Search results for " FERTILITY"
showing 10 items of 137 documents
Reproductive monopoly enforced by sterile police workers in a queenless ant
2004
In societies of totipotent insects, dyadic dominance interactions generate a hierarchy that often underlies an extreme reproductive skew. Subordinates remain infertile but can maximize their indirect fitness benefits through collective power (worker policing): interference with challenging high-rankers can prevent an untimely replacement of the reproductive. However, police workers only benefit if they favor individuals with high fertility. In the monogynous queenless ant Streblognathus peetersi, we used behavioral, physiological, and chemical methods to show that police workers have the primary role in the selection of the reproductive, and that they probably use reliable information about…
Statistical modelling and RCS detrending methods provide similar estimates of long-term trend in radial growth of common beech in north-eastern France
2011
International audience; Dendrochronological methods have greatly contributed to the documentation of past long-term trends in forest growth. These methods primarily focus on the high-frequency signals of tree ring chronologies. They require the removal of the ageing trend in tree growth, known as 'standardisation' or 'detrending', as a prerequisite to the estimation of such trends. Because the approach is sequential, it may however absorb part of the low-frequency historical signal. In this study, we investigate the effect of a sequential and a simultaneous estimation of the ageing trend on the chronology of growth. We formerly developed a method to estimate historical changes in growth, in…
Influence of plant traits, soil microbial properties, and abiotic parameters on nitrogen turnover of grassland ecosystems
2016
International audience; Although it is known that multiple interactions among plant functional traits, microbial properties , and abiotic soil parameters influence the nutrient turnover, the relative contribution of each of these groups of variables is poorly understood. We manipulated grassland plant functional composition and soil nitrogen (N) availability in a multisite mesocosm experiment to quantify their relative effects on soil N turnover. Overall, root traits, arbuscular mycorrhizal colonization, denitrification potential, as well as N availability and water availability, best explained the variation in measured ecosystem properties, especially the trade-off between nutrient sequest…
Changes in soil mineral N content and abundances of bacterial communities involved in N reactions under laboratory conditions as predictors of soil N…
2016
Proper management of soil fertility requires specific tools for predicting N availability for crops as a consequence of different fertilization strategies. More information is required, especially for organic fertilizers, depending on their mineralization rate, composition, and processing (i.e., fresh or composted manure), as well as their effects on soil properties. Laboratory soil incubations were used as a proxy for understanding plant–soil N dynamics under field conditions. Chemical and microbiological measurements as contents of mineral N, potentially mineralizable N and the abundance of key genes regulating the overall N cycle were used as predictors of mineral N availability to maize…
The cyto-protective effects of LH on ovarian reserve and female fertility during exposure to gonadotoxic alkylating agents in an adult mouse model.
2021
Abstract STUDY QUESTION Does LH protect mouse oocytes and female fertility from alkylating chemotherapy? SUMMARY ANSWER LH treatment before and during chemotherapy prevents detrimental effects on follicles and reproductive lifespan. WHAT IS KNOWN ALREADY Chemotherapies can damage the ovary, resulting in premature ovarian failure and reduced fertility in cancer survivors. LH was recently suggested to protect prepubertal mouse follicles from chemotoxic effects of cisplatin treatment. STUDY DESIGN, SIZE, DURATION This experimental study investigated LH effects on primordial follicles exposed to chemotherapy. Seven-week-old CD-1 female mice were randomly allocated to four experimental groups: C…
Tillage Changes Vertical Distribution of Soil Bacterial and Fungal Communities.
2018
Tillage can strongly affect the long-term productivity of an agricultural system by altering the composition and spatial distribution of nutrients and microbial communities. The impact of tillage methods on the vertical distribution of soil microbial communities is not well understood, and the correlation between microbial communities and soil nutrients vertical distributions is also not clear. In the present study, we investigated the effects of conventional plowing tillage (CT: moldboard plowing), reduced tillage (RT: rotary tillage), and no tillage (NT) on the composition of bacterial and fungal communities within the soil profile (0-5, 5-10, 10-20, and 20-30 cm) using high-throughput se…
Impact of poplar-based phytomanagement on soil properties and microbial communities in a metal-contaminated site
2016
Despite a long history of use in phytomanagement strategies, the impacts of poplar trees on the structure and function of microbial communities that live in the soil remain largely unknown. The current study combined fungal and bacterial community analyses from different management regimes using Illumina-based sequencing with soil analysis. The poplar phytomanagement regimes led to a significant increase in soil fertility and a decreased bioavailability of Zn and Cd, in concert with changes in the microbial communities. The most notable changes in the relative abundance of taxa and operational taxonomic units unsurprisingly indicated that root and soil constitute distinct ecological microbi…
O-195 The impact of the COVID-19 outbreak on psychological distress due to the cancellation of ART. A systematic review and meta-analysis
2021
Abstract Study question Is there evidence that infertile patients have been more likely to experience distress during the COVID-19 outbreak with the consequent interruption of treatment plans? Summary answer High levels of psychological distress among infertile patients have been found during the COVID-19 pandemic, greater than that reported in the general population. What is known already Preliminary research on the negative consequences of the COVID-19 outbreak on mental health evidenced heightened levels of anxiety, depression and post-traumatic stress in some clinical populations as well as in community samples. However, little is known about the impact of COVID-19 on psychological dist…
Does the level of serum antimüllerian hormone predict ovulatory function in women with polycystic ovary syndrome with aging?
2012
Abstract OBJECTIVE: To determine possible prediction of regular menses with aging in anovulatory women with polycystic ovary syndrome (PCOS). DESIGN: Cohort. SETTING: Academic practice. PATIENT(S): A total of 54 anovulatory women with PCOS and 28 age- and weight-matched control subjects. INTERVENTION(S): Blood and ovarian ultrasound at baseline and after 5 years. MAJOR OUTCOME MEASURE(S): Serum antimüllerian hormone (AMH), gonadotropins, androgens, insulin sensitivity, and ovarian ultrasound. RESULT(S): After 5 years, there was a significant decrease in AMH in women with PCOS and control subjects (10 of 54 anovulatory women became ovulatory after 5 years). There was a significant negative c…
The significance of sperm DNA oxidation in embryo development and reproductive outcome in an oocyte donation program: a new model to study a male inf…
2008
Objective: One byproduct resulting from free radical damage is the DNA hydroxylation also known as DNA oxidation. Our aim with this work was to determine the relevance of sperm DNA oxidation on embryo quality in oocyte donation cycles. Design: We prospectively studied pairs of oocyte donation cycles, i.e., the same oocyte donors, donating to two recipients, where the only difference between the two treatments was the use of a different sperm sample. Setting: University-affiliated private IVF setting. Patient(s): Infertile male partners from couples undergoing oocyte donation cycles (n=38): 76 semen aliquots analyzed before and after semen processing by swim up. Intervention(s): None. Main O…