cssi/SciSciGPT-SciSciNet huggingface dataset:
Barbiturate-mediated regulation of expression of the cytochrome P450BM-3 gene of Bacillus megaterium by Bm3R1 protein.

In a previous publication (Wen, L.-P., Ruettinger, R. T., and Fulco, A.J. (1989) J. Biol. Chem. 264, 10996-11003), we reported that about 1 kilobase of 5' flanking sequence was required for barbiturate-inducible expression of the cytochrome P450BM-3 gene in Bacillus megaterium. We have now found, by analysis of various deletion and frameshift derivatives of this region, that an open reading frame immediately upstream of the B. megaterium cytochrome P450BM-3 structural gene encodes a protein, designated Bm3R1, which negatively controls the expression of the P450BM-3 gene at the transcriptional level. A helix-turn-helix DNA binding motif was found near the N-terminal portion of Bm3R1 protein. The 5' terminus of the bm3R1 transcript generated in vivo was determined by nuclease S1 mapping and primer extension analysis to be 44 base pairs upstream of the translation initiation sequence GTG of bm3R1. A putative promoter sequence with a high degree of similarity to the -35 and -10 consensus sequence recognized by the Bacillus subtilis sigma-43 factor was located at an appropriate distance from the transcription start site. A B. megaterium mutant which highly constitutively produced P450BM-3 protein was isolated and complementation of this cytochrome P450BM-3-constitutive mutant by a DNA fragment containing the wild-type bm3R1 gene indicated that the mutation in this locus was trans-dominant. Sequence analysis of the bm3R1 gene and its upstream region from this mutant, after amplification by the polymerase chain reaction, identified a single base change that resulted in a glycine to glutamate substitution in the beta-turn region of the DNA binding motif. By placing the bm3R1 gene under the control of a tac promoter and changing the translation initiation sequence from GTG to ATG, we succeeded in overproducing the Bm3R1 protein in Escherichia coli. A 20-bp perfect palindromic putative operator site, located between the presumed promoter sequences and the bm3R1 structural gene, was defined both by in vivo titration of Bm3R1 repressor and by gel mobility shift assays using the cell-free extracts containing the overproduced wild-type or mutant Bm3R1 protein. The barbiturate effect in mediating the induction of cytochrome P450BM-3 appears to be indirect but probably involves, in part, the release of inhibition by Bm3R1 repressor protein by interfering with its binding to the palindromic putative operator sequence and perhaps to other sites on the regulatory region of the gene encoding cytochrome P450BM-3.
Security in computing, 3rd ed. [Book Review]

The third edition of Charles Pfleeger and Shari Pfleeger's "Security in Computing" is a worthy follow-up to its predecessor.
Qubits as Spectrometers of Quantum Noise

Electrical engineers and physicists are naturally very interested in the noise of circuits, amplifiers and detectors. This noise has many origins, some of which are completely unavoidable. For example, a dissipative element (a resistor) at finite temperature inevitably generates Johnson noise. Engineers long ago developed spectrum analyzers to measure the intensity of this noise. Roughly speaking, these spectrum analyzers consist of a resonant circuit to select a particular frequency of interest, followed by an amplifier and square law detector (e.g. a diode rectifier) which measures the mean square amplitude of the signal at that frequency.
Seeds of Diversity

The question of which forces drivebiological diversity has challenged ecologists and evolutionary biologists for decades. In his Perspective, Erwin discusses an analysis of plants and arthropods in Hawaii and the Canary Islands by Emerson and Kolm, recently published in Nature . This suggests that species begat new species as community complexity increased. A similar process may explain the fossil record of diversity.
Competition and Strategic Focus in Lending Relationships

While competition constrains the ability of banks to extract informational rents from lending relationships, their informational monopoly curtails competition through the threat of adverse selection. These opposing forces also shape banks' incentives to invest in relationship lending expertise. To analyze an intermediary's optimal strategic response to growing competition, we specify a model where the severity of asymmetric information between banks and borrowers increases with informational distance. As increased competition erodes informational rents intermediaries focus more resources on building lending relationships in their core markets. This retrenchment from peripheral loan segments permits banks to fend off the competitive threat to their captive market, even as they continue to offer transactional loans outside their core segment.
Voyager Encounters with Jupiter’s Magnetosphere: Results of the Low Energy Charged Particle (LECP) Experiment

The two Voyager spacecraft encountered the planet Jupiter and its magnetosphere during March and July 1979. Included in the payload was an instrument designed to measure hot plasmas and high energy charged particles (Eion ≳ 30 keV, Ee ≳ 15 keV). These measurements have revealed that the Jovian magnetosphere is filled with a hot (20–40 keV) multicomponent plasma consisting primarily of hydrogen, helium, oxygen, and sulfur ions which is moving in the corotation direction out to the magnetopause on the dayside (50–80 RJ) and to a distance of 100–150 RJ on the nightside. Beyond ~ 150 RJ the plasma flow changes abruptly to a generally anti-solar direction and continues in that direction to ≳ 360 RJ at the 3 AM meridian. Hot plasma velocities in this region range from ~ 300 to ≳ 1000 km/sec, and the composition is similar to that in the inner part of the magnetosphere. This phenomenon has the characteristics of a wind and has been named “magnetospheric wind”. An overall phenomenological model incorporating these features is presented and discussed.
A Pieri-Chevalley formula in the K-theory of a /-bundle

Let G be a semisimple complex Lie group, B a Borel subgroup, and T ⊆ B a maximal torus of G. The projective variety G/B is a generalization of the classical flag variety. The structure sheaves of the Schubert subvarieties form a basis of the K-theory K(G/B) and every character of T gives rise to a line bundle on G/B. This note gives a formula for the product of a dominant line bundle and a Schubert class in K(G/B). This result generalizes a formula of Chevalley which computes an analogous product in cohomology. The new formula applies to the relative case, the K-theory of a G/B-bundle over a smooth base X, and is presented in this generality. In this setting the new formula is a generalization of recent G = GLn(C) results of Fulton and Lascoux. Let G be a complex, semisimple, simply connected algebraic group and B ⊆ G a Borel subgroup. We fix a smooth closed complex projective variety X and a principal algebraic B-bundle over it: B −→ E π −→X . For any complex algebraic variety F with a left algebraic B-action, we denote by E(F ) the total space of the associated fibre bundle with fibre F . Thus E(F ) = E ×B F and the projection to X is obtained from projection on the first factor. Fix a maximal torus T ⊆ B and let W be its Weyl group. For each w ∈ W the Bruhat cell Y ◦ w = BwB ⊆ G/B and the Schubert variety Yw = BwB ⊆ G/B are Bstable subsets of G/B so we have inclusions of bundles E(Y ◦ w ) ⊆ E(Yw) ⊆ E(G/B). The closed subvarieties Ωw = E(Yw) determine classes [OΩw ] in K(E(G/B)). 1 In fact, by a well-known result of Grothendieck, these classes form a K(X)-basis for K(E(G/B)). On E(G/B)) we also have “homogeneous” line bundles associated to irreducible representations of B (see below). The main result of this announcement is a formula for the tensor product of the class of a homogeneous line bundle with a Schubert class, expressed as a K(X)-linear combination of Schubert classes. We believe that this formula is the most general uniform result in the intersection theory of Schubert classes: it is related to a recent result of Fulton and Lascoux [FL], who presented a similar formula for a GLn(C)/B-bundle. Indeed, in this case, their formula and ours coincide once one knows how to translate between their combinatorics with tableaux and ours with Littelmann paths. O. Mathieu has also proved the positivity which is implied by our formula; see [FP, p. 101]. Received by the editors February 9, 1999 and, in revised form, April 29, 1999. 1991 Mathematics Subject Classification. Primary 14M15; Secondary 14C35, 19E08. Research supported in part by National Science Foundation grant DMS-9622985. 1For any smooth variety V , K(V ) is the Grothendieck ring of coherent OV -modules. c ©1999 American Mathematical Society
Rac1 as a Potential Candidate for Improved Insulin Sensitivity Following Exercise

It has long been known that physical exercise alleviates insulin resistance in diabetes. While several mechanisms of action have been explored, a clear signaling pathway has yet to be determined. One possible candidate for involvement is Rac1, a rho GTPase. Downstream of PI3K, Rac1 is involved in actin remodeling in the context of GLUT4 translocation and is activated in response to both insulin and exercise. Although Rac1 is active during exercise, the duration of activation following exercise is yet to be determined and may be critical in the post-exercise improvements in insulin stimulated glucose uptake. The goal of my project is two-fold. First, I plan to investigate the duration of Rac1 activation following exercise. Secondly, I plan to investigate Rac1’s role in the insulin/exercise signaling pathway by examining potential upstream and downstream proteins. Experiments will be conducted in vitro, using differentiated C2C12 murine skeletal muscle cells and electrical stimulation will be used in place ...
Using the Major Field Test for a Bachelor's Degree in Business as a Learning Outcomes Assessment: Evidence From a Review of 20 Years of Institution-Based Research

By applying multilevel models with random effects, the authors reviewed and synthesized findings from 30 studies that were published in the last 20 years exploring the relationship between the Educational Testing Service Major Field Test for a Bachelor's Degree in Business (MFTB) and related factors. The results suggest that MFTB scores correlated moderately with overall grade point average (.45) and ACT or SAT scores (.56) across the studies, before accounting for imperfect reliability or range restriction issues, which supports the claim that the MFTB is a valid assessment tool to gauge information about business-related learning outcomes for a variety of colleges and universities that are similar to those included in the studies.
A further study of the exact uniqueness and multiplicity criteria for a class of lumped reaction systems

A new transformation employed here results in a considerable reduction of the set of necessary and sufficient criteria for uniqueness and multiplicity presented in Tsotsis et.al. (1982) and it allows convenient inclusion of the cases in which q ⩽ p - 1 and β < - 1. Tables 1, 2, and 3 along with eqs (4), (5) and (6) of this paper should replace tables 1, 2 and 3 and eqs (12), (13) and (15) in Tsotsis et.al. (1982), respectively The existence of five steady states for the endothermic case of a bimolecular Langmuir-Hinshelwood reaction rate form was discovered with the aid of singularity theory. In addition to replacement of the aforementioned tables and equations, the following changes should be made in Tsotsis et.al. (1982).
Ultrasound biomicroscopy in infantile glaucoma.

Background: Glaucoma in infants has many causes. Evaluation of the anatomy of the anterior segment of eyes with infantile glaucoma may help to determine the pathogenesis of an infant's disease and influence therapeutic decisions. Methods: Eleven eyes of six infants with glaucoma were evaluated with ultrasound biomicroscopy (UBM) to evaluate the anatomic characteristics and relationships of the anterior segment structures. Results: The anterior chamber angle, iris, lens, ciliary body, and posterior chamber angle could be imaged in detail. Elongated and anteriorly placed ciliary processes were noted in all eight eyes with trabeculodysgenesis. There were no apparent anomalies in the trabecular meshwork, or anterior chamber. In three eyes with dense corneal opacities, ultrasound biomicroscopy showed severe anterior segment disorganization and thin central corneas with posterior corneal excavation. Conclusions: Ultrasound biomicroscopy is a useful non-invasive method for evaluating infants with glaucoma in cases with corneal opacities. This information can help in surgical planning for glaucoma management.
Control of movements and temporal discounting of reward

Let us assume that the purpose of any movement is to position our body in a more rewarding state. People and other animals discount future reward as a function of time. Recent results suggest that there is a correlation between changes in this reward temporal discount function and changes in saccadic velocity and duration. These results suggest that each movement carries a cost because its duration delays acquisition of reward. The value that the brain assigns to the stimulus, and the rate at which it discounts this value in time, form a cost that appears to influence the motor commands that move our body.
Relation between the fluctuations in and temperature dependence of charge-carrier concentrations

A relation between carrier-number fluctuations and concentration temperature dependence is derived for extrinsic nondegenerate semiconductors. The result may be used to test whether such number fluctuations can account for typical $\frac{1}{f}$ noise.
Mechanical Properties Associated with an Aluminum Specimen during Experimental Analysis

This paper discusses the linear relationship between stress and strain for an aluminum specimen and shows how its mechanical properties and associated stress distribution may be determined. This linear relationship forms the basis of the theory of elasticity, which is widely used to determine stress or strain in structural elements under a specific tensile loading condition. Study of the plastic behavior of structural elements is concerned with the analysis of stress and strains in the plastic as well as elastic ranges.
Compact programmable monolithically integrated 10-stage multi-channel WDM dispersion equalizer on low-loss silicon nitride planar waveguide platform

We demonstrate a tunable dispersion equalizer on a low loss Si 3 N 4 /SiO 2 planar waveguide platform. The equalizer has a tuning range of ±550 ps/nm, a footprint of 222.5 mm2, and can compensate multiple WDM channels simultaneously.
A discrete Hille-Yosida-Phillips theorem☆

Abstract In this paper necessary and sufficient conditions on the resolvent of an operator T are obtained for the discrete semigroup consisting of powers of T to be uniformly bounded and quasi-bounded.
Children with new tracheostomies: planning for family education and common impediments to discharge.

Objectives To describe an educational program and timeline for the discharge of children with a new tracheostomy and identify common impediments to the education and discharge process. Methods Retrospective pilot case series of 70 children and adolescents undergoing tracheostomy placement over a 24-month period in a large urban academic pediatric hospital. Results Eleven healthcare providers with expertise with technology dependent children identified the eight most common impediments to education and discharge for children with new tracheostomies. Length of stay, impediments to both education and discharge, and medical equipment needed at the time of discharge were extracted from hospital records. Caregivers of children with new tracheostomies needed a median of 14 days (range 5–110 days) to successfully complete a tracheostomy education program. Discharge occurred a median of 6.5 days (range 0–71 days) after education was completed. Common impediments to completing the education program included social issues (e.g., lack of sibling childcare), inter-current illness of the patient and/or language barriers. Impediments to discharge included patient's inter-current illnesses, social issues (e.g., lack of running water) and unavailability of home nursing. Our cohort of patients had a total median length of stay (LOS) of 46 days. At discharge, 55% of children required two or more medical devices (in addition to their tracheostomy) and 61% had some level of dependency on positive pressure ventilation. Conclusions Pediatric patients with a new tracheostomy undergo lengthy initial hospitalizations and have complex educational and discharge needs. Multiple factors (both medical and social) can impede the child's transition to the outpatient setting. A structured education and discharge program may result in a shorter LOS for children with new tracheostomies. Impediments to family education and discharge should be anticipated. Pediatr Pulmonol. 2008; 43:788–794. © 2008 Wiley-Liss, Inc.
Phosphodiesterase Inhibition by Ro 20-1724 Reduces Hyper-IgE Synthesis by Atopic Dermatitis Cells In Vitro

Peripheral blood mononuclear leukocytes (MNL) from patients with atopic dermatitis spontaneously produce large amounts of IgE in vitro. These cells also show markedly elevated levels of cAMP phosphodiesterase (PDE) which may be responsible for the observed abnormal cAMP responsiveness. Treatment of atopic dermatitis MNL with varying concentrations of the cAMP PDE inhibitor Ro 20-1724 resulted in progressively decreasing amounts of IgE synthesis, statistically significant at the 10(-4) M and 10(-5) M concentrations. There was a close correlation between PDE inhibition and inhibition of IgE synthesis, r = 0.93, p less than 0.05. To define the cellular target of the drug, we used monoclonal antibodies directed toward MNL subsets (Lyt 3, OKT8, OKT4, monocyte-myeloid) in a modified "panning" method to perform experiments with purified subsets. With untreated subsets, removal of OKT4-positive cells significantly reduced IgE synthesis; readdition of OKT4-positive cells enhanced IgE synthesis. OKT8 cells and monocytes did not affect IgE synthesis. Pretreatment of T cell-depleted MNL with Ro 20-1724 resulted in significantly more inhibition of IgE synthesis than did pretreatment of T enriched cells prior to recombination with the reciprocal untreated subset and subsequent culture. Similarly, pretreatment of monocyte-depleted cells resulted in significantly more inhibition of IgE synthesis than pretreatment of monocyte-enriched cells prior to recombination and culture. The majority of the effect appeared to be mediated by a direct effect on the B cells. However, some inhibition of IgE synthesis was also achieved through pretreatment of T enriched cells. Since pretreatment of isolated suppressor/cytotoxic or helper/inducer T-cell subsets did not give the same degree of inhibition as with unfractionated T cells, a T-T interaction may be involved in this aspect. The imidazolidinone derivative, Ro 20-1724, significantly and consistently inhibited both the elevated cAMP phosphodiesterase activity and the elevated spontaneous IgE synthesis of MNL from patients with atopic dermatitis. These findings demonstrate a previously undescribed link between cAMP PDE levels and in vitro IgE synthesis.
Jointly optimal transmission and probing strategies for multichannel wireless systems

We consider a wireless system with multiple channels when each channel has several different transmission states. Different states are associated with different probabilities of successful transmissions. In such networks, we are faced with making transmission decisions in the presence of partial information about channel states. This (typically probabilistic) information about any channel can be refined by sending control packets in the channels. In presence of multiple alternative channels, this process of probing every channel to find the best one is onerous and resource consuming. There is a natural tradeoff between the resource consumed in probing and the estimate of channel state we can obtain. The desired tradeoff can be attained by judiciously determining which and how many channels to probe and also which channel to transmit. We present adaptive algorithms for provably approximating the desired tradeoffs within constant factors.
Lateralization of Visuospatial Attention Across Face Regions Varies With Emotional Prosody

It is well-established that linguistic processing is primarily a left-hemisphere activity, while emotional prosody processing is lateralized to the right hemisphere. Does attention, directed at different regions of the talker’s face, reflect this pattern of lateralization? We investigated visuospatial attention across a talker’s face with a dual-task paradigm, using dot detection and language comprehension measures. A static image of a talker was shown while participants listened to speeches spoken in two prosodic formats, emotional or neutral. A single dot was superimposed on the speaker’s face in one of 4 facial regions on half of the trials. Dot detection effects depended on emotion condition—in the neutral condition, discriminability was greater for the right-, than for the left-, side of the face image, and at the mouth, compared to the eye region. The opposite effects occurred in the emotional prosody condition. The results support a model wherein visuospatial attention used during language comprehension is directed by the left hemisphere given neutral emotional prosody, and by the right hemisphere given primarily negative emotional prosodic cues.
Computing with the leaky integrate-and-fire neuron: logarithmic computation and multiplication

The leaky integrate-and-fire (LIF) model of neuronal spiking (Stein 1967) provides an analytically tractable formalism of neuronal firing rate in terms of a neuron's membrane time constant, thresho...
Paleoecological and Stratigraphic Significance of the Muskrat in Pleistocene Deposits

The muskrat (Ondatra spp.), a common element in late Kansan and post-Kansan deposits, provides a valuable Stratigraphic tool for deposits of glacial age, in terms of the chronocline proposed by Semken (1966). However, specimens of interglacial age commonly appear out of sequence in the regression. In addition, the nearly ubiquitous distribution in North America of modern muskrats has precluded paleoecological interpretations other than for the presence of permanent water. Statistical analysis of 147 fossil first-lower molars of Ondatra substantiates and refines the established chronocline. Additionally, it reveals that specimens taken from deposits regarded as interglacial in age have a significantly lower length/width ratio than have those collected from deposits regarded as glacial in age. A statistical examination of 403 Recent first-lower molars from 26 of the United States and from Manitoba, Canada, indicates the following. (1) Both O. zibethicus zibethicus and O. z. cinnamonius found in southern regions exhibit a significantly lower length/width tooth ratio than do those found in northern regions. (2) The ratios, when plotted geographically, form a predictable north-south cline, which, although progressive, has a point of inflection at 42° N. lat. (Nebraska). Specimens collected to the north give a positive residual and southern specimens a negative residual to a least-squares regression. (3) O. z. zibethicus (eastern form) and O. z. cinnamonius (plains variety) are indistinguishable on dental parameters at any given latitude. In conclusion, the data suggest that the length/width ratio is a reliable tool in distinguishing between “warm” and “cool” associated members of the population. Corresponding differences in ratios in glacial and interglacial specimens support this hypothesis. The Hay Springs local fauna, as preserved in the American Museum of Natural History, probably represents a mixed collection, taken from more than one quarry, in a section where rocks of glacial and interglacial age are preserved.
Quantifying Turfgrass Cover Using Digital Image Analysis

Accurate cover estimates in turfgrass research plots are often difficult to obtain because of the time involved with traditional sampling and evaluation techniques. Subjective ratings are commonly used to estimate turfgrass cover, but the data can be quite variable and difficult to reproduce. New technologies and software related to digital image analysis (DIA) may provide an alternative method to measure turfgrass parameters more accurately and efficiently than current techniques. A series of studies was conducted to determine the applicability of DIA for turfgrass cover estimates. In the first study, plots containing a range (1-16) of bermudagrass [Cynodon dactylon (L.) Pers.] plugs of specific diameter (15.0 cm) were established to represent values of turfgrass cover from 0.75 to 12%, by 0.75% increments. Digital images (1280 by 960 pixels) were taken with a digital camera and processed for percent green color to a software package. Estimates of green turfgrass cover by DIA were highly correlated (r 2 > 0.99) to the calculated values of turfgrass cover. In a second study, DIA of turfgrass cover was compared by subjective analysis (SA) and line-intersect analysis (LIA) methods for estimating cover in eight plots of zoysiagrass (Zoysia japonica Steudel). The mean variance of percent cover determined by DIA (0.65) was significantly lower than SA (99.12) or LIA (13.18). Digital image analysis proved to be an effective means of determining turfgrass cover, producing both accurate and reproducible data. In addition, the technique effectively removes the inherent error and evaluator bias commonly associated with subjective ratings.
TOF Electron Energy Analyzer for Spin and Angular Resolved Photoemission Spectroscopy

Current pulsed laser and synchrotron x-ray sources provide new opportunities for Time-Of- Flight (TOF) based photoemission spectroscopy to increase photoelectron energy resolution and efficiency compared to current standard techniques. The principals of photoelectron timing front formation, temporal aberration minimization, and optimization of electron beam transmission are presented. We have developed these concepts into a high resolution Electron Optical Scheme (EOS) of a TOF Electron Energy Analyzer (TOF-EEA) for photoemission spectroscopy. The EOS of the analyzer includes an electrostatic objective lens, three columns of transport lenses and a 90 degree energy band pass filter (BPF). The analyzer has two modes of operation: Spectrometer Mode (SM) with straight passage of electrons through the EOS undeflected by the BPF, allowing the entire spectrum to be measured, and Monochromator Mode (MM) in which the BPF defines a certain energy window inside the scope of the electron energy spectrum.
Worldwide regulatory guidance values for surface soil exposure to carcinogenic or mutagenic polycyclic aromatic hydrocarbons

Abstract Regulatory guidance values are used worldwide to control residential exposure to surface soil contamination. A total of 1,991 values used in 44 United Nations member states plus 4 territories or administrative regions to control exposure to seven polycyclic aromatic hydrocarbons (PAH) generally considered to be carcinogenic or mutagenic (benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, dibenzo(a,h)anthracene, chrysene and indeno(1,2,3-c,d)pyrene) are examined. The distributions of these values vary over 6.3–7.2 orders of magnitude and resemble the distributions of lognormal random variables. The U.S. Environmental Protection Agency (USEPA) values fall near the low end of these distributions and exert a modest influence on the values from other U.S. jurisdictions. On average, 17 additional jurisdictions use USEPA values and 21% of all guidance values fall within uncertainty bounds approximated from the USEPA risk model. An average of 62% of U.S. guidance values fall below the median value, but this varies from 43% for chrysene to 70% for dibenz(a,h)anthracene and benzo(a)pyrene. Although the magnitudes of guidance values differ, the ratios of values often reflect the relationships implied by benzo(a)pyrene Toxicity Equivalency Factors (TEFs). This influence is strongest in RGVs from U.S. jurisdictions.
Chronic Gamma Radiation Affects the Distribution of Radial Increment in Pinus rigida Stems

Exposure of pitch pine trees to chronic ionizing radiation at rates between 1 and 5 roentgens per day for several years causes reduction of radial increment throughout the stem, the reduction being most ponounced near the base of the tree. Both the size of the tree crown and climate influence the severity of the effect, trees with large crowns showing little effect at low exposures except in years of environmental stress.
Prescribed scalar curvature on a C∞ compact Riemannian manifold of dimension two

Abstract Let (V 2 ,g) be a C ∞ compact Riemannian manifold of negative constant scalar curvature of dimension n=2 , and let f be a smooth function defined on V 2 . We intend to find conditions on f in order that f be the scalar curvature of a metric conformal to g .
UC781 Microbicide Gel Retains Anti-HIV Activity in Cervicovaginal Lavage Fluids Collected following Twice-Daily Vaginal Application

The potent nonnucleoside reverse transcriptase inhibitor UC781 has been safety tested as a vaginal microbicide gel formulation for prevention of HIV-1 sexual transmission. To investigate whether UC781 retained anti-infective activity following exposure to the female genital tract, we conducted an ex vivo analysis of the UC781 levels and antiviral activity in cervicovaginal lavage (CVL) fluids from 25 Thai women enrolled in a 14-day safety trial of twice-daily vaginal application of two concentrations of the UC781 microbicide gel. CVL samples were collected from women in the 0.1% (n = 5), 0.25% (n = 15), and placebo (n = 5) gel arms following the first application of gel (T15 min) and 8 to 24 h after the final application (T8-24 h) and separated into cell-free (CVL-s) and pelletable (CVL-p) fractions. As UC781 is highly hydrophobic, there were significantly higher levels of UC781 in the CVL-p samples than in the CVL-s samples for the UC781 gel arms. In T8-24 h CVL-p samples, 2/5 and 13/15 samples collected from the 0.1% and 0.25% UC781 gel arms, respectively, efficiently blocked infection with ≥4 log10 50% tissue culture infective dose (TCID50) of a CCR5-tropic CRF01_AE HIV-1 virus stock. Independent of the arm, the 11 CVL-p samples with UC781 levels of ≥5 μg/CVL sample reduced infectious HIV by ≥4 log10 TCID50. Our results suggest that the levels and anti-infective activities of UC781 gel formulations are likely to be associated with a cellular or pelletable component in CVL samples. Therefore, cellular and pelletable fractions should be assayed for drug levels and anti-infective activity in preclinical studies of candidate microbicides.
Man's most versatile machine

CENTURIES are remembered — not for the passage of time — but for the men, the events, the discoveries, and the innovations they produce.
Parallel Molecular Dynamics Simulations of Organic Materials

A new parallel algorithm suitable for molecular dynamics simulations of organic systems is presented. It reduces the communication cost and memory requirements of other commonly-used parallel algorithms by a factor of where P is the number of processors. The algorithm has been implemented in a CHARMM-like molecular dynamics model and its performance on 1024-processor nCUBE 2 and Intel Paragon machines is discussed.
Wormhole-induced proton decay☆

Abstract The prospect of proton decay in the presence of topology-changing field configurations in euclidean quantum gravity is studied. The recent literature has included conjectures regarding possible disastrous consequences of macroscopic wormholes. In this paper it is shown that for any realistic, anomaly-free supersymmetric grand unified theory with low-energy supersymmetry, as well as for any realistic, anomaly-free non-grand unified supersymmetric extension of the standard model, even wormholes as small as the Planck lenght will naturally generate a catastrophically high rate of proton decay.
Minimizing Pressure Pulsations in a Centrifugal Compressor

As a centrifugal impeller rotates, it converts shaft mechanical power into fluid power - static and dynamic pressure. As a result of this aerodynamic process, the flow in the compressor has steady and unsteady components. The latter is undesirable as it can manifest itself as pressure pulsations that consequently cause machine vibration, noise and alternating stress in the impeller. Typically a centrifugal compressor has strong pressure pulsation amplitude at the blade passing frequency and /or its harmonics. The installation of diffuser vanes to enhance the compressor peak efficiency further increases the magnitude of these pressure pulsations. Dominant pulsations typically occur at the impeller exit and diffuser entrance region, and are a major excitation source to a centrifugal compressor and its associated piping. This internal aeroacoustic energy source propagates pressure waves through various paths in the compressor system and eventually couples to the structure and impeller and causes structural vibration and sound radiation. This paper focuses on a technique to control pressure pulsations in a centrifugal compressor. Two examples along with test data will be discussed.Copyright © 2011 by ASME
Block Quantization Of An Annealed Binary Phase Hologram For Optical Interconnects

A binary phase hologram for optical interconnects is divided into two blocks and binary phases of each block are decided by a simulated annealing algorithm. Such a binary phase hologram showed high diffracion efficiency and was able to produce asymmetrical diffraction orders. Performance limitations of these holograms are studied.
Theorizing Land‐Cover and Land‐Use Change: The Case of the Florida Everglades and Its Degradation

Abstract This paper possesses two related objectives. The first is to unite the bid-rent model of von Thunen and urban theorists with historical analysis in the interest of providing a theoretical approach to the comprehension of regional land-cover and land-use change. The second objective is to deploy the theoretical approach in an attempt to account for a specific change process, namely loss of wetlands in South Florida. Recently, the Annals of the Association of American Geographers published a paper addressing this issue (Meindl, Alderman, and Waylen 2002). Meindl, Alderman, and Waylen describe the impact of claims making on efforts to drain and sell land in South Florida during a critical period in the early 20th century. The present paper is put forward, in part, to provide additional context. In particular, we identify claims making and the development discourse it legitimated as part of a complex evolution in the region's socionature, and the regimes governing land-cover and land-use change that ...
A paradigm for listing (s, t)-cuts in graphs

This paper studies the generation of various types of (s, t)-cuts in directed and undirected graphs. We present a general paradigm for listing such (s, t)-cuts and we identify properties of classes of cuts that allow this approach to be applied. The paradigm lists the cuts in time linear in the number of cuts, with the time-per-cut complexity dependent upon that of a "pivot" subroutine applied at each step of the procedure. In addition to unifying known routines for enumerating minimal (s, t)-cuts in undirected graphs, uniformly directed (s, t)-cuts, and antichains in partial orders, the paradigm provides efficient generation schemes for several new classes of cuts: minimal (s, t)-cuts in directed graphs, minimum weight/cardinality (s, t)-cuts, "semidirected" (s, t)-cuts, and classes of multiterminal cuts. Except for the semidirected cuts, all of the procedures have time-per-cut complexity that is linear in the size of the graph.
Timing in human-robot interaction

Timing plays a role in a range of human-robot interaction scenarios, as humans are highly sensitive to timing and interaction fluency. It is central to spoken dialogue, with turn-taking, interruptions, and hesitation influencing both task efficiency and user affect. Timing is also an important factor in the interpretation and generation of gestures, gaze, facial expressions, and other nonverbal behavior. Beyond communication, temporal synchronization is functionally necessary for sharing resources and physical space, as well as coordinating multi-agent actions. Timing is thus crucial to the success of a broad spectrum of HRI applications, including but not limited to situated dialogue; collaborative manipulation; performance, musical, and entertainment robots; and expressive robot companions. Recent years have seen a growing interest in the HRI community in the various research topics related to human-robot timing. The purpose of this workshop is to explore and discuss theories, computational models, systems, empirical studies, and interdisciplinary insights related to the notion of timing, fluency, and rhythm in human-robot interaction.
A single nucleotide primer extension assay to detect the APC I1307K gene variant.

Adenomatous polyposis coli (APC) is a tumor suppressor gene important in colorectal tumorigenesis. A genetic variant of APC, I1307K, results from a T-to-A transversion at nucleotide 3920 which converts the wild-type sequence to a homopolymer tract (A8). The I1307K alteration is not itself oncogenic, but creates a hypermutable region (A8) that is prone to frame-shift mutations. The APC I1307K variant occurs in approximately 6% of the Ashkenazi Jewish population and is reported to approximately double an individual's risk for colorectal cancer. Here we describe a single nucleotide primer extension assay for the detection of the APC I1307K mutation. Following PCR amplification, nucleotide 3920 of the APC gene is directly sequenced using single nucleotide primer extension technology. The assay is in a multiplex format allowing simultaneous forward and reverse sequencing of the I1307K variant, which provides an internal, independent confirmation of each testing result. The assay was validated against 60 samples previously characterized by an allele-specific oligonucleotide (ASO) hybridization assay, with 100% concordance of results. Compared to the ASO assay, this single nucleotide primer extension assay requires significantly less technical time to perform, and has a greatly increased throughput capacity. The single nucleotide extension assay provides a highly sensitive and specific assay to identify individuals with the APC I1307K gene variant who may benefit from increased colorectal screening.
Modulation of hepatocyte nuclear factor-4α function by the peroxisome-proliferator-activated receptor-γ co-activator-1α in the acute-phase response

HNF-4alpha (hepatocyte nuclear factor-4alpha) is a key regulator of liver-specific gene expression. To understand the mechanisms governing the regulation of HNF-4alpha function during the APR (acute-phase response), the effects of transcription co-activators, including p300, PGC-1alpha (peroxisome-proliferator-activated receptor-gamma co-activator-1alpha) and SRC (steroid receptor co-activator)-1alpha were investigated in an injury cell model. We have shown previously that the HNF-4alpha-sensitive APR genes ApoB (apolipoprotein B), TTR (transthyretin) and alpha1-AT (alpha1-antitrypsin) were regulated at the DNA binding and transcriptional levels after cytokine stimulation. We now show that co-activators have a differential impact on the transactivation of HNF-4alpha-sensitive genes via HNF-4alpha-binding sites in ApoB, TTR or alpha1-AT promoters. PGC-1alpha strongly enhances the transactivation of ApoB and alpha1-AT and, to a lesser extent, of TTR, whereas SRC-1alpha and p300 only have a weak or no effect on these three genes. More importantly, it was found that PGC-1alpha has a novel role in the modulation of the binding ability of HNF-4alpha in response to cytokine treatment. Using in vitro and in vivo approaches, electrophoretic mobility-shift and chromatin immunoprecipitation assays, we demonstrate that the reduced HNF-4alpha-DNA binding ability induced by cytokines is eliminated by overexpression of PGC-1alpha. Cytokine treatment does not significantly alter the protein levels of HNF-4alpha and PGC-1alpha, but it does reduce the recruitment of PGC-1alpha to HNF-4alpha-binding sites and thereby decreases transcriptional activity. These results establish the importance of PGC-1alpha for HNF-4alpha function and describe a new HNF-4alpha-dependent regulatory mechanism that is involved in the response to injury.
On the Evaluation of Certain Integrals Important in the Theory of Quanta

It is known [1] that the matrix of the hydrogen atom, determining the intensities of the hydrogen series lines and of their fine structure components, essentially depends on the integral [equation (1)], where the functions χ and χ' are solutions of the Schroedinger equation [2] [equation (2)]. The symbols µ, e stand for the mass and the charge of the electron; K = h/2π (h Planck's constant). The energy E and the integer k have different values in χ and χ'. These functions are supposed to be finite for r = 0 and to vanish for r = ∞. Since in the case of elliptic orbits the functions X, X' turn out to be polynomials multiplied by an exponential, the direct evaluation term by term is possible on principle. The numerical computations involved are, however, so lengthy as to make this method almost prohibitive in practice. We give, therefore, in this note a reduction of the integral (1) to a simple and convenient expression. Such a reduction is quite indispensable in the case of hyperbolic orbits. Moreover, the procedure applied has an interest beyond the special case of the Kepler motions, since quite analogous expressions occur in other problems of the quantum theory. In fact, the same method has been used by the author for reducing the intensity expressions of the components in the Stark effect.3 Only the simple closed Kepler motion, neglecting relativity effect, and spin of the electron, will be considered in the following sections.
REDESIGNING SECONDARY STRUCTURE TO INVERT COENZYME SPECIFICITY IN ISOPROPYLMALATE DEHYDROGENASE

Abstract Rational engineering of enzymes involves introducing key amino acids guided by a knowledge of protein structure to effect a desirable change in function. To date, all successful attempts to change specificity have been limited to substituting individual amino acids within a protein fold. However, the infant field of protein engineering will only reach maturity when changes in function can be generated by rationally engineering secondary structures. Guided by x-ray crystal structures and molecular modeling, site-directed mutagenesis has been used to systematically invert the coenzyme specificity of Thermus thermophilus isopropylmalate dehydrogenase from a 100-fold preference for NAD to a 1000-fold preference for NADP. The engineered mutant, which is twice as active as wild type, contains four amino acid substitutions and an alpha-helix and loop that replaces the original beta-turn. These results demonstrate that rational engineering of secondary structures to produce enzymes with novel properties is feasible.
Automating Java Program Testing Using OCL and AspectJ

Random testing can eliminate subjectiveness in constructing test data and increase the diversity of test data. However, one difficult problem is to construct test oracles that decide test results---test failures or successes. Assertions can be used as test oracles and are most effective when they are derived from formal specifications such as OCL constraints. Random testing, if fully automated, can reduce the cost of testing dramatically. We propose an automated testing approach for Java programs by combining random testing and OCL. The key idea of our approach is to use OCL constraints as test oracles by translating them to runtime checks written in AspectJ. We implement our approach by adapting existing frameworks for translating OCL to AspectJ and assertion-based random testing. We evaluate the effectiveness of our approach through case studies and experiments. The results are encouraging in that our approach can detect errors in both implementations and OCL constraints and provide a practical means for using OCL.
Acetone condensation and selective hydrogenation to MIBK on Pd and Pt hydrotalcite-derived MgAl mixed oxide catalysts

Abstract The condensation and selective hydrogenation of acetone to methyl isobutyl ketone (MIBK) was studied on a directly comparable series of 0.1–1.5 wt% Pd and Pt catalysts supported on hydrotalcite (HT)-derived Mg Al mixed-oxides in a liquid-phase batch micro-reactor at 99–153 °C and 400 psig. The support catalyzes the condensation of acetone to diacetone alcohol (DAA) and its subsequent dehydration to mesityl oxide (MO); Pd and Pt catalyze the selective hydrogenation of MO to MIBK. The net yield of MIBK is independent of metal type and loading, depending only on the wt% of exposed metal. However, the by-products are quite different-Pt/HT is more selective for the direct hydrogenation to isopropanol (IPA) while Pd/HT forms more of the intermediate diacetone alcohol (DAA). Among the Pd- and Pt-based catalysts examined, the 0.1 wt% Pd/HT gives the maximum MIBK yield of ∼32%, with an unusually low selectivity to IPA, 0.6 mol% compared to 15 mol% for the next best catalyst. This appears to be due to its higher basicity, and (to a lesser extent) to its minimal concentration of metal sites. This metal loading is sufficient to fully hydrogenate mesityl oxide to MIBK, and it also shows minimal acetone hydrogenation to isopropanol. A study of physically mixed Pd/silica + HT versus Pd/HT shows that the acid/base and hydrogenation functions need not be molecularly close.
Medical Resources on the Internet

Advances in telecommunications technology in the last decade have fostered the development of computer networks that allow access to vast amounts of information and services.Of the many computer ne...