Arsenic and selenium mobilisation from organic matter treated mine spoil with and without inorganic fertilisation

Organic matter amendments are applied to contaminated soil to provide a better habitat for re-vegetation and remediation, and olive mill waste compost (OMWC) has been described as a promising material for this aim. We report here the results of an incubation experiment carried out in flooded conditions to study its influence in As and metal solubility in a trace elements contaminated soil. NPK fertilisation and especially organic amendment application resulted in increased As, Se and Cu concentrations in pore water. Independent of the amendment, dimethylarsenic acid (DMA) was the most abundant As species in solution. The application of OMWC increased pore water dissolved organic-carbon (DOC) concentrations, which may explain the observed mobilisation of As, Cu and Se; phosphate added in NPK could also be in part responsible of the mobilisation caused in As. Therefore, the application of soil amendments in mine soils may be particularly problematic in flooded systems.

Spawning coordination of mates in a shell brooding cichlid

Aim. External fertilisation requires synchronisation of gamete release between the two sexes. Adequate synchronisation is essential in aquatic media because sperm is very short-lived in water. In the cichlid Lamprologus callipterus, fertilisation of the eggs takes place inside an empty snail shell, where females stay inside the shell and males have to ejaculate into the shell opening. This spawning pattern makes the coordination of gamete release difficult. Methods. This study examined the synchronisation of males and females during egg laying. Results. The results showed that the male initiates each spawning sequence and that sperm release and egg laying are very well synchronised. 68% of all sperm releases occurred at exactly the same time when the female laid an egg, and 99% of ejaculations occurred within ±5 seconds from egg deposition. On average 95 eggs are laid one by one with intervals of several minutes between subsequent eggs, leading to a total spawning duration in excess of six hours. Conclusions. We discuss this exceptional spawning pattern and how it might reflect a conflict between the sexes, with males attempting to induce egg laying and females extending the egg laying period to raise the chance for parasitic males to participate in spawning.

High-resolution mineral dust and sea ice proxy records from the Talos Dome ice core

In this study we report on new non-sea salt calcium (nssCa2+, mineral dust proxy) and sea salt sodium (ssNa+, sea ice proxy) records along the East Antarctic Talos Dome deep ice core in centennial resolution reaching back 150 thousand years (ka) before present. During glacial conditions nssCa2+ fluxes in Talos Dome are strongly related to temperature as has been observed before in other deep Antarctic ice core records, and has been associated with synchronous changes in the main source region (southern South America) during climate variations in the last glacial. However, during warmer climate conditions Talos Dome mineral dust input is clearly elevated compared to other records mainly due to the contribution of additional local dust sources in the Ross Sea area. Based on a simple transport model, we compare nssCa2+ fluxes of different East Antarctic ice cores. From this multi-site comparison we conclude that changes in transport efficiency or atmospheric lifetime of dust particles do have a minor effect compared to source strength changes on the large-scale concentration changes observed in Antarctic ice cores during climate variations of the past 150 ka. Our transport model applied on ice core data is further validated by climate model data. The availability of multiple East Antarctic nssCa2+ records also allows for a revision of a former estimate on the atmospheric CO2 sensitivity to reduced dust induced iron fertilisation in the Southern Ocean during the transition from the Last Glacial Maximum to the Holocene (T1). While a former estimate based on the EPICA Dome C (EDC) record only suggested 20 ppm, we find that reduced dust induced iron fertilisation in the Southern Ocean may be responsible for up to 40 ppm of the total atmospheric CO2 increase during T1. During the last interglacial, ssNa+ levels of EDC and EPICA Dronning Maud Land (EDML) are only half of the Holocene levels, in line with higher temperatures during that period, indicating much reduced sea ice extent in the Atlantic as well as the Indian Ocean sector of the Southern Ocean. In contrast, Holocene ssNa+ flux in Talos Dome is about the same as during the last interglacial, indicating that there was similar ice cover present in the Ross Sea area during MIS 5.5 as during the Holocene.

Exogenous gonadotropins do not increase the blood-follicular transportation capacity of extra-ovarian hormones such as prolactin and cortisol.

BACKGROUNDS In vitro fertilization involves high dosage gonadotropin stimulation, which apparently has some negative impact on follicular endocrine function. As chorionic gonadotropin stimulation has been shown to increase the blood-follicular permeability in animal models, this raises the question if such an effect also applies to gonadotropins in humans, possibly affecting the endocrine follicular milieu. FINDINGS Follicular fluid and serum were collected at the time of follicular aspiration in in vitro fertilisation without (Natural cycle IVF, n = 24) and with (conventional gonadotropin stimulated IVF, n = 31) gonadotropin stimulation. The concentration of the extra-ovarian hormones prolactin and cortisol were analysed by immunoassays. RESULTS Median serum prolactin and cortisol concentrations were 12.3 ng/mL and 399 nmol/L without versus 32.2 ng/mL and 623 nmol/L with gonadotropin stimulation. The corresponding concentrations in follicular fluid were 20.6 ng/mL and 445 nmol/L versus 28.8 ng/ml and 456 nmol/L for prolactin and cortisol. As a consequence, mean follicular fluid:serum ratios were significantly reduced under gonadotropin stimulation (prolactin p = 0.0138, cortisol p = 0.0001). As an enhanced blood-follicular permeability and transportation, induced by gonadotropin stimulation, would result in increased instead of decreased follicular fluid:serum ratios as found in this study, it can be assumed that this does not affect extra-ovarian protein and steroid hormones as illustrated by prolactin and cortisol. CONCLUSIONS The model of serum follicular fluid:serum ratio of hormones, produced outside the ovaries, did not reveal a gonadotropin induced increased blood-follicular transportation capacity. Therefore it can be assumed that the effect of gonadotropins on follicular endocrine function is not due to an increased ovarian permeability of extra-ovarian hormones.

Does autogamy contribute to invasion in Lilium formosanum?

The Taiwanese geophyte Lilium formosanum is invasive in the eastern parts of South Africa. Although it is capable of autogamy, a pollinator, the hawkmoth Agrius convolvuli, is present. Reproduction may therefore take place both by self- and cross-fertilisation. The relative importance of these modes of pollination for seed production is evaluated using emasculation experiments. The potential contributions of outcrossed and selfed progeny to invasion are assessed in progeny performance trials.

Fertility preservation options in breast cancer patients.

The purpose of this review is to analyse current options for fertility preservation in young women with breast cancer (BC). Considering an increasing number of BC survivors, owing to improvements in cancer treatment and delaying of childbearing, fertility preservation appears to be an important issue. Current fertility preservation options in BC survivors range from well-established standard techniques to experimental or investigational interventions. Among the standard options, random-start ovarian stimulation protocol represents a new technique, which significantly decreases the total time of the in vitro fertilisation cycle. However, in patients with oestrogen-sensitive tumours, stimulation protocols using aromatase inhibitors are currently preferred over tamoxifen regimens. Cryopreservation of embryos and oocytes are nowadays deemed the most successful techniques for fertility preservation in BC patients. GnRH agonists during chemotherapy represent an experimental method for fertility preservation due to conflicting long-term outcome results regarding its safety and efficacy. Cryopreservation of ovarian tissue, in vitro maturation of immature oocytes and other strategies are considered experimental and should only be offered within the context of a clinical trial. An early pretreatment referral to reproductive endocrinologists and oncologists should be suggested to young BC women at risk of infertility, concerning the risks and benefits of fertility preservation options.