cssi/SciSciGPT-SciSciNet huggingface dataset:
High-speed tomographic PIV measurements of strain rate intermittency and clustering in turbulent partially-premixed jet flames

Abstract The effects of combustion on the strain rate field in turbulent jets were studied using 10 kHz tomographic particle image velocimetry (TPIV). Measurements were performed in three turbulent jets: a well-studied, piloted partially-premixed methane/air jet flame, Sandia flame C, with low probability of localized extinction; a second piloted jet flame, analogous to flame C but with a reduced pilot flow rate and a high probability of localized extinction; and a non-reacting air jet. Since the jet exit Reynolds number of approximately 13000 was nearly identical in the three jets, differences in the strain rate fields were attributed to the effects of combustion. Spatiotemporal characteristics of the strain rate field were analyzed. Overall, the strain rate norm was larger in the flames than in the non-reacting jet with the most stable flame having the largest values. In all three jets, the compressive strain rate was on average the largest of the three principal strain rates. At high strain rates, the ratios of the compressive and extensive strain rate to the intermediate strain rate were similar to those found in isotropic incompressible turbulent flows. The three-dimensional velocity measurements were used to analyze the spatial distribution of strain rate clusters, defined as singly-connected groups of voxels where the strain rate magnitude exceeded a threshold value. The presence of a stable flame significantly attenuated the number of clusters of intermediate strain rate. Strain rate bursts, corresponding to sudden increases in the number of clusters, were identified in the three jets. Bursts in the non-reacting jet and the unstable flame contained up to twice as many clusters as in the stable flame. The temporal intermittency of intense strain rate clusters was analyzed using the time-series measurements. Clusters with strain rates greater than five times the standard deviation of the strain rate norm were highly intermittent.
Link between conservation tillage and factor inputs

One important issue concerning the impact of agricultural production on the environment involves the environmental consequences of conservation tillage practices. While it is generally recognized that water runoff and soil erosion will decline as no tillage and mulch tillage systems are used more extensively on cropland, what will happen to pesticide and fertilizer use remains uncertain. To gain some insight into this, the conservation tillage adoption decision is modelled. Starting with the assumption that this decision is a two step procedure‐the first is the decision whether or not to adopt a conservation tillage production system and the second is the decision on the extent to which conservation tillage should be used‐appropriate models of the Cragg and Heck‐man (dominance) type are estimated. Based on farm‐level data on corn production in the United States for 1987, the profile of a farm on which conservation tillage was adopted is that the cropland had above average slope and experienced above avera...
Correlation of the critical properties of normal alkanes and alkanols

Abstract Elhassan A.E., Barrufet M.A. and Eubank P.T., 1992. Correlation of the critical properties of normal alkanes and alkanols. Fluid Phase Equilibria , 78: 139-155. A new correlation for the critical temperature and pressure of n -alkanes and n -alkanols is presented based upon combination of the principles of congruence and corresponding states. With only three adjustable parameters, these “power law” correlations are equal to the best current four-parameter correlations. Furthermore, the present correlation is more realistic for extrapolation to high molecular weight compounds in that it does not converge to a limiting T c or to a non-zero P c .
Who predicts better?: results from an online study comparing humans and an online recommender system

Algorithmic recommender systems attempt to predict which items a target user will like based on information about the user's prior preferences and the preferences of a larger community. After more than a decade of widespread use, researchers and system users still debate whether such "impersonal" recommender systems actually perform as well as human recommenders. We compare the performance of MovieLens algorithmic predictions with the recommendations made, based on the same user profiles, by active MovieLens users. We found that algorithmic collaborative filtering outperformed humans on average, though some individuals outperformed the system substantially and humans on average outperformed the system on certain prediction tasks.
Actin filament binding by a monomeric IQGAP1 fragment with a single calponin homology domain.

IQGAP1 is a homodimeric protein that reversibly associates with F-actin, calmodulin, activated Cdc42 and Rac1, CLIP-170, β-catenin, and E-cadherin. Its F-actin binding site includes a calponin homology domain (CHD) located near the N-terminal of each subunit. Prior studies have implied that medium- to high-affinity F-actin binding (5–50 μM Kd) requires multiple CHDs located either on an individual polypeptide or on distinct subunits of a multimeric protein. For IQGAP1, a series of six tandem IQGAP coiled-coil repeats (IRs) located past the C-terminal of the CHD of each subunit support protein dimerization and, by extension, the IRs or an undefined subset of them were thought to be essential for F-actin binding mediated by its CHDs. Here we describe efforts to determine the minimal region of IQGAP1 capable of binding F-actin. Several truncation mutants of IQGAP1, which contain progressive deletions of the IRs and CHD, were assayed for F-actin binding in vitro. Fragments that contain both the CHD and at least one IR could bind F-actin and, as expected, removal of all six IRs and the CHD abolished binding. Unexpectedly, a fragment called IQGAP12-210, which contains the CHD, but lacks IRs, could bind actin filaments. IQGAP12-210 was found to be monomeric, to bind F-actin with a Kd of ∼47 μM, to saturate F-actin at a molar ratio of one IQGAP12-210 per actin monomer, and to co-localize with cortical actin filaments when expressed by transfection in cultured cells. These collective results identify the first known example of high-affinity actin filament binding mediated by a single CHD. Cell Motil. Cytoskeleton 58:231–241, 2004. © 2004 Wiley-Liss, Inc.
Continuum studies of magnetic polarons and bipolarons in antiferromagnets

We present a simple scaling model of magnetic-polaron and magnetic-bipolaron formation in antiferromagnetic systems. Within this picture, we determine the criteria for an excess electron forming a magnetic polaron and for a pair of excess electrons forming a (triplet) magnetic bipolaron. The dependence of the formation criteria on the dimensionality of the electronic system is specifically addressed. In addition, we consider the effect of the electron-lattice interaction on the size and energetic stability of magnetic polarons and bipolarons as a function of the system's dimensionality. Beyond the formation of isolated magnetic polarons and/or magnetic bipolarons, we consider how a system composed of magnetic polarons within an antiferromagnetic system is driven ferromagnetic as the density of magnetic polarons is increased. Finally, we discuss the large paramagnetic susceptibility associated with the formation of magnetic polarons. The magnetic susceptibility is composed of a Curie-like temperature-dependent component as well as a temperature-independent component. The temperature-dependent term arises from the reorienting of the magnetic polarons under the influence of a magnetic field. The temperature-independent contribution arises from the expansion and contraction of magnetic polarons which are, respectively, aligned parallel or antiparallel with the applied magnetic field.
Color vision and genetics in a case of cone dysfunction syndrome

Tests of color vision and unique hue judgments were carried out on a patient with little cone function and abnormal macular pigmentation and optic nerve appearance. These tests revealed weak cone-based dichromatic color vision yet normal red, green, and blue unique hue judgments. In addition, rod input was found to inhibit color discrimination. Genetic analysis revealed the absence of L pigment genes, but multiple M pigment genes. A mutation that inactivates the encoded pigment was identified in a subset of the M genes. One of these genes with the mutation was in the first position of the array. Thus, these visual deficits and changes in the integrity of the inner retina may be linked to defects in the photopigment genes. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S284–S287, 2001
Sulphur fertilizer effect on cotton: II. Growth characteristics, nutrient status and yield

Abstract The effect of S fertilization on growth characteristics, nutrient status and yield of cotton were studied during the growing seasons of 1980 and 1981. Four experiments were conducted on Mollic Hapludalf and Arenic Hapludalf soils using a randomized complete block design with four replications. Leaf samples were taken one week prior to boll set and analyzed for N, P, K, Ca, Mg, S, Mn, Fe, Cu, Zn and B. Yield, plant populations and plant height were measured at time of plant maturity. Percent blooms reaching maturity, staple length, micronaire and percent lint were determined at one location in 1981. Lack of yield response to S treatments suggest the initial soil SO4 =‐S level was sufficient for optimum yield. Plant height and plant populations were not affected by S. Differences in plant height due to N treatment were noted. Percent lint, staple length, micronaire, percent blooms reaching maturity and days from bloom to maturity were not affected by S treatment. There was positive correlation betw...
Cell wall anchor structure of BcpA PILI in bacillus anthracis

Assembly of pili in Gram-positive bacteria and their attachment to the cell wall envelope are mediated by sortases. In Bacillus cereus and its close relative Bacillus anthracis, the major pilin protein BcpA is cleaved between the threonine and the glycine of its C-terminal LPXTG motif sorting signal by the pilin-specific sortase D. The resulting acyl enzyme intermediate is relieved by the nucleophilic attack of the side-chain amino group of lysine within the YPKN motif of another BcpA subunit. Cell wall anchoring of assembled BcpA pili requires sortase A, which also cleaves the LPXTG sorting signal of BcpA between its threonine and glycine residues. We show here that sortases A and D require only the C-terminal sorting signal of BcpA for substrate cleavage. Unlike sortase D, which accepts the YPKN motif as a nucleophile, sortase A forms an amide bond between the BcpA C-terminal carboxyl group of threonine and the side-chain amino group of diaminopimelic acid within the cell wall peptidoglycan of bacilli. These results represent the first demonstration of a cell wall anchor structure for pili, which are deposited by sortase A into the envelope of many different microbes.
Auranofin is highly efficacious against Toxoplasma gondii in vitro and in an in vivo experimental model of acute toxoplasmosis.

Author(s): Andrade, Rosa M; Chaparro, Juan D; Capparelli, Edmund; Reed, Sharon L | Abstract: BackgroundThe mainstay of toxoplasmosis treatment targets the folate biosynthetic pathways and has not changed for the last 50 years. The activity of these chemotherapeutic agents is restricted to one lifecycle stage of Toxoplasma gondii, they have significant toxicity, and the impending threat of emerging resistance to these agents makes the discovery of new therapies a priority. We now demonstrate that auranofin, an orally administered gold containing compound that was FDA approved for treatment of rheumatoid arthritis, has activity against Toxoplasma gondii in vitro (IC50 = 0.28 µM) and in vivo (1 mg/kg).Methods/principal findingsReplication within human foreskin fibroblasts of RH tachyzoites was inhibited by auranofin. At 0.4 µM, auranofin inhibited replication, as measured by percent infected fibroblasts at 24 hrs, (10.94% vs. 24.66% of controls; p = 0.0003) with no effect on parasite invasion (16.95% vs. 12.91% p = 0.4331). After 18 hrs, 62% of extracellular parasites treated with auranofin were non-viable compared to control using an ATP viability assay (p = 0.0003). In vivo, a previously standardized chicken embryo model of acute toxoplasmosis was used. Fourteen day old chicken embryos were injected through the chorioallantoic vein with 1×104 tachyzoites of the virulent RH strain. The treatment group received one dose of auranofin at the time of inoculation (1 mg/kg estimated body weight). On day 5, auranofin-treated chicken embryos were 100% protected against death (p = 0.0002) and had a significantly reduced parasite load as determined by histopathology, immunohistochemistry and by the number of parasites quantified by real-time PCR.ConclusionsThese results reveal in vitro and in vivo activity of auranofin against T. gondii, suggesting that it may be an effective alternative treatment for toxoplasmosis.
Improved linear prediction for truncated signals of known phase

It has been suggested that increasing the dimensionality of protein NMR spectra may be a more efficient way of simplifying protein NMR spectra than increasing the resolution of conventional 2D NMR spectra (1). Because of measuring time constraints, severe truncation of the NMR signals frequently occurs in at least one and often in two dimensions of 3D and 4D data sets. Fourier transformation of such signals leads to truncation artifacts. and it has been suggested that linear prediction (LP) algorithms are more suitable for treatment of such signals. Linear prediction can be used either for measuring the frequencies, amplitudes, damping factors, and phases of all components of the NMR signal (Z-5) or, in a more conservative approach, for simply extending the time-domain data set, prior to Fourier transformation (5-9). In either case, no assumption is made about the shape of the signal apart from the assumption that it can be described by a sum of exponentially damped sinusoids. In multidimensional NMR experiments the phase of the NMR signal is well known in all the indirectly detected dimensions ( 10-12). Also, if signals are severely truncated, the small amount of signal decay during the short time domain can be described adequately by a single damping factor. However, apart from simplifying the calculation, this prior knowledge is of no immediate use for conventional linear prediction analysis of the time domain. Here we demonstrate a new method that effectively uses this prior information to obtain a better estimation of the NMR spectrum. In the case of forward linear prediction, a data point x, is expressed as a linear combination of its K preceding data points:
A source-level dynamic analysis methodology and tool for high-level synthesis

This paper presents a novel source-level dynamic analysis methodology and tool for High-Level Synthesis (HLS). It not only for the first time enables HLS to offer source-level design debugging on the `synthesized' RTL designs, but also allows the designer to analyze their dynamic characteristics, such as resource utilization, power consumption, etc., at the algorithmic (source) level. This technology has been proven in the industry as the critical element for successfully designing a microcontroller with 300+ instructions with Matisse, an interactive HLS system. Additionally, we demonstrate the use of this technology for architectural power optimization.
Ride Safe: A Child Passenger Safety Program for American Indian/Alaska Native Children

Background In American Indian/Alaska Native (AI/AN) communities, child safety seat (CSS) use rates are much lower than in non-native communities. To reduce this disparity, Indian Health Service (IHS) staff developed, pilot-tested, and implemented Ride Safe, which provided education, training, and child safety seats for children aged 3–5 participating in Tribal Head Start Centers. Methods Focus groups, key informant interviews, and technical review guided program development and implementation. Progress reports and child safety seat use observations, conducted at the beginning and end of three program years (Fall 2003 to Spring 2006), assessed program reach and impact. To examine CSS use, we used three multiple logistic regressions, including a conservative intent to treat analysis. Results Ride Safe reached approximately 3,500 children and their families at 14 sites in six states, providing over 1,700 parents/family members with educational activities, 2,916 child safety seats, and child passenger safety (CPS) technician certification training for 78 Tribal staff. Children were 2.5 times (OR = 2.55, p < .01) as likely to be observed in child safety seats comparing Rounds 1 and 2 data, with the most conservative model showing that the odds of being observed restrained were 74% higher (OR = 1.74, p = <.01) after implementation of the program. Conclusions The Ride Safe Program effectively increased child safety seat use in AI/AN communities, however, observed use rates ranging from 30% to 71% remain well below the 2006 all US rate of 93%. Results from CSS educational and distribution/installation programs such as Ride Safe should be considered in light of the need to increase distribution programs and enhance enforcement activities in AI/AN communities, thereby reducing the disparity in AI/AN motor vehicle injuries and death.
A Hybrid Adsorbent-Membrane Reactor (HAMR) System for Hydrogen Production

Design characteristics and performance of a novel reactor system, termed a hybrid adsorbent-membrane reactor (HAMR), have been investigated for hydrogen production. The recently proposed HAMR concept couples reactions and membrane separation steps with adsorption on the membrane feed-side or permeate-side. Performance of conventional reactors has been significantly improved by this integrated system. In this paper, an HAMR system has been studied involving a hybrid-type packed-bed catalytic membrane reactor undergoing methane steam reforming through a porous ceramic membrane with a CO2 adsorption system. This HAMR system is of potential interest to pure hydrogen production for fuel cells for various mobile and stationary applications. Reactor behaviors have been investigated for a range of temperature and pressure conditions. The HAMR system shows enhanced methane conversion, hydrogen yield, and product purity, and provides good promise for reducing the hostile operating conditions of conventional reformers, and for meeting the product purity requirements.
Dysfunction of amyloid precursor protein signaling in neurons leads to DNA synthesis and apoptosis.

The classic neuropathological diagnostic markers for AD are amyloid plaques and neurofibrillary tangles, but their role in the etiology and progression of the disease remains incompletely defined. Research over the last decade has revealed that cell cycle abnormalities also represent a major neuropathological feature of AD. These abnormalities appear very early in the disease process, prior to the appearance of plaques and tangles; and it has been suggested that neuronal cell cycle regulatory failure may be a significant component of the pathogenesis of AD. The amyloid precursor protein (APP) is most commonly known as the source of the β-amyloid (Aβ) peptides that accumulate in the brains of patients with AD. However, a large body of work supports the idea that APP is also a signaling receptor. Most recently, it has been shown that familial AD (FAD) mutations in APP or simple overexpression of wild type APP cause dysfunction of APP signaling, resulting in initiation of DNA synthesis in neurons and consequent apoptosis. In this article, we review the evidence that APP has the potential to activate aberrant neuronal cell cycle re-entry in AD, and we describe a signal transduction pathway that may mediate this abnormal activation of the cell cycle.
Stratospheric and tropospheric NO2 observed by SCIAMACHY: first results

Observations from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) onboard Envisat are used to quantifying the vertical distribution of stratospheric nitrogen dioxide (11–41 km) from limb scattering geometry and the tropospheric column from limb–nadir matching. SCIAMACHY is validated with spatially and temporally coincident observations from Optical Spectrograph and Infrared Imager System (OSIRIS) and from Halogen Occultation Experiment (HALOE). Comparison with the Canadian Middle Atmosphere Model provides a further check of consistency. Errors in pointing are detected and corrected using the recently developed ‘spectral knee’ technique. An instrumental artifact, presumably a tangentheight-dependent wavelength drift, is causing fine spectral structure but can be taken into account as a pseudo-absorber in the least squares fitting. Extending the fitting window to longer wavelengths than those currently employed by other optical satellite-borne NO2 sensors allows for the retrieval to penetrate the lower stratosphere. This extended fitting window is used to retrieve lower stratospheric NO2 in the denoxified Antarctic polar vortex. Finally, tropospheric NO2 columns, retrieved from limb–nadir matching, are presented. Published by Elsevier Ltd on behalf of COSPAR.
THE TUCKMAN TEACHER FEEDBACK FORM (TTFF)

The instrument was originally designed to be used to provide teachers with feedback (Tuckman, 1971)-hence its name; but it has been useful also as a quantitative tool for specifying teacher behavior consistent with a psychological model of teaching described by Tuckman (1974). It is a short, 28 item, semantic differential which generates four scores, based on a factor structure described by Tuckman (1974), in the areas of creativity, dy,namism (energy plus dominance), organized demeanor (organization plus control), and warmth and acceptance. These dimensions refer to the teacher's means of interpersonal classroom management, that is, how he or she deals with issues of control, ambiguity, and interaction.
Tail Risks across Investment Funds 1

Managed portfolios are subject to tail risks, which can be either index level (systematic) or fund-specific. Examples of fund-specific extreme events include those due to big bets or fraud. This paper studies the two components in relation to compensation structure in managed portfolios. A simple model generates fund-specific tail risk and its asymmetric dependence on the market, and makes predictions for where such risks should be concentrated. The model predicts that systematic tail risks increase with an increased weight on systematic returns in compensation and idiosyncratic tail risks increase with the degree of convexity in contracts. The model predictions are supported with empirical results. Hedge funds are subject to higher idiosyncratic tail risks and Exchange Traded Funds exhibit higher systematic tail risks. In skewness and kurtosis decompositions, I find that coskewness is an important source for fund skewness, but fund kurtosis is driven by cokurtosis, as well as volatility comovement and residual kurtosis, with the importance of these components varying across fund types. Investors are subject to different sources of skewness and fat tail risks through delegated investments. Volatility based tail risk hedging is not effective for all fund styles and types.
Ocular surface restoration using non-surgical transplantation of tissue-cultured human amniotic epithelial cells.

Purpose To assess the effect of tissue-cultured human amniotic epithelial cells (AECs) in restoring the ocular surface, transplanted using a collagen shield seeded with AECs supported by a soft contact lens. Design Prospective interventional single-institutional case series with crossover controls. Methods Three eyes in three patients were identified with persistent corneal epithelial defects (PEDs) refractory to medical therapy. Two cases were secondary to neurotrophic keratopathy, while one case was attributable to longstanding alkali injury. AECs were isolated from serologically screened donor human placenta, seeded onto collagen corneal shields, and incubated in tissue culture medium for 7 days. These collagen shields were placed over the PED and supported by an overlying soft contact lens. The collagen shields dissolved by 72 hours, and the contact lenses were removed after this time. This cycle was repeated every week until healing was achieved. As a crossover control, collagen shields without AECs were placed in the same eye 1 week before placing collagen shields containing AECs. The PED was assessed by vital staining and slit-lamp color photography. Results The PEDs had a mean duration of 4 months and involved 20% to 37% of the corneal surface area, one case secondary to longstanding alkali injury and two cases attributable to neurotrophic keratopathy. No change in PED size was observed in those control eyes receiving collagen shields without AECs. Complete resolution of the PED was seen after two cycles of AEC-seeded collagen shield in one case, and four cycles in two cases, from 7 to 12 weeks following treatment in all patients. No loss of visual acuity was seen and clinical improvement was maintained in all cases, with a mean follow-up of 6.3 months. Conclusions Nonsurgical transplantation of tissue-cultured AECs on a collagen shield provides a promising approach to restoring the ocular surface in cases of PED.
Diagenesis of the Carrizo Sandstone at Butler Salt Dome, East Texas Basin, U.S.A.: Evidence for Fluid-Sediment Interaction Near Halokinetic Structures

ABSTRACT The Eocene Carrizo Sandstone adjacent to the Butler salt dome in the East Texas basin was cemented locally as the result of processes similar to those that have created salt dome calcite cap rocks throughout the Gulf Coast. The geometry of this anomalous cemented zone was established using Carrizo exposures in a large quarry and cores in the contiguous area. The cemented zone is delimited by a steeply dipping normal fault that is radial to the dome; the cements extend southeast of the fault for about 750 m. The Carrizo is a fine- to medium-grained quartzarenite to sublitharenite with 42 to 50% cement, principally poikilotopic calcite with local pyrite. Pyrite concretions are found on both northwest and southeast sides of the fault, as well as along the fault plane, whereas the calcite cement is present only to the southeast. 13C data for calcite (-19 to -37) suggest that bicarbonate was supplied mainly by bacterial oxidation of methane, whereas 18O data for calcite (-6 to -9) indicate that meteoric water was the principal diagenetic fluid. 87Sr/86Sr values for calcite ( 0.7073) are within the range for Middle Jurassic seawater, suggesting that dissolution of anhydrite from the Louann Salt provided the Ca. Pyrite is more 34S-rich (34S range of 10 to 16) than typical sulfides in Gulf Coast salt dome cap rocks and are interpreted to represent H2S supply from deep sour gas reservoirs. Petrographic and isotope evidence suggests that early H2S supply from deep sour gas reservoirs was channeled upward along the flank of the dome and outward along the radial fault, resulting in early pyrite precipitation along the fault zone and in adjacent sediments. Early pyrite cementation along the fault may have formed a barrier to subsequent fluid circulation, blocking the northwestward movement of both Ca-rich waters from the dome and deep natural gas moving along the fault, thus confining calcite precipitation to the southeast. Bacterial oxidation of this thermogenic gas resulted in calcite precipitation, although mixing with shallow ground water bicarbonate may account for the range in 13C values in the calcite cement. We propose that this type of cementation occurs in similar settings associated with hydrocarbon leakage to shallow levels, including adjacent to many salt domes in the Gulf of Mexico Basin, and may represent a previously unrecognized self-sealing type of hydrocarbon trap.
Applications of Digital Elevation Models and Geographic Information Systems to Coastal Flood Studies along the Shoreline of Raritan Bay, New Jersey

Geographic information systems (GIS) are increasingly used in coastal hazard research for coastal management and for analysis of information following major storm events because of their ability to evaluate multiple data sets. Digital flood zone data sets and qualitative post storm flood water level observations exist for Raritan Bay, New Jersey, an urban estuary. A desktop GIS is used to overlay different digital data sets containing flood zone information and determine the number and length of roads that are within the flood zone. The elevation of the 1% probability flood zone on the digital elevation model is determined from a long-term tidal record at Sandy Hook, New Jersey and roads flooded during a major coastal storm in December 1992. In this article, 1% probability flood zones, also called the 100-year flood zone, are calculated using digital elevation models and compared to 1% probability flood zones from the Federal Emergency Management Agency and the New Jersey Department of Environmental Protection. The 1% probability flood is typically used for flood zone management. The results indicate that digital elevation models and GIS can be used to identify roads that would be flooded by the 1% probability flood comparable to roads found on existing flood zone maps.
Quality‐of‐Life Measurement in Women with Breast Cancer

: The health-related quality of life (QOL) of breast cancer patients has been the focus of study for many years. However, it is only recently that the quality-of-life construct has been precisely defined and measured with validated, reliable instruments. The measurement of health-related quality of life and the application of this data in clinical practice has been facilitated by the publication of several QOL instruments widely used in clinical trials. Knowledge of available instruments and a growing database on quality of life following treatment for breast cancer allows clinicians and patients to better collaborate to improve patient functioning following treatment. The task for practitioners is to translate current QOL data into useful information for patients.
Novel Silicon-Controlled Rectifier (SCR) for High-Voltage Electrostatic Discharge (ESD) Applications

Electrostatic discharge (ESD) protection for high-voltage integrated circuits is challenging due to the requirement of high holding voltage to minimize the risk of ESD-induced latchup and electrical overstress. In this letter, a new silicon-controlled rectifier (SCR) is developed for this particular application. The SCR is designed based on the concept that the holding voltage can be increased by reducing the emitter injection efficiency in the SCR. This is accomplished by using a segmented emitter topology. Experimental data show that the new SCR can possess a holding voltage that is larger than 40 V and a failure current It2 that is higher than 28 mA/mum.
Distributed Signature Learning and calibration for large-scale sensor networks

In this paper, we consider the problem of joint sensor calibration and target signature estimation using distributed measurements from a large-scale wireless sensor network with random link variations. Specifically, we propose a new Distributed Signature Learning and Node Calibration, D-SLANC, which can estimate the (constrained) parameters of interest, using measurements from the sensor nodes, in a distributed manner. Unlike a centralized algorithm that relies on pooling measurement vectors from the network, D-SLANC operates at the parameter space reducing the communication bandwidth. We model the sensor network as a connected graph and show that the gossip-based distributed consensus can be used to update the estimates at each iteration of the D-SLANC algorithm. As a result the proposed algorithm is robust to link and node failures, unlike previously suggested distributed subgradient methods that rely on formation and maintenance of a stable network infrastructure to perform iterations in parameter space. We prove the guaranteed convergence of the algorithm to the centralized data pooling solution and compare its performance with the derived Cramer-Rao bound, using simulations.
Measuring high pressure baroreceptor sensitivity in the rat.

Abstract Introduction The high pressure baroreceptor reflex rapidly buffers changes in systemic arterial pressure in response to postural changes, altered gravitational conditions, diseases, and pharmacological agents. Drug-induced exaggeration of changes in heart rate and in systemic arterial pressure is a leading cause of adverse events and of patients terminating use of drugs, particularly in the aging population. This paper presents a facile method for monitoring the high pressure baroreceptor reflex in rats, and presents an alternative to quantifying the magnitude of this reflex using 2 dependent variables, heart rate and systemic arterial pressure, rather than merely change in heart rate. Methods Twenty-four rats were allocated to 3 groups: group I anesthetized with 100 mg/kg thiopental, group II anesthetized with 2% isoflurane given by inhalation, group III anesthetized with thiopental but pretreated for 2 weeks with 2 μg/kg aldosterone given SQ bid. After induction to anesthesia, hair was clipped from the ventral aspect of the neck, and petrolatum was applied to the skin to permit an air-tight seal with a glass funnel attached to a source of variable and controllable negative pressure. Systemic arterial pressure, ECG, heart rate, and a force of suction applied to the neck were all recorded continuously. Results After baseline recordings, a force of − 20 mm Hg was applied for 20 s over the carotid artery. In rats receiving thiopental, the average changes in heart rate and systemic arterial pressure following the application of − 20 mm Hg neck suction were 30 ± 11 bpm and 45 ± 14 mm Hg, respectively. The ratios of change in heart and change in systemic arterial pressure to application of negative force over the carotid sinus are 1.5 ± 0.6 bpm/mm Hg and 0.7 ± 04 mm Hg/mm Hg, respectively. Mean values for heart rate and for mean systemic arterial pressure during baseline and after application of neck suction for 20 s showed little to no decrease (i.e., blunting) in rats anesthetized with isoflurane or pretreated with aldosterone. Discussion Thus this methodology was able to detect, in rats, blunting of baroreceptor function for at least 2 perturbations of this important homeostatic control system.
Retinal thickness measurements in optical coherence tomography using a Markov boundary model

We present a highly accurate, robust system for measuring retinal thickness in optical coherence tomography (OCT) images. OCT is a relatively new imaging modality giving cross sectional images that are qualitatively similar to ultrasound but with 10 /spl mu/m resolution. We begin with a 1-dimensional edge detection kernel to yield edge primitives, which are then selected, corrected, and grouped to form a coherent boundary by use of a Markov model of retinal structure. We have tested the system extensively, and only one of 650 evaluation images caused the algorithm to fail. The anticipated clinical application for this work is the automatic determination of retinal thickness. A careful quantitative evaluation of the system performance over a 1 mm region near the fovea reveals that in more than 99% of the cases, the automatic and manual measurements differed by less than 25 /spl mu/m (below clinical significance), and in 89% of the tests the difference was less than 10 /spl mu/m (near the resolution limit). Current clinical practice involves only a qualitative, visual assessment of retinal thickness. Therefore, a robust, quantitatively accurate system should significantly improve patient care.
Analysis of secA1 Gene Sequences for Identification of Nocardia Species

Molecular methodologies, especially 16S rRNA gene sequence analysis, have allowed the recognition of many new species of Nocardia and to date have been the most precise methods for identifying isolates reliably to the species level. We describe here a novel method for identifying Nocardia isolates by using sequence analysis of a portion of the secA1 gene. A region of the secA1 gene of 30 type or reference strains of Nocardia species was amplified using secA1- specific primers. Sequence analysis of 468 bp allowed clear differentiation of all species, with a range of interspecies similarity of 85.0% to 98.7%. Corresponding 16S rRNA gene sequences of a 1,285-bp region for the same isolates showed a range of interspecies similarity of 94.4 to 99.8%. In addition to the type and reference strains, a 468-bp fragment of the secA1 gene was sequenced from 40 clinical isolates of 12 Nocardia species previously identified by 16S rRNA gene sequence analysis. The secA1 gene sequences of most isolates showed >99.0% similarity to the secA1 sequences of the type or reference strain to which their identification corresponded, with a range of 95.3 to 100%. Comparison of the deduced 156 amino acid sequences of the SecA1 proteins of the clinical isolates showed between zero and two amino acid residue differences compared to that of the corresponding type or reference strain. Sequencing of the secA1 gene, and using deduced amino acid sequences of the SecA1 protein, may provide a more discriminative and precise method for the identification of Nocardia isolates than 16S rRNA gene sequencing.
Cost-Effectiveness of Integrating a Clinical Decision Rule and Staged Imaging Protocol for Diagnosis of Appendicitis

Abstract Objective To evaluate the cost-effectiveness of a diagnostic protocol for appendicitis in children, the use of a validated clinical decision rule (CDR) and a staged imaging protocol, compared with usual care. Methods We estimated the cost-effectiveness of the three competing strategies using parameters from existing literature as well as a Markov model developed to simulate the effects of exposure to ionizing radiation from a single computed tomography (CT) study in the course of diagnosis. The simulation model was applied to a hypothetical cohort of 100,000 boys and girls, age 10 years, presenting with acute abdominal pain to emergency departments in the United States. Results The integrated strategy, the CDR followed by staged imaging, was found to be the most cost-effective approach. Cost savings accrued from the reduction in CT utilization for low-risk patients compared with the other two strategies. The addition of ultrasound (US) to the CDR strategy reduced CT utilization by an additional 10.9%, its main cost advantage, with negligible change in net health benefits from false-negative US results, and associated morbidity or mortality. Conclusions Results suggest that the integration of staged imaging with the CDR for the diagnosis of appendicitis in children is a cost-effective and cost-saving approach. The model estimates a further 10.9% reduction in the number of CTs from the incorporation of US for patients scoring high or medium risk, in excess of the 19.5% reduction estimated in the CDR validation study.
Pathogenetic Events in Intestinal Chlamydial Infections Leading to Polyarthritis in Calves

The host range of chlamydiae involves many animal species, and different manifestations of overt disease have been attributed to chlamydial infections in man and domestic animals [1]. Intestinal chlamydial infections are common in cattle and sheep. The present knowledge of these intestinal infections is largely limited to the fact that chlamydial agents are present in the intestine and that they are excreted in the feces [2, 3]. From calves affected with polyarthritis, chlamydial agents were isolated from specimens of affected joints and of the intestine [4]. The chlamydial isolates from intestines were indistinguishable from those recovered from the affected joints of polyarthritic calves. Diarrhea was frequently associated with chlamydia-induced polyarthritis in calves [4]. These findings suggest a pathogenetic interrelationship of the intestinal infection with chlamydial polyarthritis in calves. The objectives of this investigation were: (1) to explore the extent and the sites of chlamydial multiplication in different portions of the gastrointestinal tract of calves after oral exposure; and (2) to study the dynamics of the systemic infection originating in the gastrointestinal tract.
High Performance Microvalve Array

The fabrication, analysis, and testing of a large flow rate and high frequency microvalve array are presented in this paper. The array consists of 88-microvalves fabricated on a silicon-on-insulator (SOI) substrate. The SOI wafer simplifies the fabrication process and eliminates the need for multi-layer surface micromachining process and bulk wafer-bonding procedures. The analytical resonant frequency of the valve is up to 50 kHz and operates at high delta pressures (i.e. 0.14 MPa). The microvalves are fabricated with various flap widths ranging from 300 to 400 μm and flap thickness ranging from 10 to 13 μm. The results indicate that flap displacement and flow rate are strongly dependent on flap thicknesses and to a lesser degree on flap widths increases. The resonance frequency with valve flap thickness increases and width decreases. Comparison between predicted and measured flow rate shows good agreement. A flow rate up to 35 cc/sec was measured. A failure criterion is also presented using the fracture stress analysis and shows good agreement with experimental result.Copyright © 2005 by ASME
Crystal-induced arthritis.

The acute arthritis in gout and in pseudogout is associated with microcrystals of monosodium urate and calcium pyrophosphate dihydrate, respectively. These conditions share certain clinical feature...
Standardization of quality assurance audit conducted in GLP facility

Quality assurance(QA) Unit should ensure that the facilities,equipment and nonclinical studies are compliant with Good Laboratory Practice(GLP) to guarantee the quality and integrity of the studies.We described the basic principle,audit type and QA statement according to both Chinese and Organization for Economic Cooperation and Development(OECD) GLP.QA Unit should explore audit method,improve audit criteria and enhance audit efficiency according to GLP principles.
Diversity of Ca2+-mobilizing mechanisms Focus on “cGMP-mediated Ca2+ release from IP3-insensitive Ca2+ stores in smooth muscle”

the current article in focus by Murthy and Makhlouf (Ref. [19][1]; see p. C1199 in this issue) reports and discusses in some detail cGMP-mediated Ca2+ release in smooth muscle cells isolated from the circular layer of the rabbit stomach. The authors note that 8-bromo-cGMP, nitric oxide (NO), and
Revisiting the Role of Explicit Genre Instruction in the Classroom.

At the end of the twentieth century, genre theorists and practitioners debated the possibility of explicitly teaching genres in classrooms. Though the debate is decades old, it continues to be rele...
MeSHDD: Literature-based drug-drug similarity for drug repositioning

Objective Drug repositioning is a promising methodology for reducing the cost and duration of the drug discovery pipeline. We sought to develop a computational repositioning method leveraging annotations in the literature, such as Medical Subject Heading (MeSH) terms. Methods We developed software to determine significantly co-occurring drug-MeSH term pairs and a method to estimate pair-wise literature-derived distances between drugs. Results We found that literature-based drug-drug similarities predicted the number of shared indications across drug-drug pairs. Clustering drugs based on their similarity revealed both known and novel drug indications. We demonstrate the utility of our approach by generating repositioning hypotheses for the commonly used diabetes drug metformin. Conclusion Our study demonstrates that literature-derived similarity is useful for identifying potential repositioning opportunities. We provided open-source code and deployed a free-to-use, interactive application to explore our database of similarity-based drug clusters (available at ).
Carrier relaxation and impact ionization in core-shell III–V nanowires

Nanowires are promising candidates for photovoltaic devices due to their large band gaps and reduced electron-phonon interactions. In the present paper, full band Monte Carlo simulations are performed on square In 0.53 Ga 0.47 As nanowires along [100] cladded with InP to study the energy relaxation of carriers in these wires. The carriers are optically excited above the band gap of the cladded nanowire and the energy relaxation times are analyzed for different cladding and core thicknesses. The percentage of carriers undergoing an impact ionization event is also presented.
A low-cost soft-switching high step-up flyback converter with stacked output cells

A low-cost isolated high step-up dc-dc converter with a single switch and multiple output cells is proposed. The magnetizing inductance of the multiple-winding transformer and a multitude of capacitors are used to form a parallel LC resonant link. The capacitors create a Zero Voltage Switching (ZVS) condition at turn-on and turn-off and reduce the switching losses of the switch and diodes. Rate of voltage change (dv/dt) on all semiconductors is limited by the link capacitors, and the diodes turn off with suppressed reverse recovery transients. The converter requires no auxiliary clamps or switches to achieve soft-switching. An analytical approach is developed to establish a relationship between link parameters, input and output voltages, and link frequency. Experimental results on a 60 V to 600 V converter at 250 W are included to corroborate the design and operation.
Data on the effect of sex on the size, cellular content, and neuronal density of the developing brain in mice exposed to isoflurane and carbon monoxide.

Abstract The data presented here detail the changes in size, cellular content, and neuronal density of the developing brain over time with respect to sex in C57Bl/6 mice following neonatal exposure to isoflurane, carbon monoxide, or their combination. Specifically, brain weight- and brain volume-to-body weight ratios are presented, representative immunoblots of whole brain cell-specific protein content are depicted, and quantification of the number of neurons in the primary somatosensory cortex and CA3 region of the hippocampus are shown. Three discrete postnatal time points are represented: P7 (prior to exposure), P14 (one-week post exposure), and P42-56 (5–7 weeks post exposure). Major findings from the data presented here are reported in the manuscript “Carbon Monoxide Incompletely Prevents Isoflurane-induced Defects in Murine Neurodevelopment" (Wang et al., in press) [1] .
Motivation, Activation, and Behavioral Integration

The lateral hypothalamus has long been regarded as an important neural substrate for the expression of motivated behavior. Electrical or chemical stimulation of the hypothalamus can elicit a wide range of species-typical responses, including feeding, drinking, attack, and mating (see, e.g., Myers, 1974; Roberts, 1970). Conversely, ablation of the hypothalamus disrupts the natural counterparts of these elicited behaviors (Anand & Brobeck, 1951; Brookhart & Dey, 1941; Caggiula, Antelman, & Zigmond, 1973; Hitt, Hendricks, Ginsberg, & Lewis, 1970; Karli & Vergnes, 1964; Teitelbaum & Epstein, 1962; Teitelbaum & Stellar, 1954; Wolgin & Teitelbaum, 1978). Historically, these results have been attributed to the direct manipulation of hypothalamic circuits mediating specific motivational states (e.g., Hoebel, 1975; Roberts, 1969, 1970; Stellar, 1954). However, during the past decade three lines of evidence have suggested that circuits subserving relatively nonspecific functions are also importantly involved. First, Valenstein and his colleagues have shown that the hypothalamic circuits mediating feeding and drinking are more “plastic” than previously thought (Valenstein, Cox, & Kakolewski, 1970). For example, feeding elicited by electrical stimulation of the hypothalamus can be transformed to drinking simply by replacing the rat’s food with a drinking tube containing water (Valenstein, Cox, & Kakolewski, 1968).