cssi/SciSciGPT-SciSciNet huggingface dataset:
Isolation of a protein C activator from Southern Copperhead venom

A protease from the venom of the Southern Copperhead snake (Agkistrodon contortrix contortrix) that activates protein C was purified to homogeneity by a combination of sulfopropyl (SP)-Sephadex C-50, Sephadex G-150 and Mono-S column chromatography. The purified enzyme is a glycoprotein, and migrated as a single band in sodium dodecylsulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 37,000 under non-reducing conditions. Upon reduction with 2-mercaptoethanol, the enzyme exhibited a Mr of 40,000. The purified enzyme prolonged the clotting time of human plasma in a dose- and temperature-dependent manner. Purified bovine protein C was completely activated within 10 minutes upon incubation with the purified protease at a 1:500 enzyme: substrate ratio. This reaction was markedly inhibited by calcium ions. The purified venom protein C activator had no effect on human fibrinogen.
40 GHz Si/Ge Uni-Traveling Carrier Waveguide Photodiode

We report a Si/Ge waveguide-coupled uni-traveling carrier (UTC) photodiode for high-power high-speed applications. Using the uni-traveling carrier structure rather than a PIN structure, capacitance and power handling are decoupled from responsivity and transit-time, enabling a detector with a 40 GHz bandwidth and a dilute absorption profile. This photodiode had a responsivity at 1550 nm of 0.5 A/W and a −1 dB compression current of 1.5 mA at 40 GHz. A longer device with the same cross-section had a 33 GHz bandwidth, responsivity of 0.7 A/W, and −1 dB compression current of 2.1 mA at 30 GHz.
Recent progress with tapered-gain-region devices

Semiconductor laser devices with tapered gain regions have recently generated much interest because they promise high output power with near-diffraction-limited spatial beam quality and good electrical to optical conversion efficiency. We report recent progress on two specific applications: a ring laser and a high- power erbium-doped fiber amplifier (EDFA). The ring laser operates unidirectionally in a single longitudinal mode with an output power of 170 mW and without a Faraday isolator. The high- power EDFA has an output power of 520 mW at 1.55 micrometers , the highest power reported to dates for an erbium-doped fiber amplifier using all semiconductor pump lasers. The common theme for both of these applications is the development of optical systems that produce high power in near-diffraction-limited collimated beams and efficient coupling into single mode optical fiber. We present an experimental procedure for quantitatively predicting the optical fiber power coupling efficiency. We have measured 64% power coupling efficiency measure fiber fact to power in the single-mode fiber, or 51% laser facet to power in the fiber, in good agreement with the predictions.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nonparametric estimation for time-varying transformation models with longitudinal data

Regression methods for longitudinal analyses have traditionally focused on conditional-mean-based models. In many situations, the relevant scientific questions could be better studied by modelling the conditional distributions of the outcome variables as a function of time and other covariates. In this paper, we propose a class of time-varying transformation models for modelling the cumulative distribution function of a response variable conditioning on a set of covariates, and develop a two-step smoothing method for estimating the time-varying parameters. Applications and finite sample properties of our models and smoothing estimators are demonstrated through a cohort study of childhood obesity and cardiovascular risk factors, and a simulation study. Theoretical properties are developed for the two-step local polynomial estimators. Our approach provides a useful statistical tool in longitudinal analysis when the conditional-mean-based methods are inappropriate.
Synthesis of cationic diiron μ-vinylcarbyne complexes

Abstract Reaction of the diiron μ-ethylidyne complex [C5H5(CO)Fe]2(μ-CO)(μ-CCH3)+BF−4 (1) with p-tolualdehyde gave a 92% yield of the μ-vinylcarbyne complex [C5H5(CO)Fe]2(μ-CO)(μ-C-E-CHCHC6H4-p-CH3)+ BF−4 (4) which was characterized by spectroscopy and single crystal X-ray diffraction. 1 reacted with para-substituted benzaldehydes, cinnamaldehyde, pivalaldehyde, acetone, cyclohexanone, and isophorone to give similar vinylcarbyne complexes in 18–95% isolated yields. Propylidyne complex [C5H5(CO)Fe]2(μ-CO)(μ-CCH2CH3)+PF−6 (12) reacted with p-tolualdehyde to give vinyl-carbyne complex [C5H5(CO)Fe]2(μ-CO)[μ-C-E-C(CH3)CHC6H4-p-CH3]+PF−6 (13) in 83% yield. These new condensations are suggested to proceed by nucleophilic attack of a neutral μ-alkenylidene complex on a protonated aldehyde or ketone followed by dehydration. 1 reacted with isobutyraldehyde to give vinylcarbyne complex [C5H5(CO) Fe]2(μ-CO)[μ-C-E-CHCHCH(CH3)2]+BF−4 (20B) which rearranged under the reaction conditions to give μ-alkenyl complex [C5H5(CO)Fe]2(μ-CO)[μ-η1,η2-E-CHCHCHC(CH3)2]+BF−4 (21B) in 88% yield. Reaction of diiron pentenylidene complex [C5H5(CO)Fe]2(μ-CO)(μ-CCHCH2CH2CH3) (9) with the hydride abstracting reagent (C6H5)3C+PF−6 gave vinylcarbyne complex [C5H5(CO)Fe]2(μ-CO)(μ-C-E-CHCHCH2CH3)+PF−6 (18P) in 80% yield. Alkenylidene complex [C5H5(CO)Fe]2(μ-CO)[μ-CC(CH3)CH2CH3] (35), reacted with (C6H5)3C+PF−6 via preferential abstraction of a secondary allylic hydrogen to give a 3.8 : 1 ratio of vinylcarbyne complexes. [C5H5(CO)Fe]2(μ-CO)[μ-CC(CH3)CH2C6H4-p-CH3] (38), reacted with (C6H5)3C+PF−6 via preferential abstraction of a primary allylic hydrogen to give an 8.4 : 1 ratio of vinylcarbyne complexes.
Gold(I)-catalyzed enantioselective [4 + 2]-cycloaddition of allene-dienes.

An enantioselective gold(I)-catalyzed intramolecular [4 + 2]-cycloaddition of allenes and dienes is reported. The reactions allow for the asymmetric synthesis of trans-hexahydroindenes and pyrrolidine products using C3-symmetric phosphitegold(I) and ortho-arylphosphoramiditegold(I) complexes as catalysts, respectively.
Biological uptake and accumulation of silica on the Amazon continental shelf

Abstract Water column and seabed samples were obtained from 92 stations on the Amazon continental shelf during October of 1979. Uptake of silica near and southeast of the river mouth began at a salinity of 8%. and accounted for 17% of the riverine silica flux to this region. Uptake northwest of the river mouth began at a salinity of 20%. and resulted in 33% removal of the riverine silica flux. Examination of filtered suspended solids revealed abundant diatoms in the surface waters, including Coscinodiscus. Skeletonema, Synedra. and Thalassiosira. The biological uptake of silica appears to be dependent on three factors: turbidity, turbulence, and nutrient availability. There was no evidence of abiological removal of silica in the Amazon estuary. 75 to 88% of the silica removed from surface waters by diatoms dissolves prior to accumulation in the seabed. Based on the mean biogenic silica content of shelf sediment (0.25%) and estimates of rates of sediment accumulation, the biogenic silica accumulation rate on the shelf is 2 × 1012 g/yr, which represents only 4% of the dissolved silica supplied by the Amazon River. Biological uptake of silica in estuarine surface waters may not accurately reflect permanent removal of biogenic silica to the seabed because of dissolution which occurs in bottom waters and near the sediment-water interface.
Time Series Analysis of Nursing Notes for Mortality Prediction via a State Transition Topic Model

Accurate mortality prediction is an important task in intensive care units in order to channel prompt care to patients in the most critical condition and to reduce nurses' alarm fatigue. Nursing notes carry valuable information in this regard, but nothing has been reported about the effectiveness of temporal analysis of nursing notes in mortality prediction tasks. We propose a time series model that uncovers the temporal dynamics of patients' underlying states from nursing notes. The effectiveness of this information in mortality prediction is examined for mortality prediction for five different time spans ranging from one day to one year. Our experiments show that the model captures both patient states and their temporal dynamics that have a strong correlation with patient mortality. The results also show that incorporating temporal information improves performance in long-term mortality prediction, but has no significant effect in short-term prediction.
CALIBRATION OF AN ARTIFICIAL MOUTH FOR AUTOMATIC PERFORMANCE OF A TRUMPET USING A GENETIC ALGORITHM

The artificial mouth is a robotic device that simulates a human mouth. It consists of moveable lips and an adjustable air supply. In this study the use of a genetic algorithm to compute air pressure and lip pressure values so that the artificial mouth can correctly play five notes on a brass instrument is investigated. In order to properly play a brass instrument, a player must apply proper tension between the lips and apply proper airflow so that the lips vibrate at the proper frequency. A fast search algorithm was needed because it takes about 4 seconds to measure the frequency produced by each combination of pressure parameters. This measurement is slow because of the slow moving mechanics of the system and a delay produced while the notes are measured for pitch. The efficiency of this algorithm was compared to an exhaustive search. Experimentation was performed using various combinations of genetic parameters, including population size, crossover rate, and mutation rate. The genetic search was shown to be about 10 times faster than the exhaustive search because the genetic algorithm searches only very small portions of the search space.
Oxygen transport and peripheral microcirculation in long-term diabetes

The purpose of this investigation was to evaluate the impact of long-term diabetes on muscle blood flow (MBF) and oxygen transport (vO2) during exercise. Twelve male patients (58 +/- 8 years, mean +/- SD), with at least a 10-year history of diabetes controlled by insulin, and seven age-matched controls (56 +/- 5 years, mean +/- SD) participated in this study. No patient had been clinically diagnosed as having peripheral vascular disease, and on the average resting ankle/arm systolic blood pressure ratios were normal. Following a baseline period, 5 min of cycle ergometer exercises at 75 W were performed in the upright position and, after 1-hr recovery, in the supine position. Continuous vO2 was determined via breath-by-breath analysis. MBF was measured in the vastus lateralis (VL) and tibialis anterior (TA) by 133Xe clearance. In the erect position, the diabetic group (compared with the control group, respectively) exhibited significantly (P less than 0.05) lower exercise MBF [ml. (100 g.min)-1] in both VL (19 +/- 2.5 vs 30.9 +/- 2) and TA (13.7 +/- 2 vs 22.0 +/- 4), a lower steady-state VO2 (1.3 +/- 0.3 vs 1.7 +/- 0.2 liters.min-1) during exercise including the values in the last 15 sec of exercise, and greater accumulation of blood lactate (35 +/- 2 vs 22.0 +/- 2 mg/100 ml). The same trends in the data were observed during supine exercise; however, the blood pressure of the diabetics was significantly elevated during exercise when compared with that of controls. The reduced exercise MBF in the TA and VL demonstrated that impaired microvascular flow, without clinically overt peripheral vascular disease, in long-term diabetics leads to reduced oxygen delivery and exercise tolerance.
Packet-Mode Asynchronous Scheduling Algorithm for Partially Buffered Crossbar Switches

Traditional crossbar switches use centralized scheduling algorithms with high time complexity. In contrast, buffered crossbar switches are capable of distributed scheduling due to crosspoint buffers, which decouple the dependency between inputs and outputs. However, crosspoint buffers are expensive on-chip memories. To reduce the hardware cost of buffered crossbar switches and make them scalable, we consider partially-buffered crossbar switches, whose crosspoint buffers can be of an arbitrarily small size and store only part of a packet instead of the entire packet. In this paper, we propose the Packet-mode Asynchronous Scheduling Algorithm (PASA) for partially buffered crossbar switches. PASA combines the features of both distributed and centralized scheduling algorithms. It works in an asynchronous mode and can directly handle variable length packets without Segmentation And Reassembly (SAR). We theoretically prove that, with a speedup of two, PASA achieves 100% throughput for any admissible traffic. We also show that outputs in PASA have a large probability to avoid the more time-consuming centralized scheduling process, and thus make fast scheduling decisions. Finally, we present simulation data to verify the analytical results and evaluate the performance of PASA.
Black-White Differences in Occupational Prestige: Their Impact on Child Development

This article examines whether differences in parental occupational prestige mediate or moderate race differences in four indicators of child development—reading scores, math scores, Behavior Problems Index, and health status—using data from the Panel Study of Income Dynamics Child Development Supplement. The authors find that although for behavioral problems there is no impact of parental occupational prestige, for reading, math, and health there are significant academic returns to parental occupational prestige, but only for White families. The authors hypothesize that this racially distinct dynamic may be a result of ongoing discrimination in the labor market, thereby reducing the association between ability (job and parenting) and prestige; or it may be a result of the difficulty of Blacks to translate occupational prestige gains into other benefits as a result of discrimination outside the labor market; or finally, it may be the result of a generational lag between occupational status and parenting pr...
Comparison of two propeller source models for aircraft interior noise studies

The advanced turboprop (ATP) engines currently under development for transport aircraft are expected to be significantly noisier than existing turboprop engines. If this proves to be the case, public acceptance and thus the ultimate success of the ATP will depend on the degree to which the passenger cabin can be isolated from propeller noise. This raises the possibility that much of the gain in fuel efficiency anticipated for the ATP-powered transport could be lost because of the weight penalty associated with passive interior noise control techniques. This concern has led to a concerted effort to develop noise control methods that do not significantly increase take-off weight. One such technique being considered is synchrophasing, in which the phase angle between propellers on opposite sides of the fuselage is controlled to a value which minimizes the sound pressure level at typical cabin interior locations. The present article investigates the sensitivity of the predicted synchrophasing effectiveness trends to the propeller source model used. The influence on synchrophasing effectiveness of the relative direction of rotation of the two propellers is also investigated.
Role of thermal processes in dewetting of epitaxial Ag(111) film on Si(111)

Abstract Epitaxially grown silver (Ag) film on silicon (Si) is an optimal plasmonic device platform, but its technological utility has been limited by its tendency to dewet rapidly under ambient conditions (standard temperature and pressure). The mechanisms driving this dewetting have not heretofore been determined. In this study, scanning probe microscopy and low-energy electron microscopy are used to compare the morphological evolution of epitaxial Ag(111)/Si(111) under ambient conditions with that of similarly prepared films heated under ultra-high vacuum (UHV) conditions. Dewetting in both cases is seen to be initiated with the formation of pinholes, which might function to relieve strain in the film. We find that in the UHV environment, dewetting is determined by thermal processes, while under ambient conditions, thermal processes are not required. We conclude that dewetting in ambient conditions is triggered by some chemical process, most likely oxidation.
Multi-dimensional treatment planning: II. Beam's eye-view, back projection, and projection through CT sections

Three features of a fully three-dimensional treatment planning program are presented: (1) The beam's-eye-view provides the user with an accurate reproduction of anatomic features from the viewpoint of a treatment source. The source can be moved to any feasible position relative to the patient, permitting a choice which allows sensitive organs to be excluded from the beam. In this view a field defining aperture can readily be designed. (2) Back-projection of such an aperture shows the parts of the original transverse CT sections, or reconstructed sagittal or coronal sections, which may be covered by the selected beam. (3) Projection through the CT data from any desired origin provides an alignment film simulation which can be used to confirm accuracy of treatment, as well as help establish anatomic relationships relative to the margins of a treatment field.
The flapping-flag instability as a nonlinear eigenvalue problem

We reconsider the classical problem of the instability of a flapping flag in an inviscid background flow with a vortex sheet wake, and reformulate it as a nonlinear eigenvalue problem. We solve the problem numerically for the 20 lowest wave number modes. We find that the lowest wave number mode is the first to become unstable, and has the fastest growth rate within 3.5 decades of the stability boundary in the parameter space of flag mass and flag rigidity. This and subsequent modes become unstable by merging into complex-conjugate pairs, which then lose conjugacy further into the region of instability. Eigenmodes exhibit sharp transitions in shape across the stability boundary. In the corresponding initial value problem, we show a correlation between the wave number of unstable modes in the small-amplitude (growth) regime and the large-amplitude (saturation) regime. Wave number increases with decreasing rigidity and shows a combination of discrete and continuous change in the shape of unstable modes. Usin...
Fluvial Morphology and Sediment-Flux Steering of Axial–Transverse Boundaries In An Experimental Basin

Abstract The distinction between depositional belts associated with the basin axis and flanking piedmont streams is a fundamental attribute of the stratigraphic architecture of intracontinental rift basins. Spatiotemporal distributions of these lithofacies associations are sensitive to a combination of factors, including basin geometry, subsidence rate, and sediment discharge; however, most studies have focused on one or two controls and one depositional component (axial or tributary) of the basin-fill succession. A new perspective on how these depositional belts develop under simple but precisely controlled boundary conditions of steady subsidence, sediment flux, and water discharge is achieved through the creation of an experimental stratigraphic succession. The Experimental EarthScape run in 2006 (XES06) focused on the geomorphic evolution of sedimentary successions within an asymmetrically subsiding basin, analogous to a simple half graben, containing four interacting supply points of sediment and water. Under the imposed conditions, the experimental system self-organized into an axial stream flanked by transverse fans. Imposition of various combinations of longitudinal and lateral sediment flux showed that the locations and widths of the axial and transverse systems were strongly controlled by relative sediment fluxes (“flux steering”), and less influenced by the location of the subsidence maximum and subsidence rate. The axial drainage was dominated by transversely sourced sediment through toe cutting of the transverse fans, except during the highest axial-sediment discharges. Footwall fans persisted even under conditions of very large axial-sediment discharge, aided by topographic inheritance of the steeper transverse depositional slopes.
A Survey of Flagellate Diversity at Four Deep-Sea Hydrothermal Vents in the Eastern Pacific Ocean Using Structural and Molecular Approaches

Eighteen strains of flagellated protists representing nine species were isolated and cultured from four deep-sea hydrothermal vents: Juan de Fuca Ridge (2,200 m), Guaymas Basin (2,000 m), 21 degrees N (2,550 m) and 9 degrees N (2,000 m). Light and electron microscopy were used to identify flagellates to genus and, when possible, species. The small subunit ribosomal RNA genes of each vent species and related strains from shallow-waters and the American Type Culture Collection were sequenced then used for comparative analysis with database sequences to place taxa in an rDNA tree. The hydrothermal vent flagellates belonged to six different taxonomic orders: the Ancyromonadida, Bicosoecida, Cercomonadida, Choanoflagellida, Chrysomonadida, and Kinetoplastida. Comparative analysis of vent isolate and database sequences resolved systematic placement of some well-known species with previously uncertain taxonomic affinities, such as Ancyromonas sigmoides, Caecitellus parvulus, and Massisteria marina. Many of these vent isolates are ubiquitous members of marine, freshwater, and terrestrial ecosystems worldwide, suggesting a global distribution of these flagellate species.
Beryllium benzene dicarboxylate: the first beryllium microporous coordination polymer

The first Be-based microporous coordination polymer is shown to have a surface area of 3500 m2/g (BET) and a maximum excess H2 uptake of 53 mg/g at 24 bar and 77 K.
Elementary Matrix Method for Dispersion Analysis in Optical Systems

In this paper, dispersion analysis of optical components and systems is presented using a formalism based on the elementary matrices and the N-matrix, first described by Jones. This approach readily incorporates both phase and amplitude dispersion in a generalized dispersion framework. The method simplifies the analysis of the combined effects of group delay, differential group delay, amplitude slope, and differential amplitude slope as compared to traditional Jones matrix methods. Higher order polarization-mode dispersion and the effects of concatenation are presented along with a discussion of measurement principles. The application of the elementary matrix concept to Mueller matrix methods in Stokes space is also discussed.
EVOLUTION OF BIOLUMINESCENCE IN MARINE DINOFLAGELLATES

Bioluminescence is broadly distributed in marine dinoflagellates and has been intensively studied in Lingulodinium (Gonyaulax) polyedra. In this species, bioluminescence is regulated in a circadian fashion; the enzyme (luciferase) and the luciferin (substrate)-binding protein are synthesized and degraded on a daily basis. Synthesis of both proteins is regulated at the level of translation. The L. polyedra luciferase gene is composed of three contiguous domains that are greater than 75% identical at the nucleic acid level. Possible explanations for the high degree of sequence conservation include: (1) the domains evolved through a recent duplication event; (2) the sequence similarity is maintained by a molecular process such as gene conversion; or (3) there is a functional role associated with the primary nucleic acid sequence, such as in the translational regulation of luciferase expression. The phylogenetic relationship of dinoflagellates predicted from 18S rDNA genes provides a framework for examining the molecular evolution of the regulation of luciferase expression and of genes encoding luciferase and the luciferin-binding protein. In particular, we are examining the evolution of the circadian rhythm of bioluminescence and of luciferase abundance, the presence/absence of the luciferin-binding protein, and the molecular structure of the luciferase gene. We anticipate that this approach will distinguish between regions of the luciferase molecule that are conserved for enzyme function versus those concerned with the regulation of protein expression. In addition, it will provide insight into the evolution of the regulatory processes and pathways.
Micro/Nanotribological Studies of Single-Crystal Silicon and Polysilicon and SiC Films for Use in MEMS Devices

MEMS devices are currently made from single-crystal silicon, LPCVD polysilicon films and other ceramic films. For high temperature applications, SiC films are being developed to replace polysilicon films. Tribology in MEMS devices is of importance. Atomic force/friction force microscopy (AFM/FFM) and nanoindentation techniques have been used for tribological studies on microscale on materials of interest. These techniques have been used to study surface roughness, adhesion, friction, scratching/wear, indentation and boundary lubrication of bulk and treated silicon, polysilicon films and SiC films. Measurements of microscale and macroscale friction show that friction values on both scales of all the silicon samples are about the same and higher than that of SiC. The microscale values are lower than the macroscale values as there is less ploughing contribution in the microscale measurements. Surface roughness has an effect on friction. Microscratching, microwear and nanoindentation studies indicate that SiC films are superior to coated/treated silicon followed by bare silicon. Chemically bonded lubricants appear to be suitable for MEMS devices.
The L6 domain tetraspanin Tm4sf4 regulates endocrine pancreas differentiation and directed cell migration

The homeodomain transcription factor Nkx2.2 is essential for pancreatic development and islet cell type differentiation. We have identified Tm4sf4, an L6 domain tetraspanin family member, as a transcriptional target of Nkx2.2 that is greatly upregulated during pancreas development in Nkx2.2–/– mice. Tetraspanins and L6 domain proteins recruit other membrane receptors to form active signaling centers that coordinate processes such as cell adhesion, migration and differentiation. In this study, we determined that Tm4sf4 is localized to the ductal epithelial compartment and is prominent in the Ngn3+ islet progenitor cells. We also established that pancreatic tm4sf4 expression and regulation by Nkx2.2 is conserved during zebrafish development. Loss-of-function studies in zebrafish revealed that tm4sf4 inhibits α and β cell specification, but is necessary for e cell fates. Thus, Tm4sf4 functional output opposes that of Nkx2.2. Further investigation of how Tm4sf4 functions at the cellular level in vitro showed that Tm4sf4 inhibits Rho-activated cell migration and actin organization in a ROCK-independent fashion. We propose that the primary role of Nkx2.2 is to inhibit Tm4sf4 in endocrine progenitor cells, allowing for delamination, migration and/or appropriate cell fate decisions. Identification of a role for Tm4sf4 during endocrine differentiation provides insight into islet progenitor cell behaviors and potential targetable regenerative mechanisms.
Reproductive isolation and genetic differentiation in North American species of Triops (Crustacea: Branchiopoda: Notostraca)

Electrophoretic analysis of 31 populations, ranging from California to Kansas, indicates that the North American tadpole shrimp Triops longicaudatus (LeConte) is actually a mixture of at least two reproductively isolated species. In the central United States, the predominant species is T. longicaudatus, which is found typically in ephemeral prairie pools. In the southwestern United States, the predominant species is Triops newberryi (Packard), which characteristically inhabits large playa pools. The two species coexist occasionally and in sympatric situations they are reproductively isolated from each other. The two species are genetically distinct at a level greater than is typical of conspecific populations. These genetic differences are correlated with subtle morphological differences and profound differences in reproductive biology. Both species represent complexes of bisexual and unisexual populations. Bisexual populations of T. longicaudatus are usually composed of males and females in approximately equal frequencies; bisexual populations of T. newberryi are composed of males in low frequencies and self-compatible hermaphrodites. Unisexual populations of both species apparently consist entirely of self-compatible hermaphrodites.
Time, temperature, and load: the flaws of carbon nanotubes.

The “mechanics of nanostructures” is of intrinsic and practical interest. An acorn turning into an oak tree can lead one to consider the (often unknown) mechanical forces exerted by, and acting on, nanostructures present in the tree. A mantra of nanotechnology [which may ultimately outpace (1) “natural” evolution] is having “a place for every atom and every atom in its place” (www.foresight.org/nano/whatismm.html). What level of perfection might be achieved considering the known laws of physics and the constraints of chemistry? In principle, there is no limitation to achieving essentially perfect covalent bonding in material structures. With increasing atom number, a size is eventually reached where the defect-free structure is not the most stable (consider the role of entropy) (2), but it may be kinetically stable if there are high barriers to the nucleation of defects. In a recent issue of PNAS, Dumitrica et al. (3) consider carbon nanotubes (CNTs) and, building on prior theoretical work by themselves and others, present the pathways to failure caused by tensile load as a function of time and temperature. Because CNTs can have different chiralities, the issue of the orientation of the C—C bonds in the different CNTs is treated and shown to critically influence the ultimate strength, the type of defects that nucleate and how they grow or propagate, and the modeled time to failure (3). The possibility of having structures entirely free of defects would seem more likely for small structures than large structures, and living organisms routinely achieve such perfection. The remarkable mechanics of biological motors (4, 5) and viral DNA packaging and ejection … *E-mail: r-ruoff{at}northwestern.edu
Profiling and Prediction of Non-Emergency Calls in NYC

Non-emergency calls, namely the 311 calls, capture different complaints of city residents and visitors about a variety of experienced problems in a city. The 311 calls in New York City (NYC) are publicly available and can provide an interesting status of the city. In this paper, we share a summary of an extensive analysis that we are performing in the 311 data of NYC, as well as a data-based prediction of the number of 311 calls. We present information about the 311 data files and content along multiple dimensions, and then proceed to present prediction results, in which we show that several semantic features affect the different types of complaints differently.
Abstract 3013: Cerebral Perfusion Parameter Differences in Clinically Relevant Categories of Carotid Stenosis/Occlusion.

Hypothesis: To determine whether clinically relevant categories of carotid stenosis are associated with changes in cerebral blood flow. Methods: We examined a consecutive cohort of stroke patients with confirmed stroke on DWI imaging who underwent CT angiography (CTA) and perfusion CT imaging on presentation with acute symptoms. Degree of carotid stenosis was measured per NASCET criteria on CTA. Perfusion CT was analyzed to calculate relative mean transit time (rMTT), relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of normal brain tissue ipsilateral to carotid disease. Measurements excluded areas of infarction to avoid confounding hemispheric perfusion changes with local changes due to distal cerebral artery occlusion(s), and subjects with MCA occlusions on any side were excluded. Results: The cohort consisted of 119 patients. Of these 8.4% had 100% ipsilateral carotid occlusion, 1.7% had near-occlusion, 5% had 70-99% stenosis, 5.9% had 50-69% stenosis, and 79% had Conclusions: This is the first reported correlation between clinically relevant categories of carotid stenosis and perfusion parameters measured by perfusion CT imaging of the brain. Subjects with 100% occlusion appeared to have hemodynamically significant changes in perfusion (increased rMTT by ∼50%, decreased rCBF by ∼30%). Patients with 70-99% stenosis had less pronounced changes in rMTT, and no change in rCBF. Interestingly, patients with carotid near-occlusion showed no significant change in perfusion parameters, suggesting that this subgroup of patients may have developed sufficient collateral circulation. Patients with 0-69% stenosis had no significant changes in perfusion parameters. These findings may have significant implications in our approach to patients with carotid occlusion/stenosis and need to be confirmed in larger patient populations.
Intrapartum Care of the Morbidly Obese Gravida: Ten Guidelines for the Obstetrician

Obesity has evolved as a major public health issue worldwide, its effects having a significant impact on obstetrical care. Morbidly obese parturients are at a significantly increased risk of complications during the intrapartum period and thus require more intervention. Guidelines are needed to address the intrapartum management of the morbidly obese gravida to reduce the risk of morbidity and mortality.
Diverting Glycolysis to Combat Oxidative Stress

Reactive oxygen species (ROS) are an intricate part of normal cellular physiology. In excess, however, ROS can damage all three major classes of macromolecules and compromise cell viability. We briefly discuss the physiology of ROS but focus on the mechanisms cells use to preserve redox homeostasis upon oxidative stress, with particular emphasis on glycolysis. ROS inhibits multiple glycolytic enzymes, including glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase M2, and phosphofructokinase-1. Consistently, glycolytic inhibition promotes flux into the oxidative arm of the pentose phosphate pathway to generate NADPH. NADPH is critically important, as it provides the reducing power that fuels the protein-based antioxidant systems and recycles oxidized glutathione. The unique ability of pyruvate kinase M2 inhibition to promote serine synthesis in the context of oxidative stress is also discussed.
Microstructural Changes within the Basal Ganglia Differ between Parkinson Disease Subtypes

Diffusion tensor imaging (DTI) of the substantia nigra has shown promise in detecting and quantifying neurodegeneration in Parkinson disease (PD). It remains unknown, however, whether differences in microstructural changes within the basal ganglia underlie PD motor subtypes. We investigated microstructural changes within the basal ganglia of mild to moderately affected PD patients using DTI and sought to determine if microstructural changes differ between the tremor dominant (TD) and postural instability/gait difficulty (PIGD) subtypes. Fractional anisotropy, mean diffusivity, radial, and axial diffusivity were obtained from bilateral caudate, putamen, globus pallidus, and substantia nigra of 21 PD patients (12 TD and 9 PIGD) and 20 age-matched healthy controls. T-tests and ANOVA methods were used to compare PD patients, subtypes, and controls, and Spearman correlations tested for relationships between DTI and clinical measures. We found our cohort of PD patients had reduced fractional anisotropy within the substantia nigra and increased mean and radial diffusivity within the substantia nigra and globus pallidus compared to controls, and that changes within those structures were largely driven by the PIGD subtype. Across all PD patients fractional anisotropy within the substantia nigra correlated with disease stage, while in PIGD patients increased diffusivity within the globus pallidus correlated with disease stage and motor severity. We conclude that PIGD patients have more severely affected microstructural changes within the substantia nigra compared to TD, and that microstructural changes within the globus pallidus may be particularly relevant for the manifestation of the PIGD subtype.
The Cambridge Introduction to Theatre and Literature of the Absurd

Michael Y. Bennett's accessible Introduction explains the complex, multidimensional nature of the works and writers associated with the absurd - a label placed upon a number of writers who revolted against traditional theatre and literature in both similar and widely different ways. Setting the movement in its historical, intellectual and cultural contexts, Bennett provides an in-depth overview of absurdism and its key figures in theatre and literature, from Samuel Beckett and Harold Pinter to Tom Stoppard. Chapters reveal the movement's origins, development and present-day influence upon popular culture around the world, employing the latest research to this often challenging area of study in a balanced and authoritative approach. Essential reading for students of literature and theatre, this book provides the necessary tools to interpret and develop the study of a movement associated with some of the twentieth century's greatest and most influential cultural figures.
Urban Mascots and Poverty Fetishism: Authenticity in the Postindustrial City

Downtown Los Angeles is undergoing a transformation from concentrated disadvantage to vibrant city center. Using ethnographic research conducted in the gentrifying Historic Core of Los Angeles, I f...
Bilingual Education Candidates' Challenges Meeting the Spanish Language/Bilingual Certification Exam and the Impact on Teacher Shortages in the State of Texas, USA.

ABSTRACTRecruiting certified bilingual teachers have been difficult since 2010 as new testing policies and exams are implemented. Advanced high levels of writing and speaking language proficiency are required from the bilingual education candidate to perform his or her job. This essay examines the impact of Texas language policy for bilingual education teachers, testing requirements, and passing rates on state certification tests previously explored by Guerrero (1997, 1999, 2000), and discusses the topic of teacher shortages that has been addressed for the past two decades. Suggestions to assist bilingual education candidates to improve their passing rates are provided.
MATHEMATICAL MODEL ON STEEL STRIP-FEEDING OF MOLD IN CONTINUOUS CASTING PROCESS

A mathematical model for feeding strip steel process has been developed using energy conservation principle on traveling thin-cell and introduction of relative steel strip feeding speed.Model equations are solved by using the finitevolume method,and computer code is made out by Visual Basic language.The numerical simulation is carried out on a typical feeding steel strip in continuous casting mold.The temperature distribution of continuous casting strand and solidification state curve of feeding strip steel are obtained.The results show that conventional temperature field and solidification behavior from surface to interior of strand are changed by a feeding strip steel process.Strip steel in mold firstly solidifies and then melts again,the superheat of molten steel and temperature gradient of strand decrease.These are beneficial for formation of equiaxed dendrite in strand.At the same time,the effects of some parameters such as size of feeding strip steel,casting speed and superheat on solidification process are also studied.
The therapeutic effect of pholcodine child cough syrup on children with acute respiratory tract infections

Objective:To evaluate the therapeutic effects of pholcodine child cough syrup on children with acute respiration tract infections.Methods:34 patients who complained of cough and expectoration caused by acute respiratory tract infections were randomly divided into treatment group (19 eases) and control group (15 cases).The treatment course was designed to be 5 days.Results:After 5 day course of treatment,the effects on cough,sputum volume and sputum viscosity were much better in treatment group than in control group.The total improvement rate of clinical symptoms was 87.7% in the treatment group and 67.8% in the control group with a statistic significance(x~2=2.524,P0.05).Conclusions:The pholcodine children cough syrup is effective and safe expectorant and cough remedy.
5-Hydroxytryptophan decarboxylase: preparation and properties.

Although 5-hydroxytryptamine was only recently discovered (l), the evidence already at hand indicates that it is present in practically all animal species (24) and that it possesses unusual pharmacological properties (5, 6). It may well rank with epinephrine, norepinephrine, and histamine as one of the important regulatory amines of the body. Studies carried on in this laboratory on the biosynthesis of 5-hydroxytryptamine in animals indicate that tryptophan is the precursor, being converted by oxidation to 5-hydroxytryptophan, which then undergoes decarboxylation to yield 5hydroxytryptamine (7). The studies reported in this paper concern the enzyme, 5-hydroxytryptophan decarboxylase. Procedures for purification of the enzyme obtained from hog and guinea pig kidney homogenates and acetone-dried powders and some properties of these preparations are described.
Worry, Intolerance of Uncertainty, and Statistics Anxiety.

Statistics anxiety is a problem for most graduate students. This study investigates the relationship between intolerance of uncertainty, worry, and statistics anxiety. Intolerance of uncertainty was significantly related to worry, and worry was significantly related to three types of statistics anxiety. Six types of statistics anxiety were significantly lower by the end of the semester. First published May 2013 at Statistics Education Graduate students ournal Archives
Vulnerabilities and Capacities: Venezuela Floods and Mudslides – December 14–16, 1999

In 1999, heavy rainfall in Venezuela [1] triggered mudslides that buried entire villages and cities. The rain lasted 2 weeks [2–4]. In just 2 days, from December 14–16, about 30,000 people were killed. Another 600,000 felt the effects of the mud and water, including thousands who lost their homes [5, 6]. Heavy rainfall and flooding are not uncommon in the area [4], but the mayor of Caracas, Antonio Ledezma, and other officials described the rain as the heaviest in 60 years [1] and the flooding that followed as the country’s worst disaster since an earthquake more than 30 years before, in 1967 [7].
Cognition and Motor Skill Acquisition: Contextual Dependencies

Every day we perform skilled activities in environments that are comprised of a wide variety of stimuli that we do not explicitly identify as important to successful completion of an intended action. Nevertheless, it appears that the environmental contexts in which we perform can exert powerful influences on our ability to retrieve and process information. For example, the seemingly “absent-minded” professor is sometimes caught off-guard when outside of the classroom setting he or she is confronted by a student in his or her class. In this situation it is not unusual for the professor to appear embarrassed by his or her inability to recall the student’s name or even recognize the student. Upon the professor’s return to class, however, the student’s name is easily recalled. In this case, reinstating the context associated with the student (the classroom) facilitated the retrieval of a specific memory (the student’s name).
The ultrasonographic evaluation of severely traumatized eyes

The complementary use of ultrasonography and computerized tomography has enabled the ophthalmologist to more accurately assess the extent of damage caused by ocular trauma. Ocular trauma includes concussion and contusion injuries, penetrating wounds, foreign body injuries and orbital and periorbital fractures. These injuries often cause cloudy or opaque media, making adequate ophthalmoscopic evaluation of the eye impossible. A series of 25 patients who sustained severe trauma were reviewed. Twenty of these patients had ultrasonographic evaluation, ten had computerized tomographic evaluation and five had both ultrasound and CT scanning performed. Thirteen patients had perforated globes, six had intraocular foreign bodies and four had severe periorbital trauma, resulting in visual disturbances.
DNA thermometry: A universal biothermometer in the 18O/16O ratio of PO4 in DNA

Oxygen isotope thermometry has been traditionally based on the ratio of 18O/16O in oxyanions of minerals such as carbonate (CaCO3) in shells/tests, and phosphate in bioapatites (Ca5(PO4)3OH) of marine invertebrates/vertebrates (for example, fish) and mammals. The requirement of mineral biomass, however, has restricted the application of oxygen isotope thermometry to only those organisms possessing biomineral hardparts. This has completely omitted from study, not only organisms lacking hard mineral tissues, but two entire Domains of life: Bacteria and Archaea. Prokaryotic organisms in the domains Bacteria and Archaea comprise the majority of earth9s biodiversity and also inhabit the most extreme environments on earth. This calls for a thermometry based on a more rudimentary component of biomass that is present in all organisms such as DNA. Our previous studies of the ubiquitous intracellular enzyme inorganic pyrophosphatase (PPase), which catalyzes oxygen isotope exchange between dissolved inorganic PO4 (Pi) and water inside of cells, suggest that DNA may contain even more information than the blueprint for life. Here we show that PO4 moieties in DNA record the temperature at which life forms and evolves. Our results demonstrate that the 18O/16O ratio of PO4 (δ18OP) in DNA as well as in bulk biomass, reflects the temperature-dependent exchange of oxygen isotopes between PO4 and intracellular water. Thus, δ18OP values of DNA may serve as both a new soft-tissue bio-thermometer and probe of intracellular PO4 or water during DNA synthesis and cellular growth. Results presented here of the first direct measurements of the oxygen isotopic composition of PO4 in microbial DNA, demonstrate systematic variation in δ18OP of DNA from several different strains of microorganisms as a function of temperature, and also extend the PO4-water O-isotope thermometer to >70 °C. A composite calibration curve based on several strains of bacteria is presented for DNA-PO4–water –temperature relations between 12 and 75 °C and suggests a “universal” DNA-based oxygen isotope thermometry for microorganisms that may further extend to all organisms. Our results open the possibility of connecting temperature with taxonomy and also expand the range of investigations of habitat temperatures and limits to life in extreme and diverse environments, from Earth9s subsurface deep biosphere to Antarctic ice sheets and extraterrestrial systems where life may have originated at extreme temperatures.
Lead Halide Perovskites: Challenges and Opportunities in Advanced Synthesis and Spectroscopy

Hybrid lead perovskites containing a mixture of organic and inorganic cations and anions have led to solar cell devices with performance and stability that are better than those of their single-halide analogs. 207Pb solid-state nuclear magnetic resonance and single-particle photoluminescence spectroscopies show that the structure and composition of mixed-halide and likely other hybrid lead perovskites are much more complex than previously thought and are highly dependent on their synthesis. While a majority of reports in the area focus on the construction of photovoltaic devices, this Perspective focuses instead on achieving a better understanding of the fundamental chemistry and photophysics of these materials, because this will aid not only in constructing improved devices but also in generating new uses for these unique materials.