cssi/SciSciGPT-SciSciNet huggingface dataset:
A Systematic Review of Pedagogical Agents’ Persona, Motivation, and Cognitive Load Implications for Learners

AbstractAfter more than a decade of pedagogical agent research, this review synthesizes the affective implications of learning with pedagogical agents. The review investigates different affective measures within 99 pedagogical agent outcome measures. The results suggest that learners may prefer pedagogical agents compared to non-agent control conditions, and pedagogical agents may provide motivational benefits for some populations under certain conditions. However, it is unclear whether pedagogical agents impose extraneous cognitive load. Overall, consistent with research around learning outcomes (Mayer, Dow, & Mayer, 2003), the results suggest that the image of the agent may not be necessary for the learner to receive the affective benefits of the interaction. We delineate limitations of the current study and future research directions.
Canavan Disease: Genomic Organization and Localization of Human ASPA to 17p13-ter and Conservation of the ASPA Gene during Evolution

Canavan disease, or spongy degeneration of the brain, is a severe leukodystrophy caused by the deficiency of aspartoacylase (ASPA). Recently, a missense mutation was identified in human ASPA coding sequence from patients with Canavan disease. The human ASPA gene has been cloned and found to span 29 kb of the genome. Human aspartoacylase is coded by six exons intervened by five introns. The exons vary from 94 (exon III) to 514 (exon VI) bases. The exon/intron splice junction sites follow the gt/ag consensus sequence rule. Southern blot analysis of genomic DNA from human/mouse somatic cell hybrid cell lines localized ASPA to human chromosome 17. The human ASPA locus was further mapped in the 17p13-ter region by fluorescence in situ hybridization. The bovine aspa gene has also been cloned, and its exon/intron organization is identical to that of the human gene. The 500-base sequence upstream of the initiator ATG codon in the human gene and that in the bovine gene are 77% identical. Human ASPA coding sequences cross-hybridize with genomic DNA from yeast, chicken, rabbit, cow, dog, mouse, rat, and monkey. The specificity of cross-species hybridization of coding sequences suggests that aspartoacylase has been conserved during evolution. It should now be possible to identify mutations in the noncoding genomic sequences that lead to Canavan disease and to study the regulation of ASPA.
Approximate Relativistic Coulomb Scattering Wave Function

A relativistic scattering wave function. which is valid to second order in alpha Z for all electron velocities, was developed. The wave function has as its dominant term the Sommerfeld-Maue function. The computational simplicity of the closed form Sommerfeld-Maue wave function was retained in this modified Sommerfeld-Maue function. Applications of the wave function to the calculation of cross sections for the scattering of polarized electrons and bremsstrallung production at the shont wave limit of the spectrum were given. A large first- order correction to the Sauter-Fano formula for the bremsstrahlung cross section was obtained. (auth)
Ultraviolet transition probabilities in N II.

Oscillator strengths were calculated for the ultraviolet transition array 2p sup 2 - 2p3s in the N II spectrum. Results obtained confirm that the 748 A intercombination line is usually strong as predicted by Fawcett (1987). The results of theoretical weighted oscillator strengths are considered to be reliable.
Cortico-thalamic interactions in response to whisker stimulation in a computer model of the rat barrel system

Abstract Recent evidence from multi-unit recording experiments in awake rats has suggested that there may be complex, nonlinear interactions between the cortex and thalamus. In order to further study the possible role of the thalamus in cortical sensory processing, we have developed a computational model of the coritco-thalamic barrel region. In the model, single whisker stimulation can produce long latency responses in thalamic cells due to feedback from the cortex. Stimulus movement across the receptor surface, in the model, shows the ability of the thalamus to produce “priming” effects in the cortex or “memory” effects depending on the frequency of the stimulation.
Experimental evidence that grooming and play are social currency in bonobos and chimpanzees

While natural observations show apes use grooming and play as social currency, no experimental manipulations have been carried out to measure the effects of these behaviours on relationship formation in apes. While previous experiments have demonstrated apes quickly learn the identity of individuals who will provide food in a variety of cooperative and non-cooperative situations, no experiment has ever examined how grooming and play might shape the preferences of apes for different individuals. We gave a group bonobos (N=25) and chimpanzees (N=30) a choice between an unfamiliar human who had recently groomed or played with them and one who had not. Both species showed a preference for the unfamiliar human that had interacted with them over the one who did not. The effect was largely driven by the males of both species while interacting with females showed little effect on their preferences for unfamiliar humans. Subjects showed this preference even though they only had social interactions with one of the unfamiliar humans for a few minutes before each trial and their choices were not rewarded with food differentially. Our results support the long held idea that grooming and play act as a form of social currency in great apes (and likely many other species) that can rapidly shape social relationships, particularly between unfamiliar individuals.
In vitro effects of the nephrotoxins ochratoxin A and citrinin upon biochemical function of porcine kidney

Ochratoxin A and citrinin are nephrotoxic mycotoxins found in a variety of foods and feeds. Before studying possible interactions between these two toxins, their individual biochemical effects were examined in vitro by using renal cortical explants derived from male swine of the Hormel-Hanford strain. The following measurements were performed: macromolecule biosynthesis (protein, RNA, and DNA), respiration (14CO2 from [14C]glucose), organic ion (tetraethyl ammonium acetate, i.e., TEA) transport, and membrane perturbation (protein leakage into medium). Levels of the toxins ranged from 0.001 to 1 mM. Ochratoxin A inhibited macromolecule biosynthesis at a lower concentration (0.001 mM) than did citrinin. Protein and DNA synthesis were particularly sensitive to ochratoxin A. Syntheses of protein and DNA were inhibited at ochratoxin A concentrations of 0.01 and 0.001 mM, respectively. RNA synthesis was less sensitive to the mycotoxin; it was inhibited only 60% at 1 mM, the highest concentration of ochratoxin A tested. Citrinin levels of 0.01 mM were required for inhibition of RNA, DNA, and protein synthesis. Inhibition by citrinin was approximately equal for all three classes of macromolecules. Citrinin was more effective than ochratoxin A in the inhibition of respiration and TEA transport; the minimum effective levels of citrinin were 1 and 0.01 mM, respectively. Serious membrane damage as evidenced by increased protein leakage was not caused by either toxin. Stimulation of respiration, perhaps reflective of uncoupling of oxidative phosphorylation, was produced by an ochratoxin A concentration of 1 mM. Inhibition of macromolecule biosynthesis does not seem to be related to the effect of either toxin upon respiration, although a causal relationship between the effects of ochratoxin A on respiration and TEA transport cannot be ruled out.
Comment on “The Lax-Onsager Regression “Theorem” revisited”

Ž We have just read the paper by Lax to appear in w x. this volume 1 and we are pleased to note that Lax and ourselves are in basic agreement; the Lax formula is correct and extremely useful for systems where the coupling is weak and only frequencies near resonance are of interest. Indeed, it is the only approximation we have for the strongly driven systems of quantum optics. We should stress that we never had objections to necessary and appropriate approximations such as the Lax formula; our objection is when these approximations are elevated to Ž general principles not by Lax himself who, in his w x Ž . initial 2 referred to as Q II by Lax and subsequent w x Ž . w x publications 3 referred to as Q III by Lax 4 Ž . w x Ž referred to as Q XI by Lax 5 referred to as Q IV . by Lax was careful to note the domain of applicabil. ity of his formula . However, we are puzzled when Lax says that the Ž . w x key statement viz. the title of Ref. 6 can be w x misleading. All we did in Ref. 6 was present an exactly solvable example demonstrating that the Onsager regression hypothesis fails in the quantum case. We then went on to point out that there is a correct and broadly applicable quantum generalization of the Onsager hypothesis: the fluctuation-disw x sipation theorem of Callen and Welton 7 . We do not agree that this is simply a mathematical statement. It is true that much of our work has involved the message that quantum noise is universal: its spectrum is that of Planck plus, where appropriate, zeropoint noise. It might be helpful to note that for classical stochastic processes, as described by a Langevin equation, there are two equivalent characŽ . terizations of a Markov process: a no memory in Ž . the dissipative term and b white noise power spectrum. In fact, in 1965, using a model of coupled oscillators to describe a heat bath, Ford, Kac and w x Mazur 8 showed that, in the context of the quantum Ž . Ž . Langevin equation, one can have a but never b . The Lax model for a maser or laser is based on the idea that accurate results are possible even if the noise is not white provided that it does not vary too much over the width of the line. Rather than trying to characterize the nature of this approximation, we feel it is best to refer to the detailed exposition given w x by Lax 4,5 and summarized by him in his present w x paper 1 . For a detailed and exact treatment of a quantum particle moving in an arbitrary potential w x and coupled to a heat bath, we refer to Ref. 9 , which also discusses various models not found in the quantum optics literature. In addition, as well as presenting a general result for the symmetric autocorrelation of the random force, we also wrote down its nonequal-time commutator so that the correspondŽ ing result for the normally ordered operators used to
Unilateral inhibition of audiogenic seizures and preyer reflexes.

EXPOSING a mouse to a loud acoustic stimulus for 30 s during a critical period of neural development will alter the animal so that a subsequent exposure days or weeks later results in convulsions which often terminate in death1. The effects of this first (priming) exposure require several days before they are overtly manifest. Fuller and Collins2 have shown that re-exposure to loud sounds every 6–12 h after priming delays the onset of convulsibility for as long as the procedure is continued, and that this effect can be lateralized within the nervous system3. This paper extends their findings by the use of a modified form of their technique which inhibited the fully developed effects of priming, and demonstrates that acoustic inhibition increases the threshold to the acoustic startle response by 21 dB, and that this effect can be lateralized to a single side of the auditory system.
Value of noninvasive techniques for predicting early complications in patients with clinical class II acute myocardial infarction

Twenty-six consecutive patients with acute clinical class II myocardial infarction were prospectively evaluated to assess the ability of two-dimensional echocardiography and gated equilibrium radionuclide angiography to predict early morbidity and mortality. Within 48 hours of the onset of symptoms, right heart catheterization, two-dimensional echocardiography arid radionuclide angiography were performed. Serious in-hospital complications developed in 7 patients (27%, Group I), while the remaining 19 patients (Group II) had no complications. Mean left ventricular stroke work index was the only hemodynamic variable that differed significantly between Group I and Group II (28 ± 8 [standard deviation] vs. 39 ± 13 g-m/m2, respectively, p It is concluded that either two-dimensional echocar-diographic or radionuclide angiographic left ventricular ejection fraction and wall motion index have additional predictive value to a history of prior myocardial infarction for identifying those patients with clinical class II myocardial infarction at risk for developing early complications.
The role of hypoxia-induced miR-210 in cancer progression.

Prolonged hypoxia, the event of insufficient oxygen, is known to upregulate tumor development and growth by promoting the formation of a neoplastic environment. The recent discovery that a subset of cellular microRNAs (miRs) are upregulated during hypoxia, where they function to promote tumor development, highlights the importance of hypoxia-induced miRs as targets for continued investigation. miRs are short, non-coding transcripts involved in gene expression and regulation. Under hypoxic conditions, miR-210 becomes highly upregulated in response to hypoxia inducing factors (HIFs). HIF-1α drives miR-210’s overexpression and the resultant alteration of cellular processes, including cell cycle regulation, mitochondria function, apoptosis, angiogenesis and metastasis. Here we discuss hypoxia-induced dysregulation of miR-210 and the resultant changes in miR-210 protein targets that regulate cancer progression. Potential methods of targeting miR-210 as a therapeutic tool are also explored.
EFECTS OF POPULATION DENSITIES ON ZOOPLANKTON RESPIRATION RATES

Measurements of respiratory rates of two species of zooplankton were made under varying degrees of confinement simulating conditions imposed on the organisms by varying population densities and in experimental techniques for respiration measurement. It was found that when Daphnia is confined to a small space its respiratory rate is much increased, but that Cnlnnus does not seem to have the same response to confinement. The respiratory rates of several species of fresh-water and marine zooplankton have been determined by a number of workers using methods which subjected the experimental animals to conditions quite unlike those of their natural environment. These methods fall into two general categories: experiments in which one or several animals are confined within a very limited volume as in the various types of microrespirometers used by Raymont and Gauld ( 1950 ) , Clarke and Bonnet ( 1939 ) , Obreshkove ( 1932 ) , and the Cartesian diver arrangement used by Zeuthen ( 1947); and experiments in which a large number of animals is confined within a bottle of larger volume as in the experiments of Marshall and Orr ( 1935) and Conover ( 1959). The experiments of these workers, which are representative of those published during the last 40 years, have one common feature: the experimental animals used were confined to small volumes during the period of measurement of their respiration. It has been shown that many types of organisms when aggregated have rates of activity which are decidedly different from the rates of isolated individuals ( Allee 1931). The previously mentioned workers do not take into account the possible effects of this crowding on the animals they used. The aim of this study was to determine whether the varying densities of a ZOOplankton population have any effect on the 1 Present address, 15572 Gulf Blvd., Redington Beach, Florida. oxygen consumption of the population. The cladoceran, Daphnia magna, and the marine copepod, Calanus finmarchicus, were used. These animals were chosen because they arc representative of the zooplankton found in fresh and salt water environments, and because much work has been done on them in the past. The author wishes to thank Professor John P. Barlow of the Department of Conservation, Cornell University, for his continued interest and encouragement in this research. He would also like to thank Professor LaMont C. Cole of the Department of Zoology, Cornell University, for his advice and assistance. For facilities made available during the summer of 1959, acknowledgment is made to Dr B. II. Ketchum of Woods Hole Oceanographic Institution with whose cooperation the part of the research concerning Calanus finmarchicus was carried out. These investigations were supported by research grant G7154 to Professor J. P. Barlow from the National Science Foundation.
A Chronological Method Applicable to the Southeast

Any archaeologist who considers that his science is pledged to the task of rediscovering unrecorded and lost history, rather than to the collection of “curios,” is hardly in a position to deny the paramount importance of chronology. Lacking a scale which demonstrates the relative ages of the various activities of an ancient people, we are at best merely the collectors of disconnected fragments of history, and can never hope to fit these fragments together to form a complete and logical story of the past.
Quantifying Manageability of Cloud Platforms

Cloud computing has changed the way companies are managing their IT infrastructure and application development and/or deployment. While there are a number of Cloud platforms available, it is a challenge to identify a cloud platform that best suits the business needs. As a consequence Cloud service providers may end up selecting a platform that is either too low- or too high-level to manage, or does not offer the paradigms needed. In this paper, we introduce the Cloud manageability metrics and an approach to quantify the manageability of cloud platforms using the introduced metrics. We then use the metrics and approach to compare manageability of different cloud IaaS and PaaS platforms for specific use case scenarios. The values for the metrics are derived by executing the use cases in each platform using test environments. Based on the results of the comparison, we recommend a cloud platform that is best suited for different organizations needs with respect to cloud management. We expect that the proposed approach will help organizations to evaluate various cloud platforms and choose the platform that best matches their needs.
Contact-dependent inhibition: bacterial brakes and secret handshakes

Interbacterial communication can be mediated by soluble secreted factors and direct cell–cell contact. Recently, Aoki et al. identified a new contact-dependent communication pathway by which strains of uropathogenic Escherichia coli can inhibit the growth of other microbes within a mixed population. Two novel gene products – CdiA and CdiB, which seem to be members of a two-partner secretion family with homologs in many pathogens – mediate this contact-dependent inhibition (CDI). A third gene product, CdiI, provides immunity to CDI, as does expression of either P or S pili. The interplay between CDI and immunity factors could directly affect the course of an infection and modulate both the dispersion and the chronic persistence of bacterial pathogens within the host.
Actin polymerization and pseudopod extension during amoeboid chemotaxis

Amoebae of the cellular slime mold Dictyostelium discoideum are an excellent model system for the study of amoeboid chemotaxis. These cells can be studied as a homogeneous population whose response to chemotactic stimulation is sufficiently synchronous to permit the correlation of the changes in cell shape and biochemical events during chemotaxis. Having demonstrated this synchrony of response, we show that actin polymerization occurs in two stages during stimulation with chemoattractants. The assembly of F-actin that peaks between 40 and 60 sec after the onset of stimulation is temporally correlated with the growth of new pseudopods. F-actin, which is assembled by 60 sec after stimulation begins, is localized in the new pseudopods that are extended at this time. Both stages of actin polymerization during chemotactic stimulation involve polymerization at the barbed ends of actin filaments based on the cytochalasin sensitivity of this response. We present a hypothesis in which actin polymerization is one of the major driving forces for pseudopod extension during chemotaxis. The predictions of this model, that localized regulation of actin nucleation activity and actin filament cross-linking must occur, are discussed in the context of current models for signal transduction and of recent information regarding the types of actin-binding proteins that are present in the cell cortex.
Mechanical failure and glass transition in metallic glasses

The current majority view on the phenomenon of mechanical failure in metallic glasses appears to be that it is caused by the activity of some structural defects, such as free-volumes or shear transformation zones, and the concentration of such defects is small, only of the order of 1%. However, the recent results compel us to revise this view. Through molecular dynamics simulation it has been shown that mechanical failure is the stress-induced glass transition. According to our theory the concentration of the liquid-like sites (defects) is well over 20% at the glass transition. We suggest that the defect concentration in metallic glasses is actually very high, and percolation of such defects causes atomic avalanche and mechanical failure. In this article we discuss the glass transition, mechanical failure and viscosity from such a point of view.
Deconstructing "Down Low" Discourse: The Politics of Sexuality, Gender, Race, AIDS, and Anxiety

Discourse regarding Black men “on the down low,” also known as “the DL,” is deconstructed to reveal public anxieties around sexuality, gender, race, and HIV/AIDS. After presenting a definition of the down low, ten basic facts are advanced: a) The down low is not new; b) the down low isn’t just Black; c) the down low isn’t just men; d) the down low discourse contributes to the spread of HIV/AIDS; e) the down low discourse feeds a neo-racist agenda; f) the down low discourse obscures the link between HIV/AIDS and poverty; g) the down low discourse contributes to homophobia in the Black community; h) the down low phenomenon suggests that there is more to sexual orientation than is currently acknowledged; i) the down low phenomenon demonstrates the need to decouple sexuality and gender; j) the down low discourse provides a new opportunity to consider questions of sexual freedom and choice.
Volumetric imaging using single chip integrated CMUT-on-CMOS IVUS array

An intravascular ultrasound (IVUS) catheter that can provide forward viewing volumetric ultrasound images would be an invaluable clinical tool for guiding interventions. Single chip integration of front-end electronics with capacitive micromachined ultrasonic transducers (CMUTs) is highly desirable to reduce the interconnection complexity and enable miniaturization in IVUS catheters. For this purpose we use the monolithic CMUT-on-CMOS integration where CMUTs are fabricated directly on top of pre-processed CMOS wafers. This minimizes parasitic capacitances associated with connection lines. We have recently implemented a system design including all the required electronics using 0.35-µm CMOS process integrated with a 1.4-mm diameter CMUT array. In this study, we present the experimental volumetric imaging results from an ex-vivo chicken heart phantom. The imaging results demonstrate that the single-chip forward looking IVUS (FL-IVUS) system with monolithically integrated electronics has potential to visualize the front view of coronary arteries.
Bayesian Decision Analysis for Plume Interception Wells

In this paper we apply the Bayesian decision analysis to the engineering design of a ground-water interception well whose purpose is to capture a contaminant plume. Two decision variables are considered: (1) pumping rate of an interception well when the desired width of interception zone is known, and (2) optimal number of slug tests needed to estimate the statistics of mean log-conductivity. The optimal number of slug tests is calculated for the case when no prior information regarding the mean of log-conductivity is available. The analysis is performed for steady-state ground-water flow in a linear-type aquifer. Two utility functions are considered. The utility functions account for the risk associated with not capturing the contaminant plume, cost of pumping, and cost of aquifer testing.
Spatial Modulation and Filtering of Diffusion Patterns for Inverse Analysis of Heat Deposition

General parameterizations are constructed for spatial modulation and filtering of heat diffusion patterns according to general energy deposition characteristics occurring within a volume of material resulting from a volumetrically coupled energy source. These parameterizations include previously constructed models of energy deposition as special cases. The construction of a general parameterization of energy deposition processes is necessary for their inverse analysis. The structure of such a parameterization follows from the concepts of model and data spaces that imply the existence of an optimal parametric representation for a given class of inverse problems. Accordingly, the optimal parametric representation is determined by the characteristics of the available data, which in principle can contain both experimental measurements and numerical simulation data. Parameterizations for spatial modulation and filtering of heat diffusion follow from the observation that many different types of energy deposition processes can be represented by weighted sums of basis functions whose general forms are that of spatially modulated or filtered diffusion. A significant aspect of the parameterizations presented is that the definition of the inverse heat deposition problem, which is adopted for their construction, provides a rigorous foundation for a highly flexible and general parameterization of energy deposition processes, which is essential for their inverse analysis. A preliminary proof is presented that shows the significance of these parameterizations for the application of similarity transformations to the inverse analysis of energy deposition processes. The applicability of similarity transforms to the inverse analysis of heat deposition is another property that follows from the specific definition of the inverse heat deposition problem considered here.
Daylighting and thermal performance of automated split-controlled blinds

Abstract Manual blinds are not often adjusted properly. Consequently, electrical lighting as well as heating and cooling loads are increased. The conventional automated control maintains the same blind tilt angle at a particular point in time. An innovative automated split blind system was developed to improve the daylighting and thermal performance of blinds as an integral part of the other building systems. The research objectives were to develop a simplified control method for the split blinds, and to analyze daylighting performance and energy savings due to the application of the split blinds and the control method. A case study that focused on three automated blind systems (conventional (optimum), split (predicted) and split (optimum)) was conducted to analyze the effectiveness of the control methods and the daylighting and thermal performance of the split blinds. Computer simulations were performed using the software EnergyPlus™ to calculate the illuminance levels and glare in a building, and energy consumption as a result of the application of these three blind systems. The simulation results showed that the split blinds (both predicted and optimum) had a better daylighting performance in the back of the room and caused lower energy consumption, especially in winter times when compared to the conventional blinds. An integration of an effective electrical lighting control system is required to fully utilize the advantages of split blinds in summer.
Phosphatidylcholine Synthesis in Castor Bean Endosperm

Three pathways for phosphatidylcholine synthesis were assayed in castor bean (Ricinus communis var. Hale) endosperm. Phosphatidylethanolamine: S-adenosylmethionine methyl transferase occurred predominantly in the endoplasmic reticulum fraction, but some activity appeared in the mitochondria. Phosphorylcholine glyceride transferase occurred exclusively in the endoplasmic reticulum. The phosphorylcholine glyceride transferase activity was approximately 20-fold greater than the methylation pathway in the endoplasmic reticulum. No exchange activity was found. The Michaelis constant for the methylation was 31 mum for S-adenosylmethionine; phosphatidylethanolamine promoted the reaction slightly while other intermediates stimulated it by about 50%. The pH optimum was 9. Phosphorylcholine glyceride transferase had a Michaelis constant of 9.7 mum for cytidine diphosphate choline but variable results were obtained from diglycerides. The pH optimum was 7.5 and a divalent cation was required, Mg(2+) giving the greatest stimulation.
Sodium borohydride in dimethyl sulfoxide or sulfolane. Convenient systems for selective reductions of primary, secondary and certain tertiary halides and tosylates

SODIUM BOROHYORIDE IN OIMETHYL SULFOXIDE OR SULFOLANE. CONVENIENT SYSTEMS FOR SELECTIVE REDUCTIONS OF PRIMARY, SECONDARY AND CERTAIN TERTIARY HALIDES AND TOSYLATES Robert 0. Hutchins, David Hake', Joseph Keogh' and David Koharski' Department of Chemistry, Drexel Institute of Technology Philadelphia, Pennsylvania 19104 (Received in USA 9 June 1969; received in UK for publication 31 July 1969) The use of various metal hydrides as selective reducing agents has attracted a considerable amount of interest in recent years (2). It occurred to us that one unexplored possibility in this area might be to employ the relatively mild reducing agent sodium borohydride in SNP rate enhancing, polar, aprotic solvents to selectively displace halogens and other good leaving groups with hydrogen without affecting other reducible functional groups. ’ We wish to report that, indeed, sodium borohydride in dimethyl sulfoxide (DMSO) or sulfolane provides a very versatile and convenient method for removing primary, secondary and, in certain cases, tertiary alkyl and benzylic halides and tosylates in the presence of other groups including carboxylic acids, esters and nitro groups. The conditions and yields for a variety of such reductions are shown in Table I. Several features of these reactions make the procedure particularily attractive for synthetic applications. First, yields of hydrogenolysis products are good to excellent (53-98%) for the examples studied. Furthermore, unlike corresponding reductions with lithium aluminum hydride (3), essentially no olefin or other organic soluble side products were isolated or detected with the exceptions of benzhydryl chloride and branide as discussed below. Also, 1,2-dibromides (i.e. entries 24 and 25) are reduced to the hydrocarbons in moderately good yields in contrast to lithium aluminum hydride reductions which afford only olefins (3). Thus, the method can be utilized to hydrogenate double bonds in sensitive compounds by way of bromination and reduction. Heterogeneous reactions appear to offer no problem as illustrated by the smooth reductions of several compounds of limited solubility (i.e. dodecyl derivatives, Table I).
Optical Absorption Spectra of Chromium-Doped Zinc Sulfide Crystals

We have measured the optical absorption spectra of twinned cubic crystals of chromiumdoped zinc sulfide between 5000 and 29 000 ${\mathrm{cm}}^{\ensuremath{-}1}$ (2-0.34 \ensuremath{\mu}m) at 4.2-500\ifmmode^\circ\else\textdegree\fi{}K. Two broad absorption bands are specific to chromium; at 77\ifmmode^\circ\else\textdegree\fi{}K, one has a maximum at 24 400 ${\mathrm{cm}}^{\ensuremath{-}1}$, the other, at 5700 ${\mathrm{cm}}^{\ensuremath{-}1}$. Weak photoconductivity is observed in the former; but none in the latter. Twelve narrow bands between 5100 and 5250 ${\mathrm{cm}}^{\ensuremath{-}1}$ are identified as zero-phonon transitions in ${\mathrm{Cr}}^{2+}$ (3${\mathrm{d}}^{4}$) substitutional at cation sites, two for the cubic structure, ten for the twin boundaries. The cubic crystal field is determined. Thirteen phonon-assisted transitions are identified and the phonon wave numbers are evaluated. We propose that the 24 400-${\mathrm{cm}}^{\ensuremath{-}1}$ band involves transitions to the conduction band edge.
A continuum theory for a random array of identical, elastic, frictional disks

Abstract We derive a stress–strain relation for static deformations of a random array of identical disks that interact through elastic, frictional contacts. In doing this, we take into account force and moment equilibrium of pairs of disks in the aggregate and average over pairs that have the same orientation. However, we defer consideration of the influence of deviations from the average packing on the stress–strain relation. We apply the result to biaxial straining at constant pressure and obtain explicit expressions for the shear stress, area strain, and the amount of contact deletion.
ORGANISM RESPONSES TO RAPID CHANGE : WHAT AQUARIA TELL US ABOUT NATURE

SYNOPSIS. Living corals are routinely collected and shipped to destinations thousands of miles from their point of origin. The fact that corals can survive the rigors of collecting, transport, and acclimation to totally artificial environments was considered impossible not long ago, but hobbyists and some researchers have persevered and have developed aquarium systems and techniques capable of maintaining corals in apparently healthy condition for many years. In particular, new lighting equipment, advances in the control of water chemistry, and new technology for simulating water movement have all contributed to the ability to keep corals alive indefinitely in captivity. Despite the completely artificial conditions of most aquariums, coral extension rates and calcification rates in some aquarium systems are close to those reported for natural reefs, although anomalies have been observed such as decreased skeletal density and unusual changes in colony morphology. Nonetheless, aquariums present real opportunities to culture corals for a variety of bioassay, medicinal, and conservation purposes. As model reef communities (“microcosms”), these systems allow us to test hypotheses concerning the effects of rapidly changing environmental conditions.
Topology identification for dynamic equivalent models of large power system networks

In this paper we propose two algorithms to identify the equivalent topology of reduced-order models of power systems using measurements of phase angles and frequencies available from Phasor Measurement Units (PMUs). We first show that the topology identification problem can be posed as a parameter estimation problem. Thereafter, we extract the slow oscillatory component of the PMU measurements using subspace identification methods and use them for identifying the topological parameters via conventional l2 minimization approach. Next, we consider the problem of identifying a sparse equivalent network topology using a l1/l2 minimization technique. We illustrate our results using a IEEE 39-bus model.
Eulerian Number Asymptotics

Asymptotic formulae for the eulerian numbers A(n, k) for n ≫ 1 are obtained directly from their recursion relation by the ray method and the method of matched asymptotic expansions. These are formal methods, so they do not prove that the formulae are asymptotic, although they suggest it. The formulae agree with the previously known results where those results are valid. They also agree very well with the exact values of A(n, k) for 1 ≼ n ≼ 170, and the agreement improves as n increases.
A structural definition of polymer brushes

In this article, we consolidate several literature re- ports in an attempt to provide a structural definition of a polymer brush as a tethered polymer layer with a high grafting density of poly- mer chains. We will try to distin- guish a brush from grafted polymer layers and coated layers and provide a reasonable approach to the descrip- tion of the brush regime with a single parameter S—reduced grafting den- sity. Furthermore, we will attempt to describe the relevance of this description to applications. This arti- cle is timely given the continuing interest relating to brushes on flat substrates, nanoparticles, and the walls of micro-channels. V C 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3505-3512, 2007
P-Selectin and Blood Coagulation: It’s Not Only About Inflammation Any More

Although P-selectin had already been established as a vascular adhesion molecule critical in the inflammatory response, in 1992 Palabrica et al were the first to demonstrate that P-selectin also played a significant role in blood coagulation and thrombosis.1 In these experiments using an arteriovenous shunt model of thrombosis in a baboon, anti–P-selectin antibodies were shown to block fibrin formation in the developing thrombus forming in a thrombogenic Dacron shunt. Shortly thereafter, P-selectin was not only shown to upregulate tissue factor generation in monocytes,2 but also to initiate signaling pathways in leukocytes and activate the elaboration of cytokines in a mechanism that involved P-selectin interaction with its receptor, PSGL-1. …
Kinetic Effects on Hydroxyapatite Whiskers Synthesized by the Chelate Decomposition Method

Hydroxyapatite (HA) whiskers have been synthesized using a number of chemical solution methods, including the chelate decomposition method. Numerous previous studies have investigated the effects of the reagents, reagent concentrations, solution pH, and reaction temperature on HA whisker morphology and composition. However, purely kinetic effects, such as the reaction heating and stirring rates, have not been rigorously investigated and are rarely reported in the literature. Therefore, the objective of this study was to investigate kinetic effects on the morphology of HA whiskers synthesized using the chelate decomposition method. In order to study the kinetic effects on the morphology of HA whiskers, three experimental parameters were varied independently: the reaction heating rate (0.36°–3.0°C/min), stirring rate (0–250 rpm), and temperature (80°–200°C). At all heating and stirring rates, precipitated whiskers were confirmed by XRD and FT-IR to comprise phase-pure, calcium-deficient HA (Ca/P=1.57–1.62). The length and aspect ratio of HA whiskers increased with decreased heating rate, decreased stirring rate, and increased reaction temperature. The mean length and aspect ratio of HA whiskers increased approximately twofold with decreased heating rate over the range studied, following a power-law relationship. Therefore, the reaction heating rate is a key variable that can be used to tailor the morphology of HA whiskers and ought to be reported in the literature. The reaction heating rate and temperature had relatively little effect on the width of HA whiskers. However, the precipitate morphology was altered significantly from micro-scale whiskers to nano-scale plates with increased stirring rate. These results offered new insights and provided clarification regarding the reaction mechanism, which is discussed in detail.
Integrating Literacy and Science for English Language Learners: From Learning-to-Read to Reading-to-Learn

ABSTRACTThe authors examined the impact of 2 subsequent, longitudinal interdisciplinary interventions for 58 Hispanic English language learners (ELLs): (a) Grade 5 science with English language/reading embedded (i.e., science intervention) and (b) K–3 English language/reading with science embedded (i.e., language/reading intervention). Results revealed that (a) in the science intervention treatment ELLs outperformed their counterparts in English-reading fluency, knowledge of word meaning, and science and reading achievement; (b) in the language/reading intervention treatment ELLs continued to develop faster than their peers in English oracy, reading fluency, and comprehension; (c) ELLs benefited more from the science intervention if they received the prior language/reading intervention. We conclude that for ELLs, the integration of science and English language/reading should primarily focus on reading in elementary grades and science in Grade 5.
Unfocused Laser Illumination Kills Dye-Targeted Mouse Neurons by Selective Photothermolysis

Selective photothermolysis (SP) is a novel technique by which brief, unfocused laser pulses are selectively absorbed by, and cause selective thermal damage to, endogenously pigmented structures. The present experiments demonstrate the feasibility of using an exogenous non-fluorescent chromophore (procion blue) to effect cellular damage by SP. Dorsal root ganglia neurons in vitro were selectively labeled with procion blue and subsequently damaged by unfocused laser illumination. Progressive cellular damage was assessed by propidium iodide (PI), a fluorescent dye that leaks through damaged membranes and binds to nucleic acids. Graded scores of intracellular PI fluorescence demonstrated a highly significant difference in amount of damage between groups of experimental and control cells. Selective photothermolysis is discussed as an experimental tool for neurobiologists in particular and for general use within the biomedical field.
The Impact of Faith-Based Screens on Investment Performance

There has been a phenomenal rise in faith-based investing in recent years. A very important question arises: do investors sacrifice satisfactory economic returns by making ethically and socially responsible investing decisions based on their faith? Using data on 36 faith-based mutual funds, this article reviews and extends previous research on the performance of faith-based investing. It examines the performance of these faith-based funds over three different five-year periods from May 2001 to February 2008. By applying a comprehensive set of tests, the authors find evidence that faith-based funds mostly outperform the market. The results also suggest that faith-based funds do better than socially responsible investing funds in general.
Self-filtering of noisy images via stochastic resonance

Nonlinear self-filtering and amplification of noisy, low-level images is demonstrated in a self-focusing photorefractive medium. Signal recovery depends sensitively on the parameters of the system and represents a new dynamical type of stochastic resonance.
Review of Hydroinformatics: Data Integrative Approaches in Computation, Analysis, and Modeling by Praveen Kumar, Jay Alameda, Peter Bajcsy, Mike Folk, and Momcilo Markus

This book is unusual in two respects: First, it is attributed to 5 authors, but in reality 15 authors have contributed different chapters. Second, each chapter is written by one or more authors. The book includes 25 chapters and 6 appendixes. For an authored book, this arrangement seems unusual. When different authors write different chapters, there is bound to be a certain degree of nonuniformity in style and breadth of coverage. This outcome is less likely when the entire book is written by the authors. Hydroinformatics is an area that is only a little over a decade old. During its short period of existence, it has witnessed phenomenal growth, fueled largely by unprecedented revolutions occurring in the information technology sector, as well as rapid advances in satellite technology, geographical information systems, data mining, database management systems, and data storage and retrieval systems. Applications of these technologies in civil, environmental, ecological, and water resources engineering have given birth to the newly emerging and rapidly expanding area called hydroinformatics. This healthy trend brings seemingly disparate areas closer. Hydroinformatics cuts across several disciplines—a point well emphasized in the book—and different disciplines now do not look so different after all. They indeed have a great deal in common—more than might appear at first sight. The book makes a real contribution in bridging different disciplines, and the authors are to be congratulated for preparing this book on hydroinformatics. The subject matter of the book is divided into six sections. After the book introduces data integrative studies in Chapter 1, the following five sections contain 24 chapters, and the remaining section contains six appendixes. The first chapter sets the stage for the material to follow, develops a rationale for the book, and goes on to describe its scope. The first section, comprising five chapters, deals with data-driven investigations and approaches in hydrology. The approaches described in these chapters have potential for application in other areas related to water and the environment. Chapter 2 deals with a unified modeling language UML . After introducing the basic aspects of UML, it discusses the framework of UML, structural software objects, UML relationships, UML diagrams, object model diagrams, and database designs and development. This introduction to the material is excellent. Chapter 3 deals with digital library technology for hydrology. This technology has applicability beyond the frontiers of hydrology. After
Efficient detection algorithm for 2Nx2N MIMO systems using alamouti code and QR decomposition

We propose an efficient 2Ntimes2N MIMO detection algorithm where the transmit signals are grouped in pairs and separately coded using the standard Alamouti space-time code. At the receiver, one or more QR decompositions are performed and the upper triangular property of the R matrices so obtained is exploited in order to successively decode the transmitted symbols starting with those interference-free symbols corresponding to the last two rows and columns of R. Bit-error-rate simulation results, for a 4times4 MIMO system and a bandwidth efficiency of 8 bits/s/Hz, show that the proposed technique, while less complex than ordered MMSE V-BLAST, outperforms the latter by 2-6 dB at a BER of 10-4
The Stroma-Rich Variant Subtype of Castleman's Disease in the Retroperitoneum: A Case Report

Castleman’s disease is a benign condition of unknown etiology characterized by angiofollicullar lymph node hyperplasia (1). It is classified into two major histological subtypes: the hyaline-vascular and the plasma cell variants. The hyaline-vascular type is more common (90%) and has greater vascularity; it is characterized by abnormal lymphoid follicles, numerous vessels and wide fibrous septa, and is generally seen as a localized disease. Meanwhile, the plasma cell type, which accounts for less than 10% of all cases of Castleman’s disease, is characterized by polyclonal mature plasma cell proliferation and fewer vessels, and is almost always associated with systemic manifestations. The disease is encountered in the mediastinum in the vast majority of cases, but it may occur anywhere along the lymphatic chains such as in the neck, axilla, mesentery, thorax, pancreas, spleen, adrenal glands and retroperitoneum (2). We report a rare stroma-rich variant of Castleman’s disease of the hyaline-vascular type that was encountered in the retroperitoneum. To the best of our knowledge, the radiologic findings of this type of Castleman’s disease have not been previously described.
A large Rab GTPase encoded by CRACR2A is a component of subsynaptic vesicles that transmit T cell activation signals

T cell activation by antigens involves the formation of a complex, highly dynamic, yet organized signaling complex at the site of the T cell receptors (TCRs). Srikanth et al. found that the lymphocyte-specific large guanosine triphosphatase of the Rab family CRACR2A-a associated with vesicles near the Golgi in unstimulated mouse and human CD4+ T cells. Upon TCR activation, these vesicles moved to the immunological synapse (the contact region between a T cell and an antigen-presenting cell). The guanine nucleotide exchange factor Vav1 at the TCR complex recruited CRACR2A-a to the complex. Without CRACR2A-a, T cell activation was compromised because of defective calcium and kinase signaling.