Reduced Fertilization Rates Research Articles

Catalyzing Sustainable Development: Assessing the Impact of Family Plan-ning Programs on Population Control, Reproductive Health, and Gender Empowerment

Population growth is a global challenge with far-reaching implications for public health, sustainable development, and gender equality. Family planning programs have emerged as pivotal tools in addressing this challenge, facilitating informed reproductive choices, and improving maternal and child health outcomes. This research undertakes a comprehensive examination of the implementation of family planning programs and their effectiveness in controlling population growth. The study employs a mixed-methods approach, combining quantitative analysis of birth rate data, surveys, and spatial analysis with qualitative insights from interviews, focus group discussions, and document analysis. The research encompasses diverse regions, cultures, and socioeconomic contexts, ensuring a holistic assessment of family planning program dynamics. The findings reveal a strong association between the availability and accessibility of family planning services and a decline in birth rates. Regions with comprehensive programs have witnessed notable reductions in birth rates, demonstrating the effectiveness of informed reproductive choices in population control. Furthermore, the research underscores the critical linkage between family planning and improved maternal and child health outcomes. Lower maternal mortality rates, decreased infant mortality, and enhanced child nutrition are observed in areas with well-established family planning services, highlighting the broader public health benefits of family planning. Gender empowerment emerges as a key theme, with women in regions with accessible family planning reporting increased autonomy in reproductive decision-making, higher educational attainment, and greater workforce participation. This underscores the transformative potential of family planning in advancing gender equity and women's participation in societal development. Cultural norms and societal beliefs are identified as significant determinants of program success, emphasizing the need for culturally sensitive approaches and community engagement strategies. Disparities in access to family planning services are evident, particularly among vulnerable populations, highlighting the imperative of targeted interventions and equitable resource allocation. The research also highlights policy implications, advocating for supportive regulatory frameworks, education initiatives, and community-driven approaches to optimize program outcomes. In conclusion, this research contributes valuable insights to the fields of population control, public health, gender empowerment, and policy development. It reinforces the significance of family planning programs as catalysts for sustainable development and underscores the importance of informed policy decisions and program enhancements in addressing global population challenges.

P-423 Effect of pergafast 201 on in vitro meiotic maturation of pig oocytes

Abstract Study question Does pergafast 201 (PF201) have harmful effects on selected markers of in vitro maturation of pig oocytes? Summary answer PF201 affects the course of in vitro oocyte maturation, reaching the metaphase II stage, formation of the meiotic spindle and methylation of selected epigenetic markers. What is known already PF201 is a chemical used as a color developer and currently serves as a replacement for bisphenol A and S in related paper and other products. Bisphenol A and S are already proven endocrine disruptors that can released into the environment and from there enter the human body, where they disrupt physiological hormonal functions. In the case of PF201, toxicity to aquatic organisms, persistence in the environment and affinity to some proteins associated with non-infectious diseases have already been confirmed. Therefore, further testing of the biological effect of PF201 is necessary to assess the risks to human health and reproduction. Study design, size, duration Cumulus-oocytes complexes (COCs) from the ovaries of slaughtered prepubertal sows were used. In vitro maturation dynamics of PF201-treated COCs were compared with control COCs (n ≥ 30). The meiotic spindle was assessed under a confocal microscope after fluorescence labeling of meiotic chromosomes and spindle microtubules. Dimethylation of histone H3 at lysine K4 (H3K4me2) and trimethylation at lysine K9 (H3K4me3) were imaged under a fluorescence microscope after fluorescent labeling, the intensity was subsequently evaluated in the ImageJ software. Participants/materials, setting, methods COCs were treated with PF201 in at least five independent experiments using the following concentrations: 300 pM, 30 nM and 3 µM, dissolved in DMSO to a final concentration of 0.05%. A vehicle control was used when COCs were cultured in medium with the same concentration of DMSO. COCs were cultured for 48 hours to metaphase II in 5.0% CO2 at 39 °C. Main results and the role of chance PF201 exposure in vitro affected meiotic maturation of pig oocytes, their ability to reach metaphase II, meiotic spindle formation, and epigenetic histone modifications. Treatment with 30 nM concentration of PF201 in vitro caused a significant accumulation of oocytes in metaphase I stage (35% vs. 7% in controls, p < 0.05), consistent with a non-linear effect. Moreover, according to our results, PF201 also disrupts the formation of the meiotic spindle in pig oocytes and probably affects the organization of the meiotic spindle at multiple levels. After 300 pM (30%) and 30 nM (25% vs. 10% in controls, p < 0.05) in vitro treatment of PF201, a significant increase in abnormalities of the meiotic spindle, most often irregular arrangement of the spindle, reduction of the meiotic figure, faulty attachment of chromosomes to tubulin and elongated poles of the meiotic spindle located far apart. A significant increase in the relative fluorescence intensity of epigenetic markers was also observed after treatment of oocytes with PF201. For histone H3K4me2, a significant increase in relative fluorescence intensity was observed after treatment with 300 pM and 3 µM concentrations, while for histone H3K9me3, a significant increase in relative intensity was observed after treatment with 30 nM and 3 µM concentrations. Limitations, reasons for caution As work with human oocytes encounters a number of ethical and legal regulations, a porcine model was chosen, which is physiologically close to the human oocyte. However, it would be great benefit if the effects of PF201 were evaluated in human discarded oocytes that can be obtained from IVF laboratories. Wider implications of the findings It is increasingly difficult for the human population to avoid exposure to environmentally toxic substances, and this fact could explain the decline in human fertility in recent decades. The finding that PF201 negatively affects meiotic maturation suggests, that it may reduce fertilization rates, thus requiring a re-evaluation of its use. Trial registration number MZE-RO0718

O-105 Chromatin accessibility of oocytes contributes to PCOS transgenerational inheritance

Abstract Study question What is the underlying mechanism contributing to the transgenerational defects of oocytes and embryos of polycystic ovary syndrome (PCOS)? Summary answer The transgenerational inheritance of abnormal chromatin accessibility in the PCOS oocytes is responsible for the defect of oocytes and embryos in transgeneration. What is known already Studies have provided evidence of compromised oocyte quality and related adverse impacts. Observed PCOS animal-model oocyte defects include meiotic abnormalities, mitochondrial dysfunction, and increased oxidative stress. Elevated androgen levels are associated with reduced fertilization rates and lower cleavage rates during in vitro fertilization (IVF) treatment. PCOS could be transgenerationally transmitted, and unique altered gene expression has been observed in metaphase II (MII) oocytes from all offspring in PCOS mice. Study design, size, duration We profiled the transcriptome and chromatin accessibility of oocytes and preimplantation embryos in F0-F2 offspring of PCOS mice, to explored whether the inheritance of chromatin accessibility defects in PCOS oocytes was responsible for the abnormalities of oocytes and embryos in PCOS offspring. Besides, oocytes from 13 healthy women and 8 women with PCOS, 24 blood samples from 24 women with/without PCOS were analyzed to validate the molecular mechanisms of PCOS inheritance. Duration: 2019.5∼2022.12. Participants/materials, setting, methods PCOS mice models were established by means of DHEA-exposure. Smart-seq2 and DNase-seq were utilized to investigate the transcriptome and chromatin accessibility of oocytes and preimplantation embryos in F0-F2 offspring of PCOS mice. Bioinformatic analysis was applied to explore the differential gene expression and chromatin accessibility of oocytes and embryos in PCOS mice and offspring comparing to controls. Common gene signatures in the tissues of PCOS women and PCOS daughters are analyzed compared to control samples. Main results and the role of chance In PCOS mice, we observed transcriptional alteration in oocytes and 2-cell embryos compared to normal mice. There are 4229 and 1197 differentially expressed genes (DEGs) in PCOS oocytes and 2-cell embryos. The DEGs includes both maternal factors and zygotic genome activation (ZGA) genes. Interestingly, in PCOS 2-cell embryos, we observed hundreds of pre-activated genes which are silence in normal 2-cell embryo but expressed in PCOS 2-cell embryos. Notably, many DEGs in the oocytes of PCOS mice were also differentially expressed in the oocytes of F2 PCOS mice compared to control mice, supporting the transgenerational inheritance of transcriptional alteration in PCOS oocytes. Mechanismly, the changes of chromatin accessibility were associated with the DEGs in PCOS oocytes and embryos. In particular, chromatin accessibility of the pre-activated gene promoters is elevated in PCOS oocytes compared to that in normal oocytes. Furthermore, many of the abnormal chromatin accessibility signals detected in F0 PCOS oocytes were also observed in F2 PCOS oocytes. Finally, our data showed that some DEGs in the oocytes of PCOS mice were also differentially expressed in human PCOS oocytes compared to the control oocytes. Common genes identified in PCOS offspring may be used as potential predictors of PCOS phenotype. Limitations, reasons for caution Which factors contribute to the abnormalities of chromatin accessibility in PCOS oocytes are still unknown. Wider implications of the findings The candidate genes may be used as potential predictors of PCOS phenotype and provide the clues for PCOS offspring . Trial registration number not applicable

Yield- and protein-neutral reduction in fertilizer rate for wheat, maize and rice can reduce the release of reactive nitrogen and greenhouse gas emissions in China

Seeking food security, contemporary Chinese agriculture has followed a trajectory of overfertilization and associated environmental problems, hence the need for nitrogen-balancing practices that do not compromise yield and quality. Here we present a national meta-analysis using 224 studies with 1972 comparisons to quantify the potential to reduce nitrogen (N) fertilization to improve environmental outcomes while maintaining yield and grain protein. We calculated a nitrogen reduction ratio (NRR), as 100 × (N C − N T)/N C; where N is N fertilizer rate and subscripts indicate farmer practice (C) and reduced N rate treatment (T). Our meta-analysis showed that the NRR that maintained yield and grain protein content at the level of current practice was up to 10% in wheat and up to 30% in maize and rice. Larger yield-neutral NRR could be achieved in more fertile, heavier-textured soils, and with practices including enhanced-efficiency N fertilizer, combined application of organic and inorganic N fertilizer, and incorporated straw. Assuming a reduction in N fertilizer usage by 10% for wheat and by 30% for maize and rice in the current cropping area, there is a potential to save 5.7 Mt N yr−1; reduce loss of reactive nitrogen by 1.26 Mt N yr−1, equivalent to 63% of annual total Nr losses for rice in China, reduce N-related greenhouse emissions by 75.2 Mt CO2-eq yr−1, equivalent to 14.5%–25% of the emissions associated with the N fertilizer chain in China; and improve N use efficiency by 23%. Our results highlight the feasibility of maintaining yield and grain protein, and achieving substantial environmental benefits with reduced fertilization rate, and the environmental and agronomic scenarios where these outcomes are more likely.

Correlates of human development in Africa: Evidence across gender and income group

Gender inequality is high in Africa compared to other regions of the world. This disparity jeopardises the efforts targeted at improving human development and economic growth in the continent. This study provides empirical evidence on the drivers of human development in Africa across gender and country income groups, covering 54 countries over the period 1990 to 2019. It employed the Mean Group estimator for analysis to accommodate slope heterogeneity and cross-sectional dependence. The paper used Human Development Index (HDI) to proxy human development, while HDI across gender was employed to capture gender differences in human development. Country income grouping followed the World Bank country classification into low, lower-middle and upper-middle-income economies. The findings showed more determinants of HDI when disaggregated across gender than otherwise. The drivers of HDI are similar across gender for each country income group, with infrastructure, particularly ICT shown to have a positive effect in the long run for all country groups. For lower-middle and upper-middle income countries, fertility rate induced a significant negative effect on HDI and gender human development but only in the long run. However, the effect was insignificant for male and female HDI in low-income countries. Moreover, an increase in real Gross Domestic Product (GDP) promotes human development regardless of a country's income classification. A larger positive effect of GDP was observed on the HDI for low-income countries. Therefore, in the bid to improve human development in Africa, efforts should continually be intensified towards promoting GDP growth regardless of the level of growth in macroeconomic income. Policies targeted at reducing fertility rates and increasing ICT are also encouraged as these will improve HDI and close the gap in HDI across gender.

Analisis Permintaan Anak pada Wanita Bekerja di Indonesia

This study aims to analyze; (1) To what extent the influence of the wife's age on the demand for children for working women in Indonesia, (2) How far the influence of the husband's age on the demand for children working women in Indonesia, (3) How far is the influence of the wife's education level on the demand for children for working women in Indonesia, ( 4) The extent to which the influence of husband's education level on the demand for children for working women in Indonesia. (5) The extent to which the influence of the type of wife's work on the demand for children for working women in Indonesia. (6) The extent to which the influence of the husband's working status on the demand for children for working women in Indonesia. (7) The extent to which the influence of the sex preference of children on the demand for children of working women in Indonesia. (8) The extent to which the influence of household income on the demand for children of working women in Indonesia. The data used in this study is cross-sectional data collected from the 2022 KOR SUSENAS data. This research method uses logistic regression analysis techniques. Based on the results of the study: the wife's age, husband's age, wife's education level, husband's education level, wife's type of work, husband's working status, child's gender preference, and household income have a positive and significant effect on children's demand for working women in Indonesia. One of the policies that can be done to reduce fertility rates is the importance of increasing education, especially for women, delaying the age of marriage, and in particular planning for the sex of the child.

Factors Associated with Women Fertility in Bangladesh: Application on Count Regression Models

Background: The current total fertility rate in Bangladesh is now 2.3 births per woman, which is still above the replacement level of 2.1. Objective: The main objective of this study was to identify potential factors associated with fertility transition in Bangladesh. Methods: This study applied several regression models to find the best-fitted model to determine factors associated with the number of children ever-born in Bangladesh and utilize data from the 2019 Bangladesh Multiple Indicator Cluster Survey. Results: Based on the principles of the AIC, BIC, and Vuong tests, the best-fit model was the Hurdle- Poisson regression model compared to other models. Findings based on the Hurdle Poisson regression result revealed that the number of children increases with the increase of women’s age, but the number of children declines if the education status of women as well as their delayed marriage increases. Women who had secondary or higher education were less likely to have children than illiterate women. Similarly, division, residential area, wealth index, women’s functional difficulties, prenatal care, and migration have significantly influenced the number of children ever born. Conclusion: Based on the findings, the study suggests that fertility can be decreased by improving female education, minimizing early marriage, and eliminating poverty for all ever-married women who were particularly live in rural areas of the Chattogram and Sylhet divisions in Bangladesh. Such steps would be the largest contribution to a future reduction in fertility rates in Bangladesh.

A Comparative Assessment of the Urbanization – Fertility Nexus in Most Urbanized Countries of Sub-Saharan Africa

Abstract There is a near-consensus in the literature that urbanization is incompatible with large family size owing to factors such as high cost of urban living, opportunity cost of having children in urban centers and increasing awareness of benefits of small family size. However, a cursory glance at the data on sub-Saharan Africa cast doubt on the incompatibility of urbanization with high fertility rate. Hence, this paper investigates the urbanization-fertility nexus in the two most urbanized countries of SSA – Nigeria and South Africa. Exploiting time series data for both countries within a Fully Modified Ordinary Least Square (FMOLS) framework, the incompatibility hypothesis is refuted in both countries. Specifically, the analysis suggests that in Nigeria and South Africa, increasing degree of urbanization is positively related with fertility rate with the magnitude of the relationship being higher in Nigeria than South Africa. These findings imply that policies aimed at improving urbanization process and reducing fertility rates are crucial in both countries.

Introducing energy into marine environments: A lab-scale static magnetic field submarine cable simulation and its effects on sperm and larval development on a reef forming serpulid

Non-chemical sources of anthropogenic environmental stress, such as artificial lights, noise and magnetic fields, are still an underestimate factor that may affect the wildlife. Marine environments are constantly subjected to these kinds of stress, especially nearby to urbanized coastal areas. In the present work, the effect of static magnetic fields, associated with submerged electric cables, was evaluated in gametes and early life stages of a serpulid polychaete, namely Ficopomatus enigmaticus. Specifically, biochemical/physiological impairments of sperm, fertilization rate inhibition and incorrect larval development were assessed. We evaluated differences between two selected magnetic field induction values (0.5 and 1 mT) along a range of exposure times (30 min–48 h), for a sound evaluation on this species. We found that a magnetic induction of 1 mT, a typical value that can be found at distance of tens of cm from a submerged cable, may be considered a biologically and ecologically relevant for sessile organisms and for coastal environments more generally. This value exerted statistically significant effects on membranes, DNA integrity, kinetic parameters and mitochondrial activity of sperm cells. Moreover, a significant reduction in fertilization rate was observed in sperm exposed to the same magnetic induction level (1 mT) for 3 h, compared to controls. Regarding early larval stages, 48-h exposure did not affect the correct development. Our results represent a starting point for a future focus of research on magnetic field effects on early life stages of aquatic invertebrates, using model species as representative for reef-forming/encrusting organisms and ecological indicators of soft sediment quality.

Analysis of the Kampung Family Planning (KB) Program Pucangsawit Village, Jebres District and Sondakan Village, Laweyan District, Surakarta City

Population growth is one of the social problems, in dealing with population growth the governmenthas a Family Planning Program (KB) . This program aims to improve public welfare and health,reduce birth rates, raise the nation's standard of living, and reduce mortality rates in pregnant womenand infants. In its implementation, the government forms the KB Village Program which is located atthe village level area. The research was conducted in KB Pucangsawit Village and KB SondakanVillage. This area was chosen based on the consideration of population growth which increases everyyear so that it needs to be studied in the implementation of the Kampung KB Program. The purpose ofthis study was to analyze the implementation of the Kampung KB program in the two regions and toanalyze the supporting and inhibiting factors found in the implementation of the Kampung KBProgram. This study uses a survey method and uses descriptive, quantitative and SWOT analysis.From the research it shows that the Kampung KB Pucangsawit has an optimal classification while theKampung KB Sondakan has a less than optimal classification. While the education factor af ects theimplementation of the Kampung KB Program 97.69%: 92.11%, then the influence of income is52.15%: 30.20%. The SWOT analysis shows the results of quadrant 1 so that there is an SO strategyto use program opportunities, so as to minimize inhibiting factors and maximize supporting factors.

The role of spermatozoa-zona pellucida interaction in selecting fertilization-competent spermatozoa in humans.

Human fertilization begins when a capacitated spermatozoon binds to the zona pellucida (ZP) surrounding a mature oocyte. Defective spermatozoa-ZP interaction contributes to male infertility and is a leading cause of reduced fertilization rates in assisted reproduction treatments (ARTs). Human ejaculate contains millions of spermatozoa with varying degrees of fertilization potential and genetic quality, of which only thousands of motile spermatozoa can bind to the ZP at the fertilization site. This observation suggests that human ZP selectively interacts with competitively superior spermatozoa characterized by high fertilizing capability and genetic integrity. However, direct evidence for ZP-mediated sperm selection process is lacking. This study aims to demonstrate that spermatozoa-ZP interaction represents a crucial step in selecting fertilization-competent spermatozoa in humans. ZP-bound and unbound spermatozoa were respectively collected by a spermatozoa-ZP coincubation assay. The time-course data demonstrated that ZP interacted with a small proportion of motile spermatozoa. Heat shock 70 kDa protein 2 (HSPA2) and sperm acrosome associated 3 (SPACA 3) are two protein markers associated with the sperm ZP-binding ability. Immunofluorescent staining indicated that the ZP-bound spermatozoa had significantly higher expression levels of HSPA2 and SPACA3 than the unbound spermatozoa. ZP-bound spermatozoa had a significantly higher level of normal morphology, DNA integrity, chromatin integrity, protamination and global methylation when compared to the unbound spermatozoa. The results validated the possibility of applying spermatozoa-ZP interaction to select fertilization-competent spermatozoa in ART. This highly selective interaction might also provide diagnostic information regarding the fertilization potential and genetic qualities of spermatozoa independent of those derived from the standard semen analysis.

Russian student family: Determinants of marriage

The birth rate reducing to the level that does not ensure even the simple reproduction of the population, which leads to problems in the economy and social sphere and to migration crises, is a challenge for many developed countries. The demographic and family policy measures aim at solving this problem, which is reflected, for instance, in the Russian National Security Strategy approved on July 2, 2021 by the Decree of the President: the increasing birth rate is declared a required condition for increasing the country’s population. In contemporary Russia, the age model of fertility has transformed: the spreading practice of postponing childbirth in the last fifteen years has led to an increase in the modal age of mothers by more than five years, which is a factor in the decline in fertility. One of the mechanisms that can change this trend but lacks the due attention is the institution of the student family. The study aims at identifying those factors that determine the marriage intentions of the student youth. The article is based on the quantitative analysis of the surveys data of the Rosstat and authors’ sociological research, including logistic models and the decision tree method, which allowed to conduct modeling and select factors to identify the determinants of student marriage. The modeling results revealed the role of the value-system structure of students and their parental family in the motivation for marriage and starting family life. One of the main conclusions of practical significance is the confirmed importance for the youth of marriage as such and as a key stage in the life path, which under the postponing childbirth and reducing birth rate determines the need for the state support for the student family. The results of the study can help to solve a complex demographic problem of the decline and aging of the birth rate, which requires systematic work to create an image of the happy student family and to introduce mechanisms for supporting it.

Subsurface fertilization boosts crop yields and lowers greenhouse gas emissions: A global meta-analysis

The subsurface application (SA) of nitrogenous fertilizers is a potential solution to mitigate climate change and improve food security. However, the impacts of SA technology on greenhouse gas (GHG) emissions and agronomic yield are usually evaluated separately and their results are inconsistent. To address this gap, we conducted a meta-analysis synthesizing 40 peer-reviewed studies on the effects of SA technology on GHG and ammonia (NH3) emissions, nitrogen uptake (NU), crop yield, and soil residual NO3-N in rice paddies and upland cropping system. Compared to the surface application of N, SA technology significantly increased rice yields by 32 % and crop yield in upland systems by 62 %. The largest SA-induced increases in crop yield were found at low N input rates (<100 kg Nha−1) in rice paddies and medium N input rates (100–200 kg Nha−1) in upland systems, suggesting that soil moisture is a key factor determining the efficiency of SA technology. SA treatments increased yields by more at reduced fertilizer rates (~30 % less N), a shallow depth (<10 cm), and with urea in both cropping systems than at the full (recommended) N rate, a deeper depth (10–20 cm), and with ammonical fertilizer. SA treatments significantly increased NU in rice paddies (34 %) and upland systems (18 %), and NO3-N (40 %) in paddyland; however, NO3-N decreased (28 %) in upland conditions. Ammonia mitigation was greater in paddyland than in upland conditions. SA technology decreased the carbon footprint (CF) in paddyland by 29 % and upland systems by 36 %, and overall by 33 %. Compared with broadcasting, SA significantly reduced CH4 emissions by 16 %, N2O emissions by 30 %, and global warming potential (GWP) by 10 % in paddy cultivation. Given SA increased grain yield and NU while reducing NH3, CF, and GWP, this practice provides dual benefits – mitigating climate change and ensuring food security.

Genes and models for estimating genetic parameters for heat tolerance in dairy cattle.

Dairy cattle are highly susceptible to heat stress. Heat stress causes a decline in milk yield, reduced dry matter intake, reduced fertility rates, and alteration of physiological traits (e.g., respiration rate, rectal temperature, heart rates, pulse rates, panting score, sweating rates, and drooling score) and other biomarkers (oxidative heat stress biomarkers and stress response genes). Considering the significant effect of global warming on dairy cattle farming, coupled with the aim to reduce income losses of dairy cattle farmers and improve production under hot environment, there is a need to develop heat tolerant dairy cattle that can grow, reproduce and produce milk reasonably under the changing global climate and increasing temperature. The identification of heat tolerant dairy cattle is an alternative strategy for breeding thermotolerant dairy cattle for changing climatic conditions. This review synthesizes information pertaining to quantitative genetic models that have been applied to estimate genetic parameters for heat tolerance and relationship between measures of heat tolerance and production and reproductive performance traits in dairy cattle. Moreover, the review identified the genes that have been shown to influence heat tolerance in dairy cattle and evaluated the possibility of using them in genomic selection programmes. Combining genomics information with environmental, physiological, and production parameters information is a crucial strategy to understand the mechanisms of heat tolerance while breeding heat tolerant dairy cattle adapted to future climatic conditions. Thus, selection for thermotolerant dairy cattle is feasible.

Reproductive toxicity in marine medaka (Oryzias melastigma) due to embryonic exposure to PCB 28 or 4’-OH-PCB 65

Previous studies have shown that juvenile or adult exposure to polychlorinated biphenyls (PCBs) induces alterations in reproductive functions (e.g., reduced fertilization rate) and behavior (e.g., reduced nest maintenance) in fish. Embryonic exposures to other endocrine disrupting chemicals have been reported to induce long-term reproductive toxicity in fish. However, the effects of embryonic exposure to PCBs or their metabolites, OH-PCBs, on long-term reproductive function in fish are unknown. In the present study, we used the marine medaka fish (Oryzias melastigma) as a model to assess the reproductive endpoints in response to embryonic exposure to either PCB 28 or 4’-OH-PCB 65. Our results showed that the sex ratio of marine medaka was feminized by exposure to 4’-OH-PCB 65. Fecundity was decreased in the medaka treated with either PCB 28 or 4’-OH-PCB 65, whereas the medaka from embryonic exposure to 4’-OH-PCB 65 additionally exhibited reduced fertilization and a reduction in the hatching success rate of offspring, as well as decreased sperm motility. Serum 11-KT concentrations were reduced in the PCB 28-treated medaka, and serum estradiol (E2)/testosterone (T) and E2/11-ketotestosterone (11-KT) ratios were decreased in the 4’-OH-PCB 65-treated medaka. To explain these observations at the molecular level, transcriptomic analysis of the gonads was performed. Bioinformatic analysis using Gene Ontology and Ingenuity Pathway Analysis revealed that genes involved in various pathways potentially involved in reproductive functions (e.g., steroid metabolism and cholesterol homeostasis) were differentially expressed in the testes and ovaries of either PCB- or OH-PCB-treated medaka. Thus, the long-term reproductive toxicity in fish due to embryonic exposure to PCB or OH-PCB should be considered for environmental risk assessment.

Cross Sectional Study of Small East African Goat Ovarian Morphology During Wet and Dry Seasons

Reproductive cycle of Small East African (SEA) goats in the tropics is characterized by a reduced fertility rate during the dry season. The reduced fertility rate has a negative impact on livestock sector development and the livelihood of rural communities. The current study was conducted to evaluate ovarian morphometric parameters and follicular atresia during dry and wet seasons. A total of 90 apparently healthy adult goats from Morogoro region in Tanzania brought for slaughter at Morogoro Municipal slaughterhouse were randomly selected for the study. Following the slaughter both left and right ovaries were collected for gross and histomorphological analysis. The results of morphometric analysis found that, length of right ovary was significantly higher than that of the left (p&lt;0.05). Histological analysis revealed a significant increase in the number of atretic follicles during the dry season when compared to the wet season (p&lt;0.05). These findings indicate that the reduced fertility rate in the SEA goat during the dry season could be contributed by an increased rate of follicular atresia

The Yield-Forming Role of Nitrogen in Rice in the Growing Seasons with Variable Thermal Conditions

A reduced basal and increased topdressing fertilizer rate (RBIT) can usually increase rice yield, but whether this practice alleviates the impact of poor weather on rice production is unknown. Thus, the effect of three integrated RBIT treatments (RBITs, including RBIT alone, RBIT in combination with straw incorporation (RBITS) or a reduced fertilizer rate (RBITR)) on rice growth and nutritional status under different weathers was investigated in a 9-year experiment. Conventional fertilization (CF) was the control. We found that daytime temperature and light (DTL) after heading were the main meteorological factors limiting rice yield increases. RBITs did not affect rice yield under High-DTL, compared with CF, but RBITS significantly increased rice yield under Low-DTL. Compared with High-DTL, the positive effect of RBIT and RBITR on the N concentration and proportion in vegetative organs under Low-DTL was higher than the K concentration in vegetative organs, but RBITS showed the opposite trend. Regression analysis indicated that the harvest index had stronger correlations with the N concentration (negative), K concentration (positive), and N/K (negative) in vegetative organs under Low-DTL than under High-DTL. Our findings suggested that RBITS could improve rice adaptability to daytime temperature and light changes after heading by balancing crop nutritional status (N/K).

Small Area Estimation of Age-Specific and Total Fertility Rates in Bangladesh

Bangladesh has experienced a rapid national decline in fertility in recent decades, however, fertility rates vary considerably at the sub-national level (i.e., division). These variations are expected to be more pronounced at lower levels of geography (e.g., district level). However, routinely conducted demographic health surveys are designed for national estimates and do not have adequate samples to produce reliable estimate of fertility rates at lower levels of administrative units, particular when considering district level age-specific fertility rates. Data extracted from the Bangladesh Demographic Health Survey 2014 are used to derive direct estimates of age-specific fertility rates and associated smoothed standard errors. These are used as inputs for developing a small area model, which is expressed in a hierarchical Bayesian framework and fitted by Markov Chain Monte Carlo simulation. The model accounts for variation at different levels—women age-group, division, and district. The modeling results show large reductions in the estimated standards errors and provide consistent estimates of fertility at the detailed district age-specific level. There are significant differences in the fertility levels within and between districts and at the division level. Fertility rates are observed to be higher for Sylhet division and for women aged 20–24 years. We use geo-spatial maps of the fertility rates to visualize the variations over districts, and identify hot and cold-spots to have better targeted local level planning and policy decision making for further reductions in fertility rates in Bangladesh.

A more accurate analysis of maternal effect genes by siRNA electroporation into mouse oocytes.

Maternal RNA and proteins accumulate in mouse oocytes and regulate initial developmental stages. Sperm DNA combines with protamine, which is exchanged after fertilization with maternal histones, including H3.3; however, the effect of H3.3 on development post-fertilization remains unclear. Herein, we established an electroporation method to introduce H3.3 siRNA into germinal vesicle (GV)-stage oocytes without removing cumulus cells. Oocyte-attached cumulus cells need to be removed during the traditional microinjection method; however, we confirmed that artificially removing cumulus cells from oocytes reduced fertilization rates, and oocytes originally free of cumulus cells had reduced developmental competence. On introducing H3.3 siRNA at the GV stage, H3.3 was maintained in the maternal pronucleus and second polar body but not in the paternal pronucleus, resulting in embryonic lethality after fertilization. These findings indicate that H3.3 protein was not incorporated into the paternal pronucleus, as it was repeatedly translated and degraded over a relatively short period. Conversely, H3.3 protein incorporated into the maternal genome in the GV stage escaped degradation and remained in the maternal pronucleus after fertilization. This new method of electroporation into GV-stage oocytes without cumulus cell removal is not skill-intensive and is essential for the accurate analysis of maternal effect genes.

Exogenous Wage Decline, Utility Changes, Endogenous Fertility, and Human Capital Accumulation

This paper analyzes the effects of wage decline by exogenous economic shock and individuals’ utility changes on fertility rate and human capital accumulation using an overlapping-generations model, which is mainly based on Groezen, Leers and Mejidam (2003) and Cardak (2004). Although Groezen, Leers and Mejidam (2003) consider childcare cost and child allowances in a model of a small open economy, they ignore educational expenditures and do not analyze human capital accumulation. Although Cardak (2004) considers human capital accumulation and assumes it is determined by governmental or parental expenditures on education and by parent’s human capital endowments, he ignores childcare cost and child allowances, and assumes population size is constant in each period. This study considers human capital accumulation in a model of a closed economy with endogenous fertility. We then consider the effects of declining wage rate on fertility rate, human capital accumulation, and economic growth when an individual’s preferences for his consumption change. This paper is motivated by declining birthrate by the cost burden of educational expenses and wage decline by the coronavirus (Covid-19) pandemic in Japan. We find that increased preference for consumption of individuals decreases the number of children (reduce fertility rate), constricts human capital accumulation, and surely impairs economic growth when wage rate declines by exogenous economic shock.