Life Sciences Commons^™

Atomic Force Microscopy Investigation Of Radiation-Induced Dna Double Strand Breaks, D. Pang, G. Popescu, J. Rodgers, B. L. Berman, A. Dritschilo

Scanning Microscopy

We have used atomic force microscopy (AFM) to study radiation-induced DNA double strand breaks. Double-stranded plasmid DNA was irradiated with 18-MeV electrons in aqueous buffer, using a medical linear accelerator. Doses of 50, 100, 150, and 200 Gy were delivered to DNA samples, and atomic force microscopy was used to measure the length of each DNA fragment. From these measurements, we obtained the average length of the irradiated DNA for each sample and found a linear-quadratic relationship between the average length and radiation dose.

Cropwatch No. 96-21, Sept. 13, 1996, Lisa Brown Jasa

Crop Watch (1994–2005)

Inside

Biological control info............144

Weed control after CRP............145

Post-CRP soil fertility............146

Post-CRP management tips............147

Erosion-reducing manure............148

A Micro-Raman Spectroscopic Study Of Hydrazine-Treated Human Dental Calculus, H. Tsuda, W. L. Jongebloed, I. Stokroos, J. Arends

Scanning Microscopy

Hydrazine has been used to remove organic components and to isolate the mineral(s) from human calculus. Micro-Raman measurements were performed on the mineral phase. After the hydrazine-treatment, not only a large reduction in fluorescence but also an increase in Raman signal was observed. The treatment was essential in minimizing thermally-induced chemical changes which could otherwise occur to the original calculus mineral due to the intense laser light. The Raman spectral features of the mineral were nearly all identical among the Raman spectra obtained at many randomly-selected sites by the micro-Raman microbe with a lateral resolution of approximately 1 μm, and …

Combined Bronchoalveolar-Vascular Casting Of The Canine Lung, John A. Nettum

Scanning Microscopy

Canine bronchoalveolar and vascular corrosion casts were prepared using unfixed tissue and Dow-Corning Room Temperature Vulcanizing Silastic® 734. The casts were observed using stereo light microscopy and scanning electron microscopy. The casts show the relationship between the vasculature and airway and demonstrate intricate microanatomical details. Also, microvasculature filling was enhanced using unfixed tissue as compared to my previously described technique using fixed tissue. Prewashing the microvasculature with cold phosphate buffered saline appeared to facilitate microvascular filling with silicone rubber. The described method is useful for rapidly making durable models for studying the normal respiratory airway and microvasculature. It should be …

Proceedings From The 33rd Annual Italian And Specialty Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.

Meeting Minutes, September 10th, 1996, National Smokejumper Association Board Of Directors

National Smokejumper Association Meeting Minutes

Agenda: Opened the meeting with an introduction; Memorandum of Understanding to be entered between the NSA and the National Forest Service Museum (NFSM).; Lifetime Membership; Purchase of a new computer for the office; Location of the next National Smokejumper Reunion; Report on the Columbia Breaks Fire Interpretive Center ; Next regular meeting of NSA Board of Directors is scheduled. The location will be determined later.; This Special Meeting of the NSA Board of Directors was adjourned 2110; Multiple addenda; Addenda:.; Letter September 10, 1996, from Earl Cooley, Rough draft.; Fund Raising Proposal, no date.; Memorandum of Understanding, signed September 16, …

Meeting Minutes, September 10th, 1996, National Smokejumper Association Executive Committee

National Smokejumper Association Meeting Minutes

Agenda: Treasurer's report; Would NSA consider the option of joining with Museum of Mountain Flying in the reconstruction of the former Smokejumper loft from Hale field to use for office space and museum? ; A furnace for the current office; Smokejumper video project; Newsletter; Request to exchange our membership lists; Master roster is intended for private and personal use only; Video agreement with Media Entertainment, Inc ; Bruce Edger and Jack Mathews recognized for the help in locating former jumpers.; Appreciation expressed to Roger Savage and Greg Lee for assistance in research for the purchase of new computer; The Highway …

Meeting Minutes, September 10th, 1996, National Smokejumper Association Board Of Directors

National Smokejumper Association Meeting Minutes

Agenda: Opened the meeting with an introduction; Memorandum of Understanding to be entered between the NSA and the National Forest Service Museum (NFSM).; Lifetime Membership; Purchase of a new computer for the office; Report on the Columbia Breaks Fire Interpretive Center ; Next regular meeting of NSA Board of Directors is scheduled. The location will be determined later.; This Special Meeting of the NSA Board of Directors was adjourned 2110; Multiple addenda;

Application Of Monte Carlo Simulations To Critical Dimension Metrology In A Scanning Electron Microscope, Jeremiah R. Lowney

Scanning Microscopy

The state of the art in Monte Carlo simulations of scanning electron microscope (SEM) signals is reviewed. Two Monte Carlo computer codes were written to simulate the transmitted-, backscattered-, and secondary-electron signals from targets in a scanning electron microscope. The first, MONSEL-11, is applied to semi-infinite lines produced lithographically on multi-layer substrates. The second, MONSEL-111, is an extension to fully three-dimensional targets. Results for a 1 μm step, etched in a silicon substrate are compared with experimental data. The comparisons show that it is possible to obtain edge locations to an uncertainty of less than 10 nm. Simulations were performed …

Atomic Force Microscopy And Optical Studies Of Organic Thin Films With Hydrogen-Bonded Networks, Arkadi L. Litvin, Valery N. Bliznyuk, Vladimir V. Tsukruk, Suresh Valiyaveettil, David L. Kaplan

Scanning Microscopy

Brewster angle microscopy and atomic force microscopy were used to characterize the surface morphology of thin films in situ or after transfer onto solid supports. Two acids were studied, differing in carboxylic acid head groups, resulting in significantly different morphological features for thin films formed from these two amphiphiles on a Langmuir trough. Differences in self-assembly and domain sizes were correlated with the formation of hydrogen-bonded networks. The influence of surface hydrophobicity or hydrophilicity during deposition on morphology was also characterized, with spherulitic features appearing in some samples.

Lter Trademark And Patent Application, Long Term Ecological Research

Long Term Ecological Research Network

U.S. Long Term Ecological Research Network application for a patent and trademark.

Hexapod Herald - Vol. 8, No. 12, September 4, 1996

Hexapod Herald and Other Entomology Department Newsletters

Grants

Departmental travelers

Congratulations

Graduate student news

Welcome

Calendar of events

Monte Carlo Simulation Of Electron Backscattering In Solids Using A General-Purpose Computer Code, E. Acosta, E. Coleoni, G. Castellano, J. A. Riveros, J. M. Fernández-Varea, F. Salvat

Scanning Microscopy

A Monte Carlo study of backscattering of kilovolt electrons in solids, a process of primary importance in electron microscopy and surface analytical techniques, is carried out. Simulations have been performed using the general-purpose simulation code PENELOPE (an acronym for "Penetration and ENErgy LOss of Positrons and Electrons"), which generates electron-photon showers in arbitrary materials. A systematic comparison of results from PENELOPE with available experimental data, and with results from simulations with a much more sophisticated code, is given for electron beams with energies between 2.5 and 60 keV and elemental solids with atomic numbers Z = 4 to 92. It …

Effects Of Castration Upon The Morphology Of The Accessory Sex Organs Of The Male Rat - A Scanning Electron Microscopy Study, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

A systematic, comparative study of the accessory sex glands of the adult male rat after androgen withdrawal was carried out. The changes were investigated by using scanning electron microscopy at different intervals after surgical castration. The main common signs of epithelial cell involution were flattening of the cell surface, reduction of the size and number of microvilli, some blurring of the cell borders, cessation of secretory activity and diminution of the luminal volume of the glands. Overall, confident signs of atrophy were evident after one week, and complete epithelial involution was reached by the third week. The epithelial cell atrophy …

Emerging Applications Of Fluorescence Spectroscopy To Cellular Imaging: Lifetime Imaging, Metal-Ligand Probes, Multi-Photon Excitation And Light Quenching, Joseph R. Lakowicz

Scanning Microscopy

Advances in time-resolved fluorescence spectroscopy can be applied to cellular imaging. Fluorescence lifetime imaging microscopy (FLIM) creates image contrast based on the decay time of sensing probes at each point in a two-dimensional image. FLIM allows imaging of Ca²⁺ and other ions without the need for wavelength-ratiometric probes. Ca²⁺ imaging can be performed by FLIM with visible wavelength excitation. Instrumentation for FLIM is potentially simple enough to be present in most research laboratories. Applications of fluorescence are often limited by the lack of suitable fluorophores. New, highly photostable probes allow off-gating of the prompt autofluorescence, and measurement of …

Scanning Electron Microscopy Of The Accessory Sex Glands Of The Adult Male Rat, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

This study describes the morphology of the accessory sex glands of the adult male rat as observed by scanning electron microscopy (SEM). The purpose was to obtain a systematic and comparative SEM description of these glands and to evaluate different preparation techniques. A common morphological feature is polyhedral delineation of the cells, which exhibited a variable convexity of their apical surface. The cell apices were more or less studded with microvilli. Nevertheless, it was possible to distinguish the glands by their surface morphology. In the ventral prostate, there was a considerable heterogeneity in cell surface appearance. The lateral lobe bad …

Does Risk Aversion Make A Case For Conservatism, Ralph M. Perhac Jr.

RISK: Health, Safety & Environment (1990-2002)

Dr. Perhac argues that risk aversion, alone, and assuming it is justifiable, does not support the prefer ability of overstating, as opposed to understating, mean risk.

Comparing Risks Thoughtfully, Adam M. Finkel

RISK: Health, Safety & Environment (1990-2002)

Dr. Finkel argues that comparing risks is neither impossible nor immoral - but is nonetheless very difficult. He then discusses two major pitfalls of making such comparisons, one commonly cited and one routinely ignored, before sketching a framework for improving them.

Lupin Logic Number 74

Lupin Logic

Contents

Change and no change

Lupin harvesting

Lupins in the United Kingdom George Milford and Ian Shield, Rothamsted

Weed control in lupins

Cladosporium

Aphid control

Lupins as food

Review Of: Peter K. Lagoy, Risk Assessment: Principles And Applications For Hazardous Waste And Related Sites (Noyes Publications 1994), Adam K. Sacharoff

RISK: Health, Safety & Environment (1990-2002)

Review of the book: Peter K. LaGoy, Risk Assessment: Principles and Applications for Hazardous Waste and Related Sites (Noyes Publications 1994). Appendices, figures, index, notes, preface, references, tables. LC 94-2510; ISBN 0-8155-1349-6. [260 pp. Cloth $48.00. 120 Mill Road, Park Ridge NJ 07656.]

High-Power Broadly Tunable Picosecond Ir Laser System For Use In Nonlinear Spectroscopic Applications, D. E. Gragson, B. M. Mccarty, G. L. Richmond, D. S. Alavi

Chemistry and Biochemistry

We developed a high-power tunable picosecond IR laser system suitable for nonlinear spectroscopic investigations. We employ a Ti:sapphire regenerative amplifier that produces 1.9-ps, 17-cm⁻¹, 800-nm pulses at 1 kHz as a pump source. White-light generation in ethylene glycol and optical parametric amplification in potassium titanyl phosphate are used to produce the IR pulses. The tuning range extends from 2.4 to 3.8 μm in the idler and 1.0 to 1.2 μm in the signal. A total efficiency (signal plus idler) as high as 20% was achieved. The spatial, spectral, and temporal characteristics of the IR beam are presented along …

Nebline, September 1996

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Horticulture

Rural $ense

Family Living

4-H & Youth

Environmental Focus

Community & Leadership Development

Extension Calendar

Expanded Food and Nutrition Education Program (EFNEP)

Nebraska Association for Family and Community Education News

and other extension news and events

Mechanical Conditioning For Controlling Excessive Elongation In Tomato Transplants: Sensitivity To Dose, Frequency, And Timing Of Brushing, Lauren C. Garner, Thomas Björkman

Horticulture and Crop Science

During production of plug transplants, the high plant density results in rapid stem elongation as plants compete for light. The resulting tall, weak-stemmed plants are difficult to transplant and are easily damaged. One technique that can prevent excessive elongation is mechanical stimulation by brushing. Wide adoption of brushing is limited by a lack of information on how plants respond to variations in applying the technique. Our investigation examined how tomato (Lycopersicon esculentum cv. Oh8245) seedling growth responded to varying doses of mechanical stimulation, varying intervals between brush strokes during stimulation, time of day that stimulation was applied, and growth stage …

Pearling And Aquaculture In The Dampier Archipelago - Existing And Proposed Operations - A Report For Public Comment, Ben Fraser

Fisheries Management Papers

This discussion paper has been prepared by the Fisheries Department of WA as part of a consultative process to enable the public to comment on existing and proposed pearling and aquaculture activities in the Dampier Archipelago. This report follows on from Fisheries Management Report 90 - the Driscoll Report - and provides more detailed information about pearling and aquaculture to enable the public to consider and comment on individual projects.

Crystal Protein Expression During Vegetative Growth Of Dictyostelium, Kristy K. Taylor, Catherine P. Chia

Papers in Microbiology

We are studying interactions between membrane proteins and the cytoskeleton of Dictyostelium discoideum. Detergent (Triton X-100) -insoluble cytoskeletons from vegetative (AX2) amebae are enriched in a 70 kDa Concanavalin A (Con A)-binding protein (gp70). An enriched fraction of gp70 was prepared by Con A affinity chromatography of cytoskeletons from axenically-grown cells. N-terminal amino acid sequence of gel-purified gp70 established its identity to a 69 kDa 'crystal protein' previously characterized by Bomblies, et al. (1990, J. Cell Biol. 110:669 -679). Enzymatic deglycosylation of gp70 resulted in a 65 kDa product that did not bind Con A, verifying the predicted number …

Collision Course: The Hazards Of Lighted Structures And Windows To Migrating Birds, Lesley J. Evans Ogden

Fatal Light Awareness Program (FLAP)

The collision of migrating birds with human-built structures and windows is a world-wide problem that results in the mortality of millions of birds each year in North America alone. Birds killed or injured at such structures are due to two main factors. The first of these is the lighting of structures at night, which “traps” many species of nocturnal migrants. The second factor contributing to the hazard is the presence of windows, which birds in flight either cannot detect, or misinterpret. In combination, these two factors result in a high level of direct anthropogenic (human-caused) mortality. Bird mortality at human-built …

Nebraska Ornithologists' Union Annual Meeting 18 May 1996, Robin Harding

Nebraska Bird Review

The 1997 Annual Meeting will be held jointly with the South Dakota and Iowa Ornithologists' Unions in South Sioux City, NE 16-18 May.

Neal Ratzlaff, President, reported on several items. Funds are being sought to publish the Breeding Bird Atlas for Nebraska. The new NOU Field Cards of Nebraska Birds are ready for distribution. The Wildlife Diversity Funding Initiative is on hold because some companies are afraid of increasing their prices. NOU members were encouraged to urge Cabela's to support the Initiative. [See NBR 63 (3) 1995, p. 91 for details.]

A request was received from Fermata, Inc., which has …

A Review Of The Status Of Limnodromus Griseus, The Short-Billed Dowitcher, In Nebraska, Joel Jorgensen

Nebraska Bird Review

The two North American dowitchers are notoriously difficult to distinguish from each other. This is not only true of field observations, but there are several instances where a specimen identified as one species was found to be the other upon review. Limnodromus scolopaceus, the Long-billed Dowitcher, has always been considered the common dowitcher in Nebraska, while Limnodromus griseus, the Short-billed Dowitcher, is less common. Confusion about identification and the lack of consistent, well-documented records have caused the status of L. griseus in Nebraska to be a matter of speculation.

Taxonomy of dowitchers was for some time confused. Studies …

Another Common Crane In Nebraska With A Summary Of North American Records, Gary Lingle

Nebraska Bird Review

On 30 March 1996 around 1000 h CST, Bob Janssen and Jim Williams of Minnetonka, Minnesota, discovered a Common Crane (Grus grus) feeding in corn stubble with a flock of Sandhill Cranes (Grus canadensis) in Section 34 T9R10 Hall County, Nebraska. The Commom Crane associated with the Sandhill Cranes, which were at peak numbers in the Platte River valley. Later that day, several observers, including myself, witnessed the bird in section 32 about 500 yards away, where it mingled with a few hundred Sandhill Cranes. The difficulty in seeing this bird was illustrated by the fact …

The Prairie Naturalist Volume 28, No. 3. September 1996

The Prairie Naturalist

REPRODUCTIVE SUCCESS OF GRASSHOPPER SPARROWS IN RELATION TO EDGE ▪ J. M Delisle, and J. A. Savidge

OBSERVATIONS ON BATS AT BADLANDS NATIONAL PARK, SOUTH DAKOTA ▪ M A. Bogan, J. G. Osborne, and J. A. Clarke

DIETS OF FEMALE WHITE-TAILED DEER IN THE CROSS-TIMBERS REGION ▪ F. C. Bryant, G. Van Vreede, T. J. Deliberto, and K. L. Gee

NOTES

Second Record of White Ibis in North Dakota ▪ J. W. Marlow, L. D. Igl, and M. R. Hartman

A Recent Record of Mountain Lion in Nebraska ▪ H. H. Genoways and P. W. Freeman

Prairie Falcon Predation on …