Production of Hypervelocity Stars through Encounters with Stellar-Mass Black Holes in the Galactic Centre

Stars within 0.1 pc of the supermassive black hole Sgr A* at the Galactic centre are expected to encounter a cluster of stellar-mass black holes (BHs) that have segregated to that region. Some of these stars will scatter off an orbiting BH and be kicked out of the Galactic centre with velocities up to ~2000 km/s. We calculate the resulting ejection rate of hypervelocity stars (HVSs) by this process under a variety of assumptions, and find it to be comparable to the tidal disruption rate of binary stars by Sgr A*, first discussed by Hills (1988). Under some conditions, this novel process is sufficient to account for all of the hypervelocity B-stars observed in the halo, and may dominate the production rate of all HVSs with lifetimes much less than the relaxation time-scale at a distance ~2 pc from Sgr A* (>~ 2 Gyr). Since HVSs are produced by at least two unavoidable processes, the statistics of HVSs could reveal bimodal velocity and mass distributions, and can constrain the distribution of BHs and stars in the innermost 0.1 pc around Sgr A*.Comment: 8 pages, 3 figures. Accepted for publication in MNRAS. Some major changes to text, however conclusions remain the sam

The Spirituality of Addictions: A Christian Patristic Model and Procedure for Assessment

Addiction theory has focused on the debilitating effects that drug addicts and alcoholics face. However, addiction can permeate much further into our lives than just through drugs and alcohol. Evagrius of Ponticus presented eight tempting thoughts that comprised all the beliefs, behaviors, items, and emotions that an individual can be disorderly attached to. These disordered attachments can have enslaving effects on an individual that constrains the person’s will and desire for freedom from these preoccupations. We also include a measure that assesses spiritual involvement and locus of control. The purpose of this study is to compile a psychological measurement that will assess the many domains of disordered attachment an individual can encounter and the degree to which it constrains their lives. This measure will consist of approximately 75 Likert scale items that include questions pertaining to pride, emotions, relations, sexuality, avarice, power/control, and problems of desire. The factors we have derived through factor analysis allow for each participant to be scored on various subscales. These scores will indicate the specific nature of the addictive tendencies. Lastly, individuals who are found to be more spiritually involved are presumed to be less attached to the constructs mentioned above

Can You Spot the Fake?

The ability to correctly interpret smiles is a skill that can be helpful in many aspects of life. One key feature that people look at is a smile, but smiles may not always be genuine. In our study, we focused on the detection of genuine and fake smiles and trained subjects to detect deception. The first training group was given applicable information, through PowerPoint, on distinguishing between smiles along with two videos presenting a genuine and fake smile. The second group viewed a PowerPoint with applicable information without videos. The third group viewed a PowerPoint containing just videos. Our control group was asked to think about situations where a fake or genuine smile would be used. Before training, participants viewed 10 smile videos and indicated whether each smile was genuine or fake. Following training, the participants viewed 10 new videos and again indicated whether each smile was genuine or fake. We hypothesized that the training groups would identify more smiles correctly than the control group. One week later, all groups viewed the same 20 videos again to determine whether the training had a lasting effect

Potential uses of AI for perioperative nursing handoffs: A qualitative study

OBJECTIVE: Situational awareness and anticipatory guidance for nurses receiving a patient after surgery are keys to patient safety. Little work has defined the role of artificial intelligence (AI) to support these functions during nursing handoff communication or patient assessment. We used interviews to better understand how AI could work in this context. MATERIALS AND METHODS: Eleven nurses participated in semistructured interviews. Mixed inductive-deductive thematic analysis was used to extract major themes and subthemes around roles for AI supporting postoperative nursing. RESULTS: Five themes were generated from the interviews: (1) nurse understanding of patient condition guides care decisions, (2) handoffs are important to nurse situational awareness, but multiple barriers reduce their effectiveness, (3) AI may address barriers to handoff effectiveness, (4) AI may augment nurse care decision making and team communication outside of handoff, and (5) user experience in the electronic health record and information overload are likely barriers to using AI. Important subthemes included that AI-identified problems would be discussed at handoff and team communications, that AI-estimated elevated risks would trigger patient re-evaluation, and that AI-identified important data may be a valuable addition to nursing assessment. DISCUSSION AND CONCLUSION: Most research on postoperative handoff communication relies on structured checklists. Our results suggest that properly designed AI tools might facilitate postoperative handoff communication for nurses by identifying specific elevated risks faced by a patient, triggering discussion on those topics. Limitations include a single center, many participants lacking of applied experience with AI, and limited participation rate

The role of mental imagery in Parkinson\u27s disease rehabilitation

Parkinson\u27s disease (PD) is a disabling neurodegenerative disease whose manifestations span motor, sensorimotor, and sensory domains. While current therapies for PD include pharmacological, invasive, and physical interventions, there is a constant need for developing additional approaches for optimizing rehabilitation gains. Mental imagery is an emerging field in neurorehabilitation and has the potential to serve as an adjunct therapy to enhance patient function. Yet, the literature on this topic is sparse. The current paper reviews the motor, sensorimotor, and sensory domains impacted by PD using gait, balance, and pain as examples, respectively. Then, mental imagery and its potential for PD motor and non-motor rehabilitation is discussed, with an emphasis on its suitability for addressing gait, balance, and pain deficits in people with PD. Lastly, future research directions are suggested

Ethylene to Linear, Alpha Olefins (1-Hexene & 1-Octene)

A chemical plant was theoretically designed to produce approximately 100 MMlbs/yr of linear alpha olefins (LAOs). 1-hexene and 1-octene were the products of the trimerization and tetramerization reactions as mentioned in the patent (US 8,076,523 B2). Based on the patent, a continuous homogeneous liquid reaction was carried out in a 30,000 gallon CSTR using a chromium based catalyst, with an activator and varying ligands for both the trimerization and tetramerization reactions. Plant calculations were performed, and the plant design simulation was completed on ASPEN PLUS®. The designed plant had the flexibility to switch between a 40:60% and 60:40% 1-hexene:1- octene by varying the amount of catalyst fed to the system. Product purity was 99.9% for 1- hexene and 99.0% for 1-octene, as required by the market. The plant despite its significant upfront capital investments ($43M) was estimated to be a profitable business venture with an IRR of 19$7.8M, assuming the plant is in operation for 15 years. Based on the economic potential of this process, the design group recommends construction of this plant with recommendations

Within-Home versus Between-Home Variability of House Dust Endotoxin in a Birth Cohort

Endotoxin exposure has been proposed as an environmental determinant of allergen responses in children. To better understand the implications of using a single measurement of house dust endotoxin to characterize exposure in the first year of life, we evaluated room-specific within-home and between-home variability in dust endotoxin obtained from 470 households in Boston, Massachusetts. Homes were sampled up to two times over 5–11 months. We analyzed 1,287 dust samples from the kitchen, family room, and baby’s bedroom for endotoxin. We fit a mixed-effects model to estimate mean levels and the variation of endotoxin between homes, between rooms, and between sampling times. Endotoxin ranged from 2 to 1,945 units per milligram of dust. Levels were highest during summer and lowest in the winter. Mean endotoxin levels varied significantly from room to room. Cross-sectionally, endotoxin was moderately correlated between family room and bedroom floor (r = 0.30), between family room and kitchen (r = 0.32), and between kitchen and bedroom (r = 0.42). Adjusting for season, the correlation of endotoxin levels within homes over time was 0.65 for both the bedroom and kitchen and 0.54 for the family room. The temporal within-home variance of endotoxin was lowest for bedroom floor samples and highest for kitchen samples. Between-home variance was lowest in the family room and highest for kitchen samples. Adjusting for season, within-home variation was less than between-home variation for all three rooms. These results suggest that room-to-room and home-to-home differences in endotoxin influence the total variability more than factors affecting endotoxin levels within a room over time

A Bayesian analysis of the time through the order penalty in baseball

As a baseball game progresses, batters appear to perform better the more times they face a particular pitcher. The apparent drop-off in pitcher performance from one time through the order to the next, known as the Time Through the Order Penalty (TTOP), is often attributed to within-game batter learning. Although the TTOP has largely been accepted within baseball and influences many managers' in-game decision making, we argue that existing approaches of estimating the size of the TTOP cannot disentangle continuous evolution in pitcher performance over the course of the game from discontinuities between successive times through the order. Using a Bayesian multinomial regression model, we find that, after adjusting for confounders like batter and pitcher quality, handedness, and home field advantage, there is little evidence of strong discontinuity in pitcher performance between times through the order. Our analysis suggests that the start of the third time through the order should not be viewed as a special cutoff point in deciding whether to pull a starting pitcher.Comment: Accepted to JQA

Entropy-Based Strategies for Multi-Bracket Pools

Much work in the March Madness literature has discussed how to estimate the probability that any one team beats any other team. There has been strikingly little work, however, on what to do with these win probabilities. Hence we pose the multi-brackets problem: given these probabilities, what is the best way to submit a set of $n$ brackets to a March Madness bracket challenge? This is an extremely difficult question, so we begin with a simpler situation. In particular, we compare various sets of $n$ randomly sampled brackets, subject to different entropy ranges or levels of chalkiness (rougly, chalkier brackets feature fewer upsets). We learn three lessons. First, the observed NCAA tournament is a "typical" bracket with a certain "right" amount of entropy (roughly, a "right" amount of upsets), not a chalky bracket. Second, to maximize the expected score of a set of $n$ randomly sampled brackets, we should be successively less chalky as the number of submitted brackets increases. Third, to maximize the probability of winning a bracket challenge against a field of opposing brackets, we should tailor the chalkiness of our brackets to the chalkiness of our opponents' brackets