Heat flow in the Western Arctic Ocean (Amerasian Basin)

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research-Solid Earth 124(8), (2019): 7562-7587, doi: 10.1029/2019JB017587.From 1963 to 1973 the U.S. Geological Survey measured heat flow at 356 sites in the Amerasian Basin (Western Arctic Ocean) from a drifting ice island (T‐3). The resulting measurements, which are unevenly distributed on Alpha‐Mendeleev Ridge and in Canada and Nautilus Basins, greatly expand available heat flow data for the Arctic Ocean. Average T‐3 heat flow is ~54.7 ± 11.3 mW/m2, and Nautilus Basin is the only well‐surveyed area (~13% of data) with significantly higher average heat flow (63.8 mW/m2). Heat flow and bathymetry are not correlated at a large scale, and turbiditic surficial sediments (Canada and Nautilus Basins) have higher heat flow than the sediments that blanket the Alpha‐Mendeleev Ridge. Thermal gradients are mostly near‐linear, implying that conductive heat transport dominates and that near‐seafloor sediments are in thermal equilibrium with overlying bottom waters. Combining the heat flow data with modern seismic imagery suggests that some of the observed heat flow variability may be explained by local changes in lithology or the presence of basement faults that channel circulating seawater. A numerical model that incorporates thermal conductivity variations along a profile from Canada Basin (thick sediment on mostly oceanic crust) to Alpha Ridge (thin sediment over thick magmatic units associated with the High Arctic Large Igneous Province) predicts heat flow slightly lower than that observed on Alpha Ridge. This, along with other observations, implies that circulating fluids modulate conductive heat flow and contribute to high variability in the T‐3 data set.B.V. Marshall of the U.S. Geological Survey (USGS) was critical to the T‐3 heat flow studies and would have been included as a coauthor on this work if he were not deceased. The original T‐3 heat flow data acquisition program was supported by the USGS and by the Naval Arctic Research Laboratory of the Office of Naval Research. Over the decade of USGS research on T‐3 Ice Island, numerous researchers and technical staff, including B.V. Marshall, P. Twichell, D. Scoboria, J. Tailleur, B. Tailleur, and others, spent months on the island and endured difficult and sometimes dangerous conditions to acquire this data set alongside colleagues from other institutions. Outstanding support from the USGS Menlo Park office, transportation and logistics assistance from other U.S. federal government agencies, Arctic expertise supplied by native Alaskan communities, and collaboration with Lamont researchers made this research program possible. B. Lachenbruch and L. Lawver revived interest in this data set in 2016, and they, along with D. Darby and J. K. Hall, provided ancillary information on T‐3 studies. B. Clarke and M. Arsenault assisted with initial data digitization. We thank M. Jakobsson, R. Saltus, and G. Oakey for providing critical shapefiles and other data and R. Jackson and S. Mukasa for clarification on unpublished information. Reviews by J. Hopper, P. Hart, and W. Jokat improved the manuscript, and V. Atnipp Cross and A. Babb were instrumental in completion of data releases. The USGS's Coastal/Marine Hazards and Resources Program supported C.R. and D.H. between 2016 and 2019, and C.R. used office space provided by the Earth Resources Laboratory at the Massachusetts Institute of Technology during completion of this work. Data in Figure 11 were provided by the U.S. Extended Continental Shelf (ECS) Project. The opinions, findings, and conclusions stated herein are those of the authors and the U.S. Geological Survey, but do not necessarily reflect those of the U.S. ECS Project. Any use of trade, firm, or product name is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital data, metadata, and supporting plots for T‐3 heat flow, navigation, and radiogenic heat content, along with Lamont gravity and magnetics data, are available from Ruppel et al. (2019), and the original T‐3 expedition report with explanatory metadata can be downloaded from Lachenbruch et al. (2019)

Twisted topological structures related to M-branes

Studying the M-branes leads us naturally to new structures that we call Membrane-, Membrane^c-, String^K(Z,3)- and Fivebrane^K(Z,4)-structures, which we show can also have twisted counterparts. We study some of their basic properties, highlight analogies with structures associated with lower levels of the Whitehead tower of the orthogonal group, and demonstrate the relations to M-branes.Comment: 17 pages, title changed on referee's request, minor changes to improve presentation, typos correcte

Mental Health Outcomes during Colorectal Cancer Survivorship: A Review of the Literature

Objective This article reviews literature on adults’ mental health outcomes during acute and long-term colorectal cancer (CRC) survivorship. Methods We identified articles that included at least one measure of psychological symptoms or mental quality of life or well-being through a search of databases (CINAHL, MEDLINE, PsycINFO, and PsycARTICLES). Articles were published between January 2004 and April 2015. Results A significant proportion of CRC survivors experience clinically meaningful levels of anxiety and depressive symptoms or reduced mental well-being across the trajectory of the illness. Demographic, medical, and psychosocial predictors of mental health outcomes were identified. However, few studies were theory-driven, and gaps remain in our understanding of risk and protective factors with respect to mental health outcomes, especially during long-term CRC survivorship. Conclusions Theory-driven longitudinal research with larger samples is required to identify subgroups of CRC survivors with different trajectories of psychological adjustment. Such research would assess adjustment as a function of internal resources (e.g., personality, coping) and external resources (e.g., finances, social support) to inform future interventions for CRC survivors

The Identification and Verification of Hazardous Convective Cells Over Oceans Using Visible and Infrared Satellite Observations

Three algorithms based on geostationary visible and infrared (IR) observations are used to identify convective cells that do (or may) present a hazard to aviation over the oceans. The performance of these algorithms in detecting potentially hazardous cells is determined through verification with Tropical Rainfall Measuring Mission (TRMM) satellite observations of lightning and radar reflectivity, which provide internal information about the convective cells. The probability of detection of hazardous cells using the satellite algorithms can exceed 90% when lightning is used as a criterion for hazard, but the false-alarm ratio with all three algorithms is consistently large (40%), thereby exaggerating the presence of hazardous conditions. This shortcoming results in part from the algorithms’ dependence upon visible and IR observations, and can be traced to the widespread prevalence of deep cumulonimbi with weak updrafts but without lightning over tropical oceans, whose origin is attributed to significant entrainment during ascent

Family Caregiving Challenges in Advanced Colorectal Cancer: Patient and Caregiver Perspectives

Purpose Family caregivers of advanced colorectal cancer patients may be at increased risk for psychological distress. Yet their key challenges in coping with the patient’s illness are not well understood. Soliciting both patient and caregiver perspectives on these challenges would broaden our understanding of the caregiving experience. Thus, the purpose of this research was to identify caregivers’ key challenges in coping with their family member’s advanced colorectal cancer from the perspective of patients and caregivers. Methods Individual, semi-structured qualitative interviews were conducted with 23 advanced colorectal cancer patients and 23 primary family caregivers. Interview data were analyzed via thematic analysis. Results In nearly all cases, patient and caregiver reports of the caregiver’s key challenge were discrepant. Across patient and caregiver reports, caregivers’ key challenges included processing emotions surrounding the patient’s initial diagnosis or recurrence and addressing the patient’s practical and emotional needs. Other challenges included coping with continual uncertainty regarding the patient’s potential functional decline and prognosis and observing the patient suffer from various physical symptoms. Conclusions Findings suggest that eliciting the perspectives of both patients and caregivers regarding caregivers’ challenges provides a more comprehensive understanding of their experience. Results also point to the need to assist caregivers with the emotional and practical aspects of caregiving

Positive changes among patients with advanced colorectal cancer and their family caregivers: a qualitative analysis

OBJECTIVE: This study assessed positive changes in patients with advanced colorectal cancer and their family caregivers following diagnosis. We compared self-reported positive changes within patient-caregiver dyads as well as self-reports and patient reports of positive changes in caregivers. DESIGN: Individual, semi-structured qualitative interviews were conducted with 23 patients with advanced colorectal cancer and 23 caregivers. A theoretical thematic analysis of interview transcripts was framed by posttraumatic growth theory. RESULTS: Patients and caregivers described five positive changes: closer relationships with others, greater appreciation of life, clarifying life priorities, increased faith, and more empathy for others. Additionally, only caregivers reported better health habits following the cancer diagnosis, and a minority of patients and caregivers reported no positive changes. In about half of cases, patients reported at least one positive change that was identical to that of their caregiver. However, in most cases, patient and caregiver reports of the caregiver's positive change were discrepant. CONCLUSION: Findings suggest that positive changes are a shared experience for many patient-caregiver dyads and obtaining both patient and caregiver reports of caregiver positive changes provides a more comprehensive understanding of their experience. Interventions may capitalise on positive changes to promote meaningful living in the context of advanced cancer

Social correlates of mental health in gastrointestinal cancer patients and their family caregivers: Exploring the role of loneliness

Purpose The present study examined the degree to which loneliness mediated the influence of negative (social constraints) and positive (emotional support) relationship qualities on the global mental health of advanced gastrointestinal (GI) cancer patients and their family caregivers. Methods Fifty patient-caregiver dyads completed measures assessing social constraints (e.g., avoidance, criticism) from the other dyad members, emotional support from others, loneliness, and global mental health. Structural equation modeling was used to examine individual models, and Actor-Partner Interdependence Mediation Modeling was used to examine dyadic associations. Results Individual path analyses for patients and caregivers demonstrated that emotional support had a significant indirect effect on mental health through loneliness (Bs = 0.32 and 0.30, respectively), but no associations were found between social constraints and mental health. In dyadic analyses, participants’ loneliness and mental health were not significantly related to their partner’s emotional support, loneliness, or mental health (Bs = − 0.18 to 0.18). Conclusions Findings suggest that for advanced GI cancer patients and caregivers, emotional support from others alleviates feelings of loneliness, which may lead to better mental health. However, the benefits of emotional support appear to be primarily intrapersonal rather than interpersonal in nature. Additionally, participants endorsed low levels of social constraints, which might explain their lack of relation to loneliness and mental health. Continued examination of interdependence in social processes between cancer patients and caregivers will inform intervention development

Inverse Modeling for MEG/EEG data

We provide an overview of the state-of-the-art for mathematical methods that are used to reconstruct brain activity from neurophysiological data. After a brief introduction on the mathematics of the forward problem, we discuss standard and recently proposed regularization methods, as well as Monte Carlo techniques for Bayesian inference. We classify the inverse methods based on the underlying source model, and discuss advantages and disadvantages. Finally we describe an application to the pre-surgical evaluation of epileptic patients.Comment: 15 pages, 1 figur

Why growth equals power - and why it shouldn't : constructing visions of China

When discussing the success of China's transition from socialism, there is a tendency to focus on growth figures as an indication of performance. Whilst these figures are indeed impressive, we should not confuse growth with development and assume that the former necessarily automatically generates the latter. Much has been done to reduce poverty in China, but the task is not as complete as some observers would suggest; particularly in terms of access to health, education and welfare, and also in dealing with relative (rather than absolute) depravation and poverty. Visions of China have been constructed that exaggerate Chinese development and power in the global system partly to serve political interests, but partly due to the failure to consider the relationship between growth and development, partly due to the failure to disaggregate who gets what in China, and partly due to the persistence of inter-national conceptions of globalised production, trade, and financial flows