cssi/SciSciGPT-SciSciNet huggingface dataset:
The Yin Yang-1 (YY1) protein undergoes a DNA-replication-associated switch in localization from the cytoplasm to the nucleus at the onset of S phase

The essential Yin Yang-1 gene (YY1) encodes a ubiquitous, conserved, multifunctional zinc-finger transcription factor in animals. The YY1 protein regulates initiation, activation, or repression of transcription from a variety of genes required for cell growth, development, differentiation, or tumor suppression, as well as from genes in some retroviruses and DNA viruses. Among the specific functions attributed to YY1 is a role in cell-cycle-specific upregulation of the replication-dependent histone genes. The YY1 protein binds to the histone alpha element, a regulatory sequence found in all replication-dependent histone genes. We therefore examined the abundance, DNA-binding activity and localization of the YY1 protein throughout the cell cycle in unperturbed, shake-off-synchronized Chinese hamster ovary and HeLa cells. We found that, whereas the DNA-binding activity of YY1 increased dramatically early in S phase, the YY1 mRNA and protein levels did not. YY1 changed subcellular distribution patterns during the cell cycle, from mainly cytoplasmic at G1 to mainly nuclear at early and middle S phase, then back to primarily cytoplasmic later in S phase. Nuclear accumulation of YY1 near the G1/S boundary coincided with both an increase in YY1 DNA-binding activity and the coordinate up-regulation of the replication-dependent histone genes. The DNA synthesis inhibitor aphidicolin caused a nearly complete loss of nuclear YY1, whereas addition of caffeine or 2-aminopurine to aphidicolin-treated cells restored both DNA synthesis and YY1 localization in the nucleus. These findings reveal a mechanism by which YY1 localization is coupled to DNA synthesis and responsive to cell-cycle signaling pathways. Taken together, our results provide insight into how YY1 might participate in the cell-cycle control over a variety of nuclear events required for cell division and proliferation.
Multimarket Contact, Economies of Scope, and Firm Performance

We integrate the efficiency and competitive effects of product-market scope choice into a comprehensive model of economic performance and empirically test the model in the context of the U.S. airli...
Using fluorescence measurement of zinc ions liberated from ZnS nanoparticle labels in bioassay for Escherichia coli O157:H7

In this study, an alternative approach using ZnS nanoparticle biolabels as fluorescence signal transducers is reported for the immunoassay of E. coli O157:H7 in tap water samples. Instead of measuring the fluorescence of ZnS nanoparticles in the assay, the fluorescence signal is generated through the binding of zinc ions released from nanoparticle labels with zinc-ion sensitive fluorescence indicator Fluozin-3. In the assay, ZnS nanoparticles around 50 nm in diameter were synthesized, bioconjugated, and applied for the detection of E. coli O157:H7. The assay shows a detection range over two orders of magnitude and a detection limit around 1000 colony-forming units (cfu) of E. coli O157:H7.
Shoreline Surface Washing Agent Test and Evaluation Protocol for Freshwater Use in the Great Lakes Region1

ABSTRACT Although opportunities exist to use shoreline surface washing agents for oil spill removal in freshwater environments, this response technique is seldom tried because little is known about its insitu effectiveness and toxicity. In January 2000, the Federal Region V Regional Response Team chartered a Subcommittee of international, federal, state and industry representatives to develop a protocol for evaluating the test use of shoreline surface washing agents in freshwater environments on oil spills of opportunity in the Great Lakes Region. Currently, mechanical and manual recovery are the primary means of oil spill cleanup in freshwater environments which can be costly, labor intensive, and often results in limited oil recovery. Oil recovery inefficiency is related to shoreline composition and complexity that allow oil to cover, fill, and penetrate the substrate. Responders, with limited options, may compromise their efforts by leaving residual oil in the environment or expend a substantial effort...
Nerve conduction abnormalities in untreated maturity-onset diabetes: relation to levels of fasting plasma glucose and glycosylated hemoglobin.

Abstract The role of metabolic abnormalities in the development of diabetic neuropathy is controversial. To investigate the influence of hyperglycemia on nerve conduction, we studied 20 untreated m...
Theory of Higher-Order Weak Interactions and CP -Invariance Violation. I. Leptonic Processes

In order to cure the divergence difficulties of higher-order weak interactions, we propose a theory in which the usual current \ifmmode\times\else\texttimes\fi{} current Lagrangian is modified by inserting the non-polynomial factor $\mathrm{exp}[f{\ensuremath{\phi}}^{\ifmmode\dagger\else\textdagger\fi{}}\ensuremath{\phi}(x)]$, where $\ensuremath{\phi}$ is a charged scalar field. We show that, as a result, the usual first-order weak amplitudes are unchanged, while second-order leptonic scattering amplitudes are finite. Explicit formulas are given for lepton-lepton scattering and the logarithmically divergent lepton self-mass. A discussion of Nth order is presented, in which it is shown that the naive degree of divergence is independent of order, and the superpropagator to all orders is derived. The groundwork is laid for the discussion in a following paper of hadronic processes and the appearance of $\mathrm{CP}$ violation as a higher-order weak effect.
Ethnocultural identity and induced abortion in Kazakstan.

This study uses data from the 1995 Demographic and Health Survey to explore the issue of abortion and its determinants in Kazakhstan (the absolute number of abortions declined in the 1980s and early 1990s whereas the abortion ratio remained in the range of 0.47-0.50 throughout the early 1990s and may be an underestimate). In order to uncover ethnocultural differentials in abortion behavior the study compares data for three ethnocultural groups: Kazaks interviewed in Kazak Kazaks interviewed in Russian and women of European origin (most of whom were interviewed in Russian). The multivariate analysis also examined differences in individual reproductive socioeconomic ethnocultural and sociodemographic characteristics. Analysis was limited to women who first became pregnant after marriage or cohabitation. Half of the women had at least one abortion: 66% of the European women almost 50% of the Russified Kazaks and 25% of the Kazaks. European women had an average of 2.3 abortions Russified Kazaks had 1.3 and Kazaks had 0.4. Europeans also had much higher abortion ratios for first second and third pregnancies and Kazaks have the lowest abortion ratios. The European ratio increases for all three pregnancies while the Kazak ratio remains stable for first and second pregnancies and declines for third pregnancies. Europeans tend to have a first abortion at the youngest age and shortest period from first marriage. Having children was a significant negative effect for ever having an abortion. It is concluded that provision of contraception may reduce the incidence of abortion but that significant reductions will require a change in the public attitude about the acceptability and desirability of abortion.
Wedge-like waves in a composite medium

Abstract A thin elastic sheet separating two viscoelastic half planes is subjected to a longitudinal load. For a relatively stiff sheet the application of the loud gives rise to a system of wedge-like and cylindrical waves. By employing the kinematical condition of compatibility the magnitudes of propagating discontinuities are obtained directly from the system of field equations. The propagating jump in the shear stress at the interface of the sheet and a half plane is not affected by the viscoelastic behavior of the half planes, but decreases exponentially due to energy radiation into the half planes. For elastic half planes the jumps in the particle velocities at the wave fronts of the wedge-like longitudinal and transverse waves remain constant along rays normal to the wave fronts. For viscoelastic half planes these jumps decrease exponentially along normal rays.
Mitochondrial recycling of ascorbic acid as a mechanism for regenerating cellular ascorbate

Mitochondria are the major source of potentially damaging reactive oxygen species in most cells. Since ascorbic acid, or vitamin C, can protect against cellular oxidant stress, we studied the ability of mitochondria prepared from guinea pig skeletal muscle to recycle the vitamin from its oxidized forms. Although ascorbate concentrations in freshly prepared mitochondria were only about 0.2 mM, when provided with 6 mM succinate and 1 mM dehydroascorbate (the two-electron-oxidized form of the vitamin), mitochondria were able to generate and maintain concentrations as high as 4 mM, while releasing most of the ascorbate into the incubation medium. Mitochondrial reduction of dehydroascorbate was strongly inhibited by 1,3-bis(chloroethyl)-1-nitrosourea and by phenylarsine oxide. Despite existing evidence that mitochondrial ascorbate protects the organelle from oxidant damage, ascorbate failed to preserve mitochondrial alpha-tocopherol during prolonged incubation in oxygenated buffer. Nonetheless, the capacity for mitochondria to recycle ascorbate from its oxidized forms, measured as ascorbate-dependent ferricyanide reduction, was several-fold greater than total steady-state ascorbate concentrations. This, and the finding that more than half of the ascorbate recycled from dehydroascorbate escaped the mitochondrion, suggests that mitochondrial recycling of ascorbate might be an important mechanism for regenerating intracellular ascorbate.
Debates over the nature of HRD: an institutional theory perspective

(2000). Debates over the nature of HRD: an institutional theory perspective. Human Resource Development International: Vol. 3, No. 3, pp. 279-283.
Evidence-based spine surgery.

STUDY DESIGN: Literature review. OBJECTIVE: To describe the state of the literature regarding the performance of lumbar fusion for low back pain due to degenerative disease of the spine. SUMMARY OF BACKGROUND DATA: The effectiveness and costs associated with spinal surgery have been a topic of significant debate in both the popular press and professional literature. METHODS: Evidence-based medicine techniques have been applied to many areas of spinal surgery. The results of these analyses are being used by practicing physicians, payors, and others to determine what procedures are appropriate for certain patient populations. RESULTS: This manuscript describes the methodology, strengths, and weaknesses of evidence-based medicine approaches to spinal surgery. The case for lumbar fusion as a treatment for chronic low back pain due to degenerative disc disease is described as an example. CONCLUSION: Evidence-based medicine is a useful tool for summarizing and grading the evidence available in the literature for or against a particular treatment strategy. Its utility is limited by the quality of the primary literature, and the absence of proof cannot be equated with the proof of absence.
Incidence, Significance and Natural History of Persistent Retrograde Venous Flow After Varicocelectomy in Children and Adolescents: Correlation with Catch-up Growth

Purpose: Varying incidences and levels of persistent retrograde venous flow have been reported following adult and adolescent varicocelectomy but the significance remains unclear. We sought to determine the incidence and natural history of persistent flow and whether it had any effect on postoperative testicular catch-up growth.Materials and Methods: We retrospectively analyzed pre-varicocelectomy and post-varicocelectomy Doppler duplex ultrasound findings. Peak retrograde venous flow, maximum vein diameter, flow quality and varicocele grade were recorded at each visit. Catch-up growth was defined as less than 15% testicular asymmetry at final visit.Results: Of 330 patients (median age 15.4 years) undergoing varicocelectomy (laparoscopic in 247, open in 83) 145 had residual retrograde venous flow after Valsalva maneuver with a mean peak of 13.3 cm per second. Of 290 patients with repeat Doppler duplex ultrasound (median followup 2.6 years) 124 had initial peak retrograde venous flow less than 20 cm per se...
Crow deaths caused by West Nile virus during winter.

In New York, an epizootic of American crow (Corvus brachyrhynchos) deaths from West Nile virus (WNV) infection occurred during winter 2004–2005, a cold season when mosquitoes are not active. Detection of WNV in feces collected at the roost suggests lateral transmission through contact or fecal contamination.
Eicosapentaenoic Acid and Docosahexaenoic Acid Block Serotonin-Induced Smooth Muscle Cell Proliferation

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) present in fish oils have been ascribed as having significant antithrombotic and antiatherosclerotic effects. Vascular smooth muscle cell (SMC) proliferation plays an important role in the pathogenesis of atherosclerosis and restenosis. Recent studies have indicated that serotonin at concentrations present at sites of vascular injury stimulates SMC proliferation and may contribute to the restenotic process. In the present study we demonstrate that among the fatty acids tested, only EPA and DHA could block the mitogenic effect of serotonin on vascular SMC. Further, when added together these fatty acids act synergistically in blocking the mitogenic effect of serotonin. EPA and DHA blocked the 5HT-induced increase in the 5-HT(2) receptor mRNA. This antimitogenic effect of EPA and DHA may partially explain some of the beneficial effects of fish oils.
Serum calcium and vitamin D regulate 1,25-dihydroxyvitamin D3 receptor concentration in rat kidney in vivo.

Abstract The effects of vitamin D status, serum calcium, and serum phosphorus levels on 1,25-dihydroxyvitamin D receptor levels in kidney were investigated. Weanling rats were fed for 4 weeks on a diet with various levels of calcium and phosphorus with or without vitamin D. The 1,25-dihydroxyvitamin D3 receptor concentration in kidney was determined by an immunoradiometric assay. In the absence of vitamin D, total receptor concentration is increased 2-fold by an increase in serum calcium concentration. At normal serum calcium levels, the administration of vitamin D resulted in a 5-fold increase in receptor concentration. In hypocalcemic animals, however, vitamin D did not change receptor levels. Serum phosphorus levels could not be linked to any changes in 1,25-dihydroxyvitamin D3 receptor concentration. This study demonstrates that serum calcium levels and vitamin D regulate 1,25-dihydroxyvitamin D3 receptor concentration in vivo in kidney. On the other hand, vitamin D is unable to exert control of receptor levels in kidney under hypocalcemic conditions.
Low affinity interaction of peptide-MHC complexes with T cell receptors

The interaction of antigen-specific T cell receptors (TCRs) with their ligands, peptides bound to molecules of the major histocompatibility complex (MHC), is central to most immune responses, yet little is known about its chemical characteristics. The binding to T cells of a labeled monoclonal antibody to the TCR was inhibited by soluble class II MHC heterodimers complexed to different peptides. Inhibition was both peptide- and TCR-specific and of low affinity, with a KD = 4 x 10(-5) to 6 x 10(-5) M, orders of magnitude weaker than comparable antibody-antigen interactions. This finding is consistent with the scanning nature of T cell recognition and suggests that antigen-independent adhesion precedes TCR engagement.
Constraint on the recurrence of great outer-rise earthquakes from seafloor bathymetry

Great outer rise earthquakes are a tsunami hazard as they occur on steeply dipping faults (Lay et al., 2009). The largest instrumentally recorded of these events are the 1933 Sanriku Japan earthquake (Mw = 8.4) and 1977 Sumba Indonesia earthquake (Mw = 8.3) (Lay et al., 2009). Seafloor bathymetry (Kobayashi et al., 1998) and plate kinematics indicate a great Mw ≥ 8 outer rise earthquake on the zone of the great Tohoku Mw 9 event can occur at most once in 7 megath-rust cycles.
Effect of dopamine on NaCl transport in the medullary thick ascending limb of the rat.

The aim of the present study was to determine whether bradykinin affects NaCl reabsorption in the medullary thick ascending limb of the loop of Henle. At 10−8 M, bradykinin significantly inhibited Cl− transport in the in vitro microperfused rat medullary thick ascending limb by 67% (P < 0.01). This inhibitory effect could be totally prevented by preincubating tubules with the bradykinin B2 receptor antagonist Nα-adamantaneacetyl-d-Arg-[Hyp3,Thi5,8,d-Phe7]bradykinin (10−6 M). In contrast, the bradykinin B1 receptor agonist des-Arg9 bradykinin (10−6 M) had no effect on Cl− transport. Bradykinin caused transient increases in intracellular Ca2+ concentration, which could be blocked by the bradykinin B2 receptor antagonist, but could not be reproduced with the bradykinin B1 receptor agonist. These data suggest that the natriuretic and diuretic effect of bradykinin in vivo is due, at least in part, to a bradykinin B2 receptor-mediated inhibition of NaCl reabsorption in the medullary thick ascending limb of the loop of Henle.
Mesoscale Frequencies and Seasonal Snowfalls for Different Types of Lake Michigan Snow Storms

Abstract Members of the Cloud Physics Laboratory, University of Chicago, have identified three different mesoscale organization patterns of lake-effect snow storms over Lake Michigan: multiple wind-parallel bands, single midlake bands, and single shoreline bands. For the 70 snowfall seasons ending with 1980/81, Braham and Dungey estimated that lake-effect snows contributed 8% of the total snowfall along the west shore of the lake, and 39% along the east shore. In the present study daily GOES satellite images and daily snowfall records are used to find the seasonal snowfall in four geographical area from each type of lake-effect storm and from nonlake-effect storms, for the snowfall seasons 1978/79 and 1979/80. Over the two seasons, 176 snowfall days were identified. Of these, 52% were nonlake-effect and 48% were lake-effect days. Of the 84 lake-effect days, 51% had wind-parallel bands, 22% had midlake bands, 2% had shoreline bands, and 25% had undetermined lake-effect cloud types. Along the west shore of ...
Islam and Exceptionalism in American Political Discourse

The phenomenal success achieved by Islamic political parties in the wake of the Arab uprisings of 2011 is one of the most significant and frequently noted developments to follow from those momentous events. Within a few months of the demise of long-standing authoritarian regimes, Islamist groups that had been banned and oppressed for decades found themselves flourishing. Soon El-Nahda in Tunisia and then Egypt's Muslim Brotherhood tasted victory in constituent assembly, legislative, and eventually presidential elections. A new area of political Islam in power had seemingly arrived.
Evaluation of total antenna (Q) in terms of the Q n of modes provided by theory of characteristic modes

The study of the antenna Quality factor (Q) has been an active topic of research for a long time. Its importance is directly related to its connection to the antenna frequency bandwidth. Many authors have discussed the problem of formulating the Q of an antenna. Chu, Mclean, Wheeler, Gustafsson, Thal, Yaghjian, Harrington and Vandenbosch were among many whom studied the Q bounds of electrically small antenna (ESA) and Q in general. Several studies were taken from Chu sphere, employing scattering theory and applying quasi-static energy approximations to name few; however, these approaches require specific assumptions on polarization and absorption efficiency, and provide little insight into the type of excitation needed to realize an optimal Q.
West Nile virus growth is independent of autophagy activation

West Nile virus (WNV) is an arthropod-borne virus with a worldwide distribution that causes neurologic disease and death. Autophagy is a cellular homeostatic mechanism involved in antiviral responses but can be subverted to support viral growth as well. We show that autophagy is induced by WNV infection in cell culture and in primary neuron cultures. Following WNV infection, lysosomes co-localize with autophagosomes resulting in LC3B-II turnover and autolysosomal acidification. However, activation or inhibition of autophagy has no significant effect on WNV growth but pharmacologic inhibition of PI3 kinases associated with autophagy reduce WNV growth. Basal levels of p62/sequestosome1(SQSTM1) do not significantly change following WNV-induced autophagy activation, but p62 is turned over or degraded by autophagy activation implying that p62 expression is increased following WNV-infection. These data show that WNV-induces autophagy but viral growth is independent of autophagy activation suggesting that WNV-specific interactions with autophagy have diverged from other flaviviruses.
The value of enhanced magnetic resonance imaging in the evaluation of endocochlear disease.

Background: Gadolinium-enhanced magnetic resonance imaging (GdMRI) is routinely used in the evaluation and management of suspected retrocochlear pathology such as vestibular schwannoma. However, its value in the evaluation and diagnosis of cochlear pathology associated with sensorineural hearing loss (SNHL) has been less clear. Study Design: Retrospective review of case histories and imaging studies of patients with SNHL and cochlear enhancement on GdMRI diagnosed between 1998 and 2000. Results: Five patients with SNHL who required gadolinium administration to establish the diagnosis of endocochlear disease were identified. Diagnosed lesions included an intralabyrinthine schwannoma, intracochlear hemorrhage, radiation-induced ischemic change, autoimmune labyrinthitis, and meningogenic labyrinthitis. In these illustrative cases, the GdMRI demonstrated intrinsic high signal or contrast enhancement within the cochlea and labyrinth in the absence of a retrocochlear mass. In one patient with meningogenic labyrinthitis, cochlear enhancement on MRI led to prompt cochlear implantation before the potential development of cochlear ossification. Conclusion: Our experience suggests that GdMRI plays a crucial role in the diagnosis of cochlear pathology associated with sensorineural hearing loss and may directly impact patient management.
Protein synthesis in nuclear residual protein

1. The incorporation of radioactive amino acids into the nuclear residual protein from calf thymus has been investigated in vitro. 2. The nuclear residue has been found to incorporate actively [14C]tryptophan into its protein. 3. Optimal incorporation of [14C]tryptophan was obtained in the presence of Mg2+, adenosine 5′-triphosphate and an adenosine-5′-triphosphate-regenerating system. 4. The addition of a full complement of ribonucleoside triphosphates and a mixture of l-amino acids to otherwise complete reaction mixtures did not stimulate the amount of [14C]tryptophan incorporated. 5. Pretreatment of the nuclear residue with deoxyribonuclease (EC 3.1.4.5) to remove deoxyribonucleic acid markedly reduced the incorporation of [14C]tryptophan; whereas a stimulation of incorporation was observed following partial proteolytic digestion of the nuclear residue with trypsin (EC 3.4.4.4). 6. Pretreatment of the nuclear residue with ribonuclease (EC 2.7.7.16) did not significantly alter the amino acid incorporation reactions studied.
Gas chromatography-tandem mass spectrometry implemented on a bench-top quadrupole ion trap-based instrument using random noise to effect collision-induced dissociation

Abstract A simple and effective method for collision-induced dissociation (CID), implemented through application of random noise to an end-cap electrode, allows gas chromatography (GC)-tandem mass spectrometry (MS-MS) experiments to be performed on a commercial bench-top quadrupole ion trap mass spectrometer. Details of the random noise CID experiment, the characteristics of the noise spectrum, and the effect of varying noise spectrum and ion trap parameters on MS-MS spectra are discussed using N,N -diethylaniline as a model compound. Compromises to the technique imposed by current software flexibility limitations are also discussed. GC-MS-MS spectra, generated using random noise CID, are shown for methamphetamine and amphetamine ionized via isobutane chemical ionization.
The initial identification of figure-ground relationships: Contributions from shape recognition processes

We tested whether shape recognition computations contribute to the initial determination of figure and ground by asking observers to report about which region of briefly exposed masked stimuli appeared to be figure. The region on one side of a figure-ground contour always denoted a meaningful shape. In full versions of the stimuli, Gestalt variables favored the other, less denotative, region; in half versions of the stimuli, Gestalt variables were absent. If shape recognition inputs do not contribute to figure-ground computations, the less denotative region should be seen as figure in the full stimuli, and both regions should be seen as figure equally often in the half stimuli. Results show otherwise, suggesting that shape recognition routines do contribute to the initial determination of figure and ground, provided they have been completed, which seems to require approximately 150 msec for canonically oriented stimuli.
Nurse-Enhanced Memory Intervention in Heart Failure: the MEMOIR study

Background Many patients with heart failure (HF) have cognitive deficits, including memory loss.
The Hippo Signaling Pathway Coordinately Regulates Cell Proliferation and Apoptosis by Inactivating Yorkie, the Drosophila Homolog of YAP

Coordination between cell proliferation and cell death is essential to maintain homeostasis in multicellular organisms. In Drosophila, these two processes are regulated by a pathway involving the Ste20-like kinase Hippo (Hpo) and the NDR family kinase Warts (Wts; also called Lats). Hpo phosphorylates and activates Wts, which in turn, through unknown mechanisms, negatively regulates the transcription of cell-cycle and cell-death regulators such as cycE and diap1. Here we identify Yorkie (Yki), the Drosophila ortholog of the mammalian transcriptional coactivator yes-associated protein (YAP), as a missing link between Wts and transcriptional regulation. Yki is required for normal tissue growth and diap1 transcription and is phosphorylated and inactivated by Wts. Overexpression of yki phenocopies loss-of-function mutations of hpo or wts, including elevated transcription of cycE and diap1, increased proliferation, defective apoptosis, and tissue overgrowth. Thus, Yki is a critical target of the Wts/Lats protein kinase and a potential oncogene.
A solid state NMR study of polycarbonate oligomer grafted onto the surface of amorphous silica

Abstract High resolution solid state 13 C and 29 Si CP/MAS NMR was used to investigate the grafting mechanism, morphology and interfacial mobility of polycarbonate (PC) oligomer and bisphenol A grafted onto silica surfaces. It was previously shown that interface modification via grafting led to composites with increased hydrolytic stability and interfacial toughness. The NMR experiments were carried out to determine the nature of the bonding of the reactants to the glass surface and to characterize the relaxation properties of the reacted species. The NMR spectra demonstrate differences between the neat and grafted PC oligomer that suggest strong bonding. A model compound, bisphenol A, was used to resolve signal overlaps caused by repeat units and to verify the formation of primary bonding at the silica surface by the existence of a downfield shift of the C 4 resonance peak and other changes in the spectrum. Proton spin-lattice relaxation times in the rotating frame offer secondary evidence of the formation of Si–O–C bonds on the silica surface. The proton spin-lattice relaxation of the grafted molecules were characterized by a bimodal distribution of relaxation times, while unreacted molecules were represented by a single relaxation time. Temperature dependent studies show that the oligomer loses mobility as a result of grafting, and that the transition responses of the material are lost. The grafted material is visualized as a low density monomolecular layer of covalently bonded material.
Soliton strings, the WZW model and modular invariance☆

Abstract It is shown that a theory of strings on a nonsimply-connected group manifold has a soliton sector that is essential for modular invariance. A semiclassical analysis of this sector is used to reduce the problem of determining the representations of the Kac-Moody algebra that appear in the theory to the relatively easy task of finding the representations of the related finite algebra that satisfy certain simple conditions. Some examples are worked out in detail, including the case of SO(3), where it is shown that half-integer representations occur for odd k /2, and the case of SU(3)/Z 3 for the first few values of k . The k = 1 SO( N ) and SU( N ) theories are also considered.
Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, eutamias minimus—II. Water balance

Abstract 1. Chipmunks were acclimatized to ad libitum and restricted water consumption regimes (equal rations of 4 and 2 ml/day) at ambient temperatures of 26, 30, and 34°C. 2. Weight loss is greatest in the semiarid population when water consumption is restricted to 4 ml/day, but greatest in the montane population when drinking 2 ml/day. 3. Urine and blood concentrations of animals on restricted water intake are similar in the two populations. The semiarid population reduces evaporative water loss and fecal water content more than does the montane population. Urine osmolarity is significantly higher in both populations when maintained on restricted water intake than on ad libitum water. 4. Hematocrit of the semiarid population is significantly lower than that of the montane population under both water regimes. 5. Evaporative water loss and evaporative heat loss are significantly greater and surface-specific dry heat conductance significantly less in the semiarid population. 6. Metabolism and body temperature measurements at different times of the year suggest a seasonal change in thermoregulatory characteristics of E. minimus.
Apoptosis and Morphologic Changes in Drug-Treated Trabecular Meshwork Cells In Vitro

Abstract Using an in vitro culture system, we investigated whether bovine trabecular meshwork cells undergo apoptosis (programmed cell death) following exposure to anti-glaucoma medications (timolol, pilocarpine and epinephrine) and known inducers of apoptosis (5-fluorouracil, mitomycin-C and dexamethasone). Third to fifth passage bovine trabecular meshwork cells were grown to confluence and incubated for 1–12 days in growth media with timolol (1–1000 μ m ), pilocarpine (15–15000 μ m ), epinephrine (5–5000 μ m ), 5-fluorouracil (10–100 μg ml −1 ), mitomycin-C (0.01–100 μg ml −1 ) and dexamethasone (0.01–100 μ m ). The cultures were evaluated for apoptosis by phase-contrast microscopy, transmission electron microscopy and in situ apoptosis labeling. 5-Fluorouracil (10–100 μg ml −1 ), mitomycin-C (0.1–100 μg ml −1 ) and epinephrine (500–5000 μ m ) induced apoptosis in a dose and time-dependent manner. Timolol, pilocarpine, and dexamethasone-treated specimens did not show evidence of apoptosis at any of the concentrations tested. Trabecular meshwork cells incubated in timolol (100–1000 μ m ) developed cytoplasmic granules, and specimens treated with pilocarpine (15000 μ m ) developed cytoplasmic vacuoles. These granules and vacuoles have the appearance of secondary lysosomes. Dexamethasone-treated cells developed an increased number of mitochondria. This study suggests that the trabecular meshwork may undergo apoptosis following exposure to 5-fluorouracil, mitomycin-C and epinephrine. Timolol, pilocarpine and dexamethasone did not induce apoptosis. However, these drugs can incite characteristic morphologic changes in cultured trabecular meshwork cells.
ATP-sensitive potassium channels and myocardial preconditioning.

The ATP-sensitive potassium channel (KATP) has been shown to serve an endogenous cardioprotective role in a number of experimental models of myocardial stunning and infarction. More importantly, a majority of evidence has also been obtained which suggests that the KATP channel may be intimately involved in both triggering and maintaining the cardioprotection afforded by the phenomenon of ischemic preconditioning particularly in large animal models such as dogs and pigs. Although the evidence for an involvement of KATP in ischemic pre-conditioning is equivocal in smaller animal species such as rabbits and rats, activation of this channel by KATP channel openers produces cardioprotection in all species studied. Whether this channel is an important mediator of ischemic preconditioning in all animal species including man and the mechanism by which this cardio-protective effect is obtained await further experimental studies. Nevertheless, the use of selective potassium channel openers to mimic preconditioning in selected clinical settings may be a desirable future therapeutic goal.
Highly reinforced structure of a C-terminal dimerization domain in von Willebrand factor.

The C-terminal cystine knot (CK) (CTCK) domain in von Willebrand factor (VWF) mediates dimerization of proVWF in the endoplasmic reticulum and is essential for long multimers required for hemostatic function. The CTCK dimer crystal structure reveals highly elongated monomers with 2 β-ribbons and 4 intra-chain disulfides, including 3 in the CK. Dimerization buries an extensive interface of 1500 A(2) corresponding to 32% of the surface of each monomer and forms a super β-sheet and 3 inter-chain disulfides. The shape, dimensions, and N-terminal connections of the crystal structure agree perfectly with previous electron microscopic images of VWF dimeric bouquets with the CTCK dimer forming a down-curved base. The dimer interface is suited to resist hydrodynamic force and disulfide reduction. CKs in each monomer flank the 3 inter-chain disulfides, and their presence in β-structures with dense backbone hydrogen bonds creates a rigid, highly crosslinked interface. The structure reveals the basis for von Willebrand disease phenotypes and the fold and disulfide linkages for CTCK domains in diverse protein families involved in barrier function, eye and inner ear development, insect coagulation and innate immunity, axon guidance, and signaling in extracellular matrices.
Automation-induced complacency for monitoring highly reliable systems : the role of task complexity, system experience, and operator trust

The increase in quantity and complexity of advanced automated systems has generated new concerns surrounding automation-induced complacency, or the difficulties operators have monitoring the status of automated systems. The present investigation consists of two studies that assessed the impact of system reliability, monitoring complexity, operator trust, and system experience on automation-induced complacency. In both studies, participants operated a manually controlled flight task while monitoring several simulated aircraft displays for failures. The ability of operators to detect a single automation failure over three experimental sessions was also assessed. Results indicated that realistic levels of system reliability severely impaired an operator's ability to monitor effectively. Further, as system experience increased, operator monitoring performance declined. The results also indicated that the complexity of the monitoring task heavily influenced operator monitoring, with poorer performance associat...
Frequent emergency department use in Sweden: implications for emergency medicine in the United States.

Address for correspondence: Robert A. Lowe, MD, MPH, University of Pennsylvania Medical Center, Center for Clinical Epidemiology and Biostatistics, 914 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021; 215-898-0845, fax 215-573-2265; E-mail rlowe@cceb.med.upenn.edu. Address for correspondence after July 1, 2001: Robert A. Lowe, MD, MPH, Oregon Health Sciences University, Department of Emergency Medicine, UHN-52, 3181 SW Sam Jackson Park Road, Portland, OR 97201-3098; 503-494-7500, fax 503-494-4997; E-mail lowero@ohsu.edu.
Equivalent circuit representation of open guided-wave structures

A modular equivalent circuit representation for modeling and analyzing open guided-wave structures, which takes into account both the guided and the continuous spectra, is discussed. In the development of the technique approximations that are valid for integrated optics in III-V compound semiconductors are utilized. The validity of these approximately was assessed on the basis of both physical arguments and numerical simulations. Results obtained with the present method are compared with the results of other methods of analysis for rectangular fiber and rib guides with sloped rib sides. The present method gives accurate results with limited computational effort and can analyze a wide variety of integrated optical components ranging from single waveguides of arbitrary cross-sectional profile to multiple coupled guides of arbitrary widths and spacings. >
eIF2α kinases GCN2 and PERK modulate transcription and translation of distinct sets of mRNAs in mouse liver

In eukaryotes, selective derepression of mRNA translation through altered utilization of upstream open reading frames (uORF) or internal ribosomal entry sites (IRES) regulatory motifs following exposure to stress is regulated at the initiation stage through the increased phosphorylation of eukaryotic initiation factor 2 on its α-subunit (eIF2α). While there is only one known eIF2α kinase in yeast, general control nonderepressible 2 (GCN2), mammals have evolved to express at least four: GCN2, heme-regulated inhibitor kinase (HRI), double-stranded RNA-activated protein kinase (PKR), and PKR-like endoplasmic reticulum-resident kinase (PERK). So far, the main known distinction among these four kinases is their activation in response to different acute stressors. In the present study, we used the in situ perfused mouse liver model and hybridization array analyses to assess the general translational response to stress regulated by two of these kinases, GCN2 and PERK, and to differentiate between the downstream effects of activating GCN2 versus PERK. The resulting data showed that at least 2.5% of mouse liver mRNAs are subject to derepressed translation following stress. In addition, the data demonstrated that eIF2α kinases GCN2 and PERK differentially regulate mRNA transcription and translation, which in the latter case suggests that increased eIF2α phosphorylation is not sufficient for derepression of translation. These findings open an avenue for more focused future research toward groups of mRNAs that code for the early cellular stress response proteins.
An integrated transcriptome and expressed variant analysis of sepsis survival and death

Sepsis, a leading cause of morbidity and mortality, is not a homogeneous disease but rather a syndrome encompassing many heterogeneous pathophysiologies. Patient factors including genetics predispose to poor outcomes, though current clinical characterizations fail to identify those at greatest risk of progression and mortality. The Community Acquired Pneumonia and Sepsis Outcome Diagnostic study enrolled 1,152 subjects with suspected sepsis. We sequenced peripheral blood RNA of 129 representative subjects with systemic inflammatory response syndrome (SIRS) or sepsis (SIRS due to infection), including 78 sepsis survivors and 28 sepsis non-survivors who had previously undergone plasma proteomic and metabolomic profiling. Gene expression differences were identified between sepsis survivors, sepsis non-survivors, and SIRS followed by gene enrichment pathway analysis. Expressed sequence variants were identified followed by testing for association with sepsis outcomes. The expression of 338 genes differed between subjects with SIRS and those with sepsis, primarily reflecting immune activation in sepsis. Expression of 1,238 genes differed with sepsis outcome: non-survivors had lower expression of many immune function-related genes. Functional genetic variants associated with sepsis mortality were sought based on a common disease-rare variant hypothesis. VPS9D1, whose expression was increased in sepsis survivors, had a higher burden of missense variants in sepsis survivors. The presence of variants was associated with altered expression of 3,799 genes, primarily reflecting Golgi and endosome biology. The activation of immune response-related genes seen in sepsis survivors was muted in sepsis non-survivors. The association of sepsis survival with a robust immune response and the presence of missense variants in VPS9D1 warrants replication and further functional studies. ClinicalTrials.gov NCT00258869. Registered on 23 November 2005.
Reversible lipidization for the oral delivery of leu-enkephalin

The endogenous opioid peptide leu-enkephalin (ENK) was chemically modified by a method known as reversible aqueous lipidization (REAL) with a novel amine-reacting lipophilic dimethylmaleic anhydrid...
The interrelationship of proteasome impairment and oligomeric intermediates in neurodegeneration

Various neurodegenerative diseases are characterized by the accumulation of amyloidogenic proteins such as tau, α-synuclein, and amyloid-β. Prior to the formation of these stable aggregates, intermediate species of the respective proteins—oligomers—appear. Recently acquired data have shown that oligomers may be the most toxic and pathologically significant to neurodegenerative diseases such as Alzheimer’s and Parkinson’s. The covalent modification of these oligomers may be critically important for biological processes in disease. Ubiquitin and small ubiquitin-like modifiers are the commonly used tags for degradation. While the modification of large amyloid aggregates by ubiquitination is well established, very little is known about the role ubiquitin may play in oligomer processing and the importance of the more recently discovered sumoylation. Many proteins involved in neurodegeneration have been found to be sumoylated, notably tau protein in brains afflicted with Alzheimer’s. This evidence suggests that while the cell may not have difficulty recognizing dangerous proteins, in brains afflicted with neurodegenerative disease, the proteasome may be unable to properly digest the tagged proteins. This would allow toxic aggregates to develop, leading to even more proteasome impairment in a snowball effect that could explain the exponential progression in most neurodegenerative diseases. A better understanding of the covalent modifications of oligomers could have a huge impact on the development of therapeutics for neurodegenerative diseases. This review will focus on the proteolysis of tau and other amyloidogenic proteins induced by covalent modification, and recent findings suggesting a relationship between tau oligomers and sumoylation.
A quantitative analysis of high performance computing with Amazon's EC2 infrastructure: The death of the local cluster?

The introduction of affordable infrastructure on demand, specifically Amazon's Elastic Compute Cloud (EC2), has had a significant impact in the business IT community and provides reasonable and attractive alternatives to locally-owned infrastructure. For scientific computation however, the viability of EC2 has come into question due to its use of virtualization and network shaping and the performance impacts of both. Several works have shown that EC2 cannot compete with a dedicated HPC cluster utilizing high-performance interconnects, but how does EC2 compare with smaller departmental and lab-sized commodity clusters that are often the primary computational resource for scientists? To answer that question we have run MPI and memory bandwidth benchmarks on EC2 clusters with each of the 64-bit instance types to compare the performance of a 16 node cluster of each to a dedicated locally-owned commodity cluster based on Gigabit Ethernet. Our results show that while EC2 does experience reduced performance, it is still viable for smaller-scale applications.
Path selection for mobile stations in IEEE 802.16 multihop relay networks

Multimedia applications over wireless mobile networks become more popular with the increasing deployment of wireless infrastructures. IEEE 802.16 standard has become an emerging technology to support broadband access and quality of service (QoS) for real-time multimedia applications over wireless networks. This paper discusses the path selection problem in IEEE 802.16 mobile multihop relay (MMR) networks where relay stations are used to extend network coverage and enhance network capacity. For real-time applications that have explicit rate and delay requirements, choosing an appropriate path between any mobile station and the base station becomes essential. In this paper, we propose a path selection metric, named normalized number of minislots (NNM), which enables a mobile station to choose a path that satisfies its application rate and delay requirements. Simulation results show that NNM outperforms existing path selection metrics, especially when network has high traffic load.
Effect of expanding the treatment zone of the Nidek EC-5000 laser on laser in situ keratomileusis outcomes.

Abstract Purpose: To evaluate the effect of expanding the treatment zone of the Nidek EC-5000 laser on postoperative visual acuity as well as night glare and halos after laser in situ keratomileusis (LASIK) using 4 ablation zone diameters. Setting: Division of Ophthalmology, Evanston Northwestern Healthcare and Northwestern University Medical School, Glenview, Illinois, USA. Methods: This prospective study comprised 301 eyes of 154 consecutive patients who had LASIK in 1 or both eyes using the Nidek EC-5000 laser by 1 surgeon with experience in keratomileusis and excimer laser refractive surgery. A 6.5 mm optical zone was used with a transition zone 1.0 mm larger than the pupil under scotopic conditions (7.5, 8.0, 8.5, or 9.0 mm). Targeted correction was calculated according to a customized clinical nomogram. All patients were queried about glare and halos preoperatively and 3 months postoperatively using a questionnaire assigning numeric values to the degree of perceived visual disturbance (0 = no glare or halos, 1=minimal, 2=moderate, 3=severe). Results: The baseline uncorrected visual acuity (UCVA) was 20/200 or worse in 293 eyes. The baseline best spectacle-corrected visual acuity was 20/20 or better. The mean preoperative refractive sphere was −6.33 diopters (D) ± 2.80 (SD) (range −1.00 to −16.25 D) and the mean preoperative refractive cylinder, 0.86 ± 0.83 D (range 0 to +3.25 D). Three months postoperatively, 78% of eyes had a UCVA of 20/20 and 99%, of 20/40 or better. Preoperatively, 94 eyes (31%) had glare and halos. At 3 months, glare, halos, or both were present in 19 eyes of 11 patients (6.3%) ( P Conclusions: The use of a peripheral transition zone 1.0 mm larger than the pupil under scotopic conditions resulted in a low incidence of glare and halos postoperatively and did not adversely affect visual acuity. There was no increase in postoperative complications including corneal ectasia.
Advanced EWOD-based digital microfluidic system for multiplexed analysis of biomolecular interactions

This paper presents a low-cost technique for the fabrication of complex electrowetting-on-dielectric (EWOD) digital microfluidic devices. Using this original technology, we have developed devices in which 560 electrodes are used to mix and split nl-size liquid droplets and transport them to 100 analysis spots patterned on a disposable plastic top plate. We demonstrate the multiplexing capability of the developed devices by creating on-chip arrays of droplets with various concentration gradients. Finally, automated biomolecular immobilization and hybridization assays are performed in nl-size droplets under numerous conditions simultaneously with only a limited number of stock solutions.