Identifying the Host Galaxy of Gravitational Wave Signals

One of the goals of the current LIGO-GEO-Virgo science run is to identify transient gravitational wave (GW) signals in near real time to allow follow-up electromagnetic (EM) observations. An EM counterpart could increase the confidence of the GW detection and provide insight into the nature of the source. Current GW-EM campaigns target potential host galaxies based on overlap with the GW sky error box. We propose a new statistic to identify the most likely host galaxy, ranking galaxies based on their position, distance, and luminosity. We test our statistic with Monte Carlo simulations of GWs produced by coalescing binaries of neutron stars (NS) and black holes (BH), one of the most promising sources for ground-based GW detectors. Considering signals accessible to current detectors, we find that when imaging a single galaxy, our statistic correctly identifies the true host ~20% to ~50% of the time, depending on the masses of the binary components. With five narrow-field images the probability of imaging the true host increases to ~50% to ~80%. When collectively imaging groups of galaxies using large field-of-view telescopes, the probability improves to ~30% to ~60% for a single image and to ~70% to ~90% for five images. For the advanced generation of detectors (c. 2015+), and considering binaries within 100 Mpc (the reach of the galaxy catalogue used), the probability is ~40% for one narrow-field image, ~75% for five narrow-field images, ~65% for one wide-field image, and ~95% for five wide-field images, irrespective of binary type.Comment: 5 pages, 2 figure

Determination of the scale of fluctuation of cone penetration test data obtained from an alluvial site in Missouri

To account for uncertainty in geotechnical projects, knowledge of the uncertainties should be understood. Many sources of uncertainties can be reduced with increased sampling and good practices, but due to the nature of geomaterials, inherent uncertainties cannot be eliminated. Inherent uncertainties can be quantified by a statistical analysis. While some statistical descriptors, such as mean and standard deviation are common, the scale of fluctuation is less studied as it requires a large amount of data. The scale of fluctuation indicates the thickness of a soil layer which has correlated properties. Large quantities of data can be obtained from the cone penetration test (CPT). The CPT was used for a site investigation for a coal combustion residual landfill, providing ideal measurements to investigate the variability of the alluvial site on the Missouri River. The goal of Sutton's thesis is to determine if side resistance measurements, reported as the friction ratio, of cone penetration testing are less correlated than cone tip resistance measurements as previous research indicates. The results of this analysis agree with earlier analyses that the variability of the cone tip resistance is less than the skin friction. The average vertical scale of fluctuation for the cone tip resistance was 1.3 feet and 1.5 feet for sand and gravelly sand, respectively. The average vertical scale of fluctuation for the friction ratio was 0.7 feet and 0.8 feet for the sand and gravelly sand, respectively. As increased computing power allows more complex modelling to become readily available, the shift to probabilistic analyses of such models allows for a more realistic assessment of the variability and correlation of subsurface properties. Several examples are discussed with show the effect of correlation and illustrate the need for both typical and site specific probabilistic parameters.Includes bibliographical reference

Processes shaping the spatial pattern and seasonality of the surface air temperature response to anthropogenic forcing

In the period 1960-2010, the land surface air temperature (SAT) warmed more rapidly over some regions relative to the global mean. Using a set of time-slice experiments, we highlight how different physical processes shape the regional pattern of SAT warming. The results indicate an essential role of anthropogenic forcing in regional SAT changes from the 1970s to 2000s, and show that both surface-atmosphere interactions and large-scale atmospheric circulation changes can shape regional responses to forcing. Single forcing experiments show that an increase in greenhouse gases (GHG) can lead to regional changes in land surface warming in winter (DJF) due to snow-albedo feedbacks, and in summer (JJA) due to soil-moisture and cloud feedbacks. Changes in anthropogenic aerosol and precursor (AA) emissions induce large spatial variations in SAT, characterized by warming over western Europe, Eurasia, and Alaska. In western Europe, SAT warming is stronger in JJA than in DJF due to substantial increases in clear sky shortwave radiation over Europe, associated with decreases in local AA emissions since the 1980s. In Alaska, the amplified SAT warming in DJF is due to increased downward longwave radiation, which is related to increased water vapor and cloud cover. In this case, although the model was able to capture the regional pattern of SAT change, and the associated local processes, it did not simulate all processes and anomalies correctly. For the Alaskan warming, the model is seen to achieve the correct regional response in the context of a wider North Pacific anomaly that is not consistent with observations. This demonstrates the importance of model evaluation that goes beyond the target variable in detection and attribution studies

The 2015 European heat wave

Summer 2015 was marked by hot and dry conditions over Central Europe, and significant increases in temperature extremes. Model experiments indicate that high temperatures were caused by a combination of forced responses and internal atmospheric variability. Model simulations suggest that changes in SST/SIE and anthropogenic forcings explain about 2/3 (1.6oC) of the observed warming (2.4oC) and changes in hot temperature extremes over Central Europe relative to 1964-1993. Interestingly, when comparing 2015SST with 2015ALL simulations, the results indicate that the impact of anthropogenic forcings plays the dominant role. About 1/3 (0.8oC) of the observed summer mean warming and changes in hot extremes is not explained by the model mean response and consequently may have resulted from internal variability, principally through physical processes associated with precipitation deficits. Thus our results indicate that anthropogenic forcings set the conditions for the development of the 2015 heatwave in Central Europe, but that internal variability was an important factor in explaining its extreme character

The 2014 hot, dry summer in Northeast Asia

Northeast Asia experienced a severe drought in summer 2014. Sea surface temperature forcing may have increased the risk of low precipitation, but model biases preclude reliable attribution to anthropogenic forcing

The effect of cash transfers on mental health – New evidence from South Africa

Mental health and poverty are strongly interlinked. There is a gap in the literature on the effects of poverty alleviation programmes on mental health. We aim to fill this gap by studying the effect of an exogenous income shock generated by the Child Support Grant, South Africa’s largest Unconditional Cash Transfer (UCT) programme, on mental health. We use biennial data on 10,925 individuals from the National Income Dynamics Study between 2008 and 2014. We exploit the programme’s eligibility criteria to estimate instrumental variable Fixed Effects models. We find that receiving the Child Support Grant improves adult mental health by 0.822 points (on a 0-30 scale), 4.1% of the sample mean. Our findings show that UCT programmes have strong mental health benefits for the poor adult population

You Have to Send the Right Message: Examining the Influence of Protective Action Guidance on Message Perception Outcomes across Prior Hazard Warning Experience to Three Hazards

A long-term goal for warning message designers is to determine the most effective type of message that can instruct individuals to act quickly and prevent loss of life and/or injury when faced with an imminent threat. One likely way to increase an individual’s behavioral intent to act when they are faced with risk information is to provide protective action information or guidance. This study investigated participant perceptions (understanding, believing, personalizing, deciding, milling, self-efficacy, and response-efficacy) in response to the National Weather Service’s experimental product Twitter messages for three hazard types (tornado, snow squall, dust storm), with each message varying by inclusion and presentation of protective action information placed in the tweet text and the visual graphic. We also examine the role of prior hazard warning experience on message perception outcomes. To examine the effects, the experiment used a between-subjects design where participants were randomly assigned to one hazard type and received one of four warning messages. Participants then took a post-test measuring message perceptions, efficacy levels, prior hazard warning experience, and demographics. The results showed that for each hazard and prior hazard experience level, messages with protective action guidance in both the text and graphic increase their understanding, belief, ability to decide, self-, and response-efficacy. These results reinforce the idea that well-designed messages, that include protective action guidance, work well regardless of hazard type or hazard warning experience

‘Just want to surf, make boards and party’: how do we identify lifestyle entrepreneurs within the lifestyle sports industry?

This paper aims to further our understanding of the identity of the lifestyle entrepreneur operating within the lifestyle sports industry. The lifestyle entrepreneur has to date been the subject of numerous definitions. However, understanding the context in which entrepreneurs operate has been identified by researchers as impacting upon the actions they take, and so therefore linking context to the entrepreneur is critical to the understanding of these individuals. A mixed methods study comprising of 80 questionnaire responses, and 21 semi-structured interviews focussed on identifying lifestyle sports entrepreneurs. Two groups of entrepreneurs were targeted; those entrepreneurs operating within a sport (Engagers) and those who run a business to participate (Enablers). Issues surrounding the identification of lifestyle entrepreneurs are presented. Through the analysis of the data, entrepreneurs identified through their own narratives how their identities are created. The results demonstrate that while the current external interpretation of the lifestyle entrepreneur is of a fixed nature, the entrepreneurs themselves evidence a much more complex approach to their identities

The effect of cash transfers on mental health – New evidence from South Africa

Background Mental health and poverty are strongly interlinked. There is a gap in the literature on the effects of poverty alleviation programmes on mental health. We aim to fill this gap by studying the effect of an exogenous income shock generated by the Child Support Grant, South Africa’s largest Unconditional Cash Transfer (UCT) programme, on mental health. Methods We use biennial data on 10,925 individuals from the National Income Dynamics Study between 2008 and 2014. We exploit the programme’s eligibility criteria to estimate instrumental variable Fixed Effects models. Results We find that receiving the Child Support Grant improves adult mental health by 0.822 points (on a 0–30 scale), 4.1% of the sample mean. Conclusion Our findings show that UCT programmes have strong mental health benefits for the poor adult population

Show Me and What Will I Remember? Exploring Recall in Response to NWS Tornado Warning Graphics

It is critical that organizations deliver timely, effective communication about potential risks and life-saving information. The National Weather Service (NWS) developed a suite of messages known as “experimental graphic products” to be automatically distributed through their local official Twitter accounts at the onset of fast-moving, severe weather events such as tornadoes. However, recent research has suggested messages need to be carefully constructed for audiences to place attention to the content, remember the content, and later act in response to the content. The purpose of this study is to explore what people recall of the NWS Twitter message. We used an online survey instrument, distributed via Qualtrics, to investigate participant responses to three open-ended questions about the message. We performed a quantitative analysis to summarize the frequency of message features recorded by participants, and a qualitative analysis to identify themes that provide a deeper description of what was recalled. We found that participants encoded the hazard type, the time the message was sent and would expire, and the types of impacts that might occur. Graphic design cues elicited attention as they “stood out” to the participants. When asked about importance and what they would tell others, respondents described protective action, indicating participants may have activated prior knowledge of the threat, as it was not included in the message. Risk, disaster, and science communicators can draw guidance about communicating during a disaster. It provides a lens for researching message construction, and the importance of communicating protective action guidance during severe weather events