ABSTRACT
Only a few studies have shown positive impacts of ecological compensation on species dynamics affected by human activities. We argue that this is due to inappropriate methods used to ...forecast required compensation in environmental impact assessments. These assessments are mostly descriptive and only valid at limited spatial and temporal scales. However, habitat suitability models developed to predict the impacts of environmental changes on potential species' distributions should provide rigorous science‐based tools for compensation planning. Here we describe the two main classes of predictive models: correlative models and individual‐based mechanistic models. We show how these models can be used alone or synoptically to improve compensation planning. While correlative models are easier to implement, they tend to ignore underlying ecological processes and lack accuracy. On the contrary, individual‐based mechanistic models can integrate biological interactions, dispersal ability and adaptation. Moreover, among mechanistic models, those considering animal energy balance are particularly efficient at predicting the impact of foraging habitat loss. However, mechanistic models require more field data compared to correlative models. Hence we present two approaches which combine both methods for compensation planning, especially in relation to the spatial scale considered. We show how the availability of biological databases and software enabling fast and accurate population projections could be advantageously used to assess ecological compensation requirement efficiently in environmental impact assessments.
Neurodegenerative (ND) complications in Langerhans cell histiocytosis (LCH) are a late‐onset but dramatic sequelae for which incidence and risk factors are not well defined. Based on a national ...prospective registry of paediatric LCH patients, we determined the incidence rate of clinical ND LCH (cND‐LCH) and analysed risk factors, taking into account disease extent and molecular characteristics. Among 1897 LCH patients, 36 (1·9%) were diagnosed with a cND‐LCH. The 10‐year cumulative incidence of cND‐LCH was 4·1%. cND‐LCH typically affected patients previously treated for a multisystem, risk organ–negative LCH, represented in 69·4% of cND‐LCH cases. Pituitary gland, skin and base skull/orbit bone lesions were more frequent (P < 0·001) in cND‐LCH patients compared to those without cND‐LCH (respectively 86·1% vs. 12·2%, 75·0% vs. 34·2%, and 63·9% vs. 28·4%). The ‘cND susceptible patients’ (n = 671) i.e., children who had experienced LCH disease with pituitary or skull base or orbit bone involvement, had a 10‐year cND risk of 7·8% vs. 0% for patients who did not meet these criteria. Finally, BRAFV600E status added important information among these cND susceptible patients, with the 10‐year cND risk of 33·1% if a BRAFV600E mutation was present compared to 2·9% if it was absent (P = 0·002).
Greater flamingos use cosmetic coloration by spreading uropygial secretions pigmented with carotenoids over their feathers, which makes the plumage redder. Because flamingos inhabit open environments ...that receive direct solar radiation during daytime, and carotenoids bleach when exposed to solar radiation, we expected that the plumage color would fade if there is no maintenance for cosmetic purposes. Here, we show that the concentrations of pigments inside feathers and on the surface of feathers were correlated, as well as that there was a correlation between the concentrations of pigments in the uropygial secretions and on the surface of feathers. There was fading in color (becoming less red) in feathers that received direct solar radiation when there was no plumage maintenance, but not so in others maintained in darkness. When we controlled for the initial color of feathers, the feathers of those individuals with higher concentration of pigments on the feather surfaces were those that lost less coloration after experimental exposure of feathers to sunny conditions. These results indicate that exposure to sunlight is correlated with the fading of feather color, which suggests that individuals need to regularly apply makeup to be more colorful. These results also reinforce the view that these birds use cosmetic coloration as a signal amplifier of plumage color. This may be important in species using highly variable habitats, such as wetlands, since the conditions experienced when molting may differ from those when the signal should be functional, usually months after molting.
Greater flamingo plumage coloration fades when there is no frequent application of cosmetics.
Most studies analyzing the effects of global warming on wild populations focus on gradual temperature changes, yet it is also important to understand the impact of extreme climatic events. Here we ...studied the effect of two cold spells (January 1985 and February 2012) on the energetics of greater flamingos (Phoenicopterus roseus) in the Camargue (southern France). To understand the cause of observed flamingo mass mortalities, we first assessed the energy stores of flamingos found dead in February 2012, and compared them with those found in other bird species exposed to cold spells and/or fasting. Second, we evaluated the monthly energy requirements of flamingos across 1980-2012 using the mechanistic model Niche Mapper. Our results show that the body lipids of flamingos found dead in 2012 corresponded to 2.6±0.3% of total body mass, which is close to results found in woodcocks (Scolopax rusticola) that died from starvation during a cold spell (1.7±0.1%), and much lower than in woodcocks which were fed throughout this same cold spell (13.0±2%). Further, Niche Mapper predicted that flamingo energy requirements were highest (+6-7%) during the 1985 and 2012 cold spells compared with 'normal' winters. This increase was primarily driven by cold air temperatures. Overall, our findings strongly suggest that flamingos starved to death during both cold spells. This study demonstrates the relevance of using mechanistic energetics modelling and body condition analyses to understand and predict the impact of extreme climatic events on animal energy balance and winter survival probabilities.
Neuroblastoma (NB) is a frequent pediatric tumor for which recurrent somatic rearrangements are known. Germline mutations of predisposing gene(s) are suspected on the basis of rare familial cases and ...the association of NB with other genetically determined congenital malformations of neural crest–derived cells—namely, Hirschsprung disease (HSCR) and/or congenital central hypoventilation syndrome (CCHS). We recently identified the paired–like homeobox 2B (
PHOX2B) gene as the major disease-causing gene in isolated and syndromic CCHS, which prompted us to regard it as a candidate gene in NB. Here, we report on germline mutations of
PHOX2B in both a familial case of NB and a patient with the HSCR-NB association.
PHOX2B, therefore, stands as the first gene for which germline mutations predispose to NB.
Ifosfamide is widely used in pediatric oncology but its nephrotoxicity may become a significant issue in survivors. This study is aimed at evaluating the incidence of late renal toxicity of ...ifosfamide and its risk factors.
Of the 183 patients prospectively investigated for renal function, 77 treated for rhabdomyosarcoma, 39 for other soft tissue sarcoma, 39 for Ewing's sarcoma, and 28 for osteosarcoma were investigated at least 5 years after treatment. No patients had received cisplatin and/or carboplatin. Glomerular and tubular functions were graded according to the Skinner system.
The median dose of ifosfamide was 54 g/m(2) (range, 18 to 117 g/m(2)). After a median follow-up of 10 years, 89.5% of patients had normal tubular function, and 78.5% had normal glomerular function rate (GFR). Serum bicarbonate and calcium were normal in all patients. Hypomagnesemia was observed in 1.2% and hypophosphatemia in 1%. The tubular threshold for phosphate was reduced in 24% of the patients (grade 1 in 15%, grade 2 in 8%, and grade 3 in 0.5%). Glycosuria was detected in 37% of the patients but was more than 0.5 g/24 hours in only 5%. Proteinuria was observed in 12%. Ifosfamide dose and interval from therapy to investigations were predictors of tubulopathy in univariate and multivariate analysis. In a multivariate analysis, an older age at diagnosis and the length of interval since treatment had independent impacts on the risk of abnormal GFR.
Renal toxicity is moderate with a moderate dose of ifosfamide. However, since it can be permanent and can get worse with time, repeated long-term evaluations are important, and this risk should be balanced against efficacy.
Accurate knowledge of the functional response of predators to prey density is essential for understanding food web dynamics, to parameterize mechanistic models of animal responses to environmental ...change, and for designing appropriate conservation measures. Greater flamingos (Phoenicopterus roseus), a flagship species of Mediterranean wetlands, primarily feed on Artemias (Artemia spp.) in commercial salt pans, an industry which may collapse for economic reasons. Flamingos also feed on alternative prey such as Chironomid larvae (e.g., Chironomid spp.) and rice seeds (Oryza sativa). However, the profitability of these food items for flamingos remains unknown. We determined the functional responses of flamingos feeding on Artemias, Chironomids, or rice. Experiments were conducted on 11 captive flamingos. For each food item, we offered different ranges of food densities, up to 13 times natural abundance. Video footage allowed estimating intake rates. Contrary to theoretical predictions for filter feeders, intake rates did not increase linearly with increasing food density (type I). Intake rates rather increased asymptotically with increasing food density (type II) or followed a sigmoid shape (type III). Hence, flamingos were not able to ingest food in direct proportion to their abundance, possibly because of unique bill structure resulting in limited filtering capabilities. Overall, flamingos foraged more efficiently on Artemias. When feeding on Chironomids, birds had lower instantaneous rates of food discovery and required more time to extract food from the sediment and ingest it, than when filtering Artemias from the water column. However, feeding on rice was energetically more profitable for flamingos than feeding on Artemias or Chironomids, explaining their attraction for rice fields. Crucially, we found that food densities required for flamingos to reach asymptotic intake rates are rarely met under natural conditions. This allows us to predict an immediate negative effect of any decrease in prey density upon flamingo foraging performance.
Feeding functional responses have been measured on the Greater Flamingo (Phoenicopterus roseus) feeding on Artemia, Chironomids larvae and rice. We found that contrary to theoretical predictions for filter feeders, intake rates did not increase linearly with increasing food density. These findings allows us to predict an immediate negative effect of any decrease in prey density upon flamingo foraging performance.
Understanding the evolution of cooperation requires determining the costs and benefits of cooperative behaviour. In cooperative breeders, where nonbreeding individuals assist in raising offspring, ...these ‘helpers’ are expected to increase the fitness of breeders and hence empirical research has focused on the effect they have on reproductive output and breeder survival. However, the effects of helpers during the postfledging period are poorly known because of the difficulty of tracking fledglings in the wild. Helper presence might be beneficial for fledglings, for example through continuous food delivery or increased predator vigilance, but potential competition between helpers and fledglings, or changes in investment of parents assisted by helpers, could counteract these positive effects and have a negative influence on postfledging survival probabilities or promote dispersal. We investigated the survival of juvenile sociable weavers, Philetairus socius, raised in pairs alone versus pairs with helpers by using capture–mark–recapture methods to control for individual detectability in survival estimation. We found that local survival in the first year was reduced in young raised by groups versus those raised by pairs. This may reflect either higher mortality or emigration of juveniles raised in groups. Hence, our study reveals significant postfledging effects of cooperative breeding that have not been reported previously and that need to be investigated in studies addressing the evolution of cooperative breeding.
Hereditary predisposition to neuroblastoma accounts for less than 5% of neuroblastomas and is probably heterogeneous. Recently, a predisposition gene has been mapped to 16p12-p13, but has not yet ...been identified. Occurrence of neuroblastoma in association with congenital central hypoventilation and Hirschsprung's disease suggests that genes, involved in the development of neural-crest-derived cells, may be altered in these conditions. The recent identification of
PHOX2B as the major disease-causing gene in congenital central hypoventilation prompted us to test it as a candidate gene in familial neuroblastoma. We report a family with three first-degree relatives with neuroblastic tumours (namely two ganglioneuromas and one neuroblastoma) in one branch and two siblings with Hirschsprung's disease in another branch. A constitutional R100L
PHOX2B mutation was identified in all three patients affected with tumours. We also report a germline
PHOX2B mutation in one patient treated for Hirschsprung's disease who subsequently developed a multifocal neuroblastoma in infancy. Both mutations disrupt the homeodomain of the
PHOX2B protein. No loss of heterozygosity at the
PHOX2B locus was observed in the tumour, suggesting that haplo-insufficiency, gain of function or dominant negative effects may account for the oncogenic effects of these mutations. These observations identify
PHOX2B as the first predisposing gene to hereditary neuroblastic tumours.
We retrospectively studied 61 patients with GH deficiency (GHD), identified among 589 patients with Langerhans cell histiocytosis (LCH) enrolled in a nationwide survey between 1993 and 2001. Overall, ...141 patients in the survey developed diabetes insipidus. The median follow-up of the 61 patients with GHD was 12 yr. The 5- and 10-yr risks of GHD among patients with diabetes insipidus were 34.7 ± 4.5% and 53.7 ± 5.2%, respectively. Growth velocity decreased soon after LCH diagnosis in patients who developed GHD, and anterior pituitary height, estimated by magnetic resonance imaging, was significantly reduced relative to patients who remained free of GHD. GH replacement therapy was administered to 47 of the 61 patients with GHD. Among GH-treated patients, median final height (−0.8 sd) was significantly greater than median height at GHD diagnosis (−1.6 sd) but remained below midparental (target) height. Among patients with pituitary involvement, the number of LCH disease episodes appeared not significantly influenced by GHD or GH administration, suggesting an absence of deleterious effect of GH therapy on LCH disease activity.
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