Stellar activity as noise in exoplanet detection I. Methods and application to solar-like stars and activity cycles

The detection of exoplanets using any method is prone to confusion due to the intrinsic variability of the host star. We investigate the effect of cool starspots on the detectability of the exoplanets around solar-like stars using the radial velocity method. For investigating this activity-caused "jitter" we calculate synthetic spectra using radiative transfer, known stellar atomic and molecular lines, different surface spot configurations, and an added planetary signal. Here, the methods are described in detail, tested and compared to previously published studies. The methods are also applied to investigate the activity jitter in old and young solar-like stars, and over a solar-like activity cycles. We find that the mean full jitter amplitude obtained from the spot surfaces mimicking the solar activity varies during the cycle approximately between 1 m/s and 9 m/s. With a realistic observing frequency a Neptune mass planet on a one year orbit can be reliably recovered. On the other hand, the recovery of an Earth mass planet on a similar orbit is not feasible with high significance. The methods developed in this study have a great potential for doing statistical studies of planet detectability, and also for investigating the effect of stellar activity on recovered planetary parameters.Comment: Accepted to MNRA

Do Respondents use Extra Information Provided in Online Best-Worst Choice Experiments?

An issue of interest to researchers is the amount of explanatory information one needs to give respondents making decisions in choice tasks. One way to resolve this issue is to let people select only relevant information from interactive information sources. This resolution poses unanswered questions: e.g., will respondents use the extra information, and potential systematic differences in information users and non-users. To shed some light on this issue, we let respondents access optional descriptive information about attributes in the form of partial (verbal) and full (verbal plus visual) glossaries associated with a Best-Worst (BW) web survey. Only a small minority with higher subjective product knowledge accessed the glossary information. We found no significant difference between verbal and visual information in attractiveness of use or impact on choice

Voice Flows To And Around Leaders: Understanding When Units Are Helped Or Hurt By Employee Voice

In two studies, we develop and test theory about the relationship between speaking up, one type of organizational citizenship behavior, and unit performance by accounting for where employee voice is flowing. Results from a qualitative study of managers and professionals across a variety of industries suggest that voice to targets at different formal power levels (peers or superiors) and locations in the organization (inside or outside a focal unit) differs systematically in terms of its usefulness in generating actions to a unit's benefit on the issues raised and in the likely information value of the ideas expressed. We then theorize how distinct voice flows should be differentially related to unit performance based on these core characteristics and test our hypotheses using time-lagged field data from 801 employees and their managers in 93 units across nine North American credit unions. Results demonstrate that voice flows are positively related to a unit's effectiveness when they are targeted at the focal leader of that unitwho should be able to take actionwhether from that leader's own subordinates or those in other units, and negatively related to a unit's effectiveness when they are targeted at coworkers who have little power to effect change. Together, these studies provide a structural framework for studying the nature and impact of multiple voice flows, some along formal reporting lines and others that reflect the informal communication structure within organizations. This research demonstrates that understanding the potential performance benefits and costs of voice for leaders and their units requires attention to the structure and complexity of multiple voice flows rather than to an undifferentiated amount of voice.Business Administratio

The Evidence Chamber: Playful Science Communication and Research Through Digital Storytelling

In a courtroom, it is essential that the scientific evidence is both understandable and understood, so that the strengths and limitations of that evidence, within the context of a legal case, can inform decision making. The Evidence Chamber brings together entertainment, public engagement with science and research into a public performance activity that is centred around digital storytelling and science communication. This experience engages public audiences with science and allows a better understanding of how people interpret scientific evidence. In this paper, we discuss how we created this experience as an in-person and fully virtual performance through successful collaboration between forensic science research, public audiences, public engagement professionals, the legal profession, and digital performance artists

Accuracy of Ultrasonography-Guided Fine-Needle Aspiration in Detecting Persistent Nodal Disease After Chemoradiotherapy

IMPORTANCE: Few patients with persistent adenopathy following chemoradiotherapy (CRT) for head and neck squamous cell carcinoma harbor viable disease. Improved selectivity for surgical salvage is needed to prevent unnecessary salvage neck dissection. OBJECTIVE: To determine whether ultrasonography-guided fine-needle aspiration (FNA) can be used to identify viable cancer cells in the lymph nodes of patients with persistent radiographic adenopathy following CRT. DESIGN, SETTING, AND PARTICIPANTS: A pilot study included patients undergoing preoperative ultrasonography-guided FNA of lymph nodes considered suspicious on radiography prior to planned neck dissection at a quaternary care facility from February 28, 2011, to March 18, 2013. Data analysis was performed from April 28 to December 24, 2013. Patients treated for head and neck squamous cell carcinoma with CRT who were determined to have persistent neck disease on a 6-week posttreatment computed tomographic scan of the neck and scheduled for salvage neck dissection were considered candidates for this pilot study. All patients enrolled in the study underwent ultrasonography-guided FNA of the suspicious lymph nodes within 2 weeks of the planned neck dissection. The cytopathologist reading the samples was blinded to the patient's identity. EXPOSURES: Fine-needle aspiration with a 23- to 25-gauge needle following CRT. MAIN OUTCOMES AND MEASURES: The accuracy of ultrasonography-guided FNA cytologic results was compared with the standard of surgical pathologic examination of neck dissection specimens. RESULTS: Fourteen patients (11 [79%] men; mean [SD] age, 57.8 [11.2] years) were enrolled in this pilot study; data were collected on 17 lymph nodes. Among these 14 patients with incomplete radiographic clinical response, 17 lymph node aspirations were performed. Ultrasonography-guided FNA identified squamous cell carcinoma in the aspirates of 4 (80%) of the 5 nodes with squamous cell carcinoma identified on pathologic testing and confirmed the absence of disease in the remaining 12 (71%) lymph nodes. The statistical analysis of these results revealed a sensitivity of 80%; specificity, 100%; positive predictive value, 100%; and negative predictive value, 92.3%. The diagnostic accuracy of ultrasonography-guided FNA at detecting residual persistent cancer was 88%. CONCLUSIONS AND RELEVANCE: This pilot study suggests that ultrasonography-guided FNA may be a feasible ancillary diagnostic imaging tool to imaging to assess patients with radiographic persistent disease prior to consideration of salvage neck dissection

Spectroscopy of 50^{50}Sc and ab initio calculations of B(M3)B(M3) strengths

The GRIFFIN spectrometer at TRIUMF-ISAC has been used to study excited states and transitions in $^{50}$Sc following the $\beta$-decay of $^{50}$Ca. Branching ratios were determined from the measured $\gamma$-ray intensities, and angular correlations of $\gamma$ rays have been used to firmly assign the spins of excited states. The presence of an isomeric state that decays by an $M3$ transition with a $B(M3)$ strength of 13.6(7)\,W.u. has been confirmed. We compare with the first {\it ab initio} calculations of $B(M3$) strengths in light and medium-mass nuclei from the valence-space in-medium similarity renormalization group approach, using consistently derived effective Hamiltonians and $M3$ operator. The experimental data are well reproduced for isoscalar $M3$ transitions when using bare $g$-factors, but the strength of isovector $M3$ transitions are found to be underestimated by an order of magnitude

A New Frontier: Lessons Learned from NDLA\u27s First Online Un-Conference

NDLA’s Health Science Information and Academic & Special Libraries Sections held its inaugural fully online “un-conference” using Blackboard Collaborate Ultra. A fully online conference can be a robust, low-cost alternative to a traditional conference that could be an advantage to librarians looking for professional development opportunities in this rural state. In this session, the planners will discuss creating this experience and lessons learned.https://commons.und.edu/cfl-lpp/1002/thumbnail.jp