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Impact Of Climate Variations On Soybean Yield In Eastern Arkansas: 1960-2014, J. W. Magugu, S. Feng, Q. Huang, K. Luthra Jan 2016

Impact Of Climate Variations On Soybean Yield In Eastern Arkansas: 1960-2014, J. W. Magugu, S. Feng, Q. Huang, K. Luthra

Journal of the Arkansas Academy of Science

Climate is the major factor affecting crop production; therefore, various agro-meteorological indicators have been frequently used to evaluate the impact of climate on crop production. In this study, we examined the temporal variations of agrometeorological indicators (growing degree days, total precipitation, dry spells and drought indices) during 1960-2014 and their impact on soybean yields in East Arkansas. Results show an increasing trend in growing degree days (GDDs) and dry spells, though the total precipitation during the soybean growing season remained nearly unchanged during the study period. Generally, GDDs and dry spells show a strong correlation with yields. We also evaluated ...


Synthesis, Characterization, And Properties Of Mononuclear And Dinuclear Ruthenium(Ii) Complexes Containing Phenanthroline And Chlorophenanthroline, Anwar A. Bhuiyan, X. Du Jan 2013

Synthesis, Characterization, And Properties Of Mononuclear And Dinuclear Ruthenium(Ii) Complexes Containing Phenanthroline And Chlorophenanthroline, Anwar A. Bhuiyan, X. Du

Journal of the Arkansas Academy of Science

The study of photophysical and photochemical properties of ruthenium complexes is of great interest for fundamental practical reasons. Ruthenium complexes have been investigated for use in artificial photosynthesis. This paper deals with the synthesis and spectroscopic investigation of custom-designed ruthenium complexes containing phenanthroline and chloro-phenanthroline ligands. These complexes maybe useful for biological electron-transfer studies. The heteroleptic ruthenium monomer complex Ru(phen)2(Cl-phen) (where phen = 1,10-phenanthroline and Cl-phen=5-chloro-1,10-phenanthroline) was prepared in a two-step procedure previously developed in our laboratory. This monomer complex was used to prepare the ruthenium homometallic dimer complex, (phen)2Ru(phen-phen)Ru(phen)2 ...


Understanding Floristic Diversity Though A Database Of Greene County Specimens, K. M. Harris, M. B. Foard, T. D. Marsico Jan 2012

Understanding Floristic Diversity Though A Database Of Greene County Specimens, K. M. Harris, M. B. Foard, T. D. Marsico

Journal of the Arkansas Academy of Science

We present a floristic list of Greene County, Arkansas, based on accessioned collections from the Arkansas State University Herbarium (STAR). Currently, there are 1569 specimens representing 540 taxa from Greene County in STAR. Using the USDA Plants Database, plant species were analyzed according to whether or not they are native to the state as well as whether or not they have been previously documented as species occurring in the county. Having analyzed all the Greene County collections from STAR, we found 225 previously undocumented species. The data suggest that most of the specimens in the STAR collection were found in ...


Comparative Leaf Decomposition Rates Including A Non-Native Species In An Urban Ozark Stream, Sarah E. Lewis, Arthur V. Brown Jan 2010

Comparative Leaf Decomposition Rates Including A Non-Native Species In An Urban Ozark Stream, Sarah E. Lewis, Arthur V. Brown

Journal of the Arkansas Academy of Science

Leaf decomposition of three species of native Ozark vegetation was compared to that of one nonnative invasive species. Leaves were placed in an urban gravel-bed stream for 23 days. Changes in mass and condition of the leaves were assessed along with stream temperature, flow, width, depth and discharge. Species native to Eastern North American forests were sycamore (Platanus occidentalis), dogwood (Cornus florida), and redbud (Cercis canadensis). The nonnative species, Japanese (Amur) honeysuckle (Lonicera maackii) comprised approximately 80% of the understory vegetation within the riparian zone of the study reach. After 23 days, Sycamore lost 24.6% mass, dogwood lost 30 ...


Algae In Agricultural Fields From St. Francis County, Arkansas, T. Smith Jan 2008

Algae In Agricultural Fields From St. Francis County, Arkansas, T. Smith

Journal of the Arkansas Academy of Science

On August 9th, 2007, two agriculture fields (rice and sorghum fields) were sampled for freshwater algae in St. Francis County. The purpose of this study was to document the algal species in the rice and sorghum fields and compare the similarities of species composition. There were a total of 53 species identified. Overall, diatoms and cyanobacteria were equally dominant with both represented by 21 species (39.6% of the total) and 11 green algal species (20.8%) were present. The sorghum field was dominated by Chlorogloeopsis fritschii and Chroococcus limneticus, while Anabeana cylindrica was abundant in the rice field.


Characterization Of Bacteriophages Of Pseudomonas Syringae Pv. Tomato, Sara E. Prior, Amanda J. Andrews, Russell O. Nordeen Jan 2007

Characterization Of Bacteriophages Of Pseudomonas Syringae Pv. Tomato, Sara E. Prior, Amanda J. Andrews, Russell O. Nordeen

Journal of the Arkansas Academy of Science

Bacteriophages from supernatants of the plant pathogenic bacteria Pseudomonas syringae pv. tomato (P. tomato) were isolated, enriched, and purified by density block centrifugation in cesium chloride (CsCl) step gradients. The DNA from purified phage was isolated and digested with the restriction endonucleases EcoRl or HindIII. Three different DNA fingerprint patterns were determined indicating 3 unique phage isolates. Genome sizes of the phage ranged from 40 to 52 kilobases (kB). Buoyant densities of phage particles in CsCI varied from 1.36 to 1.51 glml. Electron microscopy revealed a single morphological type with an elongated polyhedral head and a long tail ...


Tungoil Tree (Aleurites Fordii Hemsl.) (Euphorbiaceae): New To The Arkansas Flora, Brett Serviss, Nicole Freeman, Joslyn Hernandez, Allen Leible, Chris Talley Jan 2007

Tungoil Tree (Aleurites Fordii Hemsl.) (Euphorbiaceae): New To The Arkansas Flora, Brett Serviss, Nicole Freeman, Joslyn Hernandez, Allen Leible, Chris Talley

Journal of the Arkansas Academy of Science

No abstract provided.


Negundo Chaste Tree (Vitex Negundo L.) (Verbenaceae): New To The Arkansas Flora, Brett Serviss, Nicole Freeman, Joslyn Hernandez, Allen Leible, Chris Talley, Brent Baker Jan 2007

Negundo Chaste Tree (Vitex Negundo L.) (Verbenaceae): New To The Arkansas Flora, Brett Serviss, Nicole Freeman, Joslyn Hernandez, Allen Leible, Chris Talley, Brent Baker

Journal of the Arkansas Academy of Science

No abstract provided.


Discovery Of A Second Record Of Seaside Heliotrope (Heliotropilum Curassavicum L.) (Boraginaceae) In Arkansas, C. Renn Tumlison, Brett Serviss Jan 2007

Discovery Of A Second Record Of Seaside Heliotrope (Heliotropilum Curassavicum L.) (Boraginaceae) In Arkansas, C. Renn Tumlison, Brett Serviss

Journal of the Arkansas Academy of Science

No abstract provided.


Vascular Plant Species Inventory Of Richardson Bottoms Wildlife Viewing Area, Travis D. Marsico Jan 2004

Vascular Plant Species Inventory Of Richardson Bottoms Wildlife Viewing Area, Travis D. Marsico

Journal of the Arkansas Academy of Science

No abstract provided.


Fire Effects On Three Trophic Levels In A Central Arkansas Grassland, Laura Skelton, Amy Polk, Brenna C. Fitzgerald, Matthew D. Moran Jan 2002

Fire Effects On Three Trophic Levels In A Central Arkansas Grassland, Laura Skelton, Amy Polk, Brenna C. Fitzgerald, Matthew D. Moran

Journal of the Arkansas Academy of Science

We studied the effect of a late growing-season fire on the plant and foliar arthropod communities in a naturally occurring grassland. In central Arkansas, these grasslands are common on south-facing slopes where shallow soils and hot/dry weather conditions during the summer cannot support the growth of a forest community. Patches of grassland were burned in the autumn (4 November, late growing season), often the time of natural fires in Arkansas, and compared to unburned areas. Fire increased the biomass of forbs and decreased the biomass of grasses, although overall biomass was not different between treatments. Among the foliar arthropods ...


Plantain Sunflower (Helianthus Occidentalis Subsp. Plantagineus) In Arkansas, Daniel L. Marsh, Timothy A. Golden Jan 1996

Plantain Sunflower (Helianthus Occidentalis Subsp. Plantagineus) In Arkansas, Daniel L. Marsh, Timothy A. Golden

Journal of the Arkansas Academy of Science

No abstract provided.


Vegetation Of Maple-Leaved Oak Sites On Sugarloaf And Magazine Mountains, Arkansas, David W. Rouw, George P. Johnson Jan 1994

Vegetation Of Maple-Leaved Oak Sites On Sugarloaf And Magazine Mountains, Arkansas, David W. Rouw, George P. Johnson

Journal of the Arkansas Academy of Science

We conducted an analysis of the vegetation of the maple-leaved oak sites on Sugarloaf and Magazine Mountains, Arkansas, during September and October of 1993. The woody vegetation was sampled using the point-quarter method; on Sugarloaf Mountain five transects were sampled (950 m) and on Magazine Mountain four transects were sampled (710 m). Soil samples from each site were collected and analyzed for 15 factors. In total 27 species were recorded and measured for both sites, 18 for Sugarloaf and 19 for Magazine. The Sugarloaf site can be described as a Quercus-Juniperus community and the Magazine site can be described as ...


Sex Ratio And Success, An Assessment Of Lindera Melissifolia In Arkansas, Robert D. Wright Jan 1994

Sex Ratio And Success, An Assessment Of Lindera Melissifolia In Arkansas, Robert D. Wright

Journal of the Arkansas Academy of Science

Lindera melissifolia pondberry, is a federally endangered dioecious shrub found in Arkansas and four other southeastern states. Although by far the greatest area exists in Arkansas, it is broken into numerous small single-sex clones concentrated in two locations. Several stands have been lost during the 1980's according to records of the Arkansas Natural Heritage Commission. Even casual observation reveals that there are more males than females. This suggests dependence on vegetative reproduction, with possible bias against females. This paper reports on work investigating this suggestion. It was found that a 7:1 bias in area covered favors males. Poor ...


Bryophyte And Pteridophyte Distribution Records Of Southern Arkansas, James R. Bray, Greg A. Whitehead, Daniel L. Marsh, Dennis W. Mcmasters Jan 1994

Bryophyte And Pteridophyte Distribution Records Of Southern Arkansas, James R. Bray, Greg A. Whitehead, Daniel L. Marsh, Dennis W. Mcmasters

Journal of the Arkansas Academy of Science

No abstract provided.


First Record Of Leptodora Kindti In Dardanelle Reservoir And Status Of Other Recent Additions To Dardanelle Fauna, John D. Rickett, Robert L. Watson Jan 1994

First Record Of Leptodora Kindti In Dardanelle Reservoir And Status Of Other Recent Additions To Dardanelle Fauna, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

No abstract provided.


Stress Induced Protein Changes In Tall Fescue, R. L.G. Long, Lance T. Adams, J. D. Corely, Alvan A. Karlin, B. L. Parsons, Maurice G. Kleve, J. Henle Jan 1993

Stress Induced Protein Changes In Tall Fescue, R. L.G. Long, Lance T. Adams, J. D. Corely, Alvan A. Karlin, B. L. Parsons, Maurice G. Kleve, J. Henle

Journal of the Arkansas Academy of Science

Tall fescue (Festuca arundinacea Schreb.), the most important pasture grass in Arkansas, exhibits different agricultural properties when it is infected by its mutualistic endophyte Acremonium coenophialum Morgan-Jones and Gams. We postulate that the presence of endophyte exerts a stress on the host that enhances or detracts from the host's ability to express specific genes. We tested this hypothesis by heat stressing infected and non-infected, juvenile and mature tall fescue, and examining their protein profiles by SDS-PAGE analysis. The results indicate that mature, infected, stressed grass produced greater amounts of Rubisco (ribulose bisphosphate carboxylase-oxygenase) than all other treatments. Additionally, the ...


Effect Of Light, Nitrogen, And Water Management On Rice (Oryza Sativa) Tolerance To Fenoxaprop, Roy J. Smith Jr., Aurora M. Baltazar, Paolo Nastasi Jan 1993

Effect Of Light, Nitrogen, And Water Management On Rice (Oryza Sativa) Tolerance To Fenoxaprop, Roy J. Smith Jr., Aurora M. Baltazar, Paolo Nastasi

Journal of the Arkansas Academy of Science

The effect of light intensity, nitrogen (N), and water management on rice (Oryza sativa cv. 'Newbonnet' and 'Lemont') tolerance to fenoxaprop {(+)-2-[4[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic acid} was determined in two field studies at the Rice Research and Extension Center, Stuttgart, AR, in 1988 and 1989. In one study, 'Newbonnet' rice was treated with 0.22 kgai ha-1fenoxaprop at 0, 1, 3, 5, 7, 10, 14, and 28 days after N application and flooding. Moderate to severe foliar chlorosis, stunting, and stand and yield reductions occurred when fenoxaprop was applied within 7 days after N application and flooding. None ...


Additional Occurrences Of The Bog Clubmosses In Southern Arkansas, James R. Bray, Daniel L. Marsh Jan 1993

Additional Occurrences Of The Bog Clubmosses In Southern Arkansas, James R. Bray, Daniel L. Marsh

Journal of the Arkansas Academy of Science

No abstract provided.


Occurrence Of The Hybrid Honey Locust (Gleditsia X Texana Sarg.) In Southwest Arkansas, Brian A. Smith, Daniel L. Marsh Jan 1993

Occurrence Of The Hybrid Honey Locust (Gleditsia X Texana Sarg.) In Southwest Arkansas, Brian A. Smith, Daniel L. Marsh

Journal of the Arkansas Academy of Science

No abstract provided.


Measuring Shrubland Vegetational Structure Using Avian Habitats As An Example, Douglas A. James Jan 1992

Measuring Shrubland Vegetational Structure Using Avian Habitats As An Example, Douglas A. James

Journal of the Arkansas Academy of Science

Vegetational sampling of avian habitats stresses the use of methods primarily designed for forest birds. This paper describes a technique for sampling vegetational structure in uneven patchy habitats such as shrublands. Using the method, avian habitats in old field shrublands of northwestern Arkansas were analyzed.


Synopsis Of The Genus Tropisternus (Coleoptera Hydrophilidae) In Arkansas, George L. Harp Jan 1992

Synopsis Of The Genus Tropisternus (Coleoptera Hydrophilidae) In Arkansas, George L. Harp

Journal of the Arkansas Academy of Science

No abstract provided.


New Records Of Vertebrates In Southwestern Arkansas, C. Renn Tumlison, Mark R. Karnes, Mark E. Clark Jan 1992

New Records Of Vertebrates In Southwestern Arkansas, C. Renn Tumlison, Mark R. Karnes, Mark E. Clark

Journal of the Arkansas Academy of Science

No abstract provided.


Photosynthetic Efficiency Of Drought-Induced Leaves In Neviusia Alabamensis, Jennifer Martsolf, Robert D. Wright Jan 1991

Photosynthetic Efficiency Of Drought-Induced Leaves In Neviusia Alabamensis, Jennifer Martsolf, Robert D. Wright

Journal of the Arkansas Academy of Science

Plants in one stand of Neviusia alabamensis Gray (Rosaceae), a rare shrub, became drought deciduous in July, 1990, and grew new leaves following rains in August. In September the photosynthetic efficiency of the new leaves was compared with that of old leaves in another stand of the same population. Although leaf area from regrowth was much less than old leaf area retained, photosynthetic efficiency in new leaves was about 3 times higher than in old leaves. This response is discussed in terms of compensation for drought-induced loss of leaves.


Survey And Annotated Checklist Of The Later Summer Flora Of The Moist Soil Units At Holla Bend National Wildlife Refuge, Stephen A. Walker, George P. Johnson Jan 1991

Survey And Annotated Checklist Of The Later Summer Flora Of The Moist Soil Units At Holla Bend National Wildlife Refuge, Stephen A. Walker, George P. Johnson

Journal of the Arkansas Academy of Science

We conducted a floristic survey of 22 moist soil units at Holla Bend National Wildlife Refuge during September and October of 1990. The moist soil units range in size from 0.4 to 9.7 ha and are depressions manipulated to provide food and shelter for waterfowl. In total, 60 taxa representing 24 families and 42 genera were identified and are compiled into an annotated checklist. The flora was dominated by the following families and genera in decreasing order of importance: Asteraceae (Xanthium), Polygonaceae (Polygonum), and Amaranthaceae (Amaranthus). The Poaceae and the Cyperaceae were well represented, but were of lesser ...


Sexual Dimorphism And Intersexual Differences In Resource Allocations Of A Dioecious Shrub, Lindera Melissifolia (Walt.) Blume, Dennis J. Richardson, Robert D. Wright, Shannon Walker Jan 1990

Sexual Dimorphism And Intersexual Differences In Resource Allocations Of A Dioecious Shrub, Lindera Melissifolia (Walt.) Blume, Dennis J. Richardson, Robert D. Wright, Shannon Walker

Journal of the Arkansas Academy of Science

Morphometric data were gathered to make intersexual comparisons on the morphology and reproductive resource allocation patterns of the rare, dioecious shrub, Lindera melissifolia. Females produced significantly fewer flowers and leaves than did males. No other significant differences could be detected in morphology. Female "clones" exhibit low area coverage and low stem density, which suggests higher costs of reproduction. If this is the case, the deficits produced in resource allocations directed toward sexual reproduction seem to result in increased mortality and/or reduced vegetative reproduction.


Isolation Of Nuclei From Physarum Flavicomum: Demonstration Of Nuclear Cyclic Acid Amp Phosphodiesterase, Judith A. Bean, Maurice G. Kleve, Thomas J. Lynch Jan 1986

Isolation Of Nuclei From Physarum Flavicomum: Demonstration Of Nuclear Cyclic Acid Amp Phosphodiesterase, Judith A. Bean, Maurice G. Kleve, Thomas J. Lynch

Journal of the Arkansas Academy of Science

Cyclic AMP phosphodiesterase activity in the nucleus of the myxomycete Physarum flavicomum was demonstrated by cytochemical staining utilizing electron microscopy and by enzymatic assays with tritiated cyclic AMP as the substrate. Cytochemical staining showed Physarum's plasmodial phosphodiesterase activity to be located in the nucleus, along the plasma membrane, in vesicles, and free in the cytoplasm. Nuclear phosphodiesterase, which may be cell cycle dependent, was primarily located in the nucleolus. Nuclei from three to five day old microplasmodial cultures were isolated by the method of Henney and Yee. Whole cells were collected through centrifugation and washed. Pellets were homogenized in ...


Effects Of Juglone (5'-Hydroxy-1, 4-Naphthoquinone) On The Algae Anabaena Flos-Aquae, Nostoc Commune, And Scenedesmus Acuminatus, V. Diane Randall, Jimmy D. Bragg Jan 1986

Effects Of Juglone (5'-Hydroxy-1, 4-Naphthoquinone) On The Algae Anabaena Flos-Aquae, Nostoc Commune, And Scenedesmus Acuminatus, V. Diane Randall, Jimmy D. Bragg

Journal of the Arkansas Academy of Science

Three species of algae, Anabaena flos-aquae, Nostoc commune and Scenedesmus acuminatus were selected for their sensitivity to juglone and studied for the effects of juglone concentrations of 10, 1, 0.5, 0.1 and 0.01 μg/ml upon their growth. A. flos-aquae was most sensitive, with significant inhibition by the 0.5 μg/ml concentration. N. commune was inhibited least, with significant inhibition only in the 10 μg/ml concentration. S. acuminatus was found to be moderately inhibited at the 0.5 μg/ml concentration. All species were found to be non-viable after 14 days exposure to 10 μg ...


Gas Chromortographic Analyses Of Biocrude-Producing Trees, Roy Z. Gehring, Bob D. Johnson Jan 1984

Gas Chromortographic Analyses Of Biocrude-Producing Trees, Roy Z. Gehring, Bob D. Johnson

Journal of the Arkansas Academy of Science

Gas chromotographic procedures were used to compare commercial diesel fuel with cyclohexane, ether, and methanol extracts from various tree species. Standard n-paraffin hydrocarbons ranging from C-10 thru C-34 were used as standards. These analyses indicated that several extracts, notably those from Juniper virginiana (juniper) and Pinus echinata (pine) trees of Northeast Arkansas and the Brazilian tree Copaifera langsdorffii (copaiba), contain numerous hydrocarbon and selected chemical products which serve as potential renewable biocrude sources.


Prairie Phenology And Seed Germination, Donald E. Culwell, Robert Wright Jan 1983

Prairie Phenology And Seed Germination, Donald E. Culwell, Robert Wright

Journal of the Arkansas Academy of Science

No abstract provided.