Insights into the Assembly of Arctic Alaska: Provenance and Geochemical Data from the Doonerak Fenster and Endicott Mountains Allochthon

The Doonerak fenster of the central Brooks Range contains the Apoon assemblage, a suite of Early Paleozoic mafic-to-intermediate volcanic and siliciclastic rocks. The fenster exposes deep structural levels of the Brooks Range between regions of Laurentian and non-Laurentian origin in Arctic Alaska. During the Mesozoic to Cenozoic formation of the Brooks Range, Upper Devonian to Triassic siliciclastic and carbonate rocks of the Endicott Mountains allochthon were thrusted northward and juxtaposed over the top of this volcanic suite.;New geochemical data indicates that the Apoon assemblage formed as part of an island arc complex. The assemblage contains basaltic-to-andesitic rocks with diverse textures, including pillow basalts and cross-cutting dikes and sills. Enrichment in large ion lithophile elements (e.g. Cs, Rb, Ba, Th), depletion in high field strength elements (e.g. Nb, P, Zr, Ti), and chondrite-normalized rare-earth element (REE) trends within the Apoon volcanics are consistent with formation in an island arc setting and corroborate previous work.;Detrital zircon spectra from volcaniclastic portions of the Apoon assemblage show a prominent unimodal 440--530 Ma population centered on 504 Ma with only minor populations potentially derived from Laurentia. The siliciclastic units unconformably overlying the Apoon assemblage (Ellesmerian sequence) and those of the Endicott Mountains allochthon mostly lack detritus from this 504 Ma population and are instead dominated by 400--440 Ma populations centered on ~420 Ma. While this is dissimilar from the Apoon assemblage, detritus of this age is common in rocks of the Canadian Arctic, Svalbard, and eastern Greenland and is associated with the Caledonian orogeny.;The coexistence of Caledonian detritus alongside 800--550 Ma populations within samples from the northern margin of the fenster also indicates a connection to the Timanian orogen of northern Baltica. The youngest portions of the Apoon assemblage also show significant Laurentian and Caledonian age detritus. This shift in provenance could be explained by the closure of an oceanic basin, providing newly integrated sediment pathways. Collectively, evidence presented here indicates that the Apoon assemblage formed as part of an island arc, which initially formed in a relatively isolated geographic position and received detritus from mostly proximal sources (single unimodal 504 Ma population). This arc progressively approached and eventually docked onto the margin of northwest Laurentian during closure of the northernmost Iapetus Ocean, eventually amalgamating regions of Laurentian and non-Laurentian origin. Thus, the Doonerak fenster preserves an island arc complex and marks the location of a Paleozoic suture between Laurentian and non-Laurentian portions of Arctic Alaska

Quantifying spatial acuity of frequency resolved midair ultrasound vibrotactile stimuli

Spatial acuity is a fundamental property of any sensory system. In the case of the somatosensory system, the two-point discrimination (2PD) test has long been used to investigate tactile spatial resolution. However, the somatosensory system comprises three main mechanoreceptive channels: the slowly adapting channel (SA) responds to steady pressure, the rapidly adapting channel (RA) responds to low-frequency vibration, and the Pacinian channel (PC) responds to high-frequency vibration. The use of mechanical stimuli in the classical 2PD test means that previous studies on tactile acuity have primarily focussed on the pressure-sensitive channel alone, while neglecting other submodalities. Here, we used a novel ultrasound stimulation to systematically investigate the spatial resolution of the two main vibrotactile channels. Contrary to the textbook view of poor spatial resolution for PC-like stimuli, across four experiments we found that high-frequency vibration produced surprisingly good spatial acuity. This effect remained after controlling for interchannel differences in stimulus detectability and perceived intensity. Laser doppler vibrometry experiments confirmed that the acuity of the PC channel was not simply an artifact of the skin's resonance to high-frequency mechanical stimulation. Thus, PC receptors may transmit substantial spatial information, despite their sparse distribution, deep location, and large receptive fields

TOUCHLESS: Demonstrations of Contactless Haptics for Affective Touch

A set of demonstrators of contactless haptic principles is described in this work. The technologies are based on electrostatic piloerection, chemical compounds and ultrasound. Additionally, applications related to affective touch are presented, ranging from storytelling to biosignal transfer, accompanied with a simple application to edit dynamic tactile patterns in an easy way. The demonstrators are the result of the Touchless project, which is a H2020 european collaborative project that integrates 3 universities and 3 companies. These demostrators are contactless haptic experiences and thus facilitate the come-and-interact paradigm, where users can approach the demo booth and directly experience the applications without having to wear devices, making the experience fast and hygienic

TOUCHLESS: demonstrations of contactless haptics for affective touch

A set of demonstrators of contactless haptic principles is described in this work. The technologies are based on electrostatic piloerection, chemical compounds and ultrasound. Additionally, applications related to affective touch are presented, ranging from storytelling to biosignal transfer, accompanied with a simple application to edit dynamic tactile patterns in an easy way. The demonstrators are the result of the Touchless project, which is a H2020 european collaborative project that integrates 3 universities and 3 companies. These demostrators are contactless haptic experiences and thus facilitate the come-and-interact paradigm, where users can approach the demo booth and directly experience the applications without having to wear devices, making the experience fast and hygienic.Funded by EU Horizon 2020 research and innovation programme grant agreement No 101017746 TOUCHLESS

Quantifying spatial acuity of frequency resolved midair ultrasound vibrotactile stimuli

Abstract Spatial acuity is a fundamental property of any sensory system. In the case of the somatosensory system, the two-point discrimination (2PD) test has long been used to investigate tactile spatial resolution. However, the somatosensory system comprises three main mechanoreceptive channels: the slowly adapting channel (SA) responds to steady pressure, the rapidly adapting channel (RA) responds to low-frequency vibration, and the Pacinian channel (PC) responds to high-frequency vibration. The use of mechanical stimuli in the classical 2PD test means that previous studies on tactile acuity have primarily focussed on the pressure-sensitive channel alone, while neglecting other submodalities. Here, we used a novel ultrasound stimulation to systematically investigate the spatial resolution of the two main vibrotactile channels. Contrary to the textbook view of poor spatial resolution for PC-like stimuli, across four experiments we found that high-frequency vibration produced surprisingly good spatial acuity. This effect remained after controlling for interchannel differences in stimulus detectability and perceived intensity. Laser doppler vibrometry experiments confirmed that the acuity of the PC channel was not simply an artifact of the skin’s resonance to high-frequency mechanical stimulation. Thus, PC receptors may transmit substantial spatial information, despite their sparse distribution, deep location, and large receptive fields

Association of baseline hematoma and edema volumes with one-year outcome and long-term survival after spontaneous intracerebral hemorrhage: A community-based inception cohort study

Background Hospital-based studies have reported variable associations between outcome after spontaneous intracerebral hemorrhage and peri-hematomal edema volume. Aims In a community-based study, we aimed to investigate the existence, strength, direction, and independence of associations between intracerebral hemorrhage and peri-hematomal edema volumes on diagnostic brain CT and one-year functional outcome and long-term survival. Methods We identified all adults, resident in Lothian, diagnosed with first-ever, symptomatic spontaneous intracerebral hemorrhage between June 2010 and May 2013 in a community-based, prospective inception cohort study. We defined regions of interest manually and used a semi-automated approach to measure intracerebral hemorrhage volume, peri-hematomal edema volume, and the sum of these measurements (total lesion volume) on first diagnostic brain CT performed at ≤3 days after symptom onset. The primary outcome was death or dependence (scores 3–6 on the modified Rankin Scale) at one-year after intracerebral hemorrhage. Results Two hundred ninety-two (85%) of 342 patients (median age 77.5 y, IQR 68–83, 186 (54%) female, median time from onset to CT 6.5 h (IQR 2.9–21.7)) were dead or dependent one year after intracerebral hemorrhage. Peri-hematomal edema and intracerebral hemorrhage volumes were colinear ( R2 = 0.77). In models using both intracerebral hemorrhage and peri-hematomal edema, 10 mL increments in intracerebral hemorrhage (adjusted odds ratio (aOR) 1.72 (95% CI 1.08–2.87); p = 0.029) but not peri-hematomal edema volume (aOR 0.92 (0.63–1.45); p = 0.69) were independently associated with one-year death or dependence. 10 mL increments in total lesion volume were independently associated with one-year death or dependence (aOR 1.24 (1.11–1.42); p = 0.0004). Conclusion Total volume of intracerebral hemorrhage and peri-hematomal edema, and intracerebral hemorrhage volume alone on diagnostic brain CT, undertaken at three days or sooner, are independently associated with death or dependence one-year after intracerebral hemorrhage, but peri-hematomal edema volume is not. Data access statement Anonymized summary data may be requested from the corresponding author. </jats:sec