859 research outputs found
Sensitive Radio Survey of Obscured Quasar Candidates
We study the radio properties of moderately obscured quasars over a range of
redshifts to understand the role of radio activity in accretion using the
Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists
of optically-selected obscured quasar candidates, all of which are radio-quiet,
with typical radio luminosities of [1.4 GHz] < erg
s. Only a single source is individually detected in our deep (rms~10
Jy) exposures. This population would not be identified by radio-based
selection methods used for distinguishing dusty star-forming galaxies and
obscured active nuclei. In our pilot A-array study of z~0.5 radio-quiet
quasars, we spatially resolve four of five objects on scales ~ 5 kpc and find
they have steep spectral indices. Therefore, radio emission in these sources
could be due to jet-driven or radiatively driven bubbles interacting with
interstellar material on the scale of the host galaxy. Finally, we also study
the population of ~ 200 faint (~40 Jy - 40 mJy) radio sources observed
over ~ 120 arcmin of our data. 60% of these detections are matched in the
SDSS and/or WISE and are, in roughly equal shares, active nuclei at a broad
range of redshifts, passive galaxies with no other signs of nuclear activity
and IR-bright but optically faint sources. Spectroscopically or photometrically
confirmed star-forming galaxies constitute only a small minority of the
matches. Such sensitive radio surveys allow us to address important questions
of AGN evolution and evaluate the AGN contribution to the radio-quiet sky.Comment: 18 pages, submitted to MNRA
Gaia transient detection efficiency: hunting for nuclear transients
We present a study of the detectability of transient events associated with
galaxies for the Gaia European Space Agency astrometric mission. We simulated
the on-board detections, and on-ground processing for a mock galaxy catalogue
to establish the properties required for the discovery of transient events by
Gaia, specifically tidal disruption events (TDEs) and supernovae (SNe).
Transients may either be discovered by the on-board detection of a new source
or by the brightening of a previously known source. We show that Gaia
transients can be identified as new detections on-board for offsets from the
host galaxy nucleus of 0.1--0.5,arcsec, depending on magnitude and scanning
angle. The Gaia detection system shows no significant loss of SNe at close
radial distances to the nucleus. We used the detection efficiencies to predict
the number of transients events discovered by Gaia. For a limiting magnitude of
19, we expect around 1300 SNe per year: 65% SN Ia, 28% SN II and 7% SN Ibc, and
~20 TDEs per year.Comment: 17 pages, 10 figures, accepted by MNRA
Visual objects approaching the body modulate subsequent somatosensory processing at 4 months of age
Abstract We asked whether, in the first year of life, the infant brain can support the dynamic crossmodal interactions between vision and somatosensation that are required to represent peripersonal space. Infants aged 4 (n = 20, 9 female) and 8 (n = 20, 10 female) months were presented with a visual object that moved towards their body or receded away from it. This was presented in the bottom half of the screen and not fixated upon by the infants, who were instead focusing on an attention getter at the top of the screen. The visual moving object then disappeared and was followed by a vibrotactile stimulus occurring later in time and in a different location in space (on their hands). The 4-month-olds’ somatosensory evoked potentials (SEPs) were enhanced when tactile stimuli were preceded by unattended approaching visual motion, demonstrating that the dynamic visual-somatosensory cortical interactions underpinning representations of the body and peripersonal space begin early in the first year of life. Within the 8-month-olds’ sample, SEPs were increasingly enhanced by (unexpected) tactile stimuli following receding visual motion as age in days increased, demonstrating changes in the neural underpinnings of the representations of peripersonal space across the first year of life
Top-down Inhibitory Motor Control is Preserved in Adults with Developmental Coordination Disorder
Two paradigms were employed to disentangle information processing from executive motor inhibition in adults with Developmental Coordination Disorder (DCD). Choice Reaction and Stop Signal Tasks were compared between 13 adults fulfilling DSM-5 DCD criteria and 42 typically developing adults. Additional analyses included 16 probable DCD (pDCD) participants, who had motor difficulties but did not fulfil DSM-5 criteria. Analyses employed frequentist and Bayesian modeling. While DCD+pDCD showed slower reaction times and difficulty initiating Go responses, no impairments in Stop actions were found. These findings indicated no executive deficit in DCD, suggesting that previous results may be explained by inefficient information processing
Outcomes of patients with perforated colon cancer:A systematic review
Introduction: Perforated colon cancer (PCC) is a distinct clinical entity with implications for treatment and prognosis, however data on PCC seems scarce. The aim of this systematic review is to provide a comprehensive overview of the recent literature on clinical outcomes of PCC. Materials and methods: A systematic literature search of MEDLINE (PubMed), Embase, Cochrane library and Google scholar was performed. Studies describing intentionally curative treatment for patients with PCC since 2010 were included. The main outcome measures consisted of short-term surgical complications and long-term oncological outcomes. Results: Eleven retrospective cohort studies were included, comprising a total of 2696 PCC patients. In these studies, various entities of PCC were defined. Comparative studies showed that PCC patients as compared to non-PCC patients have an increased risk of 30-day mortality (8–33% vs 3–5%), increased post-operative complications (33–56% vs 22–28%), worse overall survival (36–40% vs 48–65%) and worse disease-free survival (34–43% vs 50–73%). Two studies distinguished free-perforations from contained perforations, revealing that free-perforation is associated with significantly higher 30-day mortality (19–26% vs 0–10%), lower overall survival (24–28% vs 42–64%) and lower disease-free survival (15% vs 53%) as compared to contained perforations. Conclusion: Data on PCC is scarce, with various PCC entities defined in the studies included. Heterogeneity of the study population, definition of PCC and outcome measures made pooling of the data impossible. In general, perforation, particularly free perforation, seems to be associated with a substantial negative effect on outcomes in colon cancer patients undergoing surgery. Better definition and description of the types of perforation in future studies is essential, as outcomes seem to differ between types of PCC and might require different treatment strategies.</p
Cross-modal interactions between audition, touch, and vision in endogenous spatial attention: ERP evidence on preparatory states and sensory modulations
Recent behavioral and event-related brain potential (ERP) studies have revealed cross-modal interactions in endogenous spatial attention between vision and audition, plus vision and touch. The present ERP study investigated whether these interactions reflect supramodal attentional control mechanisms, and whether similar cross-modal interactions also exist between audition and touch. Participants directed attention to the side indicated by a cue to detect infrequent auditory or tactile targets at the cued side. The relevant modality (audition or touch) was blocked. Attentional control processes were reflected in systematic ERP modulations elicited during cued shifts of attention. An anterior negativity contralateral to the cued side was followed by a contralateral positivity at posterior sites. These effects were similar whether the cue signaled which side was relevant for audition or for touch. They also resembled previously observed ERP modulations for shifts of visual attention, thus implicating supramodal mechanisms in the control of spatial attention. Following each cue, single auditory, tactile, or visual stimuli were presented at the cued or uncued side. Although stimuli in task-irrelevant modalities could be completely ignored, visual and auditory ERPs were nevertheless affected by spatial attention when touch was relevant, revealing cross-modal interactions. When audition was relevant, visual ERPs, but not tactile ERPs, were affected by spatial attention, indicating that touch can be decoupled from cross-modal attention when task-irrelevant
Levensmiddelenverpakkingen gemaakt van oud-papier en karton: migratie van minerale oliën : Rapportage vanuit het additioneel onderzoek-pakket binnen TiFN SD002 in opdracht van KIDV
This report gives an overview of the scientific literature on the migration of undesired substances from packages made from recycled paper & board to foodstuffs with a focus on mineral oils. The knowledge is placed into an independent scientific perspective with regard to analysis, technology, legislation and sources by Wageningen Food & Biobased Research (WFBR) and with regard to exposure, toxicology and risk assessment by TNO (organisation for applied scientific research)
- …