cssi/SciSciGPT-SciSciNet huggingface dataset:
New and emerging treatments for the prevention of recurrent diverticulitis

Sigmoid diverticulitis is a common benign condition which carries significant morbidity and socioeconomic burden. This article describes the management of sigmoid diverticulitis with a focus on indications for surgical intervention. The mainstay of management of uncomplicated diverticulitis is broad-spectrum antibiotic therapy. The old surgical dictum that two episodes of sigmoid diverticulitis warranted surgical intervention has been challenged by recently published data. Surgery for diverticulitis thus needs to be tailored to suit individual presentation; patients presenting with recurrent diverticulitis, severe symptoms or debilitating disease impacting patient’s quality of life mandate surgical intervention. Complicated diverticular disease typically prompts intervention to resect a diseased, strictured sigmoid colon, fistulizing disease, or a life-threatening colonic perforation. Laterally, minimally invasive surgery has been utilized in the management of this disease and recent data suggests that localized colonic perforation may be managed by laparoscopic peritoneal lavage, without resection. This review focuses discussion on available evidence for contemporary surgical and nonoperative management of diverticulitis.
Histochemical study of dentine in rats following hypophysectomy

Abstract Sections of the dentine from both intact and hypophysectomized animals were exposed to various histochemical methods to determine the dentine components that were influenced by the loss of the growth hormone. Although dentine from hypophysectomized animals was homogenous in nature following hematoxylin and eosin staining, differences were noted between dentine specimens from intact and hypophysectomized animals when various histochemical reactions were used. The hypophysectomized dentine stained deep red with P.A.S. and exhibited an abundance of positive alcian blue material which was also metachromatic in nature. In addition, the dentine stained faintly after the Ninhydrin-Schiff method. These staining reactions would indicate that there was an alteration in the protein portion of the protein mucopolysaccharide complex, a situation which would prevent fixation of the mucopolysaccharide in the ground substance. These events would lead to an interference in normal mineralization of the dentine.
Inferring carbon monoxide pollution changes from space-based observations

[1] We compare space-based measurements of carbon monoxide (CO) during April 1994 and October 1984 and 1994 from the early MAPS instrument with those during 2000–2004 from the MOPITT instrument. We show that a three-dimensional global composition model can be used to account for differences in retrieval sensitivity between the two instruments and between the different years of MOPITT data. This allows direct comparison of CO amounts over most of the globe at different times. These types of changes in short-lived constituents cannot be assessed with local measurements. Though the existing space-based data are too sparse both temporally and geographically to allow trend estimates, we find substantial variations in midtropospheric CO between the different years in many continental-scale regions. During April, average CO is ∼12–18 ppbv (∼10–20%) greater during 2000–2004 than during 1994 over North America, southeast Asia and North Africa though the global mean value is nearly the same. During October 1994, observations show CO enhancements of 15–20 ppbv relative to 1984 or 2000–2004 over South America and a similar, though slightly smaller (9–19 ppbv), enhancement globally. Southeast Asia, Europe and North America all show similar October CO levels in 1994 and 2000–2004, with both times showing substantially more pollution (13–29 ppbv) than 1984. Variations over Europe and Africa are consistent in both seasons, while changes elsewhere are not. Changes over southeast Asia and North Africa are substantially in excess of interannual variability, while those over North and South America and southern Africa are only marginally so. Model sensitivity studies examining the response to changes in emissions indicate probable causes of the CO changes over different regions. Over southeast Asia and North America, CO is most sensitive to industrial and biomass burning emissions, implying that changes in these sources likely account for the 13–29 ppbv increases seen there between 2000–2004 and earlier years. Over North Africa, CO is strongly influenced by numerous sources as well as meteorology, precluding attribution of increases to particular factors. Over South America and southern Africa, variations in both biomass burning and isoprene emissions likely contributed to the ∼10–20 ppbv changes.
Geometric distortion of digital angiography image

Digital angiography remains valuable in a diagnostic environment where anatomical definition is important. However it is not sufficiently reliable in circumstances where precise geometry is important. The geometric distortion of digital angiography is mainly caused by the inherent, non-uniform electromagnetic field of the image intensifier board. In this paper we quantify this distortion so as to evaluate its clinical relevance. We utilize image fusion with fiducial markers and image exploration with cursor projection in this investigation. Fiducial markers on the images were normalized first and then used as baselines to scale and orient the corresponding images so they could be accurately registered, superimposed, and subtracted. Image exploration with cursor projection allowed for easy identification of the same point on corresponding images, which provided quantitative evaluation of geometric differences between digital and analogue angiography images. Based on our study, we concluded: (1) compared with MRI geometric distortion of as much as 2 mm, digital angiography is clinically appropriate for stereotactic application; (2) with an improved test object, the results would be more accurate.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Max pressure control of a network of signalized intersections

The control of a network of signalized intersections is considered. Vehicles arrive in iid (independent, identically distributed) streams at entry links, independently make turns at intersections with fixed probabilities or turn ratios, and leave the network upon reaching an exit link. There is a separate queue for each turn movement at each intersection. These are point queues with no limit on storage capacity. At each time the control selects a ‘stage’, which actuates a set of simultaneous vehicle movements at given iid saturation flow rates. Network evolution is modeled as a controlled store-and-forward (SF) queuing network. The control can be a function of the state, which is the vector of all the queue lengths. A set of demands is said to be feasible if there is a control that stabilizes the queues, that is the time-average of every mean queue length is bounded. The set of feasible demands D is a convex set defined by a collection of linear inequalities involving only the mean values of the demands, turn ratios and saturation rates. If the demands are in the interior Do of D, there is a fixed-time control that stabilizes the queues. The max pressure (MP) control is introduced. At each intersection, MP selects a stage that depends only on the queues adjacent to the intersection. The MP control does not require knowledge of the mean demands. MP stabilizes the network if the demand is in Do. Thus MP maximizes network throughput. MP does require knowledge of mean turn ratios and saturation rates, but an adaptive version of MP will have the same performance, if turn movements and saturation rates can be measured. The advantage of MP over other SF network control formulations is that it (1) only requires local information at each intersection and (2) provably maximizes throughput. Examples show that other local controllers, including priority service and fully actuated control, may not be stabilizing. Several modifications of MP are offered including one that guarantees minimum green for each approach and another that considers weighted queues; also discussed is the effect of finite storage capacity.
Note on p-Harmonic Measure

In this paper we continue our study of the dimension of a measure associated with a positive p-harmonic function which vanishes on the boundary of a quasicircle. Under various assumptions on the quasicircle, we obtain analogues of well known theorems for the dimension of harmonic measure due to Makarov.
Utility of mini-mental state examination in assessing cognition in the elderly

The present study used a sample of 156 healthy elderly subjects between 57 and 85 years of age to examine concurrent validity of 3 MMSE components: serial seven subtractions, 3-word recall, and copying pentagons, which are most frequently used in clinical practice as indicators of specific cognitive deficits. Correlational analyses and examination of concordance rates were used to explore the relationship of 3 MMSE tasks with scores on neuropsychological tests. The results of this study indicated that performance on MMSE components by elderly individuals should be interpreted with caution due to the effect of education on individual task performance, questionable specificity of the tasks in assessing circumscribed cognitive domains, emphasis on verbal tasks and high misidentification rate. (Aging Clin. Exp. Res. 6: 427-432, 1994)
Optimising self-regulated study: The benefits—and costs—of dropping flashcards

Self-regulation of study activities is a constant in the lives of students - who must decide what to study, when to study, how long to study, and by what method to study. We investigated self-regulation in the context of a common study method: flashcards. In four experiments we examined the basis and effectiveness of a metacognitive strategy adopted almost universally by students: setting aside (dropping) items they think they know. Dropping has a compelling logic - it creates additional opportunities to study undropped items - but it rests on two shaky foundations: students' metacognitive monitoring and the value they assign to further study. In fact, being allowed to drop flashcards had small but consistently negative effects on learning. The results suggest that the effectiveness of self-regulated study depends on both the accuracy of metacognitive monitoring and the learner's understanding, or lack thereof, of how people learn.
Rare earth element systematics of acidic geothermal waters from the Taupo Volcanic Zone, New Zealand

Abstract Concentrations of rare earth elements (REE) in acidic thermal waters from the Taupo Volcanic Zone, New Zealand have been determined. Acidity in waters from Rotokawa results from oxidation of H2S upon encounter with oxygen-rich meteoric waters. The Ruapehu Crater lake is acidic due to input of magmatic volatiles such as HCl and SO2. REE concentrations in both types of water are high, ranging from 10− 3 to nearly 1 times chondrite. Chondrite-normalized patterns for heavy REE in waters from Rotokawa parallel those of their host rocks, suggesting little fractionation upon water–rock interaction. However, the light REE are depleted relative to their host rock, resulting in a “gull-wing” pattern. The hyperacidic Ruapehu Crater lake water generally does not have a “gull-wing” pattern. The patterns for these waters were invariant for several years prior to the September 1995 eruption, but changed substantially afterwards, generally decreasing in slope with time.
From Peace to Freedom: Quaker Rhetoric and the Birth of American Antislavery, 1657–1761. By Brycchan Carey. (New Haven, CT: Yale University Press, 2012. Pp. ix, 257. $35.00.)

In this insightful and accessible book, Brycchan Carey traces a continuous and evolving body of Quaker antislavery thought from founder George Fox to the decisions of the Philadelphia and London Ye...
Diastereo- and enantioselective hydrogenative aldol coupling of vinyl ketones: design of effective monodentate TADDOL-like phosphonite ligands.

We report the first enantioselective reductive aldol couplings of vinyl ketones, which were achieved through the design of a novel monodentate TADDOL-like phosphonite ligand. Specifically, hydrogenation of commercially available methyl vinyl ketone (MVK) or ethyl vinyl ketone (EVK) in the presence of aldehydes 1a−7a using cationic rhodium catalysts modified by chiral TADDOL-like phosphonite ligands AP-I and AP-IV produces aldol adducts 1b−7b and 1c−7c with excellent control of relative and absolute stereochemistry. The absolute stereochemical assignments of the aldol adducts are made in analogy to that determined for the 5-bromophthalimido derivative of aldol adduct 1b and the 2-bromo-5-nitrobenzoate of 3b, which were established by single-crystal X-ray diffraction analysis using the anomalous dispersion method.
ENERGY TRANSFER IN THE COLLISION OF ELECTRON BEAMS.

The cross section for electron-electron scattering, differential in energy transfer, is derived for the case that both electrons are in motion in the laboratory system. The result is valid for all electron energies much higher than the Rydberg energy. For the case in which both electrons are nonrelativistic and one of the electrons has an isotropic velocity distribution, the cross section is averaged over the directions of motion of that electron.
The Treatment of Separation Anxiety Disorder Employing Attachment Theory and Cognitive Behavior Therapy Techniques

This study explored a potentially important intersection between behavior therapy and attachment theory in the treatment of separation anxiety disorder (SAD). Specifically, in this article, the aut...
The Cul-de-sac Effect: Relationship between Street Design and Residential Social Cohesion

AbstractRecent debates in urban planning have centered on whether the cul-de-sac street form should be eliminated from the United States’ topography. Critics argue that these closed-off streets force residents into their automobiles, reduce communal interaction, are difficult for emergency vehicles to traverse, and are not environmentally friendly. Developers, realtors, and homebuyers, on the other hand, clamor for these streets, which are private, quiet, and safe for raising children. Lacking from debates over the future of the cul-de-sac are systematic analyses assessing the social consequences of living on these streets. This study utilized a quasi-experimental design to assess differences in residential social cohesion for residents of “bulb” cul-de-sacs, “dead-end” cul-de-sacs, and through streets. My data reveal that bulb residents experience the highest levels of attitudinal and behavioral cohesion, followed by dead-ends, then through streets. With planning debates about the future of the cul-de-sa...
Quasicrystalline grain boundary precipitates in aluminium alloys through solid‐solid transformations

SUMMARY We have observed the formation of icosahedral quasicrystals of Al-Mg-Zn, Al-Mg-Cu, Al-Li-Zn and Al-Li-Cu by low temperature annealing of solid solution alloys. The icosahedral phase particles form at the grain boundaries of the matrix alloys. The orientational relationships between the icosahedral crystallites, their corresponding Frank-Kaspar phase particles and the aluminium matrix are reported. The stability of the icosahedral phases is also discussed. Finally, the importance of grain boundary icosahedral phase particles to the physical properties of commercial aluminium alloys is pointed out.
Well-ionization chamber response relative to NIST air-kerma strength standard for prostate brachytherapy seeds.

The response of well-ionization chambers to the emissions of 103 Pd and 125 I radioactive seed sources used in prostate cancerbrachytherapy has been measured.Calibration factors relating chamber response (current or dial setting) to measured air-kerma strength have been determined for seeds from nine manufacturers, each with different designs. Variations in well-ionization chamber response relative to measured air-kerma strength have been observed because of differences in the emitted energy spectrum due to both the radionuclide support material ( 125 I seeds) and the mass ratio of 103 Pd to 102 Pd ( 103 Pd seeds). Obtaining accurate results from quality assurancemeasurements using well-ionization chambers at a therapy clinic requires knowledge of such differences in chamber response as a function of seed design.
Attitudes towards Autonomous Data Collection and Analysis in the Planetary Science Community

As missions are planned to targets further away from Earth, it becomes all but required to increase the role of autonomy in the mission. An investigation of what aspects of mission operations and decision making autonomy will be accepted in by the planetary science community is thus required to aid in development planning. This paper presents a data set collected regarding attitudes towards autonomous data collection and analysis in the planetary science community and initial analysis of this data. A survey, conducted at the 2013 Lunar and Planetary Science Conference, asked respondents to identify whether or not they would accept conclusions drawn by autonomous data collection techniques and what factors would impact this acceptance. It also looked at the acceptance of computers and computer software in the data collection and analysis process.
Instabilities in two layer Rayleigh–Bénard convection: overview and outlook

Abstract A vast amount has been learned from the single-layer Rayleigh-Benard convection pattern formation problem. By adding a second layer of fluid immiscible with the first we form a two-layer convecting system with qualitatively new and different phenomena possible, including competition between instabilities in the separate layers, the driving of one pattern by another, spatio-temporal behavior at convective onset, deformations of the interface, and interfacial surface tension driven modes. The richness of the possible behaviors is impressive, owing to the large number of potentially relevant parameters. Such systems are important any time density stratification (or stratification of thermal properties) occurs, which is the norm for situations in geophysics, atmospheric physics, astrophysics, and in industrial processes. In this paper we will describe the essential features of this flow system, some of the historical background for the problem, and our current theoretical and experimental efforts on bifurcations from the conduction state in quasi-two-dimensional channels under conditions in which buoyancy dominates the convective behavior and the interface is flat, especially for situations leading to oscillatory behavior at onset. We will also describe the exotic three-dimensional flows that may exist in a system with large lateral dimensions.
Clinical Outcomes and Late Endocrine, Neurocognitive, and Visual Profiles of Proton Radiation for Pediatric Low-Grade Gliomas

Purpose/Objective(s) Primary low-grade gliomas are common brain tumors of childhood, many of which require radiation therapy (RT) as definitive treatment. Increased conformality of RT could decrease the incidence and severity of late effects. We report our experience with 32 pediatric patients treated with proton RT. Methods and Materials Thirty-two pediatric patients with low-grade gliomas of the brain or spinal cord were treated with proton RT from 1995 to 2007. Sixteen patients received at least 1 regimen of chemotherapy before definitive RT. The median radiation dose was 52.2 Gy RBE (48.6-54 Gy RBE ). Results The median age at treatment was 11.0 years (range, 2.7-21.5 years), with a median follow-up time of 7.6 years (range, 3.2-18.2 years). The 6-year and 8-year rates of progression-free survival were 89.7% and 82.8%, respectively, with an 8-year overall survival of 100%. For the subset of patients who received serial neurocognitive testing, there were no significant declines in Full-Scale Intelligence Quotient ( P =.80), with a median neurocognitive testing interval of 4.5 years (range, 1.2-8.1 years) from baseline to follow-up, but subgroup analysis indicated some significant decline in neurocognitive outcomes for young children ( RBE to the hypothalamus, pituitary, or optic chiasm. Stabilization or improvement of visual acuity was achieved in 83.3% of patients at risk for radiation-induced injury to the optic pathways. Conclusions This report of late effects in children with low-grade gliomas after proton RT is encouraging. Proton RT appears to be associated with good clinical outcome, especially when the tumor location allows for increased sparing of the left temporal lobe, hippocampus, and hypothalamic-pituitary axis.
Genetic encoding of fluorescent RNA ensures a bright future for visualizing nucleic acid dynamics

Recently RNA localization has been appreciated as an essential post-transcriptional mechanism to program local proteome composition and function. Although RNA has been visualized using diverse techniques, the use of the bacteriophage MS2 method to encode genetically fluorescent RNA has revolutionized the study of RNA dynamics in living cells. Here, I highlight the strength of MS2 compared to other techniques, and how further evolution of this system will enable the visualization of RNA in the context of complex live-cell dynamics. Although the generation of MS2-fluorescence resonance energy transfer (FRET) and MS2-bifluorescence complementation (BiFC) will require further development, it has the potential to increase significantly the signal-to-noise ratio, which is the major obstacle to rapid live-cell imaging of RNA.
A role for coactivators and histone acetylation in estrogen receptor α-mediated transcription initiation

Transcriptional regulation by estrogen receptor α (ERα) involves protein–protein interactions among the receptor, its associated coactivators and the RNA polymerase II transcriptional machinery. We have used an in vitro chromatin assembly and transcription system to examine the biochemistry of interactions among ERα, the SRC proteins and p300/CBP. Using polypeptides designed to block specific receptor–cofactor or cofactor–cofactor interactions, we show that interactions among ERα, its coactivators and the RNA pol II machinery are all required for ERα‐ mediated transcription. Furthermore, we show that ERα–SRC–p300/CBP interactions are necessary and sufficient for the targeted acetylation of nucleosomal histones on estrogen‐responsive promoters in the absence of transcription. The protein–protein interactions required for histone acetylation constitute a subset of the interactions required for transcriptional activation. Finally, we show that the major role of SRC–p300/CBP interactions is to enhance ERα‐ mediated transcription initiation, and they have little or no role in stimulating subsequent rounds of transcription. Together, our results indicate a specific role for the SRC and p300/CBP coactivators, as well as targeted histone acetylation, in ERα‐mediated transcription.
DNA synthesis is not required for the commitment of murine erythroleukemia cells.

We have assessed the relationship between DNA synthesis and the differentiation of MEL cells induced by DMSO. Under conditions where the rate of incorporation of 3H-deoxyadenosine into DNA was inhibited by 99%, the rate at which MEL cells become committed to terminal erythroid differentiation was identical to that of a culture treated with inducer alone. We conclude that commitment of MEL cells does not require concomitant DNA synthesis.
Measuring two ultrashort pulses simultaneously using a single device and on a single shot

We demonstrate a simple device for measuring two independent ultrashort pulses, each of which can potentially be complex and can also have very different center wavelength, simultaneously in a single-shot. We call our device "double-blind" FROG and it is implemented using a polarization-gate geometry. In polarization-gate "double-blind" FROG, each pulse acts as a reference pulse for the measurement of the other and yields the intensity and phase of both pulses.
A Flaw in McIver and Carroll's Experiments to Determine Written Sources in the Gospels

Robert McIver and Marie Carroll published an article in JBL in 2002 in which they discussed experiments with Australian undergraduate students that might help with determining the existence of written sources in the Gospels. They suggested that sixteen words in exact conjoined sequence provided a clear indicator of the presence of copying. However, McIver and Carroll transferred the results of their experiments in English to the Greek Synoptics without making any adjustments for the differences in language. A noninflected language like contemporary English takes more words to say something than an inflected language like Koine Greek. The problem can be illustrated by taking McIver and Carroll’s list of Synoptic parallels that feature sixteen-word sequential agreements and higher, and comparing these parallels with English translations. In practically every case, the English sequential agreements are substantially higher. The presence of this important flaw in the conceptualizing of the experiments places a major question mark over McIver and Carroll’s case.
On certain codes admitting inverse semigroups as syntactic monoids

The purpose of this paper is to investigate under what conditions an inverse semigroup M is isomorphic to the syntactic monoid M(A)* of afinite prefix code A over an alphabet X. We find a necessary condition for this to happen. It expresses a precise link between the group of units of M and the maximal subgroups of the 0-minimal ideal of M (Theorem 2.1). The condition is shown to be sufficient in case M is an ideal extension of a Brandt semigroup by a group (Corollary 2.3). We also introduce and study stable codes (products of subsets of the alphabet) and give structural properties of their syntactic monoids (Proposition 3.3 and Theorem 3.5). Most of our results inter-relate structural properties of certain semigroups and divisibility of integers attached to them. The terminology follows [1] and [3].
Yield responses of southern US rice cultivars to CO2 and temperature

Abstract Previous studies on the effects and interactions of atmospheric carbon dioxide concentration ([CO 2 ]) and air temperatures have shown large differences in growth and yield responses among Asian rice ( Oryza sativa L.) cultivars. Far less attention has been focused on rice cultivars commonly grown in the Southern US. This 2-year study was conducted to determine the effects of [CO 2 ] and air temperature on four Southern US rice cultivars. In 2000, ‘Cocodrie’, ‘Cypress’, and ‘Jefferson’ were grown season-long in five outdoor, naturally sunlit, controlled-environment chambers in constant day–night air temperature regimes of 24, 28, 32, 36, and 40 °C under an elevated [CO 2 ] of 700 μmol mol −1 . In 2000, an additional chamber containing all three cultivars was maintained at 28 °C and an ambient [CO 2 ] treatment of 350 μmol mol −1 . In 2002, a more detailed study examining both main crop (MC) and ratoon crop (RC) yields was conducted with the rice cultivar ‘Lamont’ in these same chambers with day–night air temperature treatments of 19/15, 23/19, 27/23, 31/27, and 35/31 °C under an elevated [CO 2 ] of 700 μmol mol −1 . In 2002, an additional chamber was maintained at 27/23 °C and an ambient [CO 2 ] treatment of 350 μmol mol −1 . In the 2000 experiment, all the plants of all three cultivars in the 40 °C treatment died during early vegetative growth. In the constant 36 °C air temperature treatment, all three cultivars survived to produce panicles but failed to produce any seed yield. At the 28 °C temperature treatment, CO 2 enrichment increased grain yield by 46–71% among the three cultivars with the cultivar Cypress being the most responsive to CO 2 enrichment. In the 2002 experiment with the cultivar Lamont, plants in the 35/31 and 19/15 °C treatments survived to produce panicles but failed to produce any seed yield. In the 27/23 °C treatment, CO 2 enrichment resulted in a non-significant increase in seed yield for the MC but more than doubled RC yields. Comparisons of these results with findings from prior studies on Asian indica and japonica cultivars indicate that these Southern US rice cultivars may be more sensitive to high temperature stresses during reproductive development than previously studied Asian cultivars. These results also point to the possibility of selecting or breeding rice cultivars with enhanced capability to take advantage of future global increases in [CO 2 ].
Stability evaluation and system identification of flexible multibody systems

This paper is concerned with the linearized stability analysis and system identification of flexible multibody systems. Two closely related stability analysis approaches are summarized. Next, these approaches are extended to provide robust system identification procedures that combine least squares techniques and Kalman filters. The singular value decomposition, a numerically stable mathematical tool, is used to improve the robustness of the algorithm. The proposed algorithm identifies a minimum order plant based on input-output data, and is applicable to both experimental measurements or numerically computed responses. The proposed approaches are computationally inexpensive and consist of purely post processing steps that can be used with any multi-physics computational multibody tool or with experimental data.
Quantitative Estimation of Dynamic Contrast Enhanced MRI Parameters in Rat Brain Gliomas Using a Dual Surface Coil System

Rationale and Objectives The study of vascular targeted cancer therapies is critically dependent on the development of noninvasive methods for assessing changes in vascular permeability and blood flow in small-animal tumor models. Materials and Methods A multicoil apparatus consisting of two receive-only surface coils for observation of the rat brain and chest, a whole-body transmit-only volume coil, and the switching circuitry necessary for sharing a single receiver channel between the two surface coils was constructed for the parallel observation of left ventricular arterial input function and magnetic resonance imaging (MRI) signal intensity kinetics in the rat brain. Dynamic contrast-enhanced MRI was performed on four Fischer rats bearing intracranial 9L gliomas, and the dynamic data were evaluated using the bolus-enhanced relaxation overview (BOLERO) model yielding maps of K trans , v e , and τ i values from the tumor. Results The use of the multicoil apparatus resulted in images with high signal-to-noise ratios from the rat brain and chest in parallel, with no detectable crosstalk between the surface coils. The BOLERO method accurately fit the observed data to within experimental error. Mean values of the parameters generated by the BOLERO analysis for the tumor were K trans = 0.023 ± 0.014 s −1 , τ i = 1.3 ± 0.6 seconds, and v e = 0.51. K trans and τ i values were slightly elevated in the tumor periphery, whereas v e was elevated in the tumor core. Conclusion These results demonstrate the feasibility of measuring quantitative dynamic contrast-enhanced MRI parameters in a rat brain tumor model using a multicoil apparatus. These methods might play an important role in determining the efficacy of antiangiogenic therapies in small-animal models.
Gas-phase Meerwein–Ponndorf–Verley reaction: correlation of the 3665 cm−1 IR band with the cis-alcohol selectivity

Abstract The two Lewis acid sites assumed to catalyze the Meerwein–Ponndorf–Verley (MPV) reaction are identified by IR bands at 3782 and 3660–3680 cm −1 . Different combinations of heat-treatment protocols were used and the results indicated that the final temperature, ramp rate, and gas environment make a difference in the relative intensities of the 3782 and 3665 cm −1 bands. Combining different heat-treatment procedures, samples were produced where the 3782 and 3665 cm −1 band intensities moved in opposite directions (i.e., one increasing and the other decreasing). The MPV reduction of 4- tert -butylcyclohexanone with 2-propanol in the gas phase was studied at 100 °C in a nitrogen atmosphere. The increasing trend of the relative intensity of the 3665 cm −1 band showed a correlation in favor of the formation of cis -4- tert -butylcyclohexanol ( cis -4-TBCHL). This suggests that the species associated with the 3665 cm −1 band are likely responsible for cis -4-TBCHL selectivity.
Oscillator-strength moments, stopping powers, and total inelastic-scattering cross sections of all atoms through strontium

Systematics of the atomic properties named in the title and of other related quantities have been comprehensively studied. Our calculations are based on a single-electron approximation using the Hartree-Slater central potential---a model that represents a reasonable compromise between two goals, namely, a realistic description of the major features of atomic dynamics and an economical computation necessary for a survey over many atoms. Our results not only quantify the general trends of the atomic properties as qualitatively expected from the periodic table, but also provide a sensible guide to experiment (on atoms for which no other data are available), to theory (for which we suggest several specific aims of more advanced analysis), and to applications including radiological physics and charged-particle microscopy.
CATALYST DEACTIVATION BY PORE PLUGGING AND ACTIVE SITE POISONING MECHANISMS II. PARALLEL POISONING IN BIDISPERSE STRUCTURED CATALYST

Abstract A catalyst deactivation model is formulated which includes the combined effects of pore plugging and active site poisoning in bidisperse structured catalyst particles. Intraparticle mass transfer is described by an equation which accounts for the configurational nature of diffusion in the micropores, and poison deposition is assumed to be in accord with a parallel poisoning mechanism. The model is used to explore the effects of macroporosity and micropore size on initial activity and activity maintenance, and model predictions appear to be consistent with observations from a recent coal liquefaction catalyst development program.
Scaling of nucleate boiling rates from water to liquid helium. I: Wetting conditions on oxidized copper surfaces

Abstract Copper is a frequently used stabilizer substrate for metallic superconducting composites in magnets using low transition-temperature materials. Wetting effects, quantified by contact angle measurements, have been studied in water. The water data are used as a basis for scaling of nucleate boiling transport from high temperatures to the low boiling liquid He I (4.2 K).
Characteristics of Engine Emissions Using Biodiesel Blends in Low-Temperature Combustion Regimes

Combustion and emissions of different biodiesel−diesel blends in a multicylinder diesel engine were investigated in this study. The engine used a modern common-rail fuel injection system that can achieve high injection pressures and multiple injections. The future diesel engines are likely to be operated in low-temperature combustion regimes to reduce exhaust emissions. Therefore, the performance of biodiesel in such operating conditions needs to be determined. The present results showed that biodiesel blends generally produced lower soot emissions and higher NOx emissions compared to regular diesel fuel. Results showed that the injection timing shift is not the reason for the NOx emissions increase using biodiesel. The increase in injection pressure will reduce soot emissions, while the use of exhaust gas recirculation will reduce the NOx emissions for all fuels. Reductions in NOx and soot emissions were achieved by using double injections with appropriate injection timings and fuel distributions. It was...
Nonlinear vibrations of piezoelectric microcantilevers for biologically-induced surface stress sensing

In this paper, nonlinear vibrations of a piezoelectrically-driven microcantilever beam in presence of a biological monolayer are investigated and the corresponding equations of motion are derived and simulated. A part of the microcantilever beam surface is covered by a piezoelectric layer, which acts as an actuator. Inextensibility condition and the coupling between electrical and mechanical properties in piezoelectric materials are considered in the bending vibrations of the beam. The adsorbed biological layer is considered to be a monolayer and its adsorption induced surface stress is formulated from the molecular viewpoint. The nonlinear terms in the governing equations of motion of the beam appear in the quadratic form due to the presence of the piezoelectric layer, and the cubic form due to geometry of the beam and the adsorbed biological layer. Through extensive numerical simulations, it is demonstrated that the nonlinear effect of piezoelectric layer is significant in the microcantilever resonance sensing range. It is also shown that the effect of intermolecular attraction–repulsion on the surface stress is less dominant than other sources of surface stress (e.g., the electrostatic forces). Finally, it is observed that piezoelectrically-actuated microcantilever provides the ability of indirect measurement of vibrations and frequency response characteristics, instead of using bulky laser sensor.
Semileptonic weak and electromagnetic interactions with nuclei: Parity violations in electron scattering and abnormal-parity admixtures in nuclear states☆

Abstract We derive an expression for the difference in the differential cross section for the scattering of right- and left-handed longitudinally polarized electrons from nuclei. Our result is applicable to scattering between any two nuclear levels and includes contributions from both the parity-nonconserving weak-electromagnetic interference and from abnormal-parity admixtures in the nuclear states. It is written in terms of the same nuclear matrix elements that govern all semileptonic transitions between the two levels and these matrix elements are examined using a recently developed one-body density matrix analysis of weak and electromagnetic interactions with nuclei. By exploiting the different momentum transfer dependence of the admixture and interference contributions, we find that, for the general cases considered here, the two contributions can be observed independently. In inelastic transitions in even-even nuclei, the admixture terms dominate at low-momentum transfers allowing for a determination of the scale of the parity admixing and a check of other parity-violation experiments. In this limit the contributions from the abnormal-parity admixtures can be investigated by appealing to the long-wavelength limit of the nuclear multipole matrix elements and by specifying the nuclear-state admixing with one overall scale parameter, which may become large in cases of favorable admixing. At higher momentum transfers, the interference terms dominate, permitting an investigation of the weak neutral-current interaction. In elastic scattering, current conservation implies that the leading term of the abnormal-parity nuclear matrix element vanishes; hence, the weak-electromagnetic interference is highly dominant in these cases. These results are illustrated by two examples using a simple parity-violating nucleon-nucleon potential derived from one-pion exchange. We use previously determined one-body transition densities to calculate the asymmetry in the 0 + 0 → 1 + 1 (15.11 MeV) transition in 12 C, and perform a new calculation of the asymmetry in elastic scattering from 13 C, determining the one-body transition densities from electron scattering data.
Vibrational Spectral Investigation of a Non-Acid-Catalyzed Sol-Gel Preparation of Lithium Niobate

Abstract Lithium niobate materials were prepared by a non-acid-catalyzed sol-gel process in an air atmosphere using lithium acetate dihydrate and niobium ethoxide in methoxyethanol as the precursor materials. Both Fourier transform infrared (FTIR) and Raman spectroscopy were used to characterize the structural changes that occurred during various stages of this preparation. During the applied process, acetate groups existed in the untreated gels as bridged species. Crystalline LiNbO3 formation occurred at lower temperatures (400°C or less) along with eventual elimination of acetate groups. The heat-treated amorphous phases possessed highly-distorted NbO6 units.
Exercise-induced myocardial capillary growth in the spontaneously hypertensive rat☆

Abstract Spontaneously hypertensive rats (SHR) were studied to test the hypothesis that endurance exercise training can stimulate capillary growth and offset the decrement associated with the development of myocardial hypertrophy. The exercise group (SHR-T) was trained on a treadmill for 10 weeks at 70–90% maximum V O 2 and compared to nontrained SHR and normotensive Wistar-Kyoto (WKY) at 16 weeks of age. Thus, the training program coincided with the development of hypertension and hypertrophy in SHR. Image analysis was used to study capillaries in one micron thick left ventricular tissue samples from perfuse-fixed hearts. Training did not affect left ventricular mass or blood pressure, but reversed the characteristic decrements in capillary surface area (CSA), volume (CV), and numerical density (CD). CSA and CV were most markedly affected by exercise, as mean values for these parameters increased by 31 and 40%, respectively, compared to SHR. The magnitude of these changes approximated the magnitude of hypertrophy as evidenced by left ventricular weight/body weight ratios (42% in SHR and 37% in SHR-T). Anatomical intercapillary distance was also normalized by training ( x ± SEM ): SHR-T, 11.65 ± 0.31; SHR, 13.97 ± 0.37; WKY, 11.19 ± 0.37. These data indicate that exercise stimulates capillary growth in the face of developing hypertension and its related left ventricular hypertrophy.
CAN YOU COMPENSATE FOR A LOST HOME? AN ASSESSMENT OF THE 1970 UNIFORM RELOCATION ACT

The study assesses the impact of the 1970 Uniform Relocation Assistance and Real Property Acquisition Policies Act on residents of four urban renewal projects in Richmond, Virginia. It looks at the...
Convective Instability in a Fluid Mixture Heated from Above

Convection patterns in ethanol-water mixtures with negative {psi} are studied when the fluid is heated from above. Although the linear analysis predicts that the instability occurs at zero wave number, a large wave number pattern is observed. The onset is supercritical with a threshold that is experimentally indistinguishable from zero. The convection amplitude exhibits damped oscillations for sudden change in the forcing parameter. At the constant Rayleigh number the patterns first coarsen, then exhibit growth of narrow plumes. The instability appears to be related to salt fingering. {copyright} {ital 1998} {ital The American Physical Society}
Clonal analysis of two mutations in the large subunit of RNA polymerase II of Drosophila.

Two mutations in the gene, RpII215, were analyzed to determine their effects on cell differentiation and proliferation. The mutations differ in that one, RpII215ts(ts), only displays a conditional recessive lethality, while the other, RpII215Ubl (Ubl), is a recessive lethal mutation that also displays a dominant mutant phenotype similar to that caused by the mutation Ultrabithorax (Ubx). Ubl causes a partial transformation of the haltere into a wing; however, this transformation is more complete in flies carrying both Ubl and Ubx. The present study shows that patches of Ubl/- tissue in gynandromorphs are morphologically normal. Cuticle that has lost the wild-type copy of the RpII215 locus fails to show a haltere to wing transformation, nor does it show the synergistic enhancement of Ubx by Ubl. We conclude that an interaction between the two RpII215 alleles, Ubl and RpII215+, is responsible for the mutant phenotype. Gynandromorphs carrying the ts allele, when raised at permissive temperature, display larger patches of ts/- cuticle than expected, possibly indicating that the proliferation of ts/+ cells is reduced. This might result from an antagonistic interaction between different RpII215 alleles. Classical negative complementation does not appear to be the cause of the antagonistic interaction described above, as only one RpII215 subunit is thought to be present in an active multimeric polymerase enzyme. We have therefore coined the term ‘negative heterosis’ to describe the aforementioned interactions.
Extensions Of The Method Of Moments For Deconvolution Of Experimental Data

The Method of Moments is one of a series of closely related transform methods which have been developed primarily for the deconvolution and analysis of fluorescence decay data. The main distinguishing feature of the Method of Moments is that it has been designed to be robust with respect to several important nonrandom errors of instrumental origin. The historical development of the method is reviewed here. Several new extensions are also described, including a statistical theory, an improved global analysis, and a method for analyzing continuous distributions of lifetimes. The new statistical theory is the first to incorporate a combined treatment of exponential depression and moment index displacement, both necessary components of the Method of Moments. In comparisons with the more commonly used least squares iterative reconvolution (LSIR) approach, it is shown that, in analyses of ideal synthetic data with random noise, the Method of Moments gives deviations in recovered parameters which are slightly greater but essentially comparable to those found by the data fitting method. Real experimental data also contain nonrandom errors. In the presence of certain such errors, decay parameters recovered by the Method of Moments will be unaffected, whereas the least squares method may yield incorrect results, unless care is taken to fit all of the data errors. An example of the improved global analysis application of the Method of Moments is shown in which two rhodamine dyes with very close lifetimes are distinguished based on spectral data. Also, the use of the distribution analysis method is illustrated with the binding of the intercalating dye ethidium bromide to DNA and nucleosome core particles. At very low ionic strength the width and location of the lifetime distribution shows a time dependence, indicating time-dependent changes in the environment of the probe. Finally, examples of Method of Moments analyses are shown for a totally different kind of data, photoacoustic waveforms. Multiexponential decays can be resolved. A new version of the Method of Moments program (which runs under either DOS or OS/2 operating systems) will soon be available on request.
Tocolytic and cardiovascular effects of the calcium antagonist diltiazem in the near-term pregnant rabbit

Parturition was induced with a 1 U intravenous bolus dose of oxytocin in two groups of near-term pregnant rabbits chronically prepared with distal aortic catheters. One group (n = 7) received an intravenous infusion of diftiazem (270 Wg/kg/min) and the other (n = 7) received saline solution. Parturition was markedly inhibited in the diltiazem-treated group, based on the time to delivery of the first and subsequent fetuses and the number of fetuses undelivered at the end of each study. A significant decline in maternal blood pressure was observed in the diltiazem-treated group, but no significnat change in maternal heart rate occurred. These findings suggest that diltiazem may provide significant tocolysis without the reflex tachycardia that has been observed with other calcium antagonists. Further evaluation of the maternal and fetal cardiovascular effects of diltiazem as well as the establishment of lower effective tocolytic doses are warranted.