1,749 research outputs found
Dual mechanism of TRKB activation by anandamide through CB1 and TRPV1 receptors
Background. Administration of anandamide (AEA) or 2-arachidonoylglycerol (2AG) induces CB1 coupling and activation of TRKB receptors, regulating the neuronal migration and maturation in the developing cortex. However, at higher concentrations AEA also engages vanilloid receptor TRPV1, usually with opposed consequences on behavior. Methods and Results. Using primary cell cultures from the cortex of rat embryos (E18) we determined the effects of AEA on phosphorylated TRKB (pTRK). We observed that AEA (at 100 and 200 nM) induced a significant increase in pTRK levels. Such effect of AEA at 100 nM was blocked by pretreatment with the CBI antagonist AM251 (200 nM) and, at the higher concentration of 200 nM by the TRPV1 antagonist capsazepine (200 nM), but mildly attenuated by AM251. Interestingly, the effect of AEA or capsaicin (a TRPV1 agonist, also at 200 nM) on pTRK was blocked by TRKB.Fc (a soluble form of TRKB able to bind BDNF) or capsazepine, suggesting a mechanism dependent on BDNF release. Using the marble-burying test (MBT) in mice, we observed that the local administration of ACEA (a CBI agonist) into the prelimbic region of prefrontal cortex (PL-PFC) was sufficient to reduce the burying behavior, while capsaicin or BDNF exerted the opposite effect, increasing the number of buried marbles. In addition, both ACEA and capsaicin effects were blocked by previous administration of k252a (an antagonist of TRK receptors) into PL-PFC. The effect of systemically injected CB1 agonist WIN55,212-2 was blocked by previous administration of k252a. We also observed a partial colocalization of CBI /TRPV1 /TRKB in the PL-PFC, and the localization of TRPV1 in CaMK2+ cells. Conclusion. Taken together, our data indicate that anandamide engages a coordinated activation of TRKB, via CB1 and TRPV1. Thus, acting upon CBI. and TRPV1, AEA could regulate the TRKB-dependent plasticity in both pre- and postsynaptic compartments.Peer reviewe
Role of 5-HT1A and 5-HT2C receptors of the dorsal periaqueductal gray in the anxiety- and panic-modulating effects of antidepressants in rats
Antidepressant drugs are first-line treatment for panic disorder. Facilitation of 5-HT1A receptor-mediated neurotransmission in the dorsal periaqueductal gray (dPAG), a key panic-associated area, has been implicated in the panicolytic effect of the selective serotonin reuptake inhibitor fluoxetine. However, it is still unknown whether this mechanism accounts for the antipanic effect of other classes of antidepressants drugs (ADs) and whether the 5-HT interaction with 5-HT2C receptors in this midbrain area (which increases anxiety) is implicated in the anxiogenic effect caused by short-term treatment with ADs. The results showed that previous injection of the 5-HT1A receptor antagonist WAY-100635 in the dPAG blocked the panicolytic-like effect caused by chronic systemic administration of the tricyclic AD imipramine in male Wistar rats tested in the elevated T-maze. Neither chronic treatment with imipramine nor fluoxetine changed the expression of 5-HT1A receptors in the dPAG. Treatment with these ADs also failed to significantly change ERK1/2 (extracellular-signal regulated kinase) phosphorylation level in this midbrain area. Blockade of 5-HT2C receptors in the dPAG with the 5-HT2C receptor antagonist SB-242084 did not change the anxiogenic effect caused by a single acute injection of fluoxetine or imipramine in the Vogel conflict test. These results reinforce the view that the facilitation of 5-HT1A receptor mediated neurotransmission in the dPAG is a common mechanism involved in the panicolytic effect caused by chronic administration of ADs. On the other hand, the anxiogenic effect observed after short-term treatment with these drugs does not depend on 5-HT2C receptors located in the dPAG.Peer reviewe
As atitudes dos alunos para com a Matemática: Um estudo em duas turmas do 6.º ano do Ensino Básico
O presente artigo irá incidir sobre um estudo realizado ao longo do ano letivo de 2017/2018,
no âmbito da “Prática de Ensino Supervisionada II” do Mestrado em Ensino do 1.º Ciclo do
Ensino Básico e de Matemática e Ciências Naturais no 2.º Ciclo do Ensino Básico. Este estudo
teve como objetivo conhecer as atitudes dos alunos de uma turma do 6.º ano do ensino
básico para com a Matemática antes e após o período de intervenção, de modo a compará-las
e a compreender que aspetos da prática interventiva podem ter influenciado eventuais
mudanças de atitude. Para tal, optou-se por uma metodologia quantitativa e, como método de
recolha de dados, foram aplicados questionários, com itens fechados e abertos, antes e após o período de intervenção, assim como foram realizadas entrevistas aos alunos que mais
diferenças mostraram entre estes dois períodos. Embora não se tenha verificado uma
diferença significativa nas atitudes dos alunos para com a disciplina, em termos gerais o grupo
evoluiu no que diz respeito a este domínio. Os resultados, para além de mostrarem que os
alunos se sentem mais apoiados quando estão mais professoras presentes na sala de aula,
também evidenciam que o tipo de atividades que foram desenvolvidas durante o período de
intervenção – atividades exploratórias com recurso a materiais manipuláveis – constitui uma
motivação extra para que os discentes se envolvam no trabalho matemático em sala de aula.Abstract
This article will focus on a study carried out during 2017/2018 academic year, within the
scope of the “Supervised Teaching Practice II” of the Master in Teaching in the 1st Cycle of
Basic Education and Maths and Science in the 2nd Cycle of Basic Education. This study aimed
to know the attitudes of students in a 6th grade class of basic education towards mathematics
before and after the intervention period, in order to compare them and to understand which
aspects of the interventional practice may have influenced possible changes in attitudes. To
this end, a quantitative methodology was chosen and, as a method of data collection,
questionnaires were applied, with closed and open items, before and after the intervention
period, as well as interviews with students that most showed differences between these two
periods. Although there was no significant difference in the students' attitudes towards the
discipline, in general terms the group has evolved with respect to this domain. The results, in
addition to showing that students feel more supported when there are more teachers present
in the classroom, also show that the type of activities that were developed during the
intervention period - exploratory activities using manipulable materials - constitutes extra
motivation for students to get involved in mathematical work in the classroom.Résumé
Cet article se concentrera sur une étude réalisée au cours de l'année académique 2017/2018,
dans le cadre de la «Pratique pédagogique supervisée II» du Master en enseignement du 1er
cycle de l'enseignement de base et des mathématiques et sciences naturelles du 2e Cycle
d'éducation de base. Cette étude visait à connaître les attitudes des élèves d'une classe de
base de 6e année à l'égard des mathématiques avant et après la période d'intervention, afin de
les comparer et de comprendre quels aspects de la pratique interventionnelle ont pu
influencer possibles changements d'attitude. À cette fin, une méthodologie quantitative a été
choisie et, comme méthode de collecte des données, des questionnaires ont été appliqués,
avec des éléments fermés et ouverts, avant et après la période d'intervention, ainsi que des
entretiens avec des étudiants qui ont le plus montré des différences entre cettes deux
périodes. Bien qu'il n'y ait pas de différence significative dans les attitudes des étudiants vis-à vis de la discipline, en général le groupe a évolué par rapport à ce domaine. Les résultats, en
plus de montrer que les élèves se sentent plus soutenus lorsqu'ils sont plus d'enseignants
présents dans la salle de classe, montrent également que le type d'activités développées au
cours de la période d'intervention - activités exploratoires utilisant du matériel manipulable -
constitue également motivation supplémentaire pour les élèves à s'impliquer dans des travaux
mathématiques en classe.info:eu-repo/semantics/publishedVersio
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays
Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of
prime importance in probing new physics. Here 7421 +/- 105 signal events from
the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp
collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A
time-dependent fit to the data yields a value of
phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard
Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201
Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−
The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
Measurement of the mass and lifetime of the baryon
A proton-proton collision data sample, corresponding to an integrated
luminosity of 3 fb collected by LHCb at and 8 TeV, is used
to reconstruct , decays. Using the , decay mode for calibration, the lifetime ratio and absolute
lifetime of the baryon are measured to be \begin{align*}
\frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\
\tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the
uncertainties are statistical, systematic and from the calibration mode (for
only). A measurement is also made of the mass difference,
, and the corresponding mass, which
yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm
MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2.
\end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm
Observation of an Excited Bc+ State
Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date
Observation of associated production of a boson with a meson in the~forward region
A search for associated production of a boson with an open charm meson is
presented using a data sample, corresponding to an integrated luminosity of
of proton--proton collisions at a centre-of-mass energy
of 7\,TeV, collected by the LHCb experiment. %% Seven candidate events for
associated production of a boson with a meson and four candidate
events for a boson with a meson are observed with a combined
significance of 5.1standard deviations. The production cross-sections in the
forward region are measured to be where the first uncertainty is statistical and the
second systematic.Comment: 18 pages, 2 figure
Measurement of the lifetime
Using a data set corresponding to an integrated luminosity of ,
collected by the LHCb experiment in collisions at centre-of-mass energies
of 7 and 8 TeV, the effective lifetime in the
decay mode, , is measured to be ps. Assuming
conservation, corresponds to the lifetime of the light
mass eigenstate. This is the first measurement of the effective
lifetime in this decay mode.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-017.htm
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