cssi/SciSciGPT-SciSciNet huggingface dataset:
IMPROVING SMART GRID SECURITY USING MERKLE TREES

Presently nations worldwide are starting to convert their aging electrical power infrastructures into modern, dynamic power grids. Smart Grid offers much in the way of efficiencies and robustness to the electrical power grid, however its heavy reliance on communication networks will leave it more vulnerable to attack than present day grids. This paper looks at the threat to public key cryptography systems from a fully realized quantum computer and how this could impact the Smart Grid. We argue for the use of Merkle Trees in place of public key cryptography for authentication of devices in wireless mesh networks that are used in Smart Grid applications.
Kanamycin priming for audiogenic seizures in mice

Abstract It is well established that mice can be made to suffer epileptic-like seizures when subjected to certain kinds of loud noises. Some strains of mice are genetically susceptible while others can be made susceptible by using acoustic priming techniques. It has been suggested that priming mice with a loud bell sound at a critical development age causes hair cell damage which is a necessary part of the audiogenic seizure syndrome. Since ototoxic drugs also cause such damage, non-susceptible BALB/C mice were given kanamycin sulphate 400 mg/kg daily from age 5 days to age 21 days and then tested for audiogenic seizures at age 28 days. Eighteen of the twenty mice which survived the kanamycin treatment displayed full epileptic-like seizures when subjected to loud sounds at age 28 days. Histological surface preparations of the organ of corti from these mice revealed extensive outer hair cell damage in all turns of the cochlea while the inner hair cells and a few outer hair cells in the apical turn appeared undisturbed. All of the cochlea nerve fibres appeared normal in the histological preparations. The relationship of these results to the phenomenon of recruitment is discussed.
CW Side-Coupled Linac for the los Alamos/NBS Racetrack Microtron

A 2.7-m side-coupled linac has been built as part of the 5-MeV injector for the cw room-temperature racetrack microtron (RTM) being constructed in collaboration with the National Bureau of Standards (NBS). The linac is designed to accelerate the electron beam from 1 to 5 MeV with an accelerating gradient of 1.5 MeV/m. Fabrication of the structure started October 4, 1982 and was completed February 28, 1983, when it was tested with a cw power level of 82 kW. The structure has an effective shunt impedance (ZT2) of 82.5 M?/m. No change in field distribution was detected at any power level. The operating frequency is 2380 MHz.
A mathematical model for top-shelf vertigo: the role of sedimenting otoconia in BPPV☆

Benign paroxysmal positional vertigo (BPPV) is a mechanical disorder of the vestibular system in which calcite particles called otoconia interfere with the mechanical functioning of the fluid-filled semicircular canals normally used to sense rotation. Using hydrodynamic models, we examine the two mechanisms proposed by the medical community for BPPV: cupulolithiasis, in which otoconia attach directly to the cupula (a sensory membrane), and canalithiasis, in which otoconia settle through the canals and exert a fluid pressure across the cupula. We utilize known hydrodynamic calculations and make reasonable geometric and physical approximations to derive an expression for the transcupular pressure ΔP_c exerted by a settling solid particle in canalithiasis. By tracking settling otoconia in a two-dimensional model geometry, the cupular volume displacement and associated eye response (nystagmus) can be calculated quantitatively. Several important features emerge: (1) a pressure amplification occurs as otoconia enter a narrowing duct; (2) an average-sized otoconium requires approximately Full-size image (<1 K) to settle through the wide ampulla, where ΔP_c is not amplified, which suggests a mechanism for the observed latency of BPPV; and (3) an average-sized otoconium beginning below the center of the cupula can cause a volumetric cupular displacement on the order of Full-size image (<1 K), with nystagmus of order 2°/s, which is approximately the threshold for sensation. Larger cupular volume displacement and nystagmus could result from larger and/or multiple otoconia.
The abundance, biomass and acetylene reduction activity of bacteria associated with decomposing rhizomes of two seagrasses, Zostera marina and Thalassia testudinum

Abstract Bacteria growing on and in close association with the rhizome detritus of two seagrasses, Zostera marina L. and Thalassia testudinum Banks ex Konig, were examined using epifluorescence and scanning electron microscopy. The microbial community consisted of a diverse assemblage of bacteria dominated in biomass by large rod-shaped and filamentous cells. The large size of cells and the occurrence of measurable acetylene reduction activity suggested that a healthy, growing population of bacteria was associated with the rhizome detritus. Bacteria carbon biomass ranged betwee 5.2×10 −5 and 1.7×10 −3 g C gdw −1 of rhizome detritus. Depending on cell doubling times, bacterial metabolism could account for a substantial portion of the turnover of rhizome detritus. Estimates of potential microbial production, nitrogen fixation and the physico-chemical nature of rhizome detritus are discussed and we propose hypotheses for the disposition of this detrital organic matter.
On efficient implementation of an approximation algorithm for the Steiner tree problem

This paper studies the design and implementation of an approximation algorithm for the Steiner tree problem. Given any undirected distance graph G and a set of Steiner points S, the algorithm produces a Steiner tree with total weight on its edges no more than 2(1−1/L) times the total weight on the optimal Steiner tree, where L is the number of leaves in the optimal Steiner tree. Our implementation of the algorithm, in the worst case, makes it run in 0(¦Eg¦+¦Vg−S¦log¦Vg−S¦+¦S¦log ¦S¦) time for general graph G and in 0(¦S¦ log¦S¦+M log β(M,¦Vg−S¦)) time for sparse graph G, where Eg is the set of edges in G, Vg is the set of vertices in G, M = min {¦Eg, (¦Vg−S¦−1)2/2} and β(x,y) = min {i¦log(i)y ≦ x/y}.The implementation is not likely to be improved significantly without the improvement of the shortest paths algorithm and the minimum spanning tree algorithm as the algorithm essentially composes of the computation of the multiple sources shortest paths of a graph with ¦Vg¦ vertices and ¦Eg¦ edges and the minimum spanning tree of a graph with ¦Vg−S¦ vertices and M edges.
Anticonvulsants IV: Vinylogs, Alkyl Esters of 2-Sulfamoylcinnamic Acid and Related Compounds

Alkyl ortho-sulfamoylbenzoates (I) and ring-substituted alkyl ortho-sulfamoylbenzoates (II, III) are reported to have anti-convulsant activity in mice. It is known generally that the chemical and physiological properties of a substance and its vinylog are quite similar. This correlation might be extended to the alkyl ortho-sulfamoylcinnamates (IV), the corresponding vinylogs of I, which were prepared and tested for anticonvulsant activity in mice. Attempts to prepare the vinylogs (IV) by the method of Loev and Kormendy failed, and the compounds obtained were identified as the alkyl esters of 1,2-benzisothiazoline-3-acetic acid 1,1-dioxide (VII). Proof of the chemical structures was provided by spectra. Of the twelve compounds tested, one (V, R = s-butyl) was found to be effective against electroshock in mice at 100 mg./kg. intraperitoneally. The LD50's of these compounds were of the order of 800 mg./kg. with one exception.
N-cadherin at the glial scar in the rat.

Following injury to the central nervous system (CNS), astrocytes become reactive and in many cases form a glial scar. Very little is known about the adhesive interactions between astrocytes at the glial scar, even though reactive gliosis and scar formation are a central issue in CNS wound healing. In the present study, we examine the role of cadherin in the process of scar formation using immunohistochemistry and immunoblot methods. When a stab wound was made in the cerebral cortex of the rat, cadherins were consistently upregulated by the reactive astrocytes at the glial scar. Our immunoblot analysis demonstrates that the increase in cadherin immunoreactivity was due to a threefold upregulation of a single protein with a molecular weight of 135 kDa. The size (135 kDa) and location of the immunoreactive protein at regions of cell-cell contact in cultured astrocytes indicates that the immunoreactive protein is N-cadherin. These data are the first to demonstrate that N-cadherin plays a prominent role in the response of astrocytes to injury, including the formation and maintenance of the glial scar.
Effect of crosslink type on the fracture of natural rubber vulcanizates

The effect of the chemical nature of the crosslinks on the fatigue crack growth behavior of filled natural rubber has been investigated. By varying the ratio of sulfur to accelerator, the relative amounts of polysulfidic to monosulfidic crosslinks was controlled. Carbon-carbon crosslinking was introduced via peroxide cure. All elastomers tested were prepared at the same number average crosslink density as confirmed by equilibrium swelling and modulus measurements. At the same crosslink density, polysulfidic crosslinks were most resistant to fatigue over the range of tearing energies investigated. Vulcanizates with primarily monosulfidic crosslinks exhibited lower cut growth rates than peroxide cured specimens, although the monosulfidic network strength may have been enhanced by the presence of some polysulfidic crosslinks.
Subsolidus Equilibria and Stabilization of Tetragonal ZrO2 in the System ZrO2‐Al2O3‐SiO2

The irreversible reaction between zircon and alumina to form mullite and zirconia was observed to proceed very slowly at 1480°C, confirming the existence of a stable join between mullite and zirconia in addition to the join between mullite and zircon. Attempts to determine equilibrium assemblages in powder samples of several combinations of the constituents at 1300° and 1400°C were unsuccessful. Metastable tetragonal ZrO2 was observed in fired powder samples containing kaolinite, in fired zircon-alumina samples, and in calcined gels prepared from zirconyl nitrate, aluminum nitrate, and colloidal silica in water. Tetragonal ZrO2 was the dominant crystalline phase in gels fired for 24 h at 800°, 950°, and 1100°C; the thermal stability of the phase was enhanced by Al2O3 and by SiO2, but most effectively by mixtures of the two. Line broadening measurements and electron microscope observation indicate that the tetragonal ZrO2, with apparent crystallite sizes between 0.009 and 0.1 μm, develops as an intergrowth with, and is stabilized by, the amorphous matrix of Al2O3 and SiO2.
Preventing Apoptosis With Thioredoxin: ASK Me How

Reactive oxygen species (ROS) are critical signaling molecules in eukaryotic cells, regulating growth, survival, and death pathways. High concentrations of ROS are cytotoxic, but low concentrations can promote growth and activate critical signal pathways in many cell types.1 In the cardiovascular system, significant amounts of ROS are generated as byproducts of mitochondrial metabolism and may increase to toxic levels in the myocardium during and after periods of reduced blood flow. In addition, a number of extracellular peptide hormones are able to increase the production of ROS through receptor-mediated stimulation of membrane-bound NADPH oxidase.2,3⇓ The hypertrophic effects of angiotensin II4 and more recently other G protein–coupled receptor (GPCR) agonists5 have been shown to involve the generation of ROS through this mechanism. In addition, many apoptotic stresses in the cardiac myocyte, including ischemia-reperfusion and high concentrations of NO, signal through ROS. Oxidative stress is a central component of the mitochondrial permeability transition in cardiac myocytes, and the latter seems to underlie most pathologically relevant examples of cardiac myocyte apoptosis in vivo.6 Consequently, a clear understanding of the relationship between myocardial growth and apoptosis signaling will require a better understanding of the intracellular signals that respond to ROS. In this issue of Circulation Research , Liu and Min7 shed light on a fascinating redox-sensitive mechanism that can generate both apoptotic and hypertrophic signals in the cardiovascular system. Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family, is an upstream activator of p38 MAP kinases and c-Jun N-terminal kinases (JNKs) through MKK3/6 and MKK7, respectively.8 ASK1 itself is activated in cells undergoing various types of stress, including oxidant and cytokine exposure. ASK1 associates with TRAF2 during tumor necrosis factor-α (TNF-α) signaling and is required both for TNF-α–induced apoptosis and …
A laser diode array pumped cesium vapor laser

An efficient Cesium vapor laser pumped with a continuous wave narrowband Laser Diode Array (LDA) has been demonstrated. To obtain a high lasing efficiency, it is necessary to narrow the linewidth of the pumping LDA to match the Cs atom absorption line. An external cavity with holographic grating was used to narrow the linewidth of a commercially available LDA to a value of 11 GHz that matches the Cs vapor absorption line broadened by a buffer gas at atmospheric pressure. The developed pump source was used for pumping a Cs vapor laser, which operated at 894 nm. Preliminary experiments yielded 400 mW output power and about 20% slope efficiency. The laser efficiency can be significantly increased by optimizing the cell and cavity design and matching the pump beam to the cavity mode size.
Peritoneoscopy in the management of catheter malfunction during continuous ambulatory peritoneal dialysis

Continuous ambulatory peritoneal dialysis is widely used in the maintenance of patients with chronic renal failure. Obstruction or displacement of the chronic dialysis catheter, which prevents dialysate drainage, can compromise ongoing dialysis. Conservative approaches (body position change, saline infusion, and enema) are often unsuccessful and more aggressive therapy may be required. We report the use of peritoneoscopy to reposition malfunctioning peritoneal dialysis catheters. The procedure proved to be safe and gave excellent long-term results.
Effect of aromatic groups on localization of high energy in cellulose

When γ-radiation from 60Co interacted with fibrous cotton cellulose, the localization of at least part of the high energy resulted in cellulosic chain cleavage and loss in breaking strength of the irradiated fibers. The substitution of aromatic groups on the cotton cellulose molecule affected this localization of energy and decreased the radiation degradation of the fiber. The nature of the linkage of the aromatic group to the cellulose molecule was not as important as the radiation stability of the linkage. For example, if localization of energy occurred which cleaved the aromatic group from the cellulose molecule, the radioprotection of the cellulosic molecular chain by the aromatic group was not effective. If the aromatic group was so modified that the effective number of π-electrons was decreased, the radioprotection of the cellulosic chain was also decreased. The radioprotection of the cellulosic molecular chain by benzhydryl, trityl, benzoyl, and cinnamoyl groups was effective over distances equivalent to several cellobiose units. The radioprotection of the cellulosic chain by naphthoyl groups was significant but not as effective as the listed groups. Due to the sharing of π-electrons in the naphthoyl group, the effective number of π-electrons was reduced, and consequently the radioprotective effect of the group was also reduced. Benzyl groups were cleaved from the cellulose molecule on irradiation and offered no radioprotection to the cellulosic chain, at least at the high radiation dosages used. The ESR spectra of the irradiated celluloses, both substituted and unsubstituted, were similar. This indicated that the presence of aromatic groups did not change the nature of the long-lived free radicals induced in cellulose on irradiation. It was suggested that selective energy absorption by the aromatic group from the spur of high-energy electrons produced on interaction of γ-radiation with the cellulose molecule could account for the radioprotection of the cellulosic molecular chain.
Chromothripsis and Human Disease: Piecing Together the Shattering Process

The unprecedented resolution of high-throughput genomics has enabled the recent discovery of a phenomenon by which specific regions of the genome are shattered and then stitched together via a single devastating event, referred to as chromothripsis. Potential mechanisms governing this process are now emerging, with implications for our understanding of the role of genomic rearrangements in development and disease.
Writing secure programs: an interview with Steve Lipner

Protecting computing systems and networks from attackers and data theft is an enormously complicated problem. The individual operating systems are complex (typically more than 40 million lines of code), they are connected to an enormous Internet (on order of 1 billion hosts), and the whole network is heavily populated (more than 2.3 billion users). Hunting down and patching vulnerabilities is a losing game.
Fluid-structure interaction analysis of a thick-section composite cylinder subjected to underwater blast loading

Abstract The dynamic response of a thick-section hollow composite cylinder, under plane-strain conditions, subjected to an external blast loading, with and without fluid-coupling effects, was investigated using finite-element analysis and effective modulus theory. The blast loading profile is representative of the primary pressure pulse created by an underwater explosion occurring far from the cylinder. In this analysis, fluid-structure-coupling effects were included by employing a loading routine in the finite-element analysis. A plane incident pressure wave impacting the cylinder and propagating around it with a fixed velocity, was considered. The effects of reflected and radiated pressure components were included. The accuracy of effective modulus theory in dynamic stress analysis was briefly explored. A commercial finite-element code, ABAQUS, was used for this analysis.
Confounding factors in infant pain assessment during recovery from anesthesia.

ISSUES AND PURPOSE. To investigate in what ways infant pain assessments differed between outpatient surgical recovery areas (OPSRA) and other clinical settings that included inpatient postsurgical recovery areas. METHODS. Using a qualitative descriptive design, 8 nurse participants working in OPSRA and 7 nurse participants working in other clinical settings were interviewed. RESULTS. The assessments of participants in the OPSRA differed from those of other participants and were confounded by effects of a short-acting anesthetic, lower expectations of pain, and several extraneous factors. PRACTICE IMPLICATIONS. Recognizing infant pain in OPSRA is complex. Nurses working in OPSRA may need to assume leadership to address issues relating to accurate identification of infant pain and alleviating extraneous factors that may influence adequate treatment of pain.
Assessing Outcomes in Critical Care

The need to assess a range of outcomes in intensive care is increasingly important as more patients survive episodes of acute, severe illness. In this article, we discuss the relevance of commonly studied outcomes and the strengths and weaknesses of the techniques used to measure them. Short-term mortality is no longer the only important consideration in the evaluation of a therapy. The assessment of longer-term mortality, morbidity, and patient-centered outcomes is necessary. Randomized, controlled trials (RCTs) are frequently adapted to incorporate outcome measures that include cost and quality of life. In addition, observational studies have become more sophisticated and are being used to evaluate issues not amenable to study by RCTs. These developments will provide more comprehensive assessments of critical care interventions and will ultimately enhance the health of the patients we serve.
A performance comparison of locking methods with limited wait depth

A number of recent studies have proposed lock conflict resolution methods to improve the performance of standard locking, i.e., strict two-phase locking with the general waiting method. This paper is primarily concerned with the performance of wait depth limited methods with respect to each other and some other methods. The methods considered include the general waiting, wound-wait, and no-waiting methods, symmetric and asymmetric versions of cautious waiting and running priority methods, the wait depth limited (WDL) method, and a modified version of it. In spite of the availability of analytic solutions for most of wait depth limited methods, for reasons given in-the paper, the performance comparison is based on simulation results. The contributions of this study are as follows: 1) modeling assumptions, i.e., a careful definition of transaction restart options; 2) new results concerning the relative performance of wait depth limited methods, which show that a) the running priority method outperforms cautious waiting and may even outperform the WDL method in a system with limited hardware resource, b) WDL outperforms other methods in high lock contention, high capacity systems, and c) modified WDL has a performance comparable to WDL, but incurs less overhead in selecting the abort victim; and 3) contrary to common belief, Tay's Effective Database Size Paradigm for dealing with shared and exclusive locks and/or skewed database accesses in standard locking is applicable to some wait depth limited methods and provides acceptably accurate approximations in others-as long as locking modes for restarted transactions are not resampled.
Exchange and Crystal Field Excitations in Rare-Earth Iron and Rare-Earth Cobalt Laves-Phase Compounds

We have examined the magnetic excitations in a series of Laves-phase (Fd3m structure) compounds of heavy rare earths with Fe (RFe2) and Co (RCo2). These are prototype compounds for the study of magnetic interactions in a material with two magnetic atoms from several aspects: (1) the unit cell contains only two inequivalent sites, one for the transition metal and one for the rare earth; (2) the static structure factor separates reflections into six classes, two of which contain contributions from only one atom type, which simplifies determination of the sublattice magnetization; and (3) as shown below, the dynamic structure factor also selects out modes involving only one type of excitation (in-phase or out-of-phase spin precession) thereby greatly simplifying the analysis of spin wave data.
Characterization of Monospecies Biofilm Formation by Helicobacter pylori

As all bacteria studied to date, the gastric pathogen Helicobacter pylori has an alternate lifestyle as a biofilm. H. pylori forms biofilms on glass surfaces at the air-liquid interface in stationary or shaking batch cultures. By light microscopy, we have observed attachment of individual, spiral H. pylori to glass surfaces, followed by division to form microcolonies, merging of individual microcolonies, and growth in the third dimension. Scanning electron micrographs showed H. pylori arranged in a matrix on the glass with channels for nutrient flow, typical of other bacterial biofilms. To understand the importance of biofilms to the H. pylori life cycle, we tested the effect of mucin on biofilm formation. Our results showed that 10% mucin greatly increased the number of planktonic H. pylori while not affecting biofilm bacteria, resulting in a decline in percent adherence to the glass. This suggests that in the mucus-rich stomach, H. pylori planktonic growth is favored over biofilm formation. We also investigated the effect of specific mutations in several genes, including the quorum-sensing gene, luxS, and the cagE type IV secretion gene. Both of these mutants were found to form biofilms approximately twofold more efficiently than the wild type in both assays. These results indicate the relative importance of these genes to the production of biofilms by H. pylori and the selective enhancement of planktonic growth in the presence of gastric mucin.
Power spectra of return-to-zero optical signals

Analytical formulas for the power spectra of return-to-zero (RZ) optical signals generated by Mach-Zehnder (MZ) modulators are derived. Pulse duty cycles of 33%, 50%, and 67%, in conjunction with several modulation techniques, including binary ON-OFF keying (OOK), duobinary OOK, and M-ary differential phase-shift keying (DPSK), phase-shift keying (PSK), and quadrature-amplitude modulation (QAM), are considered. Spectral characteristics and bandwidth requirements of these different schemes are compared
Developing the Next Generation Gas Turbine Systems — A National Partnership

The U.S. Department of Energy is in its 7th year of a 9-year program to develop the next generation of advanced turbine systems (ATS). Under this program, partnerships between industry, universities, national laboratories, government agencies and institutions, and the U.S. Department of Energy (DOE) are performing research and development required to commercialize the ATS. The ATS Program is jointly sponsored by the U.S. DOE Offices of Fossil Energy and Energy Efficiency and Renewable Energy. Supporting R&D, recent ATS accomplishments and future advanced concepts for next generation gas turbine systems are described and discussed in this paper.As the ATS program winds down, DOE’s National Energy Technology Center (NETL) is evaluating the technology and market needs for continuing DOE support to develop advanced turbine systems. As part of this effort, NETL is sponsoring market and technology assessments, regional focus group discussions, and public workshops. The purpose of this paper is to provide the status of the ATS Program and the NETL perspective on potential options for future research and development needs, and public-private development programs addressing turbine based power generation for systems 30MW or greater in output.Copyright © 2000 by ASME
Performance optimization of critical nets through active shielding

We propose the concept of active shields-shields that switch concurrently with a signal wire of interest. Active shields aid signal transitions through the coupling between the signal wire and shields. For RC dominated wires, the active shields switch in the same phase as the signal wire since capacitive coupling is the dominant coupling mechanism. For wires with dominant inductive coupling, active shields switch in the opposite phase of the signal wire. We show that under fixed area and input capacitance constraints, in-phase active shielding outperforms traditional (passive) shielding and wire sizing/spacing techniques for minimizing delays and transition times on RC-dominated wires. For RLC wires, we demonstrate a region of feasibility (in terms of signal wire widths) for which opposite-phase active shielding outperforms the passive shielding technique. Opposite-phase active shielding suppresses ringing behavior to a greater degree than passive shields, providing similar performance to differential signaling while maintaining the simplicity of single ended signaling. The benefits of opposite-phase active shielding as compared to passive shielding are shown in the context of various clock net optimizations where reductions in ringing behavior (up to 4.5X) and transition times (up to 40% reduction) are achieved.
Transmit-receive antenna diversity and turbo multiuser detection

Antenna diversity and turbo multiuser detection are two promising techniques for combating channel impairments and multiple-access interference. In this paper, we propose a novel scheme for a turbo coded system with both transmit and receive antenna diversity that employs iterative multiuser detection and decoding. Multiuser detection is embedded into single-user turbo decoding. After each turbo decoding iteration, the extrinsic information of the interfering users is passed to the multiuser detector, and after each multiuser iteration, updated a posteriori probabilities are passed to the single-user turbo decoders as the soft input metrics. The proposed scheme achieves excellent performance, about 1.8 [dB] away from multiuser capacity for multiple antennas. It is shown that depending on the channel characteristics, for a fixed spectral efficiency, that is for a fixed number of virtual users K/sub v/=KT/sub x/, there exists a trade-off between the number of active users K and the number of transmit antennas T/sub x/.
THE “COMPETENT COMMUNICATOR” AS A COGNITIVE PROTOTYPE

Past theories concerned with communicative competence have assumed that perceiver's evaluations of the competence of a communicative performance are based on a conception of the “ideal communicator.” Psychological theory on categorization implies that this assumption is most viable if conceptions of “prototypes” relevant to competence in general (“the communicatively competent person”) are rich in defining characteristics relative to their logical superordinate (“the skilled person”), yet distinct from other skill-related prototypes (such as “the artistically talented person”), and if conceptions of prototypes relevant to competence in specific interactive situations are also relatively rich in defining characteristics, but similar to one another. Analysis of freely elicited lists of characteristics for categories within a taxonomic hierarchy for skill support these implications, showing that people's conceptions of “communicative competence” are organized in the manner most conducive to their use as the basis for competence evaluation. Results also point out the critical role played by concrete, rather than abstract, characteristics in differentiating among general and situation-specific prototypes.
Evaluating the Indirect Effect of Infant Weight Velocity on Insulin Resistance in Young Adulthood: A Birth Cohort Study From the Philippines

The authors assessed the relation between infant weight velocity and adult insulin resistance, specifically evaluating whether adult size and body fat distribution mediated the association. Data were from the Cebu Longitudinal Health and Nutrition Survey (Cebu, the Philippines), in which a birth cohort was followed to age 22 years (n = 1,409; 1983–2005). Insulin resistance was measured using homeostasis model assessment of insulin resistance (HOMA-IR). Weight velocity (g/month) from 0 to 4 months and from 0 to 24 months was assessed. The authors examined direct and total associations between early growth and adult HOMA-IR in linear regression models and used a nonparametric bootstrapping procedure to test indirect effects through adult body mass index (BMI; weight (kg)/height (m)2) and waist circumference. Infant weight velocity was positively associated with adult BMI and waist circumference, which positively predicted HOMA-IR. There were no total or direct effects of immediate postnatal weight velocity (0–4 months) on adult HOMA-IR, although indirect effects through BMI and waist circumference were significant. Weight velocity from 0 to 24 months positively predicted HOMA-IR among males only, while indirect effects were significant in both sexes. In a relatively lean sample of young adults from a population with rising rates of diabetes and cardiovascular disease, the authors found evidence for small indirect effects of infant weight velocity on adult insulin resistance mediated through adult BMI and waist circumference.
X-Ray Diffraction by Liquid Crystals

Abstract Following a very brief historical review, x-ray diffraction by nematic and smectic liquid crystals is critically examined in terms of the data available and the structural models and molecular theories that have been proposed to explain it. Studiesof TBBA are used to illustrate some of the principal mesophases that have been distinguished. Other types of liquid crystals and their phase transitions are also briefly reviewed. This analysis shows that careful experimental work is still needed to decide the kinds of models that best describe the various types of mesophases that have been shown to exist.
Molecular structure of RADA16-I designer self-assembling peptide nanofibers.

The designer self-assembling peptide RADA16-I forms nanofiber matrices which have shown great promise for regenerative medicine and three-dimensional cell culture. The RADA16-I amino acid sequence has a β-strand-promoting alternating hydrophobic/charged motif, but arrangement of β-strands into the nanofiber structure has not been previously determined. Here we present a structural model of RADA16-I nanofibers, based on solid-state NMR measurements on samples with different schemes for 13C isotopic labeling. NMR peak positions and line widths indicate an ordered structure composed of β-strands. The NMR data show that the nanofibers are composed of two stacked β-sheets stabilized by a hydrophobic core formed by alanine side chains, consistent with previous proposals. However, the previously proposed antiparallel β-sheet structure is ruled out by measured 13C–13C dipolar couplings. Instead, neighboring β-strands within β-sheets are parallel, with a registry shift that allows cross-strand staggering of opposi...
Comparison of IPDA lidar receiver sensitivity for coherent detection and for direct detection using sine-wave and pulsed modulation

We use theoretical models to compare the receiver signal to noise ratio (SNR) vs. average rate of detected signal photons for an integrated path differential absorption (IPDA) lidar using coherent detection with continuous wave (CW) lasers and direct detection with sine-wave and pulse modulations. The results show the coherent IPDA lidar has high receiver gain and narrow bandwidth to overcome the effects of detector circuit noise and background light, but the actual receiver performance can be limited by the coherent mixing efficiency, speckle and other factors. For direct detection, using sine-wave modulation allows the use of a low peak power laser transmitter and synchronous detection. The pulse modulation technique requires higher laser peak powers but is more efficient than sine-wave modulation in terms of average detected signal photon rate required to achieve a given receiver SNR. We also conducted experiments for the direct detection cases and the results agreed well with theory.
Lateral blood velocity measurement in the carotid artery via speckle tracking

A method for measurement of lateral blood velocity in the carotid artery is presented. Conventional Doppler methods are not capable of measuring lateral velocities since they quantify only the axial component of blood flow. 2D Speckle Tracking methods measure both axial and lateral velocity components, and recent advances in Speckle Tracking enhance its ability to calculate lateral flow velocities in vivo. Specifically, adaptive wall filtering and the implementation of nine disparate transmit beams, each with 2 parallel receive beams, are presented with application to imaging with a Siemens Elegra scanner. Phantom measurements verify the calibration and performance of the data acquisition system and flow tracking algorithm. The methods are demonstrated for flow in the common carotid arteries of five volunteers; velocity magnitude and angle profiles from the nine transmit locations are shown. Velocities computed with Speckle Tracking are highest in the center of the artery and diminish to low velocities near the vessel walls, with velocity magnitudes consistent with physiological expectations.
HYDRAULIC CONDUCTIVITY (PERMEABILITY) OF LABORATORY-COMPACTED ASPHALT MIXTURES

A flexible-wall permeameter was used to study the hydraulic conductivity (also referred to as "permeability") of asphalt mixtures commonly used in Wisconsin. Effects of saturation, hydraulic gradient, and sidewall leakage were studied to determine an appropriate testing procedure. The test procedure was then used to study how mixture design variables affect hydraulic conductivity. Four aggregate gradations were tested to develop relationships between hydraulic conductivity and volumetric properties. Two mixtures were also compacted to different heights (ranging from 37.5 mm to 110.0 mm) to evaluate how lift thickness affects hydraulic conductivity. Results of the tests indicate that back-pressure saturation can be used to ensure that specimens are saturated and that the saturated hydraulic conductivity is measured. Sidewall leakage was eliminated by using bentonite clay as a sealing agent. The hydraulic gradient was selected on the basis of a parametric experiment showing how the gradient affects hydrauli...
Multifunctionality of single-walled carbon nanotube-polytetrafluoroethylene nanocomposites

Multifunctional nanocomposites are increasingly needed for applications requiring prescribed sets of physical and chemical properties. Polytetrafluoroethylene (PTFE) is a popular solid lubricant due to its low friction coefficient, high chemical inertness, high thermal range and biocompatibility, but its use is limited by high rates of wear. Low loadings of nanoparticle fillers have reduced PTFE wear by 3–4 orders of magnitude, but these materials lack the mechanical, electrical or thermal properties needed for high performance applications. In this study, single-walled carbon nanotubes (SWCNT) are investigated as a route to improve wear resistance, toughness and electrical conductivity of PTFE without sacrificing low friction, high temperature capability or chemical inertness. Tribological, tensile and surface electrical measurements were made for 0, 2, 5, 10 and 15 wt.% SWCNT filled PTFE nanocomposites. A dramatic reduction in electrical resistance reflected networking (percolation) of the nanotubes at 2 wt.%. All of the nanocomposites had significantly improved electrical, mechanical and wear performance. Above 2 wt.%, electrical conductivity was reduced by more than six orders of magnitude. At 2 wt.%, ultimate engineering stress was improved by approximately 50%, true stress increased by 200%, engineering strain increased by two orders of magnitude (∼10,000%). At 5 wt.%, wear resistance improved by more than 20 times and friction coefficient increased by ∼50%.
Tracking the secondary photodynamics of the green/red cyanobacteriochrome RcaE from Fremyella diplosiphon

Cyanobacteriochrome RcaE regulates Type III complementary chromatic adaption in the cyanobacterium Fremyella diplosiphon by photoswitching between a green-absorbing dark state (15ZPg) and red-absorbing photoproduct (15EPr). Ultrafast photodynamics of RcaE involve tautomerization of the bilin chromophore, inhomogeneity, and the generation of three primary photointermediates in the forward reaction (Lumi-Go, Lumi-Gr, and Lumi-Gf). The secondary photodynamics reported here show that only Lumi-Go evolves to 15EPr via spectrally similar Meta-Go1 and Meta-Go2 intermediates, with a protonation reaction occurring at the final step on the millisecond timescale. Reverse reaction dynamics were characterized and reveal an unusually long-lived Lumi-Rf photoproduct and a blue-shifted Meta-Ry intermediate.
ET-11RESVERATROL REGULATES GLIOBLASTOMA AND GLIOBLASTOMA STEM-LIKE CELLS VIA ANTI-TUMORIGENIC AKT DEPHOSPHORYLATION AND p53 ACTIVATION

Resveratrol (RES), a natural non-toxic plant product, exerts broad anti-cancer effects. RES was investigated for efficacy against glioblastoma (GBM) and therapeutically resistant GBM stem-like cells (GSC) hypothesized to drive tumor recurrence. Patient-derived GSC lines (12.1, 22, 33, 44) isolated via marker-neutral sphere cultures in stem cell medium, and U87 glioma were treated with RES. Low RES (25 µM) achieved significant inhibition of U87 cell proliferation after 4 days compared to control vehicle (DMSO) treatment. RES also inhibited GSC sphere-forming ability, with 50% inhibitory concentrations (IC50) from 5-25 µM. Interestingly, both 12.1 and 22 GSC lines highly express stem cell markers and initiate focal orthotopic GBM xenografts in brains of immunodeficient mice, and were most sensitive to RES compared to 33 and 44 GSC lines that cause highly infiltrative xenografts. This suggests differential RES response by various GBM/GSC subtypes. In a Matrigel transwell assay, 50 µM RES significantly inhibited invasion (>50%) of both U87 and 44 GSCs. RES also altered GSC progenitor marker expression, with 50 µM RES inducing increased expression of neural differentiation markers GFAP (astrocyte) and βIII-tubulin (neuron) after 3 days on western immunoblotting. We observed the broad anti-tumorigenic RES effects against GBM/GSC by dephosphorylating oncogenic AKT and activating tumor suppressor p53. Quantitative PCR revealed RES activates a large p53 tumor suppressive gene network (PIGG8, CD95, TP53, and NOXA). In U87 flank xenografts, oral RES (50 mg/kg daily) significantly inhibited xenograft growth, and single intra-tumoral 1mg injections reduced tumor volume by >60% compared to injection of vehicle control. In conclusion, RES causes broad anti-GBM and anti-GSC effects via AKT dephosphorylation and p53 activation, and warrants further study as a non-toxic adjuvant GBM therapy.
Plastic Dog-Flea Collar Strips Used in Traps to Kill Mediterranean Fruit Fly in Hawaii

A plastic dog-flea collar strip (2.0 cm) secured separately from the trimedlure-baited cotton dental wick in Steiner’s plastic trap eliminated the problems of wick solidification and corroded (galvanized) wires. A strip impregnated with naled or didllorvos (9–20%) placed in conjunction with trimedlure was as effective in capturing and killing Ceratitis capitata (Wiedemann) in Hawaii as a mixture of trimedlure + 25–30% naled.
Students’ Mental Models of Evolutionary Causation: Natural Selection and Genetic Drift

In an effort to understand how to improve student learning about evolution, a focus of science education research has been to document and address students’ naive ideas. Less research has investigated how students reason about alternative scientific models that attempt to explain the same phenomenon (e.g., which causal model best accounts for evolutionary change?). Within evolutionary biology, research has yet to explore how non-adaptive factors are situated within students’ conceptual ecologies of evolutionary causation. Do students construct evolutionary explanations that include non-adaptive and adaptive factors? If so, how are non-adaptive factors structured within students’ evolutionary explanations? We used clinical interviews and two paper and pencil instruments (one open-response and one multiple-choice) to investigate the use of non-adaptive and adaptive factors in undergraduate students’ patterns of evolutionary reasoning. After instruction that included non-adaptive causal factors (e.g., genetic drift), we found them to be remarkably uncommon in students’ explanatory models of evolutionary change in both written assessments and clinical interviews. However, consistent with many evolutionary biologists’ explanations, when students used non-adaptive factors they were conceptualized as causal alternatives to selection. Interestingly, use of non-adaptive factors was not associated with greater understanding of natural selection in interviews or written assessments, or with fewer naive ideas of natural selection. Thus, reasoning using non-adaptive factors appears to be a distinct facet of evolutionary thinking. We propose a theoretical framework for an expert–novice continuum of evolutionary reasoning that incorporates both adaptive and non-adaptive factors, and can be used to inform instructional efficacy in evolutionary biology.
Vibrational Stark Effect Spectroscopy at the Interface of Ras and Rap1A Bound to the Ras Binding Domain of RalGDS Reveals an Electrostatic Mechanism for Protein−Protein Interaction

Electrostatic fields at the interface of the Ras binding domain of the protein Ral guanine nucleotide dissociation stimulator (RalGDS) with the structurally analogous GTPases Ras and Rap1A were measured with vibrational Stark effect (VSE) spectroscopy. Eleven residues on the surface of RalGDS that participate in this protein-protein interaction were systematically mutated to cysteine and subsequently converted to cyanocysteine in order to introduce a nitrile VSE probe in the form of the thiocyanate (SCN) functional group. The measured SCN absorption energy on the monomeric protein was compared with solvent-accessible surface area (SASA) calculations and solutions to the Poisson-Boltzmann equation using Boltzmann-weighted structural snapshots from molecular dynamics simulations. We found a weak negative correlation between SASA and measured absorption energy, indicating that water exposure of protein surface amino acids can be estimated from experimental measurement of the magnitude of the thiocyanate absorption energy. We found no correlation between calculated field and measured absorption energy. These results highlight the complex structural and electrostatic nature of the protein-water interface. The SCN-labeled RalGDS was incubated with either wild-type Ras or wild-type Rap1A, and the formation of the docked complex was confirmed by measurement of the dissociation constant of the interaction. The change in absorption energy of the thiocyanate functional group due to complex formation was related to the change in electrostatic field experienced by the nitrile functional group when the protein-protein interface forms. At some locations, the nitrile experiences the same shift in field when bound to Ras and Rap1A, but at others, the change in field is dramatically different. These differences identify residues on the surface of RalGDS that direct the specificity of RalGDS binding to its in vivo binding partner, Rap1A, through an electrostatic mechanism.
Coherent excitation of the 6 S 1 / 2 to 5 D 3 / 2 electric-quadrupole transition in 138 Ba +

The electric dipole-forbidden, quadrupole $6{S}_{1/2}\ensuremath{\leftrightarrow}5{D}_{3/2}$ transition in Ba${}^{+}$ near 2051 nm, with a natural linewidth of 13 mHz, is attractive for potential observation of parity nonconservation, and also as a clock transition for a barium ion optical frequency standard. This transition also offers a direct means of populating the metastable $5{D}_{3/2}$ state to measure the nuclear magnetic octupole moment in the odd barium isotopes. Light from a diode-pumped, solid-state Tm,Ho:YLF laser operating at 2051 nm is used to coherently drive this transition between resolved Zeeman levels in a single trapped ${}^{138}$Ba${}^{+}$ ion. The frequency of the laser is stabilized to a high-finesse Fabry-P\'erot cavity at 1025 nm after being frequency doubled. Rabi oscillations on this transition indicate a laser-ion coherence time of 3 ms, most likely limited by ambient magnetic field fluctuations.
The Hesitant Modernity of John Dunton

Dunton’s journalistic Athenian Mercury and his proto-novel A Voyage Round the World , both from 1691, imply through their strategies of presentation significantly different ideas of authorship. Experimenting with a participatory format that paired readers’ questions on a variety of matters with editors’ answers, Dunton enhanced the credibility of the Mercury by inventing a fictional “Athenian Society” of experts who pondered questions and provided answers. Published responses thus carried the weight of their collective authority. The Voyage used an opposite strategy, featuring two personal narrators who together recalled a fragmented history of their youth. This self-representation was harlequin-like—insistently informal, by turns irreverent or extravagant or facetious, based entirely on their changing whims. The eccentric world of their novel existed only as they imagined it. This article argues that in these publications, Dunton anticipated two modern authorial postures that have competed for literary predominance ever since—one based upon empirical reasoning and institutional authority for validation, the other insisting upon the authenticity of personal experience, self-constituted and self-sufficient. Dunton saw the advantage of both postures and did not choose between them.