473 research outputs found
Radiation can never again dominate Matter in a Vacuum Dominated Universe
We demonstrate that in a vacuum-energy-dominated expansion phase,
surprisingly neither the decay of matter nor matter-antimatter annihilation
into relativistic particles can ever cause radiation to once again dominate
over matter in the future history of the universe.Comment: updated version, as it will appear in Phys. Rev D. Title change, and
some other minor alteration
Expression of Retroviral Transduced Human CD18 in Murine Cells: An In Vitro Model of Gene Therapy for Leukocyte Adhesion Deficiency
Overview summary In developing human gene therapy clinical protocols, it is helpful to have an animal model that mimics the human disease to be treated. A natural animal model for leukocyte adhesion deficiency (LAD) does not exist. Krauss et al. have developed a clever strategy for producing a mouse model for LAD gene therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63397/1/hum.1991.2.3-221.pd
On Human Predictions with Explanations and Predictions of Machine Learning Models: A Case Study on Deception Detection
Humans are the final decision makers in critical tasks that involve ethical
and legal concerns, ranging from recidivism prediction, to medical diagnosis,
to fighting against fake news. Although machine learning models can sometimes
achieve impressive performance in these tasks, these tasks are not amenable to
full automation. To realize the potential of machine learning for improving
human decisions, it is important to understand how assistance from machine
learning models affects human performance and human agency.
In this paper, we use deception detection as a testbed and investigate how we
can harness explanations and predictions of machine learning models to improve
human performance while retaining human agency. We propose a spectrum between
full human agency and full automation, and develop varying levels of machine
assistance along the spectrum that gradually increase the influence of machine
predictions. We find that without showing predicted labels, explanations alone
slightly improve human performance in the end task. In comparison, human
performance is greatly improved by showing predicted labels (>20% relative
improvement) and can be further improved by explicitly suggesting strong
machine performance. Interestingly, when predicted labels are shown,
explanations of machine predictions induce a similar level of accuracy as an
explicit statement of strong machine performance. Our results demonstrate a
tradeoff between human performance and human agency and show that explanations
of machine predictions can moderate this tradeoff.Comment: 17 pages, 19 figures, in Proceedings of ACM FAT* 2019, dataset & demo
available at https://deception.machineintheloop.co
Small molecule SARM1 inhibitors recapitulate the SARM1 -/- phenotype and allow recovery of a metastable pool of axons fated to degenerate
Axonal degeneration is responsible for disease progression and accumulation of disability in many neurodegenerative conditions. The axonal degenerative process can generate a metastable pool of damaged axons that remain structurally and functionally viable but fated to degenerate in the absence of external intervention. SARM1, an NADase that depletes axonal energy stores upon activation, is the central driver of an evolutionarily conserved program of axonal degeneration. We identify a potent and selective small molecule isoquinoline inhibitor of SARM1 NADase that recapitulates the SARM
The Neural Correlates of Non-Spatial Working Memory in Velocardiofacial Syndrome (22q11.2 Deletion Syndrome)
Velocardiofacial syndrome (VCFS), also known as 22q11.2 deletion syndrome, is a neurogenetic disorder that is associated with both learning disabilities and a consistent neuropsychological phenotype, including deficits in executive function, visuospatial perception, and working memory. Anatomic imaging studies have identified significant volumetric reductions in the parietal lobe of individuals with VCFS, but several studies have reported that the frontal lobe is relatively preserved. We used functional magnetic resonance imaging to investigate the neural correlates of non-spatial working memory in 17 youths with VCFS, 10 of their unaffected siblings, and 10 community controls (with the same proportion of learning disabilities as the VCFS youths). Task performance of siblings tended to be more accurate than children with VCFS, who did not differ from community controls. All three-study groups recruited parietal regions that were equivalent in location and magnitude. Whereas the sibling group also recruited the dorsolateral prefrontal cortex (DLPFC), Broca\u27s area, and anterior cingulate, DLPFC activation was absent in the whole brain analyses of children with VCFS and controls. Moreover, the magnitude of frontal activation in VCFS participants was restricted relative to both siblings and controls. These findings suggest that VCFS participants exhibit frontal hypoactivation that is not attributable to performance. In addition, VCFS children and controls (many with idiopathic learning disabilities) appear to rely on phonological rehearsal to hold information on line instead of the DLPFC. Despite previous anatomic MRI reports of preserved frontal lobe volumes in VCFS therefore, these fMRI findings suggest that the frontal component of the distributed network subserving executive function and working memory may be disrupted in youth with this disorder
Of CP and other Gauge Symmetries in String Theory
We argue that \CP is a gauge symmetry in string theory. As a consequence, \CP
cannot be explicitly broken either perturbatively or non-pertubatively; there
can be no non-perturbative \CP-violating parameters. String theory is thus an
example of a theory where all angles arise due to spontaneous \CP
violation, and are in principle calculable.Comment: 8 page
Associations of resting heart rate with concentrations of lipoprotein subfractions in sedentary men
In major prospective studies it has been reported that high heart rate at rest predicts the development of coronary heart disease (CHD) or cardiovascular disease (CVD) in men, but the mechanisms producing these relationships are unknown. Since lipoprotein levels contribute strongly to the risk of CHD and CVD, we examined the relationship of resting heart rate to plasma concentrations of high-density (HDL), low-density (LDL), and very low-density (VLDL) lipoproteins, apolipoprotein (apo) A-I and A-II, and serum concentrations of lipoprotein subfractions in 81 men to determine if atherogenic lipoproteins could potentially induce the reported association of heart rate with development of CHD or CVD. The significant (p less than or equal to .05) Spearman\u27s correlations for resting heart rate vs HDL2 mass (rs = - .24), HDL3 mass (rs = - .40), HDL cholesterol (rs = - .36), apo A-I (rs = - .29), triglycerides (rs = .31), VLDL cholesterol (rs = .24), VLDL mass (rs = .27), and LDL mass of Sof 0-7 subfraction (rs = .30) lend support to our hypothesis of lipoprotein-induced relationships of CHD with heart rate. The correlations of resting heart rate vs triglycerides, HDL cholesterol, HDL3 mass, VLDL mass, and LDL mass of Sof 0-7 subfraction remain significant when adjusted for adiposity, age, smoking habits, diet, and physical fitness as measured by maximum aerobic power (VO2 max) or submaximal heart rate during a graded exercise test
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