194 research outputs found
Class A ÎČ -Lactamases as Versatile Scaffolds to Create Hybrid Enzymes: Applications from Basic Research to Medicine
Designing hybrid proteins is a major aspect of protein engineering and covers a very wide range of applications frombasic research
to medical applications. This review focuses on the use of class A -lactamases as versatile scaffolds to design hybrid enzymes
(referred to as -lactamase hybrid proteins, BHPs) in which an exogenous peptide, protein or fragment thereof is inserted at
various permissive positions.We discuss how BHPs can be specifically designed to create bifunctional proteins, to produce and to
characterize proteins that are otherwise difficult to express, to determine the epitope of specific antibodies, to generate antibodies
against nonimmunogenic epitopes, and to better understand the structure/function relationship of proteins.Peer reviewe
Aromatic oligoamide foldamers as versatile scaffolds for induced circularly polarized luminescence at adjustable wavelengths
International audienceQuinoline oligoamide foldamers appended with non-chiral fluorophores and derivatized with a camphanyl chiral inducer display strong chiroptical properties at tunable wavelengths as proved by CD and CPL spectroscopies. Induced CPL activity with high luminescence dissymmetry factors was observed in the visible range at wavelengths specific to the fluorophores
Introduced Drosophila subobscura populations perform better than native populations during an oviposition choice task due to increased fecundity but similar learning ability
The success of invasive species is tightly linked to their fitness in a putatively novel environment. While quantitative components of fitness have been studied extensively in the context of invasive species, fewer studies have looked at quali- tative components of fitness, such as behavioral plasticity, and their interaction with quantitative components, despite intuitive benefits over the course of an invasion. In particular, learning is a form of behavioral plasticity that makes it possible to finely tune behavior according to environmental conditions. Learn- ing can be crucial for survival and reproduction of introduced organisms in novel areas, for example, for detecting new predators, or finding mates or oviposition sites. Here we explored how oviposition performance evolved in relation to both fecundity and learning during an invasion, using native and introduced Drosophila subobscura populations performing an ecologically rele- vant task. Our results indicated that, under comparable conditions, invasive populations performed better during our oviposition task than did native pop- ulations. This was because invasive populations had higher fecundity, together with similar cognitive performance when compared to native populations, and that there was no interaction between learning and fecundity. Unexpectedly, our study did not reveal an allocation trade-off (i.e., a negative relationship) between learning and fecundity. On the contrary, the pattern we observed was more consistent with an acquisition trade-off, meaning that fecundity could be limited by availability of resources, unlike cognitive ability. This pattern might be the consequence of escaping natural enemies and/or competitors during the introduction. The apparent lack of evolution of learning may indicate that the introduced population did not face novel cognitive challenges in the new environment (i.e., cognitive "pre-adaptation"). Alternatively, the evolution of learning may have been transient and therefore not detected
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
New insights into the genetic etiology of Alzheimerâs disease and related dementias
Characterization of the genetic landscape of Alzheimerâs disease (AD) and related dementias (ADD) provides a unique
opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage
genome-wide association study totaling 111,326 clinically diagnosed/âproxyâ AD cases and 677,663 controls. We found 75 risk
loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau
pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive
of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain
assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from
mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the
lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
Social environment mediates cancer progression in Drosophila
The influence of oncogenic phenomena on the ecology and evolution of animal species is
becoming an important research topic. Similar to hostâpathogen interactions, cancer negatively
affects host fitness, which should lead to the selection of host control mechanisms,
including behavioral traits that best minimize the proliferation of malignant cells. Social
behavior is suggested to influence tumor progression. While the ecological benefits of
sociality in gregarious species are widely acknowledged, only limited data are available on the
role of the social environment on cancer progression. Here, we exposed adult Drosophila, with
colorectal-like tumors, to different social environments. We show how subtle variations in
social structure have dramatic effects on the progression of tumor growth. Finally, we reveal
that flies can discriminate between individuals at different stages of tumor development and
selectively choose their social environment accordingly. Our study demonstrates the reciprocal
links between cancer and social interactions and how sociality may impact health and
fitness in animals and its potential implications for disease ecology.This work was supported by the ANR (Blanc project EVOCAN to F.T. and project DROSONET to F.M. and C.S.), the CNRS (INEE and INSB), Fondation ARC (1555286 to J.M. and F.M.), The French league against Cancer (M27218 to J.M.), IDEEV program (to F.M.), by an International Associated Laboratory Project France/Australia, by the French-Australian Science Innovation Collaboration Program Early Career Fellowship (B.U.), by AndrĂ© Hoffmann (Fondation MAVA), Fyssen Foundation (to F.M. and E.H. D.) and the French Government (fellowship 2015â155 to M.D.)
Gemini multi-conjugate adaptive optics system review II: Commissioning, operation and overall performance
The Gemini Multi-conjugate Adaptive Optics System - GeMS, a facility
instrument mounted on the Gemini South telescope, delivers a uniform, near
diffraction limited images at near infrared wavelengths (0.95 microns- 2.5
microns) over a field of view of 120 arc seconds. GeMS is the first sodium
layer based multi laser guide star adaptive optics system used in astronomy. It
uses five laser guide stars distributed on a 60 arc seconds square
constellation to measure for atmospheric distortions and two deformable mirrors
to compensate for it. In this paper, the second devoted to describe the GeMS
project, we present the commissioning, overall performance and operational
scheme of GeMS. Performance of each sub-system is derived from the
commissioning results. The typical image quality, expressed in full with half
maximum, Strehl ratios and variations over the field delivered by the system
are then described. A discussion of the main contributor to performance
limitation is carried-out. Finally, overheads and future system upgrades are
described.Comment: 20 pages, 11 figures, accepted for publication in MNRA
New Insights into the Genetic Etiology of Alzheimerâs Disease and Related Dementias
Characterization of the genetic landscape of Alzheimerâs disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/âproxyâ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
Common variants in alzheimer's disease and risk stratification by polygenic risk scores
Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE É4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease
Common variants in Alzheimerâs disease and risk stratification by polygenic risk scores
Genetic discoveries of Alzheimerâs disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimerâs disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimerâs disease patients in APOE É4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimerâs disease.Fil: Dalmasso, Maria Carolina. Gobierno de la Provincia de la Pampa. Ministerio Publico. Laboratorio de Genetica Forense.; Argentina. Universitat zu Köln; Alemania. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Confluencia; ArgentinaFil: de Rojas, Itziar. Universitat Internacional de Catalunya; España. Instituto de Salud Carlos Iii (isciii); EspañaFil: Moreno Grau, Sonia. Universitat Internacional de Catalunya; España. Instituto de Salud Carlos Iii (isciii); EspañaFil: Tesi, Niccolo. Vrije Universiteit Amsterdam; PaĂses Bajos. Delft University of Technology; PaĂses BajosFil: Grenier Boley, Benjamin. Universite Lille; FranciaFil: Andrade, Victor. Universitat zu Köln; Alemania. Universitat Bonn; AlemaniaFil: Pedersen, Nancy L.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Stringa, Najada. University of Amsterdam; PaĂses BajosFil: Zettergren, Anna. University of Gothenburg; SueciaFil: HernĂĄndez, Isabel. Universitat Internacional de Catalunya; España. Instituto de Salud Carlos Iii (isciii); EspañaFil: Montrreal, Laura. Universitat Internacional de Catalunya; EspañaFil: AntĂșnez, Carmen. Hospital ClĂnico Universitario Virgen de la Arrixaca; EspañaFil: Antonell, Anna. Universidad de Barcelona; EspañaFil: Tankard, Rick M.. Murdoch University; AustraliaFil: Bis, Joshua C.. University of Washington; Estados UnidosFil: Sims, Rebecca. Cardiff University; Reino UnidoFil: Bellenguez, CĂ©line. Universite Lille; FranciaFil: Quintela, InĂ©s. Universidad de Santiago de Compostela; EspañaFil: GonzĂĄlez Perez, Antonio. Centro Andaluz de Estudios BioinformĂĄticos; EspañaFil: Calero, Miguel. Instituto de Salud Carlos Iii (isciii); España. FundaciĂłn Reina Sofia; EspañaFil: Franco MacĂas, Emilio. Universidad de Sevilla; EspañaFil: MacĂas, Juan. Hospital Universitario de Valme; EspañaFil: Blesa, Rafael. Instituto de Salud Carlos Iii (isciii); España. Universitat AutĂČnoma de Barcelona; EspañaFil: Cervera Carles, Laura. Instituto de Salud Carlos Iii (isciii); España. Universitat AutĂČnoma de Barcelona; EspañaFil: MenĂ©ndez GonzĂĄlez, Manuel. Universidad de Oviedo; EspañaFil: Frank GarcĂa, Ana. Instituto de Salud Carlos Iii (isciii); España. Universidad AutĂłnoma de Madrid; España. Instituto de Investigacion del Hospital de la Paz.; España. Hospital Universitario La Paz; EspañaFil: Royo, Jose LuĂs. Universidad de MĂĄlaga; EspañaFil: Moreno, Fermin. Instituto de Salud Carlos Iii (isciii); España. Hospital Universitario Donostia; España. Instituto Biodonostia; EspañaFil: Huerto Vilas, Raquel. Hospital Universitari Santa Maria de Lleida; España. Institut de Recerca Biomedica de Lleida; EspañaFil: Baquero, Miquel. Hospital Universitari i PolitĂšcnic La Fe; Españ
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