scholarly journals The All-Sky SignAl Short-Spacing INterferometer (ASSASSIN) – I. Global-sky measurements with the Engineering Development Array-2

2020 ◽  
Vol 499 (1) ◽  
pp. 52-67
Author(s):  
B McKinley ◽  
C M Trott ◽  
M Sokolowski ◽  
R B Wayth ◽  
A Sutinjo ◽  
...  
Keyword(s):  
Neutral Hydrogen ◽  
Real Data ◽  
Extraction Methods ◽  
Lessons Learned ◽  
Alternative Methods ◽  
Short Spacing ◽  
Engineering Development ◽  
Single Antenna ◽  
Spaced Antennas ◽  
Future Work

ABSTRACT Aiming to fill a crucial gap in our observational knowledge of the early Universe, experiments around the world continue to attempt to verify the claimed detection of the redshifted 21-cm signal from Cosmic Dawn by the EDGES experiment. This sky-averaged or ‘global’ signal from neutral hydrogen should be detectable at low radio frequencies (50–200 MHz), but is difficult to measure due to bright foreground emission and difficulties in reaching the required levels of instrumental-calibration precision. In this paper, we outline our progress toward using a novel new method to measure the global redshifted 21-cm signal. Motivated by the need to use alternative methods with very different systematic errors to EDGES for an independent result, we employ an array of closely spaced antennas to measure the global-sky signal interferometrically, rather than using the conventional approach with a single antenna. We use simulations to demonstrate our newly developed methods and show that, for an idealized instrument, a 21-cm signal could theoretically be extracted from the visibilities of an array of closely spaced dipoles. We verify that our signal-extraction methods work on real data using observations made with a Square-Kilometre-Array-like prototype, the Engineering Development Array-2. Finally, we use the lessons learned in both our simulations and observations to lay out a clear plan for future work, which will ultimately lead to a new global redshifted 21-cm instrument: the All-Sky SignAl Short-Spacing INterferometer (ASSASSIN).

scholarly journals The degeneracy between primordial non-Gaussianity and foregrounds in 21 cm intensity mapping experiments

2020 ◽  
Vol 499 (3) ◽  
pp. 4054-4067
Author(s):  
Steven Cunnington ◽  
Stefano Camera ◽  
Alkistis Pourtsidou
Keyword(s):  
Nuisance Parameter ◽  
Neutral Hydrogen ◽  
Real Data ◽  
Line Of Sight ◽  
Markov Chain Analysis ◽  
Significant Progress ◽  
Intensity Mapping ◽  
Chain Analysis ◽  
Parallel Text ◽  
Foreground Removal

ABSTRACT Potential evidence for primordial non-Gaussianity (PNG) is expected to lie in the largest scales mapped by cosmological surveys. Forthcoming 21 cm intensity mapping experiments will aim to probe these scales by surveying neutral hydrogen (H i) within galaxies. However, foreground signals dominate the 21 cm emission, meaning foreground cleaning is required to recover the cosmological signal. The effect this has is to damp the H i power spectrum on the largest scales, especially along the line of sight. Whilst there is agreement that this contamination is potentially problematic for probing PNG, it is yet to be fully explored and quantified. In this work, we carry out the first forecasts on fNL that incorporate simulated foreground maps that are removed using techniques employed in real data. Using an Monte Carlo Markov Chain analysis on an SKA1-MID-like survey, we demonstrate that foreground cleaned data recovers biased values [$f_{\rm NL}= -102.1_{-7.96}^{+8.39}$ (68 per cent CL)] on our fNL = 0 fiducial input. Introducing a model with fixed parameters for the foreground contamination allows us to recover unbiased results ($f_{\rm NL}= -2.94_{-11.9}^{+11.4}$). However, it is not clear that we will have sufficient understanding of foreground contamination to allow for such rigid models. Treating the main parameter $k_\parallel ^\text{FG}$ in our foreground model as a nuisance parameter and marginalizing over it, still recovers unbiased results but at the expense of larger errors ($f_{\rm NL}= 0.75^{+40.2}_{-44.5}$), which can only be reduced by imposing the Planck 2018 prior. Our results show that significant progress on understanding and controlling foreground removal effects is necessary for studying PNG with H i intensity mapping.

scholarly journals Assessing baseline dependency of anchor-based minimal important change (MIC): don’t stratify on the baseline score!

2021 ◽  
Author(s):  
Berend Terluin ◽  
Ewa M. Roos ◽  
Caroline B. Terwee ◽  
Jonas B. Thorlund ◽  
Lina H. Ingelsrud
Keyword(s):  
Real Data ◽  
Patient Reported Outcome ◽  
Health Condition ◽  
Important Change ◽  
Alternative Methods ◽  
Minimal Important Change ◽  
Baseline Score ◽  
Patient Reported ◽  
Before And After ◽  
Parallel Tests

Abstract Purpose The minimal important change (MIC) of a patient-reported outcome measure (PROM) is often suspected to be baseline dependent, typically in the sense that patients who are in a poorer baseline health condition need greater improvement to qualify as minimally important. Testing MIC baseline dependency is commonly performed by creating two or more subgroups, stratified on the baseline PROM score. This study’s purpose was to show that this practice produces biased subgroup MIC estimates resulting in spurious MIC baseline dependency, and to develop alternative methods to evaluate MIC baseline dependency. Methods Datasets with PROM baseline and follow-up scores and transition ratings were simulated with and without MIC baseline dependency. Mean change MICs, ROC-based MICs, predictive MICs, and adjusted MICs were estimated before and after stratification on the baseline score. Three alternative methods were developed and evaluated. The methods were applied in a real data example for illustration. Results Baseline stratification resulted in biased subgroup MIC estimates and the false impression of MIC baseline dependency, due to redistribution of measurement error. Two of the alternative methods require a second baseline measurement with the same PROM or another correlated PROM. The third method involves the construction of two parallel tests based on splitting the PROM’s item set. Two methods could be applied to the real data. Conclusion MIC baseline dependency should not be tested in subgroups based on stratification on the baseline PROM score. Instead, one or more of the suggested alternative methods should be used.

scholarly journals Integrated Robotic systems for Humanitarian Demining

10.5772/5694 ◽  
2007 ◽  
Vol 4 (2) ◽  
pp. 24 ◽  
Author(s):  
E. Colon ◽  
G. De Cubber ◽  
H. Ping ◽  
J-C Habumuremyi ◽  
H. Sahli ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Lessons Learned ◽  
Mine Detection ◽  
Detection Systems ◽  
Visual Positioning ◽  
Humanitarian Demining ◽  
Typical Data ◽  
Terrain Following ◽  
Software Interfaces ◽  
Future Work

This paper summarises the main results of 10 years of research and development in Humanitarian Demining. The Hudem project focuses on mine detection systems and aims at provided different solutions to support the mine detection operations. Robots using different kind of locomotion systems have been designed and tested on dummy minefields. In order to control these robots, software interfaces, control algorithms, visual positioning and terrain following systems have also been developed. Typical data acquisition results obtained during trial campaigns with robots and data acquisition systems are reported. Lessons learned during the project and future work conclude this paper.

scholarly journals Resistance of melon cultivars to Bemisia tabaci biotype B

2012 ◽  
Vol 30 (4) ◽  
pp. 600-606 ◽  
Author(s):  
Edson LL Baldin ◽  
José Paulo GF da Silva ◽  
Luiz Eduardo R Pannuti
Keyword(s):  
Bemisia Tabaci ◽  
Plant Resistance ◽  
Chemical Control ◽  
Alternative Methods ◽  
Silverleaf Whitefly ◽  
Trichome Density ◽  
Breeding Programs ◽  
Biotype B ◽  
Future Work ◽  
Bemisia Tabaci Biotype B

The silverleaf whitefly, Bemisia tabaci biotype B, is currently one of the most important pests of melon, causing direct and indirect damage to plants, and significantly reducing production in the field. Due to the need for alternative methods of chemical control in melon crops, the melon cultivars AF-646, AF-682, Don Luis, Frevo, Jangada, Nilo, Vereda, Amarelo Ouro and Hales Best were assessed at field, greenhouse, and laboratory trials for resistance to whitefly B. tabaci biotype B. In general, 'Hales Best' and 'Amarelo Ouro' were the most resistant, showing oviposition non-preference against whitefly. The trichome density is associated with the variation in oviposition on the cultivars and should be further investigated in future work. These results may be helpful in melon breeding programs, focusing on plant resistance to B. tabaci biotype B.

Judgments of Learning

2015 ◽  
Author(s):  
Matthew G. Rhodes
Keyword(s):  
Memory Performance ◽  
Methodological Approach ◽  
Judgments Of Learning ◽  
Alternative Methods ◽  
Theoretical Frameworks ◽  
Theoretical Approaches ◽  
History Of Research ◽  
History Of ◽  
Combine Information ◽  
Future Work

Several decades of research have examined predictions of future memory performance—typically referred to as judgments of learning (JOLs). In this chapter, I first discuss the early history of research on JOLs and their fit within a leading metacognitive framework. A common methodological approach has evolved that permits the researcher to investigate the correspondence between JOLs and memory performance, as well as the degree to which JOLs distinguish between information that is or is not remembered. Factors that influence each aspect of the accuracy of JOLs are noted and considered within theoretical approaches to JOLs. Thus far, research on JOLs had yielded a number of findings and promising theoretical frameworks that will continue to be refined. Future work will benefit by considering how learners combine information to arrive at a judgment, the implications of alternative methods of measuring JOLs, and the potential for JOLs to influence memory.

Refugee Families and Undergraduate Nursing Service-Learning

2018 ◽  
pp. 248-265
Author(s):  
Ruby K. Dunlap ◽  
Emily A. Morse
Keyword(s):  
Service Learning ◽  
Social Systems ◽  
Lessons Learned ◽  
Cultural Barriers ◽  
Health Issues ◽  
School Of Nursing ◽  
Undergraduate Nursing ◽  
Refugee Families ◽  
Problem Solve ◽  
Future Work

This chapter describes a service-learning partnership between two refugee resettlement agencies and a school of nursing. The partnership has successfully completed its goals of both service and learning over many semesters to the present. This community-based learning opportunity has entailed a variety of health interventions with refugee families while the learning has involved essential competencies of cross-cultural nursing, insights into social determinants of health, and developing confidence in being able to problem solve in a complex mix of health, social systems, poverty, language, and cultural barriers. In addition, assignments connected with this community engagement have encouraged students to develop an awareness of global health issues while intervening locally with their assigned refugee family, thus thinking and acting globally. The authors will discuss lessons learned from this long-term relationship and suggested directions for future work.

A Generic Adaptation Framework for Web-Based Hypermedia Systems

2008 ◽  
pp. 148-167
Author(s):  
Alexandros Paramythis ◽  
Constantine Stephanidis
Keyword(s):  
European Commission ◽  
Local Information ◽  
Lessons Learned ◽  
Adaptive Hypermedia ◽  
Web Based ◽  
Adaptive Hypermedia Systems ◽  
Future Work ◽  
Web Publishing

This chapter introduces a framework intended for facilitating the implementation of Web-based adaptive hypermedia systems. The framework is orthogonal to Web “serving” approaches, and poses only minimal requirements in that direction. As such, it can be easily integrated into existing, non-adaptive Web-publishing solutions. This chapter presents in detail several aspects of the framework, and provides an overview of its application in the European Commission-funded IST-1999-20656 PALIO project (“Personalised Access to Local Information and Services for Tourists”). Furthermore, it discusses some of the lessons learned from our work on the framework thus far, as well as what we consider the most likely directions of future work in the area.

scholarly journals LESSONS LEARNED FROM SAVVY EXPRESS: A FEASIBILITY STUDY OF A PSYCHODUCATIONAL INTERVENTION FOR CARE PARTNERS

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S285-S286
Author(s):  
Maria P Aranda ◽  
Debra Cherry
Keyword(s):  
Asian American ◽  
Low Income ◽  
Depressive Symptomatology ◽  
Lessons Learned ◽  
Post Intervention ◽  
Care Partners ◽  
Post Test ◽  
English Speaking ◽  
Caregiver Interventions ◽  
Future Work

Abstract An increasing number of families, funders, and community providers seek very brief psychosocial caregiver interventions, yet the evidence for such condensed interventions is not established. Based on the Savvy Caregiver Program, we explored the feasibility, acceptability, and outcome trends for a condensed 3-session version titled, Savvy Express. Based on a single-group, pre- and post-test intervention design, we examined post-intervention and 3-month data on 116 English-speaking racially and ethnically diverse care partners caring family members with Alzheimer’s disease and related dementias. 41% of the sample was non-Latino white and comprised of Latinas, African Americans and Asian American/API. Most care partners were either adult children or spouses caring for someone with AD or other dementia. Over 80% were college educated. Two of three participants completed all 3 classes. Our findings indicate significant improvements in caregiver levels of depressive symptomatology and anxiety, competence, management of the situation, reduction of expectations, making positive comparisons, and reactivity to the family member’s memory behavior. Upwards of 90% would recommend the program to other caregivers. Savvy Express is a brief caregiver intervention with high acceptability and feasibility. Improvements in care partner psychosocial outcomes signal a promising practice to reduce the burden of caregiving. A major focus of the paper focuses on barriers and facilitators to uptake of the study procedures and intervention with community-based partners. Future work is needed to establish the efficacy of Savvy Express across a longer observation period, and with less educated, low-income participants, and limited English-speaking families.

A Generic Adaptation Framework for Web-Based Hypermedia Systems

2011 ◽  
pp. 80-103 ◽  
Author(s):  
Alexandros Paramythis ◽  
Constantine Stephanidis
Keyword(s):  
European Commission ◽  
Local Information ◽  
Lessons Learned ◽  
Adaptive Hypermedia ◽  
Web Based ◽  
Adaptive Hypermedia Systems ◽  
Future Work ◽  
Web Publishing

This chapter introduces a framework intended for facilitating the implementation of Web-based adaptive hypermedia systems. The framework is orthogonal to Web “serving” approaches, and poses only minimal requirements in that direction. As such, it can be easily integrated into existing, non-adaptive Web-publishing solutions. This chapter presents in detail several aspects of the framework, and provides an overview of its application in the European Commission-funded IST-1999-20656 PALIO project (“Personalised Access to Local Information and Services for Tourists”). Furthermore, it discusses some of the lessons learned from our work on the framework thus far, as well as what we consider the most likely directions of future work in the area.

Strategies for Fostering a Quality Physical Activity-Based Mentoring Program for Female Youth: Lessons Learned and Future Directions

2017 ◽  
Vol 1 (1) ◽  
pp. 52-62
Author(s):  
Corliss Bean ◽  
Tanya Forneris
Keyword(s):  
Physical Activity ◽  
Lessons Learned ◽  
Mentoring Programs ◽  
Mentoring Program ◽  
Current Case ◽  
Program Leaders ◽  
Youth Leaders ◽  
Quality Program ◽  
Front Line Workers ◽  
Future Work

The current case outlines practical strategies used by youth leaders to implement a female-only physical activity-based mentoring program. This program was selected as the case for the current paper as it scored the highest on program quality out of 26 different sport and physical activity-based youth programs within a larger project. The two program leaders were interviewed to understand what practical strategies they used to foster a high-quality program within this context. The leaders discussed how they: (a) focused on developing individualized relationships with youth, (b) balanced structure with flexibility to allow for youth voice, (c) intentionally integrated life skills, and (d) combined engaging activities with downtime to differentiate the program from school. This case provides a practical account of how front-line workers in youth mentoring programs, specifically within sport and physical activity contexts, can deliver a quality program. Reflection on areas for future work within the field of sport psychology, including ways to bridge the gap between research and practice and the need to develop communities of practice for youth programmers, are presented.

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