Search results for "FECUNDITY"

From mammals back to birds: Host-switch of the acanthocephalan Corynosoma australe from pinnipeds to the Magellanic penguin Spheniscus magellanicus.

2017

Trophically-transmitted parasites are regularly exposed to potential new hosts through food web interactions. Successful colonization, or switching, to novel hosts, occur readily when ?donor? and ?target? hosts are phylogenetically related, whereas switching between distantly related hosts is rare and may result from stochastic factors (i.e. rare favourable mutations). This study investigates a host-switching event between a marine acanthocephalan specific to pinnipeds that is apparently able to reproduce in Magellanic penguins Spheniscus magellanicus from Brazil. Detailed analysis of morphological and morphometrical data from acanthocephalans from penguins indicates that they belong to Cor…

Diet and environmental factors affecting reproduction

2021

Abstract Diet and exposure to certain chemical compounds related to industrial development could be responsible for the increase in the incidence of human reproductive diseases and the consequent decrease in reproductive function worldwide. The role of diet and environment in fertility has received more attention in recent years because nutrition and exposure to contaminants can affect fecundity in women of reproductive age. Here, we review how diet could affect reproduction. Furthermore, we will review how the most ubiquitous contaminants could disrupt endometrial receptivity and implantation, focusing also on clinical studies performed in the last years.

2021

In fish, the lipid resources of the female form a link between the environment and progeny, contributing to the contents of the egg yolk. Variation of the environmental conditions is therefore expected to affect the egg quality via maternal pathways, reflecting the female’s response to the environmental factors before spawning. We investigated the content of lipids and thyroid hormones in the ovary and eggs of the Baltic herring during 1988–2019, when salinity of the Baltic Sea first declined and then stabilized to a lower level, and winters varied between severe and mild. The total lipid resources of spawning females decreased by 40–50% during the study, and the ovarian lipid concentration…

Hysteroscopic resection of the septum improves the pregnancy rate of women with unexplained infertility: a prospectine controlled trial

2009

Objective: To assess fecundity of infertile women after surgical correction of uterine septum. Design: Prospective controlled trial. Setting: Three academic infertility clinics. Patient(s): Forty-four women affected by septate uterus and otherwise unexplained infertility represented the study group (group A), and 132 women with unexplained infertility were enrolled as control subjects (group B). Intervention(s): Hysteroscopic metroplasty was performed in group A, and group B was managed expectantly. All women were followed-up for 1 year without any other intervention. Main Outcome Measure(s): Fecundity rate was calculated as the number of pregnancies per 100 person-months Result(s): Pregnan…

Imidazole derivative KK-42 reduces ecdysteroid titers and interferes with reproductive processes in adult females of Tenebrio molitor

2004

0048-3575 doi: DOI: 10.1016/j.pestbp.2004.07.004; KK-42, an imidazole derivative considered as potent inhibitor of ecdysteroid biosynthesis, was tested on adult females of Tenebrio molitor. The compound was applied topically (0.1, 1, 5, and 10 μg/insect) on 0- or 2-day-old adult females or added to the culture medium (1 and 10 μM) of ovaries. To test the effect of KK-42 on the reproduction capacity, ovaries were explanted from 2- and 4-day-old females corresponding, respectively, to follicles at the beginning and the end of vitellogenesis. KK-42 treatment reduced the fecundity and the longevity of females, and in addition, it delayed oviposition and affected growth and development of oocyte…

Effects of a new IGR-ovicide on a heteropteran (Oncopeltus fasciatusDallas) and lepidopteran (Manduca sextaJohansen) insect

1987

A new insect ovicide (Ov. 165049), 4-methoxy-benzoic acid propargylester, synthesized by BASF (Ludwigshafen) was tested on Oncopeltus fasciatus and Manduca sexta. In the case of O. fasciatus also the effects on last-instar larvae and adult bugs were studied. Topical application of 40 μg/larva dissolved in acetone caused a mortality exceeding 50% at day 1 after treatment. The few animals which developed into imagines did not reproduce. A treatment with 4 μg/larva had no severe impact on metamorphosis and reproduction. Adult O. fasciatus received doses of 40 μg, 20 μg and 4 μg per animal. The high dose caused mortality of 50% at day 1 as in larvae. Mating and egg deposition did not occur in s…

The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals

2015

ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single o…

Life-history of two African Sylvia warblers: low annual fecundity and long post-fledging care

2004

The investigation of factors that cause differences in life-history traits between temperate and tropical birds is often hampered by a lack of knowledge about tropical species. Even within the well-known warblers of the genus Sylvia, which include resident species from temperate and tropical regions as well as migrants, there are few data from tropical species. We investigated the breeding biology of the tropical species Sylvia lugens and S. boehmi in a 2-year study in Kenya. Both species had a clutch size of 2.0 and laid c. 3.7 clutches per year. Breeding was characterized by long incubation periods (S. lugens 14.5 days, S. boehmi 15.0 days), long nestling periods (16.0 and 12.9 days, resp…

Spore production monitoring reveals contrasting seasonal strategies and a trade‐off between spore size and number in wood‐inhabiting fungi

2023

1. Traits related to reproduction and dispersal drive the assembly and dynamics of species communities and can explain and predict how species respond to habitat loss and fragmentation and to the changing climate. For fungi, such links remain poorly known. 2. We examine how spore production rate, a key demographic trait, is influenced by the interaction between environmental conditions and species traits. We monitored the spore production of 97 wood-inhabiting fungal species on 107 decaying logs for two years and analyzed the data with a hierarchical community model. 3. Our analysis demonstrates clear species differences in seasonal patterns, with spring and summer release dominating in per…

Correction to: a predictive model for women's assisted fecundity before starting the first IVF/ICSI treatment cycle.

2019

PURPOSE: To introduce a prognostic model for women’s assisted fecundity before starting the first IVF/ICSI treatment cycle. METHODS: In contrast to previous predictive models, we analyze two groups of women at the extremes of prognosis. Specifically, 708 infertile women that had either a live birth (LB) event in the first autologous IVF/ICSI cycle (“high-assisted-fecundity women”, n = 458) or did not succeed in having a LB event after completing three autologous IVF/ICSI cycles (“low-assisted-fecundity women”, n = 250). The initial sample of 708 women was split into two sets in order to develop (n = 531) and internally validate (n = 177) a predictive logistic regression model using a forwar…