cssi/SciSciGPT-SciSciNet huggingface dataset:
Three-dimensional image-guided placement of percutaneous pedicle screws without the use of biplanar fluoroscopy or Kirschner wires: technical note.

Background Percutaneous pedicle screws are commonly used in minimally invasive spinal procedures. Traditional techniques of percutaneous pedicle screw placement have employed the use of multiplanar fluoroscopy and Kirschner wires (K-wires). The use of multiplanar fluoroscopy for the placement of percutaneous pedicle screws likely increases radiation exposure to the surgeon when compared to open techniques. K-wires can break or become bent during the procedure, making it difficult to insert and remove instrumentation over them. Additionally, there is also a risk of visceral or vascular injury with the use of K-wires. The authors present a novel method of percutaneous pedicle screw placement utilizing three-dimensional (3D) fluoroscopy-based image guidance in which K-wires are not used and there is minimal to no radiation exposure to the surgeon and operating room staff. Methods Thirty-six screws were placed in 15 patients using this technique. An independent radiologist graded screw placement using computed tomographic (CT) scans and the breach rate of the percutaneous pedicle screws was compared to the breach rate of 33 pedicle screws placed contralaterally using the mini-open technique. Results No bony breach was noted by any screw in either group and no complications occurred in this study as a result of screw placement. Conclusions Percutaneous pedicle screws can be placed accurately and safely using 3D image guidance without the use of K-wires. Little to no radiation exposure to the surgeon or OR staff occurs with this technique. No complications occurred in this study as a result of screw placement or image guidance. Copyright © 2010 John Wiley & Sons, Ltd.
A prospective assessment of auditory startle alterations in rape and physical assault survivors

This study used a prospective design to investigate startle reactivity following trauma exposure. Startle response was evaluated using loud tones during which measures of eyeblink electromyogram (EMG) and heart rate (HR) were collected. Participants were 40 female sexual or physical assault survivors assessed at 1 month and 6 months postassault. There were no significant differences in startle reactivity between posttraumatic stress disorder (PTSD) and non-PTSD groups at the initial assessment. However, at 6 months postassault there was a significantly greater EMG and HR response in the PTSD group as well as a significant increase in startle reactivity from 1 month to 6 months postassault. The findings lend support to a sensitization model of trauma reactivity in which startle response develops over time along with PTSD symptoms.
Pulsed saturation recovery 250 MHz electron paramagnetic resonance spectrometer

Pulsed saturation recovery capability has been added to the pulsed 250 MHz EPR spectrometer previously described. The design of the spectrometer is sufficiently flexible so that the only change needed was an interchangeable plug-in card that directed the VHF pulses and the low-power CW VHF to monitor the spin recovery following saturation. The plug-in module converts the ESE spectrometer to a SR spectrometer. The switch in the plug-in module for pulsed ESE or FID operation with the crossed-loop resonator (CLR) is replaced by a directional coupler. The effect of the directional coupler is to cause the low-level CW observe power to always be incident on the CLR and to direct the high-power RF pulses to the excitation side of the CLR. The pump and observe RF paths do not need to be coherent. The phase differences between the pump and observe RF paths do not have a detectable effect on the observed recovery signal because, unlike an FID or echo measurement, the SR measurement is not sensitive to phase coherence other than in the double-balanced mixer signal detector. The circuit on the plug-in card also provides signal paths for tuning both resonators of the CLR. The SR experiments are described and examples are presented of T1 measurements made possible by this new 250 MHz saturation recovery capability. © 2005 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 26B: 23–27, 2005.
The chemistry of fractionally charged atoms

An effective search for free quarks in matter requires understanding the chemistry of atoms with fractionally charged nuclei. Their chemistry is determined by interpolation in terms of the known chemistry of neutral atoms and ions. Electronegativities and ionic crystal radii of quark atoms are computed.
Reported Outcomes After the Endovascular Treatment of Chronic Cerebrospinal Venous Insufficiency

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been implicated as a potential causal factor in the development of multiple sclerosis (MS). The treatment of jugular and azygous vein stenoses, characteristic of CCSVI, has been proposed as a potential component of therapy for MS. In the few short years since Dr. Paulo Zamboni published "A Prospective Open label Study of Endovascular Treatment of Chronic Cerebrospinal Venous Insufficiency", 1 there has been tremendous patient-driven demand for treatment. Concurrently, there have been numerous publications since 2009 addressing CCSVI and its association with MS. The purpose of this article is to present a brief review of CCSVI and its association with MS and to review the available literature to date with a focus on outcomes data.
Cost-Benefit Analysis of Irrigation Projects in Northeastern Brazil

Cost-benefit analysis using empirical estimation of labor's shadow price and linear programming for crop selection is applied to major proposed irrigation projects for Brazil's Northeast. Over half the project area is approved. However, these capital intensive projects should rank below investments with similar rates of return but larger employment effects.
Dynamic reactive power and energy storage for integrating intermittent renewable energy

The role and application of energy storage and dynamic reactive power support is discussed in this paper. A well-engineered energy storage plant can help alleviate some of the problems encountered with the integration of intermittent renewable resources and at the same time make renewable power plants more cost effective in existing traditional power system. The intent of this paper is to demonstrate these features by means of a planned application of a STATCOM and Battery Energy Storage System (BESS) in a region with high penetration levels of wind and solar integration. Firstly, the paper describes the integration challenges of integrating intermittent renewable energy, followed by possible mitigation measures. Thirdly, a specific application of a STATCOM with a BESS is included and the different possible revenue streams are calculated.
The cause of blindness in dogs given hydroxypyridinethione

Abstract A brief account of the ocular pathogenesis of retinal detachment due to hydroxy-pyridinethione has been made. The mode of action of the retinal damage was postulated by analogy.
Parasitic Power Losses in Turbine Bearings

Test results indicate that 25–50 percent of total fluid film bearing losses in turbomachinery are consumed in simply feeding oil to the bearings. The two major components of these losses are evaluated in this paper: 1) through-flow losses absorbed by the oil in its passage to and from the actual load-carrying bearing elements, and 2) surface frictional drag by the oil as it contacts rotating surfaces at bearing oil feed grooves and other exposed zones. Relations are developed for estimating these parasitic losses for both fixed-element and tilting-pad journal and thrust bearings. Presented at the 44th Annual Meeting in Atlanta, Georgia May 1–4, 1989
The Storied Nature of Health Legacies in the Familial Experience of Type 2 Diabetes

In this study, we position families as pivotal anchors for coping with biophysical and psychosocial needs of members with Type 2 diabetes in two vital ways. First, we present narrative theory as a conceptual framework for moving beyond an individualistic understanding of health and healing. Second, we illustrate the efficacy of this position through an interpretive study of meaning-making about intergenerational diabetes among families living in rural Appalachian areas—contexts historically characterized by disproportionately high rates for numerous diseases including diabetes. Stories elicited from participants during interviews characterized their diabetes health legacies as dense and devastating. Our analysis illustrates how legacies evolve and shift across generations and shape how family members understand and manage diabetes, including the role of family members as intergenerational lynchpins and intergenerational buffers.
A systematic review of peer review for scientific manuscripts

Background The usefulness of peer review has been expressed as a method to improve the quality of published work. However, there has been a lack of systematic reviews to date to highlight the essential themes of the peer-review process.
Biscatecholate-monohydroxamate mixed ligand siderophore-carbacephalosporin conjugates are selective sideromycin antibiotics that target Acinetobacter baumannii.

Chemical syntheses and biological evaluation of biscatecholate–monohydroxamate mixed ligand sideromycins utilizing the carbacephalosporin β-lactam antibiotic loracarbef and the fluoroquinolone antibiotic ciprofloxacin are described. The mixed ligand β-lactam sideromycin (1b) had remarkably selective and extremely potent antibacterial activity against the Gram-negative pathogen Acinetobacter baumannii ATCC 17961 (MIC = 0.0078 μM). The antibacterial activity of the β-lactam sideromycin was inversely related to the iron(III) concentration in the testing media and was antagonized by the presence of the competing parent siderophore. These data suggested that active transport of the mixed ligand β-lactam sideromycin across the outer cell membrane of A. baumannii via siderophore-uptake pathways was responsible for the selective and potent antibacterial activity.
Chapter 1.5 Control of two-phase evaporating flows☆

Abstract This chapter discusses some of the fundamental characteristics of those flow phenomena that are encountered in multistage flash (MSF) and vertical-tube evaporator (VTE) desalination plants, and how they affect plant control and stability. Many of the factors affecting economic plant operation, such as stability, controllability, efficiency at reduced-load conditions, and nonequilibrium losses, are often not directly or easily observable, but should nonetheless be understood by the plant designer and operator. From both the modeling and the control standpoints, MSF processes are the more challenging. Descriptions of both single-phase and two-phase open-channel flow MSF models are presented, as are confirmatory data derived from a variety of experimental studies. Some of the problems to be encountered on the receiving end of the MSF process, i.e. in the control of condensation in horizontal tube bundles, especially during part-load and transient operation, are also noted briefly. VTE processes and their control characteristics and problems (or lack of problems) are outlined, along with results of some dynamics tests on VTE test beds. Finally, some research done on desalination plant process dynamics is described, including studies of various plants tied to different types of heat sources. Some control problems peculiar to MSF dual-purpose (electrical plus water) plants are also noted.
ADENOVIRUS RESPIRATORY INFECTIONS AMONG CHILDREN IN DAY CARE

Adenoviruses (AV) produce 5 to 10 percent of respiratory diseases in young children, but little information is available regarding their role in day care centers. AV infections among 123 children attending a research day care center were analyzed from data collected prospectively from 1967 through 1981. Earliest isolation of a serotype was designated as a "first" isolate, and later homotypic isolates were termed "subsequent". Day care center AV exposure correlated with acquisition of infection. Types 1, 2, and 5 were recovered during 76, 56, and 36 of the 180 study months, respectively, and by age 5 years, seroconversion to types 1, 2, and 5 occurred in 89, 78, and 59 percent of children. Through age 2 years, children were exposed to 3.4± 0.9 (mean±S.D.) different serotypes and became infected with 2.1± 0.8 types. First isolate attack rates were highest in 6 to 12 month-olds (1.4 serotypes/child-year) and lowest among children over 2 years of age (0.06 serotypes/ch-yr). Illness was associated with 83 percent of first isolates and was usually febrile and mild. Acute otitis media occurred in 37 percent of illnesses over all ages and in 49 percent of infants. Subsequent isolates were recovered less frequently than first isolates, were less often associated with illness (55%, p<0.005), and illnesses were accompanied by reduced rates of fever (19%, p=0.0197) and acute otitis media (10%, p=0.0055). This study showed infants and toddlers in a day care center to be common hosts for multiple AV infections, often associated with acute otitis media.
Reply to Edward's comment

Both Edwards et al. 1 and Barenghi et al. 2 use piecewise polynomials and a least squares criterion to obtain a representation of T58 data. The former, derived from 3601 points, is appropriate to the range of 1.6-5.2 K and uses no less than 17 segments with polynomials of degree up to the fifth. In all, 69 coefficients together with 18 break points for the segment boundaries are required. The maximum residual is 6.0 ~K. The Barenghi et al. approach uses a cubic spline representation valid over 1.0-4.215 K and based on 359 points. Its maximum residual is 22/~K and it requires a total of 48 parameters for its definition. Judged purely on the size of the maximum residual, the latter fit appears inferior. However, there is another important issue. At the break points the Edwards fit is not strictly defined (it has two values) and the important property of continuity has been abandoned. Most of the time the jump is not large, but unfortunately it is largest (4.8 ttK) at the lambda point itself. Of course, there can be no question of derivatives being given in the Edwards break points. This is a serious defect; for example, the fit is rendered useless for any critical region work near the lambda transition. The cubic spline technique is fortunately free from this drawback. Not only is the representation continuous over the whole range, but so are the first and second derivatives. Indeed, these derivatives are automatically provided by the spline fit i tself--no extra fitting is required. Insisting (for obvious physical reasons) on this degree of smoothness meant that there was a concomitant increase in the m a x i m u m residual. The residual over the whole range is shown in Fig. 4 of Ref. 2 and it is seen that from 2.16 to 2.18 K the fit is within 1 ~K. Moreover, the d P / d T derived from the fit agrees to better than 0.19 % with the published values at all temperatures. This underlines the satisfactory nature of the Barenghi et al. spline representation. In short, we contend that the size of the residual alone must not be the sole criterion for judging the usefulness of a fit. At some point the
Representing monitored systems: A critical process in data collection

Abstract Data collection is a profound step towards effective performance analysis, and it is being challenged by the fact that computing systems become more complex so that mechanical and exhaustive data collection is nearly impractical. To cope with this situation, our recent research has been aimed to improving a critical process in data collection, namely, representing monitored targets. This paper presents a declarative approach to this process, which largely departs from conventional procedure-oriented methods.
First estimates of global free-tropospheric NO 2 abundances derived using a cloud-slicing technique applied to satellite observations from the Aura Ozone Monitoring Instrument (OMI)

Abstract. We derive free-tropospheric NO2 volume mixing ratios (VMRs) by applying a cloud-slicing technique to data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud scene pressure is proportional to the NO2 VMR. In this work, we use a sample of nearby OMI pixel data from a single orbit for the linear fit. The OMI data include cloud scene pressures from the rotational-Raman algorithm and above-cloud NO2 vertical column density (VCD) (defined as the NO2 column from the cloud scene pressure to the top of the atmosphere) from a differential optical absorption spectroscopy (DOAS) algorithm. We compare OMI-derived NO2 VMRs with in situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is generally within the estimated uncertainties when appropriate data screening is applied. We then derive a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in the free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the boundary layer and then horizontally away from the source. Signatures of lightning NO2 are also shown throughout low and middle latitude regions in summer months. A profile analysis of our cloud-slicing data indicates signatures of lightning-generated NO2 in the upper troposphere. Comparison of the climatology with simulations from the global modeling initiative (GMI) for cloudy conditions (cloud optical depth > 10) shows similarities in the spatial patterns of continental pollution outflow. However, there are also some differences in the seasonal variation of free-tropospheric NO2 VMRs near highly populated regions and in areas affected by lightning-generated NOx.
Development of synthetic nuclear melt glass for forensic analysis

A method for producing synthetic debris similar to the melt glass produced by nuclear surface testing is demonstrated. Melt glass from the first nuclear weapon test (commonly referred to as trinitite) is used as the benchmark for this study. These surrogates can be used to simulate a variety of scenarios and will serve as a tool for developing and validating forensic analysis methods.
Zur Flammenemission von Kohlenstoffverbindungen

Es werden von Wasserstoff-Sauerstoff-Flammen uber Wasserstoff-Presluft bis zu Wasserstoff-Stickstoff-Diffusionsflammen die Flammenstochiometrie unter Beibehaltung des Flammenvolumens fortlaufend variiert und die auftretenden Emissionsintensitaten von CH* und C2* bei der Verbrennung von Kohlenwasserstoffen untersucht. Fur C2* kann aus der Konzentrations-abhangigkeit der Emissionsintensitaten ein Bildungsmechanismus 2. Ordnung bewiesen werden und aus der Extrapolation homologer Reihen, das Kettenbruchstucke mit zwei Kohlenstoffatomen erforderlich sind. In brennstoffreichen Flammen last sich zeigen, das CH* uberwiegend aus C2 gebildet wird, so das folgende Reaktionskette bei der Verbrennung wahrscheinlich ist: Dagegen folgt fur sauerstoffreiche Flammen die Bildung von CH* grostenteils direkt aus dem Kohlenwasserstoff wahrscheinlich nach About the Flame Emission of Hydrocarbons The stoichiometry of hydrogen-oxygen-nitrogen flames was continuously varied maintaining the volume of flame constant, and emission intensities of CH* and C2* during the combustion of hydrocarbons were investigated. From the dependency on concentration the formation of C2* was proved to be of second order. Extrapolation of homologous series shows that chain fragments with two C-atoms are necessary. For rich flames it is shown that CH* is mainly formed from C2, so that a reaction chain according to the upper two equations is probable. In lean flames the formation of CH* is mainly probable directly from the hydrocarbon according to the third equation.
Static and Dynamic Response of Beams on Nonlinear Viscoelastic Unilateral Foundations: A Multimode Approach

Nonlinear viscoelastic behavior is a characteristic of many engineering materials including flexible polyurethane foam, yet it is difficult to develop dynamic models of systems that include these materials and are able to predict system behavior over a wide range of excitations. This research is focused on a specific example system in the form of a pinned-pinned beam interacting with a viscoelastic foundation. Two cases are considered: (1) the beam and the foundation are glued so that they are always in contact and the foundation can undergo both tension and compression, and (2) the beam is not glued to the foundation and the foundation reacts only in compression so that the contact region changes with beam motion. Static as well as dynamic transverse and axial forces act on the beam, and the Galerkin method is used to derive modal amplitude equations for the beam-foundation system. In the second case of the beam on tensionless foundation, loss of contact between the beam and the foundation can arise and determination of the loss-of-contact points is integrated into the solution procedure through a constraint equation. The static responses for both cases are examined as a function of the foundation nonlinearity and loading conditions. The steady-state response of the system subject to static and harmonic loads is studied by using numerical direct time-integration. Numerical challenges and the accuracy of this approach are discussed, and predictions of solutions by the three-mode and five-mode approximate models are compared to establish convergence of solutions. Frequency responses are studied for a range of foam nonlinearities and loading conditions.
Oxygen plasma ashing effects on aluminum and titanium space protective coatings

Using variable angle spectroscopic ellipsometry and atomic force microscopy (AFM), the surface roughness and oxidation of aluminum and titanium thin films have been studied as a function of substrate deposition temperature and oxygen plasma exposure. Increasing substrate deposition temperatures affect film microstructure by greatly increasing grain size. Short exposures to an oxygen plasma environment produce sharp spikes rising rapidly above the surface as seen by AFM. Ellipsometric measurements were made over a wide range of plasma exposure times, and results at longer exposure times suggest that the surface is greater than 30% void. This is qualitatively verified by the AFM images.
Bariatric surgery and psoriasis

Obesity is associated with psoriasis and poses a significant obstacle to psoriasis management. Bariatric surgery is an effective procedure for weight loss, and some reports suggest that it may improve psoriasis. However, more evidence is needed before definitive conclusions can be drawn. Bariatric surgery procedures, in particular the Roux-en-Y gastric bypass, may one day be a viable option for obese patients with refractory psoriasis.
Why Diversity Became Orthodox in Higher Education, and How it Changed the Meaning of Race on Campus

Using qualitative data about University of Michigan between 1965 and 2005, this article shows how administrators’ diversity discourse and programs have defined race as a cultural identity, expressed through interaction, which provides instrumental benefits. It also explains three major reasons why, starting in the mid-1980s, university administrators adopted this racial orthodoxy of “diversity”: to signal compliance with—and also to redefine—law and institutional norms while still practicing race-based affirmative admissions; to frame inclusion in more complex terms than a racial binary or numerical representation amidst growing campus multiculturalism; and to market the university, especially to white students. The article advances racial formation theory by developing the concept of a racial orthodoxy. It shows that diversity discourse and programs have sometimes advanced the goal of racial minority inclusion, but at the cost of downplaying problems of racial inequality and misrepresenting racial minori...
The next reinforcer: comment on Meisch (2000)

The comment herein is a response to R.A. Meisch (2000), in which he argues for a new conceptualization of reinforcer effects, vis-a-vis relative persistence. The concept is likely to be quite helpful. It is similar to some applications derived from behavioral economics.
Circulation deposition on shock-accelerated planar and curved density-stratified interfaces: Models and scaling laws

Vorticity is deposited baroclinically by shock waves on density inhomogeneities. In two dimenslons, the circulation deposited on a planar interface may be derived analytically using shock polar analysis provided the shock refraction is regular. We present analytical expressions for Γ′, the circulation deposited per unit length of the unshocked planar interface, within and beyond the regular refraction regime. To lowest order, Γ′ scales as \[ \Gamma^\prime\propto (1-\eta^{-\frac{1}{2}})(\sin\alpha)(1+M^{-1}+2M^{-2})(M-1)(\gamma^{\frac{1}{2}}/\gamma + 1)\] where M is the Mach number of the incident shock, η is the density ratio of the gases across the interface, α is the angle between the shock and the interface and γ is the ratio of specific heats for both gases. For α ≤ 30°, the error in this approximation is less than 10% for 1.0 1, and 5.8 ≤ η ≤ 32.6 for all M. We validate our results by quantification of direct numerical simulations of the compressible Euler equations with a second-order Godunov code.We generalize the results for total circulation on non-planar (sinusoidal and circular) interfaces. For the circular bubble case, we introduce a ‘near-normality’ ansatz and obtain a model for total circulation on the bubble surface that agrees well with results of direct numerical simulations. A comparison with other models in the literature is presented.
A huge gastric diverticulum

A case is presented in which a huge gastric diverticulum produced symptoms of epigastric burning and postprandial regurgitation. Surgical resection relieved the patient's symptoms. A review of the literature reveals that this diverticulum is one of the largest reported.
Data forwarding in extremely low duty-cycle sensor networks with unreliable communication links

In extremely low duty-cycle sensor networks, end-to-end communications cannot afford to maintain an always-awake communication backbone. Low duty-cycle, accompanied by the unreliable nature of wireless communication, makes it essential to design a new data forwarding scheme for such networks, so as to achieve network energy efficiency, reliability, and timeliness in an integrated fashion.In this work, we introduce the concept of dynamic switch-based forwarding (DSF) that optimizes the (i) expected data delivery ratio, (ii) expected communication delay, or (iii) expected energy consumption. DSF is designed for networks with possibly unreliable communication links and predetermined node communication schedules. Interestingly, we reveal that allowing opportunistic looping can actually reduce the end-to-end delay. To our knowledge, these are the most encouraging results to date in this new research direction. In this paper, DSF is evaluated with a theoretical analysis, extensive simulation, and physical testbed consisting of 20 MicaZ motes. Results reveal the remarkable advantage of DSF in extremely low duty-cycle sensor networks in comparison to three well-known solutions (ETX [3], PRRxD [19] and DESS [16]). We also demonstrate our solution defaults into ETX in always-awake networks and DESS in perfect-link networks.
Pronto: a fast failover protocol for off-the-shelf commercial databases

Enterprise applications typically store their state in databases. If a database fails, the application is unavailable while the database recovers. Database recovery is time consuming because it involves replaying the persistent transaction log. To isolate end users from database failures, we introduce Pronto, a protocol to orchestrate the transaction processing by multiple, standard databases so that they collectively implement the illusion of a single, highly available database. The key challenge in implementing this illusion is to enable fast failover from one database to another so that database failures do not interrupt the transaction processing. We solve this problem with a novel replication protocol that handles non-determinism without relying on perfect failure detection.
Ustekinumab: Treatment of Adult Moderate-to-Severe Chronic Plaque Psoriasis

Objective:To systematically review the pharmacology, pharmacokinetics, clinical efficacy, and safety profile of ustekinumab to inform pharmacists and other healthcare professionals of this new biologic therapy for psoriasis.Data Sources:A search of PubMed/MEDLINE, EMBASE, and International Pharmaceutical Abstracts was performed through July 2009, limited to publications in English, using the search terms CNTO-1275, ustekinumab, interleukin-12, interleukin-23, and/or psoriasis to identify literature sources. References from the retrieved articles were also evaluated to identify relevant literature. An abstract from a Congress of the European Academy of Dermatology and Venereology and unpublished Phase 3 clinical trials in progress (using www.clinicaltrials.gov) were also reviewed. The Food and Drug Administration, European Medicines Agency, and Health Canada Web sites were used to retrieve product monographs, regulatory guidances, and advisory committee briefing packets.Study Selection and Data Extraction:...
Analysis and Design of the Dual Edge Controller for the Fast Transient Voltage Regulator

Achieving faster dynamic response is one of the big challenges for the future microprocessor voltage regulators (VR). It is well known that the system bandwidth needs to be higher to get a faster dynamic response but the system bandwidth is usually limited by the phase shift near the switching frequency. In this paper, the existing theories for this phase shift and efforts to achieve a faster transient response are summarized. A higher bandwidth design using a dual edge controller is analyzed. The bandwidth is designed to be larger than one half of the switching frequency. The design is then verified with the hardware.
Heteronuclear adiabatic relaxation dispersion (hard) for quantitative analysis of conformational dynamics in proteins

NMR relaxation methods probe biomolecular motions over a wide range of timescales. In particular, the rotating frame spin-lock R(1ρ) and Carr-Purcell-Meiboom-Gill (CPMG) R(2) experiments are commonly used to characterize μs to ms dynamics, which play a critical role in enzyme folding and catalysis. In an effort to complement these approaches, we introduced the Heteronuclear Adiabatic Relaxation Dispersion (HARD) method, where dispersion in rotating frame relaxation rate constants (longitudinal R(1ρ) and transverse R(2ρ)) is created by modulating the shape and duration of adiabatic full passage (AFP) pulses. Previously, we showed the ability of the HARD method to detect chemical exchange dynamics in the fast exchange regime (k(ex)∼10(4)-10(5) s(-1)). In this article, we show the sensitivity of the HARD method to slower exchange processes by measuring R(1ρ) and R(2ρ) relaxation rates for two soluble proteins (ubiquitin and 10C RNA ligase). One advantage of the HARD method is its nominal dependence on the applied radio frequency field, which can be leveraged to modulate the dispersion in the relaxation rate constants. In addition, we also include product operator simulations to define the dynamic range of adiabatic R(1ρ) and R(2ρ) that is valid under all exchange regimes. We conclude from both experimental observations and simulations that this method is complementary to CPMG-based and rotating frame spin-lock R(1ρ) experiments to probe conformational exchange dynamics for biomolecules. Finally, this approach is germane to several NMR-active nuclei, where relaxation rates are frequency-offset independent.
Photophysics and Molecular Electronic Applications of the Rhodopsins

This review examines the photophysical properties of an interesting and biologically important class of proteins known as the rhodopsins. The visual rhodopsins are responsible for the conversion of light into nerve impulses in the image resolving eyes of mullusks, arthropods, and vertebrates. Despite independent evolutionary development, these systems have converged on proteinand chromophore-binding site designs that are remarkably similar. The bacterial rhodopsins represent a much broader class of proteins that serve both photosynthetic and phototactic functions. The best known of this latter group is bacteriorhodopsin, which converts light into energy via photon-activated transmembrane proton pumping. Regardless of function, all rhodopsins appear to share common features, which include a retinyl chromophore in a protein-binding site formed within the inner segments of seven transmembrane helices. Upon the absorption of light, the chromophore isomerizes to generate a bathochromically shifted photoproduct that stores a significant fraction of the photon energy in both electrostatic and conformational forms. Subsequent dark reactions carry out the relevant biological function. The nature of the primary photochemical events in the rhodopsins has
Fabrication of gecko foot-hair like nano structures and adhesion to random rough surfaces

In this work the effect of substrate roughness on the adhesion of gecko foot-hair like nano structures as opposed to solid elastic materials is described and models of both synthetic nano-hairs and hair-substrate interaction are developed. First, by combining linear beam theory and geometric constraints, a nonlinear elastic model for the hair is derived. Then it is shown how for a given random surface, once its Zero Order Hold (ZOH) model is acquired through Atomic Force Microscopy, only the height distribution is needed to compute pull-off forces. In the effort of replicating gecko foot-hair adhesive properties, we synthesized arrays of nano hairs by casting polyurethane into a nano-pore array. Hairs of controlled size, in the range of 20-60 microns long and 200 nanometers thick, were thus fabricated, imaged via Scanning Electron Microscope (SEM). Elastic properties of polyurethane are measured and then fed into a model, based on cantilever beam theory, which, together with the height distribution of sample surfaces, provides a prediction for pull-off forces as well as a description of the hysteresis phenomena arising in push-in/pull-off cycles.
Magnetic resonance brain imaging lacks sensitivity for AIDS associated cytomegalovirus encephalitis

Six patients are presented who died with active cytomegalovirus (CMV) encephalitis in whom brain MR scans within 25 days of death failed to reveal distinctive findings suggesting the diagnosis of CMV encephalitis. While MR scanning is crucial to evulation of AIDS patients developing neurologic complications, it is not sensitive to the presence of CMV encephalitis even when it is quite severe. The diagnosis of CMV encephalitis during life rests on characteristic clinical findings supported by typical laboratory measures including the presence of CMV DNA in cerebrospinal fluid as detected by polymerase chain reaction.
Pilus Gene Pool Variation and the Virulence of Corynebacterium diphtheriae Clinical Isolates during Infection of a Nematode

ABSTRACT Toxigenic Corynebacterium diphtheriae strains cause diphtheria in humans. The toxigenic C. diphtheriae isolate NCTC13129 produces three distinct heterotrimeric pili that contain SpaA, SpaD, and SpaH, making up the shaft structure. The SpaA pili are known to mediate bacterial adherence to pharyngeal epithelial cells. However, to date little is known about the expression of different pili in various clinical isolates and their importance in bacterial pathogenesis. Here, we characterized a large collection of C. diphtheriae clinical isolates for their pilin gene pool by PCR and for the expression of the respective pilins by immunoblotting with antibodies against Spa pilins. Consistent with the role of a virulence factor, the SpaA-type pili were found to be prevalent among the isolates, and most significantly, corynebacterial adherence to pharyngeal epithelial cells was strictly correlated with isolates that were positive for the SpaA pili. By comparison, the isolates were heterogeneous for the presence of SpaD- and SpaH-type pili. Importantly, using Caenorhabditis elegans as a model host for infection, we show here that strain NCTC13129 rapidly killed the nematodes, the phenotype similar to isolates that were positive for toxin and all pilus types. In contrast, isogenic mutants of NCTC13129 lacking SpaA-type pili or devoid of toxin and SpaA pili exhibited delayed killing of nematodes with similar kinetics. Consistently, nontoxigenic or toxigenic isolates that lack one, two, or all three pilus types were also attenuated in virulence. This work signifies the important role of pili in corynebacterial pathogenesis and provides a simple host model to identify additional virulence factors.
Optical afterglows of gamma-ray bursts

Abstract I give a brief summary of the rapid optical follow-up observations of seven γ-ray bursts made between January and August 1997.
SPARC accelerates disease progression in experimental crescentic glomerulonephritis.

Podocytopenia characterizes many forms of glomerular disease, preceding the development of glomerulosclerosis. While detachment of viable podocytes from the underlying glomerular basement membrane is an important mechanism of podocyte loss, the underlying factors involved remain unclear. Secreted protein acidic and rich in cysteine (SPARC), a matricellular protein with counteradhesive properties, is normally expressed at low levels by the podocyte but is markedly increased following podocyte injury. Accordingly, we elucidate the role of SPARC in mediating experimental crescentic glomerulonephritis by inducing passive nephrotoxic nephritis in SPARC+/+ and SPARC−/− mice. By days 4, 7, and 21 following disease induction, podocyte number is better preserved, glomerulosclerosis is ameliorated, and proteinuria is reduced in SPARC−/− mice as compared with SPARC+/+ littermates. Moreover, the preserved podocyte number in SPARC−/− mice correlates with reduced urinary levels of both nephrin and podocin. To establish a causal role for SPARC in mediating detachment, cultured SPARC+/+ and SPARC−/− podocytes were subjected to mechanical strain as well as trypsin digestion, and detachment assays were performed. While podocytes lacking SPARC were more resistant to stretch-induced detachment, stable re-expression of SPARC restored detachment rates to levels comparable with SPARC+/+ podocytes. Taken together, this study proves that SPARC plays a causal role in mediating podocyte detachment and accelerating glomerulosclerosis in experimental crescentic glomerulonephritis.
Duration and Magnitude of Vasopressor Support Predicts Poor Outcome After Infant Cardiac Operations

Background The vasoactive inotrope score (VIS) is a sum of the total vasopressor dose at a single point in time. Incorporating duration and magnitude of vasopressor requirements during the postcardiac surgical period could improve VIS sensitivity for predicting poor outcome. Methods This is a retrospective review of 244 infants (aged ≤365 days) who underwent cardiopulmonary bypass during congenital cardiac operations from 2002 to 2011. The VIS was calculated hourly for the first 72 hours. Poor outcome was defined as prolonged mechanical ventilation (≥6 days) or intensive care length of stay (≥12 days). First, the association between the maximum VIS (maxVIS) in the first 48 postoperative hours and poor outcome was confirmed for our study population. Next, postoperative intervals and VIS values that were significantly associated with poor outcome were identified and incorporated into a formula, termed the VISindex, which was compared with the traditional maxVIS. Results The VISindex demonstrated improved sensitivity for predicting prolonged mechanical ventilation (VISindex: area under the curve [AUC], 0.85; 95% confidence interval [CI], 0.79 to 0.90; maxVIS: AUC, 0.80; 95% CI, 0.75 to 0.86) and intensive care unit length of stay (VISindex: AUC, 0.84; 95% CI, 0.79 to 0.89; maxVIS: AUC, 0.77; 95% CI, 0.71 to 0.83) after cardiac operations in infants. Conclusions Incorporating magnitude and duration of postoperative vasopressor support into the VIS improves its sensitivity for predicting poor outcome.
ATP-γ-S shifts the operating point of outer hair cell transduction towards scala tympani

ATP receptor agonists and antagonists alter cochlear mechanics as measured by changes in distortion product otoacoustic emissions (DPOAE). Some of the effects on DPOAEs are consistent with the hypothesis that ATP affects mechano-electrical transduction and the operating point of the outer hair cells (OHCs). This hypothesis was tested by monitoring the effect of ATP-gamma-S on the operating point of the OHCs. Guinea pigs anesthetized with urethane and with sectioned middle ear muscles were used. The cochlear microphonic (CM) was recorded differentially (scala vestibuli referenced to scala tympani) across the basal turn before and after perfusion (20 min) of the perilymph compartment with artificial perilymph (AP) and ATP-gamma-S dissolved in AP. The operating point was derived from the cochlear microphonics (CM) recorded in response low frequency (200 Hz) tones at high level (106, 112 and 118 dB SPL). The analysis procedure used a Boltzmann function to simulate the CM waveform and the Boltzmann parameters were adjusted to best-fit the calculated waveform to the CM. Compared to the initial perfusion with AP, ATP-gamma-S (333 microM) enhanced peak clipping of the positive peak of the CM (that occurs during organ of Corti displacements towards scala tympani), which was in keeping with ATP-induced displacement of the transducer towards scala tympani. CM waveform analysis quantified the degree of displacement and showed that the changes were consistent with the stimulus being centered on a different region of the transducer curve. The change of operating point meant that the stimulus was applied to a region of the transducer curve where there was greater saturation of the output on excursions towards scala tympani and less saturation towards scala vestibuli. A significant degree of recovery of the operating point was observed after washing with AP. Dose response curves generated by perfusing ATP-gamma-S (333 microM) in a cumulative manner yielded an EC(50) of 19.8 microM. The ATP antagonist PPADS (0.1 mM) failed to block the effect of ATP-gamma-S on operating point, suggesting the response was due to activation of metabotropic and not ionotropic ATP receptors. Multiple perfusions of AP had no significant effect (118 and 112 dB) or moved the operating point slightly (106 dB) in the direction opposite of ATP-gamma-S. Results are consistent with an ATP-gamma-S induced transducer change comparable to a static movement of the organ of Corti or reticular lamina towards scala tympani.
Modeling and Analysis of Leakage Currents in Double-Gate Technologies

This paper models and analyzes subthreshold and gate leakage currents in different double-gate (DG) devices, namely, a doped body symmetric device with polysilicon gates, an intrinsic body symmetric device with metal gates, and an intrinsic body asymmetric device with different front and back gate materials. The effect of variations in device parameters on the leakage components is also analyzed. Using the developed models, digital circuits (logic gates and static random access memory cells) designed with different DG structures are also analyzed. The analysis shows that the use of (near mid-gap) metal gate and intrinsic body devices significantly reduces both the total leakage and its sensitivity to parametric variations in DG devices and circuits
Multi-primary-color LCD: Its characteristics and extended applications

— The development of multi-primary-color (MPC) display systems is one of the big paradigm shifts in recent display technologies and induces new potentials of display devices. The development of MPC display systems for different goals is briefly reviewed. Especially, by employing MPC systems, it is possible to reproduce the real material colors faithfully and efficiently. For signal processing, MPC systems have a big advantage in the so-called color-reproduction redundancy. A number of applications can be derived from this characteristic, such as improving the viewing-angle dependency issue and power savings. On the other hand, MPC systems have a typical trade-off versus RGB-standardized input signals, especially for reproducing bright green. New algorithms to moderate this trade-off on MPC systems by employing color-reproduction redundancy are proposed. The goal of our algorithms is to maintain the compatibility with RGB-based input signals though the initial display design so that the characteristics of MPC systems are not changed or lost. These algorithms indicate that MPC display systems are applicable not only for a specifically limited objective but also for other applications, e.g., TV broadcasting.
Mind, Brain and Education: A Decade of Evolution

This article examines the evolution of Mind, Brain, and Education (MBE), the field, alongside that of the International Mind, Brain and Education Society (IMBES). The reflections stem mostly from my observations while serving as vice president, president-elect, and president of IMBES during the past 10 years. The article highlights the evolution during that time about the meaning of MBE and some of the representations that help illustrate the problems and challenges in arriving at a consensus about what MBE means and how IMBES can best serve its members. I explore how IMBES, incorporated in 2004, experimented with a number of different conference models to provide frameworks for thinking about MBE, as well as a structure for supporting collaboration between the disciplines represented in Mind, Brain, and Education. Those models help highlight what IMBES has accomplished in scaffolding the complex conversation unfolding in the field, as well as offering a strategy for a collaborative enterprise that informs practice and new research agendas in the future.
Traffic Velocity Prediction Using GPS Data: IEEE ICDM Contest Task 3 Report

This report summarizes the methodologies and techniques we developed and applied for tackling task 3 of the IEEE ICDM Contest on predicting traffic velocity based on GPS data. The major components of our solution include 1) A pre-processing procedure to map GPS data to the network, 2) A K-nearest neighbor approach for identifying the most similar training hours for every test hour, and 3) A heuristic evaluation framework for optimizing parameters and avoiding over-fitting. Our solution finished Second in the final evaluation.
Texture Photogrammetry Surface Reconstruction of Membrane Wings Using Tracking Cameras

To validate research into the aerodynamics of ornithopters (apping wing miniature aerial vehicles), a tracking camera system was developed to provide high quality images for photogrammetry. Flapping wing aerodynamics are complicated to analyze due to unsteady ow and aeroelasticity. Flapping wings are lightweight and have large amplitude motions preventing mounting sensors or using xed, noncontact sensors. For this reason, a tracking noncontact sensor was developed using high speed, digital cameras. A motion capture system is used to locate the ornithopter in realtime so that the cameras automatically pan, tilt and zoom as needed. Texture based photogrammetry is used to generate a dense surface prole of the wing in