GNSS Signal Authentication via Power and Distortion Monitoring

We propose a simple low-cost technique that enables civil Global Positioning System (GPS) receivers and other civil global navigation satellite system (GNSS) receivers to reliably detect carry-off spoofing and jamming. The technique, which we call the Power-Distortion detector, classifies received signals as interference-free, multipath-afflicted, spoofed, or jammed according to observations of received power and correlatio n function distortion. It does not depend on external hardware or a network connection and can be readily implemented on many receivers via a firmware update. Crucially, the detector can with high probability distinguish low-power spoofing from ordinary multipath. In testing against over 25 high-quality empirical data sets yielding over 900,000 separate detection tests, the detector correctly alarms on all malicious spoofing or jamming attack s while maintaining a <0.5% single-channel false alarm rate.Aerospace Engineering and Engineering Mechanic

A Core Genome Approach That Enables Prospective and Dynamic Monitoring of Infectious Outbreaks

Whole-genome sequencing is increasingly adopted in clinical settings to identify pathogen transmissions, though largely as a retrospective tool. Prospective monitoring, in which samples are continuously added and compared to previous samples, can generate more actionable information. To enable prospective pathogen comparison, genomic relatedness metrics based on single-nucleotide differences must be consistent across time, efficient to compute and reliable for a large variety of samples. The choice of genomic regions to compare, i.e., the core genome, is critical to obtain a good metric. We propose a novel core genome method that selects conserved sequences in the reference genome by comparing its k-mer content to that of publicly available genome assemblies. The conserved-sequence genome is sample set-independent, which enables prospective pathogen monitoring. Based on clinical data sets of 3436 S. aureus, 1362 K. pneumoniae and 348 E. faecium samples, ROC curves demonstrate that the conserved-sequence genome disambiguates same-patient samples better than a core genome consisting of conserved genes. The conserved-sequence genome confirms outbreak samples with high sensitivity: in a set of 2335 S. aureus samples, it correctly identifies 44 out of 44 known outbreak samples, whereas the conserved-gene method confirms 38 known outbreak samples

Epigenetic aging signatures in mice livers are slowed by dwarfism, calorie restriction and rapamycin treatment

Background: Global but predictable changes impact the DNA methylome as we age, acting as a type of molecular clock. This clock can be hastened by conditions that decrease lifespan, raising the question of whether it can also be slowed, for example, by conditions that increase lifespan. Mice are particularly appealing organisms for studies of mammalian aging; however, epigenetic clocks have thus far been formulated only in humans. Results: We first examined whether mice and humans experience similar patterns of change in the methylome with age. We found moderate conservation of CpG sites for which methylation is altered with age, with both species showing an increase in methylome disorder during aging. Based on this analysis, we formulated an epigenetic-aging model in mice using the liver methylomes of 107 mice from 0.2 to 26.0 months old. To examine whether epigenetic aging signatures are slowed by longevity-promoting interventions, we analyzed 28 additional methylomes from mice subjected to lifespan-extending conditions, including Prop1df/df dwarfism, calorie restriction or dietary rapamycin. We found that mice treated with these lifespan-extending interventions were significantly younger in epigenetic age than their untreated, wild-type age-matched controls. Conclusions: This study shows that lifespan-extending conditions can slow molecular changes associated with an epigenetic clock in mice livers

Bub1 is activated by the protein kinase p90Rsk during Xenopus oocyte maturation

AbstractBackground: The kinetochore attachment (spindle assembly) checkpoint arrests cells in metaphase to prevent exit from mitosis until all the chromosomes are aligned properly at the metaphase plate. The checkpoint operates by preventing activation of the anaphase-promoting complex (APC), which triggers anaphase by degrading mitotic cyclins and other proteins. This checkpoint is active during normal mitosis and upon experimental disruption of the mitotic spindle. In yeast, the serine/threonine protein kinase Bub1 and the WD-repeat protein Bub3 are elements of a signal transduction cascade that regulates the kinetochore attachment checkpoint. In mammalian cells, activated MAPK is present on kinetochores during mitosis and activity is upregulated by the spindle assembly checkpoint. In vertebrate unfertilized eggs, a special form of meiotic metaphase arrest by cytostatic factor (CSF) is mediated by MAPK activation of the protein kinase p90Rsk, which leads to inhibition of the APC. However, it is not known whether CSF-dependent metaphase arrest caused by p90Rsk involves components of the spindle assembly checkpoint.Results: xBub1 is present in resting oocytes and its protein level increases slightly during oocyte maturation and early embryogenesis. In Xenopus oocytes, Bub1 is localized to kinetochores during both meiosis I and meiosis II, and the electrophoretic mobility of Bub1 upon SDS-PAGE decreases during meiosis I, reflecting phosphorylation and activation of the enzyme. The activation of Bub1 can be induced in interphase egg extracts by selective stimulation of the MAPK pathway by c-Mos, a MAPKKK. In oocytes treated with the MEK1 inhibitor U0126, the MAPK pathway does not become activated, and Bub1 remains in its low-activity, unshifted form. Injection of a constitutively active target of MAPK, the protein kinase p90Rsk, restores the activation of Bub1 in the presence of U0126. Moreover, purified p90Rsk phosphorylates Bub1 in vitro and increases its protein kinase activity.Conclusions: Bub1, an upstream component of the kinetochore attachment checkpoint, is activated during meiosis in Xenopus in a MAPK-dependent manner. Moreover, a single substrate of MAPK, p90Rsk, is sufficient to activate Bub1 in vitro and in vivo. These results indicate that in vertebrate eggs, kinetochore attachment/spindle assembly checkpoint proteins, including Bub1, are downstream of p90Rsk and may be effectors of APC inhibition and CSF-dependent metaphase arrest by p90Rsk

Accuracy of Alcon WaveLight EX500 optical pachymetry during LASIK

To study the accuracy and reliability of optical pachymetry using the Alcon WaveLight FX500 during laser-assisted in situ her atomileusis (LASIK) I K). Materials and methods: This was a retrospective chart review of 90 eyes from 45 patients who had undergone LASIK (mean age 35.2 8.2 years||19 males, 26 females). The WaveLight ES200 lemtosecond laser was programmed to cut LASIK flaps at a desired depth of 120 pm. Optical low-coherence reflectometry (Wave Light KX500) was used to measure central corneal thickness prior to lifting the flap, and the residual stromal bed immediately after excimer ablation. Flap thickness (FT) was calculated using simple subtraction. Optical coherence tomography (OCT) was used to measure central corneal thickness, flap thickness, and residual stromal bed M the postoperative period and the results compared to intraoperative measurements. Results: Mean programmed FS200 FT Was 119 pm. Mean FT using EX500 optical pachymetry was 109 pm. The difference between FS200-programmed and EX500-measured FT was 9 pm (P<0.001). There was also a significant difference between the EX500 and OCT FT (109 p.m vs 119 pm, respectively||P<(1.001). Conclusion: FT values calculated tsing intraoperative FX500 optical pachymetry were significantly lower than programmed FS200 values or OCT measurements

Non-Locality and Strong Coupling in the Heavy Fermion Superconductor CeCoIn5_{5}: A Penetration Depth Study

We report measurements of the magnetic penetration depth $\lambda$ in single crystals of CeCoIn$_{5}$ down to $\sim$0.14 K using a tunnel-diode based, self-inductive technique at 28 MHz. While the in-plane penetration depth tends to follow a power law, $\lambda_{//} \sim {\it T}^{3/2}$, the data are better described as a crossover between linear ({\it T} $\gg$ ${\it T}^\ast$) and quadratic ({\it T} $\ll {\it T}^\ast$) behavior, with ${\it T}^\ast$ the crossover temperature in the strong-coupling limit. The {\it c}-axis penetration depth $\lambda_{\perp}$ is linear in {\it T}, providing evidence that CeCoIn$_{5}$ is a {\it d}-wave superconductor with line nodes along the {\it c}-axis. The different temperature dependences of $\lambda_{//}$ and $\lambda_{\perp}$ rule out impurity effects as the source of ${\it T}^{\ast}$.Comment: 4 pages, 3 figure

The Axial-Vector Current in Nuclear Many-Body Physics

Weak-interaction currents are studied in a recently proposed effective field theory of the nuclear many-body problem. The Lorentz-invariant effective field theory contains nucleons, pions, isoscalar scalar ($\sigma$) and vector ($\omega$) fields, and isovector vector ($\rho$) fields. The theory exhibits a nonlinear realization of $SU(2)_L \times SU(2)_R$ chiral symmetry and has three desirable features: it uses the same degrees of freedom to describe the axial-vector current and the strong-interaction dynamics, it satisfies the symmetries of the underlying theory of quantum chromodynamics, and its parameters can be calibrated using strong-interaction phenomena, like hadron scattering or the empirical properties of finite nuclei. Moreover, it has recently been verified that for normal nuclear systems, it is possible to systematically expand the effective lagrangian in powers of the meson fields (and their derivatives) and to reliably truncate the expansion after the first few orders. Here it is shown that the expressions for the axial-vector current, evaluated through the first few orders in the field expansion, satisfy both PCAC and the Goldberger--Treiman relation, and it is verified that the corresponding vector and axial-vector charges satisfy the familiar chiral charge algebra. Explicit results are derived for the Lorentz-covariant, axial-vector, two-nucleon amplitudes, from which axial-vector meson-exchange currents can be deduced.Comment: 32 pages, REVTeX 4.0 with 12pt.rtx, aps.rtx, revsymb.sty, revtex4.cls, plus 14 figures; two sentences added in Summary; two references adde

Coherent states for compact Lie groups and their large-N limits

The first two parts of this article surveys results related to the heat-kernel coherent states for a compact Lie group K. I begin by reviewing the definition of the coherent states, their resolution of the identity, and the associated Segal-Bargmann transform. I then describe related results including connections to geometric quantization and (1+1)-dimensional Yang--Mills theory, the associated coherent states on spheres, and applications to quantum gravity. The third part of this article summarizes recent work of mine with Driver and Kemp on the large-N limit of the Segal--Bargmann transform for the unitary group U(N). A key result is the identification of the leading-order large-N behavior of the Laplacian on "trace polynomials."Comment: Submitted to the proceeding of the CIRM conference, "Coherent states and their applications: A contemporary panorama.

Imprints of Short Distance Physics On Inflationary Cosmology

We analyze the impact of certain modifications to short distance physics on the inflationary perturbation spectrum. For the specific case of power-law inflation, we find distinctive -- and possibly observable -- effects on the spectrum of density perturbations.Comment: Revtex 4, 3 eps figs, 4 page

Development of six PROMIS pediatrics proxy-report item banks

<p>Abstract</p> <p>Background</p> <p>Pediatric self-report should be considered the standard for measuring patient reported outcomes (PRO) among children. However, circumstances exist when the child is too young, cognitively impaired, or too ill to complete a PRO instrument and a proxy-report is needed. This paper describes the development process including the proxy cognitive interviews and large-field-test survey methods and sample characteristics employed to produce item parameters for the Patient Reported Outcomes Measurement Information System (PROMIS) pediatric proxy-report item banks.</p> <p>Methods</p> <p>The PROMIS pediatric self-report items were converted into proxy-report items before undergoing cognitive interviews. These items covered six domains (physical function, emotional distress, social peer relationships, fatigue, pain interference, and asthma impact). Caregivers (n = 25) of children ages of 5 and 17 years provided qualitative feedback on proxy-report items to assess any major issues with these items. From May 2008 to March 2009, the large-scale survey enrolled children ages 8-17 years to complete the self-report version and caregivers to complete the proxy-report version of the survey (n = 1548 dyads). Caregivers of children ages 5 to 7 years completed the proxy report survey (n = 432). In addition, caregivers completed other proxy instruments, PedsQL™ 4.0 Generic Core Scales Parent Proxy-Report version, PedsQL™ Asthma Module Parent Proxy-Report version, and KIDSCREEN Parent-Proxy-52.</p> <p>Results</p> <p>Item content was well understood by proxies and did not require item revisions but some proxies clearly noted that determining an answer on behalf of their child was difficult for some items. Dyads and caregivers of children ages 5-17 years old were enrolled in the large-scale testing. The majority were female (85%), married (70%), Caucasian (64%) and had at least a high school education (94%). Approximately 50% had children with a chronic health condition, primarily asthma, which was diagnosed or treated within 6 months prior to the</p> <p>interview. The PROMIS proxy sample scored similar or better on the other proxy instruments compared to normative samples.</p> <p>Conclusions</p> <p>The initial calibration data was provided by a diverse set of caregivers of children with a variety of common chronic illnesses and racial/ethnic backgrounds. The PROMIS pediatric proxy-report item banks include physical function (mobility n = 23; upper extremity n = 29), emotional distress (anxiety n = 15; depressive symptoms n = 14; anger n = 5), social peer relationships (n = 15), fatigue (n = 34), pain interference (n = 13), and asthma impact (n = 17).</p