1,833 research outputs found
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Holographic thermalization, quasinormal modes and superradiance in Kerr-AdS
Black holes in anti-de Sitter (AdS) backgrounds play a pivotal role in the
gauge/gravity duality where they determine, among other things, the approach to
equilibrium of the dual field theory. We undertake a detailed analysis of
perturbed Kerr-AdS black holes in four- and five-dimensional spacetimes,
including the computation of its quasinormal modes, hydrodynamic modes and
superradiantly unstable modes. Our results shed light on the possibility of new
black hole phases with a single Killing field, possible new holographic
phenomena and phases in the presence of a rotating chemical potential, and
close a crucial gap in our understanding of linearized perturbations of black
holes in anti-de Sitter scenarios
Cognitive appraisal of environmental stimuli induces emotion-like states in fish
The occurrence of emotions in non-human animals has been the focus of debate over the years. Recently, an interest in expanding this debate to non-tetrapod vertebrates and to invertebrates has emerged. Within vertebrates, the study of emotion in teleosts is particularly interesting since they represent a divergent evolutionary radiation from that of tetrapods, and thus they provide an insight into the evolution of the biological mechanisms of emotion. We report that Sea Bream exposed to stimuli that vary according to valence (positive, negative) and salience (predictable, unpredictable) exhibit different behavioural, physiological and neuromolecular states. Since according to the dimensional theory of emotion valence and salience define a two-dimensional affective space, our data can be interpreted as evidence for the occurrence of distinctive affective states in fish corresponding to each the four quadrants of the core affective space. Moreover, the fact that the same stimuli presented in a predictable vs. unpredictable way elicited different behavioural, physiological and neuromolecular states, suggests that stimulus appraisal by the individual, rather than an intrinsic characteristic of the stimulus, has triggered the observed responses. Therefore, our data supports the occurrence of emotion-like states in fish that are regulated by the individual's perception of environmental stimuli.European Commission [265957 Copewell]; Fundacao para a Ciencia e Tecnologia [SFRH/BD/80029/2011, SFRH/BPD/72952/2010]info:eu-repo/semantics/publishedVersio
Hippocampal subfield volumetry: differential pattern of atrophy in different forms of genetic frontotemporal dementia
BACKGROUND: Frontotemporal dementia (FTD) is a heterogeneous neurodegenerative disorder, with a strong genetic component. Previous research has shown that medial temporal lobe atrophy is a common feature of FTD. However, no study has so far investigated the differential vulnerability of the hippocampal subfields in FTD.
OBJECTIVES: We aimed to investigate hippocampal subfield volumes in genetic FTD.
METHODS: We in6/2/2018vestigated hippocampal subfield volumes in a cohort of 75 patients with genetic FTD (age: mean (standard deviation) 59.3 (7.7) years; disease duration: 5.1(3.4) years; 29 with MAPT, 28 with C9orf72, and 18 with GRN mutations) compared with 97 age-matched controls (age: 62.1 (11.1) years). We performed a segmentation of their volumetric T1-weighted MRI scans to extract hippocampal subfields volumes. Left and right volumes were summed and corrected for total intracranial volumes.
RESULTS: All three groups had smaller hippocampi than controls. The MAPT group had the most atrophic hippocampi, with the subfields showing the largest difference from controls being CA1-4 (24–27%, p < 0.0005). For C9orf72, the CA4, CA1, and dentate gyrus regions (8–11%, p < 0.0005), and for GRN the presubiculum and subiculum (10–14%, p < 0.0005) showed the largest differences from controls.
CONCLUSIONS: The hippocampus was affected in all mutation types but a different pattern of subfield involvement was found in the three genetic groups, consistent with differential cortical-subcortical network vulnerability
State-space Manifold and Rotating Black Holes
We study a class of fluctuating higher dimensional black hole configurations
obtained in string theory/ -theory compactifications. We explore the
intrinsic Riemannian geometric nature of Gaussian fluctuations arising from the
Hessian of the coarse graining entropy, defined over an ensemble of brane
microstates. It has been shown that the state-space geometry spanned by the set
of invariant parameters is non-degenerate, regular and has a negative scalar
curvature for the rotating Myers-Perry black holes, Kaluza-Klein black holes,
supersymmetric black holes, - configurations and the
associated BMPV black holes. Interestingly, these solutions demonstrate that
the principal components of the state-space metric tensor admit a positive
definite form, while the off diagonal components do not. Furthermore, the ratio
of diagonal components weakens relatively faster than the off diagonal
components, and thus they swiftly come into an equilibrium statistical
configuration. Novel aspects of the scaling property suggest that the
brane-brane statistical pair correlation functions divulge an asymmetric
nature, in comparison with the others. This approach indicates that all above
configurations are effectively attractive and stable, on an arbitrary
hyper-surface of the state-space manifolds. It is nevertheless noticed that
there exists an intriguing relationship between non-ideal inter-brane
statistical interactions and phase transitions. The ramifications thus
described are consistent with the existing picture of the microscopic CFTs. We
conclude with an extended discussion of the implications of this work for the
physics of black holes in string theory.Comment: 44 pages, Keywords: Rotating Black Holes; State-space Geometry;
Statistical Configurations, String Theory, M-Theory. PACS numbers: 04.70.-s
Physics of black holes; 04.70.Bw Classical black holes; 04.70.Dy Quantum
aspects of black holes, evaporation, thermodynamics; 04.50.Gh
Higher-dimensional black holes, black strings, and related objects. Edited
the bibliograph
Planck intermediate results. XLI. A map of lensing-induced B-modes
The secondary cosmic microwave background (CMB) -modes stem from the
post-decoupling distortion of the polarization -modes due to the
gravitational lensing effect of large-scale structures. These lensing-induced
-modes constitute both a valuable probe of the dark matter distribution and
an important contaminant for the extraction of the primary CMB -modes from
inflation. Planck provides accurate nearly all-sky measurements of both the
polarization -modes and the integrated mass distribution via the
reconstruction of the CMB lensing potential. By combining these two data
products, we have produced an all-sky template map of the lensing-induced
-modes using a real-space algorithm that minimizes the impact of sky masks.
The cross-correlation of this template with an observed (primordial and
secondary) -mode map can be used to measure the lensing -mode power
spectrum at multipoles up to . In particular, when cross-correlating with
the -mode contribution directly derived from the Planck polarization maps,
we obtain lensing-induced -mode power spectrum measurement at a significance
level of , which agrees with the theoretical expectation derived
from the Planck best-fit CDM model. This unique nearly all-sky
secondary -mode template, which includes the lensing-induced information
from intermediate to small () angular scales, is
delivered as part of the Planck 2015 public data release. It will be
particularly useful for experiments searching for primordial -modes, such as
BICEP2/Keck Array or LiteBIRD, since it will enable an estimate to be made of
the lensing-induced contribution to the measured total CMB -modes.Comment: 20 pages, 12 figures; Accepted for publication in A&A; The B-mode map
is part of the PR2-2015 Cosmology Products; available as Lensing Products in
the Planck Legacy Archive http://pla.esac.esa.int/pla/#cosmology; and
described in the 'Explanatory Supplement'
https://wiki.cosmos.esa.int/planckpla2015/index.php/Specially_processed_maps#2015_Lensing-induced_B-mode_ma
Clinical validation of a novel postural support device for hospitalized sub-acute post stroke wheelchair users
Purpose: We present a novel wheelchair posture support device (WPSD) and its clinical validation. The device was developed in order to assure correct sitting posture and to reduce the time spent by caregivers for re-positioning of hospitalized, wheelchair-bound, post-acute stroke patients.
Method: The device was validated with 16 subjects during a period of 5 days in which use of the device was compared with regular care practice.
Results: The device was used for the five consecutive days in 69% of patients, while for 6% it was not suitable; 25% did not complete the 5 days for reasons unrelated to the device. Caregivers needed to re-position the patients that used the device for the full 5 days (n=11) on an average 52% less often when using the device, as compared to regular practice. Furthermore, the device was rated as usable and functional by the caregivers while significantly reducing perception of trunk and shoulder pain in patients during its use.
Conclusions: The newly designed WPSD is a valuable system for the improvement of medical assistance to wheelchair-bound post-stroke patients by reducing pain and number of re-positioning manoeuvres. The WPSD might be applicable to any group of patients who need posture control in either wheelchair or common chair with arms support.The FIK initiative; funding the development of the Varstiff material technology.
Fundaci on Bot ın’s ‘‘Mind the Gap’’ program co-funding the design process of the WPSD.
Spherium Biomed co-funding the study with the WPSD
Study of decays to the final state and evidence for the decay
A study of decays is performed for the first time
using data corresponding to an integrated luminosity of 3.0
collected by the LHCb experiment in collisions at centre-of-mass energies
of and TeV. Evidence for the decay
is reported with a significance of 4.0 standard deviations, resulting in the
measurement of
to
be .
Here denotes a branching fraction while and
are the production cross-sections for and mesons.
An indication of weak annihilation is found for the region
, with a significance of
2.4 standard deviations.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-2016-022.html,
link to supplemental material inserted in the reference
Análise integrada de sistemas de produção de tomateiro com base em indicadores edafobiológicos.
A análise integrada de indicadores edafobiológicos ligados ao manejo do solo constitui uma ferramenta importante para estimar níveis de sustentabilidade do agroecossistema, detectando-se pontos críticos para a devida correção de manejo. Essa ferramenta foi empregada na avaliação de sistemas de produção orgânica e convencional de tomate, em cultivo protegido e a campo aberto, no estado de São Paulo. Tomaram-se como referência solos de mata nativa e/ou pastagem natural, dependendo do local de estudo. Em Serra Negra, o solo sob sistema orgânico apresentou maior capacidade de campo e teor de argila dispersa mais baixo, indicativos da estabilidade dos agregados. No sistema convencional observou-se uma elevada condutividade elétrica, evidenciando a alta disponibilidade de sais solúveis. A análise de componentes principais (ACP) permitiu concluir que há maior grau de similaridade entre o solo sob sistema orgânico e aqueles das bases referenciais, com respeito aos indicadores químicos e biológicos. Constatou-se que C org, N total, polissacarídeos, FDA (hidrólise de diacetato de fluoresceína) e atividade enzimática de desidrogenase estão positivamente relacionados com o sistema orgânico, a mata nativa e a pastagem. Em contrapartida, a saturação por bases (V%), pH, teores de Mn, Mg e Ca, bem como a razão de dispersão estão inversamente relacionadas ao manejo orgânico. Já em Araraquara, os resultados da ACP distinguiram as áreas organicamente cultivadas das matas nativas, principalmente, com base nos indicadores biológicos
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Planck 2015 results: XXVI. The Second Planck Catalogue of Compact Sources
The Second Planck Catalogue of Compact Sources is a list of discrete objects detected in single-frequency maps from the full duration of the Planck mission and supersedes previous versions. It consists of compact sources, both Galactic and extragalactic, detected over the entire sky. Compact sources detected in the lower frequency channels are assigned to the PCCS2, while at higher frequencies they are assigned to one of two subcatalogues, the PCCS2 or PCCS2E, depending on their location on the sky. The first of these (PCCS2) covers most of the sky and allows the user to produce subsamples at higher reliabilities than the target 80% integral reliability of the catalogue. The second (PCCS2E) contains sources detected in sky regions where the diffuse emission makes it difficult to quantify the reliability of the detections. Both the PCCS2 and PCCS2E include polarization measurements, in the form of polarized flux densities, or upper limits, and orientation angles for all seven polarization-sensitive Planck channels. The improved data-processing of the full-mission maps and their reduced noise levels allow us to increase the number of objects in the catalogue, improving its completeness for the target 80% reliability as compared with the previous versions, the PCCS and the Early Release Compact Source Catalogue (ERCSC)
Psychologists’ dilemmas in career counselling practice
In this study, we explored main dilemmas psychologists face in career
counselling in two main professional settings: employment and education. Participants
included 24 experienced Portuguese psychologists, working in employment
(n = 14) and educational (n = 10) settings. We used consensual qualitative
research to conduct and analyse semi-structured interviews. Results revealed
dilemmas’ in five domains: neutrality, assessment, dual loyalty, role boundaries, and
confidentiality, with the typical dilemma in the domain of neutrality. Differences
between groups were found in the domains of dual loyalty and role boundaries.Dans cette étude, nous avons exploré les principaux dilemmes rencontrés
par les psychologues dans le conseil en orientation dans deux milieux professionnels
centraux: le placement et l’éducation. Parmi les participants figuraient 24 psychologues
portugais expérimentés travaillant dans des contextes de placement (n = 14)
et d’éducation (n = 10). Nous avons utilisé la recherche qualitative consensuelle
pour mener et analyser les entretiens semi-structurés. Les re´sultats ont révé lé des
dilemmes dans cinq domaines: la neutralité, l’évaluation, la double loyauté, les
limites du rôle, et la confidentialité, avec le dilemme typique dans le domaine de la
neutralité. Les différences entre les groupes ont été identifiees dans les domaines de
la double loyauté et les limites du rôle.In dieser Studie untersuchten wir die hauptsä chlichen Dilemmata, mit denen Psychologen in der Berufsberatung in zwei wesentlichen professionellen
Einrichtungen konfrontiert sind: Beruf und Bildung. Zu den Teilnehmern geho
¨rten 24 erfahrene portugiesische Psychologen, die in Einrichtungen von Beruf
(n = 14) und Bildung (n = 10) arbeiteten. Wir verwendeten einvernehmliche
qualitative Forschung um semi-strukturierte Interviews durchzufu¨hren und zu
analysieren. Die Ergebnisse zeigten Dilemmata in fünf Bereichen: Neutralität,
Beurteilung, doppelte Loyalität, Rollengrenzen und Vertraulichkeit, mit dem
typischen Dilemma in der Domäne der Neutralität. Unterschiede zwischen den
Gruppen wurden in den Bereichen der doppelten Loyalität und Rollengrenzen
gefunden
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