cssi/SciSciGPT-SciSciNet huggingface dataset:
SU-E-T-434: A Comparison Between Cyberknife-Based and LINAC-Based Fiducial-Less Stereotactic Body Radiotherapy of Lung Lesions Without Respiratory Gating Or Tracking

Purpose: To benchmark the tracking accuracy of Accuray Cyberknife (CK) newly released Lung Optimized Treatment (LOT) tracking algorithm in 0‐View mode and investigate the dosimetric differences of lung Stereotactic Body Radiotherapy (SBRT) based on internal target volume (ITV) using Cyberknife and LINAC. Methods: CT scans at normal inspiration and normal expiration of CIRIS thorax motion phantom were fused and an ITV was created. A 5mm expansion around the ITV resulted in the planning target volume (PTV). Two individual plans were generated in Accuray MultiPlan using LOT 0‐View technique, with two tracking distances (3.9cm and 7.1cm) from the target. Kodak EBT Gafchromic film, carefully marked to identify the target volume, was inserted in the moving target of the phantom during delivery. H‐D calibration of the film was performed for absolute dosimetry purposes. An in‐house program processed the scanned films after delivery to perform a dosimetric comparison between plan and treatment and verify tracking accuracy. Also, a LINAC‐based plan (Eclipse) and CK‐based plan (Multiplan) for the same PTV were generated to compare the two systems in the planning stage. Results: The film dosimetric results indicate that LOT algorithm in 0‐View mode is accurate. Good target coverage was achieved in both CK‐based and LINAC‐based plans: 96% and 98%, respectively. Critical structure doses for CK‐based and LINAC‐based plans, respectively, were: total lung V20/V5 9.2%/37.3% and 7.5%/21.1%, and maximum cord dose 9.8Gy and 11.14Gy. Conclusion: Current results show LINAC‐based plans are superior to CK‐based plans, achieving lower lung integral dose with minor differences in cord dose and target coverage, and having added advantages of faster delivery and confidence during setup with lesion visualization using cone beam CT (CBCT). More work will be done to examine if CK‐based plans are advantageous when treating more complex cases, when no fiducial placement and no respiratory tracking is desired.
DNA hypermethylation in lung cancer is targeted at differentiation-associated genes

Aberrant DNA hypermethylation of tumor suppressor genes is thought to be an early event in tumorigenesis. Many studies have reported the methylation status of individual genes with known involvement in cancer, but an unbiased assessment of the biological function of the collective of hypermethylated genes has not been conducted so far. Based on the observation that a variety of human cancers recapitulate developmental gene expression patterns (that is activate genes normally expressed in early development and suppress late developmental genes), we hypothesized that the silencing of differentiation-associated genes in cancer could be attributed in part to DNA hypermethylation. To this end, we investigated the developmental expression patterns of genes with hypermethylated CpG islands in primary human lung carcinomas and lung cancer cell lines. We found that DNA hypermethylation primarily affects genes that are expressed in late stages of murine lung development. Gene ontology characterization of these genes shows that they are almost exclusively involved in morphogenetic differentiation processes. Our results indicate that DNA hypermethylation in cancer functions as a selective silencing mechanism of genes that are required for the maintenance of a differentiated state. The process of cellular de-differentiation that is evident on both the microscopic and transcriptional level in cancer might at least partly be mediated by these epigenetic events. Our observations provide a mechanistic explanation for induction of differentiation upon treatment with DNA methyltransferase inhibitors.
Epstein-Barr virus vectors for gene expression and transfer

Vectors based on components of Epstein-Barr virus (EBV) have found increasingly wide applications in biotechnology. Three areas of recent advancement comprise the use of EBV vectors to improve the convenience of gene expression systems, the development of EBV vectors for gene transfer in gene therapy, and the use of EBV components to generate large vectors carrying sizable regions of genomic DNA.
Displacement of Mn2+ from RNA by K+, Mg2+, neomycin B, and an arginine-rich peptide: indirect detection of nucleic acid/ligand interactions using phosphorus relaxation enhancement.

We have developed a novel method to study the interactions of nucleic acids with cationic species. The method, called phosphorus relaxation enhancement (PhoRE), uses 1H-detected 31P NMR of exogenous probe ions to monitor changes in the equilibrium between free Mn2+ and Mn2+ bound to the RNA. To demonstrate the technique, we describe the interactions of four RNA molecules with metal ions (K+ and Mg2+), a small molecule drug (neomycin b), and a cationic peptide (RSG1.2). In each case, cationic ligand binding caused Mn2+ to be displaced from the RNA. Free Mn2+ was determined from its effect on the T2 NMR relaxation rate of either phosphite (HPO32-) or methyl phosphite (MeOPH, CH3OP(H)O2-). Using this method, the effects of [RNA] as low as 1 μM could be measured in 20 min of accumulation using a low field (200 MHz) instrument without pulsed field gradients. Cation association behavior was sequence and [RNA] dependent. At low [K+], Mn2+ association with each of the RNAs decreased with increasing [K+] until ∼40...
Vendor Relationships As Predictors of Organizational Buyer ComplaintResponse Styles

Abstract Understanding how industrial buyers complain when dissatisfied with a supplier is an increasingly important topic. Complaints from buyers can be expressed in a variety of behaviors, such as contracting the vendor about the problem, switching suppliers, and warning other buyers about poor vendor performance. The development of appropriate policies and procedures is essential in reducing buyer complaints that damage the seller's reputation. This article develops a typology of organizational buyer complaint response styles and identifies a set of variables useful in predicting these styles. Managerial implications drawn from the empirical results can help marketers develop programs to promote more favorable forms of buyer complaint behavior.
IMPACT DC: Reconceptualizing the Role of the Emergency Department for Urban Children with Asthma

With a grant from the Robert Wood Johnson Foundation, we developed and evaluated an emergency department (ED) based intervention in which patients returned to the ED for a structured 90-minute appointment during the weeks after an acute asthma visit. The intervention, which emphasized disease management using national asthma guidelines, successfully reduced overdependence on EDs for episodic care of asthma while also improving asthma-related quality of life among a cohort of low-income, urban, and largely minority children with moderate to severe asthma and a history of ED recidivism. We have since sustained and grown this multifaceted approach to addressing the disparities in asthma care and outcomes among children in our community.
Mating system evolution and worker caste diversity in Pheidole ants

The efficiency of social groups is generally optimized by a division of labour, achieved through behavioural or morphological diversity of members. In social insects, colonies may increase the morphological diversity of workers by recruiting standing genetic variance for size and shape via multiply mated queens (polyandry) or multiple-breeding queens (polygyny). However, greater worker diversity in multi-lineage species may also have evolved due to mutual worker policing if there is worker reproduction. Such policing reduces the pressure on workers to maintain reproductive morphologies, allowing the evolution of greater developmental plasticity and the maintenance of more genetic variance for worker size and shape in populations. Pheidole ants vary greatly in the diversity of worker castes. Also, their workers lack ovaries and are thus invariably sterile regardless of the queen mating frequency and numbers of queens per colony. This allowed us to perform an across-species study examining the genetic effects of recruiting more patrilines on the developmental diversity of workers in the absence of confounding effects from worker policing. Using highly variable microsatellite markers, we found that the effective mating frequency of the soldier-polymorphic P. rhea (avg. meN = 2.65) was significantly higher than that of the dimorphic P. spadonia (avg. meN = 1.06), despite a significant paternity skew in P. rhea (avg. B = 0.10). Our findings support the idea that mating strategies of queens may co-evolve with selection to increase the diversity of workers. We also detected patriline bias in the production of different worker sizes, which provides direct evidence for a genetic component to worker polymorphism.
Fabrication-tolerant high quality factor photonic crystal microcavities.

A two-dimensional photonic crystal microcavity design supporting a wavelength-scale volume resonant mode with a calculated quality factor (Q) insensitive to deviations in the cavity geometry at the level of Q 2×10^4 is presented. The robustness of the cavity design is confirmed by optical fiberbased measurements of passive cavities fabricated in silicon. For microcavities operating in the λ = 1500 nm wavelength band, quality factors between 1.3-4.0×10^4 are measured for significant variations in cavity geometry and for resonant mode normalized frequencies shifted by as much as 10% of the nominal value.
Statistics of holons in the quantum hard-core dimer gas

The nature of holons, and in particular, their statistics, are studied in the context of a two-dimensional quantum hard-core dimer gas. This model has been shown to embody the low-energy physics of the short-ranged resonating-valence-bond state. We find that, depending on detailed energetic considerations, the holons either bind a half flux quantum of "statistical flux," in which case they are fermions, or they are free, in which case they are bosons. The exchange energy is shown to favor a fermionic hole while the hole kinetic energy (which generally exceeds the exchange energy) favors bosonic holes. Finally, it is shown that even in the bosonic case, flux quantization is in units of $\frac{\mathrm{hc}}{2e}$.
Multiphoton‐absorbing organic materials for microfabrication, emerging optical applications and non‐destructive three‐dimensional imaging

Non-resonant two-photon absorption (TPA) can be defined as the simultaneous absorption of two photons, via a virtual state, in a medium. TPA exhibits a quadratic dependence of absorption on the incident light intensity, resulting in highly localized photoexcitation. Recent developments in the design and synthesis of efficient, stable TPA organic materials are discussed. Microfabrication via two-photon induced free radical polymerization of acrylate monomers and cationic polymerization of epoxide monomers was accomplished using commercially available photoinitiators, and also a custom-made compound possessing high two-photon absorptivity. Two-photon facilitated photoisomerization of a fulgide in solution and in a polymer thin film demonstrated two-photon induced photochromism and its application in interferometric image recording, respectively. Greatly enhanced signal-to-noise ratios and resolution were achieved in the non-destructive three-dimensional two-photon fluorescence imaging of a polymer-coated substrate versus conventional single-photon laser scanning confocal microscopic imaging. Multifunctional TPA organic materials and fabrication of functional microstructures are also discussed. Copyright © 2000 John Wiley & Sons, Ltd.
Distance and non-randomness of seed dispersal by the dwarf cassowary Casuarius bennetti

To determine the sources of dispersed seeds I inserted unique tags in fallen Aglaia aff. flavida seeds before dwarf cassowaries (Casuarius bennetti) ate the fruits containing the seeds. Thirty naturally-dispersed, marked seeds were re-located in cassowary droppings in a 400 ha study area. The distribution of seed dispersal distances did not differ significantly from a normal distribution with a mean dispersal distance of 388 m, SD=196.8. Mean distance of dispersed seeds to nearest mature conspecific tree was 170 m, SD=108.4 ; dispersed seeds usually landed closer to other conspecifics than their parent. The estimated distribution of all seeds (including many undispersed seeds) was leptokurtic, creating high densities near source trees (> 0.035 seeds m -2 within 100 m of bole) that quickly tapered off ( 100 m from the bole) ; any density dependent effects are liable to be manifest only near parent trees. Cassowary movement patterns and resting behavior caused non-random dispersal of seeds. Seeds were preferentially moved to level sites uphill from their source trees along routes that did not cross steep terrain. Undispersed seeds generally landed downhill from source trees. This population of Aglaia would probably contract downhill into smaller, fragmented populations in the absence of cassowary-mediated dispersal.
Wiki a la carte: Understanding participation behaviors

This panel focuses on trends in research on Wikis. Wikis have become prevalent in our society and are used for multiple purposes, such as education, knowledge sharing, collaboration, and coordination. Similar to other popular social computing tools, they raise new research questions and have attracted the attention of researchers in information science. While some focus on the semantic web, the automatic processing of data accumulated by users, and tool improvements, others discuss social implications of Wikis. This panel presents five studies that address the social uses of Wikis that support information sharing. In their studies, the panelists use a variety of novel applications of research methods, such as action research, and online ethnography, site observation, survey, and interviews. The panelists will present their findings: Shachaf and Hara will discuss Wikipedians' norms and behaviors; Bonk will present collaborative writing on Wikibook; Mackey will discuss authorship and collaboration in PBwiki.com; Hemminger will share results from the early use of wikis for conference communications; and Stvilia will outline the community mechanism of information quality assurance in Wikipedia.
Contraction ratios for graph-directed iterated constructions

We provide necessary and sufficient conditions for a graph-directed iterated function system to be strictly contracting.
Diagnosis of gastrointestinal graft- versus -host disease

Allogeneic bone marrow transplantation is becoming increasingly performed for a variety of disorders but primarily for hematological malignancies. Graft-versus-host disease (GVHD), which often involves the GI tract, is one of the most common complications of this type of transplantation. The diagnosis of GI GVHD can be difficult to establish because of the nonspecific nature of associated symptoms, few diagnostic endoscopic findings, and potential difficulty in making a histological diagnosis. In this review, we summarize current concepts and controversies regarding the diagnostic evaluation for GI GVHD.
PHOTOIONIZATION STUDY OF SUPERSONICALLY COOLED CS FORMED IN THE EXCIMER PHOTODISSOCIATION OF CS2

Abstract The photoionization efficiency spectrum of supersonically cooled CS in the region of 1000-1100 A is presented. The CS transient molecules are prepared by 193 nm photodissociation of a pulsed supersonic CS2 free jet. The ionization energy for CS is determined to be 11.318 ± 0.007 eV. The observed PIE spectrum for CS and that for SO from the 193 nm photodissociation of a SO2 free jet support the conclusion that rotational and vibrational excitations of photofragments relax efficiently in the supersonic expansion.
Ketogenic treatment reduces deleted mitochondrial DNAs in cultured human cells

Impairment of mitochondrial energy metabolism has been associated with a wide range of human disorders. Large-scale partial deletions of mitochondrial DNA (mtDNA) cause sporadic Kearns-Sayre syndrome, a fatal multisystem disorder, in which the majority of mtDNAs in affected tissues have deletions (Delta-mtDNAs). Since most mtDNA-related diseases, including Kearns-Sayre syndrome, are recessive, only a few wild-type mtDNAs can compensate for the deleterious effects of many Delta-mtDNAs. We have developed a pharmacological approach to reduce the proportion of Delta-mtDNAs in vitro, in which we grow cells in medium containing ketone bodies, replacing glucose as the carbon source. Cells containing 100% Delta-mtDNA died after 5 days of treatment, whereas those containing 100% wild-type mtDNA survived. Furthermore, in a cloned heteroplasmic cell line, the proportion of wild-type mtDNA increased from 13% initially to approximately 22% after 5 days in ketogenic medium and was accompanied by a dramatic improvement in mitochondrial protein synthesis. We also present evidence that treatment with ketone bodies caused "heteroplasmic shifting" not only among cells (ie, intercellular selection) but also within cells (ie, intracellular selection). The demonstration that ketone bodies can distinguish between normal and respiratorily compromised cells points to the potential use of a ketogenic diet to treat patients with heteroplasmic mtDNA disorders.
1192U90 in Animal Tests That Predict Antipsychotic Efficacy, Anxiolysis, and Extrapyramidal Side Effects

1192U90 was developed on the assumption that antagonism of 5-HT2 receptors efficacy yields more potently than D2 receptors against positive and negative symptoms of schizophrenia with minimal liability for extrapyramidal side effects (EPSs), and that 5-HT1A agonism further reduces EPSs and provides anxiolytic and antidepressant activity. 1192U90 was submitted to four tests that predict antipsychotic efficacy (antagonism of apomorphine-induced climbing in mouse, antagonism of apomorphine-induced circling in rats with unilateral 6-OHDA lesions, antagonism of amphetamine-induced hyperlocomotion in rat, and inhibition of conditioned avoidance in rat), two tests of 5-HT2 function (antagonism of 5-MeODMT-induced head twitches in mouse and antagonism of 5-HTP-induced wet dog shakes in rat), and three tests that predict EPS liability (antagonism of apomorphine-induced stereotypy in mouse and rat and induction of catalepsy in mouse). ED50s (mg/kg PO) were as follows: climbing 10.1, circling 7.9, hyperlocomotion 6.6, and avoidance 5.7; head twitches 5 and wet dog shakes 4.6; stereotypy in mouse 91.1, stereotypy in rat 133.4, and catalepsy 192.4. The ratio of ED50 for stereotypy antagonism to ED50 for climbing antagonism was 9 (compared to 4, 3, and 4 for clozapine, risperidone, and haloperidol). The ratio of ED50 for catalepsy induction to ED50 for climbing antagonism was 19 (compared to 7, 2, and 17 for clozapine, risperidone, and haloperidol). 1192U90 was also submitted to three tests that predict anxiolysis: It produced only a small increase in punished lever pressing for food in rat (Geller-Seifter conflict test), which is specific for rapid-onset efficacy, but produced large increases in punished key pecking for food in pigeon and cork gnawing in rat, which identify the delayed onset 5-HT1A agonists such as buspirone. The results suggest that 1192U90 would be effective for positive and negative symptoms of schizophrenia, with minimal liability for EPSs, and may also have anxiolytic properties.
Howard odum and regional sociology

Howard W. Odum, the distinguished southern sociologist whose career spanned most of the first half of the twentieth century, is now largely forgotten by his own discipline, as is the subdiscipline of regional sociology that he essentially invented. But Odum and his fellow regionalists produced a body of work devoted to detailed description of the South and its institutions that is still widely appreciated by scholars in other disciplines. Much of this work was ahead of its time, in method and assumptions, and some of it was first‐rate intellectual craftsmanship. If it is not what we understand today to be sociology, perhaps that says more about the shortcomings of sociology than of this work.
Coactivator and corepressor regulation of the agonist/antagonist activity of the mixed antiestrogen, 4-hydroxytamoxifen

Mixed antiestrogens, such as 4-hydroxytamoxifen (4HT), act as either partial agonists or antagonists of estrogen receptor (ER) function in a tissue-, cell-, and promoter-specific manner, suggesting that intracellular factors modulate their ability to regulate transcription. To determine whether coactivators and corepressors have the capacity to modulate the relative agonist/antagonist activity of 4HT, ER-dependent gene expression was measured in the absence or presence of expression vectors for SRC-1 (steroid receptor coactivator-1) or SMRT (silencing mediator of retinoic acid and thyroid hormone receptors). In Hep G2 cells in which 4HT is an agonist, exogenous SRC-1 enhanced estradiol (E2)- and 4HT-stimulated transcription in a dose-dependent manner, while SMRT overexpression strongly reduced basal and 4HT-stimulated gene expression with no effect on E2 activity. These observations were not cell- or promoter-specific inasmuch as similar results were obtained in HeLa cells under conditions in which 4HT is an antagonist. A protein-protein interaction assay indicated that the full-length ER binds to SMRT in vitro. To assess whether relative coactivator and corepressor expression within a given cell could modulate the balance of 4HT agonist/antagonist activity, SRC-1 and SMRT were coexpressed. SMRT overexpression blocked SRC-1 coactivation of 4HT-stimulated gene expression and preferentially inhibited 4HT agonist activity whether or not exogenous SRC-1 was present. The cumulative data in this model system indicate that the relative expression of coactivators and corepressors can modulate 4HT regulation of ER transcriptional activity and suggest they could contribute to the tissue-specific ability of mixed antiestrogens to activate or inhibit ER-mediated gene expression.
Cushing's disease revisited☆☆☆

Harvey Cushing [I] presented and subsequently published his extraordinary study of basophilic pituitary adenomas in 1932. Validation of these observations followed long after his death through the fortunate coincidence of two developments: first, conclusive biochemical definition of pituitary-based hypercortisolism, for the first time differentiating this distinct clinical entity from other causes of hypercortisolism [2,3], and second, the evolution of transsphenoidal microsurgery not only providing an effective means of treating the disease but also permitting unequivocal documentation of ACTH-secreting microadenomas as a distinct entity [4]. Because it is now possible, in one simultaneous maneuver, to detect and remove minute adenomas situated in a pituitary gland of normal dimensions, the management of Cushing’s disease has undergone a revolutionary change. Until a superior form of treatment evolves, microsurgical removal of these remarkably occult adenomas offers the highest probability of restoring normal pituitary function to patients affected with the disease. The endocrinologic data from our initial series of patients were reported earlier [5]. When presented with a patient with Cushing’s disease, the surgeon can assume that the pituitary gland contains an ACTH-secreting adenoma. In a series of 44 intrasellar explorations in patients with Cushing’s disease, an adenoma was removed in every case. Three tumors, the smallest in the series, were missed at exploration and identified subsequently in serial sections of the excised glands. Microadenomas (diameter less than 10 mm) constituted the majority of adenomas.
The Demise of the Gene

The gene is losing its luster as a biological explanatory principle, but those who stand to profit from its supremacy are promoting it harder than ever. It is nearly 70 years since the Nobel Prize-winning physicist Erwin Schrodinger wrote: ‘‘The chromosome structures are . . . instrumental in bringing about the development they foreshadow. They are code law and executive power, or to use another simile, they are the architect’s plan and the builder’s craft in one’’ (Schrodinger 1945). (Another Nobel Laureate, the developmental biologist Sydney Brenner [2001, 34], later called this statement ‘‘Schrodinger’s fundamental error.’’) It is almost 30 years since still another Nobelist, the cancer biologist David Baltimore (1984), termed DNA the ‘‘executive suite’’ for which the rest of the cell is the ‘‘factory floor.’’
GABAergic-serotonergic interactions in regulating lordosis.

Abstract The GABA B agonist, baclofen, causes a dose-dependent decrease in lordosis, and this effect is attenuated following hypothalamic serotonin, (5-HT) lesions. Baclofen administration is associated with decrease 5-HT activity in the medial preoptic (mPOA) and ventromedial nuclei and enhanced 5-HT activity in the midbrain central gray, and with enhanced norepinephrine activity in the mPOA. Interactions between γ-aminobutyric acid (GABA) and 5-HT may, therefore, be important for the activation of lordosis.
Analysis of yeast MSH2-MSH6 suggests that the initiation of mismatch repair can be separated into discrete steps

The yeast MSH2-MSH6 complex is required to repair both base-pair and single base insertion/deletion mismatches. MSH2-MSH6 binds to mismatch substrates and displays an ATPase activity that is modulated by mispairs that are repaired in vivo. To understand early steps in mismatch repair, we analyzed mismatch repair (MMR) defective MSH2-msh6-F337A and MSH2-msh6-340 complexes that contained amino acid substitutions in the MSH6 mismatch recognition domain. While both heterodimers were defective in forming stable complexes with mismatch substrates, only MSH2-msh6-340 bound to homoduplex DNA with an affinity that was similar to that observed for MSH2-MSH6. Additional analyses suggested that stable binding to a mispair is not sufficient to initiate recruitment of downstream repair factors. Previously, we observed that MSH2-MSH6 forms a stable complex with a palindromic insertion mismatch that escapes correction by MMR in vivo. Here we show that this binding is not accompanied by either a modulation in MSH2-MSH6 ATPase activity or an ATP-dependent recruitment of the MLH1-PMS1 complex. Together, these observations suggest that early stages in MMR can be divided into distinct recognition, stable binding, and downstream factor recruitment steps.
Structural analysis of three subunits of laminin from teratocarcinoma-derived parietal endoderm cells☆

Abstract The structure of the three polypeptide chains of the laminin subunits and the number of glycosylation sites in each polypeptide chain were determined using peptide mapping by high-performance liquid chromatography. Analysis of the [35S]methionine-labeled underglycosylated laminin isolated from tunicamycin (TM)-treated cells revealed that the three subunits of laminin contain unique polypeptide chains. Analysis of [3H]glucosamine-labeled glycosylated laminin subunits showed that they are sialylated and that each subunit has 11–14 glycosylation sites.
Role of Microvascular Endothelial Cells in Inflammation

Endothelial cells are critical elements in the evolution of ail types of cutaneous inflammation. They participate through the synthesis and secretion of pro-inflammatory cytokines, including interleukin 1 (IL-1), IL-6, and IL-8, as well as M-CSF, G-CSF, GM-CSF, groa, and MCP. They also express a series of cell-surface proteins and glycoproteins known as cell adhesion molecules that allow circulating leukocytes to bind to endothelial cells and allow endothelial cells to bind to matrix proteins. The regulated expression of these molecules, including those in the integrin, immuno- globulin gene, and selectin families, allows for the precise trafficking of circulating leukocytes to sites of inflammation, injury, or immunologic stimulation in the skin. Furthermore, emerging evidence clearly indicates that selected differences exist between endothelial cells of the microvasculature and those that line large blood vessels. These include differences in secreted products, differences in the expression of cell adhesion molecules, and differences in cytokine-induced regulation of commonly expressed cell adhesion molecules, among others. Thus, a precise delineation of the biology of cutaneous microvascular endothelial cells is important to our understanding of cutaneous inflammation.
Comparison of Muscle Function in 2D and 3D Walking Simulations

Walking requires muscle coordination to provide support and forward progression of the center of mass. Previous modeling and simulation studies [1,2] have made significant progress to understand different muscle contributions in normal gait. However, it is difficult to compare results since they were based on different models (2D vs. 3D) and experimental data [1,2].Copyright © 2007 by ASME
Classical electrodynamics in terms of direct interparticle action

Many of our present hopes to understand the behavior of matter and energy rely upon the notion of field. Consequently it may be appropriate to re-examine critically the origin and use of this century old concept. This idea developed in the study of classical electromagnetism at a time when it was considered appropriate to treat electric charge as a continuous substance. It is not obvious that general acceptance in the early 1800's of the principle of the atomicity of electric charge would have led to the field concept in its present form. Is it after all essential in classical field theory to require that a particle act upon itself? Of quantum theories of fields and their possibilities we hardly know enough to demand on quantum grounds that such a direct self-interaction should exist. Quantum theory defines those possibilities of measurement which are consistent with the principle of complementarity, but the measuring devices themselves after all necessarily make use of classical concepts to specify the quantity measured. For this reason it is appropriate to begin a re-analysis of the field concept by returning to classical electrodynamics. We therefore propose here to go back to the great basic problem of classical physics-the motion of a system of charged particles under the influence of electromagnetic forces-and to inquire what description of the interactions and motions is possible which is at the same time (1) well defined (2) economical in postulates and (3) in agreement with experience.
Effect of streamwise spacing on periodic and random unsteadiness in a bundle of short cylinders confined in a channel

While flow across long tube bundles is considered classical data, pin-fin arrays made up of short tubes have become a growing topic of interest for use in cooling gas turbine airfoils. Data from the literature indicate that decreasing streamwise spacing increases heat transfer in pin-fin arrays; however, the specific mechanism that causes increased heat transfer coefficients remains unknown. The present work makes use of time-resolved PIV to quantify the effects of streamwise spacing on the turbulent near wake throughout various pin-fin array spacings. Specifically, proper orthogonal decomposition was used to separate the (quasi-) periodic motion from vortex shedding and the random motion from turbulent eddies. Reynolds number flow conditions of 3.0 × 103 and 2.0 × 104, based on pin-fin diameter and velocity at the minimum flow area, were considered. Streamwise spacing was varied from 3.46 pin diameters to 1.73 pin diameters while the pin-fin height-to-diameter ratio was unity and the spanwise spacing was held constant at two diameters. Results indicated that (quasi-) periodic motions were attenuated at closer streamwise spacings while the level of random motions was not strongly dependent on pin-fin spacing. This trend was observed at both Reynolds number conditions considered. Because closer spacings exhibit higher heat transfer levels, the present results imply that periodic motions may not contribute to heat transfer, although further experimentation is required.
Explaining Cattle Rancher Participation in Wildlife Conservation Technical Assistance Programs in the Southeastern United States

Abstract US natural resources and wildlife agencies have been increasing their efforts to involve cattle ranchers in wildlife conservation through technical assistance programs that provide for wildlife conservation activities. Understanding why ranchers choose to be involved in these programs is fundamental to increasing participation and ensuring their success. Using the theory of planned behavior as a theoretical model, we surveyed 1 093 ranchers in Alabama, Florida, Georgia, and Mississippi to explain and predict intention to participate in technical assistance programs, specifically, wildlife workshops and field days. All three theory components—attitude, subjective norm, and perceived behavioral control—were important to intent to participate and explained 41% of the variance, with perceived behavioral control and subjective norm having the greatest standardized effects (β = 0.329 and β = 0.316, respectively). Investigation of the construct components yielded insight into how agencies could increase participation. Ranchers generally held positive attitudes toward wildlife workshops, perceiving them to be a good way to learn about wildlife management and perceiving that most ranches were suitable for wildlife, an instance of perceived behavioral control. However, ranchers did not perceive that workshops and field days were widely advertised or promoted, limiting the amount of perceived control they had over their participation. Additionally, ranchers identified normative groups whose opinions were important to them, namely their families, friends and neighbors, fellow ranchers, and agency staff. However, these same groups were not seen to actively encourage ranchers to participate in technical field days and workshops. Using key members of these normative groups to advertise and promote workshops and field days among their peers should increase rancher behavioral control and attitudes associated with technical workshops and field days. Employing strategies from this research to increase attendance at technical workshops and field days should improve wildlife conservation technical assistance program effects.
Middleware to enhance mobile communications for road safety and traffic mobility applications

Middleware has emerged as an important architectural component in supporting distributed applications. The role of middleware is to present a unified programming model to application writers and to mask out problems of heterogeneity and distribution. It is motivated by the convergence of the embedded sensor and mobile communication revolutions in the automobile industry. The vehicle fleet is morphing into a vast mobile sensor fleet. The authors provide a middleware architecture and implementation that addresses the needs of a distributed system of mobile sensors comprised of vehicles and intersections producing traffic-related data for traffic safety and operations. The authors discuss the technical challenges that the middleware addresses and describe a prototype implementation. Traffic management, intersection safety and vehicle-to-vehicle safety applications are three applications described and implemented on the middleware. The authors conclude their paper with conducting performance measures that relate to the cost of overhead incurred from using the middleware. The measurements show the middleware is efficient enough for the road safety and congestion relief applications presented.
Asymmetric information about rivals' types in standard auctions

Abstract We study auctions in which bidders may know the types of some rival bidders but not others. This asymmetry in bidders' knowledge about rivals' types has different effects on the two standard auction formats. In a second-price auction, it is weakly dominant to bid one's valuation, so the knowledge of rivals' types has no effect, and the good is allocated efficiently. In a first-price auction, bidders refine their bidding strategies based on their knowledge of rivals' types, which yields an inefficient allocation. We show that the inefficient allocation in the first-price auction translates into a poor revenue performance. Given a standard regularity condition, the seller earns higher expected revenue from the second-price auction than from the first-price auction, whereas the bidders are better off from the latter.
Designing an authoring environment for community-created virtual heritage environments: experiences with the geografia platform

The melding of geographic data and traditional storytelling methods demonstrates great potential for educators across the social sciences. However, despite the drive toward web 2.0 technologies, authoring a location-based narrative for mobile platforms remains a high-barrier proposition difficult to crowd source. Geografia is an authoring tool that gives communities the power to create a virtual heritage environment detailing their town's history. This paper discusses the design of the Geografia platform and the implications raised from its first deployment in which approximately 80 secondary school students collaborated to form a geo-narrative of an event in their community's history.
Variations Associated with Cores and Gaps of a Pacific Narrow Cold Frontal Rainband

Abstract A NOAA P-3 instrumented aircraft observed an intense, fast-moving narrow cold frontal rainband (NCFR) as it approached the California coast on 19 February 2001 during the Pacific Coastal Jets Experiment. Airborne Doppler radar data obtained while the frontal system was well offshore indicated that a narrow ribbon of very high radar reflectivity convective cores characterized the rainband at low levels with echo tops to ∼4–5 km, and pseudo-dual-Doppler analyses showed the low-level convergence of the prefrontal air. The NCFR consisted of gaps of weaker reflectivity and cores of stronger reflectivity along its length, perhaps as a result of hydrodynamic instability along its advancing leading edge. In contrast to some earlier studies of cold frontal rainbands, density-current theory described well the motion of the overall front. The character of the updraft structure along the NCFR varied systematically along the length of the precipitation cores and in the gap regions. The vertical shear of the c...
Alanine Scanning of the Hepatitis C Virus Core Protein Reveals Numerous Residues Essential for Production of Infectious Virus

Hepatitis C virus (HCV) is an important human pathogen affecting an estimated 3% of the world's population. Recent advances have enabled in vitro propagation of the virus and allow assembly and egress to be investigated for the first time. As a component of the virion, the HCV core protein likely functions primarily in infectious virus production, although little is known about the determinants of this activity. To investigate the roles of core in the viral life cycle, we performed a comprehensive deletion and alanine scanning mutagenesis study of this protein in the context of a genotype 2a reporter virus. We have confirmed that core protein is essential for infectious virion production and have identified numerous residues required for this role. The infectivity of several assembly-defective core mutants could be rescued by compensatory mutations identified in p7 and NS2, suggesting genetic interactions with core and highlighting the importance of these nonstructural proteins in infectious virion morphogenesis.
Approximately-strategyproof and tractable multi-unit auctions

We present an approximately-efficient and approximately-strategyproof auction mechanism for a single-good multi-unit allocation problem. The bidding language in our auctions allows marginal-decreasing piecewise constant curves. First, we develop a fully polynomial-time approximation scheme for the multi-unit allocation problem, which computes a (1+e)≈ in worst-case time T = O(n3/e), given n bids each with a constant number of pieces. Second, we embed this approximation scheme within a Vickrey-Clarke-Groves (VCG) mechanism and compute payments to n agents for an asymptotic cost of O(T log n). The maximal possible gain from manipulation to a bidder in the combined scheme is bounded by e/(1+e) V, where V is the total surplus in the efficient outcome.
Modeling diurnal rhythms with an array of phase dynamic oscillators

Behavior of living organisms is strongly modulated by light especially by the day and night cycle giving rise to a cyclic pattern of activities. Such a pattern helps the organism to coordinate their activities and maintain a balance between what could be performed during the dasiadaypsila and what could be relegated to dasianightpsila. This cyclic pattern, called the dasiacircadian rhythmpsila, is a biological phenomenon observed in a large number of organisms ranging from unicellular bacteria to human beings and is present in data collected at various levels viz. transcriptome, proteome etc. In this paper, our goal is to analyze transcriptome data from cyanothece, a photosynthetic cyanobacteria, for the purpose of discovering genes whose expressions are rhythmic, especially those for which these rhythms have a 24 hours cycle. Subsequently we propose a model with a network of three phase oscillators for each one of the twenty four hours cycle. Each of the three phase oscillators is chosen to maintain a phase difference of 120 degrees between each other. All the oscillators are connected to an internal clock that is designed to maintain a phase activity close to a master clock derived using KaiC proteins. In cyanobacteria it is believed that the KaiC proteins provide the internal rhythm. The model parameters, viz. connection strengths between the master clock and peripheral oscillators and the parameters computing the linear combinations of the oscillator phase variables, are optimized to provide a close match to the observed gene expressions even when the frequency of the internal clock and the natural frequencies of the oscillators vary within a certain range. As a final step, the oscillator network model has been used to isolate genes, and hence the associated subprocesses, whose expression cycles are robust with respect to variations in the oscillator frequencies.
An internet-based computing platform for the boundary element method

Computers combined with the Internet are dramatically changing the engineering practices in design and analysis. More and more engineering software applications are moving to the Internet, prompted by the promising advantages, such as easy access for users everywhere with an Internet connection, easy upgrade of the software, easy control of the software. All these advantages will contribute to faster and cost-effective engineering software development and applications. Successful applications of the Internet computing depend largely on the speed of data transfer on the network. The boundary element method (BEM) has the inherent advantages over other domain-based numerical methods, because the size of the BEM model files are always considerably smaller, leading to faster data transfer on the current network. In this paper, a successful investigation in implementing the BEM on the Internet is presented. A BEM code for 2D elastostatic problems is used as the first solver in this work. A graphical-user interface (GUI) for the pre- and post-processing using Java, which provides platform-independent applications, is developed and implemented on the Internet. Demonstration problems using the developed platform clearly show the feasibility of the Internet-based computing and the potentials of this platform for future BEM development with further research.
A pipelined 13-bit 250-ks/s 5-V analog-to-digital converter

A pipelined, 13-bit, 250-ksample/s (ks/s), 5-V, analog-to-digital (A/D) converter has been designed and fabricated in a 3- mu m, CMOS technology. Monotonicity is achieved using a reference-feedforward correction technique instead of (self-) calibration of trimming to minimize the overall cost. The prototype converter requires 3400 mil/sup 2/, and consumes 15 mW. >
Screening Patients with Stroke for Rehabilitation Needs: Validation of the Post-Stroke Rehabilitation Guidelines

Background. The authors assessed patients with acute stroke to determine whether the systematic use of brief screening measures would more efficiently detect cognitive and sensory impairment than s...
A VLSI design course for process engineers

The authors describe the background of student process engineers in microelectronic engineering and compare the basic VLSI design course requirements of these students with those in computer engineering. An outline of the course is then provided. The benefit of having both a fabrication facility and a sophisticated design environment as examples is shown to be important in an overview course. The computer engineering department serves as the role model for a sophisticated VLSI design group. Well-rounded process engineers capable of discussing design aspects of an integrated circuit problem are the desired result of this course. >
Simulating cholinesterase inhibition in birds caused by dietary insecticide exposure

Abstract We describe a stochastic simulation model that simulates avian foraging in an agricultural landscape to evaluate factors affecting dietary insecticide exposure and to predict post-exposure cholinesterase (ChE) inhibition. To evaluate the model, we simulated published field studies and found that model predictions of insecticide decay and ChE inhibition reasonably approximated most observed results. Sensitivity analysis suggested that foraging location usually influenced ChE inhibition more than diet preferences or daily intake rate. Although organophosphorus insecticides usually caused greater inhibition than carbamate insecticides, insecticide toxicity appeared only moderately important. When we simulated impact of heavy insecticide applications during breeding seasons of 15 wild bird species, mean maximum ChE inhibition in most species exceeded 20% at some point. At this level of inhibition, birds may experience nausea and/or may exhibit minor behavioral changes. Simulated risk peaked in April–May and August–September and was lowest in July. ChE inhibition increased with proportion of vegetation in the diet. This model, and ones like it, may help predict insecticide exposure of and sublethal ChE inhibition in grassland animals, thereby reducing dependence of ecological risk assessments on field studies alone.