cssi/SciSciGPT-SciSciNet huggingface dataset:
Micro-supercapacitors based on three dimensional interdigital polypyrrole/C-MEMS electrodes

Abstract Symmetric micro-supercapacitors with three dimensional (3D) interdigital electrode structures have been designed and fabricated through Carbon-microelectrochemical system (C-MEMS) technology. The micro-supercapacitor consists of a 3D C-MEMS structure which serves as a high effective surface area current collector and conformal polypyrrole (PPy) films deposited on the carbon structures as electroactive materials. The electrochemical performance of single electrodes and symmetric micro-supercapacitor cells were evaluated by cyclic voltammetry (CV) at different scan rates and galvanostatic charge/discharge tests. The effect of the 3D electrode structure on the performance of the micro-supercapacitor was studied. Single PPy/C-MEMS electrodes presented a specific capacitance of 162.07 ± 12.40 mF cm−2 and a specific power of 1.62 ± 0.12 mW cm−2 at 20 mV s−1 scan rate. The symmetric micro-supercapacitor cells exhibited an average specific capacitance of 78.35 ± 5.67 mF cm−2 and a specific power of 0.63 ± 0.04 mW cm−2 at 20 mV s−1 scan rate, demonstrating that 3D micro-supercapacitors are promising for applications that require high power in a limited footprint area of the device.
Modeling the horizontal well severance tax exemption in Louisiana

Abstract The Haynesville shale is an unconventional resource play in Louisiana that requires significant capital expenditures to develop. To produce at commercial rates, shale gas wells are drilled horizontally and fractured to release their gas, and since 1994, a severance tax exemption on horizontal wells has been in effect, offering an incentive to investors to promote industry activity. In 2011, the Haynesville shale contributed 60% to the state’s gas production, and the impact of the horizontal severance tax exemption on revenue collection has been significant. The purpose of this paper is to model the horizontal well severance tax exemption for Haynesville shale gas wells to quantify its impact and the manner in which severance tax revenues are split between the operator and government. We develop an analytic framework to value the tax exemption under prevailing production, cost, and price scenarios. We estimate that the 2011 inventory of Haynesville wells will generate between $1.2 to $1.5 billion in severance tax revenue throughout their lifetime with at least 64% accruing to the private sector. A discussion of policy issues and trade-offs in Louisiana’s horizontal severance tax exemption and implementation is provided.
Soma-Germ Line Competition for Lipid Phosphate Uptake Regulates Germ Cell Migration and Survival

Lipid phosphates can act as signaling molecules to influence cell division, apoptosis, and migration. wunen and wunen2 encode Drosophila lipid phosphate phosphohydrolases, integral membrane enzymes that dephosphorylate extracellular lipid phosphates. wun and wun2 act redundantly in somatic tissues to repel migrating germ cells, although the mechanism by which germ cells respond is unclear. Here, we report that wun2 also functions in germ cells, enabling them to perceive the wun/wun2-related signal from the soma. Upon Wun2 expression, cultured insect cells dephosphorylate and internalize exogenously supplied lipid phosphate. We propose that Drosophila germ cell migration and survival are controlled by competition for hydrolysis of a lipid phosphate between germ cells and soma.
Mechanism of inactivation of glucose-6-phosphate dehydrogenase in human erythrocytes.

Glucose-6-Phosphate Dehydrogenase and Human Erythrocytes: Mechanism of Inactivation of Glucose-6-phosphate Dehydrogenase in Human Erythrocytes
Preparation of a fluorescent-labeled derivative of calmodulin which retains its affinity for calmodulin binding proteins.

Calmodulin was derivatized with 5-[[[(iodoacetyl)amino]ethyl]amino]-1-naphthalenesulfonic acid to fluorescently label the protein. This derivative (AEDANS.CaM) stimulated the Ca2+-sensitive cyclic nucleotide phosphodiesterase and formed Ca2+-dependent complexes with troponin I and the phosphodiesterase. Association between AEDANS.CaM and these proteins was directly monitored by changes in fluorescence anisotropy. The dissociation constants for the AEDANS.CaM--troponin I and AEDANS.CaM--phosphodiesterase complexes were 60 nM and 4 nM, respectively. This fluorescent derivative of calmodulin appears suitable for direct monitoring of the complexes between calmodulin and calmodulin binding proteins. Rotational diffusion of AEDANS.CaM was also measured with fluorescence anisotropy. These measurements indicated that the shape of calmodulin in solution is best approximated by a prolate ellipsoid.
Wave transmission and input impedance of a model of skeletal muscle microvasculature.

We analyzed wave transmission properties and input impedance of a microvascular network model. The model, derived from rat spinotrapezius muscle and previously described and validated by other investigators for steady pressure-flow relations, was expanded to include pulsatile phenomena. Microvessels are considered purely elastic, with compliances a function of vessel type; viscous dissipation follows Poiseuille's law. Linear and nonlinear results are presented. In the nonlinear case, shear rate-dependent viscosity of blood and transmural pressure-dependent vascular diameters were calculated and small signal perturbations were imposed around several working points. We investigated effects on input impedance of physiological variability of network parameters and structure: distribution of capillary diameters, capillary segment length, and presence or absence of cross-connecting capillaries. Results show that although wave transmission properties are complex, input impedance is simple. Apparent wave speeds differ substantially from phase velocities and change markedly from branch to branch; pressure and flow waves appear to travel at different speeds. These features result from the mesh-like structure of the network and the prominence of reflection at branchpoints. Input impedance displays a similar form under all conditions: Magnitude is a monotonically decreasing function of frequency, and phase decreases from 0 to approximately −45°. Consideration of the characteristic impedance of a microvessel leads to modification of the three-element Windkessel as a reduced model of the observed input impedance.
ATP synthesis in Halobacterium saccharovorum: Evidence that synthesis may be catalysed by an F0F1-ATP synthase

Halobacterium saccharovorum synthesized ATP in response to a pH shift from 8 to 6.2. Synthesis was inhibited by carbonyl cyanide m-chloro-phenylhydrazone, dicyclohexylcarbodiimide, and azide. Nitrate, an inhibitor of the membrane-bound ATPase previously isolated from this organism, did not inhibit ATP synthesis. N-Ethymaleimide, which also inhibited this ATPase, stimulated the production of ATP. These observations suggested that H. saccharovorum synthesized and hydrolysed ATP using different enzymes and that the vacuolar-like ATPase activity previously described in H. saccharovorum was an ATPase whose function is yet to be identified.
Commentary: Biomechanics of various surgical procedures for the treatment of multilevel cervical spine.

COMMENTARY ON Hussain M, Nassr A, Natarajan RN, et al. Corpectomy versus discectomy for the treatment of multilevel cervical spine pathology: a finite element model analysis. Spine J 2012;12:401–8 ( in this issue ).
An identified set of visceral muscle bands is essential for the guidance of migratory neurons in the enteric nervous system of Manduca sexta.

Abstract During the formation of the enteric nervous system (ENS) in Manduca, a population of ∼300 enteric neurons (the EP cells) become distributed along the foregut and midgut by migrating onto specific sets of visceral muscle bands. Only after their migration is complete do the neurons express a variety of position-specific phenotypes, including a peptidergic phenotype that is usually restricted to a subset of EP cells on the midgut. To investigate whether direct interactions between the EP cells and these pathways are necessary for either neuronal migration or differentiation, we have investigated the developmental origins and functional role of the muscle bands in embryonic culture. Using scanning electron microscopy, immunohistochemistry, and mitotic labeling with bromodeoxyuridine, we found that the eight major muscle bands of the midgut form by the coalescence of longitudinal muscle fibers on the midgut surface, apparently in response to regional cues associated with the underlying epithelium. These bands then serve as migratory pathways for the EP cells, which travel rapidly along the bands (but not onto adjacent interband musculature) and then complete their differentiation. Dye labeling of individual EP cells revealed that prior to migration onset, each neuron extended widely distributed filopodia onto both the band and interband regions of the midgut surface. As the muscle bands coalesced, however, the leading process of each EP cell became increasingly confined to a specific band, onto which it subsequently migrated. In a series of surgical manipulations of both the muscle bands and the migratory neurons, we demonstrated that these pathways are both necessary and sufficient to support the migratory behavior of the EP cells. Surgical interventions that prevented the neurons from contacting the muscle bands inhibited migration, while contact between isolated EP cells and a muscle band supported both their migration and differentiation. However, the acquisition of mature phenotypes by the EP cells was not strictly dependent on the migration of these neurons to their expected positions. In particular, the onset of neuropeptide expression could be detected in at least some of the neurons whose migration onto the midgut had been blocked. Thus, in the embryonic ENS, the migration and delayed differentiation of the EP cells represent precisely coordinated aspects of development that are nevertheless regulated in an independent manner.
Novel approaches to the analysis of family data in genetic epidemiology

THE IMPORTANCE OF FAMILY DATA The study of Genetic Epidemiology has historically focused on the inheritance of genetic factors and phenotypes within families. In fact, much of genetics involves the study of patterns of familial resemblance and identifying the factors that explain the observed patterns. However, in recent years the most common study design for investigating the genetic determinants of diseases has become that of genome wide association studies (GWAS) utilizing samples of unrelated individuals. The popularity of this approach has been driven primarily by a flood of ever improving technologies. Unfortunately, while GWAS using unrelated individuals have revealed a great many interesting disease associated variants, these variants are typically of small effect and cannot explain the observed patterns of heritability for many traits. In contrast there are numerous examples of highly penetrant rare segregating alleles that have been discovered using family based approaches. Furthermore, family based approaches have other advantages: the ability to overcome confounding factors such as population stratification, and the numerous studies that have collected large amounts of family data and which should continue to be leveraged. Unfortunately, family based approaches to genetics have an added layer of complexity at all stages from design to analysis. This editorial introduces the Frontiers in Genetics Research Topic and Ebook: “Novel approaches to the analysis of family data in genetic epidemiology.” The papers in this issue reveal that, even with easy access to high-throughput genotyping tools such as SNP arrays and next generation sequencing, family based study designs still play an important role in untangling the complex web of environmental and genetic factors that lead to disease.
Measurement of Flame Temperature and Emittance in Gas Turbine Combustors

The radiation heat load assumes an important role in gas turbine life and performance as firing temperatures and pressures are increased. This first phase of a program for assessing radiant heat loading was mainly concerned with devising measurement techniques. An experimental method for measuring the temperature of luminous flames with a two-color pyrometer and radiant intensity by means of a total radiation pyrometer is described. Emittance data from two combustion liner configurations is included for chamber pressures of from 2 to 7.5 atmospheres over the turbine inlet temperature range of 900 to 1950 deg F.
An application of number theory to the organization of raster-graphics memory

A high-resolution raster-graphics display is usually combined with processing power and a memory organization that facilitates basic graphics operations. For many applications, including interactive text processing, the ability to quickly move or copy small rectangles of pixels is essential. This paper proposes a novel organization of raster-graphics memory that permits all small rectangles to be moved efficiently. The memory organization is based on a doubly periodic assignment of pixels to M memory chips according to a “Fibonacci” lattice. The memory organization guarantees that, if a rectilinearly oriented rectangle contains fewer than M/
Acquisition of Additional Equity Capital by Small Firms - Findings from the National Survey of Small Business Finances

While the importance of venture capital to the growth of small firms has been widely discussed during the past decade, little is known about the acquisition of additional equity capital, especially internal equity capital, by the majority of small firms in the U.S. This paper utilizes the information collected in the Federal Reserve Board’s 1993 and 1998 Small Business Finance Surveys to investigate the acquisition of additional equity capital by small firms. While the importance of public issue markets and venture capital investment in promoting the growth of small dynamic firms cannot be denied, the importance of external equity capital seems to be overstated. Only a very small number of small firms acquired additional external equity capital. It is the internal equity capital, not external, equity, that is one of the major financing sources for most small firms. We found that younger, lower quality firms were more likely to acquire additional internal equity capital than other firms. There appeared to be a “pecking order” of borrowing from internal sources to traditional lenders to non-traditional lenders. In addition, internal equity capital and debt acquired from traditional and non-traditional lenders appeared to be complementary financial resources.
Does robotic assistance confer an economic benefit during laparoscopic radical nephrectomy

Purpose: While robotic assisted radical nephrectomy is safe with outcomes and complication rates comparable to those of the pure laparoscopic approach, there is little evidence of an economic or clinical benefit.Materials and Methods: From the 2009 to 2011 Nationwide Inpatient Sample database we identified patients 18 years old or older who underwent radical nephrectomy for primary renal malignancy. Robotic assisted and laparoscopic techniques were noted. Patients treated with the open technique and those with evidence of metastatic disease were excluded from analysis. Descriptive statistics were performed using the chi-square and Mann-Whitney tests, and the Student t-test. Multiple linear regression was done to examine factors associated with increased hospital costs and charges.Results: We identified 24,312 radical nephrectomy cases for study inclusion, of which 7,787 (32%) were performed robotically. There was no demographic difference between robotic assisted and pure laparoscopic radical nephrectomy ...
The National Weather Service (NWS) United States Integrated sustained Ocean Observing System and the federal backbone - the next steps, what can the federal backbone do for you?

The U.S. Commission on Ocean Policy will make its recommendations during the summer of 2003. These recommendations are expected to fully endorse the development of a U.S. Integrated Ocean Observing System (IOOS). The form of the U.S. IOOS is emerging. Requirements have been identified, and a blueprint for the U.S. IOOS has been developed. The system would address national coastal issues as well as make a significant contribution to the larger Global Ocean Observing System (GOOS). The federal backbone components are central to the IOOS blueprint. The observing system foundation formed by the federal backbone and the services the backbone provides are critical to developing and sustaining the IOOS. The National Data Buoy Center (NDBC), a part of the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS), manages the Marine Observation Program (MOP) and operates the NWS Marine Observation Network (MON). The MON is a core element of the U.S. IOOS federal backbone. The NWS MON is an integrated, sustained ocean observation, information and product delivery system that operates in all U.S. coastal waters, as well as the offshore waters of the Pacific and Atlantic Oceans and the Gulf of Mexico. The system consists of headland and moored buoy data acquisition platforms and real-time processing and information delivery systems, as well as drifters, floats, and voluntary observing ships. The MON produces quality controlled real-time data and products that serve the NOAA storm warning and forecast mission and support research and operational requirements of other federal, state, regional, local, academic and private sponsors. Within the context of the IOOS blueprint, NOAA's NDBC has established strategic alliances with several Regional Observation Networks. This paper presents an overview of these alliances and discusses how they are evolving into full-fledged partnerships. Partnerships that will realize the goals of the U.S. IOOS.
Microstructural studies on the initiation and growth of small fatigue cracks at 298, 77 and 4.2 K in polycrystalline copper

Abstract The temperature dependence of the initiation and growth of small fatigue cracks has been studied by microscopic observations in polycrystalline copper during the early stages of fatigue. The primary procedure was to examine the same site of the specimen by SEM and TEM using surface replicas taken periodically during the fatigue tests. A periodical array of pit-shaped fatigue cracks as small as 0.1 ,um in depth forms along slip bands at 298, 77 and 4.2 K, even in an inert environment. A dislocation gliding mechanism of dislocation dipoles in the slip bands has been suggested as a possible process for the formation of these cracks. It was found that the configuration of small fatigue cracks is related to the periodically spaced dislocation regions in fatigued Cu. The growth rate of small fatigue cracks during the early stages of fatigue was measured and found to be approximately 0.1 nm/cycle at 298 and 77 K. A quantitative analysis of the net effects of temperature and environment on the fatigue crack initiation was performed.
Treatment planning of implants in posterior quadrants

Differences in anatomy and biomechanics make treatment of posterior quadrants with dental implants substantially different to that of anterior areas. Without implants, when posterior teeth were lost, treatment options included a long span fixed partial denture or a removable prosthesis, especially when no terminal abutment was available. Today, with the use of implants, options are available that allow preservation of unrestored teeth.(1) When teeth are missing, implant supported restorations can be considered the treatment of choice from the perspective of occlusal support, preservation of adjacent teeth and avoidance of a removable partial denture.
Conformal field theory, spin geometry, and quantum gravity

Abstract The invariants of knotted graphs which come from rational conformal field theories are reinterpreted as discrete path integrals. The degenerate case corresponding to classical SU(2) has already been interpreted as a path integral for 3D quantum gravity. A beginning is made toward extending this interpretation to the quantum case.
Anomalous signal indicators in protein crystallography.

A Monte Carlo procedure is described that generates random structure factors with simulated errors corresponding to an X-­ray data set of a protein of a specific size and given heavy-atom content. The simulated data set can be used to estimate Bijvoet ratios and figures of merit as obtained from SAD phasing routines and can be used to gauge the feasibility of solving a structure via the SAD method. In addition to being able to estimate results from phasing, the simulation allows the estimation of the correlation coefficient between |ΔF|, the absolute Bijvoet amplitude difference, and FA, the structure-factor amplitude of the heavy-atom model. As this quantity is used in various substructure-solution routines, the estimate provides a rough estimate of the ease of substructure solution. Furthermore, the Monte Carlo procedure provides an easy way of estimating the number of significant Bijvoet intensity differences, denoted as the measurability, and is proposed as an intuitive measure of the quality of anomalous data.
Design Optimization of a Linear-Motion Large-Displacement Micro Mechanism for High Off-Axis Stiffness

This paper presents research on the large-displacement linear-motion planar compliant mechanism (X-Bob) specific to MEMS applications. The X-Bob’s potential for high off-axis stiffness makes it a strong candidate for precision MEMs applications. Understanding the characteristics and performance of the X-Bob can lead to the ability to modify it to fit specific applications. In this work, an X-Bob design is optimized for increased off-axis stiffness while maintaining a small footprint. The results are compared to previous X-Bob designs and to folded beam suspensions. Advantages and disadvantages of each design are explained.Copyright © 2009 by ASME
Image segmentation utilizing wavelet-based spatially adaptive kernels

Most multiresolution methods of segmenting images have hitherto resolved an image into successively coarser scales and discarded high-pass edge information. We present a robust and computationally tractable method for the automated segmentation of images using spatially varying kernels derived from multiscale edge information of the image. We include examples of segmentation of synthetic and real images that demonstrate the performance of the algorithm in preserving fine detail and edge information in the segmentation maps while being robust to heavy noise.
SIMO system identification from measured ringdowns

Recent variations of Prony analysis and similar methods have proven to be valuable tools in identifying transfer functions and estimating the modal content from measured ringdowns. Such tools are becoming a standard in power system dynamic analysis. Current analysis methods assume the system to be single-input single-output (SISO) with distinct eigenvalues. Individual signals are analyzed independently often resulting in conflicting frequency and damping estimates (due to noise effects). Also, one cannot apply Prony analysis to systems with repeated or very closely-spaced poles such as in power system subsynchronous resonance problems. This paper presents a variation of Prony analysis that allows identification of a single-input multi-output (SIMO) proper model with possible repeated poles. Prony analysis as a signal analysis method is first generalized to handle multiple signals with poles that may be repeated. Expressions are then derived for the transfer function terms assuming the input is a series of square-wave pulses. Advantages of the SIMO analysis method are demonstrated on a power system Monte Carlo type simulation model. The example shows that the SIMO formulation allows for more accurate estimation of electromechanical oscillation modes under noisy conditions (such as field measured data).
MODEL CHECKING FOR VERIFICATION OF MANDATORY ACCESS CONTROL MODELS AND PROPERTIES

Mandatory access control (MAC) mechanisms control which users or processes have access to which resources in a system. MAC policies are increasingly specified to facilitate managing and maintaining access control. However, the correct specification of the policies is a very challenging problem. To formally and precisely capture the security properties that MAC should adhere to, MAC models are usually written to bridge the rather wide gap in abstraction between policies and mechanisms. In this paper, we propose a general approach for property verification for MAC models. The approach defines a standardized structure for MAC models, providing for both property verification and automated generation of test cases. The approach expresses MAC models in the specification language of a model checker and expresses generic access control properties in the property language. Then the approach uses the model checker to verify the integrity, coverage, and confinement of these properties for the MAC models and finally generates test cases via combinatorial covering array for the system implementations of the models.
The role of oxygen in the ignition of polystyrene by a small flame

The ignition of slabs of high-impact polystyrene by a lean hydrogen–oxygen flat flame was studied. The ignition delays and inital rates of flame development after ignition are reported as functions of gas temperature and the separation between flame and polymer surface. The delays follow an Arrhenius-type expression with an activation energy of 98 ± 18 kJ mol−1. The rates of flame development drop as the gas temperature increases. During long ignition delays the apparent heat transfer coefficient at the sample surface dropped from about 100 W m−2 K−1 to values close to that expected for a hot gas impinging at right angles on a cold surface. For short delays it was higher and more constant at about 100 W m−2 K−1. Although the surface temperature reached before ignition exceeded that required for nonoxidative pyrolysis, the polymer surface charred only when oxygen was present. It is concluded that both oxidative and nonoxidative pyrolysis contribute to the ignition of polystyrene.
Relevant But Long Since Absent: Re-establishing a Political Economy of the Dutch Media

Based on a literature review and interviews with scholars, this article recaptures and evaluates the political-economic approach to the Dutch media during the 1970s and its subsequent disappearance. The objective of this paper is to contribute to reinstituting that approach. Additionally, this article argues for its heightened salience, as the commercialization of the Dutch media has much increased since the 1970s.
Field programmable thermal emulator (FPTE): An all-silicon test structure for thermal characterization of integrated circuits

This paper presents an on-chip digitally programmable test structure, referred to as the field programmable thermal emulator (FPTE), for on-line characterization of power pattern, time-varying thermal field, and associated changes in the electrical characteristics of the transistors. A test chip was designed in 130nm CMOS to validate the test structure. The measurement results demonstrated the ability of FPTE to emulate various power patterns and capture the effects on temperature and circuit performance.
Co-registration of doppler tissue synchronization imaging and computer tomography with an application to pacing and cardiac resynchronization therapy

Dyssynchronous myocardial contraction can be treated with surgical implant of a pacing device. Integrated information of coronary anatomy and mechanical delay may be extremely beneficial to success of the implant but it is not available in current cardiac imaging modalities. The objective of this study is to investigate the feasibility of a point-merge co-registration approach to overcome the limitation. This study shows that our method is a reliable and fast tool useful not only to attain optimal left ventricular implantation site but also to better select patients that undergo cardiac resynchronization therapy.
Computer simulation and field measurement of dynamic pavement loading

Abstract Two methods, i.e. computer simulation and field measurement, are used in this paper to investigate dynamic pavement loading (DPL) generated by vehicle–pavement interaction. A profilometer is used for measuring road surface roughness. Based on the power spectral density of the measured surface roughness, a computer simulation program is developed using quarter vehicle model. In field measurement methods, an experiment is designed to gain the time history of DPL. An IVECO vehicle is taken as a test vehicle and eight vibration cells were used to pick up vertical accelerations of vehicle body and axle. The test data are collected and recorded while the test vehicle is moving along 11 different pavement sections of highway and bridge at six different speeds. Statistical characteristics of vertical accelerations and DPL of the test vehicle are obtained and analyzed by means of random process theory. The result of computer simulation matches the result of field measurement very well. It is found that DPL is primarily concentrated between 1.8 and 14.8 Hz and coefficient of variation of DPL falls into the range of 5–35% of static vehicle load. An approximate relationship between coefficient of variation of DPL and vehicle speed and road surface roughness is established.
Increasing expression and decreasing degradation of SMN ameliorate the spinal muscular atrophy phenotype in mice

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by reduced levels of the survival motor neuron (SMN) protein. Here we show that the proteasome inhibitor, bortezomib, increases SMN in cultured cells and in peripheral tissues of SMA model mice. Bortezomib-treated animals had improved motor function, which was associated with reduced spinal cord and muscle pathology and improved neuromuscular junction size, but no change in survival. Combining bortezomib with the histone deacetylase inhibitor trichostatin A (TSA) resulted in a synergistic increase in SMN protein levels in mouse tissue and extended survival of SMA mice more than TSA alone. Our results demonstrate that a combined regimen of drugs that decrease SMN protein degradation and increase SMN gene transcription synergistically increases SMN levels and improves the lifespan of SMA model mice. Moreover, this study indicates that while increasing SMN levels in the central nervous system may help extend survival, peripheral tissues can also be targeted to improve the SMA disease phenotype.
A study of shoulder motions as a control source for adolescents with C4 level SCI

This study quantitatively examined and compared the shoulder motions of C4 level spinal cord injury (SCI), C5 level SCI, and able-bodied persons as a command source. The study was motivated by both the success of shoulder control in functional electrical stimulation (FES) systems designed for C5 level SCI people and the lack of quantitative information on the shoulder motion of persons with C4 level SCI. A dual-axis transducer was used to monitor the elevation/depression and protraction/retraction angles of each subject's shoulder while they performed 3 experimental sections which examined: the range of active shoulder motion; the ability to move incrementally to discrete positions with the aid of visual feedback; and the ability to hold discrete shoulder positions for an extended period without visual feedback. Results indicated that each group had the largest average shoulder displacements (abled=23/spl deg//spl plusmn/4/spl deg/, C5's=14/spl deg//spl plusmn/3/spl deg/, and C4's=9/spl deg//spl plusmn/3/spl deg/) while attempting to elevate and that on average the C4 group had the smallest range of active shoulder motion. No statistically significant differences between the groups were found in either the accuracy or stability of reaching discrete positions with the aid of visual feedback or in the accuracy of holding discrete shoulder positions for an extended period without visual feedback. The results suggest that within their limited range of motion the individuals with C4 level SCI retained shoulder control sufficient for use as an neuroprosthetic command interface.
Survival and Behavioral Effects of Exposure to a Hydrokinetic Turbine on Juvenile Atlantic Salmon and Adult American Shad

This paper describes a series of experiments designed to measure the effect of exposure to a full-scale, vertical axis hydrokinetic turbine on downstream migrating juvenile Atlantic salmon (N = 175) and upstream migrating adult American shad (N = 208). Controlled studies were performed in a large-scale, open-channel flume, and all individuals approached the turbine under volitional control. No injuries were observed, and there was no measurable increase in mortality associated with turbine passage. Exposure to the turbine elicited behavioral responses from both species, however, with salmon passing primarily over the downrunning blades. Shad movement was impeded by the device, as indicated by fewer attempts of shorter duration and reduced distance of ascent up the flume. More work should be performed in both laboratory and field conditions to determine to what extent these effects are likely to influence free-swimming fish.
Visual Ecology and Functional Morphology of Cubozoa (Cnidaria)

Jellyfish belong to one of the oldest extant animal phyla, the Cnidaria. The first Cnidaria appear in the fossil record 600 million years ago, preceeding the Cambrian explosion. They are an extremely successful group present in all marine environments and some freshwater environments. In contrast to many animal phyla in which vision is a primary sense Cnidarians do not, generally, employ image forming eyes. One small class stands alone: the Cubozoa. Cubomedusae are commonly known as box jellyfish. They possess image forming eyes (Coates et al., 2001) which certainly evolved independently from other metazoans. Cubomedusae therefore offer a unique perspective on the evolution of image forming eyes. This literature review collects, into one place, what is known about: the multiple eye types of box jellyfish, cubomedusan life history and ecology, and the sensory and neural systems of box jellyfish. Here I discuss how these features set cubomedusae apart from scyphomedusae and hydromedusae. Knowledge in these areas is sparse; the work done to date inspires increased efforts.
The three-photon yield from e+ annihilation in various fluids

Positronium in the triplet state decays by the emission of three photons and it has been proposed that their simultaneous detection can be used for medical imaging. The three-photon yield has been observed to be enhanced in low O(2) levels in some fluids but has never been measured in biologically relevant liquids. In this study, the delayed three-photon decay yield, at both high and low O(2) levels, has been extracted by fitting the time dependence of the two-photon yield to a set of coupled differential equations. The differential equations, in a simple yet seemingly satisfactory fashion, account for the e(+) capture to form positronium, its decay and the interconversion of the two spin configurations. Our results indicate that the delayed three-photon fraction is 0.25% in water (or blood-like) samples and exhibits no (or exceedingly small) dependence on the dissolved oxygen content. If one assumes that the direct component contributes a fraction expected by annihilation on free electrons (1/372), then the total three-photon fraction is 0.52% in the samples of biological relevance.
Blood Pressure and Risk of All-Cause Mortality in Advanced Chronic Kidney Disease and Hemodialysis The Chronic Renal Insufficiency Cohort Study

Studies of hemodialysis patients have shown a U-shaped association between systolic blood pressure (SBP) and mortality. These studies have largely relied on dialysis-unit SBP measures and have not evaluated whether this U-shape also exists in advanced chronic kidney disease, before starting hemodialysis. We determined the association between SBP and mortality at advanced chronic kidney disease and again after initiation of hemodialysis. This was a prospective study of Chronic Renal Insufficiency Cohort participants with advanced chronic kidney disease followed through initiation of hemodialysis. We studied the association between SBP and mortality when participants (1) had an estimated glomerular filtration rate <30 mL/min/1.73 m2 (n=1705), (2) initiated hemodialysis and had dialysis-unit SBP measures (n=403), and (3) initiated hemodialysis and had out-of-dialysis-unit SBP measured at a Chronic Renal Insufficiency Cohort study visit (n=326). Cox models were adjusted for demographics, cardiovascular risk factors, and dialysis parameters. A quadratic term for SBP was included to test for a U-shaped association. At advanced chronic kidney disease, there was no association between SBP and mortality (hazard ratio, 1.02 [95% confidence interval, 0.98-1.07] per every 10 mm Hg increase). Among participants who started hemodialysis, a U-shaped association between dialysis-unit SBP and mortality was observed. In contrast, there was a linear association between out-of-dialysis-unit SBP and mortality (hazard ratio, 1.26 [95% confidence interval, 1.14-1.40] per every 10 mm Hg increase). In conclusion, more efforts should be made to obtain out-of-dialysis-unit SBP, which may merit more consideration as a target for clinical management and in interventional trials.
Experimental Study of Lightning-Induced Currents in a Buried Loop Conductor and a Grounded Vertical Conductor

Currents induced in: (1) a 100 mtimes30 m buried rectangular loop conductor (counterpoise) and (2) a grounded vertical conductor of 7-m height by natural and rocket-triggered lightning at distances ranging from 60 to 300 m were recorded in 2005 at the International Center for Lightning Research and Testing (ICLRT). The peak values of 12 triggered lightning channel-base currents and the peak values of the induced currents in the counterpoise are strongly correlated. The first few microseconds of the current induced in the vertical conductor by triggered lightning return strokes 100 m away resemble electric field time-derivative waveforms simultaneously measured at the ICLRT. During a close natural lightning flash, five pre-first-return-stroke current pulses with peak currents up to 140 A were measured in the vertical conductor. These are apparently associated with multiple attempts of an upward-moving unconnected leader occurring in response to the charge lowered by downward-propagating leader steps.
Error Analyses for a Gravity Gradiometer Mission

This paper addresses the usefulness of an orbiting gravity gradiometer as a sensor for mapping the fine structure of the Earth gravity field. The exact knowledge of this field is essential for studies of the solid Earth and the dynamics of the oceans. Although the Earth gravity tensor, measured by a gradiometer assembly, has nine components, only five components are independent. This latter fact is as a consequence of the symmetry and conservative nature of the Earth's gravity field. The most dominant component is the radial one. The error analyses considered here are therefore based only upon a single axis gradiometer sensing this radial component. The expected global gravity and geoid errors for a 50 x 50-km (1/2° x 1/2°) area utilizing a space-borne gradiometer with a precision of 10-3 EU in a 160-km circular polar orbit are about 3 mGAL and 5 cm, respectively.
Does Endovascular Repair of Ruptured Abdominal Aortic Aneurysm Confer Survival Benefits over Open Repair

mortality or vascular, neurologic or other minor postoperative complications. Conclusions: Greater hospital competition is significantly associated with increased EVAR adoption at a time when diffusion of this technology passed its tipping point. Hospital competition does not influence post-AAA repair outcomes. These results suggest that adoption of novel vascular technology is not solely driven by clinical indications, but may also be influenced by market forces.
Sequential Production Planning Over Time at Minimum Cost

Production of a given commodity is to be scheduled over time to meet known future requirements while minimizing total costs. The costs include both storage and production costs as functions of time. The unit production cost is an increasing function of the production rate. Previous solutions to this problem have involved complicated iterative procedures. A new approach brings out the basic principle involved and leads to a surprisingly simple solution. This coincides with a common-sense technique sometimes used in business.
What are they thinking? Automated analysis of student writing about acid-base chemistry in introductory biology.

Students’ writing can provide better insight into their thinking than can multiple-choice questions. However, resource constraints often prevent faculty from using writing assessments in large undergraduate science courses. We investigated the use of computer software to analyze student writing and to uncover student ideas about chemistry in an introductory biology course. Students were asked to predict acid–base behavior of biological functional groups and to explain their answers. Student explanations were rated by two independent raters. Responses were also analyzed using SPSS Text Analysis for Surveys and a custom library of science-related terms and lexical categories relevant to the assessment item. These analyses revealed conceptual connections made by students, student difficulties explaining these topics, and the heterogeneity of student ideas. We validated the lexical analysis by correlating student interviews with the lexical analysis. We used discriminant analysis to create classification functions that identified seven key lexical categories that predict expert scoring (interrater reliability with experts = 0.899). This study suggests that computerized lexical analysis may be useful for automatically categorizing large numbers of student open-ended responses. Lexical analysis provides instructors unique insights into student thinking and a whole-class perspective that are difficult to obtain from multiple-choice questions or reading individual responses.
Location Spoofing Attack Detection in Wireless Networks

While significant research effort has been dedicated to wireless localization over the past decades, most aspects of location security have been overlooked. In particular, adversaries can take advantage of security vulnerabilities of current location systems to launch location spoofing attacks, thus disguising their position in the network. In this paper, we address issues associated with location spoofing attack detection by examining relative location error rather than its absolute value. Specifically, we propose novel statistical and pattern matching techniques called relative error detection (RED) and topological residual fingerprint matching (TRFM) for detecting both signal strength and beamforming attacks. Also, the concept of geometric filtering is developed to considerably improve location reliability by exploiting the geometry of nodes.
Kinetic Parameters of Efflux of Penicillins by the Multidrug Efflux Transporter AcrAB-TolC of Escherichia coli

The multidrug efflux transporter AcrAB-TolC is known to pump out a diverse range of antibiotics, including β-lactams. However, the kinetic constants of the efflux process, needed for the quantitative understanding of resistance, were not available until those accompanying the efflux of some cephalosporins were recently determined by combining efflux with the hydrolysis of drugs by the periplasmic β-lactamase. In the present study we extended this approach to the study of a wide range of penicillins, from ampicillin and penicillin V to ureidopenicillins and isoxazolylpenicillins, by combining efflux with hydrolysis with the OXA-7 penicillinase. We found that the penicillins had a much stronger apparent affinity to AcrB and higher maximum rates of efflux than the cephalosporins. All penicillins showed strong positive cooperativity kinetics for export. The kinetic constants obtained were validated, as the MICs theoretically predicted on the basis of efflux and hydrolysis kinetics were remarkably similar to the observed MICs (except for the isoxazolylpenicillins). Surprisingly, however, the efflux kinetics of cloxacillin, for example, whose MIC decreased 512-fold in Escherichia coli upon the genetic deletion of the acrB gene, were quite similar to those of ampicillin, whose MIC decreased only 2-fold with the same treatment. Analysis of this phenomenon showed that the extensive decrease in the MIC for the acrB mutant is primarily due to the low permeation of the drug and that comparison of the MICs between the parent and the acrB strains is a very poor measure of the ability of AcrB to pump a drug out.
Rapid development of a P25 JTRS waveform

Past disaster response experience, as well as existing terrorism threats, demands close collaboration between the military and public safety command structure in possible future operations. Establishing radio communication between military commanders, soldiers and law enforcement officers is an important enabling capability to facilitate interoperability. The JTRS program is enabling communications between military branches by implementing different military radio waveforms on JTRS software-defined radio platforms. Therefore, it is natural to include a Project 25 (P25) public safety digital radio waveform in the JTRS waveform portfolio. This paper describes the rapid development of a P25 waveform on the Spectrum Signal Processing SDR-4000, a surrogate JTRS software-defined radio platform. The development process and methodology, which starts from a platform-agnostic executable waveform model in Matlab, through an intermediate implementation using open tools on generic platforms, to the final platform-specific implementation, is introduced and discussed. This paper shows that adopting this methodology can speed up waveform development and porting.
Comparative study of spine vertebra shape retrieval using learning-based feature selection

Feature extraction and selection are two important steps for shape retrieval. Given a data set, a set of features which describe the shape property from different aspects are extracted. Our goal is a learning-based methodology to select the features for improving retrieval performance. Our approach uses both global and local feature descriptors. The global shape features include geometric ones (elongation, eccentricity, roughness, and compactness), Fourier descriptors with complex coordinates, Fourier descriptors with Centroid Contour Distance Curve, Coefficients of Fourier Expansion of Bent function, moment invariants, and local shape features that include turn angle and Distance Across the Shape. We propose a learning-based feature selection algorithm as a strategy for optimizing retrieval performance. We provide results from the vertebra shape dataset created from our database containing spine x-rays from the National Health and Nutrition Examination Survey (NHANES II). Finally, we compare the retrieval performances of feature descriptors on “whole shape” and “corner shape” datasets. The experimental results show that various feature descriptors perform differently on different datasets, and that feature selection schemes improve the retrieval performance significantly.
Using Marketing Muscle to Sell Fat: The Rise of Obesity in the Modern Economy

The large increase in obesity in the past 30 years has often been explained in rational choice terms; for example, a decline in food prices has engendered greater food consumption. On closer examination, this kind of explanation does not fit the facts of the current obesity epidemic. Instead, an unprecedented expansion in the scope, power, and ubiquity of food marketing has coincided with an unprecedented expansion in food consumption in predictable ways. Ongoing protestations that the causes of the recent increase in obesity are unknown may overstate the case. Ample evidence indicates that the obesity epidemic is, at least to a large degree, the result of increased marketing power over the American diet. Only by reigning in or countering marketing power can rationality be restored to the dietary choices of Americans.