On the time lags of the LIGO signals

To date, the LIGO collaboration has detected three gravitational wave (GW) events appearing in both its Hanford and Livingston detectors. In this article we reexamine the LIGO data with regard to correlations between the two detectors. With special focus on GW150914, we report correlations in the detector noise which, at the time of the event, happen to be maximized for the same time lag as that found for the event itself. Specifically, we analyze correlations in the calibration lines in the vicinity of 35\,Hz as well as the residual noise in the data after subtraction of the best-fit theoretical templates. The residual noise for the other two events, GW151226 and GW170104, exhibits similar behavior. A clear distinction between signal and noise therefore remains to be established in order to determine the contribution of gravitational waves to the detected signals.Comment: The body of the current version is essentially identical to the previous one submitted to arxiv and JCAP. In order to meet the various suggestions of the referees, we have included an extended and detailed Appendix. This Appendix also contains significant new results that provide additional support for our conclusions. This version of our manuscript has been accepted for publication by JCA

Degeneracy of gravitational waveforms in the context of GW150914

We study the degeneracy of theoretical gravitational waveforms for binary black hole mergers using an aligned-spin effective-one-body model. After appropriate truncation, bandpassing, and matching, we identify regions in the mass--spin parameter space containing waveforms similar to the template proposed for GW150914, with masses $m_1 = 36^{+5}_{-4} M_\odot$ and $m_2 = 29^{+4}_{-4} M_\odot$, using the cross-correlation coefficient as a measure of the similarity between waveforms. Remarkably high cross-correlations are found across broad regions of parameter space. The associated uncertanties exceed these from LIGO's Bayesian analysis considerably. We have shown that waveforms with greatly increased masses, such as $m_1 = 70 M_\odot$ and $m_2 = 35 M_\odot$, and strong anti-aligned spins ($\chi_1=0.95$ and $\chi_2=-0.95$) yield almost the same signal-to-noise ratio in the strain data for GW150914.Comment: Accepted for publication in JCA

Single shot measurement of a silicon single electron transistor

We have fabricated a custom cryogenic Complementary Metal-Oxide-Semiconductor (CMOS) integrated circuit that has a higher measurement bandwidth compared with conventional room temperature electronics. This allowed implementing single shot operations and observe the real-time evolution of the current of a phosphorous-doped silicon single electron transistor that was irradiated with a microwave pulse. Relaxation times up to 90 us are observed, suggesting the presence of well isolated electron excitations within the device. It is expected that these are associated with long decoherence time and the device may be suitable for quantum information processing

Achieving Integration in Mixed Methods Designs—Principles and Practices

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101791/1/hesr12117.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101791/2/hesr12117-sup-0001-AuthorMatrix.pd

The politics, fashions, and conventions of research methods.

The results of an empirical study of any set of phenomena, whether investigating structures, processes, or combinations thereof, are influenced by the theoretical framework as well as the research methods employed. This text examines the influence of research methods on how phenomena under investigation are conceptualized, defined, measured, and interpreted. It will be argued that qualitative, quantitative, and, by extension, mixed methods research influence how phenomena are studied, and how these methods are concurrently subject to politics, fashions, and conventions. Inconsistent and impoverished research may be the consequence, particularly for mixed methods research

A mixed methods evaluation of medical tattooing for people who have experienced a burn injury

Introduction: There are no existing studies examining the psychological merits of using facial medical tattooing (MT) following burn injury. This study evaluated an MT service supported by The Katie Piper Foundation. It examined accessibility, satisfaction and whether there were improvements in quality of life (QoL). Methods: Thirty-five service-users were invited to participate in a cross-sectional online survey. Twenty-five (71%) responded (24 women; age range = 21–64 years), and of these five (4 women; age range = 26–59 years) also participated in telephone interviews, which were analysed using descriptive thematic analysis. Findings: The service was largely considered easy to access (22/25) and convenient (25/25). Most service-users (22/25) were satisfied with the results of MT. Some areas of dissatisfaction were described, by a minority of service-users, including: the procedure being painful (1/25); the tattoo being below expectation or fading over time (3/25). The majority reported that MT had improved confidence (22/25); mood (19/25); and ability to socialise (19/25). The procedure improved some service-users’ ability to carry out essential activities (14/25) and enjoyable activities (16/25). The qualitative responses provided during interview, indicated that all respondents found the procedure useful to their adjustment, although a minority (3/5) found it painful and also commented on fading (1/5). All described MT as contributing to a sense of increased normality. Conclusions: MT had the largest impact on emotional wellbeing and interpersonal domains of QoL. MT services should now improve awareness of the procedure, lobby for further support to provide wider access to the procedure, and routinely use measures assessing psychosocial outcomes

Development of quantum perspectives in modern physics

Introductory undergraduate courses in classical physics stress a perspective that can be characterized as realist; from this perspective, all physical properties of a classical system can be simultaneously specified and thus determined at all future times. Such a perspective can be problematic for introductory quantum physics students, who must develop new perspectives in order to properly interpret what it means to have knowledge of quantum systems. We document this evolution in student thinking in part through pre- and post-instruction evaluations using the Colorado Learning Attitudes about Science Survey. We further characterize variations in student epistemic and ontological commitments by examining responses to two essay questions, coupled with responses to supplemental quantum attitude statements. We find that, after instruction in modern physics, many students are still exhibiting a realist perspective in contexts where a quantum-mechanical perspective is needed. We further find that this effect can be significantly influenced by instruction, where we observe variations for courses with differing learning goals. We also note that students generally do not employ either a realist or a quantum perspective in a consistent manner.Comment: 18 pages, plus references; 3 figures; 9 tables. PACS: 01.40.Fk, 03.65._