Showing papers by "Wichita State University published in 2004"

Intermolecular and supramolecular photoinduced electron transfer processes of fullerene–porphyrin/phthalocyanine systems

Abstract: The attainment of a better understanding of the dependence of photoinduced electron transfer reaction rates on the molecular structures of the donor and acceptor entities results in improving the capture and storage of solar energy. Here, the intermolecular and supramolecular electron transfer processes from electron donors (porphyrins (P), chlorophylls (Chl), phthalocyanines (Pc) and naphthalocyanines (Nc)) and their metal derivatives to electron acceptors (fullerenes such as C 60 and C 70 ) studied by nanosecond and picosecond laser flash photolysis techniques in polar and nonpolar solvents are reviewed. For intermolecular systems in polar solvents, photoinduced electron transfer takes place via the excited triplet states of C 60 /C 70 or via the excited triplet states of P/Pc/Nc, yielding solvated radical ions in polar solvents; thus, the back electron transfer rates are generally slow. In the case of the supramolecular dyads and triads formed by axial coordination, hydrogen bonding, crown ether complexation, or rotaxane formation, the photoinduced charge separation takes place mainly from the excited singlet state of the donor; however, the back electron transfer rates are generally quite fast. The relations between structures and photochemical reactivities of these novel supramolecular systems are discussed in relation to the efficiency of charge separation and charge recombination.

Methodology to mitigate supplier risk in an aerospace supply chain

Abstract: Supply chain design is frequently performed from the perspective of a single supplier‐customer relationship. However, as a supplier provides value to different supply chains, it becomes increasingly difficult to optimize each supply chain. Each supply chain has different requirements, procedures, and formats. A member may have requirements placed upon them by one member that contradicts another member. The competitive success of a supplier depends on its ability to participate in different supply chains. This, in turn, affects the competitiveness of each of the other supply chains. This paper presents a generic prescriptive methodology for mitigating risks in an aerospace supply chain and proposes five activities. The methodology provides a mechanism to minimize conflicting objectives. A hypothetical case study is then presented on how the methodology can be applied.

Energy Transfer Followed by Electron Transfer in a Supramolecular Triad Composed of Boron Dipyrrin, Zinc Porphyrin, and Fullerene: A Model for the Photosynthetic Antenna-Reaction Center Complex

Abstract: The first example of a working model of the photosynthetic antenna-reaction center complex, constructed via self-assembled supramolecular methodology, is reported. For this, a supramolecular triad is assembled by axially coordinating imidazole-appended fulleropyrrolidine to the zinc center of a covalently linked zinc porphyrin−boron dipyrrin dyad. Selective excitation of the boron dipyrrin moiety in the boron dipyrrin−zinc porphyrin dyad resulted in efficient energy transfer (kENTsinglet = 9.2 × 109 s-1; ΦENTsinglet = 0.83) creating singlet excited zinc porphyrin. Upon forming the supramolecular triad, the excited zinc porphyrin resulted in efficient electron transfer to the coordinated fullerenes, resulting in a charge-separated state (kcssinglet = 4.7 × 109 s-1; ΦCSsinglet = 0.9). The observed energy transfer followed by electron transfer in the present supramolecular triad mimics the events of natural photosynthesis. Here, the boron dipyrrin acts as antenna chlorophyll that absorbs light energy and tra...

The effect of evaporation on the evolution of close-in giant planets

Abstract: We include the effect of evaporation in our evolutionary calculations of close-in giant planets, based on a recent model for thermal evaporation taking into account the XUV flux of the parent star (Lammer et al 2003) Our analysis leads to the existence of a critical mass for a given orbital distance mcrit(a) below which the evaporation timescale becomes shorter than the thermal timescale of the planet For planets with initial masses below mcrit, evaporation leads to a rapid expansion of the outer layers and of the total planetary radius, speeding up the evaporation process Consequently, the planet does not survive as long as estimated by a simple application of mass loss rates without following consistently its evolution We find out that the transit planet HD 209458b might be in such a dramatic phase, although with an extremely small probability As a consequence, we predict that, after a certain time, only planets above a value mcrit(a) should be present at an orbital distance a of a star For planets with initial masses above mcrit, evaporation does not affect the evolution of the radius with time

Sibling Conflict and Ineffective Parenting as Predictors of Adolescent Boys' Antisocial Behavior and Peer Difficulties: Additive and Interactional Effects

Abstract: Extensive sibling conflict is predictive of multiple poor adjustment outcomes during adolescence and early adulthood, but the frequency and developmental impact of such conflict may be conditional on ineffective parenting. Thus, sibling conflict may add to or amplify the negative effects of ineffective parenting on adolescent boys' adjustment. Hypotheses in this study were that: (a) multiple informant measures of problematic parent–child relationships and of sibling conflict would form distinct constructs rather than a single negative family process construct, and (b) ineffective parenting, sibling conflict, and their interaction measured at ages 10 to 12 would predict boys' concurrent status and developmental trajectories for antisocial behavior and peer adjustment across a 4-year span from ages 12 to 16. Confirmatory factor and latent growth modeling analyses were consistent with these hypotheses, demonstrating the important developmental impact of sibling conflict.

Elemental and Redox Analysis of Single Bacterial Cells by X-ray Microbeam Analysis

Abstract: High-energy x-ray fluorescence measurements were used to make elemental maps and qualitative chemical analyses of individual Pseudomonas fluorescens strain NCIMB 11764 cells. Marked differences between planktonic and adhered cells were seen in the morphology, elemental composition, and sensitivity to Cr(VI) of hydrated cells at spatial scales of 150 nm. This technology can be applied to natural geomicrobiological systems.

Surprising sun: a new step towards a complete picture?

Abstract: Important revisions of the solar model ingredients have appeared recently. We first show that the updated CNO composition suppresses the anomalous position of the Sun in the known galactic enrichment. The following law, $\mathrm{H}\mathrm{e}/\mathrm{H}=0.075+44.6\text{ }\mathrm{O}/\mathrm{H}$ in number fraction, is now compatible with all the indicators. We then suggest some directions of investigation to solve the discrepancies between the standard model and solar seismic observations. We finally update our predicted neutrino fluxes using a seismic model and all the recent progress. We get $5.31\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\times\else\texttimes\fi{}{10}^{6}/\mathrm{c}{\mathrm{m}}^{2}/\mathrm{s}$ for the total $^{8}\mathrm{B}$ neutrinos, $66.5\ifmmode\pm\else\textpm\fi{}4.4$ SNU and $2.76\ifmmode\pm\else\textpm\fi{}0.4$ SNU for the gallium and chlorine detectors, all in remarkable agreement with the detected values including neutrino oscillations for the last two. So, the acoustic modes and detected neutrinos see the same Sun, but the standard model fails to reproduce them.

Evolutionary dynamics of the DNA-binding domains in putative R2R3-MYB genes identified from rice subspecies indica and japonica genomes.

Abstract: The molecular evolution of the R2R3-MYB gene family is of great interest because it is one of the most important transcription factor gene families in the plant kingdom. Comparative analyses of a gene family may reveal important adaptive changes at the protein level and thereby provide insights that relate structure to function. We have performed a range of comparative and bioinformatics analyses on R2R3-MYB genes identified from the rice (Oryza sativa subsp. japonica and indica) and Arabidopsis genome sequences. The study provides an initial framework to investigate how different evolutionary lineages in a gene family evolve new functions. Our results reveal a remarkable excess of non-synonymous substitutions, an indication of adaptive selection on protein structure that occurred during the evolution of both helix1 and helix2 of rice R2R3-MYB DNA-binding domains. These flexible alpha-helix regions associated with high frequencies of excess non-synonymous substitutions may play critical roles in the characteristic packing of R2R3-MYB DNA-binding domains and thereby modify the protein-DNA interaction process resulting in the recognition of novel DNA-binding sites. Furthermore, a co-evolutionary pattern is found between the second alpha-helix of the R2 domain and the second alpha-helix of the R3 domain by examining all the possible alpha-helix pairings in both the R2 and R3 domains. This points to the functional importance of pairing interactions between related secondary structures.

Energy Analysis of MIMO Techniques in Wireless Sensor Networks

Abstract: Energy efficiency of MIMO techniques in wireless sensor networks is analyzed. Assuming a cooperative sensor network, the energy consumption of MIMO-based wireless sensor networks is compared with conventional SISO sensor networks. The dependence of energy efficiency on coherence time of the fading process and communications distance is considered. Our results show the applicability of MIMO techniques in such sensor networks with judicious system design.

Effect of concurrent aerobic and resistance circuit exercise training on fitness in older adults

Abstract: The purpose of this study was to determine the physiological effects of a programmed accommodating circuit exercise (PACE) program consisting of aerobic exercise and hydraulic-resistance exercise (HRE) on fitness in older adults. Thirty-five volunteers were randomly divided into two groups [PACE group (PG) 8 men and 10 women, 68.3 (4.9) years, and non-exercise control group (CG) 7 men and 10 women, 68.0 (3.4) years). The PG participated in a 12-week, 3 days per week supervised program consisting of 10 min warm-up and 30 min of PACE (moderate intensity HRE and aerobic movements at 70% of peak heart rate) followed by 10 min cool-down exercise. PACE increased (P<0.05) oxygen uptake (VO2) at lactate threshold [PG, pre 0.79 (0.20) l min−1, post 1.02 (0.22) l min−1, 29%; CG, pre 0.87 (0.14) l min−1, post 0.85 (0.15) l min−1, −2%] and at peak VO2 [PG, pre 1.36 (0.24) l min−1, post 1.56 (0.28) l min−1, 15%; CG, pre 1.32 (0.29) l min−1, post 1.37 (0.37) l min−1, 4%] in PG measured using an incremental cycle ergometer. Muscular strength evaluated by a HRE machine increased at low to high resistance dial settings for knee extension (9–52%), knee flexion (14–76%), back extension (18–92%) and flexion (50–70%), chest pull (6–28%) and press (3–17%), shoulder press (18–31%) and pull (26–85%), and leg press (21%). Body fat (sum of three skinfolds) decreased (16%), and high-density lipoprotein cholesterol (HDLC) increased (10.9 mg dl−1) for PG. There were no changes in any variables for CG. These results indicate that PACE training incorporating aerobic exercise and HRE elicits significant improvements in cardiorespiratory fitness, muscular strength, body composition, and HDLC for older adults. Therefore, PACE training is an effective well-rounded exercise program that can be utilized as a means to improve health-related components of fitness in older adults.

The export of e‐services in the age of technology transformation: challenges and implications for international service providers

Abstract: Advancements in information and communication technologies have created unprecedented opportunities to services providers in both developing and developed countries. The service sector represents one of the fastest growing areas of exports in the global trade. The Internet and e‐commerce make it possible to sell a variety of services, ranging from airline tickets to financial services, from anywhere in the world, around the clock. International delivery of services through electronic means is creating value in the supply chain by the reduction of many of the barriers to entry. This paper focuses on the determinants influencing the diffusion and export of e‐services across borders. The paper also presents strategic challenges, followed by implications for service providers.

Virtue as Likeness to God in Plato and Seneca

Abstract: IN THE CENTER OF RAPHAEL’S FAMOUS PAINTING, “The School of Athens,” Plato stands pointing to the heavens, and Aristotle stands pointing to the ground; there stand, that is, the mystical Plato and the down-to-earth Aristotle. Although it oversimplifies, this depiction makes sense for the same reason that Aristotle continues to enjoy a presence in modern moral philosophy that Plato does not: quite simply, Plato’s ethics looks too fantastic. And Plato’s ethics never looks more fantastic than in the claim that our highest good is to be like God. We find this view, in various forms, in the Phaedrus, Timaeus, Laws, Republic, and Theaetetus, as well as in the Phaedo and Philebus,1 and the ancient Platonist Alcinous in his Handbook of Platonism tells us that likeness to God (oJmoivwsi~ qew/`) is Plato’s “official” position on our final end.2 Nonetheless, this view receives very little press today: many philosophers are unaware of it; some have simply ignored it or dismissed it as an idle metaphor; and most of those who have taken it more seriously have also tended to find it too otherworldly to be of much relevance to us. This latter response is due in large measure to viewing likeness to God from the perspective of the ancient Neoplatonist Plotinus.3 But there is certainly no guarantee that Plotinus’s perspective on likeness to God gives us an especially accurate reconstruction of Plato’s view; indeed, the interpretation of this idea was a matter of considerable controversy among Neoplatonists, some of whom offered far less other-worldly interpretations than Plotinus’s.4

Halotolerant aerobic heterotrophic bacteria from the Great Salt Plains of Oklahoma

Abstract: The Salt Plains National Wildlife Refuge (SPNWR) near Cherokee, Oklahoma, contains a barren salt flat where Permian brine rises to the surface and evaporates under dry conditions to leave a crust of white salt. Rainfall events dissolve the salt crust and create ephemeral streams and ponds. The rapidly changing salinity and high surface temperatures, salinity, and UV exposure make this an extreme environment. The Salt Plains Microbial Observatory (SPMO) examined the soil microbial community of this habitat using classic enrichment and isolation techniques and phylogenetic rDNA studies. Rich growth media have been emphasized that differ in total salt concentration and composition. Aerobic heterotrophic enrichments were performed under a variety of conditions. Heterotrophic enrichments and dilution plates have generated 105 bacterial isolates, representing 46 phylotypes. The bacterial isolates have been characterized phenotypically and subjected to rDNA sequencing and phylogenetic analyses. Fast-growing isolates obtained from enrichments with 10% salt are predominantly from the gamma subgroup of the Proteobacteria and from the low GC Gram-positive cluster. Several different areas on the salt flats have yielded a variety of isolates from the Gram-negative genera Halomonas, Idiomarina, Salinivibrio, and Bacteroidetes. Gram-positive bacteria are well represented in the culture collection including members of the Bacillus, Salibacillus, Oceanobacillus, and Halobacillus.

Using Role-Play Scenarios in the IR Classroom: An Examination of Exercises on Peacekeeping Operations and Foreign Policy Decision Making

Abstract: Use of role-play scenarios in the classroom is just one of a number of active learning techniques that are being used more and more frequently to convey the more abstract concepts of international relations (IR) to students in a meaningful way. This paper examines the value of two specific role-play exercises used in an introduction to international relations course on the topics of peacekeeping and foreign policy decision making. The value of such interactive exercises is laid out in a section examining what learning objectives can be achieved by using role-play scenarios. These include promoting student interaction and input, and promoting student curiosity and creativity. The preparations necessary for conducting such an exercise are laid out, followed by a description of the exercises as they were conducted in the classroom. Finally, an assessment of the exercises provides useful feedback on the degree to which specific learning objectives were achieved, and how such exercises can be modified to be even more effective.

Nonoperative and Operative Management of Snapping Scapula

Abstract: Snapping scapula is a painful crepitus of the scapulothoracic articulation. This crepitus is a grinding or snapping noise with scapulothoracic motion that may or may not accompany pain. This condition is commonly seen in overhead-throwing athletes. Treatment of patients with this syndrome begins with nonoperative methods; when nonoperative treatment fails, several surgical options exist. This article will discuss both nonoperative and operative management of this common shoulder condition.

Opportunistic traffic scheduling over multiple network paths

Abstract: Multipath routing enables a network's traffic to be split among two or more possibly disjoint paths in order to reduce latency, improve throughput, and balance traffic loads. Yet, once the control plane establishes multiple routes, a policy is needed for efficiently splitting traffic among the selected paths. In this paper, we introduce opportunistic multipath scheduling (OMS), a technique for exploiting short term variations in path quality to minimize delay, while simultaneously ensuring that the splitting rules dictated by the routing protocol are satisfied. In particular, OMS uses measured path conditions on time scales of up to several seconds to opportunistically favor low-latency high-throughput paths. Consequently, OMS ensures that over longer time scales relevant for traffic management policies, traffic is split according to the ratios determined by the routing protocol. We develop a model of OMS and derive an asymptotic lower bound on the performance of OMS as a function of path conditions (mean, variance, and Hurst parameter) for self-similar traffic. An example finding from the model is that long-time-scale traffic fluctuations represented by a larger Hurst parameter improve the performance gain of OMS vs. round-robin scheduling, even under paths that are statistically identical. Finally, we use an extensive simulation-based performance study to evaluate the accuracy of the analytical model, explore the impact of OMS on TCP throughput, and study the impact of factors such as delayed measurements

Automated detection and classification of vascular abnormalities in diabetic retinopathy

Abstract: Diabetic retinopathy is a progressive ocular disease. The disease may advance from mild to severe non-proliferative diabetic retinopathy. This paper proposes a method for automated detection and classification of vascular abnormalities in diabetic retinopathy. The vascular abnormalities are detected using scale and orientation selective Gabor filter banks. The proposed method classifies the retinal image as mild or severe case based on the outputs obtained from Gabor filters.

Supramolecular Triads Formed by Axial Coordination of Fullerene to Covalently Linked Zinc Porphyrin−Ferrocene(s): Design, Syntheses, Electrochemistry, and Photochemistry

Abstract: Supramolecular triads have been constructed by using covalently linked zinc porphyrin−ferrocene(s) dyads, self-assembled via axial coordination to either pyridine- or imidazole-appended fulleropyrrolidine. These triads were characterized by optical absorption, computational, and electrochemical methods. The calculated binding constants (K) revealed stable complexation and suggested the existence of intermolecular interactions between the ferrocene and fullerene entities. Accordingly, the optimized geometry obtained by ab initio B3LYP/3-21G(*) methods revealed closely spaced ferrocene and fullerene entities in the studied triads. Photoinduced charge-separation and charge-recombination processes were examined in the dyads and triads by means of time-resolved transient absorption and fluorescence lifetime measurements. In the case of zinc porphyrin−ferrocene(s) dyads, upon photoexcitation, efficient (ΦCS = 0.98) to moderate (ΦCS = 0.54) amounts of electron transfer from the ferrocene to the singlet excited z...

The NDNQI-Adapted Index of work satisfaction.

Abstract: The valid measurement of nurses' job satisfaction is critical because job satisfaction is important for the retention of qualified nurses to provide patient care in hospitals. Two studies were conducted to adapt the Stamps Index of Work Satisfaction (1997b) to measure work satisfaction at the patient care unit level for use by the National Database of Nursing Quality Indicators (NDNQI). In Study 1 (n = 918 RNs) exploratory factor analysis of data obtained using the NDNQI-Adapted Index replicated the conceptual dimensions of the Stamps measure. Associations with scores on Job Enjoyment were evidence that the Index measured the intended construct. Using theta, the reliability of the composite subscales was .91. The adapted Work Satisfaction subscale scores explained 46% of the variance in Job Enjoyment, with each subscale contributing uniquely (p < .001). In Study 2 (n = 2277 RNs) confirmatory factor analysis using structural equation modeling supported the 7-subscale structure for the Adapted Index (CFI [719] = .88; RMR = .05). Replication of associations between scores on the Index subscales and Job Enjoyment provided further evidence regarding validity of the data, since the Work Satisfaction subscales explained 56% of the variance in Job Enjoyment. The feasibility of using an on-line version of the Adapted-Index for data collection was demonstrated. The findings from the two studies indicate that the adapted Index of Work Satisfaction has a structure similar to the original instrument and is a reliable and valid measure of work satisfaction at the patient care unit level.

A Contingency Perspective of Communication, Conflict Resolution and Buyer Search Effort in Buyer‐Supplier Relationships

Abstract: SUMMARY This study investigates the moderating effects of buying context on the relationship between communication elements and the effort buyers exert while searching for new suppliers throughout a buyer-supplier relationship development process A mail survey of members of the Institute for Supply Management™ was conducted and the data were analyzed using moderated regression The results suggest that company size, buyer experience, relationship duration and relationship importance affect the association between a buyer's search effort and the communication elements Interestingly, the buying context affects the relationship between search effort and the communication elements in different ways and to a different extent in each stage of the relationship development process

The Evolution of Irradiated Planets: Application to Transits

Abstract: Extending the theory that we derived recently for HD 209458b to different cases of strongly irradiated gaseous exoplanets, we have calculated the consistent evolution of a new transiting planet, OGLE-TR-56b, for its recently revised mass determination. The theory is shown to successfully reproduce the observed radius for the proper age of the system. We also examine the dissipation of kinetic energy at the planet's internal adiabat due to atmospheric winds and place constraints on the efficiency of this process. We show that a fraction ~0.1%-0.5% of the incident flux transformed into thermal energy deposited at the adiabatic level can accommodate the observed radii of both OGLE-TR-56b and HD 209458b. The present theory yields quantitative predictions on the evolution of the emergent spectrum and fundamental properties of hot jupiters. The predictions for radius, luminosity, temperature as a function of the planet's mass, and orbital distance can be used as benchmarks for future detections of transit planets.

An energy-efficient virtual MIMO architecture based on V-BLAST processing for distributed wireless sensor networks

Abstract: An energy-efficient virtual multiple-input multiple-output (MIMO) communication architecture based on V-BLAST receiver processing is proposed for energy-constrained, distributed wireless sensor networks. The proposed scheme does not require transmitter-side sensor cooperation unlike previously proposed virtual MlMO schemes for wireless sensor networks. In sensor networks with single-antenna data gathering nodes, the virtual MIMO operation is realized via the receiver-side local communication assuming node cooperation. Numerical results show that the significant energy savings are offered by the proposed virtual MIMO architecture in distributed wireless sensor networks. These results also indicate that while rate optimization over transmission distance may offer improved energy efficiencies in some cases, this is not essential in achieving energy savings as opposed to previously proposed Alamouti scheme-based virtual MIMO implementations. In fact, in most scenarios a fixed-rate virtual MIMO system with binary phase-shift-keying (BPSK) can achieve performance very close to that of a variable-rate system with optimized rates. However, these results also indicate that the proposed scheme can lead to larger delay penalties compared to a traditional SISO communication based sensor network as the order of the virtual MIMO architecture grows. This results in a trade-off between the achievable energy efficiency and the delay incurred, making the proposed virtual V-BLAST based MIMO scheme an especially good candidate communication architecture for energy-starved and delay-tolerant wireless sensor networks having no inter-sensor communication.

Upper Jurassic thrombolite reservoir play, northeastern Gulf of Mexico

Abstract: In the northeastern Gulf of Mexico, Upper Jurassic Smackover inner ramp, shallow-water thrombolite buildups developed on paleotopographic features in the eastern part of the Mississippi Interior Salt basin and in the Manila and Conecuh subbasins. These thrombolites attained a thickness of 58 m (190 ft) and were present in an area of as much as 6.2 km2 (2.4 mi2). Although these buildups have been exploration targets for some 30 yr, new field discoveries continue to be made in this region. Thrombolites were best developed on a hard substrate during a rise in sea level under initial zero to low background sedimentation rates in low-energy and eurytopic paleoenvironments. Extensive microbial growth occurred in response to available accommodation space. The demise of the thrombolites corresponded to changes in the paleoenvironmental conditions associated with an overall regression of the sea. The keys to drilling successful wildcat wells in the thrombolite reservoir play are to (1) use three-dimensional seismic reflection technology to find paleohighs and to determine whether potential thrombolite reservoir facies occur on the crest and/or flanks of these features and are above the oil-water contact; (2) use the characteristics of thrombolite bioherms and reefs as observed in outcrop to develop a three-dimensional geologic model to reconstruct the growth of thrombolite buildups on paleohighs for improved targeting of the preferred dendroidal and chaotic thrombolite reservoir facies; and (3) use the evaporative pumping mechanism instead of the seepage reflux or mixing zone models as a means for assessing potential dolomitization of the thrombolite boundstone.

Child Impulsiveness—Inattention, Early Peer Experiences, and the Development of Early Onset Conduct Problems

Abstract: The conjoint influence of child impulsiveness-inattention (I/I) and peer relationships on growth trajectories of conduct problems was assessed in a community sample of 267 boys and girls I/I reliably predicted teacher- and parent-reported conduct problems at kindergarten entry and growth in those problems over the next 2 years for boys and girls The relation of boys' I/I to conduct problems was mediated, in part, by peer rejection and involvement in coercive exchanges with peers The relation of girls' I/I to conduct problems was less clearly mediated by peer processes, but peer difficulties had additive effects The impact of peer relationships on trajectories of conduct problems was apparent to parents as well as to teachers Although I/I increments risk for early and persisting conduct problems in concert with poor peer relationships, it does so in complex and gender-specific ways