206 research outputs found
Identification of CNS Injury-Related microRNAs as Novel Toll-Like Receptor 7/8 Signaling Activators by Small RNA Sequencing
Toll-like receptors (TLRs) belong to pattern recognition receptors, which respond to danger signals such as pathogen-associated molecular patterns or damage-associated molecular patterns. Upon TLR activation in microglia, the major immune cells in the brain, distinct signaling cascades trigger the production of inflammatory molecules, being a critical feature in neuroinflammation and neurodegenerative processes. Recently, individual microRNAs (miRNAs) were shown to act as endogenous TLR ligands. Here, we conducted systematic screening for miRNAs as potential TLR7/8 ligands by small RNA sequencing of apoptotic neurons and their corresponding supernatants. Several miRNA species were identified in both supernatants and injured neurons, and 83.3% of the media-enriched miRNAs activated murine and/or human TLR7/8 expressed in HEK293-derived TLR reporter cells. Among the detected extracellular miRNAs, distinct miRNAs such as miR-340-3p and miR-132-5p induced cytokine and chemokine release from microglia and triggered neurotoxicity in vitro. Taken together, our systematic study establishes miRNAs released from injured neurons as new TLR7/8 activators, which contribute to inflammatory and neurodegenerative responses in the central nervous system (CNS)
Warriors and Peacekeepers: Testing a Biosocial Implicit Leadership Hypothesis of Intergroup Relations Using Masculine and Feminine Faces
This paper examines the impact of facial cues on leadership emergence. Using evolutionary social psychology, we expand upon implicit and contingent theories of leadership and propose that different types of intergroup relations elicit different implicit cognitive leadership prototypes. It is argued that a biologically based hormonal connection between behavior and corresponding facial characteristics interacts with evolutionarily consistent social dynamics to influence leadership emergence. We predict that masculine-looking leaders are selected during intergroup conflict (war) and feminine-looking leaders during intergroup cooperation (peace). Across two experiments we show that a general categorization of leader versus nonleader is an initial implicit requirement for emergence, and at a context-specific level facial cues of masculinity and femininity contingently affect war versus peace leadership emergence in the predicted direction. In addition, we replicate our findings in Experiment 1 across culture using Western and East Asian samples. In Experiment 2, we also show that masculine-feminine facial cues are better predictors of leadership than male-female cues. Collectively, our results indicate a multi-level classification of context-specific leadership based on visual cues imbedded in the human face and challenge traditional distinctions of male and female leadership
Exploration of the phase diagram of liquid water in the low-temperature metastable region using synthetic fluid inclusions
We present new experimental data of the low-temperature metastable region of liquid water derived from high-density synthetic fluid inclusions (996-916 kg m-3) in quartz. Microthermometric measurements include: (i) prograde (upon heating) and retrograde (upon cooling) liquid-vapour homogenisation. We used single ultrashort laser pulses to stimulate vapour bubble nucleation in initially monophase liquid inclusions. Water densities were calculated based on prograde homogenisation temperatures using the IAPWS-95 formulation. We found retrograde liquid-vapour homogenisation temperatures in excellent agreement with IAPWS-95. (ii) Retrograde ice nucleation. Raman spectroscopy was used to determine the nucleation of ice in the absence of the vapour bubble. Our ice nucleation data in the doubly metastable region are inconsistent with the low-temperature trend of the spinodal predicted by IAPWS-95, as liquid water with a density of 921 kg m-3 remains in a homogeneous state during cooling down to a temperature of -30.5 °C, where it is transformed into ice whose density corresponds to zero pressure. (iii) Ice melting. Ice melting temperatures of up to 6.8 °C were measured in the absence of the vapour bubble, i.e. in the negative pressure region. (iv) Spontaneous retrograde and, for the first time, prograde vapour bubble nucleation. Prograde bubble nucleation occurred upon heating at temperatures above ice melting. The occurrence of prograde and retrograde vapour bubble nucleation in the same inclusions indicates a maximum of the bubble nucleation curve in the ϱ-T plane at around 40 °C. The new experimental data represent valuable benchmarks to evaluate and further improve theoretical models describing the p-V-T properties of metastable water in the low-temperature region
Highly coherent electron beam from a laser-triggered tungsten needle tip
We report on a quantitative measurement of the spatial coherence of electrons
emitted from a sharp metal needle tip. We investigate the coherence in
photoemission using near-ultraviolet laser triggering with a photon energy of
3.1 eV and compare it to DC-field emission. A carbon-nanotube is brought in
close proximity to the emitter tip to act as an electrostatic biprism. From the
resulting electron matter wave interference fringes we deduce an upper limit of
the effective source radius both in laser-triggered and DC-field emission mode,
which quantifies the spatial coherence of the emitted electron beam. We obtain
nm in laser-triggered and nm in DC-field
emission mode, revealing that the outstanding coherence properties of electron
beams from needle tip field emitters are largely maintained in laser-induced
emission. In addition, the relative coherence width of 0.36 of the photoemitted
electron beam is the largest observed so far. The preservation of electronic
coherence during emission as well as ramifications for time-resolved electron
imaging techniques are discussed
On Activism and Academia: Reflecting Together and Sharing Experiences Among Critical Friends
In recent years HCI and CSCW work has increasingly begun to address complex social problems and issues of social justice worldwide. Such activist-leaning work is not without problems. Through the experiences and reflections of an activist becoming academic and an academic becoming an activist, we outline these difficulties such as (1) the risk of perpetuating violence, oppression and exploitation when working with marginalised communities, (2) the reception of activist-academic work within our academic communities, and (3) problems of social justice that exist within our academic communities. Building on our own experiences, practices and existing literature from a variety of disciplines we advocate for the possibility of an activist-academic practice, outline possible ways forward and formulate questions we need to answer for HCI to contribute to a more just world
Helios spacecraft data revisited: Detection of cometary meteoroid trails by in-situ dust impacts
Cometary meteoroid trails exist in the vicinity of comets, forming fine
structure of the interplanetary dust cloud. The trails consist predominantly of
cometary particles with sizes of approximately 0.1 mm to 1 cm which are ejected
at low speeds and remain very close to the comet orbit for several revolutions
around the Sun. When re-analysing the Helios dust data measured in the 1970s,
Altobelli et al. (2006) recognized a clustering of seven impacts, detected in a
very narrow region of space at a true anomaly angle of 135 deg, which the
authors considered as potential cometary trail particles. We re-analyse these
candidate cometary trail particles to investigate the possibility that some or
all of them indeed originate from cometary trails and we constrain their source
comets. The Interplanetary Meteoroid Environment for eXploration (IMEX) dust
streams in space model is a new universal model for cometary meteoroid streams
in the inner solar system, developed by Soja et al. (2015). Using IMEX we study
cometary trail traverses by Helios. During ten revolutions around the Sun, and
in the narrow region of space where Helios detected the candidate dust
particles, the spacecraft repeatedly traversed the trails of comets
45P/Honda-Mrkos-Pajduvsakova and 72P/Denning-Fujikawa. Based on the detection
times and particle impact directions, four detected particles are compatible
with an origin from these two comets. We find a dust spatial density in these
trails of about 10^-8 to 10^-7 m^-3. The in-situ detection and analysis of
meteoroid trail particles which can be traced back to their source bodies by
spacecraft-based dust analysers opens a new window to remote compositional
analysis of comets and asteroids without the necessity to fly a spacecraft to
or even land on those celestial bodies. This provides new science opportunities
for future missions like Destiny+, Europa Clipper and IMAP.Comment: 13 pages, 9 Figures, 2 Tables, accepted for pubication by Astronomy
and Astrophysic
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