Donald Farrar - Academia.edu (original) (raw)

Papers by Donald Farrar

American Journal of Botany, Nov 1, 2017

The Journal of the Iowa Academy of Science: JIAS, 1993

Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences, 1985

SynopsisPerennial indendent gametophytes of Hymenophyllaceae, Vittariaceae and Grammitidaceae are... more SynopsisPerennial indendent gametophytes of Hymenophyllaceae, Vittariaceae and Grammitidaceae are a well-known phenomenon in the eastern United States. Their persistence is attributed to the ability of gametophytes of these fern families to reproduce themselves vegetatively via gemmae. This paper reviews the biology of independent gametophytes of these families as they exist in the eastern United States and presents new evidence from enzyme electrophoresis regarding their identity and origin.

Premise of the Research. Vascular plants depend on sexual recombination for generating new geneti... more Premise of the Research. Vascular plants depend on sexual recombination for generating new genetic variability to meet environmental needs. Nevertheless, members of the early-divergent fern genus Botrychium (Ophioglossaceae) typically maintain gametophytic selfing and show strong inbreeding within populations. To explain this evolutionary anomaly, the existence of previous or current but undiscovered outcrossing, genetically rich, precursors of the existing genetically depauperate taxa has been hypothesized. Methodology. Using allele expression at thirteen independently assorting enzyme loci, we compared allelic diversity and levels of heterozygosity in 471 Botrychium lunaria individuals across sixteen populations in the Alps and Jura Mountains of Switzerland. We examined habitat characteristics influencing mating systems and investigated population genetic structure based on a discriminant analysis of principal components and a graph-theoretic framework. We tested the pattern of is...

non-coding chloroplast locus matK intro

non-coding chloroplast locus trnH–psbA intergenic space

non-coding chloroplast locus rpL16 intro

Canadian journal of botany, Nov 1, 1998

Gametophyte morphology, behavior, and growth habit of Elaphoglossum alatum Gaud., Elaphoglossum c... more Gametophyte morphology, behavior, and growth habit of Elaphoglossum alatum Gaud., Elaphoglossum callifolium (Bl.) Moore, Elaphoglossum crassifolium (Gaud.) Anderson & Crosby, Elaphoglossum marginatum (Wall ex Fee) Moore, and Elaphoglossum yoshinage (Yatabe) Makino were observed on artificial agar medium. The morphology of these gametophytes are very different from those of Bolbitis, a genus of Lomariopsidaecae thought to have a close relationship with Elaphoglossum. The growth habit of Elaphoglossum gametophytes, like many other epiphytic species, is perennial and clone forming. Isozyme analysis of naturally occurring sporophytes of E. alatum, E. crassifolium, and Elaphoglossum paleaceum (Hook. & Grev.) Sledge suggest that sporophytes of E. alatum and E. crassifolium are diploid and derived from highly outbreeding populations. Fixed heterozygosity in E. paleaceum suggests that sporophytes of this species are polyploid, but at least some outcrossing occurs. High genetic loads determined from single gametophyte cultures of E. callifolium and E. crassifolium indicate low probabilities of successful intragametophytic selfing. Several tests indicate, however, that these species neither produce nor respond to antheridiogens. Therefore, intergametophytic mating in these species is likely maintained by genetic load. This mating behavior is promoted by a perennial and clone-forming growth habit which may function to prolong the life-span and to enlarge the space occupied by individual gametophytes.Key words: Elaphoglossum, fern gametophyte, reproductive biology, breeding system.

American Journal of Botany, 1997

$Research paper thumbnail of Forest Research in Iowa\u27s State Parks - The Values of Natural Diversity$

Approximately 3% of Iowa\u27s forests are contained in state parks and preserves. In addition to ... more Approximately 3% of Iowa\u27s forests are contained in state parks and preserves. In addition to aesthetics and recreation, these protected forests provide a vital service in the unique opportunities they provide for forest research. As intact ecosystems where natural ecological processes dominate, they provide standards by which we measure the effects of livestock pasturing, methods of timber harvest, and other manipulations of managed forests. A number of current studies and public programs emphasize the importance of natural diversity in forests. They rely on state parks and preserves to provide a measure of potential diversity for a given region of the state. Future generations of Iowans will inherit the many benefits of naturally diverse old-growth forests, provided we safeguard the forests in our state parks and preserves that we have inherited

Proceedings of the Indiana Academy of Science, 1986

When Deam's Flora of Indiana (4) was first published in 1940, it included 57 species of pteridoph... more When Deam's Flora of Indiana (4) was first published in 1940, it included 57 species of pteridophytes in 24 genera. Ten years later, Clevenger (2) reported 61 total species, still in 24 genera. Today a taxonomically conservative count would yield ca. 73 species in 26 genera. Two self-evident reasons account for the increased number of pteridophytes '

Abstract : Camouflage is a broad concept incorporating the notions of hiding, blending, disguisin... more Abstract : Camouflage is a broad concept incorporating the notions of hiding, blending, disguising, or decoying to achieve countersurveillance (CS) and counter target acquisition (CTA). Both concealment and deception are involved. The purpose of camouflage is by passive means to deny, degrade, deceive, delay or otherwise interfere with hostile surveillance of friendly forces. The systems devised to accomplish these purposes are supportive rather than primary in their combat roles. Their contribution to accomplishing the combat mission is indirect, such as enhancing survival of primary firepower, enabling movement with reduced materiel losses, and reducing casualties. Camouflage measures of effectiveness (MOE) thus must measure both the direct performance of CS/CTA systems, in terms of reduced target detection/recognition/identification, and the indirect or consequential performance effects, in terms of increased survival and reduced materiel/personnel losses.

Naval Research Logistics Quarterly, 1963

The Journal of Business, 1963

The Review of Economics and Statistics, 1967

The Journal of Finance, 1962

THIS THESIS IS designed primarily to test the usefulness of a formal theoretical model in explain... more THIS THESIS IS designed primarily to test the usefulness of a formal theoretical model in explaining the investment decision under uncertainty. It is largely empirical and is analytical rather than normative in character. The model.-Conceptually, the present approach may be classified under any (or all) of three common headings: expected utility maximization, certainty equivalence, or mathematical programing. Formally, the model requires the maximization of a quadratic objective function, y iIAiA 2;2i ijyj

The Journal of Finance, 1981

BERLE AND MEANS'landmark study [1], published in 1932, attracted a great deal of attenti... more BERLE AND MEANS'landmark study [1], published in 1932, attracted a great deal of attention. The attention in part reflected historical aversion in the US to concentrations in private hands of either economic or financial power. During the 1930's interest in the ...