Environmental and Sea-Level Reconstruction in Temperate, Subtropical, and Tropical Coastal Wetlands Using Bulk Stable Carbon Isotope Geochemistry and Microfossils

Obtaining a record of present and past storms, floods and sea levels, and their extent of geological and ecological impacts, is one means to assess future risk, reveal the spatial and temporal variability of coastal inundation and decipher its relationship with global climatic changes. In the deltaic wetlands of Louisiana, I tracked sedimentation from the historic A.D. 2011 Mississippi River flood. The sediment deposited in wetlands during the 2011 flood was distinguished from earlier deposits based on biological characteristics, primarily absence of plant roots and increased presence of centric (planktonic) diatoms indicative of riverine origin. By comparison, the lithological (bulk density, organic matter content, and grain size) and chemical (stable carbon isotopes of bulk organic matter) properties of flood sediments were nearly identical to the underlying deposit. Flood sediment deposition was greatest in wetlands near the Atchafalaya and Mississippi Rivers and accounted for a substantial portion (37% to 85%) of the annual accretion measured at nearby monitoring stations. The amount of sediment delivered to those basins (1.1-1.6 g/cm) was comparable to that reported previously for hurricane sedimentation along the Louisiana coast (0.8-2.1 g/cm). My findings not only provide insight into how large-scale river floods influence wetland sedimentation, they lay the groundwork for identifying previous flood events in the stratigraphic record. In Puerto Rico, I applied bulk stable carbon isotope geochemistry of mangrove sediments in the reconstruction Holocene relative sea levels. The modern distribution of δ13C, TOC and C/N values and foraminifera was described from 56 surface samples collected from three sites containing basin and riverine mangrove stands. Vertically-zoned tidal flat (δ13C: -18.6 ± 2.8 /; TOC: 10.2 ± 5.7 %; C/N: 12.7 ± 3.1), mangrove (δ13C: -26.4 ± 1.0 /; TOC: 33.9 ± 13.4 %; C/N: 24.3 ± 6.2), brackish transition (δ13C: -28.8 ± 0.7 /; TOC: 40.8 ± 11.7 %; C/N: 21.7 ± 3.7), and freshwater swamp (δ13C: -28.4 ± 0.4 /; TOC: 42.8 ± 4.8 %; C/N: 17.0 ± 1.1) environments were identified from the modern transects with distinct δ13C, TOC and C/N values. Foraminiferal groups could not be used to interpret the fossil record, although the ratio of foraminifera to thecamoebians (F/T) was used along with δ13C, TOC and C/N values to refine the distinction between brackish and freshwater environments. Using linear discriminant analysis (LDFs), I applied the δ13C TOC, C/N and F/T distributions to reconstruct paleomangrove elevation with confidence in the continuous section of mangrove peat, with a vertical uncertainty of ± 0.12 m. I demonstrate that δ13C, TOC, and C/N values can be used along with simple microfossil metrics to reconstruct RSL in tropical environments, where records of this kind are limited. I further explored the use of bulk stable carbon isotope geochemistry for reconstructing Holocene relative sea levels in the Thames Estuary, UK. The modern distribution of bulk stable carbon isotope geochemistry was described from vegetation and surface sediment samples collected from four coastal wetlands of the Thames Estuary and Norfolk, UK. Statistically distinct bulk sediment δ13C, TOC and C/N values were observed among these elevation-dependent environments due to the relative incorporation of in situ vascular vegetation versus allochthonous particulate organic matter and algae, which varied with the degree of tidal inundation and salinity. I compiled a regional database of 349 bulk sediment δ13C, TOC and C/N analyses from published and unpublished data in the UK and the U.S. Atlantic and Pacific coasts and suggest variations among regions may be related to the dominance of C4 vegetation, climate, and local environmental conditions. The range of δ13C, TOC and C/N values from tidal flat/low marsh (δ13C: -24.9 ± 1.2 /; TOC: 3.6 ± 1.7 %; C/N: 9.9 ± 0.8), middle marsh/high marsh (δ13C: -26.2 ± 1.0 /; TOC: 9.8 ± 6.7 %; C/N: 12.1 ± 1.8), brackish transition (δ13C: -27.2 ± 1.2 /; TOC: 26.1 ± 11.5 %; C/N: 14.1 ± 1.9) reed swamp (δ13C: -28.1 ± 0.3 /; TOC: 39.1 ± 10.3 %; C/N: 13.8 ± 1.1) and fen carr (δ13C: -28.8 ± 0.7 /; TOC: 29.1 ± 17.1 %; C/N: 15.8 ± 3.3) were used along with microfossils (foraminifera, pollen, diatoms) to interpret a Holocene sediment core collected from the Thames Estuary

Residual Weighted Learning for Estimating Individualized Treatment Rules

Personalized medicine has received increasing attention among statisticians, computer scientists, and clinical practitioners. A major component of personalized medicine is the estimation of individualized treatment rules (ITRs). Recently, Zhao et al. (2012) proposed outcome weighted learning (OWL) to construct ITRs that directly optimize the clinical outcome. Although OWL opens the door to introducing machine learning techniques to optimal treatment regimes, it still has some problems in performance. In this article, we propose a general framework, called Residual Weighted Learning (RWL), to improve finite sample performance. Unlike OWL which weights misclassification errors by clinical outcomes, RWL weights these errors by residuals of the outcome from a regression fit on clinical covariates excluding treatment assignment. We utilize the smoothed ramp loss function in RWL, and provide a difference of convex (d.c.) algorithm to solve the corresponding non-convex optimization problem. By estimating residuals with linear models or generalized linear models, RWL can effectively deal with different types of outcomes, such as continuous, binary and count outcomes. We also propose variable selection methods for linear and nonlinear rules, respectively, to further improve the performance. We show that the resulting estimator of the treatment rule is consistent. We further obtain a rate of convergence for the difference between the expected outcome using the estimated ITR and that of the optimal treatment rule. The performance of the proposed RWL methods is illustrated in simulation studies and in an analysis of cystic fibrosis clinical trial data.Comment: 48 pages, 3 figure

Paper-based analytical devices for colorimetric detection of: S. aureus and E. coli and their antibiotic resistant strains in milk

Animal derived milk which is an important part of human diet due to its high nutritional value not only supports humans but also presents a growth environment for pathogenic bacteria. Milk may become contaminated with bacteria through udder infections or through contact within the dairy farm environment. Infections are treated with antibiotics, with β-lactams most commonly used in veterinary medicine. However, their frequent use leads to the emergence of β-lactam resistant bacterial strains, which causes difficulties in the treatment of infections in both humans and animals. Detection of pathogens as well as their antibiotic sensitivity is a pre-requisite for successful treatment and this is generally achieved with laboratory-based techniques such as growth inhibition assays, enzyme-linked immunosorbent assays (ELISA) or polymerase chain reactions (PCRs), which are unavailable in resource-limited settings. Here, we investigated paper-based analytical devices (μPADs) for the presumptive detection of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and their antibiotic resistant bacterial strains in milk samples. The μPADs were fabricated on filter paper using wax printing, and then impregnated with chromogenic substrates, which reacted with bacterial enzymes to form coloured products. Limits of detection of S. aureus and E. coli and their antibiotic resistant strains in milk samples were found to be 106 cfu mL-1. Enrichment of milk samples in a selective medium for 12 h enabled detection as low as 10 cfu mL-1. The paper devices tested on a set of 640 milk samples collected from dairy animals in Pakistan demonstrated more than 90% sensitivity and 100% selectivity compared to PCR, showing promise to provide inexpensive and portable diagnostic solutions for the detection of pathogenic bacteria in resource-limited settings

Paleoenvironmental Studies in Southwestern Yukon

The St. Elias Mountain region has occupied an important place in the study of the Quaternary because it presents a relatively accessible non-polar icefield and an array of environments from tundra to boreal forest. Paleoenvironmental studies in southwestern Yukon have documented the broad-scale climatic changes of the past 20 000 years, although few studies exist with well-dated sequences at high temporal resolution. Picea glauca arrived across the entire region around 10 000 years ago; however, the details regarding its migration pathways are not well known. Available records indicate few major changes in the composition of the boreal forest vegetation since that time. A slightly more intense fire regime in the early to mid Holocene has been suggested, but this conclusion is based on only a few studies. Variations in the tree line during the Holocene have been examined, but these studies also lack details. There is no evidence for more extensive grasslands in the area during the Holocene. Paleolimnological studies indicate that changes in populations of aquatic organisms have occurred in response to either Holocene climates or watershed variability.La région du mont St. Elias occupe une place importante dans l’étude du Quaternaire parce qu’elle recèle un champ de glace non polaire relativement accessible ainsi qu’une panoplie d’environnements, allant de la toundra à la forêt boréale. Des études paléoécologiques effectuées dans le sud-ouest du Yukon ont permis de documenter les changements climatiques à grande échelle des 20 000 dernières années, et ce, même s’il existe peu d’études dotées de séquences bien datées de grande résolution temporelle. Picea glauca est arrivée dans toute la région il y a environ 10 000 ans. Cependant, les détails concernant sa voie de migration ne sont pas bien connus. Les données disponibles indiquent peu de changements majeurs dans la composition de la forêt boréale depuis cette période. Un régime des feux un peu plus intense de l’Holocène inférieure à l’Holocène moyen a été suggéré, mais cette conclusion ne repose que sur un petit nombre d’études. Les variations caractérisant la limite des arbres pendant l’Holocène ont été examinées, mais ces études ne sont également pas suffisamment détaillées. Il n’existe pas de preuve qu’il existait des prairies à plus grande échelle dans la région pendant l’Holocène. Des études paléolimnologiques indiquent que des changements caractérisant les populations d’organismes se sont produits en raison de la variabilité des climats ou dans des bassins hydrographiques de l’Holocène

The BoilerWoRx Project: Mobile Public Health Advocacy

BoilerWoRx is a mobile health initiative that was created in response to Indiana\u27s opioid public health crisis. This College of Pharmacy program is multidisciplinary with students from engineering, nursing, liberal arts, and medicine. BoilerWoRx offers education to both students and community members. There is a comprehensive training for students who volunteer with the BoilerWoRx team, which include various educational Ted Talks, naloxone training, along with assessment tool trainings. For the community members at the events, drug disposal kits, wellness education, syringe service assistance, naloxone distribution, mental health assessments, and community resources are available. Currently, BoilerWoRx is working with engineering students and the research team to create and track quality outcomes from the community events. Data collection includes: location of events, how many community members engaged, how many drug destruction bags and naloxone doses distributed, and how many individuals use the destruction bags. We currently have two grants that support the BoilerWoRx program. One is the Firestarter Grant that focuses on strengthening the partnership with the Tippecanoe County Health Department (TCHD). The second grant is from North Central Indiana Area Heath Education Center (AHEC) and is focused on providing continuing education events for providers and community healthcare workers as well as community events within each of the counties in north central Indiana that AHEC serves. The continuing education will focus on harm reduction, naloxone training and distribution, and medication assisted treatment (MAT). The initial focus of BoilerWoRx has been in the Lafayette and West Lafayette area, but the partnership with AHEC has expanded our endeavors into neighboring counties. Through this initiative, the College of Pharmacy and BoilerWoRx strive to educate community members and healthcare professionals about the resources available in their own communities and surrounding areas. Over time, this should ideally translate to improved public health outcomes across various counties in Indiana

Are British Muslims alienated from mainstream politics by Islamophobia and British foreign policy?

This paper uses the 2010 Ethnic Minority British Election Study to look at the political attitudes of Muslims in Britain. It tests the relationship between political alienation and political participation on the one hand, and Islamophobia and disapproval of British military involvement in Afghanistan on the other. The principal findings are that perceptions of Islamophobia are linked to greater political alienation, to a greater likelihood of non-electoral participation and to a lower likelihood of voting among Muslims. Likewise, disapproval of the war in Afghanistan is associated with greater political alienation and a greater likelihood of some types of non-electoral participation. There is strong evidence that British Muslims are more likely to interpret discrimination they experience as motivated by their religion and that they perceive more prejudice at the group level. These findings have two theoretical implications. First, they support the theory that non-electoral participation is motivated by dissatisfaction with the party political system. Second, they suggest that perceptions of sociotropic discrimination (for minorities) and a rare salient political issue in which all parties are in opposition to most voters can lead to negative affect towards the political system and stimulate non-electoral participation at the expense of voting. </jats:p

A New Solution to the Plasma Starved Event Horizon Magnetosphere: Application to the Forked Jet in M87

Very Long Baseline Interferometry observations at 86 GHz reveal an almost hollow jet in M87 with a forked morphology. The detailed analysis presented here indicates that the spectral luminosity of the central spine of the jet in M87 is a few percent of that of the surrounding hollow jet $200 -400 \mu\rm{as}$ from the central black hole. Furthermore, recent jet models in indicate that a hollow "tubular" jet can explain a wide range of plausible broadband spectra originating from jetted plasma located within $\sim 30\mu\rm{as}$ of the central black hole, including the 230 GHz correlated flux detected by the Event Horizon Telescope. Most importantly, these hollow jets from the inner accretion flow have an intrinsic power capable of energizing the global jet out to kiloparsec scales. Thus motivated, this paper considers new models of the event horizon magnetosphere (EHM) in low luminosity accretion systems. Contrary to some models, the spine is not an invisible powerful jet. It is an intrinsically weak jet. In the new EHM solution, the accreted poloidal magnetic flux is weak and the background photon field is weak. It is shown how this accretion scenario naturally results in the dissipation of the accreted poloidal magnetic flux in the EHM not the accumulation of poloidal flux required for a powerful jet. The new solution indicates less large scale poloidal magnetic flux (and jet power) in the EHM than in the surrounding accretion flow and cannot support significant EHM driven jets.Comment: To appear in Astronomy and Astrophysics. Revision fixes typos found during proof

Experiences of online occupational therapy education during the COVID-19 pandemic at a South African university

INTRODUCTION: The COVID-19 pandemic resulted in a worldwide shift of academic programmes towards a predominantly online forum. There was therefore a need to explore how students experienced these shifts to ensure optimal learning. This study describes students' experiences of online teaching, learning and assessment and perception of their mental health during the COVID-19 pandemic&nbsp;METHODS: A descriptive cross-sectional quantitative study was employed using a four-part self-administered online survey. Following a pilot study with 11 community service occupational therapists, the survey was sent to all eligible participants (N=118) with a response rate of 85% (n=91). Data were collected from second to fourth year registered occupational therapy students at the University of KwaZulu-Natal in 2021. Data were analysed descriptively using R Studio Suite&nbsp;RESULTS: Over 50% of the students reported a positive online experience. Adequate access to infrastructure enabled optimal online learning. However, students experienced difficulty with structuring self-study time, theoretical application and time allocated for online tests. Additional challenges included stress and time management and managing the increased requirements for self-directed learning. Coping was enhanced by the availability and access to student support services&nbsp;CONCLUSION: The key issues identified in the study need to be addressed to enhance online delivery of the curriculum&nbsp;IMPLICATIONS FOR PRACTICE&nbsp;Online teaching, learning, and assessment in occupational therapy curriculum requires review and adaptation to facilitate optimal student learning On an online platform, or with digital learning, students require support with aspects such as structuring of their self-directed learning time, personal time and stress management An understanding of the online experiences of students may assist in the development and revision of curricula that are responsive to students' needs and which may aid in optimal learning outcomes