V1647 Ori: The X-ray Evolution of a Pre-main Sequence Accretion Burst

We present Chandra X-ray Observatory monitoring observations of the recent accretion outburst displayed by the pre-main sequence (pre-MS) star V1647 Ori. The X-ray observations were obtained over a period beginning prior to outburst onset in late 2003 and continuing through its apparent cessation in late 2005, and demonstrate that the mean flux of the spatially coincident X-ray source closely tracked the near-infrared luminosity of V1647 Ori throughout its eruption. We find negligible likelihood that the correspondence between X-ray and infrared light curves over this period was the result of multiple X-ray flares unrelated to the accretion burst. The recent Chandra data confirm that the X-ray spectrum of V1647 Ori hardened during outburst, relative both to its pre-outburst state and to the X-ray spectra of nearby pre-MS stars in the L1630 cloud. We conclude that the observed changes in the X-ray emission from V1647 Ori over the course of its 2003-2005 eruption were generated by a sudden increase and subsequent decline in its accretion rate. These results for V1647 Ori indicate that the flux of hard X-ray emission from erupting low-mass, pre-MS stars, and the duration and intensity of such eruptions, reflect the degree to which star-disk magnetic fields are reorganized before and during major accretion events.Comment: 12 pages, 3 figs.; accepted by the Astrophysical Journal (Letters

Recognizing Facial Mimicry In Virtual Group Conversations

With the current COVID-19 pandemic, group communication is often restricted to virtual video-conferencing platforms like Zoom in order to inhibit the spread of the virus. The virtual communication environment affects our ability to assess group emotion and support verbal messages through nonverbal communication. Because virtual meetings create visibility restrictions due to limited camera view, body language is occluded, and faces are now at the forefront of social interactions within groups. Since faces are still visible, it allows for some key components of interpersonal interactions to still occur, such as facial mimicry. Facial mimicry occurs when one person mirrors another person\u27s facial expressions. Most research on facial mimicry has been conducted on face-to-face interactions. Further studies have also shown that facial mimicry exists when an individual is reacting to a recorded video containing different expressions. However, there is limited research on facial mimicry within video-conferencing conversations. Our research aims to use facial expression recognition techniques to analyze if facial mimicry exists during group conversations over virtual platforms through facial action units and expressions. For this purpose, we used current state-of-the-art methods to recognize and analyze the activation of eye gaze, seven universal facial expressions, and seventeen commonly presented facial action units over time for each participant within various Zoom meetings that were uploaded on Youtube to measure facial mimicry. From observing the simultaneous activation of facial action units, our findings suggest that facial mimicry, specifically in reaction to smiling and positive facial expressions, does exist in video-conferencing group conversations. We plan to conduct future research to determine whether this positive facial mimicry improves group emotion and productivity.https://orb.binghamton.edu/research_days_posters_2021/1105/thumbnail.jp

Enhanced X-ray variability from V1647 Ori, the young star in outburst illuminating McNeil's Nebula

We report a ~38 ks X-ray observation of McNeil's Nebula obtained with XMM on 2004 April 4. V1647 Ori, the young star in outburst illuminating McNeil's Nebula, is detected with XMM and appears variable in X-rays. We investigate the hardness ratio variability and time variations of the event energy distribution with quantile analysis, and show that the large increase of the count rate from V1647 Ori observed during the second half of the observation is not associated with any large plasma temperature variations as for typical X-ray flares from young low-mass stars. X-ray spectral fitting shows that the bulk (~75%) of the intrinsic X-ray emission in the 0.5-8 keV energy band comes from a soft plasma component (0.9 keV) reminiscent of the X-ray spectrum of the classical T Tauri star TW Hya, for which X-ray emission is believed to be generated by an accretion shock onto the photosphere of a low-mass star. The hard plasma component (4.2 keV) contributes ~25% of the total X-ray emission, and can be understood only in the framework of plasma heating sustained by magnetic reconnection events. We find a hydrogen column density of NH=4.1E22 cm-2, which points out a significant excess of hydrogen column density compared to the value derived from optical/IR observations, consistent with the picture of the rise of a wind/jet unveiled from ground optical spectroscopy. The X-ray flux observed with XMM ranges from roughly the flux observed by Chandra on 2004 March 22 (~10 times greater than the pre-outburst X-ray flux) to a value two times greater than that caught by Chandra on 2004 March 7 (~200 times greater than the pre-outburst X-ray flux). We have investigated the possibility that V1647 Ori displays a periodic variation in X-ray brightness as suggested by the combined Chandra+XMM data set (abridged).Comment: 11 pages and 8 Figures. Accepted for publication by Astronomy & Astrophysic

Searching for coronal radio emission from protostars using Very-Long-Baseline Interferometry

In order to directly study the role of magnetic fields in the immediate vicinity of protostars, we use Very-Long-Baseline Interferometry (VLBI), aiming at the detection of non-thermal centimetric radio emission. This is technically the only possibility to study coronal emission at sub-AU resolution. We performed VLBI observations of the four nearby protostars HL Tau, LDN 1551 IRS5, EC 95, and YLW 15 in order to look for compact non-thermal centimetric radio emission. For maximum sensitivity, we used the High Sensitivity Array (HSA) where possible, involving the Very Long Baseline Array (VLBA), the phased Very Large Array (VLA), as well as the Arecibo, Green Bank, and Effelsberg radio telescopes. While all four protostars were detected in VLA-only data, only one source (YLW 15 VLA 2) was detected in the VLBI data. The possibility of non-detections due to free-free absorption, possibly depending on source geometry, is considered. For YLW 15 VLA 2, the prospects for an accurate orbit determination appear to be good.Comment: 8 pages, 4 figures, accepted for publication in A&

Endothelin‐1 response to whole‐body vibration in obese and normal weight individuals

Upregulation of endothelin‐1 (ET‐1) is the hallmark of various cardiovascular diseases (CVD). The purpose of the present study was to assess the ET‐1 response to an acute bout of whole‐body vibration (WBV) in humans and to determine the role of adiposity. Twenty‐two participants volunteered for the study; they were grouped into overweight/obese [(OW/OB): n = 11, Age: 33 ± 4 years, Body mass index (BMI): 35 ± 10 kg/m(2)] or normal weight [(NW): n = 11, Age: 28 ± 7 years, BMI: 21 ± 2 kg/m(2)]. Participants engaged in 10 cycles of WBV exercise (1 cycle = 1 min WBV followed by 30 s of rest). Blood samples were analyzed for ET‐1 pre‐WBV (PRE), immediately post (POST), 1 h (1H), 3 h (3H), and 24 h (24H) post‐WBV. There was a significant time main effect of WBV on circulating ET‐1 (F = 12.5, p < 0.001); however, the ET‐1 response was similar (F = 0.180, p = 0.677) between groups. Specifically, compared to PRE, a significant increase in ET‐1 was observed at 1H (p = 0.017) and 3H (p = 0.025). In addition, concentrations of ET‐1 were significantly lower at 24H compared to PRE (p = 0.019), 1H (p < 0.001), and 3H (p < 0.001). Maximal oxygen uptake during WBV was similar between the two groups. Acute WBV resulted in an initial rise in ET‐1, followed by a significantly lower ET‐1 at 24H in both groups. Findings support the utility of routine WBV exercise to elicit a decrease in ET‐1 and improve CVD risk, similar to what has been reported with traditional modes of exercise

AKARI observations of ice absorption bands towards edge-on young stellar objects

To investigate the composition and evolution of circumstellar ice around low-mass young stellar objects (YSOs), we observed ice absorption bands in the near infrared (NIR) towards eight YSOs ranging from class 0 to class II, among which seven are associated with edge-on disks. We performed slit-less spectroscopic observations using the grism mode of the InfraRed Camera (IRC) on board AKARI, which enables us to obtain full NIR spectra from 2.5 mu m to 5 mu m, including the CO2 band and the blue wing of the H2O band, which are inaccessible from the ground. We developed procedures to carefully process the spectra of targets with nebulosity. The spectra were fitted with polynomial baselines to derive the absorption spectra. The molecular absorption bands were then fitted with the laboratory database of ice absorption bands, considering the instrumental line profile and the spectral resolution of the grism dispersion element. Towards the class 0-I sources (L1527, IRC-L1041-2, and IRAS 04302), absorption bands of H2O, CO2, CO, and XCN are clearly detected. Column density ratios of CO2 ice and CO ice relative to H2O ice are 21-28% and 13-46%, respectively. If XCN is OCN-, its column density is as high as 2-6% relative to H2O ice. The HDO ice feature at 4.1 mu m is tentatively detected towards the class 0-I sources and HV Tau. Non-detections of the CH-stretching mode features around 3.5 mu m provide upper limits to the CH3OH abundance of 26% (L1527) and 42% (IRAS 04302) relative to H2O. We tentatively detect OCS ice absorption towards IRC-L1041-2. Towards class 0-I sources, the detected features should mostly originate in the cold envelope, while CO gas and OCN-could originate in the region close to the protostar, where there are warm temperatures and UV radiation. We detect H2O ice band towards ASR41 and 2MASSJ 1628137-243139, which are edge-on class II disks. We also detect H2O ice and CO2 ice towards HV Tau, HK Tau, and UY Aur, and tentatively detect CO gas features towards HK Tau and UY Aur

Resolved 24.5 micron emission from massive young stellar objects

Massive young stellar objects (MYSO) are surrounded by massive dusty envelopes. Our aim is to establish their density structure on scales of ~1000 AU, i.e. a factor 10 increase in angular resolution compared to similar studies performed in the (sub)mm. We have obtained diffraction-limited (0.6") 24.5 micron images of 14 well-known massive star formation regions with Subaru/COMICS. The images reveal the presence of discrete MYSO sources which are resolved on arcsecond scales. For many sources, radiative transfer models are capable of satisfactorily reproducing the observations. They are described by density powerlaw distributions (n(r) ~ r^(-p)) with p = 1.0 +/-0.25. Such distributions are shallower than those found on larger scales probed with single-dish (sub)mm studies. Other sources have density laws that are shallower/steeper than p = 1.0 and there is evidence that these MYSOs are viewed near edge-on or near face-on, respectively. The images also reveal a diffuse component tracing somewhat larger scale structures, particularly visible in the regions S140, AFGL 2136, IRAS 20126+4104, Mon R2, and Cep A. We thus find a flattening of the MYSO envelope density law going from ~10 000 AU down to scales of ~1000 AU. We propose that this may be evidence of rotational support of the envelope (abridged).Comment: 21 pages, accepted for A&

Establishing a Pragmatic Framework to Optimise Health Outcomes in Heart Failure and Multimorbidity (ARISE-HF): A Multidisciplinary Position Statement

Background Multimorbidity in heart failure (HF), defined as HF of any aetiology and multiple concurrent conditions that require active management, represents an emerging problem within the ageing HF patient population worldwide. Methods To inform this position paper, we performed: 1) an initial review of the literature identifying the ten most common conditions, other than hypertension and ischaemic heart disease, complicating the management of HF (anaemia, arrhythmias, cognitive dysfunction, depression, diabetes, musculoskeletal disorders, renal dysfunction, respiratory disease, sleep disorders and thyroid disease) and then 2) a review of the published literature describing the association between HF with each of the ten conditions. From these data we describe a clinical framework, comprising five key steps, to potentially improve historically poor health outcomes in this patient population. Results We identified five key steps (ARISE-HF) that could potentially improve clinical outcomes if applied in a systematic manner: 1) Acknowledge multimorbidity as a clinical syndrome that is associated with poor health outcomes, 2) Routinely profile (using a standardised protocol — adapted to the local health care system) all patients hospitalised with HF to determine the extent of concurrent multimorbidity, 3) Identify individualised priorities and person-centred goals based on the extent and nature of multimorbidity, 4) Support individualised, home-based, multidisciplinary, case management to supplement standard HF management, and 5) Evaluate health outcomes well beyond acute hospitalisation and encompass all-cause events and a person-centred perspective in affected individuals. Conclusions We propose ARISE-HF as a framework for improving typically poor health outcomes in those affected by multimorbidity in HF

Neural correlates of sexual cue reactivity in individuals with and without compulsive sexual behaviours

Although compulsive sexual behaviour (CSB) has been conceptualized as a "behavioural" addiction and common or overlapping neural circuits may govern the processing of natural and drug rewards, little is known regarding the responses to sexually explicit materials in individuals with and without CSB. Here, the processing of cues of varying sexual content was assessed in individuals with and without CSB, focusing on neural regions identified in prior studies of drug-cue reactivity. 19 CSB subjects and 19 healthy volunteers were assessed using functional MRI comparing sexually explicit videos with non-sexual exciting videos. Ratings of sexual desire and liking were obtained. Relative to healthy volunteers, CSB subjects had greater desire but similar liking scores in response to the sexually explicit videos. Exposure to sexually explicit cues in CSB compared to non-CSB subjects was associated with activation of the dorsal anterior cingulate, ventral striatum and amygdala. Functional connectivity of the dorsal anterior cingulate-ventral striatum-amygdala network was associated with subjective sexual desire (but not liking) to a greater degree in CSB relative to non-CSB subjects. The dissociation between desire or wanting and liking is consistent with theories of incentive motivation underlying CSB as in drug addictions. Neural differences in the processing of sexual-cue reactivity were identified in CSB subjects in regions previously implicated in drug-cue reactivity studies. The greater engagement of corticostriatal limbic circuitry in CSB following exposure to sexual cues suggests neural mechanisms underlying CSB and potential biological targets for interventions

The Poggendorff illusion affects manual pointing as well as perceptual judgements

Pointing movements made to a target defined by the imaginary intersection of a pointer with a distant landing line were examined in healthy human observers in order to determine whether such motor responses are susceptible to the Poggendorff effect. In this well-known geometric illusion observers make systematic extrapolation errors when the pointer abuts a second line (the inducer). The kinematics of extrapolation movements, in which no explicit target was present, where similar to those made in response to a rapid-onset (explicit) dot target. The results unambiguously demonstrate that motor (pointing) responses are susceptible to the illusion. In fact, raw motor biases were greater than for perceptual responses: in the absence of an inducer (and hence also the acute angle of the Poggendorff stimulus) perceptual responses were near-veridical, whilst motor responses retained a bias. Therefore, the full Poggendorff stimulus contained two biases: one mediated by the acute angle formed between the oblique pointer and the inducing line (the classic Poggendorff effect), which affected both motor and perceptual responses equally, and another bias, which was independent of the inducer and primarily affected motor responses. We conjecture that this additional motor bias is associated with an undershoot in the unknown direction of movement and provide evidence to justify this claim. In conclusion, both manual pointing and perceptual judgements are susceptible to the well-known Poggendorff effect, supporting the notion of a unitary representation of space for action and perception or else an early locus for the effect, prior to the divergence of processing streams