Scattering matrices and expansion coefficients of Martian analogue palagonite particles

We present measurements of ratios of elements of the scattering matrix of Martian analogue palagonite particles for scattering angles ranging from 3 to 174 degrees and a wavelength of 632.8 nm. To facilitate the use of these measurements in radiative transfer calculations we have devised a method that enables us to obtain, from these measurements, a normalized synthetic scattering matrix covering the complete scattering angle range from 0 to 180 degrees. Our method is based on employing the coefficients of the expansions of scattering matrix elements into generalized spherical functions. The synthetic scattering matrix elements and/or the expansion coefficients obtained in this way, can be used to include multiple scattering by these irregularly shaped particles in (polarized) radiative transfer calculations, such as calculations of sunlight that is scattered in the dusty Martian atmosphere.Comment: 34 pages 7 figures 1 tabl

Modeling Magnetite Reflectance Spectra Using Hapke Theory and Existing Optical Constants

Magnetite is an accessory mineral found in terrestrial environments, some meteorites, and the lunar surface. The reflectance of magnetite powers is relatively low [1], and this property makes it an analog for other dark Fe- or Ti-bearing components, particularly ilmenite on the lunar surface. The real and imaginary indices of refraction (optical constants) for magnetite are available in the literature [2-3], and online [4]. Here we use these values to calculate the reflectance of particulates and compare these model spectra to reflectance measurements of magnetite available on-line [5]

Kinetic Characterization of Salmonella FliK-FlhB Interactions Demonstrates Complexity of the Type III Secretion Substrate-Specificity Switch

The bacterial flagellum is a complex macromolecular machine consisting of more than 20000 proteins, most of which must be exported from the cell via a dedicated Type III secretion apparatus. At a defined point in flagellar morphogenesis, hook completion is sensed and the apparatus switches substrate specificity type from rod and hook proteins to filament ones. How the switch works is a subject of intense interest. FIiK and F1hBs play central roles. In the present study, two optical biosensing methods were used to characterize FIiK-F1hB interactions using wild-type and two variant FlhBs from mutants with severe flagellar structural defects. Binding was found to be complex with fast and slow association and dissociation components. Surprisingly, wild-type and variant FlhBs had similar kinetic profiles and apparent affinities, which ranged between I and 10.5 μM, suggesting that the specificity switch is more complex than presently understood. Other binding experiments provided evidence for a conformational change after binding. Liquid chromatography-mass spectrometry (LC-MS) and NMR experiments were performed to identify a cyclic intermediate product whose existence supports the mechanism of autocatalytic cleavage at FlhB residue N269. The present results show that while autocatalytic cleavage is necessary for proper substrate specificity switching, it does not result in an altered interaction with FIiK. strongly suggesting the involvement of other proteins in the mechanism

NIRVSS Aboard CLPS

NASA initiated the Commercial Lunar Payload Services (CLPS) program for flights to the lunar surface. Astrobotic was awarded a NASA contract to accommodate NASA payloads onto their Peregrine lander Astrobotic Mission One (ABM-1). ABM-1 is scheduled to land near Lacus Mortis, 44N 25E, in 2021. The Near-InfraRed Volatile Spectrometer System (NIRVSS) has evolved over time and was chosen as a NASA payload for ABM-1 and the flight model is scheduled to be delivered to Astrobotic at the end of March 2020

Insecticide resistance enhances male reproductive success in a beetle

peer reviewe

The Composition of Planetesimal 5145 Pholus

We present a new spectrum of 5145 Pholus between 1.15 and 2.4 microns. We model this, and the previously published (0.4-1.0 microns) spectrum, using Hapke scattering theory. The 2.04 micron band of H2O ice is seen in absorption, as well as a strong band at 2.27 Am, interpreted as frozen methanol and/or the methanol photo product hexamethylenetetramine (HMT). The presence of small molecules is indicative of a chemically primitive surface, since heating removes the light hydrocarbons in favor of macromolecular carbon typically found in carbonaceous meteorites. The unusually red slope of Pholus' spectrum is matched by fine grains of Titan tholin, as found previously. Object 1993 HA2, which has an orbit similar to that of 5145 Pholus, is similarly red, but there are as yet no observations of absorption bands in its spectrum. We present a model for the composite spectrum of all spectroscopic and photometric data available for 5145 Pholus and conclude that this is a primitive object which has yet to be substantially processed by solar heat

PHSkb: A knowledgebase to support notifiable disease surveillance

BACKGROUND: Notifiable disease surveillance in the United States is predominantly a passive process that is often limited by poor timeliness and low sensitivity. Interoperable tools are needed that interact more seamlessly with existing clinical and laboratory data to improve notifiable disease surveillance. DESCRIPTION: The Public Health Surveillance Knowledgebase (PHSkb™) is a computer database designed to provide quick, easy access to domain knowledge regarding notifiable diseases and conditions in the United States. The database was developed using Protégé ontology and knowledgebase editing software. Data regarding the notifiable disease domain were collected via a comprehensive review of state health department websites and integrated with other information used to support the National Notifiable Diseases Surveillance System (NNDSS). Domain concepts were harmonized, wherever possible, to existing vocabulary standards. The knowledgebase can be used: 1) as the basis for a controlled vocabulary of reportable conditions needed for data aggregation in public health surveillance systems; 2) to provide queriable domain knowledge for public health surveillance partners; 3) to facilitate more automated case detection and surveillance decision support as a reusable component in an architecture for intelligent clinical, laboratory, and public health surveillance information systems. CONCLUSIONS: The PHSkb provides an extensible, interoperable system architecture component to support notifiable disease surveillance. Further development and testing of this resource is needed

Scrotal cancer: Incidence, survival and second primary tumours in the Netherlands since 1989

Background: Since the 1970s there have been few epidemiological studies of scrotal cancer. We report on the descriptive epidemiology of scrotal cancer in the Netherlands. Methods: Data on all scrotal cancer patients were obtained from the Netherlands Cancer Registry (NCR) in the period 1989-2006 and age-standardised incidence rates were calculated also according to histology and stage. Relative survival was calculated and multiple primary tumours were studied. Results: The overall incidence rate varied around 1.5 per 1 000 000 person-years, most frequently being squamous cell carcinoma (27%), basal cell carcinoma (19%) and Bowen's disease (15%). Overall 5-year relative survival was 82%, being 77% and 95% for patients with squamous and basal cell carcinoma, respectively. In all, 18% of the patients were diagnosed with a second primary tumour. Conclusion: The incidence rate of scrotal cancer did not decrease, although this was expected; affected patients might benefit from regular checkups for possible new cancers