3,874 research outputs found
A novel application method for wearable bend sensors
Bend sensors fundamental characteristic is to furnish an electrical resistance value related to the angle they are bent. This feature can be successfully exploited to realize wearable systems capable to measure human static and dynamic postures. In particular some efforts have been made to determine finger joint movements of human hands and it has been demonstrated the feasibility of using the so called data glove system as a goniometric device. The repeatability of such system is quite good for general purposes but it is still not sufficient for specific applications (for instance in virtual surgery). So here we introduce a novel application method of bend sensors and demonstrate how it can be useful to improve the system repeatabilit
Limited genomic divergence between intraspecific forms of Culex pipiens under different ecological pressures
Abstract
Background: Divergent selection can be a major driver of ecological speciation. In insects of medical importance,
understanding the speciation process is both of academic interest and public health importance. In the West Nile
virus vector Culex pipiens, intraspecific pipiens and molestus forms vary in ecological and physiological traits.
Populations of each form appear to share recent common ancestry but patterns of genetic differentiation across
the genome remain unknown. Here, we undertook an AFLP genome scan on samples collected from both
sympatric and allopatric populations from Europe and the USA to quantify the extent of genomic differentiation
between the two forms.
Results: The forms were clearly differentiated but each exhibited major population sub-structuring between
continents. Divergence between pipiens and molestus forms from USA was higher than in both inter- and
intra-continental comparisons with European samples. The proportion of outlier loci between pipiens and molestus
(≈3 %) was low but consistent in both continents, and similar to those observed between sibling species of other
mosquito species which exhibit contemporary gene flow. Only two of the outlier loci were shared between
inter-form comparisons made within Europe and USA.
Conclusion: This study supports the molestus and pipiens status as distinct evolutionary entities with low genomic
divergence. The low number of shared divergent loci between continents suggests a relatively limited number of
genomic regions determining key typological traits likely to be driving incipient speciation and/or adaptation of
molestus to anthropogenic habitats
Soil-induced impacts on forest structure drive coarse woody debris stocks across central Amazonia
PublishedJournal Article© 2014, © 2014 Botanical Society of Scotland and Taylor & Francis. Background: Coarse woody debris (CWD) is an essential component in tropical forest ecosystems and its quantity varies widely with forest types. Aims: Relationships among CWD, soil, forest structure and other environmental factors were analysed to understand the drivers of variation in CWD in forests on different soil types across central Amazonia. Methods: To estimate CWD stocks and density of dead wood debris, 75 permanent forest plots of 0.5 ha in size were assessed along a transect that spanned ca. 700 km in undisturbed forests from north of the Rio Negro to south of the Rio Amazonas. Soil physical properties were evaluated by digging 2-m-deep pits and by taking auger samples. Results: Soil physical properties were the best predictors of CWD stocks; 37% of its variation was explained by effective soil depth. CWD stocks had a two-fold variation across a gradient of physical soil constraints (i.e. effective soil depth, anoxia and soil structure). Average biomass per tree was related to physical soil constraints, which, in turn, had a strong relationship with local CWD stocks. Conclusions: Soil physical properties appear to control average biomass per tree (and through this affect forest structure and dynamics), which, in turn, is correlated with CWD production and stocks
Impaired perceptual learning in a mouse model of Fragile X syndrome is mediated by parvalbumin neuron dysfunction and is reversible.
To uncover the circuit-level alterations that underlie atypical sensory processing associated with autism, we adopted a symptom-to-circuit approach in the Fmr1-knockout (Fmr1-/-) mouse model of Fragile X syndrome. Using a go/no-go task and in vivo two-photon calcium imaging, we find that impaired visual discrimination in Fmr1-/- mice correlates with marked deficits in orientation tuning of principal neurons and with a decrease in the activity of parvalbumin interneurons in primary visual cortex. Restoring visually evoked activity in parvalbumin cells in Fmr1-/- mice with a chemogenetic strategy using designer receptors exclusively activated by designer drugs was sufficient to rescue their behavioral performance. Strikingly, human subjects with Fragile X syndrome exhibit impairments in visual discrimination similar to those in Fmr1-/- mice. These results suggest that manipulating inhibition may help sensory processing in Fragile X syndrome
Analysis of symmetries in models of multi-strain infections
In mathematical studies of the dynamics of multi-strain diseases caused by antigenically diverse pathogens, there is a substantial interest in analytical insights. Using the example of a generic model of multi-strain diseases with cross-immunity between strains, we show that a significant understanding of the stability of steady states and possible dynamical behaviours can be achieved when the symmetry of interactions between strains is taken into account. Techniques of equivariant bifurcation theory allow one to identify the type of possible symmetry-breaking Hopf bifurcation, as well as to classify different periodic solutions in terms of their spatial and temporal symmetries. The approach is also illustrated on other models of multi-strain diseases, where the same methodology provides a systematic understanding of bifurcation scenarios and periodic behaviours. The results of the analysis are quite generic, and have wider implications for understanding the dynamics of a large class of models of multi-strain diseases
Formyl Peptide Receptor as a Novel Therapeutic Target for Anxiety-Related Disorders
Formyl peptide receptors (FPR) belong to a family of sensors of the immune system that detect microbe-associated molecules and inform various cellular and sensorial mechanisms to the presence of pathogens in the host. Here we demonstrate that Fpr2/3-deficient mice show a distinct profile of behaviour characterised by reduced anxiety in the marble burying and light-dark box paradigms, increased exploratory behaviour in an open-field, together with superior performance on a novel object recognition test. Pharmacological blockade with a formyl peptide receptor antagonist, Boc2, in wild type mice reproduced most of the behavioural changes observed in the Fpr2/3(-/-) mice, including a significant improvement in novel object discrimination and reduced anxiety in a light/dark shuttle test. These effects were associated with reduced FPR signalling in the gut as shown by the significant reduction in the levels of p-p38. Collectively, these findings suggest that homeostatic FPR signalling exerts a modulatory effect on anxiety-like behaviours. These findings thus suggest that therapies targeting FPRs may be a novel approach to ameliorate behavioural abnormalities present in neuropsychiatric disorders at the cognitive-emotional interface
Cell genesis and dendritic plasticity: a neuroplastic pas de deux in the onset and remission from depression
Brain neuroplasticity is increasingly considered to be an important component of both the pathology and treatment of depressive spectrum disorders. Recent studies shed light on the relevance of hippocampal cell genesis and cortico-limbic dendritic plasticity for the development and remission from depressive-like behavior. However, the neurobiological significance of neuroplastic phenomena in this context is still controversial. Here we summarize recent developments in this topic and propose an integrative interpretation of data gathered so far
The extracellular small leucine-rich proteoglycan biglycan is a key player in gastric cancer aggressiveness
Biglycan (BGN gene), an extracellular proteoglycan, has been described to be associated with cancer aggressiveness. The purpose of this study was to clarify the clinical value of biglycan as a biomarker in multiple independent GC cohorts and determine the in vitro and in vivo role of biglycan in GC malignant features. We found that BGN is commonly over-expressed in all analyzed cohorts, being associated with disease relapse and poor prognosis in patients with advanced stages of disease. In vitro and in vivo experiments demonstrated that biglycan knock-out GC cells display major phenotypic changes with a lower cell survival, migration, and angiogenic potential when compared with biglycan expressing cells. Biglycan KO GC cells present increased levels of PARP1 and caspase-3 cleavage and a decreased expression of mesenchymal markers. Importantly, biglycan deficient GC cells that were supplemented with exogenous biglycan were able to restore biological features, such as survival, clonogenic and migratory capacities. Our in vitro and in vivo findings were validated in human GC samples, where BGN expression was associated with several oncogenic gene signatures that were associated with apoptosis, cell migration, invasion, and angiogenesis. This study provided new insights on biglycan role in GC that should be taken in consideration as a key cellular regulator with major impact in tumor progression and patients’ clinical outcome.This work was funded by FEDER funds through the Operational Programme for Competitiveness Factors-COMPETE (POCI-01-0145-FEDER-016585; POCI-01-0145-FEDER-029780; POCI-01-0145-FEDER-007274; POCI-01-0145-FEDER-029780) and National Funds through the Foundation for Science and Technology (FCT), under the projects: PTDC/BBB-EBI/0567/2014 (to C.A.R.), PTDC/MED-QUI/29780/2017 (to CG), and UID/BIM/04293 supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). F.P. was funded by FCT cofinanced by Fundo Social Europeu-FSE with a grant with reference: SFRH/BPD/115730/2016
Exogenous WNT5A and WNT11 proteins rescue CITED2 dysfunction in mouse embryonic stem cells and zebrafish morphants
Mutations and inadequate methylation profiles of CITED2 are associated with human congenital heart disease (CHD). In mouse, Cited2 is necessary for embryogenesis, particularly for heart development, and its depletion in embryonic stem cells (ESC) impairs cardiac differentiation. We have now determined that Cited2 depletion in ESC affects the expression of transcription factors and cardiopoietic genes involved in early mesoderm and cardiac specification. Interestingly, the supplementation of the secretome prepared from ESC overexpressing CITED2, during the onset of differentiation, rescued the cardiogenic defects of Cited2-depleted ESC. In addition, we demonstrate that the proteins WNT5A and WNT11 held the potential for rescue. We also validated the zebrafish as a model to investigate cited2 function during development. Indeed, the microinjection of morpholinos targeting cited2 transcripts caused developmental defects recapitulating those of mice knockout models, including the increased propensity for cardiac defects and severe death rate. Importantly, the co-injection of anti-cited2 morpholinos with either CITED2 or WNT5A and WNT11 recombinant proteins corrected the developmental defects of Cited2-morphants. This study argues that defects caused by the dysfunction of Cited2 at early stages of development, including heart anomalies, may be remediable by supplementation of exogenous molecules, offering the opportunity to develop novel therapeutic strategies aiming to prevent CHD.Agência financiadora:
Fundação para a Ciência e a Tecnologia (FCT)
Comissão de Coordenação e Desenvolvimento Regional do Algarve (CCDR Algarve)
ALG-01-0145-FEDER-28044; DFG 568/17-2 Algarve Biomedical Center (ABC)
Municipio de Louléinfo:eu-repo/semantics/publishedVersio
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
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