cssi/SciSciGPT-SciSciNet huggingface dataset:
Alcohol consumption and prehypertension: an investigation of university youth.

Prehypertension and heavy alcohol consumption increase the risk for primary hypertension (PH), a major predictor of cardiovascular-related morbidity and mortality. Although undergraduate college students have exhibited prehypertensive blood pressure (BP) levels and more than 40% of undergraduates drink heavily, few researchers have examined both risk factors in the university context. In this study, the authors collected BP and self-reported quantity and frequency of alcohol consumption data from 211 undergraduates (95 women). Logistic regression analyses showed that prehypertensive undergraduates (ie, those with systolic BP ≥ 120 mm Hg or diastolic BP ≥ 85 mm Hg) were nearly 4 times more likely to consume alcohol levels associated with increased risk for developing PH. Additional research on alcohol and PH among adolescents and undergraduates is needed, with particular reference to mechanisms and reducing the risk for morbidity and mortality emanating from cardiovascular disease.
Pseudo-occlusions of the internal carotid artery: A rationale for treatment on the basis of a modified carotid duplex scan protocol

Abstract Purpose: We report on a modified duplex scanning technique that may be a means of detecting a patent internal carotid artery (ICA) previously believed to be occluded by means of magnetic resonance angiography (MRA), standard duplex protocols, or both. In addition, we attempted to develop selection criteria for operability in this setting, on the basis of the lumen diameter and wall thickness of the post-stenotic ICA segment. Method: In the past 22 months, 17 patients (12 men; 5 women) with ICA occlusions reported by means of MRA (10 patients) or by means of duplex scanning (7 patients) were found to have patent arteries when subjected to this duplex scanning protocol: (1) the use of low pulse repetition frequency (150-350 Hz), maximal persistence, and sensitivity of color and power angiography modes; (2) the use of an 8-MHz to 5-MHz probe as a means of visualizing the most distal extracranial segment of the ICA; and (3) measurements of the lumen diameter and wall thickness of the post-stenotic ICA. The age of patients ranged from 53 to 80 years (mean age, 71 years). Seven patients (41%) had no symptoms. Results: Extremely low peak systolic and end-diastolic velocities were detected distal to the stenotic segment in the ICA in all cases, and they varied from 5 to 30 cm/s (mean, 14 ± 8 cm/s) and 0 to 8 cm/s (mean, 4.5 ± 2.0 cm/s), respectively. The luminal diameter of the post-stenotic ICA varied from 0.7 to 3.6 mm (mean, 2.0 ± 1.1 mm), and the wall thickness ranged from 0.6 to 1.4 mm (mean, 0.9 ± 0.3 mm) in all patients. Twelve patients (71%) were examined with the intent of performing an endarterectomy. Of these, eight patients (47%) underwent successful operations with patches (3 vein; 5 synthetic), and four (29%) were found to have unreconstructable disease. The ICA lumen diameter and wall thickness in all eight patients who underwent endarterectomies were 2 mm or larger and 1 mm or thinner, respectively, whereas they were smaller than 2 mm and thicker than 1 mm, respectively, in the remaining four patients ( P 1 mm). Intraoperative and early postoperative duplex scanning examinations were performed in the eight ICAs that were successfully reconstructed. In these patients, the ICA lumen diameter increased from a mean of 2.9 ± 0.4 mm preoperatively to a mean of 4.4 ± 0.3 mm 2 weeks postoperatively ( P Conclusion: The proposed duplex protocol appears to be an effective means of identifying some patients with patent ICAs that were believed to be occluded by means of standard examinations. In addition, such patients may be candidates for an endarterectomy if the ICA post-stenotic lumen diameter is 2 mm or larger and the wall thickness is 1 mm or thinner. (J Vasc Surg 2002;35:340-5.)
Accumulation of different precursor ribonucleoprotein particles by various cold sensitive, antibiotic resistant mutants

Abstract An analysis was carried out of precursor ribonucleoprotein particles produced by cold sensitive (subunit assembly defective) mutants from Escherichia coli which are either resistant to spectinomycin alone or to both spectinomycin and streptomycin. It was found that while most spectinomycin-resistant mutants accumulated precursor particles sedimenting at 26-28S and around 30S, several streptomycin-spectinomycin double resistant mutants accumulated a 21S particle. Precursor 26-28S and 30S particles contain 17S precursor RNA which can be chased into mature RNA by a temperature shift-up. The nature of accumulation of precursor particles was discussed in relation to the scheme of biosynthesis of the 30S ribosomal subunit.
Performance comparison of charcoal cookstoves for Haiti: Laboratory testing with Water Boiling and Controlled Cooking Tests

Charcoal cooking accounts for a large portion of Haiti's energy usage and leads to severe economic, health, and environmental hardships. Organizations are hoping that fuel-efficient cookstoves can help solve the problem. In this study, four charcoal cookstoves intended for dissemination in Haiti were rigorously assessed and compared using Water Boiling and Controlled Cooking Tests.Due to the poor thermal efficiency of the traditional stove, all improved stoves saved fuel on average over the traditional with the majority also reducing the total emissions released. However, the traditional stove could be difficult to replace because it had the fastest time-to-boil, an important consideration for end users. Through the testing, the number of trials conducted was found to be an important consideration for error analysis. Also, noticeable differences in stove performance were seen between the two protocols, supporting arguments by prior researchers of the necessity to use multiple test protocols for practically useful comparisons.
Surface Roughening and Unstable Neck Formation in Faceted Particles: II, Mathematical Modeling

Unstable neck formation between two isolated particles was analyzed by considering the effects of both faceted and rounded (i.e., atomically rough) surfaces. Mathematical descriptions of both neck growth and rupture are developed. Calculations conducted with these formulations can explain the neck instability observed by Rankin and Boatner. The analysis and the experimental data suggest that the energy barrier associated with forming a new atomic layer on top of a faceted surface can restrict the shape evolution of a crystalline particle, even at moderately high temperatures. The analysis also indicates that this energy barrier can be overcome when the positive curvature which initially exists at a facet/rough surface boundary reverses as a result of neck growth. This latter effect offers an explanation for neck rupture which is consistent with the experimental results. In addition to providing an explanation for this phenomenon, the analyses also demonstrate that surface phase boundaries and step energy barriers can have a significant effect on microstructure evolution during solid-state sintering.
Agency culture, cumulative causation and development in Glacier National Park, Montana

Abstract Glacier National Park, Montana, and its transmountain road exemplify two critical factors in park management; the role of public demands and agency culture in policy-making, and a self-perpetuating domino effect of development. The National Park Service and the public have developed a culture of beliefs including the public's right to park access, the beneficial effects of the wilderness experience, the need for an educational program in the parks, and the propriety of the automobile to bring about these goals. Following these convictions, the Park Service at Glacier constructed a popular transmountain road which initiated a process of cumulative causation. In this process each infrastructural addition encouraged more use which in turn demanded more infrastructure. The roles of agency culture and cumulative causation have implications for national parks and reserved areas worldwide.
Association of blood pressure and aortic distensibility with P wave indices and PR interval: The Multi-Ethnic Study of Atherosclerosis (MESA)

Abstract Introduction Hypertension is an established risk factor for atrial fibrillation. Understanding the association of blood pressure (BP) levels and aortic distensibility with P wave indices (PWIs) and PR interval, intermediate phenotypes of atrial fibrillation, could provide insights into underlying mechanisms. Methods This analysis included 3180 men and women aged 45–84 years participating in the Multi-Ethnic Study of Atherosclerosis, a community-based cohort in the United States. Aortic distensibility was evaluated in 2243 of these individuals using cardiac magnetic resonance imaging. PWIs and PR interval were automatically measured in standard 12-lead ECGs. Sitting BP and other cardiovascular risk factors were assessed using standardized protocols. Left ventricular mass was measured by magnetic resonance imaging. Results Higher systolic BP, and diastolic BPs and greater pulse pressure were associated with a significantly greater P wave terminal force. These associations, however, were markedly attenuated or disappeared after adjustment for left ventricular mass. Systolic BP, diastolic BP, and pulse pressure were not strongly associated with PR interval or maximum P wave duration. Reduced aortic distensibility was associated with a longer PR interval but not with PWIs: compared with individuals in the top quartile of aortic distensibility, participants in the lowest quartile had on average a 3.7-ms longer PR interval (95% CI: 0.7, 6.7, p = 0.02), after multivariable adjustment. Conclusion In this large community-based sample, associations of BP and aortic distensibility with PWIs and PR interval differed. These results suggest that processes linking hypertension with the electrical substrate of atrial fibrillation, as characterized by these intermediate phenotypes, are diverse.
Teaching English Language Learners At Risk for Reading Disabilities to Read: Putting Research into Practice

The purpose of this article is to describe features of interventions that are empirically validated for use with first-grade students at risk for reading disabilities who are English language learners (ELLs) and whose home language is Spanish. The empirical evidence supporting these interventions is summarized. Interventions for improving oral language and reading abilities with struggling readers who are ELLs taught in either Spanish or English are described as a means to assist school districts and teachers in defining and implementing effective interventions for ELLs at risk for reading difficulties. The interventions described may be useful to educators seeking information about Response to Intervention as a means of identifying ELLs who require services for learning disabilities.
Growth Inhibition, Cell-Cycle Dysregulation, and Induction of Apoptosis by Green Tea Constituent (-)-Epigallocatechin-3-gallate in Androgen-Sensitive and Androgen-Insensitive Human Prostate Carcinoma Cells

Prostate cancer (PCA) is the most prevalent cancer diagnosed and the second leading cause of cancer-related deaths among men in the United States. Descriptive epidemiological data suggest that androgens and environmental exposures play a key role in prostatic carcinogenesis. Since androgen action is intimately associated with proliferation and differentiation, at the time of clinical diagnosis in humans most PCA represent themselves as a mixture of androgen-sensitive and androgen-insensitive cells. Androgen-sensitive cells undergo rapid apoptosis upon androgen withdrawal. On the other hand, the androgen-insensitive cells do not undergo apoptosis upon androgen blocking, but maintain the molecular machinery of apoptosis. Thus, agents capable of inhibiting growth and/or inducing apoptosis in both androgen-sensitive and androgen-insensitive cells will be useful for the management of PCA. In the present study, we show that (-)-epigallocatechin-3-gallate (EGCG), the major polyphenolic constituent present in green tea, imparts antiproliferative effects against both androgen-sensitive and androgen-insensitive human PCA cells, and this effect is mediated by deregulation in cell cycle and induction of apoptosis. EGCG treatment was found to result in a dose-dependent inhibition of cell growth in both androgen-insensitive DU145 and androgen-sensitive LNCaP cells. In both the cell types, EGCG treatment also resulted in a dose-dependent G(0)/G(1)-phase arrest of the cell cycle as observed by DNA cell-cycle analysis. As evident by DNA ladder assay, confocal microscopy, and flow cytometry, the treatment of both DU145 and LNCaP cells with EGCG resulted in a dose-dependent apoptosis. Western blot analysis revealed that EGCG treatment resulted in (i) a dose-dependent increase of p53 in LNCaP cells (carrying wild-type p53), but not in DU145 cells (carrying mutant p53), and (ii) induction of cyclin kinase inhibitor WAF1/p21 in both cell types. These results suggest that EGCG negatively modulates PCA cell growth, by affecting mitogenesis as well as inducing apoptosis, in cell-type-specific manner which may be mediated by WAF1/p21-caused G(0)/G(1)-phase cell-cycle arrest, irrespective of the androgen association or p53 status of the cells.
Very large scale integration (VLSI) implementation of block-based predictive Rice codec

This paper presents a VLSI implementation of the lossless block-based predictive Rice codec (BPRC). The BPRC uses an adaptive predictive coding algorithm to remove the redundancy in the image, codes the residue using an entropy coder. This algorithm can adapt well to local images statistics. The codec chip will encode 4 to 16-bit pixels at 10 Mpixels/sec input, and decode at 10 Mpixels/sec output. For images of normal size it requires little supports circuitry, only input data formatting and output data defomatting. Large images can be supported with external FIFOs.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Peak Capacity Optimization of Peptide Separations in Reversed-Phase Gradient Elution Chromatography: Fixed Column Format

The optimization of peak capacity in gradient elution RPLC is essential for the separation of multicomponent samples such as those encountered in proteomic research. In this work, we study the effect of gradient time (tG), flow rate (F), temperature (T), and final eluent strength (phi(final)) on the peak capacity of separations of peptides that are representative of the range in peptides found in a tryptic digest. We find that there are very strong interactions between the individual variables (e.g., flow rate and gradient time) which make the optimization quite complicated. On a given column, one should first set the gradient time to the longest tolerable and then set the temperature to the highest achievable with the instrument. Next, the flow rate should be optimized using a reasonable but arbitrary value of phi(final). Last, the final eluent strength should be adjusted so that the last solute elutes as close as possible to the gradient time. We also develop an easily implemented, highly efficient, and effective Monte Carlo search strategy to simultaneously optimize all the variables. We find that gradient steepness is an important parameter that influences peak capacity and an optimum range of gradient steepness exists in which the peak capacity is maximized.
Localization and Function of SolubleN-Ethylmaleimide-sensitive Factor Attachment Protein-25 and Vesicle-associated Membrane Protein-2 in Functioning Gastric Parietal Cells

The soluble N-ethylmaleimide-sensitive factor attachment protein of 25 kDa (SNAP-25) plays an important role in vesicle trafficking. Together with vesicle-associated membrane protein-2 (VAMP-2) and syntaxin, SNAP-25 forms a ternary complex implicated in docking and fusion of secretory vesicles with the plasma membrane during exocytosis. These so-called SNARE proteins are believed to regulate tubulovesicle trafficking and fusion during the secretory cycle of the gastric parietal cell. Here we examined the cellular localization and functional importance of SNAP-25 in parietal cell cultures. Adenoviral constructs were used to express SNAP-25 tagged with cyan fluorescent protein, VAMP-2 tagged with yellow fluorescent protein, and SNAP-25 in which the C-terminal 25 amino acids were deleted (SNAP-25 Delta181-206). Membrane fractionation experiments and fluorescent imaging showed that SNAP-25 is localized to the apical plasma membrane. The expression of the mutant SNAP-25 Delta181-226 inhibited the acid secretory response of parietal cells. Also, SNAP Delta181-226 bound poorly in vitro with recombinant syntaxin-1 compared with wild type SNAP-25, indicating that pairing between syntaxin-1 and SNAP-25 is required for parietal cell activation. Dual expression of SNAP-25 tagged with cyan fluorescent protein and VAMP-2 tagged with yellow fluorescent protein revealed a dynamic change in distribution associated with acid secretion. In resting cells, SNAP-25 is at the apical plasma membrane and VAMP-2 is associated with cytoplasmic H,K-ATPase-rich tubulovesicles. After stimulation, the two proteins co-localize on the apical plasma membrane. These data demonstrate the functional significance of SNAP-25 as a SNARE protein in the parietal cell and show the dynamic stimulation-associated redistribution of VAMP-2 from H,K-ATPase-rich tubulovesicles to co-localize with SNAP-25 on the apical plasma membrane.
Magnetic sensor operation onboard a UUV: magnetic noise investigation using a total-field gradiometer

To operate a magnetic sensor on board an Unmanned Underwater Vehicle (UUV), it is necessary to provide a means for compensating magnetic noise from a variety of sources. In previous applications involving passively towed platforms, the noise arises from the magnetic fields due to eddy currents and magnetic polarization changes occurring due to rotation of the platform in the earth's magnetic field. It has been demonstrated that this noise can be compensated with a single vector magnetometer that is rigidly attached to the sensor of interest, measuring the rotational changes in the earth's magnetic field. This compensation algorithm has been extended, for passively towed platforms, to provide both motion noise reduction and localization of magnetic dipole targets, in a single process. On a UUV, noise sources are present in addition to those induced by the earth's magnetic field. There are active elements present, such as current loops, motors, actuators, sonars, and electronic devices. To compensate for these additional sources, it is necessary to add additional reference sensors, and to employ more complex compensation models. In a recent MTS/IEEE Oceans paper, a preliminary investigation of such models was made for several prototype UUVs, for both a fluxgate tensor gradiometer and a single-axis total field gradiometer. The total-field gradiometer is the most sensitive of the devices and was operated onboard an active Bluefin BPAUV UUV. The UUV was mounted on a three-axis motion table, and the results obtained were encouraging. In the present paper, we apply a multi-reference sensor magnetic noise compensation algorithm to a single-axis total-field gradiometer operating in the environment of a completely redesigned Bluefin platform, the RELIANT UUV, again mounted on a three-axis motion table. This vehicle has a different configuration from that of the BPAUV, including a very different battery design. We examine in detail the effect of the positioning and number of reference sensors, and show that these issues are critical to performance. We investigate the effect of the positioning of the magnetic sensor relative to other platform systems and find this to be an important issue. Finally we conclude that the performance of the sensor onboard the RELIANT platform using all available reference sensors is roughly the same as that demonstrated onboard the BPAUV.
Saliva as a diagnostic fluid

In the last 10 years, the use of saliva as a diagnostic fluid has become somewhat of a translational research success story. Technologies are now available enabling saliva to be used to diagnose disease and predict disease progression. This review describes some important recent advances in salivary diagnostics and barriers to application and advancement. This review will also stimulate future research activity.
Animation of graphic symbols representing verbs and prepositions: effects on transparency, name agreement, and identification.

Purpose The effects of animation on transparency, name agreement, and identification of graphic symbols for verbs and prepositions were evaluated in preschoolers of 3 age groups. Methods A mixed-gr...
Selective Positive–Negative Feedback Produces the Winner-Take-All Competition in Recurrent Neural Networks

The winner-take-all (WTA) competition is widely observed in both inanimate and biological media and society. Many mathematical models are proposed to describe the phenomena discovered in different fields. These models are capable of demonstrating the WTA competition. However, they are often very complicated due to the compromise with experimental realities in the particular fields; it is often difficult to explain the underlying mechanism of such a competition from the perspective of feedback based on those sophisticate models. In this paper, we make steps in that direction and present a simple model, which produces the WTA competition by taking advantage of selective positive-negative feedback through the interaction of neurons via p-norm. Compared to existing models, this model has an explicit explanation of the competition mechanism. The ultimate convergence behavior of this model is proven analytically. The convergence rate is discussed and simulations are conducted in both static and dynamic competition scenarios. Both theoretical and numerical results validate the effectiveness of the dynamic equation in describing the nonlinear phenomena of WTA competition.
Proof of Weierstrass approximation theorem using band-limited functions

A proof of the Weierstrass approximation theorem is obtained using the Fourier transform and band-limited functions.
Vitamin D and prostate cancer risk.

Prostate cancer is a progressive, multistep disease which presents many stages for intervention. Microscopic cancer is found in the prostate beginning by age 30 in about 20% of men, and the incidence
Measurement of 5'-adenylic acid by stimulation of phosphorylase a.

Abstract A method for measuring 5′-adenylic acid is described which is based on its capacity to stimulate the activity of phosphorylase a in the presence of low levels of glycogen and inorganic P. The method is useful with very low concentrations of AMP (0.02 to 0.5 μ m ) and is unaffected by much higher levels of ADP and ATP. Other common mononucleotides do not interfere at concentrations likely to be encountered. Yields of final product (NADPH) as high as 500 mol/mol of AMP can be obtained. Protocols are given for measuring as much as 5 × 10−10 mol at one extreme and as little as 10−15 mol at the other.
Climate change and the world predicament: A case study for interdisciplinary research

The relationship between climatic change and issues of population, food, resources, environment and the human condition i.e., the world predicament, are explored. It is concluded that society is dangerously vulnerable to natural climatic variability at times of depleted food reserves (such as now) and that massive use of technologies (especially energy) to improve the human condition could well cause significant climatic change as early as the year 2000. Therefore, these problems cannot be addressed in the sole context of disciplinary research, and the obstacles and opportunities for interdisciplinary research at academic institutions are explored. Criteria for interdisciplinary research quality review are suggested, and contrasted to traditional peer review processes.
Kurchi Bark (Cortex Holarrhenae antidysentericae) A Drug of Great Therapeutic Potential

AbstractApproximately three hundred biological drugs are recognized in the current Pharmacopoeia of India1), a number which surpasses that of any other pharmacopeia available to us. This fact strongly indicates that natural drugs play a greater therapeutic role in India than in most other countries.
An Asymmetric Micropolar Moment Tensor Derived from a Discrete-Block Model for a Rotating Granular Substructure

Abstract I define an asymmetric moment tensor for individual slip events and for an average over multiple slip events using a discrete rigid-block model to account for the brittle deformation of a granular material. For the brittle crust, the grains are taken to be fault-bounded blocks. Permanent deformation accumulates by slip events on the boundaries of the blocks. The deformation is described by two independent motions: the local relative motion of the block centroids and the local rigid rotation of the blocks about their centroids. Averaging each of these local motions over multiple slip events in a volume defines both the macrodeformation, which consists of the macrostrain and macrorotation, and the microrotation. An asymmetric local micropolar moment tensor and an asymmetric micropolar moment-density tensor are defined from the local and the averaged motions, respectively. The model shows (1) the symmetric part of the micropolar moment tensors depends on the constant-volume local shear strain of the block centroids or its averaged equivalent, the macrostrain; (2) the antisymmetric part depends on an objective quantity defined as the difference between the rotational component associated with the centroid deformation and the local block rotation, or their averaged equivalents the macrorotation and the microrotation; and (3) the symmetric and antisymmetric parts of the micropolar moment-density tensor can be inferred up to a scalar magnitude by a micropolar inversion of standard seismic focal mechanisms. Three field tests show consistency with the theory, but definitive tests are thwarted by insufficient quantitative information or insufficient resolution of the available data.
Commentary: Relativism and justifying conclusions in naturalistic evaluations

Abstract This commentary is structured around two different definitions for the concept of relativism. The contention is that a great deal depends on the particular interpretation one gives to this concept — not only for understanding the particular positions elaborated in these papers, but also for a general understanding of the issue of justifying conclusions in evaluations.
Urban topography: 3D database construction for propagation modeling in an urban environment

ABSTRACT Construction of Digital Elevation Models (DEMs) for natural earth surfaces have now becomecommon practice. What does one do when the topography is caused by the closely-spaced tallbuildings of lower Manhattan, New York City? (What we choose to call 'urban topography.')Although the DEM principles are applicable, special problems were encountered in this veryexciting and innovative project, requiring unique solutions, which are all discussed in this article. 2. URBAN TOPOGRAPHY A unique 3-Dimensional digital propagation model of Manhattan south of 34th street was con-structed for NYNEX Science and Technology by the Center for the Applied Studies of the Envi-ronment (CAPSE). The work was done at the Hunter College Department of Geography's SpatialAnalysis and Remote Sensing Laboratory. The purpose of the model is to assist NYNEX in deter-mining the optimal distribution of broadcast and reception antenna to bring improved wirelesstelecommunication services such as cellular phone networks and interactive television, to resi-dents of Manhattan.The digital model is comprised of: (a) footprints of buildings south of 34th Street, Manhattan,stored as Arclnfo coverages with building height as a polygon attribute; and (b) a DEM of the'natural terrain'. In order to achieve a true elevation of the buildings, rather than just buildingheights, the building footprint coverage is overlaid on a digital elevation model (DEM) of the 'nat-ural terrain' of the corresponding area.
Responses of single cells in the olfactory bulb of rabbits to air flow

Responses to a purified air stream were recorded from single cells in the olfactory bulb of rabbits. A large number of cells responded to ipsilateral stimulation and some cells also to contralateral stimulation. The lowest thresholds of 10–20 cm3 air/min were observed in encephale isole preparations under local anesthesia. Most flow responses were excitatory, with phasic and tonic components. In general the phasic component showed a better correlation to the air flow rate than the tonic component. In response to continuous stimulations with constant flow intensities the responses were either constant, decremental or incremental. Incremental effects could last many seconds and declined with frequent repetitions of the stimulus. Excitatory afterresponses were generally associated with incremental responses.
Scratch resistance and durability enhancement of bulk heterojunction organic photovoltaics using ultra-thin alumina layers

Abstract Atomic layer deposition (ALD) was studied for ultra-thin (≤100 nm) barrier coating deposition onto organic photovoltaics (OPVs) to enhance device lifetime. Herein, we report the first known investigation of the mechanical characteristics of AlO x encapsulated OPVs using nanoindentation and scratch testing with deposition temperature as a tunable parameter. The higher organic content in the AlO x film, grown at lower temperatures, enhanced the interfacial bonding at the AlO x –OPV interface and provided modulus and hardness performance exceeding that of a common polymer encapsulant. Furthermore, AlO x ׳s organic content impeded fracture propagation, confirming the durability enhancement associated with this approach.
Investigating the translocation of lambda-DNA molecules through PDMS nanopores.

We investigate the translocation of λ-DNA molecules through resistive-pulse polydimethylsiloxane (PDMS) nanopore sensors. Single molecules of λ-DNA were detected as a transient current increase due to the effect of DNA charge on ionic current through the pore. DNA translocation was found to deviate from a Poisson process when the interval between translocations was comparable to the duration of translocation events, suggesting that translocation was impeded during the presence of another translocating molecule in the nanopore. Characterization of translocation at different voltage biases revealed that a critical voltage was necessary to drive DNA molecules through the nanopore. Above this critical voltage, frequency of translocation events was directly proportional to DNA concentration and voltage bias, suggesting that transport of DNA from the solution to the nanopore was the rate limiting step. These observations are consistent with experimental results on transport of DNA through nanopores and nanoslits and the theory of hydrodynamically driven polymer flow in pores.
Optical characterization of attenuated phase shifters

The optical properties of an amorphous hydrogenated carbon film utilized as an attenuated phase shifter were characterized using a n and k Analyzer. This novel instrument computes univocal values of the index of refraction n((lambda) ), extinction coefficient k((lambda) ), and film thickness from a reflectance or reflectance/transmittance single scan covering 190 nm to 900 nm. By fitting the scanned curves, values of k as a function of wavelength or energy can be calculated and then the index n is computed by using Kramers-Kronig equations. Since the n and k Analyzer calculates n, k, and thickness from a single reflectance scan, phase angles can be easily calculated at any given wavelength between 900 and 190 nm. To test the accuracy of this instrument we have compared phase angles obtained by using the n and k Analyzer against laser interferometry at 257 nm. In this technique direct phase measurements are obtained by comparing the difference in the optical path of the beams going through the quartz and the film/quartz structure. The agreement between the two techniques was very good to within 103 degrees for eight of the nine samples analyzed. Interferometer phase errors are conservatively estimated to be around +/- 3 degrees. This includes noise levels as well as day to day variations. The agreement between the two techniques resides within the experimental errors. Thus, this analyzer can give phase angle maps of a blank film on quartz substrates in a relatively short time and nondestructively.
A small metalloribozyme with a two-step mechanism.

An RNA molecule consisting of an asymmetric internal loop of six nucleotides can be rapidly and specifically cleaved by Pb2+ in the presence of Mg2+. The 5′ cleavage product terminates with a 3′ phosphomonoester generated from a 2′,3′-cyclic phosphodiester reaction intermediate. This two-step reaction mechanism resembles that of many protein ribonucleases but has not previously been observed for reactions catalysed by RNA.
Agrarianism: A Critique of Colonial Modernity in Korea

In Rescuing History from the Nation, Prasenjit Duara challenges the repressive power of the nation-state to frame historical narratives in modern China and India. According to Duara, dominant narratives in both countries have been based on a linear, evolutionary, Enlightenment model of history that stresses national progress toward modernity, whether through idealist evolutionism, anti-imperialism, or even Marxism. As a result, he argues, such narratives have excluded other important discourses on political community that rejected the modernist mode of thought. In order to provide a “multiplicity of historical representations of political community,” he examines a series of alternate narratives like federalism, which promoted goals other than the nation-state, or which expressed critiques of modernity through the promotion of “Asian values.” With this, he attempts to “rescue” historical narratives from the dominant, repressive power of the nation-state, by writing “histories that resist being pressed into the service of the national subject in its progress toward modernity.”Prasenjit Duara, Rescuing History from the Nation (Chicago: University of Chicago Press, 1995).
Studies on the Stabilization of Carotene in Dehydrated Feeds and Foods

Summary 1. The effects of various physical and chemical treatments upon the stability of carotene in dehydrated alfalfa and oats were studied. 2. Additional heat treatment was effective in decreasing the loss of carotene in dehydrated oats from 70–80 per cent to 30–50 per cent in six months. The loss in one sample of dehydrated alfalfa was reduced from 70 to 50 per cent in six months. 3. The addition of 0.9 per cent diphenylamine to dehydrated oats reduced the loss of carotene from 77 to 41 per cent in six months. The loss of carotene from dehydrated alfalfa was reduced from 60 to 30 per cent in three months by the addition of diphenylamine. 4. In the concentrations and conditions used, the following were ineffective in reducing the loss of carotene during storage: sodium thiosulfate, sulfuric acid, glucoascorbic acid, d-isoascorbic acid, sodium isoascorbate, guaiac, citric acid, tartaric acid, phosphoric acid, sodium bicarbonate, disodium phosphate, urea, ammonia, alpha-tocopherol and hydroquinone. 5. Protection of dehydrated oats from the air by pelleting and coating with Plexowax reduced the loss of carotene from 74 to 45 per cent in six months. 6. Dehydrated sweet potatoes, stored as slices, lost only 5 per cent of their carotene in six months. When ground and stored, the loss of carotene was 65 per cent in six months. 7. Dehydrated diced carrots lost no carotene during the first three months of storage, and lost 25 per cent during the second three months; when the dehydrated diced carrots were compressed into pellets, breaking the outer surface, the loss was 66 per cent in six months. The loss of carotene from dehydrated sliced carrots was much more rapid than from dehydrated diced carrots.
An overview of recent developments in genomics and associated statistical methods.

The landscape of genomics has changed drastically in the last two decades. Increasingly inexpensive sequencing has shifted the primary focus from the acquisition of biological sequences to the study of biological function. Assays have been developed to study many intricacies of biological systems, and publicly available databases have given rise to integrative analyses that combine information from many sources to draw complex conclusions. Such research was the focus of the recent workshop at the Isaac Newton Institute, ‘High dimensional statistics in biology’. Many computational methods from modern genomics and related disciplines were presented and discussed. Using, as much as possible, the material from these talks, we give an overview of modern genomics: from the essential assays that make data-generation possible, to the statistical methods that yield meaningful inference. We point to current analytical challenges, where novel methods, or novel applications of extant methods, are presently needed.
A new spring-driven implantable drug infusion pump

An implantable infusion pump which uses elastomer spring pressure to provide constant-rate drug delivery is described. Desirable features of the design are its low-cost construction, temperature and pressure insensitivity, high volumetric efficiency, and scale flexibility. Test results for prototype models are reported. Spring performance characteristics appear to be unaffected by long-term implantation. The results indicate that the pump is suitable for multiple-drug-delivery applications requiring more than an infusion port but needing a programmable device. >
Developmental toxicity evaluation of berberine in rats and mice

BACKGROUND: Berberine, a plant alkaloid, is found in some herbal teas and health-related products. It is a component of goldenseal, an herbal supplement. Berberine chloride dihydrate (BCD) was evaluated for developmental toxicity in rats and mice. METHODS: Berberine chloride dihydrate was administered in the feed to timed-mated Sprague–Dawley (CD) rats (0, 3625, 7250, or 14,500 ppm; on gestational days [GD] 6–20), and Swiss Albino (CD-1) mice (0, 3500, 5250, or 7000 ppm; on GD 6–17). Ingested doses were 0, 282, 531, and 1313 mg/kg/day (rats) and 0, 569, 841, and 1155 mg/kg/day (mice). RESULTS:There were no maternal deaths. The rat maternal lowest observed adverse effect level (LOAEL), based on reduced maternal weight gain, was 7250 ppm. The rat developmental toxicity LOAEL, based on reduced fetal body weight per litter, was 14,500 ppm. In the mouse study, equivocal maternal and developmental toxicity LOAELs were 5250 ppm. Due to scattering of feed in the high dose groups, a gavage study at 1000 mg/kg/day was conducted in both species. CONCLUSIONS: In rats, maternal, but not fetal adverse effects were noted. The maternal toxicity LOAEL remained at 7250 ppm (531 mg/kg/day) based on the feed study and the developmental toxicity NOAEL was raised to 1000 mg/kg/day BCD based on the gavage study. In the mouse, 33% of the treated females died. Surviving animals had increased relative water intake, and average fetal body weight per litter decreased 5–6% with no change in live litter size. The maternal toxicity LOAEL remained at 5250 ppm (841 mg/kg/day) BCD, based on increased water consumption. The developmental toxicity LOAEL was raised to 1000 mg/kg/day BCD based on decreased fetal body weight. Birth Defects Research (Part B) 77:195–206, 2006. Published 2006 Wiley-Liss, Inc.
Dendritic morphology and development in the ferret medial superior olivary nucleus

Dendritic morphology and development in the medial superior olivary nucleus of the ferret were studied using the Golgi method. In the adult ferret most medial superior olivary neurons had disk-shaped dendritic fields. These dendritic fields were oriented such that cells in a coronal plane of section appeared bipolar with major lateral and medial dendritic axes. In the horizontal plane the dendrites radiated about the soma. Dendrites of principal cells branched distally into tufts of numerous, tertiary processes that were beaded and thin. Peripheral cells in the fiber mantle encircling the nucleus were generally spindle-shaped or tripolar and lacked the tufted dendrites of principal cells. The dendrites of these peripheral cells coursed parallel to the nucleus both dorsoventrally and rostrocaudally. Horizontally oriented dendrites were observed even at birth for some cells in the medial superior olivary nucleus and bipolar dendritic fields were typical of most cells by the end of the second postnatal week. Dendrites of immature cells varied in caliber and radiated in all directions from the soma. Around postnatal days 8-10 transient appendages appeared on the soma and dendrites, first proximally and then more distally. These appendages persisted until the first postnatal month. Cell size and dendritic radius increased markedly during this same period. Postnatal days 28-30 were marked by the first appearance of tufts of tertiary dendritic branches. The tendril-like processes continued to increase in length until about the end of the second postnatal month.
A Case for Internet Streaming via Web Servers

Hosting Internet streaming services has its unique challenges. Aiming at making Internet streaming services be widely and easily adopted in practice, in this paper, we have designed and implemented a system, called SProxy that can leverage existing Internet infrastructure to free the streaming content providers so that they only need to host streaming content through a regular Web server. SProxy has been extensively tested and evaluated and it provides high quality streaming delivery in both local area networks and wide area networks (e.g. between Japan and US).
Effect of membrane bending stiffness on the deformation of capsules in simple shear flow

The effect of interfacial bending stiffness on the deformation of liquid capsules enclosed by elastic membranes is discussed and investigated by numerical simulation. Flow-induced deformation causes the development of in-plane elastic tensions and bending moments accompanied by transverse shear tensions due to the non-infinitesimal membrane thickness or to a preferred configuration of an interfacial molecular network. To facilitate the implementation of the interfacial force and torque balance equations involving the hydrodynamic traction exerted on either side of the interface and the interfacial tensions and bending moments developing in the plane of the interface, a formulation in global Cartesian coordinates is developed. The balance equations involve the Cartesian curvature tensor defined in terms of the gradient of the normal vector extended off the plane of the interface in an appropriate fashion. The elastic tensions are related to the surface deformation gradient by constitutive equations derived by previous authors, and the bending moments for membranes whose unstressed shape has uniform curvature, including the sphere and a planar sheet, arise from a constitutive equation that involves the instantaneous Cartesian curvature tensor and the curvature of the resting configuration. A numerical procedure is developed for computing the capsule deformation in Stokes flow based on standard boundary-element methods. Results for spherical and biconcave resting shapes resembling red blood cells illustrate the effect of the bending modulus on the transient and asymptotic capsule deformation and on the membrane tank-treading motion.
Femtosecond time-resolved measurements of optic phonon dephasing by impulsive stimulated raman scattering in α-perylene crystal from 20 to 300 K

Abstract Excitation and detection of coherent optic phonons by impulsive stimulated Raman scattering (ISRS) is reported. The technique permits femtosecond time-resolved observations of optic phonon oscillations and dephasing. Decay rates of librational and translational optic phonons in α-perylene crystals have been measured in the temperature range 20–30 K.
A Simplified Model for Assessing the Impact of Breachway Modifications on Coastal Pond Circulation and Flushing Dynamics

A simplified hydrodynamics and salt balance model system has been developed for a tidal inlet-costal pond system to predict the consequences of inlet modifications on the inlet flow rate, pond tidal range, and the pond salinity. The hydrodynamics portion of the model solves the momentum and continuity equations for the inlet where the pond behavior is incorporated in the inlet continuity relationship. The salt balance is determined using a tidal prism approach where complete mixing and steady state conditions are assumed. For a single inlet bay system and assuming no inertial acceleration term or fresh-water inflow, an approximate solution of the governing equations is presented. Extension of the model system to a multiple inlet-bay system, following the computational algorithm developed by Seelig et al, is presented and applied to the Charlestown Pond complex located on the southern Rhode Island coast.
Simultaneous separation and detection of cations and anions on a microfluidic device with suppressed electroosmotic flow and a single injection point

A rapid and simultaneous separation of cationic and anionic peptides and proteins in a glass microfluidic device that has been covalently modified with a neutral poly(ethylene glycol) (PEG) coating to minimize protein adsorption is presented. The features of the device allow samples that contain both anions and cations to be introduced from a central flow stream and separated in different channels with different outlets—all in the presence of low electroosmotic flow (EOF) imparted by the PEG coating. The analytes are electrophoretically extracted from a central hydrodynamic stream and electrophoretically separated in two different channels, in which pressure driven flow has been suppressed through the use of hydrodynamic restrictors. Having different outlets for the electrophoretic separation channels that are spatially separated from the injection enables coupling with further downstream functionalities or off-chip detection, such as mass spectrometry. A plug of charged analyte is hydrodynamically pumped to the sampling intersection and anions from the plug migrate electrophoretically toward the anode in one channel while cations migrate toward the cathode in the other channel due to suppressed EOF from the PEG coating. The separations presented here required less than a minute to complete and produced average separation efficiencies of up to about 3,500 plates from a separation length of 2 cm. The extraction efficiency of both cations and anions from the hydrodynamic stream is determined experimentally and compared with a previously reported model that was used to determine anion extraction efficiency. The extraction efficiency is determined to be 87% and 98% for the two sample mixtures analyzed, and the values predicted by the model are within 3.5% of the experimental data. It is anticipated that this basic approach for simultaneous separation of anions and cations with reduced EOF will be integrated into larger microfluidic systems because the design provides separate outlets that can feed downstream processes or linked to off-chip detection.