Quantifying hurricane wind speed with undersea sound

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2006Hurricanes, powerful storms with wind speeds that can exceed 80 m/s, are one of the most destructive natural disasters known to man. While current satellite technology has made it possible to effectively detect and track hurricanes, expensive 'hurricanehunting' aircraft are required to accurately classify their destructive power. Here we show that passive undersea acoustic techniques may provide a promising tool for accurately quantifying the destructive power of a hurricane and so may provide a safe and inexpensive alternative to aircraft-based techniques. It is well known that the crashing of wind-driven waves generates underwater noise in the 10 Hz to 10 kHz range. Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. Acoustic measurements of the underwater noise generated by hurricane Gert are correlated with meteorological data from reconnaissance aircraft and satellites to show that underwater noise intensity between 10 and 50 Hz is approximately proportional to the cube of the local wind speed. From this it is shown that it should be feasible to accurately measure the local wind speed and quantify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. It has also long been known that hurricanes generate microseisms in the 0.1 to 0.6 Hz frequency range through the non-linear interaction of ocean surface waves. Here we model microseisms generated by the spatially inhomogeneous waves of a hurricane with the non-linear wave equation where a second-order acoustic field is created by first-order ocean surface wave motion. We account for the propagation of microseismic noise through range-dependent waveguide environments from the deep ocean to a receiver on land. We compare estimates based on the ocean surface wave field measured in hurricane Bonnie with seismic measurements from Florida.Finally, I am grateful to have been awarded the Office of Naval Research Graduate Traineeship Award in Ocean Acoustics. I also thank the MIT Sea Grant office for funding portions of this research

Interleukin‐5 drives glycolysis and reactive oxygen species‐dependent citric acid cycling by eosinophils

Introduction Eosinophils have been long implicated in antiparasite immunity and allergic diseases and, more recently, in regulating adipose tissue homeostasis. The metabolic processes that govern eosinophils, particularly upon activation, are unknown. Methods Peripheral blood eosinophils were isolated for the analysis of metabolic processes using extracellular flux analysis and individual metabolites by stable isotope tracer analysis coupled to gas chromatography‐mass spectrometry following treatment with IL‐3, IL‐5 or granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). Eosinophil metabolism was elucidated using pharmacological inhibitors. Results Human eosinophils engage a largely glycolytic metabolism but also employ mitochondrial metabolism. Cytokine stimulation generates citric acid cycle (TCA) intermediates from both glucose and glutamine revealing this previously unknown role for mitochondria upon eosinophil activation. We further show that the metabolic programme driven by IL‐5 is dependent on the STAT5/PI3K/Akt signalling axis and that nicotinamide adenine dinucleotide phosphate oxidase (NOX)‐dependent ROS production might be a driver of mitochondrial metabolism upon eosinophil activation. Conclusion We demonstrate for the first time that eosinophils are capable of metabolic plasticity, evidenced by increased glucose‐derived lactate production upon ROS inhibition. Collectively, this study reveals a role for both glycolysis and mitochondrial metabolism in cytokine‐stimulated eosinophils. Selective targeting of eosinophil metabolism may be of therapeutic benefit in eosinophil‐mediated diseases and regulation of tissue homeostasis

Hair Follicle Dermal Cells Support Expansion of Murine and Human Embryonic and Induced Pluripotent Stem Cells and Promote Haematopoiesis in Mouse Cultures

In the hair follicle, the dermal papilla (DP) and dermal sheath (DS) support and maintain proliferation and differentiation of the epithelial stem cells that produce the hair fibre. In view of their regulatory properties, in this study, we investigated the interaction between hair follicle dermal cells (DP and DS) and embryonic stem cells (ESCs); induced pluripotent stem cells (iPSCs); and haematopoietic stem cells. We found that coculture of follicular dermal cells with ESCs or iPSCs supported their prolonged maintenance in an apparently undifferentiated state as established by differentiation assays, immunocytochemistry, and RT-PCR for markers of undifferentiated ESCs. We further showed that cytokines that are involved in ESC support are also expressed by cultured follicle dermal cells, providing a possible explanation for maintenance of ES cell stemness in cocultures. The same cytokines were expressed within follicles in situ in a pattern more consistent with a role in follicle growth activities than stem cell maintenance. Finally, we show that cultured mouse follicle dermal cells provide good stromal support for haematopoiesis in an established coculture model. Human follicular dermal cells represent an accessible and readily propagated source of feeder cells for pluripotent and haematopoietic cells and have potential for use in clinical applications

Converting from face-to-face to postal follow-up and its effects on participant retention, response rates and errors:lessons from the EQUAL study in the UK

Background: Prospective cohort studies are challenging to deliver, with one of the main difficulties lying in retention of participants. The need to socially distance during the COVID-19 pandemic has added to this challenge. The pre-COVID-19 adaptation of the European Quality (EQUAL) study in the UK to a remote form of follow-up for efficiency provides lessons for those who are considering changing their study design. Methods: The EQUAL study is an international prospective cohort study of patients ≥65 years of age with advanced chronic kidney disease. Initially, patients were invited to complete a questionnaire (SF-36, Dialysis Symptom Index and Renal Treatment Satisfaction Questionnaire) at research clinics every 3–6 months, known as “traditional follow-up” (TFU). In 2018, all living patients were invited to switch to “efficient follow-up” (EFU), which used an abbreviated questionnaire consisting of SF-12 and Dialysis Symptom Index. These were administered centrally by post. Response rates were calculated using returned questionnaires as a proportion of surviving invitees, and error rates presented as the average percentage of unanswered questions or unclear answers, of total questions in returned questionnaires. Response and error rates were calculated 6-monthly in TFU to allow comparisons with EFU. Results: Of the 504 patients initially recruited, 236 were still alive at the time of conversion to EFU; 111 of these (47%) consented to the change in follow-up. In those who consented, median TFU was 34 months, ranging from 0 to 42 months. Their response rates fell steadily from 88% (98/111) at month 0 of TFU, to 20% (3/15) at month 42. The response rate for the first EFU questionnaire was 60% (59/99) of those alive from TFU. With this improvement in response rates, the first EFU also lowered errors to baseline levels seen in early follow-up, after having almost trebled throughout traditional follow-up. Conclusions: Overall, this study demonstrates that administration of shorter follow-up questionnaires by post rather than in person does not negatively impact patient response or error rates. These results may be reassuring for researchers who are trying to limit face-to-face contact with patients during the COVID-19 pandemic

Comparative Toxicity of Fumigants and a Phosphine Synergist Using a Novel Containment Chamber for the Safe Generation of Concentrated Phosphine Gas

BACKGROUND: With the phasing out of ozone-depleting substances in accordance with the United Nations Montreal Protocol, phosphine remains as the only economically viable fumigant for widespread use. However the development of high-level resistance in several pest insects threatens the future usage of phosphine; yet research into phosphine resistance mechanisms has been limited due to the potential for human poisoning in enclosed laboratory environments. PRINCIPAL FINDINGS: Here we describe a custom-designed chamber for safely containing phosphine gas generated from aluminium phosphide tablets. In an improvement on previous generation systems, this chamber can be completely sealed to control the escape of phosphine. The device has been utilised in a screening program with C. elegans that has identified a phosphine synergist, and quantified the efficacy of a new fumigant against that of phosphine. The phosphine-induced mortality at 20°C has been determined with an LC(50) of 732 ppm. This result was contrasted with the efficacy of a potential new botanical pesticide dimethyl disulphide, which for a 24 hour exposure at 20°C is 600 times more potent than phosphine (LC(50) 1.24 ppm). We also found that co-administration of the glutathione depletor diethyl maleate (DEM) with a sublethal dose of phosphine (70 ppm, <LC(5)), results in a doubling of mortality in C. elegans relative to DEM alone. CONCLUSIONS: The prohibitive danger associated with the generation, containment, and use of phosphine in a laboratory environment has now been substantially reduced by the implementation of our novel gas generation chamber. We have also identified a novel phosphine synergist, the glutathione depletor DEM, suggesting an effective pathway to be targeted in future synergist research; as well as quantifying the efficacy of a potential alternative to phosphine, dimethyl disulphide

Genetic variants affecting cross-sectional lung function in adults show little or no effect on longitudinal lung function decline

Background: Genome-wide association studies have identified numerous genetic regions that influence cross-sectional lung function. Longitudinal decline in lung function also includes a heritable component but the genetic determinants have yet to be defined. Objectives: We aimed to determine whether regions associated with cross-sectional lung function were also associated with longitudinal decline and to seek novel variants which influence decline. Methods: We analysed genome-wide data from 4167 individuals from the Busselton Health Study cohort, who had undergone spirometry (12 695 observations across eight time points). A mixed model was fitted and weighted risk scores were calculated for the joint effect of 26 known regions on baseline and longitudinal changes in FEV1 and FEV1/FVC. Potential additional regions of interest were identified and followed up in two independent cohorts. Results: The 26 regions previously associated with cross-sectional lung function jointly showed a strong effect on baseline lung function (p=4.44×10−16 for FEV1/FVC) but no effect on longitudinal decline (p=0.160 for FEV1/FVC). This was replicated in an independent cohort. 39 additional regions of interest (48 variants) were identified; these associations were not replicated in two further cohorts. Conclusions: Previously identified genetic variants jointly have a strong effect on cross-sectional lung function in adults but little or no effect on the rate of decline of lung function. It is possible that they influence COPD risk through lung development. Although no genetic variants have yet been associated with lung function decline at stringent genome-wide significance, longitudinal change in lung function is heritable suggesting that there is scope for future discoveries

The burden of unintentional drowning : global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study

Background Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017. Methods Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning. Results Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531 956 (uncertainty interval (UI): 484 107 to 572 854) to 295 210 (284 493 to 306 187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100 000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45 434 (40 850 to 50 539) YLLs per 100 000 across both sexes. Conclusions There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low- and middle-income countries.Peer reviewe

Linking direct and indirect pathways mediating earthworms, deer, and understory composition in Great Lakes forests

Ahistorical drivers such as nonnative invasive earthworms and high deer densities can have substantial impacts on ecosystem processes and plant community composition in temperate and boreal forests of North America. To assess the roles of earthworm disturbance, deer, and environmental factors in the understory, we sampled 125 mixed temperate-boreal forest sites across the western Great Lakes region. We utilized structural equation modeling (SEM) to address the hypothesis that earthworm disturbance to the upper soil horizons and selective herbivory by deer are associated with depauperate understory plant communities dominated by graminoid and nonnative species. Evidence of earthworm activity was found at 93 % of our sites and 49 % had high to very high severity earthworm disturbance. The SEM fit the data well and indicated that widespread nonnative earthworm disturbance and high deer densities had similar magnitudes of impact on understory plant communities and that these impacts were partially mediated by environmental characteristics. One-third of the variation in earthworm disturbance was explained by soil pH, precipitation, and litter quality. Deer density and earthworm disturbance both increased graminoid cover while environmental variables showed direct and indirect relationships. For example, the positive relationship between temperature and graminoids was indirect through a positive temperature effect on deer density. This research characterizes an integrated set of key environmental variables driving earthworm disturbance and deer impacts on the forest understory, facilitating predictions of the locations and severity of future change in northern temperate and boreal forest ecosystems

The burden of unintentional drowning: Global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study

__Background:__ Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017. __Methods:__ Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning. __Results:__ Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531 956 (uncertainty interval (UI): 484 107 to 572 854) to 295 210 (284 493 to 306 187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100 000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45 434 (40 850 to 50 539) YLLs per 100 000 across both sexes. __Conclusions:__ There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low-and middle-income countries

Forced Expiratory Volume in One Second Predicts Length of Stay and In-Hospital Mortality in Patients Undergoing Cardiac Surgery: A Retrospective Cohort Study

Objective: An aging population and increasing use of percutaneous therapies have resulted in older patients with more co-morbidity being referred for cardiac surgery. Objective measurements of physiological reserve and severity of co-morbid disease are required to improve risk stratification. We hypothesised that FEV1 would predict mortality and length of stay following cardiac surgery. Methods: We assessed clinical outcomes in 2,241 consecutive patients undergoing coronary artery bypass grafting and/or valve surgery from 2001 to 2007 in a regional cardiac centre. Generalized linear models of the association between FEV1 and length of hospital stay and mortality were adjusted for age, sex, height, body mass index, socioeconomic status, smoking, cardiovascular risk factors, long-term use of bronchodilators or steroids for lung disease, and type and urgency of surgery. FEV1 was compared to an established risk prediction model, the EuroSCORE. Results: Spirometry was performed in 2,082 patients (93%) whose mean (SD) age was 67 (10) years. Median hospital stay was 3 days longer in patients in the lowest compared to the highest quintile for FEV1, 1.35-fold higher (95% CI 1.20–1.52; p&#60;0.001). The adjusted odds ratio for mortality was increased 2.11-fold (95% CI 1.45–3.08; p&#60;0.001) per standard deviation decrement in FEV1 (800 ml). FEV1 improved discrimination of the EuroSCORE for mortality. Similar associations were found after excluding people with known pulmonary disease and/or airflow limitation on spirometry. Conclusions: Reduced FEV1 strongly predicted increased length of stay and in-hospital mortality following cardiac surgery. FEV1 is a widely available measure of physiological health that may improve risk stratification of complex patients undergoing cardiac surgery and should be evaluated for inclusion in new prediction tools