Seasonal variability in the intermediate water of the eastern North Atlantic

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 August 1980Observational evidence of seasonal variability below the main thermocline in the eastern North Atlantic is described, and a theoretical model of oceanic response to seasonally varying windstress forcing is constructed to assist in the interpretation of the observations. The observations are historical conductivity-temperature-depth data from the Bay of Biscay region (2° to 20°W, 42° to 52°N), a series of eleven cruises over the three years 1972 through 1974, spaced approximately three months apart. The analysis of the observations utilizes a new technique for identifying the adiabatically leveled density field corresponding to the observed density field. The distribution of salinity anomaly along the leveled surfaces is examined, as are the vertical displacements of observed density surfaces from the leveled reference surfaces, and the available potential energy. Seasonal variations in salinity anomaly and vertical displacement occur as westward propagating disturbances with zonal wavelength 390 (±50) km, phase 71 (±30) days from 1 January, and maximum amplitudes of ±30 ppm and ±20 db respectively. The leveled density field varies seasonally with an amplitude corresponding to a thermocline displacement of ±15 db. The observations are consistent with the predictions of a model in which an ocean of variable stratification with a surface mixed layer and an eastern boundary is forced by seasonal changes in a sinusoidal windstress pattern, when windstress parameters calculated from the observations of Bunker and Worthington (1976) are applied.This work was supported by the Office of Naval Research under contract N00014~76-C-197, NR 083-400

Available potential energy for mode eddies

Also published as: Journal of Physical Oceanography 11 (1981): 30-47Available potential energy (APE) is defined as the difference between total potential plus internal energy of a fluid in a gravity field and a corresponding reference field in which the fluid is redistributed (leveled) adiabatically to have constant stably-stratified densities along geopotential surfaces. Potential energy changes result from local shifts of flu id mass relative to geopotential surfaces that are accompanied by local changes of enthalpy and internal energy and global shifts of mass (because volumes of fluid elements are not conserved) that do not change enthalpy or internal energy. The potential energy changes are examined separately by computing available gravitational potential energy (GPE) per unit mass and total GPE (TGPE) per unit area. A technique for estimating GPE in the ocean is developed by introducirtg a reference density field (or an equivalent specific volume anomaly field) that is a function of pressure only and is connected to the observed field by adiabatic vertical displacements. The full empirical equation of state for seawater is used in the computational algorithm. The accuracy of the estimate is limited by the data and sampling and not by the algorithm itself, which can be made as precise as desired. The reference density field defined locally for an ocean region allows redefinition of dynamic height ΔD (potential energy per unit mass) relative to the reference field. TGPE per unit area becomes simply the horizontal average of dynamic height integrated over depth in the region considered. The reference density surfaces provide a precise approximation to material surfaces for tracing conservative variables such as salinity and potential temperature and for estimating vortex stretching between surfaces. The procedure is applied to the MODE density data collected in 1973. For each group of stations within five 2-week time windows (designated Groups A-E) the estimated GPE is compared with the net APE based on the Boussinesq approximation and to the low-frequency kinetic energy measured from moored buoys. Changes of potential energy of the reference field from one time window to the next are large compared with the GPE within each window, indicating the presence of scales larger than the station grid. An analysis of errors has been made to show the sensitivity of the estimates to data accuracy and sampling frequency.Prepared for the Office of Naval Research under Contract N00014-76-C-0197

VAX-11 programs for computing available potential energy from CTD data

This report documents the W.H.O.I. VAX-11 programs used to calculate available potential energy and related quantities from CTD data using the technique described in Bray and Fofonoff (1981). The report includes examples of how the programs may be used, as well as complete listings of all the required FORTRAN files.Prepared for the Office of Naval Research under Contracts N00014-76-C-197; NR 083-400 and N00014-79-C-0071; NR 083-004 and by the National Science Foundation under Grant OCE-77-19403

The validity and inter-device variability of the Apple Watch™ for measuring maximal heart rate

Maximal heart rate (HRmax) is a fundamental measure used in exercise prescription. The Apple Watch measures heart rate yet the validity and inter-device variability of the device for measuring HRmax are unknown. Fifteen participants completed a maximal oxygen uptake test while wearing an Apple Watch on each wrist. Criterion HRmax was measured using a Polar T31 chest strap. There were good to very good correlations between the watches and criterion (left: r = 0.87 [90%CI: 0.67 to 0.95]; right: r = 0.98 [90%CI: 0.94 to 0.99]). Standardised mean bias for the left and right watches compared to the criterion were 0.14 (90%CI: -0.12 to 0.39; trivial) and 0.04 (90%CI: -0.07 to 0.15; trivial). Standardised typical error of the estimate for the left and right watches compared to the criterion were 0.51 (90%CI: 0.38 to 0.80; moderate) and 0.22 (90%CI: 0.16 to 0.34; small). Inter-device standardised typical error was 0.46 (90%CI: 0.36 to 0.68; moderate), ICC = 0.84 (90%CI: 0.65 to 0.93). The Apple Watch has good to very good criterion validity for measuring HRmax, with no substantial under- or over-estimation. There were moderate and small prediction errors for the left and right watches. Inter-device variability in HRmax is moderate

Primary care evidence in clinical guidelines: a mixed methods study of practitioners' views

BACKGROUND: Clinical practice guidelines are widely used in primary care, yet are not always based on applicable research. AIM: To explore primary care practitioners’ views on the applicability to primary care patients of evidence underpinning National Institute for Health and Care Excellence (NICE) guideline recommendations. DESIGN AND SETTING: Delphi survey and focus groups in primary care, England, UK. METHOD: Delphi survey of the perceived applicability of 14 guideline recommendations rated before and after a description of their evidence base, followed by two focus groups. RESULTS: GPs significantly reduced scores for their perceived likelihood of pursuing recommendations after finding these were based on studies with low applicability to primary care, but maintained their scores for recommendations based on highly applicable research. GPs reported they were more likely to use guidelines where evidence was applicable to primary care, and less likely if the evidence base came from a secondary care population. Practitioners in the focus groups accepted that guideline developers would use the most relevant evidence available, but wanted clearer signposting of those recommendations particularly relevant for primary care patients. Their main need was for brief, clear, and accessible guidelines. CONCLUSION: Guidelines should specify the extent to which the research evidence underpinning each recommendation is applicable to primary care. The relevance of guideline recommendations to primary care populations could be more explicitly considered at all three stages of guideline development: scoping and evidence synthesis, recommendation development, and publication. The relevant evidence base needs to be presented clearly and concisely, and in an easy to identify way

Curriculum Guidelines for Undergraduate Programs in Data Science

The Park City Math Institute (PCMI) 2016 Summer Undergraduate Faculty Program met for the purpose of composing guidelines for undergraduate programs in Data Science. The group consisted of 25 undergraduate faculty from a variety of institutions in the U.S., primarily from the disciplines of mathematics, statistics and computer science. These guidelines are meant to provide some structure for institutions planning for or revising a major in Data Science

MicroRNA-184 inhibits neuroblastoma cell survival through targeting the serine/threonine kinase AKT2

BACKGROUND: Neuroblastoma is a paediatric cancer of the sympathetic nervous system. The single most important genetic indicator of poor clinical outcome is amplification of the MYCN transcription factor. One of many down-stream MYCN targets is miR-184, which is either directly or indirectly repressed by this transcription factor, possibly due to its pro-apoptotic effects when ectopically over-expressed in neuroblastoma cells. The purpose of this study was to elucidate the molecular mechanism by which miR-184 conveys pro-apoptotic effects. RESULTS: We demonstrate that the knock-down of endogenous miR-184 has the opposite effect of ectopic up-regulation, leading to enhanced neuroblastoma cell numbers. As a mechanism of how miR-184 causes apoptosis when over-expressed, and increased cell numbers when inhibited, we demonstrate direct targeting and degradation of AKT2, a major downstream effector of the phosphatidylinositol 3-kinase (PI3K) pathway, one of the most potent pro-survival pathways in cancer. The pro-apoptotic effects of miR-184 ectopic over-expression in neuroblastoma cell lines is reproduced by siRNA inhibition of AKT2, while a positive effect on cell numbers similar to that obtained by the knock-down of endogenous miR-184 can be achieved by ectopic up-regulation of AKT2. Moreover, co-transfection of miR-184 with an AKT2 expression vector lacking the miR-184 target site in the 3\u27UTR rescues cells from the pro-apoptotic effects of miR-184. CONCLUSIONS: MYCN contributes to tumorigenesis, in part, by repressing miR-184, leading to increased levels of AKT2, a direct target of miR-184. Thus, two important genes with positive effects on cell growth and survival, MYCN and AKT2, can be linked into a common genetic pathway through the actions of miR-184. As an inhibitor of AKT2, miR-184 could be of potential benefit in miRNA mediated therapeutics of MYCN amplified neuroblastoma and other forms of cancer

Proof of concept of a personalized genetic risk tool to promote smoking cessation:High acceptability and reduced cigarette smoking

Relatively little is known about the possible effects of personalized genetic risk information on smoking, the leading preventable cause of morbidity and mortality. We examined the acceptability and potential behavior change associated with a personalized genetically-informed risk tool (RiskProfile) among current smokers. Current smokers (n=108) were enrolled in a pre-post study with three visits. At Visit 1, participants completed a baseline assessment and genetic testing via 23andMe. Participants’ raw genetic data (CHRNA5 variants) and smoking heaviness were used to create a tailored RiskProfile tool that communicated personalized risks of smoking-related diseases and evidence-based recommendations to promote cessation. Participants received their personalized RiskProfile intervention at Visit 2, approximately 6 weeks later. Visit 3 involved a telephone-based follow-up assessment 30 days after intervention. Of enrolled participants, 83% were retained across the three visits. Immediately following intervention, acceptability of RiskProfile was high (M=4.4; SD=0.6 on scale of 1 to 5); at 30-day follow-up, 89% of participants demonstrated accurate recall of key intervention messages. In the full analysis set of this single-arm trial, cigarettes smoked per day decreased from intervention to 30-day follow-up [11.3 vs. 9.8, difference=1.5, 95% CI (0.6—2.4), p=.001]. A personalized genetically-informed risk tool was found to be highly acceptable and associated with a reduction in smoking, although the absence of a control group must be addressed in future research. This study demonstrates proof of concept for translating key basic science findings into a genetically-informed risk tool that was used to promote progress toward smoking cessation