The Mimas Ghost Revisited: An Analysis of the Electron Flux and Electron Microsignatures Observed in the Vicinity of Mimas at Saturn

An analysis of the electron absorption signature observed by the Cosmic Ray System on Voyager 2 near the orbit of Mimas is presented. We find that these observations cannot be explained as the absorption signature of Mimas. Combining Pioneer 11 and Voyager 2 measurements of the electron flux at Mimas's orbit (L = 3.1), we find an electron spectrum where most of the flux above ∼100 keV is concentrated near 1 to 3 MeV. This spectral form is qualitatively consistent with the band-pass filter model of Van Allen et al. (1980b). The expected Mimas absorption signature is calculated from this spectrum neglecting radial diffusion. Since no Mimas absorption signature was observed in the inbound Voyager 2 data, a lower limit on the diffusion coefficient for MeV electrons at L = 3.1 of D > 10^(−8) R_s^² s^(−1) is obtained. With a diffusion coefficient this large, both the Voyager 2 and the Pioneer 11 small-scale electron absorption signature observations in Mimas's orbit are enigmatic. Thus we refer to the mechanism for producing these signatures as the Mimas ghost. A cloud of material in orbit with Mimas may account for the observed electron signature if the cloud is at least 1% opaque to electrons across a region extending over a few hundred kilometers

Preserving Both Privacy and Utility in Network Trace Anonymization

As network security monitoring grows more sophisticated, there is an increasing need for outsourcing such tasks to third-party analysts. However, organizations are usually reluctant to share their network traces due to privacy concerns over sensitive information, e.g., network and system configuration, which may potentially be exploited for attacks. In cases where data owners are convinced to share their network traces, the data are typically subjected to certain anonymization techniques, e.g., CryptoPAn, which replaces real IP addresses with prefix-preserving pseudonyms. However, most such techniques either are vulnerable to adversaries with prior knowledge about some network flows in the traces, or require heavy data sanitization or perturbation, both of which may result in a significant loss of data utility. In this paper, we aim to preserve both privacy and utility through shifting the trade-off from between privacy and utility to between privacy and computational cost. The key idea is for the analysts to generate and analyze multiple anonymized views of the original network traces; those views are designed to be sufficiently indistinguishable even to adversaries armed with prior knowledge, which preserves the privacy, whereas one of the views will yield true analysis results privately retrieved by the data owner, which preserves the utility. We present the general approach and instantiate it based on CryptoPAn. We formally analyze the privacy of our solution and experimentally evaluate it using real network traces provided by a major ISP. The results show that our approach can significantly reduce the level of information leakage (e.g., less than 1\% of the information leaked by CryptoPAn) with comparable utility

Toward a descriptive model of solar particles in the heliosphere

During a workshop on the interplanetary charged particle environment held in 1987, a descriptive model of solar particles in the heliosphere was assembled. This model includes the fluence, composition, energy spectra, and spatial and temporal variations of solar particles both within and beyong 1 AU. The ability to predict solar particle fluences was also discussed. Suggestions for specific studies designed to improve the basic model were also made

Addressing Vaccine Hesitancy in Vulnerable Populations

Vaccine-preventable disease outbreaks and the spread of misinformation on vaccines throughout the United States are growing public health problems. Marginalized and vulnerable communities nationwide have seen a substantial rise in parental vaccine hesitancy that has negatively affected early childhood immunization rates, intensified healthcare disparities, and decreased patient care outcomes. Advanced Practice Registered Nurses primarily work in clinical settings, but these healthcare professionals can reach the public locally and nationally by actively participating in healthcare policy development. The following PICOT question guided the objective of this policy project: In the early childhood population (P), how does the development of a comprehensive policy recommendation addressing social determinants of health risks (I) compared to existing policy (C) improve vaccination rates as endorsed by the literature (O)? The Johns Hopkins Evidence-Based Practice model and the Centers for Disease Control (CDC) POLARIS Policy Process framework were utilized to evaluate and appraise the current literature and guide the Arkansas, Florida, and Louisiana policy review. The literature review showed direct and indirect patient outcomes, common themes, underlying causes, and effective interventional strategies. A comparative analysis was conducted on each southeastern state’s existing early childhood vaccination policies, including practice recommendations, guidelines, and legislative and regulatory frameworks. The findings prompted the development of policy recommendations and included three tailored policy briefs aligned with the best practice recommendations from the CDC and evidence-based literature. This project provided insight and strategies on addressing vaccine hesitancy in vulnerable communities to improve early childhood vaccination rates through advocacy and informed policy change

Detection of the high energy component of Jovian electrons in Low Earth Orbit with the PAMELA experiment

The PAMELA experiment is devoted to the study of cosmic rays in Low Earth Orbit with an apparatus optimized to perform a precise determination of the galactic antimatter component of c.r. It is constituted by a number of detectors built around a permanent magnet spectrometer. PAMELA was launched in space on June 15th 2006 on board the Russian Resurs-DK1 satellite for a mission duration of three years. The characteristics of the detectors, the long lifetime and the orbit of the satellite, will allow to address several aspects of cosmic-ray physics. In this work we discuss the observational capabilities of PAMELA to detect the electron component above 50 MeV. The magnetic spectrometer allows a detailed measurement of the energy spectrum of electrons of galactic and Jovian origin. Long term measurements and correlations with Earth-Jupiter 13 months synodic period will allow to separate these two contributions and to measure the primary electron Jovian component, dominant in the 50-70 MeV energy range. With this technique it will also be possible to study the contribution to the electron spectrum of Jovian e- reaccelerated up to 2 GeV at the Solar Wind Termination Shock.Comment: On behalf of PAMELA collaboration. Accepted for publication on Advances in Space Researc

Maintaining the Constitutionality of the Patent System

Congress\u27 constitutional power to establish a patent system is not unrestrained. Rather, it is derived from a clause that expressly limits the reach of any patent system created by requiring it to advance the progress of science and the useful arts. Inherent in any such system is the fundamental quid pro quo between society and inventor: an inventor receives an exclusive right for a limited time to his invention, and society benefits from the full disclosure of the inventor\u27s knowledge, incentivizing research and dispersing knowledge. However, while this constitutional dictate remains unaltered, the patent system has grown and changed markedly since its inception. Congress has established statutory provisions and designated a specialized court, the Federal Circuit, to handle patent litigation appeals. Additionally, technological advancements and changes in economic commerce in patents have had a profound impact on the patent system. This note details the history behind and the meaning of the constitutional grant of power to Congress to create the patent system and then explores the effect of recent changes to and developments in the patent system and their effects on the system\u27s constitutionality. It then concludes that recent developments, particularly the Federal Circuit\u27s treatment of patents during litigation, have moved the patent system away from its constitutional dictate, and that the culminating effect of these alterations has rendered the current patent system perhaps unconstitutional and certainly in need of reform. After surveying several existing proposals for patent reform, this note suggests instituting certain changes or combinations thereof, such as maintaining and enforcing high standards for granting a patent, increasing courts\u27 willingness to find patent claims invalid during litigation, limiting the extent to which a patent monopoly may be exploited, and possibly delisting biological matter from patentable subject matter

Instantaneous ionospheric global conductance maps during an isolated substorm

International audienceData from the Polar Ionospheric X-ray Imager (PIXIE) and the Ultraviolet Imager (UVI) on board the Polar satellite have been used to provide instantaneous global conductance maps. In this study, we focus on an isolated substorm event occurring on 31 July 1997. From the PIXIE and the UVI measurements, the energy spectrum of the precipitating electrons can be derived. By using a model of the upper atmosphere, the resulting conductivity values are generated. We present global maps of how the 5 min time-averaged height-integrated Hall and Pedersen conductivities vary every 15 min during this isolated substorm. The method presented here enables us to study the time development of the conductivities, with a spatial resolution of ~ 700 km. During the substorm, a single region of enhanced Hall conductance is observed. The Hall conductance maximum remains situated between latitudes 64 and 70 corrected geomagnetic (CGM) degrees and moves eastward. The strongest conductances are observed in the pre-midnight sector at the start of the substorm expansion. Toward the end of the substorm expansion and into the recovery phase, we find the Hall conductance maximum in the dawn region. We also observe that the Hall to Pedersen conductance ratio for the regions of maximum Hall conductance is increasing throughout the event, indicating a hardening of the electron spectrum. By combining PIXIE and UVI measurements with an assumed energy distribution, we can cover the whole electron energy range responsible for the conductances. Electrons with energies contributing most to the Pedersen conductance are well covered by UVI while PIXIE captures the high energetic component of the precipitating electrons affecting the Hall conductance. Most statistical conductance models have derived conductivities from electron precipitation data below approximately 30 keV. Since the intensity of the shortest UVI-wavelengths (LBHS) decreases significantly at higher electron energies, the UVI electron energy range is more or less comparable with the energy ranges of the statistical models. By calculating the conductivities from combined PIXIE and UVI measurements to compare with the conductivities from using UVI data only, we observe significant differences in the Hall conductance. The greatest differences are observed in the early evening and the late morning sector. We therefore suggest that the existing statistical models underestimate the Hall conductance

Mesospheric Response to Impacting Relativistic Electrons

Daily maps of the spatial distributions of precipitating energetic electrons were produced for the period 10-20 May 1992. These data will serve as the input for potential changes in upper atmosphere composition

Whose Rights Are They, Anyway?

The authors discuss sovereignty and the history behind a nation’s prerogative to intercede in the affairs of other nations to protect human rights

Launch of the Space experiment PAMELA

PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of 10^-8). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15, 2006 in a 350*600 km orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger mode the Calorimeter, the neutron detector and a shower tail catcher are capable of an independent measure of the lepton component up to 2 TeV. In this work we describe the experiment, its scientific objectives and the performance in the first months after launch.Comment: Accepted for publication on Advances in Space Researc