Modeling Expert Judgments of Insider Threat Using Ontology Structure: Effects of Individual Indicator Threat Value and Class Membership

We describe research on a comprehensive ontology of sociotechnical and organizational factors for insider threat (SOFIT) and results of an expert knowledge elicitation study. The study examined how alternative insider threat assessment models may reflect associations among constructs beyond the relationships defined in the hierarchical class structure. Results clearly indicate that individual indicators contribute differentially to expert judgments of insider threat risk. Further, models based on ontology class structure more accurately predict expert judgments. There is some (although weak) empirical evidence that other associations among constructs—such as the roles that indicators play in an insider threat exploit—may also contribute to expert judgments of insider threat risk. These findings contribute to ongoing research aimed at development of more effective insider threat decision support tools

NMR Detection of Temperature-Dependent Magnetic Inhomogeneities in URu2Si2

We present 29Si-NMR relaxation and spectral data in URu2Si2. Our echo-decay experiments detect slowly fluctuating magnetic field gradients. In addition, we find that the echo-decay shape (time dependence) varies with temperature T and its rate behaves critically near the Neel temperature TN, indicating a correlation between the gradient fluctuations and the transition to small-moment order. T-dependent broadening contributions become visible below 100 Kelvin and saturate somewhat above TN, remaining saturated at lower temperatures. Together, the line width and shift suggest partial lattice distortions below TN. We propose an intrinsic minority phase below $T_{\rm N}$ and compare our results with one of the current theoretical models.Comment: 2 pages RevTeX, 1 figure, SCES 99-Japan, to appear in Physica

Some Relations between Twisted K-theory and E8 Gauge Theory

Recently, Diaconescu, Moore and Witten provided a nontrivial link between K-theory and M-theory, by deriving the partition function of the Ramond-Ramond fields of Type IIA string theory from an E8 gauge theory in eleven dimensions. We give some relations between twisted K-theory and M-theory by adapting the method of Diaconescu-Moore-Witten and Moore-Saulina. In particular, we construct the twisted K-theory torus which defines the partition function, and also discuss the problem from the E8 loop group picture, in which the Dixmier-Douady class is the Neveu-Schwarz field. In the process of doing this, we encounter some mathematics that is new to the physics literature. In particular, the eta differential form, which is the generalization of the eta invariant, arises naturally in this context. We conclude with several open problems in mathematics and string theory.Comment: 23 pages, latex2e, corrected minor errors and typos in published versio

Students with global experiences during medical school are more likely to work in settings that focus on the underserved: an observational study from a public U.S. institution

Background: Global health interest has grown among medical students over the past 20 years, and most medical schools offer global health opportunities. Studies suggest that completing global health electives during medical school may increase the likelihood of working with underserved populations in a clinical or research capacity. This study aimed to assess the association of global electives in medical school on subsequently working in global health and with underserved populations in the United States (U.S.), additionally considering students’ interests and experiences prior to medical school. We also examined whether respondents perceived benefits gained from global electives. Methods: We surveyed medical school graduates (classes of 2011-2015) from a large public medical school in the U.S. to describe current practice settings and previous global health experience. We evaluated work, volunteer, and educational experiences preceding medical school, socioeconomic status, race and ethnicity using American Medical College Application Service (AMCAS) data. We assessed the association between students’ backgrounds, completing global health electives in medical school and current work in global health or with underserved populations in the U.S. Results: In the 5 to 8 years post-graduation, 78% of 161 respondents reported work, research, or teaching with a focus on global or underserved U.S. populations. Completing a global health elective during medical school (p = 0.0002) or during residency (p = 0.06) were positively associated with currently working with underserved populations in the U.S. and pre-medical school experiences were marginally associated (p = 0.1). Adjusting for pre-medical school experiences, completing a global health elective during medical school was associated with a 22% greater prevalence of working with an underserved population. Perceived benefits from global electives included improved cultural awareness, language skills, public health and research skills, and ability to practice in technology-limited settings. Conclusion: Medical school graduates who participated in global electives as students were more likely than their peers to pursue careers with underserved populations, independent of experiences prior to medical school. We hypothesize that by offering global health experiences, medical schools can enhance the interests and skills of graduates that will make them more likely and better prepared to work with underserved populations in the U.S. and abroad

Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely-instrumented strings to the AMANDA II detector makes observations feasible. Such a configuration is competitive with current and proposed experiments.Comment: 36 pages, 21 figures, revte

Flux Stabilization in 6 Dimensions: D-terms and Loop Corrections

We analyse D-terms induced by gauge theory fluxes in the context of 6-dimensional supergravity models. On the one hand, this is arguably the simplest concrete setting in which the controversial idea of `D-term uplifts' can be investigated. On the other hand, it is a very plausible intermediate step on the way from a 10d string theory model to 4d phenomenology. Our specific results include the flux-induced one-loop correction to the scalar potential coming from charged hypermultiplets. Furthermore, we comment on the interplay of gauge theory fluxes and gaugino condensation in the present context, demonstrate explicitly how the D-term arises from the gauging of one of the compactification moduli, and briefly discuss further ingredients that may be required for the construction of a phenomenologically viable model. In particular, we show how the 6d dilaton and volume moduli can be simultaneously stabilized, in the spirit of KKLT, by the combination of an R symmetry twist, a gaugino condensate, and a flux-induced D-term.Comment: 24 pages, 1 figure v2:minor correction

Bounds on masses of bulk fields in string compactifications

In string compactification on a manifold X, in addition to the string scale and the normal scales of low-energy particle physics, there is a Kaluza-Klein scale 1/R associated with the size of X. We present an argument that generic string models with low-energy supersymmetry have, after moduli stabilization, bulk fields with masses which are parametrically lighter than 1/R. We discuss the implications of these light states for anomaly mediation and gaugino mediation scenarios.Comment: 15 page

Spectral functions of isoscalar scalar and isovector electromagnetic form factors of the nucleon at two-loop order

We calculate the imaginary parts of the isoscalar scalar and isovector electromagnetic form factors of the nucleon up to two-loop order in chiral perturbation theory. Particular attention is paid on the correct behavior of Im $\sigma_N(t)$ and Im $G_{E,M}^V(t)$ at the two-pion threshold $t_0=4 m_\pi^2$ in connection with the non-relativistic 1/M-expansion. We recover the well-known strong enhancement near threshold originating from the nearby anomalous singularity at $t_c = 4m_\pi^2-m_\pi^4/M^2 = 3.98 m_\pi^2$. In the case of the scalar spectral function Im $\sigma_N(t)$ one finds a significant improvement in comparison to the lowest order one-loop result. Higher order $\pi\pi$-rescattering effects are however still necessary to close a remaining 20%-gap to the empirical scalar spectral function. The isovector electric and magnetic spectral functions Im $G_{E,M}^V(t)$ get additionally enhanced near threshold by the two-pion-loop contributions. After supplementing their two-loop results by a phenomenological $\rho$-meson exchange term one can reproduce the empirical isovector electric and magnetic spectral functions fairly well.Comment: 10 pages, 6 figures, submitted to Physical Review

Quasars and their host galaxies

This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass estimates for quasars, and our confidence in them, have improved significantly, allowing a start on relating quasar properties such as radio jet power to fundamental parameters of the quasar such as black hole mass and accretion rate. Quasar host galaxy studies have allowed us to find and characterize the host galaxies of quasars to z>2. Despite these developments, many questions remain unresolved, in particular the origin of the close relationship between black hole mass and galaxy bulge mass/velocity dispersion seen in local galaxies.Comment: Review article, to appear in Astrophysics Update