cssi/SciSciGPT-SciSciNet huggingface dataset:
Apparent hibernation by the Atlantic loggerhead turtle Caretta caretta off cape canaveral, Florida

During the winter of 1978 large numbers of torpid loggerhead turtles Caretta caretta were taken by shrimp trawlers in the Port Canaveral Ship Channel, off the East Coast of Florida. During February and March the writers made experimental trawl drags in the same channel, and took 56 loggerheads in 123 minutes' drag time on the first trip and 100 in 128 minutes on the second trip. This represents by far the heaviest incidental trawler catch of turtles on record, and the aggregation sampled is the most concentrated ever reported for any species of sea turtle in a non-breeding habitat. The cause of the assemblage is unknown. Thermal data and other evidence strongly suggest that, on the first trip, most of the torpid turtles had been dragged out of the bottom and walls of the channel, and thus were hibernating. The implication that in temperate-zone sections of its range the loggerhead may sometimes hibernate, as some freshwater turtles do, is supported by widespread fishermen's opinion, and by the recent discovery of black turtles hibernating in the Gulf of California, at water temperatures almost identical to those recorded here for our February cruise.
Retinitis with Massive Exudates

The case here reported was that of a boy of 9 years recently found to have poor vision. The cause is unknown. The retinitis may be checked in some cases, but the function of the retina cannot be restored.
Insect predator-prey coevolution via enantiomeric specificity in a kairomone-pheromone system.

Insect predators can be guided to their prey by a kairomonal response to the prey pheromone. We found this phenomenon to be highly specific in the bark beetle predatorThanasimus dubius. Olfactory responses and behavioral tests revealed that the predator is guided to its major preyDendroctonusfrontalis by the primary enantiomer of the pheromone of the prey, (1S, 5R)-(−)-frontalin. These and other findings suggest the co-evolution of a kairomone system of the predator and the pheromone system of its prey.
Finite Element Calculations of Thermal Stresses in Passivated and Unpassivated Lines Bonded to Substrates

Thermal stresses in passivated and unpassivated aluminum lines bonded to substrates have been calculated using the MARC finite element code. Stresses in the unpassivated lines increase with increasing line width, with increasing substrate rigidity, and with decreasing distance from the substrate. Edge effects become significant for small line widths. Stresses in passivated lines increase with decreasing aspect ratio, with increasing passivation thickness, and with increasing Young's modulus of the passivation. Allowing plastic deformation to occur in the lines homogenizes and reduces the stresses. The calculated stresses in passivated lines are compared to recent measurements of stresses in encapsulated aluminum lines. The measured values are about a factor of four smaller than the calculated stresses, indicating that some deformation process besides plasticity, such as voiding or cracking, must have occurred to relieve the stresses.
Structural and electronic characterization of a dissociated 60 ° dislocation in GeSi

A dissociated $60\ifmmode^\circ\else\textdegree\fi{}$ misfit dislocation at the substrate interface of a ${\mathrm{S}\mathrm{i}/\mathrm{G}\mathrm{e}}_{x}{\mathrm{Si}}_{(1\ensuremath{-}x)}$ heterojunction has been examined using electron energy loss spectroscopy and annular dark field imaging. New spectra are obtained at the intrinsic stacking fault, at the dislocation cores, and in the strained regions on either side of the stacking fault. In-gap states are verified at the partial dislocation cores. Images resemble accepted structures except at the 90\ifmmode^\circ\else\textdegree\fi{} partial dislocation. Model structures for the object are considered to try to reconcile the imaging and spectral results.
Don't all veins look alike? Comprehensively attending to diversity within the vascular surgical specialty

Prior research has established diversity as a topic of empirical analysis in the vascular surgery literature. Building on the work of previously published articles on diversity in the Journal of Vascular Surgery and elsewhere, this article engages in a broad discussion of diversity in two interrelated arenas: educational/workplace diversity and culturally competent care. Interdisciplinary review of the literature indicates that diversity is often thought of as an end-state to be accomplished. A more fruitful way to encompass the changing aspects of diversity work is to think of diversity as a set of processes that can be adjusted based on a set of interrelated goals that matter differently to different groups. In considering diversity as a process, an approach to diversity emerges that considers both independent effects of gender and race/ethnicity as well as interactive effects between the two variables to address future trends in medical education. Such trends are diagnosed and multiple courses of intervention are offered as reasonable options for future efforts. A comprehensive definition of diversity will be established in order to encompass two different arenas in which diversity concerns arise: educational diversity and culturally competent patient care. Second, a discussion of the rationales for attention to diversity among vascular surgeons will provide different avenues into a conversation about diversity in the profession. In so doing, three successful efforts will be briefly discussed: the Ohio State University's MED-Path program, the Keck School of Medicine's chair-centered approach to diversity in residency training, and the American Association of Orthopedic Surgeons' (AAOS) approach to culturally competent care.
Detailed gravimetric geoid confirmation of sea surface topography detected by the Skylab S-193 altimeter in the Atlantic Ocean

A detailed gravimetric geoid has been computed for the Nortwest Atlantic Ocean and Caribbean Sea area in support of the calibration and evaluation of the GEOS-3 altimeter. This geoid, computed on a 15’ x 15’ grid was based upon a combination of surface gravity data and the GSFC GEM-8 gravitational field model. This gravimetric geoid has been compared with passes of SKYLAB altimeter data recorded in the Atlantic Ocean, and three typical passes are presented. The relative agreement of the two data types is quite good with differences generally less than 2 meters for these passes. Sea surface manifestations of numerous short wavelength (≈ 100 km) oceanographic features indicated in the altimeter data are also confirmed by the gravimetric geoid.
Free Energy Simulation of Grain Boundary Segregation and Thermodynamics In Ni3-xAl1+x

The free energy simulation method is employed to study segregation to Σ5 and Σ13 (001) twist grain boundaries and their free energies in ordered Ni3-xAl1+x. In the temperature range studied (300-900K), it is shown that there is almost no segregation, strong Al segregation, and weak Ni segregation to the grain boundary for the stoichiometric, Al-rich, and Ni-rich bulk compositions respectively. It is also shown that the segregation is limited to a few (002) planes around the grain boundary and its magnitude decreases with increasing temperature. For Al-rich bulk composition, it is demonstrated that segregation at low temperature substantially lowers the grain boundary free energy.
Dynamic shear plugging of beams and plates with an advancing crack

Abstract The perforation response of a thin or intermediately thick beam/plate struck by a rigid, heavy, flat-nosed projectile traveling at a high velocity is studied analytically. Based on a newly developed expression relating indentation depth to crack length, a shear-plugging model including two stages: indentation and crack growth, is proposed. In this model, shear resistance in the ligament decreases as the cracks propagate through the target thickness. The closed-form solutions for residual velocities, plastic energy, shear zone width, crack propagation speeds, and temperature rise are derived. A coupled shear–tension solution that takes into account global deformation of the plate is also developed. The coupled solution improves prediction for the case with the initial impact velocity near the ballistic limit. Comparisons with experimental results presented in the open literature are made showing rather good correlation, which validates the accuracy of the present solution.
Clinical Judgment and Clinical Significance in Psychotherapy Practice

The use of outcome measurement in psychotherapy practice is briefly discussed, as is Jacobson and Truax’s (J Consult Clin Psychol 59:12–19, 1991) conception of clinically significant change. A more flexible and user friendly application of clinically significant change compatible with clinical judgment is proposed for psychotherapy practice. Examples are given and a free Windows program is described for computing RC and estimating the probability associated with it.
Experimental study of atomic structure in strong electromagnetic fields

We have measured the energy spectrum of photoelectrons emitted in multiphoton ionization of atoms by a short-pulse, tunable laser. The spectrum shows prominent resonances, confirming the observations of Freeman et al. [Phys. Rev. Lett. 59, 1092 (1987)]. The study of the position and intensity of such resonances, as a function of laser wavelength and intensity, probes the structure of the atom in the presence of the strong electromagnetic field and allows their spectroscopic assignment. A systematic study of the ac Stark shift of one of the resonances, the 7s[3/2]\ifmmode^\circ\else\textdegree\fi{} level of xenon, is presented.
Cover art: Issues in the metric-guided and metric-less placement of random and stochastic template banks

The efficient placement of signal templates in source-parameter space is a crucial requisite for exhaustive matched-filtering searches of modeled gravitational-wave sources, as well as other searches based on more general detection statistics. Unfortunately, the current placement algorithms based on regular parameter-space meshes are difficult to generalize beyond simple signal models with few parameters. Various authors have suggested that a general, flexible, yet efficient alternative can be found in randomized placement strategies such as random placement and stochastic placement, which enhances random placement by selectively rejecting templates that are too close to others. In this article we explore several theoretical and practical issues in randomized placement: the size and performance of the resulting template banks; the very general, purely geometric effects of parameter-space boundaries; the use of quasirandom (self-avoiding) number sequences; most important, the implementation of these algorithms in curved signal manifolds with and without the use of a Riemannian signal metric, which may be difficult to obtain. Specifically, we show how the metric can be replaced with a discrete triangulation-based representation of local geometry. We argue that the broad class of randomized placement algorithms offers a promising answer to many search problems, but that the specific choice of a scheme and its implementation details will still need to be fine-tuned separately for each problem.
A generalized extension principle

We present a generalized extension principle which contains, as special cases, the calculations needed to perform arithmetic operations on both fuzzy variables and random variables.
Functional roles of bestrophins in ocular epithelia

Abstract There are four members of the bestrophin family of proteins in the human genome, of which two are known to be expressed in the eye. The gene BEST1 (formerly VMD2) which encodes the protein bestrophin-1 (Best1) was first identified in 1998. Mutations in this gene have now been associated with four clinically distinguishable human eye diseases, collectively referred to as “bestrophinopathies”. Over the last decade, laboratories have sought to understand how Best1 mutations could result in eye diseases that range in presentation from macular degeneration to nanophthalmos. The majority of our knowledge comes from studies that have sought to understand how Best1 mutations or dysfunction could induce the classical symptoms of the most common of these diseases: Best vitelliform macular dystrophy (BVMD). BVMD is a dominant trait that is characterized electrophysiologically by a diminished electrooculogram light peak with a normal clinical electroretinogram. This together with the localization of Best1 to the retinal pigment epithelium (RPE) basolateral plasma membrane and data from heterologous expression studies, have led to the proposal that Best1 generates the light peak, and that bestrophins are a family of Ca2+ activated Cl− channels (CaCCs). However, data from Best1 knock-out and knock-in mice, coupled with the recent discovery of a recessive bestrophinopathy suggest that Best1 does not generate the light peak. Recently Best2 was found to be expressed in non-pigmented epithelia in the ciliary body. However, aqueous dynamics in Best2 knock-out mice do not support a role for Best2 as a Cl− channel. Thus, the purported CaCC function of the bestrophins and how loss of this function relates to clinical disease needs to be reassessed. In this article, we examine data obtained from tissue-type and animal models and discuss the current state of bestrophin research, what roles Best1 and Best2 may play in ocular epithelia and ocular electrophysiology, and how perturbation of these functions may result in disease.
Anisotropic statics for a 2D line over a mountainous overthrust belt in Bolivia

The most important discovery made during this study was the existence of near-surface anisotropy, leading to azimuth dependent velocities and arrival times for refracted waves. A method was developed to process first-break picks from these refraction arrivals, and create a set of up-line and down-line static corrections for each shot station and receiver station in a surface consistent manner. Correct application of these azimuth dependant statics to gathers of CMP traces were used to effectively ’beam-steer’ the stack to create or destroy reflection horizon coherency depending upon the horizon dip.
Recent advances in wheat transformation

Since the first report of wheat transformation in the early 1990s, genetic engineering of wheat has evolved rapidly. Several laboratories worldwide have reported the production of fertile transgenic wheat plants using a variety of methods. While there are several innovative and promising approaches for wheat transformation using different explants as targets for transformation, different methods of transformation, and different selection schemes, the most common approach to wheat transformation is the bombardment of tissue derived from immature embryos followed by selection based on resistance to the bar gene. Even with all these successful reports, hurdles still exist for this recalcitrant crop. Of these hurdles, low transformation rates, tools for transgene expression, and transgene silencing in subsequent generations are probably the most critical. This review will provide an overview of wheat transformation in the past decade, addressing both positive and negative factors that effect transformation while highlighting the successes of the past and prospects for the future.
Modeling the tor-dotted crests, bedrock edges, and parabolic profiles of high alpine surfaces of the Wind River Range, Wyoming

Abstract Broad, low curvature surfaces common to many alpine landscapes, and particularly well expressed in the Laramide ranges of the western USA, appear to be roughly in steady state with respect to the current surface processes. Uniform, thin (order 1 m) regolith covers the crystalline bedrock with the exception of occasional tors at ridgecrests. The surfaces are commonly edged by bedrock lips, at the tops of cliffs that bound the intervening glacial troughs. Regolith production is low (order 10 μm/year) on bare bedrock and reaches a maximum under tens of centimeters of regolith. All of these characteristics may be accounted for with a numerical model that is faithful to the periglacial surface processes presently operating on these surfaces. Hillslope transport is modeled assuming the dominant process is frost creep; transport efficiency depends linearly upon local slope and appropriately vanishes in the absence of regolith. Frost frequency scales the rate of motion, while the ratio of frost penetration depth to regolith thickness dictates the degree to which the process is curtailed by available regolith. Initial conditions include initial mean slope and bedrock roughness and a uniform regolith cover. Boundary conditions are imposed by dictating that the edges of the calculation space be lowered at a rate appropriate for glacial incision. Broad convex surfaces emerge over time scales of order 1 million years. All surfaces rapidly decouple from the bounding glacial troughs, as the high negative curvature at the edges disallows accumulation of regolith. These bedrock edges lower at a few microns per year, while the troughs lower at many times this rate. As the bedrock edges, therefore, serve as the effective boundary condition for the remaining surface, the surfaces operate independently of both lowering and widening of the glacial troughs. For a reasonable set of transport and weathering rates, the final steady-state landscape is sensitive to the initial condition. In particular, the steeper the initial landscape, the more likely tors are to develop, as the high curvature disallows accumulation of regolith. These tors, in turn, limit the lowering rate of the crest, and the landscape retains significant local relief. Low relief initial conditions more likely lead to parabolic surfaces that lack tors. That tors are more likely on the crests reflects the high initial curvature at the crest. Tors on the side slopes are eliminated. The present high surfaces in the Laramide ranges of the western USA imply operation of periglacial surface processes over millions of years. The occasional tors imply a steeper rather than flatter initial landscape. The strong decoupling of surfaces from glacial troughs justifies their use as local geomorphic markers that allow calculation of relief production since glacial incision was initiated. On the other hand, their present low curvature does not require a landscape history in which these surfaces were once joined as an initially widespread erosion surface.
Effect of prostaglandin F3α on gastric mucosal injury by ethanol in rats: comparison with prostaglandin F2α

Abstract In humans eicosapentaenoic acid can be converted to 3-series prostaglandins (PGF3α, PGI3, and PGE3). Whether 3-series prostaglandins can protect the gastric mucosa from injury as effectively as their 2-series analogs is unknown. Therefore, we compared the protective effects of PGF3α and PGF2α against gross and microscopic gastric mucosal injury in rats. Animals received a subcutaneous injection of either PGF3α or PGF2α in doses raning from 0 (vehicle) to 16.8 μmol/kg and 30 min later they received intragastric administration of 1 ml of absolute ethanol. Whether mucosal injury was assessed 60 min or 5 min after ethanol, PGF3α was significantly less protective against ethanol-induced damage than PGF2α. These findings indicate that the presence of a third double bond in the prostaglandin F molecule between carbons 17 and 18 markedly reduces the protective effects of this prostaglandin on the gastric mucosa.
Make light, not heat: toward higher efficiency nitride semiconductor ultraviolet optical sources

We have used subpicosecond time-resolved photoluminescence (TRPL) downconversion techniques to study the interplay of carrier localization and radiative and nonradiative processes in the active regions of light emitting III-nitride semiconductor ultraviolet optical sources, with the goal of identifying potential approaches that will lead to higher radiative efficiency. Comparison of TRPL in (In)AlGaN multiple quantum well active regions indicate that for addition of only 0.01 In content the PL decay time in an InAlGaN MQW is more than double that in an AlGaN MQW designed to emit at the same wavelength (360 nm), thus indicating the importance of indium for improvement of material quality, most likely through the suppression of point defects. This result is further underscored by TRPL data on 320 nm InAlGaN MQW active regions, which exhibit longer PL lifetimes than expected for growth on GaN templates with dislocation densities in the mid-10 8 cm -2 range. While the PL lifetimes in these InAlGaN MQWs improve for growth on lower dislocation density HVPE bulk GaN substrates, a similar phenomenon is not observed for deposition on nearly dislocation-free bulk AlN substrates, suggesting that defect generation in the MQWs associated with lattice mismatch or AlN surface preparation may play an important role. The pump intensity dependence of the time zero signal and the TRPL decays in the MQWs implies that internal electric field-induced recombination through the barriers and interface states plays an important role in the radiative efficiency of quantum well active regions for c-axis oriented materials and devices. The effect of these internal electric fields can be mitigated through the use of nonpolar MQWs. The combination of more intense time-integrated PL spectra and shorter PL lifetimes with decreasing well width in GaN/AlGaN MQWs grown on a-plane LEO GaN for low pump intensity suggests that the radiative lifetime becomes shorter due to the accompanying increase in exciton binding energy and oscillator strength at smaller well width in these high quality samples. Finally, it is demonstrated that compositional fluctuations in AlGaN active regions grown by plasma-assisted MBE can be employed to create spatial localization that enhances the luminescence efficiency and PL lifetime (300-400 ps) despite high defect density (>10 10 cm -2 ) by inhibiting movement of carriers to nonradiative sites. Significant enhancement of this phenomenon has been obtained in a DH LED structure grown on a lower defect density (mid-10 9 cm -2 ) AlGaN template, with PL lifetime increased by nearly a factor of two, corresponding to a defect density in the mid-10 7 cm -2 range, and only a 3.3 times drop in PL intensity when the temperature is raised from 12 K to room temperature, suggesting up to ~ 30% internal quantum efficiency.
Library Exposure from the Prior Years: An Examination of Public High School Library Websites

Abstract The frequent occurrence of first-year college students showing disinterest and unfamiliarity with basic library resources is a phenomenon experienced by many academic librarians. This article aims to increase understanding of student exposure to the school library, prior to college arrival, by examining the online information and tools from high school libraries. Four hundred ninety-seven (497) public high schools from New York City were surveyed for 1) online presence of their school library programs and 2) the extent of information featured on these school library websites. Findings indicate that many public high schools have not adequately embraced web development for the purpose of educating students about information literacy.
Comparative biochemistry of parathyroid hormone and calcitonin

Abstract This is a brief summary of the current state of our knowledge concerning the chemical nature of parathyroid hormone and calcitonin from several vertebrate species, primarily mammalian. Bovine and porcine parathyroid hormone have been isolated in pure form and their structures analyzed. The complete amino acid suquence of porcine, human, ovine, bovine, and three different isohormonal forms of salmon calcitonin have been determined. Synthesis has been achieved of porcine, human, and salmon calcitonin, and, most recently, the biologically active amino terminal portion of bovine and porcine parathyroid hormone.
Dome Reversal of Metal Beverage Containers

Dome reversal in metal beverage containers refers to the event when the dome at the bottom of the containers snaps through due to overpressurization, This paper presents a combined experimental and numerical investigation of the problem. The response of the bottom of the containers considered is primarily axisymmetric prior to buckling and is characterized by a limit pressure instability. Under volume-controlled loading, collapse in an asymmetric mode occurs s hortly after the limit pressure is achieved. An axisymmetric model of the problem was sufficient to calculate the limit pressure for the case considered. Results from a nonaxisymmetric model indicated that asymmetric modes became dominant after the limit pressure had been achieved.
Preparation of submicron titanium nitride powder by vapor-phase reactions

The United States Bureau of Mines continued research on the preparation of titanium nitride powder for potential use as a substitute for imported tungsten used in metal cutting tools and wear-resistant applications. Major emphasis was directed toward improving the purity of the powder produced by vapor-phase reaction of titanium tetrachloride with magnesium in the presence of nitrogen or anhydrous ammonia at 1000 °C. Modifications were made in powder collection, handling, and purification procedures that significantly reduced the oxygen content of the product from > >5 wt pct to <<1 wt pct oxygen. Powder samples contained oxygen contents as low as 0.23 wt pct and exhibited a median particle size of 0.28 micrometer.
Flowable Conducting Particle Networks in Redox-Active Electrolytes for Grid Energy Storage

This paper reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributions (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Additionally, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.
Accuracy of Magnetic Resonance Cholangiopancreatography in the Diagnosis of Pancreas Divisum

Patients with pancreas divisum may develop pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard for diagnosing pancreas divisum. Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive test reported to be highly accurate in diagnosing pancreas divisum. To evaluate the diagnostic accuracy of MRCP in detecting pancreas divisum at our institution. We reviewed patients who underwent both ERCP and MRCP. Patients who had diagnostic endoscopic pancreatograms (ERP) after MRCP comprise the study population. Secretin was given in 113/146 patients (S-MRCP). The remaining 33/146 patients had MRCP without secretin. In 7/33 patients who underwent MRCP without secretin (21.2%), the studies were non-diagnostic and, therefore, this group was not further analyzed and the study focused on the S-MRCP group only. ERP identified pancreas divisum in 19/113 (16.8%) patients. S-MRCP identified 14/19 pancreas divisum and was false-positive in three cases (sensitivity 73.3%, specificity 96.8%, positive predictive value 82.4%, negative predictive value 94.8%). Of the eight patients with inaccurate S-MRCP, 5 (63%) had changes of chronic pancreatitis by ERP. This differs from the frequency of chronic pancreatitis by ERP in 24/105 (23%) patients with accurate MRCP findings. The ERCP findings of chronic pancreatitis were more frequent among incorrect S-MRCP interpretations than among correct interpretations (odds ratio [OR] 5.5 [95% confidence interval (CI) 1.3–25.3]). MRCP without secretin is non-diagnostic for pancreas divisum in a significant proportion of patients. S-MRCP had a satisfactory specificity for detecting pancreas divisum. However, the sensitivity of S-MRCP for the diagnosis of pancreas divisum was modest at 73.3%. This is low compared to previous smaller studies, which reported a sensitivity of MRCP of up to 100%.
Airborne nanoparticle characterization with a digital ion trap–reflectron time of flight mass spectrometer

Abstract A digital ion trap–reflectron time of flight mass spectrometer is described for airborne nanoparticle characterization. Charged particles sampled into this nanoaerosol mass spectrometer (NAMS) are captured in the ion trap and ablated with a high fluence laser pulse to reach the “complete ionization limit”. Atomic ions produced from the trapped particle(s) are mass analyzed by time of flight, and the elemental composition is determined from the relative signal intensities in the mass spectrum. The particle size range captured in the ion trap is selected by the frequency applied to the ring electrode. Size selection is based on the mass normalized particle diameter, defined as the diameter of a spherical particle with unit density that has the same mass as the particle being analyzed. For the current instrument configuration, ring electrode frequencies between 5 and 140 kHz allow selective trapping of particles with a mass normalized diameter between 7 and 25 nm with a geometric standard deviation of about 1.1. The particle detection efficiency, defined as the fraction of charged particles entering the mass spectrometer that are subsequently captured and analyzed, is between l × l0 −4 and 3 × l0 −4 over this size range. The effective particle density can be determined from simultaneous measurement of the mobility and mass normalized diameters. Test nanoparticles composed of sucrose, polyethylene glycol, polypropylene glycol, sodium chloride, ammonium sulfate and copper(II) chloride are investigated. In most cases, the measured elemental compositions match the expected elemental compositions within ±5% or less and the measured compositions do not change with particle size. The one exception is copper chloride, which does not yield a well-developed plasma when it is irradiated by the laser pulse.
Hydrogen-bonding capability of a templating difluorotoluene nucleotide residue in an RB69 DNA polymerase ternary complex.

Results obtained using 2,4-difluorotoluene nucleobase (dF) as a nonpolar thymine isostere by Kool and colleagues challenged the Watson–Crick dogma that hydrogen bonds between complementary bases are an absolute requirement for accurate DNA replication. Here, we report crystal structure of an RB69 DNA polymerase L561A/S565G/Y567A triple mutant ternary complex with a templating dF opposite dTTP at 1.8 A-resolution. In this structure, direct hydrogen bonds were observed between: (i) dF and the incoming dTTP, (ii) dF and residue G568 of the polymerase, and (iii) dF and ordered water molecules surrounding the nascent base pair. Therefore, this structure provides evidence that a templating dF can form novel hydrogen bonds with the incoming dTTP and with the enzyme that differ from those formed with a templating dT.
Dramatically stiffer elastic composite materials due to a negative stiffness phase

Composite materials of extremely high stiffness can be produced by employing one phase of negative stiffness. Negative stiffness entails a reversal of the usual codirectional relationship between force and displacement in deformed objects. Negative stiffness structures and materials are possible, but unstable by themselves. We argue here that composites made with a small volume fraction of negative stiffness inclusions can be stable and can have overall stiffness far higher than that of either constituent. This high composite stiffness is demonstrated via several exact solutions within linearized and also fully nonlinear elasticity, and via the overall modulus tensor estimate of a variational principle valid in this case. We provide an initial discussion of stability, and adduce experimental results which show extreme composite behavior in selected viscoelastic systems under sub-resonant sinusoidal load. Viscoelasticity is known to expand the space of stability in some cases. We have not yet proved that purely elastic composite materials of the types proposed and analyzed in this paper will be stable under static load. The concept of negative stiffness inclusions is buttressed by recent experimental studies illustrating related phenomena within the elasticity and viscoelasticity contexts.
AN ULTRASTRUCTURAL STUDY OF GLOMERULAR PERMEABILITY USING CATALASE AND PEROXIDASE AS TRACER PROTEINS

Mice were injected intravenously with beef liver catalase (mol wt 240,000) and very small doses of horseradish peroxidase (mol wt 40,000) and the site of localization of these enzymes in the kidney was studied by ultrastructural cytochemistry. 1 min after injection, catalase was present in glomerular capillary lumina and there was minimal permeation of the basement membrane. After 5–180 min, staining of the basement membrane increased progressively but was usually less than that in capillary lumina. At all time intervals the inner (sub-endothelial) layer of the basement membrane contained more reaction product than the lamina densa and the outer (subepithelial) layer. Catalase permeated the entire thickness of the basement membrane and extended up to the slit pore but not beyond the level of the slit diaphragm and was not seen in the urinary space or tubular lumina. Horseradish peroxidase permeated the whole thickness of the basement membrane within 2 min after injection; however, gradients of staining from the inner to outer layers of the basement membrane were frequently seen. The findings with both enzymes indicate that (a) the basement membrane restricts the passage of proteins over a wide range of molecular size with increasing impediment for larger molecules and (b) the slit pore functions as an additional barrier for molecules that cross the basement membrane.
Performance bounds for estimating vector systems

We propose a unified framework for the analysis of estimators of geometrical vector quantities and vector systems through a collection of performance measures. Unlike standard performance indicators, these measures have intuitive geometrical and physical interpretations, are independent of the coordinate reference frame, and are applicable to arbitrary parameterizations of the unknown vector or system of vectors. For each measure, we derive both finite-sample and asymptotic lower bounds that hold for large classes of estimators and serve as benchmarks for the assessment of estimation algorithms. Like the performance measures themselves, these bounds are independent of the reference coordinate frame, and we discuss their use as system design criteria.
Automated DSS for Lighting Design of Nighttime Operations in Highway Construction Projects

Nighttime construction lighting is reported to be a crucial factor affecting quality, safety, cost and productivity of nighttime construction projects. This paper presents an automated decision support system (DSS) for lighting design in highway nighttime construction projects. The DSS is designed to optimize four major objectives: (1) maximizing average illuminance; (2) maximizing lighting uniformity in the work zone; (3) minimizing glare produced by the lighting system; and (4) minimizing cost of the lighting system. Seven decision variables are optimized in this lighting design problem namely: (1) lighting equipment selection; (2) type of lamps; (3) lamp lumen output; (4) mounting height; (5) lighting towers positioning; (6) luminaires aiming angle; and (7) lighting towers rotation. A multi objective evolutionary algorithm (NSGA-II) is used to optimize this lighting design problem. The proposed DSS provides a practical tool for the design and optimization of lighting arrangements in nighttime construction operations.
Modeling personal particle-bound polycyclic aromatic hydrocarbon (pb-pah) exposure in human subjects in Southern California.

Background: Exposure to polycyclic aromatic hydrocarbon (PAH) has been linked to various adverse health outcomes. Personal PAH exposures are usually measured by personal monitoring or biomarkers, which are costly and impractical for a large population. Modeling is a cost-effective alternative to characterize personal PAH exposure although challenges exist because the PAH exposure can be highly variable between locations and individuals in non-occupational settings. In this study we developed models to estimate personal inhalation exposures to particle-bound PAH (PB-PAH) using data from global positioning system (GPS) time-activity tracking data, traffic activity, and questionnaire information. Methods: We conducted real-time (1-min interval) personal PB-PAH exposure sampling coupled with GPS tracking in 28 non-smoking women for one to three sessions and one to nine days each session from August 2009 to November 2010 in Los Angeles and Orange Counties, California. Each subject filled out a baseline questionnaire and environmental and behavior questionnaires on their typical activities in the previous three months. A validated model was used to classify major time-activity patterns (indoor, in-vehicle, and other) based on the raw GPS data. Multiple-linear regression and mixed effect models were developed to estimate averaged daily and subject-level PB-PAH exposures. The covariates we examined included day of week and time of day, GPS-based time-activity and GPS speed, traffic- and roadway-related parameters, meteorological variables (i.e. temperature, wind speed, relative humidity), and socio-demographic variables and occupational exposures from the questionnaire. Results: We measured personal PB-PAH exposures for 180 days with more than 6 h of valid data on each day. The adjusted R 2 of the model was 0.58 for personal daily exposures, 0.61 for subject-level personal exposures, and 0.75 for subject-level micro-environmental exposures. The amount of time in vehicle (averaging 4.5% of total sampling time) explained 48% of the variance in daily personal PB-PAH exposure and 39% of the variance in subject-level exposure. The other major predictors of PB-PAH exposures included length-weighted traffic count, work-related exposures, and percent of weekday time. Conclusion: We successfully developed regression models to estimate PB-PAH exposures based on GPS-tracking data, traffic data, and simple questionnaire information. Time in vehicle was the most important determinant of personal PB-PAH exposure in this population. We demonstrated the importance of coupling real-time exposure measures with GPS time-activity tracking in personal air pollution exposure assessment.
Pulse Oximetry in Methemoglobinemia

• Pulse oximetry is a major improvement in the assessment of oxygenation. The device uses plethysmography and light absorbance measurements at two wavelengths to estimate oxygen saturation. It is inaccurate, however, when more than two types of hemoglobin are present. This article describes two infants with methemoglobinemia in whom pulse oximetry overestimated oxygen saturation. We discuss the mechanism of this systematic error and emphasize that pulse oximetry should not be used to estimate true oxygen saturation in the presence of methemoglobin. However, a disparity between oxygen saturation estimates by pulse oximetry and by calculations based on the arterial partial pressure of oxygen and the oxygen-hemoglobin dissociation curve can provide an important clue to the presence of such abnormal types of hemoglobins. Therapy should be based on direct measurements of oxyhemoglobin by cooximetry and not on measurements of oxygen saturation by pulse oximetry or on saturations calculated from the Pao 2 and the oxyhemoglobin dissociation curve. ( AJDC . 1989;143:845-847)
Does Government Regulation Enhance Quality of Cardiovascular Procedures

Cardiovascular specialists encumbered with excessive intrusion into the patient-doctor relationship will likely agree with the conclusion of DiSesa et al1 that the coronary artery bypass grafting (CABG) mortality rate was not different between the 26 states with certificate-of-need (CON) programs and the 24 states without CON regulation. Data from the Society of Thoracic Surgeons’ (STS) National Cardiac Database (NCD) on 595 200 patients undergoing isolated CABG procedures for 4 consecutive years ending in 2003 used the STS NCD risk-stratification algorithm to predict an equivalent occurrence of death after CABG during hospitalization or within 30 days for both the 280 512 patients treated in non-CON states and the 314 710 patients treated CON states (Table 5 in DiSesa et al1). The observed perioperative CABG mortality rate was 2.52% for CON states and 2.62% for states without CON regulations (odds ratio [OR]=0.97, P =0.32). Article p 2122 Text in italics below represents the reflections of a hypothetical potential CABG patient. This artificial dialog was created to help cardiovascular specialists keep the patient at the center of our frame of reference when evaluating any quality-of-patient-care program. Although Dr Jones penned these words, he is not now and hopes never to be a potential CABG patient. From the perspective of an informed patient in need of CABG, my concern is that before operation, patients in both CON and non-CON states were expected to have the same operative risk, and yet an additional 1 out of 1000 patients died in non-CON states compared with CON states. One out of 1000 extra deaths does not seem like much extra risk unless you are the prospective patient. If I lived in Kansas City, Kan, …
When digital objects change — exactly what changes?

Formal accounts of digital objects often characterize them as bit strings, graphs, sets, tuples, relations, or other similar constructs from discrete mathematics. Such characterizations imply that these objects cannot undergo changes such as losing or gaining parts, or having their parts rearranged. Yet our discourse about digital objects seems, if taken literally, to imply that those objects routinely undergo such changes. One strategy for dealing with this inconsistency is to affirm an account which leaves digital objects immutable and re-locates change in the persons interacting with these objects.
Comparative Physiological Effects of Incorporated Amino Acid Analogs In Escherichia coli

The relative toxicities of several incorporated analogs of phenylalanine, methionine, arginine, and proline were assessed by a variety of criteria in a derivative of Escherichia coli 15 requiring the antagonized amino acids. Toxicity of the analog-substituted cell protein was most consistently indicated by its insolubility at graded temperatures, its increased breakdown, the relative suppression of further cell growth, and lethality. The relative toxicity of poorly utilized analogs could be judged clearly only by the first two criteria. Toxicity generally increased as follows: selenomethionine m -fluorophenylalanine o -fluorophenylalanine and norleucine p -fluorophenylalanine p -fluorophenylalanine, moderately motile with m -fluorophenylalanine, and fully motile with all methionine analogs. Usually the analog incorporations were no more than bacteriostatic in E. coli strains, canavanine killing only the E. coli 15 substrain extensively in minimal media. Selenomethionine supported indefinite growth of procaryotes such as Bacillus subtilis and certain E. coli strains, but only upon supplementation, at least initially, with many nonessential metabolites.
Sample Size Estimation in Single-Arm Clinical Trials with Multiple Testing Under Frequentist and Bayesian Approaches

In this paper, we study one-sided multiple testing problems for normal and binomial distributions. We use order statistics to test the null hypothesis {all H ( i0) are true}. This approach allows us to uniformly address frequentist and Bayesian multiple testing models. To calculate order statistics, we use confidence limits. In frequentist models, we apply an adjustment to the confidence limits that is equivalent to the Bonferroni adjustment of p-values. In the Bayesian case, we adjust the credible limits following a concept of reconciliation between the Bayesian posterior probability and the frequentist p-value. We also study the quantitative relationship between the number of tests and the sample size of a clinical trial. If the number of tests is very large, we suggest using asymptotic order statistics. We study the performance of these statistics. The asymptotic order statistics for the normal distribution are used to extend the results for independent observations to dependent observations.
A new continuous-flow cell separation method based on cell density: principle, apparatus, and preliminary application to separation of human buffy coat.

With the recent progress in transfusion medicine, separation and isolation of cells in a large quantity is becoming increasingly important. At present, the continuous cell separation method in a preparative scale is limited to apheresis and elutriation: the former is mainly used for collection of platelet and buffy coat from the whole blood, while the latter separates cells virtually according to their size. Here we introduce a continuous flow method that separates cells entirely based on cell density. The method is gentle and capable of processing a large number of cells. The potential capability of the method was demonstrated on separation of lymphocytes and granulocytes from human buffy coat. Lymphocytes were enriched to 90% in the fraction at density = 1.065 and granulocytes are isolated in fractions at density = 1.075–1.080 while red cells were completely retained at the periphery of the channel. CD34 cells were distributed around 1.065 and coeluted with lymphocytes, suggesting that further enrichment requires focusing the density gradient around 1.070. The method could process 109 nucleated cells in 2 hours. Our preliminary results suggest that the present method is an effective and efficient means to separate blood cells. J. Clin. Apheresis 16:186–191, 2001. Published 2001 Wiley-Liss, Inc.
Design and Analysis of a Parallel Data Distribution Overlay Topology

Cluster computers provide cost effective CPU and memory capacity, but many modern applications require extremely high aggregate I/O bandwidth to ac-cess large-scale, multidimensional data. Parallel file systems are one solution to this problem, but can be limited by various bottlenecks in the system. With the availability of large, cheap, fast disk drives, each cluster node can have its own copy of even large data sets, but copying the data to all the nodes becomes an impediment. Our approach uses a parallel virtual overlay topology to exploit the cluster’s network capacity to deliver a file to all nodes in roughly the same time it would cost to transfer it to a single node. The ap-proach scales because the aggregate performance grows as the cluster size increase. In this paper, we evaluate the performance of our parallel data distribution architecture, exploring scalability, topology options, and bottlenecks. Based on the analysis, we developed an analytical approach to optimizing the topology based on system constraints.