1,461 research outputs found

    Cost keeping in the leather belting industry

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    Revised copy of a paper read by Mr. Wm. F. Carroll of the L. L. Harr Corporation of New York at a meeting of the Leather Belting Exchange held at the Hotel Biltmore, New York, Wednesday, December 20, 1916. Our object in visiting the plants and making the investigations was to obtain sufficient information relative to the manufacture and sale of leather belting to enable us to design a uniform cost system for use in all of the plants of the members of the Leather Belting Exchange. Our object is not to attempt to make costs uniform in all plants, but instead, to start with the assumption that the manager of each of the plants is a practical leather belting manufacturer and knows what he is doing, and to design for use in all of the plants a simple, common-sense cost system which can be operated with the least possible amount of clerical labor and which will be absolutely devoid of red tape, but which will make it possible for each manager to know absolutely what it is costing him to produce the belting manufactured in his plant, and to know also that he is including in his costs all of the items of cost which should be included in them and which are being included by all of the other manufacturers of leather belting in the Leather Belting Exchange

    Macrohabitat Composition Surrounding Successful and Depredated Northern Bobwhite Nests

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    Relationships among macrohabitat and depredation of northern bobwhite (Colinus virginianus) nests are poorly understood. Yet, macrohabitat composition may influence the nest predator community and, therefore, the vulnerability of northern bobwhite nests to depredation. We determined if macrohabitat composition surrounding bobwhite nests influenced nest placement, nest success, and which predators were responsible for depredating nests. We characterized macrohabitats at 2 scales, 8 and 16 ha, by surrounding both bobwhite nests, and an equal number of random locations, with a circular buffer. Random points were placed within the area used by bobwhites on our study area. We then determined the acreage of each macrohabitat category within each circular buffer to determine the macrohabitat composition. Macrohabitat categories included hardwood forested drains, upland pine forests burned in March of the same calendar year, upland pine forests burned in March of the previous calendar year, and fields. We documented nest predators using infrared video cameras placed at the nest site. We monitored 104 bobwhite nests on Tall Timbers Research Station (TTRS) during 1999 and 2000. Size of the circular buffer around nests did not qualitatively affect results. Area (ha) of upland pine forests and fields were similar at depredated nests, hatched nests, and random locations. However, there was an average of 81% and 56% more area of hardwood drain in the circular buffers associated with random locations than at successful and depredated nests, respectively. Area of upland pine forests and fields were similar for nests depredated by raccoon (Procyon lotor), armadillo (Dasypus novemcinctus) and snake (Elaphus spp.). However, there was an average of 6.1 and 3.3 times more area of hardwood drain surrounding nests that were depredated by snakes relative to nests depredated by raccoons and armadillos, respectively. While our sample sizes were low, bobwhites exhibited a tendency to place nests in landscapes with less hardwood drain than were generally available on the study area. Macrohabitat surrounding nests influenced the type of nest predator to depredate nests. To minimize depredation of bobwhite nests by snakes, we suggest nesting cover should be developed away from drain edges

    Catalysis of Stark-Tuned Interactions Between Ultracold Rydberg Atoms

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    We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold 85Rb Rydberg atoms. We studied the time dependence of the process, 34p+34p→34s+35s, and observed an enhancement of 34s state population when 34d state atoms are added. We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms

    Recent Decisions

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    Comments on recent decisions by Donald L. Very, James Carroll Booth, William E. Coyle, Edward N. Denn, William C. Rindone, Jr., and Karl Jorda

    Prolegomena to Any Future Carver Studies

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    Failing of satisfactory progress in explaining the movements of the heavenly bodies on the supposition that they all revolved round the spectator, he tried whether he might not have better success if he made the spectator to revolve and the stars to remain at rest.Immanuel Kant. Preface to the Second Edition, The Critique of Pure Reason (1787) Ever since the tenth anniversary of the death of Raymond Carver (1938-1988) scholars and general readers have been uneasily aware of what has come to b..

    Prolegomena to Any Future Carver Studies

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    Failing of satisfactory progress in explaining the movements of the heavenly bodies on the supposition that they all revolved round the spectator, he tried whether he might not have better success if he made the spectator to revolve and the stars to remain at rest.Immanuel Kant. Preface to the Second Edition, The Critique of Pure Reason (1787) Ever since the tenth anniversary of the death of Raymond Carver (1938-1988) scholars and general readers have been uneasily aware of what has come to b..

    Using Microsatellite DNA to Understand Bobwhite Behavior and Population Structure (Post Abstract)

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    Northern bobwhite (Colinus virginianus) have a flexible mating system with varying degrees of parental investment in offspring. Questions of relatedness of mates and the dynamics of covey membership have not been answered. It is not known how different patterns of mating systems impact productivity of bobwhite populations. In addition to behaviors, the genetic structure of bobwhite populations likely varies across landscapes, and may depend on the distribution and abundance of habitat types. These issues have critical conservation and management implications, such as the impact of habitat fragmentation on gene flow. Recent advances in molecular techniques provide an opportunity to investigate these questions through examination of small, repetitive, highly variable regions of DNA known as microsatellites. Microsatellites provide the fine-scale resolution needed to objectively understand certain population structures and reproductive strategies. Microsatellite analysis techniques have been used successfully to research relatedness and extra-pair paternity of a number of species. Therefore, we have begun to investigate the genetic basis for many northern bobwhite behaviors related to reproduction. Our primary objectives are to determine: (1) relatedness of individuals within coveys and groups over time, (2) relatedness between reproductive pairs relative to random pairings, (3) relatedness of chicks in broods, (4) rates of extrapair fertilization, (5) rates of intra-specific nest parasitism, and (6) the relatedness of incubating birds to their eggs. To do so, we have developed a series of microsatellite markers for northern bobwhites. We radiomarked approximately 75% of bobwhites on our study area at Tall Timbers Research Station. We collected body feathers from adults and 1.5 mm patagial micro-biopsies from each chick (4 days old) found brooding with radiomarked adults for microsatellite analysis. We are determining relatedness and parentage, based on these microsatellite data, using programs RELATEDNESS and CERVUS. Additionally, we are testing our tissue collection techniques on a pen-reared population of bobwhites to determine the efficiency of DNA amplification via the polymerase chain reaction for 4 tissue collection techniques: patagial micro-biopsy, down and feather shaft, egg tooth, and egg membrane. Additionally, we are pairing pen-reared adult hens and males for different periods of time to determine the presence of sperm storage and test for evidence of sperm competition. Further, we are crossing individuals of known relatedness over several generations to test the accuracy of paternity inferences calculated by CERVUS with respect to bobwhite microsatellite data. Finally, by collecting feathers from hunterkilled bobwhites throughout the Red Hills and the southeast, we will compare the genetic structure of the bobwhite population(s) of the Red Hills, likely the last panmictic population in the southeast, to more isolated, declining populations. In our poster we present a detailed description of this research along with first year results

    Rapid consumption of phytoplankton and ice algae by Arctic soft-sediment benthic communities: Evidence using natural and 13C-labeled food materials

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    Reduction of sea ice in the Arctic may significantly alter the relative fluxes of phytoplankton and ice algae to the seafloor. To examine the response of Arctic benthic communities to changing food supplies, we incubated sediment cores collected from two sites (Smeerenburg Fjord, northwest Svalbard in May 2003 and Storfjord Trench, Barents Sea in May 2004) with controlled additions of natural phytoplankton and ice algal assemblages, and laboratory-cultured 13C-labeled ice algae (Nitzschia frigida, in 2004 only). We measured sediment respiration, pigments, lipid biomarkers, and compound-specific δ13C signals over the course of incubations. Both communities responded rapidly to the addition of food materials: regardless of food type, concentrations of organic biomarkers (pigments and fatty acids) decreased to the levels of control cores within seven days. Although we found no evidence for selective ingestion of the different food types by macrofauna, fatty acids were differentially consumed. The enriched polyunsaturated fatty acids of the ice algae were preferentially utilized compared to saturated and monounsaturated fatty acids bound in ice algae. However, the saturated and monounsaturated fatty acids of phytoplankton (with depleted polyunsaturated fatty acids) are utilized more efficiently than those counterparts bound in ice algae. Bacterial activity was stimulated by food addition, indicated by the immediate increase of bacteria-specific fatty acids, but the direct assimilation of 13C-labeled carbon into bacterial biomass was limited. Our results imply that Arctic benthic communities can meet their energetic requirements by altering strategies to assimilate different components from variable food supplies

    Composition and Biophysical Properties of the Sorting Platform Pods in the Shigella Type III Secretion System

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    Shigella flexneri, causative agent of bacillary dysentery (shigellosis), uses a type III secretion system (T3SS) as its primary virulence factor. The T3SS injectisome delivers effector proteins into host cells to promote entry and create an important intracellular niche. The injectisome’s cytoplasmic sorting platform (SP) is a critical assembly that contributes to substrate selection and energizing secretion. The SP consists of oligomeric Spa33 “pods” that associate with the basal body via MxiK and connect to the Spa47 ATPase via MxiN. The pods contain heterotrimers of Spa33 with one full-length copy associated with two copies of a C-terminal domain (Spa33C). The structure of Spa33C is known, but the precise makeup and structure of the pods in situ remains elusive. We show here that recombinant wild-type Spa33 can be prepared as a heterotrimer that forms distinct stable complexes with MxiK and MxiN. In two-hybrid analyses, association of the Spa33 complex with these proteins occurs via the full-length Spa33 component. Furthermore, these complexes each have distinct biophysical properties. Based on these properties, new high-resolution cryo-electron tomography data and architectural similarities between the Spa33 and flagellar FliM-FliN complexes, we provide a preliminary model of the Spa33 heterotrimers within the SP pods. From these findings and evolving models of SP interfaces and dynamics in the Yersinia and Salmonella T3SS, we suggest a model for SP function in which two distinct complexes come together within the context of the SP to contribute to form the complete pod structures during the recruitment of T3SS secretion substrates
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