Monitoring and predicting tropical cyclone movement using geosynchronous satellite remote sensing techniques

Data collected on special hurricane days by the VISSR Atmospheric Sounder (VAS) instrument flown on a satellite in 1981 and 1982 were studied for their usefulness in forecasting motion of hurricanes. The retrieved constant pressure heights for the 500-mb surface provided the basis for reasonable forecasts of 24 hour hurricane motion. The conclusions are illustrated with examples from Hurricane Harvey (1981) and Hurricane Irene (1981). Recommendations are made for future use of the VAS type instruments for tropical cyclone forecasting

A Side of Mercury Not Seen By Mariner 10

More than 60,000 images of Mercury were taken at ~29 deg elevation during two sunrises, at 820 nm, and through a 1.35 m diameter off-axis aperture on the SOAR telescope. The sharpest resolve 0.2" (140 km) and cover 190-300 deg longitude -- a swath unseen by the Mariner 10 spacecraft -- at complementary phase angles to previous ground-based optical imagery. Our view is comparable to that of the Moon through weak binoculars. Evident are the large crater Mozart shadowed on the terminator, fresh rayed craters, and other albedo features keyed to topography and radar reflectivity, including the putative huge ``Basin S'' on the limb. Classical bright feature Liguria resolves across the northwest boundary of the Caloris basin into a bright splotch centered on a sharp, 20 km diameter radar crater, and is the brightest feature within a prominent darker ``cap'' (Hermean feature Solitudo Phoenicis) that covers the northern hemisphere between longitudes 140-250 deg. The cap may result from space weathering that darkens via a magnetically enhanced flux of the solar wind, or that reddens low latitudes via high solar insolation.Comment: 7 pages, 4 PDF figures, pdfLaTeX, typos corrected, Fig. 2 modified slightly to add crater diameters not given in published versio

Taxonomic Features and Comparison of the Gut Microbiome from Two Edible Fungus-Farming Termites (Macrotermes falciger, M. natalensis) Harvested in the Vhembe District of Limpopo, South Africa

Background Termites are an important food resource for many human populations around the world, and are a good supply of nutrients. The fungus-farming ‘higher’ termite members of Macrotermitinae are also consumed by modern great apes and are implicated as critical dietary resources for early hominins. While the chemical nutritional composition of edible termites is well known, their microbiomes are unexplored in the context of human health. Here we sequenced the V4 region of the 16S rRNA gene of gut microbiota extracted from the whole intestinal tract of two Macrotermes sp. soldiers collected from the Limpopo region of South Africa. Results Major and minor soldier subcastes of M. falciger exhibit consistent differences in taxonomic representation, and are variable in microbial presence and abundance patterns when compared to another edible but less preferred species, M. natalensis. Subcaste differences include alternate patterns in sulfate-reducing bacteria and methanogenic Euryarchaeota abundance, and differences in abundance between Alistipes and Ruminococcaceae. M. falciger minor soldiers and M. natalensissoldiers have similar microbial profiles, likely from close proximity to the termite worker castes, particularly during foraging and fungus garden cultivation. Compared with previously published termite and cockroach gut microbiome data, the taxonomic representation was generally split between termites that directly digest lignocellulose and humic substrates and those that consume a more distilled form of nutrition as with the omnivorous cockroaches and fungus-farming termites. Lastly, to determine if edible termites may point to a shared reservoir for rare bacterial taxa found in the gut microbiome of humans, we focused on the genus Treponema. The majority of Treponemasequences from edible termite gut microbiota most closely relate to species recovered from other termites or from environmental samples, except for one novel OTU strain, which clustered separately with Treponema found in hunter-gatherer human groups. Conclusions Macrotermes consumed by humans display special gut microbial arrangements that are atypical for a lignocellulose digesting invertebrate, but are instead suited to the simplified nutrition in the fungus-farmer diet. Our work brings to light the particular termite microbiome features that should be explored further as avenues in human health, agricultural sustainability, and evolutionary research

How to calibrate your sprayer

Caption title

Non linear dynamic analysis of solids using linear triangles and tetrahedra

The basis of the FIC method is the satisfaction of the standard equations for balance of momentum (equilibrium of forces) and mass conservation in a domain of finite size and retaining higher order terms in the Taylor expansions used to express the different terms of the differential equations over the balance domain. The modified differential equations contain additional terms which introduce the necessary stability in the equations to overcome the volumetric locking problem in incompressible situations. The same ideas are applied in this paper to derive a stabilized formulation for non linear dynamic finite element analysis of quasi incompressible and fully-incompressible solids using linear triangles and tetrahedra. Examples of application of the new stabilized formulation to the semi-implicit and explicit non linear transient dynamic analysis of an impact problem and a bulk forming process are presented.Postprint (published version

The Soft X-ray Spectrum from NGC 1068 Observed with LETGS on Chandra

Using the combined spectral and spatial resolving power of the Low Energy Transmission Grating (LETGS) on board Chandra, we obtain separate spectra from the bright central source of NGC 1068 (Primary region), and from a fainter bright spot 4" to the NE (Secondary region). Both spectra are dominated by line emission from H- and He-like ions of C through S, and from Fe L-shell ions, but also include narrow radiative recombination continua, indicating that most of the soft X-ray emission arises in low-temperature (kT few eV) photoionized plasma. We confirm the conclusions of Kinkhabwala et al. (2002), based on XMM-Newton RGS observations, that the entire nuclear spectrum can be explained by recombination/radiative cascade following photoionization, and radiative decay following photoexcitation, with no evidence for hot, collisionally ionized plasma. In addition, this model also provides an excellent fit to the spectrum of the Secondary region, albeit with radial column densities a factor of three lower, as would be expected given its distance from the source of the ionizing continuum. The remarkable overlap and kinematical agreement of the optical and X-ray line emission, coupled with the need for a distribution of ionization parameter to explain the X-ray spectra, collectively imply the presence of a distribution of densities (over a few orders of magnitude) at each radius in the ionization cone. Relative abundances of all elements are consistent with Solar abundance, except for N, which is 2-3 times Solar. The long wavelength spectrum beyond 30 A is rich of L-shell transitions of Mg, Si, S, and Ar, and M-shell transitions of Fe. The velocity dispersion decreases with increasing ionization parameter, as deduced from these long wavelength lines and the Fe-L shell lines.Comment: 12 pages, 11 figures, accepted for publication in Astronomy and Astrophysic

The Influence of Patient-Centeredness on Minority and Socioeconomically-Disadvantaged Patients’ Trust in their Physicians: An Evidence-Based Structural Equation Modeling Investigation

The purpose of this investigation was to determine the effect of physician patient-centeredness on patient trust across randomly selected groups of patients from an inner city medical practice serving a preponderance of minority and socioeconomically-disadvantaged patients. METHODS: A two-factor multigroup structural equation modeling design was employed, with randomly selected test (N = 300) and cross-validation (N = 300) samples of medical practice patients. Equality constraints were established to test the invariance of effects across groups. The model was compared to its unconstrained counterpart to further test its trustworthiness. An additional 5,000 nonparametric bootstrapped samples for each group were generated to further cross-validate and assess the stability of effect estimates. RESULTS: The model fit well. Physician patient-centeredness significantly influenced patient trust, explaining 82 percent of its variability. When physician patient-centeredness increased by one unit, the predicted value for patient trust increased by 1.043 units (.903 standardized). Patient-centered physician behaviors increased patients’ confidence in and likelihood to recommend their physician. This pattern of effects held across the test and cross-validation groups. The hypothesized model was sustained when compared to its competing counterpart. CONCLUSIONS: Evidence supported the factor and structural validity of the model. This study offers a plausible two-factor model for the measurement and improvement of patient-centeredness, and concomitantly, patient trust in an inner city medical clinic serving minority and socioeconomically-disadvantaged patients. In addition to quality improvement and outcome measurement, the results have implications for improving patient-centeredness, patient trust, the patient–provider relationship, medical education, and reducing health care disparities

Galactic-Scale Outflow and Supersonic Ram-Pressure Stripping in the Virgo Cluster Galaxy NGC 4388

The Hawaii Imaging Fabry-Perot Interferometer (HIFI) on the University of Hawaii 2.2m telescope was used to map the Halpha and [O III] 5007 A emission-line profiles across the entire disk of the edge-on Sb galaxy NGC 4388. We confirm a rich complex of highly ionized gas that extends ~4 kpc above the disk of this galaxy. Low-ionization gas associated with star formation is also present in the disk. Evidence for bar streaming is detected in the disk component and is discussed in a companion paper (Veilleux, Bland-Hawthorn, & Cecil 1999; hereafter VBC). Non-rotational blueshifted velocities of 50 - 250 km/s are measured in the extraplanar gas north-east of the nucleus. The brighter features in this complex tend to have more blueshifted velocities. A redshifted cloud is also detected 2 kpc south-west of the nucleus. The velocity field of the extraplanar gas of NGC 4388 appears to be unaffected by the inferred supersonic (Mach number M ~ 3) motion of this galaxy through the ICM of the Virgo cluster. We argue that this is because the galaxy and the high-|z| gas lie behind a Mach cone with opening angle ~ 80 degrees. The shocked ICM that flows near the galaxy has a velocity of ~ 500 km/s and exerts insufficient ram pressure on the extraplanar gas to perturb its kinematics. We consider several explanations of the velocity field of the extraplanar gas. Velocities, especially blueshifted velocities on the N side of the galaxy, are best explained as a bipolar outflow which is tilted by > 12 degrees from the normal to the disk. The observed offset between the extraplanar gas and the radio structure may be due to buoyancy or refractive bending by density gradients in the halo gas. Velocity substructure in the outflowing gas also suggests an interaction with ambient halo gas.Comment: 29 pages including 5 figures, Latex, requires aaspp4.sty, to appear in ApJ, 520 (July 20, 1999 issue

Laser assisted charge transfer reactions in slow ion–atom collisions: Coupled dressed quasimolecular‐states approach

This is the published version, also available here: http://dx.doi.org/10.1063/1.447712.Semiclassical coupled dressed quasimolecular states (DQMS) approaches are presented for the nonperturbative treatment of charge transferreactions at low collision velocities and high laser intensities. The DQMS are first obtained via the Floquet theory. The laser assisted collision process can then be treated as the electronic transitions among the DQMS driven by the nuclear motion only. The expansion of the total electronic wave function in a truncated DQMS basis results in a set of coupled a d i a b a t i c equations. The adiabatic DQMS and their associated quasienergies (depending parametrically upon the internuclear separation R) exhibit regions of avoided crossings, where the electronic transition probabilities are large due to strong radial couplings induced by the nuclear movement. By further transforming the a d i a b a t i c DQMS into an appropriate d i a b a t i c DQMS representation, defined via the vanishing of the aforementioned radial couplings, we obtain a new set of coupled d i a b a t i c equations which offer computational advantage. The method is illustrated by a case study of the laser assisted charge exchange process He+ ++H(1s)+ℏω→He+(n=2)+H+, in a two‐state approximation, for the velocity range from 1.5×105 to 2×107 cm/s and for the laser intensity in the range of 0.4 to 4.0 TW/cm2. Results of exact coupled diabatic DQMS calculations are presented along with several approximation calculations, using first order perturbation theory, the Magnus approximation, and the average cross section