2,116 research outputs found
Affective iconic words benefit from additional soundâmeaning integration in the left amygdala
Recent studies have shown that a similarity between sound and meaning of a word (i.e., iconicity) can help more readily access the meaning of that word, but the neural mechanisms underlying this beneficial role of iconicity in semantic processing remain largely unknown. In an fMRI study, we focused on the affective domain and examined whether affective iconic words (e.g., high arousal in both sound and meaning) activate additional brain regions that integrate emotional information from different domains (i.e., sound and meaning). In line with our hypothesis, affective iconic words, compared to their nonâiconic counterparts, elicited additional BOLD responses in the left amygdala known for its role in multimodal representation of emotions. Functional connectivity analyses revealed that the observed amygdalar activity was modulated by an interaction of iconic condition and activations in two hubs representative for processing sound (left superior temporal gyrus) and meaning (left inferior frontal gyrus) of words. These results provide a neural explanation for the facilitative role of iconicity in language processing and indicate that language users are sensitive to the interaction between sound and meaning aspect of words, suggesting the existence of iconicity as a general property of human language
Cross-shell excitation in two-proton knockout: Structure of Ca
The two-proton knockout reaction Be(Ti,Ca) has
been studied at 72 MeV/nucleon. Besides the strong feeding of the Ca
ground state, the only other sizeable cross section proceeds to a 3 level
at 3.9 MeV. There is no measurable direct yield to the first excited 2
state at 2.6 MeV. The results illustrate the potential of such direct reactions
for exploring cross-shell proton excitations in neutron-rich nuclei and
confirms the doubly-magic nature of Ca
The role of the g9/2 orbital in the development of collectivity in the A = 60 region: The case of 61Co
An extensive study of the level structure of 61Co has been performed
following the complex 26Mg(48Ca, 2a4npg)61Co reaction at beam energies of 275,
290 and 320 MeV using Gammasphere and the Fragment Mass Analyzer (FMA). The
low-spin structure is discussed within the framework of shell-model
calculations using the GXPF1A effective interaction. Two quasi-rotational bands
consisting of stretched-E2 transitions have been established up to spins I =
41/2 and (43/2), and excitation energies of 17 and 20 MeV, respectively. These
are interpreted as signature partners built on a neutron {\nu}(g9/2)2
configuration coupled to a proton {\pi}p3/2 state, based on Cranked Shell Model
(CSM) calculations and comparisons with observations in neighboring nuclei. In
addition, four I = 1 bands were populated to high spin, with the yrast dipole
band interpreted as a possible candidate for the shears mechanism, a process
seldom observed thus far in this mass region
Water maser detections in southern candidates to post-AGB stars and Planetary Nebulae
We intended to study the incidence and characteristics of water masers in the
envelopes of stars in the post-AGB and PN evolutionary stages.
We have used the 64-m antenna in Parkes (Australia) to search for water maser
emission at 22 GHz, towards a sample of 74 sources with IRAS colours
characteristic of post-AGB stars and PNe, at declination . In our
sample, 39% of the sources are PNe or PNe candidates, and 50% are post-AGB
stars or post-AGB candidates.
We have detected four new water masers, all of them in optically obscured
sources: three in PNe candidates (IRAS 12405-6219, IRAS 15103-5754, and IRAS
16333-4807); and one in a post-AGB candidate (IRAS 13500-6106). The PN
candidate IRAS 15103-5754 has water fountain characteristics, and it could be
the first PN of this class found.
We confirm the tendency suggested in Paper I that the presence of water
masers in the post-AGB phase is favoured in obscured sources with massive
envelopes. We propose an evolutionary scenario for water masers in the post-AGB
and PNe stages, in which ``water fountain'' masers could develop during
post-AGB and early PN stages. Later PNe would show lower velocity maser
emission, both along jets and close to the central objects, with only the
central masers remaining in more evolved PNe.Comment: 11 pages, 5 figures. Accepted by Astronomy and Astrophysic
Non-linear electromagnetic response of graphene
It is shown that the massless energy spectrum of electrons and holes in
graphene leads to the strongly non-linear electromagnetic response of this
system. We predict that the graphene layer, irradiated by electromagnetic
waves, emits radiation at higher frequency harmonics and can work as a
frequency multiplier. The operating frequency of the graphene frequency
multiplier can lie in a broad range from microwaves to the infrared.Comment: 5 pages, 3 figure
Cerebral effects of glucagonâlike peptideâ1 receptor blockade before and after RouxâenâY gastric bypass surgery in obese women: A proofâofâconcept restingâstate functional MRI study
Aim:
To assess the effects of RouxâenâY gastric bypass surgery (RYGB)ârelated changes in glucagonâlike peptideâ1 (GLPâ1) on cerebral restingâstate functioning in obese women.
Materials and Methods:
In nine obese females aged 40â54âyears in the fasted state, we studied the effects of RYGB and GLPâ1 on five a priori selected networks implicated in foodâ and rewardârelated processes as well as environment monitoring (default mode, right frontoparietal, basal ganglia, insula/anterior cingulate and anterior cingulate/orbitofrontal networks).
Results:
Before surgery, GLPâ1 receptor blockade (using exendin9â39) was associated with increased right caudate nucleus (basal ganglia network) and decreased right middle frontal (right frontoparietal network) connectivity compared with placebo. RYGB resulted in decreased right orbitofrontal (insula/anterior cingulate network) connectivity. In the default mode network, after surgery, GLPâ1 receptor blockade had a larger effect on connectivity in this region than GLPâ1 receptor blockade before RYGB (all PFWEâ<â.05). Results remained similar after correction for changes in body weight. Default mode and right frontoparietal network connectivity changes were related to changes in body mass index and food scores after RYGB.
Conclusions:
These findings suggest GLPâ1 involvement in restingâstate networks related to food and reward processes and monitoring of the internal and external environment, pointing to a potential role for GLPâ1âinduced changes in restingâstate connectivity in RYGBâmediated weight loss and appetite control
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
New neighbours: V. 35 DENIS late-M dwarfs between 10 and 30 parsecs
This paper reports updated results on our systematic mining of the DENIS
database for nearby very cool M-dwarfs (M6V-M8V, 2.0<I-J<3.0, photometric
distance within 30 pc), We calibrate the DENIS (M_I, I-J) colour-luminosity
relationship from M dwarfs with well measured parallaxes (HIP, GCTP,...),
obtaining distance errors for single dwarfs of 25%. Using proper motions
measured on archive Schmidt plates for stars that meet the photometric
selection criteria, we eliminate the giants by a Reduced Proper Motion cutoff,
which is significantly more selective than a simple proper motion cutoff.
Here we present new data for 62 red dwarf candidates selected over 5700
square degrees in the DENIS database. 26 of those originate in the 2100 square
degrees analysed in Paper I, with improved parameters here, and 36 were found
in 3600 additional square degrees. 25 of those are new nearby dwarfs. We
determine from that sample of 62 stars a stellar density for 12.0<M_I<14.0 of
2.2(+-0.4)E-3 stars/pc^3/mag. This value is consistent with photometric
luminosity functions measured from deeper and smaller-field observations, but
not with the nearby star luminosity function. In addition we cross-identified
the NLTT and DENIS catalogues to find 15 similar stars, in parts of the sky not
yet covered by the colour-selected search.Comment: Accepted by Astronomy & astrophysics. 17 pages, 8 figure
Circulating endothelial cell-derived extracellular vesicles mediate the acute phase response and sickness behaviour associated with CNS inflammation.
Brain injury elicits a systemic acute-phase response (APR), which is responsible for co-ordinating the peripheral immunological response to injury. To date, the mechanisms responsible for signalling the presence of injury or disease to selectively activate responses in distant organs were unclear. Circulating endogenous extracellular vesicles (EVs) are increased after brain injury and have the potential to carry targeted injury signals around the body. Here, we examined the potential of EVs, isolated from rats after focal inflammatory brain lesions using IL-1ÎČ, to activate a systemic APR in recipient naĂŻve rats, as well as the behavioural consequences of EV transfer. Focal brain lesions increased EV release, and, following isolation and transfer, the EVs were sequestered by the liver where they initiated an APR. Transfer of blood-borne EVs from brain-injured animals was also enough to suppress exploratory behaviours in recipient naĂŻve animals. EVs derived from brain endothelial cell cultures treated with IL-1ÎČ also activated an APR and altered behaviour in recipient animals. These experiments reveal that inflammation-induced circulating EVs derived from endothelial cells are able to initiate the APR to brain injury and are sufficient to generate the associated sickness behaviours, and are the first demonstration that EVs are capable of modifying behavioural responses
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