Prenatal incision of ureterocele causing bladder outlet obstruction: a multicenter case series

We reviewed data from a cohort of fetuses with ureterocele diagnosed and operated prenatally in four fetal therapy centers. Inclusion criteria were (1) ureterocele confirmed on detailed fetal ultrasound examination, (2) absence of additional fetal malformations, and (3) fetal intervention to decompress the ureterocele with local institutional review boards' approval. Data on sonographic follow-up, obstetrical, neonatal outcome, and postnatal evaluation were collected. Ten cases of prenatally treated ureterocele are described. Six cases benefited from a fetoscopy for laser incision and decompression, two cases had an ultrasound guided puncture before resorting to a fetoscopy with laser incision, one case had a balloon catheterization under ultrasound guidance, and one case had an ultrasound-guided opening of the ureterocele with a laser fiber passed through a 20-gauge needle. Mean gestational age at diagnosis was 21.6 GW. Two cases underwent termination of pregnancy. The remaining eight cases recovered normal amniotic fluid volume and delivered a liveborn child at a mean gestational age of 38.6 GW with normal creatinine levels during the first week of life. Prenatal incision provided complete treatment of severely obstructive ureteroceles in 80% of the cases and allowed improvement of urinary electrolytes, renal size and echogenicity, bladder filling in all survivors, and recollection of normal amniotic fluid volume, in case of oligoanhydramnios. © 2017 John Wiley & Sons, Ltd.     

A multi-event model to study stage-dependent dispersal in radio-collared hares: when hunting promotes costly transience

Behavioral ecologists have often assumed that dispersal is costly mainly because of unfamiliarity with traversed habitats during dispersal and energy costs of the movement per se; thus, dispersers that have successfully settled should experience survival rates comparable to those of philopatric individuals. In this paper, we tested that hypothesis using 152 radio-collared European hares in a harvested population. We developed a multi-event capture recapture model, combining telemetry data and recoveries and separately modeling the foray probability, the settlement probability, and the permanent dispersal probability. The parameterization introduced here raises the possibility of separately testing effects on survival and dispersal probabilities at each stage of dispersal (departure, transience, and settlement). In accordance with our expectations, we reveal that dispersers incur higher mortality risks during transience and the early settlement period than philopatric individuals or settled dispersers. We also found that dispersers suffer from higher risks of being shot. Those results illustrate that unfamiliarity with the habitat during transience makes dispersal costly and that settled dispersers may enjoy survival rates comparable to those of philopatric individuals. Surprisingly, we also found that individuals have a higher probability of foraying during the hunting season. We suggest that hunting and related disturbances increase dispersal costs both by increasing mortality risk during transience and (perhaps) by increasing movement rates. We emphasize the need to take human pressures into account as factors that may drive the demographics of movements in populations.     

Tracking habitat and resource use for the jumbo squid Dosidicus gigas: a stable isotope analysis in the Northern Humboldt Current System

To determine the habitat and resource use of Dosidicus gigas in the Northern Humboldt Current System, we analysed carbon and nitrogen stable isotopes of 234 individuals collected during 2008–2010. Large variations in mantle stable isotope ratios were recorded, with values ranging from −19.1 to −15.1 ‰ (δ¹³C) and from 7.4 to 20.5 ‰ (δ¹⁵N). Most of the variation was explained by latitude, followed by distance to shelf break for carbon and by squid size for nitrogen. Latitudinal variations with increasing values from north to south were also found in zooplankton samples and were related to changes in isotope baseline values probably due to oxygen minimum zones that occur off Peru. This similar latitudinal trend in both zooplankton and D. gigas samples reveals that D. gigas is a relatively resident species at the scale of its isotopic turnover rate (i.e. a few weeks), even if this is not necessarily the case at the scale of its life. A small but significant size effect on δ¹³C values suggests that jumbo squid perform offshore–onshore ontogenic migration, with juveniles distributed offshore. For nitrogen, the high inter-individual variability observed with mantle length indicates that D. gigas can prey on a high variety of resources at any stage of their life cycle. This large-scale study off the coast of Peru provides further evidence that D. gigas have the capability to explore a wide range of habitats and resources at any stage of their life.     

Intraguild predation and mesopredator release effect on long-lived prey

Complete extirpation of a species can generate cascading effects throughout an ecosystem, yet are precisely the goal of island eradications of pest species. “Mesopredator release effect”, an asymmetrical special case of intraguild predation, has been hypothesised as a possible indirect effect from eradications, where superpredator removal can generate a mesopredator increase which may increase the impact on their shared prey. Theoretically this suggests that for intraguild predators, the superpredator may protect the shared prey from mesopredation, and removal of superpredators alone is not recommended. We create a model of long-lived age-structured shared prey and explore the non-equilibrium dynamics of this system. The superpredator can impact all prey life-stages (adult survival and reproductive success) whereas the smaller mesopredator can only impact early life-stages (reproductive success). This model is independently tested with data from a closed oceanic island system where eradication of introduced intraguild predators is possible for conservation of threatened birds. Mesopredator release only occurs in strongly top-down moderated (resource-abundant) systems. Even when mesopredator release can occur, the negative impact of more mesopredators is outweighed by the benefit of superpredator removal, allowing recovery of the prey population. Results are robust to 10% variation in model parameters. The consideration of age-structured prey contradicts previous theoretical results for mesopredator release effect and intraguild predation. Superpredator eradication is vital for population recovery of long-lived insular species. Nonetheless island conservation must retain a whole-ecosystem perspective given the complex trophic relationships among multiple species on islands.     

Tissue,ontogenic and sex-related differences in δ<Superscript>13</Superscript>C and δ<Superscript>15</Superscript>N values of the oceanic squid <Emphasis Type="Italic">Todarodes filippovae</Emphasis> (Cephalopoda: Ommastrephidae)

Stable isotopes are increasingly used in the study of trophic interactions of many aquatic animals and most recently cephalopods. To evaluate the application of the method to squids, it is important to assess isotopic differences among and within consumer tissues that may confound the resolution of ecological relationships. Inter- and intra-tissue isotopic variation was examined in 55 individuals of the oceanic squid Todarodes filippovae that were collected at the beginning of April 2000 in the southwestern Indian Ocean (between 44°S, 76°E, and Saint Paul and Amsterdam islands, 38°S, 78°E). Delipidated soft tissues (mantle, arm, buccal mass, gill and reproductive organs) showed small δ¹³C and δ¹⁵N differences, which were probably tissue-specific. A lower carbon value was observed in the digestive gland as a consequence of incomplete lipid removal. Hard tissues, such as beaks and gladii, had lower ¹⁵N values than soft tissues, which can be explained by the presence of chitin, a ¹⁵N-depleted molecule. Females (n = 38) and males (n = 17) had identical δ¹³C values, but females showed higher δ¹⁵N values than males. The difference was size-related rather than sex-related, however, as females were generally larger than males. A comparison of similar-sized females and males produced identical nitrogen values. These data suggest dietary shifts from lower to higher trophic levels during growth, because δ¹⁵N values of large T. filippovae were much higher than that of small specimens. As expected, nitrogen values of lower beaks and gladii of large squids increased from the oldest to the most recently formed region, reflecting the progressive growth of chitinized tissues in parallel with dietary changes. Sequential sampling along the growth increments of squid beaks and gladii can likely be used to produce a chronological record of dietary information throughout an individual’s history.     

Evaluation of the phytotoxicity of contaminated sediments deposited "on soil": II. Impact of water draining from deposits on the development and physiological status of neighbouring plants at growth stage

As part of a study of the phytotoxic risk of spreading contaminated sediments "on soil", a laboratory experiment was carried out to assess the impact of water draining from sediments on peripheral vegetation. Drainage water was obtained in the laboratory by settling three sediments with different pollutants levels, and the supernatant solutions (respectively A1, B1, C1 drainage waters) were used as soaking water for maize (Zea ma?s L.) and ryegrass (Lolium perenne L.). The physicochemical characteristics of the supernatant water, particularly metal contents, showed a pattern of contamination, with C1>A1>B1. The plants tested were grown on soil for 21 days, before being soaked for another 21-day period with drainage water (treatments) and distilled water (control). Biomass parameters (fresh weight, length, etc.), enzymatic activity [glutamine synthetase (GS), phosphoenolpyruvate carboxylase (PEPc)] and Zn, Cu, Cd and Cr contents were measured on both the shoots and roots of each plant. Biomass parameters were stimulated by C1, not affected by A1 and decreased with B1 for maize, whereas they increased for ryegrass in all the treatments. Compared to the control, GS activity was stimulated by C1 in the shoots of both plants and inhibited by treatments B1 and C1 in maize roots. PEPc activity in ryegrass was 1.5-5 times higher with contaminated water treatment, while contrasting effects were observed in maize plants. Both plants showed greater accumulation of chromium and zinc than cadmium and copper. Treatment A1 was found to be less active on plant growth and have a lower impact on the physiological status (enzymatic activities) of both plants. Treatment C1 stimulated the growth and physiological status of the plants, especially in shoots, with higher metal accumulation values in both plants. Treatment B1 was found to show more variable effects on growth indices, enzymatic activity and metal accumulation according to plant species.