cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism-based approach to the successful prevention of cocaine inhibition of the neuronal (alpha 3 beta 4) nicotinic acetylcholine receptor.

The nicotinic acetylcholine receptor (nAChR) belongs to a family of five channel-forming proteins that regulate communication between the approximately 10 1 2 cells of the nervous system. A minimum mechanism of inhibitionof the muscle-type nAChR (1) by the noncompetitive inhibitors cocaine and MK-801 [(+)-dizocilpine, an anticonvulsant] indicated they bind to a regulatory site, with higher affinity for the closed-channel form than for the open-channel form, thus shifting the equilibrium toward the closed-channel form and inhibiting receptor function. The mechanism predicts that compounds that bind to this regulatory site with equal or higher affinity for the open-channel conformation than for the closed-channel conformation will prevent receptor inhibition (1). Does a neuronal form of the receptor behave similarly? The mechanism of inhibition of the neuronal nAChR by cocaine and MK-801 using rapid chemical kinetic techniques was investigated. The α3β4 nAChR stably expressed in HEK 293 cells was used in these investigations. Whole-cell currents originated from a major and minor nAChR isoform. Only the major isoform has been characterized. For the dominant, rapidly desensitizing isoform, the carbamoylcholine dissociation constant for the site controlling receptor activation, K d , is 2 mM; the channel-opening equilibrium constant, Φ - 1 , is 4; and the dominant desensitization rate constant, k 3 4 , is 20 s - 1 . Cocaine inhibits the receptor noncompetitively, with an apparent K 1 of 84 and 26 μM at high and low carbamoylcholine concentrations, at which concentrations the receptor is mainly in the open- or closed-channel form, respectively. Similar results were obtained with MK-801. A combinatorially synthesized RNA ligand and a cocaine analogue alleviated cocaine inhibition of this neuronal receptor.
Erratum: “Dynamic Bargaining with Transaction Costs”

Erratum to Cramton, Peter C. 1991. Dynamic bargaining with transaction costs. Management Sci.37 1221--1233.
Gender Differences in Leader Emergence Persist Even for Dominant Women: An Updated Confirmation of Role Congruity Theory

Role congruity theory predicts that women will be less likely than men to emerge as leaders when expectations for the leader role are incongruent with gender stereotypes. A 2 × 2 × 3 design that crossed the sex of the dominant partner, mixed- and same-sex dyads, and masculine, feminine, and neutral tasks involved 120 dyads of unacquainted college students in which one partner scored higher in dominance. In same-sex partnerships, the dominant member consistently emerged as leader. In mixed-sex dyads, the gender typing of the task did not influence dominant male ascendance but it did affect women's. When the task was masculine-typed or neutral, less dominant men were more likely to emerge as the leader of the dyad, frequently being appointed by the dominant woman herself. Thus, even when women possess the agentic quality of dominance consistent with the leader role, the incongruence between masculinized task demands and gender stereotypes mitigate against women's leadership emergence.
Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter

Dihydrofolate reductase activity is required for many biosynthetic pathways including nucleotide synthesis. Its expression is therefore central to cellular growth, and it has become a key target for cancer chemotherapy. Transcription of the dihydrofolate reductase gene is regulated with growth, being expressed maximally in late G1/early S phase following serum stimulation of quiescent cells. This regulation is directed by a promoter which contains binding sites for only the transcription factors Sp1 and E2F. In this study, the role of these promoter elements in growth/cell cycle regulation of dihydrofolate transcription was addressed directly by transient transfection of Balb/c 3T3 cells with mutant promoter-reporter gene constructs. The E2F sites were found to repress transcription in G0 and early G1 but did not contribute to the level of transcription in late G1/S phase. In contrast, Sp1 sites were able to mediate induction of transcription from the dihydrofolate reductase promoter, as well as a heterologous promoter, following serum stimulation of quiescent cells. These findings add dihydrofolate reductase to a growing list of genes at which E2F sites are primarily repressive elements and delineate a role for Sp1 sites in the growth/cell cycle regulation of transcription. J. Cell. Biochem. 67: 24–31, 1997. © 1997 Wiley-Liss, Inc.
Solution growth of magnesium oxide crystals

Abstract The growth of magnesia by both hydrothermal and fluxed-melt techniques has been achieved. In the latter process, growth of an appreciable volume of material on a seed crystal was obtained by temperature gradient transport. The quality of the product was generally superior to that of the staring material, although microscopic inclusions of flux were commonly observed. The latter probably arise partly through temperature fluctuations during growth.
Assessing repolarization: alternate hypotheses.

c t r b ( p Sudden cardiac arrest remains a leading cause of death, the underlying cause typically being ventricular tachycardia or ventricular fibrillation (VT/VF). The mechanism for VT/VF is thought to be reentry in most cases, but our inadequate understanding of how reentry is initiated hampers our ability both to identify those at greatest risk and to design preventive strategies. The theory of repolarization alternans has been proposed as an explanation of how reentry is induced in the absence of identifiable anatomic obstacles. The induction of reentrant VT/VF requires heterogeneous excitability leading to conduction block (“wave break”) of a premature stimulus at an area of temporary refractoriness while conduction persists in adjoining tissue. The resulting wave of depolarization can lead to further wave break and propagation of daughter waves, resulting in meandering, multiwave fibrillation. While Antzelevitch et al have shown that significant transmural gradients of reolarization heterogeneity exist even in normal ventricles, ource-sink mismatch prevents the induction of reentry by ypical premature foci. Under stressful conditions, that is, high stimulation rates, drugs that alter ion channel kinetics, or sympathetic stimulation, spatially differential variability in repolarization may occur transiently, increasing the risk for wave break in the presence of a premature stimulus. When the duration of the action potential alternately shortens and prolongs in a fixed short-long-short-long pattern, repolarization alternans exists. If repolarization alternans occurs in a consistent manner across a region of the ventricular wall, it is considered spatially concordant alternans. If, however, an area of myocardium manifests action potential prolongation and shortening while an adjacent area manifests alternans in the opposite phase, that is, long-short in one area and short-long in another, it is referred to as spatially discordant alternans. Discordant alternans have
Issues in Corporate IS Planning

The most prevalent planning models that originated in the late sixties are the rational or top-down models, where the underlying notion of organizational level inputs to the IS plan became accepted as normative. However, with the increasing complexity of the IT environment, the applicability of the top-down model comes into question. In an attempt to place the crucial issue of IS planning in perspective, this paper discusses the top-down models of planning and the other approaches to planning that have become popular over the past decade. Specifically, three additional planning approaches are discussed, namely, the competitive analysis approaches, contingency approaches and the information economy. Critical conceptual issues are then raised on the viability of a simple top-down approach in the future.
Label-Free, Longitudinal Visualization of PDT Response In Vitro with Optical Coherence Tomography

A major challenge in creating and optimizing therapeutics in the fight against cancer is visualizing and understanding the microscale spatiotemporal treatment response dynamics that occur in patients. This is especially true for photodynamic therapy (PDT), where therapeutic optimization relies on understanding the interplay between factors such as photosensitizer localization and uptake, in addition to light dose and delivery rate. In vitro 3D culture systems that recapitulate many of the biological features of human disease are powerful platforms for carrying out detailed studies on PDT response and resistance. Current techniques for visualizing these models, however, often lack accuracy due to the perturbative nature of the sample preparation, with light attenuation complicating the study of intact models. Optical coherence tomography (OCT) is an ideal method for the long-term, non-perturbative study of in vitro models and their response to PDT. Monitoring the response of 3D models to PDT by time-lapse OCT methods promises to provide new perspectives and open the way to cancer treatment methodologies that can be translated towards the clinic.
Alterations of mouse adrenal medullary catecholamines and enzymes in response to attack: effect of pre- and post-treatment with phenobarbital.

Group-housed male C57BR/cdJ mice (victims) were exposed to attack for 10 min daily for up to 14 days by male Swiss-Webster mice, made aggressive by prolonged isolation. Their adrenal glands were analyzed for tyrosine hydroxylase (TH) and phenylethanolamine-N-methyltransferase (PNMT) activities and for norepinephrine (NE) and epinephrine (EPI) concentrations. TH was increased to 41% above control after two exposures and remained elevated through 14 exposures to attack. PNMT was increased to 29% above control after 2 days and increased further to 50% above control after 14 days of attack. Both NE and EPI increased to 88% and 51% above control, respectively, after 7 days. In victim mice recuperating after 1 week of daily stress, EPI levels and PNMT activities were back to normal after 4 days whereas NE levels and TH activities returned to normal only after 1 week. Phenobarbital (40 mg/kg, i.m.) was effective in preventing the biochemical changes when given 2 h prior to each daily attack but was ineffective when given immediately after each daily stress.
Imaging Evidence for Renomegaly in Patients with POEMS Syndrome

Rationale and Objectives Organomegaly in POEMS syndrome generally refers to the liver, spleen, and lymph nodes. This study investigates whether there is a significant difference in kidney sizes in patients with POEMS compared to normal controls. Materials and Methods Calculated kidney volumes from 77 patients with POEMS syndrome who had undergone imaging by computed tomography or magnetic resonance imaging were compared to frequency-matched controls. For the POEMS patients and the controls, the volume of each kidney was obtained from a three-dimensional segmentation algorithm. Univariate and multiple variable linear regression models were used to identify any differences in kidney size between normal and POEMS patients. Results There was a univariate statistically significant association between disease state and the difference in kidney volume; having POEMS was associated with 16.3 cm 3 greater kidney volume difference compared to control patients, P 3 greater kidney volume compared to control patients, P Conclusion This confirms what is known or suspected clinically, that organomegaly in POEMS includes renomegaly.
Examining sensory reweighting in healthy elderly and in those with brain injury

We investigated the manner in which complementary and conflicting visual and physical motion signals affect postural responses in healthy elderly individuals vs. an age-matched group that had experienced cortical or subcortical strokes (stroke). Subjects stood on a motion platform located within a virtual reality environment and were asked to maintain their balance in response to different combinations of platform and visual scene motions. Stroke subjects exhibited greater linearity in their kinematic responses, and appeared to place greater reliance on visual input, even when it conflicted with platform motion. We conclude this explains why stroke subjects exhibit a less stable postural response and a greater tendency to fall than healthy subjects.
Ca(2+)-dependence of structural changes in troponin-C in demembranated fibers of rabbit psoas muscle

The Ca(2+)-dependence of structural changes in troponin-C (TnC) has been detected by monitoring the fluorescence from TnC labeled at Methionine-25, in the NH2-terminal domain, with danzylaziridine (TnC-DANZ) and then exchanged for endogenous TnC in glycerinated single fibers. The fluorescence-pCa relation obtained from fibers stretched to a sarcomere length greater than 4.0 microns evidenced two transitions: a small one, attributable to the binding of Ca2+ to the high affinity, Ca(2+)-Mg(2+)-binding sites of TnC; and a large one, attributable to the binding of Ca2+ to the low affinity, Ca(2+)-specific binding sites of TnC. In the fluorescence-pCa relation determined with fibers set to a sarcomere length of 2.4 microns, hence obtained in the presence of cycling cross-bridges, the large transition had the same Ca(2+)-dependence as did the development of tension. These results indicate that the NH2-terminal globular domain of TnC is modified by the binding of Ca2+ to sites located in both globular domains and that the structural changes in TnC resulting from the binding of Ca2+ to the low-affinity sites, but not to the high-affinity sites, are directly associated with the triggering of contraction.
Guiding Research and Practice: A Conceptual Model for Aerobic Exercise Training in Alzheimer’s Disease

Alzheimer's disease is a global, epidemic problem affecting mainly older adults with tremendous social and financial burdens. Older adults with Alzheimer's disease showed reduced physical activity and cognitive changes that are probably amenable to aerobic exercise training. The purpose of this paper is to develop a conceptual model to guide future aerobic exercise research and practice by synthesizing the current state of the science on aerobic exercise training in older adults with AD. The literature review found 12 qualified studies that met the eligibility criteria for inclusion in this review and revealed six constructs (aerobic exercise training, physical fitness, physical performance, activities of daily living limitations, cognition, and psychological and behavioral symptoms), which composed the Functional Impact of aerobic exercise Training in Alzheimer's disease (FIT-AD) model. The state of science on each construct in older adults with Alzheimer's disease is reviewed and summarized. The emerging evidence suggests that aerobic exercise training might positively impacts all five other constructs. The implications of the FIT-AD model for future research and practice are discussed highlighted.
Genetic selection for aflatoxin B1 resistance influences chicken T-cell and thymocyte proliferation.

Abstract Studies were conducted with two lines of chickens that were selected for high and low plasma protein concentrations in response to aflatoxin B 1 (AFB 1 ) exposure. The experiments were designed to determine genetic differences in the responses of T cells and thymocytes to the toxin. Chicks were orally administered AFB 1 at a rate of 0, 100, or 500 μg/kg body weight up to 21 days of age. At 4 weeks of age, concanavalin A (Con A, 2.5 μg/mL) stimulated T-cell proliferation was similar for untreated chicks from the low line (LL) and the high line (HL). However, AFB 1 reduced the responses of T cells with HL cells being more sensitive. In a second experiment, immature chickens were bled and peripheral blood lymphocytes were cultured with Con A and either 0, 3.125, 6.25, 12.5, or 25 μg/mL AFB 1 . T cells from LL had greater responses to Con A than those from HL, and LL T-cells were also more resistant to in vitro AFB 1 exposure. Furthermore, thymocyte proliferation was greater for LL chicks; but when thymocytes were cultured with 25 μg/mL AFB 1 , 3 H-thymidine incorporation was similarly reduced in both lines. Cell cycle analysis indicated that there were more LL thymocytes in S phase, and the percentages for both lines decreased with AFB 1 treatment. Although there were no differences between the lines for percent G 2 /M cells, AFB 1 treatment increased the percentages of thymocytes in G 2 /M. These studies showed that selection for plasma protein response also changed T-cell and thymocyte proliferative activity.
Low phytonutrient, semipurified liquid diets depress plasma total antioxidant status in renal dialysis patients

Consumption of essential nutrients in amounts generally considered adequate does not ensure maximal antioxidant capacities. Three week consumption of any of three semipurified, liquid formulas, as a sole nutrition source, depressed values for plasma total antioxidant status (TAS) in renal dialysis patients. Each formula contained the essential nutrients in amounts generally considered adequate, but did not contain major sources of phytonutrients. The fall in TAS values could not be attributed to altered plasma values for vitamin E, B-carotene or uric acid. Therefore, these results suggest that low phytonutrient intake adversely affects antioxidant capacities.
Removing confounding factors via constraint-based clustering

ObjectivesConfounding factors in unsupervised data can lead to undesirable clustering results. For example in medical datasets, age is often a confounding factor in tests designed to judge the severity of a patient's disease through measures of mobility, eyesight and hearing. In such cases, removing age from each instance will not remove its effect from the data as other features will be correlated with age. Motivated by the need to find homogeneous groups of multiple sclerosis (MS) patients, we apply our approach to remove physician subjectivity from patient data. MethodsWe present a method based on constraint-based clustering to remove the impact of such confounding factors. Given knowledge about which feature (or set of features) is a confounding factor, call it F. Our method first partitions the data into b bins: if F is categorical, instances from the same category construct one bin; if F is numeric, then we split bins such that each bin contains instances of similar F value. Thus each instance is assigned to a single bin for factor F. We then remove feature F from each instance for the remaining steps. Next, we cluster the data separately in each bin. Using these clustering results, we generate pair-wise constraints and then run a constraint-based clustering algorithm to produce a final grouping. ResultsIn a series of experiments with synthetic datasets, we compare our proposed methods to detrending when one has numeric confounding factors. We apply our method to the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Womens Hospital dataset, and find a novel grouping of patients that can help uncover the factors that impact disease progression in MS. ConclusionsOur method groups data removing the effect of confounding factors without making any assumptions about the form of the influence of these factors on the other features. We identified clusters of MS patients that have clinically recognizable differences. Because patients more likely to progress are found using this approach, our results have the potential to aid physicians in tailoring treatment decisions for MS patients.
Children’s Asthma Experience and the Importance of Place

Asthma is increasing dramatically among poor, inner-city children. Fourteen children with, and twelve without, asthma were interviewed and observed to examine how children with asthma understand their illness and how the asthma experience shapes their sense of place. Quantitative data showed no difference in objective preferences for particular places, but qualitative analysis showed important differences. We identified eight place-related themes, and on seven there were clear differences between children with and without asthma - offering freedom, being aesthetically pleasing, being comfortable, nature of social contact, being isolating, being familiar and being safe. Children experienced asthma as an interruption in daily life that influences time spent outside, being active and being with friends. Children with asthma are more sensitive to places that are ‘dirty’ or contain asthma triggers, are less likely to explore new or people-free places and emphasize family interactions, while children without as...
Measurement of Static and Dynamic Performance Characteristics of Electric Propulsion Systems

Today’s unmanned aerial vehicles are being utilized by numerous groups around the world for various missions. Most of the smaller vehicles that have been developed use commercially-off-the-shelf parts, and little information about the performance characteristics of the propulsion systems is available in the archival literature. In light of this, the aim of the present research was to determine the performance of various small-scale propellers in the 4.0 to 6.0 inch diameter range driven by an electric motor. An experimental test stand was designed and constructed in which the propeller/electric motor was mounted in a wind tunnel for both static and dynamic testing. Both static and dynamic results from the present experiment were compared to those from previous studies. For static testing, the coefficient of thrust, the coefficient of propeller power, and the overall efficiency, defined as the ratio of the propeller output power to the electrical input power, were plotted versus the propeller rotational speed. For dynamic testing, the rotational speed of the propeller was held constant at regular intervals while the freestream airspeed was increased from zero to the windmill state. The coefficient of thrust, the coefficient of power, the propeller efficiency and the overall efficiency were plotted versus the advance ratio for various rotational speeds. The thrust and torque were found to increase with rotational speed, propeller pitch and diameter, and decrease with airspeed. Using the present data and data from the archival and non-archival sources, it was found that the coefficient of thrust increases with propeller diameter for square propellers where D = P. The coefficient of thrust for a family of propellers (same manufacturer and application) was found to have a good correlation from static conditions to the windmill state. While the propeller efficiency was well correlated for this family of propellers, the goodness of fit parameter was improved by modifying the propeller efficiency with D/P.
Invertebrate communities of groundwater-dependent refugia with varying hydrology and riparian cover during a supraseasonal drought

Extreme disturbances eliminate aquatic biota and alter community structure and function. During a supraseasonal drought in north-central Texas in the summer and fall 2006, macroinvertebrate communities from persistent groundwater-dependent macrohabitats of varying hydrology and riparian shading were investigated to study their role as invertebrate refugia, and to characterize the taxonomic and functional community structure of benthic assemblages. Ash Creek was the only stream with surface flow within a 35-km radius during the drought. Two perennial and three intermittent stream sites were studied that included perennial riffles, a perennial pool, shaded disconnected pools, and disconnected pools in full sun. Riffles had significantly higher taxa richness, EPT (Ephemeroptera, Plecoptera, and Trichoptera) richness, proportion of lotic taxa, and diversity than other macrohabitats. Macrohabitats were refugia for 106 benthic macroinvertebrate taxa, and perennially flowing habitats contained 19 taxa (17.9% of ...
Daniel Dennett's Breaking the Spell : An Unapologetic Apology

Proposals for a scientific study of religion have never been realised because, Daniel Dennett argues in Breaking the Spell , religion is surrounded by a spell that protects it from the critical inquiry characteristic of other academic fields of study. Dennett suggests two reasons for proposing such a study anew at this time. The first is political, namely, major policy decisions are currently being made on the basis of perceptions about religion; the second is theoretical, namely the establishment of an evolutionary psychology and of a cognitive science of religion which can provide the basis for such a study. Surprisingly, a number of those scholars in the field who are well-known for advocating precisely such a scientific study of religion have reacted negatively to Dennett's proposal. Do their very reactions confirm his thesis that an enchanting spell surrounding religion remains unbroken?
Microscale variability in the distributions of large fluorescent particles observed in situ with a planar laser imaging fluorometer

Abstract It has been known for decades that particle-size and biomass spectra show regular patterns in the ocean, and that these patterns often show systematic variations with other properties such as total biomass, nutrient concentration, season, and distance (both vertical and horizontal). The recent finding of the ubiquitous nature of layers of phytoplankton
Evidence That the DNA Binding Specificity of Winged Helix Proteins Is Mediated by a Structural Change in the Amino Acid Sequence Adjacent to the Principal DNA Binding Helix

We present the first structural evidence supporting the hypothesis that the binding specificity of the winged helix DNA binding motif is mediated by residues adjacent to the alpha-helix (H3), the moiety which is primarily involved in the interaction with DNA. Using NMR to determine secondary structural elements of a winged helix family member, Genesis (formerly HFH-2), and comparing these with those found in the X-ray crystal structure of the HNF-3gamma/DNA complex [Clark, K. L., Halay, E. D., Lai, E., & Burley, S. K. (1993) Nature 364, 412-420], we show that the major differences observed occur for H3 and the region immediately prior to this. H3 in Genesis is slightly shorter than in HNF-3gamma and, in addition, we observe an extra small helix (H4) in the region between H2 and H3 which is not found in the HNF-3gamma/DNA complex. This is significant as it has been shown previously [Overdier, D. G., Porcella, A., & Costa R. H. (1994) Mol. Cell. Biol. 14, 2755-2766] that the DNA-binding specificity is influenced by amino acid residues in this region.
Toll-like receptor signalling in the intestinal epithelium: how bacterial recognition shapes intestinal function

A single layer of epithelial cells lines the small and large intestines and functions as a barrier between commensal bacteria and the rest of the body. Ligation of Toll-like receptors (TLRs) on intestinal epithelial cells by bacterial products promotes epithelial cell proliferation, secretion of IgA into the gut lumen and expression of antimicrobial peptides. As described in this Review, this establishes a microorganism-induced programme of epithelial cell homeostasis and repair in the intestine. Dysregulation of this process can result in chronic inflammatory and over-exuberant repair responses, and it is associated with the development of colon cancer. Thus, dysregulated TLR signalling by intestinal epithelial cells may explain how colonic bacteria and inflammation promote colorectal cancer.
Study of the ESI-mass spectrometry ionization mechanism of Fischer carbene complexes.

By means of deuterium-labeling experiments, we have carried out a systematic ESI-MS study to determine the mechanism of ESI ionization of alkenyl and alkynyl group 6 Fischer carbene complexes. These compounds can be ionized under ESI conditions only in the presence of additives such as hydroquinone (HQ) or tetrathiafulvalene (TTF). Our results demonstrate that in the ESI source an anion-radical is formed after the initial HQ- or TTF-mediated electron transfer to the metallic carbene complex. For alkenyl carbene complexes, this species evolves by extrusion of a hydrogen radical to form an allenylchromium anion that is detected as the [M − H]- ion in the mass spectrum. The preference for this mechanistic pathway could be rationalized by DFT calculations. In the case of alkynyl carbene complexes, experiments combining deuterated substrate, additive, and solvent demonstrate that the previously proposed allene−anion carbene complex is not formed. Instead, the H transfer from the ethoxy group in the anion radic...
Writing about technology

Communication skills are essential to a successful career in computing. You may be an excellent programmer, but if you can't explain your work to your peers then your career will quickly plateau. This means the most important language you should master during your graduate studies is not C# or Java -- it's English.Whether it's writing reports for class, writing conference or journal papers to summarize research results, or writing a long document such as a thesis or a dissertation, it's all writing. Your special challenge is explaining complex concepts to your readers in a way that they can easily understand. Fortunately, this is a skill that you can learn.
Scattering by plasmon polaritons on a metal surface with a detuned roughness spectrum

The effects of plasmon polariton excitation on a metal surface with weak one-dimensional roughness are studied experimentally. It is shown that backscattering enhancement requires the excitation of counterpropagating polaritons, whereas surface waves traveling in one direction produce diffuse scatter without a strong backscattering peak.
For Richer or for Poorer? The Role of Science, Politics, and Ethics in the Global Climate Change Policy Debate:

Addressing the issue of global climate change (GCC) requires the cooperation of all nations of the world. Although the industrial nations of the north have the financial and technological resources to begin addressing the problem, they ultimately remain vulnerable to the actions of the developing nations of the south. The negotiation process—now a decade old—has, thus far, failed to produce a universal agreement on greenhouse gas (GHG) reductions. This failure is attributed to the lack of a unifying principle capable of overcoming the short-term differences in interest among the two groups of countries. Science and politics, the two forces driving the GCC debate, have inherent weaknesses that prevent them from providing the leadership necessary to secure universal cooperation in combating this major threat to the global environment. Ethics, specifically the principles of equity and justice, is proposed as a possible unifying principle. An analysis of the four main issues that must be resolved before a uni...
Silicon in organic syntheis. 13. The 1-trimethylsilylcyclopropyl anion and its formal equivalent

Reaction of lithio 1-trimethylsilylcyclopropane or its formal equivalent [CH2 = C(Li)SiMe3; CH2I2, EtZnI] with carbonyl compounds leads to carbinols which dehydrate without rearrangement. Other attempts to induce ring expansion of the silicon substituted three-membered ring by ionic pathways are reported.
On a regularity problem occurring in connection with Anosov diffeomorphisms

Let ℳ be aC∞-manifold and ℱs and ℱu be two Holder foliations, transverse, and with uniformlyC∞ leaves. If a functionf is uniformlyC∞ along the leaves of the two foliations, then it isC∞ on ℳ. The proof is elementary.
Stent Thrombosis An Issue Revisited in a Changing World

The concept of stenting—intravascular mechanical support by transluminally placed endoprostheses—was first proposed by Charles Dotter >30 years ago.1 As an intrinsic property of the metallic endoprostheses, early thrombotic occlusion of freshly deployed stents has been a concern since their introduction to human coronary circulation in 1986.2 The unacceptably high rates (up to 24%) of thrombotic events seen in early clinical experience were first approached pharmacologically by aggressive anticoagulation with low-molecular-weight dextran, dipyridamole, and warfarin. Although this strategy helped reduce the incidence of stent thrombosis into a single-digit range, the benefit was obtained at a cost of significantly longer hospitalization and increased hemorrhagic/vascular complications. As intravascular ultrasound (IVUS) began to have widespread use in the clinical environment in the early 1990s, the importance of mechanical optimization at stent deployment for the prevention of stent thrombosis was underscored. The collaborative work of J.M. Tobis and A. Colombo demonstrated an unexpectedly high percentage of IVUS-detected stent deployment issues, including incomplete stent expansion, incomplete apposition, and asymmetric expansion, even after angiographically successful results.3,4 These observations led to the concept of high-pressure stent deployment with IVUS guidance, achieving lower rates of subacute thrombosis with antiplatelet therapy alone (aspirin and ticlopidine).5 The superiority of this antiplatelet therapy after “optimal” stent expansion with routine high pressure post-dilatation was subsequently confirmed by several randomized trials when compared with other antithrombotic regimens.6,7 See p 43 Nevertheless, stent thrombosis has not been eliminated; in this modern stent era, the incidence is reported to be ≈1% overall and can be more frequent in high-risk patient/lesion subsets or multivessel procedures.6,8 Despite the reduced relative incidence, the absolute number of patients with stent thrombosis is increasing in parallel with the exponential increase in the use of stents in the broad spectrum of complex lesions. The clinical consequences …
On the formation of the TPN requiring glyceraldehyde-3-phosphate dehydrogenase during the production of chloroplasts in Euglena gracilis

Abstract Green Euglena cells possess a TPN-requiring glyceraldehyde phosphate dehydrogenase in addition to the DPN-requiring enzyme. The dark-grown, colorless cells contain only the DPN enzyme. In resting colorless cells exposed to light, the course of formation of the TPN enzyme follows closely that of chlorophyll. Removal of light during this process results a cessation of both enzyme production and chlorophyll synthesis. Cultivation of the green cells at 34° in the light produces an inhibition of chloroplast synthesis, and return of the cells to a lower temperature brings about a rapid resumption of chloroplast synthesis after a lag period of one to two days. The production of the TPN enzyme follows very closely that of the chloroplasts, both during the inhibition and the recovery. The synthesis of the DPN enzyme, on the other hand, is linked to the multiplication of the cells during this process.
Rapid Startup of a PEM Fuel Cell From Subzero Temperature

Current-ramping strategy can be used for rapid startup of PEM fuel cells (PEMFC) from subzero temperatures. Via numerical modeling a series of parametric studies are performed in this work to explore the optimum parameter set for current-ramping cold-start. A PEMFC with standard cell thermal mass, 0.4 J/cm2 /K, starting from −30°C is of primary interest in this work. It is found that either a small initial current density (100mA/cm2 ) combined with an intermediate ramping rate, or a relatively large initial current density (200 mA/cm2 ) in combination with a small ramping rate, can lead to successful self-starts if the membrane electrode assembly (MEA) is sufficiently dry prior to startups. However, the current-ramping cold-start with a too small initial current density (≤50mA/cm2 ) is found to shut down with whatever the current-ramping rate. More rapid self-start can be achieved by increasing the initial current density, which is limited mainly by the initial water content in the MEA. Hence, keeping the MEA mildly hydrated prior to cold start can be favorable to the rapid current-ramping startup. This is particularly important for the rapid startup of next-generation PEMFCs with reduced thermal mass. Results show that a PEMFC with 0.2 J/cm2 /K thermal mass and a relatively wetted MEA can be successfully started up from −30°C in a few seconds if it is possible to draw the current density as high as 1 A/cm2 right from the beginning.Copyright © 2009 by ASME
Microencapsulation and dissolution parameters of undecenovanillylamide: A potential coyote deterrent

The microencapsulation and dissolution of undecenovanillylamide (I), a potential coyote-aversive agent for use on sheep, were studied. While I has been shown to protect sheep, its short duration of action makes it economically unfeasible. Compound I microcapsules were prepared, and optimum conditions for encapsulation via complex coacervation were determined. Microcapsules that were hardened for 0.5, 1, and 2 hr, as well as I powder, were characterized according to their dissolution. Longer hardening times resulted in slower release, with all encapsulated I forms being released slower than the powder. The dissolution t50 for unencapsulated powder was less than 3 min; for microcapsules hardened for 30 min, the dissolution t50 was 7.3 min; for those hardened 60 min, the t50 was 17.7 min; and for those hardened 120 min, the t50 was 28 min. The encapsulated I would have a longer field life and, therefore, might be a viable economic and ecologic answer to coyote protection for sheep.
A proposed curriculum of cryptography courses

The Cryptography Course is a major part of Computer security, Information security, Network security and all Information security related courses [12, chapter 1]. This course could be offered to undergraduate level (S level) or graduate level students. This article focuses on the problem:If the Cryptography course is offered as two consecutive courses, there is no problem because there are about 30-32 weeks of instruction for the 3-credit course (about 100 hours). This quantity of time is quite ample to cover the major Cryptography subjects (including mathematics, classical algorithms, Block algorithms, Stream cipher Public Key, Crypto hash functions, Authentication and Identification, Key management protocols, Cryptography application: web security, PKI, Email, internet, and all other Cryptography algorithms). However, the problem arises when there is only one course with 3 credit hours per week equaling 45 hours. The course has to be designed for the students' level of studies.This short paper proposes a Cryptography curriculum designed as one course to suit both the undergraduate and graduate level. The curriculum is detailed and distributed over 15 weeks.
Simulation-based analysis of UML statechart diagrams: methods and case studies

We present a comprehensive unified modeling language (UML) statechart diagram analysis framework. This framework allows one to progressively perform different analysis operations to analyze UML statechart diagrams at different levels of model complexity. The analysis operations supported by the framework are based on analyzing Petri net models converted from UML statechart diagrams using a previously proposed transformation approach. After introducing the general framework, the paper emphasizes two simulation-based analysis operations from the framework: direct MSC inspection, which provides a visual representation of system behavior described by statechart diagrams; and a pattern-based trace query technique, which can be used to define and query system properties. Two case-study examples are presented with different emphasis. The gas station example is a simple multi-object system used to demonstrate both the visual and query-based analysis operations. The early warning system example uses only one object, but features composite states and includes analysis specifically aimed at one composite state feature, history states.
Atypical Femoral fractures: A Review of the Literature

Bisphosphonates are the most commonly used drugs worldwide for treating osteoporosis. Atypical femoral fractures most commonly are associated with prolonged bisphosphonate use. They also may occur with denosumab use or in patients without a history of using these drugs. In this article, we provide a comprehensive review of the mechanism of action of bisphosphonate and the definition, incidence, epidemiology, pathogenesis, diagnosis, management, and prevention of atypical femoral fractures.
Solar seeing and the spatial properties of the five-minute oscillations.

A numerical simulation of observations of the spatial properties of the five-minute oscillations is carried out, assuming the oscillations are internal gravity waves excited by granular convection according to the theory of Thomas et al. (1971). The simulation includes the effects of seeing and finite aperture. The details of the simulation are chosen to model the observational method of Frazier (1968a, b). The results show that the peak in the observed power spectrum of the oscillations can occur at a wavelength considerably longer than the true wavelength of the oscillations. In particular, the peak in Frazier's observed power spectra at wavelength λ ≈ 5000 km is consistent with the considerably shorter true wavelength λ ≈ 1500 km predicted by the gravity wave theory.
Design of robust global power and ground networks

We consider the problem of determining optimal wire widths for a power or ground network, subject to limits on wire widths, voltage drops, total wire area, current density, and power dissipation. To account for the variation of the current demand, we model it as a random vector with known statistics, possibly including correlation between subsystem currents. Other researchers have shown that when the variation in the current is not taken into account, the optimal network topology is a tree. A tree topology is, however, almost never used in practice, because it is not robust with respect to variations in the lock currents. We show that when the current variation is taken into account, the optimal network is usually not a tree.We formulate a heuristic method based on minimizing a linear combination of total average power and total wire area. We show that this results in designs that obey the reliability constraints, occupy small area, and most importantly are robust against variations in block currents. The problem can be formulated as a nonlinear convex optimization problem that can be globally solved very effciently.
Global trends and the rapid growth of East Asia in IEEE publications

We organized a database of IEEE Periodicals from a period of over 15 years for quantitative and collective analysis. We found that the IEEE experienced globalization and more active international competition. East Asian countries and regions have grown dramatically and become major players in the IEEE during globalization over the last decade, and: 1) East Asia surpassed North America in research related to electrical and electronics fields; 2) China has the most balanced and rapidly increasing number of articles in all fields; 3) Taiwan specializes in circuits, systems, and electronic devices; 4) South Korea specializes in consumer electronics, broadcasting, and communications; and 5) Singapore owes much to the existence of two research universities.
Preliminary palynological investigation of Saudi Arabian Upper Ordovician glacial sediments

Abstract An Ordovician stratigraphically admixed palynomorph assemblage that contains palynomorphs eroded from Middle through Upper Ordovician strata characterizes the Hawban Member (restricted) of the Sarah Formation in central Saudi Arabia. This distinctive assemblage, combined with detailed sedimentology, helps identify the presence of Hirnantian Gondwanan glacial sediments on the Arabian Plate. Similar Ordovician admixed assemblages have been recognized from Upper Ordovician glacial sediments elsewhere along the Gondwanan margin. Within Saudi Arabia the composition of reworked assemblages depends upon the stratigraphic succession exposed to glacial erosion. Sylvanidium ? hawbanense , which is one of the acritarchs found in glacial sediments, is newly described from Arabian Upper Ordovician strata.
Robust joint sparse recovery on data with outliers

We propose a method to solve the multiple measurement vector (MMV) sparse signal recovery problem in a robust manner when data contains outlier points which do not fit the shared sparsity structure otherwise contained in the data. This scenario occurs frequently in the applications of MMV models due to only partially known source dynamics. The algorithm we propose is a modification of MMV-based sparse bayesian learning (M-SBL) by incorporating the idea of least trimmed squares (LTS), which has previously been developed for robust linear regression. Experiments show a significant performance improvement over the conventional M-SBL under different outlier ratios and amplitudes.
CO2 exposure at pressure impacts metabolism and stress responses in the model sulfate-reducing bacterium Desulfovibrio vulgaris strain Hildenborough.

Geologic carbon dioxide (CO2) sequestration drives physical and geochemical changes in deep subsurface environments that impact indigenous microbial activities. The combined effects of pressurized CO2 on a model sulfate-reducing microorganism, Desulfovibrio vulgaris, have been assessed using a suite of genomic and kinetic measurements. Novel high-pressure NMR time-series measurements using 13C-lactate were used to track D. vulgaris metabolism. We identified cessation of respiration at CO2 pressures of 10 bar, 25 bar, 50 bar, and 80 bar. Concurrent experiments using N2 as the pressurizing phase had no negative effect on microbial respiration, as inferred from reduction of sulfate to sulfide. Complementary pressurized batch incubations and fluorescence microscopy measurements supported NMR observations, and indicated that non-respiring cells were mostly viable at 50 bar CO2 for at least four hours, and at 80 bar CO2 for two hours. The fraction of dead cells increased rapidly after four hours at 80 bar CO2. Transcriptomic (RNA-Seq) measurements on mRNA transcripts from CO2-incubated biomass indicated that cells up-regulated the production of certain amino acids (leucine, isoleucine) following CO2 exposure at elevated pressures, likely as part of a general stress response. Evidence for other poorly understood stress responses were also identified within RNA-Seq data, suggesting that while pressurized CO2 severely limits the growth and respiration of D. vulgaris cells, biomass retains intact cell membranes at pressures up to 80 bar CO2. Together, these data show that geologic sequestration of CO2 may have significant impacts on rates of sulfate reduction in many deep subsurface environments where this metabolism is a key respiratory process.
Experimental Methodology for Studying Strain Heterogeneity with Microstructural Data from High Temperature Deformation

An experimental methodology has been developed to study materials deformed at high temperatures using high resolution ex situ digital image correlation (DIC). This study is an advancement of techniques that have used sub-grain level strain measurements and linked them to microstructural data obtained with electron back-scatter diffraction (EBSD). The approach utilized air blasting particles that were capable of remaining unchanged onto a sample surface and loading the sample at elevated temperatures in vacuum to prevent oxidation. Two tensile experiments were performed at temperatures of 700 and 800 °C on Haynes 230 (a nickel-based superalloy) using DIC at high magnifications in order to study the heterogeneous strain fields. Overlaying the strain fields and microstructure data, global trends and areas of high strain were studied. The strain evolution at these areas was compared to the mean strain accumulation. This study represents an advancement of the usefulness of high resolution DIC by expanding the loading conditions that can be studied and provided experimental results to prove the feasibility.