Plasma electrons above Saturn's main rings: CAPS observations

We present observations of thermal ( similar to 0.6 - 100eV) electrons observed near Saturn's main rings during Cassini's Saturn Orbit Insertion (SOI) on 1 July 2004. We find that the intensity of electrons is broadly anticorrelated with the ring optical depth at the magnetic footprint of the field line joining the spacecraft to the rings. We see enhancements corresponding to the Cassini division and Encke gap. We suggest that some of the electrons are generated by photoemission from ring particle surfaces on the illuminated side of the rings, the far side from the spacecraft. Structure in the energy spectrum over the Cassini division and A-ring may be related to photoelectron emission followed by acceleration, or, more likely, due to photoelectron production in the ring atmosphere or ionosphere

Discovery of heavy negative ions in Titan's ionosphere

Titan's ionosphere contains a rich positive ion population including organic molecules. Here, using CAPS electron spectrometer data from sixteen Titan encounters, we reveal the existence of negative ions. These ions, with densities up to similar to 100 cm similar to 3, are in mass groups of 10-30, 30-50, 50-80, 80-110, 110-200 and 200+ amu/charge. During one low encounter, negative ions with mass per charge as high as 10,000 amu/q are seen. Due to their unexpectedly high densities at similar to 950 km altitude, these negative ions must play a key role in the ion chemistry and they may be important in the formation of organic-rich aerosols (tholins) eventually falling to the surface

Magnetic signatures of plasma-depleted flux tubes in the Saturnian inner magnetosphere

Initial Cassini observations have revealed evidence for interchanging magnetic flux tubes in the inner Saturnian magnetosphere. Some of the reported flux tubes differ remarkably by their magnetic signatures, having a depressed or enhanced magnetic pressure relative to their surroundings. The ones with stronger fields have been interpreted previously as either outward moving mass-loaded or inward moving plasma-depleted flux tubes based on magnetometer observations only. We use detailed multi-instrumental observations of small and large density depletions in the inner Saturnian magnetosphere from Cassini Rev. A orbit that enable us to discriminate amongst the two previous and opposite interpretations. Our analysis undoubtedly confirms the similar nature of both types of reported interchanging magnetic flux tubes, which are plasma-depleted, whatever their magnetic signatures are. Their different magnetic signature is clearly an effect associated with latitude. These Saturnian plasma-depleted flux tubes ultimately may play a similar role as the Jovian ones

Scalar and vector Slepian functions, spherical signal estimation and spectral analysis

It is a well-known fact that mathematical functions that are timelimited (or spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the finite precision of measurement and computation unavoidably bandlimits our observation and modeling scientific data, and we often only have access to, or are only interested in, a study area that is temporally or spatially bounded. In the geosciences we may be interested in spectrally modeling a time series defined only on a certain interval, or we may want to characterize a specific geographical area observed using an effectively bandlimited measurement device. It is clear that analyzing and representing scientific data of this kind will be facilitated if a basis of functions can be found that are "spatiospectrally" concentrated, i.e. "localized" in both domains at the same time. Here, we give a theoretical overview of one particular approach to this "concentration" problem, as originally proposed for time series by Slepian and coworkers, in the 1960s. We show how this framework leads to practical algorithms and statistically performant methods for the analysis of signals and their power spectra in one and two dimensions, and, particularly for applications in the geosciences, for scalar and vectorial signals defined on the surface of a unit sphere.Comment: Submitted to the 2nd Edition of the Handbook of Geomathematics, edited by Willi Freeden, Zuhair M. Nashed and Thomas Sonar, and to be published by Springer Verlag. This is a slightly modified but expanded version of the paper arxiv:0909.5368 that appeared in the 1st Edition of the Handbook, when it was called: Slepian functions and their use in signal estimation and spectral analysi

Morphometry of the Cranial Base in Subjects with Class III Malocclusion

The significance of the cranial base in the development of Class III malocclusion remains uncertain. The purpose of this study was to determine whether the form of the cranial base differs between prepubertal Class I and Class III subjects. Lateral cephalographs of 73 children of European-American descent aged between 5 and 11 years with Class III malocclusion were compared with those of their counterparts with a normal, Class I molar occlusion. The cephalographs were traced, checked, and subdivided into seven age- and sex-matched groups. Average geometries, scaled to an equivalent size, were generated based on 13 craniofacial landmarks by means of Procrustes analysis, and these configurations were statistically tested for equivalence. Bivariate and multivariate analyses utilizing 5 linear and angular measurements were undertaken to corroborate the Procrustes analysis. Graphical analysis, utilizing thin-plate spline and finite element methods, was performed for localization of differences in cranial base morphology. Results indicated that cranial base morphology differed statistically for all age-wise comparisons. Graphical analysis revealed that the greatest differences in morphology occurred in the posterior cranial base region, which generally consisted of horizontal compression, vertical expansion, and size contraction. The sphenoidal region displayed expansion, while the anterior regions showed shearing and local increases in size. It is concluded that the shape of the cranial base differs in subjects with Class III malocclusion compared with the normal Class I configuration, due in part to deficient orthocephalization, or failure of the cranial base to flatten during development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67377/2/10.1177_00220345970760021101.pd

Chronic breast abscess due to Mycobacterium fortuitum: a case report

<p>Abstract</p> <p>Introduction</p> <p><it>Mycobacterium fortuitum </it>is a rapidly growing group of nontuberculous mycobacteria more common in patients with genetic or acquired causes of immune deficiency. There have been few published reports of <it>Mycobacterium fortuitum </it>associated with breast infections mainly associated with breast implant and reconstructive surgery.</p> <p>Case presentation</p> <p>We report a case of a 51-year-old Caucasian woman who presented to our one-stop breast clinic with a two-week history of left breast swelling and tenderness. Following triple assessment and subsequent incision and drainage of a breast abscess, the patient was diagnosed with <it>Mycobacterium fortuitum </it>and treated with antibiotic therapy and surgical debridement.</p> <p>Conclusion</p> <p>This is a rare case of a spontaneous breast abscess secondary to <it>Mycobacterium fortuitum </it>infection. Recommended treatment is long-term antibacterial therapy and surgical debridement for extensive infection or when implants are involved.</p

Comparing orbiter and rover image-based mapping of an ancient sedimentary environment, Aeolis Palus, Gale crater, Mars

This study provides the first systematic comparison of orbital facies maps with detailed ground-based geology observations from the Mars Science Laboratory (MSL) Curiosity rover to examine the validity of geologic interpretations derived from orbital image data. Orbital facies maps were constructed for the Darwin, Cooperstown, and Kimberley waypoints visited by the Curiosity rover using High Resolution Imaging Science Experiment (HiRISE) images. These maps, which represent the most detailed orbital analysis of these areas to date, were compared with rover image-based geologic maps and stratigraphic columns derived from Curiosity's Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI). Results show that bedrock outcrops can generally be distinguished from unconsolidated surficial deposits in high-resolution orbital images and that orbital facies mapping can be used to recognize geologic contacts between well-exposed bedrock units. However, process-based interpretations derived from orbital image mapping are difficult to infer without known regional context or observable paleogeomorphic indicators, and layer-cake models of stratigraphy derived from orbital maps oversimplify depositional relationships as revealed from a rover perspective. This study also shows that fine-scale orbital image-based mapping of current and future Mars landing sites is essential for optimizing the efficiency and science return of rover surface operations