cssi/SciSciGPT-SciSciNet huggingface dataset:
Reversible bistable switching in nanoscale thiol-substituted oligoaniline molecular junctions.

Single molecular monolayers of oligoaniline dimers were integrated into sub-40-nm-diameter metal nanowires to form in-wire molecular junctions. These junctions exhibited reproducible room temperature bistable switching with zero-bias high- to low-current state conductance ratios of up to 50, switching threshold voltages of approximately ±1.5 V, and no measurable decay in the high-state current over 22 h. Such switching was not observed in similarly fabricated saturated dodecane (C12) or conjugated oligo(phenylene ethynylene) (OPE) molecular junctions. The low- and high-state current versus voltage was independent of temperature (10−300 K), suggesting that the dominant transport mechanism in these junctions is coherent tunneling. Inelastic electron tunneling spectra collected at 10 K show a change in the vibrational modes of the oligoaniline dimers when the junctions are switched from the low- to the high-current state. The results of these measurements suggest that the switching behavior is an inherent mo...
Clinical outcome after treatment of rest angina with calcium blockers: Comparative experience during the initial year of therapy with diltiazem, nifedipine, and verapamil

Abstract The clinical outcome after the initial year of therapy with either diltiazem (D), nifedipine (N), or verapamil (V) was examined in 45 patients with rest angina. Age, frequency of angina, duration of symptoms, and ejection fraction were similar in all three treatment groups. Coronary artery disease was present in 60% of patients (5 of 13 given D, 8 of 16 given N, and 14 of 16 given V). Coronary spasm was suspected (ST elevation with angina) or documented (angiographically) in 35 (78%) patients. Twenty-nine (64%) patients had >50% decrease in angina without a coronary event (9 taking D, 11 taking N, and 9 taking V). Coronary events (sudden death, infarction, and hospitalization for unacceptable angina control or bypass surgery) occurred in 13 (29%) patients (two taking D, four taking N, and seven taking V). To achieve these responses, 20 (44%) patients required additional antianginal drugs (long-acting nitrates, beta blockers, or other calcium blockers). Four of these 20 patients were taking D, nine were taking N, and seven were taking V. Seventeen (38%) patients experienced a side effect (none taking D, 6 taking N, and 11 taking V). Although rest angina can be controlled in the majority of patients during the initial year of treatment with calcium blockers, additional therapy is often required. Furthermore, the clinical course of patients presenting with rest angina remains unpredictable, even during calcium blocker treatment. Morbid events continue to occur, related in part to the extent of coronary artery disease.
Exact Solutions for Two-Dimensional Reactive Flow for Verificaiton of Numerical Algorithms

New exact solutions of oblique detonations are developed for the supersonic irrotational o w of an inviscid calorically perfect ideal gas which undergoes a one-step, irreversible, exothermic, zero activation energy reaction as it passes through a straight shock over a curved wedge. A full exact solution gives expressions for the velocity, pressure, density, temperature, and position as parametric functions of a variable characterizing the extent of reaction. Three limiting cases are then studied in which all variables are obtained as functions of position. The rst, obtained in the asymptotic high Mach number limit, gives a simple exponential form at leading order while conning the eects of heat release to higher order. An improvement is realized in the second asymptotic limit, which better accounts for nite heat release at the expense of a more elaborate form in terms of the Lambert W function. The third, obtained for a Chapman-Jouguet condition with no additional asymptotic limits, gives all variables in terms of the Lambert W function. The solutions provide a more compact and rened description of oblique detonation; moreover, they are in harmony with long-held understanding of such o ws. As the simple model employed is a rational limit of models used in the computational simulation of complex supersonic reactive o ws, the solutions can serve as benchmarks for mathematical verication of general computational algorithms. An example of such a verication is given by comparing the predictions a modern shock-capturing code to those of the full exact solution. The realized spatial convergence rate is 0.779, far less than the fth order accuracy which the chosen algorithm would exhibit for smooth o ws, but consistent with the predictions of all shock-capturing codes, which never converge with greater than rst order accuracy for o ws with embedded discontinuities.
Nicotinic receptor signaling in nonexcitable cells

The finding that neuronal nicotinic acetylcholine receptors (nAChRs) are present in non-neuronal cells both within and outside the nervous system raises some interesting issues. The mechanisms underlying receptor signaling and its downstream consequences in these cells remain to be elucidated. Factors controlling the release of acetylcholine and the extent of its diffusion are likely to be different for these cells than for traditional neuronal synapses. Recent advances on the physiologic functions of some of these cell types have provided a better insight into possible functional roles for nAChRs in nonexcitable cells. The presence of nAChRs on these cells also implies a broader scope for the actions of nicotine that needs to be considered from a clinical viewpoint. Revealing the potential physiologic roles for nAChRs on nonexcitable cells is likely to provide a more complete understanding of cholinergic signaling.
The effects of student higher education grants

Abstract This review article identifies basic issues involved in the subsidy of higher education in the United States. Specifically it evaluates the contributions in the papers by Schwartz and by Ehrenberg and Luzadis to improve our understanding of these issues.
The Evolution of Ethnographic Research Methods: Curiosities and Contradictions in the Qualitative Research Literature

This article evaluates six recent contributions to the literature on ethnographic research methods. Four concern collecting and analyzing texts, one introduces the use of textual and numerical data, and one illustrates the use of quantitative methods for qualitative data. The first four books reveal that current thinking in qualitative methods continues to privilege inexplicit criteria for data collection and analysis despite recognizing that explicit criteria work best. The last two books show how to effectively integrate qualitative and quantitative data in ways that resolve these contradictions. W. PENN HANDWERKER (Ph.D. Oregon, 1971) is Professor of Anthropology and Public Health and Department Head at the University of Connecticut. Trained as a general anthropologist with a great appreciation of explicit methods, he developed new methods to study cultures while investigating topics including entrepreneurship, corruption, human fertility, and the causes and consequences of violence to women and childr...
Reduction potential of yeast cytochrome c peroxidase and three distal histidine mutants: dependence on pH.

Abstract The pH dependence of the Fe(III) reduction potential, E 0 ′, for yeast cytochrome c peroxidase (yCcP) and three distal pocket mutants, CcP(H52L), CcP(H52Q), and CcP(R48L/W51L/H52L), has been determined between pH 4 and 8. E 0 ′ values at pH 7.0 for the yCcP, CcP(H52L), CcP(H52Q), and CcP(R48L/W51L/H52L) are − 189, − 170, − 224, and − 146 mV, respectively. A heme-linked ionization in the reduced enzyme affects the reduction potential for yCcP and all three mutants. Apparent pK A values for the heme-linked ionization are 7.5 ± 0.2, 6.5 ± 0.3, 6.4 ± 0.2, and 7.0 ± 0.3 for yCcP and the H52L, H52Q, and R48L/W51L/H52L mutants, respectively. A cooperative, two-proton ionization causing a spectroscopically-detectable transition was observed in the ferrous states of yCcP, CcP(H52L) and CcP(H52Q), with apparent pK A values of 7.7 ± 0.2, 7.4 ± 0.1 and 7.8 ± 0.1, respectively. These data indicate that: (1) the distal histidine in CcP is not the site of proton binding upon reduction of the ferric CcP, (2) the distal histidine is not one of the two groups involved in the cooperative, two-proton ionization observed in ferrous CcP, and (3) the proton-binding site is not involved in the cooperative, two-proton ionization observed in the reduced enzyme.
Laboratory Management: Quality in Laboratory Diagnosis

Written by Candis A. Kinkus, MBA; Series editor: Michael Laposata, MD, PhD 103 pages. New York, NY: Demos Medical Publishing. $40.00. ISBN: 978-1936287451 Laboratory Management: Quality in Laboratory Diagnosis is one of a series of useful books that covers key areas of management in today’s complex clinical laboratory. Laboratory Management is a concise review of certain responsibilities of laboratory leaders and how those leaders can best manage some of the more common problems that they face. For managers, supervisors, lead technologists, and aspiring laboratory leaders, this book serves as guide to …
Hydrogen and proton exchange membrane fuel cells for clean road transportation

Abstract In this paper the main issues related to the working of hydrogen fuel cells and their utilization in the transportation field are presented and discussed, starting from the experimental analysis of dynamic performance of a laboratory fuel cell system based on a 20 kWe H2/air proton exchange membrane stack. The experiments were carried out on successive load steps characterized by low reactant relative pressures (15–50 kPa) and stack temperature of 310–350 K. The effect of air flow rate, hydrogen purge and membrane humidification strategy on stack output voltage was evaluated evidencing the role of different sub-systems in stack management (for reactant feeding, stack cooling, membrane humidification) and their effect on efficiency losses of the overall system. The results presented in this paper provide experimental indications about potentialities of hydrogen fuel cell systems as clean electric energy generators for automotive applications.
Three-Dimensional Superresolution Using Single-Molecule Photoswitches and a Double-Helix PSF

Superresolution detail provided by fluorescence imaging of optically controllable single-molecule emitters can be extended to three dimensions using a novel double-helix point-spread function. Molecules and methods enabling this advance will be reviewed.
Effects of Practice on SISI Scores with Normal-Hearing Subjects

A series of experiments investigated practice effects on 1.25-dB SISI scores with three groups of normal-hearing subjects. All tests were administered at 20-dB SL. The experiments investigated the ...
Probing the use of small‐angle light scattering for characterizing structure of titanium dioxide/low‐density polyethylene nanocomposites

Small-angle light scattering (SALS) measurements were used to study the structure of titanium dioxide (TiO2)/low-density polyethylene (LDPE) nanocomposites. The results showed that the scattering from LDPE crystalline structures and the scattering from TiO2 nanoparticles can be resolved and separated. It is shown that the independent effects of crystallization conditions and the presence of nanoparticle aggregates on the spherulitic structure of the LDPE matrix can be determined by analyzing the scattering patterns using the methods proposed. From the SALS results, we conclude that the nanoparticle surface chemistry affects both nucleation of spherulites and their structure particularly under rapid cooling conditions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1084–1095, 2006
Membrane permeability and receptor function

Abstract This paper presents a model of receptor function for receptors that mediate selective increases in ionic permeabilities (e.g. receptors that are sensitive to acetylcholine and gamma-aminobutyric acid). The model distinguishes itself from previous models by the qualitative and quantitative application of current biophysical approaches to ion permeation. Explicit consideration of receptor-controlled permeation sites and membrane permeability results in a specific and testable theory into which complex receptor phenomena can easily be incorporated. Examination of agonist concentration-conductance data from a well-studied GABAnergic receptor allows invalidation of a standard assumption for determining kinetic constants of agonist-receptor interactions. Specifically, calculations are presented which indicate that the size of an individual receptor (elementary) conductance event can vary with agonist concentration. The following section develops the expressions relating agonist concentration to total membrane conductance for possible receptor models which incorporate variations in the amplitude of elementary conductance events. In the case of desensitization, the “inactivated” receptor is suggested to result from occupation and inactivation, not at the agonist-binding (activation) site of the receptor, but at the ionophore. The ionophore occupation model provides a parsimonious explanation of different types of desensitization. In addition, incorporation of this model into the cyclic reaction model of Katz & Thesleff (1957) provides increased specification for the cyclic model and results in new experimental predictions.
Propagation of CaMKII translocation waves in heterogeneous spiny dendrites

CaMKII (Ca2+-calmodulin-dependent protein kinase II) is a key regulator of glutamatergic synapses and plays an essential role in many forms of synaptic plasticity. It has recently been observed experimentally that stimulating a local region of dendrite not only induces the local translocation of CaMKII from the dendritic shaft to synaptic targets within spines, but also initiates a wave of CaMKII translocation that spreads distally through the dendrite with an average speed of order 1μm/s. We have previously developed a simple reaction–diffusion model of CaMKII translocation waves that can account for the observed wavespeed and predicts wave propagation failure if the density of spines is too high. A major simplification of our previous model was to treat the distribution of spines as spatially uniform. However, there are at least two sources of heterogeneity in the spine distribution that occur on two different spatial scales. First, spines are discrete entities that are joined to a dendritic branch via a thin spine neck of submicron radius, resulting in spatial variations in spine density at the micron level. The second source of heterogeneity occurs on a much longer length scale and reflects the experimental observation that there is a slow proximal to distal variation in the density of spines. In this paper, we analyze how both sources of heterogeneity modulate the speed of CaMKII translocation waves along a spiny dendrite. We adapt methods from the study of the spread of biological invasions in heterogeneous environments, including homogenization theory of pulsating fronts and Hamilton–Jacobi dynamics of sharp interfaces.
Lack of spontaneous ocular neovascularization and attenuated laser-induced choroidal neovascularization in IGF-I overexpression transgenic mice

Robust IGF-I overexpression induces ocular angiogenesis in mice. To investigate the effect of subtle IGF-I overexpression, we examined the ocular phenotype of IGF-II promoter-driven IGF-I transgenic mice. Despite 2.5-fold elevation of IGF-I mRNA in the retina and 29 and 52% increase of IGF-I protein in the retina and aqueous humor, respectively, no ocular abnormality was observed in these transgenics. This was correlated with unaltered VEGF mRNA levels in the transgenic retina. The transgene was also associated with an attenuated laser-induced choroidal neovascularization. Differential expression levels and pattern of IGF-I gene may underlie the different retinal phenotypes in different transgenic lines.
An ungrounded tactile feedback device to portray force and torque-like interactions in virtual environments

Our lab has developed a haptic feedback device to provide ungrounded tactile feedback through the motion of actuated sliding plate contactors. Interaction with a virtual environment is provided to a user through a device equipped with tactile feedback and six degree-of-freedom spatial position sensing. Our tactile feedback device is composed of three sliding plate skin stretch displays positioned around the handle, providing feedback to a user's palm. Our dual-handed tactile feedback system allows independent motion of hands, while providing feedback that creates a kinesthetic experience. We demonstrate fundamental physical interactions such as mass, spring, and damper interactions, which are the building blocks used in every virtual model. Various virtual environments are used to demonstrate physical interactions with objects.
Youth mentoring: Investigation of relationship characteristics and perceived benefits

This research examined associations among characteristics of relationships formed in two community-based mentoring programs and their linkages with ratings of perceived benefits for youth. Volunteer mentors in a Big Brothers/Big Sisters program completed a questionnaire on a monthly basis for a period of six months, whereas undergraduate students serving as mentors through a service-learning course completed a questionnaire on one occasion only. Mentors' ratings of emotional closeness with youth were found to be associated with reports of fewer contacts with program staff and relationship obstacles in each program. Reports of more extensive amounts of mentor-youth contact and feelings of closeness were, in turn, each associated with ratings of greater benefits for youth. Findings also indicated a tendency for mentors in longer term relationships in the Big Brothers/Big Sisters program to perceive greater benefits for youth, but this was evident only after controlling for a countervailing tendency of mentors in these relationships to report spending less time with youth. Implications for the design and evaluation of youth mentoring programs are discussed. © 1997 John Wiley & Sons, Inc.
PAQO: Preference-aware query optimization for decentralized database systems

The declarative nature of SQL has traditionally been a major strength. Users simply state what information they are interested in, and the database management system determines the best plan for retrieving it. A consequence of this model is that should a user ever want to specify some aspect of how their queries are evaluated (e.g., a preference to read data from a specific replica, or a requirement for all joins to be performed by a single server), they are unable to. This can leave database administrators shoehorning evaluation preferences into database cost models. Further, for distributed database users, it can result in query evaluation plans that violate data handling best practices or the privacy of the user. To address such issues, we have developed a framework for declarative, user-specified constraints on the query optimization process and implemented it within PosgreSQL. Our Preference-Aware Query Optimizer (PAQO) upholds both strict requirements and partially ordered preferences that are issued alongside of the queries that it processes. In this paper, we present the design of PAQO and thoroughly evaluate its performance.
Protective Mechanism Against Acoustic Insult in the Mouse.

Practically all experimental animals except the small rodents show evidence of cochlear degeneration when exposed to prolonged acoustic insult. Experimental degenerations of the cochlea have been employed as a method of determining specific pitch areas in the organ of Corti. There is, however, a difference in opinion on the causal factor of the lesion. The majority hold it is due to an excessive stimulation dependent on the pitch and intensity and is, therefore, a criterion of a specific area of reception. The minority holds the degeneration does not appear until the intrinsic muscles have been fatigued and that it may represent a result of clatter in the ossicular apparatus. This would mean the lesion is not dependent on the pitch. If the mouse really escapes intact under conditions which cause lesions in other experimental animals, then an additional protective mechanism in the middle ear must be sought. Small rodents show a rather remarkable departure from the usual middle ear picture. The stapes is tr...
Development of highly dense four-stage flat-gain 1-W 6-18-GHz MMIC power amplifier chip

A state-of-the-art dual-channel four-stage MMIC power chip operating over C-X-Ku bands has been produced. The chip, which is only 4.35 mm*5.1 mm, operates over 6-17 GHz with very small gain ripple. At 25 degrees C each one of its channels provides 29.5+or-0.5 dBm at 2-dB compression (2 dBc) from a small-signal gain of 19.5+or-1.5 dB. The drain bias is 7 V. and the power added efficiency is 11-14%. At 85 degrees C, power and gain decrease by 0.5-1 and 3.5-4 dB, respectively. The design was iterated once to produce an all-monolithic amplifier chip that operates over the full 6-18-GHz frequency band and provides more than 1 W at 18 GHz. The architecture and size were maintained in the iterated design. The excellent power and gain ripple performances of the C-X-Ku chip extended to 18 GHz with a small-signal gain reduction of 0.5-1 dB. The chip is designed for use with inputs and outputs coupled externally for additional 2-2.5 dB of power. Excellent performance over 6-18 GHz was achieved using Lange couplers on 10-mil alumina. >
Classical Sociological Theory and Modern Social Problems: Marx's cOncept of the Camera Obscura and the Fallacy of Individualistic Reductionism

Marx viewed ideological and classed based understandings of the social world as analogous to images in a “camera obscura”, where the outcome is backwards or distorted. Commonplace discourse “gets i...
The rise of Web-based simulation: implications for the high level architecture

The relationship between the High Level Architecture and Web-based simulation is discussed. The notion of interoperability is suggested as a binding force between these initiatives. The question is posed whether the HLA could serve as an interoperability technology for the commercial and academic sectors in the age of Web-based simulation. Using the development and adoption of parallel discrete event simulation technologies as a case study, some of the potential barriers to DoD technology transfer are illustrated, and mechanisms through which these barriers may be overcome are suggested.
Mechanism of action of clentiazem on human coronary artery and myocardium.

We evaluated the pharmacologic action of clentiazem, a new diltiazem derivative, on isolated human coronary artery and right ventricular trabeculae. In addition to its Ca2+ blocking action, clentiazem demonstrated both vasorelaxing and negative inotropic actions, similar to our reference Ca2+ antagonists. The coronary vasorelaxing action of clentiazem on the tonic KCl contraction (EC50=2.21×10−7M) was 3.1 times more potent than diltiazem (EC50=6.94×10−7M) and 28.8 times less potent than nifedipine (EC50=7.67×10−9 M). The negative inotropic action of clentiazem (IC50=8.78×10−6 M) was similar to diltiazem (IC50=7.18×10−6M) and was 21.1 times less potent than nifedipine (IC50=3.98×10−7 M). Selectivity ratios, comparing the effectiveness in cardiac muscle to coronary artery, were nifedipine (51.9)>clentiazem (39.7)>diltiazem (10.3), when calculated from the EC50 and the IC50, and clentiazem (24.2)>nifedipine (15.9)>diltiazem (9.3), when calculated from the EC20 and the IC20. In conclusion, clentiazem is a Ca2+ antagonist and demonstrates comparable vasoselectivity to the 1,4-dihydropyridine derivative, nifedipine. Moreover, it has longer lasting action than diltiazem.
Paleocurrent directions from paleomagnetic reorientation of magnetic fabrics in deep-sea sediments at the Antarctic Peninsula Pacific margin (ODP Sites 1095, 1101)

We have determined the azimuth of bottom-current flow in drift deposit sediments recovered at ODP Sites 1095 and 1101, Antarctic Peninsula, using paleomagnetic reorientation of anisotropy of magnetic susceptibility (AMS) ellipsoids. A total of 38 cores from the two ODP sites have been measured, providing spatial and directional information on the physical record of the ACC (Antarctic Circumpolar Current) in the Plio-Pleistocene. Declination and inclination of the paleomagnetic vector of each core segment were used to reorient the AMS principal axes to the geographic coordinates. The cores were reoriented using the measured direction of the characteristic remanent magnetization (ChRM) with respect to a common reference line for the core, from which we are able to determine the orientation of the paleocurrent flow for Sites 1095 (Drift 7) and 1101 (Drift 4) relative to the geographic coordinates. Both sites have paleocurrent directions trending ~NW–SE, which in the former locality are parallel to a sediment wave field. Our study shows that a combination of magnetic fabric analysis and paleomagnetism allows deep-sea sedimentary fabric to be used as a long-term proxy of bottom-current flow history. © 2007 Elsevier B.V. All rights reserved.
Stability and Convergence Analysis of Fully Discrete Fourier Collocation Spectral Method for 3-D Viscous Burgers' Equation

This paper analyzes the stability and convergence of the Fourier pseudospectral method coupled with a variety of specially designed time-stepping methods of up to fourth order, for the numerical solution of a three dimensional viscous Burgers' equation. There are three main features to this work. The first is a lemma which provides for an L 2 and H 1 bound on a nonlinear term of polynomial type, despite the presence of aliasing error. The second feature of this work is the development of stable time-stepping methods of up to fourth order for use with pseudospectral approximations of the three dimensional viscous Burgers' equation. Finally, the main result in this work is that the pseudospectral method coupled with the carefully designed time-discretizations is stable provided only that the time-step and spatial grid-size are bounded by two constants over a finite time. It is notable that this stability condition does not impose a restriction on the time-step that is dependent on the spatial grid size, a fact that is especially useful for three dimensional simulations.
Defocus as an ineffective means of changing spot size for fluctuation microscopy

We examine the use of defocus for changing the effective spot size in fluctuation microscopy. Our conclusions relate to other coherent techniques. While it is possible to increase the illuminated spot size by defocusing, the number of phase oscillations inside the illuminated spot increases. As a result the stationary phase region increases with defocus at a slower rate than the spot size. Therefore, the effective spot size for fluctuation microscopy is not the beam size, and the phase interference is increasingly diluted by incoherent contributions, rendering defocus an ineffective means of changing the spot size for fluctuation microscopy.
Distribution fault diagnosis using a hybrid algorithm of fuzzy classification and artificial immune systems

Effective distribution outage cause identification can help expedite the restoration procedure and improve the system availability. The fuzzy classification E-algorithm and the immune system inspired classification algorithm, artificial immune recognition system (AIRS), have demonstrated good capabilities in outage cause identification, especially with the existence of imbalanced data. E-algorithm extracts inference rules but is computational demanding; AIRS has the quick searching capability but is lack of rule extraction capability. In this paper, fuzzy artificial immune recognition system (FAIRS) has been proposed to take advantage of the strengths of E-algorithm and AIRS. FAIRS is applied to Duke Energy outage data for cause identification using three major customer interruption causes (tree, animal, and lightning) as prototypes; and FAIRS achieves comparable fault diagnosis performance with two base algorithms while being able to extract linguistic rules to explain the inference within significantly reduced computing time than E-algorithm.
A Noncanonical Function of Sortase Enables Site-Specific Conjugation of Small Molecules to Lysine Residues in Proteins†

We provide the first demonstration that isopeptide ligation, a noncanonical activity of the enzyme sortase A, can be used to modify recombinant proteins. This reaction was used in vitro to conjugate small molecules to a peptide, an engineered targeting protein, and a full-length monoclonal antibody with an exquisite level of control over the site of conjugation. Attachment to the protein substrate occurred exclusively through isopeptide bonds at a lysine e-amino group within a specific amino acid sequence. This reaction allows more than one molecule to be site-specifically conjugated to a protein at internal sites, thereby overcoming significant limitations of the canonical native peptide ligation reaction catalyzed by sortase A. Our method provides a unique chemical ligation procedure that is orthogonal to existing methods, supplying a new method to site-specifically modify lysine residues that will be a valuable addition to the protein conjugation toolbox.
Design and Fabrication of an Injection Tool for Neuromuscular Microstimulators

The injection of small implants into precisely localized sites within the body is a difficult task usually undertaken by surgeons or interventive radiologists. We have designed, produced and tested a simple tool for implanting BION™ wireless microstimulators as an outpatient office procedure. The ability of BIONs to elicit a desired muscle contraction depends on their placement near the motor fibers that innervate the muscle fibers, providing both the requirement and a means for achieving accurate placement. The implant is preloaded into the tip of the cannula of a two-piece insertion tool made from non-conductive polymers. Trial stimulation pulses are generated by the implant as the tool is manipulated into the desired position. The implant is released by withdrawing the cannula over the implant, preserving both the relative location of the implant’s electrodes with respect to the target and determining its desired axial orientation, which is important for implants containing motion sensors. The BION Insertion Tool has been used for over 30 BION implants in human subjects to date.
Paradoxical Effect of Dopamine Medication on Cognition in Parkinson's Disease: Relationship to Side of Motor Onset

Parkinson's disease (PD) is characterized by asymmetric motor symptom onset attributed to greater degeneration of dopamine neurons contralateral to the affected side. However, whether motor asymmetries predict cognitive profiles in PD, and to what extent dopamine influences cognition remains controversial. This study evaluated cognitive variability in PD by measuring differential response to dopamine replacement therapy (DRT) based on hemispheric asymmetries. The influence of DRT on cognition was evaluated in mild PD patients (n = 36) with left or right motor onset symptoms. All subjects were evaluated on neuropsychological measures on and off DRT and compared to controls (n = 42). PD patients were impaired in executive, memory and motor domains irrespective of side of motor onset, although patients with left hemisphere deficit displayed greater cognitive impairment. Patients with right hemisphere deficit responded to DRT with significant improvement in sensorimotor deficits, and with corresponding improvement in attention and verbal memory functions. Conversely, patients with greater left hemisphere dopamine deficiency did not improve in attentional functions and declined in verbal memory recall following DRT. These findings support the presence of extensive mild cognitive deficits in early PD not fully explained by dopamine depletion alone. The paradoxical effects of levodopa on verbal memory were predicted by extent of fine motor impairment and sensorimotor response to levodopa, which reflects extent of dopamine depletion. The findings are discussed with respect to factors influencing variable cognitive profiles in early PD, including hemispheric asymmetries and differential response to levodopa based on dopamine levels predicting amelioration or overdosing.
A method to estimate the additional uncertainty in gap-filled NEE resulting from long gaps in the CO2 flux record

Missing values in any data set create problems for researchers. The process by which missing values are replaced, and the data set is made complete, is generally referred to as imputation. Within the eddy flux community, the term ‘‘gap filling’’ is more commonly applied. A major challenge is that random errors in measured data result in uncertainty in the gap-filled values. In the context of eddy covariance flux records, filling long gaps (days to weeks), which are usually the result of instrument malfunction or system failure, is especially difficult because underlying properties of the ecosystem may change over time, resulting in additional uncertainties. We used synthetic data sets, derived by assimilating data from a range of FLUXNET sites into a simple ecosystem model, to evaluate the relationship between gap length and uncertainty in net ecosystem exchange (NEE) of CO2. Uncertainty always increased with gap length and there were seasonal patterns in this relationship. These patterns varied among ecosystem types, but were similar within the same ecosystem type (e.g., deciduous forests). In general, gaps of � 3 weeks during the winter dormant season resulted in little additional uncertainty at any of the sites studied. At worst (i.e., during spring green-up in a deciduous forest) a week-long gap could result in an additional uncertainty of roughly � 30 g C m � 2 year � 1 (at 95% confidence). This uncertainty adds to the roughly � 30 g C m � 2 year � 1 (at 95% confidence) uncertainty that arises from random measurement error. Unlike uncertainties due to random error, long gap uncertainties can be minimized through vigilance and a rapid response to system failure. Some strategies for reducing the occurrence of long gaps are discussed. # 2007 Elsevier B.V. All rights reserved.
Two Experimental Devices to Study the 1D and 3D Seepage Process of Water Inside Natural Soils: A Lisimeter and a Physical Model of Slope

This technical report describes two experimental devices: a lisimeter and a physical model of slope, developed at Department of Geotechnical Engineering of University of Naples Federico II, to study the effects of the rainfall on the natural slope stability. It is well know as different types of slope instability are strictly related to significant rain events due to the interaction between the fluid phase and the soil structure. In facts change of the water quantity stored inside the soil can affect the mechanic behaviour of the soil. In particular the lisimeter has developed to investigate the relationship between the variation of water content and the related change of the idro-mechanical behaviour of the soil. The slope the pysical model can be used to study those factors affecting rain induced flowslide in pyroclastic soils. The physical model of slope and the lisimeter are presented along with experimental procedures.
Siomycin A targets brain tumor stem cells partially through a MELK-mediated pathway

Glioblastoma multiforme (GBM) is a devastating disease, and the current therapies have only palliative effect. Evidence is mounting to indicate that brain tumor stem cells (BTSCs) are a minority of tumor cells that are responsible for cancer initiation, propagation, and maintenance. Therapies that fail to eradicate BTSCs may ultimately lead to regrowth of residual BTSCs. However, BTSCs are relatively resistant to the current treatments. Development of novel therapeutic strategies that effectively eradicate BTSC are, therefore, essential. In a previous study, we used patient-derived GBM sphere cells (stemlike GBM cells) to enrich for BTSC and identified maternal embryonic leucinezipper kinase (MELK) as a key regulator of survival of stemlike GBM cells in vitro. Here, we demonstrate that a thiazole antibiotic, siomycin A, potently reduced MELK expression and inhibited tumor growth in vivo. Treatment of stemlike GBM cells with siomycin A resulted in arrested self-renewal, decreased invasion, and induced apoptosis but had little effect on growth of the nonstem cells of matched tumors or normal neural stem/progenitor cells. MELK overexpression partially rescued the phenotype of siomycin A‐treated stemlike GBM cells. In vivo, siomycin A pretreatment abraded the sizes of stemlike GBM cell‐derived tumors in immunodeficient mice. Treatment with siomycin A of mice harboring intracranial tumors significantly prolonged their survival period compared with the control mice. Together, this study may be the first
Long-distance propagation of forces in a cell.

A fundamental question in the field of mechanotransduction is how forces propagate inside a cell. Recent experiments have shown that a force of a physiological magnitude, applied via a focal adhesion, can propagate a long distance into the cell. This observation disagrees with existing models that regard the cell as a homogeneous body. We show that this ‘‘action at a distance’’ results from the inhomogeneity in the cell: a prestressed and stiff actin bundle guides the propagation of forces over long distances. Our models highlight the enormous ratios of the prestress and the modulus of the actin bundle to the modulus of the cytoskeleton network. For a normal cell, the models predict that forces propagate over characteristic lengths comparable to the size of the cell. The characteristic lengths can be altered, however, by treatments of the cell. We provide experimental evidence and discuss biological implications. � 2005 Elsevier Inc. All rights reserved.
β-Glucuronidase activity following complex coacervation and spray drying microencapsulation

The objective was to develop a microencapsulation process suitable for the controlled release of an active protein drug. beta-glucuronidase was selected as a model protein and a combination of complex coacervation (gelatin/sodium alginate, gelatin/acacia and albumin/acacia) and spray drying was investigated. Coacervates were either spray dried or glutaraldehyde crosslinked to form microcapsules. Polyvinylpyrrolidone (PVP) and polyethylene glycol were investigated as potential coacervate enhancers and stabilizers. beta-glucuronidase/polymer mixtures were spray dried to determine any polymer protective effects on protein activity. A BUCHI 190 Spray Drier was used, beta-glucuronidase activity was determined using a Sigma Kit and microcapsule particle size was measured by Accusizer analysis (light blockage). All non-crosslinked coacervates investigated, with the exceptions of albumin/acacia and albumin/acacia/beta-glucuronidase/PVP, were unsuitable for spray drying as they rapidly phase separated and blocked the spray drier nozzle. beta-glucuronidase activity in the albumin/acacia coacervates approximated to 99% prior to and 80% following spray drying. This can be compared to activities of approximately 30% and 68% when spray dried alone and with albumin, respectively, and of 18% in albumin/acacia microcapsules crosslinked with glutaraldehyde. Microcapsule particle size was affected by coacervation pH, additives and spray drying. In vitro beta-glucuronidase release was biphasic, with an initial burst release followed by a zero order release phase and continued over the 12 day study period. In conclusion, the spray drying albumin/acacia/PVP method described is useful for the preparation and collection of controlled release microcapsules with minimal loss of beta-glucuronidase activity.
A first step in form‐based category abstraction by 12‐month‐old infants

The present experiments investigate how young language learners begin to acquire form-based categories and the relationships between them. We investigated this question by exposing 12-month-olds to auditory structure of the form aX and bY (infants had to learn that a-elements grouped with Xs and not Ys). Infants were then tested on strings from their training language versus strings from the other language using a preferential-listening procedure. Importantly, the X and Y elements were new at test, requiring infants to generalize to novel pairings. We also manipulated the probability of encountering grammatical structures of the training language by mixing strings from two artificial languages according to 83/17 and 67/33 percentage ratios in Experiment 2. Experiment 1 shows that 12-month-olds are capable of forming categories of X- and Y-elements based on a shared feature and, furthermore, form associations between particular a- and b-elements and these categories. Experiment 2 shows that learning was sustained even when 17% of instances from another language were present during training. However, infants failed to generalize when exposed to a larger percentage of strings from another language. The findings demonstrate that the first step of form-based category abstraction (the ability to generalize based on marker-feature pairings) is in place by 12 months of age.
An unbiased approach to identify genes involved in development in a turtle with temperature-dependent sex determination

Many reptiles exhibit temperature-dependent sex determination (TSD). The initial cue in TSD is incubation temperature, unlike genotypic sex determination (GSD) where it is determined by the presence of specific alleles (or genetic loci). We used patterns of gene expression to identify candidates for genes with a role in TSD and other developmental processes without making a priori assumptions about the identity of these genes (ortholog-based approach). We identified genes with sexually dimorphic mRNA accumulation during the temperature sensitive period of development in the Red-eared slider turtle (Trachemys scripta), a turtle with TSD. Genes with differential mRNA accumulation in response to estrogen (estradiol-17β; E2) exposure and developmental stages were also identified. Sequencing 767 clones from three suppression-subtractive hybridization libraries yielded a total of 581 unique sequences. Screening a macroarray with a subset of those sequences revealed a total of 26 genes that exhibited differential mRNA accumulation: 16 female biased and 10 male biased. Additional analyses revealed that C16ORF62 (an unknown gene) and MALAT1 (a long noncoding RNA) exhibited increased mRNA accumulation at the male producing temperature relative to the female producing temperature during embryonic sexual development. Finally, we identified four genes (C16ORF62, CCT3, MMP2, and NFIB) that exhibited a stage effect and five genes (C16ORF62, CCT3, MMP2, NFIB and NOTCH2) showed a response to E2 exposure. Here we report a survey of genes identified using patterns of mRNA accumulation during embryonic development in a turtle with TSD. Many previous studies have focused on examining the turtle orthologs of genes involved in mammalian development. Although valuable, the limitations of this approach are exemplified by our identification of two genes (MALAT1 and C16ORF62) that are sexually dimorphic during embryonic development. MALAT1 is a noncoding RNA that has not been implicated in sexual differentiation in other vertebrates and C16ORF62 has an unknown function. Our results revealed genes that are candidates for having roles in turtle embryonic development, including TSD, and highlight the need to expand our search parameters beyond protein-coding genes.
Reducing Food Insecurity and Improving Fruit and Vegetable Intake Among Farmers' Market Incentive Program Participants.

Abstract Objective To determine whether participation in a farmers' market incentive pilot program had an impact on food security and fruit and vegetable (F&V) intake of participants. Methods Participants in the Supplemental Nutrition Assistance Program were eligible to receive a dollar-per-dollar match up to $10/wk in farmers' market incentives. The researchers used a pretest-posttest design to measure F&V intake and food security status of 54 adult participants before and after receiving farmers' market incentives. The 6-item Behavior Risk Factor Surveillance System questionnaire and US Household Food Security Survey Module were used to measure F&V intake and food security, respectively. Wilcoxon signed-rank test was used to compare scores of F&V intake. Results After receiving incentives, fewer individuals reported experiencing food insecurity–related behaviors. A significantly increased intake (P Conclusion and Implications Participation in a farmers' market incentive program was positively related to greater food security and intake of select vegetables among participants in the Supplemental Nutrition Assistance Program.
Tumors of the Heart

Tumors of the heart, particularly primary cardiac tumors, are one of the least investigated subjects in oncology. As such cardiac tumors and their associated complications rarely gain clinical attention despite their potentially serious sequela. Early recognition and diagnosis of a cardiac tumor by a combination of clinical symptoms and the use of modern imaging tools, could lead to the institution of appropriate management in a timely manner. This in turn may lead to better morbidity and mortality outcomes for these patients.
Learning invariants using decision trees and implication counterexamples

Inductive invariants can be robustly synthesized using a learning model where the teacher is a program verifier who instructs the learner through concrete program configurations, classified as positive, negative, and implications. We propose the first learning algorithms in this model with implication counter-examples that are based on machine learning techniques. In particular, we extend classical decision-tree learning algorithms in machine learning to handle implication samples, building new scalable ways to construct small decision trees using statistical measures. We also develop a decision-tree learning algorithm in this model that is guaranteed to converge to the right concept (invariant) if one exists. We implement the learners and an appropriate teacher, and show that the resulting invariant synthesis is efficient and convergent for a large suite of programs.
High-scale axions without isocurvature from inflationary dynamics

Observable primordial tensor modes in the cosmic microwave background (CMB) would point to a high scale of inflation ${H}_{I}$. If the scale of Peccei-Quinn (PQ) breaking ${f}_{a}$ is greater than $\frac{{H}_{I}}{2\ensuremath{\pi}}$, CMB constraints on isocurvature naively rule out QCD axion dark matter. This assumes the potential of the axion is unmodified during inflation. We revisit models where inflationary dynamics modify the axion potential and discuss how isocurvature bounds can be relaxed. We find that models that rely solely on a larger PQ-breaking scale during inflation ${f}_{I}$ require either late-time dilution of the axion abundance or highly super-Planckian ${f}_{I}$ that somehow does not dominate the inflationary energy density. Models that have enhanced explicit breaking of the PQ symmetry during inflation may allow ${f}_{a}$ close to the Planck scale. Avoiding disruption of inflationary dynamics provides important limits on the parameter space.
Whole-genome sequencing of a malignant granular cell tumor with metabolic response to pazopanib.

Granular cell tumors are an uncommon soft tissue neoplasm. Malignant granular cell tumors comprise T transitions, particularly when immediately preceded by a 5' G. A loss-of-function mutation was detected in a newly recognized tumor suppressor candidate, BRD7. No mutations were found in known targets of pazopanib. However, we identified a receptor tyrosine kinase pathway mutation in GFRA2 that warrants further evaluation. To the best of our knowledge, this is only the second reported case of a malignant granular cell tumor exhibiting a response to pazopanib, and the first whole-genome sequencing of this uncommon tumor type. The findings provide insight into the genetic basis of malignant granular cell tumors and identify potential targets for further investigation.