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

Digital Commons Network™

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

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 13171 - 13200 of 14008

Full-Text Articles in Entire DC Network

Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, G. R. Ditullio, R. B. Dunbar, C. E. Hare, P. A. Lee, M. Lohan, M. Long, W. O. Smith Jr., B. Sohst, S. Tozzi, Y. Zhang, D. A. Hutchins Jan 2009

Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, G. R. Ditullio, R. B. Dunbar, C. E. Hare, P. A. Lee, M. Lohan, M. Long, W. O. Smith Jr., B. Sohst, S. Tozzi, Y. Zhang, D. A. Hutchins

OES Faculty Publications

Iron availability and temperature are important limiting factors for the biota in many areas of the world ocean, and both have been predicted to change in future climate scenarios. However, the impacts of combined changes in these two key factors on microbial trophic dynamics and nutrient cycling are unknown. We examined the relative effects of iron addition (+1 nM) and increased temperature (+4° C) on plankton assemblages of the Ross Sea, Antarctica, a region characterized by annual algal blooms and an active microbial community. Increased iron and temperature individually had consistently significant but relatively minor positive effects on total phytoplankton …

Go to article

Spatial Variation In Otolith Chemistry Of Atlantic Croaker Larvae In The Mid-Atlantic Bight, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones Jan 2009

Spatial Variation In Otolith Chemistry Of Atlantic Croaker Larvae In The Mid-Atlantic Bight, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones

OES Faculty Publications

Larval Atlantic croaker Micropogonias undulatus (1 to 7 mm in standard length) were collected on the east coast of the United States from North Carolina to Delaware during 2000. We defined 3 water-mass boundaries for potential groups of spawning Atlantic croaker using temperature and salinity measured at each sampling station. We tested the hypothesis that distinct otolith chemistries existed among 3 groups of larval Atlantic croaker collected from these water masses using solution-based inductively coupled plasma-mass spectrometry. Multivariate analysis of variance indicated that otolith chemistry differed significantly among water masses. Using a quadratic discriminant function, we were able to correctly …

Go to article

Patterns Of Larval Atlantic Croaker Ingress Into Chesapeake Bay, Usa, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones Jan 2009

Patterns Of Larval Atlantic Croaker Ingress Into Chesapeake Bay, Usa, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones

OES Faculty Publications

We compared ingress patterns of Atlantic croaker Micropogonias undulatus larvae into Chesapeake Bay, USA, with published ingress patterns through barrier island inlets, the accepted model for larval fish ingress. This model asserts that larvae ingress on night flood tides at the flooddominated side of the inlet and at all depths. At the Chesapeake Bay mouth and in the adjacent coastal waters, we compared the distribution of abundance, size, age, and growth rates of croaker prior to ingress, In contrast to the barrier island inlet model, croaker larvae were more abundant at depth than closer to the surface regardless of location. …

Go to article

Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee Jan 2009

Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee

OES Faculty Publications

Rates of peptide hydrolysis (using the fluorescent substrate, lucifer yellow anhydride-labeled tetra-alanine) and dipeptide uptake (using dually labeled, 15N and 13C, dialanine) were measured in phytoplankton cultures and in natural populations during algal blooms dominated by one or two taxa. During most sampling events, both peptide hydrolysis and dipeptide uptake were greatest in the size fraction containing the dominant phytoplankter, suggesting that phytoplankton contribute substantially to or may even dominate observed extracellular peptide hydrolysis and dipeptide uptake in the environment. These are the first data suggesting that dipeptides may be taken up directly by phytoplankton and this may …

Go to article

Cross-Basin Comparison Of Phosphorus Stress And Nitrogen Fixation In Trichodesmium, Annette M. Hynes, P. Dreux Chappell, Sonya T. Dyhrman, Scott C. Doney, Eric A. Webb Jan 2009

Cross-Basin Comparison Of Phosphorus Stress And Nitrogen Fixation In Trichodesmium, Annette M. Hynes, P. Dreux Chappell, Sonya T. Dyhrman, Scott C. Doney, Eric A. Webb

OES Faculty Publications

We investigated the phosphorus (P) status and N2 fixation rates of Trichodesmium populations from the North Pacific, western South Pacific, and western North Atlantic. Colonies of Trichodesmium were collected and analyzed for endogenous alkaline phosphatase (AP) activity using enzyme-labeled fluorescence ( ELF) and for nitrogenase activity using acetylene reduction. AP hydrolyzes dissolved inorganic phosphate (DIP) from dissolved organic phosphorus and is active in Trichodesmium colonies experiencing P stress. Across multiple stations in the subtropical North and South Pacific, there was low to moderate ELF labeling in Trichodesmium, although labeling was present in other taxa. In contrast, Trichodesmium ELF …

Go to article

On The Interpretation Of Caribbean Paleo-Temperature Reconstructions During The Younger Dryas, Xiuquan Wan, Ping Chang, R. Saravanan, Rong Zhang, Matthew W. Schmidt Jan 2009

On The Interpretation Of Caribbean Paleo-Temperature Reconstructions During The Younger Dryas, Xiuquan Wan, Ping Chang, R. Saravanan, Rong Zhang, Matthew W. Schmidt

OES Faculty Publications

A conundrum exists regarding whether the sea-surface temperatures decreased or increased over the southern Caribbean and the western Tropical Atlantic region during the Younger Dryas when the North Atlantic cooled substantially and the Atlantic thermohaline circulation was weakened significantly. Despite the proximity of core locations, some proxy reconstructions record a surface cooling, while others indicate a warming. We suggest that this seemingly paradoxical finding may, at least partially, be attributed to the competing physical processes that result in opposing signs of temperature change in the region in response to weakened North Atlantic meridional overturning circulation. Our coupled ocean-atmosphere model experiments …

Go to article

Toxicity Assessment Of Single-Walled Carbon Nanotubes, Eva Herzog Jan 2009

Toxicity Assessment Of Single-Walled Carbon Nanotubes, Eva Herzog

Doctoral

The objective of this study was to investigate the potential adverse health effects of occupational exposure to SWCNT dust using various in vitro approaches. Lung epithelium (represented by A549 and NHBE cells) was chosen as target cell model and exposed to minimally processed particle samples under submerse conditions and effects were compared to that of carbon black and crocidolite asbestos exposure. Cytotoxicity studies indicated low acute cytotoxicity of SWCNT. Morphological changes included decreases in microvilli and increased numbers of surfactant storing lamellar bodies and changes in cytoskeleton. Due to interactions of SWCNT and toxicity indicator dyes, the clonogenic assay was …

Go to article

Continuous Monitoring Of Spatial Queries, Kyriakos Mouratidis Jan 2009

Continuous Monitoring Of Spatial Queries, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

No abstract provided.

Go to article

Efficient Valid Scope Computation For Location-Dependent Spatial Queries In Mobile And Wireless Environments, Ken C. K. Lee, Wang-Chien Lee, Hong Va Leong, Brandon Unger, Baihua Zheng Jan 2009

Efficient Valid Scope Computation For Location-Dependent Spatial Queries In Mobile And Wireless Environments, Ken C. K. Lee, Wang-Chien Lee, Hong Va Leong, Brandon Unger, Baihua Zheng

Research Collection School Of Computing and Information Systems

In mobile and wireless environments, mobile clients can access information with respect to their locations by submitting Location-Dependent Spatial Queries (LDSQs) to Location-Based Service (LBS) servers. Owing to scarce wireless channel bandwidth and limited client battery life, frequent LDSQ submission from clients must be avoided. Observing that LDSQs issued from similar client positions would normally return the same results, we explore the idea of valid scope, that represents a spatial area in which a set of LDSQs will retrieve exactly the same query results. With a valid scope derived and an LDSQ result cached at the client side, a client …

Go to article

Experimental Techniques In Infrared Measurements Of Thin-Film Plastics, Robert F. Hawkins Jan 2009

Experimental Techniques In Infrared Measurements Of Thin-Film Plastics, Robert F. Hawkins

Theses

No abstract provided.

Go to article

Georgia Southern University Fact Book, Georgia Southern University Jan 2009

Georgia Southern University Fact Book, Georgia Southern University

Georgia Southern Fact Books (1976-2022)

No abstract provided.

Go to article

Signal Detection With Criterion Noise: Applications To Recognition Memory, Aaron S. Benjamin, Michael Diaz, Wee, Serena Jan 2009

Signal Detection With Criterion Noise: Applications To Recognition Memory, Aaron S. Benjamin, Michael Diaz, Wee, Serena

Research Collection School of Social Sciences

A tacit but fundamental assumption of the theory of signal detection is that criterion placement is a noise-free process. This article challenges that assumption on theoretical and empirical grounds and presents the noisy decision theory of signal detection (ND-TSD). Generalized equations for the isosensitivity function and for measures of discrimination incorporating criterion variability are derived, and the model's relationship with extant models of decision making in discrimination tasks is examined, An experiment evaluating recognition memory for ensembles of word stimuli revealed that criterion noise is not trivial in magnitude and contributes substantially to variance in the slope of the isosensitivity …

Go to article

Traditions Of Philanthropic Order, Christine Dunn Henderson Jan 2009

Traditions Of Philanthropic Order, Christine Dunn Henderson

Research Collection School of Social Sciences

Individuals act more or less simultaneously as economic agents, citizens, and participants in civil society. Their interactions and their ways of fulfilling these roles take many forms. Not all of them can be said to be self-organizing, yet in several instances patterns of organization emerge spontaneously without being deliberately designed. Of course, the market economy—or “catallaxy,” as F. A. Hayek called it—remains the best example of such “spontaneous orders.” But there are others. Gus diZerega (2000), for example, has identified science and democracy as being similarly constituted by self-referential, self-organizing (some authors prefer the term autopoietic) processes. In this paper …

Go to article

Synthesis Of 3,6-Bis(5’-Bromo-3’-Indolyl)-1,4-Dimethypiperazine-2,5-Dione, Stephen N. Crooke, C. Michele Davis Mcgibony, Christine R. Whitlock Jan 2009

Synthesis Of 3,6-Bis(5’-Bromo-3’-Indolyl)-1,4-Dimethypiperazine-2,5-Dione, Stephen N. Crooke, C. Michele Davis Mcgibony, Christine R. Whitlock

Chemistry: Faculty Publications (1990-2023)

The one-pot synthesis of 3,6-bis(5’-bromo-3’-indolyl)-1,4-dimethylpiperazine- 2,5-dione is reported. Sarcosine anhydride is brominated and immediately reacted with 5-bromoindole to produce the product, which is characterized by 1H NMR, MS and microanalysis.

Go to article

If We Seek, Do We Learn?: Predicting Knowledge Of Global Warming, Leeann Kahlor, Sonny Rosenthal Jan 2009

If We Seek, Do We Learn?: Predicting Knowledge Of Global Warming, Leeann Kahlor, Sonny Rosenthal

Research Collection College of Integrative Studies

Derived from the risk information seeking and processing model (RISP), this study sought to isolate predictors of the public's knowledge of global warming. Using a national sample ( N = 805), multiple regression yielded a number of significant relationships among 13 moderators. Notably, the number of media sources used for information about global warming, information seeking effort, and general education were relatively strong predictors of knowledge. Counter to expectations, informational subjective norms were inversely related to knowledge.

Go to article

Chaos And Uncertainty, M. Thulasidas Jan 2009

Chaos And Uncertainty, M. Thulasidas

Research Collection School Of Computing and Information Systems

The end of 2008 in the finance industry can be summarized in two words – chaos and uncertainty. The subprime crisis, where everybody lost; the dizzying commodity price movements; the pink slip syndrome; the spectacular bank busts; and the gargantuan bail-outs all vouch for it.

Go to article

Undergraduate And Graduate Catalog [2008-2009], Georgia Southern University Jan 2009

Undergraduate And Graduate Catalog [2008-2009], Georgia Southern University

Undergraduate & Graduate Catalogs

No abstract provided.

Go to article

A Study Of Georgia Elementary Teachers' Beliefs And Practices Concerning Grade Level Retention, Anna Jean Hill Jan 2009

A Study Of Georgia Elementary Teachers' Beliefs And Practices Concerning Grade Level Retention, Anna Jean Hill

College of Graduate Studies: Theses & Dissertations

The purpose of this study was to identify Georgia elementary teachers' beliefs and practices of student grade-level retention. Overall, elementary teachers consider grade level retention to be an acceptable school practice to improve a student's academic success and that grade level retention also provides for long-term academic success. Georgia elementary teachers with master's degrees and above, teachers in suburban communities, teachers with more experience, and fourth grade teachers believe more strongly than elementary teachers with bachelor's degrees, teachers in rural and urban areas, and third and fifth grade elementary teachers, that students who do not meet academic standards should be …

Go to article

School Size And Its Effect On School Climate And Academic Achievement In Rural South Georgia High Schools, James Benjamin Lawhorn Jan 2009

School Size And Its Effect On School Climate And Academic Achievement In Rural South Georgia High Schools, James Benjamin Lawhorn

College of Graduate Studies: Theses & Dissertations

While leaders in rural South Georgia have continued to debate the notion of school size as it applies to high schools, limited research was available to support staying small or continued growth through consolidation. In this study, schools from rural South Georgia were examined in order to collect data that could provide communities with the resources available to either advocate for large or small rural high schools. Moreover, it could also provide the rationalization necessary for some larger schools to split. The purpose was to establish the relationship between school size and academic achievement, and the relationship was between school …

Go to article

The Perspective Of School Personnel In A Georgia School District Concerning The Recruitment Of Minority Teachers, Shyla D. Ridley Jan 2009

The Perspective Of School Personnel In A Georgia School District Concerning The Recruitment Of Minority Teachers, Shyla D. Ridley

College of Graduate Studies: Theses & Dissertations

Recruiting and attracting minorities into the teaching profession is difficult. Given the competitiveness of the current job market and the heavy emphasis on standardized testing for all teacher candidates, the difficulties of attracting quality minority teachers are becoming more challenging. The lack of a racially and culturally diverse teaching staff remains a major issue in education nationally and locally, especially since projections indicate that the representation of minority teachers is declining while the number of minority students is increasing. This need for more minority teachers is even more critical in urban public schools characterized by large percentages of minority students …

Go to article

The Grasp Of Physics Concepts Of Motion: Identifying Particular Patterns In Students' Thinking, Ihab Obaidat, Ehab Malkawi Jan 2009

The Grasp Of Physics Concepts Of Motion: Identifying Particular Patterns In Students' Thinking, Ihab Obaidat, Ehab Malkawi

International Journal for the Scholarship of Teaching & Learning

No abstract provided.

Go to article

Using Modeling And Creating A Research Discourse Community To Teach A Doctoral Action Research Course, Cher Hendricks Jan 2009

Using Modeling And Creating A Research Discourse Community To Teach A Doctoral Action Research Course, Cher Hendricks

International Journal for the Scholarship of Teaching & Learning

The purpose of this study was to investigate the effectiveness of teaching action research through modeling. Participants were 11 doctoral students enrolled in a two-semester practitioner-based research course. In this study, I was both instructor and member of the research community. I modeled the steps of action research as I conducted a study of my practice, which focused on having students engage in reflective activities for the purpose of aligning their core educational values and the actions taken in their research studies. The students and I engaged in discussions of our research projects, and as part of the research community, …

Go to article

Inter-Port Competition And Inland Container Transport: A Multiple Criteria Decision-Making Approach To Achieve Lntermodal Transport System Development Strategies In Taiwan, Yih-Ching Juang Jan 2009

Inter-Port Competition And Inland Container Transport: A Multiple Criteria Decision-Making Approach To Achieve Lntermodal Transport System Development Strategies In Taiwan, Yih-Ching Juang

Plymouth Business School Theses

Inland container transport has intensified over the past thirty years in Taiwan. It is closely related to inter-port competition and port selection by container carriers. In the 1980's, large containerships only berthed at Kaohsiung port due to the limit of container terminal operation capacities of Keelung port and the carrier's regional hub port decision in the country region. The container traffic of the south-north motorways made them more crowded and increased road maintenance expenses. The purpose of this research is to study inter-port competition and inland container transport flows in Taiwan. Although Taiwan is an island, the freight transport policy …

Go to article

Inter-Port Competition And Inland Container Transport: A Multiple Criteria Decision-Making Approach To Achieve Intermodal Transport System Development Stratergies In Taiwan., Yhi-Ching Juang Jan 2009

Inter-Port Competition And Inland Container Transport: A Multiple Criteria Decision-Making Approach To Achieve Intermodal Transport System Development Stratergies In Taiwan., Yhi-Ching Juang

Plymouth Business School Theses

Inland container transport has intensified over the past thirty years in Taiwan. It is closely related to inter-port competition and port selection by container carriers. In the 1980's, large containerships only berthed at Kaohsiung port due to the limit of container terminal operation capacities of Keelung port and the carrier's regional hub port decision in the country region. The container traffic of the south-north motorways made them more crowded and increased road maintenance expenses. The purpose of this research is to study inter-port competition and inland container transport flows in Taiwan. Although Taiwan is an island, the freight transport policy …

Go to article

Oxorhenium(V)-Mediated Syntheses And Structures Of Oxypyridinium-Ammonium Zwitterions, Abubak'r Abrahams, Thomas Gerber, Eric Hosten, Peter Mayer Jan 2009

Oxorhenium(V)-Mediated Syntheses And Structures Of Oxypyridinium-Ammonium Zwitterions, Abubak'r Abrahams, Thomas Gerber, Eric Hosten, Peter Mayer

Turkish Journal of Chemistry

Treatment of N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl) dimethylamine (H_2had) with trans-[ReO_2(py)_4]I in acetone affords the iodide salts of the oxypyridinium-ammonium zwitterions N^1-(2-hydroxybenzyl)-N^2,N^2-dimethyl-N^1-((2-oxypyridinium)-1- methyl)ethane-1,2-diamine [Hhpd]^+ and N^2,N^2-dimethyl-N^1- bis((2-oxypyridinium)-1- methyl)ethane-1,2-diamine [dod]^+. The products were characterized by X-ray structure analysis, and NMR and IR spectroscopy.

Go to article

Hydrogen Storage Via Physisorption: The Combined Role Of Adsorption Enthalpy And Entropy, Carlos Otero Arean, Barbara Bonelli, Montserrat Rodriguez Delgado, Edoardo Garrone Jan 2009

Hydrogen Storage Via Physisorption: The Combined Role Of Adsorption Enthalpy And Entropy, Carlos Otero Arean, Barbara Bonelli, Montserrat Rodriguez Delgado, Edoardo Garrone

Turkish Journal of Chemistry

Materials capable of cost-effective on-board hydrogen storage and delivery are currently being sought worldwide as a means to facilitate a hydrogen-based energy transition in the transportation sector. Among the solutions proposed, hydrogen storage by physisorption on porous solids constitutes a main avenue of research, and for intelligent design of such materials a detailed knowledge of gas adsorption thermodynamics is of the utmost importance. Analysis of the available data for hydrogen adsorption on alkali and alkaline-earth cation exchanged zeolites clearly shows that standard adsorption enthalpy (\Delta H^0) and entropy (\Delta S^0) are correlated, in the sense that larger \Delta S^0 values …

Go to article

Spectroscopic Studies And Hartree-Fock Ab Initio Calculations Of A Substituted Amide Of Pyrazine-2-Carboxylic Acid - C_{16}H_{18}Cln_3o, Chacko Yohannan Panicker, Hema Tresa Vanghese, Thaha Thansani Jan 2009

Spectroscopic Studies And Hartree-Fock Ab Initio Calculations Of A Substituted Amide Of Pyrazine-2-Carboxylic Acid - C_{16}H_{18}Cln_3o, Chacko Yohannan Panicker, Hema Tresa Vanghese, Thaha Thansani

Turkish Journal of Chemistry

A substituted amide of pyrazine-2-carboxylic acid was prepared and the IR spectrum was recorded and analysed. The compound prepared was identified by NMR and mass spectra. The vibrational frequencies of the title compound were computed using the Hartree-Fock level of theory using the 6-31G* basis set and compared with the experimental data. The red shift of the NH stretching frequency indicates weakening of the NH bond. The splitting of the NH stretching bond is due to Davidov coupling between neighbouring units. The first hyperpolarizability, infrared intensities, and Raman activities are reported. Methyl substitution affects all the carbon-nitrogen and carbon-carbon bond …

Go to article

Determination Of Trace Borohydride In Basic Solutions Using Differential Pulse Polarography, Ülkü Ünal, Güler Somer Jan 2009

Determination Of Trace Borohydride In Basic Solutions Using Differential Pulse Polarography, Ülkü Ünal, Güler Somer

Turkish Journal of Chemistry

Synthesis of borohydride is important because of its use as a hydrogen energy source. The objective of this study was to develop a new and simple method for the trace determination of borohydride so that it can be used during the investigation of a new reaction for its synthesis or in some kinetic studies. A differential pulse polarographic method has been developed for this purpose since the results obtained with this method are very reproducible and the instrument used is not expensive. The optimum working condition was found to be as 0.05 M phosphate buffer (pH 9), containing 0.1 M …

Go to article

Synthesis And Physical Studies Of Polycarbonate Of P-Tert-}Butylcalix[4]Arene: A Highly Selective Receptor For Na^+, Muhammad Ashram, Nawash Al Ghezawi, Ibrahim Abu Awaad, Gülsen Asman Jan 2009

Synthesis And Physical Studies Of Polycarbonate Of P-Tert-}Butylcalix[4]Arene: A Highly Selective Receptor For Na^+, Muhammad Ashram, Nawash Al Ghezawi, Ibrahim Abu Awaad, Gülsen Asman

Turkish Journal of Chemistry

The synthesis and characterization of a polycarbonate of p-tert-butylcalix[4]arene 4 are reported. It was synthesized by condensation of p-tert-butylcalix[4]arenetetraol derivative 3 with ethyl chloroformate. This new polymer possesses a hydrolyzable backbone and tunable hydrophobic/hydrophilic properties. The experimental results indicate that the polycarbonate was successfully synthesized with average molecular weight \overline{M}_{w}, (2.328 \times 10^4 g/mol), which was determined by static light scattering method using a Berry plot. The structure of this polymer was determined by IR spectroscopy. The thermal properties were investigated using differential scanning calorimetry (DSC). The degree of crystallinity was measured by means of XRD. The extraction ability of …

Go to article

Dynamic ^1h-Nmr Demonstration Of Anomeric Effect And Structure: Conformational And Configurational Analysis Of N-2-(1,4-Dioxane)-N'-(P-Methylbenzenesulfonyl)- O-(P-Methylphenoxy) İsourea, Ali Reza Modarresi-Alam, Hossein A. Dabbagh Jan 2009

Dynamic ^1h-Nmr Demonstration Of Anomeric Effect And Structure: Conformational And Configurational Analysis Of N-2-(1,4-Dioxane)-N'-(P-Methylbenzenesulfonyl)- O-(P-Methylphenoxy) İsourea, Ali Reza Modarresi-Alam, Hossein A. Dabbagh

Turkish Journal of Chemistry

The conformational and configurational behavior and the structure of N-2-(1,4-dioxane)-N'-(p-methylbenzenesulfonyl)-O- (p-methylphenoxy) isourea (1) were studied using dynamic NMR. The endo-anomeric effect, hydrogen bonding, temperature, and polarity of solvent control the population of dioxane ring conformers or anomers but not the configuration interconversion of the imine of the imidoyl moiety. Dynamic ^1H-NMR, \Delta H°, \Delta S°, \Delta G°, and \Delta G^{\ddag} analysis of 1 demonstrates that the dioxane ring adopts the chair conformation, that the imidoyl amino group prefers axial conformation, and that the tosyl and tolyl groups about the C=N bond retain the E configuration.

Go to article

First Prev Next Last