Using Regional Data Sets to Study Source to Sink Sedimentary Processes

The study of sediment provenance, transport, and deposition encompasses a diverse set of geomorphological settings and processes. For a variety of reasons, “source to sink” sedimentary systems have historically been difficult to characterize due to operational limitations of the scientists studying them. Consequently, these systems are understood through the comparison of small-scale observational case studies. This lack of quantitative unity between studies has stymied attempts at building generalizable theory. The purpose of this dissertation is to reevaluate some longstanding intuitions in the field of sedimentary geomorphology by taking a broader vantage and integrating observations from expansive regional scopes into unified frames of reference. This undertaking has revealed important insights about the behavior of several source to sink systems that would not have been noticeable if they were studied in a narrower context. An overview of these insights by chapter is as follows: Chapter 1: As would traditionally be expected, coastal emergent wetland inventories showed significant individual correlations with respect to wave energy and relief. Terrestrial sediment flux to the ocean, on the other hand, apparently only contributes to large scale wetland abundance when present above a threshold quantity. This suggests that estuarine processes in the vicinity of wetlands play a larger role in promoting marsh abundance than fluvial sediment supply does. Chapter 2: Despite the complex cascade of expected landscape responses to urbanization, suspended sediment yields of U.S. Piedmont streams consistently were an order of magnitude higher in watersheds with spatial indices of extensive population growth and urban development. Chapter 3: A comparison between modeled and measured sediment properties of marsh cores along the Northwest Atlantic coast showed that the contemporary modeling paradigm of marsh accretion can occasionally reproduce actual marsh soil characteristics. Nevertheless, rapidly subsiding Louisiana marshes as well as marshes with extreme values in organic matter density systematically deviated from modeled expectations. Current models fail to parameterize potentially important aspects of accretion and compressibility in a large number of wetlands across the United States, casting doubt on our current capacity to reasonably predict marsh vertical response to accelerated sea level rise in a variety of locations.Doctor of Philosoph

Accretion Patterns of Newly Built Marshland

Marshes are among the most important ecosystems in the world, but also are rapidly disappearing on a global scale, making it necessary but difficult to understand the processes behind natural marsh building. In this study, 210Pb-derived accretion rates are examined in a marsh at the Newport-River mouth, (NC), a location that has experienced ongoing emergence of new marshland over the past several decades. Accretion rates at all marsh-sampling sites shifted from slow sedimentation emblematic of the bay-bottom to rapid sedimentation that persisted as each site progressed from being an exposed mudflat to eventually becoming a newly colonized marsh table. This transition occurred asynchronously across the marsh and prior to vegetative colonization. This indicates that a physical transition occurred, likely due to a decrease in erosive processes such as wave-stirring. Creating a local regime of quiescence, these transitions promoted accretion and initiated marsh building that continues today

Is Google Trends a useful tool for tracking mental and social distress during a public health emergency? A time–series analysis

Background: Google Trends data are increasingly used by researchers as an indicator of population mental health, but few studies have investigated the validity of this approach during a public health emergency.Methods: Relative search volumes (RSV) for the topics depression, anxiety, self-harm, suicide, suicidal ideation, loneliness, and abuse were obtained from Google Trends. We used graphical and time-series approaches to compare daily trends in searches for these topics against population measures of these outcomes recorded using validated self-report scales (PHQ-9; GAD-7; UCLA-3) in a weekly survey (n=~70,000) of the impact COVID-19 on psychological and social experiences in the UK population (12/03/2020 to 21/08/ 2020).Results: Self-reported levels of depression, anxiety, self-harm/suicidal ideation, self-harm, loneliness and abuse decreased during the period studied. There was no evidence of an association between self-reported anxiety, self-harm, abuse and RSV on Google Trends. Trends in Google topic RSV for depression and suicidal ideation were inversely associated with self-reports of these outcomes (p=0.03 and p=0.04 respectively). However, there was statistical and graphical evidence that self-report and Google searches for loneliness (p<0.001) tracked one another. Limitations: No age/sex breakdown of Google Trends data are available. Survey respondents were not representative of the UK population and no pre-pandemic data were available. Conclusion: Google Trends data do not appear to be a useful indicator of changing levels of population mental health during a public health emergency, but may have some value as an indicator of loneliness. Keywords: Mental Health, Pandemic, Suicide, Depression, Loneliness, Anxiety, Domestic violenc

Suicide Information Database-Cymru: a protocol for a population-based, routinely collected data linkage study to explore risks and patterns of healthcare contact prior to suicide to identify opportunities for intervention

Introduction Prevention of suicide is a global public health challenge extending beyond mental health services. Linking routinely collected health and social care system data records for the same individual across different services and over time has enormous potential in suicide research. Most previous research linking suicide mortality data with routinely collected electronic health records involves only one or two domains of healthcare provision such as psychiatric inpatient care. This protocol paper describes the development of a population-based, routinely collected data linkage study: the Suicide Information Database Cymru (SID-Cymru). SID-Cymru aims to contribute to the information available on people who complete suicide. Methods and analysis SID-Cymru will facilitate a series of electronic case–control studies based in the Secure Anonymised Information Linkage (SAIL) Databank. We have identified 2664 cases of suicide in Wales between 2003 and 2011 from routinely collected mortality data using International Classification of Diseases, Tenth Revision, codes X60–X84 (intentional self-harm) and Y10–Y34 (undetermined intent). Each case will be matched by age and sex to at least five controls. Records will be collated and linked from routinely collected health and social data in Wales for each individual. Conditional logistic regression will be applied to produce crude and confounder (including general practice, socioeconomic status) adjusted ORs. Ethics and dissemination The SAIL Databank has the required ethical permissions in place to analyse anonymised data. Ethical approval has been granted by the Information Governance Review Panel (IGRP). Findings will be disseminated through peer-reviewed publications, consultations with stakeholders and national/international conference presentations. The improved understanding of the prior health, nature of previous contacts with services and wider social circumstances of those who complete suicide will assist in prevention policy, service organisation and delivery. SID-Cymru is funded through the National Institute for Social Care and Health Research, Welsh Government (RFS-12-25)

A state level analyses of suicide and the COVID-19 pandemic in Mexico

BACKGROUND: While suicide rates in high- and middle-income countries appeared stable in the early stages of the pandemic, we know little about within-country variations. We sought to investigate the impact of COVID-19 on suicide in Mexico’s 32 states and to identify factors that may have contributed to observed variations between states. METHODS: Interrupted time-series analysis to model the trend in monthly suicides before COVID-19 (from Jan 1, 2010, to March 31, 2020), comparing the expected number of suicides derived from the model with the observed number for the remainder of the year (April 1 to December 31, 2020) for each of Mexico’s 32 states. Next, we modeled state-level trends using linear regression to study likely contributing factors at ecological level. RESULTS: Suicide increased slightly across Mexico during the first nine months of the pandemic (RR 1.03; 95%CI 1.01–1.05). Suicides remained stable in 19 states, increase in seven states (RR range: 1.12–2.04) and a decrease in six states (RR range: 0.46–0.88). Suicide RR at the state level was positively associated with population density in 2020 and state level suicide death rate in 2019. CONCLUSIONS: The COVID-19 pandemic had a differential effect on suicide death within the 32 states of Mexico. Higher population density and higher suicide rates in 2019 were associated with increased suicide. As the country struggles to cope with the ongoing pandemic, efforts to improve access to primary care and mental health care services (including suicide crisis intervention services) in these settings should be given priority. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-022-04095-8

Using Data Linkage to Investigate Inconsistent Reporting of Self-Harm and Questionnaire Non-Response

The objective of this study was to examine agreement between self-reported and medically recorded self-harm, and investigate whether the prevalence of self-harm differs in questionnaire responders vs. non-responders. A total of 4,810 participants from the Avon Longitudinal Study of Parents and Children (ALSPAC) completed a self-harm questionnaire at age 16 years. Data from consenting participants were linked to medical records (number available for analyses ranges from 205-3,027). The prevalence of self-harm leading to hospital admission was somewhat higher in questionnaire non-responders than responders (2.0 vs. 1.2%). Hospital attendance with self-harm was under-reported on the questionnaire. One third reported self-harm inconsistently over time; inconsistent reporters were less likely to have depression and fewer had self-harmed with suicidal intent. Self-harm prevalence estimates derived from self-report may be underestimated; more accurate figures may come from combining data from multiple sources

Suicide and self-harm related internet use:a cross-sectional study and clinician focus groups

Abstract. Background: The rise in Internet use adds a new dimension to suicide prevention. We investigated suicide/self-harm (S/Sh)-related Internet use among patients presenting to hospital with self-harm. Method: We asked 1,198 adult and 315 child and adolescent patients presenting to hospital following self-harm in a city in South West England about Internet use associated with their hospital presentation. Associations between Internet use and sociodemographic and clinical characteristics were investigated using multivariable logistic regression models. Focus groups with clinicians explored the acceptability and utility of asking about Internet use. Results: The prevalence of S/Sh-related Internet use was 8.4% (95% CI: 6.8–10.1%) among adult hospital presentations and 26.0% (95% CI = 21.3–31.2%) among children's hospital presentations. In both samples, S/Sh-related Internet use was associated with higher levels of suicidal intent. Mostly, clinicians found it acceptable to ask about Internet use during psychosocial assessments and believed this could inform perceptions of risk and decision-making. Limitations: It is unclear whether the findings in this study are applicable to the general self-harm patient population because only those who had psychosocial assessments were included. Conclusion: S/Sh-related Internet use is likely to become increasingly relevant as the Internet-native generation matures. Furthermore, Internet use may be a proxy marker for intent. </jats:p