Season and Frequency of Cycas micronesica Leaf and Reproductive Events

2018 ◽  
Author(s):  
Nirmala Dongol ◽  
Thomas E. Marler
Keyword(s):  
Reproductive Events

scholarly journals COVID-19: Uncertainties from Conception to Birth

2021 ◽  
Vol 43 (01) ◽  
pp. 054-060
Author(s):  
Bruno Ramalho de Carvalho ◽  
Karina de Sá Adami ◽  
Walusa Assad Gonçalves-Ferri ◽  
Marise Samama ◽  
Rui Alberto Ferriani ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Present Article ◽  
Vertical Transmission ◽  
Scientific Information ◽  
Obstetric Outcomes ◽  
Reproductive Events ◽  
The Impact ◽  
Initial Impressions ◽  
Quality Evidence

AbstractScientific information on the impact of the new coronavirus (SARS-CoV-2) on the health of pregnant women, fetuses and newborns is considered of limited confidence, lacking good-quality evidence, and drawing biased conclusions. As a matter of fact, the initial impressions that the evolution of COVID-19 was no different between pregnant and non-pregnant women, and that SARS-CoV-2 was not vertically transmitted, are confronted by the documentation of worsening of the disease during pregnancy, poor obstetric outcomes, and the possibility of vertical transmission. The present article aims to compile the data available on the association of COVID-19 and reproductive events, from conception to birth.

scholarly journals Variations in reproductive events across life: a pooled analysis of data from 505 147 women across 10 countries

2019 ◽  
Vol 34 (5) ◽  
pp. 881-893 ◽  
Author(s):  
Keyword(s):  
Age At Menarche ◽  
Age At First Birth ◽  
First Birth ◽  
Natural Menopause ◽  
Individual Level ◽  
Level Data ◽  
Education Levels ◽  
Reproductive Events ◽  
Racial Ethnic ◽  
Reproductive Indices

Abstract STUDY QUESTION How has the timing of women’s reproductive events (including ages at menarche, first birth, and natural menopause, and the number of children) changed across birth years, racial/ethnic groups and educational levels? SUMMARY ANSWER Women who were born in recent generations (1970–84 vs before 1930) or those who with higher education levels had menarche a year earlier, experienced a higher prevalence of nulliparity and had their first child at a later age. WHAT IS KNOWN ALREADY The timing of key reproductive events, such as menarche and menopause, is not only indicative of current health status but is linked to the risk of adverse hormone-related health outcomes in later life. Variations of reproductive indices across different birth years, race/ethnicity and socioeconomic positions have not been described comprehensively. STUDY DESIGN, SIZE, DURATION Individual-level data from 23 observational studies that contributed to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) consortium were included. PARTICIPANTS/MATERIALS, SETTING, METHODS Altogether 505 147 women were included. Overall estimates for reproductive indices were obtained using a two-stage process: individual-level data from each study were analysed separately using generalised linear models. These estimates were then combined using random-effects meta-analyses. MAIN RESULTS AND THE ROLE OF CHANCE Mean ages were 12.9 years at menarche, 25.7 years at first birth, and 50.5 years at natural menopause, with significant between-study heterogeneity (I2 > 99%). A linear trend was observed across birth year for mean age at menarche, with women born from 1970 to 1984 having menarche one year earlier (12.6 years) than women born before 1930 (13.5 years) (P for trend = 0.0014). The prevalence of nulliparity rose progressively from 14% of women born from 1940–49 to 22% of women born 1970–84 (P = 0.003); similarly, the mean age at first birth rose from 24.8 to 27.3 years (P = 0.0016). Women with higher education levels had fewer children, later first birth, and later menopause than women with lower education levels. After adjusting for birth year and education level, substantial variation was present for all reproductive events across racial/ethnic/regional groups (all P values < 0.005). LIMITATIONS, REASONS FOR CAUTION Variations of study design, data collection methods, and sample selection across studies, as well as retrospectively reported age at menarche, age at first birth may cause some bias. WIDER IMPLICATIONS OF THE FINDINGS This global consortium study found robust evidence on variations in reproductive indices for women born in the 20th century that appear to have both biological and social origins. STUDY FUNDING/COMPETING INTEREST(S) InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). GDM is supported by the Australian National Health and Medical Research Council Principal Research Fellowship (APP1121844).

scholarly journals Decline in the frequency and benefits of multiple brooding in great tits as a consequence of a changing environment

2009 ◽  
Vol 276 (1663) ◽  
pp. 1845-1854 ◽  
Author(s):  
Arild Husby ◽  
Loeske E.B. Kruuk ◽  
Marcel E. Visser
Keyword(s):  
Life History Traits ◽  
Parus Major ◽  
Population Level ◽  
Climatic Conditions ◽  
Long Term Study ◽  
Double Brooding ◽  
First Clutch ◽  
Second Clutch ◽  
Reproductive Events

For multiple-brooded species, the number of reproductive events per year is a major determinant of an individual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits ( Parus major ) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.

Effects of Antibodies to Steroid Hormones on Reproductive Events of Sheep and Cattle

1986 ◽  
pp. 351-366 ◽  
Author(s):  
R. M. Hoskinson ◽  
R. J. Scaramuzzi ◽  
B. K. Campbell ◽  
J. A. Downing ◽  
R. J. Welch ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Reproductive Events

scholarly journals MicroRNA-8 targets the Wingless signaling pathway in the female mosquito fat body to regulate reproductive processes

2015 ◽  
Vol 112 (5) ◽  
pp. 1440-1445 ◽  
Author(s):  
Keira J. Lucas ◽  
Sourav Roy ◽  
Jisu Ha ◽  
Amanda L. Gervaise ◽  
Vladimir A. Kokoza ◽  
...  
Keyword(s):  
Blood Meal ◽  
Molecular Mechanisms ◽  
Fat Body ◽  
Control Strategies ◽  
Functional Characterization ◽  
Target Prediction ◽  
Underlying Mechanism ◽  
Female Mosquito ◽  
Reproductive Events

Female mosquitoes require a blood meal for reproduction, and this blood meal provides the underlying mechanism for the spread of many important vector-borne diseases in humans. A deeper understanding of the molecular mechanisms linked to mosquito blood meal processes and reproductive events is of particular importance for devising innovative vector control strategies. We found that the conserved microRNA miR-8 is an essential regulator of mosquito reproductive events. Two strategies to inhibit miR-8 function in vivo were used for functional characterization: systemic antagomir depletion and spatiotemporal inhibition using the miRNA sponge transgenic method in combination with the yeast transcriptional activator gal4 protein/upstream activating sequence system. Depletion of miR-8 in the female mosquito results in defects related to egg development and deposition. We used a multialgorithm approach for miRNA target prediction in mosquito 3′ UTRs and experimentally verified secreted wingless-interacting molecule (swim) as an authentic target of miR-8. Our findings demonstrate that miR-8 controls the activity of the long-range Wingless (Wg) signaling by regulating Swim expression in the female fat body. We discovered that the miR-8/Wg axis is critical for the proper secretion of lipophorin and vitellogenin by the fat body and subsequent accumulation of these yolk protein precursors by developing oocytes.

scholarly journals COMPORTAMENTO FENOLÓGICO DE Emmotum nitens (Benth.) Miers (METTENIUSACEAE) EM FRAGMENTO DE CERRADÃO

Nativa ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Patrícia Oliveira da Silva
Keyword(s):  
Rainy Season ◽  
Reproductive Phenology ◽  
Fruit Maturation ◽  
Ripe Fruit ◽  
Flower Bud ◽  
Circular Statistic ◽  
Immature Fruit ◽  
Temperature And Precipitation ◽  
Continuous Reproduction ◽  
Reproductive Events

Emmotum nitens é uma espécie bem conhecida em termos de florística e fitossociologia, entretanto, há poucos trabalhos que tratam-se de sua fenologia. Este estudo buscou avaliar a fenologia reprodutiva de uma população de E. nitens no Município de Rio Verde, Goiás. Observou-se mensalmente as fenofases reprodutivas (botão, antese, fruto imaturo e maduro) de 15 indivíduos. Para a coleta dos dados utilizou-se o método de Fournier e presença/ausência, e para analisar os mesmos utilizou-se a estatística circular e correlação com as variáveis meteorológicas (temperatura e precipitação). E. nitens produziu botões e flores de modo irregular ao longo do estudo, no entanto se correlacionaram positivamente com a temperatura. Durante todo estudo registrou-se frutos imaturos, embora as maiores concentrações ocorreram na transição do período seco-chuvoso e durante as chuvas, correlacionando-se positivamente com a precipitação. A maturação dos frutos iniciou-se no final da estação das chuvas, com maiores intensidades no período seco. Para E. nitens é mais vantajoso apresentar reprodução continua já que a mesma não é fortemente limitada pelas variáveis climáticas da área de estudo, do que seguir um padrão sazonal.Palavra-chave: fenologia, espécie de cerrado, eventos reprodutivos, correlação com metereologia. PHENOLOGICAL BEHAVIOR OF EMMOTUM NITENS (BENTH.) MIERS (METTENIUSACEAE) ON CERRADÃO FRAGMENT ABSTRACT:Emmotum nitens is a well-known species in terms of floristic and phytosociology, however, there are few studies that deal with its phenology. The objective of this study was to evaluate the reproductive phenology of a population of E. nitens in the municipality of Rio Verde, Goiás. The reproductive phenomena (flower bud, anthesis, immature fruit and ripe fruit) were observed monthly in 15 individuals. Fournier method and presence/absence were used to collect the data, and to analyze them, the circular statistic and correlation with the meteorological variables (temperature and precipitation) were used. E. nitens produced flower bud and flowers irregularly throughout the study, however they correlated positively with temperature. During the whole study immature fruits were recorded, although the highest concentrations occurred in the transition from the dry-rainy season and during the rains, correlating positively with the precipitation. Fruit maturation began at the end of the rainy season, with higher intensities in the dry season. For E. nitens it is more advantageous to present continuous reproduction since it is not strongly limited by the climatic variables of the study area, rather than following a seasonal pattern.Keywords: phenology, species of cerrado, reproductive events, correlation with meteorology. DOI:

scholarly journals Sex Matters: Effects of Sex and Mating in the Presence and Absence of a Protective Microbe

2021 ◽  
Vol 11 ◽  
Author(s):  
Anke Kloock ◽  
Lena Peters ◽  
Charlotte Rafaluk-Mohr
Keyword(s):  
Staphylococcus Aureus ◽  
Reproductive Success ◽  
Resource Availability ◽  
Behavioral Activity ◽  
Lifetime Reproductive Success ◽  
Offspring Production ◽  
Female Survival ◽  
Female Investment ◽  
Reproductive Events ◽  
Pathogenic Infection

In most animals, female investment in offspring production is greater than for males. Lifetime reproductive success (LRS) is predicted to be optimized in females through extended lifespans to maximize reproductive events by increased investment in immunity. Males, however, maximize lifetime reproductive success by obtaining as many matings as possible. In populations consisting of mainly hermaphrodites, optimization of reproductive success may be primarily influenced by gamete and resource availability. Microbe-mediated protection (MMP) is known to affect both immunity and reproduction, but whether sex influences the response to MMP remains to be explored. Here, we investigated the sex-specific differences in survival, behavior, and timing of offspring production between feminized hermaphrodite (female) and male Caenorhabditis elegans following pathogenic infection with Staphylococcus aureus with or without MMP by Enterococcus faecalis. Overall, female survival decreased with increased mating. With MMP, females increased investment into offspring production, while males displayed higher behavioral activity. MMP was furthermore able to dampen costs that females experience due to mating with males. These results demonstrate that strategies employed under pathogen infection with and without MMP are sex dependent.

Sign in / Sign up

Export Citation Format

Share Document