237 research outputs found
X-ray flares on the UV Ceti-type star CC Eridani: a "peculiar" time-evolution of spectral parameters
Context: Weak flares are supposed to be an important heating agent of the
outer layers of stellar atmospheres. However, due to instrumental limitations,
only large X-ray flares have been studied in detail until now.
Aims: We used an XMM-Newton observation of the very active BY-Dra type binary
star CC Eri in order to investigate the properties of two flares that are
weaker than those typically studied in the literature.
Methods: We performed time-resolved spectroscopy of the data taken with the
EPIC-PN CCD camera. A multi-temperature model was used to fit the spectra. We
inferred the size of the flaring loops using the density-temperature diagram.
The loop scaling laws were applied for deriving physical parameters of the
flaring plasma. We also estimated the number of loops involved in the observed
flares.
Results: A large X-ray variability was found. Spectral analysis showed that
all the regions in the light curve, including the flare segments, are
well-described by a 3-T model with variable emission measures but,
surprisingly, with constant temperatures (values of 3, 10 and 22 MK). The
analysed flares lasted ~ 3.4 and 7.1 ks, with flux increases of factors
1.5-1.9. They occurred in arcades made of a few tens of similar coronal loops.
The size of the flaring loops is much smaller than the distance between the
stellar surfaces in the binary system, and even smaller than the radius of each
of the stars. The obtained results are consistent with the following ideas: (i)
the whole X-ray light curve of CC Eri could be the result of a superposition of
multiple low-energy flares, and (ii) stellar flares can be scaled-up versions
of solar flares.Comment: 14 pages, 12 figures. Accepted for publication in Astronomy &
Astrophysic
Optical spectroscopy of X-ray sources in the Taurus molecular cloud: discovery of ten new pre-main sequence stars
We have analyzed optical spectra of 25 X-ray sources identified as potential
new members of the Taurus molecular cloud (TMC), in order to confirm their
membership in this SFR. Fifty-seven candidates were previously selected among
the X-ray sources in the XEST survey, having a 2MASS counterpart compatible
with a PMS star based on color-magnitude and color-color diagrams. We obtained
high-resolution optical spectra for 7 of these candidates with the SARG
spectrograph at the TNG telescope, which were used to search for Li absorption
and to measure the Ha line and the radial and rotational velocities; 18
low-resolution optical spectra obtained with DOLORES for other candidate
members were used for spectral classification, for Ha measurements, and to
assess membership together with IR color-color and color-magnitude diagrams and
additional information from the X-ray data. We found that 3 sources show Li
absorption, with equivalent widths of ~500 mA, broad spectral line profiles,
indicating v sin i ~20-40 km/s, radial velocities consistent with those for
known members, and Ha emission. Two of them are classified as new WTTSs, while
the EW (~ -9 Ang) of the Ha line and its broad asymmetric profile clearly
indicate that the third star (XEST-26-062) is a CTTS. Fourteen sources observed
with DOLORES are M-type stars. Fifteen sources show Ha emission; 6 of them have
spectra that indicate surface gravity lower than in MS stars, and their
de-reddened positions in IR color-magnitude diagrams are consistent with their
derived spectral type and with PMS models at the distance of the TMC. The
K-type star XEST-11-078 is confirmed as a new member from the strength of its
Ha emission line. Overall, we confirm membership to the TMC for 10 out of 25
X-ray sources observed in the optical. Three sources remain uncertain.Comment: 15 pages, 7 figures, accepted by Astronomy & Astrophysic
Issues and challenges in the application of Husserlian phenomenology to the Lived Experience of Hate Crime and Its Legal Aftermath
The field of hate crime research addresses the presence, sources and impact of particular types of expressions of prejudice, often perceived as particularly damaging and hurtful forms of interpersonal abuse and violence. Little, if any, credible academic research seeks to vindicate the specific racist, gendered and other vicious prejudices articulated by many perpetrators of hate crime. In turn, this raises the reflexive question of the possibilities of researchers themselves ever being able to adopt a truly "unprejudiced" approach to the presence of such damaging prejudices. Can this goal be realised without a researcher necessarily losing an experientially-grounded understanding of what these meanings, values and purposes have come to mean, and how they are themselves interpretatively re-constituted anew, including within the lived experience of victims, witnesses, police, prosecutors, judges and victim support workers?
A possible philosophically-informed approach to the dilemmas posed by this topic is offered by Husserl's phenomenology. Husserl's perpetually unfinished philosophical methodology strives, with concerted if sometimes tragic reflective rigor, to "suspend," "bracket out" and "neutralise" those core presuppositions constitutive of the research field that typically pre-judge precisely whatever demands to be questioned and explored in a radically non-prejudicial manner. This study critically explores the possibilities, reflective stages and theoretical limitations of a sympathetically reconstructed Husserlian approach to hate crime, itself understood as a would-be qualitative "science of consciousness." It argues that despite its manifest tensions, gaps, ambiguities and internal contradictions, aspects of the Husserlian philosophical approach directed towards the different levels of experienced hate crime still retain the potential to both challenge and advance our understanding of this topic. It is the "instructive" part of "instructive failure" that this article highlights
The Gender Congruency Effect across languages in bilinguals: A meta-analysis
In the study of gender representation and processing in bilinguals, two contrasting perspectives exist: integrated vs. the autonomous (Costa, Kovacic, Fedorenko, & Caramazza, 2003). In the former, cross-linguistic interactions during the selection of grammatical gender values are expected; in the latter, they are not. To address this issue, authors have typically explored the cross-linguistic Gender Congruency Effect (GCE: a facilitation on the naming or translation of second language [L2] nouns when their first language [L1] translations are of the same gender, in comparison to those of a different gender). However, the literature suggests that this effect is sometimes difficult to observe and might vary as a function of variables such as the syntactic structure produced to translate or name the target (bare nouns vs. noun phrases), the phonological gender transparency of both languages (whether or not they have phonological gender cues associated with the ending letter [e.g., “–a” for feminine words and “–o” for masculine words in Romance languages]), the degree of L2 proficiency, and task requirements (naming vs. translation). The aim of the present quantitative meta-analysis is to examine the robustness of the cross-linguistic GCE obtained during language production. It involves 25 experiments from 11 studies. The results support a bilingual gender-integrated view, in that they show a small but significant GC effect regardless of the variables mentioned above.This paper was funded through the state budget with reference IF / 00784/2013 / CP1158 / CT0013. The study has also been partially supported by the FCT and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). Government of Spain—Ministry of Education, Culture and Sports—through the Training program for Academic Staff (Ayudas para la Formación del Profesorado Universitario, FPU grant BOE-B-2017-2646), the research project (reference PSI2015-65116-P) granted by the Spanish Ministry of Economy and Competitiveness, and the grant for research groups (reference ED431B 2019/2020) from the Galician Government, as well as by the FCT (Foundation for Science and Technology, Portugal) through the state budget (reference IF / 00784/2013 / CP1158 / CT0013). Finally, the study has also been partially supported by the FCT and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653
Auditory-Visual Object Recognition Time Suggests Specific Processing for Animal Sounds
cote interne IRCAM: Suied09bNone / NoneNational audienceAuditory-visual object recognition time suggests specific processing for animal sound
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Conversation therapy with people with aphasia and conversation partners using video feedback: a group and case series investigation of changes in interaction
Conversation therapies employing video for feedback and to facilitate outcome measurement are increasingly used with people with post-stroke aphasia and their conversation partners; however the evidence base for change in everyday interaction remains limited. We investigated the effect of Better Conversations with Aphasia (BCA), an intervention that is freely available online at https://extend.ucl.ac.uk/. Eight people with chronic agrammatic aphasia, and their regular conversation partners participated in the tailored 8 week program involving significant video feedback. We explored changes in: (i) conversation facilitators (such as multi-modal turns by people with aphasia); and (ii) conversation barriers (such as use of test questions by conversation partners). The outcome of intervention was evaluated directly by measuring change in video-recorded everyday conversations. The study employed a pre-post design with multiple 5 minute samples of conversation before and after intervention, scored by trained raters blind to the point of data collection. Group level analysis showed no significant increase in conversation facilitators. There was, however, a significant reduction in the number of conversation barriers. The case series data revealed variability in conversation behaviors across occasions for the same dyad and between different dyads. Specifically, post-intervention there was a significant increase in facilitator behaviors for two dyads, a decrease for one and no significant change for five dyads. There was a significant decrease in barrier behaviors for five dyads and no significant change for three dyads. The reduction in barrier behaviors was considerable; on average change from over eight to fewer than three barrier behaviors in 5 minutes of conversation. The pre-post design has the limitation of no comparison group. However, change occurs in targeted conversational behaviors and in people with chronic aphasia and their partners. The findings suggest change can occur after eight therapy sessions and have implications for clinical practice. A reduction in barrier behaviors may be easier to obtain, although the controlled case series results demonstrate a significant increase in conversation facilitators is also possible. The rehabilitation tool is available online and video technology was central to delivering intervention and evaluating change
Neural Correlates of Experience-Induced Deficits in Learned Vocal Communication
Songbirds are one of the few vertebrate groups (including humans) that evolved the ability to learn vocalizations. During song learning, social interactions with adult models are crucial and young songbirds raised without direct contacts with adults typically produce abnormal songs showing phonological and syntactical deficits. This raises the question of what functional representation of their vocalizations such deprived animals develop. Here we show that young starlings that we raised without any direct contact with adults not only failed to differentiate starlings' typical song classes in their vocalizations but also failed to develop differential neural responses to these songs. These deficits appear to be linked to a failure to acquire songs' functions and may provide a model for abnormal development of communicative skills, including speech
Masked suffix priming and morpheme positional constraints
Although masked stem priming (e.g., dealer\u2013DEAL) is one of the most established effects in visual word identification (e.g., Grainger et al., 1991), it is less clear whether primes and targets sharing a suffix (e.g., kindness\u2013WILDNESS) also yield facilitation (Giraudo & Grainger, 2003; Du\uf1abeitia et al., 2008). In a new take on this issue, we show that prime nonwords facilitate lexical decisions to target words ending with the same suffix (sheeter\uac\u2013TEACHER) compared to a condition where the critical suffix was substituted by another one (sheetal\u2013TEACHER) or by an unrelated non\u2013morphological ending (sheetub\u2013 TEACHER). We also show that this effect is genuinely morphological, as no priming emerged in non\u2013complex items with the same orthographic characteristics (sportel\u2013BROTHEL vs. sportic\u2013BROTHEL vs. sportur\u2013BROTHEL). In a further experiment, we took advantage of these results to assess whether suffixes are recognized in a position\u2013specific fashion. Masked suffix priming did not emerge when the relative order of stems and suffixes was reversed in the prime nonwords\u2014ersheet did not yield any time saving in the identification of teacher as compared to either alsheet or obsheet. We take these results to show that \u2013er was not identified as a morpheme in ersheet, thus indicating that suffix identification is position specific. This conclusion is in line with data on interference effects in nonword rejection (Crepaldi, Rastle, & Davis, 2010), and strongly constrains theoretical proposals on how complex words are identified. In particular, because these findings were reported in a masked priming paradigm, they suggest that positional constraints operate early, most likely at a pre\u2013lexical level of morpho\u2013orthographic analysi
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