In this paper, we examine the motivations for research on cognitive architectures and review some candidates that have been explored in the literature. After this, we consider the capabilities that a ...cognitive architecture should support, some properties that it should exhibit related to representation, organization, performance, and learning, and some criteria for evaluating such architectures at the systems level. In closing, we discuss some open issues that should drive future research in this important area.
This study presents research evidence from the UK, the USA and Australia regarding the prevalence of aggression directed at child protection social workers by parents or their partners. It identifies ...gaps in current programmes of qualifying training for social workers in these countries. Adopting a critical case approach, this study analyses a number of serious case reviews conducted in England in which the aggression of a parent or their partner was a key contributing factor in the failure of social services to protect a child from harm. By examining the dynamics between social workers and parents illuminated by these critical cases, the study identifies the theories, knowledge base and skills which would rectify the deficits in the curriculum, not only of social work courses in England and elsewhere in the UK, but also of those presently being delivered in the USA and Australia.
We discuss the relationship between rest-frame color and optical luminosity for X-ray sources in the range 0.6< z <1.4 selected from the Chandra survey of the Extended Groth Strip. These objects are ...almost exclusively active galactic nuclei (AGNs). While there are a few luminous QSOs, most are relatively weak or obscured AGNs whose optical colors should be dominated by host galaxy light The vast majority of AGN hosts at z 6 1 are luminous and red, with very few objects fainter than M sub(B) = -20.5 or bluer than U-B = 0.6. This places the AGNs in a distinct region of color-magnitude space, on the "red sequence" or at the top of the "blue cloud," with many in between these two modes in galaxy color. A key stage in the evolution of massive galaxies is when star formation is quenched, resulting in a migration from the blue cloud to the red sequence. Our results are consistent with scenarios in which AGNs either cause or maintain this quenching. The large number of red-sequence AGNs implies that strong, ongoing star formation is not a necessary ingredient for AGN activity, as black hole accretion appears often to persist after star formation has been terminated.
We use morphological information of X-ray selected active galactic nuclei (AGN) hosts to set limits on the fraction of the accretion density of the Universe at z≈ 1 that is not likely to be ...associated with major mergers. Deep X-ray observations are combined with high-resolution optical data from the Hubble Space Telescope in the All-wavelength Extended Groth strip International Survey, Great Observatories Origins Deep Survey (GOODS) North and GOODS South fields to explore the morphological breakdown of X-ray sources in the redshift interval 0.5 < z < 1.3. The sample is split into discs, early-type bulge-dominated galaxies, peculiar systems and point sources in which the nuclear source outshines the host galaxy. The X-ray luminosity function and luminosity density of AGN at z≈ 1 are then calculated as a function of morphological type. We find that disc-dominated hosts contribute 30 ± 9 per cent to the total AGN space density and 23 ± 6 per cent to the luminosity density at z≈ 1. We argue that AGN in disc galaxies are most likely fuelled not by major merger events but by minor interactions or internal instabilities. We find evidence that these mechanisms may be more efficient in producing luminous AGN compared to predictions for the stochastic fuelling of massive black holes in disc galaxies.
We investigate the relationship between active galactic nucleus (AGN) activity and host galaxy properties using a sample of massive galaxies at z ∼ 2 in the Chandra Deep Field-South (CDFS). A sample ...of 268 galaxies with M
* > 1010.5 M⊙ at 1.4 < z < 3 are selected from Hubble Space Telescope wide field camera 3 (WFC3) H-band observations in CDFS taken as part of the cosmic assembly near-infrared deep extragalactic legacy survey (CANDELS) survey. We find that a large fraction (22.0 ± 2.5 per cent) are detected in the 4 Ms Chandra/Advanced CCD Image Spectrometer observations in the field, implying a high AGN content in these massive galaxies. To investigate further the relationship between these AGN and their hosts, we create four subsamples, based on their star formation rates (star-forming versus quiescent) and galaxy size (compact versus extended), following Barro et al. and perform X-ray spectral fitting. We find a clear effect whereby the AGN in compact galaxies – be they star forming or quiescent – show significantly higher luminosities and levels of obscuration than the AGN in extended galaxies. These results provide clear evidence for two modes of black hole growth in massive galaxies at high redshift. The dominant growth mode is a luminous, obscured phase which occurs overwhelmingly in compact galaxies while another lower luminosity, unobscured phase is predominantly seen in extended galaxies. Both modes could produce AGN feedback, with violent transformative feedback in the former and a gentler ‘maintenance mode’ produced by the latter.
Methylglyoxal (MG) is a metabolite of glucose that may contribute to peripheral neuropathy and pain in diabetic patients. MG increases intracellular calcium in sensory neurons and produces behavioral ...nociception via the cation channel transient receptor potential ankyrin 1 (TRPA1). However, rigorous characterization of an animal model of methylglyoxal-evoked pain is needed, including testing whether methylglyoxal promotes negative pain affect. Furthermore, it remains unknown whether methylglyoxal is sufficient to activate neurons in the spinal cord dorsal horn, whether this requires TRPA1, and if the calcium-sensitive adenylyl cyclase 1 isoform (AC1) contributes to MG-evoked pain. We administered intraplantar methylglyoxal and then evaluated immunohistochemical phosphorylation of extracellular signal-regulated kinase (p-ERK) and multiple pain-like behaviors in wild-type rats and mice and after disruption of either TRPA1 or AC1. Methylglyoxal produced conditioned place avoidance (CPA) (a measure of affective pain), dose-dependent licking and lifting nociceptive behaviors, hyperalgesia to heat and mechanical stimulation, and p-ERK in the spinal cord dorsal horn. TRPA1 knockout or intrathecal administration of a TRPA1 antagonist (HC030031) attenuated methylglyoxal-evoked p-ERK, nociception, and hyperalgesia. AC1 knockout abolished hyperalgesia but not nociceptive behaviors. These results indicate that intraplantar administration of methylglyoxal recapitulates multiple signs of painful diabetic neuropathy found in animal models of or patients with diabetes, including the activation of spinal nociresponsive neurons and the potential involvement of a TRPA1-AC1 sensitization mechanism. We conclude that administration of MG is a valuable model for investigating both peripheral and central components of a MG-TRPA1-AC1 pathway that contribute to painful diabetic neuropathy.
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