Micropsephodes bahamaensis, a new species of Anamorphinae (Coleoptera: Cucujoidea: Endomychidae) from the Bahamas, with a key to the New World genera of Anamorphinae

A new species of anamorphine endomychid, Micropsephodes bahamaensis Shockley is described from a small series of 3 specimens collected on North Andros Island in the Bahamas. Besides being the only species known from the Bahamas, M. bahamaensis is readily recognizable from its congeners based on its much larger size, more elongate habitus and features of the galeae and maxillary palpomere IV. Keys to the known species of Micropsephodes and to the adults of the genera of Anamorphinae that occur in the Western Hemisphere are provided

Discolomopsis dominicana : a new genus and species of Endomychidae (Coleoptera) from Dominican amber

Discolomopsis, a new genus of Endomychidae (Coleoptera: Cucujoidea), is described and illustrated based on a fossil endomychid embedded in amber resin from the Dominican Republic. Discolomopsis dominicana sp. nov. is designated as the type species for the genus

NASA scientific and technical program: User survey

Results are presented of an intensive user requirements survey conducted by NASA's Scientific and Technical Information (STI) Program with the goal of improving the foundation for the user outreach program. The survey was carried out by interviewing 550 NASA scientists, engineers, and contractors and by analyzing 650 individual responses to a mailed out questionnaire. To analyze the user demographic data, a data base was built and used, and will be applied to ongoing analysis by the NASA STI Program

NASA gateway requirements analysis

NASA devotes approximately 40 percent of its budget to R&D. Twelve NASA Research Centers and their contractors conduct this R&D, which ranges across many disciplines and is fueled by information about previous endeavors. Locating the right information is crucial. While NASA researchers use peer contacts as their primary source of scientific and technical information (STI), on-line bibliographic data bases - both Government-owned and commercial - are also frequently consulted. Once identified, the STI must be delivered in a usable format. This report assesses the appropriateness of developing an intelligent gateway interface for the NASA R&D community as a means of obtaining improved access to relevant STI resources outside of NASA's Remote Console (RECON) on-line bibliographic database. A study was conducted to determine (1) the information requirements of the R&D community, (2) the information sources to meet those requirements, and (3) ways of facilitating access to those information sources. Findings indicate that NASA researchers need more comprehensive STI coverage of disciplines not now represented in the RECON database. This augmented subject coverage should preferably be provided by both domestic and foreign STI sources. It was also found that NASA researchers frequently request rapid delivery of STI, in its original format. Finally, it was found that researchers need a better system for alerting them to recent developments in their areas of interest. A gateway that provides access to domestic and international information sources can also solve several shortcomings in the present STI delivery system. NASA should further test the practicality of a gateway as a mechanism for improved STI access

Theory of spin-polarized transport in semiconductor heterojunctions: Proposal for spin injection and detection in silicon

Spin injection and detection in silicon is a difficult problem, in part because the weak spin-orbit coupling and indirect gap preclude using standard optical techniques. We propose two ways to overcome this difficulty, and illustrate their operation by developing a model for spin-polarized transport across a heterojunction. We find that equilibrium spin polarization of holes leads to a strong modification of the spin and charge dynamics of electrons, and we show how the symmetry properties of the charge current can be exploited to detect spin injection in silicon using currently available techniques.Comment: 4 pages, 4 figures, added footnot

Exciton Dissociation Dynamics in Model Donor-Acceptor Polymer Heterojunctions: I. Energetics and Spectra

In this paper we consider the essential electronic excited states in parallel chains of semiconducting polymers that are currently being explored for photovoltaic and light-emitting diode applications. In particular, we focus upon various type II donor-acceptor heterojunctions and explore the relation between the exciton binding energy to the band off-set in determining the device characteristic of a particular type II heterojunction material. As a general rule, when the exciton binding energy is greater than the band off-set at the heterojunction, the exciton will remain the lowest energy excited state and the junction will make an efficient light-emitting diode. On the other hand, if the off-set is greater than the exciton binding energy, either the electron or hole can be transferred from one chain to the other. Here we use a two-band exciton to predict the vibronic absorption and emission spectra of model polymer heterojunctions. Our results underscore the role of vibrational relaxation and suggest that intersystem crossings may play some part in the formation of charge-transfer states following photoexcitation in certain cases

Mountain Sickness

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Cathodoluminescence of stacking fault bound excitons for local probing of the exciton diffusion length in single GaN nanowires

We perform correlated studies of individual GaN nanowires in scanning electron microscopy combined to low temperature cathodoluminescence, microphotoluminescence, and scanning transmission electron microscopy. We show that some nanowires exhibit well localized regions emitting light at the energy of a stacking fault bound exciton (3.42 eV) and are able to observe the presence of a single stacking fault in these regions. Precise measurements of the cathodoluminescence signal in the vicinity of the stacking fault give access to the exciton diffusion length near this location

Artifact Simulating Fracture on Cervical Spine Computed Tomography

We present the case of a 31-year-old trauma patient with computed tomography concerning significant C3–C4 subluxation. The abnormality is due to an artifact with which emergency physicians should be aware

Review of the Natural History of the Handsome Fungus Beetles (Coleoptera: Cucujoidea: Endomychidae)

The literature pertaining to natural history of Endomychidae (Coleoptera: Cucujoidea) is reviewed. One hundred fungal host records are provided for 32 endomychid species. Twenty-three records of endomychid yeast endosymbionts are compiled. Summaries are also presented for feeding preferences, interactions with natural enemies, non-lethal symbiotic relationships, and pest activity within the family. Unusual endomychid behaviors and habitats are reviewed, with particular attention to gregariousness and defensive strategies within Endomychidae