Chemistry vs. Physics: A Comparison of How Biology Majors View Each Discipline

A student's beliefs about science and learning science may be more or less sophisticated depending on the specific science discipline. In this study, we used the physics and chemistry versions of the Colorado Learning Attitudes about Science Survey (CLASS) to measure student beliefs in the large, introductory physics and chemistry courses, respectively. We compare how biology majors -- generally required to take both of the courses -- view these two disciplines. We find that these students' beliefs are more sophisticated about physics (more like the experts in that discipline) than they are about chemistry. At the start of the term, the average % Overall Favorable score on the CLASS is 59% in physics and 53% in chemistry. The students' responses are statistically more expert-like in physics than in chemistry on 10 statements (P lesser-than-or-equal-to 0.01), indicating that these students think chemistry is more about memorizing disconnected pieces of information and sample problems, and has less to do with the real world. In addition, these students' view of chemistry degraded over the course of the term. Their favorable scores shifted -5.7% and -13.5% in 'Overall' and the 'Real World Connection' category, respectively; in the physics course, which used a variety of research-based teaching practices, these scores shifted 0.0% and +0.3%, respectively. The chemistry shifts are comparable to those previously observed in traditional introductory physics courses

Experiences of Canadian Oncologists with Difficult Patient Deaths and Coping Strategies Used

Objectives We aimed to explore and identify what makes patient death more emotionally difficult for oncologists and how oncologists cope with patient death. Methods A convenience sample of 98 Canadian oncologists (50 men, 48 women) completed an online survey that included a demographics section and a section about patient death. Results More than 80% of oncologists reported that patient age, long-term management of a patient, and unexpected disease outcomes contributed to difficult patient loss. Other factors included the doctor–patient relationship, identification with the patient, caregiver-related factors, oncologist-related factors, and “bad deaths.” Oncologists reported varying strategies to cope with patient death. Most prevalent was peer support from colleagues, including nurses and other oncologists. Additional strategies included social support, exercise and meditation, faith, vacations, and use of alcohol and medications. Conclusions Oncologists listed a number of interpersonal and structural factors that make patient death challenging for them to cope with. Oncologists reported a number of coping strategies in responding to patient death, including peer support, particularly from nursing colleagues. No single intervention will be suitable for all oncologists, and institutions wishing to help their staff cope with the emotional difficulty of patient loss should offer a variety of interventions to maximize the likelihood of oncologist participation

Sequential Deliberation for Social Choice

In large scale collective decision making, social choice is a normative study of how one ought to design a protocol for reaching consensus. However, in instances where the underlying decision space is too large or complex for ordinal voting, standard voting methods of social choice may be impractical. How then can we design a mechanism - preferably decentralized, simple, scalable, and not requiring any special knowledge of the decision space - to reach consensus? We propose sequential deliberation as a natural solution to this problem. In this iterative method, successive pairs of agents bargain over the decision space using the previous decision as a disagreement alternative. We describe the general method and analyze the quality of its outcome when the space of preferences define a median graph. We show that sequential deliberation finds a 1.208- approximation to the optimal social cost on such graphs, coming very close to this value with only a small constant number of agents sampled from the population. We also show lower bounds on simpler classes of mechanisms to justify our design choices. We further show that sequential deliberation is ex-post Pareto efficient and has truthful reporting as an equilibrium of the induced extensive form game. We finally show that for general metric spaces, the second moment of of the distribution of social cost of the outcomes produced by sequential deliberation is also bounded

The nature and origins of the low surface brightness outskirts of massive, central galaxies in Subaru HSC

We explore the stellar mass density and colour profiles of 118 low redshift, massive, central galaxies, selected to have assembled 90 percent of their stellar mass 6 Gyr ago, finding evidence of the minor merger activity expected to be the driver behind the size growth of quiescent galaxies. We use imaging data in the $g, r, i, z, y$ bands from the Subaru Hyper Suprime-Cam survey and perform SED fitting to construct spatially well-resolved radial profiles in colour and stellar mass surface density. Our visual morphological classification reveals that $\sim 42$ percent of our sample displays tidal features, similar to previous studies, $\sim 43$ percent of the remaining sample display a diffuse stellar halo and only $\sim 14$ percent display no features, down to a limiting $\mu_{r\mathrm{-band}}$ $\sim$ 28 mag arcsec$^{-2}$. We find good agreement between the stacked colour profiles of our sample to those derived from previous studies and an expected smooth, declining stellar mass surface density profile in the central regions (< 3 R$_{\mathrm{e}}$). However, we also see a flattening of the profile ($\Sigma_* \sim 10^{7.5}$ M$_\odot$ kpc$^{-2}$) in the outskirts (up to 10 R$_{\mathrm{e}}$), which is revealed by our method of specifically targeting tidal/accretion features. We find similar levels of tidal features and behaviour in the stellar mass surface density profiles in a younger comparison sample, however a lack of diffuse haloes. We also apply stacking techniques, similar to those in previous studies, finding such procedures wash out tidal features and thereby produces smooth declining profiles. The stellar material in the outskirts contributes on average $\sim 10^{10}$ M$_\odot$ or a few percent of the total stellar mass and has similar colours to SDSS satellites of similar stellar mass.Comment: 14 pages, 9 figures, 1 tabl

PETROLOGICAL CHARACTERS OF THE EARLY CRETACEOUS BOEOTHIAN FLYSCH, (CENTRAL GREECE)

This paper is aimed to study the petrographic characters of the Boeothian Flysch, an Early Cretaceous turbidite deposit which marks the boundary between the External/Internal Hellenides in central-southern Greece, in order to define a preliminary palaeogeographic reconstruction of the Pindos segment of the Alpine Tethys. The Boeothian Flysch is mainly made up by basal conglomerates and arenaceous-pelitic lithofacies, locally interlayered with Calpionellid micrite limestones. This formation is here supposed to belong to the Early Cretaceous flysch family, which marks the contact between the internal and external areas along all the western and central European Alpine Chains for more than 7,000 km, from the Gibraltar Arc to the Balkans via the Calabria-Peloritani Arc. Provenance of these flysch is commonly connected to internal areas, mainly made up by Hercynian crystalline basements and, locally, by ophiolitic complexes. The petrographic data obtained from representative sandstones of the Boeothian Flysch suggest a provenance from internal sources, formed by a Jurassic carbonate platform, metamorphic basements and by ophiolitic complexes, which can be identified with the Pelagonian Terranes (Auct.). An Early Cretaceous uplift and rejuvenation processes, probably related to the late Cretaceous tectogenesis, widely recorded in almost all the central-western Alpine Tethis, affected these internal domains with consequent production of abundant detrital supply in the innermost sector of the Pindos Ocean, whose external margin was bounded by the Parnassos microcontinent

Medical Imaging Utilization Trends in Radiation Oncology over the Past Decade

Purpose/Objective(s): We quantify the increase in use of pre-treatment imaging and verification imaging in radiation oncology over the past decade. We also quantify the trend towards hypofractionation, which has partially led to increased imaging. Materials/Methods: The pre-treatment and verification imaging data used are from a single, tertiary, university-affiliated cancer center. Pre-treatment imaging was defined as magnetic resonance imaging (MRI), positron emission tomography (PET) and four-dimensional computed tomography (4DCT). Verification imaging was defined as cone-beam computed tomography (CBCT). All treatment approved plans were included from 2012 to 2021. Data extraction was performed using custom scripts interfacing with the treatment planning system (TPS) and patient information system. All registered image-sets of planning CT images with either advanced pre-treatment advanced imaging or verification images in the TPS were included. Hypofractionation sub-analysis was performed according to plans above and below 4 Gy per fraction that received a combination of pre-treatment and verification imaging. Results: Between 2012 and 2021, a total of 42,214 plans were included. In 2021, MRI, PET, and 4DCT pre-treatment imaging modalities were used for 14%, 5%, and 3% of patients, respectively, which was an increase from 5%, 2%, and 0%, in 2012. In 2021, 55% of patients received CBCT for verification imaging compared to only 2% of patients in 2012. In the sub-analysis, cohort receiving greater than or equal to 4 Gy per fraction from 2012 to 2021, the percent of patients receiving one of MRI or PET for pre-treatment imaging and CBCT guidance for verification imaging increased from 1% to 22%. For the cohort receiving less than 4 Gy per fraction, there was an increase from 2012 to 2021 of 0% to 14% of patients receiving at least one of MRI or PET pretreatment imaging and CBCT for verification imaging. Table 1: Annual use of advanced pre-treatment, verification imaging, hypofractionation, and associated combination imaging shown. Entries indicate the percent (%) of patients per year with the imaging modality used in their treatment. Conclusion: An increase in the adoption of advanced medical imaging was observed in standard of care treatments over the past 10 years. Imaging utilization continues to increase as clinical trial evidence matures. Further analysis could focus on the gap between desired standard of care for patients and the current offerings as well as the increase in capital and human resource requirement for implementation of these advancements

The Impact of Implementing Hypofractionation Prescription Regimens and Modernizing Delivery Technique on Treatment Resources in Breast Radiotherapy

Purpose/Objective(s): To determine the change in treatment resources due to the implementation of hypofractionated prescription regimen. Materials/Methods: All patients between January 1, 2012 and December 31, 2021 receiving curative intent breast radiotherapy at a tertiary cancer center were included. Plan and patient data were extracted from the patient database with the treatment planning system and direct database query. Treatment plan categorization was completed using data elements to include only curative intent. Treatment plans for seroma boost or supraclavicular irradiation were excluded to ensure this analysis did not double-count regional nodal irradiation contribution or confound boost with hypofractionation. Treatment delivery time is recorded in the database for each patient treatment delivered. Average patient treatment time per year was estimated by multiplying the average fractions each year by average time in the same year. The standard fractionation regimens (95% of patients) are 42.56 Gy in 16, 40 Gy in 16, 27 Gy in 5 (accelerated partial breast irradiation), and 26 Gy in 5 (FAST-Forward). In the analysis, implementation milestones are indicated for new prescription regimens and delivery technique changes including deep inspiration breath hold (DIBH) for left-sided patient treatments and daily verification imaging. Results: A total of 6505 patients were included. Table 1 details the total number of patients per year, the average number of fractions treated per patient, and the average treatment time of each patient plan. The average total fractions per treatment decreased from 17.5 in 2012 to 10.9 in 2021. The average treatment delivery time increased from 12.9 minutes to 21.4 minutes. Conclusion: In considering total treatment resources, the interplay between hypofractionation and modernization delivery techniques is complex. The impact of hypofractionation reduced the average number of fractions but total treatment resources are offset with the implementation of modern treatment delivery techniques. Hypofractionated prescription regimens reduce the time and travel commitment required of patients on an individual basis, contributing to person-centered care

The Peculiar Motions of Early-Type Galaxies in Two Distant Regions VI: The Maximum Likelihood Gaussian Algorithm

The EFAR project is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. Here we describe the maximum likelihood algorithm we developed to investigate the correlations between the parameters of the EFAR database. One-, two-, and three-dimensional gaussian models are constructed to determine the mean value and intrinsic spread of the parameters, and the slopes and intrinsic parallel and orthogonal spread of the Mgb'-Mg2, Mg2-sigma, Mgb'-sigma relations, and the Fundamental Plane. In the latter case, the cluster peculiar velocities are also determined. We show that this method is superior to ``canonical'' approaches of least-squares type, which give biased slopes and biased peculiar velocities. We test the algorithm with Monte Carlo simulations of mock EFAR catalogues and derive the systematic and random errors on the estimated parameters. We find that random errors are always dominant. We estimate the influence of systematic errors due to the way clusters were selected and the hard limits and uncertainties in the selection function parameters for the galaxies. We explore the influence of uniform distributions in the Fundamental Plane parameters and the errors. We conclude that the mean peculiar motions of the EFAR clusters can be determined reliably. In particular, the placement of the two EFAR sample regions relative to the Lauer and Postman dipole allows us to strongly constrain the amplitude of the bulk motion in this direction.Comment: 43 pages, 19 figures, accepted for publication in MNRA

Magnetic activity and the solar corona: first results from the Hinode satellite

The structure, dynamics and evolution of the solar corona are governed by the magnetic field. In spite of significant progresses in our insight of the physics of the so- lar corona, several problems are still under debate, e.g. the role of impulsive events and waves in coronal heating, and the origin of eruptions, flares and CMEs. The Hinode mis- sion has started on 22 september 2006 and aims at giving new answers to these questions. The satellite contains three main instruments, two high resolution telescopes, one in the optical and one in the X-ray band, and an EUV imaging spectrometer. On the Italian side, INAF/Osservatorio Astronomico di Palermo has contributed with the ground-calibration of the filters of the X-ray telescope. We present some preliminary mission results, with partic- ular attention to the X-ray telescope data