cssi/SciSciGPT-SciSciNet huggingface dataset:
Breakdown of energy equipartition in a 2D binary vibrated granular gas.

We report experiments on the equipartition of kinetic energy in a mixture of pairs of different types of grains vibrated in two dimensions. In general, the two types of grains do not attain the same granular temperature, ${T}_{g}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/2m〈{\mathbf{v}}^{2}〉$. However, the temperature ratio is constant in the bulk of the system and independent of the vibration velocity. The ratio depends strongly on the ratio of mass densities of the grains, but not on their inelasticity. Also, the temperature ratio is insensitive to compositional variables such as the number fraction of each component and the total number density. We conclude that a single granular temperature, as traditionally defined, does not characterize a multicomponent mixture.
Determination of the MRI contrast agent concentration time course in vivo following bolus injection: Effect of equilibrium transcytolemmal water exchange

For bolus-tracking studies, it is commonly assumed that CR concentration bears a linear relationship with the measured (usually longitudinal) 1H2O relaxation rate constant, R*1 ≡(T1 *)–1. This requires that equilibrium transcytolemmal water exchange be in the fast exchange limit (FXL). However, though systems remain in fast exchange, the FXL will not usually obtain. Here, the consequences are considered: 1) the measurement of R1 * itself can be affected, 2) the resultant non-linear [CR]-dependence causes significant error by assuming FXL, 3) the thermodynamic [CR] (based on the space in which CR is actually distributed) can be determined, 4) transcytolemmal water permeability may be estimated, and 5) the pharmacokinetic parameters can be factored. For a 30-sec, 0.17 mmol/kg dose of GdDTPA2–, the FXL assumption underestimates the [CR] maximum in rat thigh muscle by a factor of almost two. Similar results are obtained for a rat brain GS-9L gliosarcoma tumor model. Magn Reson Med 44:563–574, 2000. Published 2000 Wiley-Liss, Inc.
Use of Activation Analysis in Problems of Drug Control

Two major problems in drug control are the manufacture of counterfeit drugs and the diversion of legitimate drugs into illegal underground channels of distribution. In this study the use of neutron activation analysis was investigated for identification of the source of a drug product by analysis of certain trace elements added to it during manufacture, or by analysis of natural trace elements or contaminants already present. The usefulness of added trace elements was found to depend on the levels of natural contaminants. A level too high of the latter would require the addition of larger amounts of additives than physiological considerations permit. Thus, each drug product should be considered individually, after first establishing its natural contaminant content. Samples of dextroamphetamine tablets and capsules from five manufacturers, along with common tablet and capsule ingredients, were analyzed for natural contaminants. In the group, 17 elements were detected in amounts of less than 1 part per billion to over 0.1 per cent. The contaminants present in the tablets and capsules from the five manufacturers indicated each product was readily distinguishable from the others.
Sequence Recognition of DNA by Protein-Induced Conformational Transitions

The binding of proteins to specific sequences of DNA is an important feature of virtually all DNA transactions. Proteins recognize specific DNA sequences using both direct readout (sensing types and positions of DNA functional groups) and indirect readout (sensing DNA conformation and deformability). Previously we showed that the P22 c2 repressor N-terminal domain (P22R NTD) forces the central non-contacted 5'-ATAT-3' sequence of the DNA operator into the B' state, a state known to affect DNA hydration, rigidity and bending. Usually the B' state, with a narrow minor groove and a spine of hydration, is reserved for A-tract DNA (TpA steps disrupt A-tracts). Here, we have co-crystallized P22R NTD with an operator containing a central 5'-ACGT-3' sequence in the non-contacted region. C.G base pairs have not previously been observed in the B' state and are thought to prevent it. However, P22R NTD induces a narrow minor groove and a spine of hydration to 5'-ACGT-3'. We observe that C.G base pairs have distinctive destabilizing and disordering effects on the spine of hydration. It appears that the reduced stability of the spine results in a higher energy cost for the B to B' transition. The differential effect of DNA sequence on the barrier to this transition allows the protein to sense the non-contacted DNA sequence.
Identification of complex aromatic molecules in individual interplanetary dust particles.

Seventeen stratospherically collected particles—eight of which are classified as interplanetary dust particles (IDPs), seven of which are classified as probable terrestrial contaminants, and two of which have uncertain origins—were studied with a microprobe two-step laser mass spectrometer. Many polycyclic aromatic hydrocarbons(PAHs) and their alkylated derivatives were identified in two of the eight IDPs. The PAHs observed include a high-mass envelope not found in meteorites or terrestrial contaminants and prominent odd-mass peaks suggestive of nitrogen-containing functional groups attached to aromatic chromophores. In addition, the complexity of the IDP mass spectra has no precedence in previous studies of meteorite samples or their acid residues. Extensive checks were performed to demonstrate that the PAH signals are not caused by terrestrial contaminants.
Subcellular fractionation enhances proteome coverage of pancreatic duct cells

Abstract Objectives Subcellular fractionation of whole cell lysates offers a means of simplifying protein mixtures, potentially permitting greater depth of proteomic analysis. Here we compare proteins identified from pancreatic duct cells (PaDC) following organelle enrichment to those identified from PaDC whole cell lysates to determine if the additional procedures of subcellular fractionation increase proteome coverage. Methods We used differential centrifugation to enrich for nuclear, mitochondrial, membrane, and cytosolic proteins. We then compared – via mass spectrometry-based analysis – the number of proteins identified from these four fractions with four biological replicates of PaDC whole cell lysates. Results We identified similar numbers of proteins among all samples investigated. In total, 1658 non-redundant proteins were identified in the replicate samples, while 2196 were identified in the subcellular fractionation samples, corresponding to a 30% increase. Additionally, we noted that each organelle fraction was in fact enriched with proteins specific to the targeted organelle. Conclusions Subcellular fractionation of PaDC resulted in greater proteome coverage compared to PaDC whole cell lysate analysis. Although more labor intensive and time consuming, subcellular fractionation provides greater proteome coverage, and enriches for compartmentalized sub-populations of proteins. Application of this subcellular fractionation strategy allows for a greater depth of proteomic analysis and thus a better understanding of the cellular mechanisms of pancreatic disease.
Adverse early experiences affect noradrenergic and serotonergic functioning in adult primates

It has been proposed that certain adverse early experiences may play a role in determining subsequent susceptibility to adult anxiety and affective disorders and this relationship may be the result of altered neurodevelopment of the noradrenergic and/or serotonergic systems. In this study of nonhuman primates, the predictability of foraging requirements for mothers during an early period of their infants' lives was manipulated. When the offspring were young adults, these early manipulations were related to differences in behavioral response to acute administration of two putative anxiety-provoking agents: the noradrenergic probe, yohimbine, and the serotonergic probe, mCPP. These long-term effects of the developmental environment on subsequent pharmacological responsivity suggest that both neuronal systems may be permanently altered by early experiential factors.
Shame aversion therapy

Abstract Shame aversion therapy is a new technique for the treatment of persons practicing deviant sexual acts such as transvestism, voyeurism, pedophilia, exhibitionism and frotteurism. It consists of having the subject who is embarrassed or self conscious about the act he performs perform the act on demand in front of a number of observers. The act is made to continue for 15 to 35 min and its style kept as close to the in vivo situation as is possible. The patient is told simply to observe himself and be aware of being observed. Eight patients have been treated to date, five of whom have remained free of their associal behavior during a 6 month followup.
Nicotinic receptors in circuit excitability and epilepsy.

Neuronal nicotinic acetylcholine receptors belong to the family of excitatory ligand-gated channels and result from the assembly of five subunits. Functional heteromeric nictonic receptors are present in the hippocampus and neocortex, thalamus, mesolimbic dopamine system and brainstem motor nuclei, where they may play a role, respectively, in memory, sensory processing, addiction and motor control. Some forms of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) have been found to be associated with mutations in the genes coding for the alpha 4 or beta2 subunits of the nicotinic receptor. Mutant receptors display an increased acetylcholine sensitivity with respect to normal receptors. Since the thalamus and the cortex are strongly innervated by cholinergic neurons projecting from the brainstem and basal forebrain, an unbalance between excitation and inhibition, brought about by the presence of mutant receptors, could generate seizures by facilitating and synchronizing spontaneous oscillations in thalamo-cortical circuits.
Variation in crambe,Crambe abyssinica hochst

One hundred sixty-two lines were used to detect genotypic diversity for 7 characters inCrambe abyssinica Hochst during 1970 and 1972. Lines used were from 2000 randomly selected out of PI247310 and PI279345, and reselected on the basis of their progeny performance in head row nurseries. The cultivars, ‘Prophet,’ ‘Meyer,’ and ‘Indy,’ were used as checks. Characters studied were seed yield, test wt, plant ht, % oil (measured gravimetrically and by nuclear magnetic resonance), days to bloom, and % glucosinolates. Statistical differences were detected among lines for all characters except % glucosinolates, based on individual year and combined analyses of variance. Broad sense heritability estimates ranged from .22–.88. Gains from selection, as a % of the mean for each character, were estimated at 1.13–14.11. Intercharacter relationships were analyzed by correlation. The ranges in variation for traits are considered limited for good progress from selection within the germplasm represented, but advances can be expected.
A model for asymmetry of immediate recall in relational triads

Attribute-object-value triads (e.g., Ann’s father is Ken) have played a major role in process models of human memory and verbal behavior, but little evidence exists about how humans use them. Forty-five Ss, randomly divided into three groups of 15, were tested for symmetry of recall in triads consisting of a family relationship (R) and two names (B and C), e.g., R of B is C. It was found that the Ss could recall the attribute almost as rapidly as the value but that they needed a significantly longer amount of time to recall the object or object and attribute. It is proposed that Ss have explicit operations for retrieving the value or attribute of a triad, but that they recall the object by generating feasible objects and testing them in the triad. It is argued that this information-processing system developed as a result of the differences in the restrictiveness of the inverse questions and differences in the frequency of occurrence of the types of questions in normal language usage.
The dog pancreatic X cell: A light and electron microscopic study

A light and electron microscopic study was conducted on the X cell of the normal dog pancreas. These cells were identified by their acidophilic cytoplasmic granules which do not stain with iron or phosphotungstic acid hematoxylin and also show a distinctive multilobate nucleus. They were found to be neither argyrophilic nor argentaffinic. Ultrastructurally, when fixed in osmium alone, the X cell cytoplasm contained numerous rounded, smooth membrane bound secretory granules with content of low electron density. However, after double fixation in glutaraldehyde and osmium the granules appeared irregularly round, ovoid or kidney shaped with content which may vary from electron lucent to homogeneously electron dense with gradations between. The functional significance of the X cell is unknown. However, its structure showed it to be a distinct, active secretory element, independent of other pancreatic exocrine and endocrine cell types.
Three generations of post-war study of Judaism in Germany: Goldberg, Schaefer, Houtman and Becker and the demolition of historical Judaism

German academic anti-Judaism—theological contempt for the religion set forth out of Scripture by the Rabbinic sages of antiquity—begins with Martin Luther and survives the Third Reich. That is shown by the nihilistic representation of Rabbinic Judaism in post World-War II German scholarship, which denies to Judaism a determinate textual corpus, a synchronic venue, a diachronic context. Three generations—Arnold M. Goldberg, his disciple, Peter Schaefer, and Schaefer's disciples, Alberdina Houtman and Hans-Juergen Becker—have systematically denied to Judaism the possibility of historical study as a culture in dialogue with a particular social order. The outcome of the German academic tradition is a religion without determinate texts, religious texts out of all context—and texts without contents: the nullification of Judaism as a fact of history and culture.
Double reflection of capillary/gravity waves by a non-uniform current : A boundary layer theory

When a train of gravity waves encounters an opposing current, the wavelength is shortened and the waves may be reflected. If capillarity is included, the shortened waves may be reflected for a second time and experience further shortening. By this process the initially long gravity waves can be damped by viscosity quickly without breaking. In this paper a boundary-layer approximation is obtained close to the reflection points, and is matched to the ray approximations outside. This is then applied to the propagation of a wavepacket. Damping is accounted for in the ray solution and the result is compared to the undamped solution. The case where the two reflection points coalesce is also considered. It is found that as the separation between the reflection points decreases, the wavepacket appears to remain longer in the region of reflections relative to the width of this region.
Adaptation through insurance: lessons from the NFIP

Purpose – Insurance is widely regarded as a key adaptation option for climate change. Yet, the experience of the insurance sector in dealing with climatic hazards, particularly flooding, has been highly varied. Drawing from the experience of the US National Flood Insurance Program (NFIP), the purpose of this paper is to identify opportunities and challenges associated with using insurance as an adaptation strategy for climate change.Design/methodology/approach – This article critically reviews the history and recent performance of the NFIP and considers lessons for climate change adaptation through insurance.Findings – The US NFIP offers government‐subsidized flood insurance for firms and residences. Over its 40‐year history, the NFIP has struggled with financial instability and low levels of public participation in the program. The experience of the NFIP offers several lessons regarding the viability of insurance as an adaptation strategy: increasing insurance premiums to account for new climatic risks m...
Constructing instruction traces from cache-filtered address traces (CITCAT)

Instruction traces are useful tools for studying many aspects of computer systems, but they are difficult to gather without perturbing the systems being traced. In the past, researchers have collected instruction traces through various techniques, including single-stepping, instruction inlining, hardware monitoring, and processor simulation. These approaches, however, fail to produce accurate traces because they interfere with the processor's normal execution.Because processors are deterministic machines, their behavior can be predicted if their initial states and external inputs are known. We have developed a technique, called "CITCAT," which exploits this fact to generate nearly perfect instruction traces through trace-driven simulation. CITCAT combines the best features of instruction inlining, hardware monitoring, and processor simulation to produce long, accurate instruction traces without perturbing the system being traced. Because CITCAT instruction traces are computed, rather than stored, this hybrid technique delivers not just accurate traces, but also an extremely efficient trace compression algorithm.
Induction of murine hepatic glutathione S-transferase by dietary dehydroepiandrosterone

The naturally occurring steroid dehydroepiandrosterone (DHEA), when administered as a supplement to the diet of mice and rats, produces alterations in the relative concentrations of specific liver proteins; among these, a protein of Mr approximately 28 K is markedly induced by DHEA action. In the present study we identified the murine hepatic approximately 28 kDa protein as glutathione S-transferase subtype GT-8.7. Glutathione S-transferases belong to a gene superfamily that encode closely related proteins which are induced in liver and other tissues by various chemicals, including carcinogens and chemoprotective agents such as dietary antioxidants. Based on the above finding, we evaluated glutathione S-transferase activity in cytosols and microsomes prepared from liver tissue of mice fed either a control diet or a DHEA-containing diet (0.45%, by weight). The specific activity of hepatic cytosolic glutathione S-transferase in mice treated with DHEA up to 7 days was either unchanged or slightly decreased when compared to controls; however, treatment for 14 days or longer resulted in significant increases in activity. The specific activity of microsomal glutathione S-transferase also was increased by long-term DHEA treatment; however, its activity was approximately one-tenth of that in corresponding cytosols.
Developing High-Potential Employees In The New Business Reality

John, a graduate of an elite MBA program, takes a job in the finance division of a Fortune500 company. Anxious to progress in the corporation, John is concerned about career development. The company assigns him to treasury for his first position. Twelve months pass and John is moved to a financial
The Civility of Indifference: On Domesticating Ethnicity

The Civility of Indifference: On Domesticating Ethnicity. F. G. Bailey. Ithaca, NY: Cornell University Press, 1996. xvi. 184 pp., plates, notes, references, index.
Diazepam enhances the action but not the binding of the GABA analog, THIP

GABA (4-aminobutyric acid) and its bicyclic analog THIP (4,5,6,7-tetrahydroisoxazolo-[4,5-c]-pyridin-3-ol) produced membrane hyperpolarization and increased chloride ion conductance of mouse spinal cord neurons in cell culture. Above 1 nM diazepam enhanced the actions of both GABA and THIP with similar potency and efficacy. Diazepam has been shown to enhance the binding of [3H]GABA to rat brain membranes over similar concentration ranges, with the EC50 values for enhancement of [3H]GABA binding and increase in membrane conductance being similar. In contrast, binding of [3H]THIP has been shown to be unaltered by diazepam under a variety of conditions. The possible reasons for such a discrepancy between these electrophysiological and neurochemical results with THIP are discussed.
Predictors of Response and Mechanisms of Change in an Organizational Skills Intervention for Students with ADHD.

The purpose of the study was to evaluate predictors of response and mechanisms of change for the Homework, Organization, and Planning Skills (HOPS) intervention for middle school students with Attention-Deficit/Hyperactivity Disorder (ADHD). Twenty-three middle school students with ADHD (grades 6–8) received the HOPS intervention implemented by school mental health providers and made significant improvements in parent-rated materials organization and planning skills, impairment due to organizational skills problems, and homework problems. Predictors of response examined included demographic and child characteristics, such as gender, ethnicity, intelligence, ADHD and ODD symptom severity, and ADHD medication use. Mechanisms of change examined included the therapeutic alliance and adoption of the organization and planning skills taught during the HOPS intervention. Participant implementation of the HOPS binder materials organization system and the therapeutic alliance as rated by the student significantly predicted post-intervention outcomes after controlling for pre-intervention severity. Adoption of the binder materials organization system predicted parent-rated improvements in organization, planning, and homework problems above and beyond the impact of the therapeutic alliance. These findings demonstrate the importance of teaching students with ADHD to use a structured binder organization system for organizing and filing homework and classwork materials and for transferring work to and from school.
Kinetics and Reaction Coordinates of the Reassembly of Protein Fragments Via Forward Flux Sampling

We studied the mechanism of the reassembly and folding process of two fragments of a split lattice protein by using forward flux sampling (FFS). Our results confirmed previous thermodynamics and kinetics analyses that suggested that the disruption of the critical core (of an unsplit protein that folds by a nucleation mechanism) plays a key role in the reassembly mechanism of the split system. For several split systems derived from a parent 48-mer model, we estimated the reaction coordinates in terms of collective variables by using the FFS least-square estimation method and found that the reassembly transition is best described by a combination of the total number of native contacts, the number of interchain native contacts, and the total conformational energy of the split system. We also analyzed the transition path ensemble obtained from FFS simulations using the estimated reaction coordinates as order parameters to identify the microscopic features that differentiate the reassembly of the different split systems studied. We found that in the fastest folding split system, a balanced distribution of the original-core amino acids (of the unsplit system) between protein fragments propitiates interchain interactions at early stages of the folding process. Only this system exhibits a different reassembly mechanism from that of the unsplit protein, involving the formation of a different folding nucleus. In the slowest folding system, the concentration of the folding nucleus in one fragment causes its early prefolding, whereas the second fragment tends to remain as a detached random coil. We also show that the reassembly rate can be either increased or decreased by tuning interchain cooperativeness via the introduction of a single point mutation that either strengthens or weakens one of the native interchain contacts (prevalent in the transition state ensemble).
A Nutritional Role for Amino Acid Transport in Filter-Feeding Marine Invertebrates

SYNOPSIS. Filter-feeding invertebrates are exposed to a small but continuous source of potential foodstuffs in the form of dissolved free amino acids (DFAA). Studies with two genera of bivalve molluscs, Mytilus and Modiolus , indicate the existence of carrier-mediated transport processes for DFAA, and that these processes are capable of a net accumulation of substrate from external solution. The kinetics of DFAA transport in bivalve gill, the primary organ for uptake, reveal these processes to be well-adapted for the efficient utilization of substrate at the extremely low concentrations (approximately 1 μM) characteristic of the water column: Michaelis constants for uptake are in the micromolar range, resulting in transport rates that are a significant fraction of the maximum capacity of the system. Comparison of potential rates of DFAA accumulation to rates of oxidative metabolism suggest that DFAA can serve as an important nutritional supplement to these animals. Future work should emphasize new analytical procedures, including the use of high performance liquid chromatography, to identify levels of DFAA in specific environments and rates of net DFAA uptake into organisms from these habitats.
Theoretical Study of the Flow of Highly Viscous Materials

Injection molding of thermosetting elastomers has become an important processing technique within recent years. The material enters the injection head at a temperature below the vulcanization point. It is fed by a screw and injected with a ram-like action into a closed mold. Vulcanization of the rubber occurs in the heated mold. The elastomer must flow from the injection chamber into the closed mold through nozzles, channels, sprues, and gates. Pressure drops occur and the material temperature increases as heat is transferred from the mold walls and internal heat is generated by viscous shear. Analytical methods of describing this flow are useful in modifying the mold configuration to increase flow.The basic flow equations are discussed, simplifications are made and a numerical solution of the set of equations describing the flow of a highly viscous non-Newtonian fluid is outlined. Heat transfer from the wall and generation of heat due to viscous shear is considered. The mathematical model is used to gene...
Narrow-band kilometric radio emission as observed by the Galileo plasma wave instrument

Abstract Jovian narrow-band kilometric (nKOM) radio emissions have been well-studied, and are believed to have source regions near the outer edge of the Io torus. Recent investigations have indicated that these emissions increase in intensity associated with magnetic storm-like behavior in the Jovian magnetosphere. The orbit of Galileo affords the opportunity to pass close to the suggested source region near each perijove. We have examined the plasma wave spectra of nKOM on all orbital passes, and we present three cases in some detail. The nKOM emission is seen to increase in intensity at the outer edge of the plasma torus near the edge of the magnetic equator/current sheet crossings. Near perijove, and also associated with magnetic equator crossings, intense bursty (probably electrostatic) and narrow-banded emissions similar to upper hybrid emission seen at Earth are observed. We postulate that these emissions are related to the source of the nKOM emission.
Landing aircraft tracking using fusion of FLIR and laser range finder

An algorithm is presented for tracking a landing aircraft using two different passive sensors, a laser range finder and an infrared camera. The main feature of this algorithm is that it is able to identify and compensate for abrupt disturbances. The algorithm is based on the extended Kalman filter (EKF) and the filtering confidence function (FCF) which introduces a learning approach to the tracking problem. The results of simulation using this learning tracking algorithm and the extended Kalman filter alone are presented and compared.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Further Validation of the Special Favorable Response Occurring during Unconscious Self-Evaluation

Although 31 male students did not recognize their own shadow profiles, these were rated as more friendly and intelligent than profiles of others. For 23 Ss favorableness of self ratings of profiles correlated .36 with thresholds for a tachistoscopically presented picture having a narcissistic theme. Data are intepreted in terms of perceptual defense.
Association and chance occurrence of aniridia and retinoblastoma.

Purpose/Methods A 9-month-old infant had inherited aniridia and unilateral retinoblastoma. Family history disclosed three generations of aniridia; yet there were no instances of retinoblastoma. The coincidental occurrence of retinoblastoma and aniridia is rare. Results/Conclusions With DNA probes from within the retinoblastoma gene, we were able to determine that a retinoblastoma-predisposing mutation was not inherited with aniridia in this family. The occurrence of these two diseases in the same individual therefore represents a chance event.
Chromatin biochemistry enters the next generation of code 'seq-ing'

Barcoded semisynthetic nucleosomes combined with massively parallel sequencing provide an innovative new platform for analyzing the histone-recognition and histone-modifying activities of chromatin-associated proteins.
Family strengths and challenges in the USA

Abstract Families in the United States are faced with many challenges both within the family and in the social environment. To balance this discussion of challenges, an exploration of how the strengths of families and couples—their positive abilities and attitudes toward life and each other—help to create an intimate family environment in which love, satisfaction, happiness, and comfort predominate. The discussion will focus on the work of two research teams whose work led to the development of the International Family Strengths Model by Stinnett, DeFrain, and their colleagues, and the development of the Couple and Family Systems Model (also known as the Circumplex Model) developed by Olson and his colleagues. Outcomes point out that though it is clearly important to learn and acknowledge dysfunction, it is also of utmost importance that we learn about family and couple strengths to develop models of family dynamics that lead people to more satisfying relationships.
Schistosoma mansoni: Protein phosphorylation during transformation of cercariae to schistosomula

Abstract Infectivity of the multicellular pathogen Schistosoma mansoni for the human host is dependent upon the ability of free-living cercariae to transform rapidly into parasitic schistosomula. The biochemical pathways that regulate this transitional period are unknown. The role of protein phosphorylation was investigated by examining the incorporation of [32Pi]phosphate into proteins of S. mansoni. A sevenfold increase in total phosphorylation was found in 3-hr-old schistosomula as compared to cercariae. Analysis of radiolabeled proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography demonstrated that a 14-kDa protein served as a marker for transformation, being phosphorylated in schistosomula but not cercariae. The protein was phosphorylated on a serine residue. Phosphorylation was stimulated by a shift of parasites from water to salt-containing medium at 23 °C. Incubation of organisms in water at 37 °C did not initiate phosphorylation of this protein. The 14-kDa phosphoprotein was extracted from parasite homogenates with 1 M NaCl but was insoluble in 1% Triton X-100. Protein phosphorylation during the cercarial-schistosomula transformation may represent an important biochemical event that regulates infectivity of the parasite for the human host.
Valence Theories and the Magnetic Properties of Complex Salts

NATURE of September 5, containing the letter of one of us and the courteous criticisms of Dr. Jackson, reached the library of the Institute at the very time that we were engaged in a task suggested in Dr. Jackson's note. When writing on July 23, we were of the belief that it would be impossible to explain magnetic anomalies in complex salts until detailed information should become available regarding the orientations of the orbital planes. It was the explanation given by Oseen1 of Ingersoll's non-magnetic nickel which suggested to us that the problem might be simpler. It suggested that we need only to consider the number of electrons in certain levels associated with the central metal atom, and that we may, for the present purpose, disregard the matter of orientation.
Nefertiti: a query by content software for three-dimensional models databases management

This paper presents a new approach for the classification and retrieval of three-dimensional images and models from databases. A set of retrieval algorithms is introduced. These algorithms are content-based, meaning that the input is not made out of keywords but of three-dimensional models. Tensor of inertia, distribution of normals, distribution of cords and multiresolution analysis are used to describe each model. The database can be searched by scale, shape or color or any combination of these parameters. A user friendly interface makes the retrieval operation simple and intuitive and allows to edit reference models according to the specifications of the user. Experimental results using a database of more than 400 range images and 1000 VRML models are presented.
Steric effects on the rate of hydrolysis by palladium(II) complexes of the C-terminal amide bond in a series of methionine-containing dipeptides AcMet-Aa *

A series of N-acetylated, methionine-containing dipeptides designated AcMet-Aa containing various C-terminal amino acids designated Aa are hydrolyzed in aqueous solution at 50 oC and 0.95 < pD < 1.10 in the presence of three cis-Pd(L)(H 2 O) 2 2+ complexes, in which L are bidentate ligands en, Me 4 en, and 3-OH-dtco. The reactions were monitored by 1 H-NMR spectroscopy. The rate constant for hydrolytic cleavage of the Met-Aa bond decreases as the steric bulk of the amino acid Aa increases. Correlations to Taft's Es values were made. The substituents on -C and -C atoms lower the rate constant most, those on the -C atom lower it less, and those on the -C have no detectable effect. Partial selectivity for leaving amino acid Aa is attributed to differences in the volume of the side chain and to discrimination between leaving groups of similar volume but different branching patterns.
A Look at an Implementation of the Quality Matters Program in a Collegiate Environment: Benefits and Challenges.

As traditional universities grapple with an onslaught of demand for distance education a recurring call to ensure quality in such offerings arises. The Quality Matters Program intends to guarantee such quality through a peer-centered process and offers a certification process to help assure quality in online and blended courses. This report is a preliminary look at perceived benefits and challenges that implementing the process entails.
Toward secure network coding in wireless networks: Threats and challenges

In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network coding in wireless networks. Although the theoretical foundations of network coding are well understood, a real-world system needs to solve a plethora of practical aspects before network coding can meet its promised potential. These practical design choices expose network coding systems to a wide range of attacks. In this paper, we identify two general frameworks that encompass several network coding-based systems proposed for unicast in wireless networks. Our systematic analysis of the components of these frameworks reveals vulnerabilities to a wide range of attacks, which may severely degrade system performance. Adequate understanding of these threats is essential to effectively design secure practical network coding systems.
Nanoscale depth-resolved electronic properties of SiO 2 /SiO x /SiO 2 gate dielectrics for radiation-tolerant electronics

We have combined nanoscale depth-resolved cathodoluminescence spectroscopy (DRCLS) and spectroscopic ellipsometry (SE) to measure the energies and depth distribution of charge traps in SiO 2 /SiO x /SiO 2 gate dielectrics for radiation-tolerant electronics. It is now known that suboxide layers within silicon-on-oxide (SOI) structures result in Si nanoclusters that can reduce the shift of the flatband voltage by trapping protons formed during hole injection [1]. Previous studies based on ion implantation showed that positive charge trapping is due to proton trapping at network oxygen atoms having large Si-O-Si bond angles. Such traps can be used to reduce the net positive charge during exposure to ionizing radiation that result in negative flatband voltage shifts and pathways for charge leakage. We used thermal oxidation to prepare SiO 2 /SiO x /SiO 2 gate dielectrics with reduced oxide concentrations and monitored their optical absorption and emission features with annealing and irradiation. These nanoscale film structures are known to phase segregate with annealing from amorphous Si (a-Si) into nanocrystalline surrounded by a SiO 2 shell [2]. The use of cathodoluminescence and UV SE enables us to measure optical transitions at energies involving not only intra- but also interphase transitions due to their intimate contact and high area. Understanding the physical nature of such traps may enable control of radiation-induced holes in higher-K dielectric SOI structures.
Food subsidies and market interdependence: The case of the Moroccan soft wheat subsidy

Abstract Among the several propositions advanced to explain the rising cost of subsidizing soft wheat production and consumption in Morocco are the indirect effects emanating from related markets, namely the hard wheat and barley markets. A three-sector supply-demand model, described in this paper, was used to estimate the direct and indirect (induced) effects on government cost of changes in the soft wheat subsidy. The results show that virtually all the indirect effects come from the soft wheat market itself. The indirect effects emanating from the related markets are negligible.
Derivation of the photopigment absorption spectra in anomalous trichromats.

We describe a method of deriving the absorption curves of the anomalous pigments of sex-linked anomalous color vision. The approach is based on combining Rayleigh-equation data with standard shapes for the visual pigments. For normal pigments, we used a standard shape derived from corrected dichromatic sensitivity curves, with λmax = 534 and 560 nm for the middle- and long-wavelength sensitivities, respectively. For anomalous pigments, two shapes were evaluated: (i) Dartnall’s shape, defined by rhodopsin, and (ii) the shape defined by the normal middle- and long-wavelength-sensitive human cone photopigments. When the anomalous pigments are assumed to have the absorption spectrum of rhodopsin, no solutions fitting the protanomalous and deuteranomalous Rayleigh equations were possible. When the anomalous pigments are assumed to have the absorption spectrum of the normal middle- and long-wavelength-sensitive human cone photopigments, the solutions were an anomalous long-wavelength sensitive pigment for the protanomal peaking at 541.6 nm, and an anomalous middle-wavelength sensitive pigment for the deuteranomal, peaking at 554.6 nm.
Stability (over time) of modified-CS for recursive causal sparse reconstruction

In this work, we obtain sufficient conditions for the “stability” of our recently proposed algorithm, modified-CS (for noisy measurements), designed for recursive reconstruction of sparse signal sequences from noisy measurements. By “stability” we mean that the number of misses from the current support estimate and the number of extras in it remain bounded by a time-invariant value at all times. The concept is meaningful only if the bound is small compared to the current signal support size. A direct corollary is that the reconstruction errors are also bounded by a time-invariant and small value. We show that “stability” holds under mild assumptions (bounded noise, high enough SNR and large enough measurements at every time) for a simple deterministic signal model with fixed signal power and support set size; support set changes allowed at every time; and gradual coefficient magnitude increase/decrease.
Improved method to evaluate the adhesion properties of thin film conformal coatings

Conformal coatings are widely used by the electronics industry to protect sensitive equipment from moisture and corrosion [i]. Of these, parylene thin-film coatings have many material properties such as low dielectric and dissipation factors, high operating temperatures, excellent conformability and low moisture permeability, which make them an attractive conformal material for numerous applications. However, adhesion of parylene coatings is critical to the overall reliability of the coating and is especially problematic on inorganic surfaces. A number of techniques can potentially improve adhesion including adhesion promoters and plasma treatment, but a robust method for evaluating adhesion has been lacking. In response, we developed a method based upon a standard die-shear test that can calculate the adhesion strength of different interfaces when multiple failure modes are active. This process uses pre-shear and post-shear images to calculate the area of each failure mode. Those areas are then used in combination with the measured breaking load to calculate the adhesion strength of the different interfaces using an iterative solver. This method provides an accurate, quantitative measure of thin-film adhesion even when mixed failure modes are active.
CHINESE POVERTY: ASSESSING THE IMPACT OF ALTERNATIVE ASSUMPTIONS

This paper investigates how estimates of the extent and trend of consumption poverty in China between 1990 and 2004 vary as a result of alternative plausible assumptions concerning the poverty line and estimated levels of consumption. Our methodology focuses on the following sources of variation: purchasing power exchange rates (used to convert an international poverty line), alternative levels and distributions of private incomes, alternative estimates of the propensity to consume of different income groups, and alternative spatial and temporal price indices. We report national, urban and rural poverty estimates corresponding to distinct assumptions. It is widely believed that substantial poverty reduction took place in China in the 1990s, and we find this conclusion to be largely robust to the choice of assumptions, although estimates of the extent of Chinese poverty, and therefore of world poverty, in any year are greatly influenced by this choice.
Expression of neurotrophin receptor Trk-C in nevi and melanomas.

Background: Neurotrophins (NTs) are growth factors for neurons and other neural crest-derived cells. Their functions are mediated by 75-kDa low-affinity glycoprotein receptor (p75) NT receptor and a family of tyrosine kinase receptors (Trks) that includes Trk-A, -B, and -C. Signal transduction through the Trk receptors has been shown to regulate growth and apoptosis of tumors of neuronal origin. In addition, Trk oncogenes have been shown to be rearranged in some non-neuronal neoplasms. Recently, immunoexpression of NT-3 has been shown to be significantly higher in melanomas than in banal nevi on cryostat tissue. Methods: Since the biologic function of NT-3 is mediated primarily through Trk-C, we investigated Trk-C immunoexpression on paraffin sections of 10 compound nevi and 63 melanomas. Results: The expression of Trk-C was relatively low in compound nevi (30%). Trk-C expression was overall 62% in melanomas of various stages. Our data show that the expression of Trk-C increased as melanoma progressed from in situ (58%) to papillary dermal invasion (91%), and then declined in deeper (57%) and metastatic melanomas (31%). Conclusion: These findings suggest a possible role of Trk-C in the progression of early stages of melanoma.
Incidence of and risk factors for residual posterior capsule opacification after cataract surgery.

Purpose: To evaluate the incidence of and determine the risk factors for residual posterior capsule opacification (PCO). Setting: University of New Mexico Health Sciences Center and the Veterans Administration Medical Center, Albuquerque, New Mexico, USA. Methods: This study evaluated 194 uneventful cataract surgeries. Immature cataracts were graded for nuclear sclerosis (NS), posterior subcapsular cataract (PSC), and anterior cortical spokes on a 1 to 4 scale. Preoperative Snellen best corrected visual acuity was converted to the logMAR scale. The posterior capsule was examined after polishing and was classified as clear or as having residual opacity. Those with residual capsule opacity were evaluated 6 weeks postoperatively for the presence of visually significant PCO. Results: The incidence of residual capsule opacity was 23% (44 eyes). Seven (54%) of 13 eyes with white mature cataract had residual capsule opacity. In contrast, 37 (20%) of 181 eyes with immature cataract had residual capsule opacity (P = .01). In eyes with immature cataract, the mean preoperative logMAR acuity was +1.14 ± 0.60 (SD) in the residual capsule opacity group and +0.73 ± 0.46 in the clear group (P<.001). In eyes with immature cataract, the adjusted odds ratio for each increasing grade of NS was 2.3 and of PSC, 1.8 (P = .002 and P<.001, respectively). Eleven percent (5 eyes) of residual capsule opacities resulted in visually significant PCO 6 weeks postoperatively. All 5 opacities were centrally located at surgery. Conclusions: Results indicate that aggressive polishing of peripheral or adherent residual capsule opacities is not advisable as only 5 eyes with central residual capsule opacities developed visually significant PCO.
EpsR Modulates Production of Extracellular Polysaccharides in the Bacterial Wilt Pathogen Ralstonia (Pseudomonas) solanacearum

Ralstonia solanacearum is the causal agent of bacterial wilt of many agriculturally important crops. Exopolysaccharide synthesized by products of the epsI operon is the major virulence factor for R. solanacearum. Expression of epsI has been demonstrated to be under the control of several proteins, including several two-component regulators. Overexpression of EpsR was found previously to reduce the amount of synthesis specifically from the epsI promoter. Here we present data that a single chromosomal copy of epsR activates the epsI promoter, suggesting that EpsR is a concentration-dependent effector of epsI gene expression. Furthermore, the ability of EpsR to modulate epsI expression is dependent on the phosphorylation state of EpsR. Gel mobility shift assays suggest that EpsR can specifically bind the epsI promoter and that this binding requires a phosphorylated form of EpsR.
Reporting the International System: Attention to Foreign Leaders in the US News Media, 1950–2008

Information on foreign affairs reaches Americans primarily through the news media, yet we know little about why some global actors receive more attention than others. We constructed a new data set describing media attention to, and US state actions and discourse about, foreign leaders from 1950 to 2008 to assess which leaders receive more attention and why. The results of our analyses suggest that media attention is disproportionately allotted to (1) leaders of the most powerful countries in the international system; (2) leaders of countries experiencing instability and violence; (3) leaders of countries that domestic political elites (Congress and the president) pay attention to, or where the US is currently fighting a war; and (4) leaders of countries whose connections to global networks signal positions of neutrality vis-a-vis the Cold War superpowers. We do not find any evidence that media attention diffuses through connections in the world polity. We conclude that media attention to foreign leaders is a reflection of the dynamics of geopolitical struggles and conflicts rather than global interconnectedness. Thus, in the context of attention to world leaders, news values favoring conflict and struggle resonate more than news values favoring connections and cooperation.