258 research outputs found
Breaking the Binary: Desegregation of Bathrooms
This note discusses how the binary view of gender in relation to public bathroom segregation is insufficient to meet the diverse needs of the public and proposes the desegregation of bathrooms as the solution to promote gender equality and reduce gender-based social imbalances. This note will focus on the bathroom rights of individuals who identify outside of the binary options of male and female, viewed through the lens of how transgender people identifying within the binary have been treated by the courts. For the purposes of this note, the term non-binary will be used to refer to these individuals. Part I provides a brief overview of recent bathroom legislation in the United States, the statutory and constitutional framework that has been applied to sex discrimination claims, and the courts’ treatment of gender-based discrimination claims under each law. Part II analyzes gender-based discrimination claims in relation to public bathroom access under this framework in light of how courts have treated gender litigation and addresses widespread myths about privacy and safety concerns. Part III proposes the complete desegregation of bathrooms based on gender, considers which legal claim is the best avenue of implementing desegregation, delineates the benefits of such implementation, and addresses potential concerns raised by this proposal
A brief history of long memory: Hurst, Mandelbrot and the road to ARFIMA
Long memory plays an important role in many fields by determining the
behaviour and predictability of systems; for instance, climate, hydrology,
finance, networks and DNA sequencing. In particular, it is important to test if
a process is exhibiting long memory since that impacts the accuracy and
confidence with which one may predict future events on the basis of a small
amount of historical data. A major force in the development and study of long
memory was the late Benoit B. Mandelbrot. Here we discuss the original
motivation of the development of long memory and Mandelbrot's influence on this
fascinating field. We will also elucidate the sometimes contrasting approaches
to long memory in different scientific communitiesComment: 40 page
The off-axis channel macroplate
High-gain microchannel plates (MCPs) which utilize curvature of the channel to inhibit ion feedback (C-plate MCRs) have demonstrated excellent performance characteristics. However, C-plate MCPs are at present costly to fabricate, and the shearing process used to curve the channels produces a low device yield. Described here is a totally new type of high-gain MCP structure in which each channel has an axially symmetric curvature. Initial tests of proof-of-concept units of these MCPs with 75-micron-diameter channels (macroplates) suggest that their performance characteristics have the potential to be equal to those of a C-plate MCP while the fabrication process is no more complex than that of a conventional straight-channel MCP
Experimental investigation of electron multipactor discharges at very high frequency
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2006.Includes bibliographical references (p. 159-166).Multipactor discharges are a resonant condition in which electrons impact a surface in phase with an alternating electric field. The discharge is sustained by electron multiplication from secondary emission. As motivation, multipactor discharges can adversely affect many different rf systems in vacuum, and this work provides an improved general understanding of multipactor and gives promising results for improved performance and reliability of these systems. The Coaxial Multipactor Experiment (CMX) creates and investigates multipactor discharges in both parallel plate and coaxial geometries at very high frequency (VHF). CMX provides the first detailed investigation of multipactor energy distribution functions for both coaxial and parallel plate geometries with the use of retarding potential analyzers (RPA). A 1-D particle tracking simulation supports these experimental distributions and yields the underlying physics behind the distribution shape. Experimental and simulation energy distributions have a low energy population of defocused electrons due to space charge effects and RPA emission, and a high energy population responsible for sustaining the discharge. Results show a higher energy distribution for the coaxial geometry as compared to the parallel plate geometry with the same electrode spacing, implying that coaxial geometries are more susceptible to multipactor. These results are supported by CMX susceptibility data, which are provided for both coaxial and parallel plate electrodes. Lastly, similar multipactor experiments were performed on Alcator C-Mod rf systems, allowing the discovery of multipactor-induced glow discharge in these systems.(cont.) Results suggest the onset of this glow discharge causes the observed C-Mod neutral pressure limits. These results are further supported by CMX experiments, and a new, 50 pim sandblasted copper surface treatment has been shown to sufficiently lower 6 < 1 for multipactor prevention on CMX and raise the minimum pressure for glow discharge breakdown. This surface treatment shows no significant degradation of high voltage handling, and it is proposed for implementation on the multipactor-susceptible regions of C-Mod rf systems.by Timothy P. Graves.Ph.D
Bayesian Flow Networks
This paper introduces Bayesian Flow Networks (BFNs), a new class of
generative model in which the parameters of a set of independent distributions
are modified with Bayesian inference in the light of noisy data samples, then
passed as input to a neural network that outputs a second, interdependent
distribution. Starting from a simple prior and iteratively updating the two
distributions yields a generative procedure similar to the reverse process of
diffusion models; however it is conceptually simpler in that no forward process
is required. Discrete and continuous-time loss functions are derived for
continuous, discretised and discrete data, along with sample generation
procedures. Notably, the network inputs for discrete data lie on the
probability simplex, and are therefore natively differentiable, paving the way
for gradient-based sample guidance and few-step generation in discrete domains
such as language modelling. The loss function directly optimises data
compression and places no restrictions on the network architecture. In our
experiments BFNs achieve competitive log-likelihoods for image modelling on
dynamically binarized MNIST and CIFAR-10, and outperform all known discrete
diffusion models on the text8 character-level language modelling task
Systematic inference of the long-range dependence and heavy-tail distribution parameters of ARFIMA models
Long-Range Dependence (LRD) and heavy-tailed distributions are ubiquitous in natural and socio-economic data. Such data can be self-similar whereby both LRD and heavy-tailed distributions contribute to the self-similarity as measured by the Hurst exponent. Some methods widely used in the physical sciences separately estimate these two parameters, which can lead to estimation bias. Those which do simultaneous estimation are based on frequentist methods such as Whittle’s approximate maximum likelihood estimator. Here we present a new and systematic Bayesian framework for the simultaneous inference of the LRD and heavy-tailed distribution parameters of a parametric ARFIMA model with non-Gaussian innovations. As innovations we use the α-stable and t-distributions which have power law tails. Our algorithm also provides parameter uncertainty estimates. We test our algorithm using synthetic data, and also data from the Geostationary Operational Environmental Satellite system (GOES) solar X-ray time series. These tests show that our algorithm is able to accurately and robustly estimate the LRD and heavy-tailed distribution parameters
Variation in transcriptional regulation of cyclin dependent kinase inhibitor p21(waf1/cip1 )among human bronchogenic carcinomas
BACKGROUND: Cell proliferation control depends in part on the carefully ordered regulation of transcription factors. The p53 homolog p73, contributes to this control by directly upregulating the cyclin dependent kinase inhibitor, p21(waf1/cip1). E2F1, an inducer of cell proliferation, directly upregulates p73 and in some systems upregulates p21 directly. Because of its central role in controlling cell proliferation, upregulation of p21 has been explored as a modality for treating bronchogenic carcinoma (BC). Improved understanding of p21 transcriptional regulation will facilitate identification of BC tissues that are responsive to p21-directed therapies. Toward this goal, we investigated the role that E2F1 and p73 each play in the transcriptional regulation of p21. RESULTS: Among BC samples (N = 21) p21 transcript abundance (TA) levels varied over two orders of magnitude with values ranging from 400 to 120,000 (in units of molecules/10(6 )molecules β-actin). The p21 values in many BC were high compared to those observed in normal bronchial epithelial cells (BEC) (N = 18). Among all BC samples, there was no correlation between E2F1 and p21 TA but there was positive correlation between E2F1 and p73α (p < 0.001) TA. Among BC cell lines with inactivated p53 and wild type p73 (N = 7) there was positive correlation between p73α and p21 TA (p < 0.05). Additionally, in a BC cell line in which both p53 and p73 were inactivated (H1155), E2F1 TA level was high (50,000), but p21 TA level was low (470). Transiently expressed exogenous p73α in the BC cell line Calu-1, was associated with a significant (p < 0.05) 90% increase in p21 TA and a 20% reduction in E2F1 TA. siRNA mediated reduction of p73 TA in the N417 BC cell line was associated with a significant reduction in p21 TA level (p < 0.01). CONCLUSION: p21 TA levels vary considerably among BC patients which may be attributable to 1) genetic alterations in Rb and p53 and 2) variation in TA levels of upstream transcription factors E2F1 and p73. Here we provide evidence that p73 upregulates p21 TA in BC tissues and upregulated p21 TA may result from E2F1 upregulation of p73 but not from E2F1 directly
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