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61.
62.
François Blanc Laure Blanc-Vernet Alain Laurec Joël Le Campion Léo Pastouret 《Palaeogeography, Palaeoclimatology, Palaeoecology》1975,18(4):293-312
The principal component analysis method is applied to the study of associations of different Pleistocene and Holocene planktonic Foraminifera in five cores from the eastern Mediterranean. Comparison of the fossil foraminiferal distribution with the distribution of living species leads to grouping of the fossil microfauna on the basis of paleoecological controls. Factor 1 is interpreted as representing thermal control. We recognize as warm-water species Globigerinoides trilobus, Globigerinoides trilobus sacculifer, Orbulina universa, Globigerinella siphonifera, Globigerinoides ruber. Cold-water species are Globigerina pachyderma, Globorotalia scitula, Globigerina quinqueloba, Globigerinita glutinata. Species considered to be of intermediate character are Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides. Factor 2 also leads to the grouping of these last species and may reflect the contributing influence of productivity phenomena. A quadratic liaison interpreted as the “Guttman effect” relates factors 1 and 2. Factor 3 introduces complications resulting from apparently sporadic, irregular events affecting the distribution of certain species, notably Globoratalia inflata, Globorotalia truncatulinoides and Globigerina dutertrei. 相似文献
63.
It is predicted that warmer conditions should lead to a loss of trophic levels, as larger bodied consumers, which occupy higher trophic levels, experience higher metabolic costs at high temperature. Yet, it is unclear whether this prediction is consistent with the effect of warming on the trophic structure of natural systems. Furthermore, effects of temperature at the species level, which arise through a change in species composition, may differ from those at the population level, which arise through a change in population structure. We investigate this by building species-level trophic networks, and size-structured trophic networks, as a proxy for population structure, for 18 648 stream fish communities, from 4 145 234 individual fish samples, across 7024 stream locations in France from 1980 to 2008. We estimated effects of temperature on total trophic diversity (total number of nodes), vertical trophic diversity (mean and maximum trophic level) and distribution of biomass across trophic level (correlation between trophic level and biomass) in these networks. We found a positive effect of temperature on total trophic diversity in both species- and size-structured trophic networks. We found that maximum trophic level and biomass distribution decreased in species-level and size-structured trophic networks, but the mean trophic level decreased only in size-structured trophic networks. These results show that warmer temperatures associate with a lower vertical trophic diversity in size-structured networks, and a higher one in species-level networks. This suggests that vertical trophic diversity is shaped by antagonistic effects of temperature on population structure and on species composition. Our results hence demonstrate that effects of temperature do not only differ across trophic levels, but also across levels of biological organisation, from population to species level, implying complex changes in network structure and functioning with warming. 相似文献
64.
Systematic Parasitology - The proteocephalid genus Pseudoendorchis (Cestoda: Onchoproteocephalidea) has recently been proposed to accommodate seven species/species-level lineages of tapeworm... 相似文献
65.
Jian-Jun Jia Roni M Lahr Michael T Solgaard Bruno J Moraes Roberta Pointet An-Dao Yang Giovanna Celucci Tyson E Graber Huy-Dung Hoang Marius
R Niklaus Izabella A Pena Anne K Hollensen Ewan M Smith Malik Chaker-Margot Leonie Anton Christopher Dajadian Mark Livingstone Jaclyn Hearnden Xu-Dong Wang Yonghao Yu Timm Maier Christian K Damgaard Andrea J Berman Tommy Alain Bruno D Fonseca 《Nucleic acids research》2021,49(6):3461
66.
Christoph Engelhardt Valérie Malfroy Camine David Ingram Philippe Müllhaupt Alain Farron Dominique Pioletti 《Computer methods in biomechanics and biomedical engineering》2013,16(12):1272-1279
The estimation of muscle forces in musculoskeletal shoulder models is still controversial. Two different methods are widely used to solve the indeterminacy of the system: electromyography (EMG)-based methods and stress-based methods. The goal of this work was to evaluate the influence of these two methods on the prediction of muscle forces, glenohumeral load and joint stability after total shoulder arthroplasty. An EMG-based and a stress-based method were implemented into the same musculoskeletal shoulder model. The model replicated the glenohumeral joint after total shoulder arthroplasty. It contained the scapula, the humerus, the joint prosthesis, the rotator cuff muscles supraspinatus, subscapularis and infraspinatus and the middle, anterior and posterior deltoid muscles. A movement of abduction was simulated in the plane of the scapula. The EMG-based method replicated muscular activity of experimentally measured EMG. The stress-based method minimised a cost function based on muscle stresses. We compared muscle forces, joint reaction force, articular contact pressure and translation of the humeral head. The stress-based method predicted a lower force of the rotator cuff muscles. This was partly counter-balanced by a higher force of the middle part of the deltoid muscle. As a consequence, the stress-based method predicted a lower joint load (16% reduced) and a higher superior–inferior translation of the humeral head (increased by 1.2 mm). The EMG-based method has the advantage of replicating the observed cocontraction of stabilising muscles of the rotator cuff. This method is, however, limited to available EMG measurements. The stress-based method has thus an advantage of flexibility, but may overestimate glenohumeral subluxation. 相似文献
67.
Anne-Laure Huber Justine Lebeau Patricia Guillaumot Virginie Pétrilli Mouhannad Malek Julien Chilloux Frédérique Fauvet Léa Payen Alain Kfoury Toufic Renno Eric Chevet Serge N. Manié 《Molecular cell》2013,49(6):1049-1059
Highlights? Transformation-associated glucose shortage triggers ER stress ? The ER stress acts as barrier to malignancy by triggering UPR-dependent apoptosis ? p58IPK expression removes the UPR barrier by attenuating its PERK-CHOP branch ? This adaptive mechanism enables implementation of UPR cytoprotective features 相似文献
68.
Hadjila Chabane Christelle Lamazzi Valerie Thiery Alain Pierre Stephane Leonce Bruno Pfeiffer 《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):167-174
Novel thiazolocarbazole derivatives have been synthesized via the corresponding imino-1,2,3-dithiazoles. In vitro antitumor activity of these polyheterocyclic compounds was studied. 相似文献
69.
Patrick Gérardin Adrian Fianu Alain Michault Corinne Mussard Karim Boussa?d Olivier Rollot Philippe Grivard Somar Kassab Eric Bouquillard Gianandrea Borgherini Bernard-Alex Gaüzère Denis Malvy Gérard Bréart Fran?ois Favier 《Arthritis research & therapy》2013,15(1):R9
Introduction
Long-lasting relapsing or lingering rheumatic musculoskeletal pain (RMSP) is the hallmark of Chikungunya virus (CHIKV) rheumatism (CHIK-R). Little is known on their prognostic factors. The aim of this prognostic study was to search the determinants of lingering or relapsing RMSP indicative of CHIK-R.Methods
Three hundred and forty-six infected adults (age ≥ 15 years) having declared RMSP at disease onset were extracted from the TELECHIK cohort study, Reunion island, and analyzed using a multinomial logistic regression model. We also searched for the predictors of CHIKV-specific IgG titres, assessed at the time of a serosurvey, using multiple linear regression analysis.Results
Of these, 111 (32.1%) reported relapsing RMSP, 150 (43.3%) lingering RMSP, and 85 (24.6%) had fully recovered (reference group) on average two years after acute infection. In the final model controlling for gender, the determinants of relapsing RMSP were the age 45-59 years (adjusted OR: 2.9, 95% CI: 1.0, 8.6) or greater or equal than 60 years (adjusted OR: 10.4, 95% CI: 3.5, 31.1), severe rheumatic involvement (fever, at least six joints plus four other symptoms) at presentation (adjusted OR: 3.6, 95% CI: 1.5, 8.2), and CHIKV-specific IgG titres (adjusted OR: 3.2, 95% CI: 1.8, 5.5, per one unit increase). Prognostic factors for lingering RMSP were age 45-59 years (adjusted OR: 6.4, 95% CI: 1.8, 22.1) or greater or equal than 60 years (adjusted OR: 22.3, 95% CI: 6.3, 78.1), severe initial rheumatic involvement (adjusted OR: 5.5, 95% CI: 2.2, 13.8) and CHIKV-specific IgG titres (adjusted OR: 6.2, 95% CI: 2.8, 13.2, per one unit increase). CHIKV specific IgG titres were positively correlated with age, female gender and the severity of initial rheumatic symptoms.Conclusions
Our data support the roles of age, severity at presentation and CHIKV specific IgG titres for predicting CHIK-R. By identifying the prognostic value of the humoral immune response of the host, this work also suggest a significant contribution of the adaptive immune response to the physiopathology of CHIK-R and should help to reconsider the paradigm of this chronic infection primarily shifted towards the involvement of the innate immune response. 相似文献70.
Jennifer Dieppedale Gael Gesbert Elodie Ramond Cerina Chhuon Iharilalao Dubail Marion Dupuis Ida Chiara Guerrera Alain Charbit 《Molecular & cellular proteomics : MCP》2013,12(8):2278-2292
Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. In vivo, this facultative intracellular bacterium survives and replicates mainly in the cytoplasm of infected cells. We have recently identified a genetic locus, designated moxR that is important for stress resistance and intramacrophage survival of F. tularensis. In the present work, we used tandem affinity purification coupled to mass spectrometry to identify in vivo interacting partners of three proteins encoded by this locus: the MoxR-like ATPase (FTL_0200), and two proteins containing motifs predicted to be involved in protein–protein interactions, bearing von Willebrand A (FTL_0201) and tetratricopeptide (FTL_0205) motifs. The three proteins were designated here for simplification, MoxR, VWA1, and TPR1, respectively. MoxR interacted with 31 proteins, including various enzymes. VWA1 interacted with fewer proteins, but these included the E2 component of 2-oxoglutarate dehydrogenase and TPR1. The protein TPR1 interacted with one hundred proteins, including the E1 and E2 subunits of both oxoglutarate and pyruvate dehydrogenase enzyme complexes, and their common E3 subunit. Remarkably, chromosomal deletion of either moxR or tpr1 impaired pyruvate dehydrogenase and oxoglutarate dehydrogenase activities, supporting the hypothesis of a functional role for the interaction of MoxR and TPR1 with these complexes. Altogether, this work highlights possible links between stress resistance and metabolism in F. tularensis virulence.Francisella tularensis is responsible for the disease tularamia in a large number of animal species. This highly infectious bacterial pathogen can be transmitted to humans in numerous ways (1, 2, 3), including direct contact with sick animals, inhalation, ingestion of contaminated water or food, or by bites from ticks, mosquitoes, or flies. Four different subspecies (subsp.) of F. tularensis that differ in virulence and geographic distribution exist, designated subsp. tularensis (type A), subsp. holarctica (type B), subsp. Novicida, and subsp. mediasiatica, respectively. F. tularensis subsp. tularensis is the most virulent subspecies causing a severe disease in humans, whereas F. tularensis subsp. holarctica causes a similar disease but of less severity (4). Because of its high infectivity and lethality, F. tularensis is considered a potential bioterrorism agent (5).F. tularensis is able to survive and to replicate in the cytoplasm of a variety of infected cells, including macrophages. To resist this stressful environment, the bacterium must have developed stress resistance mechanisms, most of which are not yet well characterized. We recently reported the identification of a novel genetic locus that is important for stress resistance and intracellular survival of F. tularensis (6). This locus was designated moxR because the first gene FTL_0200, encodes a protein belonging to the AAA+ ATPase of the MoxR family ((7) and references therein). The data obtained in that first study had led us to suggest that the F. tularensis MoxR-like protein might constitute, in combination with other proteins of the locus, a chaperone complex contributing to F. tularensis pathogenesis.To further validate this hypothesis and expand our initial observations, we here decided to perform tandem affinity purification (TAP),1 using a dual affinity tag approach coupled to mass spectroscopy analyses (8), to identify proteins interacting in vivo with three proteins encoded by the proximal portion of the moxR locus. For this, we chose as baits: the MoxR-like protein (FTL_0200) and two proteins bearing distinct motifs possibly involved in protein–protein interactions, FTL_0201 (Von Willebrand Factor Type A domain, or VWA) and FTL_0205 (tetratrichopeptide repeat or TPR). The three proteins were designated here for simplification, MoxR, VWA1, and TPR1; and the corresponding genes moxR, vwa1, and tpr1, respectively.VWA domains are present in all three kingdoms of life. They consist of a β-sheet sandwiched by multiple α helices. Frequently, VWA domain-containing proteins function in multiprotein complexes (9). TPR typically contain 34 amino acids. Many three-dimensional structures of TPR domains have been solved, revealing amphipathic helical structures (10). TPR-containing proteins are also found in all kingdoms of life. They can be involved in a variety of functions, and generally mediate protein–protein interactions. In the past few years, several TPR-related proteins have been shown to be involved in virulence mechanisms in pathogenic bacteria ((11) and references therein).Our proteomic approach allowed us to identify a series of protein interactants for each of the three moxR-encoded proteins. Remarkably, the protein TPR1 interacted with all the subunits of the pyruvate dehydrogenase (PDH) and 2-oxoglutarate dehydrogenase (OGDH) complexes. Furthermore, inactivation of tpr1 also severely impaired the activities of these two enzymes. Inactivation of tpr1 affected bacterial resistance to several stresses (and in particular oxidative stress), intramacrophagic bacterial multiplication and bacterial virulence in the mouse model. Functional implications and possible relationship between bacterial metabolism, stress defense, and bacterial virulence are discussed. 相似文献