42 research outputs found
Detection of growth-related QTLs in turbot (Scophtalmus maximux)
Background The turbot (Scophthalmus maximus) is a highly appreciated European aquaculture species. Growth related traits constitute the main goal of the ongoing genetic breeding programs of this species. The recent construction of a consensus linkage map in this species has allowed the selection of a panel of 100 homogeneously distributed markers covering the 26 linkage groups (LG) suitable for QTL search. In this study we addressed the detection of QTL with effect on body weight, length and Fulton's condition factor.
Results Eight families from two genetic breeding programs comprising 814 individuals were used to search for growth related QTL using the panel of microsatellites available for QTL screening. Two different approaches, maximum likelihood and regression interval mapping, were used in order to search for QTL. Up to eleven significant QTL were detected with both methods in at least one family: four for weight on LGs 5, 14, 15 and 16; five for length on LGs 5, 6, 12, 14 and 15; and two for Fulton's condition factor on LGs 3 and 16. In these LGs an association analysis was performed to ascertain the microsatellite marker with the highest apparent effect on the trait, in order to test the possibility of using them for marker assisted selection.
Conclusions The use of regression interval mapping and maximum likelihood methods for QTL detection provided consistent results in many cases, although the high variation observed for traits mean among families made it difficult to evaluate QTL effects. Finer mapping of detected QTL, looking for tightly linked markers to the causative mutation, and comparative genomics are suggested to deepen in the analysis of QTL in turbot so they can be applied in marker assisted selection programs
Automated calibration of FEM models using LiDAR point clouds
In present work it is pretended to estimate elastic parameters of beams through the combined use of precision geomatic techniques (laser scanning) and structural behaviour simulation tools. The study has two aims, on the one hand, to develop an algorithm able to interpret automatically point clouds acquired by laser scanning systems of beams subjected to different load situations on experimental tests; and on the other hand, to minimize differences between deformation values given by simulation tools and those measured by laser scanning. In this way we will proceed to identify elastic parameters and boundary conditions of structural element so that surface stresses can be estimated more easily.Ministerio de Interior | Ref. SPIP2017-02122Ministerio de EconomĂa, Industria y Competitividad | Ref. EUIN2017- 87598Ministerio de EducaciĂłn, Cultura y Deporte | Ref. CAS15/00126Xunta de Galicia | Ref. ED431C2016â03
Validation of the neuroconnective endophenotype questionnaire (NEQ): a new clinical tool for medicine and psychiatry resulting from the contribution of EhlersâDanlos syndrome
IntroductionThe link between anxiety disorders and joint hypermobility syndrome (now under hypermobility spectrum disorders, which include hypermobile EhlersâDanlos syndrome) has been widely replicated over the past 30 years and has grown beyond the initial nosological limits. To integrate clinical and research progress in this field, a new neuroconnective endophenotype (NE) and its corresponding instrument, the Neuroconnective Endophenotype Questionnaire (NEQ), have been developed. This new clinical construct, created with the active participation of patients, includes both somatic and psychological dimensions and symptoms and resilience items.MethodsThe NE includes five dimensions: (1) sensorial sensitivity, (2) body signs and symptoms, (3) somatic conditions, (4) polar behavioral strategies, and (5) psychological and psychopathological dimensions. The NEQ information is collected through four self-administered questionnaires (sensorial sensitivity, body signs and symptoms, polar behavioral strategies, and psychological characteristics) and a structured diagnostic part that should be completed by a trained observer. This hetero-administered part incorporates (a) psychiatric diagnoses (using structured criteria, e.g., MINI), (b) somatic disorders diagnosis, using structured criteria, and (c) assessment of joint hypermobility criteria.ResultsIn a sample of 36 anxiety cases with 36 matched controls, the NEQ obtained high scores for testâretest, inter-rater reliability, and internal consistency. As for predictive validity, cases and controls significantly differed in all five dimensions and hypermobility measurements.DiscussionWe can conclude that the NEQ has achieved acceptable reliability and validity values and, therefore, is ready to be used and tested in different samples. This original and consistent construct including somatic and mental items may improve clinical specificity, the search for more comprehensive therapies, and their genetic and neuroimaging bases
Lipid vesicles trigger α-synuclein aggregation by stimulating primary nucleation.
α-Synuclein (α-syn) is a 140-residue intrinsically disordered protein that is involved in neuronal and synaptic vesicle plasticity, but its aggregation to form amyloid fibrils is the hallmark of Parkinson's disease (PD). The interaction between α-syn and lipid surfaces is believed to be a key feature for mediation of its normal function, but under other circumstances it is able to modulate amyloid fibril formation. Using a combination of experimental and theoretical approaches, we identify the mechanism through which facile aggregation of α-syn is induced under conditions where it binds a lipid bilayer, and we show that the rate of primary nucleation can be enhanced by three orders of magnitude or more under such conditions. These results reveal the key role that membrane interactions can have in triggering conversion of α-syn from its soluble state to the aggregated state that is associated with neurodegeneration and to its associated disease states.This work was supported by the UK BBSRC and the Wellcome Trust (CMD, TPJK, MV), the
Frances and Augustus Newman Foundation (TPJK), Magdalene College, Cambridge (AKB) , St Johnâs College,
Cambridge (TCTM), the Cambridge Home and EU Scholarship Scheme (GM), Elan Pharmaceuticals
(CMD, TPJK, MV, CG) and the Leverhulme Trust (AKB).This is the accepted manuscript. The final version is available from NPG at http://www.nature.com/nchembio/journal/v11/n3/abs/nchembio.1750.htm
Confocal Raman thermometer for microfluidic devices
A confocal Raman microscopy technique has been designed and demonstrated that measures the temperature rise and profile in microfluidic devices. The system is based in the deformation of the water Raman peak assigned to the O-H stretching at 3400 cmâ1 that occurs with temperature keeping an isosbectic point at 3425 cmâ1 . Hence two photon counting detectors that sample the Raman emission at each side of the isosbectic point are used to monitor the water temperature. Using a confocal detection scheme the spatial resolution of a confocal microscope can be obtained to map the temperature profile within small microfluidic structure in a noninvasive manner. The differential signal between the two channels normalized by the added signals has a linear dependence with temperature that yields a sensitivity of 0.8 K using a 1s integration time and a count rate per channel of 1.5 · 105 . The pump laser used had a 405 nm wavelength and 20 mW average power. The confocal collection was performed by a single mode optical fiber and the explored volume was of about 40 ÎŒm3 . The temperature rise in electrotrofluidic devices was studied showing that the temperature increase depended on the power used to move the sample along the channel (electroosmotic flow) and the particular design and structure of the device that determines the heat dissipation mechanism. The scheme proved useful to evaluate and prevent detrimental temperature effects with the advantage that no specific temperature sensitive particle needs to be added to the fluid, and has the additional virtue of allowing spatial scans in 3D.Fil: Brinatti Vazquez, Guillermo Daniel. Universidad de Buenos Aires. Facultad de IngenierĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Martinez, Oscar Eduardo. Universidad de Buenos Aires. Facultad de IngenierĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Cabaleiro, Juan Martin. Universidad de Buenos Aires. Facultad de IngenierĂa; Argentina. Universidad de la Marina Mercante; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaSPIE Photonics West BiOSSan FranciscoEstados UnidosSPI
Biochemistry shapes growth kinetics of nitrifiers and defines their activity under specific environmental conditions
Is it possible to find trends between the parameters that define microbial growth to help us explain the vast microbial diversity? Through an extensive database of kinetic parameters of nitrifiers, we analysed if the dominance of specific populations of nitrifiers could be predicted and explained. We concluded that, in general, higher growth yield (YXS) and ammonia affinity (a0 NH3) and lower growth rate (”max) are observed for ammonia-oxidising archaea (AOA) than bacteria (AOB), which would explain their considered dominance in oligotrophic environments. However, comammox (CMX), with the maximum energy harvest per mole of ammonia, and some AOB, have higher a0 NH3 and lower ”max than some AOA. Although we were able to correlate the presence of specific terminal oxidases with observed oxygen affinities (a0 O2) for nitrite-oxidising bacteria (NOB), that correlation was not observed for AOB. Moreover, the presumed dominance of AOB over NOB in O2-limiting environments is discussed. Additionally, lower statistical variance of a0 O2 values than for ammonia and nitrite affinities was observed, suggesting nitrogen limitation as a stronger selective pressure. Overall, specific growth strategies within nitrifying groups were not identified through the reported kinetic parameters, which might suggest that mostly, fundamental differences in biochemistry are responsible for underlying kinetic parameters
Multiscale models driving hypothesis and theory-based research in microbial ecology
Hypothesis and theory-based studies in microbial ecology have been neglected in favour of those that are descriptive and aim for data-gathering of uncultured microbial species. This tendency limits our capacity to create new mechanistic explanations of microbial community dynamics, hampering the improvement of current environmental biotechnologies. We propose that a multiscale modelling bottom-up approach (piecing together sub-systems to give rise to more complex systems) can be used as a framework to generate mechanistic hypotheses and theories (in-silico bottom-up methodology). To accomplish this, formal comprehension of the mathematical model design is required together with a systematic procedure for the application of the in-silico bottom-up methodology. Ruling out the belief that experimentation before modelling is indispensable, we propose that mathematical modelling can be used as a tool to direct experimentation by validating theoretical principles of microbial ecology. Our goal is to develop methodologies that effectively integrate experimentation and modelling efforts to achieve superior levels of predictive capacity. BT/Environmental Biotechnolog
A framework based on fundamental biochemical principles to engineer microbial community dynamics
Microbial communities are complex but there are basic principles we can apply to constrain the assumed stochasticity of their activity. By understanding the trade-offs behind the kinetic parameters that define microbial growth, we can explain how local interspecies dependencies arise and shape the emerging properties of a community. If we integrate these theoretical descriptions with experimental âomicsâ data and bioenergetics analysis of specific environmental conditions, predictions on activity, assembly and spatial structure can be obtained reducing the a priori unpredictable complexity of microbial communities. This information can be used to define the appropriate selective pressures to engineer bioprocesses and propose new hypotheses which can drive experimental research to accelerate innovation in biotechnology
Validation of the neuroconnective endophenotype questionnaire (NEQ): a new clinical tool for medicine and psychiatry resulting from the contribution of EhlersâDanlos syndrome
International audienceIntroduction: The link between anxiety disorders and joint hypermobility syndrome (now under hypermobility spectrum disorders, which include hypermobile Ehlers-Danlos syndrome) has been widely replicated over the past 30 years and has grown beyond the initial nosological limits. To integrate clinical and research progress in this field, a new neuroconnective endophenotype (NE) and its corresponding instrument, the Neuroconnective Endophenotype Questionnaire (NEQ), have been developed. This new clinical construct, created with the active participation of patients, includes both somatic and psychological dimensions and symptoms and resilience items.Methods: The NE includes five dimensions: (1) sensorial sensitivity, (2) body signs and symptoms, (3) somatic conditions, (4) polar behavioral strategies, and (5) psychological and psychopathological dimensions. The NEQ information is collected through four self-administered questionnaires (sensorial sensitivity, body signs and symptoms, polar behavioral strategies, and psychological characteristics) and a structured diagnostic part that should be completed by a trained observer. This hetero-administered part incorporates (a) psychiatric diagnoses (using structured criteria, e.g., MINI), (b) somatic disorders diagnosis, using structured criteria, and (c) assessment of joint hypermobility criteria.Results: In a sample of 36 anxiety cases with 36 matched controls, the NEQ obtained high scores for test-retest, inter-rater reliability, and internal consistency. As for predictive validity, cases and controls significantly differed in all five dimensions and hypermobility measurements.Discussion: We can conclude that the NEQ has achieved acceptable reliability and validity values and, therefore, is ready to be used and tested in different samples. This original and consistent construct including somatic and mental items may improve clinical specificity, the search for more comprehensive therapies, and their genetic and neuroimaging bases
Environmental and ecological controls of the spatial distribution of microbial populations in aggregates
In microbial communities, the ecological interactions between species of different populations are responsible for the spatial distributions observed in aggregates (granules, biofilms or flocs). To explore the underlying mechanisms that control these processes, we have developed a mathematical modelling framework able to describe, label and quantify defined spatial structures that arise from microbial and environmental interactions in communities. An artificial system of three populations collaborating or competing in an aggregate is simulated using individual-based modelling under different environmental conditions. In this study, neutralism, competition, commensalism and concurrence of commensalism and competition have been considered. We were able to identify interspecific segregation of communities that appears in competitive environments (columned stratification), and a layered distribution of populations that emerges in commensal (layered stratification). When different ecological interactions were considered in the same aggregate, the resultant spatial distribution was identified as the one controlled by the most limiting substrate. A theoretical modulus was defined, with which we were able to quantify the effect of environmental conditions and ecological interactions to predict the most probable spatial distribution. The specific microbial patterns observed in our results allowed us to identify the optimal spatial organizations for bacteria to thrive when building a microbial community and how this permitted co-existence of populations at different growth rates. Our model reveals that although ecological relationships between different species dictate the distribution of bacteria, the environment controls the final spatial distribution of the community.BT/Environmental Biotechnolog