cssi/SciSciGPT-SciSciNet huggingface dataset:
A tail of histone acetylation and DNA recombination

To generate the huge diversity of antigen receptors expressed on T and B cells, the cell has come up with an elegant recombination dance between a series of V, D, and J gene segments that can be spliced together in numerous permutations. But how this recombination is regulated is not clear. Now, in a Perspective, Schlissel explains new findings (McMurry and Krangel) showing that histone acetylation correlates with V(D)J recombination. Selective addition of acetyl groups to histone proteins (components of nucleosomes that are the structural "beads" in chromatin around which the DNA is wound) is believed to alter the packaging of chromatin. In areas where the chromatin structure is relaxed, the new work suggests that recombinase enzymes can slide into the chromatin and cleave and splice the V, D, and J genes in this region.
Low-literacy interventions to promote discussion of prostate cancer: a randomized controlled trial.

Background Professional organizations recommend that physicians discuss prostate cancer with patients to make individual screening decisions. However, few studies have tested strategies to encourage such discussions, particularly among high-risk populations. We examined the effects of two low-literacy interventions on the frequency of prostate cancer discussion and screening. Design Randomized, blinded, controlled trial with concealed allocation. Setting/Participants Inner-city primary care clinic, serving a predominately African-American population. Participants were men aged 45–70 with no history of prostate cancer, presenting for a regular appointment. Interventions While waiting to see their physician, patients received a patient education handout on prostate cancer screening (PtEd), a handout simply encouraging patients to talk to their doctor about prostate cancer (Cue), or a control handout. The interventions did not advocate for or against screening. Measures Patient-reported discussion of prostate cancer with the physician and chart reviews determine prostate-specific antigen (PSA) test orders and performance of digital rectal examination (DRE). Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were computed. Data were collected in 2003, and analyses were completed in 2006. Results Most of the 250 subjects (90.4%) were African American and 78.8% read below the ninth grade level. Overall, 48.4% reported discussing prostate cancer during the appointment. Compared to the control group (37.3%), discussions were significantly more common in the Cue group (58.0%, aOR=2.39 [1.26–4.52]), as well as in the PtEd group (50.0%, aOR=1.92 [1.01–3.65]). When prostate cancer was discussed, patients in the intervention groups more commonly initiated the conversation (47.6% PtEd and 40.0% Cue, vs 9.7% control, p Conclusions Two simple low-literacy interventions significantly increased discussion of prostate cancer and PSA test orders but not performance of DRE. Both interventions were effective in empowering low-literacy patients to initiate conversations about prostate cancer with their physician.
Distributed fractional packing and maximum weighted b-matching via tail-recursive duality

We present efficient distributed δ-approximation algorithms for FRACTIONAL PACKING AND MAXIMUM WEIGHTED b-MATCHING in hypergraphs, where δ is the maximum number of packing constraints in which a variable appears (for MAXIMUM WEIGHTED b-MATCHING δ is the maximum edge degree -- for graphs δ = 2). (a) For δ = 2 the algorithm runs in O(logm) rounds in expectation and with high probability. (b) For general δ, the algorithm runs in O(log2 m) rounds in expectation and with high probability.
Phase precipitation and time–temperature-transformation diagram of Hastelloy X

Abstract Transmission electron microscopy (TEM) was employed to study the phase precipitation in Hastelloy X heat-treated at 750, 850, and 900°C for 26 and 100 h. Phase identification was made by electron micro-diffraction and energy dispersion spectroscopy (EDS) X-ray micro-chemical analysis. In addition to the fcc matrix, four different precipitation phases were observed: M6C, M23C6, σ, and μ. The current observations were combined with literature results to build a time–temperature-transformation (TTT) diagram for this alloy. This TTT diagram depicted time–temperature regimes where various phases were formed; thus, it provided information about the general precipitation kinetics for the alloy.
Reduction of fan noise in an anechoic chamber by reducing chamber wall induced inlet flow disturbances

The difference between the flight and ground static noise of turbofan engines presents a significant problem in engine noise testing. The additional noise for static testing has been attributed to inlet flow disturbances or turbulence interacting with the fan rotor. In an attempt to determine a possible source of inflow disturbances entering fans tested in the Lewis Research Center anechoic chamber, the inflow field was studied using potential flow analysis. These potential flow calculations indicated that there was substantial flow over the wall directly behind the fan inlet that could produce significant inflow disturbances. Fan noise tests were run with various extensions added to the fan inlet to move the inlet away from this backwall and thereby reduce the inlet flow disturbances. Significant noise reductions were observed with increased inlet length. Over 5 db reduction of the blade passage tone sound power level was observed between the shortest and longest inlets at 90% fan speed and the first overtone was reduced 9 db. High frequency broadband noise was also reduced.
Glutamine synthetase in newborn mice homozygous for lethal albino alleles.

Abstract Glutamine synthetase (GS) activity was studied in newborn mice homozygous for radiation-induced lethal albino alleles that cause multiple biochemical deficiencies. GS was found to be decreased in the liver of both homozygous mutants studied, whereas enzyme levels were normal in the eye and brain. The results support the interpretation that the neonatal lethal deletion alleles are mutations of a regulatory genome that normally controls the activities of multiple enzymes.
Little River revisited - thirty-five years after Hack and Goodlett

Abstract In possibly the first detailed study to relate geomorphology, vegetation, and hydrology at a watershed scale, Hack and Goodlett (1960) documented variation in the eastern forest with topograhic positions of cove, side slope, and nose. Runoff identified as convergent, parallel, or divergent, supported forest types, respectively, of northern hardwood, oak, and yellow pine. The study, conducted in the Little River Basin of northwestern Virginia, also described effects on landforms and vegetation of a catastrophic flood that occurred in June, 1949. Field investigations, conducted nearly 4 decades later, review selected parts of the study by Hack and Goodlett (1960). Replicate data provide a basis to evaluate interpretations of Hack and Goodlett, to document geomorphic change within the Little River Basin since the 1949 flood, and to identify vegetation change in uplands and bottomlands. Results suggest that change to hillslope landforms has been minor since 1949, but that changes have occurred to the Little River and its tributaries, seemingly during flow events of 1952, 1955, and 1985. Change in areal extent of forest types was not detected. Change in the relative abundances of dominant species may have resulted from 20th-century fire suppression.
Structural analysis of lignin-derived carbon composite anodes

The development of novel lignin-based carbon composite anodes consisting of nanocrystalline and amorphous domains motivates the understanding of a relationship of the structural properties characterizing these materials, such as crystallite size, intracrystallite dspacing, crystalline volume fraction and composite density, with their pair distribution functions (PDF), obtained from both molecular dynamics simulation and neutron scattering. A model for these composite materials is developed as a function of experimentally measurable parameters and realized in fifteen composite systems, three of which directly match all parameters of their experimental counterparts. The accurate reproduction of the experimental PDFs using the model systems validates the model. The decomposition of the simulated PDFs provides an understanding of each feature in the PDF and allows for the development of a mapping between the defining characteristics of the PDF and the material properties of interest.
Correlation Between Psychological Test Scores, Language Aptitude Test Scores, and Semester Grades

T HIS investigation adds evidence for the necessity of reckoning with individual differences in modern foreign language classes by the use of prognostic testing, so that maximum achievement can be guaranteed for time and effort expended. It concerns 103 Freshman students of the West Virginia State College in beginning classes in French, Spanish, and German, divided among the three languages in enrollments of 51, 36, and 16, in the order named.
Preignition reactions of AP-HTPB propellants studied by IR spectrometry

IR absorption spectrometry was used to follow the disappearance of NH and CH bonds during the pyrolysis of a polymer film containing 30 weight percent ammonium perchlorate (AP). The remaining 70 weight percent consisted of a mixture of 92.5 weight percent hydroxyl-terminated polybutadiene (HTPB) and 7.5 weight percent isophrone diisocyanate (IPDI). The results indicate that polymer decomposition is induced by products of AP decomposition, and that about 2.5 CH bonds disappear for each NH bond that disappears. The diffusion process occurring in the later stages of the reaction is analyzed in an attempt to account for the unexpectedly low activation energy.
The Structure of Reseller Goals and Performance in Marketing Channels

The typical view of a marketing channel is that of a manufacturer-designed and-controlled distribution system. However, today, marketing functions, as well as market power, are more evenly distributed in the channel. In organizing and managing the modern channel, it is important to understand the business circumstances and priorities confronting channel members. This article studies how reseller firms establish their goal hierarchies and how these goals are related to performance. It hypothesizes that goal priorities emerge in relation to the environmental imperatives faced by the firm. The article develops hypotheses that are tested on survey data collected from a sample of franchisee firms, using structural equation models. The results support all the hypotheses about the effects of primary goals on performance. The effects of secondary goals are not unequivocal but informative nevertheless. Overall, the study points to interesting theoretical and managerial conclusions.
Racial/Ethnic Differences in Multiple Self-Care Behaviors in Adults with Diabetes

To assess racial/ethnic differences in multiple diabetes self-care behaviors. Cross-sectional study. 21,459 participants with diabetes in the 2003 Behavioral Risk Factor Surveillance survey. The study assessed self-care behaviors including physical activity, fruits/vegetables consumption, glucose testing, and foot examination, as well as a composite of the 4 self-care behaviors across racial/ethnic groups. Multiple logistic regression was used to assess the independent association between race/ethnicity, the composite variable, and each self-care behavior controlling for covariates. STATA was used for statistical analysis. Overall, 6% engaged in all 4 self-care behaviors, with a range of 5% in non-insulin users to 8% in insulin users. Blacks were less likely to exercise (OR 0.63, 95% CI 0.51, 0.79), while Hispanics and “others” were not significantly different from whites. Hispanics (OR 0.64, 95% CI 0.49, 0.82) and others (OR 0.69, 95% CI 0.49, 0.96) were less likely to do home glucose testing, while blacks were not significantly different from whites. Blacks (OR 1.42, 95% CI 1.12, 1.80) were more likely to do home foot examinations, while Hispanics and others were not significantly different from whites. Blacks (OR 0.56, 95% CI 0.36, 0.87) were less likely to engage in all 4 behaviors, while Hispanics and others were not significantly different from whites. There were no significant racial/ethnic differences in fruit and vegetable consumption. Few patients engage in multiple self-care behaviors at recommended levels, and there are significant racial/ethnic differences in physical activity, dietary, and foot care behaviors among adults with diabetes.
Noradrenergic receptor function and aging: Beyond the binding

Quantitative studies of noradrenergic binding sites with aging probably underestimate the functional alterations in this, and other, central synaptic systems. Transmitters like norepinephrine, whose actions are based on amplification and interaction of interneuronal signalling capacity, rely on interactions among receptor subtypes for their complete effect. Thus, slight losses of one or both receptor subtypes with normal aging may have far more devastating effects.
On the possibility of obtaining relative paleointensities from lake sediments

Abstract Relative paleointensities are obtained from a 6-m sediment core from Lake St. Croix, Minnesota, spanning the time range from 445 to 1740 years B.P. To normalize the natural remanent magnetization (NRM) for variations in the magnetic content, a laboratory-induced remanence is chosen, whose alternating field (AF) demagnetization curves most closely resemble the NRM demagnetization curves. By plotting the ratio of the NRM to the normalizing remanence versus AF demagnetizing field, H AF , for samples of the same sediment horizon, as well as for samples from different horizons, estimates are obtained for expected uncertainties in the relative paleointensities. For the Lake St. Croix sediments the anhysteretic remanence (ARM) demagnetization curves are very similar to those of the NRM's, and ARM is therefore used as the normalization parameter. Because the sediment exhibits homogeneous remanence properties throughout, and H AF = 100Oe is the optimum “cleaning” field for the entire core, NRM 100 /ARM 100 is evaluated to represent the fluctuations of the relative paleointensity. Our relative paleointensity data exhibit the same general features as obtained from archeomagnetic studies. The intensity increases as one goes back in time with a peak near 800 years B.P., representing an increase in the intensity of up to 60%. Apparent periodicities in the intensity of 300–400 years are observed.
Interpreting the low-frequency radio spectra of starburst galaxies: a pudding of Strömgren spheres

The low frequency radio emission of starburst galaxies is informative, but it can be absorbed in several ways. Most importantly, starburst galaxies are home to many H II regions, whose free-free absorption blocks low frequency radio waves. These H II regions are discrete objects, but most multiwavelength models of starbursts assume a uniform medium of ionized gas, if they include the absorption at all. I calculate the effective absorption coefficient of H II regions in starbursts, which is ultimately a cross section times the density of H II regions. The cross sections are calculated by assuming that H II regions are Stromgren spheres. The coefficient asymptotes to a constant value at low frequencies, because H II regions partially cover the starburst, and are buried part way into the starburst's synchrotron emitting material. Considering Stromgren spheres around either OB stars or Super Star Clusters, I demonstrate the method by fitting to the low frequency radio spectrum of M82. I discuss implications of the results for synchrotron spectrum shape, H II region pressure, and free-free emission as a star-formation rate indicator. However, these results are preliminary, and could be affected by systematics. I argue that there is no volume-filling warm ionized medium in starbursts, and that H II regions may be the most important absorption process down to ~10 MHz. Future data at low and high radio frequency will improve our knowledge of the ionized gas.
Rapid propagation of roses in vitro.

Abstract A method for the rapid micropropagation of 7 rose cultivars by the stimulation of axillary buds was developed. The effects of a range of hormone supplements and environmental conditions were examined and the final medium adopted was that of Murashige and Skoog (1962) supplemented with naphthalene acetic acid and 6-benzylaminopurine. Rates of multiplication of between 3 and 5 per 4-week period were attained over a series of sub-cultures. Rooting of propagules was achieved under standard greenhouse conditions. Several hundred plants of one cultivar have been grown and are being compared with those propagated by budded rootstocks.
PROTECTION OF NATURAL RESOURCES AGAINST OIL SPILLS BY BOOM ARRANGEMENTS

ABSTRACT An experiment and a computational approach were used to study flow fields around boom arrangements. A volume analysis was performed to quantify the effectiveness of the boom arrangements. The open-channel experiment showed that the booms were most effective when placed at 60° to the shoreline with cylinders placed along the center line. The results of the numerical algorithm were compared with the experimental results, which showed the influence of the cylinders and the recirculation formed between the walls to corral the oil.
Targeted Muscle Reinnervation of a Muscle-Free Flap for Improved Prosthetic Control in a Shoulder Amputee: Case Report

We report a case of targeted muscle reinnervation of a muscle free flap for improved prosthetic control in a patient who had an amputation of the left upper extremity at the level of the shoulder after a severe electrical burn. The reinnervated muscle free flap receives signals from the brachial plexus, and these signals are amplified to provide an interface for a myoelectric prosthesis. This allows for more coordinated and efficient control of the artificial limb.
Time frequency characterization of hand-transmitted, impulsive vibrations using analytic wavelet transform

Abstract Current guidelines to assess health risk of hand–arm vibration are based on the frequency-weighted rms acceleration level, therefore do not fully consider the effect of temporal variations of the spectral energy. Time averaging effect involved with the frequency analysis may severely underestimate the risk of impact tools. A time–frequency (T–F) analysis is necessary to characterize a highly transient signal whose spectral characteristics change rapidly in time. The analytic wavelet transform (AWT) is an ideal T–F analysis tool as it possesses the advantages of both the Fourier and wavelet transforms. The AWT is applied to acceleration signals measured from six tools, five impact type tools and one relatively steady-type tool, to explore possible improvements of the current risk assessment method of hand–arm vibration exposure. Based on the unique capability of the AWT, several new concepts including frequency-weighted time history, cumulative injury function, and cumulative injury index are defined in this study. Possible applications of these new concepts to hand–arm vibration research are described. Based on the results from this study, needs for future research are discussed.
When Territory Deborders Territoriality

The focus is on the misalignment between territory and the legal construct encasing the sovereign authority of the state over its territory—territoriality. The aim is to make visible that territory cannot be reduced to either national territory or state territory, and thereby to give the category territory a measure of conceptual autonomy from the nation-state. Beyond an intellectual project, this analysis seeks to enable a conceptual mobilizing of the category territory, here understood as a complex capability with embedded logics of power/empowerment and of claim making, some worthy and some more akin to power-grabs. Extracto La atencion se centra en el desfase entre el territorio y la construccion legal que encierra la autoridad territorial soberana del Estado, es decir, la territorialidad. La finalidad es hacer ver que el territorio no puede reducirse a un territorio nacional o territorio estatal, y de este modo otorgar a la categoria de territorio una medida de autonomia conceptual del estado-nacion....
Haemolytic anaemia as a complication following colic surgery in a 10-year-old Arabian stallion

Immune-mediated haemolytic anaemia is rare in the horse. This case report discusses the clinical presentation and treatment of this condition in an Arabian stallion following abdominal surgery for large colon volvulus. On Day 10 of hospitalisation the stallion's PCV dropped by 10% whilst his total solids remained stable, consistent with haemolytic anaemia. The stallion was treated with whole blood transfusions and dexamethasone and recovered to be discharged on Day 42. This is an interesting example of immune mediated haemolytic anaemia associated with a complicated gastrointestinal condition. It demonstrates the wide variety of potential aetiologies underlying a haemolytic episode and the necessity for expedient treatment.
Observation of emotional functioning in young handicapped children.

Summary Young children with handicaps are at greater risk of emotional problems than young children without handicaps because of several factors, two of which include (a) altered parent–child interaction patterns from infancy onward and (b) societal attitudes regarding handicaps. Early interventionists are in a unique position to observe signs of emotional problems and assist families in obtaining psychological help. Greenspan's framework for systematically observing aspects of emotional development is described, and ways of drawing conclusions from observations are presented in order to assist interventionists from many disciplines to observe emotional development with greater clarity.
The Molecular Basis of K+ Exclusion by the Escherichia coli Ammonium Channel AmtB

Members of the Amt family of channels mediate the transport of ammonium. The form of ammonium, NH3 or NH4+, carried by these proteins remains controversial, and the mechanism by which they select against K+ ions is unclear. We describe here a set of Escherichia coli AmtB proteins carrying mutations at the conserved twin-histidine site within the conduction pore that have altered substrate specificity and now transport K+. Subsequent work established that AmtB-mediated K+ uptake occurred against a concentration gradient and was membrane potential-dependent. These findings indicate that the twin-histidine element serves as a filter to prevent K+ conduction and strongly support the notion that Amt proteins transport cations (NH4+ or, in mutant proteins, K+) rather than NH3 gas molecules through their conduction pores.
A modular and power-intelligent architecture for wireless sensor nodes

The current state of the art in wireless sensor nodes, both in academia and industry, is a fractured landscape of designs mostly addressing individual problems. The most common commercial design derives directly from a mote developed at the University of California, Berkeley around 1999, and presents only moderate, incremental improvements over the original design. No designs yet present a comprehensive, intelligent solution befitting a modern system. By using dynamic power management, deep system configurability, autonomous peripheral modules, and multiple CPU architectures, this paper presents a flexible and efficient node architecture. Modules on a sensor node communicate with each other to coordinate their activities and power levels. Special attention is given to power sourcing and distribution. The platform may be configured to efficiently work with most networks, sensor types and power sources due to its improved connectivity and hierarchical design. The resulting Configurable Sensor Node (CoSeN) architecture is competitive with existing designs on price, size and power while greatly exceeding most of them on performance, configurability and application potential. CoSeN is validated through prototype implementation.
Development of a micromachining process for the fabrication of a superconductor magnetic-field sensor

This paper reports an effort to introduce high temperature superconductor (HTS) into the MEMS (microelectromechanical systems) field, to develop fabrication procedures suitable for HTS, and using them to fabricate a prototype superconductor microsensor for magnetic field detection. The prototype device fabricated is a sensor based on the giant magnetoresistivity of a high temperature superconductor around its critical temperature. It was fabricated using optical lithography and electrodeposition of Tl1Ba2Ca2Cu3Ox (Tl-1223) type high T C superconductors. The test results of the prototype sensor fabricated show that the prototype sensor has a very high magnetoresistivity at medium to strong magnetic field strength and low magnetoresistivity at weak magnetic field. Our work suggests that in order to develop a high precision magnetic sensor for the detection of very weak magnetic fields, other HTS materials with less flux pinning effect and more weak links need to be pursued. The MEMS fabrication process developed is simple, repeatable, and applicable to microfabrication of other types of superconductor devices.
Coalition Formation with Binding Agreements

We study coalition formation in “real time”, a situation in which coalition formation is intertwined with the ongoing receipt of pay-offs. Agreements are assumed to be permanently binding: They can only be altered with the full consent of existing signatories. For characteristic function games we prove that equilibrium processes—whether or not these are history dependent—must converge to efficient absorbing states. For three-player games with externalities each player has enough veto power that a general efficiency result can be established. However, there exist four-player games in which all Markov equilibria are inefficient from every initial condition, despite the ability to write permanently binding agreements. Copyright 2007, Wiley-Blackwell.
Interplanetary Magnetic Clouds: Statistical Patterns and Radial Variations

Abstract Pioneer Venus IMF data have been used to study the correlation between the structure of magnetic clouds in the inner heliosphere and the evolution of solar magnetic fields in the course of the solar cycle. We find that the leading polarity of these magnetic clouds follows the global polarity of the sun's magnetic field. In addition if we interpret the polarity structure of the clouds in terms of twisted magnetic fields, we find that the axes of these twisted ropes must vary greatly over the course of the solar cycle. The helicity of the ropes show no obvious pattern of behavior. Case studies of flux ropes seen at both Earth and the NEAR spacecraft are used to test a new technique for determining the radial variation of flux rope speeds.
A comparison of 650 programming methods

An evaluation of an automatic programming method can be made from many points of view. Two recent articles give evaluations of two compilers for the IBM 650 based on the method of decomposition of compiler statements into machine language [1, 2]. This paper briefly describes these two compilers, appraises them for the ease with which they can be used and for the efficiency of the programs they produce. While this approach is of less theoretical interest than the evaluations presented in the referenced articles, it is of substantially more practical significance to a programmer or to an installation which is seeking to answer the following questions: Should a compiler be used? If so, which compiler? It will be noted that no universal answers are possible since such factors as relative costs and availability of machine time and programmer time, the skill and predilections of programmers, and the type of problems are of major importance. Nevertheless, the results presented below, we believe, provide the best available guide for arriving at reasonable answers.
The Expansion of the Universe and the Intensity of Cosmic Rays.

It was pointed out by Zwicky(1) that the distance which a light quantum can travel is, perhaps, limited. Its frequency v and energy hv are affected by the astronomical red shift and may be reduced to the vanishing point if the distance is sufficiently large. Experimentally the dependence of the red shift upon the travel time t – t0 follows very nearly (within the limits of error) a linear law up to t – t0 = 10^(8) years and amounts to k = -▲v/v = 0.56 X 10^(-9) per year. If it is permissible to extrapolate the linear law to larger distances, the light quantum will vanish for t – t0 = 1.8 X 10^(9) years. All the radiation received by a terrestrial observer must, in this case, be derived from a space limited by this radius and this involves serious difficulties for the explanation of the rather high intensity of cosmic rays.
Inhibition of complement by a substance isolated from human erythrocytes. I. Extraction from human erythrocyte stromata.

Abstract Extraction of human E stromata with n -butanol was used to isolate an inhibitor which was capable of interfering with complement mediated hemolysis of antibody sensitized sheep E. When the extraction process was carried out at a low ionic strength a single substance could be detected by agar gel electrophoresis. Re-extraction at a higher tonic stength caused an apparent separation of the material into two substances which were detectable by agar-gel electrophoresis. Evidence was presented which indicated the slowest migrating component was responsible for the inhibitory activity. Preparative block electrophoresis was used as means for partial purification of the inhibitory substance and preliminary physical-chemical characteristics were determined.
Modeling Cerebellar Flocculus and Paraflocculus Involvement in Complex Predictive Smooth Eye Pursuit in Monkeys

: The role of flocculus and paraflocculus neurons in the cerebellar control of predictive eye movements was examined using two modeling techniques. The first study characterized the dependence of individual Purkinje-cell firing patterns on oculomotor output, visual input, and response timing using multilinear regression techniques. Interestingly, no dependence on visual input was detected. Purkinje cell firing was explained by sensitivities to eye position and eye velocity alone. However, complex responses occurred when sensitivity vectors pointed in different directions. For example, some neurons showed a preference for circular pursuit in a particular rotation direction. Responses also tended to lead the eye during predictable pursuit and to lag during unpredictable, visually driven pursuit. This suggests that flocculus and paraflocculus neurons played a stronger role during predictive pursuit than visually driven pursuit. A second modeling study demonstrated how the flocculus/paraflocculus system might generate predictive pursuit. A biologically realistic neural network was simulated based on the known anatomy and physiology of this cerebellar system. It included mossy and climbing fibers with realistic responses, Purkinje cells acting on well-characterized brain-stem circuits, and granule, Golgi, basket, and stellate cells with appropriate connections. The network was able to learn new pursuit trajectories based on long-term alterations in synaptic connectivity at parallel-to-Purkinje synapses. Interestingly, this model was able to generate predictive pursuit without visual input based only on eye-motion input. Thus, both models provide complementary evidence for the generation of nonvisual predictive control by flocculus and paraflocculus neurons.
Optimal control of linear systems with time-varying lags

Systems whose dynamics and controls contain time-varying lags are formulated as a set of linear hyperbolic systems and a functional differential equation. Quadratic cost functionals are used in the optimal control analysis. The optimal control is given by a linear transformation on the current state, delayed state, and delayed control.
Long-time behaviour of particles diffusing in strongly disordered medium, revisited

We reexamine the heuristic Lifshitz argument for the long-time behaviour of classical diffusion in the strongly disordered regime. The deviation of the density at the origin behaves as exp{−ctψ} with ψ=d~/(2+d~), where d~ is the spectral dimension of the cluster. Typical clusters yield ψ∼2/5. We argue, however, that the long-time behaviour is dominated by more ramified clusters with d~=1, leading to a one-dimensional behaviour, ψ=1/3, in any dimension On reexamine l'argument heuristique de Lifshitz pour le comportement a longue duree de la diffusion classique dans le regime fortement desordonne. La deviation de la densite a l'origine suit un comportement en exp {−ctψ} avec ψ=d~/(2+d~), ou d~ est la dimension spectrale de l'amas. L'amas typique donne ψ∼2/5, mais on montre que le comportement asymptotique est domine par des amas plus ramifies avec d~=1. Ceci produit un comportement typiquement unidimensionnel, ψ=1/3, en toute dimension
Electron-positron P-and K-space densities in YBa2Cu3O7-δ

Abstract We have performed an ultra-high precision measurement (5 × 10 8 coincidence counts) of the basal-plane electron-positron momentum density (MD) in well oxygenated, twin-free, single crystals of YBa 2 Cu 3 O 7δ . The anisotropies of the raw and processed MD spectra and LCW-transformed spectra (k-space densities) not only show the D 2 symmetry appropriate to the untwinned crystals but, more importantly, unambiguously show a dear image of a major Fermi surface sheet. The form of the FS image is in substantial agreement with theoretical predictions of a Γ-X electron ridge section associated with states in the Cu-O chains.
Novel tissue phantom for testing a dual-modality diagnostic system: time-resolved fluorescence spectroscopy and high frequency ultrasound

A unique tissue phantom is reported here that mimics the optical and acoustical properties of biological tissue and enables testing and validation of a dual-modality clinical diagnostic system combining time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and ultrasound backscatter microscopy (UBM). The phantom consisted of contrast agents including silicon dioxide particles with a range of diameters from 0.5 to 10 μm acting as optical and acoustical scatterers, and FITC-conjugated dextran mimicking the endogenous fluorophore in tissue. The agents were encapsulated in a polymer bead attached to the end of an optical fiber with a 200 μm diameter using a UV-induced polymerization technique. A set of beads with fibers were then implanted into a gel-based matrix with controlled patterns including a design with lateral distribution and a design with successively changing depth. The configuration presented here allowed the validation of the hybrid fluorescence spectroscopic and ultrasonic system by detecting the lateral and depth distribution of the contrast agents, as well as for coregistration of the ultrasonic image with spectroscopic data. In addition, the depth of the beads in the gel matrix was changed to explore the effect of different concentration ratio of the mixture on the fluorescence signal emitted.
Multiscale modeling of the brain should be validated in more detail against the biological data

Wright & Liley provide an advance in addressing the interaction of multiple scales of processing in the brain. It should address in more detail the biological evidence that underlies the models it proposes to replace.
COMPARATIVE YIELDS OF ($gamma$,2n) AND ($gamma$,pn) PROCESSES FOR Fe$sup 54$ INDUCED BY 70-Mev BREMSSTRAHLUNG

Relative yields of ${\mathrm{Fe}}^{54}(\ensuremath{\gamma}, 2n){\mathrm{Fe}}^{52}:{\mathrm{Fe}}^{54}(\ensuremath{\gamma}, pn){\mathrm{Mn}}^{52}:{\mathrm{Fe}}^{54}(\ensuremath{\gamma}, pn){\mathrm{Mn}}^{52m}$ were found to be 1:8:19 for irradiations by 70-Mev bremsstrahlung. These yields were compared with yields of the same products by alpha-particle bombardment, and results were discussed in terms of a statistical model for the reactions.
Synthesis and Reactivity of 5-Fluorouracil/Cytarabine Mutual Prodrugs

Two mutual prodrugs, in which two different anti-cancer drugs are attached to the same molecule via labile linkages, are synthesized and examined kinetically. One of the mutual prodrugs loses a drug component under physiological conditions within an hour, but the other mutual prodrug (having a longer spacer between the two drugs) is stable to chemical degradation even at higher pH values. Thus, enzymatic hydrolysis alone will release the two anti-cancer drugs. The potential value of anti-cancer mutual prodrugs is discussed.
Transient creep and semibrittle behavior of crystalline rocks

We review transient creep and semibrittle behavior of crystalline solids. The results are expected to be pertinent to crystalline rocks undergoing deformation in the depth range 5 to 20 km, corresponding to depths of focus of many major earthquakes. Transient creep data for crystalline rocks at elevated temperatures are analyzed but are poorly understood because of lack of information on the deformation processes which, at low to moderate pressure, are likely to be semibrittle in nature. Activation energies for transient creep at high effective confining pressure are much higher than those found for atmospheric pressure tests in which thermally-activated microfracturing probably dominates the creep rate. Empirical transient creep equations are extrapolated at 200° to 600°C, stresses from 0.1 to 1.0 kbar, to times ranging from 3.17 × 102 to 3.17 × 108 years. At the higher temperatures, appreciable transient creep strains may take place but the physical significance of the results is in question because the flow mechanisms have not been determined. The purpose of this paper is to stimulate careful research on this important topic.
Response to Grazi et al.

In the accompanying letter to the editor, Dr. Grazi and his colleagues have suggested an alternative explanation for the interpretation of our recent study of the effects of immobilization on S1. They raise the possibility that the free [Mg2+] is reduced by binding to PEG, which reduces [MgATP], and that this accounts for the inhibition of MgATPase activity when S1 is aggregated by high [PEG]. While it is true that [Mg2+] binds to PEG in solution, a simple calculation demonstrates that the reduction in [MgATP] is not sufficient to account for the observed changes in S1 activity.
Peace Research: Dialectics and Development:

When scholars committed to peace and conflict research first began consciously separating themselves from the older discipline of international relations, particularly during the period of explosive development of new institutions and working groups in the late fifties and early sixties, much time was spent trying to figure out the logical basis for an essentially intuitive revolt against the "IR Establishment." Intuitions of a new way of thinking have a way of leaping out of the existing fields of one's conceptual structures, leaving the mind with the task of reorganizing cognitive maps. In the course of cognitive reorganization that followed on the initial intuitive leap, peace researchers elaborated so many different ways of mapping the peace research field that they acquired a somewhat illusory sense of working in an intellectual movement of enormous diversity in terms of conceptualizations and substantive interests. At the time of the 1969 UNESCO advisory meeting of experts on peace research, Kenneth Boulding and I took the occasion to examine this assumed diversity, in an analysis of the areas covered by peace research journals and international relations journals in the previous ten years, based on an admittedly cursory survey of titles of articles published. At that time we wrote:
Activation-dependent exposure of the inter-EGF sequence Leu83-Leu88 in factor Xa mediates ligand binding to effector cell protease receptor-1.

Abstract Binding of factor Xa to human umbilical vein endothelial cells (HUVEC) is contributed by effector cell protease receptor-1 (EPR-1). The structural requirements of this recognition were investigated. Factor Xa or catalytically inactive 5-dimethylaminonaphthalene-1sulfonyl (dansyl) Glu-Gly-Arg-(DEGR)-chloromethylketone-factor Xa bound indistinguishably to HUVEC and EPR-1 transfectants, and inhibited equally well the binding of 125I-factor Xa to these cells. Similarly, factor Xa active site inhibitors TAP or NAP5 did not reduce ligand binding to EPR-1. A factor X peptide duplicating the inter-EGF sequence Leu83-Phe84-Thr85-Arg86-Lys87-Leu88-(Gly) inhibited factor V/Va-independent prothrombin activation by HUVEC and blocked binding of 125I-factor Xa to these cells in a dose-dependent manner (IC50 ~ 20–40 μM). In contrast, none of the other factor X peptides tested or a control peptide with the inter-EGF sequence in scrambled order was effective. A recombinant chimeric molecule expressing the factor X sequence Leu83-Leu88 within a factor IX backbone inhibited binding of 125I-factor Xa to HUVEC and EPR-1 transfectants in a dose-dependent fashion, while recombinant factor IX or plasma IXa had no effect. An antibody generated against the factor X peptide 83–88, and designated JC15, inhibited 125I-factor Xa binding to HUVEC. The JC15 antibody bound to factor Xa and the recombinant IX/X83-88 chimera in a concentration dependent manner, while no specific reactivity with factors X or IXa was observed. Furthermore, binding of 125I-factor Xa to immobilized JC15 was inhibited by molar excess of unlabeled factor Xa, but not by comparable concentrations of factors X or IXa. These findings identify the inter-EGF sequence Leu83-Leu88 in factor Xa as a novel recognition site for EPR-1, and suggest its potential role as a protease activation-dependent neo-epitope. This interacting motif may help elucidate the contribution of factor Xa to cellular assembly of coagulation and vascular injury.
Effect of arrhythmogenic doses of deslanoside on the uptake of monoamines in brain tissue and in cardiac tissue

Abstract The purpose of our study was to determine whether a toxic arrhythmogenic dose of digitalis administered to an in vivo preparation would affect the neuronal uptake of norepinephrine, serotonin and dopamine in brain tissue and norepinephrine in cardiac tissue. This was investigated by intoxicating anesthetized cats with deslanoside, removing cardiac and brain tissue at the onset of ventricular fibrillation, and examining the ability of brain tissue to accumulate [ 3 H]-NE, [ 3 H]-5-HT and [ 3 H]-DA and cardiac tissue to accumulate [ 3 H]-NE. It was found that deslanoside inhibited uptake of [ 3 H]-NE into the left ventricle and [ 3 H]5-HT into the area postrema. These selective effects may reflect greater blood flow to these regions or different sensitivities of the transport mechanisms for these amines. This inihibition of uptake into both left ventricular tissue and area postrema may contribute to some of the cardiovascular and emetic effects seen with digitalis drugs.
A Computationally Efficient Aerosol Nucleation/ Condensation Method: Pseudo-Steady-State Sulfuric Acid

In order to model accurately the size and number of atmospheric particles, it is necessary to predict aerosol nucleation rates. However, the explicit prediction of the sulfuric acid vapor concentration may become computationally intensive when nucleation and condensation are simultaneously occurring. In this article, we develop and test a computationally efficient solution to the problem of solving for the sulfuric acid vapor concentration. Rather than explicitly solving the differential equation for the temporal profile of sulfuric acid vapor, we assume that the sulfuric acid vapor is at the concentration in steady state with its source (oxidation of SO2) and sinks (condensation and nucleation); this is known as the Pseudo-Steady-State Approximation (PSSA). Two versions of a box model with online size-resolved aerosol microphysics were developed to test the PSSA; (1) a “benchmark model” that solves explicitly for the sulfuric acid vapor concentration, and (2) a “PSSA model” that uses the PSSA. A wide arr...
White light-informed optical properties improve ultrasound-guided fluorescence tomography of photoactive protoporphyrin IX.

Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX concentration, including the lowest concentration used, 0.025 μg/ml . White light spectroscopy informed optical properties, which improved fluorescence reconstruction accuracy compared to the use of fixed, literature-based optical properties, reduced reconstruction error and reconstructed fluorescence standard deviation by factors of 8.9 and 2.0, respectively. Recovered contrast-to-background error was 25% and 74% for inclusion phantoms without and with a 2-mm skin-like layer, respectively. Preliminary mouse-model imaging demonstrated system feasibility for subsurface fluorescence measurement in vivo. These data suggest that this implementation of USFT is capable of regional PpIX mapping in human skin tumors during photodynamic therapy, to be used in dosimetric evaluations.
Distributed Computing Systems for Multiple-Processor Industrial Control

Summary Interest in the use of multiple processors in real-time, on-line machinery control systems has grown rapidly in recent years. The trend set is toward higher levels of performance and sophistication with low cost mass produced processors. While multiple processor systems can be structured to logically mimic a single processor, a prospect for the future has been the use of multiple interacting processors. Decentralization and distribution of control in a network of processors leads to increased reliability, fault tolerance and flexibility when compared to a single processor system of comparable performance. These benefits are obtained through the application of distributed processing concepts to control system design. This paper describes the essential characteristics of distributed processing systems and relates the attributes of alternative systems to the requirements of industrial control. Choice to be made in the design of such a system are reviewed as are alternative network architectures and methods for synchronizing events in more than one processor. An application example is also discussed.
Distinguishing between ruminative and distractive responses in dysphoric college students: does indication of past depression make a difference?

Abstract In this study, a model of affectivity as a mediator of the influence of ruminative and distractive response styles (Nolen-Hoeksema, 1991) on depressive symptoms and life satisfaction is proposed and examined among a self-reported group of never-depressed (n=78) and previously-depressed college students (n=66). As predicted, significant differences were found between the two groups on measures of negative affectivity, depressive symptoms, and life satisfaction. Results of conducting path analyses indicated important differences between the two groups in how affectivity mediated the link between response styles and psychological adjustment. For never-depressed students, positive affectivity was found to mediate the link between distraction and psychological adjustment. For previously-depressed students, the link between rumination and depressive symptoms was found to be fully mediated by negative affectivity, whereas the link between distraction and life satisfaction was found to be fully mediated by positive affectivity. The present findings are discussed in terms of response style theory.