Extent Of Feedback Research Articles

Formation of Massive and Wide First-star Binaries in Radiation Hydrodynamic Simulations

We study the formation of Population III stars by performing radiation hydrodynamic simulations for three different initial clouds extracted from cosmological hydrodynamic simulations. Starting from the cloud collapse stage, we follow the growth of protostars by accretion for ∼105 yr until the radiative feedback from the protostars suppresses the accretion and the stellar properties are nearly fixed. We find that Population III stars form in massive and wide binary/small-multiple stellar systems, with masses >30 M ⊙ and separations >2000 au. We also find that the properties of the final stellar system correlate with those of the initial clouds: the total mass increases with the cloud-scale accretion rate, and the angular momentum of the binary orbit matches that of the initial cloud. While the total mass of the system in our simulations is consistent with our previous single-star formation simulations, individual masses are lower due to mass sharing, suggesting potential modification in the extent of feedback from Population III stars in the subsequent evolution of the Universe. We also identify such systems as mini-binaries embedded in a wider outer multiple-star system, which could evolve into progenitors for observed gravitational wave events.

Curvilinear Relationship between Constructive Feedback and Behavioral Outcomes via Felt Obligation

Leader’s providing constructive feedback has been deemed a desirable behavior for preventing negative outcomes. Yet, previous studies found mixed effects suggesting a potential curvilinearity based on the extent of feedback. Grounded in social exchange theory and the too-much-of-a-good-thing effect, we proposed and tested a possibility of curvilinear relationships between constructive feedback citizenship behaviors and task performance, that are mediated by felt obligation. We further reasoned that the reciprocity norm between constructive feedback and felt obligation would be affected by followers’ interpretation of leader’s behavior. The current research used relational attributions and relational identification to test the moderating effect. To test our hypotheses, we conducted two studies. In Study 1, three-wave (10 days interval) data was collected from two construction companies from South Korea (N = 207) and the U.S. (N = 205). However, the results indicated that no significant effect was found in curvilinearity and moderating effect of relational attributions. In Study 2, we collected 10 days of three-wave (10 hours) data from a construction company from South Korea. 108 employees completed a total of 756 questionnaires. Although the curvilinearity was not found at the within-person level, we found the curvilinear relationship between constructive feedback and felt obligation at between-person level. Also the curvilinear associations between constructive feedback and OCB and task performance were mediated by felt obligation. While relational identification did not moderate the curvilinearity, relational attributions were found to neutralize the curvilinearity. The implications of our findings for both theory and practice were discussed.

Spectroscopy of Galaxies: Evolution of Escape Fractions, Metallicity Gradients and Stellar Metallicity

We use spectroscopic observations to investigate galaxies from the age of reionization to the peak of star formation, and the local universe. This thesis presents three projects to better understand characteristics of galactic feedback, i.e., how it regulates galactic gas flows. We used deep absorption line spectroscopy to estimate the escape fractions fesc of star-forming gravitationally-lensed galaxies at z ≃ 5. The approach is to measure the covering fraction of neutral hydrogen in a galaxy from the amount of non-ionizing UV radiation absorbed by low-ionization metal species. With the boost of signal by gravitational lensing, we observed four 4 Spatially resolved spectroscopic observations of galaxies at the peak era of star-formation activities are effective in providing insight into the primitive disks. Specifically, we used metallicity gradients to provide constraints on the amount and extent of feedback produced in star-forming galaxies. We observed 15 star-forming galaxies at z ~ 2 with OSIRIS to obtain their kinematic properties and gas-phase metallicity gradients. With helps from AO correction and gravitational lensing, the typical spatial resolution in our study is less than a half-light radius of a typical L* galaxies at z ≃ 2. Combining with the sample in Jones et al., 2013, we approximately tripled the existing metallicity gradient measurements. We found a lower fraction of rotationally-supported systems than reported from larger kinematic surveys with coarser spatial resolution, which might be partially due to a our improved spatial resolution. We demonstrated that a high spatial resolution is crucial for an accurate diagnosis of the kinematic properties and dynamical maturity of z ≃ 2 galaxies. As for metallicity gradients, we found a much higher fraction of z ≃ 2 galaxies having weak or flat metallicity gradients than in previous studies. We correlated the metallicity gradient with the total metallicity and found that all galaxies with low total metallicities have flat gradients ( 0.1), there is a divergence between isolated or rotationally-supported and dynamically-immature systems with the latter showing zero gradients irrespective of the integrated metallicity. The results indicate that relatively strong feedback (e.g. high mass loading factors or high SN energy output) is required in order to explain the majority of the observed flat gradients. In the second part of the thesis, we observed quiescent galaxies at z Lastly, we measured magnesium (Mg) abundances and extended the observed redshift to z ~ 0.55. We found that while the mass-[Fe/H] relation evolves significantly over the observed redshift range, the mass-[Mg/H] relation does not. This is due to the shorter star formation histories of quiescent galaxies at higher redshifts. Fe is mainly produced in Type Ia SN. It has a longer recycling time than Mg, which is mainly produced in core-collapse SN. Using core-collapse SN elements as a metal indicator lessens the complication of delayed recycling time and allows us to effectively use galactic chemical models with instantaneous recycling to quantify average outflows that these galaxies experience over their lifetime. We found that the average mass-loading factor η is a power-law function of galaxy stellar mass, η ∝ M*-0.21±0.09, consistent with the results of other observational methods and with the predictions where outflow is caused by star formation feedback in turbulent disks.

Regional working in the East of England: using the UK National Standards for Public Involvement

Plain English summaryInvolving patients and members of the public to help shape and carry out research is recommended in health research in the United Kingdom (UK). There are a number of regional networks of Patient and Public Involvement (PPI) groups, which support the collaboration between researchers, patients and public members. We are a group of researchers, patients and public members who came together via a PPI regional network in the East of England to collaborate on a research study about the extent of feedback from researchers to PPI contributors.The aim of this paper is to use the recently developed UK National Standards for Public Involvement to structure our thinking about what worked well and what did not, within our recently completed study. We believe this paper is one of the first to use the National Standards to structure a retrospective reflection on PPI within a study.Our findings showed that there are benefits of regional working, including easier access to public members and bringing together researchers, public members and those who run PPI groups for research collaboration. The main challenges included involvement of people before studies are funded and working across organisations with different payment processes.The National Standards for Public Involvement has provided a useful framework to consider how best to involve patients and members of the public in research and could be a helpful structure to reflect on successes and challenges in individual projects and also regional, national or international comparisons of PPI in research.BackgroundRegional networks of Patient and Public Involvement (PPI) organisations, including academic institutions, health and social care services, charities, patient and public groups and individuals, can play an important part in carrying out health research. In the UK, recommendations by the National Institute of Health Research (NIHR) encourage the use of regional, collaborative networks with shared resources and training.MethodsThe newly developed UK National Standards for Public Involvement were used as a framework for a retrospective reflection of PPI within a recently completed research study which focused on feedback from researchers to PPI contributors. PPI contributors, those running PPI groups (PPI leads) and researchers involved in the study have contributed to this reflection by completing evaluation forms throughout the research alongside notes of meetings and co-authors’ final reflections.ResultsResults revealed a number of successes where the regional network was particularly useful in bringing together PPI contributors, those who lead PPI groups and researchers. The regional network helped researchers to get in touch with patients and members of the public. Challenges included involving people before funding and bureaucratic and financial barriers when working across different organisations in the region. The importance of working together in flexible, informal ways was key and on-going support for the PPI contributors was vital for continued involvement, including emotional support not just monetary. The first four National Standards of inclusive opportunities, working together, support and learning and communications were particularly useful as means of structuring our reflections.ConclusionsTo our knowledge, this is one of the first research studies to use the UK National Standards for Public Involvement as a framework to identify what worked well and the challenges of PPI processes. It is suggested that as more reflective papers are published and the National Standards are more widely used in the UK, many lessons can be learnt and shared on how to improve our Patient and Public Involvement within research studies. Evaluations or reflections such as these can further enhance our understanding of PPI with implications for regional, national and international comparisons.

Pervasive Positive and Negative Feedback Regulation of Insulin-Like Signaling in Caenorhabditis elegans.

The Caenorhabditis elegans insulin-like signaling network supports homeostasis and developmental plasticity. The genome encodes 40 insulin-like peptides and one known receptor. Feedback regulation has been reported, but the extent of feedback and its effect on signaling dynamics in response to changes in nutrient availability has not been determined. We measured messenger RNA expression for each insulin-like peptide, the receptor daf-2, components of the PI3K pathway, and its transcriptional effectors daf-16/FoxO and skn-1/Nrf at high temporal resolution during transition from a starved, quiescent state to a fed, growing state in wild type and mutants affecting daf-2/InsR and daf-16/FoxO. We also analyzed the effect of temperature on insulin-like gene expression. We found that most PI3K pathway components and insulin-like peptides are affected by signaling activity, revealing pervasive positive and negative feedback regulation at intra- and intercellular levels. Reporter gene analysis demonstrated that the daf-2/InsR agonist daf-28 positively regulates its own transcription and that the putative agonist ins-6 cross-regulates DAF-28 protein expression through feedback. Our results show that positive and negative feedback regulation of insulin-like signaling is widespread, giving rise to an organismal FoxO-to-FoxO signaling network that supports homeostasis during fluctuations in nutrient availability.

Experiences of medical teachers about methods, types and barriers of giving feedback

Background: The aims of the research that formed the basis of the current study are as follows: Determining methods that are used by teachers for giving feedback in clinical settings. Determining types of feedback, teachers give to their students in clinical settings. Determining barriers of giving feedback and its important teachers’ experience in clinical settings. Methods: This applied research was a cross-sectional study that involved 131 medical clinical teachers. Using resources in the library and on the web, we developed a questionnaire comprising two parts: the first part of the questionnaire focused on assessing the methods and types of giving feedback used by the participants (a total of 25 items); the second part focused on determining barriers that teachers experience when giving feedback in clinical setting (8 items). Responses to each question were on a Likert Scale. The validity of the questionnaire was determined using content validity index (CVI) measures, and was confirmed by 10 experts. Reliability was evaluated with Cronbach’s alpha coefficient. Results: Most of the teachers (57.49%) in this study reported giving oral feedback to students, 39.1% reported giving nonverbal feedback and a few of them (3.41%) gave written feedback. Participants allowed to nominate more than one type of feedback. Teachers reported many barriers to giving feedback to students, including lack of knowledge and skill about giving feedback, large numbers of students, lack of time, and fear of students’ negative reaction to feedback. Also, concern about negatively impacting the relationship between students and teachers, and students feeling humiliated were considered moderately important. Conclusions: In general results show that there is considerable capacity to improve the quality and extent of feedback given to health sciences students in clinical settings.

THE RELATIONSHIPS BETWEEN SCHOOL INSPECTIONS, SCHOOL CHARACTERISTICS AND SCHOOL IMPROVEMENT

ABSTRACT: The effects of school inspections on school improvement have been investigated only to a limited degree. The investigation reported on in this article is meant to expand our knowledge base regarding the impact of school inspections on school improvement. The theoretical framework for this research is partly based on the policy theory behind the Dutch Educational School Supervision Act (the latter includes assumptions about how school inspections lead to school improvement). Interviews and a survey with school inspectors gave insight into how school inspectors implement the Supervision Act and how they assess schools, and stimulate schools to improve. The results of ten case studies showed that all schools started to improve after a school visit. The innovation capacity of the school and the school environment do not seem to contribute to school improvement after school inspections. No effects were found on school-improvement processes of the number of insufficient scores that schools received from inspectors, the extent of feedback and suggestions for improvement, and the number of agreements. The provision of feedback about weaknesses, the assessment of these weak points as unsatisfactory, and the agreements between an inspector and the school regarding improvement activities do appear to make a difference in promoting school improvement.

Radio galaxies in a cosmological context

Some of the evidence supporting a ‘standard model’ for cosmology is described, together with a brief survey of issues in the understanding of galaxy formation in this model. Radio galaxies fit into this picture as the more massive end of the galaxy distribution, and provide good test cases for alleviating our ignorance of some key ingredient in galaxy formation, namely the role of black holes and the nature and extent of feedback.

The Explanation of Artifact Variability

We furnish a theoretical framework for explaining that portion of formal variability in artifacts attributable to the behavior of the artisan. Major causal factors are the artisan's knowledge and experience, extent of feedback on performance in activities along the artifact's behavioral chain, situational factors in behavioral chain activities, technological constraints, and social processes of conflict and negotiation. In identifying the causal factors at work in a specific case, the investigator must focus analytically on activities-that is, on people-people, people-artifact, and artifact-artifact interactions-and on the performance characteristics relevant to each. Application of this behavioral framework allows abandonment of many cherished but unhelpful concepts, including style and function. Ceramic artifacts, the low-fired, clay cooking pot in particular, are employed for illustrative purposes.

Audience role in the evolution of fictional television content

Most models of the communication process include feedback as a necessary component in the functioning of the system. Although feedback is relatively easy to understand in an interpersonal context, the role and extent of feedback in mass communication is less obvious. This study examined audience ratings as a component of the feedback processes in the evolution of program types. Strong relationships were found between audience ratings and the number of programs of a given type subsequently aired.