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3. Impacts of sea ice melting procedures on measurements of microbial community structure

Author

Chamberlain, E. J., Balmonte, John Paul, Torstensson, Anders, Fong, A. A., Snoeijs-Leijonmalm, P., Bowman, J. S., Chamberlain, E. J., Balmonte, John Paul, Torstensson, Anders, Fong, A. A., Snoeijs-Leijonmalm, P., and Bowman, J. S.

Abstract

Microorganisms play critical roles in sea ice biogeochemical processes. However, microbes living within sea ice can be challenging to sample for scientific study. Because most techniques for microbial analysis are optimized for liquid samples, sea ice samples are typically melted first, often applying a buffering method to mitigate osmotic lysis. Here, we tested commonly used melting procedures on three different ice horizons of springtime, first year, land-fast Arctic sea ice to investigate potential methodological impacts on resulting measurements of cell abundance, photophysiology, and microbial community structure as determined by 16S and 18S rRNA gene amplicon sequencing. Specifically, we compared two buffering methods using NaCl solutions (???seawater,??? melting the ice in an equal volume of 35-ppt solution, and ???isohaline,??? melting with a small volume of 250-ppt solution calculated to yield meltwater at estimated in situ brine salinity) to direct ice melting (no buffer addition) on both mechanically ???shaved??? and ???non-shaved??? samples. Shaving the ice shortened the melting process, with no significant impacts on the resulting measurements. The seawater buffer was best at minimizing cell lysis for this ice type, retaining the highest number of cells and chlorophyll a concentration. Comparative measurements of bacterial (16S) community structure highlighted ecologically relevant subsets of the community that were significantly more abundant in the buffered samples. The results for eukaryotic (18S) community structure were less conclusive. Taken together, our results suggest that an equivalent-volume seawater-salinity buffered melt is best at minimizing cell loss due to osmotic stress for springtime Arctic sea ice, but that either buffer will reduce bias in community composition when compared to direct melting. Overall, these findings indicate potential methodological biases that should be considered before developing a sea ice melting protocol for mi

Published
2022
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7. Abstracts of Papers Presented at the 51st Annual Meeting Eastern Branch Entomological Society of America Hershey, Pa. September 26, 27 and 28, 1979

Author

Akers, R. C., Robinson, W. H., Akram, M., Forgash, A. J., Averill, A. L., Prokopy, R. J., Bacon, N. P., Bajusz, B. A., Smilowitz, Z., Mack, T. P., Petitt, F. L., Martinka, C. A., Whalon, M. E., Beal, R., Bean, Richard A., Denno, Robert F., Bowman, J. S., Eaton, A. T., Briggs, S. P., Allen, W. A., Brushwein, J. R., Granett, J., Burger, T. L., Cannon, K. F., Clark, R. A., Cochran, D. G., Cope, S. E., Catts, E. P., Cowden, R. L., Cromartie, W. J., Rivera, M. A., Gfrorer, J., Maser, D., Davis, M. A., DeGrandi, G. L., Collison, C. H., Dodds, P. J., Dowd, P. F., Kok, L. T., Rabb, R. L., Van Duyn, J. W., Elliott, N. B., Shlotzhauer, T., Engebretson, J. A., Mullins, D. E., Evans, E. W., Fernald, G. P., Burger, J. F., Fiori, B. J., Lamb, R. C., Gelman, D. B., Hayes, D. K., Greenplate, J. T., Greenberg, S., Stuart, A. M., Hansens, E. J., Johnson, W. M., Crans, W. J., Kamran, M. A., Keil, C. B., Klemas, V., Kolodny-Hirsch, D. M., Harrison, F. P., Lake, D. J., Logan, P. A., Casagrande, R. A., McClintock, J. T., Reichelderfer, C. F., McClure, M. S., MacCollom, G. B., Baumann, G., Welch, J. G., Madhavan, M. M., Madhavan, K., Magnarelli, L. A., Mahaney, J. H., Maier, C. T., Mastro, V. C., Mather, T. N., Mellors, W. K., Helgesen, R. G., Michelotti, F. W., Seidenberger, J. W., Mkhize, J., Gupta, A. P., Murphy, J. W., Smith, J. C., Nechols, J. R., Newton, W. G., Parrella, M. P., Horsburgh, R. L., Nolan, E. S., Powell, P. K., Rajotte, E. G., Roberts, R. B., Raupp, M. J., Denno, R. F., Rexrode, C. O., Ringo, J. M., Roitberg, B. D., Rossiter, M. C., Schneider, J. C., Schultz, P. B., Schwalbe, C. P., Paszek, E. C., Schweitzer, D. F., Semtner, P. J., Terrill, T. R., Shapiro, J. P., Hagedorn, H. H., Herbert,, E. W., Shimanuki, H., Shasha, B. S., Smith,, I. B., Caron, D. M., Sofield, R. K., Stiller, D., Frerichs, W. M., Leatch, G., Kuttler, K. L., Sunzenauer, I. M., Elden, T., Steinhauer, A. L., Swift, F. C., Blaustein, L., Treichler, R., Trumble, J. T., Tweeten, K. A., Tysowsky, M., Uebel, E. C., Warthen,, J. D., Webb, J. W., Weires, R. W., Leeper, J. R., Wheeler,, A. G., Valley, K., and Winegar, J. J.

Published
1980

10. Frost flowers on young Arctic sea ice: The climatic, chemical, and microbial significance of an emerging ice type

Author

Barber, D. G., Ehn, J. K., Pucko, M., Rysgaard, S., Deming, J. W., Bowman, J. S., Papakyriakou, T., Galley, R. J., and Sogaard, D. H.

Abstract

Ongoing changes in Arctic sea ice are increasing the spatial and temporal range of young sea ice types over which frost flowers can occur, yet the significance of frost flowers to ocean-sea ice-atmosphere exchange processes remains poorly understood. Frost flowers form when moisture from seawater becomes available to a cold atmosphere and surface winds are low, allowing for supersaturation of the near-surface boundary layer. Ice grown in a pond cut in young ice at the mouth of Young Sound, NE Greenland, in March 2012, showed that expanding frost flower clusters began forming as soon as the ice formed. The new ice and frost flowers dramatically changed the radiative and thermal environment. The frost flowers were about 5 degrees C colder than the brine surface, with an approximately linear temperature gradient from their base to their upper tips. Salinity and O-18 values indicated that frost flowers primarily originated from the surface brine skim. Ikaite crystals were observed to form within an hour in both frost flowers and the thin pond ice. Average ikaite concentrations were 1013 mu molkg(-1) in frost flowers and 1061 mu molkg(-1) in the surface slush layer. Chamber flux measurements confirmed an efflux of CO2 at the brine-wetted sea ice surface, in line with expectations from the brine chemistry. Bacteria concentrations generally increased with salinity in frost flowers and the surface slush layer. Bacterial densities and taxa indicated that a selective process occurred at the ice surface and confirmed the general pattern of primary oceanic origin versus negligible atmospheric deposition.

Published
2014

11. Selective occurrence of Rhizobiales in frost flowers on the surface of young sea ice near Barrow, Alaska and distribution in the polar marine rare biosphere

Author

Bowman, J. S., Larose, Catherine, Vogel, Timothy, Deming, Jody, Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), School of Oceanography [Seattle], and University of Washington [Seattle]

Subjects
DNA, Bacterial, Arctic Regions, fungi, Molecular Sequence Data, food and beverages, Biodiversity, Sequence Analysis, DNA, Microarray Analysis, DNA, Ribosomal, RNA, Ribosomal, 16S, [SDE]Environmental Sciences, Cluster Analysis, Ice Cover, Cloning, Molecular, Alaska, Phylogeny, Polymorphism, Restriction Fragment Length, Alphaproteobacteria
Abstract

International audience; Frost flowers are highly saline ice structures that grow on the surface of young sea ice, a spatially extensive environment of increasing importance in the Arctic Ocean. In a previous study, we reported organic components of frost flowers in the form of elevated levels of bacteria and exopolymers relative to underlying ice. Here, DNA was extracted from frost flowers and young sea ice, collected in springtime from a frozen lead offshore of Barrow, Alaska, to identify bacteria in these understudied environments. Evaluation of the distribution of 16S rRNA genes via four methods (microarray analysis, T-RFLP, clone library and shotgun metagenomic sequencing) indicated distinctive bacterial assemblages between the two environments, with frost flowers appearing to select for Rhizobiales. A phylogenetic placement approach, used to evaluate the distribution of similar Rhizobiales sequences in other polar marine studies, indicated that some of the observed strains represent widely distributed members of the marine rare biosphere in both the Arctic and Antarctic.

Published
2012

14. Did life originate from a global chemical reactor?

Author

Stüeken, E. E., primary, Anderson, R. E., additional, Bowman, J. S., additional, Brazelton, W. J., additional, Colangelo‐Lillis, J., additional, Goldman, A. D., additional, Som, S. M., additional, and Baross, J. A., additional

Published
2013
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16. Spin-tunnel investigation of a 1/13-scale model of the NASA AD-1 oblique-wing research aircraft

Author

White, W. L and Bowman, J. S., Jr

Subjects
Aerodynamics
Abstract

The spin and recovery characteristics of a 1/13-scale model of the NASA AD-1 oblique-wing research aircraft at wing-skew positions of 0, 25, 45, and 60 deg (right wing forward) were investigated. Spins were obtained for all wing-skew positions tested. For the unskewed wing position, two spin modes were possible. One spin mode was very steep and recoveries were obtained within 1 turn or less by rudder reversal. The second spin mode was flat and fast; the angle of attack was about 75 deg and the spin rate was about 145 deg/sec (2.5 seconds per turn). For the skewed wing positions, spins were obtained only in the direction of the forward-skewed wing (right wing forward). No spins were obtained to the left when the wing was skewed with the right wing forward. Recoveries should be attempted by deflecting the rudder to full against the spin, the ailerons to full with the spin, and movement of the wings to 0 deg skew. If the wing is skewed, the recovery may not be effected until the wing skew approaches 0 deg.

Published
1982

17. Stall/spin research status report

Author

Bowman, J. S., Jr and Burk, S. M., Jr

Subjects
Aircraft
Abstract

Description of a program aimed at improving the design and evaluation techniques relative to stall/spin characteristics of general-aviation aircraft. The program encompasses analytical studies, full-scale and model wind-tunnel tests, a radio-control model, and full-scale flight tests. Initial spin-tunnel results of several tail designs on a representative light aircraft are discussed.

Published
1974

18. The influence of wing, fuselage and tail design on rotational flow aerodynamics data obtained beyond maximum lift with general aviation configurations

Author

Bihrle, W., Jr and Bowman, J. S., Jr

Subjects
Aircraft Stability And Control
Abstract

The NASA Langley Research Center has initiated a broad general aviation stall/spin research program. A rotary balance system was developed to support this effort. Located in the Langley spin tunnel, this system makes it possible to identify an airplane's aerodynamic characteristics in a rotational flow environment, and thereby permits prediction of spins. This paper presents a brief description of the experimental set-up, testing technique, five model programs conducted to date, and an overview of the rotary balance results and their correlation with spin tunnel free-spinning model results. It is shown, for example, that there is a large, nonlinear dependency of the aerodynamic moments on rotational rate and that these moments are pronouncedly configuration-dependent. Fuselage shape, horizontal tail and, in some instances, wing location are shown to appreciably influence the yawing moment characteristics above an angle of attack of 45 deg.

Published
1980

20. Spin-tunnel investigation of the spinning characteristics of typical single-engine general aviation airplane designs. 2: Low-wing model A; tail parachute diameter and canopy distance for emergency spin recovery

Author

Burk, S. M., Jr, Bowman, J. S., Jr, and White, W. L

Subjects
Aerodynamics
Abstract

A spin tunnel study is reported on a scale model of a research airplane typical of low-wing, single-engine, light general aviation airplanes to determine the tail parachute diameter and canopy distance (riser length plus suspension-line length) required for energency spin recovery. Nine tail configurations were tested, resulting in a wide range of developed spin conditions, including steep spins and flat spins. The results indicate that the full-scale parachute diameter required for satisfactory recovery from the most critical conditions investigated is about 3.2 m and that the canopy distance, which was found to be critical for flat spins, should be between 4.6 and 6.1 m.

Published
1977

21. Spin-Tunnel Investigation of the Spinning Characteristics of Typical Single-Engine General Aviation Airplane Designs. 1. Low-Wing Model A: Effects of Tail Configurations

Author

Burk, S. M., Jr, Bowman, J. S., Jr, and White, W. L

Subjects
Aerodynamics
Abstract

The effects of tail design on spin and recovery were investigated in a spin tunnel. A 1/11-scale model of a research airplane which represents a typical low-wing, single engine, light general aviation airplane was used. A tail design criterion for satisfactory spin recovery for light airplanes was evaluated. The effects of other geometric design features on the spin and recovery characteristics were also determined. Results indicate that the existing tail design criterion for light airplanes, which uses the tail damping power factor as a parameter, cannot be used to predict spin-recovery characteristics.

Published
1977

22. Summary of spin technology as related to light general-aviation airplanes

Author

Bowman, J. S., Jr

Subjects
Aircraft
Abstract

A summary was made of all NASA (and NACA) research and experience related to the spin and recovery characteristics of light personal-owner-type general-aviation airplanes. Very little of the research deals with light general-aviation airplanes as such, but many of the airplanes and models tested before and during World War II were similar to present-day light general-aviation airplanes with regard to the factors that are important in spinning. The material is based mainly on the results of spin-tunnel tests of free-spinning dynamically scaled models of about 100 different airplane designs and, whenever possible, includes correlation with full-scale spin tests. The research results are discussed in terms of airplane design considerations and the proper use of controls for recovery.

Published
1971

26. Airplane spinning.

Author

Bowman, J. S

Subjects
Aircraft
Abstract

Aircraft spinning problems, noting mass distribution and tail design factors for satisfactory spin recovery characteristics

Published
1966

27. Airplane spinning

Author

Bowman, J. S

Subjects
Aircraft
Abstract

Aircraft spin and spin-recovery characteristics

Published
1965

28. Stall/spin studies relating to light general-aviation aircraft.

Author

Bowman, J. S., Jr and Burk, S. M., Jr

Subjects
Aircraft
Abstract

The present paper discusses the NASA Langley Research Center stall/spin research program to improve the design and the evaluation techniques relative to stall/spin characteristics of general-aviation aircraft. The program encompasses model wind-tunnel tests, spin-tunnel and radio-control model tests, and full-scale airplane spin tests. Initial spin-tunnel results on models with several tail designs representative of light airplanes and several testing techniques are discussed.

Published
1973

30. Five Year Plan for Fiscal Years 1991-1995

Author

NAVAL SUBMARINE MEDICAL RESEARCH LAB GROTON CT, Bowman, J S, Monty, S D, NAVAL SUBMARINE MEDICAL RESEARCH LAB GROTON CT, Bowman, J S, and Monty, S D

Abstract

This report is the Five Year Plan of the Naval Submarine Medical Research Laboratory for 1991-1995.

Published
1990

37. Relationship of Hydroxamic Acid Content in Corn and Resistance to the Corn Leaf Aphid1

Author

Long, B. J., Dunn, G. M., Bowman, J. S., and Routley, D. G.

Abstract

The cyclic hydroxamate, 2,4‐dihydroxy.7‐methoxy‐l,4‐benzoxazin‐ 3‐one (DIMBOA), has been implicated in the resistance of corn (Zea maysL.) to fungi and insects. In our study, bioassay and field experiments tested the relationship between hydroxamate concentration and resistance to corn leaf aphid (Rhopalosiphum maidis(Fitch)). In the bioassay, various concentrattons of DIMBOA were added to an artificial diet fed to corn leaf aphids. DIMBOA concentrations of 0.1, 0.25, and 0.5 mg/g diet caused 5.1, 12.8, and 20.8% mortality, respectively. In field trials, 12 inbred lines were evaluated for corn leaf aphid resistance under natural infestation. Aphid infestation was evaluated at mid‐silking stage with a visual rating scale and index system. Cyclic hydroxamate concentration in a separate set of the same lines was estimated by a rapid procedure based upon the colorimetric reaction of hydroxamates with ferric chloride. Aphid infestation values ranged from 119 to 366. Hydroxamate concentration ranged from 0.08 to 1.48 mg/g fresh weight. A highly significant correlation (r = 0.72) was obtained between aphid infestation and hydroxamate concentration. Eighteen hybrids derived from crosses among 12 inbred lines were also evaluated for corn leaf aphid resistance in the field. Aphid infestation values from high ✕ high, intermediate ✕ intermediate, and low ✕ low DIMBOA lines were generally low, intermediate, and high, respectively. Hybrids derived from crossing high ✕ low, high ✕ intermediate, and intermediate ✕ low DIMBOA lines produced infestation values between the parental extremes.

Published
1977
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38. Biochemical Basis of Resistance in Corn to the Corn Leaf Aphid1

Author

Beck, D. L., Dunn, G. M., Routley, D. G., and Bowman, J. S.

Abstract

Field experiments were conducted to determine the relationship between hydroxamic acid, total phenol, and orthodihydroxyphenol concentrations in corn (Zea maysL.) tassels and resistance to the corn leaf aphid [Rhopalosiphum maidis(Fitch)]. Eleven corn inbreds were evaluated for aphid resistance soon after tassel emergence using a visual rating scale and index system. The corn tassels were harvested and analyzed for hydroxamic acid, total phenol, and orthodihydroxyphenol content. A highly significant negative correlation (r = −0.63) was obtained between aphid infestation and hydroxamic acid concentration. Poor correlations were found between aphid infestation and both the total phenol and orthodihydroxyphenol concentrations. Seven corn inbred lines were further evaluated for corn leaf aphid resistance by artificial infestation in the greenhouse. A highly significant correlation (r = 0.90) was found between the greenhouse and field results.

Published
1983
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39. The Body Burden of Organic Vapors in Artificial Air Trial Measurements Aboard a Moored Submarine

Author

NAVAL SUBMARINE MEDICAL RESEARCH LAB GROTON CT, Knight, D. R., O'Neill, H. J., Gordon, S. M., Luebcke, E. H., Bowman, J. S., NAVAL SUBMARINE MEDICAL RESEARCH LAB GROTON CT, Knight, D. R., O'Neill, H. J., Gordon, S. M., Luebcke, E. H., and Bowman, J. S.

Abstract

The success of the submarine atmosphere control program has depended solely upon periodic identification of contaminants in the ship's atmosphere. Substances found to exceed safeguard concentrations are controlled by restricting their use aboard ship or scrubbing them from the atmosphere. But, this approach tends to ignore the human host. Advancements in technology now enable biomedical scientists to identify organic gases absorbed by the human body during exposures to industrial environments. We evaluated the potential application of computer-assisted gas chromatography mass spectrometry (GC/MS/COMP) to measuring of volatile organic compounds (VOC's) absorbed by submarine crewmembers. Expired breath samples were collected from watchstanders stationed in the forward space, torpedo room, forward engine space, and engineering space of a fast-attack submarine. Thirteen of the 17 highest concentrations of VOC's were acyclic, C7-C11 alkanes. Assuming that most of the expired VOC's were derived from the submarine, the hydrocarbon composition of the atmosphere was more concentrated and complex than in residential dwellings. This indicates that crewmembers absorb atmospheric VOC's during patrol and desorb the contaminants at home.

Published
1984

50. C. Everett Koop as Surgeon General: a national survey of public health educators.

Author

Bowman JS

Subjects
Evaluation Studies as Topic, Faculty statistics & numerical data, History, 20th Century, Politics, Surveys and Questionnaires, United States, United States Public Health Service statistics & numerical data, Attitude of Health Personnel, Leadership, Public Health education, United States Public Health Service organization & administration
Published
1992

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