Examination of Organizational Information Security Strategy: A Pilot Study

The prevailing approach to cyber security continues to be the implementation of controls—technical, formal, and informal. We have seen little departure from a fundamentally preventive strategy. The criminal justice field has called for an increased emphasis on deterrence strategies, specifically Situational Crime Prevention (SCP). This paper presents the results of an exploratory (pilot) study based on interviews of CISOs (or approximate equivalents). We found that while the balance of controls does appear to be improving, technical controls are still the priority— particularly in small organizations. We found that IS security strategies are still predominantly preventive; organizations do not view offender deterrence as a strategy. The respondents definitely see room for strategic improvement. By and large, the information security professionals interviewed believe that cyber offenders are rational decision makers, that reducing anticipated benefit would be the most lucrative influence, followed by perceived effort required and perceived risk of being caught, in that order

Laguerre semigroup and Dunkl operators

We construct a two-parameter family of actions \omega_{k,a} of the Lie algebra sl(2,R) by differential-difference operators on R^N \setminus {0}. Here, k is a multiplicity-function for the Dunkl operators, and a>0 arises from the interpolation of the Weil representation of Mp(N,R) and the minimal unitary representation of O(N+1,2) keeping smaller symmetries. We prove that this action \omega_{k,a} lifts to a unitary representation of the universal covering of SL(2,R), and can even be extended to a holomorphic semigroup \Omega_{k,a}. In the k\equiv 0 case, our semigroup generalizes the Hermite semigroup studied by R. Howe (a=2) and the Laguerre semigroup by the second author with G. Mano (a=1). One boundary value of our semigroup \Omega_{k,a} provides us with (k,a)-generalized Fourier transforms F_{k,a}, which includes the Dunkl transform D_k (a=2) and a new unitary operator H_k (a=1), namely a Dunkl-Hankel transform. We establish the inversion formula, and a generalization of the Plancherel theorem, the Hecke identity, the Bochner identity, and a Heisenberg uncertainty inequality for F_{k,a}. We also find kernel functions for \Omega_{k,a} and F_{k,a} for a=1,2 in terms of Bessel functions and the Dunkl intertwining operator.Comment: final version (some few typos, updated references

On the optimality of gluing over scales

We show that for every $\alpha > 0$, there exist $n$-point metric spaces (X,d) where every "scale" admits a Euclidean embedding with distortion at most $\alpha$, but the whole space requires distortion at least $\Omega(\sqrt{\alpha \log n})$. This shows that the scale-gluing lemma [Lee, SODA 2005] is tight, and disproves a conjecture stated there. This matching upper bound was known to be tight at both endpoints, i.e. when $\alpha = \Theta(1)$ and $\alpha = \Theta(\log n)$, but nowhere in between. More specifically, we exhibit $n$-point spaces with doubling constant $\lambda$ requiring Euclidean distortion $\Omega(\sqrt{\log \lambda \log n})$, which also shows that the technique of "measured descent" [Krauthgamer, et. al., Geometric and Functional Analysis] is optimal. We extend this to obtain a similar tight result for $L_p$ spaces with $p > 1$.Comment: minor revision

Metric structures in L_1: Dimension, snowflakes, and average distortion

We study the metric properties of finite subsets of L_1. The analysis of such metrics is central to a number of important algorithmic problems involving the cut structure of weighted graphs, including the Sparsest Cut Problem, one of the most compelling open problems in the field of approximation algorithms. Additionally, many open questions in geometric non-linear functional analysis involve the properties of finite subsets of L_1.Comment: 9 pages, 1 figure. To appear in European Journal of Combinatorics. Preliminary version appeared in LATIN '0

Criterion-referenced mCAFT cut-points to identify metabolically healthy cardiorespiratory fitness among adults aged 18–69 years: An analysis of the Canadian Health Measures Survey

Objective: This study aimed to develop and validate health-related criterion-referenced cutpoints for the modified Canadian Aerobic Fitness Test (mCAFT), a field-based measure to predict cardiorespiratory fitness (CRF) among adults (18–69 years). Methods: Criterionreferenced mCAFT cut-points were developed using nationally representative data from cycles 1 (2007–09) and 2 (2009–11) of the Canadian Health Measures Survey (CHMS). Receiver operating characteristic curves were used to identify age- and sex-specific cut-points for measured waist circumference, blood pressure, and high-density lipoprotein. Cut-points were validated against metabolic syndrome using a fasted sub-sample (n=1,093) from cycle 5 (2016– 17). Results: 4,967 participants (50% women) were retained for the main analyses. The mCAFT cut-points ranged from 28 to 43 mL•kg–1•min–1 (AUC: 0.60-0.87) among men, and 23 to 37 mL•kg–1•min–1 (AUC: 0.61-0.86) among women. The likelihood of meeting the new mCAFT cut-points decreased with an increase in the presence of metabolic risk factors. In total, 54% (95%CI: 42 to 67%) of Canadian adults met the new mCAFT cut-points in 2016–17. Conclusion: This study developed and validated the first health-related criterion-referenced mCAFT cutpoints for metabolic health among Canadian adults aged 18–69 years. These mCAFT cut-points may be useful in health surveillance, clinical, and public health settings. Novelty bullets We developed and validated new criterion-referenced cut-points for the modified Canadian Aerobic Fitness Test to help identify adults at potential risk of poor metabolic health. These new cut-points could help support national health surveillance efforts

Photoconductance Quantization in a Single-Photon Detector

We have made a single-photon detector that relies on photoconductive gain in a narrow electron channel in an AlGaAs/GaAs 2-dimensional electron gas. Given that the electron channel is 1-dimensional, the photo-induced conductance has plateaus at multiples of the quantum conductance 2e$^{2}$/h. Super-imposed on these broad conductance plateaus are many sharp, small, conductance steps associated with single-photon absorption events that produce individual photo-carriers. This type of photoconductive detector could measure a single photon, while safely storing and protecting the spin degree of freedom of its photo-carrier. This function is valuable for a quantum repeater that would allow very long distance teleportation of quantum information.Comment: 4 pages, 4 figure

Galaxy redshift surveys selected by neutral hydrogen using FAST

We discuss the possibility of performing a substantial spectroscopic galaxy redshift survey selected via the 21cm emission from neutral hydrogen using the Five-hundred metre Aperture Spherical Telescope (FAST) to be built in China. We consider issues related to the estimation of the source counts and optimizations of the survey, and discuss the constraints on cosmological models that such a survey could provide. We find that a survey taking around two years could detect ~10^7 galaxies with an average redshift of ~0.15 making the survey complementary to those already carried out at optical wavelengths. These conservative estimates have used the z=0 HI mass function and have ignored the possibility of evolution. The results could be used to constrain Gamma = (Omega_m h) to 5 per cent and the spectral index, n_s, to 7 per cent independent of cosmic microwave background data. If we also use simulated power spectra from the Planck satellite, we can constrain w to be within 5 per cent of -1.Comment: 13 pages, 15 figures, Accepted by MNRAS, minor correction

Rac1 GTPase-deficient mouse lens exhibits defects in shape, suture formation, fiber cell migration and survival

AbstractMorphogenesis and shape of the ocular lens depend on epithelial cell elongation and differentiation into fiber cells, followed by the symmetric and compact organization of fiber cells within an enclosed extracellular matrix-enriched elastic capsule. The cellular mechanisms orchestrating these different events however, remain obscure. We investigated the role of the Rac1 GTPase in these processes by targeted deletion of expression using the conditional gene knockout (cKO) approach. Rac1 cKO mice were derived from two different Cre (Le-Cre and MLR-10) transgenic mice in which lens-specific Cre expression starts at embryonic day 8.75 and 10.5, respectively, in both the lens epithelium and fiber cells. The Le-Cre/Rac1 cKO mice exhibited an early-onset (E12.5) and severe lens phenotype compared to the MLR-10/Rac1 cKO (E15.5) mice. While the Le-Cre/Rac1 cKO lenses displayed delayed primary fiber cell elongation, lenses from both Rac1 cKO strains were characterized by abnormal shape, impaired secondary fiber cell migration, sutural defects and thinning of the posterior capsule which often led to rupture. Lens fiber cell N-cadherin/β-catenin/Rap1/Nectin-based cell–cell junction formation and WAVE-2/Abi-2/Nap1-regulated actin polymerization were impaired in the Rac1 deficient mice. Additionally, the Rac1 cKO lenses were characterized by a shortened epithelial sheet, reduced levels of extracellular matrix (ECM) proteins and increased apoptosis. Taken together, these data uncover the essential role of Rac1 GTPase activity in establishment and maintenance of lens shape, suture formation and capsule integrity, and in fiber cell migration, adhesion and survival, via regulation of actin cytoskeletal dynamics, cell adhesive interactions and ECM turnover