cssi/SciSciGPT-SciSciNet huggingface dataset:
Time-resolved ring structure of circularly polarized beams backscattered from forward scattering media

The backscattering of circularly polarized light at normal incidence to a half-space of scattering particles is studied using the Electric Field Monte Carlo (EMC) method. The spatial distribution of the backscat-tered light intensity is examined for both the time-resolved and continuous wave cases for large particles with anisotropy factor, g, in the range 0.8 to 0.97. For the time-resolved case, the backscattered light with the same helicity as that of the incident beam (co-polarized) is found to form a ring centered on the point of incidence. The ring expands and simultaneously grows weak as time increases. The intensity of backscattered light with helicity opposite to that of the incident beam (cross-polarized) is found to exhibit a ring behavior for g ≥ 0.85, with significant backscattering at the point of incidence. For the continuous-wave case no such ring pattern is observed in backscattered light for either helicity. The present EMC study suggests that the ring behavior can only be observed in the time domain, in contrast to previous studies of light backscattered from forward scattering media based on the scalar time-independent Fokker-Planck approximation to the radiative transfer equation. The time-dependent ring structure of backscattered light may have potential use in subsurface imaging applications.
The asymptotic distribution of the suprema of the standardized empirical processes under the Koziol–Green model

Abstract Let S X (t) denote the m.l.e. of the survival function S X ( t ) based on the right censored data ( Z 1 , δ 1 ),…,( Z n , δ n ) and the proportional hazards model of random censorship. The asymptotic distribution of certain linear combinations of the supremum of the standardized process { n ( S X (t)−S X (t)) : t>0} is shown to be an extreme value distribution. This limiting distribution is used to construct asymptotically exact confidence bands for the survival function S X over the entire range of the observations. These bands are found to be narrower at both ends of the survival function when compared to the bands obtained by Hollander and Pena. If the proportion of uncensored data, α n , is greater than 1 2 , the bands narrow to zero width at both ends of the survival function. The bands are illustrated using simulated as well as real life data sets.
A Cu2O/TiO2 heterojunction thin film cathode for photoelectrocatalysis

Abstract A thin film heterojunction photocathode was developed consisting of 100 nm of n-type titanium dioxide (TiO2) cathode surface deposited on p-type cuprous oxide (Cu2O). The cuprous oxide was deposited electrochemically on Ti foil. A photocurrent of 0.7 mA / cm 2 (at −1 V bias) and an open circuit photovoltage of 460 mV were obtained under an illumination of 700 W / m 2 . The photoresponse as a function of pH demonstrated that the TiO2 film protected the Cu2O underlayer against corrosion. These results suggest that using a simple and inexpensive heterostucture configuration, the corrosion limitations of Cu2O alone may be overcome while maintaining a relatively high efficiency for photoelectrolysis.
An analysis of the Reich and Stivala algorithm for determining the reaction mechanism from TG data

Abstract The mechanisms indicated by the Reich and Stivala algorithm were evaluated for the decomposition of (NH 4 ) 2 CO 3 , NH 4 HCO 3 , and trans -[Co(NH 3 ) 4 Cl 2 ]BrO 3 ·H 2 O. Different mechanisms are indicated when data from different TG runs are used. Also, the data points selected within the same two runs influence the type of mechanism that best represents the data. Apparently, sample-to-sample variations can preclude the unambiguous assignment of a mechanism.
A Photometer for Measurement of Sky Brightness Near the Sun

Measurement of the brightness of the sky near the sun is difficult because instrumental scattered light originating in the solar disk is usually many times brighter than light from the sky. An optical system for eliminating this scattered light and providing means for a visual photometric comparison between the sky and the sun has been constructed and tested. The principles of the instrument are explained in sufficient detail to permit the design of similar instruments for a wide range of applications.
Technology Use in Science Instruction (TUSI): Aligning the Integration of Technology in Science Instruction in Ways Supportive of Science Education Reform

This study describes the development of an instrument to investigate the extent to which technology is integrated in science instruction in ways aligned to science reform outlined in standards documents. The instrument was developed by: (a) creating items consistent with the five dimensions identified in science education literature, (b) establishing content validity with both national and international content experts, (c) refining the item pool based on content expert feedback, (d) piloting testing of the instrument, (e) checking statistical reliability and item analysis, and (f) subsequently refining and finalization of the instrument. The TUSI was administered in a field test across eleven classrooms by three observers, with a total of 33 TUSI ratings completed. The finalized instrument was found to have acceptable inter-rater intraclass correlation reliability estimates. After the final stage of development, the TUSI instrument consisted of 26-items separated into the original five categories, which aligned with the exploratory factor analysis clustering of the items. Additionally, concurrent validity of the TUSI was established with the Reformed Teaching Observation Protocol. Finally, a subsequent set of 17 different classrooms were observed during the spring of 2011, and for the 9 classrooms where technology integration was observed, an overall Cronbach alpha reliability coefficient of 0.913 was found. Based on the analyses completed, the TUSI appears to be a useful instrument for measuring how technology is integrated into science classrooms and is seen as one mechanism for measuring the intersection of technological, pedagogical, and content knowledge in science classrooms.
Fiberoptics In Medicine

Fiberoptics are utilized in medicine by fields which have classically used light for either diagnosis or treatment. The specialities that have adopted the use of lasers have included the light for treatment and diagnosis group and those who have a problem with hemostasis in their treatment regimen. Table 1 lists the specialities which utilizes the diagnostic applications of fiberoptics. The diagnostic applications can be divided into the use of coherent fiber bundles for visualization and incoherent fiber bundles for illumination. Endoscopy is the introduction of a tube containing both coherent and incoherent fiber bundles into body orifices either natural or man made. Peritonoscopy inspects the abdomen through a small incision and enables the physician to observe from the reproduction tract in the pelvis to the dome of the liver. Gastrointestinal endoscopy uses these techniques through different instruments to explore the upper tract through the mouth or the lower tract through the anus. Pulmonary endoscopy called bronchoscopy enters the respiratory tract through the mouth. Urology investigates the bladder in cystoscopy through the urethra. All these diagnostic applications can also take biopsies through these instruments for diagnoses of anatomical abnormalities visualized through the endoscopic instruments.© (1978) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
NOTES Otolith Morphology and Increment Validation in Young Lost River and Shortnose Suckers

Abstract Morphology, time of formation and deposition of the first increment, and rate of increment deposition were determined for sagittae, lapilli, and asterisci from Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris. Sagittae and lapilli form on the day of hatch, and asterisci form after 41–52 d in Lost River sucker and after 14–25 d in shortnose sucker. Lapillus increments were validated by using known-age hatchery-raised larvae and wild-caught larvae and juveniles marked by immersion in water with an alizarin complexone concentration of 50 mg/L for 4 h and 18 h, respectively. A transition from relatively wide to relatively narrow increments was sometimes seen during the second week after hatch and appears to be associated with yolk absorption. Because of their readability and conservative growth, lapilli are the preferred otolith structure for age determination of larval and juvenile suckers, whereas sagittae are preferred for nonostariophysan fishes.
k=0 Libron Spectrum for Solid Hydrogen in the Pa3 and C mmm Structures

The libron wave spectrum at zero wave vector for solid hydrogen in the Pa3 and Cmmm structures is calculated at zero temperature. Interactions other than the electrostatic interactions between molecular quadrupole moments are treated perturbatively. Comparison of our numerical and analytic results for libron frequencies and Raman intensities with the observed Raman spectrum gives strong evidence for the Pa3 structure. The scaling relation between the frequencies of the classical and quantum-librational systems is found to hold for the Pa3 but not for the Cmmm structure. The effects of zero-point librations and libron-libron interactions are studied to lowest order in 1/z, where z is the number of nearest neighbors. Although the static effects are quite small, the shifts in the libron frequencies due to these interactions are of order 15%. Disciplines Physics | Quantum Physics This journal article is available at ScholarlyCommons: http://repository.upenn.edu/physics_papers/402 PHYSICAL REVIEW 8 VOLUME 2, NUMBER 4 15 AUGUST 1970 k=0 Libron Spectrum for Solid Hydrogen in the Pa3 and C Structures* Cornelius F. Coll, III, and A. Brooks Harris DePa&ment of Physics', &nivet'sity of Pennsylvania, PhgadelPhia, Pennsylvania (Received 27 March 1970) The libron wRve spectruIIl at zelo wRve vector fox' solid h/drogen in the Pa3 Rnd C~~ structures is calculated at zexo temperature. Interactions other than the electrostatic interactions between moleculax' quadrupole moments are treated perturbatively. CompRx'lson of our numerlcR1 and anal/tie results for libron flequencles Rnd BamRn intensities with the obsexved Baman spectxum gives strong evidence for the Pa3 structuxe. The scaling x'61Rtlon between the fx'equencies of the clR88lcR1 Rnd quRntuIQ-librRtlonRl 8+stems is found to hold for the Pa3 but not for the C~~ structure. The effects of zero-point librations and libron-libron interactions are studied to lowest order in 1/g, where z is the number of nearest neighbors. Although the static effects are quite small, the shifts in the libron frequencies due to these interactions are of order 15%.
The bulk composition of Mars

Abstract An accurate assessment of the bulk chemical composition of Mars is fundamental to understanding planetary accretion, differentiation, mantle evolution, the nature of the igneous parent rocks that were altered to produce sediments on Mars, and the initial concentrations of volatiles such as H, Cl and S, important constituents of the Martian surface. This paper reviews the three main approaches that have been used to estimate the bulk chemical composition of Mars: geochemical/cosmochemical, isotopic, and geophysical. The standard model is one developed by Wanke and Dreibus in a series of papers, which is based on compositions of Martian meteorites. Since their groundbreaking work, substantial amounts of data have become available to allow a reassessment of the composition of Mars from elemental data, including tests of the basic assumptions in the geochemical models. The results adjust some of the concentrations in the Wanke–Dreibus model, but in general confirm its accuracy. Bulk silicate Mars has roughly uniform depletion of moderately volatile elements such as K (0.6 × CI), and strong depletion of highly volatile elements (e.g., Tl). The highly volatile elements are within uncertainties uniformly depleted at about 0.06 CI abundances. The highly volatile chalcophile elements are likewise roughly uniformly depleted, but with more scatter, with normalized abundances of 0.03 CI. Bulk planetary H 2 O is much higher than estimated previously: it appears to be slightly less than in Earth, but D / H is similar in Earth and Mars, indicating a common source of water-bearing material in the inner solar system. K/Th ranges from ∼3000 to ∼5000 among the terrestrial planets, a small range compared to CI chondrites (19,000). FeO varies throughout the inner solar system: ∼3 wt% in Mercury, 8 wt% in Earth and Venus, and 18 wt% in Mars. These differences can be produced by varying oxidation conditions, hence do not suggest the terrestrial planets were formed from fundamentally different materials. The broad chemical similarities among the terrestrial planets indicate substantial mixing throughout the inner solar system during planet formation, as suggested by dynamical models.
Mechanistic study of cationic dye interactions with clay-polymer dispersions via metachromatic effect, aggregation, and surface charge

Interactions for a series of aqueous dispersions of a clay, Laponite, and nonionic difunctional triblock copolymer, Pluronic L62, with two cationic dyes, crystal violet and brilliant green, are studied using UV–vis spectroscopy, dynamic light scattering (DLS), and electrophoretic mobility (EPM) to better understand the adsorption mechanisms. Different concentrations for clay, 0.1–2.0 g/L, mixed with polymer, 0.125–0.5 g/L to produce an organoclay, were tested with a fixed dye concentration, 2.0 × 10−5 mol/L. The aggregation states of the cationic dyes interacting with the clay–polymer dispersions were characterized by UV–vis absorbance. The dyes changed aggregation states from monomer to dimer and higher aggregate states upon addition to varying Laponite–polymer dispersion concentrations. DLS was used to understand the adsorbed polymer and dye interactions on the clay particle showing longer relaxation times for the largest aggregates observed from UV–vis absorbance. The EPM was used to characterize the surface charge of the clay relative to the polymer–dye interactions, which showed that the surface charge approached zero as the dyes interacted with clay–polymer dispersions. The most significant changes occurred with a reduction in light scattering intensity and longer relaxation decay at 0.1 g/L Laponite and 0.5 g/L Pluronic L62 concentrations in the presence of cationic dyes. The study of the clay–polymer–dye interactions help to better understand and design chemical templates for removal of contaminates in waste-water treatment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40141.
Cell Host Response to Infection with Novel Human Coronavirus EMC Predicts Potential Antivirals and Important Differences with SARS Coronavirus

ABSTRACT A novel human coronavirus (HCoV-EMC) was recently identified in the Middle East as the causative agent of a severe acute respiratory syndrome (SARS) resembling the illness caused by SARS coronavirus (SARS-CoV). Although derived from the CoV family, the two viruses are genetically distinct and do not use the same receptor. Here, we investigated whether HCoV-EMC and SARS-CoV induce similar or distinct host responses after infection of a human lung epithelial cell line. HCoV-EMC was able to replicate as efficiently as SARS-CoV in Calu-3 cells and similarly induced minimal transcriptomic changes before 12 h postinfection. Later in infection, HCoV-EMC induced a massive dysregulation of the host transcriptome, to a much greater extent than SARS-CoV. Both viruses induced a similar activation of pattern recognition receptors and the interleukin 17 (IL-17) pathway, but HCoV-EMC specifically down-regulated the expression of several genes within the antigen presentation pathway, including both type I and II major histocompatibility complex (MHC) genes. This could have an important impact on the ability of the host to mount an adaptive host response. A unique set of 207 genes was dysregulated early and permanently throughout infection with HCoV-EMC, and was used in a computational screen to predict potential antiviral compounds, including kinase inhibitors and glucocorticoids. Overall, HCoV-EMC and SARS-CoV elicit distinct host gene expression responses, which might impact in vivo pathogenesis and could orient therapeutic strategies against that emergent virus. IMPORTANCE Identification of a novel coronavirus causing fatal respiratory infection in humans raises concerns about a possible widespread outbreak of severe respiratory infection similar to the one caused by SARS-CoV. Using a human lung epithelial cell line and global transcriptomic profiling, we identified differences in the host response between HCoV-EMC and SARS-CoV. This enables rapid assessment of viral properties and the ability to anticipate possible differences in human clinical responses to HCoV-EMC and SARS-CoV. We used this information to predict potential effective drugs against HCoV-EMC, a method that could be more generally used to identify candidate therapeutics in future disease outbreaks. These data will help to generate hypotheses and make rapid advancements in characterizing this new virus.
The lithium isotope ratio in Population II halo dwarfs - A proposed test of the late decaying massive particle nucleosynthesis scenario

It is shown that observations of the lithium isotope ratio in high surface temperature Population II stars may be critical to cosmological nucleosynthesis models. In particular, decaying particle scenarios as derived in some supersymmetric models may stand or fall with such observations.
Seasonal variations in glucose metabolism of reindeer (Rangifer tarandus L.) estimated with (U- 14 C)glucose and (3- 3 H)glucose.

1. The pool size, space and rate of irreversible loss of glucose were estimated with primed infusions of [U- 14 C]glucose in reindeer cows within 6 h of being taken from outdoor pens or from free grazing in the field. 2. In conjunction with primed infusions of [U- 14 C]glucose, single injections of [3- 3 H]glucose were also used to estimate pool size, space, transfer rate, and turnover time of glucose. 3. Except in a period of severe undernutrition, the concentration of glucose in plasma was higher (range 0·76–1·40 mg/ml) than that recorded for other ruminants. 4. The size of the glucose pool (range 8–35 g) varied in parallel with plasma glucose concentration and was generally distributed in a space in excess of the extracellular fluid volume. 5. The lowest rates of irreversible loss of glucose (approximately 1·7 mg/min per kg 0·75 ) were measured when cows were in mid pregnancy and when available food was scarce; the highest rate (5·5 mg/min per kg 0·75 ) was found in cows during mid summer. 6. Changes in irreversible loss and transfer rate of glucose are interpreted in relation to changes in body composition (estimated in a parallel study), subjective assessment of available food and factors known to control glucose metabolism in other ruminants. 7. The difference between glucose transfer rate and rate of irreversible loss of glucose was used as an index of the rate of resynthesis of glucose from products of glucose catabolism. The rates of glucose resynthesis were highest during a period of rapid growth (4·52 mg/min per kg 0·75 or 45% of the glucose transfer rate) and in mid and late pregnancy (respectively 4·14 and 4·28 mg/min per kg 0·75 or 71 and 59% of the transfer rate).
Incubation Conditions and Hatchability of Turkey Eggs

Abstract MANUFACTURERS of some forced draft incubators recommend that turkey eggs be removed from the incubator to a separate hatcher at 24 days’ incubation. This change involves a drop in incubation temperature from 99¾ to 97°F., cessation of turning, and a change in position from an angle of 45 degrees from horizontal to a horizontal position in which the eggs lie on their sides. The experiments reported herein were undertaken to determine the effects of transfer to the hatcher and to each of the hatcher conditions at 12, 15, 18, 21, 24, and 25 days’ incubation, respectively. The effects of hatcher temperatures of 93, 95, 97, 98, 99¾ and 102°F. were also determined. Egg length was measured prior to incubation so that its relation to hatchability under the various experimental conditions might be determined. Romanoff (1935) reported experiments in which turkey eggs were incubated for three weeks in a forced draft . . .
Molecular and cytogenetic characterization of a novel rearrangement involving chromosomes 9, 12, and 17 resulting in ETV6 (TEL) and ABL fusion

We performed chromosome analysis on the bone marrow of a patient with BCR/ABL negative chronic myelogenous leukemia (CML). By interphase fluorescence in situ hybridization (FISH), an extra ABL signal was present in interphase nuclei and appeared to be located at 17p in the metaphase cells. Chromosome analysis showed a subtle abnormality at 17p13 and 12p13 but no visible rearrangement at 9q34 (ABL). Additional FISH experiments disclosed a rearrangement between the short arms of chromosomes 12 and 17 at approximately bands 12p13 and 17p13, respectively. In addition, subtelomeric FISH analysis confirmed the presence of terminal 12p at 17p13 and showed terminal 9q34 to be intact on each chromosome 9. Taken together, these results indicated a rearrangement involving chromosomes 9, 12, and 17 that suggested the possibility of juxtaposition of part of the ETV6 (also known as TEL) locus (12p13) with a portion of ABL (9q34) together at 17p13. The ETV6/ABL fusion was confirmed by RT-PCR, which showed that the first 5 exons of ETV6 were fused in frame with ABL at exon 2. Wild-type ETV6 and ABL were also expressed, in accordance with the FISH results that showed no loss of the second ETV6 or ABL allele.
First Chronic Platelet Glycoprotein IIb/IIIa Integrin Blockade A Randomized, Placebo-Controlled Pilot Study of Xemilofiban in Unstable Angina With Percutaneous Coronary Interventions

Background Clinical studies have demonstrated the efficacy of intravenous administration of agents that block platelet glycoprotein IIb/IIIa receptors in the setting of percutaneous coronary revascularization. Although the optimal duration of treatment has not been determined, more prolonged receptor blockade has been associated with increased efficacy. Orally active glycoprotein IIb/IIIa receptor antagonists may be advantageous and required for chronic therapy. Methods and Results Thirty patients with unstable angina who were undergoing percutaneous coronary interventions were randomized to placebo or Xemilofiban 35 mg orally before and 20 to 25 mg TID for 30 days after angioplasty. Bleeding events, platelet aggregation, and pharmacokinetic and hematologic parameters were assessed during hospitalization and at 2 and 4 weeks after drug initiation. Xemilofiban produced a rapid, sustained, marked inhibition of platelet aggregation. ADP-induced platelet aggregation at 2 hours after the initial dose at 2 and ...
Genetics and Epigenetics of the Skin Meet Deep Sequence

Rapid advances in next-generation sequencing technology are revolutionizing approaches to genomic and epigenomic studies of skin. Deep sequencing of cutaneous malignancies reveals heavily mutagenized genomes with large numbers of low-prevalence mutations and multiple resistance mechanisms to targeted therapies. Next-generation sequencing approaches have already paid rich dividends in identifying the genetic causes of dermatologic disease, both in heritable mutations and the somatic aberrations that underlie cutaneous mosaicism. Although epigenetic alterations clearly influence tumorigenesis, pluripotent stem cell biology, and epidermal cell lineage decisions, labor and cost-intensive approaches long delayed a genome-scale perspective. New insights into epigenomic mechanisms in skin disease should arise from the accelerating assessment of histone modification, DNA methylation, and related gene expression signatures.
Shared operator recognition specificity between Trp repressor and the repressors of bacteriophage 434

Trp repressor is the only DNA-binding regulatory protein having a helix-turn-helix motif that has been reported to engage its operator target by a mechanism termed indirect readout: the Trp repressor-DNA interface is replete with hydrogen bonds between amino acid residues and non-esterified oxygen atoms of the sugar-phosphate backbone, and contains numerous specifically positioned water molecules. In Escherichia coli mutants deleted for trpR, the immunity repressor of phage 434 led to an eightfold reduction in trp promoter utilization. The Cro434 repressor also inhibited transcription from the trp promoter. The 434 repressors, considered to interact directly with operator targets, carry recognition helices positioned near the N terminus of each protein. The DNA-recognizing elements of Trp repressor lie toward the C terminus. The trp operator thus appears to possess significant plasticity in terms of its ability to assume conformational states that allow complex formation with more than one class of regulatory protein.
Partial redundancy elimination for access expressions by speculative code motion

We present a new memory access optimization for Java to perform aggressive code motion for speculatively optimizing memory accesses by applying partial redundancy elimination (PRE) techniques. First, to reduce as many barriers as possible and to enhance code motion, we perform alias analysis to identify all the regions in which each object reference is not aliased. Secondly, we find all the possible barriers. Finally, we perform code motions in three steps. For the first step, we apply a non-speculative PRE algorithm to move load instructions and their following instructions in the backwards direction of the control flow graph. For the second step, we apply a speculative PRE algorithm to move some of them aggressively before the conditional branches. For the third step, we apply our modified version of a non-speculative PRE algorithm to move store instructions in the forward direction of the control flow graph and to even move some of them after the merge points. We implemented our new algorithm in our production-level Java just-in-time compiler. Our experimental results show that our speculative algorithm improves the average (maximum) performance by 13.1% (90.7%) for jBYTEmark and 1.4% (4.4%) for SPECjvm98 over the fastest algorithm previously described, while it increases the average (maximum) compilation time by 0.9% (2.9%) for both benchmark suites.
Temperature Dependence of the Solar Absorptance and Thermal Emittance of Copper, Gold, Nickel, and Silver

Solar absorptance and thermal emittance of copper, gold, nickel and silver as function of temperature
Self-steepening of light pulses.

Light pulses self steepening resulting from propagation in medium with intensity dependent refractive index
Lactic acid enhancement can improve the fresh and cooked color of dark-cutting beef.

Two experiments were conducted to compare the effects of enhancing dark-cutting (DC) strip loins with lactic acid (LAC) on fresh and cooked beef color, as well as sensory attributes, with nonenhanced, normal pH strip loins (CH). Strip loins, with an average ultimate pH of 6.70 ± 0.11 (Exp. 1) and 6.78 ± 0.11 (Exp. 2), were cut into 2 equal-length sections, and DC sections were randomly assigned as either nonenhanced DC or DC enhanced with 0.15 (Exp. 1), 0.35 (Exp. 1 and 2), or 0.50% (Exp. 2) LAC at a target of either 105 (Exp. 1) or 112% (Exp. 2) of the raw product weight. Enhancement with 0.15 and 0.35% LAC did not (P > 0.05) affect postenhancement pH of DC strip loins when enhanced at a target of 105% (Exp. 1); however, postenhancement pH was reduced (P 0.05) to those of CH strip loin sections (Exp. 2). In Exp. 1, raw steaks from CH strip loins had greater (P 0.05) differ when cooked to 71°C in Exp. 2. Fresh and cooked color of DC beef was only minimally altered when enhanced with 0.35% LAC at 105% of the fresh product weight; however, when DC beef was enhanced with 0.35 and 0.50% LAC at a target of 112%, fresh and cooked color were improved close to that of CH beef. Because the persistent red or pink cooked color of DC was virtually eliminated by 0.50% LAC enhancement, LAC-enhanced DC beef may be suitable for food-service markets; however, the raw or fresh color results of Exp. 2 suggested that the fresh color of DC beef can be improved to the color of normal pH beef by postmortem acidification, leading to the possible recoupment of most, if not all, of the lost value associated with DC beef.
Multiple Scattering and Nuclear Information

One-dimensional scattering from two mobile rectangular potential wells in a bound state is studied in order to investigate the contributions from the overlapping-potential region. The above model is used to compare the exact solution in the "fixed-scatterer" approximation with the corresponding ones obtained assuming non-overlapping potentials and additivity of phase shifts. The kinematics of the "fixed-scatterer" and "impulse" approximations are also examined, and the differences are found to be still significant at intermediate energies. For non-overlapping potentials the composite scattering is completely determined in terms of the individual scattering coefficients or on-shell information, and the solution is given by a linear system of coupled algebraic equations. Unfortunately, as far as scattering information is concerned the overlapping-potential region is the interesting one, since it offers the possibility of discriminating among phase-shift-equivalent potentials and of determining the short-range behavior of the wave function. Our results suggest that the predictions provided by the non-overlapping potentials or additivity of phase-shifts assumptions deviate sufficiently from the exact result to render ambiguous the extraction of the distribution function or two-body interaction from elastic intermediate-energy scattering in terms of either of these two models.
Time Scales for Unsteady Mass Transfer From a Sphere at Low-Finite Reynolds Numbers

The problem of unsteady mass transfer from a sphere that impulsively moves from rest to a finite velocity in a non-uniform concentration distribution is studied. A range of low Reynolds numbers (Re<1) and moderate Peclet numbers (Pe ranges from 5.6 to 300) is investigated (typical of the parameters encountered in anchorage dependent cell cultures in micro gravity). Using time scales, the effects of flow field development, concentration boundary layer development and free stream concentration variation are investigated. For the range of parameters considered, the development of the flow field has a negligible effect on the time variation of the Sherwood number (Sh). The Sh time dependence is dominated by concentration boundary layer development for early times and free stream concentration variations at later times
Anatomy of the Squirrel Wrist: Bones, Ligaments, and Muscles

Anatomical differences among squirrels are usually most evident in the comparison of flying squirrels and nongliding squirrels. This is true of wrist anatomy, probably reflecting the specializations of flying squirrels for the extension of the wing tip and control of it during gliding. In the proximal row of carpals of most squirrels, the pisiform articulates only with the triquetrum, but in flying squirrels there is also a prominent articulation between the pisiform and the scapholunate, providing a more stable base for the styliform cartilage, which supports the wing tip. In the proximal wrist joint, between these carpals and the radius and ulna, differences in curvature of articular surfaces and in the location of ligaments also correlate with differences in degree and kind of movement occurring at this joint, principally reflecting the extreme dorsal flexion and radial deviation of the wrist in flying squirrels when gliding. The distal wrist joint, between the proximal and distal rows of carpals, also shows most variation among flying squirrels, principally in the articulations of the centrale with the other carpal bones, probably causing the distal row of carpal bones to function more like a single unit in some animals. There is little variation in wrist musculature, suggesting only minor evolutionary modification since the tribal radiation of squirrels, probably in the early Oligocene. Variation in the carpal bones, particularly the articulation of the pisiform with the triquetrum and the scapholunate, suggests a different suprageneric grouping of flying squirrels than previously proposed by McKenna (1962) and Mein (1970). J. Morphol. 246:85-102, 2000. Published 2000 Wiley-Liss, Inc.
Single-temperature desorption from porous catalysts

Abstract Comparison between continuous-flow stirred tank and column models for single-temperature desorption processes, with and without intraparticle considerations, shows the effect of dispersion, mass transfer, and diffusion phenomena on temporal moment expressions for output concentrations. Substantial differences are found between stirred-tank and column models for beds of porous spherical particles. Elution curves for adsorption sites with different values of the equilibrium coefficient K are constructed from the moments. Bimodal peaks are predicted for a single-temperature desorption if the K values for two different sites are sufficiently different. Commonly used shape indicators are related to the temporal moments.
CLATHRATE EUSTASY : METHANE HYDRATE MELTING AS A MECHANISM FOR GEOLOGICALLY RAPID SEA-LEVEL FALL

Although submarine methane hydrates or clathrates have been highlighted as potential amplifiers of modern global climate change and associated glacio-eustatic sea-level rise, their potential role in sea-level fall has not been appreciated. Recent estimates of the total volume occupied by gas hydrates in marine sediments vary 20-fold, from 1.2 x 10{sup 14} to 2.4 x 10{sup 15} m{sup 3}. Using a specific volume change on melting of {minus}21%, dissociation of the current global inventory of hydrate would result in a decrease of submarine hydrate volume of 2.4 x 10{sup 13} to 5.0 x 10{sup 14} m{sup 3}. Release of free gas bubbles present beneath hydrates would increase these volumes by 1.1 --2.0 x 10{sup 13} m{sup 3}. The combined effects of hydrate melting and subhydrate gas release would result conservatively in a global sea-level fall of 10--146 cm. Such a mechanism may offset some future sea-level rise associated with thermal expansion of the oceans. It could also explain anomalous sea-level drops during ice-free periods such as the early Eocene, the Cretaceous, and the Devonian.
Critical contributions of amino-terminal extracellular domains in agonist binding and activation of secretin and vasoactive intestinal polypeptide receptors. Studies of chimeric receptors.

Secretin and vasoactive intestinal polypeptide (VIP) receptors are closely related G protein-coupled receptors in a recently described family possessing a large amino-terminal ectodomain. We postulated that this domain might be critical for agonist recognition and therefore constructed a series of six chimeric receptors, exchanging the amino terminus, the first extracellular loop, or both in secretin and VIP receptors. Constructs were expressed in COS cells and characterized by cAMP generation and binding of both secretin and VIP radioligands. Wild type receptors demonstrated high affinity binding of respective ligands (IC50 values (in nM): at the secretin receptor: 2.2 for secretin, >1000 for VIP; at the VIP receptor: 2.2 for VIP, >1000 for secretin) and appropriately sensitive and selective biological responses (EC50 values (in nM): at the secretin receptor: 1.5 for secretin, 127 for VIP; at the VIP receptor: 1.0 for VIP, 273 for secretin). Replacement of the secretin receptor amino terminus with that of the VIP receptor resulted in biological responsiveness typical of the VIP receptor (EC50 = 120 nM for secretin, 1.7 nM for VIP). The converse was not true, with this domain of the secretin receptor not able to provide the same response when incorporated into the VIP receptor (EC50 = 50 nM for VIP, 30 nM for secretin). The addition of both the first loop and the amino terminus of the secretin receptor was effective in yielding a secretin receptor-like response (EC50 = 2.0 nM for secretin, 47 nM for VIP). All chimeric constructs expressing selectivity for secretin-stimulated activity bound this hormone with high affinity (IC50 = 0.2-2.2 nM); however, there was divergence between VIP binding and biological activity. Thus, the amino terminus of secretin and VIP receptors plays a key role in agonist recognition and responsiveness, with the first loop playing a critical complementary role for the secretin receptor.
Igneous activity in the Comstock District, Nevada

The oldest igneous rocks in the Comstock District are amphibolites probably derived from basalts and of Triassic age. These are intruded by pre-Tertiary quartz monzonlte and by granodiorite of Sierran facies, the latter not being exposed on the surface but found on mine-dumps. Igneous activity recorded mainly in volcanic rocks was almost continuous throughout the Tertiary. Its products, in order of age, were as follows: Eocene—Rhyolitic flows aggregating a few hundred feet in thickness: One intrusive plug of rhyolite occurs. Eocene or Miocene—Hornblende-auglte andesite intrusive into the rhyolite, type locality American Ravine.
π-π Scattering in the boundary-condition model

The boundary-condition model is used to generate pionpion amplitudes in theT=0, 2S-states and theT=1P-state. The parameters of the model are restricted by three crossing symmetry conditions at the symmetry point, reducing the number of independent parameters to as few as three. The remaining parameters are used to fit the data available from multi-pion production experiments. Conclusions are obtained with respect to the distribution of Yukawa potentials of range ∼0.5µ−1, and the boundary conditions at a radius⩽0.25µ−1. TheP-state model has a repulsive potential tail and an attractive core. It leads to the asymmetry of the ρ-mass distribution seen in some experiments. Contributions from ω decay are not required. TheT=2S-state results tend toward a hard core with an attractive tail. The model of theT=0S-state interaction can be either a nonresonanting constant boundary condition with tail, or a resonanting pole-type boundary condition.
A Unified Account of General Learning Mechanisms and Theory‐of‐Mind Development

Modularity theorists have challenged that there are, or could be, general learning mechanisms that explain theory-of-mind development. In response, supporters of the ‘scientific theory-theory’ account of theory-of-mind development have appealed to children's use of auxiliary hypotheses and probabilistic causal modeling. This article argues that these general learning mechanisms are not sufficient to meet the modularist's challenge. The article then explores an alternative domain-general learning mechanism by proposing that children grasp the concept belief through the progressive alignment of relational structure that occurs as a result of structural-comparison. The article also explores the implications of the proposed account for Fodor's puzzle of conceptual learning.
N-Alkylation of Secondary Amine Tricyclic Antidepressants as a General Method for Their Quantitation by GC-MS-SIM Technique. Preparation of N-Ethyl Derivatives of Desimipramine, Nortriptyline, Protiptyline and Desmethyldoxepin

Abstract A simple method for the preparation of N-ethyl derivatives of secondary amino tricyclic antidepressants is described, using dimethylformamide diethyl acetal as the alkylating reagent. The GC data and electron impact and chemical ionization mass spectra of N-ethyl derivatives are presented. The use of these derivatives in the quantitation of plasma levels of these drugs in clinical studies is discussed.
Identification of some antigenic precursors of bacteriophage T4

Abstract Immunoelectrophoresis of a lysate of bacteria infected by wild-type phage T4 gives at least nine precipitin lines against anti-T4 serum. These antigens have been found to be precursors of the phage particle. Some of the antigens (three tail fiber, three head and probably five tail precursor antigens) have been characterized with respect to sedimentation, polypeptide composition and controlling genes. A head surface antigen under the control of gene 49 gives a strong precipitin line against anti-T4 and anti-capsid sera. Its major component has a sedimentation coefficient of 4.5 s and consists of protein with a molecular weight of 55,000; however, gene 49 appears not to be the structural gene for this component. A significant amount of uncleaved product of gene 23 is present, probably in monomeric form, in lysates made with phage defective in head genes 20, 21, 22, 24 and 40 as well as T4+ lysates, but not in 23- or 31 -lysates. Uncleaved and cleaved products of gene 23 appear to be strikingly different in antigenicity, as shown by electron microscopy and immunoelectrophoresis.
Sensory Attributes and Instron Measurements of Reduced‐Nitrite Poultry Frankfurters With Sorbic Acid or Potassium Sorbate

Poultry frankfurters (0 and 40 ppm nitrite) with sorbic acid or potassium sorbate were studied. Flavor characteristics were influenced by nitrite but not by ascorbic acid or potassium sorbate. Frankfurters with sorbic acid were softer and those with potassium sorbate were firmer than those without. Nitrite alone increased firmness. Sorbic acid appeared to counteract that increased firmness and potassium sorbate enhanced the increase in firmness when those compounds were used in combination with nitrite in the poultry frankfurters. Simulated-teeth attachments for the Inston gave results similar to sensory firmness scores. Frankfurters with sorbic acid added had lower pH than frankfurters from other treatments.
Current status of pediatric practice-based research networks.

Summary PBRNs have become a major factor in the pediatric research landscape and hold great promise for generating new knowledge about child health. Much remains to be learned about the content of children's health care. More importantly, there is great room for improvement in the delivery of primary care to children. In wedding the knowledge and expertise of academic researchers and pediatric practitioners, PBRNs will become agents to transform and improve pediatric practice by identifying areas of care in need of improvement, developing and testing interventions to improve pediatric practice, and disseminating this knowledge to the pediatric community.
Laboratory and field evaluation of insect repellents as larvicides against the mosquitoes Aedes albopictus and Anopheles albimanus.

. Acute toxicity and persistence of three insect repellents, deet and two piperidines (AI3-35765 and AI3-37220), were evaluated against mosquito larvae of Aedes albopictus (Skuse) and Anopheles albimanus Wiedemann (Diptera: Culicidae) in the laboratory, and against natural populations of Ae. albopictus in the field. In laboratory studies, the LC50 values of the repellents for first instars ranged between 0.005 and 0.021% (Ae. albopictus) and between 0.01 and 0.014% (An. albimanus) and, for fourth instars, between 0.019 and 0.034% (Ae. albopictus) and between 0.015 and 0.024% (An. albimanus). A 0.1% concentration of deet caused 90–100% mortality in first-instar Ae. albopictus for 4 weeks, whereas AI3-35765 and AI3-37220 at the same concentration killed 95–100% of larvae for 12 weeks and 98–100% of larvae for 33 weeks post-treatment, respectively. Deet and AI3-35765 at 0.1% concentration resulted in complete mortality of first-instar An. albimanus for 3 weeks post-treatment, whereas AI3-37220 resulted in 91–99% larval mortalities for 35 weeks post-treatment. A 0.1% concentration of AI3-37220 provided 77–98% larval mortality for 20 weeks and 63–97% larval mortality for 12 weeks post-treatment, respectively, against fourth-instar Ae. albopictus and An. albimanus. In the field, in artificial containers, the reduction of Ae. albopictus larvae caused by deet, AI3-35765 and AI3-37220 was 88–95% for 3–4 weeks, 98–100% for 7 weeks, and 82–100% for 13 weeks post-treatment, respectively. In used tyres, the same concentration of the repellents resulted in 100% reduction of Ae. albopictus larvae for 2 weeks (deet), 4 weeks (AI3-35765) and 5 weeks (AI3-37220) post-treatment. In cemetery flower vases, Aedes spp. larvae were eliminated for 4 weeks (deet) and 6 weeks post-treatment by both AI3-35765 and AI3-37220. These topical repellents (particularly AI3-37220) have good potential for development and use in the management of container-inhabiting mosquitoes because they deter oviposition and kill larvae.
Estrogen receptors and responsiveness of advanced breast cancer to chemotherapy.

We reviewed 89 patients with disseminated breast cancer who had at least one valid estrogen receptor (ER) assay and who underwent one or several trials of chemotherapy. The responses were assessed by two independent extramural reviewers. Of the 89 patients, 81 were evaluable; 28 of 36 (77.8%) ER− positive (ER+) and 28 of 45 (60.7%) ER− negative (ER−) tumors reached at least one remission. Of patients who had received Adriamycin-containing therapy, 13/20 (65%) ER+ and 12/34 (35.3%) ER− tumors experienced a remission. ER+ breast cancer tends to respond better to Adriamycin-containing combinations than ER− negative tumors. This study does not support the thesis that lack of estrogen receptor in breast cancer predicts favorably for response to chemotherapy.
Characterization of hemocytes from the yellow fever mosquito, Aedes aegypti

Mosquitoes are the most important arthropod disease vectors, transmitting a broad range of pathogens that cause diseases such as malaria, lymphatic filariasis, and yellow fever. Mosquitoes and other insects are able to mount powerful cellular and humoral immune responses against invading pathogens. To date, most studies have concentrated on the humoral response. In the current study we describe the hemocytes (blood cells) of the yellow fever mosquito, Aedes aegypti, by means of morphology, lectin binding, and enzyme activity and immunocytochemistry. Our light and electron microscopic studies suggest the presence of four distinct hemocyte types: granulocytes, oenocytoids, adipohemocytes, and thrombocytoids. We believe granulocytes and oenocytoids are true circulating hemocytes, but adipohemocytes and thrombocytoids are likely adhered to fixed tissues. Granulocytes, the most abundant cell type, have acid phosphatase and alpha-naphthyl acetate esterase activity, and bind the exogenous lectins WGA, HPA, and GNL. Phenoloxidase, an essential enzyme in the melanotic encapsulation immune response, was detected inside oenocytoids. This is, to our knowledge, the first report that has detected phenoloxidase inside mosquito hemocytes at the ultrastructural level. These results have begun to form a knowledge base for our ongoing studies on the function of Ae. aegypti hemocytes, and their involvement in controlling infections.
Signal transduction from the cell surface to the nucleus through the phosphorylation of transcription factors

The activation of several transcription factors in response to extracellular stimuli is fairly well understood. In all cases, activation is mediated through phosphorylation by signal responsive protein kinases. The specificity of transcription factor phosphorylation is likely to be ensured by physical interactions between the protein kinases and their substrates. Distinct biological responses are likely to be mediated through activation of different constellations of protein kinases, resulting in phosphorylation of different transcription factors.