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Full-Text Articles in Life Sciences

The Principle Of Linearized Stability For Size-Structured Population Models, M. El-Doma Dec 2011

The Principle Of Linearized Stability For Size-Structured Population Models, M. El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

The principle of linearized stability for size-structured population dynamics models is proved giving validity to previous stability results reported in, for example, El-Doma (2008-1). In particular, we show that if all the roots of the characteristic equation lie to the left of the imaginary axis then the steady state is locally exponentially stable, and on the other hand, if there is at least one root that lies to the right of the imaginary axis then the steady state is unstable. We also point out cases when there is resonance


The Dynamics Of Stage Structured Prey-Predator Model Involving Parasitic Infectious Disease, Raid K. Naji, Dina S. Al-Jaf Dec 2011

The Dynamics Of Stage Structured Prey-Predator Model Involving Parasitic Infectious Disease, Raid K. Naji, Dina S. Al-Jaf

Applications and Applied Mathematics: An International Journal (AAM)

In this paper a prey-predator model involving parasitic infectious disease is proposed and analyzed. It is assumed that the life cycle of predator species is divided into two stages immature and mature. The analysis of local and global stability of all possible subsystems is carried out. The dynamical behaviors of the model system around biologically feasible equilibria are studied. The global dynamics of the model are investigated with the help of Suitable Lyapunov functions. Conditions for which the model persists are established. Finally, to nationalize our analytical results, numerical simulations are worked out for a hypothetical set of parameter values.


Modeling Spread Of Polio With The Role Of Vaccination, Manju Agarwal, Archana S. Bhadauria Dec 2011

Modeling Spread Of Polio With The Role Of Vaccination, Manju Agarwal, Archana S. Bhadauria

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we have proposed and analyzed a nonlinear mathematical model for the spread of Polio in a population with variable size structure including the role of vaccination. A threshold parameter, R , is found that completely determines the stability dynamics and outcome of the disease. It is found that if R 1, the disease free equilibrium is stable and the disease dies out. However, if R >1, there exists a unique endemic equilibrium that is locally asymptotically stable. Conditions for the persistence of the disease are determined by means of Fonda’s theorem. Moreover, numerical simulation of the proposed …


Mathematical Modeling Of Peristaltic Flow Of Chyme In Small Intestine, Daniel N. Riahi, Ranadhir Roy Dec 2011

Mathematical Modeling Of Peristaltic Flow Of Chyme In Small Intestine, Daniel N. Riahi, Ranadhir Roy

Applications and Applied Mathematics: An International Journal (AAM)

Mathematical models based on axisymmetric Newtonian incompressible fluid flow are studied for the peristaltic flow of chyme in the small intestines, which is an axisymmetric cylindrical tube. The flow is modeled more realistically modeled by assuming that the peristaltic rush wave is a non-periodic mode composed of two sinusoidal waves of different wavelengths, which propagate at the same speed along the outer boundary of the tube. Both cases of flow in a tube and in an annulus that are modeled and investigated in the present paper correspond respectively to the cases of flow of chyme in the small intestine in …


2011 Meeting Missing Abstracts Oct 2011

2011 Meeting Missing Abstracts

Virginia Journal of Science

Abstracts not included in Virginia Journal of Science Volume 62, No. 1 and 2, presented at the 89th Annual Meeting of the Virginia Academy of Science, May 25-27, 2011, at the University of Richmond, Richmond VA.


Breeding Biology Of Oryzomys Palustris, The Marsh Rice Rat, In Eastern Virginia, Robert K. Rose, Erin A. Dreelin Oct 2011

Breeding Biology Of Oryzomys Palustris, The Marsh Rice Rat, In Eastern Virginia, Robert K. Rose, Erin A. Dreelin

Virginia Journal of Science

The objectives of our study were to determine the age of maturity, litter size, and the timing of the breeding season of marsh rice rats (Oryzomys palustris) of coastal Virginia. From May 1995 to May 1996, monthly samples of rice rats were live-trapped in two coastal tidal marshes of eastern Virginia, and then necropsied. Sexual maturity was attained at 30-40 g for both sexes. Mean litter size of 4.63 (N= 16) did not differ among months or in mass or parity classes. Data from two other studies conducted in the same county, one of them contemporaneous, also were …


A Cellular Automata Model Of Infection Control On Medical Implants, Alicia Prieto-Langarica, Hristo Kojouharov, Benito Chen-Charpentier, Liping Tang Jun 2011

A Cellular Automata Model Of Infection Control On Medical Implants, Alicia Prieto-Langarica, Hristo Kojouharov, Benito Chen-Charpentier, Liping Tang

Applications and Applied Mathematics: An International Journal (AAM)

S. epidermidis infections on medically implanted devices are a common problem in modern medicine due to the abundance of the bacteria. Once inside the body, S. epidermidis gather in communities called biofilms and can become extremely hard to eradicate, causing the patient serious complications. We simulate the complex S. epidermidis-Neutrophils interactions in order to determine the optimum conditions for the immune system to be able to contain the infection and avoid implant rejection. Our cellular automata model can also be used as a tool for determining the optimal amount of antibiotics for combating biofilm formation on medical implants.


Shooting Neural Networks Algorithm For Solving Boundary Value Problems In Odes, Kais I. Ibraheem, Bashir M. Khalaf Jun 2011

Shooting Neural Networks Algorithm For Solving Boundary Value Problems In Odes, Kais I. Ibraheem, Bashir M. Khalaf

Applications and Applied Mathematics: An International Journal (AAM)

The objective of this paper is to use Neural Networks for solving boundary value problems (BVPs) in Ordinary Differential Equations (ODEs). The Neural networks use the principle of Back propagation. Five examples are considered to show effectiveness of using the shooting techniques and neural network for solving the BVPs in ODEs. The convergence properties of the technique, which depend on the convergence of the integration technique and accuracy of the interpolation technique are considered.


Uptake Of Nanoparticles Of Cerium Oxide And Yttrium Oxide By Acanthamoeba Castellanii (Protozoa) And Daphnia Magna (Crustacea), James R. Palmieri, Geneva Gehring, Catherine Minichino, Shaadi F. Elswaifi Apr 2011

Uptake Of Nanoparticles Of Cerium Oxide And Yttrium Oxide By Acanthamoeba Castellanii (Protozoa) And Daphnia Magna (Crustacea), James R. Palmieri, Geneva Gehring, Catherine Minichino, Shaadi F. Elswaifi

Virginia Journal of Science

Currently, nanoparticles are synthesized and used at an unprecedented rate for industrial, medical, and research applications. The use of cerium oxide nanoparticles (CeONP) and yttrium oxide nanoparticles (YtONP) results in their spread as contaminants into the environment. Once in the environment, CeONP and YtONP can be taken up by organisms in the food chain where they may pose a public health risk. In this study we determine whether Acanthamoeba castellanii and Daphnia magna uptake CeONP or YtONP from their environment and thereby play a role in the transmission of the nanoparticles. Using electron microscopy, orgranisms exposed to the nanoparticles were …


Section Abstracts: Biology With Microbiology And Molecular Biology Apr 2011

Section Abstracts: Biology With Microbiology And Molecular Biology

Virginia Journal of Science

Abstracts of the Biology with Microbiology and Molecular Biology Section for the 89th Annual Meeting of the Virginia Academy of Science, May 25-27, 2011, University of Richmond, Richmond VA.


Section Abstracts: Natural History And Biodiversity Apr 2011

Section Abstracts: Natural History And Biodiversity

Virginia Journal of Science

Abstracts of the Natural History and Biodiversity Section for the 89th Annual Meeting of the Virginia Academy of Science, May 25-27, 2011, University of Richmond, Richmond VA.


Distributions And Abundances Of Microstegium Vimineum Along Forest Roadsides At The Grassy Hill Natural Area, Franklin County, Virginia, Gregory D. Turner Jan 2011

Distributions And Abundances Of Microstegium Vimineum Along Forest Roadsides At The Grassy Hill Natural Area, Franklin County, Virginia, Gregory D. Turner

Virginia Journal of Science

In summer 2005, plots were surveyed along roads passing through forest habitats at the Grassy Hill Natural Area Preserve in Franklin County, Virginia to assess the distributions and abundances of Microstegium vimineum in transects located at increasing distances away from roadsides into forest interiors. Across plots, Microstegium was encountered almost exclusively in roadside transects, where abundances were relatively high. While forest composition and topographic features were similar across plots, percent canopy cover and leaf litter depth were greater in interior compared to roadside transects due to undisturbed tree canopies and ground cover located in interior plot areas. Results imply that …


Biosolar Conversion Of N2 And H2o To Ammonia By Engineered N2-Fixing Cyanobacteria, Seth T. Harris Jan 2011

Biosolar Conversion Of N2 And H2o To Ammonia By Engineered N2-Fixing Cyanobacteria, Seth T. Harris

The Journal of Undergraduate Research

The cyanobacterium Anabaena sp. PCC 7120 is capable of using solar energy to produce ammonia through conversion of atmospheric dinitrogen in differentiated cells called heterocysts. Harnessing this system could enable cyanobacteria to be used in ammoniafertilizer production, creating a renewable alternative to the current Haber-Bosch process. The genes patA and alr3304 in the Anabaena 7120 genome are important in heterocyst formation; an increase in heterocyst formation is seen with over-expression of patA or inactivation of alr3304. This research aims to create a novel mutant that forms more heterocysts by simultaneously over-expressing patA and inactivating alr3304, producing higher amounts of ammonia. …


Preservation And Use Of Natural Resources In The Developing World: A Case Study Of The Can Gio Biosphere Reserve, Ho Chi Minh City, Vietnam, Emily Green Jan 2011

Preservation And Use Of Natural Resources In The Developing World: A Case Study Of The Can Gio Biosphere Reserve, Ho Chi Minh City, Vietnam, Emily Green

Occam's Razor

Developing nations often overlook the environmental effects of industrialization. However, these nations need healthy, sustainable resources in order to become prosperous and stable countries. Additionally, developed nations depend upon the natural resources of developing nations as raw materials. Loss of natural resources in developing nations therefore has effects at both national and global levels. A key challenge across the globe is balancing the human need for development with the necessity of the sustainable use and protection of natural resources. In the process of finding this balance, developing nations are revising both their national definition of conservation as well as the …


Occam's Razor Vol. 1 - Full (2011) Jan 2011

Occam's Razor Vol. 1 - Full (2011)

Occam's Razor

No abstract provided.


President's Message, Justin K. Wyatt Jan 2011

President's Message, Justin K. Wyatt

Journal of the South Carolina Academy of Science

No abstract provided.


Scas Officers And Council Members 2010 - 2011 Jan 2011

Scas Officers And Council Members 2010 - 2011

Journal of the South Carolina Academy of Science

No abstract provided.


Gold Nanospheres As Inhibitors Of Amyloid- Β Protein Aggregation Involved In Alzheimer’S Disease, Mihyun Lim, Deborah Soto-Ortega, Rahina Mahtab, Melissa Moss Jan 2011

Gold Nanospheres As Inhibitors Of Amyloid- Β Protein Aggregation Involved In Alzheimer’S Disease, Mihyun Lim, Deborah Soto-Ortega, Rahina Mahtab, Melissa Moss

Journal of the South Carolina Academy of Science

No abstract provided.


Phenolic Constituents Of Hypericum Triquetrifolium Turra (Guttiferae) Growing In Turkey: Variation Among Populations And Plant Parts, Cüneyt Çirak, Jolita Radusiene, Valdimaras Janulis, Liudas Ivanauskas, Necdet Çamaş, Ali̇ Kemal Ayan Jan 2011

Phenolic Constituents Of Hypericum Triquetrifolium Turra (Guttiferae) Growing In Turkey: Variation Among Populations And Plant Parts, Cüneyt Çirak, Jolita Radusiene, Valdimaras Janulis, Liudas Ivanauskas, Necdet Çamaş, Ali̇ Kemal Ayan

Turkish Journal of Biology

Hypericum triquetrifolium Turra (Guttiferae) has received considerable scientific interest in recent years, as it is a source of a variety of biologically active compounds including phenolics. The present study was conducted to determine the variation in the content of several phenolics, namely phenylpropane chlorogenic acid and flavonoids such as rutin, hyperoside, apigenin-7-O-glucoside, kaempferol, quercitrin, quercetin and amentoflavone among four H. triquetrifolium populations from the Central Black Sea Region of Turkey. The aerial parts representing a total of 30 shoots were collected at full flowering in each population. After drying at room temperature, they were dissected into floral, leaf and stem …


Investigation Of Legionella Pneumophila And Free Living Amoebas In The Domestic Hot Water Systems In İstanbul, Di̇lara Meryem Burak, Zuhal Zeybek Jan 2011

Investigation Of Legionella Pneumophila And Free Living Amoebas In The Domestic Hot Water Systems In İstanbul, Di̇lara Meryem Burak, Zuhal Zeybek

Turkish Journal of Biology

Legionella pneumophila (L. pneumophila), known to cause legionnaires' disease, has been found in various aquatic environments and man-made water systems. Free living amoebas (FLAs) live in the same environments and can cause infections such as encephalitis, keratitis. Moreover, FLAs play a major role in L. pneumophila transmission. In the present study, the presence of L. pneumophila and FLAs was examined in water and swab samples obtained from shower heads (hot water) in 61 houses in İstanbul. Nonnutrient agar (NNA) was used for isolation of FLAs in all samples and buffered charcoal yeast extract (BCYE) agar with addition of glycine, vancomycine, …


Production Of A Novel Bifunctional Catalase-Phenol Oxidase Of Scytalidium Thermophilum In The Presence Of Phenolic Compounds, Yonca Yüzügüllü, Zümrüt Begüm Ögel, Ufuk Bölükbaşi, Nursen Çoruh, Gürkan Karakaş Jan 2011

Production Of A Novel Bifunctional Catalase-Phenol Oxidase Of Scytalidium Thermophilum In The Presence Of Phenolic Compounds, Yonca Yüzügüllü, Zümrüt Begüm Ögel, Ufuk Bölükbaşi, Nursen Çoruh, Gürkan Karakaş

Turkish Journal of Biology

A novel bifunctional catalase with additional phenol oxidase activity (CATPO) is produced by the thermophilic fungus, Scytalidium thermophilum, in a growth-associated manner. In order to study the biological significance of this dual enzyme in relation to phenolic compounds, 14 phenolics were tested for their effect on growth and CATPO production. It was determined that some phenolics exerted a negative effect on growth (catechol, coumaric acid, hydroquinone, kaempferol, myricetin), while others either did not influence growth in a negative manner or enhanced growth by a maximum of 50% increase in biomass (caffeic acid, chlorogenic acid, catechin, gallic acid, resorcinol, vanillic acid). …


Uv-B Induces Cell Death In The Lichen Physcia Semipinnata (J.F.Gmel), Di̇lek Ünal, Yi̇ği̇t Uyanikgi̇l Jan 2011

Uv-B Induces Cell Death In The Lichen Physcia Semipinnata (J.F.Gmel), Di̇lek Ünal, Yi̇ği̇t Uyanikgi̇l

Turkish Journal of Biology

We have examined the consequences of Ultraviolet-B (UV-B) irradiation in the thallus of the lichen Physcia semipinnata (J.F.Gmel) in terms of cell viability and apoptotic-like formation. UV-B induced oligonucleosomal DNA fragmentation was detected by TUNEL assay and this is the first study showing DNA fragmentation in thalli. The intensity of TUNEL-positive cells after exposure to UV-B at doses up to 95.9 J/cm2 was higher in the photobiont layer than the mycobiont layer.


Table Of Contents Jan 2011

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Inverse Correspondence Of Amh And Fsh Levels In Women Presenting For Infertility Treatments, Amara Iverson, Abdelmonium Younis, William Butler, William Roudebush Jan 2011

Inverse Correspondence Of Amh And Fsh Levels In Women Presenting For Infertility Treatments, Amara Iverson, Abdelmonium Younis, William Butler, William Roudebush

Journal of the South Carolina Academy of Science

No abstract provided.


Advertisement Call And Distribution Of The Treefrogs Hyla Chrysoscelis And Hyla Versicolor In Virginia, Joseph C. Mitchell, Christopher A. Pague Jan 2011

Advertisement Call And Distribution Of The Treefrogs Hyla Chrysoscelis And Hyla Versicolor In Virginia, Joseph C. Mitchell, Christopher A. Pague

Virginia Journal of Science

The gray treefrog complex consists of two sibling species that are indistinguishable morphologically, the diploid Hyla chrysoscelis and the tetraploid Hyla versicolor. Identification is possible in the field only by audio recognition of male advertisement call trill rates (pulses/second). During 1979-1983 we evaluated taped calls of these two species taken from 89 populations from throughout Virginia to map their respective ranges and to evaluate differences in call parameters. Hyla chrysoscelis occurs in the Coastal Plain, eastern and southern Piedmont, and in southwestern Virginia. Hyla versicoloroccurs in the Piedmont, Blue Ridge, and Ridge and Valley regions south to Wythe …


Evaluation Of The Antioxidant And Acetylcholinesterase Inhibitory Activities Of Arnebia Densiflora Ledeb., İlkay Orhan, F. Sezer Şenol, Ufuk Koca, Tuğba Erçeti̇n, Gülnur Toker Jan 2011

Evaluation Of The Antioxidant And Acetylcholinesterase Inhibitory Activities Of Arnebia Densiflora Ledeb., İlkay Orhan, F. Sezer Şenol, Ufuk Koca, Tuğba Erçeti̇n, Gülnur Toker

Turkish Journal of Biology

Arnebia densiflora Ledeb. (Boraginaceae), a medicinal plant growing in Turkey, has been reported to contain a well-known red pigment, shikonin, a naphthoquinone derivative. In the current study, the acetylcholinesterase (AChE) inhibitory and antioxidant activities of the chloroform, ethyl acetate, methanol, and water extracts of the root, stem, and flowers of the plant, as well as shikonin, were investigated. AChE inhibition was tested using an ELISA microplate reader at 250, 500, 1000, and 2000 µg mL^{-1}. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test and the Fe+2-ferrozine test system for metal chelating power. The results indicated that the …


Nanocarriers For Biomedical Applications, Shuyi Li, Lynsa Nguyen, Hairong Xion, Meiyao Wang, Tom C.-C. Hu, Jin-Xiong She, Steven M. Serkiz, George G. Wicks, William S. Dynan Jan 2011

Nanocarriers For Biomedical Applications, Shuyi Li, Lynsa Nguyen, Hairong Xion, Meiyao Wang, Tom C.-C. Hu, Jin-Xiong She, Steven M. Serkiz, George G. Wicks, William S. Dynan

Journal of the South Carolina Academy of Science

No abstract provided.


The Effects Of Uv Radiation On Some Structural And Ultrastructural Parameters In Pepper (Capsicum Longum A.Dc.), Siavash Hosseini Sarghein, Jirair Carapetian, Jalil Khara Jan 2011

The Effects Of Uv Radiation On Some Structural And Ultrastructural Parameters In Pepper (Capsicum Longum A.Dc.), Siavash Hosseini Sarghein, Jirair Carapetian, Jalil Khara

Turkish Journal of Biology

The objective of this study was to evaluate the effects on the structure and ultrastructure of pepper plants (Capsicum longum A.DC.) exposed to UV radiation under greenhouse conditions. The plants were grown in a growth chamber under uniform environmental conditions and after 35 days were exposed to UV-A and UV-C radiation for 15 and 8 days, respectively. Changes in root growth were not significant, but shoot growth decreased in UV-R-exposed plants and decreased significantly in UV-C-exposed plants. Leaf area also decreased in UV-R-exposed plants and decreased significantly in UV-C-exposed plants. Root thickness was not affected by UV treatment, but stem …


The Effect Of Diazinon On Egg Fertility And Development In Drosophila Melanogaster, Ayla Karataş, Zafer Bahçeci̇, Ensar Başpinar Jan 2011

The Effect Of Diazinon On Egg Fertility And Development In Drosophila Melanogaster, Ayla Karataş, Zafer Bahçeci̇, Ensar Başpinar

Turkish Journal of Biology

This study investigated the effects of diazinon, an organic phosphoric insecticide, on some developmental features of Drosophila melanogaster. The aim was to determine if any developmental inhibition occurs when diazinon is applied and if so, to determine which developmental stages are affected. Therefore, diazinon was applied to Drosophila melanogaster eggs, larvae, and adults, and its effects were observed. During the experiments 3 concentrations with values lower than LC_{50} were utilized (6 × 10^{-5}, 6 × 10^{-6}, 6 × 10^{-7} ppm). Diazinon solution was applied to Drosophila melanogaster by means of nutrition, adding it to the culture medium. The results show …


Characterization Of Poly Phenol Oxidase In Two In Vitro Regenerated Cultivars Of Mucuna: Mucuna Pruriens L. And Mucuna Prurita H., Raghavendra Sathyanarayana, Vadlapudi Kumar, Chapeyil Kumaran Ramesh, Mahadevappa Parmesha, Mahaboob Habeebulla Moinuddin Khan Jan 2011

Characterization Of Poly Phenol Oxidase In Two In Vitro Regenerated Cultivars Of Mucuna: Mucuna Pruriens L. And Mucuna Prurita H., Raghavendra Sathyanarayana, Vadlapudi Kumar, Chapeyil Kumaran Ramesh, Mahadevappa Parmesha, Mahaboob Habeebulla Moinuddin Khan

Turkish Journal of Biology

Polyphenol oxidases (PPOs EC 1.14.18.1) were isolated from Mucuna pruriens and Mucuna prurita and confirmed as tyrosinases involved in L-DOPA production. PPOs were extracted by using a 0.05 M phosphate buffer, pH 7.0. The purified enzyme was resolved into a single band by PAGE, the enzyme was confirmed as PPO by activity staining, and SDS-PAGE analysis revealed that the purified PPO of both the species is a tetramer. Substrate specificity experiments were carried out with catechol, L-DOPA, L-tyrosine, and p-cresol. Of these, catechol was evaluated as the most suitable substrate based on the determined K_{m} and V_{max} values. The optimum …