Digital Commons Network^™

Arabidopsis Glabrous1 Gene Requires Downstream Sequences For Function, John C. Larkin, David G. Oppenheimer, Susan Pollock, M. David Marks

School of Biological Sciences: Faculty Publications

The Arabidopsis GLABROUSl (GL1) gene is a myb gene homolog required for the initiation of trichome development. In situ hybridiration revealed that the highest levels of GL1 transcripts were present in developing trichomes. In contrast, previous work had shown that putative promoter sequences from the 5‘ noncoding region of the GL1 gene directed the expression of a β-glucuronidase (GUS) reporter gene only in stipules. Deletion analysis of the 3’ noncoding region of GL1 has identified an enhancer that is essential for GL1 function. Sequences fmm the region containing the enhancer, in conjunction with GL1 upstream sequences, direct the expression of …

Meristic And Organogenetic Variation In Ruppia Occidentalis And R. Maritima, Robert B. Kaul

School of Biological Sciences: Faculty Publications

Floral meristic and organogenetic variation was sampled in Ruppia occidentalis from an alkaline lake of the Nebraska Sandhills and in Ruppia maritima var. rostrata from a saline, non-Sandhills lake nearby. The androecium is meristically stable, always having two stamens, but the gynoecium is not. Seventy-two percent of the flowers of R. maritima had four carpels and the others had three, and in 80% of inflorescences the two flowers had the same number. In about one-third of inflorescences having dissimilar carpel numbers, the four-carpellate flower was uppermost. The number of carpels in each flower of R. occidentalis ranged from four to …

Molecular Approaches For Control Of Tomato Bushy Stunt Virus, H. B. Scholthof, M. Borja, Thomas Jack Morris, A. O. Jackson

School of Biological Sciences: Faculty Publications

I N this overview strategies are discussed that are currently being tested in our laboratory in an effort to engineer resistance against tomato bushy stunt virus (TBSV) in plants. TBSV is chosen as a model-system since this is an economically important RNA virus that is well characterized at the molecular level and the virus has some interesting and potentially useful features that can be exploited to produce resistant plants. Moreover, we anticipate that the information derived from our studies with TBSV will be applicable in developing resistance to other plant viruses. Some approaches that we are attempting to apply to …

Morfología Y Moléculas: Bases Complementarias De La Sistemática Moderna, Rafael O. De Sá, David M. Hillis

Biology Faculty Publications

RESUMEN

El auge de las técnicas moleculares en las últimas dos décadas ha traído nuevos enfoques en los estudios sistemáticos. Aquí presentaremos una revisión del uso, las aplicaciones, y los problemas de las principales metodologías de trabajo. Cada una de estas técnicas es aplicable a algunos problemas e inapropiada para otros, y es importante entender las suposiciones y limitaciones de cada técnica. Concluimos que el uso combinado de los enfoques morfológicos y moleculares otorga mejor resolución a los problemas sistemáticos.

ABSTRACT

The development of molecular techniques during the last two decades has brought new approaches to the analysis of systematic …

Leaf Anatomy, Chloroplast Organization And Photosynthetic Rate Of Hyperhydric Eucalyptus Saligna Sm. Material, Philippa M. Drennan

Biology Faculty Works

No abstract provided.

" Further Remarks On The Identification Of Sudanonautes Orthostylis With Comparisons With Other Species From Nigeria And Cameroon" , Neil Cumberlidge

Journal Articles

No abstract provided.

" Two New Species Of Potamonemus Cumberlidge And Clark From The Rain Forests Of West Africa" , Neil Cumberlidge

Journal Articles

No abstract provided.

"Redescription Of Sudanonautes Granulatus From West Africa" , Neil Cumberlidge

Journal Articles

No abstract provided.

Effects Of Perinatal Cocaine Exposure On Sexual Differentiation In The Rat Brain, Heather L. Maecker

Master's Theses

No abstract provided.

A Study Of Science Teacher Perceptions And The Implementation Of Science-Technology-Society Education In Iowa Senior High Schools, David L. Johnson

Dissertations and Theses @ UNI

The purpose of this study was to determine the extent to which Science-Technology Society (STS) education has been implemented into the science curriculum and if teachers perceptions and personal assessment of STS education in Iowa senior high schools vary with the teacher's STS background or educational degree. Consisting of 190 senior high school science teachers (grades 9-12) in forty-nine schools distributed throughout the state of Iowa, the sample was obtained by a systematic, stratified sampling of school districts by enrollment size and Area Education Agency districts. Teachers were asked to complete questionnaires designed to collect data concerning: STS background, level …

The Genus Urochloa (Poaceae: Paniceae) In Texas, Including One Previously Unreported Species For The State, J. K. Wipff, Robert I. Lonard, Stanley D. Jones, Stephan L. Hatch

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Urochloa is represented in Texas by three species, U. mosambicensis, U. panicoides, and U. reptans. Urochloa mosambicensis is being reported new for Texas. Urochloa panicoides has recently been reported in the state and is listed in the Federal Noxious Weed Act. Urochloa reptans has been recognized in Texas and the U. S. as Panicum reptans or, more recently, Brachiaria reptans. A key to distinguish related genera, a key to the species of Urochloa in Texas, species descriptions, and their distribution in Texas are provided.

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Urochloa está representada en Texas por tres especies, U. mosambicensis, U. panicoides y U. reptans. …

Biology Of The Palo Alto Battlefield Site: A Summary, Norman L. Richard, Alfred Richardson

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

No abstract provided.

Where Environmental Law And Biology Meet: Of Pandas' Thumbs, Statutory Sleepers, And Effective Law, William H. Rodgers, Jr.

Articles

The purpose of this article is to introduce some of the recent findings of evolutionary biology to the legal community and to urge their consideration in developing a more effective law. As background, Part II of this article will present a brief evolutionary history of our own species.

Part III offers a primer on Darwin's theory of natural selection and the concept of adaptation, with special attention to the elaboration of altruism as it is known in modern biology. Part IV discusses maladaptation as a counterpoise to adaptation and underscores the notion with some stories from natural history on subjects …

The Nfiii/Oct-1 Binding Site Stimulates Adenovirus Dna Replication In Vivo And Is Functionally Redundant With Adjacent Sequences, Lianna K. Etchberger, P. Hearing

Biology Faculty Publications

The inverted terminal repeat (ITR) of adenovirus type 5 (Ad5) is 103 bp in length and contains the origin of DNA replication. Cellular transcription factors NFI/CTF and NFIII/OCT-1 bind to sites within the ITR and participate in the initiation of viral DNA replication in vitro. The ITR also contains multiple copies of two conserved sequence motifs that bind the cellular transcription factors SP1 and ATF. We have analyzed a series of viruses that carry deletions at the left terminus of Ad5. A virus carrying a deletion of the NFIII/OCT-1, SP1, and ATF sites within the ITR (mutant dl309-44/107) was wild …

Connexin Expression During Heart Development In The Chick Embryo, Lisa Jo Jensen

Dissertations and Theses @ UNI

Gap junctions are thought to be important during development because they interconnect cells for communication via signaling molecules. In the developmental process, the heart is coupled via gap junctions. The heart has many migratory, proliferative, and differentiation events in which gap junctions may serve a central role in development. The goal of this study was to measure the connexin levels throughout selected stages of cardiac development and to ascertain the normal connexin levels to use as comparisons in experimental systems such as microgravity. This study measured the amount of connexin protein in the embryonic heart at 1.5-, 2-, 3-, 4-, …

Calcospherites In Rabbit Incisor Predentin, H. Mishima, Y. Kunuki, T. Sakae, Y. Kozawa, N. Watabe

Scanning Microscopy

Calcospherites from the lower incisor dentin of rabbits were investigated by scanning and transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and electron diffraction analyses. In the labial predentin, globular calcospherites of 8-31 μm were present at the root apex, decreasing in size toward the incisal region. The calcospherites at the intermediate region were of mulberry- as well as of spindle-shape of 1.5-4 μm diameter. The incisal pulp horn contained micro-calcospherites of 0.3-0.6 μmin diameter. In the lingual predentin, small granular calcospherites of 1. 8-3 μm were present at the root apex, increasing in size toward the intermediate region. Ultrathin …

Ultra-High Resolution Scanning Electron Microscopic Studies On The Sarcoplasmic Reticulum And Mitochondria In Various Muscles: A Review, Takuro Ogata, Yuichi Yamasaki

Scanning Microscopy

The three-dimensional structure of the sarcoplasmic reticulum (SR), transverse (T)-axial tubular system and mitochondria in various muscles was examined by means of ultra-high resolution scanning electron microscopy (SEM) after removal of the cytoplasmic matrices and myofilaments by the aldehyde-osmium-DMSO-osmium procedure. The striated muscles reviewed and presented are twitch and slow fibers of the frog, twitch and slow fibers of the chicken, twitch extrafusal fibers and intrafusal fibers of the rat, and cardiac muscle fibers of the rat and dog. In all of these striated muscle fibers, T-tubules run transversely and are coupled with terminal cisternae forming triads or dyads. Sarcotubules …

Influence Of Annealing On The Interface Structure And Strain Relief In Si/Ge Heterostructures On (100) Si, D. J. Lockwood, J. -M. Baribeau, T. E. Jackman, P. Aebi, T. Tyliszczak, A. P. Hitchcock, R. L. Headrick

Scanning Microscopy

Research work on the general problem of the nature and thermal stability of the Si/Ge semiconductor interface is reviewed. We report on our recent studies of the interface structure in [(Si)_m(Ge)_n]_p superlattices and (Ge)_n layers buried in Si as revealed by Raman scattering, extended X-ray absorption fine structure, and X-ray techniques. Strain relaxation and interdiffusion in the superlattices caused by annealing have been investigated, and it is found that considerable strain-enhanced intermixing together with partial relaxation of Ge-Ge bonds occurs even for very short anneal times at 700°C. Further annealing leads to diffusion at …

Strain Distribution During Growth Of Ge/Si(001) And The Effect Of Surfactant Layers, J. E. Macdonald, J. M. C. Thornton, A. A. Williams, P. Ashu, C. C. Matthai, H. A. Van Der Vegt, E. Vlieg

Scanning Microscopy

Grazing incidence X-ray diffraction has been employed to determine directly the distribution of strain in the plane of the interface during deposition of Ge onto Si(001). The corresponding strain distribution has also been deduced for a relaxed island whose atomic structure has been determined by molecular dynamics. The results illustrate the central role of elastic deformation of islands in the initial stage of strain relief. The results are also compared with those for growth with a Sb surfactant layer which suppresses island formation. An investigation of surfactant-like behaviour is also presented for homoepitaxial growth of Ag on Ag(111), where sub-monolayer …

Present Developments In Image Analysis, Peter Smart, Xiaoling Leng

Scanning Microscopy

The paper discusses novel methods of analysing oriented textures, explains some of the problems which had to be overcome to make these methods work, and indicates where future developments might be expected. This has required improvements in the methods of intensity gradient analysis, the development of large filter methods for mapping features defined in terms of their texture, and the introduction of ideas from the theory of regionalised variables.

Electron Beam Lithography For Large Area Patterning 3: Data Conversion And Electron Beam Deflection Control, Susumu Hoshinouchi, Hiroaki Tobuse, Hidenobu Murakami, Ryuichi Shimizu

Scanning Microscopy

Electron beam direct writing technologies, specifically for the large area patterning of electronic devices such as printed wiring boards, are studied in this paper. The vector scanning method with two kinds of beam deflection, main-deflection and sub-deflection, has been adopted for the fabrication of circuit patterns of various line widths. The sub-deflection of high frequency oscillation is superimposed on the main-deflection, which allows for controlling each line width with ease. A data conversion and a deflection control system with several strategies have been developed to reduce the conversion time and the volume of output data. It is revealed that circuit …

Electron Beam Lithography For Large Area Patterning 4: Exposure Of Resist On Internal Surface Of A Through-Hole, Susumu Hoshinouchi, Akio Yoshida, Hidenobu Murakami

Scanning Microscopy

Electron beam direct writing technologies, specifically for the large area patterning of electronic devices such as printed wiring boards, are studied in this paper. The exposure characteristics of the resist on the internal surface of a through-hole are examined. A thick film resist which is composed mainly of unsaturated acrylic resins is prepared on the internal surface of the hole by an electrodeposition process.

It is proven that a 20 μm thick resist on the internal surface can be exposed efficiently by a 60 keV electron beam. This phenomenon becomes even stronger by placing a gold plated metal plate on …

A Scanning Electron Microscopic Study Of The Chick Chorioallantoic Membrane: Cell Death And The Involvement Of Oxygen Free Radicals, A. Easterling, G. J. Burton, J. N. Skepper, M. H. Nasr-Esfahani

Scanning Microscopy

Cell death is a normal feature within the chick chorioallantoic membrane, occurring principally between days 10 and 14 of incubation.

Samples of chorioallantoic membrane were obtained on days 6, 8, 10, 12 and 14 of incubation, after the creation of artificial air chambers on day 3. These were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) after staining for acid phosphatase activity, and by light microscopy after demonstrating oxygen free radicals with nitro blue tetrazolium. On day 6, small defects in the plasmalemma, approximately 200 nm in diameter, could be seen by SEM. A sequence of events leading …

Denitrification And Oxygen Consumption In Sediments Of Two South Texas Estuaries, Won Bae Yoon, Ronald Benner

Faculty Publications

Spatial and temporal variations in rates of denitrification and oxygen consumption were measured in sediments of the Nueces and Guadalupe Estuaries in southern Texas, USA. Denitrification rates varied from 4.0 to 71.1 µmol N₂ m^-2 h^-1 in the Nueces Estuary and from 4.6 to 34.7 µmol N₂ m^-2 h^-1 in the Guadalupe Estuary. Denitrification accounted for 29 to 80% of total benthic N flux in the study areas. Oxygen consumption rates ranged from 176 to 818 µmol O₂ m^-2 h^-1 in Nueces Estuary and from 208 to 550 µmol O_{2 …}

X-Ray Microanalysis Of Epithelial And Secretory Cells In Culture, Anne Von Euler, Eva Pålsgård, Christina Vult Von Steyern, Godfried M. Roomans

Scanning Microscopy

Cell cultures can be used to study ion transport processes. X-ray microanalysis of cell cultures at the cellular level gives interesting information that can complement electrophysiological and tracer studies. In this paper, methods for culturing and preparing a variety of epithelial and secretory cells (fibroblasts, insulinoma cells, bovine mammary epithelial cells, colon cancer cells) for X-ray microanalysis are presented. Results show that sometimes cell cultures are not homogeneous with respect to ion content or reaction to physiological stimuli. In colon cancer cell cultures, a "high K" and a "low K" cell subpopulation was found; these subpopulations also differed with respect …

Ultrastructural Features Of Human Reissner's Membrane, Anne De Fraissinette, Heidi Felix, Jannie Nievergelt, Michael Gleeson

Scanning Microscopy

Ultrastructural features of human Reissner' s membrane were investigated in two groups of similarly aged patients. Five patients had age-related normal hearing (ARNH) and four patients had acquired sensorineural hearing loss (SNHL) from causes other than age. The membrane consisted of a mesothelium facing the perilymph and an epithelium facing the endolymph. The two cell layers were separated by a basement membrane. The mesothelium was formed by wide spread thin cells with a smooth surface. The epithelial cells assumed two different shapes, flat and rounded. Both epithelial cell types were covered with many short microvilli. In all specimens, the rounded …

Recent Advances In Measurement Of Oxalate In Biological Materials, S. Sharma, R. Nath, S. K. Thind

Scanning Microscopy

Hyperoxaluria is the predominant risk factor in urinary stone disease. A specific, accurate and reliable oxalate assay for urine and plasma is very important for both the diagnosis and efficient management of patients. A review of the advantages and disadvantages of various methods of oxalate determination is presented and is followed by the authors' recommendations.

Microvascular Architecture Of The Filiform Papillae In Primates And Insectivores, S. Okada, Y. Ohta, N. Matsukawa, S. Sugioka

Scanning Microscopy

The microvascular architecture of filiform papillae was investigated under a scanning electron microscope in man, Japanese monkeys, common squirrel monkeys, common marmosets, common tree shrews, large Japanese moles and dwarf shrews utilizing microvascular corrosion casts. Filiform papillae were circularly arranged in primates, and each of them was supplied by a hairpin capillary loop. These papillae sometimes were aggregated. The filiform papillae of Japanese monkeys exhibited markedly locational differences on the lingual dorsum and were supplied by circularly arranged capillary loops or by an intrapapillary capillary network. Small filiform papillae were located on an epithelial eminence in the lingual radix, each …

High-Resolution Scanning Electron Microscopy Of Rat Incisor Ameloblasts, A. Nanci, S. Zalzal, F. W. K. Kan

Scanning Microscopy

The internal three-dimensional organization of secretory and maturation stage ameloblasts was examined using field emission scanning electron microscopy. Particular attention was given to the structure of the Golgi apparatus, the distribution of smooth membrane tubulo-vesicular elements and their relationship with endosomal/lysosomal components. Rat incisors were fixed by intracardiac perfusion with glutaraldehyde, decalcified and divided into segments. The tissues were cryoprotected with glycerol and freeze-fractured. They were then macerated in osmium, and after conductive staining with osmium/tannic acid, the samples were critical-point dried and sputtered with gold. High-resolution scanning electron microscopy showed that ameloblasts contain a well-developed Golgi apparatus, even in …

Distribution Of Connectin (Titin) And Transverse Tubules At Myotendinous Junctions, Y. Shimada, F. Atsuta, M. Sonoda, M. Shiozaki, K. Maruyama

Scanning Microscopy

The ends of muscle fibers form many longitudinal projections which are further divided into numerous processes and attach to the collagen fibrils of tendons to form myotendinous junctions (MTJs). Immunocytochemical and electron microscopic observations on pectoralis muscles of the chicken revealed the presence of an elastic filamentous protein, connectin (titin), within the terminal sarcomere on the side adjacent to the terminal Z bands, and the absence of connectin and myosin and the presence of actin at the apical sarcoplasmic region of MTJ processes between the terminal Z band and the MTJ sarcolemma. Intermediate voltage electron microscopy showed that T tubules …