166 research outputs found
A Report on Drosophila Collections in Nebraska
Until rather recently little has been known of the Drosophila species of Nebraska. Sturtevant (1921) lists Nebraska as one of seven states from which no Drosophila had been reported. Patterson and Wagner (1943) show that collections of Drosophila pseudoobscura had been made in the vicinities of Scottsbluff and Kearney, but no other Drosophila species are reported from Nebraska in their publication
Further Observations on Polymegaly in Species of the \u3ci\u3eDrosophila affinis\u3c/i\u3e Subgroup
Polymegaly, or the production of two or more size class of sperms by the same male, has been known in Drosophila for more than a decade. More recently polymegaly (dimegaly, or two size classes) was found in the Drosophila affinis subgroup. Additional observations on polymegaly in six D. affinis subgroup species: D. affinis, D. algonquin, D. athabasca, D. azteca, D. narragansett, and D. tolteca are reported here. The two kinds of sperms differ strikingly in the nature of the head, which is elongate (threadlike) in long sperms, short and dense in short sperms. Ultraviolet fluorescence following treatment with 4\u27, 6-diamidino-2-phenylindole (DAPI) made it possible to recognize these distinctive heads in developing spermatids and in mature sperms. Investigations of spermatids were supplemented with observations of Feulgen-stained preparations and by electron microscopy. Short sperms were found to be much more numerous than long ones in the seminal vesicles of males and in the uteri of recently inseminated females. However, the proportions of short sperms were greatly reduced in the sperm storage organs of mated females. Inspection of squash preparations of newly laid eggs revealed flagella of long sperms but no unequivocal evidence of short sperms
Further Observations on Polymegaly in Species of the \u3ci\u3eDrosophila affinis\u3c/i\u3e Subgroup
Polymegaly, or the production of two or more size class of sperms by the same male, has been known in Drosophila for more than a decade. More recently polymegaly (dimegaly, or two size classes) was found in the Drosophila affinis subgroup. Additional observations on polymegaly in six D. affinis subgroup species: D. affinis, D. algonquin, D. athabasca, D. azteca, D. narragansett, and D. tolteca are reported here. The two kinds of sperms differ strikingly in the nature of the head, which is elongate (threadlike) in long sperms, short and dense in short sperms. Ultraviolet fluorescence following treatment with 4\u27, 6-diamidino-2-phenylindole (DAPI) made it possible to recognize these distinctive heads in developing spermatids and in mature sperms. Investigations of spermatids were supplemented with observations of Feulgen-stained preparations and by electron microscopy. Short sperms were found to be much more numerous than long ones in the seminal vesicles of males and in the uteri of recently inseminated females. However, the proportions of short sperms were greatly reduced in the sperm storage organs of mated females. Inspection of squash preparations of newly laid eggs revealed flagella of long sperms but no unequivocal evidence of short sperms
Effect of Ozone Addition on Combustion Efficiency of Hydrogen: Liquid-Oxygen Propellant in Small Rockets
An experimental study shows that 2 percent by weight ozone in oxygen has little effect on overall reactivity for a range of oxidant-fuel weight ratios from 1 to 6. This conclusion is based on characteristic-velocity measurements in 200-pound-thrust chambers at a pressure of 300 pounds per square inch absolute with low-efficiency injectors. The presence of 9 percent ozone in oxygen also did not affect performance in an efficient chamber. Explosions were encountered when equipment or procedure permitted ozone to concentrate locally. These experiments indicate that even small amounts of ozone in oxygen can cause operational problems
Bacillus thuringiensis Cry5B protein as a new pan-hookworm cure
Hookworms are intestinal nematode parasites that infect nearly half a billion people and are globally one of the most important contributors to iron-deficiency anemia. These parasites have significant impacts in developing children, pregnant women and working adults. Of all the soil-transmitted helminths or nematodes (STNs), hookworms are by far the most important, with disease burdens conservatively estimated at four million DALYs (Disability-Adjusted Life Years) and with productivity losses of up to US$139 billion annually. To date, mainly one drug, albendazole is used for hookworm therapy in mass drug administration, which has on average approximately 80% cure rate that is lower ( \u3c 40%) in some places. Given the massive numbers of people needing treatment, the threat of parasite resistance, and the inadequacy of current treatments, new and better cures against hookworms are urgently needed. Cry5B, a pore-forming protein produced by the soil bacterium Bacillus thuringiensis (Bt) has demonstrated good efficacy against Ancylostoma ceylanicum hookworm infections in hamsters. Here we broaden studies of Cry5B to include tests against infections of Ancylostoma caninum hookworms in dogs and against infections of the dominant human hookworm, Necator americanus, in hamsters. We show that Cry5B is highly effective against all hookworm parasites tested in all models. Neutralization of stomach acid improves Cry5B efficacy, which will aid in practical application of Cry5B significantly. Importantly, we also demonstrate that the anti-nematode therapeutic efficacy of Cry5B is independent of the host immune system and is not itself negated by repeated dosing. This study indicates that Bt Cry5B is a pan-hookworm anthelmintic with excellent properties for use in humans and other animals
The Vehicle, 1965, Vol. 7
Vol. 7
Table of Contents
CommentaryElaine Lancepage 3
Lost Island and The Unseen SeaDaun Alan Leggpage 5
ElegyWilliam Mosierpage 6
AwayDavid Dixpage 7
DulceyRoberta Mathewspage 8
Alarum Tuam JonneDavid Walkerpage 11
Little BrotherSteve Gibbspage 13
River RunningDaun Alan Leggpage 15
PortraitRobert D. Thomaspage 16
The RockRoger Lewis Hudsonpage 17
Jarman HospitalElaine Lancepage 18
Of Domes and DiamondsDwight Ashbypage 19
Friday NightRoger J. Barrypage 20
MurderHelen Coxpage 23
Vigil SongDaun Alan Leggpage 24
Had You But Been the OneDavid Helmpage 25
To A Useless WeaponDarlene Brewerpage 25
Out of the NightPat Hartpage 26
La MortAdrian Beardpage 28
Mrs. Milton\u27s LamentBob Millerpage 30
Cockle CoveSusan McCabepage 31
Loss of VirtueJim Rinnertpage 32
The KeepsakeDwight Ashbypage 33
The RuinsRoger Lewis Hudsonpage 35
Ante Major OdysseyDaun Alan Leggpage 38
ReligionAnthony Barrettepage 39
All JoyJim Rinnertpage 40
SesameElaine Lancepage 40
CenterpieceDwight Ashbypage 41
A Great White WaveJohn Rhodespage 42
QueryElaine Lancepage 44
PistachioRita Salyerspage 45
FacadeKathleen McCormackpage 46
Winter Wisp AwaySteve Gibbspage 46
ScenarioDavid Dixpage 47
Damn-GodSteve Gibbspage 48
AccidentElaine Lancepage 48https://thekeep.eiu.edu/vehicle/1013/thumbnail.jp
pubmed2ensembl: A Resource for Mining the Biological Literature on Genes
The last two decades have witnessed a dramatic acceleration in the production of genomic sequence information and publication of biomedical articles. Despite the fact that genome sequence data and publications are two of the most heavily relied-upon sources of information for many biologists, very little effort has been made to systematically integrate data from genomic sequences directly with the biological literature. For a limited number of model organisms dedicated teams manually curate publications about genes; however for species with no such dedicated staff many thousands of articles are never mapped to genes or genomic regions.To overcome the lack of integration between genomic data and biological literature, we have developed pubmed2ensembl (http://www.pubmed2ensembl.org), an extension to the BioMart system that links over 2,000,000 articles in PubMed to nearly 150,000 genes in Ensembl from 50 species. We use several sources of curated (e.g., Entrez Gene) and automatically generated (e.g., gene names extracted through text-mining on MEDLINE records) sources of gene-publication links, allowing users to filter and combine different data sources to suit their individual needs for information extraction and biological discovery. In addition to extending the Ensembl BioMart database to include published information on genes, we also implemented a scripting language for automated BioMart construction and a novel BioMart interface that allows text-based queries to be performed against PubMed and PubMed Central documents in conjunction with constraints on genomic features. Finally, we illustrate the potential of pubmed2ensembl through typical use cases that involve integrated queries across the biomedical literature and genomic data.By allowing biologists to find the relevant literature on specific genomic regions or sets of functionally related genes more easily, pubmed2ensembl offers a much-needed genome informatics inspired solution to accessing the ever-increasing biomedical literature
Transcription activation by the siderophore sensor Btr is mediated by ligand-dependent stimulation of promoter clearance
Bacterial transcription factors often function as DNA-binding proteins that selectively activate or repress promoters, although the biochemical mechanisms vary. In most well-understood examples, activators function by either increasing the affinity of RNA polymerase (RNAP) for the target promoter, or by increasing the isomerization of the initial closed complex to the open complex. We report that Bacillus subtilis Btr, a member of the AraC family of activators, functions principally as a ligand-dependent activator of promoter clearance. In the presence of its co-activator, the siderophore bacillibactin (BB), the Btr:BB complex enhances productive transcription, while having only modest effects on either RNAP promoter association or the production of abortive transcripts. Btr binds to two direct repeat sequences adjacent to the −35 region; recognition of the downstream motif is most important for establishing a productive interaction between the Btr:BB complex and RNAP. The resulting Btr:BB dependent increase in transcription enables the production of the ferric-BB importer to be activated by the presence of its cognate substrate
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