110 research outputs found
Associative learning in the cnidarian Nematostella vectensis.
The ability to learn and form memories allows animals to adapt their behavior based on previous experiences. Associative learning, the process through which organisms learn about the relationship between two distinct events, has been extensively studied in various animal taxa. However, the existence of associative learning, prior to the emergence of centralized nervous systems in bilaterian animals, remains unclear. Cnidarians such as sea anemones or jellyfish possess a nerve net, which lacks centralization. As the sister group to bilaterians, they are particularly well suited for studying the evolution of nervous system functions. Here, we probe the capacity of the starlet sea anemone Nematostella vectensis to form associative memories by using a classical conditioning approach. We developed a protocol combining light as the conditioned stimulus with an electric shock as the aversive unconditioned stimulus. After repetitive training, animals exhibited a conditioned response to light alone indicating that they learned the association. In contrast, all control conditions did not form associative memories. Besides shedding light on an aspect of cnidarian behavior, these results root associative learning before the emergence of NS centralization in the metazoan lineage and raise fundamental questions about the origin and evolution of cognition in brainless animals
Tissue-selective estrogen complexes with bazedoxifene prevent metabolic dysfunction in female mice
Pairing the selective estrogen receptor modulator bazedoxifene (BZA) with estrogen as a tissue-selective estrogen complex (TSEC) is a novel menopausal therapy. We investigated estrogen, BZA and TSEC effects in preventing diabetisity in ovariectomized mice during high-fat feeding. Estrogen, BZA or TSEC prevented fat accumulation in adipose tissue, liver and skeletal muscle, and improved insulin resistance and glucose intolerance without stimulating uterine growth. Estrogen, BZA and TSEC improved energy homeostasis by increasing lipid oxidation and energy expenditure, and promoted insulin action by enhancing insulin-stimulated glucose disposal and suppressing hepatic glucose production. While estrogen improved metabolic homeostasis, at least partially, by increasing hepatic production of FGF21, BZA increased hepatic expression of Sirtuin1, PPARα and AMPK activity. The metabolic benefits of BZA were lost in estrogen receptor-α deficient mice. Thus, BZA alone or in TSEC produces metabolic signals of fasting and caloric restriction and improves energy and glucose homeostasis in female mice
High biomass yield increases in a primary effluent wastewater phytofiltration are associated to altered leaf morphology and stomatal size in Salix miyabeana
Municipal wastewater treatment using willow ‘phyto’-filtration has the potential for reduced environmental impact compared to conventional treatment practices. However, the physiological adaptations underpinning tolerance to high wastewater irrigation in willow are unknown. A one-hectare phytofiltration plantation established using the Salix miyabeana cultivar ‘SX67’ in Saint-Roch-de-l'Achigan, Quebec, Canada, tested the impact of unirrigated, potable water or two loads of primary effluent wastewater 19 and 30 ML ha−1 yr−1. A nitrogen load of 817 kg N ha−1 from wastewater did not increase soil pore water nitrogen concentrations beyond Quebec drinking water standards. The willow phytofiltration phenotype had increased leaf area (+106–142%) and leaf nitrogen (+94%) which were accompanied by significant increases in chlorophyll a + b content. Wastewater irrigated trees had higher stomatal sizes and a higher stomatal pore index, despite lower stomatal density, resulting in increased stomatal conductance (+42–78%). These developmental responses led to substantial increases in biomass yields of 56–207% and potable water controls revealed the nitrogen load to be necessary for the high productivity of 28–40 t ha−1 yr−1 in wastewater irrigated trees. Collectively, this study suggests phytofiltration plantations could treat primary effluent municipal wastewater at volumes of at least 19 million litres per hectare and benefit from increased yields of sustainable biomass over a two-year coppice cycle. Added-value cultivation practices, such as phytofiltration, have the potential to mitigate negative local and global environmental impact of wastewater treatment while providing valuable services and sustainable bioproducts
Real time noninvasive assessment of external trunk geometry during surgical correction of adolescent idiopathic scoliosis
Multi-isotopic analysis reveals the early stem turtle Odontochelys as a nearshore herbivorous forager
IntroductionAfter decades of debate on the origin of turtles, it is now widely accepted that they are diapsid reptiles originating in the Permian from a terrestrial ancestor. It seems that the initial development of the structures that will later form the unique turtle bony shell took place as a response to a fossorial lifestyle. However, the earliest stem turtle with a fully complete plastron, Odontochelys semitestacea from the Late Triassic (lower Carnian) of China, is somewhat controversially interpreted as an aquatic or even a marine form, raising the question of the environment in which the completion of the plastron happened.MethodsHere, we analyzed the stable carbon, oxygen and sulfur isotope compositions (δ13C, δ18O and δ34S) of bones from two specimens of Odontochelys along with bones and teeth of two associated specimens of the marine ichthyosaur Guizhouichthyosaurus tangae.Results and discussionWe first show that δ18O values of Odontochelys are incompatible with a terrestrial lifestyle and imply a semi-aquatic to aquatic lifestyle. Isotopic results also demonstrate that the aquatic environment of Odontochelys was submitted to a strong marine influence, therefore excluding the possibility of a strict freshwater aquatic environment. Additionally, an unusual carbon isotope composition shows that O. semitestacea was herbivorous, probably consuming macrophytic algae in coastal zones like the extant green sea turtle (Chelonia mydas) or the marine iguana (Amblyrhynchus cristatus) do
Predicting Protests by Disadvantaged Skilled Immigrants: A Test of an Integrated Social Identity, Relative Deprivation, Collective Efficacy (SIRDE) Model
In Canada, skilled immigrants with foreign credentials tend to experience difficulty in obtaining a suitable job in their chosen profession. This is because employers do not recognize the full value of such qualifications. We used structural equation modeling to test a social identity, relative deprivation, collective efficacy model in a prospective study of a sample of skilled immigrants (N = 234) disadvantaged by this “credentialing” problem. In this model, variables measured at time 1 successfully predicted participation in protest actions during the following 4 months, measured at time 2. First, we conceptualized the affective component of collective relative deprivation (CRD) as (i) the perception of discrimination by the majority group and (ii) the emotional reaction of anger, resentment and frustration in response to that discrimination. The results suggested that the latter positively influenced participation in protest actions but, unexpectedly, the former had the opposite effect. Second, the evidence suggested that respondents’ identification with Canada, but not their cultural group, indirectly influenced such participation through collective efficacy and the two components of affective CRD. Third, the novel hypothesis that status insecurity mediates the relationship between cognitive CRD and the two components of affective CRD was supported. Finally, the results suggest that collective efficacy was a strong and direct determinant of participation in protest actions. The implications of these results for the development of an integrated social psychological theory that can predict participation in political protests are discussed
Dietary index based on the Food Standards Agency nutrient profiling system and risk of Crohn's disease and ulcerative colitis
Background: Nutri-score is now widely available in food packages in Europe. Aim: To study the overall nutritional quality of the diet in relation to risks of Crohn's disease (CD) and ulcerative colitis (UC), in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Methods: We collected dietary data at baseline from validated food frequency questionnaires. We used a dietary index based on the UK Food Standards Agency modified nutrient profiling system (FSAm-NPS-DI) underlying the Nutri-Score label, to measure the nutritional quality of the diet. We estimated the association between FSAm-NPS-DI score, and CD and UC risks using Cox models stratified by centre, sex and age; and adjusted for smoking status, BMI, physical activity, energy intake, educational level and alcohol intake. Results: We included 394,255 participants (68.1% women; mean age at recruitment 52.1 years). After a mean follow-up of 13.6 years, there were 184 incident cases of CD and 459 incident cases of UC. Risk of CD was higher in those with a lower nutritional quality, that is higher FSAm-NPS-DI Score (fourth vs. first quartile: aHR: 2.04, 95% CI: 1.24–3.36; p-trend: <0.01). Among items of the FSAm-NPS-DI Score, low intakes of dietary fibre and fruits/vegetables/legumes/nuts were associated with higher risk of CD. Nutritional quality was not associated with risk of UC (fourth vs. first quartile of the FSAm-NPS-DI Score: aHR: 0.91, 95% CI: 0.69–1.21; p-trend: 0.76). Conclusions: A diet with low nutritional quality as measured by the FSAm-NPS-DI Score is associated with a higher risk of CD but not UC
Optimisation de la capacité de traitement des eaux usées municipales des plantations filtrantes de saules
RÉSUMÉ: Les plantations filtrantes de saules (PFS) représentent une technologie qui a un potentiel élevé pour procéder au traitement des eaux usées des petites municipalités (entre 300 à 800 habitants). Pour ces municipalités la technologie des PFS peut représenter une alternative moins coûteuse et plus facile que les systèmes de traitement conventionnel, qui demande des infrastructures importantes et une main d’oeuvre qualifiée. Les PFS permettent, de leur côté, d’utiliser les nutriments contenus dans les eaux usées et l’eau en vue d’assurer la croissance de la plantation de saules. Les saules peuvent par la suite être valorisés (à des fins énergétiques par exemple). En contrepartie, les PFS requièrent un espace important et nécessitent un étang de stockage pendant la période hivernale. L’optimisation de la capacité de traitement des PFS permettrait d’élargir la plage d’accessibilité du procédé et réduire l’espace de culture.----------ABSTRACT: Short-rotation willow coppice used as a vegetation filter (SRWC) is a technology, which offers great potential for the treatment of wastewater from small municipalities (between 300 to 800 population equivalent). For those municipalities, SRWC could be less expensive and easier to apply than conventional treatments, which require additional qualified personnel and larger infrastructure. SWRC uses the water and its nutrients contained in the wastewater to fulfill the plant’s needs. Afterward, the willow can be valorized. To reach acceptable performance, the SWRC requires significant space and a storage to accumulate water during winter. However, optimization of the wastewater treatment capacity of SWRC, as proposed in this work, could expand the process's accessibility range and reduce the space required
High-precision 34S/32S measurements in vertebrate bioapatites using purge-and-trap elemental analyser/isotope ratio mass spectrometry technology
International audienceRATIONALE: In ecological studies, the sulfur isotope compositions (à34S values) of soft tissues (e.g. hair, skin, nail, muscle, collagen) allow the determination of both past and present-day living environments of organisms. However, technical limitations have so far prevented reliable sulfur isotope analyses of minerals having low sulfur content, such as bioapatite, which is the crystalline component of skeletal tissues. The development of ‘purge-and-trap’ technology in elemental analysers recently demonstrated new possibilities to solve some of those technical difficulties.METHODS: We have used a VarioPYROcube elemental analyser (EA) equipped with ‘purge-and-trap’ technology, interfaced in continuous flow mode to an Isoprime 100 isotope ratio mass spectrometer, to measure the sulfur isotope compositions of bioapatite samples. We first characterised a working calibrated material of chemical composition close to those of our samples, the low-S bearing phosphorite BCR32, against the two à34SV-CDT reference-calibrated materials, NBS-127 and IAEA-SO-5. We have confirmed a 34SV-CDT value of +18.4‰ (1 = 0.5; n = 18) in agreement with the previously published value. Using BCR32 as a compositional and isotopic reference material, we have then measured the à34SV-CDT values of various bioapatite tissues (bone, dentine and enamel) from both modern and fossil vertebrates living in different environments (marine, freshwater and terrestrial).RESULTS: Our results demonstrate the capacity of this analytical setup to measure the à34SV-CDT values of low-S bioapatite samples (0.14 to 1.19 wt%) with a good analytical precision (1 = 0.5; n = 14). Our results also show that the à34SV-CDT values of modern and fossil vertebrate bioapatites allow discrimination between marine environments and freshwater or terrestrial ones.CONCLUSIONS: Sulfur isotope analysis of bioapatite has great potential to track the living environment of extinct vertebrates for which only fossilised bones or teeth have been preserved
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