509 research outputs found
The use of test structures to perform chip level characterisation studies of Ni and NiFe electrochemical deposition
Climate Change and Biosphere Response: Unlocking the Collections Vault
Natural history collections (NHCs) are an important source of the long-term data needed to understand how biota respond to ongoing anthropogenic climate change. These include taxon occurrence data for ecological modeling, as well as information that can be used to reconstruct mechanisms through which biota respond to changing climates. The full potential of NHCs for climate change research cannot be fully realized until high-quality data sets are conveniently accessible for research, but this requires that higher priority be placed on digitizing the holdings most useful for climate change research (e.g., whole-biota studies, time series, records of intensively sampled common taxa). Natural history collections must not neglect the proliferation of new information from efforts to understand how present-day ecosystems are responding to environmental change. These new directions require a strategic realignment for many NHC holders to complement their existing focus on taxonomy and systematics. To set these new priorities, we need strong partnerships between NHC holders and global change biologists
Gauging the impact of glacioeustasy on a mid-latitude early Silurian basin margin, mid Wales, UK
The early Silurian (Llandovery) Gondwanan South Polar ice sheet experienced episodes of ice retreat and re-advance. Marine base level curves constructed for the interval are widely assumed to provide a record of the associated glacioeustasy. In revealing a series of progradational sequences (progrades) bounded by flooding surfaces, recent work on the Type Llandovery succession in mid Wales (UK) has provided an opportunity to test this hypothesis. The grouping of these progrades into three composite sequences underpins the construction of both low order (small amplitude, high frequency) and high order (large amplitude, low frequency) base level movement curves. Revised biostratigraphical datasets for the type succession permit the accurate dating of base level events. The composite sequences record progradational acmes in the acinaces, lower convolutus and upper sedgwickii-halli graptolite biozones. A series of transgressions that postdate the Hirnantian glacial maximum culminated in an upper persculptus Biozone high-stand. Maximum flooding events also occurred during the revolutus and lower sedgwickii biozones, and the base of the early Telychian guerichi Biozone also marked the onset of a pronounced deepening. A review of 62 published datasets, including global and other regional base level curves, records of glacial activity, isotope data, patterns of facies and faunal flux and putative climate models, permits an evaluation of the origins of these local base level events. The concept of a Eustasy Index is introduced and shows that the impacts of global sea level movements can only be demonstrated within narrow ‘eustatic windows’ coincident with times of ice sheet collapse. At other times, the geometry of Llandovery area progrades reflects their accumulation across a faulted basin margin where, during periods of slow ice sheet advance, epeirogenic processes outstripped sea level movements as the dominant forcing factors. Increased levels of Telychian subsidence at first enhanced and then overwhelmed the influence of glacioeustasy as part of the region's response to the north European Scandian deformation
RNAi gene knockdown in the poultry red mite, Dermanyssus gallinae (De Geer 1778), a tool for functional genomics
The authors gratefully acknowledge funding for this project from the Scottish Government Rural Affairs, Food and the Environment (RAFE) Strategic Research Portfolio 2016-2021. DRGP is supported by a research fellowship provided by the Moredun Foundation. WC is supported by a studentship provided by the University of Aberdeen and the Moredun Foundation.Peer reviewedPublisher PD
I've seen enough! Prolonged and repeated exposure to disgusting stimuli increases oculomotor avoidance
Electrical stimulation using conductive polymer polypyrrole promotes differentiation of human neural stem cells: a biocompatible platform for translational neural tissue engineering
Conductive polymers (CPs) are organic materials that hold great promise for biomedicine. Potential applications include in vitro or implantable electrodes for excitable cell recording and stimulation, and conductive scaffolds for cell support and tissue engineering. Here we demonstrate the utility of electroactive CP Polypyrrole (PPy) containing the anionic dopant dodecylbenzenesulfonate (DBS) to differentiate novel clinically relevant human neural stem cells (hNSCs). Electrical stimulation of PPy(DBS) induced hNSCs to predominantly β-III Tubulin (Tuj1) expressing neurons, with lower induction of glial fibrillary acidic protein (GFAP) expressing glial cells. In addition, stimulated cultures comprised nodes or clusters of neurons with longer neurites and greater branching than unstimulated cultures. Cell clusters showed a similar spatial distribution to regions of higher conductivity on the film surface. Our findings support the use of electrical stimulation to promote neuronal induction and the biocompatibility of PPy(DBS) with hNSCs, and opens up the possibility of identifying novel mechanisms of fate determination of differentiating human stem cells for advanced in vitro modelling, translational drug discovery and regenerative medicine
Late Silurian event stratigraphy and facies of South Wales and the Welsh Borderland, United Kingdom
Lithofacies and biostratigraphical analysis has enabled the establishment of a stratigraphic event framework for Ludfordian and Pridoli strata in south Wales and the Welsh Borderland. In SW Wales, the Golden Grove Axis acted as a structural hinge separating the shallow marine storm-influenced Cae’r mynach Seaway from a pediment surface above which Ludfordian colluvium (Abercyfor Formation) was deposited. The Axis seeded four NW-derived river-influenced delta progrades of Leintwardinian to early Pridoli age (Tilestones Formation). A NE-sourced early Pridoli wave-influenced delta deposited the Downton Castle Sandstone Formation (DCSF), coeval to the youngest Tilestones prograde, with a lateral interface existing between Mynydd Epynt and the Clun Forest area. Except for the Malverns area, the DCSF is no longer recognized south of the Neath Disturbance. Early Pridoli forced regression promoted widespread subaerial exposure north of the Neath Disturbance, with incision into tracts close to the Welsh Borderland Fault System. The basinward-shift in facies belts resulted in marine erosion and deposition of a phosphatic ravinement pebble lag. The wave-influenced Clifford’s Mesne Sandstone Formation delta subsequently seeded on the Gorsley Axis with tidally influenced Rushall Formation accumulating in a back-barrier setting. The Pwll-Mawr Formation records the easterly advance of coeval coastal deposits on the western side of the remnant Cae’r mynach Seaway. Behind migrating delta coastlines, green muds accumulated on coastal plains (Temeside Mudstone Formation) with better drained red dryland alluvium (Moor Cliffs Formation) charting expansion of Old Red Sandstone lithofacies. Mid-Pridoli incision preserves the Pont ar Llechau Formation estuarine valley fill
Investigating the psychometric properties of the Suicide Stroop task
Behavioral measures are increasingly used to assess suicidal thoughts and behaviors. Some measures, such as the Suicide Stroop Task, have yielded mixed findings in the literature. An understudied feature of these behavioral measures has been their psychometric properties, which may affect the probability of detecting significant effects and reproducibility. In the largest investigation of its kind, we tested the internal consistency and concurrent validity of the Suicide Stroop Task in its current form, drawing from seven separate studies (N = 875 participants, 64% female, aged 12 to 81 years). Results indicated that the most common Suicide Stroop scoring approach, interference scores, yielded unacceptably low internal consistency (rs = -.09-.13) and failed to demonstrate concurrent validity. Internal consistency coefficients for mean reaction times (RTs) to each stimulus type ranged from rs = .93-.94. All scoring approaches for suicide-related interference demonstrated poor classification accuracy (AUCs = .52-.56) indicating that scores performed near chance in their ability to classify suicide attempters from nonattempters. In the case of mean RTs, we did not find evidence for concurrent validity despite our excellent reliability findings, highlighting that reliability does not guarantee a measure is clinically useful. These results are discussed in the context of the wider implications for testing and reporting psychometric properties of behavioral measures in mental health research
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Predicting suicide attempts in depressed adolescents: Clarifying the role of disinhibition and childhood sexual abuse
Background
Suicide is the second leading cause of death among adolescents, and depressed youth are six times more likely to make suicide attempts as compared to non-depressed adolescents. The present study examined the unique and interactive effects of two well-established correlates of suicidality – childhood sexual abuse (CSA) and disinhibition – in predicting suicide attempts among depressed adolescents.
Method
Participants were 163 adolescents (125 females) aged 13 to 18 (M = 15.60, SD = 1.27) diagnosed with Major Depressive Disorder (n = 95, 58.3%) and/or Dysthymia (n = 69, 42.3%) recruited from an acute residential treatment service. Participants completed interviews assessing psychopathology and suicidality, self-report measures of depressive symptoms and CSA, and a computerized disinhibition task.
Results
Consistent with hypotheses, CSA moderated the association between disinhibition and adolescents' report of their past year and lifetime suicide attempts. Specifically, higher disinhibition was associated with a greater likelihood of having made a suicide attempt among adolescents with a history of CSA, but not among those without. The same pattern of results held in analyses of suicide attempt frequency.
Limitations
Primary findings were based on observational, cross-sectional data, and therefore, causal relationships cannot be inferred. The gender imbalance in the sample precluded stratifying our analyses by gender. CSA was ascertained by self-report; replication of the results with more objective measures is warranted.
Conclusions
Our findings indicate that CSA and disinhibition may work together to predict elevated suicide risk, and these results have implications for early identification efforts in youth at high risk for suicide.Psycholog
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