394 research outputs found
The ‘4.2 kyr event’ in the British Isles: evidence for an abrupt climate event in the North Atlantic?
No full textPalaeoenvironmental and archaeological data from several regions around the world show evidence of a multi-centennial climatic event occurring approximately 4.2 cal. kyr BP. Abrupt climate change events (ACCs) in the early-Holocene were dominated by meltwater pulse events associated with the final stages of deglaciation, a mechanism unlikely to have driven subsequent ACCs in the mid- and late-Holocene. A study of the ‘4.2 kyr event’ therefore provides an opportunity to study ACCs in the context of comparable environmental conditions to those of the modern day, thus providing valuable lessons for the future. Whilst the climatic change and/or impact of the 4.2 kyr event is clear in certain regions (such as southwest Asia), more work must be done to disentangle the timing and magnitude of change at this time in other regions, including northwest Europe. A more comprehensive reconstruction of the event’s spatial and temporal variability will help determine the likely drivers of this event. Here we present the results of a multi-proxy examination of a peat sequence from Sluggan Moss, Northern Ireland. A range of palaeohydrological proxy analyses have been undertaken, including: humification, plant macrofossil and testate amoebae analyses. Furthermore, stable isotopic analysis (13C and 18O) of Sphagnum ?-cellulose presents an opportunity to examine changes in atmospheric circulation across the 4.2 kyr event. The chronological resolution on the sequence is exceptionally high, providing an excellent opportunity to determine the synchroneity of the climatic signal across the North Atlantic region around 4.2 cal. kyr BP
Was there a ‘4.2 kyr event’ in Great Britain and Ireland? Evidence from the peatland record
No full textPalaeoenvironmental and archaeological data from several regions of the world show evidence of a multi-centennial climatic event c. 4200 cal yr BP. Owing to the absence of continental ice-sheets, studies of this mid-Holocene event provide an opportunity to examine abrupt climatic change within an environmental context comparable to that of the modern day. Whilst the climatic change and/or impact of the event is clear in certain regions, such as western Asia, more work must be done to disentangle the timing and magnitude of changes in other regions, including northern Europe. A more comprehensive reconstruction of the event’s spatial and temporal variability will help determine the likely drivers of the event. Presented here are the results of a temporally-focussed, high-resolution and multi-proxy (testate amoebae, plant macrofossil, peat humification and stable isotopic analyses) examination of peat sequences from northern Ireland, with radiocarbon chronologies supplemented by the region’s excellent tephrochronolog
Was there a '4.2 kyr event' in Great Britain and Ireland? Evidence from the peatland record
No full textPalaeoenvironmental and archaeological data from several regions around the world show evidence of a multi-centennial climatic event occurring approximately 4200 cal yr BP. Abrupt climate change (ACC) events in the early-Holocene were dominated by meltwater pulse events associated with the final stages of deglaciation, a mechanism unlikely to have driven subsequent ACC events in the mid- and late-Holocene. A study of the ‘4.2 kyr event’ therefore provides an opportunity to study an ACC event in the context of environmental conditions comparable to those of the modern day, thus providing valuable lessons for the future. Whilst the climatic change and/or impact of the 4.2 kyr event is clear in certain regions, such as western Asia, more work must be done to disentangle the timing and magnitude of change at this time in other regions, including northwest Europe. A more comprehensive reconstruction of the event’s spatial and temporal variability will help determine the likely drivers of this event. Presented here are the results of a multi-proxy examination of two peat sequences from Sluggan Moss and Fallahogy Bog in the North of Ireland. A range of palaeohydrological proxy analyses have been undertaken, including: peat humification, plant macrofossil and testate amoebae analyses. Furthermore, stable isotopic analysis (13C and 18O) of Sphagnum ?-cellulose was included to determine whether this novel technique can, as a proxy for changing atmospheric circulation and/or bog surface wetness, contribute to our understanding of the nature and/or cause of the 4.2 kyr event. The chronological resolution of these sequences is exceptionally high, with radiocarbon dating supplemented by the excellent tephrochronology of the region. Together, these high-resolution palaeoecological and stable isotopic records provide the best opportunity to examine this event in northwest Europe, in terms of their potential for climatic sensitivity and chronological constraint. After inter-site comparison, plant macrofossil and peat humification records were found to be climatically complacent. Testate amoebae records, however, were regionally coherent and were subsequently combined to produce a regional climatic record. From this, it was concluded that there was no compelling evidence to support the existence of a 4.2 kyr event in Great Britain and Ireland. In addition, data suggested that peat-based stable isotopic analysis cannot currently be accepted as a robust proxy for past palaeohydrological change. It is proposed that a lack of biomechanical understanding and standardised methodology is significantly hindering the potential of the technique’s application in peat-based palaeoclimatic studies
Education for a new 'museology'
No full textThis article provides a critical reading of a curriculum initiative in tertiary education designed to address students who are traditionally marginalised in the Australian tertiary sector. An argument is made that this curriculum approach with its emphases on authenticity, identity, agency and embodied learning addresses issues of the disjunct between access to knowledge, museums and cultural capital. The political work of this curriculum is situated in the new museology. The author draws on Ellsworth's sensation of learning to elaborate the contributions made possible by the curriculum Learning and teaching in public spaces to museum education and tertiary education
Therapeutic efficacy of antimalarial drugs targeting DosRS signaling in Mycobacterium abscessus
No full textPre-print manuscript.Final version: Belardinelli JM, Verma D, Li W, Avanzi C, Wiersma CJ, Williams JT, Johnson BK, Zimmerman M, Whittel N, Angala B, Wang H, Jones V, Dartois V, de Moura VCN, Gonzalez-Juarrero M, Pearce C, Schenkel AR, Malcolm KC, Nick JA, Charman SA, Wells TNC, Podell BK, Vennerstrom JL, Ordway DJ, Abramovitch RB, Jackson M. Therapeutic efficacy of antimalarial drugs targeting DosRS signaling in Mycobacterium abscessus. Sci Transl Med. 2022 Feb 23;14(633):eabj3860. doi: 10.1126/scitranslmed.abj3860. Epub 2022 Feb 23. PMID: 35196022.Includes bibliographical references.A search for alternative Mycobacterium abscessus treatments led to our interest in the two-component regulator DosRS, which, in Mycobacterium tuberculosis, is required for the bacterium to establish a state of nonreplicating, drug-tolerant persistence in response to a variety of host stresses. We show here that the genetic disruption of dosRS impairs the adaptation of M. abscessus to hypoxia, resulting in decreased bacterial survival after oxygen depletion, reduced tolerance to a number of antibiotics in vitro and in vivo, and the inhibition of biofilm formation. We determined that three antimalarial drugs or drug candidates, artemisinin, OZ277, and OZ439, can target DosS-mediated hypoxic signaling in M. abscessus and recapitulate the phenotypic effects of genetically disrupting dosS. OZ439 displayed bactericidal activity comparable to standard-of-care antibiotics in chronically infected mice, in addition to potentiating the activity of antibiotics used in combination. The identification of antimalarial drugs as potent inhibitors and adjunct inhibitors of M. abscessus in vivo offers repurposing opportunities that could have an immediate impact in the clinic
Estimating the level of functional ability of children identified as likely to have an intellectual disability
No full textScreening tools can provide an indication of whether a child may have an intellectual disability (ID). Item response theory (IRT) analyses can be used to assess whether the statistical properties of the tools are such that their utility extends beyond their use as a screen for ID. We used non-parametric IRT scaling analyses to investigate whether the Child and Adolescent Intellectual Disability Screening Questionnaire (CAIDS-Q) possessed the statistical properties that would suggest its use could be extended to estimate levels of functional ability and to estimate which (if any) features associated with intellectual impairment are consistently indicative of lower or higher levels of functional ability. The validity of the two proposed applications was assessed by evaluating whether the CAIDS-Q conformed to the properties of the Monotone Homogeneity Model (MHM), characterised by uni-dimensionality, local independence and latent monotonicity and the Double Monotone Model (DMM), characterised by the assumptions of the MHM and, in addition, of non-intersecting item response functions. We analysed these models using CAIDS-Q data from 319 people referred to child clinical services. Of these, 148 had a diagnosis of ID. The CAIDS-Q was found to conform to the properties of the MHM but not the DMM. In practice, this means that the CAIDS-Q total scores can be used to quickly estimate the level of a person's functional ability. However, items of the CAIDS-Q did not show invariant item ordering, precluding the use of individual items in isolation as accurate indices of a person's level of functional ability
Impaired Competence for Pretense in Children with Autism: Exploring Potential Cognitive Predictors.
No full textLack of pretense in children with autism has been explained by a number of theoretical explanations, including impaired mentalising, impaired response inhibition, and weak central coherence. This study aimed to empirically test each of these theories. Children with autism (n=60) were significantly impaired relative to controls (n=65) when interpreting pretense, thereby supporting a competence deficit hypothesis. They also showed impaired mentalising and response inhibition, but superior local processing indicating weak central coherence. Regression analyses revealed that mentalising significantly and independently predicted pretense. The results are interpreted as supporting the impaired mentalising theory and evidence against competing theories invoking impaired response inhibition or a local processing bias. The results of this study have important implications for treatment and intervention
Visual discomfort and depth-of-field
No full textThis research was part funded by the BBSRC and EPSRC.Visual discomfort has been reported for certain visual stimuli and under particular viewing conditions, such as stereoscopic viewing. In stereoscopic viewing, visual discomfort can be caused by a conflict between accommodation and convergence cues that may specify different distances in depth. Earlier research has shown that depth-of-field, which is the distance range in depth in the scene that is perceived to be sharp, influences both the perception of egocentric distance to the focal plane, and the distance range in depth between objects in the scene. Because depth-of-field may also be in conflict with convergence and the accommodative state of the eyes, we raised the question of whether depth-of-field affects discomfort when viewing stereoscopic photographs. The first experiment assessed whether discomfort increases when depth-of-field is in conflict with coherent accommodation–convergence cues to distance in depth. The second experiment assessed whether depth-of-field influences discomfort from a pre-existing accommodation–convergence conflict. Results showed no effect of depth-of-field on visual discomfort. These results suggest therefore that depth-of-field can be used as a cue to depth without inducing discomfort in the viewer, even when cue conflicts are large.Peer reviewe
The 5.2 ka climate event: Evidence from stable isotope and multi-proxy palaeoecological peatland records in Ireland
No full textAbstractEvidence for a major climate event at 5.2 ka has been reported globally and is associated with considerable societal disruption, but is poorly characterised in northwest Europe. This event forms part of a broader period of re-organisation in the Earth's ocean-atmosphere circulation system between 6 and 5 ka. This study tests the nature and timing of the event in northwest Europe, a region highly sensitive to change in meridional overturning circulation and mid-latitude westerly airflow. Here we report three high-resolution Irish multi-proxy records obtained from ombrotrophic peatlands that have robust chronological frameworks. We identify the 5.2 ka event by a sustained decrease in δ18Ocellulose at all three sites, with additional and parallel changes in δ13Ccellulose and palaeoecological (testate amoebae, plant macrofossil and humification) data from two sites in northern Ireland. Data from Sluggan Moss demonstrate a particularly coherent shift towards wetter conditions. These data support the hypothesis that the event was caused by a prolonged period of positive North Atlantic Oscillation conditions, resulting in pervasive cyclonic weather patterns across northwest Europe, increasing precipitation over Ireland
Xenophobic experiences of foreign African women residing in a low income community in KwaZulu-Natal, South Africa
No full textAbstract: The International Organisation for migration in South Africa (2016: 14) defines ‘xenophobia’ as the “attitudes, prejudices and behaviour that reject, exclude and often vilify persons based on the perceptions that they are outsiders or foreigners to the community, society or national identity”. In Fanon’s (1967) conceptualisation of the colonialist mentality, he argues that xenophobic violence is testimony of internalised oppression and that through institutionalised racism, Africans tend to emulate their oppressors. Moreover, the author is of the view that irresponsible comments made by the Zulu Monarch, King Zwelitini in April 2015, when he stated that foreign nationals are enjoying wealth and services that are meant for local citizens; was perceived as a primary cause of a spate of xenophobic attacks against foreign nationals across the country (Hans, 2015; Muthuki, 2013; Adam & Moodley, 2015). Researchers such as Ndlovu-Gatsheni (2018), Neocosmos (2010), Piper and Charman (2016) argued that in the Post-1994 era, such anti-migration sentiments stem from the politics of nationalism and dire socio-economic challenges experienced in the country..
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