Artificial Dendritic Neuron: A Model of Computation and Learning Algorithm

Dendrites are root-like extensions from the neuron cell body and have long been thought to serve as the predominant input structures of neurons. Since the early twentieth century, neuroscience research has attempted to define the dendrite’s contribution to neural computation and signal integration. This body of experimental and modeling research strongly indicates that dendrites are not just input structures but are crucial to neural processing. Dendritic processing consists of both active and passive elements that utilize the spatial, electrical and connective properties of the dendritic tree. This work presents a neuron model based around the structure and properties of dendrites. This research assesses the computational benefits and requirements of adding dendrites to a spiking artificial neuron model. A list of the computational properties of actual dendrites that have shaped this work is given. An algorithm capable of generating and training a network of dendritic neurons is created as an investigative tool through which computational challenges and attributes are explored. This work assumes that dendrites provide a necessary and beneficial function to biological intelligence (BI) and their translation into the artificial intelligence (AI) realm would broaden the capabilities and improve the realism of artificial neural network (ANN) research. To date there have been only a few instances in which neural network-based AI research has ventured beyond the point neuron; therefore, the work presented here should be viewed as exploratory. The contribution to AI made by this work is an implementation of the artificial dendritic (AD) neuron model and an algorithm for training AD neurons with spatially distributed inputs with dendrite-like connectivity

Cycles of Failure: The War on Family, The War on Drugs, and The War on Schools Through HBO’s \u3cem\u3eThe Wire\u3c/em\u3e

Freamon, Bodie, and Zenobia’s statements cut straight to the heart of The Wire’s overarching theme: Individuals are trapped in a complex “cycle of harm” where social problems of inequality, crime, and violence are constantly reinforced. The Wire was a television drama that ran on HBO from 2002 through 2008, created by David Simon. The show focuses on the narcotics scene in Baltimore through the perspective of different stakeholders and residents of the city. The Wire highlights how self-perpetuating, interconnected, and broken social institutions act in concert to limit individual opportunity. These institutions squash attempts at reform by punishing good ideas and reinforcing the status quo. The Wire’s characters are all trapped in this cycle of harm. No matter how desperately individuals want to make change, the house always wins, and attempts to reform institutions often do more harm than good. This paper will discuss three specific institutions that play central roles in The Wire: The family unit, the War on Drugs, and the public-school systems. Each section will focus particularly on how past efforts at reform have contributed to institutional failure. David Simon’s critique of each institution and The Wire’s relevant lessons are also examined. Ultimately, this paper recognizes that because society’s failing institutions are inextricably linked, efforts at reform must target structural problems, in order to effect genuine change

Do exercisers maximize their pleasure by default? Using prompts to enhance the affective experience of exercise

Researchers and practitioners are increasingly recognizing the importance of maximizing pleasure during exercise in order to promote exercise behavior. Self-selected intensity exercise can increase pleasure during exercise, but it is not yet known whether participants maximize pleasure during self-selected intensity exercise by default. We hypothesized that prompting participants to maximize pleasure and enjoyment would result in more positive affective valence during (H1) and after (H2) exercise, greater remembered pleasure following exercise (H3), and greater enjoyment of exercise (H4). In this within-subjects experiment, 39 inactive adults completed two 10-min stationary cycling sessions at a self-selected intensity. During the experimental condition, participants were reminded (five times during the 10-min session) to maximize pleasure and enjoyment, and that they could change the intensity if they wanted. Affective valence, heart rate, and ratings of perceived exertion were measured every two minutes during exercise. Affective valence, enjoyment, and remembered pleasure were measured after each exercise session. The control condition was identical, except no prompts were provided. Each hypothesis was supported (p < .05). Prompting participants to maximize their pleasure and enjoyment resulted in increased pleasure as the exercise session progressed. After receiving prompts, participants also reported more positive post-exercise affective valence and rated the session as more pleasant and enjoyable. These results suggest that participants do not maximize pleasure and enjoyment by default (i.e., in the absence of reminders to do so). Researchers can build on these results to determine the mechanisms and whether prompting exercisers to maximize pleasure and enjoyment can promote exercise behavior

Project MERCI (Medical Emergency Response Care Initiative)

This project proposed a program intended to foster a greater sense of community, shared responsibility, and mutual aid within Virginia Commonwealth University. The group members saw an opportunity to develop the expectation that students, faculty and staff will come to one another’s aid, and to provide the tools necessary to help ensure our mutual safety and health. The medical emergencies as an initial project were selected, focusing their research on the current status of CPR and first-aid training and the placement of automated external defibrillators (AEDs) at VCU

Reproducibility in high-throughput density functional theory: a comparison of AFLOW, Materials Project, and OQMD

A central challenge in high throughput density functional theory (HT-DFT) calculations is selecting a combination of input parameters and post-processing techniques that can be used across all materials classes, while also managing accuracy-cost tradeoffs. To investigate the effects of these parameter choices, we consolidate three large HT-DFT databases: Automatic-FLOW (AFLOW), the Materials Project (MP), and the Open Quantum Materials Database (OQMD), and compare reported properties across each pair of databases for materials calculated using the same initial crystal structure. We find that HT-DFT formation energies and volumes are generally more reproducible than band gaps and total magnetizations; for instance, a notable fraction of records disagree on whether a material is metallic (up to 7%) or magnetic (up to 15%). The variance between calculated properties is as high as 0.105 eV/atom (median relative absolute difference, or MRAD, of 6%) for formation energy, 0.65 {\AA}$^3$/atom (MRAD of 4%) for volume, 0.21 eV (MRAD of 9%) for band gap, and 0.15 $\mu_{\rm B}$/formula unit (MRAD of 8%) for total magnetization, comparable to the differences between DFT and experiment. We trace some of the larger discrepancies to choices involving pseudopotentials, the DFT+U formalism, and elemental reference states, and argue that further standardization of HT-DFT would be beneficial to reproducibility.Comment: Authors VIH and CKHB contributed equally to this wor

20 years of research on the Alcator C-Mod tokamak

The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only high-power radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components—approaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and the Enhanced Dα H-mode regimes, which have high performance without large edge localized modes and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and demonstrated that self-generated flow shear can be strong enough in some cases to significantly modify transport. C-Mod made the first quantitative link between the pedestal temperature and the H-mode's performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. RF research highlights include direct experimental observation of ion cyclotron range of frequency (ICRF) mode-conversion, ICRF flow drive, demonstration of lower-hybrid current drive at ITER-like densities and fields and, using a set of novel diagnostics, extensive validation of advanced RF codes. Disruption studies on C-Mod provided the first observation of non-axisymmetric halo currents and non-axisymmetric radiation in mitigated disruptions. A summary of important achievements and discoveries are included.United States. Dept. of Energy (Cooperative Agreement DE-FC02-99ER54512)United States. Dept. of Energy (Cooperative Agreement DE-FG03-94ER-54241)United States. Dept. of Energy (Cooperative Agreement DE-AC02-78ET- 51013)United States. Dept. of Energy (Cooperative Agreement DE-AC02-09CH11466)United States. Dept. of Energy (Cooperative Agreement DE-FG02-95ER54309)United States. Dept. of Energy (Cooperative Agreement DE-AC02-05CH11231)United States. Dept. of Energy (Cooperative Agreement DE-AC52-07NA27344)United States. Dept. of Energy (Cooperative Agreement DE-FG02- 97ER54392)United States. Dept. of Energy (Cooperative Agreement DE-SC00-02060

Alcator C-Mod: research in support of ITER and steps beyond

This paper presents an overview of recent highlights from research on Alcator C-Mod. Significant progress has been made across all research areas over the last two years, with particular emphasis on divertor physics and power handling, plasma–material interaction studies, edge localized mode-suppressed pedestal dynamics, core transport and turbulence, and RF heating and current drive utilizing ion cyclotron and lower hybrid tools. Specific results of particular relevance to ITER include: inner wall SOL transport studies that have led, together with results from other experiments, to the change of the detailed shape of the inner wall in ITER; runaway electron studies showing that the critical electric field required for runaway generation is much higher than predicted from collisional theory; core tungsten impurity transport studies reveal that tungsten accumulation is naturally avoided in typical C-Mod conditions.United States. Department of Energy (DE-FC02-99ER54512-CMOD)United States. Department of Energy (DE-AC02-09CH11466)United States. Department of Energy (DE-FG02-96ER-54373)United States. Department of Energy (DE-FG02-94ER54235

Comprehensive Genomic Profiling of Pancreatic Acinar Cell Carcinomas

significantly enriched for genomic alterations (GAs) causing inactivation of DNA repair genes (45%); these GAs have been associated with sensitivity to platinum-based therapies and PARP inhibitors. Collectively, these results identify potentially actionable GAs in the majority of PACCs, and provide a rationale for using personalized therapies in this disease. Statement of Significance PACC is genomically distinct from other pancreatic cancers. Fusions in RAF genes and mutually exclusive inactivation of DNA repair genes represent novel potential therapeutic targets that are altered in over two-thirds of these tumors