Wenli; Huang, Qiaoyun

2018-01-01

Nitrification is the two-step aerobic oxidation of ammonia to nitrate via nitrite in the nitrogen-cycle on earth. However, very limited information is available on how fertilizer regimes affect the distribution of nitrite oxidizers, which are involved in the second step of nitrification, across aggregate size classes in soil. In this study, the community compositions of nitrite oxidizers (Nitrobacter and Nitrospira) were characterized from a red soil amended with four types of fertilizer regimes over a 26-year fertilization experiment, including control without fertilizer (CK), swine manure (M), chemical fertilization (NPK), and chemical/organic combined fertilization (MNPK). Our results showed that the addition of M and NPK significantly decreased Nitrobacter Shannon and Chao1 index, while M and MNPK remarkably increased Nitrospira Shannon and Chao1 index, and NPK considerably decreased Nitrospira Shannon and Chao1 index, with the greatest diversity achieved in soils amended with MNPK. However, the soil aggregate fractions had no impact on that alpha-diversity of Nitrobacter and Nitrospira under the fertilizer treatment. Soil carbon, nitrogen and phosphorus in the soil had a significant correlation with Nitrospira Shannon and Chao1 diversity index, while total potassium only had a significant correlation with Nitrospira Shannon diversity index. However, all of them had no significant correlation with Nitrobacter Shannon and Chao1 diversity index. The resistance indices for alpha-diversity indexes (Shannon and Chao1) of Nitrobacter were higher than those of Nitrospira in response to the fertilization regimes. Manure fertilizer is important in enhancing the Nitrospira Shannon and Chao1 index resistance. Principal co-ordinate analysis revealed that Nitrobacter- and Nitrospira-like NOB communities under four fertilizer regimes were differentiated from each other, but soil aggregate fractions had less effect on the nitrite oxidizers community. Redundancy analysis and Mantel test indicated that soil nitrogen, carbon, phosphorus, and available potassium content were important environmental attributes that control the Nitrobacter- and Nitrospira-like NOB community structure across different fertilization treatments under aggregate levels in the red soil. In general, nitrite-oxidizing bacteria community composition and alpha-diversity are depending on fertilizer regimes, but independent of the soil aggregate. PMID:29867799

Identifying N fertilizer regime and vegetable production system in tropical Brazil using (15) N natural abundance.

PubMed

Inácio, Caio T; Urquiaga, Segundo; Chalk, Phillip M; Mata, Maria Gabriela F; Souza, Paulo O

2015-12-01

This study was conducted in areas of vegetable production in tropical Brazil, with the objectives of (i) measuring the variation in δ(15)  N in soils, organic N fertilizer sources and lettuce (Lactuca sativa L.) from different farming systems, (ii) measuring whether plant δ(15)  N can differentiate organic versus conventional lettuce and (iii) identifying the factors affecting lettuce δ(15)  N. Samples of soil, lettuce and organic inputs were taken from two organic, one conventional and one hydroponic farm. The two organic farms had different N-sources with δ(15)  N values ranging from 0.0 to +14.9‰ (e.g. leguminous green manure and animal manure compost, respectively), and differed significantly (P < 0.05) in lettuce δ(15)  N (+9.2 ± 1.1‰ and +14.3 ± 1.0‰). Conventional lettuce δ(15)  N (+8.5 ± 2.7‰) differed from hydroponic lettuce δ(15)  N (+4.5 ± 0.2‰) due to manure inputs. The N from leguminous green manure made a small contribution to the N nutrition of lettuce in the multi-N-source organic farm. To differentiate organic versus conventional farms using δ(15)  N the several subsets of mode of fertilization should be considered. Comparisons of δ(15)  N of soil, organic inputs and lettuce allowed a qualitative analysis of the relative importance of different N inputs. © 2015 Society of Chemical Industry.

Developmental programming by androgen affects the circadian timing system in female mice.

PubMed

Mereness, Amanda L; Murphy, Zachary C; Sellix, Michael T

2015-04-01

Circadian clocks play essential roles in the timing of events in the mammalian hypothalamo-pituitary-ovarian (HPO) axis. The molecular oscillator driving these rhythms has been localized to tissues of the HPO axis. It has been suggested that synchrony among these oscillators is a feature of normal reproductive function. The impact of fertility disorders on clock function and the role of the clock in the etiology of endocrine pathology remain unknown. Polycystic ovarian syndrome (PCOS) is a particularly devastating fertility disorder, affecting 5%-10% of women at childbearing age with features including a polycystic ovary, anovulation, and elevated serum androgen. Approximately 40% of these women have metabolic syndrome, marked by hyperinsulinemia, dyslipidemia, and insulin resistance. It has been suggested that developmental exposure to excess androgen contributes to the etiology of fertility disorders, including PCOS. To better define the role of the timing system in these disorders, we determined the effects of androgen-dependent developmental programming on clock gene expression in tissues of the metabolic and HPO axes. Female PERIOD2::luciferase (PER2::LUC) mice were exposed to androgen (dihydrotestosterone [DHT]) in utero (Days 16-18 of gestation) or for 9-10 wk (DHT pellet) beginning at weaning (pubertal androgen excess [PAE]). As expected, both groups of androgen-treated mice had disrupted estrous cycles. Analysis of PER2::LUC expression in tissue explants revealed that excess androgen produced circadian misalignment via tissue-dependent effects on phase distribution. In vitro treatment with DHT differentially affected the period of PER2::LUC expression in tissue explants and granulosa cells, indicating that androgen has direct and tissue-specific effects on clock gene expression that may account for the effects of developmental programming on the timing system. © 2015 by the Society for the Study of Reproduction, Inc.

Frost hardiness of mycorrhizal and non-mycorrhizal Scots pine under two fertilization treatments.

PubMed

Korhonen, Anna; Lehto, Tarja; Repo, Tapani

2015-07-01

Survival and functioning of mycorrhizal associations at low temperatures are not known well. In an earlier study, ectomycorrhizas did not affect the frost hardiness of Scots pine (Pinus sylvestris L.) roots, but here we studied whether differential nutrient availability would change the result and additionally, alter frost hardiness aboveground. The aim in this experiment was to compare the frost hardiness of roots and needles of mycorrhizal (Hebeloma sp.) and non-mycorrhizal Scots pine seedlings raised using two fertilization treatments and two cold-hardening regimes. The fertilization treatments were low (LF) and high (HF) application of a complete nutrient solution. Three hundred mycorrhizal and non-mycorrhizal seedlings were cultivated in growth chambers in four blocks for 16 weeks. For the first 9 weeks, the seedlings grew in long-day and high-temperature (LDHT) with low fertilization and then they were raised for 3 weeks in LDHT with either low or high fertilization. After this, half of the plants in each treatment combination remained in LDHT, and half were transferred to short-day and low-temperature (SDLT) conditions to cold acclimatize. The frost hardiness of the roots and needles was assessed using controlled freezing tests followed by electrolyte leakage tests (REL). Mycorrhizal roots were slightly more frost hardy than non-mycorrhizal roots, but only in the growing-season conditions (LDHT) in low-nutrient treatment. In LDHT and LF, the frost hardiness of the non-mycorrhizal roots was about -9 °C, and that of the non-mycorrhizal HF roots and the mycorrhizal roots in both fertilization levels was about -11 °C. However, no difference was found in the roots within the SDLT regime, and in needles, there was no difference between mycorrhizal and fertilization treatments. The frost hardiness of needles increased by SDLT treatment, being -8.5 and -14.1 °C in LDHT and SDLT, respectively. The dry mass of roots, stems, and needles was lower in LF than in HF and lower in SDLT than in LDHT. Mycorrhizal treatment did not affect the dry mass or its allocation. Although the mycorrhizal roots were slightly more frost hardy in the growing-season conditions, this is not likely to have significance in the field.

Transcriptome profiling and cataloging differential gene expression in floral buds of fertile and sterile lines of cotton (Gossypium hirsutum L.).

PubMed

Hamid, Rasmieh; Tomar, Rukam S; Marashi, Hassan; Shafaroudi, Saeid Malekzadeh; Golakiya, Balaji A; Mohsenpour, Motahhareh

2018-06-20

Cytoplasmic Male Sterility is maternally inherited trait in plants, characterized by failure to produce functional pollen during anther development. Anther development is modulated through the interaction of nuclear and mitochondrial genes. In the present study, differential gene expression of floral buds at the sporogenous stage (SS) and microsporocyte stage (MS) between CGMS and its fertile maintainer line of cotton plants was studied. A total of 320 significantly differentially expressed genes, including 20 down-regulated and 37 up-regulated in CGMS comparing with its maintainer line at the SS stage, as well as and 89 down-regulated and 4 up-regulated in CGMS compared to the fertile line at MS stage. Comparing the two stages in the same line, there were 6 down-regulated differentially expressed genes only induced in CGMS and 9 up-regulated differentially expressed gene only induced in its maintainer. GO analysis revealed essential genes responsible for pollen development, and cytoskeleton category show differential expression between the fertile and CGMS lines. Validation studies by qRT-PCR shows concordance with RNA-seq result. A set of novel SSRs identified in this study can be used in evaluating genetic relationships among cultivars, QTL mapping, and marker-assisted breeding. We reported aberrant expression of genes related to pollen exine formation, and synthesis of pectin lyase, myosine heavy chain, tubulin, actin-beta, heat shock protein and myeloblastosis (MYB) protein as targets for CMS in cotton. The results of this study contribute to basic information for future screening of genes and identification of molecular portraits responsible for CMS as well as to elucidate molecular mechanisms that lead to CMS in cotton. Copyright © 2018 Elsevier B.V. All rights reserved.

Borderline ovarian tumors, fertility-sparing surgery and pregnancy outcome.

PubMed

Frega, A; Coluccia, A C; Di Martino, G; Catalano, A; Milazzo, G N; Assorgi, C; Manzara, F; Romeo, G D; Gentile, M; Marziani, R; Moscarini, M

2014-01-01

Borderline ovarian tumors (BOTs) represent a type of epithelial tumors having a biologic intermediate behavior between clearly malignant and straight benign tumors. Most of BOTs interest women during fertile age, for which it is necessary to consider a fertility sparing surgery. To evaluate the clinical aspects and pregnancy rate of women affected by borderline ovarian tumors who have undergone fertility sparing surgery. A study of 22 patients affected by BOTs who have been treated with a fertility sparing surgery was conducted between January 2005 and October 2011 at Sant'Andrea Hospital, "Sapienza" University of Rome. The patients' characteristics analyzed were: age, histological type, tumor size, adnexal surgery, pre-operative serum CA-125, diagnostic circumstances, number of patients who became pregnant and number of overall pregnancies. Among the 22 patients treated with a fertility sparing surgery, only sixteen wanted to get pregnant. Eleven patents out of 16 accomplished it. The pregnancy rate was 68.7%. Fertility sparing surgery can be considered a safe procedure for young women affected by borderline ovarian tumors.

In vitro differentiation of fertile sperm from cryopreserved spermatogonia of the endangered endemic cyprinid honmoroko (Gnathopogon caerulescens)

NASA Astrophysics Data System (ADS)

Higaki, Shogo; Shimada, Manami; Kawamoto, Kazuaki; Todo, Takaaki; Kawasaki, Toshihiro; Tooyama, Ikuo; Fujioka, Yasuhiro; Sakai, Noriyoshi; Takada, Tatsuyuki

2017-02-01

Many endemic fish species are threatened with extinction. Conservation strategies and the restoration of endemic fish after extinction must therefore be investigated. Although sperm cryopreservation is indispensable for the conservation of endangered fishes, the limited number of mature fish and limited availability (volume and period) of sperm from small endemic fish hinders the optimization and practical use of this material. In this report, we demonstrate the in vitro differentiation of fertile sperm from cryopreserved spermatogonia of juveniles of the endangered small cyprinid honmoroko (Gnathopogon caerulescens), which is endemic to Lake Biwa in Japan. The entire process of spermatogenesis was recapitulated in vitro using cryopreserved spermatogonia of non-spawning adult and juvenile fish. The differentiation of sperm from spermatogonia was captured as a time-lapse video and confirmed by 5-ethynyl-2‧-deoxyuridine (EdU) incorporation into sperm. Fertility was demonstrated by artificial insemination. These results suggest that the combination of cryopreservation of spermatogonia and in vitro sperm differentiation will provide a new and promising strategy for the preservation of paternal genetic materials.

[An attempt to explain fertility differentials in Upper Volta and in Ghana].

PubMed

Coulibaly, S P; Pool, I

1975-01-01

This study examines fertility differentials in Western Africa, notably in Upper Volta and in Ghana. The relationship between social and cultural transformation and fertility rate is usually seen as a matter of cause and effect. Direct variables caused by social transformation would be education, migration, and urbanization. This is not necessarily so, at least according to the Davis-Blake paradigm, which says that there are intermediate variables which intervene between fertility rate and the social system. For West Africa such variables are of 3 distinct types: 1) those which upset the normal flow of the family, such as separation due to migration, divorce, and marriage age; 2) those which influence conception itself, such as birth control, lactation and sexual abstinence; and, 3) cultural factors, such as poligamy and monogamy, type of conjugal union, and postpartum sexual abstinence. The central point of this study is that direct variables, i.e. migration, education and urbanization, do not directly influence fertility, but they influence the so-called intermediate variables, which, in turn, cause a change in fertility patterns. It must be remembered that birth control is still practically unknown in Western Africa.

Comparison of Quinn's Advantage fertilization medium and tissue culture medium 199 for in vitro maturation of oocytes.

PubMed

Lin, Yu-Hung; Hwang, Jiann-Loung; Huang, Lee-Wen; Seow, Kok-Min; Hsieh, Bih-Chwen; Tzeng, Chii-Ruey

2014-03-01

The purpose of the study was to compare the Quinn's Advantage fertilization medium (Q1) and the tissue culture medium 199 (TCM199) for in vitro maturation (IVM) of oocytes and ammonium production during IVM. The immature murine oocytes were randomly added into Q1 and TCM199. Ammonium concentrations were measured at the start and after 18 hours of IVM, and the mature oocytes were fertilized and cultured into blastocysts. The blastocysts were then stained for inner cell mass (ICM) and trophectoderm. The maturation rate was higher in Q1 than in TCM199 (85.7% vs. 76.6%, p = 0.024). The fertilization and blastocyst rates were slightly higher in Q1, but not significant. Differential staining of the blastocysts showed slightly higher ICM ratio in the blastocysts derived from Q1. Mean ammonium concentrations in Q1 and TCM199 at Time 0 were 184.9 and 339.2 μg/dL, respectively (p = 0.05), and after 18 hours of IVM were 268.7 and 443.6 μg/dL, respectively (p = 0.045). Addition of ammonium chloride into Q1 adversely affects IVM. Q1 is superior to TCM199 in terms of oocyte maturation, which may be due to lower ammonium concentration. Copyright © 2014. Published by Elsevier B.V.

FGF signaling supports Drosophila fertility by regulating development of ovarian muscle tissues

PubMed Central

Irizarry, Jihyun; Stathopoulos, Angelike

2015-01-01

The thisbe (ths) gene encodes a Drosophila fibroblast growth factor (FGF), and mutant females are viable but sterile suggesting a link between FGF signaling and fertility. Ovaries exhibit abnormal morphology including lack of epithelial sheaths, muscle tissues that surround ovarioles. Here we investigated how FGF influences Drosophila ovary morphogenesis and identified several roles. Heartless (Htl) FGF receptor was found expressed within somatic cells at the larval and pupal stages, and phenotypes were uncovered using RNAi. Differentiation of terminal filament cells was affected, but this effect did not alter ovariole number. In addition, proliferation of epithelial sheath progenitors, the apical cells, was decreased in both htl and ths mutants, while ectopic expression of the Ths ligand led to these cells’ over-proliferation suggesting that FGF signaling supports ovarian muscle sheath formation by controlling apical cell number in the developing gonad. Additionally, live imaging of adult ovaries was used to show that htl RNAi mutants, hypomorphic mutants in which epithelial sheaths are present, exhibit abnormal muscle contractions. Collectively, our results demonstrate that proper formation of ovarian muscle tissues is regulated by FGF signaling in the larval and pupal stages through control of apical cell proliferation and is required to support fertility. PMID:25958090

How development programs can affect fertility: the case of Bangladesh.

PubMed

Robey, B

1988-09-01

Improving living standards and increasing productivity in developing countries may result in fertility reduction. In Bangladesh, government policy stresses rural development and fertility reduction. Programs that raise women's status reduce fertility. Educational level is inversely correlated to childbearing. Women aged 25-29 with a Secondary School Certificate have 2.4 children, versus 4.0 for those with no education. Employment also decreases fertility. Thus, improving the educational and employment status of women could have major effects on fertility. Studying the Bangladesh Rural Social Services program revealed that community organization efforts and self-help programs for economic and social improvement also decrease fertility. Rural electrification programs, which have been emphasized in development planning, contribute to changing attitudes and behavior of residents of these regions. In addition to electrification, improved transportation and communications should enhance the spread of information to rural areas. Agricultural development programs, such as the Comilla development program, have not affected fertility. This is attributed to the concentration of benefits to a few farms, with the majority becoming poorer. Unless agricultural development benefits are widely distributed, there will probably be little effect on fertility. Thus, the development programs most likely to affect fertility are those which emphasize female education and employment, open rural areas to information and ideas, and are open to a whole community.

Effects of fertilization of four hemlock species on Adelges tsugae (Hemiptera: Adelgidae) growth and feeding preference of predators.

PubMed

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

2011-02-01

Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to the adelgid and to determine whether it affected feeding preferences of the adelgid predators Laricobius nigrinus Fender and Sasajiscymnus tsugae (Sasaji & McClure). Treatments were long-term fertilization (from June 2008 to June 2009), short-term fertilization (from March to June 2009), and no fertilizer. Fertilizer was applied biweekly with 240 ppm N by using water-soluble fertilizer (N-P-K, 20:20:20). Plants (>1 yr old) were artificially infested with adelgids on 31 March 2009. Among unfertilized hemlocks (n=10 per species), foliar N was highest in Tsuga mertensiana (Bong.) CarriBre and lowest in T. chinensis (Franch.) E. Pritz. Significantly more progredien ovisacs or sisten eggs were present on T. mertensiana than on the other hemlock species with none on unfertilized T. chinensis. A. tsugae adults on T. heterophylla (Raf.) Sarg. were unaffected by fertility, but densities of developing A. tsugae nymphs were higher on unfertilized T. heterophylla plants than on fertilized T. heterophylla plants regardless of fertilizer treatment. Both L. nigrinus and S. tsugae consumed more adelgid eggs that developed on fertilized T. canadensis than from unfertilized plants. The predators did not exhibit this preference for adelgid eggs from females that developed on T. heterophylla or T. mertensiana.

Meeting the Sustainable Development Goals leads to lower world population growth

PubMed Central

Abel, Guy J.; Barakat, Bilal; KC, Samir; Lutz, Wolfgang

2016-01-01

Here we show the extent to which the expected world population growth could be lowered by successfully implementing the recently agreed-upon Sustainable Development Goals (SDGs). The SDGs include specific quantitative targets on mortality, reproductive health, and education for all girls by 2030, measures that will directly and indirectly affect future demographic trends. Based on a multidimensional model of population dynamics that stratifies national populations by age, sex, and level of education with educational fertility and mortality differentials, we translate these goals into SDG population scenarios, resulting in population sizes between 8.2 and 8.7 billion in 2100. Because these results lie outside the 95% prediction range given by the 2015 United Nations probabilistic population projections, we complement the study with sensitivity analyses of these projections that suggest that those prediction intervals are too narrow because of uncertainty in baseline data, conservative assumptions on correlations, and the possibility of new policies influencing these trends. Although the analysis presented here rests on several assumptions about the implementation of the SDGs and the persistence of educational, fertility, and mortality differentials, it quantitatively illustrates the view that demography is not destiny and that policies can make a decisive difference. In particular, advances in female education and reproductive health can contribute greatly to reducing world population growth. PMID:27911797

Meeting the Sustainable Development Goals leads to lower world population growth.

PubMed

Abel, Guy J; Barakat, Bilal; Kc, Samir; Lutz, Wolfgang

2016-12-13

Here we show the extent to which the expected world population growth could be lowered by successfully implementing the recently agreed-upon Sustainable Development Goals (SDGs). The SDGs include specific quantitative targets on mortality, reproductive health, and education for all girls by 2030, measures that will directly and indirectly affect future demographic trends. Based on a multidimensional model of population dynamics that stratifies national populations by age, sex, and level of education with educational fertility and mortality differentials, we translate these goals into SDG population scenarios, resulting in population sizes between 8.2 and 8.7 billion in 2100. Because these results lie outside the 95% prediction range given by the 2015 United Nations probabilistic population projections, we complement the study with sensitivity analyses of these projections that suggest that those prediction intervals are too narrow because of uncertainty in baseline data, conservative assumptions on correlations, and the possibility of new policies influencing these trends. Although the analysis presented here rests on several assumptions about the implementation of the SDGs and the persistence of educational, fertility, and mortality differentials, it quantitatively illustrates the view that demography is not destiny and that policies can make a decisive difference. In particular, advances in female education and reproductive health can contribute greatly to reducing world population growth.

Discovery of a haplotype affecting fertility in Ayrshire dairy dattle and identification of a putative causal variant

USDA-ARS?s Scientific Manuscript database

Initial genomic test results for US Ayrshire dairy cattle became available in January of 2013. Several haplotypes that showed a deficiency of homozygotes were investigated to determine if they had an effect on fertility. A haplotype on chromosome 17 was determined to affect fertility, indicating tha...

Does Electrification Spur the Fertility Transition? Evidence From Indonesia.

PubMed

Grimm, Michael; Sparrow, Robert; Tasciotti, Luca

2015-10-01

We analyze various pathways through which access to electricity affects fertility in Indonesia, using a district difference-in-difference approach. The electrification rate increased by 65 % over the study period, and our results suggest that the subsequent effects on fertility account for about 18 % to 24 % of the overall decline in fertility. A key channel is increased exposure to television. Using in addition several waves of Demographic and Health Surveys, we find suggestive evidence that increased exposure to TV affects, in particular, fertility preferences and increases the effective use of contraception. Reduced child mortality seems to be another important pathway.

Consanguinity and its relationship to differential fertility and mortality in the Kotia: a tribal population of Andhra Pradesh, India.

PubMed

Yasim; Naidu, J M; Mascie-Taylor, C G

1997-04-01

Data on patterns of marriage, differential fertility and mortality were collected from 211 Kotia women residing in Visakhapatnam district of Andhra Pradesh, India. Consanguineous marriages made up just over a quarter of the total, and of these, father's sister's daughter (FSD) were more common than mother's brother's daughter (MBD). The mean inbreeding coefficient for the sample (F) was 0.0172. Women in consanguineous marriages had a lower mean number of total conceptions, live births and living offspring (net fertility) than women in non-consanguineous marriages. Significant heterogeneity was found in the means of living offspring for FSD, MBD and non-consanguineous couples, but not for conceptions and live births.

Effects of education on reproductive behavior: lessons from Pakistan.

PubMed

Greenspan, A

1992-12-01

Evidence from the Pakistan Demographic and Health Survey 1990/91 (PDHS) and a 1987 study by Zeba A. Sathar and Karen Oppenheim on women's fertility in Karachi and the impact of educational status, corroborates the correlation between improved education for women and fertility decline. PDHS revealed that current fertility is 5.4 children/ever married woman by the end of the reproductive period. 12% currently use a contraceptive method compared to 49% in India, 40% in Bangladesh, and 62% in Sri Lanka. The social environment of high illiteracy, low educational attainment, poverty, high infant and child and maternal mortality, son preference, and low status of women leads to high fertility. Fertility rates vary by educational status; i.e., women with no formal education have 2 more children than women with at least some secondary education. Education also affects infant and child mortality and morbidity. Literacy is 31% for women and 43% for men. 30% of all males and 20% of all females have attended primary school. Although most women know at least 1 contraceptive method, it is the urban educated woman who is twice as likely to know a source of supply and 5 times more likely to be a user. The Karachi study found that lower fertility among better educated urban women is an unintended consequence of women's schooling and deliberate effort to limit the number of children they have. Education-related fertility differentials could not be explained by the length of time women are at risk of becoming pregnant (late marriage age). Fertility limitation may be motivated by the predominant involvement in the formal work force and higher income. The policy implications are the increasing female schooling is a good investment in lowering fertility; broader improvements also need to be made in economic opportunities for women, particularly in the formal sector. Other needs are for increasing availability and accessibility of contraceptive and family planning services and increasing availability and accessibility of contraceptive and family planning services and increasing knowledge of contraception. The investment will impact development and demography and is an adjunct to child health an survival.

WNT4 signaling in female gonadal development.

PubMed

Pellegrino, Miriam; Maiorino, Raffaella; Schonauer, Sergio

2010-06-01

WNT4 signaling pathways represent an important step in the multi-faceted process of mammalian gonadal differentiation and the development of internal genitalia. WNT4 protein controls the cytoplasmatic stability of specific transcriptional coactivator beta catenin during both embriogenesis and adult homeostasis. The biological significance of WNT4 consists in determining the final female reproductive system, inhibiting Wolff ducts' differentiation, male steroidogenesis and vascular cell migration. An overview of WNT4 cellular mechanisms is given in order to understand its critical role in the genesis of various human diseases such as congenital malformations and gynecological disorders like polycystic ovary syndrome (PCOS). The final discussion focusses on several possible therapeutic uses of Wnt4 both during pregnancy in order to correct the genetic loss of function of the protein and during adulthood in order to normalize fertility in PCOS-affected females planning pregnancy.

[Testicular tissue vitrification: evolution or revolution?].

PubMed

Wyns, C; Abu-Ghannam, G; Poels, J

2013-09-01

Preservation of reproductive health is a major concern for patient long-term quality of life. While sperm freezing has proven to be effective to preserve fertility after puberty, cryopreservation of immature testicular tissue (ITT) is emerging as a promising approach for fertility preservation in young boys. Slow-freezing (SF) is the conventional method used to preserve ITT and has resulted in the birth of mice offspring. In humans, methods to preserve ITT are still at the research stage. Controlled SF using dimethyl sulfoxide showed preservation of proliferative spermatogonia after thawing in a xenotransplantation model used to evaluate the efficiency of freezing and thawing procedures. However, spermatogonial recovery was low and normal differentiation could not be achieved. Both freezing/thawing and the environment of the xenotransplantation model may be implicated. Indeed, with SF, ice crystal formation could damage tissue and cells. For this reason, vitrification, leading to solidification of a liquid without crystallization, may be a promising alternative. ITT vitrification has been investigated in different species and shown spermatogonial survival and differentiation to the round or elongated spermatids stage. Offspring were also recently obtained after vitrification and allotransplantation in avians, confirming the potential of vitrification for fertility preservation. In humans, vitrification appears to be as efficient as SF in terms of spermatogonial survival and initiation of differentiation after xenotransplantation. However, before validation of such fertility preservation methods, completion of normal spermatogenesis and the fertilization capacity of sperm retrieved from cryopreserved and transplanted tissue should be fully investigated. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Variation within and between Frankliniella Thrips Species in Host Plant Utilization

PubMed Central

Baez, Ignacio; Reitz, Stuart R.; Funderburk, Joseph E.; Olson, Steve M.

2011-01-01

Anthophilous flower thrips in the genus Frankliniella (Thysanoptera: Thripidae) exploit ephemeral plant resources and therefore must be capable of successfully locating appropriate hosts on a repeated basis, yet little is known of interspecific and intraspecific variation in responses to host plant type and nutritional quality. Field trials were conducted over two seasons to determine if the abundance of males and females of three common Frankliniella species, F. occidentalis (Pergande), F. tritici (Fitch) and F. bispinosa (Morgan), their larvae, and a key predator, Orius insidiosus (Say) (Hemiptera: Anthocoridae) were affected by host plant type and plant nutritional quality. Two host plants, pepper, Capsicum annuum L. (Solanales: Solanaceae) and tomato, Solanum lycopersicum L. that vary in suitability for these species were examined, and their nutritional quality was manipulated by applying three levels of nitrogen fertilization (101 kg/ha, 202 kg/ha, 404 kg/ha). F. occidentalis females were more abundant in pepper than in tomato, but males did not show a differential response. Both sexes of F. tritici and F. bispinosa were more abundant in tomato than in pepper. Larval thrips were more abundant in pepper than in tomato. Likewise, O. insidiosus females and nymphs were more abundant in pepper than in tomato. Only F. occidentalis females showed a distinct response to nitrogen fertilization, with abundance increasing with fertilization. These results show that host plant utilization patterns vary among Frankliniella spp. and should not be generalized from results of the intensively studied F. occidentalis. Given the different pest status of these species and their differential abundance in pepper and tomato, it is critical that scouting programs include species identifications for proper management. PMID:21539418

DNA repair decline during mouse spermiogenesis results in the accumulation of heritable DNA damage

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

Marchetti, Francesco; Marchetti, Francesco; Wryobek, Andrew J

The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-inducedmore » heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7- 1 dbf). Analysis of chromosomalaberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.« less

DNA Repair Decline During Mouse Spermiogenesis Results in the Accumulation of Heritable DNA Damage

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

Marchetti, Francesco; Marchetti, Francesco; Wyrobek, Andrew J.

The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-inducedmore » heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7-1 dbf). Analysis of chromosomal aberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.« less

Novel methods of treating ovarian infertility in older and POF women, testicular infertility, and other human functional diseases.

PubMed

Bukovsky, Antonin

2015-02-25

In vitro maturation (IVM) and in vitro fertilization (IVF) technologies are facing with growing demands of older women to conceive. Although ovarian stem cells (OSCs) of older women are capable of producing in vitro fresh oocyte-like cells (OLCs), such cells cannot respond to IVM and IVF due to the lack of granulosa cells required for their maturation. Follicular renewal is also dependent on support of circulating blood mononuclear cells. They induce intermediary stages of meiosis (metaphase I chromosomal duplication and crossover, anaphase, telophase, and cytokinesis) in newly emerging ovarian germ cells, as for the first time demonstrated here, induce formation of granulosa cells, and stimulate follicular growth and development. A pretreatment of OSC culture with mononuclear cells collected from blood of a young healthy fertile woman may cause differentiation of bipotential OSCs into both developing germ and granulosa cells. A small blood volume replacement may enable treatment of ovarian infertility in vivo. The transferred mononuclear cells may temporarily rejuvenate virtually all tissues, including improvement of the function of endocrine tissues. Formation of new follicles and their development may be sufficient for IVM and IVF. The novel proposed in vitro approaches may be used as a second possibility. Infertility of human males affects almost a half of the infertility cases worldwide. Small blood volume replacement from young healthy fertile men may also be easy approach for the improvement of sperm quality in older or other affected men. In addition, body rejuvenation by small blood volume replacement from young healthy individuals of the same sex could represent a decline of in vitro methodology in favor of in vivo treatment for human functional diseases. Here we propose for the first time that blood mononuclear cells are essential for rejuvenation of those tissues, where immune system components participate in an appropriate division and differentiation of tissue stem cells. If needed, small blood volume replacement from distinct young healthy individuals could be utilized in six month intervals for repair of young altered or aged reproductive and other tissue functions. Systemic and local use of honey bee propolis tincture is an alternative option for functional rejuvenation of some tissues.

Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae).

PubMed

Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

2017-12-01

The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m ), finite rate of increase (λ), net reproductive rate (R 0 ), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m , λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.

The Drosophila bag of marbles Gene Interacts Genetically with Wolbachia and Shows Female-Specific Effects of Divergence

PubMed Central

Flores, Heather A.; Bubnell, Jaclyn E.; Aquadro, Charles F.; Barbash, Daniel A.

2015-01-01

Many reproductive proteins from diverse taxa evolve rapidly and adaptively. These proteins are typically involved in late stages of reproduction such as sperm development and fertilization, and are more often functional in males than females. Surprisingly, many germline stem cell (GSC) regulatory genes, which are essential for the earliest stages of reproduction, also evolve adaptively in Drosophila. One example is the bag of marbles (bam) gene, which is required for GSC differentiation and germline cyst development in females and for regulating mitotic divisions and entry to spermatocyte differentiation in males. Here we show that the extensive divergence of bam between Drosophila melanogaster and D. simulans affects bam function in females but has no apparent effect in males. We further find that infection with Wolbachia pipientis, an endosymbiotic bacterium that can affect host reproduction through various mechanisms, partially suppresses female sterility caused by bam mutations in D. melanogaster and interacts differentially with bam orthologs from D. melanogaster and D. simulans. We propose that the adaptive evolution of bam has been driven at least in part by the long-term interactions between Drosophila species and Wolbachia. More generally, we suggest that microbial infections of the germline may explain the unexpected pattern of evolution of several GSC regulatory genes. PMID:26291077

Peroxisome Proliferator-Activated Receptors in Female Reproduction and Fertility

PubMed Central

Carta, Gaspare; Artini, Paolo Giovanni

2016-01-01

Reproductive functions may be altered by the exposure to a multitude of endogenous and exogenous agents, drug or environmental pollutants, which are known to affect gene transcription through the peroxisome proliferator-activated receptors (PPARs) activation. PPARs act as ligand activated transcription factors and regulate metabolic processes such as lipid and glucose metabolism, energy homeostasis, inflammation, and cell proliferation and differentiation. All PPARs isotypes are expressed along the hypothalamic-pituitary-gonadal axis and are strictly involved in reproductive functions. Since female fertility and energy metabolism are tightly interconnected, the research on female infertility points towards the exploration of potential PPARs activating/antagonizing compounds, mainly belonging to the class of thiazolidinediones (TZDs) and fibrates, as useful agents for the maintenance of metabolic homeostasis in women with ovarian dysfunctions. In the present review, we discuss the recent evidence about PPARs expression in the hypothalamic-pituitary-gonadal axis and their involvement in female reproduction. Finally, the therapeutic potential of their manipulation through several drugs is also discussed. PMID:27559343

MULTIGENERATIONAL ASPECTS OF SOCIAL STRATIFICATION: ISSUES FOR FURTHER RESEARCH.

PubMed

Mare, Robert D

2014-03-01

The articles in this special issue show the vitality and progress of research on multigenerational aspects of social mobility, stratification, and inequality. The effects of the characteristics and behavior of grandparents and other kin on the statuses, resources, and positions of their descendants are best viewed in a demographic context. Intergenerational effects work through both the intergenerational associations of socioeconomic characteristics and also differential fertility and mortality. A combined socioeconomic and demographic framework informs a research agenda which addresses the following issues: how generational effects combine with variation in age, period, and cohort within each generation; distinguishing causal relationships across generations from statistical associations; how multigenerational effects vary across socioeconomic hierarchies, including the possibility of stronger effects at the extreme top and bottom; distinguishing between endowments and investments in intergenerational effects; multigenerational effects on associated demographic behaviors and outcomes (especially fertility and mortality); optimal tradeoffs among diverse types of data on multigenerational processes; and the variability across time and place in how kin, education, and other institutions affect stratification.

MULTIGENERATIONAL ASPECTS OF SOCIAL STRATIFICATION: ISSUES FOR FURTHER RESEARCH

PubMed Central

Mare, Robert D.

2014-01-01

The articles in this special issue show the vitality and progress of research on multigenerational aspects of social mobility, stratification, and inequality. The effects of the characteristics and behavior of grandparents and other kin on the statuses, resources, and positions of their descendants are best viewed in a demographic context. Intergenerational effects work through both the intergenerational associations of socioeconomic characteristics and also differential fertility and mortality. A combined socioeconomic and demographic framework informs a research agenda which addresses the following issues: how generational effects combine with variation in age, period, and cohort within each generation; distinguishing causal relationships across generations from statistical associations; how multigenerational effects vary across socioeconomic hierarchies, including the possibility of stronger effects at the extreme top and bottom; distinguishing between endowments and investments in intergenerational effects; multigenerational effects on associated demographic behaviors and outcomes (especially fertility and mortality); optimal tradeoffs among diverse types of data on multigenerational processes; and the variability across time and place in how kin, education, and other institutions affect stratification. PMID:24748709

Interracial-Interethnic Unions and Fertility in the United States

ERIC Educational Resources Information Center

Fu, Vincent Kang

2008-01-01

How does the fertility of interracial and interethnic couples compare to the fertility of endogamous couples? If exogamous couples have transcended the boundary between them, then exogamy should not affect fertility. Alternatively, opposition to the relationship from the couple's family and friends may reduce fertility. This study uses 2000-2005…

Basic Sciences Fertilizing Clinical Microbiology and Infection Management

PubMed Central

2017-01-01

Abstract Basic sciences constitute the most abundant sources of creativity and innovation, as they are based on the passion of knowing. Basic knowledge, in close and fertile contact with medical and public health needs, produces distinct advancements in applied sciences. Basic sciences play the role of stem cells, providing material and semantics to construct differentiated tissues and organisms and enabling specialized functions and applications. However, eventually processes of “practice deconstruction” might reveal basic questions, as in de-differentiation of tissue cells. Basic sciences, microbiology, infectious diseases, and public health constitute an epistemological gradient that should also be an investigational continuum. The coexistence of all these interests and their cross-fertilization should be favored by interdisciplinary, integrative research organizations working simultaneously in the analytical and synthetic dimensions of scientific knowledge. PMID:28859345

Empirical findings on socioeconomic determinants of fertility differentials in Costa Rica.

PubMed

Carvajal, M J; Geithman, D T

1986-01-01

"This paper seeks to (1) identify socioeconomic variables that are expected to generate fertility differentials; (2) hypothesize the direction and magnitude of the effect of each variable by reference to a demand-for-children model; and (3) test empirically the model using evidence from Costa Rica. The estimates are obtained from a ten-percent systematic random sample of all Costa Rican individual-family households. There are 15,924 families in the sample...." The authors specifically seek "to capture the effects of changing relative prices and available income and time constraints on parental preferences for children. Least-squares estimates show statistically significant relationships between household fertility and opportunity cost of time, parental education, occurrence of an extended family, medical care, household sanitation, economic sector of employment, and household stock of nonhuman capital." excerpt

Long-term nutrient addition differentially alters community composition and diversity of genes that control nitrous oxide flux from salt marsh sediments

NASA Astrophysics Data System (ADS)

Kearns, Patrick J.; Angell, John H.; Feinman, Sarah G.; Bowen, Jennifer L.

2015-03-01

Enrichment of natural waters, soils, and sediments by inorganic nutrients, including nitrogen, is occurring at an increasing rate and has fundamentally altered global biogeochemical cycles. Salt marshes are critical for the removal of land-derived nitrogen before it enters coastal waters. This is accomplished via multiple microbially mediated pathways, including denitrification. Many of these pathways, however, are also a source of the greenhouse gas nitrous oxide (N2O). We used clone libraries and quantative PCR (qPCR) to examine the effect of fertilization on the diversity and abundance of two functional genes associated with denitrification and N2O production (norB and nosZ) in experimental plots at the Great Sippewissett Salt Marsh (Falmouth, MA, USA) that have been enriched with nutrients for over 40 years. Our data showed distinct nosZ and norB community structures at different nitrogen loads, especially at the highest level of fertilization. Furthermore, calculations of the Shannon Diversity Index and Chao1 Richness Estimator indicated that nosZ gene diversity and richness increased with increased nitrogen supply, however no such relationship existed with regard to richness and diversity of the norB gene. Results from qPCR demonstrated that nosZ gene abundance was an order of magnitude lower in the extra-highly fertilized plots compared to the other plots, but the abundance of norB was not affected by fertilization. The majority of sequences obtained from the marsh plots had no close cultured relatives and they were divergent from previously sequenced norB and nosZ fragments. Despite their divergence from any cultured representatives, most of the norB and nosZ sequences appeared to be from members of the Alpha- and Betaproteobacteria, suggesting that these classes are particularly important in salt marsh nitrogen cycling. Our results suggest that both norB and nosZ containing microbes are affected by fertilization and that the Great Sippewissett Marsh may harbor distinct clades of novel denitrifying microorganisms that are responsible for both the production and removal of N2O.

Proximate determinants of fertility in peninsular Malaysia.

PubMed

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

2012-05-01

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

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

PubMed

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

2009-10-01

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

New Markers for Predicting Fertility of the Male Gametes in the Post Genomic Age.

PubMed

Dipresa, Savina; De Toni, Luca; Foresta, Carlo; Garolla, Andrea

2018-04-18

A number of test have been proposed to assess male fertility potential, ranging from routine testing by light microscopic method for evaluating semen samples, to screening test for DNA integrity aimed to look at sperm chromatin abnormalities. Spermatozoa are an extremely differentiated cell, they have critical functions for embryo development and heredity, in addiction to delivering a haploid paternal genome to the oocyte. Towards this goal certain requirements must always be met. The ability of spermatozoa to perform its reproductive function taking place in the spermatogenesis, a highly specialized process depending on multiple factors with effect on male fertility. In the past 30 years, large-scale analyses of transcriptomic and genome expression in mammals have generated a large amount of informations on numberless biomolecules involved in spermatogenesis and male germ cell reproductive function. Sperm proteome represents the protein content that spermatozoa needs to survive and work correctly and modifications of sperm proteome play a role in determining functional changes leading to a decrease of reproductive competence into affected spermatozoa. The post-genomic approach consists of different methodologies for concurrently testicular transcriptome studies, protein compositional analysis and metabolomics findings of the spermatozoa in humans. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Microgravity effects during fertilization, cell division, development, and calcium metabolism in sea urchins

NASA Technical Reports Server (NTRS)

Schatten, Heide

1996-01-01

The overall objectives of this project are to explore the role of microgravity during fertilization, early development, cytoskeletal organization, and skeletal calcium deposition in a model development system: the sea urchin eggs and embryos. While pursuing these objectives, we have also helped to develop, test, and fly the Aquatic Research Facility (ARF) system. Cells were fixed at preselected time points to preserve the structures and organelles of interest with regards to cell biology events during development. The protocols used for the analysis of the results had been developed during the earlier part of this research and were applied for post-flight analysis using light and (immuno)fluorescence microscopy, scanning electron microscopy, and transmission electron microscopy. The structures of interest are: microtubules during fertilization, cell division, and cilia movement; microfilaments during cell surface restructuring and cell division; centrosomes and centrioles during cell division, cell differentiation, and cilia formation and movement; membranes, Golgi, endoplasmic reticulum, mitochondria, and chromosomes at all stages of development; and calcium deposits during spicule formation in late-stage embryos. In addition to further explore aspects important or living in space, several aspects of this research are also aimed at understanding diseases that affect humans on Earth which may be accelerated in space.

Sea urchin egg fertilization and development

NASA Technical Reports Server (NTRS)

Young, R. S.

1971-01-01

The effects of subgravity (much less than unit gravity) on fertilization, cell division, differentiation, and growth of a relatively simple biological system (eggs of the sea urchin Arbacia punctulata) were considered. The experiment was flown on Gemini 3 and recovered as scheduled. However, the experiment objectives were not achieved, primarily for mechanical reasons.

[Effects of bio-organic fertilizer on soil enzyme activities and microbial community in kiwifruit orchard.

PubMed

Sun, Jia Un; Fu, Qing Xia; Gu, Jie; Wang, Xiao Juan; Gao, Hua

2016-03-01

A field experiment was conducted to compare the effects of three fertilizer managements (bio-organic fertilizer, traditional organic fertilizer and chemical fertilizer) and a no-fertilizer control on soil enzyme activities and microbial community functional diversity in a kiwifruit orchard. The results showed that the soil invertase and FDA hydrolase activities in the bio-organic fertilizer treatment were 12.2%-129.4% and 18.8%-87.4% higher than those in the no-fertilizer control during kiwifruit growth period, respectively. The application of bio-organic fertilizer also increased soil urease and acid phosphatase activities at the expanding stage and maturity stage. The Biolog results suggested that bio-organic fertilizer treatment improved the average well color development (AWCD) and increased the species diversity, richness and evenness. The relative ratios of six groups of carbon sources by microbes were changed to some extent after the application of bio-organic fertilizer. Compared with the no-fertilizer control, bio-organic fertilizer application decreased the capacity of microbes in using amino acids, but enhanced the utilization of polyphenols and polyamines. The principal components analysis demonstrated that the differentiation of microbial community was mainly in utilization of carbohydrates, amino acids and carboxylic acids.

Population and nutrition; implications of sociodemographic trends and differentials for food and nutrition policy in Central America and Panama.

PubMed

Teller, C; Sibrian, R; Talavera, C; Bent, V; Del Canto, J; Saenz, L

1979-01-01

This paper looks into some of the sociodemographic trends and differentials that may be influencing the lack of improvement in the food and nutrition situation in rural Central America. Evidence is presented that indicates that it is more difficult to reduce malnutrition and fertility than it was to reduce infant and child mortality initially. When sociostructural changes are not forthcoming after the initiation of the mortality decline, then resultant population growth, distribution and composition dynamics can hinder improvement in nutrition. In particular, changes in the social composition differentials as a result of selectivity in mortality, fertility and migration have apparently contributed to the increasing nutrition gap between the well-fed and the poorly-fed classes.

Differential phytosociological interactions involving male and female atriplex bonnevillensis

USGS Publications Warehouse

Sinclair, J.; Emlen, J.M.; Rinella, M.; Snelgrove, J.; Freeman, D.C.

2009-01-01

Wind-pollinated dioecious plants often exhibit spatial segregation of the sexes. This partial niche separation has most often been explored using abiotic niche axes. However, if the sexes are truly separated in space, then they are apt to encounter different plant species that may heavily affect growth and reproduction. Also, to the extent that their niches differ, the sexes may respond differently to the same co-occurring species. Here we examine interspecific interactions that influence male and female reproductive potential in Atriplex bonnevillensis. Using Emlen's interaction assessment, a technique which assesses species interactions based on cover classes, we show that Salsola species compete significantly with females but not males, while Halogeton glomeratus competes with males but not females. The effect of competition only became apparent when we corrected for site-specific fertility. These results imply that differential competition must be considered when studying dioecious plants that display spatial segregation of the sexes.

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

PubMed

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

2007-09-01

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

Homozygous Mutations in WEE2 Cause Fertilization Failure and Female Infertility.

PubMed

Sang, Qing; Li, Bin; Kuang, Yanping; Wang, Xueqian; Zhang, Zhihua; Chen, Biaobang; Wu, Ling; Lyu, Qifeng; Fu, Yonglun; Yan, Zheng; Mao, Xiaoyan; Xu, Yao; Mu, Jian; Li, Qiaoli; Jin, Li; He, Lin; Wang, Lei

2018-04-05

Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when deleted in vivo. In clinical practice, some infertility case subjects suffer from recurrent failure of in vitro fertilization and intracytoplasmic sperm injection attempts due to fertilization failure, but the genetic basis of fertilization failure in humans remains largely unknown. Wee2 is a key oocyte-specific kinase involved in the control of meiotic arrest in mice, but WEE2 has not been associated with any diseases in humans. In this study, we identified homozygous mutations in WEE2 that are responsible for fertilization failure in humans. All four independent affected individuals had homozygous loss-of-function missense mutations or homozygous frameshift protein-truncating mutations, and the phenotype of fertilization failure was shown to follow a Mendelian recessive inheritance pattern. All four mutations significantly decreased the amount of WEE2 protein in vitro and in affected individuals' oocytes in vivo, and they all led to abnormal serine phosphorylation of WEE2 and reduced tyrosine 15 phosphorylation of Cdc2 in vitro. In addition, injection of WEE2 cRNA into affected individuals' oocytes rescued the fertilization failure phenotype and led to the formation of blastocysts in vitro. This work presents a novel gene responsible for human fertilization failure and has implications for future therapeutic treatments for infertility cases. Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Male fertility potential alteration in rheumatic diseases: a systematic review.

PubMed

Tiseo, Bruno Camargo; Cocuzza, Marcello; Bonfa, Eloisa; Srougi, Miguel; Silva, Clovis A

2016-01-01

Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy.

Effects of root herbivory by nematodes on the performance and preference of a leaf-infesting generalist aphid depend on nitrate fertilization.

PubMed

Kutyniok, Magdalene; Persicke, Marcus; Müller, Caroline

2014-02-01

The performance and behavior of herbivores is strongly affected by the quality of their host plants, which is determined by various environmental conditions. We investigated the performance and preference of the polyphagous shoot-infesting aphid Myzus persicae on the host-plant Arabidopsis thaliana in a two-factorial design in which nitrate fertilization was varied by 33 %, and the root-infesting cyst-nematode Heterodera schachtii was present or absent. Aphid performance was influenced by these abiotic and biotic factors in an interactive way. Nematode presence decreased aphid performance when nitrate levels were low, whereas nematode infestation did not influence aphid performance under higher nitrate fertilization. Aphids followed the "mother knows best" principle when given a choice, settling preferentially on those plants on which they performed best. Hence, they preferred nematode-free over nematode-infested plants in the low fertilization treatment but host choice was not affected by nematodes under higher nitrate fertilization. The amino acid composition of the phloem exudates was significantly influenced by fertilization but also by the interaction of the two treatments. Various glucosinolates in the leaves, which provide an estimate of phloem glucosinolates, were not affected by the individual treatments but by the combination of fertilization and herbivory. These changes in primary and secondary metabolites may be decisive for the herbivore responses. Our data demonstrate that abiotic and biotic factors can interactively affect herbivores, adding a layer of complexity to plant-mediated herbivore interactions.

Isolation of genes from female sterile flowers in Medicago sativa.

PubMed

Capomaccio, Stefano; Barone, Pierluigi; Reale, Lara; Veronesi, Fabio; Rosellini, Daniele

2009-06-01

A better knowledge of female sporogenesis and gametogenesis could have several practical applications, from commercial hybrid seed production to gene containment in GM crops. With the purpose of isolating genes involved in the megasporogenesis process, the cDNA-AFLP technique was employed to isolate transcript-derived fragments (TDF) differentially expressed between female-fertile and female-sterile full-sib alfalfa plants. This female sterility trait involves female-specific arrest of sporogenesis at early prophase associated with ectopic, massive callose deposition within the nucellus. Ninety-six TDFs were generated and BLAST analyses revealed similarities with genes involved in different Gene Ontology categories. Three TDFs were selected based on their putative functions: showing high similarity to a soybean flower-expressed beta 1,3-glucanase, to an Arabidopsis thaliana MAPKKK, and to an A. thaliana eukaryotic initiation translation factor eIF4G III, respectively. The full length mRNA sequences were obtained. RT-PCR and in situ hybridizations were performed to confirm differential expression during flower development. The genomic organization of the three genes was assessed through sequencing and Southern experiments. Sequence polymorphisms were found between sterile and fertile plants. Our approach based on differential display and bulked segregant analysis was successful in isolating genes that were differentially expressed between fertile and sterile alfalfa plants.

[Phosphorus availability in cropland soils of China and related affecting factors].

PubMed

Wang, Yong-Zhuang; Chen, Xin; Shi, Yi

2013-01-01

Soil phosphorus (P) availability directly determines cropland productivity. Based on the long-term fertilization experiments in different climatic zones of China, this paper summarized the P content, its availability, and the factors affecting the P transformation in China cropland soils. The total and available P contents in different types of China cropland soils were 0.31-1.72 g x kg(-1) and 0.1-228.8 mg x kg(-1), respectively. Soil parent material, soil physical and chemical prosperities, and fertilization practices were the main factors affecting the soil P availability. It was suggested that more attentions should be paid on the mixed application of organic manure and chemical fertilizers to improve the P availability of cropland soils and on the potential environmental impacts of this fertilization.

High resolution light microscopic evaluation of boar semen quality sperm cytoplasmic droplet retention in relationship with boar fertility parameters.

PubMed

Lovercamp, K W; Safranski, T J; Fischer, K A; Manandhar, G; Sutovsky, M; Herring, W; Sutovsky, P

2007-01-01

The purpose of this study was to investigate the relationship between fertility and quantitative measures of boar semen quality, including various patterns of sperm cytoplasmic droplet (CD) retention, as determined by high power differential interference contrast (DIC) microscopy. A total of 116 ejaculates were collected from a nucleus herd of 18 Large White boars over an eight month period. Semen quality parameters were analyzed for each ejaculate by calculating the percentage of normal spermatozoa, spermatozoa possessing a CD in the proximal, distal, or distal midpiece reflex position, total spermatozoa with an attached cytoplasmic droplet, spermatozoa with non-CD related aberrations and total spermatozoa with abnormalities. Of the 116 ejaculates received, 71 ejaculates from 13 boars had corresponding fertility data from single-sire inseminations of multiparous sows. The fertility data included farrowing rate (FR) and total number born (TNB). The monthly FR encompassed one month before and one month after the date of semen collection. Detection of differences for fertility and semen quality parameters was performed by separating the boars into either an above-average or below-average group based on the mean FR (74.01 +/- 1.43%) or TNB (12.34 +/- 0.17) for the study. For FR, the boars in the below-average group had a significantly lower percentage of normal spermatozoa and significantly higher percentage of spermatozoa possessing distal CDs, total attached CDs and total abnormalities compared to the boars in the above-average group. Conversely, for TNB there were no significant differences between the above- and below-average groups for the semen quality parameters. These data suggest that the attached CD may negatively affect FR, but not TNB. The detection of relationships between the boar fertility parameters and the retention of the sperm CD after ejaculation, document the advantage of high power DIC microscopy in conventional semen evaluation.

Effects of N Fertilizer Sources and Tillage Practices on NH3 Volatilization, Grain Yield, and N Use Efficiency of Rice Fields in Central China

PubMed Central

Liu, Tianqi; Huang, Jinfeng; Chai, Kaibin; Cao, Cougui; Li, Chengfang

2018-01-01

Tillage practices and nitrogen (N) sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH3 volatilization, nitrogen use efficiency (NUE), and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N fertilizer alone, organic N fertilizer plus inorganic N fertilizer, and slow-release N fertilizer plus inorganic N fertilizer) and tillage practices (no-tillage [NT] and conventional intensive tillage [CT]) on NH3 flux, grain yield, and NUE in the rice field of central China. N sources significantly affected NH3 volatilization, as the cumulative volatilization from the treatments of inorganic N fertilizer, organic N fertilizer, organic N fertilizer plus inorganic N fertilizer, slow-release N fertilizer plus inorganic N fertilizer was 4.19, 2.13, 3.42, and 2.23 folds in 2013, and 2.49, 1.68, 2.08, and 1.85 folds in 2014 compared with that under no N fertilizer treatment, respectively. The organic N fertilizer treatment had the lowest grain yield and NUE among all N fertilizer treatments, while slow-release N fertilizer plus inorganic N fertilizer treatment led to relatively higher grain yield and the greatest N use efficiency. Moreover, NT only markedly increased NH3 volatilization from basal fertilizer by 10–14% in average compared with CT, but had no obvious effects on total volatilization during the whole seasons. Tillage practices had no significant effects on grain yield and NUE. Our study suggested that the combination of slow-release N fertilizer plus inorganic N fertilizer and NT might be a sustainable method for mitigating greenhouse gas and NH3 emissions and improving grain yield and NUE in paddy fields of central China. PMID:29623086

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

PubMed

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

2008-02-22

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. 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. 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.

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

PubMed Central

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

2008-01-01

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

A meta-analysis of the effects of pesticides and fertilizers on survival and growth of amphibians.

PubMed

Baker, Nick J; Bancroft, Betsy A; Garcia, Tiffany S

2013-04-01

The input of agrochemicals has contributed to alteration of community composition in managed and associated natural systems, including amphibian biodiversity. Pesticides and fertilizers negatively affect many amphibian species and can cause mortality and sublethal effects, such as reduced growth and increased susceptibility to disease. However, the effect of pesticides and fertilizers varies among amphibian species. We used meta-analytic techniques to quantify the lethal and sublethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date and produce generalized conclusions. We found that pesticides and fertilizers had a negative effect on survival of -0.9027 and growth of -0.0737 across all reported amphibian species. We also observed differences between chemical classes in their impact on amphibians: inorganic fertilizers, organophosphates, chloropyridinyl, phosphonoglycines, carbamates, and triazines negatively affected amphibian survival, while organophosphates and phosphonoglycines negatively affected amphibian growth. Our results suggest that pesticides and fertilizers are an important stressor for amphibians in agriculturally dominated systems. Furthermore, certain chemical classes are more likely to harm amphibians. Best management practices in agroecosystems should incorporate amphibian species-specific response to agrochemicals as well as life stage dependent susceptibility to best conserve amphibian biodiversity in these landscapes. Copyright © 2013 Elsevier B.V. All rights reserved.

Stem growth and respiration in loblolly pine plantations differing in soil resource availability

Treesearch

Chris A. Maier

2001-01-01

Stem respiration and growth in 10-year-old loblolly pine (Pinus taeda L.) plantations were measured monthly during the third year of fertilization and irrigation treatments to determine whether soil resource availability differentially altered growth and respiration in stem tissue. Fertilized trees had significantly greater stem biomass, stem...

Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer.

PubMed

Aqueel, Muhammad A; Raza, Abu-bakar M; Balal, Rashad M; Shahid, Muhammad A; Mustafa, Irfan; Javaid, Muhammad M; Leather, Simon R

2015-12-01

Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid-parasitoid relationship provides an ideal system to investigate tritrophic interactions (as the parasitoids are completely dependent for their development upon their hosts) and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani (V.) reared on Sitobion avenae (F.) and Aphidius rhopalosiphi (D.) reared on Rhopalosiphum padi (L.) were measured. Parasitism and percent emergence of parasitoids were positively affected by nitrogen fertilizer treatments while developmental duration (egg, larval, and pupal stages) was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions. © 2014 Institute of Zoology, Chinese Academy of Sciences.

Protect Your Fertility

MedlinePlus

... your teens and early twenties can affect your fertility for years to come. This prevention guide was written by ... loss of testic- ulor size, see your doctor. Fertility is something that you ... approximately 40 percent of infertile couples, the male partner is ...

Reducing the time rabbit sperm are held at 5 °C negatively affects their fertilizing ability after cryopreservation.

PubMed

Mocé, E; Blanch, E; Talaván, A; Viudes de Castro, M P

2014-10-15

Cooling sperm to and equilibrating the sperm at 5 °C require the most time in any sperm cryopreservation protocol. Reducing the time required for these phases would simplify sperm freezing protocols and allow greater number of ejaculates to be processed and frozen in a given time. This study determined how holding rabbit sperm at 5 °C for different lengths of time (0, 10, 15, 20, 30, or 45 minutes) affected the quality of rabbit sperm, measured by in vitro assays, and if reducing the cooling time to only 10 minutes affected the fertilizing ability of the sperm. Reducing the time sperm were held at 5 °C to 10 minutes did not affect the in vitro quality of the sperm (percent motile and with intact plasma membranes), although eliminating the cooling phase completely (directly freezing the sperm from room temperature) decreased in vitro assessed sperm quality (P<0.01). However, reducing the time sperm were held at 5 °C, from 45 to 10 minutes, negatively affected the fertilizing ability of sperm in vivo (P<0.05). In conclusion, completely eliminating cooling rabbit sperm to 5 °C before freezing is detrimental for rabbit sperm cryosurvival, and although shortening the time sperm are held at 5 °C to 10 minutes does not reduce in vitro sperm quality, it does reduce the fertility of rabbit sperm. Therefore, the length of time rabbit sperm equilibrate at 5 °C is crucial to the fertilizing ability of rabbit sperm and must be longer than 10 minutes. Currently, it is not known if holding rabbit sperm at 5 °C for less than 45 minutes will affect sperm fertilizing ability. Copyright © 2014 Elsevier Inc. All rights reserved.

Influence of damaged spermatozoa on the fertility of turkey semen stored 24 hours at 5 C.

PubMed

Sexton, T J

1988-10-01

Turkey semen was stored for 24 h at 5 C in the presence or absence of added spermatozoa that were damaged by emersion in liquid nitrogen. The fertility of semen stored in the presence of damaged spermatozoa was significantly lower than semen stored in their absence. Unstored semen was not affected by the presence of damaged spermatozoa. Fertility was affected by a significant semen treatment x holding time interaction.

Basic Sciences Fertilizing Clinical Microbiology and Infection Management.

PubMed

Baquero, Fernando

2017-08-15

Basic sciences constitute the most abundant sources of creativity and innovation, as they are based on the passion of knowing. Basic knowledge, in close and fertile contact with medical and public health needs, produces distinct advancements in applied sciences. Basic sciences play the role of stem cells, providing material and semantics to construct differentiated tissues and organisms and enabling specialized functions and applications. However, eventually processes of "practice deconstruction" might reveal basic questions, as in de-differentiation of tissue cells. Basic sciences, microbiology, infectious diseases, and public health constitute an epistemological gradient that should also be an investigational continuum. The coexistence of all these interests and their cross-fertilization should be favored by interdisciplinary, integrative research organizations working simultaneously in the analytical and synthetic dimensions of scientific knowledge. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Lactobacillus rhamnosus Accelerates Zebrafish Backbone Calcification and Gonadal Differentiation through Effects on the GnRH and IGF Systems

PubMed Central

Avella, Matteo A.; Place, Allen; Du, Shao-Jun; Williams, Ernest; Silvi, Stefania; Zohar, Yonathan; Carnevali, Oliana

2012-01-01

Endogenous microbiota play essential roles in the host’s immune system, physiology, reproduction and nutrient metabolism. We hypothesized that a continuous administration of an exogenous probiotic might also influence the host’s development. Thus, we treated zebrafish from birth to sexual maturation (2-months treatment) with Lactobacillus rhamnosus, a probiotic species intended for human use. We monitored for the presence of L. rhamnosus during the entire treatment. Zebrafish at 6 days post fertilization (dpf) exhibited elevated gene expression levels for Insulin-like growth factors -I and -II, Peroxisome proliferator activated receptors -α and -β, VDR-α and RAR-γ when compared to untreated-10 days old zebrafish. Using a gonadotropin-releasing hormone 3 GFP transgenic zebrafish (GnRH3-GFP), higher GnRH3 expression was found at 6, 8 and 10 dpf upon L. rhamnosus treatment. The same larvae exhibited earlier backbone calcification and gonad maturation. Noteworthy in the gonad development was the presence of first testes differentiation at 3 weeks post fertilization in the treated zebrafish population -which normally occurs at 8 weeks- and a dramatic sex ratio modulation (93% females, 7% males in control vs. 55% females, 45% males in the treated group). We infer that administration of L. rhamnosus stimulated the IGF system, leading to a faster backbone calcification. Moreover we hypothesize a role for administration of L. rhamnosus on GnRH3 modulation during early larval development, which in turn affects gonadal development and sex differentiation. These findings suggest a significant role of the microbiota composition on the host organism development profile and open new perspectives in the study of probiotics usage and application. PMID:23029107

Hindu-Muslim differentials in fertility and population growth in India: role of proximate variables.

PubMed

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 pronatalist religions; however, the 2 religions differ in regard to their beliefs concerning marriage, reproductive behavior, and fertility control, and these differences may have a different impact on the intermediate variables which influence fertility. These intermediate variables include age at marriage, marriage stability, and contraceptive use. For example, Islamic beliefs, in contrast to Hindu beliefs, support polygamy, allow for easy divorce in case of infertility, and allow widows to remarry. These beliefs tend to increase exposure to the risk of pregnancy for Muslim women. Hindu women are more likely than Muslim women to return to their family of orientation for a period of time following the birth of their 1st and 2nd children, and this practice reduces exposure to the risk of pregnancy for Hindu women. Muslim women are also less receptive to family planning than Hindu women. A national survey indicated that 17% of Hindu women compared to 13% of Muslim women ever used contraception. Sterilization rates are also higher among Hindus than among Muslims. As the modernization process unfolds in India, the impact of religious beliefs on the intermediate variables will decrease, and religious differentials in fertility will decline.

Knowledge about factors that influence fertility among Australians of reproductive age: a population-based survey.

PubMed

Hammarberg, Karin; Setter, Tracey; Norman, Robert J; Holden, Carol A; Michelmore, Janet; Johnson, Louise

2013-02-01

To explore knowledge about the effects on fertility of age, obesity, smoking, and timing of intercourse among Australians of reproductive age. Telephone survey of a representative sample of Australians. Not applicable. Australians aged 18 to 45 years who wish to have a child or another child now or in the future. None. Knowledge about the effect on fertility of age, obesity, smoking, and timing of intercourse. A total of 462 interviews were conducted. The majority of respondents underestimated, by about 10 years, the age at which male and female fertility starts to decline. Only one in four correctly identified that female fertility starts to decline before age 35, and one in three identified that male fertility starts to decline before age 45. Most (59%) were aware that female obesity and smoking affect fertility, but fewer recognized that male obesity (30%) and smoking (36%) also influence fertility. Almost 40% of respondents had inadequate knowledge of when in the menstrual cycle a woman is most likely to conceive. Considerable knowledge gaps about modifiable factors that affect fertility were identified. These are targeted in a national education campaign to promote awareness of factors that influence fertility. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

India's needs and priorities in fertility regulation research.

PubMed

Puri, C P

1999-02-01

This article evaluates the needs and priorities of India in fertility regulation research. There are multivariate factors that affect the perceptions of people about fertility regulation in India. The socioeconomic status, level of education and religious beliefs have strong influences on their decision on the family size, spacing between children and also the sex of the children. Moreover, a large number of people are either quite ignorant of or cannot afford to avail with the technologies and services for controlling their fertility. These factors generally perpetuate high fertility, which strongly affect the infant and maternal mortality, and eventually the quality of life both for the present and the future generation. The International Conference on Population and Development Program of Action has provided India with an alternative to develop newer methods of fertility regulation so as to widen contraceptive choices. The objective of research in fertility regulation should ensure the fertility control of couples and ability to plan the number and spacing of children. Research in fertility regulation should be aimed at expanding contraceptive choices by improving the accessibility and acceptability of good quality contraceptive products and services. It would necessitate: improving the quality of care; increasing awareness about sexuality and fertility regulation; empowering women; and increasing male-female partnership in sharing responsibilities for family planning and parenthood.

Towards a causal model of childbearing and abortion attitudes in contemporary Japan.

PubMed

Ogawa, N; Hodge, R W

1983-01-01

Described in this paper is the rationale and thinking behind the development of a causal model of childbearing and abortion attitudes in contemporary Japan. This effort represents one of the 1st attempts to build a multiple equation, micro-level model of fertility and fertility related behavior and attitudes in Japan. The results are almost wholely consistent with received demographic theory. Japan has now reached the last stage of her demographic transition and the results are consistent with the view that social and economic differentials in fertility are gradually eroded over the course of the transition. There are still statistically significant residues of these differentials in contemporary Japan, but they are at best modest in scope. Fertility in modern Japan is largely a matter of age and personal desires. Even abortion, which was so instrumental in moving Japan through the middle stages of her demographic transition in the immediate postwar period, exhibits only weak relationships with the social and economic position of women; attitudes about abortion are even more weakly linked to the social order. In sum, as of 1981, the process of family formation appears to have evolved to the point where it is largely homogeneous with respect to social and economic status. The differentials which remain are the expected ones, but their magnitude is not overwhelming and the force of social location is at most only a modest constraint on fertility behavior and fertility related beliefs and attitudes. This is the exact scenario one expects to find in a nation which is at the final stage of its demographic transition. The present analysis is current and cross-sectional. It is largely exploratory and as such, represents one of the very 1st efforts to develop a structural equation model of individual fertility behavior in Japan. The findings are based on the analysis of the data gathered in Japan in connection with ESCAP Study on the Relationship Between Fertility Behavior and Size, Structure and Function of the Family, funded by UNFPA. (Project No. RAS/77P14). Evaluated are: 1) the background, work experience, type of marriage and patrilocality; 2) ideal, desired and actual family size including of children ever born; 3) abortions and attitudes toward them; and 4) a path analysis and model evaluation.

Male fertility potential alteration in rheumatic diseases: a systematic review

PubMed Central

Tiseo, Bruno Camargo; Cocuzza, Marcello; Bonfá, Eloisa; Srougi, Miguel; Clovis, A

2016-01-01

ABSTRACT Background Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. Materials and Methods A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. Results A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Conclusions Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy. PMID:27120778

Spermatozoa from patients with seminal alterations exhibit a differential micro-ribonucleic acid profile.

PubMed

Salas-Huetos, Albert; Blanco, Joan; Vidal, Francesca; Godo, Anna; Grossmann, Mark; Pons, Maria Carme; F-Fernández, Silvia; Garrido, Nicolás; Anton, Ester

2015-09-01

To compare the microRNA (miRNA) expression profile in spermatozoa from three infertile populations vs. a group of fertile men. Evaluation of the expression level of 736 miRNAs in human spermatozoa using TaqMan quantitative reverse transcription-polymerase chain reaction. University research facility. Semen samples with a single seminal alteration were collected from infertile individuals: asthenozoospermic (n = 10), teratozoospermic (n = 10), and oligozoospermic (n = 10). None. Correlation of the expression level of each miRNA with seminal parameters, age, and chromosome instability; clustering of the individuals according to their miRNA expression profiles and influence of the seminogram, age, chromosome instability, and assisted reproductive technology outcome in the clustering; analysis of the differentially expressed miRNAs (DE-miRNAs) in each infertile population; genome annotation of these DE-miRNAs; and ontological analysis of their predicted targets. The hsa-miR-34b-3p correlated with age, the hsa-miR-629-3p with sperm motility, and the hsa-miR-335-5p, hsa-miR-885-5p, and hsa-miR-152-3p with sperm concentration. The individuals clustered into two groups, and only the seminogram was differentially distributed. We identified 32 DE-miRNAs in the asthenozoospermic group, 19 in the teratozoospermic group, and 18 in the oligozoospermic group. The up-regulated miRNAs presented an enriched localization in introns, affecting relevant genes for spermatogenesis. The predicted targets of the DE-miRNAs contained critical genes associated to infertility, and their ontological analysis revealed significantly associated functions related to the seminal alterations of each group. Spermatozoa from patients with seminal alterations exhibit a differential miRNA profile. This provides new evidence that miRNAs have an essential role in spermatogenesis, contributing to the mechanisms involved in human fertility. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Fertilization of black spruce or poor site peatland in Minnesota.

Treesearch

David H. Alban; Richard F. Watt

1981-01-01

Fertilization of poor site black spruce on organic soil with various rates of nitrogen and phosphorus increased height and diameter growth from 2 to 4 times. The growth response declined with time but was still apparent 16 years after fertilization. Shrub biomass and coverage, and nutrient levels of spruce foliage were strongly affected by fertilization.

Effects of different sources of fertilizer nitrogen on growth and nutrition of western hemlock seedlings.

Treesearch

M.A. Radwan; Dean S. DeBell

1980-01-01

Twelve different nitrogen (N) fertilizer treatments were tested on potted western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings. Fertilizers affected soil N and pH, and growth and foliar chemical composition of seedlings. Urea plus N-Serve and sulfur-coated urea appear more promising for promoting growth than other fertilizers tested. Results...

Long-term agricultural fertilization alters arbuscular mycorrhizal fungal community composition and barley (Hordeum vulgare) mycorrhizal carbon and phosphorus exchange.

PubMed

Williams, Alwyn; Manoharan, Lokeshwaran; Rosenstock, Nicholas P; Olsson, Pål Axel; Hedlund, Katarina

2017-01-01

Agricultural fertilization significantly affects arbuscular mycorrhizal fungal (AMF) community composition. However, the functional implications of community shifts are unknown, limiting understanding of the role of AMF in agriculture. We assessed AMF community composition at four sites managed under the same nitrogen (N) and phosphorus (P) fertilizer regimes for 55 yr. We also established a glasshouse experiment with the same soils to investigate AMF-barley (Hordeum vulgare) nutrient exchange, using carbon ( 13 C) and 33 P isotopic labelling. N fertilization affected AMF community composition, reducing diversity; P had no effect. In the glasshouse, AMF contribution to plant P declined with P fertilization, but was unaffected by N. Barley C allocation to AMF also declined with P fertilization. As N fertilization increased, C allocation to AMF per unit of P exchanged increased. This occurred with and without P fertilization, and was concomitant with reduced barley biomass. AMF community composition showed no relationship with glasshouse experiment results. The results indicate that plants can reduce C allocation to AMF in response to P fertilization. Under N fertilization, plants allocate an increasing amount of C to AMF and receive relatively less P. This suggests an alteration in the terms of P-C exchange under N fertilization regardless of soil P status. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Nitrous oxide emissions affected by biochar and nitrogen stabilizers

USDA-ARS?s Scientific Manuscript database

Both biochar and N fertilizer stabilizers (N transformation inhibitors) are potential strategies to reduce nitrous oxide (N2O) emissions from fertilization, but the mechanisms and/or N transformation processes affecting the N dynamics are not fully understood. This research investigated N2O emission...

Socioeconomic Status and Net Fertility during the Fertility Decline: A Comparative Analysis of Canada, Iceland, Sweden, Norway and the United States

PubMed Central

Dribe, Martin; Hacker, J. David; Scalone, Francesco

2014-01-01

Most previous work on the historical fertility transition has been macro-oriented, using aggregate data to examine economic correlates of demographic behaviour at regional or national levels, while much less has been done using micro data, and specifically looking at behavioural differentials among social groups. In this paper we study at the impact of socioeconomic status on net fertility during the fertility transition in five Northern American and European Countries (Canada, Iceland, Norway, Sweden and the USA). We use micro-level census data in 1900, containing information on number of children by age, occupation of the mother and father, place of residence and household context. The results show highly similar patterns across countries, with the elite and upper middle classes having considerably lower net fertility early in the transition. These patterns remain also after controlling for a range of individual and community-level fertility determinants and geographical unobserved heterogeneity. PMID:24684711

Religious Affiliation and Fertility in a Sub-Saharan Context: Dynamic and Lifetime Perspectives.

PubMed

Agadjanian, Victor; Yabiku, Scott T

2014-10-01

We use uniquely detailed data from a predominantly Christian high-fertility area in Mozambique to examine denominational differentials in fertility from two complementary perspectives-dynamic and cumulative. First, we use event-history analysis to predict yearly risks of birth from denominational affiliation. Then, we employ Poisson regression to model the association between the number of children ever born and share of reproductive life spent in particular denominations or outside organized religion. Both approaches detect a significant increase in fertility associated with membership in a particular type of African-initiated churches which is characterized by strong organizational identity, rigid hierarchy, and insular corporate culture. Membership in the Catholic Church is also associated with elevated completed fertility. We relate these results to extant theoretical perspectives on the relationship between religion and fertility by stressing the interplay between ideological, social, and organizational characteristics of different types of churches and situate our findings within the context of fertility transition and religious demographics in Mozambique and elsewhere in sub-Saharan Africa.

Male fertility: psychiatric considerations.

PubMed

Hall, Elise; Burt, Vivien K

2012-02-01

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

Fertility and Female Employment: Problems of Causal Direction.

ERIC Educational Resources Information Center

Cramer, James C.

1980-01-01

Considers multicollinearity in nonrecursive models, misspecification of models, discrepancies between attitudes and behavior, and differences between static and dynamic models as explanations for contradictory information on the causal relationship between fertility and female employment. Finds that initially fertility affects employment but that,…

Female status and fertility in Pakistan.

PubMed

Syed, S H

1978-01-01

The roles of education and labor force participation in the reproductive behavior of women (aged 20-29 and 30-39) were analyzed using data from the 1975 Pakistan Fertility Survey. Analysis shows that urban women of both age groups fare better than rural women with respect to overall literacy and educational achievement. No significant differentials were observed between urban and rural women as regards labor force participation. The difficulty in presenting a true picture of the work status of Pakistani women is attributed to the difficulty of defining the concept of female labor force participation, not to mention biases in response and enumeration during the survey. Nevertheless, it is suggested that most urban and rural women are either not economically active or are engaged in traditional activities which do not provide stimulus for changes in their fertility behavior. With respect to education, the data shows that the effect of education on contraceptive use is statistically significant for urban women, but not for rural women, urban women being 3 times greater users of contraceptives than rural women. Work status did not significantly affect ever contraceptive use. The findings lend support to the hypothesis that education reduces female vulnerability to unwanted pregnancies by increasing age at 1st marriage, by becoming more aware of available contraceptive methods, and by limiting family size. Thus, policy should be geared towards providing educational opportunities for both rural and urban women.

Developmental Constraints in a Wild Primate

PubMed Central

Lea, Amanda J.; Altmann, Jeanne; Alberts, Susan C.; Tung, Jenny

2015-01-01

Early-life experiences can dramatically affect adult traits. However, the evolutionary origins of such early-life effects are debated. The predictive adaptive response hypothesis argues that adverse early environments prompt adaptive phenotypic adjustments that prepare animals for similar challenges in adulthood. In contrast, the developmental constraints hypothesis argues that early adversity is generally costly. To differentiate between these hypotheses, we studied two sets of wild female baboons: those born during low-rainfall, low-quality years and those born during normal-rainfall, high-quality years. For each female, we measured fertility-related fitness components during years in adulthood that matched and mismatched her early conditions. We found support for the developmental constraints hypothesis: females born in low-quality environments showed greater decreases in fertility during drought years than females born in high-quality environments, even though drought years matched the early conditions of females born in low-quality environments. Additionally, we found that females born in low-quality years to high-status mothers did not experience reduced fertility during drought years. These results indicate that early ecological adversity did not prepare individuals to cope with ecological challenges in later life. Instead, individuals that experienced at least one high-quality early environment—either ecological or social—were more resilient to ecological stress in later life. Together, these data suggest that early adversity carries lifelong costs, which is consistent with the developmental constraints hypothesis. PMID:25996865

Differences in plant function in phosphorus- and nitrogen-limited mangrove ecosystems.

PubMed

Lovelock, Catherine E; Feller, Ilka C; Ball, Marilyn C; Engelbrecht, Bettina M J; Ewe, Mei Ling

2006-01-01

Mangrove ecosystems can be either nitrogen (N) or phosphorus (P) limited and are therefore vulnerable to nutrient pollution. Nutrient enrichment with either N or P may have differing effects on ecosystems because of underlying differences in plant physiological responses to these nutrients in either N- or P-limited settings. Using a common mangrove species, Avicennia germinans, in sites where growth was either N or P limited, we investigated differing physiological responses to N and P limitation and fertilization. We tested the hypothesis that water uptake and transport, and hydraulic architecture, were the main processes limiting productivity at the P-limited site, but that this was not the case at the N-limited site. We found that plants at the P-deficient site had lower leaf water potential, stomatal conductance and photosynthetic carbon-assimilation rates, and less conductive xylem, than those at the N-limited site. These differences were greatly reduced with P fertilization at the P-limited site. By contrast, fertilization with N at the N-limited site had little effect on either photosynthetic or hydraulic traits. We conclude that growth in N- and P-limited sites differentially affect the hydraulic pathways of mangroves. Plants experiencing P limitation appear to be water deficient and undergo more pronounced changes in structure and function with relief of nutrient deficiency than those in N-limited ecosystems.

Prospective Study of Fertility Concerns and Preservation Strategies in Young Women With Breast Cancer

PubMed Central

Ruddy, Kathryn J.; Gelber, Shari I.; Tamimi, Rulla M.; Ginsburg, Elizabeth S.; Schapira, Lidia; Come, Steven E.; Borges, Virginia F.; Meyer, Meghan E.; Partridge, Ann H.

2014-01-01

Purpose Most research regarding fertility in young women with breast cancer has focused on long-term survivors. Little is known about how fertility concerns affect treatment decisions or fertility preservation strategies at the time of initial cancer diagnosis. Patients and Methods As part of an ongoing prospective multicenter cohort study, we surveyed women with newly diagnosed early-stage breast cancer at age ≤ 40 years. The baseline survey included sociodemographic, medical, and treatment data as well as a modified Fertility Issues Survey, including fertility concern and preservation items. Univariable and multivariable modeling were used to investigate predictors of greater fertility concern. Results Among the first 620 eligible respondents included in this analysis, median age was 37 years (range, 17 to 40 years); 425 women (68%) discussed fertility issues with their physicians before starting therapy, and 319 (51%) were concerned about becoming infertile after treatment. Because of concerns about fertility, four women (1%) chose not to receive chemotherapy, 12 (2%) chose one chemotherapy regimen over another, six (1%) considered not receiving endocrine therapy, 19 (3%) decided not to receive endocrine therapy, and 71 (11%) considered receiving endocrine therapy for < 5 years; 65 (10%) used fertility preservation strategies. Greater concern about fertility was associated with younger age, nonwhite race, not having children, and receipt of chemotherapy. Conclusion Many young women with newly diagnosed breast cancer have concerns about fertility, and for some, these substantially affect their treatment decisions. Only a minority of women currently pursue available fertility preservation strategies in this setting. PMID:24567428

Copper and thermal perturbations on the early life processes of the hard coral Platygyra acuta

NASA Astrophysics Data System (ADS)

Kwok, C. K.; Lam, K. Y.; Leung, S. M.; Chui, A. P. Y.; Ang, P. O.

2016-09-01

Anthropogenic pollutants and climate change are major threats to coral reefs today. Yet interactions between chemical and thermal perturbations have not been fully explored in reef studies. Here, we present the single and combined effects of copper (Cu) with thermal stress on five early life-history stages/processes (fertilization, larval mortality, swimming ability, metamorphosis and growth of juvenile recruits) of the massive coral Platygyra acuta in Hong Kong. In the first four experiments, coral gametes and larvae were exposed to different Cu doses (0-200 μg L-1, apart from the fertilization assay in which 0-1000 μg L-1 was used) and temperature treatments (ambient and ambient +2 or +3 °C as a thermal stress treatment) following a factorial experimental design. Exposure time was 5 h for the fertilization assay and 48 h for the other experiments. The last experiment on growth of coral recruits was conducted over 56 d with 0-80 μg L-1 Cu used. Cu significantly reduced percent fertilization success, percentage of active swimming larvae and larval survivorship (EC50s, the half maximal effective concentrations, for percent fertilization success and percentage of active swimming larvae were 92-145 and 45-47 μg L-1 respectively. While LC50, the lethal concentration that kills 50% of the population, was 101-110 μg L-1), while growth of coral recruits was not affected at 80 μg L-1 Cu for 56 d. No settling cues were used in the settlement experiment. In their absence, percent metamorphosis increased with Cu doses, in sharp contrast to earlier findings. Settlement and metamorphosis may thus be strategies for coral larvae to escape from Cu toxicity. Thermal treatment did not significantly affect any experimental end points. This is likely because the thermal regimes used in the experiments were within the range experienced by local corals. The high variability in Cu toxicities indicates differential susceptibilities of the various life-history stages/processes of P. acuta. The level of Cu tolerance was also markedly higher than that reported in the literature for other coral species. This provides evidence to suggest possible adaptation of this species to survive in a highly polluted marine environment like that in Hong Kong.

Soil management shapes ecosystem service provision and trade-offs in agricultural landscapes.

PubMed

Tamburini, Giovanni; De Simone, Serena; Sigura, Maurizia; Boscutti, Francesco; Marini, Lorenzo

2016-08-31

Agroecosystems are principally managed to maximize food provisioning even if they receive a large array of supporting and regulating ecosystem services (ESs). Hence, comprehensive studies investigating the effects of local management and landscape composition on the provision of and trade-offs between multiple ESs are urgently needed. We explored the effects of conservation tillage, nitrogen fertilization and landscape composition on six ESs (crop production, disease control, soil fertility, water quality regulation, weed and pest control) in winter cereals. Conservation tillage enhanced soil fertility and pest control, decreased water quality regulation and weed control, without affecting crop production and disease control. Fertilization only influenced crop production by increasing grain yield. Landscape intensification reduced the provision of disease and pest control. We also found tillage and landscape composition to interactively affect water quality regulation and weed control. Under N fertilization, conventional tillage resulted in more trade-offs between ESs than conservation tillage. Our results demonstrate that soil management and landscape composition affect the provision of several ESs and that soil management potentially shapes the trade-offs between them. © 2016 The Author(s).

Pathways from education to fertility decline: a multi-site comparative study

PubMed Central

Colleran, Heidi

2016-01-01

Women's education has emerged as a central predictor of fertility decline, but the many ways that education affects fertility have not been subject to detailed comparative investigation. Taking an evolutionary biosocial approach, we use structural equation modelling to examine potential pathways between education and fertility including: infant/child mortality, women's participation in the labour market, husband's education, social network influences, and contraceptive use or knowledge across three very different contexts: Matlab, Bangladesh; San Borja, Bolivia; and rural Poland. Using a comparable set of variables, we show that the pathways by which education affects fertility differ in important ways, yet also show key similarities. For example, we find that across all three contexts, education is associated with delayed age at first birth via increasing women's labour-force participation, but this pathway only influences fertility in rural Poland. In Matlab and San Borja, education is associated with lower local childhood mortality, which influences fertility, but this pathway is not important in rural Poland. Similarities across sites suggest that there are common elements in how education drives demographic transitions cross-culturally, but the differences suggest that local socioecologies also play an important role in the relationship between education and fertility decline. PMID:27022083

Conventional and organic soil fertility management practices affect corn plant nutrition and Ostrinia nubilalis (Lepidoptera: Crambidae) larval performance.

PubMed

Murrell, Ebony G; Cullen, Eileen M

2014-10-01

Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition.

IMPACT OF SEX COMPOSITION OF LIVING CHILDREN AND COUPLES' AGREEMENT ON SUBSEQUENT FERTILITY IN INDIA.

PubMed

Kastor, Anshul; Chatterjee, Sayantani

2017-11-23

The desire for children could be considered a reliable predictor of subsequent fertility. At the same time, the sex composition of surviving children, along with other demographic and socioeconomic factors, may affect a couple's fertility desire and, therefore, their subsequent fertility. This study examined the impact of the sex composition of living children and a couple's agreement on fertility desire on their subsequent fertility in India using data came from two rounds of nationally representative surveys: the India Human Development Survey (IHDS)-I (2004-05) and IHDS-II (2011-12). To understand which factors affect the chances of an additional pregnancy or childbirth, a random effects logistic regression model was applied to the panel data. It was found that the fertility desires of both marital partners were important in determining the chances of subsequent fertility. About 35% of the couples wanting to limit children had undergone pregnancy or childbirth, while 76% of the couples wanting more children had conceived or given birth to children. In the case of discordance between the spouses, subsequent fertility was found to remain intermediate between those agreeing to continue childbirth and those wanting to limit it. The findings also affirmed that child sex preference, specifically son preference, still persists in Indian society. More than 80% of the couples with only daughters in IHDS-I mutually wanted to have additional children, whereas in families that only had sons, the chance of a subsequent pregnancy was inversely associated with the number of sons. Strong patriarchal settings, combined with cultural and socioeconomic factors, affect the persistence of sex preference in India. Programmes aimed at increasing family planning use need to address son preference and should include components that promote the value of girl children.

Effects of Plant Diversity, Functional Group Composition, and Fertilization on Soil Microbial Properties in Experimental Grassland

PubMed Central

Strecker, Tanja; Barnard, Romain L.; Niklaus, Pascal A.; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Scheu, Stefan; Eisenhauer, Nico

2015-01-01

Background Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant diversity and fertilization. Methodology/Principal Findings We investigated the effects of plant diversity, functional community composition, and fertilization on the biomass and respiration of soil microbial communities in a long-term biodiversity experiment in semi-natural grassland (Jena Experiment). Plant species richness enhanced microbial basal respiration and microbial biomass, but did not significantly affect microbial specific respiration. In contrast, the presence of legumes and fertilization significantly decreased microbial specific respiration, without altering microbial biomass. The effect of legumes was superimposed by fertilization as indicated by a significant interaction between the presence of legumes and fertilization. Further, changes in microbial stoichiometry (C-to-N ratio) and specific respiration suggest the presence of legumes to reduce N limitation of soil microorganisms and to modify microbial C use efficiency. Conclusions/Significance Our study highlights the role of plant species and functional group diversity as well as interactions between plant community composition and fertilizer application for soil microbial functions. Our results suggest soil microbial stoichiometry to be a powerful indicator of microbial functioning under N limited conditions. Although our results support the notion that plant diversity and fertilizer application independently affect microbial functioning, legume effects on microbial N limitation were superimposed by fertilization, indicating significant interactions between the functional composition of plant communities and nutrient inputs for soil processes. PMID:25938580

Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis - ultrafiltration bioreactor.

PubMed

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

2017-09-01

In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55days. The FDFO performance was first investigated in terms of flux decline with various fertilizers draw solution. Flux decline was very severe with all fertilizers due to the absence of aeration and the sticky property of sludge. Flux recovery by physical cleaning varied significantly amongst tested fertilizers which seriously affected biofouling in FDFO via reverse salt flux (RSF). Besides, RSF had a significant impact on nutrient accumulation in the bioreactor. These results indicated that nutrient accumulation negatively influenced the anaerobic activity. To elucidate these phenomena, bacterial and archaeal community structures were analyzed by pyrosequencing. Results showed that bacterial community structure was affected by fertilizer properties with less impact on archaeal community structure, which resulted in a reduction in biogas production and an increase in nitrogen content. Copyright © 2017 Elsevier Ltd. All rights reserved.

The oviductal transcriptome is influenced by a local ovarian effect in the sow.

PubMed

López-Úbeda, Rebeca; Muñoz, Marta; Vieira, Luis; Hunter, Ronald H F; Coy, Pilar; Canovas, Sebastian

2016-07-22

Oviducts participate in fertilization and early embryo development, and they are influenced by systemic and local circulation. Local functional interplay between ovary, oviduct and uterus is important, as deduced from the previously observed differences in hormone concentrations, presence of sperm, or patterns of motility in the oviduct after unilateral ovariectomy (UO). However, the consequences of unilateral ovariectomy on the oviductal transcriptome remain unexplored. In this study, we have investigated the consequences of UO in a higher animal model as the pig. The influence of UO was analyzed on the number of ovulations on the contra ovary, which was increased, and on the ipsilateral oviductal transcriptome. Microarray analysis was performed and the results were validated by PCR. Differentially expressed genes (DEGs) with a fold change ≥ 2 and a false discovery rate of 10 % were analyzed by Ingenuity Pathway Analysis (IPA) to identify the main biofunctions affected by UO. Data revealed two principal effects in the ipsilateral oviduct after UO: i) down-regulation of genes involved in the survival of sperm in the oviduct and early embryonic development, and ii) up-regulation of genes involved in others functions as protection against external agents and tumors. Results showed that unilateral ovariectomy results in an increased number of ovulation points on the contra ovary and changes in the transcriptome of the ipsilateral oviduct with consequences on key biological process that could affect fertility output.

piRNA-associated proteins and retrotransposons are differentially expressed in murine testis and ovary of aryl hydrocarbon receptor deficient mice

PubMed Central

Rico-Leo, Eva M.; Moreno-Marín, Nuria; González-Rico, Francisco J.; Barrasa, Eva; Ortega-Ferrusola, Cristina; Martín-Muñoz, Patricia; Sánchez-Guardado, Luis O.; Llano, Elena; Alvarez-Barrientos, Alberto; Infante-Campos, Ascensión; Catalina-Fernández, Inmaculada; Hidalgo-Sánchez, Matías; de Rooij, Dirk G.; Pendás, Alberto M.; Peña, Fernando J.; Merino, Jaime M.

2016-01-01

Previous studies suggested that the aryl hydrocarbon receptor (AhR) contributes to mice reproduction and fertility. However, the mechanisms involved remain mostly unknown. Retrotransposon silencing by Piwi-interacting RNAs (piRNAs) is essential for germ cell maturation and, remarkably, AhR has been identified as a regulator of murine B1-SINE retrotransposons. Here, using littermate AhR+/+ and AhR−/− mice, we report that AhR regulates the general course of spermatogenesis and oogenesis by a mechanism likely to be associated with piRNA-associated proteins, piRNAs and retrotransposons. piRNA-associated proteins MVH and Miwi are upregulated in leptotene to pachytene spermatocytes with a more precocious timing in AhR−/− than in AhR+/+ testes. piRNAs and transcripts from B1-SINE, LINE-1 and IAP retrotransposons increased at these meiotic stages in AhR-null testes. Moreover, B1-SINE transcripts colocalize with MVH and Miwi in leptonema and pachynema spermatocytes. Unexpectedly, AhR−/− males have increased sperm counts, higher sperm functionality and enhanced fertility than AhR+/+ mice. In contrast, piRNA-associated proteins and B1-SINE and IAP-derived transcripts are reduced in adult AhR−/− ovaries. Accordingly, AhR-null female mice have lower numbers of follicles when compared with AhR+/+ mice. Thus, AhR deficiency differentially affects testis and ovary development possibly by a process involving piRNA-associated proteins, piRNAs and transposable elements. PMID:28003471

Natalist Policies in the United States

ERIC Educational Resources Information Center

Lopoo, Leonard M.; Raissian, Kerri M.

2012-01-01

This retrospective reviews the policies that affect the fertility of American women, both policies designed to alter fertility intentionally as well as those that change childbearing unintentionally. Becker's seminal work on the economics of fertility serves as the theoretical foundation for this literature. After describing Becker's economic…

Effects of fertilization on CO2 efflux in a two-year-old loblolly pine stand on the Virginia Piedmont

Treesearch

Michael Tyree; John Seiler; Thomas R. Fox

2006-01-01

Fertilization is becoming a common, cost effective treatment within managed forests of the Southeastern United States. However, there is little known about how fertilization will affect the belowground processes that drive soil CO2

Modeling human infertility with pluripotent stem cells.

PubMed

Chen, Di; Gell, Joanna J; Tao, Yu; Sosa, Enrique; Clark, Amander T

2017-05-01

Human fertility is dependent upon the correct establishment and differentiation of the germline. This is because no other cell type in the body is capable of passing a genome and epigenome from parent to child. Terminally differentiated germline cells in the adult testis and ovary are called gametes. However, the initial specification of germline cells occurs in the embryo around the time of gastrulation. Most of our knowledge regarding the cell and molecular events that govern human germline specification involves extrapolating scientific principles from model organisms, most notably the mouse. However, recent work using next generation sequencing, gene editing and differentiation of germline cells from pluripotent stem cells has revealed that the core molecular mechanisms that regulate human germline development are different from rodents. Here, we will discuss the major molecular pathways required for human germline differentiation and how pluripotent stem cells have revolutionized our ability to study the earliest steps in human embryonic lineage specification in order to understand human fertility. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Farm-Nonfarm Differentials in Fertility: The Effects of Compositional and Sex-Role Factors.

ERIC Educational Resources Information Center

Johnson, Nan E.; And Others

Data derived from the 1970 National Fertility Study (NFS II included post-married women, information on all compositional factors for each respondent, and an 18-item section on sex-role ideology) were used to test the following hypotheses: farm women are more traditional in sex-role ideology than nonfarm women; the higher the sex-role…

The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility

PubMed Central

Fontana, Roberta; Della Torre, Sara

2016-01-01

In female mammals, mechanisms have been developed, throughout evolution, to integrate environmental, nutritional and hormonal cues in order to guarantee reproduction in favorable energetic conditions and to inhibit it in case of food scarcity. This metabolic strategy could be an advantage in nutritionally poor environments, but nowadays is affecting women’s health. The unlimited availability of nutrients, in association with reduced energy expenditure, leads to alterations in many metabolic pathways and to impairments in the finely tuned inter-relation between energy metabolism and reproduction, thereby affecting female fertility. Many energetic states could influence female reproductive health being under- and over-weight, obesity and strenuous physical activity are all conditions that alter the profiles of specific hormones, such as insulin and adipokines, thus impairing women fertility. Furthermore, specific classes of nutrients might affect female fertility by acting on particular signaling pathways. Dietary fatty acids, carbohydrates, proteins and food-associated components (such as endocrine disruptors) have per se physiological activities and their unbalanced intake, both in quantitative and qualitative terms, might impair metabolic homeostasis and fertility in premenopausal women. Even though we are far from identifying a “fertility diet”, lifestyle and dietary interventions might represent a promising and invaluable strategy to manage infertility in premenopausal women. PMID:26875986

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed Central

Nivelle, Elodie; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate. PMID:28552945

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed

Nivelle, Elodie; Verzeaux, Julien; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate.

The fate of nitrogen affected by biochar and fertilizer source

USDA-ARS?s Scientific Manuscript database

Continuous improvement of nitrogen (N) use efficiency (NUE) and minimizing environmental loss is necessary to address the issues related to N fertilizer use in agronomic systems. The objective of this research was to determine the effectiveness of biochar amendment and fertilizer source on NUE impro...

Plastome-Genome Interactions Affect Plastid Transmission in Oenothera

PubMed Central

Chiu, W. L.; Sears, B. B.

1993-01-01

Plastids of Oenothera, the evening primrose, can be transmitted to the progeny from both parents. In a constant nuclear background, the frequency of biparental plastid transmission is determined by the types of plastid genomes (plastomes) involved in the crosses. In this study, the impact of nuclear genomes on plastid inheritance was analyzed. In general, the transmission efficiency of each plastome correlated strongly with its compatibility with the nuclear genome of the progeny, suggesting that plastome-genome interactions can influence plastid transmission by affecting the efficiency of plastid multiplication after fertilization. Lower frequencies of plastid transmission from the paternal side were observed when the pollen had poor vigor due to an incompatible plastome-genome combination, indicating that plastome-genome interactions may also affect the input of plastids at fertilization. Parental traits that affect the process of fertilization can also have an impact on plastid transmission. Crosses using maternal parents with long styles or pollen with relatively low growth capacity resulted in reduced frequencies of paternal plastid transmission. These observations suggest that degeneration of pollen plastids may occur as the time interval between pollination and fertilization is lengthened. PMID:8462856

Differential gene expression in the endometrium reveals cytoskeletal and immunological genes in lactating dairy cows genetically divergent for fertility traits.

PubMed

Moran, Bruce; Butler, Stephen T; Moore, Stephen G; MacHugh, David E; Creevey, Christopher J

2017-02-01

Profitable milk production in dairy cows requires good reproductive performance. Calving interval is a trait used to measure reproductive efficiency. Herein we used a novel lactating Holstein cow model of fertility that displayed genetic and phenotypic divergence in calving interval, a trait used to define reproductive performance using a national breeding index in Ireland. Cows had similar genetic merit for milk production traits, but either very good genetic merit for fertility (Fert+; n=7) or very poor genetic merit for fertility (Fert-; n=6). We tested the hypothesis that Fert+ cows would have a corresponding detectable difference in endometrial gene expression compared with the Fert- cows. To do this, we sequenced the transcriptome of endometrial biopsies collected on Day 7 of the oestrous cycle (non-pregnant). This is an important stage for uterine remodelling and initiation of histotroph secretion. Significant differential expression (false discovery rate-adjusted P<0.1) of 403 genes between Fert+ and Fert- cows was found. A novel network-based functional analysis highlighted 123 genes from three physiologically relevant networks of the endometrium: (1) actin and cytoskeletal components; (2) immune function; and (3) ion transportation. In particular, our results indicate an overall downregulation of inflammation-related genes and an upregulation of multiple ion transporters and gated-voltage channels and cytoskeletal genes in Fert+ cows. These three topics, which are discussed in terms of the uterus and in the context of fertility, provide molecular evidence for an association between gene expression in the uterine environment and genetic merit for fertility in dairy cows.

The long-term effects of acute exposure to ionising radiation on survival and fertility in Daphnia magna

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

Sarapultseva, Elena I.

The results of recent studies have provided strong evidence for the transgenerational effects of parental exposure to ionising radiation and chemical mutagens. However, the transgenerational effects of parental exposure on survival and fertility remain poorly understood. To establish whether parental irradiation can affect the survival and fertility of directly exposed organisms and their offspring, crustacean Daphnia magna were given 10, 100, 1000 and 10,000 mGy of acute γ-rays. Exposure to 1000 and 10,000 mGy significantly compromised the viability of irradiated Daphnia and their first-generation progeny, but did not affect the second-generation progeny. The fertility of F{sub 0} and F{sub 1}Daphniamore » gradually declined with the dose of parental exposure and significantly decreased at dose of 100 mGy and at higher doses. The effects of parental irradiation on the number of broods were only observed among the F{sub 0}Daphnia exposed to 1000 and 10,000 mGy, whereas the brood size was equally affected in the two consecutive generations. In contrast, the F{sub 2} total fertility was compromised only among progeny of parents that received the highest dose of 10,000 mGy. We propose that the decreased fertility observed among the F{sub 2} progeny of parents exposed to 10,000 mGy is attributed to transgenerational effects of parental irradiation. Our results also indicate a substantial recovery of the F{sub 2} progeny of irradiated F{sub 0}Daphnia exposed to the lower doses of acute γ-rays. - Highlights: • Viability of irradiated daphnids and their F{sub 1} progeny is compromised. • Viability of the F{sub 2} progeny of irradiated parents is not affected. • Total fertility of irradiated daphnids and their F{sub 1} progeny declines with the dose. • Total fertility of the F{sub 2} progeny of parents exposed to 10,000 mGy is compromised. • The decreased fertility among the F{sub 2} progeny is transgenerational phenomenon.« less

Economic recession and fertility in the developed world.

PubMed

Sobotka, Tomáš; Skirbekk, Vegard; Philipov, Dimiter

2011-01-01

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

Kinship and the decline of fertility.

PubMed

Zhou, Y

1996-01-01

China's family planning and population control policies, together with the move toward a more market-oriented economy since the 1980s, have led to significant change in people's reproductive values and behavior and a substantial decline in fertility. Traditional kinship in China, its terminology, and the impact of fertility decline on kinship in China and Chinese society are discussed. The decline in fertility is affecting or will affect China's kinship system, the corresponding pattern of terminology, and the social structure. In the more market-oriented economy which has been developing in China, the simplification of the kinship system will help change the structure of Chinese society and weaken the traditional patriarchal culture. A more individualized, contractualized social structure and relationships will result.

Present-day nearshore pH differentially depresses fertilization in congeneric sea urchins.

PubMed

Frieder, Christina A

2014-02-01

Ocean acidification impacts fertilization in some species of sea urchin, but whether sensitivity is great enough to be influenced by present-day pH variability has not been documented. In this study, fertilization in two congeneric sea urchins, Strongylocentrotus purpuratus and S. franciscanus, was found to be sensitive to reduced pH, <7.50, but only within a range of sperm-egg ratios that was species-specific. By further testing fertilization across a broad range of pH, pH-fertilization curves were generated and revealed that S. purpuratus was largely robust to pH, while fertilization in S. franciscanus was sensitive to even modest reductions in pH. Combining the pH-fertilization response curves with pH data collected from these species' habitat demonstrated that relative fertilization success remained high for S. purpuratus but could be as low as 79% for S. franciscanus during periods of naturally low pH. In order for S. franciscanus to maintain high fertilization success in the present and future, adequate adult densities, and thus sufficient sperm-egg ratios, will be required to negate the effects of low pH. In contrast, fertilization of S. purpuratus was robust to a broad range of pH, encompassing both present-day and future ocean acidification scenarios, even though the two congeners have similar habitats.

40 CFR 62.6613 - Identification of plan-negative declaration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Montana Fluoride Emissions from Existing Phosphate Fertilizer Plants § 62.6613 Identification of plan... 14, 2001, that there are no phosphate fertilizer plants in Montana that meet the definition of... fertilizer plants in Montana that meet the definition of affected facility under any of the subparts T, U, V...

40 CFR 62.6613 - Identification of plan-negative declaration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Montana Fluoride Emissions from Existing Phosphate Fertilizer Plants § 62.6613 Identification of plan... 14, 2001, that there are no phosphate fertilizer plants in Montana that meet the definition of... fertilizer plants in Montana that meet the definition of affected facility under any of the subparts T, U, V...

Fertilizer placement to maximize nitrogen use by fescue

USDA-ARS?s Scientific Manuscript database

The method of fertilizer nitrogen(N) application can affect N uptake in tall fescue and therefore its yield and quality. Subsurface-banding (knife) of fertilizer maximizes fescue N uptake in the poorly-drained clay–pan soils of southeastern Kansas. This study was conducted to determine if knifed N r...

Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells

PubMed Central

Brieño-Enríquez, Miguel A.; García-López, Jesús; Cárdenas, David B.; Guibert, Sylvain; Cleroux, Elouan; Děd, Lukas; Hourcade, Juan de Dios; Pěknicová, Jana; Weber, Michael; del Mazo, Jesús

2015-01-01

In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation. PMID:25897752

Generation of male differentiated germ cells from various types of stem cells.

PubMed

Hou, Jingmei; Yang, Shi; Yang, Hao; Liu, Yang; Liu, Yun; Hai, Yanan; Chen, Zheng; Guo, Ying; Gong, Yuehua; Gao, Wei-Qiang; Li, Zheng; He, Zuping

2014-06-01

Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10-15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells 'especially functional spermatids' is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients. © 2014 Society for Reproduction and Fertility.

Development of a health promotion programme to improve awareness of factors that affect fertility, and evaluation of its reach in the first 5 years.

PubMed

Hammarberg, Karin; Norman, Robert J; Robertson, Sarah; McLachlan, Robert; Michelmore, Janet; Johnson, Louise

2017-06-01

Awareness among people of reproductive age about the factors that influence fertility and reproductive outcomes, including medically assisted reproduction outcomes, is generally low. To improve awareness about the potentially modifiable factors that affect fertility and reproductive outcomes, 'Your Fertility', a fertility health promotion programme funded by the Australian Government, was established in 2011. This paper describes the development and evaluation of the reach of the Your Fertility programme from its inception in 2011 to June 2016. Systematically recorded outcomes for the programme's key focus areas and Google Analytics data were collated. Key achievements include developing and maintaining an internationally renowned website that experiences high growth and demand for fertility-related information; by 2016, over 5 million users had viewed more than 10 million webpages, and over 96,000 users had engaged in programme messages across social media. Programme messages have reached more than 4 million Australian social media users, and a potential audience of 150 million through media coverage across more than 320 media features. More than 4200 education and health professionals have completed online learning modules, and external partnerships have been established with 14 separate organizations. Data collected over 5 years indicate that the Your Fertility programme meets a need for targeted, evidence-based, accessible fertility-related information.

The nuclear form of glutathione peroxidase 4 is associated with sperm nuclear matrix and is required for proper paternal chromatin decondensation at fertilization.

PubMed

Puglisi, Rossella; Maccari, Irene; Pipolo, Simona; Conrad, Marcus; Mangia, Franco; Boitani, Carla

2012-04-01

The nuclear isoform of the selenoprotein Phospholipid Hydroperoxide Glutathione Peroxidase (nGPx4) is expressed in haploid male germ cells, contains several cysteines and is able to oxidize protein thiols, besides glutathione. In this study we have investigated the subnuclear localization of this isoform in isolated mouse male germ cells at different steps of maturation. Immunoblotting and confocal microscopy analyses of subnuclear fractions showed that nGPx4 is localized to the nuclear matrix together with well known markers of this subnuclear compartment like lamin B and topoisomerase IIβ at all stages of germ cell differentiation. The peculiar nGPx4 distribution was confirmed by both biochemical and morphological analyses of COS-1 cells overexpressing Flag-tagged nGPx4. To test the functional role of nGPx4 in the process of chromatin assembly, sperm isolated from the caput and the cauda epididymides of wild-type (WT) and genetically deficient in nGPx4 (nGPx4-KO) mice were analyzed in an in vitro chromatin decondensation assay. Results showed that sperm from nGPx4-KO mice were more prone to decondense than those from WT mice at all stages of epididymal maturation, providing conclusive evidence that nGPx4 is required for a correct sperm chromatin compaction. We next addressed the issue of whether the lack of nGPx4 impacts on early events occurring at fertilization. Indeed, in vitro fertilization experiments showed an acceleration of sperm chromatin dispersion in oocytes fertilized by nGpx4-KO sperm compared with control. Overall these data indicate that the absence of nGPx4 leads to sperm nuclear matrix/chromatin instability that may negatively affect the embryo development. Copyright © 2011 Wiley Periodicals, Inc.

Long-term affects of a single P fertilization on Hedley P pools in a South Carolina loblolly pine plantation

Treesearch

Bradley W. Miller; Thomas R. Fox

2010-01-01

While phosphorus (P) fertilization increases plant available or “labile” P immediately after fertilization, it is uncertain how it influences P pools over the long term in forest soils. Phosphorus pools from a 22-year-old loblolly pine (Pinus taeda L.) fertilization study were quantified using the Hedley sequential fractionation procedure, Mehlich-1...

[Differences between married and unmarried cohabiting women in the Netherlands].

PubMed

Swinkels, H

1985-03-01

An analysis of consensual unions in the Netherlands is presented. Particular attention is given to differences between the characteristics of those in consensual unions and those who marry. Data are from the Netherlands Fertility Survey of 1982. Factors considered include attitudes toward marital roles, sexuality, and individualism; religion; political attitudes; educational status; geographic differences; urban or rural residence; and differential fertility. (summary in ENG)

Dynamic adjustment in agricultural practices to economic incentives aiming to decrease fertilizer application.

PubMed

Sun, Shanxia; Delgado, Michael S; Sesmero, Juan P

2016-07-15

Input- and output-based economic policies designed to reduce water pollution from fertilizer runoff by adjusting management practices are theoretically justified and well-understood. Yet, in practice, adjustment in fertilizer application or land allocation may be sluggish. We provide practical guidance for policymakers regarding the relative magnitude and speed of adjustment of input- and output-based policies. Through a dynamic dual model of corn production that takes fertilizer as one of several production inputs, we measure the short- and long-term effects of policies that affect the relative prices of inputs and outputs through the short- and long-term price elasticities of fertilizer application, and also the total time required for different policies to affect fertilizer application through the adjustment rates of capital and land. These estimates allow us to compare input- and output-based policies based on their relative cost-effectiveness. Using data from Indiana and Illinois, we find that input-based policies are more cost-effective than their output-based counterparts in achieving a target reduction in fertilizer application. We show that input- and output-based policies yield adjustment in fertilizer application at the same speed, and that most of the adjustment takes place in the short-term. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Symmetric Two-Locus Fertility Model

PubMed Central

Feldman, Marcus W.; Liberman, Uri

1985-01-01

A model in which selection is mediated by differential fertilities among the genotypes at two diallelic loci is proposed. Fertility depends only on the number of heterozygous loci participating in the mating. Classes analogous to symmetric equilibria in symmetric viability models are determined explicitly and shown to exhibit stability behavior very different from the viability results. Linkage equilibrium is shown to occur in a relatively asymmetric fashion and to overlap in stability with linkage disequilibrium. In many cases single-locus or two-locus polymorphism is shown to be stable simultaneously with chromosome fixation even under very tight linkage. It is suggested that historical effects may be of great significance in the evolution of systems in which fertility is the primary agent of natural selection. PMID:3967817

Demography and the Evolution of Educational Inequality.

ERIC Educational Resources Information Center

Mare, Robert D.

The combined effects of differential fertility, differential mortality, and intergenerational educational mobility on the distribution of educational attainment in the United States were studied for women in the past half century. A simple model for the reproduction of educational hierarchies was used that takes these factors, plus age structure…

Initial substrate moisture content and storage temperature affects chemical properties of bagged substrates containing controlled release fertilizer at two different temperatures

USDA-ARS?s Scientific Manuscript database

Bagged potting mixes can be stored for weeks or months before being used by consumers. Some bagged potting mixes are amended with controlled release fertilizers (CRF). The objective of this research was to observe how initial substrate moisture content and storage temperature affect the chemical p...

Long-term Effects of Organic Waste Fertilizers on Soil Structure, Tracer Transport, and Leaching of Colloids.

PubMed

Lekfeldt, Jonas Duus Stevens; Kjaergaard, Charlotte; Magid, Jakob

2017-07-01

Organic waste fertilizers have previously been observed to significantly affect soil organic carbon (SOC) content and soil structure. However, the effect of organic waste fertilizers on colloid dispersibility and leaching of colloids from topsoil has not yet been studied extensively. We investigated how the repeated application of different types of agricultural (liquid cattle slurry and solid cattle manure) and urban waste fertilizers (sewage sludge and composted organic household waste) affected soil physical properties, colloid dispersion from aggregates, tracer transport, and colloid leaching from intact soil cores. Total porosity was positively correlated with SOC content. Yearly applications of sewage sludge increased absolute microporosity (pores <30 μm) and decreased relative macroporosity (pores >30 μm) compared with the unfertilized control, whereas organic household waste compost fertilization increased both total porosity and the absolute porosity in all pore size classes (though not significant for 100-600 μm). Treatments receiving large amounts of organic fertilizers exhibited significantly lower levels of dispersible colloids compared with an unfertilized control and a treatment that had received moderate applications of cattle slurry. The content of water-dispersible colloids could not be explained by a single factor, but differences in SOC content, electrical conductivity, and sodium adsorption ratio were important factors. Moreover, we found that the fertilizer treatments did not significantly affect the solute transport properties of the topsoil. Finally, we found that the leaching of soil colloids was significantly decreased in treatments that had received large amounts of organic waste fertilizers, and we ascribe this primarily to treatment-induced differences in effluent electrical conductivity during leaching. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

PubMed

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

2015-01-01

It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Direct but no transgenerational effects of decitabine and vorinostat on male fertility.

PubMed

Kläver, Ruth; Sánchez, Victoria; Damm, Oliver S; Redmann, Klaus; Lahrmann, Elisabeth; Sandhowe-Klaverkamp, Reinhild; Rohde, Christian; Wistuba, Joachim; Ehmcke, Jens; Schlatt, Stefan; Gromoll, Jörg

2015-01-01

Establishment and maintenance of the correct epigenetic code is essential for a plethora of physiological pathways and disturbed epigenetic patterns can provoke severe consequences, e.g. tumour formation. In recent years, epigenetic drugs altering the epigenome of tumours actively have been developed for anti-cancer therapies. However, such drugs could potentially also affect other physiological pathways and systems in which intact epigenetic patterns are essential. Amongst those, male fertility is one of the most prominent. Consequently, we addressed possible direct effects of two epigenetic drugs, decitabine and vorinostat, on both, the male germ line and fertility. In addition, we checked for putative transgenerational epigenetic effects on the germ line of subsequent generations (F1-F3). Parental adult male C57Bl/6 mice were treated with either decitabine or vorinostat and analysed as well as three subsequent untreated generations derived from these males. Treatment directly affected several reproductive parameters as testis (decitabine & vorinostat) and epididymis weight, size of accessory sex glands (vorinostat), the height of the seminiferous epithelium and sperm concentration and morphology (decitabine). Furthermore, after decitabine administration, DNA methylation of a number of loci was altered in sperm. However, when analysing fertility of treated mice (fertilisation, litter size and sex ratio), no major effect of the selected epigenetic drugs on male fertility was detected. In subsequent generations (F1-F3 generations) only subtle changes on reproductive organs, sperm parameters and DNA methylation but no overall effect on fertility was observed. Consequently, in mice, decitabine and vorinostat neither affected male fertility per se nor caused marked transgenerational effects. We therefore suggest that both drugs do not induce major adverse effects-in terms of male fertility and transgenerational epigenetic inheritance-when used in anti-cancer-therapies.

New Promising Strategies in Oncofertility

PubMed Central

Hudson, Janella N.; Stanley, Nathanael B.; Nahata, Leena; Bowman-Curci, Meghan; Quinn, Gwendolyn P.

2017-01-01

Introduction Approximately 70,000 adolescent and young adults (AYA) are diagnosed with cancer each year. While advancements in treatment have led to improved prognosis and survival for patients, these same treatments can adversely affect AYA reproductive capacity. Localized treatments such as surgery and radiation therapy may affect fertility by removing or damaging reproductive organs, and systemic therapies such as chemotherapy can be toxic to gonads, (ovaries and testicles), thus affecting fertility and/or endocrine function. This can be traumatic for AYA with cancer as survivors often express desire to have genetic children and report feelings of regret or depression as a result of infertility caused by cancer treatments. Areas Covered Emerging technologies in the field of assisted reproductive technology offer new promise for preserving the reproductive capacity of AYA cancer patients prior to treatment as well as providing alternatives for survivors. The following review revisits contemporary approaches to fertility preservation as well newly developing technologies. Expert Commentary There are several advances in ART that hold promise for patients and survivors. However there are challenges that inhibit uptake including poor communication between providers and patients about risks and fertility preservation options; high costs; and lack of insurance coverage for fertility preservation services. PMID:28959743

Preservation of fertility in women affected by cancer. An audit of the cryopreservation services provided for women at Human Assisted Reproduction Ireland.

PubMed

O'Donovan, M; Harrison, R F

2005-10-01

There has been a remarkable improvement in survival rates for adult and childhood cancers, due to progress in cancer treatments. However multiagent chemotherapy and radiotherapy are associated with gonadal failure. Whereas sperm banking is commonly performed, female gametes are not so amenable to cryopreservation. Options available to women for fertility preservation include, embryo and oocyte cryopreservation. Our unit established an oocyte/embryo cryopreservation service for women affected by cancer in October 2003. Ninteen women have been referred and five (26%) women have had oocytes cryopreserved. The mean age of women in the group cryopreserved was 34 years (range 21-41). Their mean day 3 FSH was 6.2 IU (range 5.5-6.8). The mean dose of rFSH used was 1870 units (range 1500-2600). The mean number of oocytes cryopreserved was 8 (range 3-16). Preservation of fertility is of major concern to women affected by cancer. This service offers them hope for their future fertility.

Evaluation of fertilization-to-planting and fertilization-to-harvest intervals for safe use of noncomposted bovine manure in Wisconsin vegetable production.

PubMed

Ingham, Steven C; Fanslau, Melody A; Engel, Rebecca A; Breuer, Jeffry R; Breuer, Jane E; Wright, Thomas H; Reith-Rozelle, Judith K; Zhu, Jun

2005-06-01

Fresh bovine manure was mechanically incorporated into loamy sand and silty clay loam Wisconsin soils in April 2004. At varying fertilization-to-planting intervals, radish, lettuce, and carrot seeds were planted; crops were harvested 90, 100, 110 or 111, and 120 days after manure application. As an indicator of potential contamination with fecal pathogens, levels of Escherichia coli in the manure-fertilized soil and presence of E. coli on harvested vegetables were monitored. From initial levels of 4.0 to 4.2 log CFU/g, E. coli levels in both manure-fertilized soils decreased by 2.4 to 2.5 log CFU/g during the first 7 weeks. However, E. coli was consistently detected from enriched soil samples through week 17, perhaps as a result of contamination by birds and other wildlife. In the higher clay silty clay loam soil, the fertilization-to-planting interval affected the prevalence of E. coli on lettuce but not on radishes and carrots. Root crop contamination was consistent across different fertilization-to-harvest intervals in silty clay loam, including the National Organic Program minimum fertilization-to-harvest interval of 120 days. However, lettuce contamination in silty clay loam was significantly (P < 0.10) affected by fertilization-to-harvest interval. Increasing the fertilization-to-planting interval in the lower clay loamy sand soil decreased the prevalence of E. coli on root crops. The fertilization-to-harvest interval had no clear effect on vegetable contamination in loamy sand. Overall, these results do not provide grounds for reducing the National Organic Program minimum fertilization-to-harvest interval from the current 120-day standard.

Chemically-dispersed crude oil and dispersant affects sperm fertilizing ability, but not sperm swimming behaviour in capelin (Mallotus villosus).

PubMed

Beirão, José; Litt, Margaret A; Purchase, Craig F

2018-06-05

The effects of petroleum aromatic hydrocarbons (PAHs) on the embryonic and larval life stages of teleosts have been extensively examined. However, very little work has been conducted on how spilled oil affects fish sperm and there is no related knowledge concerning oil dispersing agents. The objective of our study was to determine sperm performance of a teleost fish under direct exposure to different concentrations of WAF (water accommodated fraction) and CEWAF (chemically enhanced water accommodated fraction). Capelin sperm motility, swimming behaviour, and sperm fertilization ability were evaluated in a scenario of an oil spill untreated (WAF) and treated (CEWAF) with the dispersant Corexit ® EC9500A. Sperm fertilizing ability was lower when exposed to CEWAF concentrations of 16.1 × 10 3  μg/L total petroleum hydrocarbons and 47.9 μg/L PAH, and when exposed to the dispersant alone. The mechanism responsible for this reduced fertilizing ability is not clear. However, it is not related to the percentage of motile sperm or sperm swimming behaviour, as these were unaffected. WAF did not alter sperm swimming characteristics nor the fertilizing ability. We suggest the dispersant rather than the dispersed oil is responsible for the decrease in the sperm fertilizing ability and hypothesize that the surfactants present in the dispersant affect sperm membrane functionality. Copyright © 2018. Published by Elsevier Ltd.

Fertilizing Douglas-fir forests.

Treesearch

Richard E. Miller; Roger D. Right

1979-01-01

This report supplements a slide-tape presentation of the same title. Part I of the report describes the current practice of nitrogen fertilization of Douglas-fir forests in western Washington and Oregon and the effects of this fertilization on tree growth and water quality. Part II discusses factors that affect costs and revenues from investments in forest...

Streamside Management Zones Affect Movement of Silvicultural Nitrogen and Phosphorus Fertilizers to Piedmont Streams

Treesearch

Joseph M. Secoges; Wallace M. Aust; John R. Seiler; C. Andrew Dolloff; William A. Lakel

2013-01-01

Forestry best management practices (BMP) recommendations for streamside management zones (SMZs) are based on limited data regarding SMZ width, partial harvests, and nutrient movements after forest fertilization. Agricultural fertilization is commonly linked to increased stream nutrients. However, less is known about effectiveness of SMZ options for controlling nutrient...

How does conversion from peat swamp forest to oil palm plantation affect emissions of nitrous oxide from the soil? A case study in Jambi, Indonesia

NASA Astrophysics Data System (ADS)

Hartill, Jodie; Hergoualc'h, Kristell; Comeau, Louis-Pierre; Jo, Smith; Lou, Verchot

2017-04-01

Half of the peatlands across Peninsular Malaysia, Borneo and Sumatra are 'managed'. Conversion of peat swamp forest to workable oil palm plantation requires a drastic, potentially irreversible, change to the landscape, to which fertilizers are then routinely applied. A combination of these factors is now widely thought to increase soil nitrous oxide (N2O) emissions, although there is high uncertainty due to gaps in the knowledge, both regionally and nationally. Despite the widespread use of fertilizers in plantations on peats, studies observing their effects remain very limited. Therefore, there is a need for in situ studies to evaluate how environmental parameters (edaphic properties, climate, soil moisture and N availability indicators) influence soil emissions. This 18 month study was located in plots local to each other, representing the start, intermediate and end of the land conversion process; namely mixed peat swamp forest, drained and logged forest and industrial oil palm plantation. Spatial variability was taken into account by differentiating the hollows and hummocks in the mixed peat swamp forest, and the fertilized zone and the zone without fertilizer addition in the oil palm plantation. Gas samples were collected each month from static chambers at the same time as key environmental parameters were measured. Intensive sampling was performed during a 35 day period following two fertilizer applications, in which urea was applied to palms at rates of 0.5 and 1 kg urea palm-1. Soil N2O emissions (kg N ha-1 y-1 ± SE) were low overall, but they were greater in the oil palm plantation (0.8 ± 0.1) than in the mixed peat swamp forest (0.3 ± 0.0) and the drained/logged forest (0.2 ± 0.0). In the mixed peat swamp forest, monthly average fluxes of N2O (g N ha-1 d-1 ± SE) were similar in the hollows (0.6 ± 0.2) and the hummocks (0.3 ± 0.1), whereas in the oil palm plantation they were consistently higher in the zone without fertilizer (2.5 ± 0.4) than in the fertilized zone (0.5 ± 0.1), even after fertilizer application. In the fertilized zones, the N2O fluxes following the two fertilizer applications were 2.4 and 4.5 times higher respectively than fluxes observed in the absence of fertilizers. No change in emissions was observed in the neighboring unfertilized zone at the time of fertilizer application. Soil N2O emissions were related to changes in air and soil temperature in the mixed peat swamp forest, air temperature and water table depth in the drained and logged forest, and rainfall on the day of measurement in the oil palm plantation. This research confirms that peat forest conversion to oil palm plantation has negative consequences on the emissions of N2O. It also corroborates an increase in emission due to fertilizer application, with a magnitude comparable to the emission factor provided by the IPCC guidelines, but this is restricted to the limited area of fertilizer application.

Effects of shading on spike differentiation and grain yield formation of summer maize in the field

NASA Astrophysics Data System (ADS)

Cui, Haiyan; Camberato, James J.; Jin, Libin; Zhang, Jiwang

2015-09-01

A field experiment was conducted to study the effects of shading on tassel and ear development and yield formation of three summer maize hybrids Zhenjie 2 (ZJ2), Denghai 605 (DH605), and Zhengdan 958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth stages from silking stage (R1) to physiological maturity stage (R6) (treatment S1), from the sixth extended leaf stage (V6) to R1 (treatment S2) and from seeding to R6 (treatment S3). Shading had no significant effect on the time from seeding to shoot emergence (VE); however, subsequent growth and development were delayed with shading beyond this point. The differentiation time of both tassel and ear delayed, and female spike (tassel) floret differentiation, sexual organ formation time, and anthesis-silking interval (ASI) were lengthened. After shading, the total number of floret, silk, and fertilization floret reduced significantly; the number of abortive seeds increased, and the total setting percentage among different treatments showed that CK>S2>S1>S3; and the total setting percentages in S1, S2, and S3 of ZD958 were 44, 72, and 15 % respectively. The total floret number of tassel primordium differentiation, fertility rate, and seed setting rate of florets in S3 treatment was the minimum; kernels per ear decreased seriously and single ear setting percentage was only 16 %; although floret degeneration number of S2 during ear differentiation stages increased and floret fertility rate reduced than that of CK, fertilization flower seed production increased and abortive seed decreased after canceling shading. Aborted kernel of S1 increased and kernel dry weight reduced, resulting in a significant decrease of kernel number per ear and kernel weight, and the grain abortive rate of 40-62 %. In conclusion, shading changed the growth and development process and caused infertility of tassel and ear; tassel branches decreased, reducing pollen vitality and silks differentiation cut down; and grain dry matter accumulation and setting percentage decreased, causing yield reduction. Grain yield and biomass reduced 66, 36, and 93 % compared to the control by shading treatments of S1, S2, and S3, respectively.

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Fertility intentions and outcomes: Implementing the Theory of Planned Behavior with graphical models.

PubMed

Mencarini, Letizia; Vignoli, Daniele; Gottard, Anna

2015-03-01

This paper studies fertility intentions and their outcomes, analyzing the complete path leading to fertility behavior according to the social psychological model of Theory Planned Behavior (TPB). We move beyond existing research using graphical models to have a precise understanding, and a formal description, of the developmental fertility decision-making process. Our findings yield new results for the Italian case which are empirically robust and theoretically coherent, adding important insights to the effectiveness of the TPB for fertility research. In line with TPB, all intentions' primary antecedents are found to be determinants of the level of fertility intentions, but do not affect fertility outcomes, being pre-filtered by fertility intentions. Nevertheless, in contrast with TPB, background factors are not fully mediated by intentions' primary antecedents, influencing directly fertility intentions and even fertility behaviors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Time course of soil carbon storage, 15N and radiocarbon signature in top- and subsoil of a 60-years agricultural field trial - indications for compensating effects of carbon input and turnover

NASA Astrophysics Data System (ADS)

Leifeld, Jens; Conen, Franz; Oberholzer, Hans Rudolf; Jochen, Mayer

2014-05-01

Soil carbon dynamics are controlled by the delicate balance between carbon inputs and outputs which both are co-regulated by land use and management (LUM) as important anthropogenic drivers. Upon land use change to cropland carbon stocks generally tend to decline but often the contribution of two opposing factors, namely changes in input and decomposition rates, to soil carbon stock changes is indistinguishable. Here we report on an ongoing cropland experiment in Zurich, Switzerland, named ZOFE (Zurich Organic Fertilization Experiment), established on former grassland in 1949. ZOFE encompasses a range of mineral and organic fertilization practices and a zero fertilizer treatment as control. The experiment has a block design with five replicates per treatment. We make use of productivity and fertilization gradients in selected treatments of the ZOFE trial to evaluate how low or high inputs (induced by differential yields and organic fertilization) may affect soil organic carbon storage and transformation. For the most recent sampling that also included subsoil down to 0.9 m, all properties were measured for every single replicate. Topsoil carbon storage declined after grassland conversion at rates of c. 0.2 t C ha-1 a-1, particularly in treatments with mineral fertilizer and high yields, and without fertilization and low yields. Organic matter amendments such as manure or compost could partially offset but not fully compensate some of the topsoil carbon loss. Over time the soil's delta 15N signature declined as well, probably due to increased atmospheric nitrogen deposition. It increased from the top- to the subsoil, indicating increasing microbial transformation, particularly with manure added. The soil's radiocarbon signature revealed distinct bomb peak patterns in all treatments but only in the topsoil. The 14C data confirmed that with higher productivity more recent organic matter was incorporated, both in top and subsoil. Because, in contrast to topsoil, subsoil carbon storage was similar among treatments, the results tentatively indicate that in the ZOFE trial higher subsoil carbon inputs, owing to high productivity and additional organic amendments, do not enhance subsoil carbon storage but higher inputs are counterbalanced by faster soil organic matter decomposition.

Pine straw harvesting, fire, and fertilization affect understory vegetation within a Louisiana longleaf pine stand

Treesearch

James D. Haywood

2012-01-01

Pine straw harvesting can provide an economic benefit to landowners, but the practice may also change the composition of plant communities. This research was initiated in a 34-year-old stand of longleaf pine (Pinus palustris Mill.) established in 1956 to study how pine straw management practices (fertilization, prescribed fire, and straw harvesting) affected plant...

Farmers behavior on using fertilizer in West Java

NASA Astrophysics Data System (ADS)

Perdana, Tomy; Renaldy, Eddy; Utami, Hesty Nurul; Sadeli, Agriani Hermita; Mahra Arari, H.; Ginanjar, Tetep; Ajeng Sesy N., P.; Fernianda Rahayu, H.; Sanjaya, Sonny

2018-02-01

Fertilizer is one of the important materials in farming system to improve quality and quantity of harvest. Most of farmers in Indonesia using fertilizer, one of substantial fertilizer is NPK that contain of complex nutrient, there are nitrogen, phosphorus and potassium. There are tendency for farmers using NPK based on quality products and speed of decomposition. Nowadays, market size for NPK fertilizer has been dramatically increase and it will impact on intensify of fertilizer use. The potential requirement in marketing does not balanced with consumer behavior analysis. Meanwhile, agricultural sector (include horticulture, floriculture, bio-pharmacy and plantation) have been wieldly increase of the farming system annualy. This research is study case which is analyzed local NPK fertilizer competitive advantage compared to imported NPK fertilizer through consumer point of view towards product quality in four districts in West Java province, i.e., West Bandung, Garut, Bogor and Cianjur District with target respondents are farmers who use NPK fertilizer. NPK fertilizer qualities are based on product attributes, which are; availability, nutrient content, price, basic ingredients, form of fertilizer, speed of decomposition, label, color, type, design and size of packaging. It was analyzed using sematic differential attitude models and multi attribute attitude snake diagram model. The evaluation ranking of consumers interests towards fertilizer attribute characteristics showed that consumer intention before deciding to buy or use a NPK fertilizer will consider nutrient content, speed of decomposition, form of fertilizer and availability of products. Consumer's attitude towards all NPK fertilizer attribute quality illustrated that imported fertilizer is considered to be more positive than local fertilizer. Fertilizer companies or industries should be able to maintain their fertilizer production especially concerning nutrient content and availability of products through a better production which appropriate with consumer's needs. Nutrient contents, form and speed of decomposition of fertilizer should be adapted with current state of farming activities

Alterations in oxidative responses and post-translational modification caused by p,p´-DDE in Mus spretus testes reveal Cys oxidation status in proteins related to cell-redox homeostasis and male fertility.

PubMed

Alhama, José; Fuentes-Almagro, Carlos A; Abril, Nieves; Michán, Carmen

2018-09-15

The major derivate of DDT, 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p´-DDE), is a persistent pollutant previously associated with oxidative stress. Additionally, p,p´-DDE has been linked to several metabolic alterations related to sexual function in rodents. In this study, we analysed the effects of a non-lethal p,p´-DDE dose to Mus spretus mice in testes, focusing on oxidative damage to biomolecules, defence mechanisms against oxidative stress and post-translational protein modifications. No increase in lipid or DNA oxidation was observed, although antioxidative enzymatic defences and redox status of glutathione were altered in several ways. Global protein carbonylation and phosphorylation were significantly reduced in testes from p,p´-DDE-exposed mice; however, the total redox state of Cys thiols did not exhibit a defined pattern. We analysed the reversible redox state of specific Cys residues in detail with differential isotopic labelling and a shotgun labelling-based MS/MS proteomic approach for identification and quantification of altered peptides. Our results show that Cys residues are significantly affected by p,p´-DDE in several proteins related to oxidative stress and/or male fertility, particularly those participating in fertilization, sperm capacitation and blood coagulation. These molecular changes could explain the sexual abnormalities previously described in p,p´-DDE exposed organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Chinese culture and fertility decline.

PubMed

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-reliance, education and cultivation of moral character, and atheism. Confucian beliefs that interfere with fertility decline are the advocacy of self-sufficient livelihood, the emphasis on family and lineage, autocracy, patriarchy and feudal rule, the 5 constant virtues, contempt for labor and working people, science and technology, and a closed-door policy. Socialism hindered fertility decline by promoting population growth as a symbol of the superiority of socialism and by lack of recognition of population or environmental problems in socialist countries. The goal is to accept Westernization, reduce obstacles, develop economically, and use cultural influence positive to fertility decline.

WHITE-NONWHITE DIFFERENTIALS IN HEALTH, EDUCATION, AND WELFARE.

ERIC Educational Resources Information Center

Department of Health, Education, and Welfare, Washington, DC.

THIS COLLECTION CONTAINS SEVEN PAPERS OF ANALYSES OF WHITE-NONWHITE DIFFERENTIALS IN HEALTH, EDUCATION, AND WELFARE. NONWHITES MAKE UP ALMOST 12 PERCENT OF THE POPULATION, 92 PERCENT OF WHOM ARE NEGROES. THE FERTILITY OF NONWHITES IS HIGHER, ESPECIALLY AMONG THE RURAL, LESS EDUCATED GROUP, BUT THE BIRTH RATE SEEMS TO BE FALLING FASTER, MOST…

Nitrogen losses, uptake and abundance of ammonia oxidizers in soil under mineral and organo-mineral fertilization regimes.

PubMed

Florio, Alessandro; Felici, Barbara; Migliore, Melania; Dell'Abate, Maria Teresa; Benedetti, Anna

2016-05-01

A laboratory incubation experiment and greenhouse studies investigated the impact of organo-mineral (OM) fertilization as an alternative practice to conventional mineral (M) fertilization on nitrogen (N) uptake and losses in perennial ryegrass (Lolium perenne) as well as on soil microbial biomass and ammonia oxidizers. While no significant difference in plant productivity and ammonia emissions between treatments could be detected, an increase in soil total N content and an average 17.9% decrease in nitrates leached were observed in OM fertilization compared with M fertilization. The microbial community responded differentially to treatments, suggesting that the organic matter fraction of the OM fertilizer might have influenced N immobilization in the microbial biomass in the short-medium term. Furthermore, nitrate contents in fertilized soils were significantly related to bacterial but not archaeal amoA gene copies, whereas in non-fertilized soils a significant relationship between soil nitrates and archaeal but not bacterial amoA copies was found. The application of OM fertilizer to soil maintained sufficient productivity and in turn increased N use efficiency and noticeably reduced N losses. Furthermore, in this experiment, ammonia-oxidizing bacteria drove nitrification when an N source was added to the soil, whereas ammonia-oxidizing archaea were responsible for ammonia oxidation in non-fertilized soil. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Factors affecting the fertility of ewes after intrauterine insemination with frozen-thawed semen during the non-breeding season.

PubMed

Fukui, Yutaka; Kohno, Hirohide; Okabe, Kentaro; Katsuki, Sara; Yoshizawa, Masahiro; Togari, Tetsuro; Watanabe, Hiroyuki

2010-08-01

In this study, two successive field trials were conducted during the non-breeding season to investigate various factors affecting on fertility of Suffolk ewes after intrauterine insemination with frozen-thawed semen. In the first year (Experiment 1), three sperm numbers per insemination dose (0.25, 0.5 and 1 million sperm) and five sheep farms were used, and in the second year (Experiment 2), parity, age, body weight, body condition score (BCS) and postpartum days were investigated to compare pregnancy and lambing rates. High pregnancy and lambing rates (70.6 and 70.6%, respectively) were obtained with 0.25 million sperm per dose. There were no significant differences in the pregnancy and lambing rates among the five farms, but there was a tendency for one farm to have higher pregnancy (75.8%, P=0.065) and lambing (72.7%, P=0.077) rates than those (46.7-53.3% and 45.2-53.3% for the pregnancy and lambing rates, respectively) of the other farms. In Experiment 2, ewe age significantly affected both the pregnancy and lambing rates. Nulliparous ewes had a higher lambing rate (72.0%) than that (44.2%) of multiparous ewes, but a significant difference was not revealed. Regardless of body weight, BCS tended to be an important factor influencing on fertility of ewes. Body weight and the postpartum days did not affect the fertility of ewes. It was concluded from these results that the fertility of Suffolk ewes after intrauterine insemination with frozen semen was significantly influenced by sperm number per dose and ewe age. Nulliparous ewes at less than three years of age and with a BCS of more than 3.0 are expected to have higher fertility than other ewes.

Racial, socioeconomic, and demographic disparities in access to fertility preservation in young women diagnosed with cancer.

PubMed

Letourneau, Joseph M; Smith, James F; Ebbel, Erin E; Craig, Amaranta; Katz, Patricia P; Cedars, Marcelle I; Rosen, Mitchell P

2012-09-15

This study seeks to examine the relation between sociodemographic characteristics and the utilization of fertility preservation services in reproductive age women diagnosed with cancer. A total of 1041 women diagnosed with cancer between the ages of 18 and 40 years responded to a retrospective survey on demographic information and reproductive health history. Five cancer types were included: leukemia, Hodgkin disease, non-Hodgkin lymphoma, breast cancer, and gastrointestinal cancer. Nine hundred eighteen women reported treatment with potential to affect fertility (chemotherapy, pelvic radiation, pelvic surgery, or bone marrow transplant). Student t test, linear regression, and multivariate logistic regression were used where appropriate to determine the relation between sociodemographic characteristics and the odds of using fertility preservation services. Sixty-one percent of women were counseled on the risk of cancer treatment to fertility by the oncology team. Overall, 4% of women pursued fertility preservation. In multivariate analysis, women who had not attained a bachelor's degree (odds ratio [OR], 0.7; 95% confidence interval [CI], 0.5-0.9) were less likely to be counseled. Trends also suggested possible disparities in access to fertility preservation with age older than 35 years (OR, 0.1; 95% CI, 0.0-1.4) or previous children (OR, 0.3; 95% CI, 0.1-1.1) at diagnosis. Disparities in access to fertility preservation based on ethnicity and sexual orientation were also observed. Sociodemographic health disparities likely affect access to fertility preservation services. Although awareness of fertility preservation has improved in the past decade, an unmet need remains for reproductive health counseling and fertility preservation in reproductive age women diagnosed with cancer. Copyright © 2012 American Cancer Society.

Does being overweight affect seminal variables in fertile men?

PubMed

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

2016-12-01

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

Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

PubMed Central

Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

2016-01-01

The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees.

PubMed

Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

2016-01-01

The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees.

Psychosocial Predictors of Life Quality: How Are They Affected by Infertility, Gender, and Parenthood?

ERIC Educational Resources Information Center

Abbey, Antonia; And Others

1994-01-01

Longitudinally examined effects of infertility on marital and global life quality with 174 infertile couples and 74 fertile couples. By third interview, 42% of infertile couples and 36% of fertile couples were parents. Psychosocial predictors of life quality were highly similar for members of infertile and fertile couples and for couples with and…

Poplar trees for phytoremediation of high levels of nitrate and applications in bioenergy.

PubMed

Castro-Rodríguez, Vanessa; García-Gutiérrez, Angel; Canales, Javier; Cañas, Rafael A; Kirby, Edward G; Avila, Concepción; Cánovas, Francisco M

2016-01-01

The utilization of high amounts of nitrate fertilizers for crop yield leads to nitrate pollution of ground and surface waters. In this study, we report the assimilation and utilization of nitrate luxuriant levels, 20 times more than the highest N fertilizer application in Europe, by transgenic poplars overexpressing a cytosolic glutamine synthetase (GS1). In comparison with the wild-type controls, transgenic plants grown under high N levels exhibited increased biomass (171.6%) and accumulated higher levels of proteins, chlorophylls and total sugars such as glucose, fructose and sucrose. These plants also exhibited greater nitrogen-use efficiency particularly in young leaves, suggesting that they are able to translocate most of the resources to the above-ground part of the plant to produce biomass. The transgenic poplar transcriptome was greatly affected in response to N availability with 1237 genes differentially regulated in high N, while only 632 genes were differentially expressed in untransformed plants. Many of these genes are essential in the adaptation and response against N excess and include those involved in photosynthesis, cell wall formation and phenylpropanoid biosynthesis. Cellulose production in the transgenic plants was fivefold higher than in control plants, indicating that transgenic poplars represent a potential feedstock for applications in bioenergy. In conclusion, our results show that GS transgenic poplars can be used not only for improving growth and biomass production but also as an important resource for potential phytoremediation of nitrate pollution. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Xenotransplantation as a model for human testicular development.

PubMed

Hutka, Marsida; Smith, Lee B; Mitchell, Rod T

The developing male reproductive system may be sensitive to disruption by a wide range of exogenous 'endocrine disruptors'. In-utero exposure to environmental chemicals and pharmaceuticals have been hypothesized to have an impact in the increasing incidence of male reproductive disorders. The vulnerability to adverse effects as a consequence of such exposures is elevated during a specific 'window of susceptibility' in fetal life referred to as the masculinisation programing window (MPW). Exposures that occur during prepuberty, such as chemotherapy treatment for cancer during childhood, may also affect future fertility. Much of our current knowledge about fetal and early postnatal human testicular development derives from studies conducted in animal models predictive for humans. Therefore, over recent years, testicular transplantation has been employed as a 'direct' approach to understand the development of human fetal and prepubertal testis in health and disease. In this review we describe the potential use of human testis xenotransplantation to study testicular development and its application for (i) assessing the effects of environmental exposures in humans, and (ii) establishing fertility preservation options for prepubertal boys with cancer. Copyright © 2017 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

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

PubMed

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

2012-06-28

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

The influence of granting npk fertilizer and nanosilic fertilizers on the growth of Ganyong plant (Canna edulis Ker.)

NASA Astrophysics Data System (ADS)

Barita, Yahya; Prihastanti, Erma; Haryanti, Sri; Subagio, Agus; Ngadiwiyana

2018-05-01

Ganyong is a herbaceous plant which included in the tuberous plant group. One of the ways to increase the growth of ganyong plants is by combining Nanosilica and NPK. Nanosilica is an fertilizer with nutrient contain nano size of silica. This research was conducted using Completely Randomized Design (CRD) and consisted of 6 treatments with 3 replication were control (without nanosil and NPK fertilizers); (combination 0% nanosilic and 100% NPK); (combination 25% nanosilic and 75% NPK); (50% nanosilic and 50% NPK); (75% nanosilic and 25% NPK) and (100% nanosilic and 0% NPK). Parameters of this research consisted stomata and growth rate: plant height, leaf quantity, leaf color, wet weight and dry weight. Analysis of Variance (Anova) were used to analyze the data, and if significant difference were found, the data tested further by Duncan Multiple Range Test (DMRT) at 95% significant level. The results showed that the combination of Nanosilica and NPK fertilizers affected plant height, dry weight and wet weight of the plant. The combination of 75% nanosil fertilizer and 25% optimal NPK fertilizer increased plant height, dry weight and wet weight on ganyong. The combination of nanosilic and NPK did not affected to amount stomata in ganyong.

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments.

PubMed

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-04-15

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability.

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments

PubMed Central

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-01-01

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability. PMID:27079657

Environmental and epigenetic effects upon preimplantation embryo metabolism and development

PubMed Central

Chason, Rebecca J; Csokmay, John; Segars, James H.; DeCherney, Alan H.; Armant, D. Randall

2011-01-01

In vitro fertilization has provided a unique window into the metabolic processes that drive embryonic growth and development from a fertilized ovum to a competent blastocyst. Post-fertilization development is dependent upon a dramatic reshuffling of the parental genomes during meiosis, as well as epigenetic changes that provide a new and autonomous set of instructions to guide cellular differentiation both in the embryo and beyond. While early literature focused simply on the substrates and culture conditions required for progress through embryonic development, more recent insights lead us to suggest that the surrounding environment can alter the epigenome, which can, in turn, impact embryonic metabolism and developmental competence. PMID:21741268

Sex and death: the effects of innate immune factors on the sexual reproduction of malaria parasites.

PubMed

Ramiro, Ricardo S; Alpedrinha, João; Carter, Lucy; Gardner, Andy; Reece, Sarah E

2011-03-01

Malaria parasites must undergo a round of sexual reproduction in the blood meal of a mosquito vector to be transmitted between hosts. Developing a transmission-blocking intervention to prevent parasites from mating is a major goal of biomedicine, but its effectiveness could be compromised if parasites can compensate by simply adjusting their sex allocation strategies. Recently, the application of evolutionary theory for sex allocation has been supported by experiments demonstrating that malaria parasites adjust their sex ratios in response to infection genetic diversity, precisely as predicted. Theory also predicts that parasites should adjust sex allocation in response to host immunity. Whilst data are supportive, the assumptions underlying this prediction - that host immune responses have differential effects on the mating ability of males and females - have not yet been tested. Here, we combine experimental work with theoretical models in order to investigate whether the development and fertility of male and female parasites is affected by innate immune factors and develop new theory to predict how parasites' sex allocation strategies should evolve in response to the observed effects. Specifically, we demonstrate that reactive nitrogen species impair gametogenesis of males only, but reduce the fertility of both male and female gametes. In contrast, tumour necrosis factor-α does not influence gametogenesis in either sex but impairs zygote development. Therefore, our experiments demonstrate that immune factors have complex effects on each sex, ranging from reducing the ability of gametocytes to develop into gametes, to affecting the viability of offspring. We incorporate these results into theory to predict how the evolutionary trajectories of parasite sex ratio strategies are shaped by sex differences in gamete production, fertility and offspring development. We show that medical interventions targeting offspring development are more likely to be 'evolution-proof' than interventions directed at killing males or females. Given the drive to develop medical interventions that interfere with parasite mating, our data and theoretical models have important implications.

Sex and Death: The Effects of Innate Immune Factors on the Sexual Reproduction of Malaria Parasites

PubMed Central

Ramiro, Ricardo S.; Alpedrinha, João; Carter, Lucy; Gardner, Andy; Reece, Sarah E.

2011-01-01

Malaria parasites must undergo a round of sexual reproduction in the blood meal of a mosquito vector to be transmitted between hosts. Developing a transmission-blocking intervention to prevent parasites from mating is a major goal of biomedicine, but its effectiveness could be compromised if parasites can compensate by simply adjusting their sex allocation strategies. Recently, the application of evolutionary theory for sex allocation has been supported by experiments demonstrating that malaria parasites adjust their sex ratios in response to infection genetic diversity, precisely as predicted. Theory also predicts that parasites should adjust sex allocation in response to host immunity. Whilst data are supportive, the assumptions underlying this prediction – that host immune responses have differential effects on the mating ability of males and females – have not yet been tested. Here, we combine experimental work with theoretical models in order to investigate whether the development and fertility of male and female parasites is affected by innate immune factors and develop new theory to predict how parasites' sex allocation strategies should evolve in response to the observed effects. Specifically, we demonstrate that reactive nitrogen species impair gametogenesis of males only, but reduce the fertility of both male and female gametes. In contrast, tumour necrosis factor-α does not influence gametogenesis in either sex but impairs zygote development. Therefore, our experiments demonstrate that immune factors have complex effects on each sex, ranging from reducing the ability of gametocytes to develop into gametes, to affecting the viability of offspring. We incorporate these results into theory to predict how the evolutionary trajectories of parasite sex ratio strategies are shaped by sex differences in gamete production, fertility and offspring development. We show that medical interventions targeting offspring development are more likely to be ‘evolution-proof’ than interventions directed at killing males or females. Given the drive to develop medical interventions that interfere with parasite mating, our data and theoretical models have important implications. PMID:21408620

Effects of nitrogen fertilization on the phenolic composition and antioxidant properties of basil (Ocimum basilicum L.).

PubMed

Nguyen, Phuong M; Niemeyer, Emily D

2008-09-24

Many herbs and spices have been shown to contain high levels of polyphenolic compounds with potent antioxidant properties. In the present study, we explore how nutrient availability, specifically nitrogen fertilization, affects the production of polyphenolic compounds in three cultivars (Dark Opal, Genovese, and Sweet Thai) of the culinary herb, basil ( Ocimum basilicum L.). Nitrogen fertilization was found to have a significant effect on total phenolic levels in Dark Opal ( p < 0.001) and Genovese ( p < 0.001) basil with statistically higher phenolic contents observed when nutrient availability was limited at the lowest (0.1 mM) applied nitrogen treatment. Similarly, basil treated at the lowest nitrogen fertilization level generally contained significantly higher rosmarinic ( p = 0.001) and caffeic ( p = 0.001) acid concentrations than basil treated at other nitrogen levels. Nitrogen fertilization also affected antioxidant activity ( p = 0.002) with basil treated at the highest applied nitrogen level, 5.0 mM, exhibiting lower antioxidant activity than all other nitrogen treatments. The anthocyanin content of Dark Opal basil was not affected by applied nitrogen level, but anthocyanin concentrations were significantly impacted by growing season ( p = 0.001). Basil cultivar was also determined to have a statistically significant effect on total phenolic levels, rosmarinic and caffeic acid concentrations, and antioxidant activities.

Pre-exposure prophylaxis does not affect the fertility of HIV-1-uninfected men.

PubMed

Were, Edwin O; Heffron, Renee; Mugo, Nelly R; Celum, Connie; Mujugira, Andrew; Bukusi, Elizabeth A; Baeten, Jared M

2014-08-24

There is a paucity of data on the effect of antiretroviral medications on male fertility. Couples affected by HIV-1 often have fertility intentions, and antiretroviral medications, as both treatment of HIV-1-infected persons and pre-exposure prophylaxis (PrEP) for uninfected persons, are part of peri-conception risk reduction. Within a randomized, placebo-controlled trial of daily oral tenofovir disoproxil fumarate (TDF) and combination emtricitabine (FTC)/TDF PrEP for HIV-1 prevention conducted among heterosexual HIV-1-serodiscordant couples, we assessed the impact of TDF and FTC/TDF use on male fertility, measured as incident pregnancy in female partners of men assigned to PrEP vs. placebo. Of the 2962 HIV-1-uninfected men partners, 986 were randomized to TDF, 1013 to FTC/TDF, and 963 to placebo. The overall pregnancy incidence in their HIV-1-infected female partners was 12.9 per 100 person-years and did not differ significantly across the study arms (13.2 TDF, 12.4 FTC/TDF, 13.2 placebo). The frequency of live births, pregnancy losses, and gestational age at birth or loss was also statistically similar in the three randomization groups. TDF and FTC/TDF, when used as PrEP by HIV-1-uninfected men, did not adversely affect male fertility or pregnancy outcomes.

Amino acid carryover in the subzonal space of mouse fertilized ova affects subsequent transport kinetics.

PubMed

Rudraraju, Nirmala; Baltz, Jay M

2009-11-01

SummaryWe have investigated whether culture in glycine-containing medium affects subsequent glycine transport by the specific transport system, GLYT1, which is the sole glycine transporter in fertilized mouse ova. When fertilized ova were maintained for 6 h in culture with a physiological level of glycine (1 mM), subsequent transport of radiolabelled glycine was decreased by 40% compared with fertilized ova that had been maintained in glycine-free medium. Kinetic measurements showed that the apparent glycine affinity was decreased after culture with glycine (Km increased from 0.20 to 0.41 mM), but maximal transport rate was unchanged (similar Vmax of 20 and 23 fmol/fertilized ovum/min). These findings could have reflected activation of GLYT1 by prolonged substrate starvation, similar to some other amino acid transport systems. However, our findings were instead consistent with the alteration in glycine transport being due to trapping of glycine within the zona pellucida resulting in competitive transport inhibition even after ova were removed from glycine-containing media. First, even very brief exposures to glycine resulted in decreased subsequent glycine transport rates, with a maximal effect apparent within ~6 min. Second, extensive washing (at least six) reversed the effect. Third, the effect was absent when zona-free fertilized ova were used. Thus, it appears that components of the external environment of preimplantation embryos may continue to affect transport kinetics for a period even after embryos are removed from environments that contain them.

A Genome-Wide RNAi Screen for Factors Involved in Neuronal Specification in Caenorhabditis elegans

PubMed Central

Cochella, Luisa; Flowers, Eileen B.; Hobert, Oliver

2011-01-01

One of the central goals of developmental neurobiology is to describe and understand the multi-tiered molecular events that control the progression of a fertilized egg to a terminally differentiated neuron. In the nematode Caenorhabditis elegans, the progression from egg to terminally differentiated neuron has been visually traced by lineage analysis. For example, the two gustatory neurons ASEL and ASER, a bilaterally symmetric neuron pair that is functionally lateralized, are generated from a fertilized egg through an invariant sequence of 11 cellular cleavages that occur stereotypically along specific cleavage planes. Molecular events that occur along this developmental pathway are only superficially understood. We take here an unbiased, genome-wide approach to identify genes that may act at any stage to ensure the correct differentiation of ASEL. Screening a genome-wide RNAi library that knocks-down 18,179 genes (94% of the genome), we identified 245 genes that affect the development of the ASEL neuron, such that the neuron is either not generated, its fate is converted to that of another cell, or cells from other lineage branches now adopt ASEL fate. We analyze in detail two factors that we identify from this screen: (1) the proneural gene hlh-14, which we find to be bilaterally expressed in the ASEL/R lineages despite their asymmetric lineage origins and which we find is required to generate neurons from several lineage branches including the ASE neurons, and (2) the COMPASS histone methyltransferase complex, which we find to be a critical embryonic inducer of ASEL/R asymmetry, acting upstream of the previously identified miRNA lsy-6. Our study represents the first comprehensive, genome-wide analysis of a single neuronal cell fate decision. The results of this analysis provide a starting point for future studies that will eventually lead to a more complete understanding of how individual neuronal cell types are generated from a single-cell embryo. PMID:21698137

Developmental exposure of zebrafish (Danio rerio) to 17α-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny.

PubMed

Volkova, Kristina; Reyhanian Caspillo, Nasim; Porseryd, Tove; Hallgren, Stefan; Dinnétz, Patrik; Porsch-Hällström, Inger

2015-07-01

Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and non-reproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17α-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6ng/L EE2. After remediation for 82days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 1.2 and 1.6ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects. Copyright © 2015. Published by Elsevier Inc.

Drug use among men with unfulfilled wish to father children: a retrospective analysis and discussion of specific drug classes.

PubMed

Pompe, Sina V; Strobach, Dorothea; Stief, Christian G; Becker, Armin J; Trottmann, Matthias

2016-06-01

Male infertility is a multifactorial state. Among other risk factors, drugs can adversely affect male fertility and male sexual function. In a retrospective study we aimed to analyse how many involuntarily childless men seeking fertility evaluation consume drugs, which drugs and if these are potentially affecting male reproductive function. We retrospectively identified involuntarily childless men presenting for fertility evaluation at an andrologic outpatient department from 2011 to 2014. Medical records were searched for current drug use, age, diseases affecting male fertility, and number and kind of drugs. Drugs were classified according to their Anatomical Therapeutic Chemical code. Adverse drug reactions on male sexual function and fertility were searched in two independent literature sources. Drug use was documented for 244 of 522 patients (46.7%). The patients' mean age was 37.7 ± 8.7; the total number of drug intakes was 554 (mean 2.3 ± 1.9), corresponding to 201 different drugs. The most often involved Anatomical Therapeutic Chemical groups were nervous system (N), alimentary tract/metabolism (A), cardiovascular (C), and respiratory system (R) (n = 277; 50.0%). Fertility impairment was reported for 15.9%, and adverse drug reactions on male sexual function were found for 51.2% of all identified drugs. Underreporting of consumed drugs was likely, especially for non-prescription drugs. A high percentage of involuntarily childless men is taking drugs that can potentially influence male reproductive function. As drug intake represents a modifiable risk factor, fertility evaluation requires a comprehensive medication review including prescription and non-prescription drugs. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The evolved psychological mechanisms of fertility motivation: hunting for causation in a sea of correlation

PubMed Central

McAllister, Lisa S.; Pepper, Gillian V.; Virgo, Sandra

2016-01-01

Cultural, ecological, familial and physiological factors consistently influence fertility behaviours, however, the proximate psychological mechanisms underlying fertility decisions in humans are poorly understood. Understanding the psychological mechanisms underlying human fertility may illuminate the final processes by which some of these known predictors have their influence. To date, research into the psychological mechanisms underlying fertility has been fragmented. Aspects of reproductive psychology have been examined by researchers in a range of fields, but the findings have not been systematically integrated in one review. We provide such a review, examining current theories and research on psychological mechanisms of fertility. We examine the methods and populations used in the research, as well as the disciplines and theoretical perspectives from which the work has come. Much of the work that has been done to date is methodologically limited to examining correlations between ecological, social and economic factors and fertility. We propose, and support with examples, the use of experimental methods to differentiate causal factors from correlates. We also discuss weaknesses in the experimental research, including limited work with non-WEIRD (western, educated, industrialized, rich and democratic) populations. PMID:27022078

How does obesity affect fertility in men - and what are the treatment options?

PubMed

Stokes, Victoria J; Anderson, Richard A; George, Jyothis T

2015-05-01

Adiposity is associated with reduced fertility in men. The aetiology is multifactorial, with obese men at greater risk of suffering from impaired spermatogenesis, reduced circulating testosterone levels, erectile dysfunction and poor libido. The diagnosis and treatment of reduced fertility observed in obese men therefore requires insight into the underlying pathology, which has hormonal, mechanical and psychosocial aspects. This article summarises the current epidemiological, experimental and clinical trial evidence from the perspective of a practicing clinician. The following conclusions and recommendations can be drawn: Obesity is associated with low serum testosterone concentrations, but treatment with exogenous testosterone is likely to adversely impact on fertility. It is important to discuss this with men prior to initiation of testosterone therapy. Obesity adversely affects sperm concentration and may affect sperm quality. However, whether or not weight loss will correct these factors remain to be established. Oestrogen receptor modulators (and aromatase inhibitors) are unlicensed in the treatment for male hypogonadism and/or infertility. These treatments should hence be considered experimental approach until ongoing clinical trials report their outcomes. © 2014 John Wiley & Sons Ltd.

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

USGS Publications Warehouse

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

2001-01-01

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

Intensive straw harvesting, fertilization, and fertilizer source affect nitrogen mineralization and soil labile carbon of a loblolly pine plantation

Treesearch

K. Ellum; H.O. Liechty; M.A. Blazier

2013-01-01

Straw harvesting can supplement traditional revenues generated by loblolly pine (Pinus taeda L.) plantation management. However, repeated raking may alter soil properties and nutrition. In northcentral Louisiana, a study was conducted to evaluate the long-term effects of intensive straw raking and fertilizer source (inorganic or organic) on nitrogen...

Pinus Taeda L. response to fertilization, Herbaceous plant control, and woody plant control

Treesearch

Allan E. Tiarks; James D. Haywood

1986-01-01

On an intensively prepared site, a complete fertilizer applied at planting, and control of herbaceous and woody plants for the first 4 years, increased Pinus taeda L. volume at age 5 to 25.9 m3/ha compared to 11.8 m3/ha without the treatments. The fertilizer and competition control factors affected pine...

Leachate Concentrations of Ammonium, Nitrate, and Phosphorus as Affected by Nutrient Release from Four Different Types of Controlled-Release Fertilizers and Crop Development of Containerized Waxleaf Privet.

USDA-ARS?s Scientific Manuscript database

Concentrations of ammonium, nitrate, and phosphorus in irrigation leachate were measured weekly over a 47-week period from a high-fertility, neutral-pH substrate into which four types of 12-month controlled-release fertilizers (Osmocote, Nutricote, Polyon, or Multicote) were incorporated. Containers...

Leachate Concentrations of Ammonium, Nitrate, and Phosphorus as Affected by Nutrient Release From Four Different Types of Controlled-Release Fertilizers and Crop Development of Containerized Azaleas

USDA-ARS?s Scientific Manuscript database

Concentrations of ammonium, nitrate, and phosphorus in irrigation leachate were measured weekly over a 47-week period from a low-fertility, acid-based substrate into which four types of 12-month controlled-release fertilizers (Osmocote, Nutricote, Polyon, or Multicote) were incorporated. Containers ...

A single nucleotide polymorphism in COQ9 affects mitochondrial and ovarian function and fertility in Holstein cows

USDA-ARS?s Scientific Manuscript database

A single missense mutation at position 159 of COQ9 (GàA) has been associated with genetic variation in fertility in Holstein cattle, with the A allele associated with higher fertility. COQ9 is involved in the synthesis of coenzyme COQ10, a component of the electron transport system of the mitochondr...

CO2 and fertility affect growth and reproduction but not susceptibility to aphids in field grown Solanum ptycanthum

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

Long, T.M.

1995-09-01

In general, C3 annual plants respond positively in terms of growth, reproduction and biomass accrued when grown under elevated levels of atmospheric carbon dioxide. However, most studies documenting this response have been conducted in growth chambers where plants can be reared under conditions free form environmental stressors such as nutrient and water constraints, UV exposure and damage from pests. During the 1993 fieldseason, I grew 200 individuals of Solanum ptycanthum in an array of 10 outdoor, open-topped CO2 enclosures (5 @ 700 ppm CO2) at the University of Michigan Biological Station in Pellston, MI. Half of the plants were grownmore » in a 50;50 mix of native C-horizon soil and topsoil (low fertility); the other half were grown in 100% topsoil (high-fertility). Plants were censused throughout the growing season for flower and fruit production, growth rate and degree of infestation of aphids. Fertility and CO2 both significantly affected production of flowers and fruits, but only fertility was significantly related to vegetative growth. Aphid infestation varied significantly among enclosures, but was not related to CO2 or fertility.« less

Dry period management and optimization of post-partum reproductive management in dairy cattle.

PubMed

Gumen, A; Keskin, A; Yilmazbas-Mecitoglu, G; Karakaya, E; Wiltbank, Mc

2011-09-01

Dry period and early post-partum management are decisive factors for fertility in lactating dairy cows. Previous studies have shown that decreased dry matter intake (DMI) and increased non-esterified fatty acids (NEFA) negatively affect fertility and subsequent milk production. The traditional dry period decreases DMI prior to parturition, resulting in a decrease in energy intake. A negative energy balance increases NEFA concentration, and increased NEFA may impair the immune system, especially by decreasing neutrophil function prior to parturition. Earlier studies have shown that post-partum health disorders, including retained placenta and metritis, were correlated with periparturient neutrophil function. In addition, decreased DMI is also linked to a reduced body condition score (BCS) in dairy cows. These events in the periparturient period negatively affect fertility. Some manipulation, such as shortening the dry period, may be a solution to increased DMI in the periparturient period, preventing post-partum disorders and subsequent fertility issues. This article aims to explain the effects of shortening the dry period on reproduction and early post-partum treatments to improve fertility. In addition, timed artificial insemination protocols will be discussed for use during the post-partum period to improve fertility in dairy cows. © 2011 Blackwell Verlag GmbH.

Proteomic analysis of human follicular fluid in poor ovarian responders during in vitro fertilization.

PubMed

Oh, Jae Won; Kim, Seul Ki; Cho, Kyung-Cho; Kim, Min-Sik; Suh, Chang Suk; Lee, Jung Ryeol; Kim, Kwang Pyo

2017-03-01

Poor ovarian response (POR) in controlled ovarian stimulation is often observed during in vitro fertilization and embryo transfer cycles and it is a major problem. A POR has been found to be related to several factors, including advanced age, high body mass index, and history of ovarian or pelvic surgery. However, it is difficult to predict POR, as there are no specific biomarkers known. In this study, we used quantitative proteomic analyses to investigate potential biomarkers that can predict poor response during in vitro fertilization based on follicular fluid samples. A total of 1079 proteins were identified using a high-resolution orbitrap mass spectrometer coupled online to a nanoflow-LC system. It is notable that 65 upregulated and 66 downregulated proteins were found to be functionally enriched in poor responders. We also validated these differentially expressed proteins using a triple-quadrupole mass spectrometer for quantification of targeted proteins. Of the differentially expressed proteins, three proteins (pregnancy zone protein, renin, and sushi repeat-containing protein SRPX) were regarded as statistically significant (p < 0.05). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Organic and Waste-Derived Fertilizers on Yield, Nitrogen and Glucosinolate Contents, and Sensory Quality of Broccoli (Brassica oleracea L. var. italica).

PubMed

Øvsthus, Ingunn; Breland, Tor Arvid; Hagen, Sidsel Fiskaa; Brandt, Kirsten; Wold, Anne-Berit; Bengtsson, Gunnar B; Seljåsen, Randi

2015-12-23

Organic vegetable production attempts to pursue multiple goals concerning influence on environment, production resources, and human health. In areas with limited availability of animal manure, there is a need for considering various off-farm nutrient resources for such production. Different organic and waste-derived fertilizer materials were used for broccoli production at two latitudes (58° and 67°) in Norway during two years. The fertilizer materials were applied at two rates of total N (80 and 170 kg ha(-1)) and compared with mineral fertilizer (170 kg ha(-1)) and no fertilizer. Broccoli yield was strongly influenced by fertilizer materials (algae meal < unfertilized control < sheep manure < extruded shrimp shell < anaerobically digested food waste < mineral fertilizer). Yield, but not glucosinolate content, was linearly correlated with estimated potentially plant-available N. However, extruded shrimp shell and mineral NPK fertilizer gave higher glucosinolate contents than sheep manure and no fertilizer. Sensory attributes were less affected by fertilizer material and plant-available N.

Analysis of the effectiveness of fertilizer subsidy policy and its effect on rice production in Karanganyar Regency

NASA Astrophysics Data System (ADS)

Mulyadiana, A. T.; Marwanti, S.; Rahayu, W.

2018-03-01

The research aims to know the factors which affecting rice production, and to know the effectiveness of fertilizer subsidy policy on rice production in Karanganyar Regency. The fertilizer subsidy policy was based on four indicators of fertilizer subsidy namely exact price, exact place, exact time, and exact quantity. Data was analyzed using descriptive quantitative and qualitative and multiple linear regression. The result of research showed that fertilizer subsidy policy in Karanganyar Regency evaluated from four indicators was not effective because the distribution of fertilizer subsidy to farmers still experience some mistakes. The result of regression analysis showed that production factors such as land area, use of urea fertilizer, use of NPK fertilizer, and effectiveness of fertilizer subsidy policy had positive correlation and significant influence on rice production, while labor utilization and use of seeds factors had no significant effect on rice production in Karanganyar Regency. This means that if the fertilizer subsidy policy is more effective, rice production is also increased.

Female labor force behavior and fertility in the United States.

PubMed

Lehrer, E; Nerlove, M

1986-01-01

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

Influence of negative energy balance on cyclicity and fertility in the high producing dairy cow.

PubMed

Wathes, D C; Fenwick, M; Cheng, Z; Bourne, N; Llewellyn, S; Morris, D G; Kenny, D; Murphy, J; Fitzpatrick, R

2007-09-01

The peripartum period is of critical importance to subsequent health and fertility. Most cows enter a state of negative energy balance (NEB) associated with many metabolic changes which have carry over effects on the resumption and normality of estrous cyclicity and the success of subsequent inseminations. A dataset on 500 lactations explored the relationships between metabolic traits measured before and after calving with fertility. Stepwise multiple regression analysis showed that longer calving to conception intervals were associated with altered profiles of IGF-I, urea and body condition score. These relationships between metabolic profiles and fertility differed between first lactation cows (which are still growing but produce less milk) and mature animals. Early postpartum the liver undergoes extensive biochemical and morphological modifications to adapt to NEB, the uterus is extensively remodeled and must clear bacterial infections, and the ovary must resume ovulatory cycles. RNA isolated from liver and uterine tissues harvested 2 weeks postpartum from cows in mild (MNEB) and severe (SNEB) energy balance was used to screen the Affymetrix 23K bovine microarray. In liver, SNEB resulted in differential expression of key genes involved in lipid catabolism, gluconeogenesis, and the synthesis and stability of IGF-I. This was accompanied by reduced systemic concentrations of IGF-I which is likely to impact on ovarian function and early embryo development. Within endometrium, cows in SNEB showed histological evidence for higher levels of inflammation and the microarray analysis identified groups of differentially expressed genes involved in tissue remodeling and immune response. This may delay uterine repair after calving, likely contributing to the observed reduction in fertility.

Toxicity of marine pollutants on the ascidian oocyte physiology: an electrophysiological approach.

PubMed

Gallo, Alessandra

2018-02-01

In marine animals with external fertilization, gametes are released into seawater where fertilization and embryo development occur. Consequently, pollutants introduced into the marine environment by human activities may affect gametes and embryos. These xenobiotics can alter cell physiology with consequent reduction of fertilization success. Here the adverse effects on the reproductive processes of the marine invertebrate Ciona intestinalis (ascidian) of different xenobiotics: lead, zinc, an organic tin compound and a phenylurea herbicide were evaluated. By using the electrophysiological technique of whole-cell voltage clamping, the effects of these compounds on the mature oocyte plasma membrane electrical properties and the electrical events of fertilization were tested by calculating the concentration that induced 50% normal larval formation (EC50). The results demonstrated that sodium currents in mature oocytes were reduced in a concentration-dependent manner by all tested xenobiotics, with the lowest EC50 value for lead. In contrast, fertilization current frequencies were differently affected by zinc and organic tin compound. Toxicity tests on gametes demonstrated that sperm fertilizing capability and fertilization oocyte competence were not altered by xenobiotics, whereas fertilization was inhibited in zinc solution and underwent a reduction in organic tin compound solution (EC50 value of 1.7 µM). Furthermore, fertilized oocytes resulted in a low percentage of normal larvae with an EC50 value of 0.90 µM. This study shows that reproductive processes of ascidians are highly sensitive to xenobiotics suggesting that they may be considered a reliable biomarker and that ascidians are suitable model organisms to assess marine environmental quality.

Nano-nutrition of chicken embryos. The effect of in ovo administration of diamond nanoparticles and L-glutamine on molecular responses in chicken embryo pectoral muscles.

PubMed

Grodzik, Marta; Sawosz, Filip; Sawosz, Ewa; Hotowy, Anna; Wierzbicki, Mateusz; Kutwin, Marta; Jaworski, Sławomir; Chwalibog, André

2013-11-20

It has been demonstrated that the content of certain amino acids in eggs is not sufficient to fully support embryonic development. One possibility to supply the embryo with extra nutrients and energy is in ovo administration of nutrients. Nanoparticles of diamond are highly biocompatible non-toxic carbonic structures, and we hypothesized that bio-complexes of diamond nanoparticles with L-glutamine may affect molecular responses in breast muscle. The objective of the investigation was to evaluate the effect of diamond nanoparticle (ND) and L-glutamine (Gln) on expression of growth and differentiation factors of chicken embryo pectoral muscles. ND, Gln, and Gln/ND solutions (50 mg/L) were injected into fertilized broiler chicken eggs at the beginning of embryogenesis. Muscle tissue was dissected at day 20 of incubation and analysed for gene expression of FGF2, VEGF-A, and MyoD1. ND and especially Gln/ND up-regulated expression of genes related to muscle cell proliferation (FGF2) and differentiation (MyoD1). Furthermore, the ratio between FGF2 and MyoD1 was highest in the Gln/ND group. At the end of embryogenesis, Gln/ND enhanced both proliferation and differentiation of pectoral muscle cells and differentiation dominated over proliferation. These preliminary results suggest that the bio-complex of glutamine and diamond nanoparticles may accelerate growth and maturation of muscle cells.

Quantum cascade laser photoacoustic detection of nitrous oxide released from soils for biofuel production

NASA Astrophysics Data System (ADS)

Couto, F. M.; Sthel, M. S.; Castro, M. P. P.; da Silva, M. G.; Rocha, M. V.; Tavares, J. R.; Veiga, C. F. M.; Vargas, H.

2014-12-01

In order to investigate the generation of greenhouse gases in sugarcane ethanol production chain, a comparative study of N2O emission in artificially fertilized soils and soils free from fertilizers was carried out. Photoacoustic spectroscopy using quantum cascade laser with an emission ranging from 7.71 to 7.88 µm and differential photoacoustic cell were applied to detect nitrous oxide (N2O), an important greenhouse gas emitted from soils cultivated with sugar cane. Owing to calibrate the experimental setup, an initial N2O concentration was diluted with pure nitrogen and detection limit of 50 ppbv was achieved. The proposed methodology was selective and sensitive enough to detect N2O from no fertilized and artificially fertilized soils. The measured N2O concentration ranged from ppmv to ppbv.

Transcriptome profile analysis of young floral buds of fertile and sterile plants from the self-pollinated offspring of the hybrid between novel restorer line NR1 and Nsa CMS line in Brassica napus

PubMed Central

2013-01-01

Background The fertile and sterile plants were derived from the self-pollinated offspring of the F1 hybrid between the novel restorer line NR1 and the Nsa CMS line in Brassica napus. To elucidate gene expression and regulation caused by the A and C subgenomes of B. napus, as well as the alien chromosome and cytoplasm from Sinapis arvensis during the development of young floral buds, we performed a genome-wide high-throughput transcriptomic sequencing for young floral buds of sterile and fertile plants. Results In this study, equal amounts of total RNAs taken from young floral buds of sterile and fertile plants were sequenced using the Illumina/Solexa platform. After filtered out low quality data, a total of 2,760,574 and 2,714,441 clean tags were remained in the two libraries, from which 242,163 (Ste) and 253,507 (Fer) distinct tags were obtained. All distinct sequencing tags were annotated using all possible CATG+17-nt sequences of the genome and transcriptome of Brassica rapa and those of Brassica oleracea as the reference sequences, respectively. In total, 3231 genes of B. rapa and 3371 genes of B. oleracea were detected with significant differential expression levels. GO and pathway-based analyses were performed to determine and further to understand the biological functions of those differentially expressed genes (DEGs). In addition, there were 1089 specially expressed unknown tags in Fer, which were neither mapped to B. oleracea nor to B. rapa, and these unique tags were presumed to arise basically from the added alien chromosome of S. arvensis. Fifteen genes were randomly selected and their expression levels were confirmed by quantitative RT-PCR, and fourteen of them showed consistent expression patterns with the digital gene expression (DGE) data. Conclusions A number of genes were differentially expressed between the young floral buds of sterile and fertile plants. Some of these genes may be candidates for future research on CMS in Nsa line, fertility restoration and improved agronomic traits in NR1 line. Further study of the unknown tags which were specifically expressed in Fer will help to explore desirable agronomic traits from wild species. PMID:23324545

Transcriptome profile analysis of young floral buds of fertile and sterile plants from the self-pollinated offspring of the hybrid between novel restorer line NR1 and Nsa CMS line in Brassica napus.

PubMed

Yan, Xiaohong; Dong, Caihua; Yu, Jingyin; Liu, Wanghui; Jiang, Chenghong; Liu, Jia; Hu, Qiong; Fang, Xiaoping; Wei, Wenhui

2013-01-16

The fertile and sterile plants were derived from the self-pollinated offspring of the F1 hybrid between the novel restorer line NR1 and the Nsa CMS line in Brassica napus. To elucidate gene expression and regulation caused by the A and C subgenomes of B. napus, as well as the alien chromosome and cytoplasm from Sinapis arvensis during the development of young floral buds, we performed a genome-wide high-throughput transcriptomic sequencing for young floral buds of sterile and fertile plants. In this study, equal amounts of total RNAs taken from young floral buds of sterile and fertile plants were sequenced using the Illumina/Solexa platform. After filtered out low quality data, a total of 2,760,574 and 2,714,441 clean tags were remained in the two libraries, from which 242,163 (Ste) and 253,507 (Fer) distinct tags were obtained. All distinct sequencing tags were annotated using all possible CATG+17-nt sequences of the genome and transcriptome of Brassica rapa and those of Brassica oleracea as the reference sequences, respectively. In total, 3231 genes of B. rapa and 3371 genes of B. oleracea were detected with significant differential expression levels. GO and pathway-based analyses were performed to determine and further to understand the biological functions of those differentially expressed genes (DEGs). In addition, there were 1089 specially expressed unknown tags in Fer, which were neither mapped to B. oleracea nor to B. rapa, and these unique tags were presumed to arise basically from the added alien chromosome of S. arvensis. Fifteen genes were randomly selected and their expression levels were confirmed by quantitative RT-PCR, and fourteen of them showed consistent expression patterns with the digital gene expression (DGE) data. A number of genes were differentially expressed between the young floral buds of sterile and fertile plants. Some of these genes may be candidates for future research on CMS in Nsa line, fertility restoration and improved agronomic traits in NR1 line. Further study of the unknown tags which were specifically expressed in Fer will help to explore desirable agronomic traits from wild species.

Occurrence of maternal and paternal spindles in unfertilized human oocytes: possible relationship to nucleation defects after silent fertilization.

PubMed

Van Blerkom, Jonathan; Davis, Patrick; Alexander, Samuel

2004-04-01

Experience with conventional clinical IVF indicates that a first cleavage can occur in the absence of detectable pronuclear formation (so-called silent fertilization). In these instances, the first division is often asymmetrical and delayed when compared with normally fertilized siblings. In this study, DNA configurations and spindle organization were examined by fluorescence microscopy in metaphase II human oocytes that remained unfertilized after conventional IVF and were considered likely candidates for silent fertilization. The results show comparatively high frequencies of penetration in the absence of detectable pronuclear evolution, and that both a maternal meiotic and a sperm-derived mitotic-like spindle can coexist in the same oocyte. Patterns of cell division and blastomere nucleation in silent fertilizations suggest the possibility that this division may involve uniparental chromosomal segregation in which maternal and paternal DNA is differentially partitioned into daughter blastomeres. This pattern of inheritance may generate certain types of ploidy and nucleation defects detected at the 2- to 4-cell stage.

Is Low Fertility Really a Problem? Population Aging, Dependency, and Consumption*

PubMed Central

2015-01-01

Longer lives and fertility far below the replacement level of 2.1 births per woman are leading to rapid population aging in many countries. Many observers are concerned that aging will adversely affect public finances and standards of living. Analysis of newly available National Transfer Accounts data for 40 countries shows that fertility well above replacement would typically be most beneficial for government budgets. However, fertility near replacement would be most beneficial for standards of living when the analysis includes the effects of age structure on families as well as governments. And fertility below replacement would maximize per capita consumption when the cost of providing capital for a growing labor force is taken into account. While low fertility will indeed challenge government programs and very low fertility undermines living standards, we find that moderately low fertility and population decline favor the broader material standard of living PMID:25301626

Molecular cloning of Foxl2 gene and the effects of endocrine-disrupting chemicals on its mRNA level in rare minnow, Gobiocypris rarus.

PubMed

Wang, Houpeng; Wu, Tingting; Qin, Fang; Wang, Lihong; Wang, Zaizhao

2012-06-01

Endocrine-disrupting chemicals (EDCs) can affect normal sexual differentiation in fish. Foxl2, one forkhead transcription factor, plays an important role in ovarian differentiation in the early development of the female gonad in mammals and fish. How EDCs affect Foxl2 expression is little known. In this study, we isolated a Foxl2 cDNA from the ovary of rare minnow Gobiocypris rarus and examined its expression during early development stages and in different adult tissues. Then, we analyzed Foxl2 expression in G. rarus juvenile following 3-day exposure to 17α- ethinylestradiol (EE2), 4-n-nonylphenol (NP), and bisphenol A (BPA). Alignment of known Foxl2 sequences among vertebrates showed high identity in forkhead domain and C-terminal region with other vertebrate proteins. Quantitative RT-PCR analysis showed that Foxl2 expression was linear decrease and cyp19a1a, the downstream target gene of Foxl2, had no correlation with Foxl2 from 18 to 50 days post fertilization (dpf). Among different adult tissues, Foxl2 is mainly expressed in ovary, brain, gill, eye, and male spleen. In the 3-day exposure, the juvenile fish to EDCs, 0.1 nM EE2, and 1 nM BPA significantly up-regulated the expression of Foxl2 gene, while NP had no effect on Foxl2 expression. Altogether, these results provide basic data for further study on how Foxl2 mediates EDCs impact on the sexual differentiation in G. rarus.

Diffusion Performance of Fertilizer Nutrient through Polymer Latex Film.

PubMed

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

2017-12-20

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

Effects of Nitrogen Fixing Pre-Crops and Fertilizers on Physical and Chemical Properties Down the Soil Profile

NASA Astrophysics Data System (ADS)

Hobley, E.; Honermeier, B.; Don, A.; Gocke, M. I.; Amelung, W.; Kogel-Knabner, I.

2016-12-01

We investigated the effects of pre-crops with and without biological nitrogen fixation capacity (fava beans, clover mulch, fodder maize) and fertilization (no fertilizer, NPK fertilizer, PK fertilizer) on soil physico-chemical properties (bulk density, electrical conductivity, soil organic carbon (SOC) concentration and stocks, N concentration and stocks) and their depth distribution (down to 1 m) at a long-term field experiment set up in 1982 in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the entire soil profile. The soil was physically and chemically affected by the type of pre-crop. Plots with fava beans and maize had lower bulk densities in the subsoil than those with clover. Pre-crop type also significantly affected the depth distribution of both N and SOC. Specifically, clover pre-cropping led to an enrichment of N at the surface compared with fava beans and maize. SOC enrichment at the surface was also observed under clover, with the effect most pronounced under PK fertilization. Combined with the bulk density effects, this shift in N distribution resulted in significantly higher N stocks under clover than under fava beans. However, the total stocks of SOC were not affected by pre-crop or fertilizer regime. Our results indicate that humans influence C and N cycling and distribution in soils through the selection of pre-crops and that the influence of crop type is greater than that of fertilization regimes. Pre-cropping with clover, which is used as a mulch, leads to N enrichment in the topsoil, reducing the need for N fertilizer for the subsequent cereal crop. In contrast, the use of fava beans as a pre-crop does not lead to N enrichment. We believe this is due to the greater rooting depth of fava beans compared with clover, resulting in lower bulk density in the subsoil and associated lower stocks. Additionally, the harvest of fava beans removes N-rich biomass from the soil, lowering N-input. Lastly, the uptake of water at depth may facilitate subsoil N uptake, so that fava bean N is utilized by the cereal crop but does not lead to its enrichment in the subsoil.

Dominant Douglas-fir respond to fertilizing and thinning in southwest Oregon

Treesearch

Richard E. Miller; Richard L. Williamson

1974-01-01

In 30-year-old, Site IV Douglas-fir in southwest Oregon, fertilizing increased average 4-year basal area growth of dominant trees by 57 and 28 percent on clay loam and sandy loam soils, respectively. Fertilizing with thinning increased growth by 94 and 132 percent over untreated growth. Thinning on clay loam soil increased growth by 53 percent. Treatment did not affect...

Economic and Fertility Differences between Legal and Illegal Migrant Mexican Families: The Potential Effects of Immigration Policy Changes.

ERIC Educational Resources Information Center

Falasco, Dee; Heer, David M.

How the fertility of currently undocumented migrants might be affected by amnesty was examined within the context of Economic Theory of Fertility. Data were collected in 1980-81 from a sample of births recorded in Los Angeles County in which the mother or father was reported to be of Mexican descent. Multiple regression analyses for male and…

The Effects of Ammonium Perchlorate on Reproduction and Development of Amphibians

DTIC Science & Technology

2008-01-01

Abstract: Ammonium perchlorate is a pervasive pollutant primarily from rocket fuel and fertilizers . It is know , among other things , to affect...females, their ovulated eggs collected, and in vitro fertilization conducted. Healthy ovulated eggs were selected and placed in Petri dishes...used and fertilization accomplished in vitro in the presence of perchlorate concentrations. *These tasks were not completed. Studies with Sodium

Ice damage effects on an old-field, thinned and fertilized loblolly pine stand in South Carolina

Treesearch

Bryan C. McElvany; Beth W. Richardson; E. David Dickens

2006-01-01

On January 26, 2004, an ice storm impacted 15 South Carolina counties. An established fertilization study area in Clarendon County, SC, was in the affected region. This old-field, thinned, loblolly pine (Pinus taeda L.) stand was fertilized in the spring of 1998. Treatments consisted of: (1) control; (2) poultry litter (7 tons acre-1); and (3)...

Fertility and the economy.

PubMed

Becker, G S

1992-08-01

Fertility and the economy is examined in the context of the Malthusian question about the links between family choices and longterm economic growth. Micro level differences are not included not are a comprehensive range of economic or determinant variables. Specific attention is paid to income and price effects, the quality of children, overlapping generations, mortality effects, uncertainty, and economic growth. Fertility and the demand for children in linked to parental incomes and the cost of rearing children, which is affected by public policies that change the costs. Demand is also related to child and adult mortality, and uncertainty about sex of the child. Fertility in one generation affects fertility in the next. Malthusian and neoclassical models do not capture the current model of modern economies with rising income/capita and human and physical capital, extensive involvement of married women in the labor force, and declining fertility to very low levels. In spite of the present advances in firm knowledge about the relationships between fertility and economic and social variables, there is still much greater ignorance of the interactions. The Malthusian utility function that says fertility rises and falls with income did hold up to 2 centuries of scrutiny, and the Malthusian inclusion of the shifting tastes in his analysis could be translated in the modern context to include price of children. The inclusion of net cost has significant consequences, i.e., rural fertility can be higher because the cost of rearing when children contribute work to maintaining the farm is lower than in the city. An income tax deduction for children in the US reduces cost. Economic growth raises the cost of children due the time spent on child care becoming more valuable. The modern context has changed from Malthusian time, and the cost of education, training, and medical care is relevant. The implication is that a rise in income could reduce the demand for children when education and training of children increases. Quality is substituted for quantity. The neoclassical model that "the capital-labor ratio and the degree of capital deepening" is affected by population growth is examined as well as the modern approach, and the implications are expressed, i.e., intergenerational transfers and parental altruism.

Effect of Increasing Nitrogen Deposition on Soil Microbial Communities

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

Xiao, Shengmu; Xue, Kai; He, Zhili

2010-05-17

Increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity are three main environmental changes occurring on a global scale. The BioCON (Biodiversity, CO2, and Nitrogen) ecological experiment site at the University of Minnesota's Cedar Creek Ecosystem Science Reserve started in 1997, to better understand how these changes would affect soil systems. To understand how increasing nitrogen deposition affects the microbial community diversity, heterogeneity, and functional structure impact soil microbial communities, 12 samples were collected from the BioCON plots in which nitrogenous fertilizer was added to simulate the effect of increasing nitrogen deposition and 12 samples from without added fertilizer. DNAmore » from the 24 samples was extracted using a freeze-grind protocol, amplified, labeled with a fluorescent dye, and then hybridized to GeoChip, a functional gene array containing probes for genes involved in N, S and C cycling, metal resistance and organic contaminant degradation. Detrended correspondence analysis (DCA) of all genes detected was performed to analyze microbial community patterns. The first two axes accounted for 23.5percent of the total variation. The samples fell into two major groups: fertilized and non-fertilized, suggesting that nitrogenous fertilizer had a significant impact on soil microbial community structure and diversity. The functional gene numbers detected in fertilized samples was less that detected in non-fertilizer samples. Functional genes involving in the N cycling were mainly discussed.« less

Securing Gender Equality through a Nexus of Energy Policy Performance and Relative Political Performance

NASA Astrophysics Data System (ADS)

Perkins-Ozuagiemhe, Andrea Christen

This dissertation presents what is believed to be the first empirical study that measures the effect of increasing access to modern household energy sources upon advancing gender equality within developing countries. As a powerful and fundamental public infrastructural socio-economic building block, improved access to modern energy in developing countries delivers the necessary economic ingredient of time as a major component of household production and consumption and captures the interdependence between market and household economies. Thus, because it has been empirically proven that men and women differ in their utilization of household energy with women spending more time engaged in non-market household labor than men, improving access to modern household energy in developing countries, especially in rural areas, theoretically would disproportionately affect women's lives. Essentially, the element of "time" not only extends the day for women to use towards more economically and educationally productive activities, but also lessens the burden of domestic chores from women with technological advancements in more time-efficient household appliances and cleaner modern energy sources. This dissertation introduces gender differentiation in a model in the form of a gender relative status composite measure comparing socio-economic achievements in secondary education, life expectancy, and labor force participation rates by varying degree of demographic transition, thereby, measuring the effect of improved access to modern household energy upon overall gender equality. Fixed effects panel regressions employing a Driscoll-Kraay non-parametric covariance matrix, and estimated and interpreted adjusted predictions and marginal effects of the two-way interaction between a country's available access to residential electric power (kWh per capita) and the level of relative political performance against predicted values of gender relative status are employed. The models confirm that, in fact, that women are not impacted equally by energy policy preferences as men and that women in developing countries benefit from increased access to modern household energy. Thus, gender-differentiated energy usage illustrates why treating population as a homogenous group fails to capture how energy policy preferences and energy policy performance can affect different subgroups of population in terms of individual choices and how those differences can affect an overall economic growth and development. Fundamental theoretical implications emerge from this dissertation's empirical findings. First, improving gender equality through technological advancements in household electricity facilitates the progress of demographic transition in terms of reducing fertility rates. Time altering effects of increased access and use of household electricity modify intra-household relations by diminishing differing roles between men and women. When women gain greater autonomy facilitated by increasing time via access to modern household electricity for more economically and educationally productive activities, fertility rates and child births tend to decrease by altering choice in family size with increased investments in children. The effect that the reduction in fertility generated by increased gender equality has upon demographic transition is that it alters the change in age structure in a developing country by decreasing youth dependency ratios generating the demographic dividend. Gender equality-generated fertility reductions may also facilitate the return to human capital by lessening the burden of non-SNA work and activities including reducing child care, increasing female labor force participation rates.

Fertility of the male alpaca: effect of daily consecutive breeding.

PubMed

Bravo, P W; Solis, P; Ordoñez, C; Alarcon, V

1997-04-01

The fertility of the male alpaca under different frequencies of daily consecutive matings was evaluated. Fifteen adult male Huacaya alpacas were divided randomly into three groups of five each to breed lactating female alpacas. The schedule of daily matings was two, four and six consecutive breeding per group and for nine consecutive days. Ovulation was determined by progesterone at seven days after breeding. Pregnancy was determined by ultrasonography at 15 and 30 days after breeding. Two hundred and eighty females were bred with some males not fulfilling their schedule of breeding. There were differences (P < 0.05) in the fertility rate of males breeding two and four times daily (76%) in contrast to 59% for males breeding six times. There were also differences (P < 0.05) in the fertility of individual males. Length of copulation was affected (P < 0.05) by schedule of matings, day of breeding and male. Ovulation was independent of length of copulation. Overall, it seems the fertility of the male alpaca is affected significantly when consecutive matings are over four times a day and for nine consecutive days.

The fertility and fecundity of patients with psychoses.

PubMed

McGrath, J J; Hearle, J; Jenner, L; Plant, K; Drummond, A; Barkla, J M

1999-06-01

Previous research has suggested that patients with schizophrenia have fewer offspring compared to the general population. Reduced fertility in a disorder with a strong genetic component and an apparently stable incidence has implications for models of genetic transmission. There is also a need to obtain contemporary estimates of the prevalence of parenthood among subjects with psychotic disorders in order to inform service planning. The aim of this study was to determine the fertility and fecundity of a representative sample of individuals with psychoses who were in contact with mental health services, and to explore the interactions between age at first diagnosis and fertility. All clients of two community mental health clinics and an extended-care psychiatric hospital were surveyed. Data on diagnosis, age at first diagnosis, and the number and age of offspring were collected. Based on interviews with the proband and chart review, a genogram of the probands' family was drawn that identified sex, age, affected status and the number of offspring for each patient and their siblings. In total, 36% of all patients were parents. Most women with psychoses (59%) were mothers. Patients with psychoses had fewer offspring compared to their unaffected same-sex siblings. This was especially the case for men with non-affective psychoses. Higher levels of fertility were associated with a later age at first diagnosis. The consistent finding of reduced 'reproductive fitness' in those with non-affective psychoses needs to be incorporated in the genetic epidemiology of these disorders. Despite this reduction in fertility and fecundity, many patients with psychoses are parents. Services need to remain mindful of the special needs of these patients.

Trivial role for NSMCE2 during in vitro proliferation and differentiation of male germline stem cells.

PubMed

Zheng, Yi; Jongejan, Aldo; Mulder, Callista L; Mastenbroek, Sebastiaan; Repping, Sjoerd; Wang, Yinghua; Li, Jinsong; Hamer, Geert

2017-09-01

Spermatogenesis, starting with spermatogonial differentiation, is characterized by ongoing and dramatic alterations in composition and function of chromatin. Failure to maintain proper chromatin dynamics during spermatogenesis may lead to mutations, chromosomal aberrations or aneuploidies. When transmitted to the offspring, these can cause infertility or congenital malformations. The structural maintenance of chromosomes (SMC) 5/6 protein complex has recently been described to function in chromatin modeling and genomic integrity maintenance during spermatogonial differentiation and meiosis. Among the subunits of the SMC5/6 complex, non-SMC element 2 (NSMCE2) is an important small ubiquitin-related modifier (SUMO) ligase. NSMCE2 has been reported to be essential for mouse development, prevention of cancer and aging in adult mice and topological stress relief in human somatic cells. By using in vitro cultured primary mouse spermatogonial stem cells (SSCs), referred to as male germline stem (GS) cells, we investigated the function of NSMCE2 during spermatogonial proliferation and differentiation. We first optimized a protocol to generate genetically modified GS cell lines using CRISPR-Cas9 and generated an Nsmce2 -/- GS cell line. Using this Nsmce2 -/- GS cell line, we found that NSMCE2 was dispensable for proliferation, differentiation and topological stress relief in mouse GS cells. Moreover, RNA sequencing analysis demonstrated that the transcriptome was only minimally affected by the absence of NSMCE2. Only differential expression of Sgsm1 appeared highly significant, but with SGSM1 protein levels being unaffected without NSMCE2. Hence, despite the essential roles of NSMCE2 in somatic cells, chromatin integrity maintenance seems differentially regulated in the germline. © 2017 Society for Reproduction and Fertility.

Nutrient losses from manure and fertilizer applications as impacted by time to first runoff event.

PubMed

Smith, D R; Owens, P R; Leytem, A B; Warnemuende, E A

2007-05-01

Nutrient losses to surface waters following fertilization contribute to eutrophication. This study was conducted to compare the impacts of fertilization with inorganic fertilizer, swine (Sus scrofa domesticus) manure or poultry (Gallus domesticus) litter on runoff water quality, and how the duration between application and the first runoff event affects resulting water quality. Fertilizers were applied at 35 kg P ha-1, and the duration between application and the first runoff event varied between 1 and 29 days. Swine manure was the greatest risk to water quality 1 day after fertilization due to elevated phosphorus (8.4 mg P L-1) and ammonium (10.3 mg NH4-N L-1) concentrations; however, this risk decreased rapidly. Phosphorus concentrations were 2.6 mg L-1 29 days after fertilization with inorganic fertilizer. This research demonstrates that manures might be more environmentally sustainable than inorganic fertilizers, provided runoff events do not occur soon after application.

The impact of labor-saving technology on first birth intervals in rural Ethiopia.

PubMed

Gibson, Mhairi; Mace, Ruth

2002-02-01

Across the developing world labor-saving technologies introduce considerable savings in the time and energy that women allocate to work. Hormonal studies on natural fertility populations indicate that such a reduction in energetic expenditure (rather than improved nutritional status alone) can lead to increased ovarian function. Other qualitative studies have highlighted a link between labor-saving technology and behavioral changes affecting subsequent age at marriage, which may affect fertility. This biodemographic study was designed to investigate whether these physiological and behavioral changes affect fertility at a population level by focusing on a recent water development scheme in Southern Ethiopia. The demographic consequences of a reduction in women's workload following the installation of water points, specifically the variation in length of first birth interval (time lapsed between marriage and first birth), are investigated. First birth interval length is closely associated with lifetime fertility in populations that do not practice contraception, longer intervals being associated with lower fertility. Using life tables and multivariate hazard modeling techniques a number of significant predictors of first birth interval length are identified. Covariates such as age at marriage, season of marriage, village ecology, and access to improved water supply have significant effects on variation in first birth intervals. When entered into models as a time-varying covariate, access to a water tap stand is associated with an immediate reduction in length of first birth intervals.

Fertility knowledge and intentions to have children in a national study of Australian secondary school students.

PubMed

Heywood, Wendy; Pitts, Marian K; Patrick, Kent; Mitchell, Anne

2016-10-01

This paper reports on fertility knowledge and intentions to have children among a national sample of students in years 10-12. Data were from the Fifth National Survey of Australian Secondary Students and Sexual Health. Students identified factors that could affect fertility, if they wanted children and at what age. Most students wanted to have children (77%). Of those who wanted children or were unsure (n=1,780), 54% were able to identify six of eight factors that could affect fertility. Male students had poorer knowledge than females. Poorer knowledge was also reported by male students who were born overseas or used marijuana and by female students who were sexually active or religious. More than half the students (59%) wanted their first child aged 25-29, while 19% wanted their first child after 30. Intentions to have children at an earlier age were associated with being religious, sexually active (females), and using marijuana (males). Students not exclusively attracted to the opposite sex were more likely to want children at an older age. Most students typically want children in their late 20s. Many were unaware of factors that could affect their fertility and there was a mismatch between intentions and likely behaviour. These factors could be addressed as part of relationship education. © 2016 Public Health Association of Australia.

[Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].

PubMed

Lu, Yan-yan; Wang, Ming-wei; Chen, Xiao-vun; Liu, Man-qiang; Chen, Xiao-min; Cheng, Yan-hong; Huang, Qian-ru; Hu, Feng

2016-01-01

The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment increased the proportion of fungivores especially in the drought period, suggesting the biochar was the preferred fungal energy channel in comparison to soil without biochar addition. In summary, complex patterns occurred not only due to the application rate of biochar as well as their interactions with N fertilization but also due to the drought and wet periods. It is, therefore, necessary to consider different ecological factors when evaluating the effects of biochar in future.

Repeated administrations of carbon nanotubes in male mice cause reversible testis damage without affecting fertility.

PubMed

Bai, Yuhong; Zhang, Yi; Zhang, Jingping; Mu, Qingxin; Zhang, Weidong; Butch, Elizabeth R; Snyder, Scott E; Yan, Bing

2010-09-01

Soluble carbon nanotubes show promise as materials for in vivo delivery and imaging applications. Several reports have described the in vivo toxicity of carbon nanotubes, but their effects on male reproduction have not been examined. Here, we show that repeated intravenous injections of water-soluble multiwalled carbon nanotubes into male mice can cause reversible testis damage without affecting fertility. Nanotubes accumulated in the testes, generated oxidative stress and decreased the thickness of the seminiferous epithelium in the testis at day 15, but the damage was repaired at 60 and 90 days. The quantity, quality and integrity of the sperm and the levels of three major sex hormones were not significantly affected throughout the 90-day period. The fertility of treated male mice was unaffected; the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those that mated with untreated male mice.

Repeated administrations of carbon nanotubes in male mice cause reversible testis damage without affecting fertility

NASA Astrophysics Data System (ADS)

Bai, Yuhong; Zhang, Yi; Zhang, Jingping; Mu, Qingxin; Zhang, Weidong; Butch, Elizabeth R.; Snyder, Scott E.; Yan, Bing

2010-09-01

Soluble carbon nanotubes show promise as materials for in vivo delivery and imaging applications. Several reports have described the in vivo toxicity of carbon nanotubes, but their effects on male reproduction have not been examined. Here, we show that repeated intravenous injections of water-soluble multiwalled carbon nanotubes into male mice can cause reversible testis damage without affecting fertility. Nanotubes accumulated in the testes, generated oxidative stress and decreased the thickness of the seminiferous epithelium in the testis at day 15, but the damage was repaired at 60 and 90 days. The quantity, quality and integrity of the sperm and the levels of three major sex hormones were not significantly affected throughout the 90-day period. The fertility of treated male mice was unaffected; the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those that mated with untreated male mice.

Fertility is reduced in women and in men with type 1 diabetes: results from the Type 1 Diabetes Genetics Consortium (T1DGC).

PubMed

Wiebe, Julia C; Santana, Angelo; Medina-Rodríguez, Nathan; Hernández, Marta; Nóvoa, Javier; Mauricio, Dídac; Wägner, Ana M

2014-12-01

A recent Finnish study described reduced fertility in patients with childhood-onset type 1 diabetes. The Type 1 Diabetes Genetics Consortium (T1DGC) is an international programme studying the genetics and pathogenesis of type 1 diabetes that includes families with the disease. Our aim was to assess fertility, defined as number of offspring, in the affected and unaffected siblings included in the T1DGC. Clinical information from participants aged ≥18 years at the time of examination was included in the present analysis. The number of offspring of affected and unaffected siblings was compared (in families including both) and the influence of birth year, disease duration and age of onset was assessed, the last in affected siblings only, using Poisson regression models. A total of 3010 affected and 801 unaffected adult siblings that belonged to 1761 families were assessed. The mean number of offspring was higher in the unaffected than in the affected individuals, and the difference between the two groups was more pronounced in women than men. Poisson regression analysis showed that both sex and birth cohort significantly affected the differences between groups. In the affected siblings, adult onset (≥18 years), female sex and older birth cohort were associated with higher fertility. Patients with type 1 diabetes have fewer children than their unaffected siblings. This effect is more evident in women and in older birth cohorts. Onset of type 1 diabetes as an adult rather than a child is associated with a higher number of offspring, even after accounting for birth cohort and disease duration.

Sex-specific inhibition and stimulation of worker-reproductive transition in a termite.

PubMed

Sun, Qian; Haynes, Kenneth F; Hampton, Jordan D; Zhou, Xuguo

2017-09-06

In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.

Sex-specific inhibition and stimulation of worker-reproductive transition in a termite

NASA Astrophysics Data System (ADS)

Sun, Qian; Haynes, Kenneth F.; Hampton, Jordan D.; Zhou, Xuguo

2017-10-01

In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.

In ovo exposure to o,p -DDE affects sexual development but not sexual differentiation in Japanese medaka (Oryzias latipes).

USGS Publications Warehouse

Papoulias, D.M.; Villalobos, Sergio A.; Meadows, J.; Noltie, Douglas B.; Giesy, J.P.; Tillitt, D.E.

2003-01-01

Despite being banned in many countries, dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) continue to be found in fish tissues at concentrations of concern. Like o,p -DDT, o,p -DDE is estrogenic and is believed to exert its effects through binding to the estrogen receptor. The limited toxicologic data for o,p -DDE suggest that it decreases fecundity and fertility of fishes. We conducted an egg injection study using the d-rR strain of medaka and environmentally relevant concentrations of o,p -DDE to examine its effects on sexual differentiation and development. The gonads of exposed fish showed no evidence of sex reversal or intersex. However, other gonad abnormalities occurred in exposed individuals. Females exhibited few vitellogenic oocytes and increased atresia. Male testes appeared morphologically normal but were very small. Gonadosomatic index values for both sexes were lower for exposed fish. Our observations of abnormal female and very small male gonads after in ovo o,p -DDE exposure may be indicative of effects on early endocrine processes important for normal ovarian and testicular development.

Fertility information needs and concerns post-treatment contribute to lowered quality of life among young adult female cancer survivors.

PubMed

Benedict, Catherine; Thom, Bridgette; Friedman, Danielle N; Pottenger, Elaine; Raghunathan, Nirupa; Kelvin, Joanne F

2018-07-01

Cancer treatment may lead to premature menopause and infertility. Young adult female cancer survivors (YAFCS) are often concerned about their fertility and future family-building options, but research is limited on how concerns may affect more general quality of life (QOL) domains. This study examined how fertility factors relate to QOL among YAFCS who received gonadotoxic therapy. A national sample of YAFCS completed an online, anonymous survey. The survey included investigator-designed questions about perceived fertility information needs (five items; Cronbach's α = .83) and general QOL (four items; α = .89), the Reproductive Concerns after Cancer Scale (RCACS) and Decisional Conflict Scale (DCS). Analyses included Pearson's correlation, t tests, and stepwise regression. Participants (N = 314) were an average of 30 years old (SD = 4.1) and 5 years (SD = 5.4) post-treatment; 31% reported being infertile and 19% had undergone fertility preservation (FP). Overall, QOL was relatively high (M = 7.3, SD = 1.9, range 0-10) and did not vary by fertility status (t[272] = .743, p = .46), prior FP (t[273] = .53, p = .55) or sociodemographic/clinical factors (p's > .05) except socioeconomic indicators (p's < .05).In separate models, greater unmet fertility information needs (β = - .19, p = .004) and, among fertile women, greater reproductive concerns (β = - .26, p = .001) related to lower QOL. Among fertile women without prior FP, greater decisional distress about future FP related to lower QOL (β = - .19, p = .03). These preliminary findings suggest that unaddressed fertility information needs, concerns, and decision distress may affect general QOL among post-treatment YAFCS who hope to have children in the future. Future work should identify ways to optimally incorporate fertility counseling and support resources into survivorship care programs, including referrals to reproductive specialists as appropriate.

International Fertility Change: New Data and Insights from the Developmental Idealism Framework

PubMed Central

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

2012-01-01

Many scholars have offered structural and ideational explanations for the fertility changes occurring around the world. This paper focuses on the influence of developmental idealism—a schema or set of beliefs endorsing development, fertility change, and causal connections between development and fertility. Developmental idealism is argued to be an important force affecting both population policy and the fertility behavior of ordinary people. We present new survey data from ordinary people in six countries—Argentina, China, Egypt, Iran, Nepal, and the United States—about the extent to which developmental idealism is known and believed. We ask individuals if they believe that fertility and development are correlated, that development is a causal force in changing fertility levels, and that fertility declines enhance the standard of living and intergenerational relations. We also ask people about their expectations concerning future trends in fertility in their countries and whether they approve or disapprove of the trends they expect. The data show widespread linkage in the minds of ordinary people between fertility and development. Large fractions of people in these six settings believe that fertility and development are correlated, that development reduces fertility, and that fertility declines foster development. Many also expect and endorse future declines in fertility. PMID:22403035

Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by use of Nitrogen, Oxygen, and Boron Isotopic Tracers

NASA Astrophysics Data System (ADS)

Lockhart, K.; Harter, T.; Grote, M.; Young, M. B.; Eppich, G.; Deinhart, A.; Wimpenny, J.; Yin, Q. Z.

2014-12-01

Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide, an example of which is the San Joaquin Valley, California. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are the major sources of nitrate in groundwater in the San Joaquin Valley, however, septic waste can be a major source in some areas. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Consumption of water containing nitrate above the drinking water limit has been linked to major health effects including low blood oxygen in infants and certain cancers. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Nitrogen, oxygen, and boron isotopes can be used as tracers to differentiate between the three main nitrate sources. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. Bayesian statistics used in conjunction with mixing models can incorporate variability in the source signature. We developed a Bayesian mixing model on a pilot network of 32 private domestic wells in the San Joaquin Valley for which nitrate as well as nitrogen, oxygen, and boron isotopes were measured. Probability distributions for nitrogen, oxygen, and boron isotope source signatures for manure, fertilizer, and septic waste were compiled from the literature and from a previous groundwater monitoring project on several dairies in the San Joaquin Valley. Median percent contribution of nitrate to wells from fertilizer, manure, and septic waste generally match the expected source based on land use patterns, with some exceptions.

Fungal community profiles in agricultural soils of a long-term field trial under different tillage, fertilization and crop rotation conditions analyzed by high-throughput ITS-amplicon sequencing

PubMed Central

Geistlinger, Joerg; Wibberg, Daniel; Deubel, Annette; Zwanzig, Jessica; Babin, Doreen; Schlüter, Andreas; Schellenberg, Ingo

2018-01-01

Fungal communities in agricultural soils are assumed to be affected by soil and crop management. Our intention was to investigate the impact of different tillage and fertilization practices on fungal communities in a long-term crop rotation field trial established in 1992 in Central Germany. Two winter wheat fields in replicated strip-tillage design, comprising conventional vs. conservation tillage, intensive vs. extensive fertilization and different pre-crops (maize vs. rapeseed) were analyzed by a metabarcoding approach applying Illumina paired-end sequencing of amplicons generated by two recently developed primer pairs targeting the two fungal Internal Transcribed Spacer regions (ITS1, ITS2). Analysis of 5.1 million high-quality sequence reads uncovered a diverse fungal community in the two fields, composed of 296 fungal genera including 3,398 Operational Taxonomic Units (OTUs) at the 97% sequence similarity threshold. Both primer pairs detected the same fungal phyla (Basidio-, Asco-, Zygo-, Glomero- and Chytridiomycota), but in different relative abundances. OTU richness was higher in the ITS1 dataset, while ITS2 data were more diverse and of higher evenness. Effects of farming practice on fungal community structures were revealed. Almost two-thirds of the fungal genera were represented in all different soil treatments, whereas the remaining genera clearly responded to farming practice. Principal Component Analysis revealed four distinct clusters according to tillage practice and pre-crop. Analysis of Variance (ANOVA) substantiated the results and proved significant influences of tillage and pre-crop, while fertilization had the smallest and non-significant effect. In-depth analysis of putative phytopathogenic and plant beneficial fungal groups indicated distinct responses; for example Fusarium was significantly enriched in the intensively fertilized conservation tillage variants with the pre-crop maize, while Phoma displayed significant association with conventional tillage and pre-crop rapeseed. Many putative plant beneficial fungi also reacted differentially to farming practice with the most distinct responders identified among the Glomeromycota (arbuscular mycorrhizal fungi, AMF). PMID:29621291

Effect of in ovo administration of an adult-derived microbiota on establishment of the intestinal microbiome in chickens.

PubMed

Pedroso, Adriana A; Batal, Amy B; Lee, Margie D

2016-05-01

OBJECTIVE To determine effects of in ovo administration of a probiotic on development of the intestinal microbiota of 2 genetic lineages (modern and heritage) of chickens. SAMPLE 10 newly hatched chicks and 40 fertile eggs to determine intestinal microbiota at hatch, 900 fertile eggs to determine effects of probiotic on hatchability, and 1,560 chicks from treated or control eggs. PROCEDURES A probiotic competitive-exclusion product derived from adult microbiota was administered in ovo to fertile eggs of both genetic lineages. Cecal contents and tissues were collected from embryos, newly hatched chicks, and chicks. A PCR assay was used to detect bacteria present within the cecum of newly hatched chicks. Fluorescence in situ hybridization and vitality staining were used to detect viable bacteria within intestines of embryos. The intestinal microbiota was assessed by use of 16S pyrosequencing. RESULTS Microscopic evaluation of embryonic cecal contents and tissues subjected to differential staining techniques revealed viable bacteria in low numbers. Development of the intestinal microbiota of broiler chicks of both genetic lineages was enhanced by in ovo administration of adult microbiota. Although the treatment increased diversity and affected composition of the microbiota of chicks, most bacterial species present in the probiotic were transient colonizers. However, the treatment decreased the abundance of undesirable bacterial species within heritage lineage chicks. CONCLUSIONS AND CLINICAL RELEVANCE In ovo inoculation of a probiotic competitive-exclusion product derived from adult microbiota may be a viable method of managing development of the microbiota and reducing the prevalence of pathogenic bacteria in chickens.

Abnormal development of floral meristem triggers defective morphogenesis of generative system in transgenic tomatoes.

PubMed

Chaban, Inna; Khaliluev, Marat; Baranova, Ekaterina; Kononenko, Neonila; Dolgov, Sergey; Smirnova, Elena

2018-04-21

Parthenocarpy and fruit malformations are common among independent transgenic tomato lines, expressing genes encoding different pathogenesis-related (PR) protein and antimicrobal peptides. Abnormal phenotype developed independently of the expression and type of target genes, but distinctive features during flower and fruit development were detected in each transgenic line. We analyzed the morphology, anatomy, and cytoembryology of abnormal flowers and fruits from these transgenic tomato lines and compared them with flowers and fruits of wild tomatoes, line YaLF used for transformation, and transgenic plants with normal phenotype. We confirmed that the main cause of abnormal flower and fruit development was the alterations of determinate growth of generative meristem. These alterations triggered different types of anomalous growth, affecting the number of growing ectopic shoots and formation of new flowers. Investigation of the ovule ontogenesis did not show anomalies in embryo sac development, but fertilization did not occur and embryo sac degenerated. Nevertheless, the ovule continued to differentiate due to proliferation of endothelium cells. The latter substituted embryo sac and formed pseudoembryonic tissue. This process imitated embryogenesis and stimulated ovary growth, leading to the development of parthenocarpic fruit. We demonstrated that failed fertilization occurred due to defective male gametophyte formation, which was manifested in blocked division of the nucleus in the microspore and arrest of vegetative and generative cell formation. Maturing pollen grains were overgrown microspores, not competent for fertilization but capable to induce proliferation of endothelium and development of parthenocarpic ovary. Thus, our study provided new data on the structural transformations of reproductive organs during development of parthenocarpic fruits in transgenic tomato.

Factors affecting the toxicity of trace metals to fertilization success in broadcast spawning marine invertebrates: A review.

PubMed

Hudspith, M; Reichelt-Brushett, Amanda; Harrison, Peter L

2017-03-01

Significant amounts of trace metals have been released into both nearshore and deep sea environments in recent years, resulting in increased concentrations that can be toxic to marine organisms. Trace metals can negatively affect external fertilization processes in marine broadcast spawners and may cause a reduction in fertilization success at elevated concentrations. Due to its sensitivity and ecological importance, fertilization success has been widely used as a toxicity endpoint in ecotoxicological testing, which is an important method of evaluating the toxicity of contaminants for management planning. Ecotoxicological data regarding fertilization success are available across the major marine phyla, but there remain uncertainties that impair our ability to confidently interpret and analyse these data. At present, the cellular and biochemical events underlying trace metal toxicity in external fertilization are not known. Metal behavior and speciation play an important role in bioavailability and toxicity but are often overlooked, and disparities in experimental designs between studies limit the degree to which results can be synthesised and compared to those of other relevant species. We reviewed all available literature covering cellular toxicity mechanisms, metal toxicities and speciation, and differences in methodologies between studies. We conclude that the concept of metal toxicity should be approached in a more holistic manner that involves elucidating toxicity mechanisms, improving the understanding of metal behavior and speciation on bioavailability and toxicity, and standardizing the fertilization assay methods among different groups of organisms. We identify opportunities to improve the fertilization assay that will allow robust critical and comparative analysis between species and their sensitivities to trace metals during external fertilization, and enable data to be more readily extrapolated to field conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Fertility awareness among medical and non-medical students: a case-control study.

PubMed

Nouri, Kazem; Huber, Dagmar; Walch, Katharina; Promberger, Regina; Buerkle, Bernd; Ott, Johannes; Tempfer, Clemens B

2014-09-26

To compare the understanding and perceptions of fertility issues among medical and non-medical University students. In a prospective case-control study, using a 43 item questionnaire with 5 sections and 43 questions regarding personal data (8 questions), lifestyle factors (9 questions), plans on having children (5 questions), age and fertility (5 questions), and lifestyle and fertility (16 questions), knowledge of fertility and influencing factors, desired age at commencement and completion of childbearing, among male and female medical and non-medical students in their first academic year at Vienna University, Vienna, Austria were evaluated. 340 students were included. 262/340 (77%) participants planned to have children in the future. Medical students (n = 170) planned to have fewer and later children and had a higher awareness of the impact of age on fertility than non-medical students (n = 170; estimated knowledge probability 0.55 [medical students] vs. 0.47 [non-medical students]; F (1, 336) = 5.18 and p = .024 (η p = .015). Gender did not independently affect estimated knowledge probability (F (1, 336) = 1.50 and p = .221). More female and male medical students had a positive attitude towards Assisted Reproductive Technology in case of infertility than non-medical students (47 and 55% vs. 23 and 29%, respectively; p = <.001). Medical students had a healthier lifestyle than non-medical students. A healthy lifestyle and female gender were associated with higher fertility awareness. Medical students have a higher awareness of fertility issues than non-medical students. Choice of academic study, gender, and personal life style are important factors affecting fertility awareness. These data may be helpful to address knowledge gaps among young non-medical Academics.

Understanding N timing in corn yield and fertilizer N recovery: An insight from an isotopic labeled-N determination

PubMed Central

de Almeida, Rodrigo Estevam Munhoz; Pierozan Junior, Clovis; Lago, Bruno Cocco; Trivelin, Paulo Cesar Ocheuze

2018-01-01

Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications. PMID:29462178

Fertilizer application timing influences greenhouse gas fluxes over a growing season.

PubMed

Phillips, Rebecca L; Tanaka, Donald L; Archer, David W; Hanson, Jon D

2009-01-01

Microbial production and consumption of greenhouse gases (GHG) is influenced by temperature and nutrients, especially during the first few weeks after agricultural fertilization. The effect of fertilization on GHG fluxes should occur during and shortly after application, yet data indicating how application timing affects both GHG fluxes and crop yields during a growing season are lacking. We designed a replicated (n = 5) field experiment to test for the short-term effect of fertilizer application timing on fluxes of methane (CH(4)), carbon dioxide (CO(2)), and nitrous oxide (N(2)O) over a growing season in the northern Great Plains. Each 0.30-ha plot was planted to maize (Zea mays L.) and treated similarly with the exception of fertilizer timing: five plots were fertilized with urea in early spring (1 April) and five plots were fertilized with urea in late spring (13 May). We hypothesized time-integrated fluxes over a growing season would be greater for the late-spring treatment, resulting in a greater net GHG flux, as compared to the early-spring treatment. Data collected on 59 dates and integrated over a 5-mo time course indicated CO(2) fluxes were greater (P < 0.0001) and CH(4) fluxes were lower (P < 0.05) for soils fertilized in late spring. Net GHG flux was also significantly affected by treatment, with 0.84 +/- 0.11 kg CO(2) equivalents m(-2) for early spring and 1.04 +/- 0.13 kg CO(2) equivalents m(-2) for late spring. Nitrous oxide fluxes, however, were similar for both treatments. Results indicate fertilizer application timing influences net GHG emissions in dryland cropping systems.

Thyroid dysfunction and thyroid autoimmunity in euthyroid women in achieving fertility.

PubMed

Medenica, S; Nedeljkovic, O; Radojevic, N; Stojkovic, M; Trbojevic, B; Pajovic, B

2015-01-01

Thyroid disease is the second most common endocrine condition in women of childbearing age. Thyroid hormones are involved in control of menstrual cycle and in achieving fertility affecting the actions of follicle-stimulating hormone and luteinizing hormone on steroid biosynthesis by specific triiodothyronine sites on oocytes; therefore, affect all aspects of reproduction. It remains controversial if pregnant women should be screened for thyroid dysfunction. Purpose of this review was to examine recent studies on the assessment of thyroid dysfunction in pregnancy, its treatment and newly perspective of thyroid autoimmunity in pregnant euthyroid women in achieving fertility. An electronic search was conducted using the internet medical databases: Medline/PubMed, EMBASE, EBSCO, and the Cochrane library. Thyroid gland faces great challenge in pregnancy when many hormonal changes occur. Precondition for normal follicular development and ovulation is pulsate gonadothropin realizing hormone secretion. Thyroid dysfunction in pregnancy is classified as forms of hypothyroidism (positivity of thyroid autoantibody, isolated hypothyroidism, and subclinical or overt hypothyroidism), hyperthyroidism, and autoimmune disease, but also thyroid nodules and cancer, iodine insufficiency and postpartum thyroiditis. These conditions can cause adverse effects on mother and fetus including pregnancy loss, gestational hypertension, or pre-eclampsia, pre-term delivery, low birth weight, placental abruption and postpartum hemorrhage. There is an evidence that thyroid autoimmunity, in thyroid dysfunction adversely affects conception and pregnancy outcomes, but it is unclear what impact has isolated eumetabolic thyroid autoimmunity in achieving fertility, especially in women undergoing in vitro fertilization. Treatment of euthyroid pregnant women with positive thyroid peroxides antibodies is still controverse, but not few studies show that levothyroxine substitution is able to lower the chance of miscarriage and premature delivery. Further randomized trials are needed to expand our knowledge of physiologic changes in thyroid function during the pregnancy and to reveal mechanisms by which thyroid autoimmunity in euthyroid women affect fertility, especially the success of assisted reproductive technology in achieving the same and validity of levothyroxine administration in thyroid autoimmunity positive women.

Sea urchin fertilization in a warm, acidified and high pCO2 ocean across a range of sperm densities.

PubMed

Byrne, Maria; Soars, Natalie; Selvakumaraswamy, Paulina; Dworjanyn, Symon A; Davis, Andrew R

2010-05-01

Marine invertebrate gametes are being spawned into an ocean simultaneously warming, acidifying and increasing in pCO(2). Decreased pH/increased pCO(2) narcotizes sperm indicating that acidification may impair fertilization, exacerbating problems of sperm limitation, with dire implications for marine life. In contrast, increased temperature may have a stimulatory effect, enhancing fertilization. We investigated effects of ocean change on sea urchin fertilization across a range of sperm densities. We address two predictions: (1) low pH/increased pCO(2) reduces fertilization at low sperm density and (2) increased temperature enhances fertilization, buffering negative effects of acidification and increased pCO(2). Neither prediction was supported. Fertilization was only affected by sperm density. Increased acidification and pCO(2) did not reduce fertilization even at low sperm density and increased temperature did not enhance fertilization. It is important to identify where vulnerabilities lie across life histories and our results indicate that sea urchin fertilization is robust to climate change stressors. However, developmental stages may be vulnerable to ocean change. Copyright 2009 Elsevier Ltd. All rights reserved.

Six-year growth of Eucalyptus saligna plantings as affected by nitrogen and phosphorous fertilizer

Treesearch

Craig D. Whitesell; Dean S. DeBell; Thomas H. Schubert

1987-01-01

Growth responses of Eucalyptus saligna to nitrogen (N) and phosphorus (P) fertilizers were assessed in bioenergy plantations on abandoned sugarcane land in Hawaii. Fertilizers were applied three times (0, 6, and 15 months after planting) in a factorial design with four dosages each of N (0, 25, 50, and 75 g urea per tree) and P (0, 30, 60, and 90 g...

Male coping with cancer-fertility issues: putting the 'social' into biopsychosocial approaches.

PubMed

Crawshaw, Marilyn

2013-09-01

Biopsychosocial approaches in infertility and cancer services and research pay limited attention to 'social dimensions'. Additionally, existing cancer-related male infertility research is dominated by sperm banking studies even though fertility-related social concerns in the long term are reported to have an adverse effect on wellbeing. This paper considers whether social influences affected the fertility-related experiences of 28 men interviewed as part of a mixed-gender qualitative study of 'South Asian' and 'White' cancer survivors and their professional carers. Findings are reported under: managing stigma; sexuality and virility; ambiguity in fertile status; relationship to sperm; and meaning of fatherhood. Gender and other social influences were ambiguous, fluid and subtle--yet powerful. Combinations were neither standard nor static, indicating the dangers of practitioners stereotyping, and/or assuming homogeneity of, (in)fertile men and being unaware of their own socialized expectations. Social structures and attitudes towards valued male social roles as well as the men's psychological capacity and bodily state appear to affect experience. Men may more readily be engaged if practitioners proactively attend to the impact of social concerns, including employment and financial matters, on their perceived capacity to be fathers as a route into raising issues of sexuality and fertility. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Dynamics of floret initiation/death determining spike fertility in wheat as affected by Ppd genes under field conditions.

PubMed

Prieto, Paula; Ochagavía, Helga; Savin, Roxana; Griffiths, Simon; Slafer, Gustavo A

2018-04-27

As wheat yield is linearly related to grain number, understanding the physiological determinants of the number of fertile florets based on floret development dynamics due to the role of the particular genes is relevant. The effects of photoperiod genes on dynamics of floret development are largely ignored. Field experiments were carried out to (i) characterize the dynamics of floret primordia initiation and degeneration and (ii) to determine which are the most critical traits of such dynamics in establishing genotypic differences in the number of fertile florets at anthesis in near isogenic lines (NILs) carrying photoperiod-insensitive alleles. Results varied in magnitude between the two growing seasons, but in general introgression of Ppd-1a alleles reduced the number of fertile florets. The actual effect was affected not only by the genome and the doses but also by the source of the alleles. Differences in the number of fertile florets were mainly explained by differences in the floret generation/degeneration dynamics, and in most cases associated with floret survival. Manipulating photoperiod insensitivity, unquestionably useful for changing flowering time, may reduce spike fertility but much less than proportionally to the change in duration of development, as the insensitivity alleles did increase the rate of floret development.

Definitions and the experience of fertility problems: infertile and sub-fertile women, childless mothers, and honorary mothers in two southern Nigerian communities.

PubMed

Whitehouse, Bruce; Hollos, Marida

2014-03-01

Although infertility causes women considerable grief, social stigma, and economic deprivation, scholars have paid little attention to infertility's definitions that may depart from the standard Western usage and how such definitions influence the way women experience the condition. This article, by listening to individual women's experiences of infertility in two Nigerian communities, examines these definitions and differentiates between culturally salient categories of infertility. In distinguishing between different kinds of childless women and those with low fertility, we intend to enhance understandings of infertility by considering women's subjective understandings of the condition and thus moving beyond the current medical definition. By comparing women's experiences in two different ethnic groups in Nigeria, we show how distinct forms of kinship structures and social organizations shape the ways low fertility is defined, managed, and experienced. © 2013 by the American Anthropological Association.

Definitions and the Experience of Fertility Problems: Infertile and Sub-fertile Women, Childless Mothers, and Honorary Mothers in Two Southern Nigerian Communities

PubMed Central

Whitehouse, Bruce; Hollos, Marida

2015-01-01

Although infertility causes women considerable grief, social stigma, and economic deprivation, scholars have paid little attention to infertility’s definitions that may depart from the standard Western usage and how such definitions influence the way women experience the condition. This article, by listening to individual women’s experiences of infertility in two Nigerian communities, examines these definitions and differentiates between culturally salient categories of infertility. In distinguishing between different kinds of childless women and those with low fertility, we intend to enhance understandings of infertility by considering women’s subjective understandings of the condition and thus moving beyond the current medical definition. By comparing women’s experiences in two different ethnic groups in Nigeria, we show how distinct forms of kinship structures and social organizations shape the ways low fertility is defined, managed, and experienced. PMID:24578250

77 FR 33985 - Proposed Establishment of the Indiana Uplands Viticultural Area and Modification of the Ohio...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... silty clay loam. Due to the relatively low fertility of these soils, applications of lime and fertilizer... increased breakdown of organic material in the soil. The increased precipitation does not negatively affect...

Reproductive Management for Optimal Oocyte Development to Enhance Fertility

USDA-ARS?s Scientific Manuscript database

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

Garlic (Allium sativum L.) fertility: transcriptome and proteome analyses provide insight into flower and pollen development

PubMed Central

Shemesh-Mayer, Einat; Ben-Michael, Tomer; Rotem, Neta; Rabinowitch, Haim D.; Doron-Faigenboim, Adi; Kosmala, Arkadiusz; Perlikowski, Dawid; Sherman, Amir; Kamenetsky, Rina

2015-01-01

Commercial cultivars of garlic, a popular condiment, are sterile, making genetic studies and breeding of this plant challenging. However, recent fertility restoration has enabled advanced physiological and genetic research and hybridization in this important crop. Morphophysiological studies, combined with transcriptome and proteome analyses and quantitative PCR validation, enabled the identification of genes and specific processes involved in gametogenesis in fertile and male-sterile garlic genotypes. Both genotypes exhibit normal meiosis at early stages of anther development, but in the male-sterile plants, tapetal hypertrophy after microspore release leads to pollen degeneration. Transcriptome analysis and global gene-expression profiling showed that >16,000 genes are differentially expressed in the fertile vs. male-sterile developing flowers. Proteome analysis and quantitative comparison of 2D-gel protein maps revealed 36 significantly different protein spots, 9 of which were present only in the male-sterile genotype. Bioinformatic and quantitative PCR validation of 10 candidate genes exhibited significant expression differences between male-sterile and fertile flowers. A comparison of morphophysiological and molecular traits of fertile and male-sterile garlic flowers suggests that respiratory restrictions and/or non-regulated programmed cell death of the tapetum can lead to energy deficiency and consequent pollen abortion. Potential molecular markers for male fertility and sterility in garlic are proposed. PMID:25972879

Polygyny among the Tsimane of Bolivia: an improved method for testing the polygyny–fertility hypothesis

PubMed Central

Winking, Jeffrey; Stieglitz, Jonathan; Kurten, Jenna; Kaplan, Hillard; Gurven, Michael

2013-01-01

The polygyny–fertility hypothesis states that polygyny is associated with reduced fertility for women and is supported by a large body of literature. This finding is important, because theoretical models of polygyny often differentiate systems based on the degree to which women are forced or willingly choose to enter polygynous marriages. The fact that polygyny tends to be associated with reduced fertility has been presented as evidence that polygyny is often less favourable for women, and that women must, therefore, be pressured into accepting such arrangements. Previous studies, however, have been hampered by the non-random assignment of women into monogamous and polygynous unions (i.e. self-selection), as differences between these groups of women might explain some of the effects. Furthermore, the vast majority of such studies focus on sub-Saharan populations. We address these problems in our analysis of women's fertility in polygynous marriages among the Tsimane of Bolivia. We offer a more robust method for assessing the impact of polygynous marriage on reproductive outcomes by testing for intra-individual fertility effects among first wives as they transition from monogamous to polygynous marriage. We report a significant link between polygyny and reduced fertility when including all cases of polygyny; however, this association disappears when testing only for intra-individual effects. PMID:23407840

Evidence for Different Reaction Pathways for Liquid and Granular Micronutrients in a Calcareous Soil

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

Hettiarachchi, Ganga M.; McLaughlin, Mike J.; Scheckel, Kirk G.

2008-06-16

The benefits of Mn and Zn fluid fertilizers over conventional granular products in calcareous sandy loam soils have been agronomically demonstrated. We hypothesized that the differences in the effectiveness between granular and fluid Mn and Zn fertilizers is due to different Mn and Zn reaction processes in and around fertilizer granules and fluid fertilizer bands. We used a combination of several synchrotron-based x-ray techniques, namely, spatially resolved micro-x-ray fluorescence (?-XRF), micro-x-ray absorption near edge structure spectroscopy (?-XANES), and bulk-XANES and -extended x-ray absorption fine structure (EXAFS) spectroscopy, along with several laboratory-based x-ray techniques to speciate different fertilizer-derived Mn and Znmore » species in highly calcareous soils to understand the chemistry underlying the observed differential behavior of fluid and granular micronutrient forms. Micro-XRF mapping of soil-fertilizer reactions zones indicated that the mobility of Mn and Zn from liquid fertilizer was greater than that observed for equivalent granular sources of these micronutrients in soil. After application of these micronutrient fertilizers to soil, Mn and Zn from liquid fertilizers were found to remain in comparatively more soluble solid forms, such as hydrated Mn phosphate-like, Mn calcite-like, adsorbed Zn-like, and Zn silicate-like phases, whereas Mn and Zn from equivalent granular sources tended to transform into comparatively less soluble solid forms such as Mn oxide-like, Mn carbonate-like, and Zn phosphate-like phases.« less

Effects of exposure to BPF on development and sexual differentiation during early life stages of zebrafish (Danio rerio).

PubMed

Yang, Qian; Yang, Xianhai; Liu, Jining; Chen, Yingwen; Shen, Shubao

2018-05-16

Bisphenol F (BPF) has become a predominant bisphenol contaminant in recent years. It has significant estrogenic properties in both in vivo and in vitro studies. We have previously studied the disrupting mechanisms of BPF on the hypothalamic-pituitary-gonadal axis of adult zebrafish. However, the effects of BPF exposure on development and sexual differentiation of zebrafish embryos/larvae remain unclear. To determine the effects of BPF on the critical stage of sex differentiation in zebrafish, zebrafish embryos/larvae were exposed to 1, 10, 100, and 1000 μg/L BPF from fertilization to 60 days post-fertilization (dpf). Developmental malformations were induced by exposure to BPF from 2 h post-fertilization (hpf), with a LC 50 of 10,030 μg/L at 96 hpf and 9391 μg/L at 120 hpf. Long-term exposure during sex differentiation tended to result in a female sex ratio bias. Histological analyses at 60 dpf indicated that the development of ovo-testes and immature ovaries was induced by 100 and 1000 μg/L BPF. Homogenate testosterone levels decreased and 17β-estradiol levels increased in zebrafish in a concentration-dependent manner. BPF exposure suppressed gene expression of double sex, Mab3-related transcription factor 1(dmrt1), fushi tarazu factor 1d (ff1d), sry-box containing gene 9a (sox9a) and anti-Mullerian hormone (amh); induced expression of the forkhead box L2 transcription factor (foxl2), leading to increased expression of aromatase (cyp19a1a), which promoted production of estrogens, and further caused phenotypic feminization of zebrafish. These results suggest that developmental exposure to BPF has adverse effects on sexual differentiation, and the results were useful for a BPF risk assessment. Copyright © 2018. Published by Elsevier Inc.

In utero exposure to low doses of environmental pollutants disrupts fetal ovarian development in sheep

PubMed Central

Fowler, Paul A.; Dorà, Natalie J.; McFerran, Helen; Amezaga, Maria R.; Miller, David W.; Lea, Richard G.; Cash, Phillip; McNeilly, Alan S.; Evans, Neil P.; Cotinot, Corinne; Sharpe, Richard M.; Rhind, Stewart M.

2008-01-01

Epidemiological studies of the impact of environmental chemicals on reproductive health demonstrate consequences of exposure but establishing causative links requires animal models using ‘real life’ in utero exposures. We aimed to determine whether prolonged, low-dose, exposure of pregnant sheep to a mixture of environmental chemicals affects fetal ovarian development. Exposure of treated ewes (n = 7) to pollutants was maximized by surface application of processed sewage sludge to pasture. Control ewes (n = 10) were reared on pasture treated with inorganic fertilizer. Ovaries and blood were collected from fetuses (n = 15 control and n = 8 treated) on Day 110 of gestation for investigation of fetal endocrinology, ovarian follicle/oocyte numbers and ovarian proteome. Treated fetuses were 14% lighter than controls but fetal ovary weights were unchanged. Prolactin (48% lower) was the only measured hormone significantly affected by treatment. Treatment reduced numbers of growth differentiation factor (GDF9) and induced myeloid leukaemia cell differentiation protein (MCL1) positive oocytes by 25–26% and increased pro-apoptotic BAX by 65% and 42% of protein spots in the treated ovarian proteome were differently expressed compared with controls. Nineteen spots were identified and included proteins involved in gene expression/transcription, protein synthesis, phosphorylation and receptor activity. Fetal exposure to environmental chemicals, via the mother, significantly perturbs fetal ovarian development. If such effects are replicated in humans, premature menopause could be an outcome. PMID:18436539

Synergistic roles of bone morphogenetic protein 15 and growth differentiation factor 9 in ovarian function.

PubMed

Yan, C; Wang, P; DeMayo, J; DeMayo, F J; Elvin, J A; Carino, C; Prasad, S V; Skinner, S S; Dunbar, B S; Dube, J L; Celeste, A J; Matzuk, M M

2001-06-01

Knockout mouse technology has been used over the last decade to define the essential roles of ovarian-expressed genes and uncover genetic interactions. In particular, we have used this technology to study the function of multiple members of the transforming growth factor-beta superfamily including inhibins, activins, and growth differentiation factor 9 (GDF-9 or Gdf9). Knockout mice lacking GDF-9 are infertile due to a block in folliculogenesis at the primary follicle stage. In addition, recombinant GDF-9 regulates multiple cumulus granulosa cell functions in the periovulatory period including hyaluronic acid synthesis and cumulus expansion. We have also cloned an oocyte-specific homolog of GDF-9 from mice and humans, which is termed bone morphogenetic protein 15 (BMP-15 or Bmp15). To define the function of BMP-15 in mice, we generated embryonic stem cells and knockout mice, which have a null mutation in this X-linked gene. Male chimeric and Bmp15 null mice are normal and fertile. In contrast to Bmp15 null males and Gdf9 knockout females, Bmp15 null females (Bmp15(-/-)) are subfertile and usually have minimal ovarian histopathological defects, but demonstrate decreased ovulation and fertilization rates. To further decipher possible direct or indirect genetic interactions between GDF-9 and BMP-15, we have generated double mutant mice lacking one or both alleles of these related homologs. Double homozygote females (Bmp15(-/-)Gdf9(-/-)) display oocyte loss and cysts and resemble Gdf9(-/-) mutants. In contrast, Bmp15(-/-)Gdf9(+/-) female mice have more severe fertility defects than Bmp15(-/-) females, which appear to be due to abnormalities in ovarian folliculogenesis, cumulus cell physiology, and fertilization. Thus, the dosage of intact Bmp15 and Gdf9 alleles directly influences the destiny of the oocyte during folliculogenesis and in the periovulatory period. These studies have important implications for human fertility control and the maintenance of fertility and normal ovarian physiology.

Plant Identity Exerts Stronger Effect than Fertilization on Soil Arbuscular Mycorrhizal Fungi in a Sown Pasture.

PubMed

Zheng, Yong; Chen, Liang; Luo, Cai-Yun; Zhang, Zhen-Hua; Wang, Shi-Ping; Guo, Liang-Dong

2016-10-01

Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

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

PubMed

Cáceres-Delpiano, Julio

2012-02-01

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

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

PubMed

Alkhader, Asad M F; Abu Rayyan, Azmi M

2013-01-01

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

Nutrient Presses and Pulses Differentially Impact Plants, Herbivores, Detritivores and Their Natural Enemies

PubMed Central

Murphy, Shannon M.; Wimp, Gina M.; Lewis, Danny

2012-01-01

Anthropogenic nutrient inputs into native ecosystems cause fluctuations in resources that normally limit plant growth, which has important consequences for associated food webs. Such inputs from agricultural and urban habitats into nearby natural systems are increasing globally and can be highly variable, spanning the range from sporadic to continuous. Despite the global increase in anthropogenically-derived nutrient inputs into native ecosystems, the consequences of variation in subsidy duration on native plants and their associated food webs are poorly known. Specifically, while some studies have examined the effects of nutrient subsidies on native ecosystems for a single year (a nutrient pulse), repeated introductions of nutrients across multiple years (a nutrient press) better reflect the persistent nature of anthropogenic nutrient enrichment. We therefore contrasted the effects of a one-year nutrient pulse with a four-year nutrient press on arthropod consumers in two salt marshes. Salt marshes represent an ideal system to address the differential impacts of nutrient pulses and presses on ecosystem and community dynamics because human development and other anthropogenic activities lead to recurrent introductions of nutrients into these natural systems. We found that plant biomass and %N as well as arthropod density fell after the nutrient pulse ended but remained elevated throughout the nutrient press. Notably, higher trophic levels responded more strongly than lower trophic levels to fertilization, and the predator/prey ratio increased each year of the nutrient press, demonstrating that food web responses to anthropogenic nutrient enrichment can take years to fully manifest themselves. Vegetation at the two marshes also exhibited an apparent tradeoff between increasing %N and biomass in response to fertilization. Our research emphasizes the need for long-term, spatially diverse studies of nutrient enrichment in order to understand how variation in the duration of anthropogenic nutrient subsidies affects native ecosystems. PMID:22952814

Methods for Improving In Vitro and In Vivo Boar Sperm Fertility.

PubMed

Funahashi, H

2015-07-01

Fertility of boar spermatozoa is changed after ejaculation in vivo and in vitro. During processing for in vitro fertilization (IVF), although spermatozoa are induced capacitation, resulting in a high penetration rate, persistent obstacle of polyspermic penetration is still observed with a high incidence. For artificial insemination (AI), we still need a large number of spermatozoa and lose a majority of those in the female reproductive tract. Fertility of cryopreserved boar spermatozoa is still injured through freezing and thawing process. In the present brief review, factors affecting fertility of boar sperm during IVF, AI and cryopreservation are discussed in the context of discovering methodologies to improve it. © 2015 Blackwell Verlag GmbH.

Effect of nitrogen and fish manure fertilization on growth and chemical composition of lettuce

NASA Astrophysics Data System (ADS)

Yildirim, Ertan; Kul, Raziye; Turan, Metin; Ekinci, Melek; Alak, Gonca; Atamanalp, Muhammet

2016-04-01

Present experiment was designed to determine the response of various dozes of fish manure (FM) and commercial fertilizers on plant growth, yield and nutrient content of lettuce. The treatments consisted of fish manure, commercial fertilizer and the combination of fish manure and commercial fertilizer with four dozes of nitrogen (0 kg/ha, 100 kg/ha, 150 kg/ha and 200 kg/ha). The results of the study showed that treatments significantly affected the growth and chemical characteristics of lettuce. The best results in regard to plant growth and yield were obtained from 100 and 150 kg kg/ha nitrogen dozes of the combination of fish manure and commercial fertilizer.

Marital fertility and income: moderating effects of the Church of Jesus Christ of Latter-day Saints religion in Utah.

PubMed

Stanford, Joseph B; Smith, Ken R

2013-03-01

Utah has the highest total fertility of any state in the United States and also the highest proportion of population affiliated with the Church of Jesus Christ of Latter-day Saints (the LDS or Mormon Church). Data were used from the 1996 Utah Health Status Survey to investigate how annual household income, education and affiliation with the LDS Church affect fertility (children ever born) for married women in Utah. Younger age and higher education were negatively correlated with fertility in the sample as a whole and among non-LDS respondents. Income was negatively associated with fertility among non-LDS respondents. However, income was positively correlated with fertility among LDS respondents. This association persisted when instrumental variables were used to address the potential simultaneous equations bias arising from the potential endogeneity of income and fertility. The LDS religion's pronatalist stance probably encourages childbearing among those with higher income.

Does Haplodiploidy Purge Inbreeding Depression in Rotifer Populations?

PubMed Central

Tortajada, Ana M.; Carmona, María José; Serra, Manuel

2009-01-01

Background Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. Methodology/Principal Findings We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed) and interclonal (outcrossed) crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured. Conclusions/Significance Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation. PMID:19997616

Explaining Religious Differentials in Family Size Preferences: Evidence from Nepal in 1996

PubMed Central

Pearce, Lisa D.; Brauner-Otto, Sarah; Ji, Yingchun

2015-01-01

This paper presents an examination of how religio-ethnic identity, individual religiosity, and family members’ religiosity are related to preferred family size in Nepal. Analyses of survey data from the Chitwan Valley Family Study show that socioeconomic characteristics and individual experiences can suppress, as well as largely account for, religio-ethnic differences in fertility preferences. These religio-ethnic differentials are associated with variance in particularized religious theologies or general value orientations (like son preference) across groups. In addition, individual and family religiosity are both positively associated with preferred family size, seemingly because of their association with religious beliefs that are likely to shape fertility strategies. These findings suggest improvements in how we conceptualize and empirically measure supra-individual religious influence in a variety of settings and for a range of demographically interesting outcomes. PMID:25685878

Explaining religious differentials in family-size preference: Evidence from Nepal in 1996.

PubMed

Pearce, Lisa D; Brauner-Otto, Sarah R; Ji, Yingchun

2015-01-01

We examine how religio-ethnic identity, individual religiosity, and family members' religiosity were related to preferred family size in Nepal in 1996. Analyses of survey data from the Chitwan Valley Family Study show that socio-economic characteristics and individual experiences can suppress, as well as largely account for, religio-ethnic differences in fertility preference. These religio-ethnic differentials are associated with variance in particularized theologies or general value orientations (like son preference) across groups. In addition, individual and family religiosity are both positively associated with preferred family size, seemingly because of their association with religious beliefs—beliefs that are likely to shape fertility strategies. These findings suggest the need for improvements in how we conceptualize and measure supra-individual religious influence in a variety of settings and for a range of demographically interesting outcomes.

Propagation of Obesity Across Generations: The Roles of Differential Realized Fertility and Assortative Mating by Body Mass Index

PubMed Central

Dawson, John A.; Dhurandhar, Emily J.; Vazquez, Ana I.; Peng, Bo; Allison, David B.

2013-01-01

Background/Aims To quantify the extent to which the increase in obesity observed across recent generations of the American population is associated with the individual or combined effects of assortative mating for body mass index (BMI; kg/m2) and differential realized fertility by BMI. Methods A Monte Carlo framework is formed and informed using data collected from the National Longitudinal Survey of Youth (NLSY). The model has two portions, one that generates childbirth events on an annual basis and another that produces a BMI for each child. Once the model is informed using the data, a reference distribution of offspring BMIs is simulated. We quantify the effects of our factors of interest by removing them from the model and comparing the resulting offspring BMI distributions with that of the baseline scenario. Results An association between maternal BMI and number of offspring is evidenced in the NLSY data, as well as the presence of assortative mating. These two factors combined are associated with increased mean BMI (+0.067, C.I. [0.056, 0.078]), increased BMI variance (+0.578, C.I. [0.418, 0.736]) and increased prevalence of obesity (RR 1.032, 95% C.I. [1.023, 1.041]) and BMIs over 40 (RR 1.083, 95% C.I. [1.053, 1.118]) among offspring. Conclusion Our investigation suggests that both differential realized fertility and assortative mating by BMI appear to play a role in the increasing prevalence of obesity in America. PMID:24081235

Quinoa Seed Quality Response to Sodium Chloride and Sodium Sulfate Salinity

PubMed Central

Wu, Geyang; Peterson, Adam J.; Morris, Craig F.; Murphy, Kevin M.

2016-01-01

Quinoa (Chenopodium quinoa Willd.) is an Andean crop with an edible seed that both contains high protein content and provides high quality protein with a balanced amino acid profile in embryonic tissues. Quinoa is a halophyte adapted to harsh environments with highly saline soil. In this study, four quinoa varieties were grown under six salinity treatments and two levels of fertilization, and then evaluated for quinoa seed quality characteristics, including protein content, seed hardness, and seed density. Concentrations of 8, 16, and 32 dS m-1 of NaCl and Na2SO4, were applied to the soil medium across low (1 g N, 0.29 g P, 0.29 g K per pot) and high (3 g N, 0.85 g P, 0.86 g K per pot) fertilizer treatments. Seed protein content differed across soil salinity treatments, varieties, and fertilization levels. Protein content of quinoa grown under salinized soil ranged from 13.0 to 16.7%, comparable to that from non-saline conditions. NaCl and Na2SO4 exhibited different impacts on protein content. Whereas the different concentrations of NaCl did not show differential effects on protein content, the seed from 32 dS m-1 Na2SO4 contained the highest protein content. Seed hardness differed among varieties, and was moderately influenced by salinity level (P = 0.09). Seed density was affected significantly by variety and Na2SO4 concentration, but was unaffected by NaCl concentration. The samples from 8 dS m-1 Na2SO4 soil had lower density (0.66 g/cm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4, 0.74 and 0.72g/cm3, respectively. This paper identifies changes in critical seed quality traits of quinoa as influenced by soil salinity and fertility, and offers insights into variety response and choice across different abiotic stresses in the field environment. PMID:27375648

75 FR 9593 - Agency Information Collection Activities; Proposed Renewal of Several Currently Approved...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

... institutions participating in pesticide, fertilizer, and other agricultural chemical manufacturing [[Page 9595...: Entities potentially affected by this ICR include individuals or entities engaged in pesticide, fertilizer, and other agricultural chemical manufacturing (North American Industrial Classification System (NAICS...

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

PubMed

Henley, David

2006-11-01

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

How Does Recycling of Livestock Manure in Agroecosystems Affect Crop Productivity, Reactive Nitrogen Losses, and Soil Carbon Balance?

PubMed

Xia, Longlong; Lam, Shu Kee; Yan, Xiaoyuan; Chen, Deli

2017-07-05

Recycling of livestock manure in agroecosystems to partially substitute synthetic fertilizer nitrogen (N) input is recommended to alleviate the environmental degradation associated with synthetic N fertilization, which may also affect food security and soil greenhouse gas (GHG) emissions. However, how substituting livestock manure for synthetic N fertilizer affects crop productivity (crop yield; crop N uptake; N use efficiency), reactive N (Nr) losses (ammonia (NH 3 ) emission, N leaching and runoff), GHG (methane, CH 4 ; and nitrous oxide, N 2 O; carbon dioxide) emissions and soil organic carbon (SOC) sequestration in agroecosystems is not well understood. We conducted a global meta-analysis of 141 studies and found that substituting livestock manure for synthetic N fertilizer (with equivalent N rate) significantly increased crop yield by 4.4% and significantly decreased Nr losses via NH 3 emission by 26.8%, N leaching by 28.9% and N runoff by 26.2%. Moreover, annual SOC sequestration was significantly increased by 699.6 and 401.4 kg C ha -1 yr -1 in upland and paddy fields, respectively; CH 4 emission from paddy field was significantly increased by 41.2%, but no significant change of that was observed from upland field; N 2 O emission was not significantly affected by manure substitution in upland or paddy fields. In terms of net soil carbon balance, substituting manure for fertilizer increased carbon sink in upland field, but increased carbon source in paddy field. These results suggest that recycling of livestock manure in agroecosystems improves crop productivity, reduces Nr pollution and increases SOC storage. To attenuate the enhanced carbon source in paddy field, appropriate livestock manure management practices should be adopted.

A single nucleotide polymorphism in COQ9 affects mitochondrial and ovarian function and fertility in Holstein cows.

PubMed

Ortega, M Sofia; Wohlgemuth, Stephanie; Tribulo, Paula; Siqueira, Luiz G B; Cole, John B; Hansen, Peter J

2017-03-01

A single missense mutation at position 159 of coenzyme Q9 (COQ9) (G→A; rs109301586) has been associated with genetic variation in fertility in Holstein cattle, with the A allele associated with higher fertility. COQ9 is involved in the synthesis of coenzyme COQ10, a component of the electron transport system of the mitochondria. Here we tested whether reproductive phenotype is associated with the mutation and evaluated functional consequences for cellular oxygen metabolism, body weight changes, and ovarian function. The mutation in COQ9 modifies predicted tertiary protein structure and affected mitochondrial respiration of peripheral blood mononuclear cells. The A allele was associated with low resting oxygen consumption and high electron transport system capacity. Phenotypic measurements for fertility were evaluated for up to five lactations in a population of 2273 Holstein cows. There were additive effects of the mutation (P < 0.05) in favor of the A allele for pregnancy rate, interval from calving to conception, and services per conception. There was no association of genotype with milk production or body weight changes postpartum. The mutation in COQ9 affected ovarian function; the A allele was associated with increased mitochondrial DNA copy number in oocytes, and there were overdominance effects for COQ9 expression in oocytes, follicle number, and antimullerian hormone concentrations. Overall, results show how a gene involved in mitochondrial function is associated with overall fertility, possibly in part by affecting oocyte quality. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

EFFECTS OF IN VITRO RADIOCOBALT IRRADIATION OF RABBIT OVA ON SUBSEQUENT DEVELOPMENT IN VIVO WITH SPECIAL REFERENCE TO THE IRRADIATION OF MATERNAL ORGANISM

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

Chang, M.C.; Hunt, D.M.

Fertilized rabbit ova recovered one to six days after mating were irradiated in vitro from a radiocobalt source and then transplanted into recipient animals. When examined 22 to 28 days later 44, 33, 8 and 0% of ova irradiated respectively at 50, 100, 1,000 and 5,000 r developed into apparently normal fetuses without external or internal malformation. No significant differential sensitivity was apparent in ova irradiated at different ages. It was found further that 34, 36, 19 and 10% of two-, 4-, and 6-day ova irradiated respectively in vitro at 200, 400, 600, and 800 r developed into "normal" fetuses.more » Again no malformation of fetuses and no differential radiosensitivity between ova of different ages were observed. Following whole body irradiation at 400 r, it was found that 40% of non-irradiated ova developed into normal fetuses when transplanted into recipient animals that had been irradiated (vs. 36% in the irradiation of ova alone). However, only 17% of estimated ova developed into "normal" fetuses when pregnant rabbits were irradiated 2, 4 or 6 days after insemination (vs. 64% in the control). It appears that irradiation of the maternal organism influences embryonic development and that irradiation of pregnant animals exerts a combination of ill effects, on the ova and on their environment. Cytological study of irradiated blastocysts revealed no chromosomal breakage immediately after irradiation. Chromosomal abnormalities, fragmentation and condensation of chromatin were observed during the culture of irradiated blastocysts in accordance with the dosages applied. From this study it is concluded that (1) although 50 r may affect embryonic development, there seems to be no differential effect up to 400 r, above which greater prenatal death occurs; (2) before implantation, irradiated ova either die or develop into apparently normal fetuses and there is no evidence of differential radiosensitivity at various stages of development; (3) irradiation of the maternal organism alone also affects embryonic development; and (4) radiation damage affects a fundamental biological system which leads to the nuclear damage and failure of mitosis, and the death of ova. (auth)« less

Single layer centrifugation-selected boar spermatozoa are capable of fertilization in vitro

PubMed Central

2013-01-01

Background Good quality spermatozoa are important to achieve fertilization, viable embryos and offspring. Single Layer Centrifugation (SLC) through a colloid (Androcoll-P) selects good quality spermatozoa. However, it has not been established previously whether porcine spermatozoa selected by this method maintain their fertility. Methods The semen was prepared either by SLC or by standard centrifugation (control) and used for in vitro fertilization (IVF) at oocyte:spermatozoa ratios of 1:50; 1:100 and 1:300 (or 4 x 103, 8 x 103 and 24 x 103 spermatozoa/ml) to evaluate their subsequent ability to generate blastocysts. In addition, sperm motility was assessed by computer assisted sperm motility analysis. Results Total and progressive motility were significantly higher in sperm samples prepared by SLC compared to uncentrifuged samples. Sperm binding ability, polyspermy, cleavage and blastocyst rates were affected by the oocyte:sperm ratio, but not by sperm treatment. Conclusion The use of SLC does not adversely affect the in vitro fertilizing and embryo-generating ability of the selected spermatozoa compared to their unselected counterparts, but further modifications in the IVF conditions would be needed to improve the monospermy in IVF systems. Since SLC did not appear to have a negative effect on sperm fertilizing ability, and may in fact select for spermatozoa with a greater potential for fertilization, an in vivo trial to determine the usefulness of this sperm preparation technique prior to artificial insemination is warranted. PMID:23497680

The Effect of Female Education on Fertility and Infant Health: Evidence from School Entry Policies Using Exact Date of Birth

PubMed Central

McCrary, Justin

2011-01-01

This paper uses age-at-school-entry policies to identify the effect of female education on fertility and infant health. We focus on sharp contrasts in schooling, fertility, and infant health between women born just before and after the school entry date. School entry policies affect female education and the quality of a woman’s mate and have generally small, but possibly heterogeneous, effects on fertility and infant health. We argue that school entry policies manipulate primarily the education of young women at risk of dropping out of school. PMID:21490880

Agricultural management affects below ground carbon input estimations

NASA Astrophysics Data System (ADS)

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Mayer, Jochen

2017-04-01

Root biomass and rhizodeposition carbon (C release by living roots) are among the most relevant root parameters for studies of plant response to environmental change, soil C modelling or estimations of soil C sequestration. Below ground C inputs of agricultural crops are typically estimated from above ground biomass or yield, thereby implying constant below to above ground C ratios. Agricultural management practices affect above ground biomass considerably; however, their effects on below ground C inputs are only poorly understood. Our aims were therefore to (i) quantify root biomass C and rhizodeposition C of maize and wheat grown in agricultural management systems with different fertilization intensities and (ii) determine management effects on below/above ground C ratios and vertical distribution of below ground C inputs into soil. We conducted a comprehensive field study on two Swiss long-term field trials, DOK (Basel) and ZOFE (Zurich), with silage (DOK) and grain (ZOFE) maize in 2013 and winter wheat in 2014 (ZOFE) and 2015 (DOK). Three treatments in DOK (2 bio-organic, 1 mixed conventional) and 4 treatments in ZOFE (1 without, 1 manure, 2 mineral fertilization) reflected increasing fertilization intensities. In each of 4 replicated field plots per treatment, one microplot (steel tube of 0.5m depth) was inserted into soil, covering an area of 0.1m2. The microplot plants were pulse-labelled with 13C-CO2 in weekly intervals throughout the respective growing season. After harvest, the microplot soil was sampled in three soil depths (0 - 0.25, 0.25 - 0.5, 0.5 - 0.75m), roots were separated from soil by picking and wet sieving, and root and soil samples were analysed for their δ13C values by IRMS. Carbon rhizodeposition was calculated from 13C-excess values in bulk soil and roots. (i) Average root biomasses of maize and wheat were 1.9 and 1.4 tha 1, respectively, in DOK and 0.9 and 1.1 tha 1, respectively, in ZOFE. Average amounts of C rhizodeposition of maize and wheat were 1.4 and 0.7 tha 1, respectively, in DOK and 0.5 and 0.6 tha 1, respectively, in ZOFE. Both root biomass and C rhizodeposition were similar among treatments on both sites but were significantly higher for silage maize (DOK) than for grain maize (ZOFE) and winter wheat (DOK and ZOFE). (ii) With increasing fertilization intensities, below/above ground C ratios of both maize and wheat significantly decreased from 0.43 to 0.16 for maize and 0.57 to 0.15 for wheat. Vertical distribution of below ground C inputs into soil was not affected by agricultural management but differed significantly between crops: In the subsoil (0.5 - 0.75m), below ground C inputs of wheat were twice as high as those of maize on both sites. Increasing fertilization intensity leads to a considerable increase in above ground biomass but does not affect below ground C inputs of maize and wheat on two Swiss agricultural sites. This finding shows that below ground C inputs cannot be estimated from above ground biomass in order to provide soil C models with input data. A differentiation according to the management system is strongly needed.

Deficiencies in extrusion of the second polar body due to high calcium concentrations during in vitro fertilization in inbred C3H/He mice.

PubMed

Ohta, Yuki; Nagao, Yoshikazu; Minami, Naojiro; Tsukamoto, Satoshi; Kito, Seiji

2016-08-01

Successful in vitro fertilization (IVF) of all inbred strains of laboratory mice has not yet been accomplished. We have previously shown that a high calcium concentration improved IVF in various inbred mice. However, we also found that in cumulus-free ova of C3H/He mice such IVF conditions significantly increased the deficiency of extrusion of the second polar body (PBII) in a dose-dependent manner (2% at 1.71 mM and 29% at 6.84 mM, P < 0.05) and that PBII extrusion was affected by high calcium levels at 2-3 h post-insemination. While developmental competence of ova without PBII extrusion to blastocysts after 96 h culture was not affected, a significant reduction in the nuclear number of the inner cell mass was observed in blastocyst fertilized under high calcium condition. We also examined how high calcium concentration during IVF affects PBII extrusion in C3H/He mice. Cumulus cells cultured under high calcium conditions showed a significantly alleviated deficient PBII extrusion. This phenomenon is likely to be specific to C3H/He ova because deficient PBII extrusion in reciprocal fertilization between C3H and BDF1 gametes was observed only in C3H/He ova. Sperm factor(s) was still involved in deficient PBII extrusion due to high calcium concentrations, as this phenomenon was not observed in ova activated by ethanol. The cytoskeletal organization of ova without PBII extrusion showed disturbed spindle rotation, incomplete formation of contractile ring and disturbed localization of actin, suggesting that high calcium levels affect the anchoring machinery of the meiotic spindle. These results indicate that in C3H/He mice high calcium levels induce abnormal fertilization, i.e. deficient PBII extrusion by affecting the cytoskeletal organization, resulting in disturbed cytokinesis during the second meiotic division. Thus, use of high calcium media for IVF should be avoided for this strain.

Self-fertilization is the main sexual reproduction mechanism in native wine yeast populations.

PubMed

Cubillos, Francisco A; Vásquez, Claudia; Faugeron, Sylvain; Ganga, Angélica; Martínez, Claudio

2009-01-01

Saccharomyces cerevisiae is a model eukaryotic organism for classical genetics and genomics, and yet its ecology is still largely unknown. In this work, a population genetic analysis was performed on five yeast populations isolated from wine-making areas with different enological practices using simple sequence repeats and restriction fragment length polymorphism of mitochondrial DNA as molecular markers on 292 strains. In accordance with other studies, genome size estimation suggests that native S. cerevisiae strains are mainly homothallic and diploids. Analysis of mtDNA data showed that yeast populations from nonindustrial areas have 40% higher genetic diversity than populations isolated from industrial areas, demonstrating that industrial enological practices are likely to affect native yeast populations negatively by reducing its biodiversity. On the other hand, genetic differentiation analysis based on their microsatellite showed no correlation between genetic and geographic distance and a nonsignificant value when a Mantel test was applied. Finally, in the five populations studied, positive inbreeding (F(is)) values from 0.4 to 0.75, a low but significant level of linkage disequilibrium and a high number of multilocus genotypes were detected. These results strongly advocate that sexual reproduction is frequent enough to erase clonal signature in natural populations and that self-fertilization is the main mating system.

Two HAP2-GCS1 homologs responsible for gamete interactions in the cellular slime mold with multiple mating types: Implication for common mechanisms of sexual reproduction shared by plants and protozoa and for male-female differentiation.

PubMed

Okamoto, Marina; Yamada, Lixy; Fujisaki, Yukie; Bloomfield, Gareth; Yoshida, Kentaro; Kuwayama, Hidekazu; Sawada, Hitoshi; Mori, Toshiyuki; Urushihara, Hideko

2016-07-01

Fertilization is a central event in sexual reproduction, and understanding its molecular mechanisms has both basic and applicative biological importance. Recent studies have uncovered the molecules that mediate this process in a variety of organisms, making it intriguing to consider conservation and evolution of the mechanisms of sexual reproduction across phyla. The social amoeba Dictyostelium discoideum undergoes sexual maturation and forms gametes under dark and humid conditions. It exhibits three mating types, type-I, -II, and -III, for the heterothallic mating system. Based on proteome analyses of the gamete membranes, we detected expression of two homologs of the plant fertilization protein HAP2-GCS1. When their coding genes were disrupted in type-I and type-II strains, sexual potency was completely lost, whereas disruption in the type-III strain did not affect mating behavior, suggesting that the latter acts as female in complex organisms. Our results demonstrate the highly conserved function of HAP2-GCS1 in gamete interactions and suggest the presence of additional allo-recognition mechanisms in D. discoideum gametes. Copyright © 2016 Elsevier Inc. All rights reserved.

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

PubMed

Wirakartakusumah, M D

1988-06-01

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

Development of an In Vitro Assay to Quantitate Hematopoietic Stem and Progenitor Cells (HSPCs) in Developing Zebrafish Embryos.

PubMed

Berrun, A C; Stachura, D L

2017-11-30

Hematopoiesis is an essential cellular process in which hematopoietic stem and progenitor cells (HSPCs) differentiate into the multitude of different cell lineages that comprise mature blood. Isolation and identification of these HSPCs is difficult because they are defined ex post facto; they can only be defined after their differentiation into specific cell lineages. Over the past few decades, the zebrafish (Danio rerio) has become a model organism to study hematopoiesis. Zebrafish embryos develop ex utero, and by 48 h post-fertilization (hpf) have generated definitive HSPCs. Assays to assess HSPC differentiation and proliferation capabilities have been developed, utilizing transplantation and subsequent reconstitution of the hematopoietic system in addition to visualizing specialized transgenic lines with confocal microscopy. However, these assays are cost prohibitive, technically difficult, and time consuming for many laboratories. Development of an in vitro model to assess HSPCs would be cost effective, quicker, and present fewer difficulties compared to previously described methods, allowing laboratories to quickly assess mutagenesis and drug screens that affect HSPC biology. This novel in vitro assay to assess HSPCs is performed by plating dissociated whole zebrafish embryos and adding exogenous factors that promote only HSPC differentiation and proliferation. Embryos are dissociated into single cells and plated with HSPC-supportive colony stimulating factors that cause them to generate colony forming units (CFUs) that arise from a single progenitor cell. These assays should allow more careful examination of the molecular pathways responsible for HSPC proliferation, differentiation, and regulation, which will allow researchers to understand the underpinnings of vertebrate hematopoiesis and its dysregulation during disease.

Smoke-related DNA methylation changes in the etiology of human disease.

PubMed

Besingi, Welisane; Johansson, Asa

2014-05-01

Exposure to environmental and lifestyle factors, such as cigarette smoking, affect the epigenome and might mediate risk for diseases and cancers. We have performed a genome-wide DNA methylation study to determine the effect of smoke and snuff (smokeless tobacco) on DNA methylation. A total of 95 sites were differentially methylated [false discovery rate (FDR) q-values < 0.05] in smokers and a subset of the differentially methylated loci were also differentially expressed in smokers. We found no sites, neither any biological functions nor molecular processes enriched for smoke-less tobacco-related differential DNA methylation. This suggests that methylation changes are not caused by the basic components of the tobacco but from its burnt products. Instead, we see a clear enrichment (FDR q-value < 0.05) for genes, including CPOX, CDKN1A and PTK2, involved in response to arsenic-containing substance, which agrees with smoke containing small amounts of arsenic. A large number of biological functions and molecular processes with links to disease conditions are also enriched (FDR q-value < 0.05) for smoke-related DNA methylation changes. These include 'insulin receptor binding', and 'negative regulation of glucose import' which are associated with diabetes, 'positive regulation of interleukin-6-mediated signaling pathway', 'regulation of T-helper 2 cell differentiation', 'positive regulation of interleukin-13 production' which are associated with the immune system and 'sertoli cell fate commitment' which is important for male fertility. Since type 2 diabetes, repressed immune system and infertility have previously been associated with smoking, our results suggest that this might be mediated by DNA methylation changes.

Influence of Long-Term Fertilization on Spore Density and Colonization of Arbuscular Mycorrhizal Fungi in a Brown Soil

NASA Astrophysics Data System (ADS)

Li, Dongdong; Luo, Peiyu; Yang, Jinfeng

2017-12-01

This study aims to explore changes of long-term fertilization on spore density and colonization of AMF (Arbuscular mycorrhizal fungi) under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm,20-40cm,40-60cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen andphosphate fertilizer).Spores were isolated from soils by wet sieving and sucrose density gradient centrifugation; mycorrhizal colonization levels were determined by the gridline intersect. The spore density was highest in the topsoils (0-20 cm), and was decreased with increasing of soil depth in each treatment. The spores density of M2N1P treatment was significantly higher than that of other treatments in each soil layer. Application of inorganic fertilizer (especially inorganic with organic fertilizer) can greatly improve the level of colonization. Our results suggested that long-term fertilization significantly affects spore density and colonization of AMF, however, spore density is not related to colonization rate.

[Analysis of soil humus and components after 26 years' fertilization by infrared spectroscopy method].

PubMed

Zhang, Yu-Lan; Sun, Cai-Xia; Chen, Zhen-Hua; Li, Dong-Po; Liu, Xing-Bin; Chen, Li-Jun; Wu, Zhi-Jie; Du, Jian-Xiong

2010-05-01

The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years' fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1 N and M2 N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy.

Nanopurification of semen improves AI pregnancy rates in beef cattle

USDA-ARS?s Scientific Manuscript database

Reproductive efficiency is several times more important than any other factor affecting economic efficiency in beef production. Multiple studies have been conducted to improve fertility of beef cows, but few studies have been conducted to improve fertility in sires. Also, with current improvements...

Irrigation frequency and timing influence pepper yields

USDA-ARS?s Scientific Manuscript database

Information on how fertilizer and irrigation affect production of vegetables can help growers improve resource use efficiency and profitability. Fertilizer was applied at the recommended rate and twice the recommended rate to bell and non-pungent jalapeno peppers, both Capsicum annuum L., in 2009 a...

Host suitability of Phaseolus lunata for Trichoplusia ni (lepidoptera: noctuidae) in controlled carbon dioxide atmospheres

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

Osbrink, W.L.A.; Trumble, J.T.; Wagner, R.E.

1987-06-01

Elevated atmospheric carbon dioxide (CO/sub 2/) levels of 1000 parts per million (ppm) significantly increased consumption of foliage by Trichoplusia ni (Huebner) and significantly enhanced growth of Phaseolus lunata L. when compared with ambient levels of 340 ppm. Mean pupal weight was less under treatments with elevated atmospheric CO/sub 2/ under a high fertilization regime, but larval survival and percent nitrogen content of pupae were not affected by level of CO/sub 2/ treatments at high, medium, or low fertilizer rates. Regardless of CO/sub 2/ concentration, larval survival and pupal weight were reduced in absence of fertilizer. Nitrogen and protein consumptionmore » increased with fertilization rate. Because percent leaf area of plants consumed by T. ni larvae was not affected by CO/sub 2/ concentration, this study suggests that increased plant growth resulting from elevated atmospheric CO/sub 2/ may benefit the plant proportionately more than the insect.« less

Profiling contents of water-soluble metabolites and mineral nutrients to evaluate the effects of pesticides and organic and chemical fertilizers on tomato fruit quality.

PubMed

Watanabe, Masami; Ohta, Yuko; Licang, Sun; Motoyama, Naoki; Kikuchi, Jun

2015-02-15

In this study, the contents of water-soluble metabolites and mineral nutrients were measured in tomatoes cultured using organic and chemical fertilizers, with or without pesticides. Mineral nutrients and water-soluble metabolites were determined by inductively coupled plasma-atomic emission spectrometry and (1)H nuclear magnetic resonance spectrometry, respectively, and results were analysed by principal components analysis (PCA). The mineral nutrient and water-soluble metabolite profiles differed between organic and chemical fertilizer applications, which accounted for 88.0% and 55.4%, respectively, of the variation. (1)H-(13)C-hetero-nuclear single quantum coherence experiments identified aliphatic protons that contributed to the discrimination of PCA. Pesticide application had little effect on mineral nutrient content (except Fe and P), but affected the correlation between mineral nutrients and metabolites. Differences in the content of mineral nutrients and water-soluble metabolites resulting from different fertilizer and pesticide applications probably affect tomato quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Roles of the oviduct in mammalian fertilization

PubMed Central

Coy, P; García-Vázquez, FA; Visconti, PE; Avilés, M

2014-01-01

The oviduct or Fallopian tube is the anatomical region where every new life begins in mammalian species. After a long journey, the spermatozoa meet the oocyte in the specific site of the oviduct named ampulla, and fertilization takes place. The successful fertilization depends on several biological processes which occur in the oviduct some hours before this rendezvous and affect both gametes. Estrogen and progesterone, released from the ovary, orchestrate a series of changes by genomic- and non-genomic pathways in the oviductal epithelium affecting gene expression, proteome and secretion of its cells into the fluid bathing the oviductal lumen. In addition, new regulatory molecules are being discovered playing important roles in oviductal physiology and fertilization. The present review tries to describe these processes, building a comprehensive map of the physiology of the oviduct, to better understand the importance of this organ in reproduction. With this purpose, gamete transport, sperm and oocyte changes in the oviductal environment and other interactions between gametes and oviduct are discussed in light of recent publications in the field. PMID:23028122

Effect of Fresh Poultry Litter and Compost on Soil Physical and Chemical Properties

NASA Technical Reports Server (NTRS)

Carr, Stacy; Tsegaye, Teferi; Coleman, Tommy

1998-01-01

Application of poultry litter and compost as a substitute for fertilizer not only uses unwanted waste and decreases expenditures for commercial fertilizer, it adds nutrients to soil for plant uptake. The properties of soil affected by poultry litter were analyzed to determine the positive and negative aspects of using this substitute fertilizer. This study focused on changes associated with saturated hydraulic conductivity, bulk density, nitrate concentrations, and pH after application of varying concentrations of poultry litter and compost. Soil samples from Tennessee Valley Substation in Alabama were analyzed in a laboratory at Alabama A&M University. As a result of the application of fresh poultry litter and compost, we found that the saturated hydraulic conductivity increased and the bulk density decreased, while the pH was generally not affected. Using poultry litter and compost as an alternative commercial fertilizers could be adapted by the farming community to protect the sustainability of our environment. Unwanted waste is used productively and soil is enriched for farming.

Reproductive and fertility effects of an extract of Andrographis paniculata in male Wistar rats.

PubMed

Allan, J Joshua; Pore, Mukul P; Deepak, M; Murali, B; Mayachari, Anand S; Agarwal, Amit

2009-01-01

The possible effect of extract of Andrographis paniculata Nees (A paniculata) standardized to >or=10% andrographolide, the main bioactive component, on male fertility in albino Wistar rats was evaluated, by orally administering 0, 20, 200, and 1000 mg/kg of body weight per day, for 65 days prior to mating and 21 days during mating. The treated groups showed no signs of dose-dependent toxicity. The body weight gain and feed consumption were not affected at any of the dose levels. The testosterone levels and fertility indices in treatment groups were found to be comparable with that of the control indicating no effect on fertility. Total sperm count and sperm motility were not affected. The testes and epididymides did not show any gross and histopathological changes. Based on these findings, it can be concluded that the no-observed adverse effect level of extract of A paniculata (>or=10% andrographolide) was found to be more than 1000 mg/kg per day.

The Soviet Union: population trends and dilemmas.

PubMed

Feshbach, M

1982-08-01

Focus in this discussion of population trends and dilemmas in the Soviet Union is on demographic problems, data limitations, early population growth, geography and resources, the 15 republics of the Soviet Union and nationalities, agriculture and the economy, population growth over the 1950-1980 period (national trend, regional differences); age and sex composition of the population, fertility trends, nationality differentials in fertility, the reasons for fertility differentials (child care, divorce, abortion and contraception, illegitimacy), labor shortages and military personnel, mortality (mortality trends, life expectancy), reasons for mortality increases, urbanization and emigration, and future population prospects and projections. For mid-1982 the population of the Soviet Union was estimated at 270 million. The country's current rate of natural increase (births minus deaths) is about 0.8% a year, higher than current rates of natural increase in the U.S. (0.7%) and in developed countries as a whole (0.6%). Net immigration plays no part in Soviet population growth, but emigration was noticeable in some years during the 1970s, while remaining insignificant relative to total population size. National population growth has dropped by more than half in the last 2 decades, from 1.8% a year in the 1950s to 0.8% in 1980-1981, due mostly to declining fertility. The national fertility decline masks sharp differences among the 15 republics and even more so among the some 125 nationalities. In 1980, the Russian Republic had an estimated fertility rate of 1.9 births/woman, and the rate was just 2.0 in the other 2 Slavic republics, the Ukraine and Belorussia. In the Central Asian republics the rates ranged up to 5.8. Although the Russians will no doubt continue to be the dominant nationality, low fertility and a relatively higher death rate will reduce their share of the total population by less than half by the end of the century. Soviet leaders have launched a pronatalist policy which they hope will lead to an increase in fertility, at least among the dominant Slavic groups of the multinational country. More than 9 billion rubles (U.S. $12.2 billion) is to be spent over the next 5 years to implement measures aimed at increasing state aid to families with children, to be carried out step by step in different regions of the country. It is this writer's opinion that overall fertility is not likely to increase markedly despite the recent efforts of the central authorities, and the Russian share of the total population will probably continue to drop while that of Central Asian Muslim peoples increases.

Adverse Effect of Antifouling Compounds on the Reproductive Mechanisms of the Ascidian Ciona intestinalis

PubMed Central

Gallo, Alessandra; Tosti, Elisabetta

2013-01-01

Fertilization and embryo development that occur in sea water are sensitive to xenobiotics from anthropogenic sources. In this work, we evaluated the influence of two antifouling biocides, tributyltin (TBT) and diuron, on the reproductive mechanisms of the marine invertebrate Ciona intestinalis. By using electrophysiological techniques, we examined the impact of these compounds on the electrical properties of the mature oocytes and of events occurring at fertilization. With different toxicity assays, we studied the effect of the two biocides on the gametes by evaluating fertilization rate and embryo development. Results show that sodium (Na+) currents were significantly reduced by either of the two biocides, whereas conductance was significantly increased. The fertilization current frequency and amplitude, fertilization rate and larval development were affected only by TBT. This study suggests that: (i) the two biocides affect either the electrical properties of the oocyte plasma membrane and the reproductive success representing a risk factor for the survival of the species exposed to environmental pollution; (ii) the ascidian Ciona intestinalis may represent a good model organism to test toxicity of marine pollutants. Possible mechanisms of action of the two biocides are discussed. PMID:24065165

Female employment and fertility in Peninsular Malaysia: the maternal role incompatibility hypothesis reconsidered.

PubMed

Mason, K O; Palan, V T

1981-11-01

Multivariate analysis of the 1974 Malaysian Fertility and Family Survey tests the hypothesis that an inverse relationship between women's work and fertility occurs only when there are serious conflicts between working and caring for children. The results are only partly consistent with the hypothesis and suggest that normative conflicts between working and mothering affect the employment-fertility relationship in Malaysia more than spacio-temporal conflicts do. The lack of consistent evidence for the hypothesis, as well as some conceptual problems, lead us to propose an alternative framework for understanding variation in the employment-fertility relationship, both in Malaysia and elsewhere. This framework incorporates ideas from the role incompatibility hypothesis but views the employment-fertility relationship as dependent not just on role conflicts but more generally on the structure of the household's socioeconomic opportunities.

Nano-Nutrition of Chicken Embryos. The Effect of in Ovo Administration of Diamond Nanoparticles and l-Glutamine on Molecular Responses in Chicken Embryo Pectoral Muscles

PubMed Central

Grodzik, Marta; Sawosz, Filip; Sawosz, Ewa; Hotowy, Anna; Wierzbicki, Mateusz; Kutwin, Marta; Jaworski, Sławomir; Chwalibog, André

2013-01-01

It has been demonstrated that the content of certain amino acids in eggs is not sufficient to fully support embryonic development. One possibility to supply the embryo with extra nutrients and energy is in ovo administration of nutrients. Nanoparticles of diamond are highly biocompatible non-toxic carbonic structures, and we hypothesized that bio-complexes of diamond nanoparticles with l-glutamine may affect molecular responses in breast muscle. The objective of the investigation was to evaluate the effect of diamond nanoparticle (ND) and l-glutamine (Gln) on expression of growth and differentiation factors of chicken embryo pectoral muscles. ND, Gln, and Gln/ND solutions (50 mg/L) were injected into fertilized broiler chicken eggs at the beginning of embryogenesis. Muscle tissue was dissected at day 20 of incubation and analysed for gene expression of FGF2, VEGF-A, and MyoD1. ND and especially Gln/ND up-regulated expression of genes related to muscle cell proliferation (FGF2) and differentiation (MyoD1). Furthermore, the ratio between FGF2 and MyoD1 was highest in the Gln/ND group. At the end of embryogenesis, Gln/ND enhanced both proliferation and differentiation of pectoral muscle cells and differentiation dominated over proliferation. These preliminary results suggest that the bio-complex of glutamine and diamond nanoparticles may accelerate growth and maturation of muscle cells. PMID:24264045

Effects of modification of in vitro fertilization techniques on the sex ratio of the resultant bovine embryos.

PubMed

Iwata, H; Shiono, H; Kon, Y; Matsubara, K; Kimura, K; Kuwayama, T; Monji, Y

2008-05-01

The duration of sperm-oocyte co-incubation has been observed to affect the sex ratio of in vitro produced bovine embryos. The purpose of this study was to investigate some factors that may be responsible for the skewed sex ratio. The factors studied were selected combinations of the duration of co-incubation, the presence or absence of cumulus cells, and the level of hyaluronic acid (HA) in the culture medium. Experiment 1 examined the effect of selected combinations of different factors during the fertilization phase of in vitro oocyte culture. The factors were the nature of the sperm or its treatment, the duration of the sperm-oocyte co-incubation, and the level of hyaluronic acid in the culture medium. In experiment 2, the capacitation of frozen-thawed-Percoll-washed sperm (control), pre-incubated, and non-binding sperm was evaluated by the zona pellucida (ZP) binding assay and the hypo-osmotic swelling test (HOST). The purpose of experiment 3 was to determine the oocyte cleavage rate and sex ratio of the embryos (>5 cells) produced as a consequence of the 10 treatments used in experiment 1. In treatments 1-3 (experiments 1 and 3) COC were co-cultured with sperm for 1, 5 or 18 h. Polyspermic fertilization rose as the co-incubation period increased (1 h 6.5%, 5 h 15.9%, 18 h 41.8%; P<0.05), and the highest rate of normal fertilization was observed for 5h culture (73.4%; P<0.05). The sex ratio was significantly (P<0.05) skewed from the expected 50:50 towards males following 1 h (64.4%) and 5 h (67.3%) co-incubation, but was not affected by 18 h incubation (52.3%). In treatment 4, sperm was pre-incubated for 1h and cultured with COC for 5 h. Relative to control sperm, pre-incubation of sperm increased ZP binding (116 versus 180 per ZP; P<0.05) and decreased the proportion of HOST positive sperm (65.8-48.6%; P<0.05; experiment 2). Pre-incubation did not affect the rates of polyspermy, normal fertilization or the sex ratio of the embryos (experiments 1 and 3). The oocytes used in treatments 5-10 of experiments 1 and 3 were denuded prior to fertilization. Co-incubation of denuded oocytes for 1h (treatment 5) or 5h (treatment 6) resulted in levels of polyspermic fertilization similar to that for treatment 2 with significantly lower levels of normal fertilization (41.7% and 52.6%, respectively; P<0.05), and the 1h co-incubation significantly skewed (P<0.05) the proportion of male embryos to 70.0%. Denuded oocytes were fertilized for 5h with sperm unable to bind to cumulus cells (NB sperm) in treatment 7 or those that bound to cumulus cells (B) in treatment 8. These two treatments had similar rates of polyspermic, normal and non-fertilization. However, the B sperm caused the sex ratio of the embryos to be significantly skewed to males (63.9%; P<0.05). Fertilization of denuded oocytes in medium containing hyaluronic acid (0.1 mg/ml, treatment 9; 1.0 mg/ml treatment 10) significantly (P<0.05) reduced the incidence of polyspermic fertilization relative to treatments 2 and 6, and normal fertilization relative to treatment 2, but did not affect the sex ratio of the embryos. It was concluded that exposure of sperm to cumulus cells, either before fertilization of denuded oocytes or during the process of fertilization of complete COC, increased the proportion of male embryos produced by in vitro culture. It was hypothesized that this may be due to the capacitation state of the sperm, the cumulus-sperm interaction, and/or the ability of the sperm to bind to cumulus cells or oocytes.

Cover Crops and Fertilization Alter Nitrogen Loss in Organic and Conventional Conservation Agriculture Systems

PubMed Central

Shelton, Rebecca E.; Jacobsen, Krista L.; McCulley, Rebecca L.

2018-01-01

Agroecosystem nitrogen (N) loss produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, conservation agricultural management practices aimed at reducing N loss are increasingly adopted. However, the ecosystem consequences of these practices have not been well-studied. We quantified N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant and soil pools of corn conservation agroecosystems in Kentucky, USA. Three systems were evaluated: (1) an unfertilized, organic system with cover crops hairy vetch (Vicia villosa), winter wheat (Triticum aestivum), or a mix of the two (bi-culture); (2) an organic system with a hairy vetch cover crop employing three fertilization schemes (0 N, organic N, or a fertilizer N-credit approach); and (3) a conventional system with a winter wheat cover crop and three fertilization schemes (0 N, urea N, or organic N). In the unfertilized organic system, cover crop species affected NO3-N leaching (vetch > bi-culture > wheat) and N2O-N emissions and yield during corn growth (vetch, bi-culture > wheat). Fertilization increased soil inorganic N, gaseous N loss, N leaching, and yield in the organic vetch and conventional wheat systems. Fertilizer scheme affected the magnitude of growing season N2O-N loss in the organic vetch system (organic N > fertilizer N-credit) and the timing of loss (organic N delayed N2O-N loss vs. urea) and NO3-N leaching (urea >> organic N) in the conventional wheat system, but had no effect on yield. Cover crop selection and N fertilization techniques can reduce N leaching and greenhouse gas emissions without sacrificing yield, thereby enhancing N conservation in both organic and conventional conservation agriculture systems. PMID:29403512

The Growth of Agarwood Plants on the Different Canopy Covers Level and Fertilizer in Oil Palm Plantation

NASA Astrophysics Data System (ADS)

Rahayu Prastyaningsih, Sri; Azwin

2017-12-01

The development of agar wood plants in oil palm plantation requires the forestry techniques in order to obtain maximum production. In an oil palm stands, the age of plant will affect the height, diameter, population and stands density. The older age of an oil palm stands will affect the canopy cover on the forest floor. Agar wood plants are semi-tolerant growth and oil palm can be used as shade. Unilak has an oil palm plantation area of 10 hectares around the campus with 10 years old and 20 years old. The soil condition at the study is Podsolik Merah Kuning (PMK) which poor nutrient and needs fertilization to increase soil fertility. This study aims to find out the effect of age of oil palm stands and fertilization for optimal growth. The split plot design with 2 main plots of the age of palm tree ( 10 years old and 20 years old) and five kinds of fertilizing sub plot (without fertilizer, 40 gram/plant of NPK, 80 gram/plat of NPK, 120 gram/plant of NPK and 180 gram/plant of NPK were used. The results of this research showed that the age of palm tree (canopy cover) treatment gave non-significant influence on the growing of agar wood until it reaches 4 months of growth. The canopyy cover by 10 years old of oil palm tree produce the best response on height (15 cm) and diameter (0,4 cm) growth of agar woods..Fertilizing treatment di not give any significant influence on the heigh and diameter growth of agarwood plants until reach 3 months. The interaction by 10 years old of palm with fertilizing gave non significant results.

Web-based survey of fertility issues in young women with breast cancer.

PubMed

Partridge, Ann H; Gelber, Shari; Peppercorn, Jeffrey; Sampson, Ebonie; Knudsen, Katherine; Laufer, Marc; Rosenberg, Randi; Przypyszny, Michele; Rein, Alison; Winer, Eric P

2004-10-15

Young women with breast cancer often seek advice about whether treatment will affect their fertility. We sought to gain a better understanding of women's attitudes about fertility and how these concerns affect decision making. We developed a survey about fertility issues for young women with a history of early-stage breast cancer. The survey was e-mailed to all registered Young Survival Coalition survivor members (N = 1,702). E-mail reminders were used. Six hundred fifty-seven eligible respondents completed the survey. Mean age at breast cancer diagnosis was 32.9 years; mean current age was 35.8 years. Ninety percent of women were white; 62% were married; 76% were college graduates. Stages at diagnosis were as follows: 0, 10%; I, 27%; II, 47%; III, 13%. Sixty-two percent of women were within 2 years of diagnosis. Fifty-seven percent recalled substantial concern at diagnosis about becoming infertile with treatment. In multivariate logistic regression, greater concern about infertility was associated with wish for children/more children (odds ratio [OR], 120; P < .0001), number of prior pregnancies (OR, 0.78; P = .01), and prior difficulty conceiving (OR, 1.86; P = .08). Twenty-nine percent of women reported that infertility concerns influenced treatment decisions. Seventy-two percent of women reported discussing fertility concerns with their doctors; 51% felt their concerns were addressed adequately. Women seemed to overestimate their risk of becoming postmenopausal with treatment. Fertility after treatment is a major concern for young women with breast cancer. There is a need to communicate with and educate young patients regarding fertility issues at diagnosis and a need for future research directed at preserving fertility for young breast cancer survivors.

Leaf Fertilizers Affect Survival and Behavior of the Neotropical Stingless Bee Friesella schrottkyi (Meliponini: Apidae: Hymenoptera).

PubMed

Rodrigues, Cleiton G; Krüger, Alexandra P; Barbosa, Wagner F; Guedes, Raul Narciso C

2016-04-11

The ongoing concern about bee decline has largely focused on honey bees and neonicotinoid insecticides, while native pollinators such as Neotropical stingless bees and agrochemicals such as other insecticide groups, pesticides in general, and fertilizers-especially leaf fertilizers-remain neglected as potential contributors to pollination decline. In an effort to explore this knowledge gap, we assessed the lethal and sublethal behavioral impact of heavy metal-containing leaf fertilizers in a native pollinator of ecological importance in the Neotropics: the stingless beeFriesella schrottkyi(Friese). Two leaf fertilizers-copper sulfate (24% Cu) and a micronutrient mix (Arrank L: 5% S, 5% Zn, 3% Mn, 0.6% Cu, 0.5% B, and 0.06% Mo)-were used in oral and contact exposure bioassays. The biopesticide spinosad and water were used as positive and negative controls, respectively. Copper sulfate compromised the survival of stingless bee workers, particularly with oral exposure, although less than spinosad under contact exposure. Sublethal exposure to both leaf fertilizers at their field rates also caused significant effects in exposed workers. Copper sulfate enhanced flight take-off on stingless bee workers, unlike workers exposed to the micronutrient mix. There was no significant effect of leaf fertilizers on the overall activity and walking behavior of worker bees. No significant effect was observed for the respiration rate of worker bees under contact exposure, but workers orally exposed to the micronutrient mix exhibited a reduced respiration rate. Therefore, leaf fertilizers do affectF. schrottkyi, what may also occur with other stingless bees, potentially compromising their pollination activity deserving attention. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed

Lan, Manyu; Kuang, Yaoqiu

2016-01-01

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

DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

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

Marchetti, Francesco; Wyrobek, Andrew J.

Exposure to ionizing radiation and other environmental agents can affect the genomic integrity of germ cells and induce adverse health effects in the progeny. Efficient DNA repair during gametogenesis and the early embryonic cycles after fertilization is critical for preventing transmission of DNA damage to the progeny and relies on maternal factors stored in the egg before fertilization. The ability of the maternal repair machinery to repair DNA damage in both parental genomes in the fertilizing egg is especially crucial for the fertilizing male genome that has not experienced a DNA repair-competent cellular environment for several weeks prior to fertilization.more » During the DNA repair-deficient period of spermatogenesis, DNA lesions may accumulate in sperm and be carried into the egg where, if not properly repaired, could result in the formation of heritable chromosomal aberrations or mutations and associated birth defects. Studies with female mice deficient in specific DNA repair genes have shown that: (i) cell cycle checkpoints are activated in the fertilized egg by DNA damage carried by the sperm; and (ii) the maternal genotype plays a major role in determining the efficiency of repairing genomic lesions in the fertilizing sperm and directly affect the risk for abnormal reproductive outcomes. There is also growing evidence that implicates DNA damage carried by the fertilizing gamete as a mediator of postfertilization processes that contribute to genomic instability in subsequent generations. Transgenerational genomic instability most likely involves epigenetic mechanisms or error-prone DNA repair processes in the early embryo. Maternal and embryonic DNA repair processes during the early phases of mammalian embryonic development can have far reaching consequences for the genomic integrity and health of subsequent generations.« less

Fertility comparison between wild type and transgenic mice by in vitro fertilization.

PubMed

Vasudevan, Kuzhalini; Raber, James; Sztein, Jorge

2010-08-01

Transgenic mice are increasingly used as animal models for studies of gene function and regulation of mammalian genes. Although there has been continuous and remarkable progress in the development of transgenic technology over several decades, many aspects of the resulting transgenic model's phenotype cannot be completely predicted. For example, it is well known that as a consequence of the random insertion of the injected DNA construct, several founder mice of the new line need to be analyzed for possible differences in phenotype secondary to different insertion sites. The Knock out technique for transgenic production disrupts a specific gene by insertion or homologous recombination creating a null expression or replacement of the gene with a marker to localize it expression. This modification could result in pleiotropic phenotype if the gene is also expressed in tissues other than the target organs. Although the future breeding performance of the newly created model is critical to many studies, it is rarely anticipated that the new integrations could modify the reproductive profile of the new transgenic line. To date, few studies have demonstrated the difference between the parent strain's reproductive performance and the newly developed transgenic model. This study was designed to determine whether a genetic modification, knock out (KO) or transgenics, not anticipated to affect reproductive performance could affect the resulting reproductive profile of the newly developed transgenic mouse. More specifically, this study is designed to study the impact of the genetic modification on the ability of gametes to be fertilized in vitro. We analyzed the reproductive performance of mice with different background strains: FVB/N, C57BL/6 (129Sv/J x C57Bl/6)F1 and outbred CD1((R)) and compared them to mice of the same strain carrying a transgene or KO which was not anticipated to affect fertility. In vitro Fertilization was used to analyze the fertility of the mice. Oocytes from superovulated females were inseminated with sperm of same background. Fertility rate was considered as the percentage of two cell embryos scored 24 h after insemination. The data collected from this study shows that the fertilization rate is affected (reduced to half fold) in some of the transgenic mice compared to the respective Wild Type (WT) mice. For the WT the average fertility rate ranged from 80% (C57BL/6), 90% (FVB/N), 45% (129Sv/J x C57Bl/6)F1 and 43% (CD1). For transgenic mice it was 52% (C57BL/6), 65% (FVB/N), 22% (129Sv/J x C57Bl/6)F1 and 25% (CD1).

The Effect of Gender Policies on Fertility: The Moderating Role of Education and Normative Context.

PubMed

Baizan, Pau; Arpino, Bruno; Delclòs, Carlos Eric

In this paper, we aim to assess the extent to which individual-level completed fertility varies across contexts characterized by policies supporting different gender division of labor models. We examine key labor market and care policies that shape gender relations in households and in the public domain. We also consider the role of gender norms, which can act as both a moderator and a confounding factor for policy effects. We hypothesize that, by facilitating role compatibility and reducing the gendered costs of childrearing, policies that support gender equality lead to an increase in fertility levels and to a reduction in fertility differentials by the level of education. Using individual-level data from the European Union Survey on Income and Living Conditions for 16 countries, combined with country-level data, we analyze completed fertility through multilevel Poisson's models. We find that the national level of childcare coverage is positively associated with fertility. Family allowances, prevalence of women's part-time employment and length of paid leaves were also found to be positively associated with completed fertility, though the associations were not statistically significant. These variables show a significant positive pattern according to education. A high number of average working hours for men are negatively associated with completed fertility and show a strong negative pattern by educational level. The prevalence of gender-egalitarian norms is highly predictive of fertility levels, yet we found no consistent evidence of a weaker association of gender-equality policies in countries where egalitarian values are less prevalent.

The relationship between poverty and fertility in some less developed countries.

PubMed

Chin Ptc

1985-12-01

The author investigates the extent to which both absolute and relative poverty affect population growth in developing countries. Aggregate data from U.N. sources for 26 countries at various stages of the fertility transition are used. The results indicate that the most significant steps in reducing fertility would be more effective provision of basic human needs and reforms in land tenure. The need to distinguish between absolute and relative poverty in formulating population policies is noted.

Precipitation of impurities in 9-32-0 grade fluid fertilizers

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

Dillard, E.F.; Scheib, R.M.; Greenwell, B.E.

1986-01-01

For several years TVA has been studying production of 9-32-0 ammonium polyphosphate suspension produced from ammoniated merchant-grade wet-process orthophosphoric acid. Suspensions containing polyphosphate have an advantage over those that contain only orthophosphate in that they can be stored satisfactorily at much lower temperature. However, the introduction of polyphosphate (pyrophosphate anion) complicates the precipitation of impurities and has yielded inconsistent storage characteristics in 9-32-0 fluid fertilizers. Fluorine also has been shown to affect suspension fertilizer properties. The viscosity of 13-38-0 orthophosphate suspension fertilizers is affected by the atomic ratios F:(Al + Fe + Mg). Addition of fluorine prevents sludges and precipitatesmore » in ammonium polyphosphate fertilizer solutions - the proper amount of fluorine is related to the amount of each of the metallic impurities present and also to the fraction of the phosphate present as pyrophosphate. Incorporation of polyphosphate or fluorine or both has been shown to have positive effects on ammoniated wet-process phosphoric acid (WPPA), but they do not report the solubility relationships of the cation impurities (Fe, Al, Mg, and Ca) with respect to the anion constituents (PO/sub 4/, P/sub 2/O/sub 7/, and F). Therefore, a factorial study was developed to determine the solubility relationships of the precipitated metal impurities encountered in 9-32-0 fluid fertilizers. 10 refs., 1 fig., 20 tabs.« less

Commodity aspirations in Easterlin's relative income theory of fertility.

PubMed

Ahlburg, D A

1984-01-01

This paper presents the preference ordering that underlies Easterlin's relative income theory of fertility. Commodity aspirations are a key component of the theory and the paper explores how the introduction of commodity aspirations into the utility function affects the consumption of commodities and bearing of children. The formation and empirical specification of commodity aspirations are also discussed. Commodity aspirations are formed by the material environment experienced during childhood and are primarily a function of parental income. Easterlin, Leibenstein and Ben-Porath argus that it is the parental consumption or standard of living that determines the child's testes or aspirations. It is the parents' spending on themseleves rather than total parental income that can be used as a proxy for the child's commodity aspirations. Bagozzi and Van Loo identify 4 significant contributions made by Easterlinhs theory of fertility. They cite his stress on potential income flow through time as being pertinent to household decision making; tastes being an explicit determinant of fertility; background charactersticis and norms as to standards of child care and family size affecting fertility indirectly through tastes rather than directly; and the fact that relative income has an effect on fertility in addition to the influence of the absolute level of income. The number of children demanded is a negative function of commodity aspirations, as is the utility of the family. Studies of the demand for commodities and children should include data on parental resources.

The potential for chromium to affect the fertilization process of Chinook salmon (Oncorhynchus tshawytscha) in the Hanford reach of the Columbia River, Washington, USA.

PubMed

Farag, A M; Harper, D D; Cleveland, L; Brumbaugh, W G; Little, E E

2006-05-01

The Hanford Nuclear Reservation in south central Washington was claimed by the federal government as a site for the production of plutonium. During the course of production and operation of the facilities at Hanford, radionuclides and chromium were discharged directly into the river and also contaminated the groundwater. This study was designed to assess the effects of chromium (Cr) on Chinook salmon (Oncorhynchus tshawytscha) fertilization under exposure conditions similar to those of the Hanford Reach of the Columbia River. Chinook salmon gametes were exposed to aqueous Cr concentrations ranging from 0 to 266 microg Cr l(-1). The current ambient water-quality criteria (AWQC) established for the protection of aquatic life (United States Environmental Protection Agency [USEPA] 1986) is 11 microg Cr l(-1). Cr has been measured in pore water from bottom sediments of the Columbia River at concentrations >600 microg Cr l(-1). Under exposure conditions designed to closely mimic events that occur in the river, the fertilization of Chinook salmon eggs was not affected by concentrations of Cr ranging from 11 to 266 microg Cr l(-1). Data suggest that the instantaneous nature of fertilization likely limits the potential effects of Cr on fertilization success. As a result, the current AWQC of 11 mug Cr l(-1) is most likely protective of Chinook salmon fertilization.

The potential for chromium to affect the fertilization process of Chinook salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River, Washington, USA

USGS Publications Warehouse

Farag, A.M.; Harper, D.D.; Cleveland, L.; Brumbaugh, W.G.; Little, E.E.

2006-01-01

The Hanford Nuclear Reservation in south central Washington was claimed by the federal government as a site for the production of plutonium. During the course of production and operation of the facilities at Hanford, radionuclides and chromium were discharged directly into the river and also contaminated the groundwater. This study was designed to assess the effects of chromium (Cr) on Chinook salmon (Oncorhynchus tshawytscha) fertilization under exposure conditions similar to those of the Hanford Reach of the Columbia River. Chinook salmon gametes were exposed to aqueous Cr concentrations ranging from 0 to 266 μg Cr l−1. The current ambient water-quality criteria (AWQC) established for the protection of aquatic life (United States Environmental Protection Agency [USEPA] 1986) is 11 μg Cr l−1. Cr has been measured in pore water from bottom sediments of the Columbia River at concentrations >600 μg Cr l−1. Under exposure conditions designed to closely mimic events that occur in the river, the fertilization of Chinook salmon eggs was not affected by concentrations of Cr ranging from 11 to 266 μg Cr l−1. Data suggest that the instantaneous nature of fertilization likely limits the potential effects of Cr on fertilization success. As a result, the current AWQC of 11 μg Cr l−1 is most likely protective of Chinook salmon fertilization.

Deficiencies in the uterine environment and failure to support embryo development

USDA-ARS?s Scientific Manuscript database

Pregnancy failure in livestock can result from failure to fertilize the oocyte or embryonic loss during gestation. Although fertilization failure occurs, embryonic mortality has a greater contribution to pregnancy failure. The focus of this review is on cattle and factors affecting, and mechanisms r...

A mechanist understanding of tree responses to thinning and fertilization from stable isotopes in tree rings

EPA Science Inventory

Carbon sequestration and the possible associated economic credits have focused renewed interest in understanding how forest management affects forest growth over timescales of decades. Two of the most common forest management tools are thinning and fertilization, and yet details ...

Dynamic constraints on CO2 uptake by an iron-fertilized Antarctic

NASA Technical Reports Server (NTRS)

Peng, Tsung-Hung; Broecker, Wallace S.; Oestlund, H. G.

1992-01-01

The topics covered include the following: tracer distribution and dynamics in the Antarctic Ocean; a model of Antarctic and Non-Antarctic Oceans; effects on an anthropogenically affected atmosphere; effects of seasonal iron fertilization; and implications of the South Atlantic Ventilation Experiment C-14 results.

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

PubMed

Weinstein, J

1978-01-01

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

Mental disorders in childhood and young adulthood among children born to women with fertility problems.

PubMed

Svahn, M F; Hargreave, M; Nielsen, T S S; Plessen, K J; Jensen, S M; Kjaer, S K; Jensen, A

2015-09-01

Is the risk of hospital admission or outpatient contact for mental disorders increased in children born to women with fertility problems compared with children born to women without fertility problems? We found an increased risk of hospital admission or outpatient contact for mental disorders in children born to women with fertility problems. Few studies have investigated the risk of mental disorders in children born after fertility treatment and although some studies have pointed to an increased risk, others found no association. The inconsistent results may be due to methodological constraints in many previous studies, including small sample size and short follow-up, resulting in imprecise risk estimates and lack of information on risk patterns of mental disorders in adulthood. This nationwide retrospective register-based cohort study included all 2 412 721 children born in Denmark between 1969 and 2006. All children were followed from date of birth until date of hospital contact for a mental disorder, date of emigration, date of death or 31 December 2009, whichever occurred first. Information concerning maternal fertility status for all children in the cohort was obtained by linkage to the Danish Infertility Cohort, which contains data on nearly all women with fertility problems in Denmark since 1963. A total of 124 269 (5%) children were born to women with fertility problems and 2 288 452 (95%) to women without fertility problems. To identify children hospitalized for a mental disorder, the cohort was linked to the Danish Psychiatric Central Research Registry. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between maternal fertility status and the risk of hospital admission or outpatient contact for various groups of mental disorders, including any mental disorder and all 11 main discharge diagnostic groups, classified according to the International Classification of Diseases, version 10. During a mean follow-up period of 21 years (range, 0-40 years), 168 686 (7%) children were admitted to hospital or had an outpatient contact for a mental disorder. Children born to women with fertility problems had a significantly higher risk of any mental disorder (HR 1.23; 95% CI 1.20-1.26) and for most of the 11 main discharge groups, including schizophrenia (HR 1.16; 95% CI 1.07-1.27), mood (affective) disorders (HR 1.21; 95% CI 1.15-1.28) and disorders of psychological development (HR 1.15; 95% CI 1.09-1.21) as well as the subgroup of attention-deficit/hyperactivity disorders (HR 1.36; 95% CI 1.29-1.45) compared with children born to women without fertility problems. The risk estimates did not change markedly when analyses were performed separately for mental disorders diagnosed during childhood (0-19 years) and in young adulthood (20-40 years). The true risk of mental disorders may be somewhat underestimated, as only severe disorders requiring hospital admission or outpatient contact were considered as events. Furthermore, we could not determine whether the increased risks observed were due to factors related to the underlying infertility or to fertility treatment procedures. This is the first report on mental disorders in adulthood among children born to women with fertility problems. Furthermore, we have assessed the risk of several severe mental disorders not previously studied (e.g. neurotic, stress-related and somatoform disorders and disorders of adult personality and behaviour). These important findings should be investigated further in large epidemiological studies designed to differentiate between factors related to fertility treatment and to the underlying infertility. The study was supported by internal funding from the Unit of Virus, Lifestyle and Genes at the Danish Cancer Society Research Center. All authors report no conflicts of interest. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Abortion legalization and childbearing in Mexico1

PubMed Central

Gutierrez Vazquez, Edith Y.; Parrado, Emilio A.

2016-01-01

In 2007 abortion was legalized in the Federal District of Mexico, making the largest jurisdiction in Latin America, outside of Cuba, to allow women to have abortions on request during the first trimester of pregnancy. While the implications of the law for women's health and maternal mortality have been investigated, its potential association with fertility behavior has yet to be assessed. In this paper, we examine metropolitan area differences in overall and parity-specific, as well as the age pattern of childbearing between 2000 and 2010 to more precisely isolate the contribution of abortion legalization to fertility in Mexico. Our statistical specification applies difference-in-difference regression methods that control for concomitant changes in other socioeconomic predictors of fertility to assess the differential influence of the law across age groups. In addition, we account for prior fertility levels and change to better separate the effect of the law from preceding trends. Overall, the evidence suggests a systematic association between abortion legalization and fertility. The law appears to have contributed to lower fertility in Mexico City compared to other metropolitan areas and prior trends, though the influence is mostly visible among women aged 20-34 in connection with the transition to first and second child with limited impact on teenage fertility. There is some evidence that its effect might be diffusing to the greater Mexico City metropolitan area. PMID:27285423

Fertility and Child Mortality in Urban West Africa: Leveraging geo-referenced data to move beyond the urban/rural dichotomy

PubMed Central

Corker, Jamaica

2016-01-01

Demographic research in sub-Saharan Africa (SSA) has long relied on a blunt urban/rural dichotomy that may obscure important inter-urban fertility and mortality differentials. This paper uses Demographic and Health Survey (DHS) geo-referenced data to look beyond the simple urban/rural division by spatially locating survey clusters along an urban continuum and producing estimates of fertility and child mortality by four city size categories in West Africa. Results show a gradient in urban characteristics and demographic outcomes: the largest cities are the most advantaged and smaller cities least advantaged with respect to access to urban amenities, lower fertility and under-5 survival rates. There is a difference in the patterns of fertility and under-five survival across urban categories, with fertility more linearly associated with city size while the only significant distinction for under-5 survival in urban areas is broadly between the larger and smaller cities. Notably, the small urban “satellite cities” that are adjacent to the largest cities have the most favorable outcomes of all categories. Although smaller urban areas have significantly lower fertility and child mortality than rural areas, in some cases this difference is nearly as large between the smallest and largest urban areas. These results are used to argue for the need to give greater consideration to employing an urban continuum in demographic research. PMID:28943812

Abortion Legalization and Childbearing in Mexico.

PubMed

Gutiérrez Vázquez, Edith Y; Parrado, Emilio A

2016-06-01

In 2007 abortion was legalized in the Federal District of Mexico, making it the largest jurisdiction in Latin America, outside of Cuba, to allow women to have abortions on request during the first trimester of pregnancy. While the implications of the law for women's health and maternal mortality have been investigated, its potential association with fertility behavior has yet to be assessed. We examine metropolitan-area differences in overall and parity-specific childbearing, as well as the age pattern of childbearing between 2000 and 2010 to identify the contribution of abortion legalization to fertility in Mexico. Our statistical specification applies difference-in-difference regression methods that control for concomitant changes in other socioeconomic predictors of fertility to assess the differential influence of the law across age groups. In addition, we account for prior fertility levels and change to better separate the effect of the law from preceding trends. Overall, the evidence suggests a systematic association between abortion legalization and fertility. The law appears to have contributed to lower fertility in Mexico City compared to other metropolitan areas and prior trends. The influence is mostly visible among women aged 20-34 in connection with the transition to first and second child, with limited impact on teenage fertility. There is some evidence that its effect might be diffusing to the Greater Mexico City Metropolitan area. © 2016 The Population Council, Inc.

Stem cells, in vitro gametogenesis and male fertility.

PubMed

Nagamatsu, Go; Hayashi, Katsuhiko

2017-12-01

Reconstitution in culture of biological processes, such as differentiation and organization, is a key challenge in regenerative medicine, and one in which stem cell technology plays a central role. Pluripotent stem cells and spermatogonial stem cells are useful materials for reconstitution of germ cell development in vitro , as they are capable of differentiating into gametes. Reconstitution of germ cell development, termed in vitro gametogenesis, will provide an experimental platform for a better understanding of germ cell development, as well as an alternative source of gametes for reproduction, with the potential to cure infertility. Since germ cells are the cells for 'the next generation', both the culture system and its products must be carefully evaluated. In this issue, we summarize the progress in in vitro gametogenesis, most of which has been made using mouse models, as well as the future challenges in this field. © 2017 Society for Reproduction and Fertility.

Differential proteomics of human seminal plasma: A potential target for searching male infertility marker proteins.

PubMed

Tomar, Anil Kumar; Sooch, Balwinder Singh; Singh, Sarman; Yadav, Savita

2012-04-01

The clinical fertility tests, available in the market, fail to define the exact cause of male infertility in almost half of the cases and point toward a crucial need of developing better ways of infertility investigations. The protein biomarkers may help us toward better understanding of unknown cases of male infertility that, in turn, can guide us to find better therapeutic solutions. Many clinical attempts have been made to identify biomarkers of male infertility in sperm proteome but only few studies have targeted seminal plasma. Human seminal plasma is a rich source of proteins that are essentially required for development of sperm and successful fertilization. This viewpoint article highlights the importance of human seminal plasma proteome in reproductive physiology and suggests that differential proteomics integrated with functional analysis may help us in searching potential biomarkers of male infertility. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Juvenile exposure to vinclozolin shifts sex ratios and impairs reproductive capacity of zebrafish.

PubMed

Lor, Yer; Revak, Andrew; Weigand, Jenna; Hicks, Elisabeth; Howard, David R; King-Heiden, Tisha C

2015-12-01

Exposure to endocrine disruptors during critical periods of development can impact the sustainability of wild fish populations. Anti-androgenic compounds have received less attention, but are capable of modulating gonad differentiation and maturation, and impairing reproduction in fish. The fungicide vinclozolin (VZ) has been shown to impair reproduction in adult fish, but less is known about its effects following exposure earlier in development. Here we show that waterborne exposure to 400μg VZ/L during critical periods of sex differentiation (21-35 days post fertilization) permanently shifts sex ratios towards females, and alters the maturation of the gonad. Both fecundity and fertility were reduced, even when oogenesis and spermatogenesis recover and sperm motility is not altered. These results demonstrate the need to better understand the impacts of early exposure to anti-androgenic compounds on fish. Copyright © 2015 Elsevier Inc. All rights reserved.

Hybrid male sterility and genome-wide misexpression of male reproductive proteases.

PubMed

Gomes, Suzanne; Civetta, Alberto

2015-07-06

Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation.

Hybrid male sterility and genome-wide misexpression of male reproductive proteases

PubMed Central

Gomes, Suzanne; Civetta, Alberto

2015-01-01

Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation. PMID:26146165

Dynamics of maize carbon contribution to soil organic carbon in association with soil type and fertility level.

PubMed

Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

2015-01-01

Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition.

Dynamics of Maize Carbon Contribution to Soil Organic Carbon in Association with Soil Type and Fertility Level

PubMed Central

Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

2015-01-01

Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition. PMID:25774529

Performance of low-input turfgrass species as affected by mowing and nitrogen fertilization in Minnesota

USDA-ARS?s Scientific Manuscript database

In Minnesota, most lawns and higher cut turfgrass areas consist primarily of species such as Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.) that require significant management inputs such as frequent mowing and nitrogen fertility. Several studies have shown that oth...

The response of ammonia-oxidizer activity and community structure to fertilizer amendment of orchard soils

USDA-ARS?s Scientific Manuscript database

Soil microorganisms have the potential to dramatically alter the nitrogen (N) availability in agricultural systems, and therefore affect the efficiency of fertilizer application. Data regarding the effects of cereal management systems on the soil microbiology functional to N cycling have yielded var...

A mechanistic understanding of tree responses to hinning and fertilization from stable isotopes in tree rings

EPA Science Inventory

Carbon sequestration has focused renewed interest in understanding how forest management affects forest carbon gain over timescales of decades. Two of the most common forest management tools are thinning and fertilization, and yet details on physiological responses to these tools...

Extrinsic and intrinsic factors controlling spermatogonial stem cell self-renewal and differentiation.

PubMed

Mei, Xing-Xing; Wang, Jian; Wu, Ji

2015-01-01

Spermatogonial stem cells (SSCs), the stem cells responsible for male fertility, are one of a small number of cells with the abilities of both self-renewal and generation of large numbers of haploid cells. Technology improvements, most importantly, transplantation assays and in vitro culture systems have greatly expanded our understanding of SSC self-renewal and differentiation. Many important molecules crucial for the balance between self-renewal and differentiation have been recently identified although the exact mechanism(s) remain largely undefined. In this review, we give a brief introduction to SSCs, and then focus on extrinsic and intrinsic factors controlling SSCs self-renewal and differentiation.

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

PubMed

Kuniansky, A

1983-06-01

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

Distinct Microbial Limitations in Litter and Underlying Soil Revealed by Carbon and Nutrient Fertilization in a Tropical Rainforest

PubMed Central

Fanin, Nicolas; Barantal, Sandra; Fromin, Nathalie; Schimann, Heidy; Schevin, Patrick; Hättenschwiler, Stephan

2012-01-01

Human-caused alterations of the carbon and nutrient cycles are expected to impact tropical ecosystems in the near future. Here we evaluated how a combined change in carbon (C), nitrogen (N) and phosphorus (P) availability affects soil and litter microbial respiration and litter decomposition in an undisturbed Amazonian rainforest in French Guiana. In a fully factorial C (as cellulose), N (as urea), and P (as phosphate) fertilization experiment we analyzed a total of 540 litterbag-soil pairs after a 158-day exposure in the field. Rates of substrate-induced respiration (SIR) measured in litter and litter mass loss were similarly affected by fertilization showing the strongest stimulation when N and P were added simultaneously. The stimulating NP effect on litter SIR increased considerably with increasing initial dissolved organic carbon (DOC) concentrations in litter, suggesting that the combined availability of N, P, and a labile C source has a particularly strong effect on microbial activity. Cellulose fertilization, however, did not further stimulate the NP effect. In contrast to litter SIR and litter mass loss, soil SIR was reduced with N fertilization and showed only a positive effect in response to P fertilization that was further enhanced with additional C fertilization. Our data suggest that increased nutrient enrichment in the studied Amazonian rainforest can considerably change microbial activity and litter decomposition, and that these effects differ between the litter layer and the underlying soil. Any resulting change in relative C and nutrient fluxes between the litter layer and the soil can have important consequences for biogeochemical cycles in tropical forest ecosystems. PMID:23272052

Do in vitro fertilization treatments result in healthy babies?

PubMed

Kaartinen, Noora; Tinkanen, Helena

In Finland, the proportion of children born as a result of in vitro fertilization treatments is annually approximately 3.3%, and the percentage proportion of the population is growing. Their general somatic health status and cognitive development do not differ from spontaneously fertilized children. In vitro fertilization treatments are, however, associated with a slightly elevated risk of preterm delivery, low birth weight and structural abnormalities. The risk of childhood cancer does not appear to be increased in IVF children. The in vitro fertilization process affects the embryonic epigenome, which organizes itself during early embryonic development. These changes may influence the phenotype and health profile of the unborn child. The effect of in vitro fertilization treatments on an individual's long-term health is poorly understood, requiring prospective follow-up studies with sufficiently large datasets. In vitro fertilization treatments are the most effective way to treat infertility, and the treatments are generally safe both for the future mother and the baby being born.

Fertility Preservation for Cancer Patients: A Review

PubMed Central

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

2010-01-01

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

Post-Disaster Fertility: Hurricane Katrina and the Changing Racial Composition of New Orleans

PubMed Central

Seltzer, Nathan; Nobles, Jenna

2017-01-01

Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences—beyond migration-driven population change—generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster’s wake. PMID:29200546

Post-Disaster Fertility: Hurricane Katrina and the Changing Racial Composition of New Orleans.

PubMed

Seltzer, Nathan; Nobles, Jenna

2017-06-01

Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences-beyond migration-driven population change-generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster's wake.

COMPLETED FERTILITY DURING THE TWENTIETH CENTURY: AN EXAMPLE FROM SIX SETTLEMENTS IN NORTHERN GREECE.

PubMed

Zafeiris, Konstantinos N; Kaklamani, Stamatina

2018-02-06

This study aimed to delineate temporal trends and differentials of completed fertility and their relationship with some characteristics of the marriage system in specific anthropological populations of northern Greece. The analysis was based on the life history of quinquennial and decennial birth cohorts of married women born in the 20th century who reproduced solely within the settlements studied. The variables studied were: children ever born, mean age of mother at first marriage, mean age of mother at first child (live birth), mean age of mother at last child and reproductive span. The results indicated that there were significant differences in the demographic characteristics of marriage and that there was an ongoing fertility transition in the 20th century in the populations studied. The mechanism of fertility decline was connected with the gradual reduction of the mean age of the mother at last child, the parallel decrease in the mean age at childbearing and a shortening of the reproductive span. Fertility levels at all times maintained a dynamic character imposed by local cultural, economic and social structures, which, in turn, were part of broader national and international structures, in all the populations studied. A strong trend of convergence of fertility levels was observed among the populations studied.

Cloning and expression analysis of a new anther-specific gene CaMF4 in Capsicum annuum.

PubMed

Hao, Xuefeng; Chen, Changming; Chen, Guoju; Cao, Bihao; Lei, Jianjun

2017-03-01

Our previous study on the genic male sterile-fertile line 114AB of Capsicum annuum indicated a diversity of differentially expressed cDNA fragments in fertile and sterile lines. In this study, a transcript-derived fragment (TDF), male fertile 4 (CaMF4) was chosen for further investigation to observe that this specific fragment accumulates in the flower buds of the fertile line. The full genomic DNA sequence of CaMF4 was 894 bp in length, containing two exons and one intron, and the complete coding sequence encoded a putative 11.53 kDa protein of 109 amino acids. The derived protein of CaMF4 shared similarity with the members of PGPS/D3 protein family. The expression of CaMF4 was detected in both the flower buds at stage 8 and open flowers of the male fertile line. In contrast to this observation, expression of CaMF4 was not detected in any organs of the male sterile line. Further analysis revealed that CaMF4 was expressed particularly in anthers of the fertile line. Our results suggest that CaMF4 is an anther-specific gene and might be indispensable for anther or pollen development in C. annuum.

Effects of different fertilizers on growth and nutrient uptake of Lolium multiflorum grown in Cd-contaminated soils.

PubMed

Liu, Mohan; Li, Yang; Che, Yeye; Deng, Shaojun; Xiao, Yan

2017-10-01

This study aimed to explore the effects of different fertilizers and their combinations on growth and nutrient and Cd uptake of Lolium multiflorum. Compared with control treatment, chemical fertilizer, organic manure, and their conjunctions with biofertilizer increased shoot biomass. Biofertilizers were found to cause significant reductions in shoot biomass of plants grown in organic manure-treated and control soil. Decreased soil-available N and P and shoot N and K concentrations in biofertilizer amendment treatments indicated that plant growth and nutrient absorption might be negatively affected under nutrient deficiency conditions. Elevated shoot biomasses contributed to the highest shoot Cd contents in chemical fertilizer and chemical fertilizer + biofertilizer treatments among all treatments. But the maximum translocation efficiency occurred in biofertilizer + chemical fertilizer + organic manure treatment, followed by organic manure and chemical fertilizer + organic manure treatments. Based on the results, we can conclude that the application of only the biofertilizer Bacillus subtilis should be avoided in nutrient-limited soils. Chemical fertilizer application could benefit the amount of Cd in shoots, and organic manure application and its combinations could result in the higher translocation efficiency.

Long-term organic-inorganic fertilization ensures great soil productivity and bacterial diversity after natural-to-agricultural ecosystem conversion.

PubMed

Xun, Weibing; Xu, Zhihui; Li, Wei; Ren, Yi; Huang, Ting; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

2016-09-01

Natural ecosystems comprise the planet's wild plant and animal resources, but large tracts of land have been converted to agroecosystems to support the demand for agricultural products. This conversion limits the number of plant species and decreases the soil biological diversity. Here we used high-throughput 16S rRNA gene sequencing to evaluate the responses of soil bacterial communities in long-term converted and fertilized red soils (a type of Ferralic Cambisol). We observed that soil bacterial diversity was strongly affected by different types of fertilization management. Oligotrophic bacterial taxa demonstrated large relative abundances in chemically fertilized soil, whereas copiotrophic bacterial taxa were found in large relative abundances in organically fertilized and fallow management soils. Only organic-inorganic fertilization exhibited the same local taxonomic and phylogenetic diversity as that of a natural ecosystem. However, the independent use of organic or inorganic fertilizer reduced local taxonomic and phylogenetic diversity and caused biotic homogenization. This study demonstrated that the homogenization of bacterial communities caused by natural-to-agricultural ecosystem conversion can be mitigated by employing rational organic-inorganic fertilization management.

VOC emissions and carbon balance of two bioenergy plantations in response to nitrogen fertilization: A comparison of Miscanthus and Salix.

PubMed

Hu, Bin; Jarosch, Ann-Mareike; Gauder, Martin; Graeff-Hönninger, Simone; Schnitzler, Jörg-Peter; Grote, Rüdiger; Rennenberg, Heinz; Kreuzwieser, Jürgen

2018-06-01

Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from Miscanthus and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha -1 yr -1 ). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH . reactivity resulting from individual VOC emitted. Total VOC emissions from Salix was 1.5- and 2.5-fold higher compared to Miscanthus in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in Salix (80-130 μg g -1 DW h -1 ), whereas it was negligible in Miscanthus. We identified twenty-eight VOC compounds, which were released by Miscanthus with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by Salix. OH . reactivity from VOC released by Salix was ca. 8-times higher than that of Miscanthus. N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized Miscanthus compared to Salix together with the considerably lower OH . reactivity per weight unit of biomass produced, qualified the C 4 -perennial grass Miscanthus as a superior source of future bioenergy production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Markov modeling and reliability analysis of urea synthesis system of a fertilizer plant

NASA Astrophysics Data System (ADS)

Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram; Garg, Tarun Kr.

2015-12-01

This paper deals with the Markov modeling and reliability analysis of urea synthesis system of a fertilizer plant. This system was modeled using Markov birth-death process with the assumption that the failure and repair rates of each subsystem follow exponential distribution. The first-order Chapman-Kolmogorov differential equations are developed with the use of mnemonic rule and these equations are solved with Runga-Kutta fourth-order method. The long-run availability, reliability and mean time between failures are computed for various choices of failure and repair rates of subsystems of the system. The findings of the paper are discussed with the plant personnel to adopt and practice suitable maintenance policies/strategies to enhance the performance of the urea synthesis system of the fertilizer plant.

Reduced embryonic survival in rainbow trout resulting from paternal exposure to the environmental estrogen 17 alpha- ethynylestradiol during late sexual maturation

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

Brown, Kim H.; Schultz, Irvin R.; Nagler, James J.

Exposure of fishes to environmental estrogens is known to affect sexual development and spawning, but little information exists regarding effects on gametes. This study evaluated embryonic survival of offspring from male rainbow trout (Oncorhynchus mykiss) exposed to 17a-ethynylestradiol (EE 2)using an in vitro fertilization protocol. Males were exposed at either 1800 or 6700 degree days (8d) (i.e. 161 or 587 days post-fertilization (dpf)) to test for effects on testes linked to reproductive ontogeny. At 18008d, fish were beginning testicular differentiation and were exposed to 109 ng EE 2/l for 21 days. At 67008d, fish have testes containing spermatocytes and spermatidsmore » and were exposed for 56 days to either 0.8, 8.3, or 65 ng EE 2/l. Semen was collected at full sexual maturity in each group and used to fertilize eggs pooled from several non-exposed females. Significant decreases in embryonic survival were observed only with the 67008d exposure. In 0.8 and 8.3 ng EE 2/l treatments, embryo survival was significantly reduced at 19 dpf when compared with the control. In contrast, an immediate decrease in embryonic survival at 0.5 dpf was observed in the 65 ng EE 2/l treatment. Blood samples collected at spawning from 67008d exposed males revealed a significant decrease in 11-ketotestosterone and a significant increase in luteinizing hormone levels for the 65 ng EE 2/l treatment when compared with the other treatment groups. Results indicate that sexually maturing male rainbow trout are susceptible to EE 2 exposure with these fish exhibiting two possible mechanisms of reduced embryonic survival through sperm varying dependant« less

Marchantia MpRKD Regulates the Gametophyte-Sporophyte Transition by Keeping Egg Cells Quiescent in the Absence of Fertilization.

PubMed

Rövekamp, Moritz; Bowman, John L; Grossniklaus, Ueli

2016-07-11

Unlike in animals, the life cycle of land plants alternates between two multicellular generations, the haploid gametophyte and the diploid sporophyte [1]. Gamete differentiation initiates the transition from the gametophyte to the sporophyte generation and, upon maturation, the egg cell establishes a quiescent state that is maintained until fertilization. This quiescence represents a hallmark of the gametophyte-sporophyte transition. The underlying molecular mechanisms are complex and best characterized in the flowering plant Arabidopsis thaliana [2-4]. However, only few genes with egg cell-specific expression or defects have been identified [5-10]. Intriguingly, ectopic expression of members of a clade of RWP-RK domain (RKD)-containing transcription factors, which are absent from animal genomes [11-13], can induce an egg cell-like transcriptome in sporophytic cells of A. thaliana. Yet, to date, loss-of-function experiments have not produced phenotypes affecting the egg cell, likely due to genetic redundancy and/or cross-regulation among the five RKD genes of A. thaliana [10]. To reduce genetic complexity, we explored the genome of Marchantia polymorpha, a liverwort belonging to the basal lineage of extant land plants [14-17]. Based on sequence homology, we identified a single M. polymorpha RKD gene, MpRKD, which is orthologous to all five A. thaliana RKD genes. Analysis of the MpRKD expression pattern and characterization of lines with reduced MpRKD activity indicate that it functions as a regulator of gametophyte development and the gametophyte-sporophyte transition. In particular, MpRKD is required to establish and/or maintain the quiescent state of the egg cell in the absence of fertilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reduced embryonic survival in rainbow trout resulting from paternal exposure to the environmental estrogen 17α-ethynylestradiol during late sexual maturation

PubMed Central

Brown, Kim H; Schultz, Irvin R; Nagler, James J

2007-01-01

Exposure of fishes to environmental estrogens is known to affect sexual development and spawning, but little information exists regarding effects on gametes. This study evaluated embryonic survival of offspring from male rainbow trout (Oncorhynchus mykiss) exposed to 17α-ethynylestradiol (EE2) using an in vitro fertilization protocol. Males were exposed at either 1800 or 6700 degree days (°d) (i.e. 161 or 587 days post-fertilization (dpf)) to test for effects on testes linked to reproductive ontogeny. At 1800°d, fish were beginning testicular differentiation and were exposed to 109 ng EE2/l for 21 days. At 6700°d, fish have testes containing spermatocytes and spermatids and were exposed for 56 days to either 0.8, 8.3, or 65 ng EE2/l. Semen was collected at full sexual maturity in each group and used to fertilize eggs pooled from several non-exposed females. Significant decreases in embryonic survival were observed only with the 6700°d exposure. In 0.8 and 8.3 ng EE2/l treatments, embryo survival was significantly reduced at 19 dpf when compared with the control. In contrast, an immediate decrease in embryonic survival at 0.5 dpf was observed in the 65 ng EE2/l treatment. Blood samples collected at spawning from 6700°d exposed males revealed a significant decrease in 11-ketotestosterone and a significant increase in luteinizing hormone levels for the 65 ng EE2/l treatment when compared with the other treatment groups. Results indicate that sexually maturing male rainbow trout are susceptible to EE2 exposure with these fish exhibiting two possible mechanisms of reduced embryonic survival through sperm varying dependant on EE2 exposure concentrations experienced. PMID:17965256

Abiotic processes are insufficient for fertile island development: A 10-year artificial shrub experiment in a desert grassland

NASA Astrophysics Data System (ADS)

Li, Junran; Gilhooly, William P.; Okin, Gregory S.; Blackwell, John

2017-03-01

The relative importance of biotic and abiotic processes in the development of "fertile islands" in dryland systems has rarely been investigated. Here we approached this question by using artificial shrubs, which exclude plant litter production and soil nutrient uptake, but retain the functions of trapping windblown material, funneling of stemflow, and differential rain splash. We conducted a vegetation manipulation study more than a decade ago in the desert grassland of southern New Mexico and subsequently revisited the site in 2012 and 2015. The results show that no notable soil mounds were observed under the artificial shrubs; however, soil texture under the artificial shrubs has gradually changed to resemble the patterns of soil particle-size distribution under natural shrubs. Our results highlight that with the exclusion of direct biotic additions, soils captured by shrub canopies are not necessarily fertile and thus do not themselves contribute to the development of fertile islands.

In Vitro Measures for Assessing Boar Semen Fertility.

PubMed

Jung, M; Rüdiger, K; Schulze, M

2015-07-01

Optimization of artificial insemination (AI) for pig production and evaluation of the fertilizing capacity of boar semen are highly related. Field studies have demonstrated significant variation in semen quality and fertility. The semen quality of boars is primarily affected by breed and season. AI centres routinely examine boar semen to predict male fertility. Overall, the evaluation of classical parameters, such as sperm morphology, sperm motility, sperm concentration and ejaculate volume, allows the identification of ejaculates corresponding to poor fertility but not high-efficiency prediction of field fertility. The development of new sperm tests for measuring certain sperm functions has attempted to solve this problem. Fluorescence staining can categorize live and dead spermatozoa in the ejaculate and identify spermatozoa with active mitochondria. Computer-assisted semen analysis (CASA) provides an objective assessment of multiple kinetic sperm parameters. However, sperm tests usually assess only single factors involved in the fertilization process. Thus, basing prediction of fertilizing capacity on a selective collection of sperm tests leads to greater accuracy than using single tests. In the present brief review, recent diagnostic laboratory methods that directly relate to AI performance as well as the development of a new boar fertility in vitro index are discussed. © 2015 Blackwell Verlag GmbH.

Organically fertilized onions (Allium cepa L.): effects of the fertilizer placement method on quercetin content and soil nitrogen dynamics.

PubMed

Mogren, Lars M; Caspersen, Siri; Olsson, Marie E; Gertsson, Ulla E

2008-01-23

Field-cured onions cv. Hyskin ( Allium cepa L.) supplied with organic nitrogen fertilizer were studied. The fertilizer was applied by broadcasting and harrowing, broadcasting and rotary cultivation, or placement between rows. Nitrogen dynamics were monitored throughout the growing season by soil sampling. Variation in quercetin content in the onion scales was analyzed by HPLC. The organically fertilized onions were compared with inorganically fertilized onions grown in the same field. Inoculation with arbuscular mycorrhizal fungi (AMF) in the row at sowing or during commercial transplant production was tested but did not significantly affect mycorrhizal root colonization levels in the field. Onions that received no fertilizer at all or that had fertilizer placed between rows had better establishment, probably due to more favorable soil nitrogen concentrations for seedling emergence. Broadcast application led to higher nitrogen concentration in the root zone, resulting in fewer but larger individual onions. Quercetin levels were not significantly altered as a result of nitrogen fertilizer source (inorganic or organic), application method, or mycorrhizal inoculation. However, variation between years was significant, with quercetin levels in 2004 almost twice as high as those in 2005.

Two bHLH-type transcription factors, JA-ASSOCIATED MYC2-LIKE2 and JAM3, are transcriptional repressors and affect male fertility

PubMed Central

Nakata, Masaru; Ohme-Takagi, Masaru

2013-01-01

The jasmonate (JA) plant hormones regulate responses to biotic and abiotic stress and aspects of plant development, including male fertility in Arabidopsis thaliana. The bHLH-type transcription factor JA-ASSOCIATED MYC2-LIKE1 (JAM1) negatively regulates JA signaling and gain-of-function JAM1 transgenic plants have impaired JA-mediated male fertility. Here we report that JAM2 and JAM3, 2 bHLHs closely related to JAM1, also act as transcriptional repressors. Moreover, overexpression of JAM2 and JAM3 also results in reduced male fertility. These results suggest that JAM1, JAM2, and JAM3 act redundantly as negative regulators of JA-mediated male fertility. PMID:24056034

Development, Characterization, and Pluripotency Analysis of Buffalo (Bubalus bubalis) Embryonic Stem Cell Lines Derived from In Vitro–Fertilized, Hand-Guided Cloned, and Parthenogenetic Embryos

PubMed Central

Shah, Syed Mohmad; Saini, Neha; Ashraf, Syma; Zandi, Mohammad; Manik, Radhey Sham; Singla, Suresh Kumar; Palta, Prabhat

2015-01-01

Abstract We present the derivation, characterization, and pluripotency analysis of three buffalo embryonic stem cell (buESC) lines, from in vitro–fertilized, somatic cell nuclear–transferred, and parthenogenetic blastocysts. These cell lines were developed for later differentiation into germ lineage cells and elucidation of the signaling pathways involved. The cell lines were established from inner cell masses (ICMs) that were isolated manually from the in vitro–produced blastocysts. Most of the ICMs (45–55%) resulted in formation of primary colonies that were subcultured after 8–10 days, leading subsequently to the formation of three buESC lines, one from each blastocyst type. All the cell lines expressed stem cell markers, such as Alkaline Phosphatase, OCT4, NANOG, SSEA1, SSEA4, TRA-1-60, TRA-1-81, SOX2, REX1, CD-90, STAT3, and TELOMERASE. They differentiated into all three germ layers as determined by ectodermal, mesodermal, and endodermal RNA and protein markers. All of the cell lines showed equal expression of pluripotency markers as well as equivalent differentiation potential into all the three germ layers. The static suspension culture–derived embryoid bodies (EBs) showed greater expression of all the three germ layer markers as compared to hanging drop culture–derived EBs. When analyzed for germ layer marker expression, EBs derived from 15% fetal bovine serum (FBS)-based spontaneous differentiation medium showed greater differentiation across all the three germ layers as compared to those derived from Knock-Out Serum Replacement (KoSR)-based differentiation medium. PMID:26168169

[Anti-Müllerian hormone levels as a predictor of ovarian reserve in systemic lupus erythematosus patients: a review].

PubMed

Gasparin, Andrese Aline; Chakr, Rafael Mendonça da Silva; Brenol, Claiton Viegas; Palominos, Penélope Ester; Xavier, Ricardo Machado; Souza, Lucian; Brenol, João Carlos Tavares; Monticielo, Odirlei André

2015-01-01

The anti-Müllerian hormone (AMH) is secreted from granulosa cells of growing ovarian follicles and appears to be the best endocrine marker capable of estimating ovarian reserve. Systemic lupus erythematosus (SLE) is an autoimmune disease that predominantly affects women of reproductive age and may negatively affect their fertility due to disease activity and the treatments used. Recently, several studies assessed AMH levels to understand the real impact of SLE and its treatment on fertility. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

Fertility-related knowledge and information-seeking behaviour among people of reproductive age: a qualitative study.

PubMed

Hammarberg, Karin; Zosel, Rebecca; Comoy, Caroline; Robertson, Sarah; Holden, Carol; Deeks, Mandy; Johnson, Louise

2017-06-01

Some potentially modifiable factors adversely affect fertility and pregnancy health. To inform a fertility health promotion programme, this study investigated fertility knowledge and information-seeking behaviour among people of reproductive age. This was a qualitative study involving six focus group discussions with women and men who intended to have children in the future and eight paired interviews with couples who were actively trying to conceive. Participants (n = 74) themselves generally claimed 'low' to 'average' levels of knowledge about fertility. Most of them overestimated women's reproductive lifespan and had limited knowledge about the 'fertile window' of the menstrual cycle. The Internet was a common source of fertility-related information and social media was viewed as a potential effective avenue for dissemination of messages about fertility and how to protect it. Most participants agreed that primary health care providers, such as general practitioners (GPs), are well placed to provide information regarding fertility and pregnancy health. This study identified several gaps in knowledge among people of reproductive age about factors that influence fertility and pregnancy health negatively. Addressing these knowledge gaps in school curricula, primary care and health promotion would assist people to realize their reproductive goals and reduce the risk of infertility and adverse obstetric outcomes.

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands

PubMed Central

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-01-01

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0–20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization. PMID:27492771

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands

NASA Astrophysics Data System (ADS)

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-08-01

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands.

PubMed

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-08-05

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.

Paternity in horseshoe crabs when spawning in multiple-male groups.

PubMed

Brockmann; Nguyen; Potts

2000-12-01

Unpaired or satellite male horseshoe crabs, Limulus polyphemus, are attracted to and often form a group around a pair (a female with an attached male) that is nesting in the high intertidal zone. These males are engaged in sperm competition. We observed nesting pairs and their associated satellites in the wild, collected and reared their eggs and used genetic markers to examine paternity. We found that the unpaired, satellite males are highly successful at fertilizing eggs; two satellites can leave the attached male with few fertilizations. Two satellites together are each as successful as one spawning with a pair. A satellite's location around the female greatly affects his success, and males compete for access to a position over the dorsal canal between the prosoma and opisthosoma of the female and under the front margin of the paired male where they are most likely to fertilize eggs. Although eggs and sperm retain their viability for some time after spawning, nearly all eggs are fertilized by the satellites that are around the nesting pair at the time of egg laying and by the attached male. A number of factors including beach current, female size and male behaviour affect the outcome of sperm competition in this externally fertilizing species. Copyright 2000 The Association for the Study of Animal Behaviour.

Citrus limon extract: possible inhibitory mechanisms affecting testicular functions and fertility in male mice.

PubMed

Singh, Nidhi; Singh, Shio Kumar

2016-01-01

The effect of oral administration of 50% ethanolic leaf extract of Citrus limon (500 and 1,000 mg/kg body weight/day) for 35 days on fertility and various male reproductive endpoints was evaluated in Parkes strain of mice. Testicular indices such as histology, 3β- and 17β-HSD enzymes activity, immunoblot expression of StAR and P450scc, and germ cell apoptosis by TUNEL and CASP- 3 expression were assessed. Motility, viability, and number of spermatozoa in the cauda epididymidis, level of serum testosterone, fertility indices, and toxicological parameters were also evaluated. Histologically, testes in extract-treated mice showed nonuniform degenerative changes in the seminiferous tubules. Treatment had adverse effects on steroidogenic markers in the testis and induced germ cell apoptosis. Significant reductions were noted in epididymal sperm parameters and serum level of testosterone in Citrus-treated mice compared to controls. Fertility of the extract-treated males was also suppressed, but libido remained unaffected. By 56 days of treatment withdrawal, alterations induced in the above parameters returned to control levels suggesting that Citrus treatment causes reversible suppression of spermatogenesis and fertility in Parkes mice. Suppression of spermatogenesis may result from germ cell apoptosis because of decreased production of testosterone. The present work indicated that Citrus leaves can affect male reproduction.

Long-term primary culture of neurons taken from chick embryo brain: A model to study neural cell biology, synaptogenesis and its dynamic properties.

PubMed

Kumar, Awanish; Mallick, Birendra Nath

2016-04-01

Studying neuronal growth, development and synaptogenesis are among the hot research topics. However, it is faced with various challenges and technical limitations that include but not limited to donor's species and health, threat to life, age of embryo, glial contamination, real-time tracking, and follow-up. We have successfully standardized a method for long-term primary culture of neurons collected from post-fertilized 9 day incubated chicken embryo brain overcoming the limitations mentioned above. Fertilized eggs were incubated in the laboratory and neurons from the embryonic brain were collected and low-density culture, apparently without glial contamination, was studied at least for 35 days in vitro (DIV). Neurons were characterized by double immunostaining using stringent neuronal and glial markers. Neuronal differentiation, cytomorphology, neurite and axon formation, development and maturation, spine formation and synaptogenesis were tracked in real-time in a stage and time dependent manner. The neurons were transfected with Synaptophysin-RFP to label synaptic vesicles, which were followed in real-time under live-cell imaging. Every step was carried out under controlled laboratory conditions. Eggs are easily available, easy to handle, neurons from desired day of incubation could be conveniently studied for long period in apparently glia-free condition. In addition to common factors affecting primary culture, selection of culture media and cover glass coating are other key factors affecting neuronal cultures. We describe an inexpensive, simpler pure primary neuronal culture method for studying neuronal cell-biology, synaptogenesis, vesicular dynamics and it has potential to grow 3D-multilayered brain in vitro. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of management and soil moisture regimes on wetland soils total carbon and nitrogen in Tanzania

NASA Astrophysics Data System (ADS)

Kamiri, Hellen; Kreye, Christine; Becker, Mathias

2013-04-01

Wetland soils play an important role as storage compartments for water, carbon and nutrients. These soils implies various conditions, depending on the water regimes that affect several important microbial and physical-chemical processes which in turn influence the transformation of organic and inorganic components of nitrogen, carbon, soil acidity and other nutrients. Particularly, soil carbon and nitrogen play an important role in determining the productivity of a soil whereas management practices could determine the rate and magnitude of nutrient turnover. A study was carried out in a floodplain wetland planted with rice in North-west Tanzania- East Africa to determine the effects of different management practices and soil water regimes on paddy soil organic carbon and nitrogen. Four management treatments were compared: (i) control (non weeded plots); (ii) weeded plots; (iii) N fertilized plots, and (iv) non-cropped (non weeded plots). Two soil moisture regimes included soil under field capacity (rainfed conditions) and continuous water logging compared side-by-side. Soil were sampled at the start and end of the rice cropping seasons from the two fields differentiated by moisture regimes during the wet season 2012. The soils differed in the total organic carbon and nitrogen between the treatments. Soil management including weeding and fertilization is seen to affect soil carbon and nitrogen regardless of the soil moisture conditions. Particularly, the padddy soils were higher in the total organic carbon under continuous water logged field. These findings are preliminary and a more complete understanding of the relationships between management and soil moisture on the temporal changes of soil properties is required before making informed decisions on future wetland soil carbon and nitrogen dynamics. Keywords: Management, nitrogen, paddy soil, total carbon, Tanzania,

Long-Term Exposure to Environmental Concentrations of the Pharmaceutical Ethynylestradiol Causes Reproductive Failure in Fish

PubMed Central

Nash, Jon P.; Kime, David E.; Van der Ven, Leo T. M.; Wester, Piet W.; Brion, François; Maack, Gerd; Stahlschmidt-Allner, Petra; Tyler, Charles R.

2004-01-01

Heightened concern over endocrine-disrupting chemicals is driven by the hypothesis that they could reduce reproductive success and affect wildlife populations, but there is little evidence for this expectation. The pharmaceutical ethynylestradiol (EE2) is a potent endocrine modulator and is present in the aquatic environment at biologically active concentrations. To investigate impacts on reproductive success and mechanisms of disruption, we exposed breeding populations (n = 12) of zebrafish (Danio rerio) over multiple generations to environmentally relevant concentrations of EE2. Life-long exposure to 5 ng/L EE2 in the F1 generation caused a 56% reduction in fecundity and complete population failure with no fertilization. Conversely, the same level of exposure for up to 40 days in mature adults in the parental F0 generation had no impact on reproductive success. Infertility in the F1 generation after life-long exposure to 5 ng/L EE2 was due to disturbed sexual differentiation, with males having no functional testes and either undifferentiated or inter-sex gonads. These F1 males also showed a reduced vitellogenic response when compared with F0 males, indicating an acclimation to EE2 exposure. Depuration studies found only a partial recovery in reproductive capacity after 5 months. Significantly, even though the F1 males lacked functional testes, they showed male-pattern reproductive behavior, inducing the spawning act and competing with healthy males to disrupt fertilization. Endocrine disruption is therefore likely to affect breeding dynamics and reproductive success in group-spawning fish. Our findings raise major concerns about the population-level impacts for wildlife of long-term exposure to low concentrations of estrogenic endocrine disruptors. PMID:15579420

The histone demethylase KDM1A is essential for the maintenance and differentiation of spermatogonial stem cells and progenitors.

PubMed

Lambrot, Romain; Lafleur, Christine; Kimmins, Sarah

2015-11-01

Little is known of the fundamental processes governed by epigenetic mechanisms in the supplier cells of spermatogenesis, the spermatogonial stem cells (SSCs). The histone H3 lysine demethylase KDM1A is expressed in spermatogonia. We hypothesized that KDM1A serves in transcriptional regulation of SSCs and fertility. Using a conditional deletion of Kdm1a [conditional knockout (cKO)] in mouse spermatogonia, we determined that Kdm1a is essential for spermatogenesis as adult cKO males completely lack germ cells. Analysis of postnatal testis development revealed that undifferentiated and differentiating spermatogonial populations form in Kdm1a-cKO animals, yet the majority fail to enter meiosis. Loss of germ cells in the cKO was rapid with none remaining by postnatal day (PND) 21. To gain insight into the mechanistic implications of Kdm1a ablation, we isolated PND 6 spermatogonia enriched for SSCs and analyzed their transcriptome by RNA sequencing. Loss of Kdm1a was associated with altered transcription of 1206 genes. Importantly, differentially expressed genes between control and Kdm1a-cKO animals included those that are essential for SSC and progenitor maintenance and spermatogonial differentiation. The complete loss of fertility and failure to establish spermatogenesis indicate that Kdm1a is a master controller of gene transcription in spermatogonia and is required for SSC and progenitor maintenance and differentiation. © FASEB.

Nitrogen transformation and nitrous oxide emissions affected by biochar amendment and fertilizer stabilizers

USDA-ARS?s Scientific Manuscript database

Biochar as a soil amendment and the use of fertilizer stabilizers (N transformation inhibitors) have been shown to reduce N2O emissions, but the mechanisms or processes involved are not well understood. The objective of this research was to investigate N transformation processes and the relationship...

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

USDA-ARS?s Scientific Manuscript database

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

Net global warming potential and greenhouse gas intensity influenced by irrigation, tillage, crop rotation, and nitrogen fertilization

USDA-ARS?s Scientific Manuscript database

Little information exists about sources and sinks of greenhouse gases (GHGs) affected by management practices to account for net emissions from agroecosystems. We evaluated the effects of irrigation, tillage, crop rotation, and N fertilization on net global warming potential (GWP) and greenhouse gas...

Assessing fertilizer N placement on CH4 and N2O emissions in irrigated rice systems

USDA-ARS?s Scientific Manuscript database

Improved N fertilizer management practices can increase rice yields and mitigate global warming potential (GWP). While banding N has been shown to have positive effects on yield and nitrogen use efficiency (NUE), there is little information in how it affects greenhouse gas (GHG) emissions from flood...

Ectomycorrhizal Colonization of Container-Grown Northern Red Oak as Affected by Fertility

Treesearch

John L. Ruehle

1980-01-01

Abstract - The effects of different fertility regimes on Pisolithus tinctorius ectomycorrhizal development on northern red oak grown in containers was tested in the greenhouse. Artificial infestation of a milled pine bark-sewage sludge growing medium produced the best ectomycorrhizal development (63 percent) when a nutrient solution with 100pg/ml N...

Growth and stem form quality of clonal Pinus taeda following fertilization in the Virginia Piedmont

Treesearch

Jeremy P. Stovall; Colleen A. Carlson; John R. Seiler; Thomas R. Fox

2013-01-01

Clonal forestry offers the opportunity to increase yields, enhance uniformity, and improve wood characteristics. Intensive silvicultural practices, including fertilization, will be required to capture the full growth potential of clonal plantations. However, variation in nutrient use efficiency that exists among clones could affect growth responses. Our research...

Effect of Calcium, Magnesium, and Aluminum-Iron on the Susceptibility of Loblolly Pine Seedlings to Fusiform Rust

Treesearch

S.J. Rowan

1979-01-01

The susceptibility (percentage of seedlings infected) of Pinus taeda seedlings to infection by Cronartium quercuum f. sp. fusiforme was not affected by fertilization with calcium, magnesium, or aluminum-iron. Fertilization with Al as Al2(SO4)2,and Fe as FeCl

Effects of supplementation of fertilizers on human selenium status in Finland.

PubMed

Aro, A; Alfthan, G; Varo, P

1995-03-01

The Se concentration of foods can be increased by supplementing fertilizers with soluble Se compounds. In Finland the availability of soil Se for plants is poor owing to the relatively low Se concentration, low pH and high iron content of the soil. Since 1984 multimineral fertilizers have been supplemented with Se (16 mg kg-1 to fertilizers for grain production and 6 mg kg-1 to those for fodder production) in the form of sodium selenate. Within two years a three-fold increase of mean Se intake was observed. The supplementation affected the Se content of all major food groups with the exception of fish. The concomitant human serum Se concentration increased by 70%. In 1990 the amount of Se that was supplemented was reduced to 6 mg kg-1 for all fertilizers. This reduced the mean Se intake by 30% and the serum Se concentration decreased by 25% from the highest levels observed in 1989. Plants take up part of the supplemented selenate and transform it into organic Se compounds, mainly selenomethionine. This affects human nutrition by increasing the Se content of foods of both animal and vegetable origin. According to data obtained in Finland, supplementation of fertilizers with Se is a safe and effective means of increasing the Se intake of both animals and humans that is feasible in countries with relatively uniform geochemical conditions. This kind of intervention requires careful monitoring of the effects on both animal and human nutrition and the environment.

The Control of Male Fertility by Spermatozoan Ion Channels

PubMed Central

Lishko, Polina V.; Kirichok, Yuriy; Ren, Dejian; Navarro, Betsy; Chung, Jean-Ju

2014-01-01

Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calcium entry and sperm hyperactivated motility. Many other channels had been proposed as regulating sperm activity without direct measurements. With the development of the sperm patch-clamp technique, CatSper and KSper have been confirmed as the primary spermatozoan ion channels. In addition, the voltage-gated proton channel Hv1 has been identified in human sperm tail, and the P2X2 ion channel has been identified in the midpiece of mouse sperm. Mutations and deletions in sperm-specific ion channels affect male fertility in both mice and humans without affecting other physiological functions. The uniqueness of sperm ion channels makes them ideal pharmaceutical targets for contraception. In this review we discuss how ion channels regulate sperm physiology. PMID:22017176

Reproductive effects in birds exposed to pesticides and industrial chemicals.

PubMed Central

Fry, D M

1995-01-01

Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p'-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted "hot spots" in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. PMID:8593865

Stabilization process of human population: a descriptive approach.

PubMed

Kayani, A K; Krotki, K J

1981-01-01

An attempt is made to inquire into the process of stabilization of a human population. The same age distribution distorted by past variations in fertility is subjected to several fixed schedules of fertility. The schedules are different from each other monotonically over a narrow range. The primary concern is with the process, almost year by year, through which the populations become stable. There is particular interest in the differential impact in the same original age distribution of the narrowly different fixed fertility schedules. The exercise is prepared in 3 stages: general background of the process of stabilization; methodology and data used; and analysis and discussion of the stabilization process. Among the several approaches through which the analysis of stable population is possible, 2 are popular: the integral equation and the projection matrix. In this presentation the interest is in evaluating the effects of fertility on the stabilization process of a population. Therefore, only 1 initial age distribution and only 1 life table but a variety of narrowly different schedules of fertility have been used. Specifically, the U.S. 1963 female population is treated as the initial population. The process of stabilization is viewed in the light of the changes in the slopes between 2 successive age groups of an age distribution. A high fertility schedule with the given initial age distribution and mortality level overcomes the oscillations more quickly than the low fertility schedule. Simulation confirms the intuitively expected positive relationship between the mean of the slope and the level of fertility. The variance of the slope distribution is an indicator of the aging of the distribution.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Responses of Bacterial Communities in Arable Soils in a Rice-Wheat Cropping System to Different Fertilizer Regimes and Sampling Times

PubMed Central

Zhao, Jun; Ni, Tian; Li, Yong; Xiong, Wu; Ran, Wei; Shen, Biao; Shen, Qirong; Zhang, Ruifu

2014-01-01

Soil physicochemical properties, soil microbial biomass and bacterial community structures in a rice-wheat cropping system subjected to different fertilizer regimes were investigated in two seasons (June and October). All fertilizer regimes increased the soil microbial biomass carbon and nitrogen. Both fertilizer regime and time had a significant effect on soil physicochemical properties and bacterial community structure. The combined application of inorganic fertilizer and manure organic-inorganic fertilizer significantly enhanced the bacterial diversity in both seasons. The bacterial communities across all samples were dominated by Proteobacteria, Acidobacteria and Chloroflexi at the phylum level. Permutational multivariate analysis confirmed that both fertilizer treatment and season were significant factors in the variation of the composition of the bacterial community. Hierarchical cluster analysis based on Bray-Curtis distances further revealed that bacterial communities were separated primarily by season. The effect of fertilizer treatment is significant (P = 0.005) and accounts for 7.43% of the total variation in bacterial community. Soil nutrients (e.g., available K, total N, total P and organic matter) rather than pH showed significant correlation with the majority of abundant taxa. In conclusion, both fertilizer treatment and seasonal changes affect soil properties, microbial biomass and bacterial community structure. The application of NPK plus manure organic-inorganic fertilizer may be a sound fertilizer practice for sustainable food production. PMID:24465530

Sub-fertile sperm cells exemplify telomere dysfunction.

PubMed

Biron-Shental, Tal; Wiser, Amir; Hershko-Klement, Anat; Markovitch, Ofer; Amiel, Aliza; Berkovitch, Arie

2018-01-01

The purpose of this study was to evaluate telomere homeostasis in sub-fertile compared to fertile human sperm. This observational, comparative study included 16 sub-fertile men who required intracytoplasmic sperm injection and 10 fertile men. At least 100 sperm cells from each participant were assessed. Main outcome measures were telomere length and telomere aggregates. Telomerase RNA component (TERC) copy number and telomere capture were assessed using fluorescence in situ hybridization technique and human telomerase reverse transcriptase (hTERT) using immunohistochemistry. Clinical backgrounds were similar. The percentage of sperm cells with shorter telomeres was higher among the sub-fertile compared to the fertile participants (3.3 ± 3.1 vs. 0.6 ± 1.2%, respectively; P < 0.005). The percentage of cells with telomere aggregates was significantly higher in the sub-fertile group (15.12 ± 3.73 vs. 4.73 ± 3.73%; P < 0.005). TERC gene copy number was similar between groups. The percentage of cells that were positive for hTERT was lower in the sub-fertile group (3.81 ± 1.27 vs. 8.42 ± 1.80%; P < 0.005). Telomere capture rates were higher among the sub-fertile sperm cells (P < 0.005). Sub-fertile sperm cells have short telomeres that are elongated by the alternative pathway of telomere capture. Dysfunctional telomeres may affect sperm fertilizability.

Fennel induces cytotoxic effects against testicular germ cells in mice; evidences for suppressed pre-implantation embryo development.

PubMed

Minas, Aram; Najafi, Gholamreza; Jalali, Ali Shalizar; Razi, Mazdak

2018-05-15

Foeniculum vulgare (FVE; fennel) is an aromatic plant belonging to Umbelliferae family, which is widely used in traditional societies because of its different pharmaceutical properties. To uncover the fennel-derived essential oil (FVEO)-induced effects on male reproductive potential, 24 mature male albino mice were divided into, control, 0.37, 0.75, and 1.5 mg kg -1 FVEO-received groups. Following 35 days, the animals were euthanized and the testicular tissue and sperm samples were collected. The histological alterations, tubular differentiation (TDI), spermiogenesis (SPI) indices, apoptosis ratio, and RNA damage of germinal cells were analyzed. Moreover, the sperm count, motility, viability, chromatin condensation, and DNA fragmentation were assessed. Finally, the pre-implantation embryo development including; the percentage of zygote, 2-cell embryos and blastocysts were assessed. Observations showed that the FVEO, dose dependently, increased histological damages, resulted in germ cells dissociation, depletion, nuclear shrinkage and significantly (P < .05) decreased tubular differentiation and spermiogenesis ratios. Moreover, the FVEO-received animals (more significantly in 1.5 mg kg -1 -received group) exhibited decreased sperm count, viability, and motility and represented enhanced percentage of sperms with decondensed chromatin and DNA fragmentation. Finally, the animals in FVEO-received group showed diminished zygote formation and represented decreased pre-implantation embryo development compared to control animals. In conclusion, our data showed that, FVEO albeit at higher doses, is able to adversely affect cellular DNA and RNA contents, which in turn is able to negatively affect the sperm count and morphology. All these impairments are able to negatively affect the fertilization potential as well as pre-implantation embryo development. © 2018 Wiley Periodicals, Inc.

Fertility depression among cheese‐making Penicillium roqueforti strains suggests degeneration during domestication

PubMed Central

Ropars, Jeanne; Lo, Ying‐Chu; Dumas, Emilie; Snirc, Alodie; Begerow, Dominik; Rollnik, Tanja; Lacoste, Sandrine; Dupont, Joëlle; Giraud, Tatiana; López‐Villavicencio, Manuela

2016-01-01

Genetic differentiation occurs when gene flow is prevented, due to reproductive barriers or asexuality. Investigating the early barriers to gene flow is important for understanding the process of speciation. Here, we therefore investigated reproductive isolation between different genetic clusters of the fungus Penicillium roqueforti, used for maturing blue cheeses, and also occurring as food spoiler or in silage. We investigated premating and postmating fertility between and within three genetic clusters (two from cheese and one from other substrates), and we observed sexual structures under scanning electron microscopy. All intercluster types of crosses showed some fertility, suggesting that no intersterility has evolved between domesticated and wild populations despite adaptation to different environments and lack of gene flow. However, much lower fertility was found in crosses within the cheese clusters than within the noncheese cluster, suggesting reduced fertility of cheese strains, which may constitute a barrier to gene flow. Such degeneration may be due to bottlenecks during domestication and/or to the exclusive clonal replication of the strains in industry. This study shows that degeneration has occurred rapidly and independently in two lineages of a domesticated species. Altogether, these results inform on the processes and tempo of degeneration and speciation. PMID:27470007

Progestin treatment of atypical hyperplasia and well-differentiated adenocarcinoma of the endometrium to preserve fertility.

PubMed

Koskas, Martin; Azria, Elie; Walker, Francine; Luton, Dominique; Madelenat, Patrick; Yazbeck, Chadi

2012-03-01

To evaluate the outcome of a cohort of young women treated with progestin for fertility-sparing management of endometrial atypical hyperplasia (AH) and endometrial carcinoma (EC). This retrospective multicentre cohort study included women under the age of 40 years treated conservatively for AH and EC to preserve fertility using progestin for at least 3 months. Four inclusion criteria were defined: (i) the presence of AH or grade 1 EC confirmed by two pathologists (including a reference pathologist); (ii) the use of conservative management for fertility sparing; (iii) adequate radiological examination before conservative management; and (iv) a minimal follow-up time of one year. Twenty-two patients fulfilled the inclusion criteria (8 had EC, and 14 had AH). After progestin treatment, 17 patients responded. Among the 17 patients who experienced remission, three also experienced disease relapse. One patient initially diagnosed with AH experienced progression of her disease to stage IIIA EC. Ten pregnancies were achieved in eight patients. Fertility-sparing management using progestin offers the opportunity to fulfil maternal desires in young patients diagnosed with AH and EC. However, progression of the disease is possible and close follow-up is needed.

The effect of numbers of frozen-thawed boar sperm and addition of prostaglandin F2α at insemination on fertility in pigs.

PubMed

Knox, Robert V; Yantis, Brandon M

2014-12-30

Frozen-thawed boar sperm (FTS) has reduced fertility compared to liquid semen. Exogenous prostaglandin administered at insemination has been reported to improve cases of low fertility. This experiment tested the effect of number of FTS and addition of prostaglandin (PGF2α) on fertility. The experiment was performed in replicates using weaned sows (n=24) and synchronized gilts (n=94). All females were induced into estrus using PG600® at weaning or following estrus synchronization. At estrus, females received 0.5, 1.0, or 2 billion motile FTS (n=9 boars) with 0 or 5mg of PGF2α added into each AI dose at insemination. Inseminations occurred at 24 and 36h after onset of estrus and ovulation was monitored by ultrasound. Pregnancy and litter size were determined for sows at farrowing and d 50 of gestation for gilts at slaughter. There was no effect of PGF2α and no interaction with dose of FTS or parity on fertility (P>0.10). Pregnancy rate was affected by FTS dose (P<0.001) with 2.0×10(9) (76.3%) greater than 0.5×10(9) (46.2%) and 1.0×10(9) sperm (48.8±8.0%). Pregnancy rate was not affected by parity (P>0.10) but was influenced by boar (P<0.05). Number of fetuses was also affected by FTS dose (P<0.001) with 2.0×10(9) (10.1) and 1.0×10(9) (9.4) producing more pigs than 0.5×10(9) sperm (6.9±0.9). Litter size was also affected by parity (P=0.001) and boar (P<0.01). These results indicate that AI using 2.0×10(9) FTS can result in acceptable pregnancy rates and litter sizes but with no measurable benefit for addition of prostaglandin. Copyright © 2014 Elsevier B.V. All rights reserved.

Nitrates and herbicides cause higher mortality than the traditional organic fertilizers on the grain beetle, Tenebrio molitor.

PubMed

Castilla, Aurora M; Dauwe, Tom; Mora, Isabel; Malone, Jim; Guitart, Raimon

2010-01-01

We examined experimentally whether fertilizers or herbicides commonly used by farmers affect mortality of the adult grain beetle Tenebrio molitor. After a period of 4 weeks in direct contact with all treatments, a higher percentage of mortality occurred in contact with nitrates than with pig manure or turkey litter. Herbicides (a mixture of glyphosate and 2,4-D: ) caused 100% mortality. Our results also indicate that more beetles escaped from the herbicides and nitrate treatments than from the others, suggesting some kind of behavioural avoidance of toxic environments. The traditional organic fertilizers appear to be less toxic than inorganic fertilizers for Tenebrio molitor.

How Personal Is the Political? Democratic Revolution and Fertility Decline

PubMed Central

Bailey, Amy Kate

2010-01-01

Existing theory has identified the capacity of political revolutions to effect change in a variety of social institutions, although relationships between revolution and many institutions remain unexplored. Using historical data from 22 European and four diaspora countries, I examine the temporal relationship between timing of revolution and onset of fertility decline. I hypothesize that specific kinds of revolutionary events affect fertility by engendering ideological changes in popular understandings of the individual’s relationship to society, and ultimately the legitimacy of couples’ authority over their reproductive capacities. Results demonstrate that popular democratic revolution – but not institutionalized democratic structures – predict the timing of the onset of fertility decline. PMID:19999826

Agents affecting health of mother and child in a rural area of Kenya. XVIII. Fertility, mortality and migration in 1975-1978.

PubMed

Van Ginneken, J K; Voorhoeve, A M; Omondi-Odhiambo; Muller, A S; Blok, P G; W'Oigo, H O

1980-06-01

The results reported here are based on age-specific rates and are, therefore, more sensitive and meaningful as indicators of fertility and mortality than the crude rates mentioned in the previous article. The results confirm that, compared to world standards, the study area is characterized by a high level of fertility and a fairly low level of mortality. Fertility and mortality are, however, lower in the study area in comparison to Kenya as a whole. Another characteristic is high population mobility which is of two types: temporary migration of absent members of the population, and permanent in- and out-migration.

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

PubMed

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

2011-01-01

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

Speciation and Distribution of Phosphorus in a Fertilized Soil: A Synchrotron-Based Investigation

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

Lombi, E.; Scheckel, K.G.; Armstrong, R.D.

2008-06-09

Phosphorus availability is often a limiting factor for crop production around the world. The efficiency of P fertilizers in calcareous soils is limited by reactions that decrease P availability; however, fluid fertilizers have recently been shown, in highly calcareous soils of southern Australia, to be more efficient for crop (wheat [Triticum aestivum L.]) P nutrition than granular products. To elucidate the mechanisms responsible for this differential response, an isotopic dilution technique (E value) coupled with a synchrotron-based spectroscopic investigation were used to assess the reaction products of a granular (monoammonium phosphate, MAP) and a fluid P (technical-grade monoammonium phosphate, TG-MAP)more » fertilizer in a highly calcareous soil. The isotopic exchangeability of P from the fluid fertilizer, measured with the E-value technique, was higher than that of the granular product. The spatially resolved spectroscopic investigation, performed using nano x-ray fluorescence and nano x-ray absorption near-edge structure (n-XANES), showed that P is heterogeneously distributed in soil and that, at least in this highly calcareous soil, it is invariably associated with Ca rather than Fe at the nanoscale. 'Bulk' XANES spectroscopy revealed that, in the soil surrounding fertilizer granules, P precipitation in the form of octacalcium phosphate and apatite-like compounds is the dominant mechanism responsible for decreases in P exchangeability. This process was less prominent when the fluid P fertilizer was applied to the soil.« less

Long-term balanced fertilization increases the soil microbial functional diversity in a phosphorus-limited paddy soil.

PubMed

Su, Jian-Qiang; Ding, Long-Jun; Xue, Kai; Yao, Huai-Ying; Quensen, John; Bai, Shi-Jie; Wei, Wen-Xue; Wu, Jin-Shui; Zhou, Jizhong; Tiedje, James M; Zhu, Yong-Guan

2015-01-01

The influence of long-term chemical fertilization on soil microbial communities has been one of the frontier topics of agricultural and environmental sciences and is critical for linking soil microbial flora with soil functions. In this study, 16S rRNA gene pyrosequencing and a functional gene array, geochip 4.0, were used to investigate the shifts in microbial composition and functional gene structure in paddy soils with different fertilization treatments over a 22-year period. These included a control without fertilizers; chemical nitrogen fertilizer (N); N and phosphate (NP); N and potassium (NK); and N, P and K (NPK). Based on 16S rRNA gene data, both species evenness and key genera were affected by P fertilization. Functional gene array-based analysis revealed that long-term fertilization significantly changed the overall microbial functional structures. Chemical fertilization significantly increased the diversity and abundance of most genes involved in C, N, P and S cycling, especially for the treatments NK and NPK. Significant correlations were found among functional gene structure and abundance, related soil enzymatic activities and rice yield, suggesting that a fertilizer-induced shift in the microbial community may accelerate the nutrient turnover in soil, which in turn influenced rice growth. The effect of N fertilization on soil microbial functional genes was mitigated by the addition of P fertilizer in this P-limited paddy soil, suggesting that balanced chemical fertilization is beneficial to the soil microbial community and its functions. © 2014 John Wiley & Sons Ltd.

Nitrous oxide emission and denitrifier communities in drip-irrigated calcareous soil as affected by chemical and organic fertilizers.

PubMed

Tao, Rui; Wakelin, Steven A; Liang, Yongchao; Hu, Baowei; Chu, Guixin

2018-01-15

The effects of consecutive application of chemical fertilizer with or without organic fertilizer on soil N 2 O emissions and denitrifying community structure in a drip-irrigated field were determined. The four fertilizer treatments were (i) unfertilized, (ii) chemical fertilizer, (iii) 60% chemical fertilizer plus cattle manure, and (iv) 60% chemical fertilizer plus biofertilizer. The treatments with organic amendments (i.e. cattle manure and biofertilizer) reduced cumulative N 2 O emissions by 4.9-9.9%, reduced the N 2 O emission factor by 1.3-42%, and increased denitrifying enzyme activities by 14.3-56.2%. The nirK gene copy numbers were greatest in soil which received only chemical fertilizer. In contrast, nirS- and nosZ-copy numbers were greatest in soil amended with chemical fertilizer plus biofertilizer. Chemical fertilizer application with or without organic fertilizer significantly changed the community structure of nirK-type denitrifiers relative to the unfertilized soil. In comparison, the nirS- and nosZ-type denitrifier genotypes varied in treatments receiving organic fertilizer but not chemical fertilizer alone. The changes in the denitrifier communities were closely associated with soil organic carbon (SOC), NO 3 - , NH 4 + , water holding capacity, and soil pH. Modeling indicated that N 2 O emissions in this soil were primarily associated with the abundance of nirS type denitrifying bacteria, SOC, and NO 3 - . Overall, our findings indicate that (i) the organic fertilizers increased denitrifying enzyme activity, increased denitrifying-bacteria gene copy numbers, but reduced N 2 O emissions, and (ii) nirS- and nosZ-type denitrifiers were more sensitive than nirK-type denitrifiers to the organic fertilizers. Copyright © 2017. Published by Elsevier B.V.

Natural selection among Kinnaura of the Himalayan highland: A comparative analysis with other Indian and Himalayan populations

PubMed Central

Gautam, Rajesh K.; Kapoor, Anup K.; Kshatriya, G. K.

2009-01-01

The present investigation on fertility and mortality differential among Kinnaura of the Himalayan highland is based on data collected from 160 post-menopausal women belonging to the middle and high altitude region of Kinnaur district of Himachal Pradesh (Indian Himalayas). Selection potential based on differential fertility and mortality was computed for middle-and high-altitude women. Irrespective of the methodology, the total index of selection was found to be highest among middle-altitude women (0.386) as compared with high-altitude (0.370) women, whereas for the total population it is estimated to be 0.384. It was found that the Kinnaura of the Himalayan highland showing moderate index of total selection and relative contribution of the mortality component (Im) to the index of total selection is higher than the corresponding fertility component (If). The analysis of embryonic and post-natal mortality components shows that the post-natal mortality components are higher in comparison with the embryonic mortality components among highlanders and needs special intervention and health care. The present findings are compared with other Indian tribes as well as non-tribes of the Himalayan region and other parts of the country. It reveals that this index among Kinnaura is moderate than the other population groups; among the Himalayan population, the highest was reported for Galong (It = 1.07) of Arunachal, whereas the lowest was reported from Ahom (It = 0.218) of Manipur. The correlation and regression analysis between total index of selection (It) and fertility (If) and mortality (Im) components for pooled data of populations of the Indian Himalayan states show that If and Im account for 21.6 and 29.1% variability, respectively. In Crow's total index of selection (It) along with strong association, which is significant at the 1% level, this indicates that mortality plays a greater role in natural selection in comparison with fertility among populations of the Indian Himalayas. PMID:21088718

Integrated transcriptome catalogue and organ-specific profiling of gene expression in fertile garlic (Allium sativum L.).

PubMed

Kamenetsky, Rina; Faigenboim, Adi; Shemesh Mayer, Einat; Ben Michael, Tomer; Gershberg, Chen; Kimhi, Sagie; Esquira, Itzhak; Rohkin Shalom, Sarit; Eshel, Dani; Rabinowitch, Haim D; Sherman, Amir

2015-01-22

Garlic is cultivated and consumed worldwide as a popular condiment and green vegetable with medicinal and neutraceutical properties. Garlic cultivars do not produce seeds, and therefore, this plant has not been the subject of either classical breeding or genetic studies. However, recent achievements in fertility restoration in a number of genotypes have led to flowering and seed production, thus enabling genetic studies and breeding in garlic. A transcriptome catalogue of fertile garlic was produced from multiplexed gene libraries, using RNA collected from various plant organs, including inflorescences and flowers. Over 32 million 250-bp paired-end reads were assembled into an extensive transcriptome of 240,000 contigs. An abundant transcriptome assembled separately from 102,000 highly expressed contigs was annotated and analyzed for gene ontology and metabolic pathways. Organ-specific analysis showed significant variation of gene expression between plant organs, with the highest number of specific reads in inflorescences and flowers. Analysis of the enriched biological processes and molecular functions revealed characteristic patterns for stress response, flower development and photosynthetic activity. Orthologues of key flowering genes were differentially expressed, not only in reproductive tissues, but also in leaves and bulbs, suggesting their role in flower-signal transduction and the bulbing process. More than 100 variants and isoforms of enzymes involved in organosulfur metabolism were differentially expressed and had organ-specific patterns. In addition to plant genes, viral RNA of at least four garlic viruses was detected, mostly in the roots and cloves, whereas only 1-4% of the reads were found in the foliage leaves. The de novo transcriptome of fertile garlic represents a new resource for research and breeding of this important crop, as well as for the development of effective molecular markers for useful traits, including fertility and seed production, resistance to pests and neutraceutical characteristics.

Factors Affecting Tocopherol Concentrations in Soybean Seeds.

PubMed

Carrera, Constanza S; Seguin, Philippe

2016-12-21

Soybean seeds contain several health-beneficial compounds, including tocopherols, which are used by the nutraceutical and functional food industries. Soybean tocopherol concentrations are, however, highly variable. Large differences observed in tocopherol concentrations among soybean genotypes together with the relatively simple biosynthetic pathway involving few genes support the feasibility of selecting for high-tocopherol soybean. Tocopherol concentrations are also highly influenced by environmental factors and field management. Temperature during seed filling and soil moisture appear to be the main factors affecting tocopherol concentrations; other factors such as soil fertility and solar radiation also affect concentrations and composition. Field management decisions including seeding date, row spacing, irrigation, and fertilization also affect tocopherols. Knowledge of factors affecting soybean tocopherols is essential to develop management strategies that will lead to the production of seeds with consistent target concentrations that will meet the needs of the nutraceutical and functional food industries.

Fertilizer nitrogen, soil chemical properties, and their determinacy on rice yield: Evidence from 92 paddy fields of a large-scale farm in the Kanto Region of Japan

NASA Astrophysics Data System (ADS)

Li, D.; Nanseki, T.; Chomei, Y.; Yokota, S.

2017-07-01

Rice, a staple crop in Japan, is at risk of decreasing production and its yield highly depends on soil fertility. This study aimed to investigate determinants of rice yield, from the perspectives of fertilizer nitrogen and soil chemical properties. The data were sampled in 2014 and 2015 from 92 peat soil paddy fields on a large-scale farm located in the Kanto Region of Japan. The rice variety used was the most widely planted Koshihikari in Japan. Regression analysis indicated that fertilizer nitrogen significantly affected the yield, with a significant sustained effect to the subsequent year. Twelve soil chemical properties, including pH, cation exchange capacity, content of pyridine base elements, phosphoric acid, and silicic acid, were estimated. In addition to silicic acid, magnesia, in forms of its exchangeable content, saturation, and ratios to potassium and lime, positively affected the yield, while phosphoric acid negatively affected the yield. We assessed the soil chemical properties by soil quality index and principal component analysis. Positive effects were identified for both approaches, with the former performing better in explaining the rice yield. For soil quality index, the individual standardized soil properties and margins for improvement were indicated for each paddy field. Finally, multivariate regression on the principal components identified the most significant properties.

Factors of a noninfectious nature affecting fertility after artificial insemination in lactating dairy cows. A review.

PubMed

López-Gatius, F

2012-04-01

After 80 years of the commercial application of artificial insemination (AI) in the cow, the method still has numerous benefits over natural insemination including worldwide gene improvement. The efficiency of insemination depends, among many other factors, on the delivery of an appropriate number of normal spermatozoa to the appropriate reproductive tract site at the appropriate time of estrus. The metabolic clearance of steroid hormones and pregnancy associated glycoproteins and the negative effects of different types of stress related to high milk production makes the high-producing dairy cow a good animal model for addressing factors affecting fertility. Nevertheless, extensive studies have shown a positive link between high milk production in an individual cow and high fertility. When a cow becomes pregnant, the effect of pregnancy loss on its reproductive cycle is also a topic of interest. This paper reviews the factors of a noninfectious nature that affect the fertility of lactating dairy cows following AI. Special attention is paid to factors related to the cow and its environment and to estrus confirmation at insemination. Pregnancy maintenance during the late embryonic/early fetal period is discussed as a critical step. Finally, the use of Doppler ultrasonography is described as an available research tool for improving our current understanding of the health of the genital structures and conceptus. Copyright © 2012 Elsevier Inc. All rights reserved.

Aqueous fruit extract of Mimusops elengi causes reversible suppression of spermatogenesis and fertility in male mice.

PubMed

Singh, N; Singh, S K

2016-09-01

Antifertility efficacy of oral administration of aqueous fruit extract of Mimusops elengi (200, 400 and 600 mg kg(-1) body weight/day for 35 days) was evaluated in Parkes strain male mice. Various reproductive end points such as histopathology, sperm parameters, testosterone level, haematology, serum biochemistry and fertility indices were assessed; activities of 3β- and 17β-hydroxysteroid dehydrogenases, and immunoblot expressions of StAR and P450scc in the testis were also assessed. Histologically, testes in Mimusops-treated mice showed nonuniform and diverse degenerative changes in the seminiferous tubules; both affected and normal tubules were observed in the same sections of testis. The treatment had adverse effects on testicular hydroxysteroid dehydrogenases and StAR and P450scc, serum level of testosterone and on motility, viability and number of spermatozoa in cauda epididymis. However, serum levels of alanine aminotransferase, aspartate aminotransferase and creatinine, and haematological parameters were not affected by the treatment. Also, libido was not affected in treated males, but their fertility was markedly suppressed. By 56 days of treatment withdrawal, the alterations caused in the above parameters recovered to control levels, suggesting that Mimusops treatment causes reversible suppression of spermatogenesis and fertility in Parkes mice. Further, there were no detectable signs of toxicity in treated males. © 2016 Blackwell Verlag GmbH.

Opportunity for natural selection among some selected population groups of Northeast India

PubMed Central

Das, Farida Ahmed; Mithun, Sikdar

2010-01-01

BACKGROUND: Selection potential based on differential fertility and mortality has been computed for seven population groups inhabiting different geographical locations of Northeast India. MATERIALS AND METHODS: Crow’s as well as Johnston and Kensinger’s index have been used for the present purpose. RESULTS AND CONCLUSION: Irrespective of the methodology, the total index of selection was found to be highest among the Deoris followed by the Kaibartas. The lowest selection index was found among the Oraon population. If the relative contribution of fertility and mortality components to the total index is considered to be multiplicative, it is observed that in all these communities the fertility component exceeds that of mortality component, which may indicate initiation of demographic transitional phase in the selected populations with the betterment of healthcare and socioeconomic condition within the last few decades. PMID:21031053

Simultaneous investigation of intracellular Ca2+ increase and morphological events upon fertilization in the sand dollar egg.

PubMed

Hamaguchi, Y; Hamaguchi, M S

1990-06-01

An increase in intracellular Ca2+ concentration ([Ca2+]) and morphological were simultaneously observed by epifluorescence and differential interference contrast (DIC) microscopy during fertilization of the sand dollar, Clypeaster japonicus. [Ca2+], which was detected by a Ca2+ indicator, Fluo-3, initially increased just beneath the sperm-attached site on the egg surface 8.6 sec after attachment. The increase spread into the egg as a concentric sphere to the egg center and, thereafter, propagated in the egg cytoplasm as a planar wave rather than a spherical wave. It reached the site opposite the initiation site across the egg 24.2 sec after initiation. The fertilization envelope (FE) began to elevate 10.3 sec after the initiation of the increase in [Ca2+] and 21.2 sec after sperm attachment.

Roles of epigenome in mammalian spermatogenesis.

PubMed

Song, Ning; Endo, Daisuke; Koji, Takehiko

2014-04-01

Mammalian spermatogenesis is a successive process consisting of spermatogonial proliferation, spermatocytic meiosis, and spermiogenesis, representing the maturation of haploid spermatids. During the process, 25-75 % of the expected sperm yield is thought to be lost through apoptosis. In addition, spermatogenesis is considered to be a process undergoing successive heterochromatinization, finally reaching a complete condensed form in the sperm head. Thus, cell proliferation, differentiation and death may be strictly regulated by epigenetic factors in this process. This review describes the current understanding of the role of epigenome in spermatogenesis, especially focusing on the following aspects; DNA methylation, modification of histones, and small RNA function. These epigenetic factors affect each other and play a central role in events essential for spermatogenesis, fertilization and embryogenesis, through the regulation of gene expression, transposon activities, meiotic sex chromosome inactivation, histone remodeling and genome imprinting. Finally, a brief discussion of future avenues of study is highlighted.

Factors influencing infant/child mortality in Bangladesh: implication for family planning programs and policies.

PubMed

Miah, M M

1993-01-01

"This study examined a host of socio-economic and demographic factors (including their interactions) that determine infant/child mortality of married women at the different parity levels in Bangladesh [using data from] a multivariate analysis of the 1975-76 Bangladesh Fertility Survey.... The major hypothesis of this research is that the higher the level of fertility of a married woman, the higher will be her experience of infant/child mortality. However, a woman's family planning practice may interact with fertility and affect the total infant/child deaths...." excerpt

Trading Population for Productivity: Theory and Evidence

PubMed Central

Galor, Oded; Mountford, Andrew

2013-01-01

This research argues that the differential effect of international trade on the demand for human capital across countries has been a major determinant of the distribution of income and population across the globe. In developed countries the gains from trade have been directed towards investment in education and growth in income per capita, whereas a significant portion of these gains in less developed economies have been channeled towards population growth. Cross-country regressions establish that indeed trade has positive effects on fertility and negative effects on education in non-OECD economies, while inducing fertility decline and human capital formation in OECD economies. PMID:25089061

The influence of the Chinese zodiac on fertility in Hong Kong SAR.

PubMed

Yip, Paul S F; Lee, Joseph; Cheung, Y B

2002-11-01

The annual total of births in Hong Kong SAR fell substantially in the past 20 years; hence the total fertility rate (TFR) followed the downward trend and dropped to a low of 0.9 below replacement level in 2000. Despite the long-term downward trend, short-run increases in the annual total of births and the TFR were exhibited. Such temporary fertility increases are identified in the Dragon Years of 1988 and 2000. The phenomenon of fertility changes associated with zodiacal animal years is examined in this paper with a view to gaining some insight into whether Chinese cultural preferences and folklore beliefs might have influenced prospective parents' reproductive behaviour. The paper explains the underlying philosophy of the Chinese astrological tradition and discusses how zodiacal preferences affect fertility between 1976 and 2000. The paper also explores why zodiacal influences on Chinese fertility before 1976 did not exist. It is unquestionable that the Dragon Year preference exerts an influence on fertility of modern Chinese populations through zodiacal birth-timing motivations. Birth rate rise in the Dragon Year is due to changes in timing of births that will have little effect on cumulative fertility.

Semen collection and fertility in naturally fertile sandhill cranes

USGS Publications Warehouse

Chen, G.; Gee, G.F.; Nicolich, Jane M.; Taylor, J.A.; Urbanek, R.P.; Stahlecker, D.W.

1997-01-01

Aviculturists often ask if semen collection will interfere with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had produced fertile eggs in previous years and were in out-of-doors pens scattered throughout different pen complexes, within auditory range but physically isolated. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection did not affect semen quality or quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm live, sperm number per collection, and male response to semen collection exhibited significant daily variation (P < 0.05). Although semen collection began 13 days before the first egg in the experimental group, we observed no differences in the date of first egg laid or in fertility between experimental and control groups. Also, we observed no differences in the interval between clutches or in the percentage of broken eggs between experimental and control groups. Sires consistently producing better semen samples produced fewer fertile eggs than sires producing poorer semen samples (r = 0.60).

THE DELINKING OF SEX AND MARRIAGE: PATHWAYS TO FERTILITY AMONG YOUNG FILIPINO WOMEN.

PubMed

Gipson, Jessica D; Hicks, Andrew L

2017-01-01

Partnership and fertility patterns of young Filipinos have changed dramatically from previous generations, with a widening gap between sexual initiation and marriage, and concurrent increases in teenage pregnancy and unwanted fertility. Further understanding of young adults' social contexts and partnership patterns are needed to inform reproductive health programmes and policies affecting young Filipinos. Multivariate Poisson regression models were conducted with longitudinal and inter-generational data from the Cebu Longitudinal Health and Nutrition Survey (1998-2009) to examine the predictors of young women's fertility. Age at first sex, and number and duration of partnerships each independently and significantly predicted women's fertility by 2009 after controlling for contextual influences. Young women with more conservative attitudes towards dating, sex and marriage, and who perceived their mothers to have more conservative attitudes, had higher fertility than their peers, as did young women with mothers who reported more adolescent sexual behaviours. In contrast, fertility was lower among daughters who had higher levels of communication with their mothers. Given high levels of unintended fertility and teenage pregnancy in the Philippines, the findings indicate that the interval between sexual initiation and first and subsequent partnerships may be ideal intervention points for reproductive health services for young Filipinos.

A discussion of key values to inform the design and delivery of services for HIV-affected women and couples attempting pregnancy in resource-constrained settings.

PubMed

Heffron, Renee; Davies, Natasha; Cooke, Ian; Kaida, Angela; Mergler, Reid; van der Poel, Sheryl; Cohen, Craig R; Mmeje, Okeoma

2015-01-01

HIV-affected women and couples often desire children and many accept HIV risk in order to attempt pregnancy and satisfy goals for a family. Risk reduction strategies to mitigate sexual and perinatal HIV transmission include biomedical and behavioural approaches. Current efforts to integrate HIV and reproductive health services offer prime opportunities to incorporate strategies for HIV risk reduction during pregnancy attempts. Key client and provider values about services to optimize pregnancy in the context of HIV risk provide insights for the design and implementation of large-scale "safer conception" programmes. Through our collective experience and discussions at a multi-disciplinary international World Health Organization-convened workshop to initiate the development of guidelines and an algorithm of care to support the delivery of services for HIV-affected women and couples attempting pregnancy, we identified four values that are key to the implementation of these programmes: (1) understanding fertility care and an ability to identify potential fertility problems; (2) providing equity of access to resources enabling informed decision-making about reproductive choices; (3) creating enabling environments that reduce stigma associated with HIV and infertility; and (4) creating enabling environments that encourage disclosure of HIV status and fertility status to partners. Based on these values, recommendations for programmes serving HIV-affected women and couples attempting pregnancy include the following: incorporation of comprehensive reproductive health counselling; training to support the transfer and exchange of knowledge between providers and clients; care environments that reduce the stigma of childbearing among HIV-affected women and couples; support for safe and voluntary disclosure of HIV and fertility status; and increased efforts to engage men in reproductive decision-making at times that align with women's desires. Programmes, policies and guidelines that integrate HIV treatment and prevention, sexual and reproductive health and fertility care services in a manner responsive to user values and preferences offer opportunities to maximize demand for and use of these services. For HIV-affected women and couples attempting pregnancy, the provision of comprehensive services using available tools - and the development of new tools that are adaptable to many settings and follow consensus recommendations - is a public health imperative. The impetus now is to design and deliver value-driven inclusive programming to achieve the greatest coverage and impact to reduce HIV transmission during pregnancy attempts.

Motility and centrosomal organization during sea urchin and mouse fertilization

NASA Technical Reports Server (NTRS)

Schatten, Heide; Schatten, Gerald

1986-01-01

It is noted that microfilaments are essential for incorporation of sperm in sea urchins and for pronuclear apposition in mice. The ability of sea urchin sperm to fertilize eggs is lowered by latrunculin, giving evidence that acrosomal microfilaments are of importance to the process of fertilization. Due to the uncertainty regarding the presence of microfilaments in various mammalian sperm, it is interesting that latrunculin does not noticeably affect the ability of mouse sperm to fertilize oocytes. The movements of the sperm and egg nuclei at the time of sea urchin fertilization are dependent on microtubules arranged into a radial monastral array (the sperm aster). In the mouse egg, microtubule activity is also required during pronuclear apposition, but they are arranged by a number of egg cytoplasmic sites. Results of the investigations show that both microtubules and microfilaments are necessary for the successful completion of fertilization in both mice and sea urchins, but at different stages. Also, it is demonstrated that centrosomes are contributed by the sperm in the process of sea urchin fertilization, but in mammals they may be inherited maternally.

Egg water from the amphibian Bufo arenarum induces capacitation-like changes in homologous spermatozoa.

PubMed

Krapf, Darío; Visconti, Pablo E; Arranz, Silvia E; Cabada, Marcelo O

2007-06-15

Mammalian sperm acquire fertilizing capacity after residing in the female tract, where physiological changes named capacitation take place. In animals with external fertilization as amphibians, gamete interactions are first established between sperm and molecules of the egg jelly coat released into the medium. Since dejellied oocytes are not normally fertilized, the aim of this study was to determine if the jelly coat of the toad Bufo arenarum promotes a "capacitating" activity on homologous sperm. We found that sperm incubation in diffusible substances of the jelly coat (egg water) for 90-180 s is sufficient to render sperm transiently capable of fertilizing dejellied oocytes. The fertilizing state was correlated with an increase of protein tyrosine phosphorylation and a decrease of sperm cholesterol content. Inhibition of either the increase in tyrosine phosphorylation or cholesterol efflux affected the acquisition of fertilizing capacity. Phosphorylation and fertilization could be promoted with NaHCO(3) and also by addition of beta cyclodextrin. Moreover, sperm could gain the ability to fertilize dejellied oocytes in the presence of these compounds. These data indicate that sperm should undergo a series of molecular changes to gain fertilizing capacity; these changes are reminiscent of mammalian sperm capacitation and take place before the acrosome reaction.

Egg water from the amphibian Bufo arenarum induces capacitation-like changes in homologous spermatozoa

PubMed Central

Krapf, Darío; Visconti, Pablo E.; Arranz, Silvia E; Cabada, Marcelo O

2007-01-01

Mammalian sperm acquire fertilizing capacity after residing in the female tract, where physiological changes named capacitation take place. In animals with external fertilization as amphibians, gamete interactions are first established between sperm and molecules of the egg jelly coat released into the medium. Since dejellied oocytes are not normally fertilized, the aim of this study was to determine if the jelly coat of the toad Bufo arenarum promotes a “capacitating” activity on homologous sperm. We found that sperm incubation in diffusible substances of the jelly coat (Egg Water) for 90–180 sec is sufficient to render sperm transiently capable of fertilizing dejellied oocytes. The fertilizing state was correlated with an increase of protein tyrosine phosphorylation and a decrease of sperm cholesterol content. Inhibition of either the increase in tyrosine phosphorylation or cholesterol efflux affected the acquisition of fertilizing capacity. Phosphorylation and fertilization could be promoted with NaHCO3, and also by addition of beta cyclodextrin. Moreover, sperm could gain the ability to fertilize dejellied oocytes in the presence of these compounds. These data indicate that sperm should undergo a series of molecular changes to gain fertilizing capacity; these changes are reminiscent of mammalian sperm capacitation and take place before the acrosome reaction. PMID:17459363

Education, labor-force participation, and fertility in the USSR.

PubMed

Berliner, J S

1983-01-01

The effect of education on Soviet fertility and female labor participation is analyzed in terms of the neoclassical theory of the household. Using this theory, child worth in terms of services and real consumption or distribution of income are analyzed as factors in fertility decision making. The hypotheses are tested by multivariate analysis of Soviet census data. The contribution of husband and wife to family income is different from that in the West. The effect of female education on fertility should be in the range of small and negative to moderately positive. The effect of male education should be moderately negative. The effect of an individual family's education level on its fertility is often influenced by the community's education level. Rising educational levels of males have contributed most to the decline of Soviet fertility recently. The rising education of females has tended to offset this negative influence, however. The rural Soviet data support this. The female labor-force participation rates are negative and significant. Of the total (positive) effect of female higher education on fertility; half operates indirectly-by decreasing labor participation which in turn increases fertility. The other half affects fertility directly. These results imply a backward-bending female labor supply curve at the higher education level.

Reproductive health laws and fertility decline in Ghana.

PubMed

Finlay, Jocelyn E; Fox, Ashley M

2013-11-01

An unresolved debate in demography concerns the causal sequence between the supply of contraception and the demand for smaller families in fertility decline. Through a mixed-methods approach, we explored the effect of a sudden increase in access to legal abortion on subsequent fertility decline when Ghana's criminal code was amended in 1985. Using Ghana Demographic and Health Surveys, we constructed a panel of women aged 15-34 years and undertook a spline regression analysis to examine the effect of legal changes in 1985 and fertility decline controlling for social determinants of fertility. In addition, we conducted 17 key informant interviews (KIIs) to understand the reasons for the legal change and competing explanations for fertility decline. Multivariate results indicated that the timing of the liberalization of the abortion law coincided with the onset of Ghana's fertility decline. The KIIs indicated that the reasons for the liberalization of reproductive health laws were in response to famine and physician advocacy. While the timing of the abortion law liberalization coincided with the fertility decline in Ghana, we are unable to decouple the effect of the legal change from the effects of a severe famine that affected the region at the same time. Further research on documented and undocumented abortion in Ghana should be conducted to validate the contribution of legal abortion to fertility decline. © 2013.

Parental genetic material and oxygen concentration affect hatch dynamics of mouse embryo in vitro.

PubMed

Zhan, Shaoquan; Cao, Shanbo; Du, Hongzi; Sun, Yuan; Li, Li; Ding, Chenhui; Zheng, Haiyan; Huang, Junjiu

2018-04-21

Hatching is crucial for mammalian embryo implantation, since difficulties during this process can lead to implantation failure, ectopic pregnancy and consequent infertility. Despite years of intensive researches, how internal and external factors affecting embryo hatch are still largely unclear. The effects of parental genetic material and oxygen concentration on hatch process were examined. Fertilized and parthenogenetic mouse preimplantation embryos were cultured in vitro under 5 and 20% oxygen for 120 h. Zona pellucida drilling by Peizo micromanipulation were performed to resemble the breach by sperm penetration. Firstly, parthenogenetic embryos had similarly high blastocyst developmental efficiency as fertilized embryos, but significantly higher hatch ratio than fertilized embryos in both O 2 concentrations. 5% O 2 reduced the hatch rate of fertilized embryos from 58.2 to 23.8%, but increased that of parthenogenetic embryos from 81.2 to 90.8% significantly. Analogously, 5% O 2 decreased the ratio of Oct4-positive cells in fertilized blastocysts, whereas increased that in parthenogenetic blastocysts. Additionally, 5% O 2 increased the total embryonic cell number in both fertilized and parthegenetic embryos, when compared to 20% O 2 , and the total cell number of fertilized embryos was also higher than that of parthegenetic embryos, despite O 2 concentration. Real-time PCR revealed that the expression of key genes involving in MAPK pathway and superoxide dismutase family might contribute to preimplantation development and consequent blastocyst hatch in vitro. Finally, we showed that fertilized and parthenogenetic embryos have diverse hatch dynamics in vitro, although the zona pellucida integrity is not the main reason for their mechanistic differences. Both parental genetic material and O 2 concentration, as the representative of intrinsic and extrinsic factors respectively, have significant impacts on mouse preimplantation development and subsequent hatch dynamics, probably by regulating the gene expression involving in MAPK pathway and superoxide dismutase family to control embryonic cell proliferation and allocation of ICM cells.

Genetic effects and correlations between production and fertility traits and their dependency on the lactation-stage in Holstein Friesians

PubMed Central

2012-01-01

Background This study focused on the dynamics of genome-wide effects on five milk production and eight fertility traits as well as genetic correlations between the traits. For 2,405 Holstein Friesian bulls, estimated breeding values (EBVs) were used. The production traits were additionally assessed in 10-day intervals over the first 60 lactation days, as this stage is physiologically the most crucial time in milk production. Results SNPs significantly affecting the EBVs of the production traits could be separated into three groups according to the development of the size of allele effects over time: 1) increasing effects for all traits; 2) decreasing effects for all traits; and 3) increasing effects for all traits except fat yield. Most of the significant markers were found within 22 haplotypes spanning on average 135,338 bp. The DGAT1 region showed high density of significant markers, and thus, haplotype blocks. Further functional candidate genes are proposed for haplotype blocks of significant SNPs (KLHL8, SICLEC12, AGPAT6 and NID1). Negative genetic correlations were found between yield and fertility traits, whilst content traits showed positive correlations with some fertility traits. Genetic correlations became stronger with progressing lactation. When correlations were estimated within genotype classes, correlations were on average 0.1 units weaker between production and fertility traits when the yield increasing allele was present in the genotype. Conclusions This study provides insight into the expression of genetic effects during early lactation and suggests possible biological explanations for the presented time-dependent effects. Even though only three markers were found with effects on fertility, the direction of genetic correlations within genotype classes between production and fertility traits suggests that alleles increasing the milk production do not affect fertility in a more negative way compared to the decreasing allele. PMID:23244492

Adolescent Birth Intentions: Social Disadvantage, and Behavioral Outcomes.

ERIC Educational Resources Information Center

Trent, Katherine; Crowder, Kyle

1997-01-01

Uses national survey data to examine the extent to which group differentials in early nonmarital childbearing are a function of normative differences in fertility intentions. Results indicate that birth intentions do vary by race and ethnicity, poverty status, and family structure. (RJM)

Short communication: A missense mutation in the PROP1 (prophet of Pit 1) gene affects male fertility and milk production traits in the US Holstein population.

PubMed

Lan, X Y; Peñagaricano, F; DeJung, L; Weigel, K A; Khatib, H

2013-02-01

In previous studies, we reported significant associations of the POU1F1 pathway genes with reproduction and production traits in several dairy cattle populations. Polymorphisms in genes of this pathway were found to be associated with both female and male fertility traits in dairy cattle. The POU1F1 gene is a direct downstream target for the regulation of the prophet of Pit1 (PROP1) gene, also known as PROP paired-like homeobox 1. Interestingly, the position of PROP1 coincides with a quantitative trait locus affecting ovulation rate in cattle. Therefore, the objective of this study was to investigate whether PROP1 affects fertility and milk production traits in Holstein cattle. Using the DNA pooling sequencing approach, a missense single nucleotide polymorphism that replaces a histidine amino acid with an arginine was detected in exon 3 of PROP1. The arginine allele was found to be associated with a decrease in sire conception rate and an increase in productive life, protein yield, and net merit index in a population of 1,951 Holstein bulls. The transcription factors produced from the histidine and arginine isoforms are known to have different transcription, DNA binding, and regulation activities. As such, we propose that the association of the arginine isoform with decreased bull fertility is likely caused by reduced activity of this allele in male functions. The findings of this study suggest PROP1 polymorphisms as candidates in selection programs for fertility, health, and milk production traits in dairy cattle. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Transporters involved in pH and K + homeostasis affect pollen wall formation, male fertility, and embryo development

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

Padmanaban, Senthilkumar; Czerny, Daniel D.; Levin, Kara A.

Flowering plant genomes encode multiple cation/H + exchangers (CHXs) whose functions are largely unknown. AtCHX17, AtCHX18, and AtCHX19 are membrane transporters that modulate K+ and pH homeostasis and are localized in the dynamic endomembrane system. Loss of function reduced seed set, but the particular phase(s) of reproduction affected was not determined. Pollen tube growth and ovule targeting of chx17chx18chx19 mutant pollen appeared normal, but reciprocal cross experiments indicate a largely male defect. Although triple mutant pollen tubes reach ovules of a wild-type pistil and a synergid cell degenerated, half of those ovules were unfertilized or showed fertilization of the eggmore » or central cell, but not both female gametes. Fertility could be partially compromised by impaired pollen tube and/or sperm function as CHX19 and CHX18 are expressed in the pollen tube and sperm cell, respectively. When fertilization was successful in self-pollinated mutants, early embryo formation was retarded compared with embryos from wild-type ovules receiving mutant pollen. Thus CHX17 and CHX18 proteins may promote embryo development possibly through the endosperm where these genes are expressed. The reticulate pattern of the pollen wall was disorganized in triple mutants, indicating perturbation of wall formation during male gametophyte development. Lastly, as pH and cation homeostasis mediated by AtCHX17 affect membrane trafficking and cargo delivery, these results suggest that male fertility, sperm function, and embryo development are dependent on proper cargo sorting and secretion that remodel cell walls, plasma membranes, and extracellular factors.« less

Assessment of the toxic effect of pesticides on honey bee drone fertility using laboratory and semifield approaches: A case study of fipronil.

PubMed

Kairo, Guillaume; Poquet, Yannick; Haji, Haïthem; Tchamitchian, Sylvie; Cousin, Marianne; Bonnet, Marc; Pelissier, Michel; Kretzschmar, André; Belzunces, Luc P; Brunet, Jean-Luc

2017-09-01

Concern about the reproductive toxicity of plant protection products in honey bee reproducers is increasing. Because the reproductive capacity of honey bees is not currently considered during the risk assessment procedure performed during plant protection product registration, it is important to provide methods to assess such potential impairments. To achieve this aim, we used 2 different approaches that involved semifield and laboratory conditions to study the impact of fipronil on drone fertility. For each approach, the drones were reared for 20 d, from emergence to sexual maturity, and exposed to fipronil via a contaminated sugar solution. In both groups, the effects of fipronil were determined by studying life traits and fertility indicators. The results showed that the survival and maturity rates of the drones were better under laboratory conditions than under semifield conditions. Moreover, the drones reared under laboratory conditions produced more seminal fluid. Although these differences could be explained by environmental factors that may vary under semifield conditions, it was found that regardless of the approach used, fipronil did not affect survival rates, maturity rates, or semen volumes, whereas it did affect fertility by inducing a decrease in spermatozoa quantity that was associated with an increase in spermatozoa mortality. These results confirm that fipronil affects drone fertility and support the relevance of each approach for assessing the potential reproductive toxicity of plant protection products in honey bees. Environ Toxicol Chem 2017;36:2345-2351. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Transporters involved in pH and K + homeostasis affect pollen wall formation, male fertility, and embryo development

DOE PAGES

Padmanaban, Senthilkumar; Czerny, Daniel D.; Levin, Kara A.; ...

2017-02-23

Flowering plant genomes encode multiple cation/H + exchangers (CHXs) whose functions are largely unknown. AtCHX17, AtCHX18, and AtCHX19 are membrane transporters that modulate K+ and pH homeostasis and are localized in the dynamic endomembrane system. Loss of function reduced seed set, but the particular phase(s) of reproduction affected was not determined. Pollen tube growth and ovule targeting of chx17chx18chx19 mutant pollen appeared normal, but reciprocal cross experiments indicate a largely male defect. Although triple mutant pollen tubes reach ovules of a wild-type pistil and a synergid cell degenerated, half of those ovules were unfertilized or showed fertilization of the eggmore » or central cell, but not both female gametes. Fertility could be partially compromised by impaired pollen tube and/or sperm function as CHX19 and CHX18 are expressed in the pollen tube and sperm cell, respectively. When fertilization was successful in self-pollinated mutants, early embryo formation was retarded compared with embryos from wild-type ovules receiving mutant pollen. Thus CHX17 and CHX18 proteins may promote embryo development possibly through the endosperm where these genes are expressed. The reticulate pattern of the pollen wall was disorganized in triple mutants, indicating perturbation of wall formation during male gametophyte development. Lastly, as pH and cation homeostasis mediated by AtCHX17 affect membrane trafficking and cargo delivery, these results suggest that male fertility, sperm function, and embryo development are dependent on proper cargo sorting and secretion that remodel cell walls, plasma membranes, and extracellular factors.« less

Biochar affects soil organic matter cycling and microbial functions but does not alter microbial community structure in a paddy soil.

PubMed

Tian, Jing; Wang, Jingyuan; Dippold, Michaela; Gao, Yang; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2016-06-15

The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, microbial community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the microbial community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the microbial community compared with the control, but altered the microbial community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related microbial community structure. The particulate organic N explained the largest variation in the microbial community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected microbial community composition and functions, which consequently influenced SOM cycling. Copyright © 2016 Elsevier B.V. All rights reserved.

The effects of shade, fertilizer, and pruning on eastern hemlock trees and hemlock woolly adelgid

Treesearch

Thomas McAvoy; Ryan Mays; Nels Johnson; Scott Salom

2017-01-01

Hemlock woolly adelgid (HWA), Adelges tsugae Annand, an invasive insect native to the Pacific Northwest and Asia, is responsible for widespread health decline and mortality of native hemlocks (Tsuga spp.) in the eastern United States. Shading and fertilizer has been found to affect the survival and health of both HWA and...

Genotype X Fertility Interactions in Seedling Sweetgum

Treesearch

Scott X. Chang; Daniel J. Robison

2002-01-01

Genotype x fertility interactions may affect the suitability of sweetgum (Liquidambar styraciflua L.) for specific sites or the efficiency of nutrient use. To gain a better understanding of these interactions, 2-year-old sweetgum seedlings from two half-sib families were tested for growth response to N (0 and 100 kg/ha equivalent) and P (0 and 50 kg...

A polymorphism in myostatin influences puberty but not fertility in beef heifers, whereas µ-calpain affects first calf birth weight

USDA-ARS?s Scientific Manuscript database

The use of genetic markers to aid in selection decisions to improve carcass and growth characteristics is of great interest to the beef industry. However, it is important to examine potential antagonistic interactions with fertility in the cows before widespread application of marker-assisted selec...

Effects of Watering and Fertilization on Carbohydrate Reserves in Sugar Maple Seedlings

Treesearch

Clayton M., Jr. Carl; John R. Donnelly; Boyd W. Post

1978-01-01

Sugar maple seedlings, grown under three nutrient and three moisture levels, were analyzed after three growing seasons for starch and ethanol-soluble sugars. Analytical procedures are detailed in the appendix. Fertilization did not affect carbohydrate levels in stems or roots. Water stress caused a significant reduction in the amount of carbohydrates in stems and roots...

A model for estimating understory vegetation response to fertilization and precipitation in loblolly pine plantations

Treesearch

Curtis L. VanderSchaaf; Ryan W. McKnight; Thomas R. Fox; H. Lee Allen

2010-01-01

A model form is presented, where the model contains regressors selected for inclusion based on biological rationale, to predict how fertilization, precipitation amounts, and overstory stand density affect understory vegetation biomass. Due to time, economic, and logistic constraints, datasets of large sample sizes generally do not exist for understory vegetation. Thus...

Decomposition and nutrient release from fresh and dried pine roots under two fertilizer regimes

Treesearch

Kim H. Ludovici; Lance W. Kress

2006-01-01

Root decomposition and nutrient release are typically estimated from dried root tissues; however, it is unlikely that roots dehydrate prior to decomposing. Soil fertility and root diameter may also affect the rate of decomposition. This study monitored mass loss and nutrient concentrations of dried and fresh roots of two size classes (

Influence of pine straw harvesting, prescribed fire, and fertilization on a Louisiana longleaf pine site

Treesearch

James D. Haywood

2009-01-01

This research was initiated in a 34-year-old, direct-seeded stand of longleaf pine (Pinus palustris Mill.) to study how pine straw management practices (harvesting, fire, and fertilization) affected the longleaf pine overstory and pine straw yields. A randomized complete block split-plot design was installed with two main plot treatments...

Increased frequency of self-fertile isolates in Phytophthora infestans may attribute to their higher fitness relative to the A1 isolates

PubMed Central

Zhu, Wen; Shen, Lin-Lin; Fang, Zhi-Guo; Yang, Li-Na; Zhang, Jia-Feng; Sun, Dan-Li; Zhan, Jiasui

2016-01-01

Knowledge of population dynamics of mating types is important for better understanding pathogen’s evolutionary potential and sustainable management of natural and chemical resources such as host resistances and fungicides. In this study, 2250 Phytophthora infestans isolates sampled from 61 fields across China were assayed for spatiotemporal dynamics of mating type frequency. Self-fertile isolates dominated in ~50% of populations and all but one cropping region with an average frequency of 0.64 while no A2 isolates were detected. Analyses of 140 genotypes consisting of 82 self-fertile and 58 A1 isolates indicated that on average self-fertile isolates grew faster, demonstrated higher aggressiveness and were more tolerant to fungicides than A1 isolates; Furthermore, pattern of association between virulence complexity (defined as the number of differential cultivars on which an isolate can induce disease) and frequency was different in the two mating types. In A1 isolates, virulence complexity was negatively correlated (r = −0.515, p = 0.043) with frequency but this correlation was positive (r = 0.532, p = 0.037) in self-fertile isolates. Our results indicate a quick increase of self-fertile isolates possibly attributable to their higher fitness relative to A1 mating type counterpart in the field populations of P. infestans in China. PMID:27384813

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

PubMed Central

Kaplan, Hillard S.; Hooper, Paul L.

2016-01-01

The role that social status plays in small-scale societies suggests that status may be important for understanding the evolution of human fertility decisions, and for understanding how such decisions play out in modern contexts. This paper explores whether modelling competition for status—in the sense of relative rank within a society—can help shed light on fertility decline and the demographic transition. We develop a model of how levels of inequality and status competition affect optimal investment by parents in the embodied capital (health, strength, and skills) and social status of offspring, focusing on feedbacks between individual decisions and socio-ecological conditions. We find that conditions similar to those in demographic transition societies yield increased investment in both embodied capital and social status, generating substantial decreases in fertility, particularly under conditions of high inequality and intense status competition. We suggest that a complete explanation for both fertility variation in small-scale societies and modern fertility decline will take into account the effects of status competition and inequality. PMID:27022077

The Role of SPRASA in Female Fertility

PubMed Central

Wagner, Angela; Tong, Mancy; Shelling, Andrew N.; Chamley, Lawrence W.

2014-01-01

Fertility is a complex process and infertility can have many causes. Sperm protein reactive with antisperm antibody (SPRASA)/sperm lysozyme-like protein 1 is a protein discovered as the target of autoantibodies in infertile men and previously thought to be expressed only in sperm. Using a bovine in vitro fertilization model, we have shown that SPRASA antiserum reduced sperm binding to zona-free oocytes and the development of embryos to morulae but did not affect the postfertilization cleavage rate to 2 cells or sperm motility. We demonstrated that SPRASA was expressed in ovarian follicles, corpora lutea, and oocytes by a combination of reverse transcription-polymerase chain reaction and immunohistochemistry. Female mice immunized with SPRASA had profound infertility following timed matings and those mice that did become pregnant had reduced fetal viability. The levels of antibodies reactive with SPRASA in 204 fertile and 202 infertile couples were elevated in 3 infertile but no fertile women. Together, these results indicate that SPRASA has a role in female fertility. PMID:25038051

Do children make you happier? Sustained child-wish and mental health in women 11-17 years after fertility treatment.

PubMed

Gameiro, Sofia; van den Belt-Dusebout, Alexandra W; Bleiker, Eveline; Braat, Didi; van Leeuwen, Flora E; Verhaak, Christianne M

2014-10-10

Are fertility treatment-related factors, parenthood status and sustained child-wish associated with women's long-term mental health? Sustaining a child-wish is more strongly associated with women's long-term mental health than fertility treatment-related factors and parenthood status. About one-third of the couples starting fertility treatment do not achieve parenthood and have to adjust to an unfulfilled child-wish. In women, remaining childless after treatment is associated with less favourable mental health. It is unclear if this is only related to their childlessness or if adjustment after unsuccessful treatment is affected by other variables. These include diagnostic and treatment-related factors (cause of fertility problems, age at first consultation, type and number of treatments) and the psychological ability to come to terms with the unfulfilled child-wish. Differentiating the relative contribution of these factors to women's long-term mental health will provide useful knowledge to support patients adjusting to negative treatment outcomes. A cross-sectional study with a nationally representative sample of 7148 women who started fertility treatment at any of the 12 IVF hospitals in the Netherlands from 1995 through 2000. Of 16 482 women who were invited to participate, 7148 (43.4%) provided psychological data. The average age of women was 47 years and the average age at first fertility consultation was 30 years. Fifty-one per cent of women did IUI and 85% did IVF/ICSI. Ninety per cent of women were married/cohabiting, 20.9% remained childless and 5.9% had a child-wish. Women completed a questionnaire assessing diagnostic and treatment factors (retrospective data), parenthood status, sustained child-wish and mental health. A multiple regression analysis controlling for background variables showed that, first, male factor (P < 0.05) and/or idiopathic infertility (P < 0.001) were associated with better mental health. Secondly, starting fertility treatment at an older age was associated with better mental health (P < 0.01). Thirdly, the interaction between parenthood status and sustained child-wish was significant (P < 0.01). Having a child-wish was associated with worse mental health for women with (β = -0.058, P < 0.01) and without children (β =-0.136, P < 0.001), but associations were stronger for the latter. Predictive factors accounted for <5% of the variation in mental health status in the study population. The sample was large and nationally representative. Response rate was in line with other studies but women without psychological data were less likely to have biological children and 15.9% of non-responders considered the questionnaire to be too confronting or to elicit too emotional memories. This could reflect an underestimation of the proportion of women with a sustained child-wish. Sustaining a child-wish is a more important risk for long-term adjustment problems than parenthood status. Women adjust better when they start treatment at older ages and know they were not responsible for the cause of the fertility problem. Fertility staff can play an important role in preparing patients for the possibility of treatment failure and the associated grief process. They can also inform patients about the positive effect of refocusing their life goals. This study was supported by a grant from the Dutch Cancer Society (2006-3631). No competing interests exist. N/A. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Focus on: epigenetics and fetal alcohol spectrum disorders.

PubMed

Kobor, Michael S; Weinberg, Joanne

2011-01-01

Epigenetic changes-stable but potentially reversible alterations in a cell's genetic information that result in changes in gene expression but do not involve changes in the underlying DNA sequence-may mediate some of the detrimental effects of prenatal alcohol exposure and contribute to the deficits and abnormalities associated with fetal alcohol spectrum disorders. These epigenetic processes are linked to the chromatin (i.e., DNA, histone proteins, and other associated proteins) and commonly involve chemical modifications (e.g., methylation) of these molecules, which may result in altered expression of the affected genes. Even alcohol exposure prior to conception appears to be able to induce epigenetic changes in the parental genetic material that can be passed on to the offspring and affect offspring outcome. Similarly, epigenetic processes may occur as a result of maternal alcohol consumption during the period between fertilization of the egg and implantation in the uterus. The period most sensitive to alcohol's adverse effects appears to be gastrulation, which corresponds to prenatal weeks 3 to 8 in the human and prenatal days 7 to 14 in the mouse, when cells are differentiating to form organs. One way in which alcohol exposure may induce epigenetic changes, particularly abnormal DNA methylation, is by affecting a set of biochemical reactions called the methionine-homocysteine cycle.

Focus On: Epigenetics and Fetal Alcohol Spectrum Disorders

PubMed Central

Kobor, Michael S.; Weinberg, Joanne

2011-01-01

Epigenetic changes—stable but potentially reversible alterations in a cell’s genetic information that result in changes in gene expression but do not involve changes in the underlying DNA sequence—may mediate some of the detrimental effects of prenatal alcohol exposure and contribute to the deficits and abnormalities associated with fetal alcohol spectrum disorders. These epigenetic processes are linked to the chromatin (i.e., DNA, histone proteins, and other associated proteins) and commonly involve chemical modifications (e.g., methylation) of these molecules, which may result in altered expression of the affected genes. Even alcohol exposure prior to conception appears to be able to induce epigenetic changes in the parental genetic material that can be passed on to the offspring and affect offspring outcome. Similarly, epigenetic processes may occur as a result of maternal alcohol consumption during the period between fertilization of the egg and implantation in the uterus. The period most sensitive to alcohol’s adverse effects appears to be gastrulation, which corresponds to prenatal weeks 3 to 8 in the human and prenatal days 7 to 14 in the mouse, when cells are differentiating to form organs. One way in which alcohol exposure may induce epigenetic changes, particularly abnormal DNA methylation, is by affecting a set of biochemical reactions called the methionine–homocysteine cycle. PMID:23580038

The presence of human papillomavirus in semen does not affect the integrity of sperm DNA.

PubMed

Cortés-Gutiérrez, E I; Dávila-Rodríguez, M I; Fernández, J L; de la O-Pérez, L O; Garza-Flores, M E; Eguren-Garza, R; Gosálvez, J

2017-12-01

It remains unknown whether human papillomaviruses (HPVs) in semen affect sperm DNA integrity. We investigated whether the presence of these viruses in semen was associated with an elevated sperm DNA fragmentation index. Semen samples of 22 normozoospermic patients undergoing infertility treatment, nine fertile donors and seven fertile men with a risk of HPV infection (genital warts or condylomas) were included in the study. The samples were examined by an INNO-LiPA test PCR-based reverse hybridisation array that identifies 28 types of HPVs as simple or multiple infections. Sperm DNA integrity was determined by sperm chromatin dispersion assay (SCD). Our preliminary findings demonstrate an increase in HPV infection in infertile men with respect to fertile men. However, the sperm DNA fragmentation index was not increased in semen containing these viruses. © 2017 Blackwell Verlag GmbH.

Transcriptome analysis of cytoplasmic male sterility and restoration in CMS-D8 cotton.

PubMed

Suzuki, Hideaki; Rodriguez-Uribe, Laura; Xu, Jiannong; Zhang, Jinfa

2013-10-01

A global view of differential expression of genes in CMS-D8 of cotton was presented in this study which will facilitate the understanding of cytoplasmic male sterility in cotton. Cytoplasmic male sterility (CMS) is a maternally inherited trait in higher plants which is incapable of producing functional pollen. However, the male fertility can be restored by one or more nuclear-encoded restorer genes. A genome-wide transcriptome analysis of CMS and restoration in cotton is currently lacking. In this study, Affymetrix GeneChips© Cotton Genome Array containing 24,132 transcripts was used to compare differentially expressed (DE) genes of flower buds at the meiosis stage between CMS and its restorer cotton plants conditioned by the D8 cytoplasm. A total of 458 (1.9 %) of DE genes including 127 up-regulated and 331 down-regulated ones were identified in the CMS-D8 line. Quantitative RT-PCR was used to validate 10 DE genes selected from seven functional categories. The most frequent DE gene group was found to encode putative proteins involved in cell wall expansion, such as pectinesterase, pectate lyase, pectin methylesterase, glyoxal oxidase, polygalacturonase, indole-3-acetic acid-amino synthetase, and xyloglucan endo-transglycosylase. Genes in cytoskeleton category including actin, which plays a key role in cell wall expansion, cell elongation and cell division, were also highly differentially expressed between the fertile and CMS plants. This work represents the first study in utilizing microarray to identify CMS-related genes by comparing overall DE genes between fertile and CMS plants in cotton. The results provide evidence that many CMS-associated genes are mainly involved in cell wall expansion. Further analysis will be required to elucidate the molecular mechanisms of male sterility which will facilitate the development of new hybrid cultivars in cotton.

Direct effects of increasing carbon dioxide on vegetation

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

Strain, B R; Cure, J D

1985-12-01

CO/sub 2/ is an essential environmental resource. It is required as a raw material of the orderly development of all green plants. As the availability of CO/sub 2/ increases, perhaps reaching two or three times the concentration prevailing in preindustrial times, plants and all other organisms dependent on them for food will be affected. Humans are releasing a gaseous fertilizer into the global atmosphere in quantities sufficient to affect all life. This volume considers the direct effects of global CO/sub 2/ fertilization on plants and thus on all other life. Separate abstracts have been prepared for individual papers. (ACR)

Yield and fruit quality of four sweet corn hybrids (Zea mays) under conventional and integrated fertilization with vermicompost.

PubMed

Lazcano, Cristina; Revilla, Pedro; Malvar, Rosa Ana; Domínguez, Jorge

2011-05-01

Vermicompost has been proposed as a valuable fertilizer for sustainable agriculture. The effects of vermicompost on yield and quality of sweet corn were evaluated in this study. In two field trials, sweet corn plants were grown under (i) a conventional fertilization regime with inorganic fertilizer, and integrated fertilization regimes in which 75% of the nutrients were supplied by the inorganic fertilizer and 25% of the nutrients were supplied by either (ii) rabbit manure, or (iii) vermicompost. All three types of fertilization regime were supplied at two doses. Two pairs of nearly isogenic sweet corn hybrids homozygous for sugary1 and shrunken2 mutants were included in the trials to explore fertilizer × genotype interactions. Growth, yield and ear quality of the plants were evaluated in relation to the three fertilization regimes. In general, the integrated regimes yielded the same productivity levels as the conventional treatment. Moreover, both vermicompost and manure produced significant increases in plant growth and marketable yield, and also affected the chemical composition and quality of the marketable ear. Nevertheless, most of the observed effects of the organic fertilizers were genotype-dependent. The results confirm that the use of organic fertilizers such as vermicompost has a positive effect on crop yield and quality. Nevertheless, these effects were not general, indicating the complexity of the organic amendment-plant interactions and the importance of controlling genetic variation when studying the effects of vermicompost on plant growth. Copyright © 2011 Society of Chemical Industry.

Fertilization with urea, ammonium and nitrate produce different effects on growth, hydraulic traits and drought tolerance in Pinus taeda seedlings.

PubMed

Faustino, Laura I; Moretti, Ana P; Graciano, Corina

2015-10-01

Urea fertilization decreases Pinus taeda L. growth in clay soils of subtropical areas. The negative effect of urea is related to changes in some hydraulic traits, similar to those observed in plants growing under drought. The aims of this work were (i) to determine whether different sources of nitrogen applied as fertilizers produce similar changes in growth and hydraulic traits to those observed by urea fertilization and (ii) to analyze the impact of those changes in plant drought tolerance. Plants fertilized with urea, nitrate [Formula: see text] or ammonium [Formula: see text] were grown well watered or with reduced water supply. Urea and [Formula: see text] fertilization reduced plant growth and increased root hydraulic conductance scaled by root dry weight (DW). [Formula: see text] fertilization did not reduce plant growth and increased shoot hydraulic conductance and stem hydraulic conductivity. We conclude that [Formula: see text] is the ion involved in the changes linked to the negative effect of urea fertilization on P. taeda growth. [Formula: see text] fertilization does not change drought susceptibility and it produces changes in shoot hydraulic traits, therefore plants avoid the depressive effect of fertilization. Urea and [Formula: see text] fertilizers induce changes in DW and root hydraulic conductance and consequently plants are less affected by drought. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inhibiting Sperm Pyruvate Dehydrogenase Complex and Its E3 Subunit, Dihydrolipoamide Dehydrogenase Affects Fertilization in Syrian Hamsters

PubMed Central

Sailasree, Purnima; Singh, Durgesh K.; Kameshwari, Duvurri B.; Shivaji, Sisinthy

2014-01-01

Background/Aims The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc) and its E3 subunit, dihydrolipoamide dehydrogenase (DLD) in hamster in vitro fertilization (IVF) via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. Methodology and Principal Findings Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid). Oocytes fertilized with MICA-treated (MT) [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. Conclusions This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In addition, the observations made in the IVF studies in hamsters suggest that capacitation failures could be a plausible cause of unsuccessful fertilization encountered during human assisted reproductive technologies, like IVF and ICSI. Our studies indicate a role of sperm capacitation in the post-penetration events during fertilization. PMID:24852961

Triennial Reproduction Symposium: influence of follicular characteristics at ovulation on early embryonic survival.

PubMed

Geary, T W; Smith, M F; MacNeil, M D; Day, M L; Bridges, G A; Perry, G A; Abreu, F M; Atkins, J A; Pohler, K G; Jinks, E M; Madsen, C A

2013-07-01

Reproductive failure in livestock can result from failure to fertilize the oocyte or embryonic loss during gestation. Although fertilization failure occurs, embryonic mortality represents a greater contribution to reproductive failure. Reproductive success varies among species and production goals but is measured as a binomial trait (i.e., pregnancy), derived by the success or failure of multiple biological steps. This review focuses primarily on follicular characteristics affecting oocyte quality, fertilization, and embryonic health that lead to pregnancy establishment in beef cattle. When estrous cycles are manipulated with assisted reproductive technologies and ovulation is induced, duration of proestrus (i.e., interval from induced luteolysis to induced ovulation), ovulatory follicle growth rate, and ovulatory follicle size are factors that affect the maturation of the follicle and oocyte at induced ovulation. The most critical maturational component of the ovulatory follicle is the production of sufficient estradiol to prepare follicular cells for luteinization and progesterone synthesis and prepare the uterus for pregnancy. The exact roles of estradiol in oocyte maturation remain unclear, but cows that have lesser serum concentrations of estradiol have decreased fertilization rates and decreased embryo survival on d 7 after induced ovulation. When length of proestrus is held constant, perhaps the most practical follicular measure of fertility is ovulatory follicle size because it is an easily measured attribute of the follicle that is highly associated with its ability to produce estradiol.

Motility and fertilizing ability of cryopreserved Caspian brown trout (Salmo trutta caspius) sperm: Effect of post-thaw storage time and different sperm-to-egg ratios.

PubMed

Golshahi, Karim; Shabani, Nariman; Aramli, Mohammad Sadegh; Noori, Elnaz

2015-10-01

This study was designed to test the effect of post-thaw storage time on sperm motility parameters of Caspian brown trout (n=7). Furthermore, we investigated the effect of sperm-to-egg ratios of 100,000:1, 300,000:1 and 600,000:1 on fertility of cryopreserved Caspian brown semen. Quality was assessed by measuring sperm motility parameters and fertilization rates at the eyed and hatching stages. The percentage of post-thawed sperm motility, curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH) were not affected by 60 min of storage, whereas a decrease in straight line velocity (VSL), average path velocity (VAP) and linearity (LIN) were found in cryopreserved semen. Thus, the cryopreserved sperm of Caspian brown trout could be stored up to 60 min without loss of the percentage of sperm motility. The fertilization rate was not affected by 60 min of post-thaw storage and was over 70% for sperm-to-egg ratios of both 300,000 and 600,000:1. To our knowledge, this study is the first to report the high post-thaw fertilization ability of Caspian brown trout semen at a sperm-to-egg ratio as low as 300,000:1. This procedure after scaling up can be recommended for routine Caspian brown trout sperm cryopreservation. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of Nitrogen and Phosphorus Fertilizer and Topsoil Amendment on Native Plant Cover in Roadside Revegetation Projects

NASA Astrophysics Data System (ADS)

Hillhouse, Heidi L.; Schacht, Walter H.; Soper, Jonathan M.; Wienhold, Carol E.

2018-01-01

Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction ("cut-slope soils") is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warm-season grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and phosphorus fertilization, and also topsoil amendment, on the foliar cover of seeded and non-seeded species planted into two post-construction roadside sites in eastern Nebraska. We also examined soil movement to determine how planting protocols and plant growth may affect erosion potential. Three years after planting, we found no consistent effects of N or P fertilization on foliar cover. Plots receiving topsoil amendment had 14% greater cover of warm-season grasses, 10% greater total foliar cover, and 4-13% lower bare ground (depending on site) than plots without topsoil. None of the treatments consistently affected soil movement. We recommend that NDOT change their protocols to remove N and P fertilization and focus on stockpiling and spreading topsoil following construction.

Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica.

PubMed

Marvasi, Massimiliano; George, Andrée S; Giurcanu, Mihai; Hochmuth, George J; Noel, Jason T; Gause, Elizabeth; Teplitski, Max

2014-10-01

Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structure of bacterial communities in soil following cover crop and organic fertilizer incorporation.

PubMed

Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

2016-11-01

Incorporation of organic material into soils is an important element of organic farming practices that can affect the composition of the soil bacterial communities that carry out nutrient cycling and other functions crucial to crop health and growth. We conducted a field experiment to determine the effects of cover crops and fertilizers on bacterial community structure in agricultural soils under long-term organic management. Illumina sequencing of 16S rDNA revealed diverse communities comprising 45 bacterial phyla in corn rhizosphere and bulk field soil. Community structure was most affected by location and by the rhizosphere effect, followed by sampling time and amendment treatment. These effects were associated with soil physicochemical properties, including pH, moisture, organic matter, and nutrient levels. Treatment differences were apparent in bulk and rhizosphere soils at the time of peak corn growth in the season following cover crop and fertilizer application. Cover crop and fertilizer treatments tended to lower alpha diversity in early season samples. However, winter rye, oilseed radish, and buckwheat cover crop treatments increased alpha diversity in some later season samples compared to a no-amendment control. Fertilizer treatments and some cover crops decreased relative abundance of members of the ammonia-oxidizing family Nitrosomonadaceae. Pelleted poultry manure and Sustane® (a commercial fertilizer) decreased the relative abundance of Rhizobiales. Our data point to a need for future research exploring how (1) cover crops influence bacterial community structure and functions, (2) these effects differ with biomass composition and quantity, and (3) existing soil conditions and microbial community composition influence how soil microbial populations respond to agricultural management practices.

Fertility and apparent genetic anticipation in Lynch syndrome.

PubMed

Stupart, Douglas; Win, Aung Ko; Jenkins, Mark; Winship, Ingrid M; Goldberg, Paul; Ramesar, Rajkumar

2014-09-01

Genetic anticipation is the phenomenon in which age of onset of an inherited disorder decreases in successive generations. Inconsistent evidence suggests that this occurs in Lynch syndrome. A possible cause for apparent anticipation is fecundity bias, which occurs if the disease adversely affects fertility. The purpose of this study was to determine the effect of age of diagnosis of colorectal cancer (CRC) on lifetime fertility in Lynch syndrome, and whether this can falsely create the appearance of genetic anticipation. A computer model simulated age of diagnosis of CRC in hypothetical Lynch syndrome carriers and their offspring. The model assumed similar age distribution of CRC across generations (i.e. that there was no true anticipation). Age distribution of CRC diagnosis, and lifetime fertility rates (grouped by age of diagnosis of CRC) were determined from the Australasian Colorectal Cancer Family Registry (ACCFR). Apparent anticipation was calculated by comparing ages of diagnosis of CRC in affected parent-child pairs. A total of 1,088 patients with CRC were identified from the ACCFR. Total lifetime (cohort) fertility was related to age of diagnosis of CRC (correlation coefficient 0.13, P = 0.0001). In the simulation, apparent anticipation was 1.8 ± 0.54 years (P = 0.0044). Observed apparent anticipation in the ACCFR cohort was 4.8 ± 1.73 years (P = 0.0064). There was no difference in apparent anticipation between the simulate d and observed parent-child pairs (P = 0.89). The appearance of genetic anticipation in Lynch syndrome can be falsely created due to changes in fertility.

Interaction Effect Between Herbivory and Plant Fertilization on Extrafloral Nectar Production and on Seed Traits: An Experimental Study With Ricinus communis (Euphorbiaceae).

PubMed

De Sibio, P R; Rossi, M N

2016-08-01

It is known that the release of volatile chemicals by many plants can attract the natural enemies of herbivorous insects. Such indirect interactions are likely when plants produce nectar from their extrafloral nectaries, and particularly when the production of extrafloral nectar (EFN) is induced by herbivory. In the present study, we conducted experiments to test whether foliar herbivory inflicted by Spodoptera frugiperda Smith (Noctuidae) increases nectar production by extrafloral nectaries on one of its host plants, Ricinus communis L. (Euphorbiaceae). Due to the current economic importance of R. communis, we also investigated whether the following seed traits-water content, dry mass, and essential oil production-are negatively affected by herbivory. Finally, we tested whether or not nectar production and seed traits are influenced by plant fertilization (plant quality). We found that nectar production was increased after herbivory, but it was not affected by the type of fertilization. Seed dry mass was higher in plants that were subjected to full fertilization, without herbivory; plants maintained in low fertilization conditions, however, had higher seed mass when subjected to herbivory. The same inverted pattern was observed for oil production. Therefore, our results suggest that EFN production in R. communis may act as an indirect defense strategy against herbivores, and that there is a trade-off between reproduction and plant growth when low-fertilized plants are subjected to herbivory. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of genetic captive-breeding protocols on sperm quality and fertility in the white-footed mouse.

PubMed

Malo, Aurelio F; Martinez-Pastor, Felipe; Alaks, Glen; Dubach, Jean; Lacy, Robert C

2010-10-01

Mice (Peromyscus leucopus noveboracensis) from a captive-breeding program were used to test the effects of three genetic breeding protocols (minimizing mean kinship [MK], random breeding, and selection for docility [DOC]) and inbreeding levels on sperm traits and fertility. Earlier, in generation 8, one DOC replicate went extinct because of poor reproductive success. By generation 10, spermatozoa from DOC mice had more acrosome and midpiece abnormalities, which were shown to be strong determinants of fertility, as well as lower sperm production and resistance to osmotic stress. In addition, determinants of fertility, including male and female components, were assessed in a comprehensive manner. Results showed that the probability (P) of siring litters is determined by sperm number, sperm viability, and midpiece and acrosome abnormalities; that the P of siring one versus two litters is determined by tail abnormalities; and that the total number of offspring is influenced by female size and proportion of normal sperm, showing the relative importance of different sperm traits on fertility. On average, males with 20% normal sperm sired one pup per litter, and males with 70% normal sperm sired eight pups per litter. Interestingly, the proportion of normal sperm was affected by docility but not by relatively low inbreeding. However, inbreeding depression in sperm motility was detected. In the MK group, inbreeding depression not only affected sperm motility but also fertility: An increase in the coefficient of inbreeding (f) of 0.03 reduced sperm motility by 30% and translated into an offspring reduction of three pups in second litters. A genetic load of 48 fecundity equivalents was calculated.

Sperm competition, but not major histocompatibility divergence, drives differential fertilization success between alternative reproductive tactics in Chinook salmon.

PubMed

Lehnert, S J; Helou, L; Pitcher, T E; Heath, J W; Heath, D D

2018-01-01

Post-copulatory sexual selection processes, including sperm competition and cryptic female choice (CFC), can operate based on major histocompatibility (MH) genes. We investigated sperm competition between male alternative reproductive tactics [jack (sneaker) and hooknose (guard)] of Chinook salmon (Oncorhynchus tshawytscha). Using a full factorial design, we examined in vitro competitive fertilization success of paired jack and hooknose males at three time points after sperm activation (0, 15 and 60 s) to test for male competition, CFC and time effects on male fertilization success. We also examined egg-mediated CFC at two MH genes by examining both the relationship between competitive fertilization success and MH divergence as well as inheritance patterns of MH alleles in resulting offspring. We found that jacks sired more offspring than hooknose males at 0 s post-activation; however, jack fertilization success declined over time post-activation, suggesting a trade-off between sperm speed and longevity. Enhanced fertilization success of jacks (presumably via higher sperm quality) may serve to increase sneaker tactic competitiveness relative to dominant hooknose males. We also found evidence of egg-mediated CFC (i.e. female × male interaction) influencing competitive fertilization success; however, CFC was not acting on the MH genes as we found no relationship between fertilization success and MH II β 1 or MH I α 1 divergence and we found no deviations from Mendelian inheritance of MH alleles in the offspring. Our study provides insight into evolutionary mechanisms influencing variation in male mating success within alternative reproductive tactics, thus underscoring different strategies that males can adopt to attain success. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

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

PubMed

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

2018-01-01

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

Girl child marriage and its effect on fertility in Pakistan: findings from Pakistan Demographic and Health Survey, 2006-2007.

PubMed

Nasrullah, Muazzam; Muazzam, Sana; Bhutta, Zulfiqar A; Raj, Anita

2014-04-01

Child marriage (before 18 years) is prevalent in Pakistan, which disproportionately affects young girls in rural, low income and low education households. Our study aims to determine the association between early marriage and high fertility and poor fertility health indicators among young women in Pakistan beyond those attributed to social vulnerabilities. Nationally representative data from Pakistan Demographic and Health Survey, 2006-2007, a cross-sectional observational survey, were limited to ever-married women aged 20-24 years (n = 1,560; 15% of 10,023) to identify differences in poor fertility outcomes [high fertility (three or more childbirths); rapid repeat childbirth (<24 months between births); unwanted pregnancy (any ever); pregnancy termination (any stillbirth, miscarriage or abortion ever)] by early (<18) versus adult (≥18) age at marriage. Associations between child marriage and fertility outcomes were assessed by calculating adjusted odds ratios (AORs) using logistic regression models after controlling for demographics, social equity indicators (education, wealth index, rural residence), contraception use, marriage duration and culture-specific factors (husband's desire for more children, son preference). Overall, 50% of ever-married women aged 20-24 years in Pakistan were married before the age of 18 years. Girl child marriage was significantly (p < 0.001) associated with low social equity indicators (poverty, rural residence, and no formal education). Adjusted logistic regression models showed that girl child marriage was significantly associated with high fertility (AOR 6.62; 95% CI 3.53-12.43), rapid repeat childbirth (AOR 2.88; 95% CI 1.83-4.54), unwanted pregnancy (AOR 2.90; 95% CI 1.75-4.79), and pregnancy termination (AOR 1.75; 95% CI 1.10-2.78). Girl child marriage affects half of all ever-married women aged 20-24 years in Pakistan, and increases their risk for high fertility and poor fertility health indicators, highlighting the need of increasing the age of marriage among women in Pakistan. Efforts to eliminate girl child marriage by strict law enforcement, promoting civil, sexual and reproductive health rights for women can help eliminate girl child marriage in Pakistan.

The genetic basis of postzygotic reproductive isolation between Drosophila santomea and D. yakuba due to hybrid male sterility.

PubMed

Moehring, Amanda J; Llopart, Ana; Elwyn, Susannah; Coyne, Jerry A; Mackay, Trudy F C

2006-05-01

A major unresolved challenge of evolutionary biology is to determine the nature of the allelic variants of "speciation genes": those alleles whose interaction produces inviable or infertile interspecific hybrids but does not reduce fitness in pure species. Here we map quantitative trait loci (QTL) affecting fertility of male hybrids between D. yakuba and its recently discovered sibling species, D. santomea. We mapped three to four X chromosome QTL and two autosomal QTL with large effects on the reduced fertility of D. yakuba and D. santomea backcross males. We observed epistasis between the X-linked QTL and also between the X and autosomal QTL. The X chromosome had a disproportionately large effect on hybrid sterility in both reciprocal backcross hybrids. However, the genetics of hybrid sterility differ between D. yakuba and D. santomea backcross males, both in terms of the magnitude of main effects and in the epistatic interactions. The QTL affecting hybrid fertility did not colocalize with QTL affecting sexual isolation in this species pair, but did colocalize with QTL affecting the marked difference in pigmentation between D. yakuba and D. santomea. These results provide the basis for future high-resolution mapping and ultimately, molecular cloning, of the interacting genes that contribute to hybrid sterility.

Effect of Thawing Time, Cooling Rate and Boron Nutrition on Freezing Point of the Primordial Shoot in Norway Spruce Buds

PubMed Central

RÄISÄNEN, MIKKO; REPO, TAPANI; LEHTO, TARJA

2006-01-01

• Background Effects of cooling rates on bud frost hardiness have been studied but there is little information on bud responses to thawing. Since the cell wall pore size has been found to increase with boron (B) deficiency, B deficiency may affect the supercooling ability of buds in winter. • Methods The effects of duration of thawing time and rate of cooling on bud frost hardiness of Norway spruce (Picea abies) were studied in a B fertilization trial in February 2003 and March 2005. Frost hardiness of apical buds was determined by differential thermal analysis (DTA) and visual scoring of damage. • Key Results In 2003, the freezing point of primordial shoots of buds (Tf), i.e. the low-temperature exotherm (LTE), was, on average, −39 °C when buds were thawed for less than 3 h and the Tf increased to −21 °C after 18 h of thawing. During the first 4 h of thawing, the rate of dehardening was 6 °C h−1. In 2005, buds dehardened linearly from −39 °C to −35 °C at a rate of 0·7 °C h−1. In 2003, different cooling rates of 1–5 °C h−1 had a minor effect on Tf but in 2005 with slow cooling rates Tf decreased. In both samplings, at cooling rates of 2 and 1 °C h−1, Tf was slightly higher in B-fertilized than in non-fertilized trees. By contrast, at very short thawing times in 2003, Tf was somewhat lower in B-fertilized trees. • Conclusions There was little evidence of reduced frost hardiness in trees with low B status. This study showed that buds deharden rapidly when exposed to above-freezing temperatures in winter, but if cooled again they reharden more slowly. According to this study, rapid dehardening of buds has to be taken into account in assessments of frost hardiness. PMID:16464880

Educational differentials in cohabitors' marriage intentions at different childbearing stages in seven European countries.

PubMed

Vergauwen, Jorik; Neels, Karel; Wood, Jonas

2017-07-01

Several studies have looked into the socio-economic gradients of cohabitation and non-marital fertility. According to the theory of the Second Demographic Transition, highly educated individuals can be considered as forerunners in the Western European spread of non-marital family forms after the 1970s. In Central and Eastern Europe (CEE), however, research has provided evidence for a Pattern of Disadvantage where those with the lowest education have been the most likely to adopt such family forms. Hitherto, few studies have considered the educational gradient of the intentions underlying these behaviors. This contribution uses information on marriage and fertility intentions from the Generations and Gender Surveys for seven European countries to assess educational differentials. In Western Europe we observe no strong educational gradients in marriage intentions at any childbearing stage (before, during or following). In CEE countries, however, less educated cohabitors more frequently choose for cohabitation during childbearing. Copyright © 2017 Elsevier Inc. All rights reserved.

Differential diagnosis between complete mole and hydropic abortus by deoxyribonucleic acid fingerprints.

PubMed

Nobunaga, T; Azuma, C; Kimura, T; Tokugawa, Y; Takemura, M; Kamiura, S; Saji, F; Tanizawa, O

1990-08-01

We used a new method of deoxyribonucleic acid fingerprint analysis to obtain the differential diagnosis between complete mole and hydropic abortus. This method with a deoxyribonucleic acid minisatellite probe requires only a small amount of tissue sample and peripheral blood, and presents individual specific restriction fragment length polymorphisms (deoxyribonucleic acid "fingerprints") by simultaneous detection of many hypervariable regions (minisatellite regions) widely dispersed in the human genome. Southern blot hybridization showed that in cases of complete mole, all polymorphic fragments were exclusively inherited from the father. Some of the polymorphic bands of paternal deoxyribonucleic acid were not observed in molar deoxyribonucleic acid. However, in the hydropic abortus, the polymorphic fragments could be traced back to its parent. These results indicate that deoxyribonucleic acid fingerprints could distinguish the abnormal fertilization of complete mole (androgenesis) from the normal fertilization of hydropic abortus by identifying the difference in genetic variations between complete mole and hydropic abortus at the deoxyribonucleic acid level.

Atlantic salmon eggs favour sperm in competition that have similar major histocompatibility alleles.

PubMed

Yeates, Sarah E; Einum, Sigurd; Fleming, Ian A; Megens, Hendrik-Jan; Stet, René J M; Hindar, Kjetil; Holt, William V; Van Look, Katrien J W; Gage, Matthew J G

2009-02-07

Polyandry and post-copulatory sexual selection provide opportunities for the evolution of female differential sperm selection. Here, we examined the influence of variation in major histocompatibility (MH) class I allelic composition upon sperm competition dynamics in Atlantic salmon. We ran in vitro fertilization competitions that mimicked the gametic microenvironment, and replicated a paired-male experimental design that allowed us to compare differences in sperm competition success among males when their sperm compete for eggs from females that were genetically either similar or dissimilar at the MH class I locus. Concurrently, we measured variation in spermatozoal traits that are known to influence relative fertilization success under these conditions. Contrary to the findings demonstrating mechanisms that promote MH complex heterozygosity, our results showed that males won significantly greater relative fertilization success when competing for eggs from genetically similar females at the MH class I. This result also showed covariation with the known influences of sperm velocity on relative fertilization success. We discuss these unexpected findings in relation to sperm-egg recognition and hybridization avoidance mechanisms based upon immunogenetic variation.

The Demography of Canada and the United States from the 1980s to the 2000s A Summary of Changes and a Statistical Assessment

PubMed Central

Barbieri, Magali; Ouellette, Nadine

2013-01-01

Canada and the United States have enjoyed vigorous population growth since the early 1980s. Although mortality is slightly higher in the United States than in Canada, this is largely offset by much higher fertility, with a total fertility rate at replacement level, compared with just 1.5 children per woman in Canada. The United States is also the world’s largest immigrant receiving country, although its immigration rate is only half that of Canada, where today one person in five is foreign-born, versus one in eight in the United States. Based on recent trends in fertility, mortality and international migration, the populations of these two North American countries will continue to grow over the next five decades, but at a progressively slower pace. The most acute demographic issue today is not, as in Europe, that of imminent population decline, but rather of the geographic and social inequalities which have increased steadily since the early 1980s and which are reflected in major fertility and health differentials between regions and social groups. PMID:24032004

Pretreatment fertility counseling and fertility preservation improve quality of life in reproductive age women with cancer.

PubMed

Letourneau, Joseph M; Ebbel, Erin E; Katz, Patricia P; Katz, Audra; Ai, Wei Z; Chien, A Jo; Melisko, Michelle E; Cedars, Marcelle I; Rosen, Mitchell P

2012-03-15

The post-treatment quality of life (QOL) impacts of receiving precancer-treatment infertility counseling and of pursuing fertility preservation have not been described in large-scale studies of reproductive age women with cancer. In total, 1041 women who were diagnosed between ages 18 and 40 years responded to a retrospective survey and reported whether they received infertility counseling before cancer treatment and whether they took action to preserve fertility. Five cancer types were included: leukemia, Hodgkin disease, non-Hodgkin lymphoma, breast cancer, and gastrointestinal cancer. Validated QOL scales were used: the Decision Regret Score, the Satisfaction with Life Scale (SWLS), and the brief World Health Organization QOL questionnaire. Overall, 560 women (61%) who received treatment that potentially could affect fertility were counseled by the oncology team, 45 (5%) were counseled by fertility specialists, and 36 (4%) took action to preserve fertility. Pretreatment infertility counseling by a fertility specialist and an oncologist resulted in lower regret than counseling by an oncologist alone (8.4 vs 11.0; P < .0001). The addition of fertility preservation (6.6 vs 11.0; P < .0001) also was associated with even lower regret scores than counseling by an oncologist alone. Further improvements also were observed in SWLS scores with the addition of fertility specialist counseling (23.0 vs 19.8; P = .09) or preserving fertility (24.0 vs 19.0; P = .05). Receiving specialized counseling about reproductive loss and pursuing fertility preservation is associated with less regret and greater QOL for survivors, yet few patients are exposed to this potential benefit. Women of reproductive age should have expert counseling and should be given the opportunity to make active decisions about preserving fertility. Copyright © 2011 American Cancer Society.

Pre-treatment fertility counseling and fertility preservation improve quality of life in reproductive age women with cancer

PubMed Central

Letourneau, Joseph M; Ebbel, Erin E; Katz, Patricia P; Katz, Audra; Ai, Wei Z; Chien, A Jo; Melisko, Michelle E; Cedars, Marcelle I; Rosen, Mitchell P

2011-01-01

Background The post-treatment quality of life (QOL) impacts of receiving pre-cancer-treatment infertility counseling and of pursuing fertility preservation have not been described in large-scale studies of reproductive age women with cancer. Methods 1041 women diagnosed between the ages of 18 and 40 responded to a retrospective survey and reported whether they received infertility counseling before cancer treatment and whether they took action to preserve fertility. Five cancer types were included: leukemia, Hodgkin’s disease, non-Hodgkin lymphoma, breast cancer, and gastrointestinal cancer. Validated QOL scales were used: Decision Regret Score (DRS), Satisfaction with Life Scale (SWLS), and World Health Organization QOL BREF (WHOQOL-BREF). Results 560 women (61%) whose treatment could affect fertility were counseled by the oncology team, 45 (5%) were counseled by fertility specialists, 36 (4%) took action to preserve fertility. Pre-treatment infertility counseling by a fertility specialist and an oncologist resulted in lower regret than counseling by an oncologist alone (8.4 vs. 11.0, P<0.0001). The addition of fertility preservation (6.6 vs. 11.0, P<0.0001) was also associated with even lower regret scores than counseling by an oncologist alone.. Further improvements were similarly seen in SWLS with the addition of fertility specialist counseling (23.0 vs. 19.8, P=0.09) or preserving fertility (24.0 vs. 19.0, P=0.05). Conclusions Receiving specialized counseling about reproductive loss and pursuing fertility preservation is associated with less regret and greater QOL for survivors, yet few patients are exposed to this potential benefit. Reproductive aged women should have expert counseling and be given the opportunity to make active decisions about preserving fertility. PMID:21887678

Impact of ART on the fertility of HIV-positive women in sub-Saharan Africa.

PubMed

Yeatman, Sara; Eaton, Jeffrey W; Beckles, Zosia; Benton, Lorna; Gregson, Simon; Zaba, Basia

2016-09-01

Understanding the fertility of HIV-positive women is critical to estimating HIV epidemic trends from surveillance data and to planning resource needs and coverage of prevention of mother-to-child transmission services in sub-Saharan Africa. In the light of the considerable scale-up in antiretroviral therapy (ART) coverage over the last decade, we conducted a systematic review of the impact of ART on the fertility outcomes of HIV-positive women. We searched Medline, Embase, Popline, PubMed and African Index Medicus. Studies were included if they were conducted in sub-Saharan Africa and provided estimates of fertility outcomes (live births or pregnancies) among women on ART relative to a comparison group. Of 2070 unique references, 18 published papers met all eligibility criteria. Comparisons fell into four categories: fertility of HIV-positive women relative to HIV-negative women; fertility of HIV-positive women on ART compared to those not yet on ART; fertility differences by duration on ART; and temporal trends in fertility among HIV-positive women. Evidence indicates that fertility increases after approximately the first year on ART and that while the fertility deficit of HIV-positive women is shrinking, their fertility remains below that of HIV-negative women. These findings, however, were based on limited data mostly during the period 2005-2010 when ART scaled up. Existing data are insufficient to characterise how ART has affected the fertility of HIV-positive women in sub-Saharan Africa. Improving evidence about fertility among women on ART is an urgent priority for planning HIV resource needs and understanding HIV epidemic trends. Alternative data sources such as antenatal clinic data, general population cohorts and population-based surveys can be harnessed to understand the issue. © 2016 John Wiley & Sons Ltd.

Potassium fertilizer applied immediately after planting had no impact on Douglas-fir seedling mortality caused by laminated root rot on a forested site in Washington State.

Treesearch

Walter G. Thies; Rick G. Kelsey; Douglas J. Westlind; Jeff Madsen

2006-01-01

Phellinus weirii causes laminated root rot (LRR), a major disease affecting growth and survival of Pseudotsuga menziesii (Douglas-fir) and other commercially important conifer species throughout the Pacific Northwest. Increasing tree vigor and resistance to pathogens through application of K fertilizer is a suggested disease...

Bacterial and archaeal ammonia oxidizers respond differently to long-term tillage and fertilizer management at a continuous maize site

USDA-ARS?s Scientific Manuscript database

Fertilizer use and tillage affect both the general soil microbial community and speci'c N-utilizing microbial groups, but likely to varying degrees. To assess these impacts, soil was collected on three key dates from a long-term (26+ years), rainfed, continuous maize site where tillage (no-till and ...

Review of nitrogen fate models applicable to forest landscapes in the Southern U.S.

Treesearch

D. M. Amatya; C. G. Rossi; A. Saleh; Z. Dai; M. A. Youssef; R. G. Williams; D. D. Bosch; G. M. Chescheir; G. Sun; R. W. Skaggs; C. C. Trettin; E. D. Vance; J. E. Nettles; S. Tian

2013-01-01

Assessing the environmental impacts of fertilizer nitrogen (N) used to increase productivity in managed forests is complex due to a wide range of abiotic and biotic factors affecting its forms and movement. Models developed to predict fertilizer N fate (e.g., cycling processes) and water quality impacts vary widely in their design, scope, and potential application. We...

Resin flow responses to fertilization, wounding and fungal inoculation in loblolly pine (Pinus taeda) in North Carolina

Treesearch

Larissa Knebel; Daniel J. Robinson; Thomas R. Wentworth; Kier D. Klepzig

2009-01-01

Resin flow is the primary means of natural defense against southern pine beetle (Dendroctonus frontalis Zimm.), the most important insect pest of Pinus spp. in the southern United States. As a result, factors affecting resin flowa are of interest to researchers and forest managers. We examined the influence of fertilization, artificial...

Mother's Schooling, Fertility, and Children's Education: Evidence from a Natural Experiment. NBER Working Paper No. 16856

ERIC Educational Resources Information Center

Lavy, Victor; Zablotsky, Alexander

2011-01-01

This paper studies the effect of mothers' education on their fertility and their children's schooling. We base our evidence on a natural experiment that sharply reduced the cost of attending school and, as a consequence, significantly increased the education of affected cohorts. This natural experiment was the result of the de facto revocation in…

The effect of glucocorticoids on ERK-1/2 phosphorylation during maturation of lamb oocytes and their subsequent fertilization and cleavage ability in vitro.

PubMed

González, Raquel; Ruiz-León, Yolanda; Gomendio, Montserrat; Roldan, Eduardo R S

2010-04-01

High levels of glucocorticoids may alter reproduction, but little is known about their direct actions on oocyte maturation, fertilization and subsequent development. Earlier work suggested negative effects of cortisol or dexamethasone on oocyte maturation but differences were noted between animal models. Both glucocorticoids reduce the p34(cdc2)-cyclin B1 complex but it is unknown if other signaling pathways important for meiosis progression are affected. In this study, using sheep oocytes as a model system, we assessed in vitro the effects of increasing concentration of glucocorticoids (0-250 microM) on oocyte maturation and underlying changes in the MAP kinase pathway, and the ability of oocytes to undergo fertilization and embryo development. Cortisol decreased oocyte maturation but only at the highest concentration, whereas dexamethasone had no effect. Fertilization and cleavage were not affected. On the other hand, both cortisol and dexamethasone inhibited ERK-1/2 activation in a concentration-dependent manner. It thus seems that oocytes can overcome deleterious effects of glucocorticoids during maturation despite the decrease in ERK-1/2 activity, but repercussions in vivo should be further explored. Copyright 2009 Elsevier Inc. All rights reserved.