Explorations to the seafloors of Earth and Europa

Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 23-24).Hydrothermal vents on Earth's seafloor host entire ecosystems that live off energy from chemosynthesis rather than photosynthesis. This energy process uses chemical reactions between metals and hot gases from inside Earth's mantle to fuel thriving communities of exotic organisms. Some researchers think life originated at these vents and if they're right, that means there's a chance life could have also originated near similar hydrothermal vents on other planets or moons. One of the most promising places to search is the suspected sub-ice ocean on Jupiter's moon, Europa. This is the story of humankind's efforts to understand the origins of life by looking for it in extreme environments where life thrives without relying on the sun as an energy source. It follows an oceanographic expedition to the Mid-Cayman Rise, led by Chris German of the Woods Hole Oceanographic Institution and NASA's efforts to plan a future mission to Europa. By understanding how life can live without the sun, we may discover how life began on our planet and whether or not Earth is the only place in the universe capable of supporting a biosphere.by Garret R. Fitzpatrick.S.M.in Science Writin

Market Discipline by Depositors: A Summary of the Theoretical and Empirical Arguments

Fifty-four banks failed in the first quarter of 1987, more than in any quarter since 1933. Because bank failures are linked to bank risk, most of the regulatory proposals offered to control the growing number of bank failures are designed to encourage depositors to exert market discipline on bank officers and directors, thereby decreasing bank risk and lowering the incidence of bank failure. For policies relying on depositor discipline to be effective, depositors\u27 assets must be exposed to some risk, so that depositors will have an incentive to check the soundness of the banks in which they have deposited their money. At present, however, bank failure policy uses federal bailouts and arranged mergers for most failing banks, providing essentially complete protection for all depositors, regardless of the size of their deposits. This policy reduces the effectiveness of depositor discipline. In addition, the policy removes the incentive for bank managers to limit risk-taking, in effect subsidizing poorly managed, risky banks, and increases the likelihood of bank failures

Psychology, environment and climate change: foregrounding justice (part one)

We are living through unprecedented global heating,environmental pollution, chemical toxicity, biodiversityloss, extractivism, environmental militarisation, exclusionof marginalised people in decision-making processes,violence directed at environmental defenders and limitsto public engagement, to name a few issues (IPCC, 2022,Menton & Le Billon, 2021, Noyes et al., 2009, Sealey-Huggins,2018). While psychologists are paying increasing attentionto environmental degradation and climate change (Bailey,Pool & James, 2021, Wainwright and Mitchell, 2021), thediscipline has been somewhat slow to address the politicaland structural dimensions that underpin those issues.Importantly, mainstream psychological scholarship hasneglected marginalised people who are disproportionatelyaffected and underrepresented in environmental andclimate scholarship and practice

Psychology, environment and climate change: foregrounding justice (part two)

The world is experiencing unprecedented heating, extreme weather patterns, natural disasters, pollution, biodiversity loss, and environmental destruction with disproportionate impacts on marginalised peoples’ physical and mental health. Environmental and climate justice is increasingly used to frame research, practice and praxis. For example, activists on the margins are increasingly demanding that their voices are heard despite extreme levels of physical and epistemic violence. Countries in the global South are demanding reparations for the disproportionate harm caused by industrialised nations. For the first time, the latest IPCC report acknowledged the impacts of colonisation on climate change. However, much work needs to be done.  With planetary health at a tipping point, it is crucial for all sectors and disciplines to urgently mobilise to acknowledge disproportionate impacts and reverse environmental degradation and climate change

Locus coeruleus to basolateral amygdala noradrenergic projections promote anxiety-like behavior

Increased tonic activity of locus coeruleus noradrenergic (LC-NE) neurons induces anxiety-like and aversive behavior. While some information is known about the afferent circuitry that endogenously drives this neural activity and behavior, the downstream receptors and anatomical projections that mediate these acute risk aversive behavioral states via the LC-NE system remain unresolved. Here we use a combination of retrograde tracing, fast-scan cyclic voltammetry, electrophysiology, and in vivo optogenetics with localized pharmacology to identify neural substrates downstream of increased tonic LC-NE activity in mice. We demonstrate that photostimulation of LC-NE fibers in the BLA evokes norepinephrine release in the basolateral amygdala (BLA), alters BLA neuronal activity, conditions aversion, and increases anxiety-like behavior. Additionally, we report that β-adrenergic receptors mediate the anxiety-like phenotype of increased NE release in the BLA. These studies begin to illustrate how the complex efferent system of the LC-NE system selectively mediates behavior through distinct receptor and projection-selective mechanisms

Prospects for probing the gluon density in protons using heavy quarkonium hadroproduction

We examine carefully bottomonia hadroproduction in proton colliders, especially focusing on the LHC, as a way of probing the gluon density in protons. To this end we develop some previous work, getting quantitative predictions and concluding that our proposal can be useful to perform consistency checks of the parameterization sets of different parton distribution functions.Comment: LaTeX, 14 pages, 6 EPS figure

Myocardial Ischemia with Penetrating Thoracic Trauma

Penetrating trauma is a rare cause of myocardial infarction. Our report describes a 47-year-old female who presented with a gunshot wound from a shotgun and had an ST-elevation myocardial infarction. The patient received emergent coronary angiography, which demonstrated no evidence of coronary atherosclerotic disease but did show occlusion of a marginal vessel secondary to a pellet. The patient was managed medically for the myocardial infarction without cardiac sequelae. Patients with penetrating trauma to the chest should be evaluated for myocardial ischemia. Electrocardiography, echocardiography and cardiac angiography play vital roles in evaluating these patients and helping to guide management

Intravascular ultrasound aids in the performance of endovascular repair of abdominal aortic aneurysm

AbstractPurpose: The purpose of this retrospective review was to assess the accuracy of aortic measurements with intravascular ultrasound scan (IVUS) compared with computed tomographic (CT) scan and to assess the role of IVUS in the performance of endovascular repair of abdominal aortic aneurysms (AAAs). Methods: Seventy-eight patients undergoing repair of AAA with the AneuRx stent graft (Medtronic AVE, Inc, Santa Rosa, Calif) underwent measurement with CT scan and IVUS. The initial selection of stent graft size was made on the basis of the CT scan measurements, but the final decision for size was made on the basis of the IVUS measurements. Standard measurements of a phantom tube obtained with IVUS, CT scan, and digital caliper were also compared. Results: IVUS measurements of the phantom standard agreed closely with CT scan measurements. However, stent graft size initially selected with CT measurement was altered in 28% of cases on the basis of intraoperative IVUS measurements. No type I endoleaks were encountered in our series, and no aortic cuffs were necessary for endoleak repair. Conclusion: IVUS accurately measures the aorta for selection of stent grafts for endovascular repair of AAA and may prevent type I endoleaks and remedial procedures for their repair. (J Vasc Surg 2003;37:615-8

Circadian clock proteins regulate neuronal redox homeostasis and neurodegeneration

Brain aging is associated with diminished circadian clock output and decreased expression of the core clock proteins, which regulate many aspects of cellular biochemistry and metabolism. The genes encoding clock proteins are expressed throughout the brain, though it is unknown whether these proteins modulate brain homeostasis. We observed that deletion of circadian clock transcriptional activators aryl hydrocarbon receptor nuclear translocator-like (Bmal1) alone, or circadian locomotor output cycles kaput (Clock) in combination with neuronal PAS domain protein 2 (Npas2), induced severe age-dependent astrogliosis in the cortex and hippocampus. Mice lacking the clock gene repressors period circadian clock 1 (Per1) and period circadian clock 2 (Per2) had no observed astrogliosis. Bmal1 deletion caused the degeneration of synaptic terminals and impaired cortical functional connectivity, as well as neuronal oxidative damage and impaired expression of several redox defense genes. Targeted deletion of Bmal1 in neurons and glia caused similar neuropathology, despite the retention of intact circadian behavioral and sleep-wake rhythms. Reduction of Bmal1 expression promoted neuronal death in primary cultures and in mice treated with a chemical inducer of oxidative injury and striatal neurodegeneration. Our findings indicate that BMAL1 in a complex with CLOCK or NPAS2 regulates cerebral redox homeostasis and connects impaired clock gene function to neurodegeneration