cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrafast molecular beam epitaxy (MBE) CdTe photoconductor array for synchrotron radiation

MBE (molecular beam epitaxy) grown CdTe layers were processed to fabricate a photoconductor array for the diagnosis of short x-ray pulses from synchrotron radiation sources. The MBE (111)B CdTe layers were grown on (100)Si substrates. Photoconductor arrays were fabricated with gaps of 5 - 50 micrometers using conventional photolithography. Electroless Au or sputtered Au/Ni was used as a contact metal. The temporal response of the resulting CdTe photoconductor was measured with mode-locked 100 fsec Ti:Sapphire laser pulses. The FWHM of single crystalline CdTe photoconductor response pulse is as short as 37 psec with a 20 psec risetime. The photoconductor responds linearly to the x-ray tube photon flux with fixed accelerating voltage up to 40 kV. A significant response increase to the x-ray beam is observed for a layer with good crystalline quality. Spatial response of the CdTe photoconductor array was measured using rotating anode and synchrotron x rays for different beam sizes. Excellent spatial resolution was obtained from narrow angular radiation synchrotron x rays. The CdTe photoconductor was exposed to synchrotron x rays for 60 hours without any noticeable degradation.
Triamcinolone Reduces Neovascularization, Capillary Density and IGF-1 Receptor Phosphorylation in a Model of Oxygen-Induced Retinopathy

Increasing evidence links inflammation to retinovascular diseases. Several studies have shown that ocular fluid from diabetics have measurable inflammatory cytokines,1,2 and in an animal model of retinal neovascularization (NV), IL-6, and TNF-αwere temporally associated with subsequent release of angiogenic growth factors and the development of intravitreous NV.3 Inflammatory cells, such as leukocytes, have been implicated in the creation of avascular retinal areas in animal models of diabetes through endothelial cell apoptosis.4,5 These avascular retinal regions have been postulated to be the stimulus for NV6 through the overexpression of angiogenic growth factors,7 including vascular endothelial growth factor (VEGF). Conversely, an isoform of VEGF has been shown to increase leukocyte adherence to endothelial cells (ECs) leading to apoptosis and retinal avascularity.8 Thus, inflammation has been shown to cause NV through release of inflammatory cytokines and through the creation of avascularity, both linked to the increased expression of angiogenic factors. Anti-inflammatory therapy has been used to reduce NV in clinical inflammatory diseases such as posterior uveitis.9 Corticosteroids have been shown to downregulate induced VEGF in cultured Muller cells and in an RPE cell line.10,11 In addition, in a mouse model of oxygen-induced vaso-obliteration,12 the corticosteroid triamcinolone (TA) reduced capillary proliferation into the vitreous. Based on these findings, local delivery of corticosteroids into the eye has been considered to treat several retinovascular diseases.13–15 Clinical trials are under way to test intravitreous TA (1 mg/mL in vitreous) for macular edema in diabetic retinopathy and retinal vein occlusion.13 In addition, some investigators have tested the effects of TA in persistent NV after laser treatment in retinopathy of prematurity (ROP; Tawansy KA, et al. IOVS 2005;46:ARVO E-Abstract 3493). Besides the known clinical risks of cataract formation and increased intraocular pressure, recent studies have shown a toxic effect of TA on several retinal cell lines.16 To understand further the effect of TA in vivo, we used a well-accepted animal model of oxygen-induced retinopathy (OIR)17 that uses oxygen extremes similar to that of a preterm infant at risk for severe ROP,18 to study the effect of intravitreous injection of TA on NV, capillary density, and EC viability. In our short-term study, we found a dose-related decrease in NV and capillary density of the vascularized retina that appeared to be related to a delay in vascularization and the signaling pathway of insulin-like growth factor (IGF)-1. We also found a significant dose-dependent decrease in systemic weight gain of pups given intravitreous TA. Our findings may be relevant to the use of intravitreous TA in the management of retinovascular diseases, particularly those with ongoing intraretinal vascular development, such as ROP.
Effective Opportunity and Democratic Deliberation

This article develops a conception of effective opportunities of minority speakers that is tied to the possibilities of conceptual innovation in informally inclusive democratic deliberation. My argument proceeds through a critical engagement with Brian Barry and Bikhu Parekh on what it means to have an equal opportunity in a multicultural society. I claim that the exchange between Barry and Parekh reaches a conceptual deadlock over the possibility of producing a substantive revision in the concept of equality. I break this conceptual deadlock, however, by appeal to the potential of diverse speakers in informal deliberation to reinvent the meanings of their basic political terms of co-operation.
Engineering students and the education of the disadvantaged&#8212;The dartmouth experience

The current interest of college students in helping to solve society's problems is attacked in two novel programs at Dartmouth College, Hanover, N. H. Both undergraduate and graduate engineering students are involved in teaching, learning, and working at off-campus sites for a term. One group is in Jersey City, N. J., where they help to teach the ECCP developed "Man-Made World" (MMW) to inner-city high school seniors while working for the city government. Another group is at Tuskegee Institute in Alabama, where they help to teach a novel freshman engineering course based on the MMW as well as attend regular classes. Results of the programs are discussed and future plans are indicated.
Zoos: Their Changing Roles

The expansion of urban populations now makes it necessary for zoos to educate the generations growing up without any natural contact with wild creatures. Except at the zoo, the opportunities to know or even to become interested in wild creatures are largely vicarious for most city dwellers. Yet, the opinions of these urbanites may ultimately shape the future policies of conserv-ation in this country. Seen in this light, the educational challenges to the zoo naturalist and the conservationist are identical. The educational functions and methods of zoos (as of museums) are not those of the classroom, although zoos do collaborate with schools to supplement classroom education. Departments of education at several zoos, such as those in London, San Diego, and New York, supply programs, lectures, and tours for the local schools. The education departments of the San Diego and Bronx zoos now send lecturers with living animals to nearby elementary and secondary schools, operate an inservice teachers' course on the use of the zoo, conduct special summer courses, give tours, and manage an educational film program. In Philadelphia and Chicago, "zoo mobiles," each containing animal exhibits and a lecturer, visit schools and playgrounds. Zoos and universities located close to each other often establish joint programs. Subjects that might be taught in zoos include geography, evolution, and an appreciation of the term "renewable resoruces." At the 1967 annual conference of the American Association of Zoological Parks and Aquariums, in a symposium entitled "The use of zoos and aquaria in teaching animal behavior," A. W. Stokes remarked that
Reply to Dr. Beauchesne

We thank Dr. Beauchesne’s comment [1] regarding our work on extracranial glioblastoma [2] and, hereby, address the issues raised by him. First, the following search terms were used in the selection of published literature: (i) extracranial glioblastoma, and (ii) extracranial metastasis glioblastoma. Using these terms we identified 88 cases of this disorder. However, as Dr. Beauchesne pointed out, there are other nomenclatures that describe this disorder, most notably extra-neural glioblastoma. In our opinion, extracranial glioblastoma is a more commonly used, as well as a more appropriate, term to describe this type of metastasis outside of the cranium. Quite often, only the end organ involved is noted in the literature. When the term extra-neural is used, it excludes involvement of the peripheral nervous system. However, we think that glioblastoma from the brain or the spinal cord spreading to the peripheral nervous system would still offer a very important insight into the biology of extracranial glioblastoma. Therefore, the nomenclature of extracranial glioblastoma requires further definition and a consensus needs to be adopted for it use in describing this phenomenon. Second, although our data only included 88 published literatures, and according to Dr. Beauchesne this is underrepresentative to the overall literature of extracranial glioblastoma, our findings are still relevant. Significantly, we found that there was a lead-time bias in the survival of patients as a result of the introduction of modern neuroimaging, like CT and MRI. Furthermore, patients with lung metastases have a poorer prognosis than those with liver or neck metastases. Clearly, our findings are provocative and remain to be validated in a larger sample size. Lastly, it is an affirmation that our work is important when our discordant findings strike such a nerve in our colleague across the Atlantic. Traditionally, extracranial glioblastoma is viewed as an anomaly by neuro-oncologists. However, when we view it within the context of immunological surveillance and immune editing of metastases, it becomes clear that extracranial metastasis of glioblastoma is no different from systemic malignancies that metastasize to the brain. It also dispels the dogma that glioblastoma never goes outside of the brain—we just have not looked hard enough. Therefore, I agree with Dr. Beauchesne that more research needs to be done to determine the fundamental biology of extracranial glioblastoma.
Evaluation of tumor energy metabolism and microvascular blood flow after glucose or mannitol administration using 31P nuclear magnetic resonance spectroscopy and laser Doppler flowmetry.

Abstract The effects of intraperitoneally administered glucose or mannitol (5 mg/g body weight, 25% solutions) on tumor energy metabolism and tumor red blood cell flux were studied using 31 P-nuclear magnetic resonance spectroscopy and laser Doppler flowmetry. Isotransplants of a spontaneous murine fibrosarcoma growing in the hind foot dorsum were used. 31 P-nuclear magnetic resonance and laser Doppler flowmetry studies in glucose treated animals were performed on small (≅100 MM) and large (≅300 mm 3 ) tumors. In mannitol treated animals, tumors with an average volume of ≅200 mm 3 were used. Using this tumor model, intraperitoneally administration of the hypertonic sugar solutions caused similar declines in tumor microcirculation (mannitol, 60 ± 8% flow reduction; glucose, 72 ± 4% flow reduction; t=60 min). These changes were not glucose-specific and can primarily be explained by a water shift into the abdominal cavity and an associated hypovolemic hemoconcentration. A stable (small tumors) or transiently increased (large tumors) tumor energy metabolism which occurred after glucose administration was probably caused by a transiently increased glucose availability. The decline in energy metabolism after mannitol, a non-metabolized sugar alcohol, and the earlier decline in tumor pH seen in the glucose treated animals, supports this conclusion. The differences in the high energy phosphate response to glucose seen in small compared with large tumors, suggests that the baseline metabolic state of larger tumors includes a glucose deficiency in addition to tumor hypoxia.
Immunity and protection against Brucella abortus

Brucella abortus is an intracellular pathogen that causes disease in cattle and in humans. The response against B. abortus involves the whole gamut of the immune system, from innate to adaptive immunity resulting from stimulation of antigen-presenting cells, NK cells, CD4(+) and CD8(+) T cells, and B cells.
Metabolic adaptation with physical training: 14C-acetate incorporation into tissue lipids.

were significantly higher in the trained rats. In contrast, corresponding TC and FC concentrations for these three tissues varied. liver TC level was significantly less for the trained group, probably due to a reduction in the esterified moiety, since liver FC measures were unchanged. Training resulted in significantly lower TC concentrations in the selected tissues studied even though specific activity curves appeared similar for both groups. Our conclusions are that lipid metabolic adaptation; studied in vivo, occurs in tissues with training, but that these adaptations are not uniform across tissues, lipid moieties, or measurement parameters. P REVIOUS STUDIES on the effectiveness of physical training in altering lipid metabolism in experimental animals have primarily been concerned with changes in serum concentration or, to a lesser extent, with alterations in tissue lipid levels. Regardless of the tissue studied equivocal results have been obtained. For example, there have been reports of decreases in serum lipid concentrations’- as well as no differences4-6 following training. In a limited number of training studies measuring tissue lipid concentration changes conflicting results have also been reported for the liver,6,7 for skeletal muscle,3*4,8 and heart muscle.3’9 These discrepancies in lipid concentrations make it difficult to discern whether true adaptations in lipid metabolism occur with training. Furthermore, if adaptations in lipid metabolism do occur with training, determinations of changes in lipid concentrations alone do not give an indication of the underlying mechanisms. Since lipid concentrations may reflect the combined effects of both biosynthesis and degradation it seems reasonable that assessment of at least two of these three important parameters must be made if tissue adaptations to training are to be identified and better understood. In this study the hypothesis that physical training causes no adaptations in functionally different tissues as
DIAGNOSIS AND MANAGEMENT OF CHILDHOOD CHRONIC ITP 12

Immune thrombocytopenic purpura (ITP) in children may present either as an acute, self-limited, immune mediated condition or as a chronic autoimmune disorder. Ten to 20% of children develop chronic ITP with similar clinical features to those seen in adults. In acute ITP a cross-reactive immune response directed against an infectious agent has been proposed, while chronic ITP may be perpetuated by a constant HLA-DR - stimulated immune response with enhanced cylokine production, increased activation of T-cells and increased production of specific autoantibodies.
Gene-physical activity interactions in the etiology of obesity: behavioral considerations.

Understanding how genes, environment, and personal motivation operate to influence physical activity will require (i) inclusion of properly validated measures of putative mediators (e.g., cultural values, efficacy and control beliefs, goals, intentions, enjoyment, and self-management skills) and moderators (e.g., age or maturation, personality, race/ethnicity, fitness, fatness, skill, and competing behaviors) of physical activity, (ii) a search for candidate genes involved with motivational systems of energy expenditure in addition to energy intake pathways, (iii) assessment of specific features physical activity exposure (i.e., type, intensity, timing, and context), (iv) manipulation of physical activity or prospective observation of change in physical activity at multiple times, rather than cross-sectional association and linkage studies, and (v) use of statistical procedures that permit multilevel modeling (i.e., personal and group-level variables) of direct, indirect (i.e., mediated), and moderated (i.e., interactions of mediators with external factors) relations with physical activity within theoretical gene–environment networks.
Is a baccalaureate in nursing worth it? The return to education, 2000-2008.

Objective. A registered nurse (RN) license can be obtained by completing a baccalaureate degree (BSN), an associate degree (AD), or a diploma program. The aim of this article is to examine the return to baccalaureate education from the perspective of the nurse. Data Sources. National Sample Survey of Registered Nurses, 2000, 2004, and 2008. Study Design. The effect of education on RN wages is estimated using multivariate regression, both for initial education and for completing a second degree. The coefficients are used to calculate lifetime expected earnings. Multinomial logistic regression is used to examine the relationship between education and job title. Principal Findings. Lifetime earnings for nurses whose initial education is the BSN are higher than those of AD nurses only if the AD program requires 3 years and the discount rate is 2 percent. For individuals who enter nursing with an AD, lifetime earnings are higher if they complete a BSN. The BSN is associated with higher likelihood of being an advanced practice registered nurse, having an academic title, and having a management title. Conclusions. Because baccalaureate education confers benefits both for RNs and their patients, policies to encourage the pursuit of BSN degrees need to be supported.
Ralph W. Tyler: Mentor and Force for Excellence

(1985). Ralph W. Tyler: Mentor and Force for Excellence. Kappa Delta Pi Record: Vol. 22, No. 1, pp. 18-22.
Fluorescence Lifetime Imaging and Intravascular Ultrasound: Co-Registration Study Using Ex Vivo Human Coronaries

Fluorescence lifetime imaging (FLIM) has demonstrated potential for robust assessment of atherosclerotic plaques biochemical composition and for complementing conventional intravascular ultrasound (IVUS), which provides information on plaque morphology. The success of such a bi-modal imaging modality depends on accurate segmentation of the IVUS images and proper angular registration between these two modalities. This paper reports a novel IVUS segmentation methodology addressing this issue. The image preprocessing consisted of denoising, using the Wiener filter, followed by image smoothing, implemented through the application of the alternating sequential filter on the edge separability metric images. Extraction of the lumen/intima and media/adventitia boundaries was achieved by tracing the gray-scale peaks over the A-lines of the IVUS preprocessed images. Cubic spline interpolation, in both cross-sectional and longitudinal directions, ensured boundary smoothness and continuity. The detection of the guide-wire artifact in both modalities is used for angular registration. Intraluminal studies were conducted in 13 ex vivo segments of human coronaries. The IVUS segmentation accuracy was assessed against independent manual tracings, providing 91.82% sensitivity and 97.55% specificity. The proposed methodology makes the bi-modal FLIM and IVUS approach feasible for comprehensive intravascular diagnosis by providing co-registered biochemical and morphological information of atherosclerotic plaques.
SC-32TARGETING PROLIFERATION AND INVASION IN GLIOBLASTOMA VIA MITOTIC KINESINS

The nearly universal tumor recurrence seen in glioblastoma is driven by a myriad of factors including the invasive nature of the disease and a cellular heterogeneity that includes a more treatment resistant population termed glioblastoma stem cells (GSCs). In an effort to identify novel therapeutic targets for GBM with potential efficacy against the GSC sub-population, we queried the mRNA levels of mitotic regulators between GSCs and the neoplastic cells without stem cell characteristic, or non-GSCs. One target, the mitotic kinesin, Eg5, was consistently elevated in GSCs on both the mRNA and protein levels with increased expression correlated with higher-grade glioma and poor prognosis. Highly specific inhibitors of Eg5 are available and several have moved to phase I and II clinical trials in patients with solid malignancies. We found that GSCs exhibited a greater sensitivity to the Eg5 inhibitor ispinesib compared to non-GSCs from the same tumor and that inhibition of Eg5 compromised the key stem cell characteristics of self-renewal and tumor initiation. Using an orthotopic xenograft model, we demonstrated the first in vivo evidence for efficacy of Eg5 inhibition on glioblastoma tumor progression. An unexpected impact on invasion was observed following Eg5 inhibition resulting in the identification of a hitherto unappreciated role for Eg5 outside of cellular proliferation. We therefore propose that Eg5 inhibitors hold promise in preventing treatment resistance and recurrence in GBM and may provide a novel therapeutic target for GSCs.
Anomalous diffusion on and elastic vibrations of two square hierarchical lattices

Square hierarchical lattices are two-dimensional self-similar space-filling lattices which lack translational symmetry. In this paper, we report our study of the anomalous diffusion and lattice vibration properties of two distinct square hierarchical lattices.
On the representation types of category algebras of finite EI categories

Abstract A finite EI category is a small category with finitely many morphisms such that every endomorphism is an isomorphism. They include finite groups, finite posets and free categories of finite quivers as special cases. In this paper we consider category algebras of finite EI categories with two or three objects, describe some criteria for finite representation type, and classify the representation types for certain classes of finite EI categories with extra properties.
Pavage Grants and Urban Street Paving in Medieval England, 1249–1462:

Going back to the time of Henry III, pavage grants were presented by the Crown to the burgesses, bailiffs, and mayors of English towns, allowing those officials to assess tolls on imports and exports. They used the funds from these tolls for paving and repairing streets. The records of pavage grants are found primarily in the Calendar of Patent Rolls. The demands of an increasingly commercial economy that required better roads to lower transport costs and enable faster delivery to market are reflected in the local and national concern regarding urban street paving. In addition, the rising investment in public works by the Crown and local officials is reflected by the increase in the number of grants between the mid-thirteenth century and the mid-fifteenth. Greater commercialisation throughout England was promoted by use of the grants to improve roads.
Effects of platelet-rich plasma at the cellular level on healing of autologous bone-grafted mandibular defects in dogs.

Purpose This study describes the effect of platelet-rich plasma (PRP) at the cellular level on immediate autologous bone grafts in dog mandibles. Materials and Methods Twelve adult dogs weighing 40 to 50 pounds received bilateral inferior mandibular border resections measuring 2 cm × 1 cm. The right side was grafted with milled autologous iliac corticocancellous bone along with 2 cc of PRP taken from the same animal. The left side had the same amount of milled bone placed in the defect without PRP. Three animals were sacrificed at 1, 2, 3, and 6 months postsurgery. Ten and 3 days before sacrifice, all dogs received 10 mg/kg body weight of intravenous tetracycline. At sacrifice, the grafts along with adjacent native bone were harvested and immediately fixed in Carson’s fixative for 48 to 72 hours. The samples were then dehydrated over a 2-week period in a graded ethanol series and embedded in Spurr’s plastic. Two 100-μ sections from the center of each graft were cut, mounted on glass slides, ground to 40 μ, and stained. A digitally generated grid was superimposed over each section, to give 32 fields of 2.5 mm2. Each of these fields was examined at a magnification of ×100 to determine the number of osteoblasts and osteoclasts present. Results The mean average of the total numbers of osteoblasts and osteoclasts were significantly higher in the PRP graft sites than in the non-PRP graft sites at 1 month. However, if specific fields were compared, then 14 of the 32 fields showed no difference in the number of osteoblasts and osteoclasts. At 2, 3, and 6 months, there was no significant difference in the total number of osteoblasts or osteoclasts in the PRP and non-PRP grafts, or in any of the 32 fields. Conclusions At the cellular level, PRP increased the number of osteoblasts and osteoclasts recruited to the graft site at 1 month, and this overall increase was more evident at the superior and lateral margins of the graft than in other areas. Fields along the inferior margin showed the fewest number of cells for both the PRP and non-PRP grafts. At later times there was no significant difference in the number of osteoblasts and osteoclasts in the PRP and non-PRP graft sites in any region of the grafts. This study indicates that the increased number of osteoblasts and osteoclasts in the graft sites due to the addition of PRP was short-lived, and that autologous bone grafts without PRP had similar numbers of active bone cells after 1 month in this animal model.
An Experimental Study on Subsurface Mechanical Behavior, Residual Stress, and Microstructure Induced by Process Dynamics in Machining

Surface integrity of machined components is critical for product performance in service. Process dynamic parameters, such as cutting speed and the changing contact condition between the tool flank face and machined surface, have a significant influence on surface integrity of a machined surface. Due to the very small scale of surface integrity factors on a machined surface, nanoindentation can be used to determine the surface/subsurface mechanical properties. However, the test data may be significantly influenced by machining induced residual stresses, strain hardening, and microstructure changes. The fundamental relationships between residual stress, microstructure, and nanohardness in the machined surface are yet to be understood. Further, it is not clear how to determine residual stress, at least its nature of tensile or compressive, from the nanoindentation data with the presence of complex residual stress state, strain hardening, and microstructure changes. This study focuses on the effects of cutting speed and machining system damping or rigidity (through varying tool flank wear) on subsurface mechanical state and the basic relationships between residual stress, white layer, and nanohardness. A series of nanoindentation tests were conducted to machined samples with distinct surface integrity by hard turning, grinding, and honing. It was found that white layer increases nanohardness and dark layer decreases nanohardness in subsurface, while strain hardening only slightly increases subsurface hardness. The research results indicate that subsurface residual stress can be qualitatively characterized by the load-displacement curve pattern and its parameters such as slope at initial loading, total depth, residual depth, and the ratio of residual depth to total depth. Residual stress would affect a load-displacement curve shape only at onset of yielding. Microstructure changes would make a significant difference on the characteristics of a load-displacement curve, while strain hardening exerts slight influence on the curve characteristics. In addition, the mechanism of residual stress on indentation depth was explained using a Mohr’s circle.© 2004 ASME
“...when no one is hearing them swear” - Youth Safety and the Pedagogy of Surveillance

In this piece I examine the production and proliferation of adult surveillance practices online through Internet safety discourses. Specifically, through an analysis of youth Internet safety curricula provided to adults, along with interviews with parents, law enforcement officers and school officials, I describe the mechanisms by which adults are positioned as agents of surveillance relative to social networks and youth Internet practice. As I argue, youth Internet safety discourses represent what can be conceptualized as a pedagogy of surveillance – reconfiguring both adult and youth conceptions of online practice in ways which establish “trusted adults” as final arbiters of risk and appropriateness, while casting suspicion on the everyday social practices of youth. Through the pedagogy of surveillance provided by youth Internet safety materials, parents and guardians are encouraged to conceptualize social networking sites and other information technologies used by youth as surveillance tools, rather than as social spaces. Additionally, these materials provide adults with a particular conceptual frame through which to make sense of youth sociality online, commonly interpreting everyday communication and actions from the standpoint of an imagined “21 st Century” employer.
Portable rhizotron and color scanner system for monitoring root development

Rhizotrons allow the examination of spatial and temporal in situ root development. Permanent rhizotron installations provide 2-D images of whole root profiles, but their immobility limits the number of soil-plant systems that can be studied. Our objectives were to develop a portable rhizotron and color scanning system for studying the development of whole root systems. Potato root development was monitored in an irrigated experiment at Othello, WA. Covered, rectangular hollow boxes with a transparent glass face were installed perpendicular to planted potato rows, and a seed piece was planted in the soil adjacent to the glass. Rooting in the hill furrow topography was measured 2 to 4 week intervals. Images of roots growing along the glass face were captured with five scans with a portable, color scanner and a portable computer. Image thresholding discriminated roots from soil using primary color values, color intensity differences, color proportions, or overall intensity. Seasonal patterns of computed root lengths by image analysis were comparable to manual tracing. Primary roots extended to 15 cm from the seed piece prior to shoot emergence, 21 days after planting. Lateral roots began to develop shortly thereafter. Potato roots extended to depths of 60 cm by 4 to 6 weeks after planting, and maximum root density in the hill and furrow was observed by tuber initiation to early tuber bulking. Temporal and spatial trends were similar to previous results using destructive sampling. The method has promise for studying the root growth and development of field-grown plants.
The Origins of Entrepreneurial Opportunities

Kirzner's (1973) theory of entrepreneurship emphasizes the equilibrating role of entrepreneurship. When the market is not in equilibrium, profit opportunities exist, and entrepreneurs discover and act on these profit opportunities to equilibrate the market. Because Kirzner focuses on entrepreneurial actions when profit opportunities exist, and does not describe where they come from, one could imagine a fixed stock of profit opportunities that get used up as entrepreneurs discover them. But new profit opportunities are being created constantly. A taxonomy of the origins of entrepreneurial opportunities includes factors that disequilibrate the market, factors that enhance production possibilities, and most notably, opportunities created from previous acts of entrepreneurship. Entrepreneurial actions do not use up profit opportunities, but create them, and the critical role of entrepreneurship in the creation of new profit opportunities is emphasized. This line of reasoning leads directly to policy implications regarding the economic environment conducive to entrepreneurial discovery and the role of government in research and development. This paper enhances Kirzner's theory of entrepreneurship by illustrating how entrepreneurship enlarges the stock of future entrepreneurial opportunities, and points to entrepreneurship as the engine of economic progress. Entrepreneurship occurs when an individual acts to take advantage of a profit opportunity that presents itself in the economy. In its simplest form, the entrepreneur might notice that one person is willing to sell something for less than someone else is willing to pay for it, so the entrepreneur can act as a middle man, profiting from buying at the lower price and selling for more. The profit, which is the return to the entrepreneur's alertness to the opportunity, was created entirely by the entrepreneur's activity, because the sale would not have taken place without someone having noticed the profit opportunity. The entrepreneur's activity benefits the buyer, the seller, and more generally, the entire economy. Furthermore, the entrepreneur's profit signals potential suppliers and demanders about their market opportu- nities, and even signals other potential middlemen of the profit opportunity for facilitating exchanges. Eventually the ability to earn above-normal profits will be competed away, but only after those profits have served their role in signaling a way in which resources could be more efficiently allocated in the economy. Entrepreneurship is indispensable for economic progress, but entrepreneurial activity is possible only when profit opportunities are available to the entrepreneur. This paper discusses the ways in which those profit opportunities can arise in an economy.
The extracellular N-terminal domain and transmembrane domains 1 and 2 mediate oligomerization of a yeast G protein-coupled receptor.

G protein-coupled receptors (GPCRs) can form homodimers/oligomers and/or heterodimers/oligomers. The mechanisms used to form specific GPCR oligomers are poorly understood because the domains that mediate such interactions and the step(s) in the secretory pathway where oligomerization occurs have not been well characterized. Here we have used subcellular fractionation and fluorescence resonance energy transfer (FRET) experiments to show that oligomerization of a GPCR (α-factor receptor; STE2 gene product) of the yeast Saccharomyces cerevisiae occurs in the endoplasmic reticulum. To identify domains of this receptor that mediate oligomerization, we used FRET and endocytosis assays of oligomerization in vivo to analyze receptor deletion mutants. A mutant lacking the N-terminal extracellular domain and transmembrane (TM) domain 1 was expressed at the cell surface but did not self-associate. In contrast, a receptor fragment containing only the N-terminal extracellular domain and TM1 could self-associate and heterodimerize with wild type receptors. Analysis of other mutants suggested that oligomerization is facilitated by the N-terminal extracellular domain and TM2. Therefore, the N-terminal extracellular domain, TM1, and TM2 appear to stabilize α-factor receptor oligomers. These domains may form an interface in contact or domain-swapped oligomers. Similar domains may mediate dimerization of certain mammalian GPCRs.
Modeling and Analysis of American Chestnut Populations Subject to Various Stages of Infection

AbstractAmerican chestnuts, Castanea dentata, were once a dominant tree in eastern deciduous forests of the United States before the chestnut blight fungus, Cryphonectria parasitica, was introduced unintentionally in the early 1900s in New York. This fungus rapidly devastated American chestnut populations until a hypovirus infection of the fungus began to reduce pathogen virulence on chestnut trees. The subsequent reappearance of large reproducing chestnut trees, associated with a large proportion of blight-infected isolates being parasitized by this hypovirus, is currently taken to indicate recovery of American chestnut populations. We explore, using previously-established matrix population models, the dynamics of healthy, fungus-infected, and hypovirus-infected American chestnut populations to test the efficacy of this recovery. Our main result is that populations transitioning from being fungus-infected to hypovirus-infected are predicted to show large transient amplifications as a result of demographi...
Facilitated intravenous access through local application of nitroglycerin ointment

Thirty-four patients with diminutive peripheral veins requiring peripheral IV access (PIVA) in the emergency department setting were randomly assigned to one of two treatment groups. One group of patients (Group A) received application of a bland ointment to the dorsum of the hand prior to attempts at cannulation, while the other group (Group B) received application of 2% nitroglycerin ointment to the dorsum of the hand prior to cannulation attempts. Cannulation was achieved in all 34 patients in the study, but required significantly fewer attempts in Group B patients (P = .04). No side effects of the drug were observed in any patient or any staff member applying the ointments. We conclude that application of 2% nitroglycerin ointment to the dorsum of the hand is a safe, effective method of inducing local venodilation that will ensure PIVA with significantly fewer attempts at cannulation.
Real-Time Task Assignment in Rechargeable Multiprocessor Systems

This paper introduces the scheduling of frame-based real-time tasks in partitioning schemes for multiprocessor systems powered by rechargeable batteries. In frame-based real-time systems, a set of tasks must execute in a frame, and the whole frame is repeated. This system model is widely used in real-time communication, real-time imaging and a lot of other real-time/embedded systems. Nowadays, many of these systems are powered by rechargeable batteries. Scheduling real-time tasks on these rechargeable systems is an important yet largely ignored issue. The problem for uniprocessor systems had been studied in (A. Allavena and D. Mosse, 2001), in which an algorithm of complexity O(N) was proposed for determining the feasibility of the task set. However, it poses a challenge when doing so in a rechargeable multiprocessor system considering different characteristics of the batteries. In this paper, we first show this problem to be NP-hard, and then propose efficient algorithms to overcome it. The simulation results have shown that our algorithms exhibit very good behaviors and they can be considered as solutions to the problem.
Revision open anterior approaches for spine procedures.

Abstract Background context Anterior exposure has become an increasingly popular procedure for the general and vascular surgeon due to the increased use of anterior lumbar interbody fusion and artificial disc replacement for the treatment of many spinal problems. Purpose Because of this increase, revision operations have become increasing necessary. Despite this, there is almost no literature dealing with the issues related to these complex revision operations. Study design A retrospective review of charts was performed on patients operated on from April 2002 until October 2004 in two tertiary care hospitals. Methods In total, 218 open exposures for anterior lumbar spinal approaches were performed of which 9 patients required revision lumbar spinal operations. Seven patients were approached again anteriorly (78%), and 2 (22%) patients required a combined anterior and posterior approach. Results The nine cases were the number of revision procedures performed over the 16-month period of this study. The average age was 44 overall (range, 25–89) and 53 (33–73) for the revision operations, p>.05. All revision operations attempted were successful. Seven (78%) of the secondary procedures could be approached retroperitoneally whereas 2 (22%) patients required transperitoneal approaches owing to the degree of adhesions. The average length until revision surgery was 13 months (range 6–24). No patients required early revision defined as surgery within 30 days from the primary surgery. Early complications occurred in 4 patients (44%), and included dural tear, median nerve dysthesia, left common femoral nerve palsy further complicated by prolonged postoperative ileus and retrograde ejaculation. Late complications occurred in one patient and consisted of a deep venous thrombosis and urinary tract infection. The average length of stay was 6 days (SD 2.7 days) (range 4–12) compared with 4 days (SD 2.3 days) (range 2–22) for the index operations, p>.05. Conclusion Revision anterior open exposure to the lumbar and lumbosacral vertebral bodies can be performed safely, but is associated with an increased rate of early complications. Nonetheless, these complications are self-limited and highlight the importance of a multidisciplinary approach in maximizing the various surgical skills of spine (orthopedic and neurosurgical) and exposure (vascular and general) surgeons in reducing serious complications in revision anterior lumbar spinal surgery.
Gadara: dynamic deadlock avoidance for multithreaded programs

Deadlock is an increasingly pressing concern as the multicore revolution forces parallel programming upon the average programmer. Existing approaches to deadlock impose onerous burdens on developers, entail high runtime performance overheads, or offer no help for unmodified legacy code. Gadara automates dynamic deadlock avoidance for conventional multithreaded programs. It employs whole-program static analysis to model programs, and Discrete Control Theory to synthesize lightweight, decentralized, highly concurrent logic that controls them at runtime. Gadara is safe, and can be applied to legacy code with modest programmer effort. Gadara is efficient because it performs expensive deadlock-avoidance computations offline rather than online. We have implemented Gadara for C/Pthreads programs. In benchmark tests, Gadara successfully avoids injected deadlock faults, imposes negligible to modest performance overheads (at most 18%), and outperforms a software transactional memory system. Tests on a real application show that Gadara identifies and avoids both previously known and unknown deadlocks while adding performance overheads ranging from negligible to 10%.
A new method for the measurement of the natural periods of buildings

It is shown that the inertia force obtained by a man moving his body back and forth in synchronism with the natural period of vibration of a large structure is sufficient to build up a measurable amplitude of motion. By recording such structural vibrations versus time, the natural period and damping of several of the lower modes of vibration can be determined. The amplitudes of motion set up in this way are for many structures significantly larger than can be obtained from wind excitation, which has been used in the past for the measurement of the period of the fundamental mode.
Developing adaptive auction mechanisms

Mechanism design has traditionally been a largely analytic process, relying on assumptions such as fully rational bidders. In practice, however, these assumptions may not hold, making bidder behavior difficult to model and complicating the design process. To address this issue, we propose a different approach to mechanism design. Instead of relying on analytic methods that require specific assumptions about bidders, our approach is to create a self-adapting mechanism that adjusts auction parameters in response to past auction results. In this paper, we describe our approach and then present an example of its implementation to illustrate its efficacy.
Real-time imaging of regional myocardial function using fast-SENC.

A technique for fast imaging of regional myocardial function using a spiral acquisition in combination with strain-encoded (SENC) magnetic resonance imaging (MRI) is presented in this paper. This technique, which is termed fast-SENC, enables scan durations as short as a single heartbeat. A reduced field of view (FOV) without foldover artifacts was achieved by localized SENC, which selectively excited the region around the heart. The two images required for SENC imaging (low- and hightuning) were acquired in an interleaved fashion throughout the cardiac cycle to further shorten the scan time. Regional circumferential contraction and longitudinal shortening of both the left ventricle (LV) and right ventricle (RV) were examined in longand short-axis views, respectively. The in vivo results obtained from five human subjects and five infarcted dogs are presented. The results of the fast-SENC technique in a single heartbeat acquisition were comparable to those obtained by conventional SENC in a long acquisition time. Therefore, fast-SENC may prove useful for imaging during stress or arrhythmia. Magn Reson Med 55:386 –395, 2006. © 2006 Wiley-Liss, Inc.
Development Sociology at the Subnational Scale: Open Questions About State and Market Processes Across the United States

Sociologists have long studied subnational development across the United States focusing on state and market forces that contribute to spatial inequality and uneven development. Subnational research is central to development sociology9s concern with the present neoliberal stage of capitalism and to numerous theoretical, substantive, and policy issues that revolve around poverty and prosperity within the nation. Yet the body of work faces a number of challenges. Research is fragmented and its potential for building broader development sociology overlooked. We provide a critical analysis of this research tradition focusing on its theoretical development and identifying a wave of shifts in economic structure and the state that require new engagement. Our analysis raises challenges for development sociology as a broader field of study. Profound state and market changes are unfolding within the United States but they remain under-theorized with implications for limiting progress in the field as a whole. We identify a series of questions that offer promising directions for future research.
A new approach to rapid PN code acquisition using iterative message passing techniques

Iterative message passing algorithms on graphs, which are generalized from the well-known turbo decoding algorithm, have been studied intensively in recent years because they can provide near-optimal performance and significant complexity reduction. In this paper, we demonstrate that this technique can be applied to pseudorandom code acquisition problems as well. To do this, we represent good pseudonoise (PN) patterns using sparse graphical models, then apply the standard iterative message passing algorithms over these graphs to approximate maximum-likelihood synchronization. Simulation results show that the proposed algorithm achieves better performance than both serial and hybrid search strategies in that it works at low signal-to-noise ratios and is much faster. Compared with full parallel search, this approach typically provides significant complexity reduction.
Post-Manufacture Tuning for Nano-CMOS Yield Recovery Using Reconfigurable Logic

In this paper, an architectural framework for post-silicon tuning of nanoscale CMOS circuits is developed. The tuning methodology is driven by a ?tunable? gate design that allows the gate to be switched from a high-speed/high-power mode to a low-speed/low-power mode under digital control. A small number of ?critical? logic gates are replaced with tunable gates for post-silicon power-performance tuning. In addition, supply voltage and body bias can be employed as hardware ?tuning knobs? as well to deal with delay and leakage variations. After silicon is manufactured, the hardware ?knobs? are programmed through the use of an implicit self-test methodology that can be exercised by the proposed self-adaptation architectural framework. It is seen that the delay yield can be improved by an average of 40% with minimal impact on area.