cssi/SciSciGPT-SciSciNet huggingface dataset:
Post-modification of preformed liposomes with novel non-phospholipid poly(ethylene glycol)-conjugated hexadecylcarbamoylmethyl hexadecanoic acid for enhanced circulation persistence in vivo

We report synthesis and characterization of a novel PEG2000-conjugated hexadecylcarbamoylmethyl hexadecanoate (HDAS-PEG) as a PEG-phospholipid substitute for enhancing circulation persistence of liposomes. HDAS-PEG showed critical micelle concentration of 4.25 μM. We used post-insertion technique to introduce HDAS-PEG in outer lipid layer of the preformed liposomes. The presence of surface HDAS-PEG was confirmed by altered electrophoretic mobility, confocal microscopy and PEG estimation by ELISA. The post-inserted HDAS-PEG desorbed at approximately half the rate at which post-inserted DSPE-PEG desorbed from the liposome surface. HDAS-PEG significantly reduced liposome-induced complement activation (C4d, Bb and SC5b); HDAS-PEG was more effective than more commonly used DSPE-PEG in this capacity. For studying circulation persistence, the liposomes were labeled with (99m)Tc radionuclide and administered in rats. (99m)Tc-HDAS-PEG-liposomes showed prolonged persistence in blood as compared to that shown by (99m)Tc-plain liposomes. After 24 h of administration, <1% of (99m)Tc-plain liposomes remained in blood, whereas approximately 28% of injected (99m)Tc-HDAS-PEG-liposomes were present in blood. In comparison, only 4.8% of (99m)Tc-DSPE-PEG-liposomes were measured in blood after 24 h. As expected, the clearance route of the liposomes was through liver and spleen. These results demonstrate the potential of a novel non-phosphoryl HDAS-PEG for surface modification of preformed liposomes with a goal of prolonging their circulation persistence and more effective inhibition of complement activation.
SPIN GLASS DYNAMICS ON A HIERARCHICAL TREE

The configuration space of spin glasses is characterized by the existence of quasidegenerate equilibrium states separated by barriers, ∆(T). A temperature cycling protocol allows extraction of the temperature dependence of a specific barrier. We find ∂∆(T)/∂T depends only on the particular value of ∆(T) and not on the temperature. Using either a power law or an exponential fit (either is equally accurate), integration leads to a divergence of ∆(T) at a particular temperature T* as the temperature decreases, characteristic of the particular barrier considered. This is interpreted as a continuous divergence of barriers as the temperature is lowered, beginning at Tg. Between these divergent barriers, barriers of finite height exist. The time decay of the thermoremanent magnetization at measurement times t much greater than the waiting time tw is a measure of the correlation of the spin glass at time t with the field-cooled state. Using ultrametricity, this enables the extraction of the branching ratio of the “tree” according to which the spin glass states are organized. Experiments are interpreted in terms of a constant branching ratio for the ultrametric tree within the (small) range of overlaps accessible because of the experimental time window.
CT image-based quantification of sub-pixel diameter microparticle accumulations in tissues using á priori biological information

With the increasing use of microspheres and nanoparticles for diagnostic and therapeutic purposes, the need to quantify the spatial distribution and concentration of those particles in a minimally invasive manner, such as by imaging, is required. In the case of CT-imaging, labelling of those particles with elements that have high contrast, and when possible that is specific for that element, is an obvious approach, but this still begs the question as to what extent particles that are smaller than the detector pixel can be quantified over relatively large volumes of tissue. This study is an exploration of three approaches to quantify the spatial distribution and/or size of those microscopic particles by use of; (i) a model of the impact of high contrast opaque particle on the detected x-ray attenuation, (ii) quasi-monochromatic energy CT and (iii) the statistics of random clustering of particles resulting in clusters that are larger than detector pixels and using that information to extrapolate to sub-resolution information about individual particles. To explore the role of particle size relative to detector pixel size we recorded x-ray attenuation in detector pixels smaller than the particle and then retrospectively increased the effective detector pixel size by summing the x-ray signal in contiguous pixels around the particle location.
Calcium and phosphorus requirements in bone mineralization of preterm infants.

We studied postnatal bone mineralization, as measured by photon absorptiometry, in 36 preterm infants (birth weight
What cooks with solar neutrinos

Two desperate explanations of the solar neutrino puzzle are proposed, one involving experimental nuclear physics and the other theoretical solar structure and evolution.
Analysis of photoacoustic waveforms using the Method of Moments

In many ways, the analysis of waveforms from pulsed-laser photoacoustics is analogous to the analysis of timeresolved fluorescence data obtained from single-photon counting techniques. We have shown previously that the Method of Moments can be used to analyze photoacoustic data (E.W. Small et al., Fluorescence Detection III, E.R. Menzel, ed., SPIE Proceedings 1054, pp. 36-53, 1989). Difficulties arose in attempts to analyze the magnitude of very fast decays, those with lifetimes less than the digitization channel width. While these decays may often be regarded as an error such as scatter in the case of fluorescence, they represent important fast relaxation processes in the case of photoacoustics, and their magnitude must be accurately determined. We present here three approaches to making the Method of Moments more applicable to photoacoustic waveform analysis. One approach involves using the method required for measuring a scatter component in a fluorescence decay. Other approaches include using a Cheng-Eisenfeld filter to fix a lifetime in order to recover its amplitude, and analyzing for MDO (moment index displacement 0), which is intrinsically sensitive to short lifetimes. The relative merits of the techniques are evaluated, and a successful approach to analyzing noisy synthetic data of up to three components is demonstrated. Preliminary studies on the performance of the Method of Moments in handling nonrandom errors in photoacoustic data are also shown.
Molecular structures of [CpRu(PPh3)(dtoxa-H2O)]BF4 and {[CpRu(PPh3)2]2(μ-dtoxa)}(BF4)2, dtoxa=dithiooxamide

The reaction of [CpRu(PPh3)2(n-C3H7SH)]BF4 with dithiooxamide (dtoxa) gave two products: {[CpRu(PPh3)2]2(μ-dtoxa)} (BF4)2,1, and [CpRu(PPh3)(dtoxa-H2O)]BF4,2. The structures of both complexes were determined by X-ray diffraction techniques. Compound1 crystallized in the triclinic space groupP¯1,a=12.822(4),b=14.16(1),c=23.631(8) A,α=84.57(4),β=83.64(3), γ=83.57(4)°,Z=2,R=0.069,Rw=0.084. The structure of1 shows two CpRu(PPh3)2+ units bridged through the S atoms of the dtoxa ligand. Ru-S distances are 2.377(6)A for Ru1-S1 and 2.368(6) A for Ru2-S2. Compound2 crystallized in the monoclinic space groupP21/c,a=13.446(3),b=13.461(7),c=31.214(7) A,β=100.78(3)°,Z=8,R=0.054,Rw=0.055. The structure of2 has two molecules in the asymmetric unit. The Ru is chelated to the dtoxa through the S atoms: Ru1-S1, 2.307(4); Ru1-S2, 2.300(4); Ru2-S3, 2.295(4); Ru2-S4, 2.287(4) A. The coordination sphere of the Ru in2 is completed by a cyclopentadienyl ligand and a triphenylphosphine.
Influence of iron efficiency in soybeans on concentration of many trace elements in plant parts and implications on iron‐efficiency mechanisms

Abstract Hawkeye and PI‐54619–5–1 (also known as T‐203) soybeans (Glycine max [L] Merr. Bragg) are iron‐efficient and iron‐inefficient representatives, respectively, of the species. The iron‐efficient characteristics seem to involve both proton expulsion and production of reductants. Increased uptake of iron by Hawkeye plants compared with the PI‐54619–5–1 plants is not the only result of the efficiency. The Hawkeye usually has slightly lower yields than PI‐54619–5–1 when iron deficiency is not involved. The Hawkeye has larger amounts of zinc, copper, manganese, nickel, cobalt, and lead, whether grown in soil or solution, although occasionally there is an exception. When grown in soil, the Hawkeye usually has more aluminum than the PI‐54619–5–1; silicon is more nearly equal in each. Heavy metal toxicity seems to inactiviate part of the iron‐efficiency mechanisms, but not all of them; because even though the heavy metals decrease plant uptake of iron and zinc and sometimes other trace elements, the ability...
Correlation of enzymatic activities and aggregation state in chicken liver fatty acid synthase.

Abstract The relationships between the aggregation state and the enzymatic activities of chicken liver fatty acid synthase have been explored by monitoring the changes in light scattering, fluorescence, and the overall, β-ketoacyl synthase, β-ketoacyl reductase and enoyl reductase activities during dissociation and reassociation of the enzyme. The data obtained indicate that the enzyme dissociates at low temperature in both 0.1 M potassium phosphate (pH 7.0), 1 mM EDTA, and 5 mM Tris(hydroxymethyl)aminomethane, 35 mM glycine (pH 8.3) and 1 mM EDTA, but the extent of dissociation is less in the phosphate buffer. The assay conditions influence the assessment of the degree of dissociation and association: high temperatures, phosphate (high salt), NADPH and acetoacetyl-coenzyme A promote association of the monomeric enzyme, whereas dilution in the Tris-glycine buffer (low salt) and low temperature promote dissociation. Both the rate and extent of association and dissociation are altered by substrates. The monomeric enzyme does not possess β-ketoacyl synthase and β-ketoacyl reductase activities. Results obtained with the 1,3-dibromo-2-propanone cross-linked enzyme, which lacks β-ketoacyl synthase activity, indicate that the NADPH-binding site of β-ketoacyl reductase is disrupted at low ionic strength. In contrast, changes in ionic strength have little effect on the enoyl reductase activity. The dimer is stabilized by both electrostatic and hydrophobic interactions, with the former being of special importance for maintenance of the β-ketoacyl reductase active site.
Two families of TARP isoforms that have distinct effects on the kinetic properties of AMPA receptors and synaptic currents.

Summary Transmembrane AMPA receptor regulatory proteins (TARPs) are auxiliary AMPA receptor subunits that regulate both the trafficking and gating properties of AMPA receptors, and different TARP isoforms display distinct expression patterns in brain. Here, we compared the effects of four TARP isoforms on the kinetics of AMPA receptor currents. Each isoform slowed the deactivation of GluR1 currents, but the slowing was greatest with γ-4 and γ-8. Isoform-specific differences in desensitization were also observed that correlated with effects on deactivation. TARP isoforms also differentially modulated responses to trains of glutamate applications designed to mimic high-frequency presynaptic firing. Importantly, whereas both stargazin and γ-4 rescued excitatory synaptic transmission in cerebellar granule cells from stargazer mice, the decay of miniature EPSCs was 2-fold slower in neurons expressing γ-4. The results show that heterogeneity in the composition of AMPA receptor/TARP complexes contributes to synapse-specific differences in EPSC decays and frequency-dependent modulation of neurotransmission.
Enhancing Practice Models by Recruiting Pharmacists with Specialty Training

The Director's Forum series is designed to guide pharmacy leaders in establishing patient-centered services in hospitals and health systems. Evaluation of pharmacy practice models across the countr...
Catalysis of superoxide dismutation by manganese aminopolycarboxylate complexes.

Abstract Complexes of manganese, copper, cobalt, and iron with a variety of aminopolycar-boxylates at concentrations from 2 × 107 to 3 × 10−6 m were tested for superoxide dismutase activity with horse ferricytochrome c as the competing reagent for superoxide. In the presence of excess ligand only manganous nitrilotriacetate and manganous ethylenediaminediacetate showed activity with catalytic rate constants of 2.2 × 107 and 1.8 × 107 m −1 s −1, respectively, at pH 6, 22 ± 1 °C, and 10 m m ionic strength. These rate constants decrease considerably at higher pH. Manganous N-hydroxyethylethylenediaminetriacetate is oxidized by superoxide, but does not appear to have catalytic activity. From the experimental conditions under which the two complexes mentioned above exhibit catalysis, and the inactivity of other metal chelates, it is concluded that an open coordination site is essential but not sufficient to catalyze the dismutation reaction.
Nutrient distribution in an 8-year-oldPinus virginiana (Mill.) stand

Half-sib progeny from ten selected Virginia pine trees were grown on two randomized blocks and harvested at age eight. The trees were divided into four components: foliage, branches, bolewood, and bolebark. The concentration of N, P, K, and Ca was determined for each component of each tree. The results were combined with dry matter distribution data to find the total content of each nutrient for each tree.
Anomalous linewidths and peak-height ratios in137Ba hyperfine lines

We have investigated several effects of optical pumping in the hyperfine spectrum of the6s6p1P1⇔6s21S0 transition in137Ba. Most of these effects are explained by absorption strength changes which occur because of redistribution of population among magnetic substates. At very low laser intensities, no redistribution effects are observed. At higher intensities, it is possible to either empty the magnetic substates that are accessible to optical excitation, or to redistribute the population among these states until a steady-state condition is achieved. The first case results in the familiar disappearance of a hyperfine line. The less familiar second case can result in peak-height ratios in the Ba1P1⇔1S0 hyperfine spectrum that differ by almost a factor of three from the low-intensity case. In this second case, the observed linewidth can either broaden or narrow, depending on whether redistribution decreases or increases absorption strength. At high intensities, saturation effects dominate and branching to intermediateD states becomes apparent. We report here the result of a numerically integrated rate equation model which shows good agreement with our experiments.
Completely unimodal numberings of a simple polytope

Abstract A completely unimodal numbering of the m vertices of a simple d-dimensional polytope is a numbering 0, 1, …,m−1 of the vertices such that on every k-dimensional face (2≤k≤d) there is exactly one local minimum (a vertex with no lower-numbered neighbors on that face). Such numberings are abstract objective functions in the sense of Adler and Saigal [1]. It is shown that a completely unimodal numbering of the vertices of a simple polytope induces a shelling of the facets of the dual simplicial polytope. The h-vector of the dual simplicial polytope is interpreted in terms of the numbering (with respect to using a local-improvement algorithm to locate the vertex numbered 0). In the case that the polytope is combinatorially equivalent to a d-dimensional cube, a ‘successor-tuple’ for each vertex is defined which carries the crucial information of the numbering for local-improvement algorithms. Combinatorial properties of these d-tuples are studied. Finally the running time of one particular local-improvement algorithm, the Random Algorithm, is studied for completely unimodal numberings of the d-cube. It is shown that for a certain class of numberings (which includes the example of Klee and Minty [8] showing that the simplex algorithm is not polynomial and all Hamiltonian saddle-free injective pseudo-Boolean functions [6]) this algorithm has expected running time that is at worst quadratic in the dimension d.
Enhanced expression of the Flt-1 and Flk-1 receptor tyrosine kinases in a newborn piglet model of ischemic tolerance

Vascular endothelial growth factor (VEGF), an angiogenic factor induced by hypoxia, also exerts direct effects on neural tissues. VEGF up-regulation after hypoxia coincides with expression of its two tyrosine kinase receptors Flt-1(VEGFR-1) and Flk-1 (KDR/VEGFR-2), which are the key mediators of physiological angiogenesis. We have recently shown that hypoxic-preconditioning (PC) leading to tolerance to hypoxia-ischemia in neonatal piglet brain resulted in increased expression of VEGF. In this study, we used a hypoxic-preconditioning model of ischemic tolerance to analyze the expression and cellular distribution of VEGF receptors and phosphorylation of cAMP-response element-binding protein (CREB) in newborn piglet brain. The response of Flt-1 and Flk-1 mRNA to PC alone was biphasic with peaks early (6 h) and late (1 week) after PC. The mRNA expression of Flt-1 and Flk-1 in piglets preconditioned 24 h prior to hypoxia-ischemia was significantly higher than non-preconditioned piglets and remained up-regulated up to 7 days. Furthermore, PC prior to hypoxia-ischemia significantly increased the protein levels of Flt-1 and Flk-1 compared with hypoxia-ischemia in a time-dependent manner. Double-immunolabeling indicated that both Flt-1 and Flk-1 are expressed in neurons and endothelial cells with a similar time course of expression following PC and that PC leads to the growth of new vessels. Finally, our data demonstrate that PC significantly phosphorylated and activated cAMP-response element-binding protein in nucleus. These results suggest that mechanism(s) initiated by PC can induce VEGF receptor up-regulation in newborn brain and that VEGF-VEGF receptor-coupled signal transduction pathways could contribute to the establishment of tolerance following hypoxia-ischemia.
Mass spectrometry in structural and stereo‐chemical problems—CCXXIV: Fragmentation of cyclopropanes

Generalizations for interpreting the mass spectra of cyclopropanes are enumerated and are based on the examination of many deuterium labeled substrates. Most cyclopropyl fragmentations can be visualized as resulting from ionization of the most substituted cyclopropyl bond in which the positive charge is localized on the most substituted carbon atom. Subsequent hydrogen shifts and/or simple scissions produce an array of predictable fragment ions.
Domestic violence and primary care. Attitudes, practices, and beliefs

Objective To assess the attitudes and beliefs of the primary care provider team (physicians, physician assistants, nurses, and medical assistants) toward the identification and management of abused patients and perpetrators of domestic violence (DV). Design Survey of the health care team using a confidential questionnaire. Setting and subjects Five primary care clinics with 240 providers at a large urban health maintenance organization. Results The response rate was 86% (206 respondents). Fifty percent of clinicians and 70% of nurses/assistants believed that the prevalence of DV in their practice was 1% or loss; 1 in 10 clinicians and nearly half of nurses/assistants had never identified an abused person; 45% of clinicians never or seldom asked about DV when examining injured patients; and all participants were much less confident in asking about DV than about smoking or consuming alcohol. Twenty-five percent believed the abused person's personality led to the violence; 28% believed they did not have strategies to help abused persons; and 20% were concerned for their personal safety in discussing DV. Only 10% believed they had management information, but 77% had not attended any educational programs on DV in the past year. Conclusions This study provides important information about current knowledge, attitudes, and beliefs of health care providers toward the diagnosis and management of DV. This information should prove useful to all who attempt to design clinical strategies and educational programs to address this issue.
Making Sense of Issues Through Media Frames: Understanding the Kosovo Crisis

How do people make sense of politics? Integrating empirical results in communication studies on framing with models of comprehension in cognitive psychology, we argue that people understand complicated event sequences by organizing information in a manner that conforms to the structure of a good story. To test this claim, we carried out a pair of experiments. In each, we presented people with news reports on the 1999 Kosovo crisis that were framed in story form, either to promote or prevent U.S. intervention. Consistent with expectations, we found that framing news about the crisis as a story affected what people remembered, how they structured what they remembered, and the opinions they expressed on the actions government should take.
Clawtoe Deformity Following Vascularized Fibula Graft

The free vascularized fibula graft has been an increasingly useful tool in orthopaedic surgery. In addition to its many applications, the reported low donor site morbidity has helped make this a popular treatment modality. Isolated flexor hallucis longus flexion contracture has been reported in the literature; however, multiple ipsilateral clawtoe deformity has not been reported. We describe two cases of multiple clawtoe deformity following ipsilateral harvest of a free vascularized fibula graft.
Computational holographic image reconstruction

Computational methods for image plane reconstruction form a hologram are developed. The methods are based on use of Fast Fourier Transform which greatly aids the computation speed. Even more computing speed is afforded by a special-purpose digital signal processor programmed for this application. The goal is to greatly speed up the process of quantitative image reconstruction as compared to 3D scanning of optically reconstructed images. Examples of in-line holographically recorded images of marine micro-organisms are shown and computed images from computationally synthesized particle field hologram are provided since this is of interest for 3D particle image velocimetry. A fast computational method of counting the number of small objects recorded on a hologram is developed and used. A measure of the depth of field is given which shows that for very fine depth resolution, off- axis holograms are recommended. However, these require more pixels and image memory so they are limited to smaller areas than in-line holograms.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The effects of rhBMP-2 released from biodegradable polyurethane/microsphere composite scaffolds on new bone formation in rat femora

Scaffolds prepared from biodegradable polyurethanes (PUR) have been investigated as a supportive matrix and delivery system for skin, cardiovascular, and bone tissue engineering. While previous studies have suggested that PUR scaffolds are biocompatible and moderately osteoconductive, the effects of encapsulated osteoinductive molecules, such as recombinant human bone morphogenetic protein (rhBMP-2), on new bone formation have not been investigated for this class of biomaterials. The objective of this study was to investigate the effects of different rhBMP-2 release strategies on new bone formation in PUR scaffolds implanted in rat femoral plug defects. In the simplest approach, rhBMP-2 was added as a dry powder prior to the foaming reaction, which resulted in a burst release of 35% followed by a sustained release for 21 days. Encapsulation of rhBMP-2 in either 1.3-micron or 114-micron PLGA microspheres prior to the foaming reaction reduced the burst release. At 4 weeks post-implantation, all rhBMP-2 treatment groups enhanced new bone formation relative to the scaffolds without rhBMP-2. Scaffolds incorporating rhBMP-2 powder promoted the most extensive new bone formation, while scaffolds incorporating rhBMP-2 encapsulated in 1.3-micron microspheres, which exhibited the lowest burst release, promoted the least extensive new bone formation. Thus our observations suggest that an initial burst release followed by sustained release is better for promoting new bone formation.
The universe between z = 10 and and z = 1000 - Spectral constraints on reheating

The possible thermal histories of the universe during the epoch z = 10-1000 are studied. Expressions for the fractional ionization and electron temperature are given in the case of homogeneous heating as a function of the parameters of arbitrary ionizing sources. It is shown that present and future limits on spectral distortions to the microwave background radiation do not provide very restrictive constraints on possible thermal histories of the universe. If H(0) = 50 km/s Mpc, the universe could have been completely ionized throughout its history with no observable spectral effects even if Omega = 1 and the universe is entirely made of baryons. Heating by cosmic rays and very massive stars is briefly discussed.
Probability-based load combinations for design of Category I structures — Overview of research program and recent results

Abstract This paper discusses the probability-based load combinations for the program dealing with the design of Category I structures, currently being worked on at Brookhaven National Laboratory (BNL) for the Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission (NRC). The objective of this program is to develop a probabilistic approach for the safety evaluations of reactor containments and other seismic Category I structures subjected to multiple static and dynamic loadings. Furthermore, on the basis of the developed probabilistic approach, a load combination methodology for the design of seismic Category I structures will also be established. The major tasks of this program are: (1) establish probabilistic representations for various loads and structural resistance, (2) select appropriate structural analysis methods and identify limit states of structures, (3) develop a reliability analysis method applicable to nuclear structures, (4) apply the developed methodology to existing Category I structures in order to evaluate the reliability levels implied in the current design criteria, and (5) recommend load combination design criteria for Category I structures. When the program is completed, it will be possible to (1) provide a method that can evaluate the safety margins of existing containment and other Category I structures and (2) recommend probability-based load combinations and load factors for the design of Category I structures. At the present time, a reliability analysis method for seismic Category I concrete structures has been completed. By utilizing this method, it is possible to evaluate the safety of structures under various static and dynamic loads. In this paper, results of a reliability analysis of a realistic reinforced concrete containment structure under dead load, accidental pressure, and earthquake ground acceleration are presented to demonstrate the feasibility of the methodology.
Participating in Communities of Practice

Hospital librarians understand they need to move outside the four walls of the physical library and provide information support for clinicians in various settings. Librarians round with patient care teams as clinical librarians. They sit on quality improvement and patient safety committees in order to provide information to those groups. Many are members of their organization's Institutional Review Board. Some of these activities are done for a specific purpose and are short-lived. Other activities become institutionalized as the value of the librarian's contribution is recognized. This article will describe examples in which hospital librarians are part of multidisciplinary teams created to improve patient care in their hospital.
Dynamics of drop coalescence at fluid interfaces

Drop coalescence was studied using numerical simulations. Liquid drops were made to coalesce with a body of the same liquid, either a reservoir or a drop of different size, each with negligible impact velocity. We considered either gas or liquid as a surrounding fluid, and experimental results are discussed for the gas–liquid set-up. Under certain conditions, a drop will not fully coalesce with the liquid reservoir, leaving behind a daughter drop. Partial coalescence is observed for systems of low viscosity, characterized by a small Ohnesorge number, where capillary waves remain sufficiently vigourous to distort the drop significantly. For drops coalescing with a flat interface, we determine the critical Ohnesorge number as a function of Bond number, as well as density and viscosity ratios of the fluids. Studying the coalescence of two drops of different sizes reveals that partial coalescence may occur in low-viscosity systems provided the size ratio of the drops exceeds a certain threshold. We also determine the extent to which the process of partial coalescence is self-similar and find that the viscosity of the drop has a large effect on the droplet's vertical velocity after pinch off. Finally, we report on the formation of satellite droplets generated after a first pinch off and on the ejection of a jet of tiny droplets during coalescence of a parent drop significantly deformed by gravity.
Crystallization and Polymorphism of Conformationally Flexible Molecules: Problems, Patterns, and Strategies

Two effects of conformational flexibility on crystallization, namely conformational polymorphism and reduction of crystallization tendency, are discussed using examples from the literature and our own studies. The preferred molecular conformations observed in several polymorphic systems are correlated with the nature of the forces present in the crystals. The reduction of crystallization tendency for conformationally flexible molecules arises from the presence of multiple conformers in the crystallizing media and the need for certain molecules to crystallize in high-energy conformations. Despite their peculiarities, the control of crystallization of conformationally flexible molecules should begin with traditional approaches applicable to most crystallization situations. However, special techniques, including conformational mimicry, solvent-mediated self-assembly, and templated growth, have been devised to introduce molecular-level control to the crystallization process.
Improved GLC Determination of Plasma Nitroglycerin Concentrations

A specific and quantitative assay for determining nanogram levels of nitroglycerin in plasma was developed. The method involves stabilization of the drug in plasma with silver nitrate, followed by multiple extraction using purified hexane. Isosorbide dinitrate is added as the internal standard. The hexane extract is subsequently concentrated and injected into a glass column packed with 3% SP-2401 on 100--120-mesh Supelcoport at 140 degrees. A 63Ni-electron-capture detector gives a linear response over the range of 0.1--50 ng of nitroglycerin/ml of rat plasma. From spiked samples, the procedure gave a recovery of about 90%. There was little or no interference from the isomeric glyceryl dinitrates and endogenous compounds in rat or human plasma.
WICK CULTURE OF SEEDLINGS WITH DIFFERENT RATES OF WATER FLOW

THE APPARATIUS described in this paper is a modification of an arrangement previously described (Raines, 1935). Its main essentials are shown in the accompanying diagram (fig. 1). The supply reservoir (c) is an obDlong iron pan coated with white vitreous enamel, provided with a projecting lip (d) along one side and with an overflow outlet (g). This pan is 62 cm. long, 30 cm. wide at the bottom, and 8 cm. deep. It forms the top of a chamber whose ends, back, and bottom are of sheet metal. Th-e bottom is provided with a waste outlet (e). Culture solution is primarily supplied by a drip from a supply tube (f), which maintains a constant level in the reservoir. The chamber front (about 85 cm. high and 65 cm. wide), which slants at an angle of about 15 degrees from the vertical, somewhat like that of Sachs's classical root box (Sachs, 1874), consists of a
Direct measurement of prepulse suppression by use of a plasma shutter

A direct measurement is presented that quantifies prepulse reduction in an intense, ultrashort pulse on reflection from a high-density plasma created from a SiO(2) target at Brewster's angle. The contrast between the intense ultrashort pulse and prepulse energy was improved by a factor of >625. Pulse-width reduction, spectral broadening, and spatial filtering are also observed in the reflected pulse.
EVALUATING PUBLIC EXPENDITURE MANAGEMENT SYSTEMS An Experimental Methodology with an Application to the Australia and New Zealand Reforms

This article examines how institutional arrangements affect the size, allocation, and use of public expenditures. It identifies a set of arrangements that can address underlying problems and affect three levels of expenditure outcomes - aggregate fiscal discipline, strategic prioritization, and technical efficiency in the use of resources. A diagnostic questionnaire is constructed which produces index values for each arrangement. This methodology is used to analyze the radical reforms introduced by New Zealand and Australia. The results show that New Zealand sought to achieve aggregate fiscal discipline and enhance technical efficiency through formal mechanisms for transparency and accountability. The Australian reforms sought to improve strategic prioritization through transparency of the medium-term costs of competing policies, and the devolution of detailed program decisions to line ministries within hard budgets.
Investigating data quality problems in the PSP

The Personal Software Process (PSP) is used by software engineers to gather and analyze data about their work. Published studies typically use data collected using the PSP to draw quantitative conclusions about its impact upon programmer behavior and product quality. However, our experience using PSP in both industrial and academic settings revealed problems both in collection of data and its later analysis. We hypothesized that these two kinds of data quality problems could make a significant impact upon the value of PSP measures. To test this hypothesis, we built a tool to automate the PSP and then examined 89 projects completed by ten subjects using the PSP manually in an educational setting. We discovered 1539 primary errors and categorized them by type, subtype, severity, and age. To examine the collection problem we looked at the 90 errors that represented impossible combinations of data and at other less concrete anomalies in Time Recording Logs and Defect Recording Logs. To examine the analysis problem we developed a rule set, corrected the errors as far as possible, and compared the original and corrected data. This resulted in significant differences for measures such as yield and the cost-performance ratio, confirming our hypothesis. Our results raise questions about the accuracy of manually collected and analyzed PSP data, indicate that integrated tool support may be required for high quality PSP data analysis, and suggest that external measures should be used when attempting to evaluate the impact of the PSP upon programmer behavior and product quality.
Criticality Analysis of Water Distribution Pipelines

An approach to evaluate the relative criticality of different pipes in a water distribution system is presented. To quantify the relative criticality of pipelines, a term, relative criticality index (RCI), has been defined and measured. RCI was developed by summing up the effects of reliability, cost of break repairs, and energy required to repair breaks in pipelines. These three components have been quantified and added appropriately to obtain an overall criticality index of pipelines in water distribution systems. The model is demonstrated by using a 9.4-square-mile area of a water distribution system comprising downtown Phoenix, Arizona. The overall system availability of the selected land use is found to be 46.6%, and the relative criticality index clearly indicates that galvanized steel pipes followed by regular steel and ductile iron pipes in the system are most critical (i.e., vulnerable). The analysis also presents predicted future costs and energy requirements to repair breaks in the water distri...
The Shape of Neural Dependence

The product-moment correlation coefficient is often viewed as a natural measure of dependence. However, this equivalence applies only in the context of elliptical distributions, most commonly the multivariate gaussian, where linear correlation indeed sufficiently describes the underlying dependence structure. Should the true probability distributions deviate from those with elliptical contours, linear correlation may convey misleading information on the actual underlying dependencies. It is often the case that probability distributions other than the gaussian distribution are necessary to properly capture the stochastic nature of single neurons, which as a consequence greatly complicates the construction of a flexible model of covariance. We show how arbitrary probability densities can be coupled to allow greater flexibility in the construction of multivariate neural population models.
Robust Vehicle Detection for Tracking in Highway Surveillance Videos Using Unsupervised Learning

This paper presents a novel approach to vehicle detection in highway surveillance videos. This method incorporates well-studied computer vision and machine learning techniques to form an unsupervised system, where vehicles are automatically “learned” from video sequences. First an enhanced adaptive background mixture model is used to identify positive and negative examples. Then a classifier is trained with these examples. In the detection phase, both background subtraction and the classifier are used to achieve very accurate results while not compromising efficiency. We tested our method with very low-, medium- and high-quality, crowded and very crowded surveillance videos and got detection accuracies ranging between 90% to 96%.
United States Antitrust Aspects of East-West Countertrade

In the typical East-West countertrade agreement, a U.S. firm agrees to export a product from the United States to a foreign country and to import a product made in that foreign country into the United States. Since such a transaction has a substantial foreseeable effect on U.S. foreign commerce. it is subject to U.S. antitrust laws under which federal courts and antitrust authorities have prescriptive jurisdiction [1]. U.S. Courts also have. at a minimum. personal jurisdiction over the American firm [2]. Regardless of the court's ability to exercise personal jurisdiction over the foreign firm, the foreign firm's conduct is subject to antitrust scrutiny, and the court may cancel the contracts in question without the foreign firm's presence as a party to the suit [3]. In recent years, the Justice Department has taken the position that the U.S. antitrust laws should not be enforced to protect foreign persons in foreign markets [4] and should not be applied to activities by U.S. firms outside the United States which have no direct or intended effect on U.S. consumers or export opportunities [5]. Under this view, if the only persons injured by countertrade activity are non-Americans outside the United States, the U.S. antitrust laws should not be applied. Until recently, this position expressed enforcement policy rather than the law. Indeed, the Supreme Court has held that foreign persons, including foreign governments, have standing to sue for violations of the U.S. antitrust laws [6]. On October 8, 1982. however, President Reagan signed Title IV of the Export Trading Company Act of 1982 [7]. This statute amends the Sherman and Federal Trade Commission Acts to apply only to activities that have a "direct, substantial, and reasonably foreseeable effect" on U.S. import commerce or on the export commerce of a
Three-pulse scattering for femtosecond dephasing studies: theory and experiment

A novel transient three-pulse scattering technique for measuring ultrafast dephasing times in condensed matter is analyzed using a perturbative solution of the density matrix equation. The advantages of this technique include subpulsewidth resolution, a clear distinction between homogeneous and inhomogeneous broadening, and sensitivity to spectral cross-relaxation. Its application to the case of a multilevel resonance is also considered. We report results of femtosecond dephasing experiments with dye molecules in liquids and in a polymer host. The dephasing time is determined to be less than 20 fsec for dyes in solution at room temperature. At low temperatures in polymers, a transition from homogeneous to inhomogeneous broadening has been observed and studied as a function of temperature.
Estimation of an Exponential Distribution

Consider a sample from an exponential distribution with unknown parameter θ From the sample, we wish to estimate the entire distribution, (Borel sets). If an estimator is used for , we are concerned with proximity of to , under total variation distance, the maximum likelihood estimate of θ, define , where , the 1 – (a/2) percentile from the standard normal. Then, . The preceding approximation to the 1 — α percentile of is very accurate even for small n We also consider the problem of obtaining a confidence band for the survival function, possessing minimal maximum width. Finally, a class of estimators of is compared to the maximum likelihood estimator from the viewpoint of total variation distance loss function.
Effects of Continuous Positive Airway Pressure Versus Supplemental Oxygen on 24-Hour Ambulatory Blood Pressure

Obstructive sleep apnea (OSA) is associated with recurrent episodes of nocturnal hypoxia and increased risk for development of systemic hypertension. Prior studies have been limited, however, in their ability to show reduction in blood pressure after continuous positive airway pressure (CPAP) therapy, and the effect of supplemental oxygen alone on blood pressure in OSA has not been evaluated. We performed a randomized, double-blind, placebo-controlled study comparing the effects of 2 weeks of CPAP versus sham-CPAP versus supplemental nocturnal oxygen on 24-hour ambulatory blood pressure in 46 patients with moderate-severe OSA. We found that 2 weeks of CPAP therapy resulted in a significant reduction in daytime mean arterial and diastolic blood pressure and nighttime systolic, mean, and diastolic blood pressure (all Ps <0.05). Although nocturnal supplemental oxygen therapy improved oxyhemoglobin saturation, it did not affect blood pressure. We conclude that CPAP therapy reduces both daytime and nighttime blood pressure in patients with OSA, perhaps through mechanisms other than improvement of nocturnal oxyhemoglobin saturation.
A Relational Approach to Religion and Spirituality in Marriage: The Role of Couples’ Religious Communication in Marital Satisfaction

Using a relational model of religion and spirituality in marriage, the role of individual relationship with God, couple’s joint religious communication, and forgiveness were examined as predictors of marital satisfaction. Data from 342 heterosexual married couples were analyzed using an actor partner interdependence model and path analyses. Results indicate that one’s individual relationship with God is important to marital quality indirectly as it appears to manifest itself in religious communication between partners, which in turn is directly linked to martial quality. Also, one’s own forgiveness and forgiveness of the spouse are both positively linked to marital quality, whereas one’s tendency not to forgive and one’s spouse’s tendency not to forgive are both detrimental to marital quality. Finally, joint religious communication is more strongly associated with marital satisfaction among mixed-faith couples than same-faith couples.
Three dimensional subband video analysis and synthesis with adaptive clustering in high frequency subbands

This paper presents a hybrid analysis and synthesis scheme for video coding aimed at developing a video communication system that can consistently transmit high quality video signals with high compression ratios. The scheme is based on a 3D subband decomposition of video signal. To best take advantage of the characteristics of high frequency subbands, an adaptive clustering algorithm with Gibbs random field model is applied to the high frequency subbands to achieve an adaptive quantization with spatial constraints. The adaptive quantization reduces significantly the activity of high frequency bands and makes the entire scheme amenable to efficient video coding. The resultant reconstruction noise can be suppressed using again a Gibbs random field based algorithm. Preliminary results have shown the potential of this methods over existing methods. >
Error floors in LDPC codes: Fast simulation, bounds and hardware emulation

The error-correcting performance of low-density parity check (LDPC) codes, when decoded using practical iterative decoding algorithms, is known to be very close to Shannon limits in the asymptotic limit of large blocklengths. A substantial limitation to the use of finite-length LDPC codes is the presence of an error floor in the low frame error rate (FER) region. This paper develops two methods, a stochastic one based on importance sampling and a deterministic one based on high SNR asymptotics, as applied to suitably defined absorbing structures within the LDPC code, to predict error floors. Our results are in very close agreement with hardware-based experimental results, and moreover extend the prediction of the error probability to as low as 10-30. Our deterministic estimates are guaranteed to be a lower bound to the error probability in the high SNR regime.
A Method for Fast Radio Frequency Direction Finding Using Wireless Sensor Networks

We present the design of a remotely deployable distributed wireless antenna system formed from wireless sensor network nodes. Specifically, the focus is on enhancing the detection range of a distributed wireless antenna system. The primary objective is to create a methodology to steer the beam in the desired direction to enhance radio frequency (RF) direction finding and follow-on signal reception. The distributed wireless antenna system uses a combination of time difference of arrival (TDOA) and adaptive beamforming to localize the target and enhance the reception in the target direction. The TDOA lines-of-bearing are calculated using a combination of the Cross- Ambiguity Function to calculate the actual time difference and the Newton-Raphson technique to focus the beamforming efforts. A Least Mean Squares (LMS) adaptive beamforming algorithm is then used to localize the target for further prosecution.
Ectromelia in Morelet's crocodile from Belize.

Two Morelet's crocodiles (Crocodylus moreletii) captured on 21 March 1997 and 20 April 1998 in the New River system, Belize exhibited ectromelia of one forelimb. External and radiograph examination appears to indicate limb agenesis of unknown etiology, as there is no apparent scarring or skeletal trauma. These two individuals represent the only cases of missing limbs from 642 individuals captured in this study and to our knowledge, the first reported cases in Morelet's crocodile. Several factors including age and diet of the reproducing female, extremes in nest conditions (egg incubation temperature and humidity), and exposure to environmental contaminants can cause developmental abnormalities in crocodilians and may have contributed to the condition observed in these animals. Survival rates for hatchling crocodilians are generally low, and embryonic malformations such as ectromelia may constitute an added disadvantage to survival. However, both individuals examined in this study were vigorous and appeare...