2,468 research outputs found
Vaporization of thermionic refractory materials final report
Vaporization of thermionic refractory material
Vaporization of thermionic refractory materials fourteenth status report, 1 dec. 1964 - 28 feb. 1965
Sublimation rate of rhenium measured for determining source of contamination - vaporization of thermionic refractory material
Alien Registration- Plante, Annette R. (Sanford, York County)
https://digitalmaine.com/alien_docs/3632/thumbnail.jp
The critical reception of Edith Wharton's fiction in America and England, with and annotated enumerative bibliography of Wharton criticism from 1900 to 1961
Thesis (Ph.D.)--Boston UniversityThis study is divided into two parts. Part One consists of an analysis of the critical reception of each. of Edith Wharton's works of fiction. The aim of Part One is to trace the history of Wharton criticism in the past sixty years in order to discover the possible patterns of critical attitudes towards her fiction both when it first appeared and in the present day. Part Two consists of an enumerated annotated listing of all biographical and critical studies of Edith Wharton and her fiction subject to the limitations stated in the work. Since all present listings of secondary sources on Wharton are at best fragmentary, the purpose of Part Two is to compile as complete a bibliography as possible in order to help future students in further research [TRUNCATED
Transition to J-STD-001DS: A Guide for Implementation. NASA Workmanship Standards Program
No abstract availabl
Coelacanth population, conservation and fishery activity at Grande Comore, West Indian Ocean
The only known population of coelacanths, in the Comores, western Indian Ocean, is endangered by human predation. Historical catch data from Grande Comore reveal that annual catch rates increased steadily from 1954 until the 1970s. This trend was temporarily interrupted due to an international policy introducing motorized boats and promoting offshore fishing techniques. Coelacanths are only caught from traditional unmotorized outrigger canoes as an incidental by-catch of deep water line fishing. A complete survey of all motorized and unmotorized vessels in 1995 at Grande Comore in comparison to earlier years indicated that a recent decreased use of motors and increase of unmotorized canoe fishing has led to an increase in coelacanth catches. Conservation measures and strategies for reducing the fishing pressure exerted on coelacanths are discussed. The southwest coast of Grande Comore should be designated as a nature reserve and protected area where immediate protection measures should be taken, an opinion which is supported by Comorian authorities
Predicting Cell Death and Mutation Frequency for a Wide Spectrum of LET by Assuming DNA Break Clustering Inside Repair Domains
Cosmic radiation, which is composed of high charged and energy (HZE) particles, is responsible for cell death and mutation, which may be involved in cancer induction. Mutations are consequences of mis-repaired DNA breaks especially double-strand breaks (DSBs) that induce inter- and intra-chromosomal rearrangements (translocations, deletions, inversion). In this study, a computer simulation model is used to investigate the clustering of DSBs in repair domains, previously evidenced by our group in human breast cells [1]. This model is calibrated with experimental data measuring persistent 53BP1 radiation-induced foci (RIF) and is used to explain the high relative biological effectiveness (RBE) of HZE for both cell death and DNA mutation frequencies. We first validate our DSB cluster model using a new track structure model deployed on a simple geometrical configuration for repair domains in the nucleus; then we extend the scope from cell death to mutation induction. This work suggests that mechanism based on DSB repair process can explain several biological effects induced by HZE particles on different type of living cell
Biodiversity loss through speciation collapse: Mechanisms, warning signals, and possible rescue
Speciation is the process that generates biodiversity, but recent empirical findings show that it can also fail, leading to the collapse of two incipient species into one. Here, we elucidate the mechanisms behind speciation collapse using a stochastic individual-based model with explicit genetics. We investigate the impact of two types of environmental disturbance: deteriorated visual conditions, which reduce foraging ability and impede mate choice, and environmental homogenization, which restructures ecological niches. We find that: (1) Species pairs can collapse into a variety of forms including new species pairs, monomorphic or polymorphic generalists, or single specialists. Notably, polymorphic generalist forms may be a transient stage to a monomorphic population; (2) Environmental restoration enables species pairs to re-emerge from single generalist forms, but not from single specialist forms; (3) Speciation collapse is up to four orders of magnitude faster than speciation, while the re-emergence of species pairs can be as slow as de novo speciation; (4) While speciation collapse can be predicted from either demographic, phenotypic, or genetic signals, observations of phenotypic changes allow the most general and robust warning signal of speciation collapse. We conclude that factors altering ecological niches can reduce biodiversity by reshaping the ecosystem's evolutionary attractors
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