Manuscript E

Timeline of African American history in Rhode Island, from 1652 to 1955, including the introduction of slavery; African American participation in the American Revolution; the abolition of slavery; the establishment and development of African American churches; notable African Americans; and African American firsts in Rhode Island

History of Free and Accepted Masons, (Prince Hall) in Rhode Island \u27From Whence We Came\u27

Timeline of the history of freemasonry in Rhode Island, including the establishment and development of African American lodges

Growth and Characterization of Molybdenum Disulfide Thin Films

Two-dimensional materials, or materials that are only one atomic layer thick, have seen much research in recent years because of their interesting electrical properties. The first of these materials, graphene, was found to have incredible electrical properties but lacked a bandgap in intrinsic films. Without a bandgap, graphene cannot create transistors that can be shut off. Molybdenum disulfide, however, is a two-dimensional semiconductor with a large bandgap. The main issue of molybdenum disulfide is that synthesized films are a much lower quality than their exfoliated counterparts. For molybdenum disulfide to be able to be used practically, a method of synthesis must be found that can reliably create quality large area monolayer films. In this thesis, three methods of molybdenum disulfide film synthesis are presented. Methods implemented used a tube furnace as a chemical vapor deposition system to evaporate source materials to synthesize thin films of molybdenum disulfide. An exploration into the different synthesis parameters shows optimal conditions for these specific methods. Then a discussion of these different methods is presented by judging films grown by using these methods on relevant criteria. This work shows methods to synthesize large area, polycrystalline, small grain, multilayer films, both intrinsic and doped, and to synthesize small area, single crystal and polycrystalline, monolayer films of molybdenum disulfide

Why ex post peer review encourages high-risk research while ex ante review discourages it

Peer review is an integral component of contemporary science. While peer review focuses attention on promising and interesting science, it also encourages scientists to pursue some questions at the expense of others. Here, we use ideas from forecasting assessment to examine how two modes of peer review -- ex ante review of proposals for future work and ex post review of completed science -- motivate scientists to favor some questions instead of others. Our main result is that ex ante and ex post peer review push investigators toward distinct sets of scientific questions. This tension arises because ex post review allows an investigator to leverage her own scientific beliefs to generate results that others will find surprising, whereas ex ante review does not. Moreover, ex ante review will favor different research questions depending on whether reviewers rank proposals in anticipation of changes to their own personal beliefs, or to the beliefs of their peers. The tension between ex ante and ex post review puts investigators in a bind, because most researchers need to find projects that will survive both. By unpacking the tension between these two modes of review, we can understand how they shape the landscape of science and how changes to peer review might shift scientific activity in unforeseen directions.Comment: 11 pages, 4 figures, 1 appendix. Version 2 includes revamped notation and some text edits to the discussio

Direct Robot Configuration Space Construction using Convolutional Encoder-Decoders

Intelligent robots must be able to perform safe and efficient motion planning in their environments. Central to modern motion planning is the configuration space. Configuration spaces define the set of configurations of a robot that result in collisions with obstacles in the workspace, C-clsn, and the set of configurations that do not, C-free. Modern approaches to motion planning first compute the configuration space and then perform motion planning using the calculated configuration space. Real-time motion planning requires accurate and efficient construction of configuration spaces. We are the first to apply a convolutional encoder-decoder framework for calculating highly accurate approximations to configuration spaces. Our model achieves an average 97.5% F1-score for predicting C-free and C-clsn for 2-D robotic workspaces with a dual-arm robot. Our method limits undetected collisions to less than 2.5% on robotic workspaces that involve translation, rotation, and removal of obstacles. Our model learns highly transferable features between robotic workspaces, requiring little to no fine-tuning to adapt to new transformations of obstacles in the workspace.Comment: 6 pages, 7 figures, 4 table

Publication bias and the canonization of false facts

In the process of scientific inquiry, certain claims accumulate enough support to be established as facts. Unfortunately, not every claim accorded the status of fact turns out to be true. In this paper, we model the dynamic process by which claims are canonized as fact through repeated experimental confirmation. The community's confidence in a claim constitutes a Markov process: each successive published result shifts the degree of belief, until sufficient evidence accumulates to accept the claim as fact or to reject it as false. In our model, publication bias --- in which positive results are published preferentially over negative ones --- influences the distribution of published results. We find that when readers do not know the degree of publication bias and thus cannot condition on it, false claims often can be canonized as facts. Unless a sufficient fraction of negative results are published, the scientific process will do a poor job at discriminating false from true claims. This problem is exacerbated when scientists engage in p-hacking, data dredging, and other behaviors that increase the rate at which false positives are published. If negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims can be more readily distinguished. To the degree that the model accurately represents current scholarly practice, there will be serious concern about the validity of purported facts in some areas of scientific research

Imaging Gold Nanoparticles in Living Cells Environments using Heterodyne Digital Holographic Microscopy

This paper describes an imaging microscopic technique based on heterodyne digital holography where subwavelength-sized gold colloids can be imaged in cell environment. Surface cellular receptors of 3T3 mouse fibroblasts are labeled with 40 nm gold nanoparticles, and the biological specimen is imaged in a total internal reflection configuration with holographic microscopy. Due to a higher scattering efficiency of the gold nanoparticles versus that of cellular structures, accurate localization of a gold marker is obtained within a 3D mapping of the entire sample's scattered field, with a lateral precision of 5 nm and 100 nm in the x,y and in the z directions respectively, demonstrating the ability of holographic microscopy to locate nanoparticles in living cells environments

Towards Subject-Specific Therapy Planning for Non-Invasive Blood Brain Barrier Opening in Mice by Focused Ultrasound

Focused ultrasound (FUS) is a promising method to open the blood brain barrier (BBB) for treatment of neurodegenerative diseases. Accurate targeting is essential for a successful BBB opening (BBBo). We aim to develop a robust therapy planning for BBBo in mice, which is challenging due to the size of the brain and the influence of the skull on the ultrasound pressure distribution. For enabling mouse individual therapy planning, a simulation tool is proposed, developed and validated. We used the k-Wave toolbox to enable 3D acoustic simulations of the commercial FUS system from Image Guided Therapy (IGT). Micro-CT scans were used to model the geometry of skulls. Simulations using a mouse skull showed an attenuation of approx. 20–24% depending on the position of penetration, which was validated by hydrophone measurements in the same range. Based on these validations we planned BBBo in m ice by placing the transducer at different positions over the mouse brain and varying the excitation amplitude. With different transducer positions, the peak pressure in the brain varied between 0.54 MPa and 0.62 MPa at 11% output level, which is expected to enable safe BBBo. Subsequently, in vivo experiments were conducted using the aforementioned simulation parameters. BBBo was confirmed by contrast enhanced T1 weighted magnetic resonance images immediately after sonication