Observations, inferences, and mechanisms of the Atlantic Meridional Overturning Circulation: A review

This is a review about the Atlantic Meridional Overturning Circulation (AMOC), its mean structure, temporal variability, controlling mechanisms, and role in the coupled climate system. The AMOC plays a central role in climate through its heat and freshwater transports. Northward ocean heat transport achieved by the AMOC is responsible for the relative warmth of the Northern Hemisphere compared to the Southern Hemisphere and is thought to play a role in setting the mean position of the Intertropical Convergence Zone north of the equator. The AMOC is a key means by which heat anomalies are sequestered into the ocean's interior and thus modulates the trajectory of climate change. Fluctuations in the AMOC have been linked to low-frequency variability of Atlantic sea surface temperatures with a host of implications for climate variability over surrounding landmasses. On intra-annual timescales, variability in AMOC is large and primarily reflects the response to local wind forcing; meridional coherence of anomalies is limited to that of the wind field. On interannual to decadal timescales, AMOC changes are primarily geostrophic and related to buoyancy anomalies on the western boundary. A pacemaker region for decadal AMOC changes is located in a western “transition zone” along the boundary between the subtropical and subpolar gyres. Decadal AMOC anomalies are communicated meridionally from this region. AMOC observations, as well as the expanded ocean observational network provided by the Argo array and satellite altimetry, are inspiring efforts to develop decadal predictability systems using coupled atmosphere-ocean models initialized by ocean data.United States. National Oceanic and Atmospheric Administration (NA10OAR4310199)Unites States. National Oceanic and Atmospheric Administration (NA13OAR4310134)United States. National Oceanic and Atmospheric Administration (NA150AR4310100)United States. National Oceanic and Atmospheric Administration (NA09OAR4310058)United States. National Oceanic and Atmospheric Administration (NA14OAR4310160)National Science Foundation (U.S.) (1338427)United States. National Aeronautics and Space Administration (NNX14AM19G

So That the People May Live (Hecel Lena Oyate Ki Nipi Kte): Lakota and Dakota Elder Women as Reservoirs of Life and Keepers of Knowledge about Health Protection and Diabetes Prevention

Around the world, Type 2 diabetes is on the rise, affecting adults and youth from societies in the throes of industrialization. Over time, uncontrolled diabetes can leave in its wake people facing renal failure, blindness, and heart disease, and communities daunted by new, chaotic phenomena. Westernized lifestyles are a recognized explanation for the escalating prevalence. The web of causation, however, may be broader and thicker, woven by complex interactions with environmental, sociological, and historical roots. The purpose of this participatory ethnographic study was to document, understand, and support Lakota and Dakota elder women’s beliefs and knowledge about health protection and diabetes prevention. In-depth interviews were conducted with nine elder women to learn: (1) about the factors attributable to diabetes, (2) about related narratives addressing health protection and diabetes prevention, and (3) how knowledge about health protection is shared. The elders saw diabetes as an outside, unnatural disorder, the contributing influences of which are external as well as internal. They offered narratives about chaos, restitution, testimony, and quests for cures and meaning. The elders connected health to traditional values and ways, the land, and memory. Reservoirs of wisdom reside in the knowledge systems of tribal elders who remember when diabetes was unknown. Health leaders at local and national levels would be wise to respect and draw upon this knowledge for guidance in program planning and policy development

Nanosatellite Launch Adapter System (NLAS)

The utility of small spacecraft based on the University cubesat standard is becoming evident as more and more agencies and organizations are launching or planning to include nanosatellites in their mission portfolios. Cubesats are typically launched as secondary spacecraft in enclosed, containerized deployers such as the CalPoly Poly Picosat Orbital Deployer (P-POD) system. The P-POD allows for ease of integration and significantly reduces the risk exposure to the primary spacecraft and mission. NASA/ARC and the Operationally Responsive Space office are collaborating to develop a Nanosatellite Launch Adapter System (NLAS), which can accommodate multiple cubesat or cubesat-derived spacecraft on a single launch vehicle. NLAS is composed of the adapter structure, P-POD or similar spacecraft dispensers, and a sequencer/deployer system. This paper describes the NLAS system and it s future capabilities, and also provides status on the system s development and potential first use in space

Bridging the gap for future clinician‐educators

Background In contrast to the training required in the UK, opportunities for medical education training in the USA are limited. Resident‐as‐teacher programmes are typically insufficient to prepare trainees to be successful clinician‐educators, but few pursue formal education degrees. We sought to assess the need for, and feasibility of, a training pathway for subspecialty fellows in a large Department of Medicine that would prepare our trainees to become effective educators. Methods Quantitative and qualitative methods were used. Previous fellowship applicants and current programme directors were surveyed to determine the potential benefits of the programme. A pilot programme was conducted with fellows interested in education to determine the feasibility of the programme. Pilot participants were interviewed regarding the benefits that they gained from the pilot and the logistical challenges that they experienced. In contrast to the training required in the UK, opportunities for medical education training in the USA are limited Results Five highly ranked fellows would have scored our programmes higher if we offered this training pathway. Pilot participants and fellowship programme directors agreed that there is a compelling need for such a training pathway. A number of themes arose from the interviews that enabled us to build the framework for a strong programme. Discussion Our findings suggest that a clinician‐educator training pathway that draws from multiple subspecialties has the potential to improve recruitment, provide needed career counselling and skills development to trainees, and to build a community of educators that will benefit the institution. Important insights from pilot participant interviews will inform the programme design, in order to keep trainees engaged and overcome logistical challenges

Intraaortic balloon pumping for cardiac support: Trends in practice and outcome, 1968 to 1995

AbstractObjectives: A total of 4756 cases of intraaortic balloon pump support have been recorded at the Massachusetts General Hospital since the first clinical insertion for cardiogenic shock in 1968. This report describes the patterns of intraaortic balloon use and associated outcomes over this time period.Methods: A retrospective record review was conducted.Results: Balloon use has increased to more than 300 cases a year at present. The practice of balloon placement for control of ischemia (2453 cases, 11.9% mortality) has become more frequent, whereas support for hemodynamic decompensation (congestive heart failure, hypotension, cardiogenic shock) has been relatively constant (1760 cases, 38.2% mortality). Mean patient age has increased from 54 to 66 years, and mortality has fallen from 41% to 20%. Sixty-five percent (3097/4756) of the total patient population receiving balloon support underwent cardiac surgery. Placement before the operation (2038 patients) was associated with a lower mortality (13.6%) than intraoperative (771 patients, 35.7% mortality) or postoperative use (276 patients, 35.9% mortality). Independent predictors of death with balloon pump support were insertion in the operating room or intensive care unit, transthoracic insertion, age, procedure other than angioplasty or coronary artery bypass, and insertion for cardiogenic shock. Independent predictors of death with intraoperative balloon insertion were age, mitral valve replacement, prolonged cardiopulmonary bypass, urgent or emergency operation, preoperative renal dysfunction, complex ventricular ectopy, right ventricular failure, and emergency reinstitution of cardiopulmonary bypass.Conclusions: Balloons are being used more frequently for control of ischemia in more patients who are elderly with lower mortality. An institutional bias toward preoperative use of the balloon pump appears to be associated with improved outcomes. (J Thorac Cardiovasc Surg 1997;113:758-69

Evaluation of Eu:LiCAF for Neutron Detection Utilizing SiPMs and Portable Electronics

With the increasing cost and decreasing availability of 3He, there have been many efforts to find alternative neutron detection materials. Lithium calcium aluminum fluoride (LiCAF) enriched to 95% 6Li doped with europium was evaluated here as a replacement material for 3He. Wafers 0.5 cm thick, consisting of LiCAF crystals in a rubberized matrix, were embedded with wavelength shifting fibers (WSF) and mated to silicon photo-multipliers (SiPMs) to measure the photon response in a flux of neutrons from a DD neutron generator. Excellent discrimination was realized between neutrons and gammas, and both pulse-height discrimination and pulse-shape analysis were explored. A Figure of Merit (FoM) of 1.03 was achieved. By applying pulse-shape analysis, a simple neutron count output was generated by utilizing a low-pass filter to suppress fast pulses from the SiPM output and subsequently applying a threshold to the remaining signal. Custom electronics were built to bias the SiPMs, then amplify, filter, discriminate, and digitize the LiCAF/WSF scintillation photons, resulting in a digital pulse that can easily be counted with any microcontroller or field programmable gate array. A significant advantage of LiCAF is that it can be fabricated into any shape/size (when embedded in a rubberized matrix), and the light output and transparency is sufficient to allow for thicker scintillators which enable detection of both thermal and epithermal neutrons. This work demonstrated that Eu:LiCAF is capable of discriminating gammas from neutrons and is a potential replacement material for 3He, especially for nuclear security applications and neutron spectroscopy

Central spindle self-organization and cytokinesis in artificially activated sea urchin eggs

Author Posting. © Marine Biological Laboratory, 2016. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 230, no.2 (2016): 85-95.The ability of microtubules of the mitotic apparatus to control the positioning and initiation of the cleavage furrow during cytokinesis was first established from studies on early echinoderm embryos. However, the identity of the microtubule population that imparts cytokinetic signaling is unclear. The two main––and not necessarily mutually exclusive–– candidates are the central spindle and the astral rays. In the present study, we examined cytokinesis in ammonia-activated sea urchin eggs, which lack paternally derived centrosomes and undergo mitosis mediated by unusual anastral, bipolar mini-spindles. Live cell imaging and immunolabeling for microtubules and the centralspindlin constituent and kinesin-related protein, MKLP1, demonstrated that furrowing in ammonia-activated eggs was associated with aligned arrays of centralspindlin-linked, opposed bundles of antiparallel microtubules. These autonomous, zipper- like arrays were not associated with a mitotic apparatus, but did possess characteristics similar to the central spindle region of control, fertilized embryos. Our results highlight the self-organizing nature of the central spindle region and its ability to induce cytokinesis-like furrowing, even in the absence of a complete mitotic apparatus.This research was supported by student/faculty summer research grants from the Dickinson College Research and Development Committee to JHH; Laura and Arthur Colwin Summer Research Fellowships from the MBL to JHH and CBS; a National Science Foundation Major Research Instrumentation grant to JHH (MRI-0320606); and a NSF collaborative research grant to JHH (MCB-1412688) and to CBS (MCB- 1412734)