Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 48

Full-Text Articles in Life Sciences

Comparative Pollination Biology Of Sympatric And Allopatric Andean Iochroma (Solanaceae)1, Steven J. Hall, Stacy Dewitt Smith, Pablo R. Izquierdo, David A. Baum Dec 2008

Comparative Pollination Biology Of Sympatric And Allopatric Andean Iochroma (Solanaceae)1, Steven J. Hall, Stacy Dewitt Smith, Pablo R. Izquierdo, David A. Baum

Steven J. Hall

Field studies were conducted for 15 species of Iochroma Benth. and the nested genus Acnistus Schott to quantify the diversity of pollination systems and to assess the potential contribution of pollinator behavior to the persistence of closely related species in sympatry. We combined measures of pollinator visitation and pollen deposition to estimate the importance of major groups of pollinators for each species, and we calculated proportional similarity in the pollinator assemblage among species. We found that 12 species of Iochroma, encompassing a range of flower colors and sizes, were principally pollinated by hummingbirds and, in many cases, by the same …


Melamine Contamination Of Infant Formula In China: The Causes, Food Safety Issues And Public Health Implications, Emmanuel Ohene Afoakwa Nov 2008

Melamine Contamination Of Infant Formula In China: The Causes, Food Safety Issues And Public Health Implications, Emmanuel Ohene Afoakwa

Professor Emmanuel Ohene Afoakwa

No abstract provided.


No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater Nov 2008

No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater

Kurt A. Rosentrater

The possibility that Bacillus thuringiensis (Bt) corn (Zea mays L.) residues resist decomposition compared to non-Bt residues would present direct (soil carbon turnover times) and indirect (changes in tillage practices) effects on carbon budgets in agricultural systems. We evaluated the relative decomposition of residue from two pairs of Bt and non-Bt corn hybrids from different seed manufacturers buried in the root zone of adjacent Bt and non-Bt corn plots over a period of 384 d. We found no persistent differences in residue decomposition among the different hybrids regardless of the seed manufacturer or the presence of the Bt genes (both …


Web-Based Arabidopsis Functional And Structural Genomics Resources, Yan Lu, Robert Last Oct 2008

Web-Based Arabidopsis Functional And Structural Genomics Resources, Yan Lu, Robert Last

Yan Lu

No abstract provided.


In Vitro Clonal Propagation Of Bael (Aegle Marmelos Corr.) Cv. Cishb1 Through Enhanced Axillary Branching, Rajesh Pati Oct 2008

In Vitro Clonal Propagation Of Bael (Aegle Marmelos Corr.) Cv. Cishb1 Through Enhanced Axillary Branching, Rajesh Pati

Rajesh Pati

Rapid clonal micropropagation protocol of Aegle marmelos (L.) Corr. cv. CISH-B1 was achieved by nodal stem segment of mature bearing tree. Three centimeter long shoots having one axillary bud excised from 10-15th nodal region of shoots during September gave quick in vitro bud burst (5.33 days) when cultured on MS medium supplemented with BAP, 8.84 μM + IAA 5.7 μM. The maximum number of proliferated shoots (9.0/explant) were obtained on same medium supplemented with BAP 8.84 μM + IAA 5.7 μM. The micro shoots were rooted (100 %) on ½ strength MS medium supplemented with IBA 49.0 + IAA 5.7 …


In Vitro Regeneration And Genetic Fidelity Testing Of Aegle Marmelos (Corr.) Plants, Rajesh Pati Oct 2008

In Vitro Regeneration And Genetic Fidelity Testing Of Aegle Marmelos (Corr.) Plants, Rajesh Pati

Rajesh Pati

No abstract provided.


In Vitro Plant Regeneration From Mature Explant Of Aegle Marmelos Corr. Cv. Cish-B2, Rajesh Pati Oct 2008

In Vitro Plant Regeneration From Mature Explant Of Aegle Marmelos Corr. Cv. Cish-B2, Rajesh Pati

Rajesh Pati

No abstract provided.


Exploitative Competition Between Invasive Herbivores Benefits A Native Host Plant, Joseph Elkinton, E. L. Preisser Oct 2008

Exploitative Competition Between Invasive Herbivores Benefits A Native Host Plant, Joseph Elkinton, E. L. Preisser

Joseph Elkinton

Although biological invasions are of considerable concern to ecologists, relatively little attention has been paid to the potential for and consequences of indirect interactions between invasive species. Such interactions are generally thought to enhance invasives' spread and impact (i.e., the “invasional meltdown” hypothesis); however, exotic species might also act indirectly to slow the spread or blunt the impact of other invasives. On the east coast of the United States, the invasive hemlock woolly adelgid (Adelges tsugae, HWA) and elongate hemlock scale (Fiorinia externa, EHS) both feed on eastern hemlock (Tsuga canadensis). Of the two insects, HWA is considered far more …


Gfp Tagging Of Sieve Element Occlusion (Seo) Proteins Results In Green Fluorescent Forisomes, Hélène Pélissier, Winfried Peters, Ray Collier, Aart Van Bel, Michael Knoblauch Sep 2008

Gfp Tagging Of Sieve Element Occlusion (Seo) Proteins Results In Green Fluorescent Forisomes, Hélène Pélissier, Winfried Peters, Ray Collier, Aart Van Bel, Michael Knoblauch

Winfried S. Peters

Forisomes are Ca2+-driven, ATP-independent contractile protein bodies that reversibly occlude sieve elements in faboid legumes. They apparently consist of at least three proteins; potential candidates have been described previously as ‘FOR’ proteins. We isolated three genes from Medicago truncatula that correspond to the putative forisome proteins and expressed their green fluorescent protein (GFP) fusion products in Vicia faba and Glycine max using the composite plant methodology. In both species, expression of any of the constructs resulted in homogenously fluorescent forisomes that formed sieve tube plugs upon stimulation; no GFP fluorescence occurred elsewhere. Isolated fluorescent forisomes reacted to Ca2+ and chelators …


School Feeding Programmes In Africa - A Case Study, Emmanuel Ohene Afoakwa Jul 2008

School Feeding Programmes In Africa - A Case Study, Emmanuel Ohene Afoakwa

Professor Emmanuel Ohene Afoakwa

No abstract provided.


Improving Productivity In Mixed-Species Plantations, Mila Bristow, J Doland Nichols, Jerome K. Vanclay Jun 2008

Improving Productivity In Mixed-Species Plantations, Mila Bristow, J Doland Nichols, Jerome K. Vanclay

Professor Jerome K Vanclay

Mixed species plantations are often promoted as being environmentally preferable to monocultures, but are rarely considered operationally viable by commercial forest growers. Despite many publications documenting benefits demonstrated in research studies (e.g., Kelty 2006; Forrester et al. 2006b; Wood and Vanclay 1995), and despite continuing calls from a wide range of advocates for mixed-species plantations, polyculture remains the exception rather than the rule in industrial plantation forestry (Nichols et al 2006)...


Extraction Of Lipids From Buttermilk Using Supercritical Carbon Dioxide, Harit K. Vyas, Johanna C. Astaire, Rafael Jiménez-Flores May 2008

Extraction Of Lipids From Buttermilk Using Supercritical Carbon Dioxide, Harit K. Vyas, Johanna C. Astaire, Rafael Jiménez-Flores

Rafael Jiménez-Flores

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Disulfide Bonding Patterns Between Β-Lactoglobulin And Κ-Casein In A Heated And Spray-Dried Milk-Model, Annie Bienvenue, C. S. Norris, Michael J. Boland, Lawrence K. Creamer, Rafael Jiménez-Flores May 2008

Disulfide Bonding Patterns Between Β-Lactoglobulin And Κ-Casein In A Heated And Spray-Dried Milk-Model, Annie Bienvenue, C. S. Norris, Michael J. Boland, Lawrence K. Creamer, Rafael Jiménez-Flores

Rafael Jiménez-Flores

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Iron Fertilization Of Kentucky Bluegrass, David Wehner, Jean Haley May 2008

Iron Fertilization Of Kentucky Bluegrass, David Wehner, Jean Haley

David J. Wehner

Iron applications are sometimes used to enhance the color (darker green) of turfgrass stands even when iron is not deficient. A study was conducted to determine the feasibility of replacing a portion of the total yearly N applied to Kentucky bluegrass (Poa pratensis L.) with iron. Turfgrass response to iron chelate (Sequestrene 330) applications at 2.2 kg Fe ha-1 in combination with three liquid-applied N sources (urea, Formolene, and FLUF) at 25 kg N ha-1 was compared to turf response from applications of the N sources at 49 kg N ha-1. Iron was substituted for …


Building Sustainable Agricultural Development Through Home-Grown School Feeding - The African Approach, Emmanuel Ohene Afoakwa, Linley Chiwona-Karltun Apr 2008

Building Sustainable Agricultural Development Through Home-Grown School Feeding - The African Approach, Emmanuel Ohene Afoakwa, Linley Chiwona-Karltun

Professor Emmanuel Ohene Afoakwa

Proper nutrition is critical for optimal growth, cognitive development, general well-being and academic performance of children. Access to good nutrition either at home or through the educational system can contribute to the elimination of malnutrition and its associated health and developmental problems. In this regard, The 2005 UN World Summit recommended the expansion of local school feeding programmes, using home-grown foods where possible as one of the “Quick impact initiatives” to achieve the Millennium Development Goals, especially for rural areas facing the dual challenge of high chronic malnutrition and low agricultural productivity.


A Microecosystem For Fertilizer And Pesticide Fate Research, B. E. Branham, David J. Wehner, W. A. Torello, A. J. Turgeon Apr 2008

A Microecosystem For Fertilizer And Pesticide Fate Research, B. E. Branham, David J. Wehner, W. A. Torello, A. J. Turgeon

David J. Wehner

A microecosystem was designed to study the behavior of pesticides, fertilizers, or related compounds applied to plant stands. The system consists of three parts: a brass base that holds the plant growth media, a glass atmospheric chamber that rests on the base, and a set of analytical traps. The brass base is fitted with a porous ceramic plate so that tension can be applied to the water in the growing media. Air enters the bottom of the glass atmospheric chamber and exits through the top into appropriate trapping systems to recover volatilized pesticides, ammonia, or metabolized 14CO2 from labeled compounds. …


The Fate Of Diazinon Applied To Thatched Turf, B. E. Branham, David J. Wehner Apr 2008

The Fate Of Diazinon Applied To Thatched Turf, B. E. Branham, David J. Wehner

David J. Wehner

Diazinon (0,0-diethyl-0-(2-isopropyl-6-methyl-4-primidinyl) phosphorothioate) is widely used to control turfgrass insect pests. Poor control of soil-inhabiting insects has been found where diazinon has been applied to thatched turfgrass stands. The purpose of this study was to evaluate the environmental fate of diazinon applied to turfgrass stands. A microecosystem was used to follow the fate of radiolabeled diazinon surface applied to Kentucky bluegrass (Poa pratensis L.) turfs, with or without a thatch layer, growing on Flanigan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) irrigated daily or every 4 days. Loss of diazinon by volatilization, leaching, and degradation accompanied by release of …


Heat Tolerance Screening Of Field-Grown Cultivars Of Kentucky Bluegrass And Perennial Ryegrass, D. D. Minner, P. H. Dernoeden, David J. Wehner, M. S. Mcintosh Apr 2008

Heat Tolerance Screening Of Field-Grown Cultivars Of Kentucky Bluegrass And Perennial Ryegrass, D. D. Minner, P. H. Dernoeden, David J. Wehner, M. S. Mcintosh

David J. Wehner

The quality of cool-season turfgrasses frequently declines during periods of high temperature stress. Simple tests are needed to rapidly identify heat tolerant germplasm for incorporation into breeding programs. Facilitative screening tests have been devised, however, in the few studies that have been performed only immature and greenhouse or growth chamber-grown plants have been evaluated. To be of practical value, results of screening tests, employing plants grown under artificial conditions, should correlate closely with results of tests involving field grown plants. The objective of this research was to evaluate the heat tolerance of several cultivars of Kentucky bluegrass (Poa pratensis L.) …


Urease Activity In A Kentucky Bluegrass Turf, W. A. Torello, David J. Wehner Apr 2008

Urease Activity In A Kentucky Bluegrass Turf, W. A. Torello, David J. Wehner

David J. Wehner

The components of a turfgrass ecosystem, including plants, an intervening layer of thatch and the underlying soil, influence the fate of topically applied urea fertilizer. The loss of urea N by ammonia volatilization may be governed by the rate of urea hydrolysis. The main objective of this study was to determine the extent of urease activity associated with turfgrass plant tissue, thatch, and the underlying soil. This information may help elucidate the mechanism of ammonia loss following urea application. Because a turfgrass stand frequently possesses an extensive thatch layer that may serve as the primary plant growth medium, additional objectives …


Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke Apr 2008

Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke

David J. Wehner

Use of cool-season turfgrasses in transitional environments is limited, in part, by their heat tolerance. Development of a rapid heat tolerance screening technique would be of value in determining the potential of turf•grasses for use in warmer areas. The heat tolerance of 22 Kentucky bluegrass (Poa pratensis L.) cultivars, Poa annua L., and four perennial ryegrass cultivars (Lolium perenne L.) was evaluated by exposing plants for 30 min to temperatures ranging from 41 to 49 C in single degree intervals. Ten-week-old plants, which had been grown under a low level of N fertilization and watered infrequently to maximize heat tolerance …


Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke Apr 2008

Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke

David J. Wehner

Use of cool-season turfgrasses in transitional environments is limited, in part, by their heat tolerance. Development of a rapid heat tolerance screening technique would be of value in determining the potential of turf•grasses for use in warmer areas. The heat tolerance of 22 Kentucky bluegrass (Poa pratensis L.) cultivars, Poa annua L., and four perennial ryegrass cultivars (Lolium perenne L.) was evaluated by exposing plants for 30 min to temperatures ranging from 41 to 49 C in single degree intervals. Ten-week-old plants, which had been grown under a low level of N fertilization and watered infrequently to maximize heat tolerance …


Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth Apr 2008

Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth

David J. Wehner

Information is needed concerning the effects of different soil fertility levels on the activity of turfgrass roots in that part of the soil profile sampled for routine soil tests. In Pennsylvania, a sampling depth of 5 to 7.5 cm is suggested for established turf. A study was conducted on 'Merion' Kentucky bluegrass (Poa pratensis L.) to determine relationships among lime, phosphorus, and potassium applications; soil test results; foliar growth and elemental analysis; and root activity as determined by 32P uptake from three soil depths. In the field, soil pH values were 5.8 and 7.0, P ranged from 13 to 137 …


Models For Predicting The Lower Limit Of The Canopy-Air Temperature Difference Of Two Cool Season Grasses, Dennis Martin, David Wehner, C. Throssell Apr 2008

Models For Predicting The Lower Limit Of The Canopy-Air Temperature Difference Of Two Cool Season Grasses, Dennis Martin, David Wehner, C. Throssell

David J. Wehner

Estimation of the lower limit of the canopy-air temperature differential, (Tc–Ta)LL, is required for calculation of an empirically-based crop water stress, index. This research determined the complexity of model needed for accurate estimation of (Tc–Ta)LL for several field grown cultivars of Kentucky bluegrass (Poa pratensis L.) and for creeping bentgrass (Agrostis stolonifera L. var. palustris (Huds.) Farw.). Regression models using vapor pressure deficit of the air (VPD), net radiation load (Rn), and wind speed (WS) were developed for predicting (Tc–Ta …


Melamine/Urea And Oxamide Fertilization Of Kentucky Bluegrass, David Wehner, Dennis Martin Apr 2008

Melamine/Urea And Oxamide Fertilization Of Kentucky Bluegrass, David Wehner, Dennis Martin

David J. Wehner

The commercial lawn care industry represents a large market for N sources. A formulated melamine (2,4,6-triamino-s-triazine) plus urea combination (MLU) (45% melamine by weight) and oxamide were evaluated for use by the lawn care industry by comparing turfgrass response from these fertilizers to that from urea, sulfur coated urea (SCU), ureaformaldehyde (Nitroform), and a non-fertilized check. Fertilizers were applied four times per year to field plots of Kentucky bluegrass (Poa pratensis L.) growing on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) at a rate of 49 kg N ha-1 per application. Color ratings and clipping weights were determined …


New Connections Across Pathways And Cellular Processes: Industrialized Mutant Screening Reveals Novel Associations Between Diverse Phenotypes In Arabidopsis, Yan Lu, Linda Savage, Imad Ajjawi, Kathreen Imre, David Yoder, Christoph Benning, Dean Dellapenna, John Ohlrogge, Katherine Osteryoung, Andreas Weber, Curtis Wilkerson, Robert Last Mar 2008

New Connections Across Pathways And Cellular Processes: Industrialized Mutant Screening Reveals Novel Associations Between Diverse Phenotypes In Arabidopsis, Yan Lu, Linda Savage, Imad Ajjawi, Kathreen Imre, David Yoder, Christoph Benning, Dean Dellapenna, John Ohlrogge, Katherine Osteryoung, Andreas Weber, Curtis Wilkerson, Robert Last

Yan Lu

No abstract provided.


Anisotropic Contraction In Forisomes: Simple Models Won't Fit, Winfried Peters, Michael Knoblauch, Stephen Warmann, William Pickard, Amy Shen Mar 2008

Anisotropic Contraction In Forisomes: Simple Models Won't Fit, Winfried Peters, Michael Knoblauch, Stephen Warmann, William Pickard, Amy Shen

Winfried S. Peters

Forisomes are ATP-independent, Ca2+-driven contractile protein bodies acting as reversible valves in the phloem of plants of the legume family. Forisome contraction is anisotropic, as shrinkage in length is associated with radial expansion and vice versa. To test the hypothesis that changes in length and width are causally related, we monitored Ca2+- and pH-dependent deformations in the exceptionally large forisomes of Canavalia gladiata by high-speed photography, and computed time-courses of derived geometric parameters (including volume and surface area). Soybean forisomes, which in the resting state resemble those of Canavalia geometrically but have less than 2% of the volume, were also …


First Report Of Downy Mildew On Lepidium Sativum In India, Kunal Mandal Jan 2008

First Report Of Downy Mildew On Lepidium Sativum In India, Kunal Mandal

Kunal Mandal

Downy mildew caused by Hyaloperonospora parasitica on different members of Brassicaceae has been reported from different parts of the world. In India, the pathogen is recorded for the first time on Lepidium sativum. Proper management strategies need to be formulated against this disease as incidence is increasing.


Effect Of Different Levels Of N, P And K On Downy Mildew (Peronospora Plantaginis) And Seed Yield Of Isabgol (Plantago Ovata), Kunal Mandal, R. Saravanan, S. Maiti Jan 2008

Effect Of Different Levels Of N, P And K On Downy Mildew (Peronospora Plantaginis) And Seed Yield Of Isabgol (Plantago Ovata), Kunal Mandal, R. Saravanan, S. Maiti

Kunal Mandal

The study showed that application of different doses of inorganic nutrients had considerable influence on growth, yield and downy mildew interaction in isabgol (Plantago ovata). It included three levels of nitrogen (0, 30, 60 kg N ha–1), two levels of phosphorous (0, 30 kg P ha–1) and two levels of potash (0, 40 kg K ha–1) for 2 consecutive years. The highest N supply (60 kg ha–1) caused more than 65% increase in disease severity compared with the control. However, application of 40 kg K ha–1 reduced percent disease index (PDI) by more than 10% compared with 0 kg K …


Clonal Propagation Of Dalbergia Sissoo Roxb. And Associated Metabolic Changes During Adventitious Root Primordium Development, Azamal Husen Jan 2008

Clonal Propagation Of Dalbergia Sissoo Roxb. And Associated Metabolic Changes During Adventitious Root Primordium Development, Azamal Husen

Dr. Azamal Husen

No abstract provided.


Stock-Plant Etiolation Causes Drifts In Total Soluble Sugars And Anthraquinones, And Promotes Adventitious Root Formation In Teak (Tectona Grandis L. F.) Coppice Shoots, Azamal Husen Jan 2008

Stock-Plant Etiolation Causes Drifts In Total Soluble Sugars And Anthraquinones, And Promotes Adventitious Root Formation In Teak (Tectona Grandis L. F.) Coppice Shoots, Azamal Husen

Dr. Azamal Husen

No abstract provided.