cssi/SciSciGPT-SciSciNet huggingface dataset:
A note on sequence-dependence of DNA structure.

A circular dichroism study was conducted on the solution structure of several different oligonucleotides, whose X-ray structures have been solved. It is suggested that in aqueous solution the oligonucleotides can form structures that maintain geometrical elements which are typical of B-DNA, A-DNA, and their intermediate forms. It is shown that 5′GGATGGGAG: 5′CTCCCATCC, which forms an A-DNA helix in the crystal state (McCall et al. 1986), in aqueous solution maintains an A-DNA like structure at temperatures below 10°C. At temperatures between 10°C and 25°C it shows a tendency to form an intermediate structure between A-DNA and B-DNA. Also, it is shown that TFE does not cause a transition from B-DNA to A-DNA helix in short DNA fragments, but instead disrupts the helix.
William James, ‘The World Of Sense’ and Trust in Testimony

: William James argued that we ordinarily think of the objects that we can observe—things that belong to ‘the world of sense’—as having an unquestioned reality. However, young children also assert the existence of entities that they cannot ordinarily observe. For example, they assert the existence of germs and souls. The belief in the existence of such unobservable entities is likely to be based on children’s broader trust in other people’s testimony about objects and situations that they cannot directly observe for themselves.
Rural Food Deserts: Low-Income Perspectives on Food Access in Minnesota and Iowa.

Abstract Objective To investigate how low-income rural residents living in food deserts access the normal food system and food safety net services within their communities, and explore how social, personal, and environment drives food access and food choice. Design Seven focus groups (90 minutes each) were conducted with 2 moderators present and were audiotaped. Setting Food deserts in rural Minnesota and Iowa. Participants Fifty-seven residents (Minnesota: 13 females and 8 males; Iowa: 24 females and 12 males). Most participants were white and had not completed high school or higher education. Phenomenon of Interest Food choice and food access among rural residents. Analysis Transcripts were evaluated for consistency and coded for themes and subthemes. Results Three dominant themes influence food access and choice and were identified as: (a) personal and household determinants of food; (b) social and cultural environment; and (c) structure of place or the external environment. Conclusions and Implications Personal, environmental, and dietary behavioral factors are all interconnected; each plays a major role in influencing dietary behavior and the resulting health outcomes in rural Minnesotans and Iowans living in food deserts. However, although personal factors impact eating behavior for rural people, it is the physical and social environments that place constraints on food access, even in civically engaged communities. Food access may be improved in communities where civic engagement is strong, and where local organizations join in providing solutions to decrease barriers of food access by increasing access to the normal and food safety net systems and by creating informal alternatives, such as community gardens and informal transportation networks, or enhancing federal programs through greater volunteer involvement.
Radiocapitellar stability: the effect of soft tissue integrity on bipolar versus monopolar radial head prostheses

Introduction Radiocapitellar stability depends, in part, on concavity-compression mechanics. This study was conducted to examine the effects of the soft tissues on radiocapitellar stability with radial head prostheses. Hypothesis Monopolar radial head implants are more effective in stabilizing the radiocapitellar joint than bipolar radial head prostheses, with the soft tissues intact or repaired. Materials and methods Twelve fresh frozen elbow specimens were used to evaluate radiocapitellar stability with monopolar and bipolar radial heads. The study variables focused on varying soft tissue conditions and examined the mean peak subluxation forces put forth by each prosthesis design. Results With the soft tissues intact, the mean peak force resisting posterior subluxation depended significantly on the radial head used (P = .03). Peak force was greatest for the native radial head (32 ± 7 N) and least with the bipolar prosthesis (12 ± 3 N), with the monopolar prosthesis falling in between (21 ± 4 N). The presence of soft tissues significantly affected the bipolar implant’s ability to resist subluxation, though it did not significantly impact the native or monopolar radial heads. Discussion This study reveals the dependence of radiocapitellar stability on soft tissue integrity, particularly for bipolar prostheses. Overall, monopolar prostheses have a better capacity to resist radiocapitellar subluxation. Conclusion From a biomechanical perspective, the enhancement of elbow stability with a monopolar radial head prosthesis is superior to that with a bipolar design. This is especially true when the integrity of the soft tissues has been compromised, such as in trauma.
Lysyl oxidase deficiency in lung and fibroblasts from mice with hereditary emphysema.

Abstract Lysyl oxidase activity was measured in the lungs and from cultured fibroblasts of Blotchy mice. A marked decrease in lysyl oxidase activity was observed in lungs of affected mice as compared to normal litter mates. Fibroblasts cultured from Blotchy mice were also deficient in lysyl oxidase, producing less than half of normal enzyme levels. Normal and Blotchy fibroblasts which had been maintained in culture for several months and had undergone spontaneous transformation, continued to show the same magnitude of difference in lysyl oxidase levels. The data suggest that the deficiency of lysyl oxidase is inherent in Blotchy fibroblasts and support the idea that the deficiency of this enzyme is the metabolic lesion that leads to the connective tissue defects observed in these animals.
Power dissipation in frame-transfer charge-coupled devices

The power dissipation for large-area high-speed charge-coupled device (CCD) arrays is analyzed. The four mechanisms responsible for power dissipation in a CCD are carrier lift and friction within the CCD channel, load currents through the on-chip output amplifiers, capacitive charge and discharge currents through the epitaxial layer or substrate, and currents flowing through the polysilicon clock register electrodes. These processes are easily calculated for small or slow devices. For large high-speed devices, on the other hand, the conventional analytical techniques are inadequate. The large device area leads to high resistive-capacitive constants in the parallel clock registers, causing clock pulses to degrade in shape as they travel along a clock electrode. A distributed system analysis based on lumped circuit parameters for each pixel is necessary to calculate the current and thus the power dissipated at each point on the surface of the COD. A computer simulation of a standard frame-transfer CCD was performed using SPICE software. The results of the simulation indicate a much lower power dissipation than previously assumed and also point out various problems with conventional device architectures for large-area high-speed CCDs.
Statistics of momentum flux estimation using the dual coplanar beam technique

We examine the statistical estimation error for the dual coplanar beam momentum flux estimator in the presence of geophysical noise. Included in our derivation are the effects of measurement noise and finite spatial correlation of the wind fluctuations. We show that there is an optimal beam separation that minimizes the statistical estimation error at a value nearly equal to the irreducible error observed by an “ideal” anemometer measuring u and w at a point. For typical mesopause parameters this beam separation is approximately ±13°. The optimal angle is dependent in part on the ratio of vertical to horizontal wind variances and is therefore variable. For optimal momentum flux measurements a system, radar or lidar, with steerable beams becomes necessary.
Computing Massey product invariants of links

Abstract The Massey product invariants of a link in S3 are expressed in terms of Magnus coefficients of relations in a Wirtinger presentation of the fundamental group of its complement. This formula underlies a computer program which calculates these invariants. As the Massey product invariants include Milnor's μ-invariants, these can be calculated with the program, and a small table of invariants is included. Formerly, a degree q μ-invariant has been identified with the value of a degree q Massey product on an appropriate homology class. We reduce the number of calculations required to compute such an invariant by identifying it with the value of adegree q − 1 Massey product on a particular homology class.
224Ra distribution in surface and deep water of Long Island Sound: sources and horizontal transport rates

Abstract Measurements of surface water and deep water 224 Ra (half-life 3.64 days) distributions in Long Island Sound (LIS) were conducted in July 1991. Because the pycnocline structure of LIS had been in place for about 50 days in July (long compared to the half-life of 224 Ra), 224 Ra in the surface water and the deep water operate as separate systems. In the surface water, the fine-grain sediments of nearshore and saltmarsh environments provide a strong source of 224 Ra, which is horizontally mixed away from the shore to central LIS. A one-dimensional model of 224 Ra distribution suggests across-LIS horizontal eddy dispersivity of 5–50 m 2 s −1 . In the deep water, the mid-LIS sediment flux of 224 Ra is enhanced by ∼2x relative to the periphery, and the horizontal eddy flux is from central LIS to the periphery. A second one-dimensional model suggests a cross-LIS horizontal eddy dispersivity below the thermocline of 5–50 m 2 s −1 . 224 Ra fluxes into the deep water of the central LIS are likely enhanced by (1) inhomogeneous sediment or (2) a reduced scavenging of 224 Ra in the sediments of central LIS brought about by low oxygen conditions (hypoxia) and the loss of the MnO 2 scavenging layer in the sediments. These rates of horizontal eddy dispersivity are significantly less than the estimate of 100–650 m 2 s −1 (Riley, 1967) but are consistent with the transport necessary to explain the dynamics of oxygen depletion in summer LIS. These results demonstrate the use of 224 Ra for quantifying the parameters needed to describe estuarine mixing and transport.
Scalable, fault tolerant membership for MPI tasks on HPC systems

Reliability is increasingly becoming a challenge for high-performance computing (HPC) systems with thousands of nodes, such as IBM's Blue Gene/L. A shorter mean-time-to-failure can be addressed by adding fault tolerance to reconfigure working nodes to ensure that communication and computation can progress. However, existing approaches fall short in providing scalability and small recon guration overhead within the fault-tolerant layer.This paper contributes a scalable approach to recon gure the communication infrastructure after node failures. We propose a decentralized (peer-to-peer) protocol that maintains a consistent view of active nodes in the presence of faults. Our protocol shows response times in the order of hundreds of microseconds and single-digit milliseconds for recon guration using MPI over BlueGene/L and TCP over Gigabit, respectively. The protocol can be adapted to match the network topology to further increase performance. We also verify experimental results against a performance model, which demonstrates the scalability of the approach. Hence, the membership service is suitable for deployment in the communication layer of MPI runtime systems, and we have integrated an early version into LAM/MPI.
Invasive rodents on islands: integrating historical and contemporary ecology

The colonization of islands by humans dramaticallytransformed environments, initiating extinctions,extirpations, and a complex array of ecosystemchanges (e.g. Kirch 1997; Grayson 2001; Anderson2008; Athens et al. 2002; McConkey and Drake2002; Steadman 2006; Kennett et al. 2006).Researchers in historical ecology have describedthese human-induced transformations as conse-quences of forest clearing, ﬁre, and the introductionand establishment of a portmanteau biota (Crosby2004). Rodents (especially the rats Rattus exulans, R.rattus, and R. norvegicus) may have been the mostwidely introduced vertebrates to accompany humansin our history of global dispersal. Indeed, one couldargue that rats (Rattus spp.) are the original invasive‘‘species’’—from the colonization of the PaciﬁcIslands to the global expansion of Europeans. Eco-logical, palaeoecological, and archaeological studieshave documented the direct and indirect impacts ofrodents on native plants and animals, and implicatedthem in transforming many island environments (e.g.Atkinson 1985; Diamond 1985; Athens et al. 2002;Steadman 2006; Towns et al. 2006; Hunt 2007; Joneset al. 2008). However, in some cases, effectsattributed to rodents are based on circumstantialevidence, and a better understanding of the roleplayed by rodents awaits integration of historical andcontemporary ecology. Today, the integration ofthese ﬁelds has become increasingly important,because invasions and threats of extinction continue,and because ecological restoration of islands fre-quently depends on understanding rodent ecology inorder to predict the consequences of their removal(Towns and Broome 2003; Caut et al. 2007).Based on the dramatic ecological impactsobserved in contemporary ﬁeld studies, ecologistshave typically adopted a default hypothesis thatinvasive rats must have had strong impacts in the past(see critical review by Towns et al. 2006). In contrast,archaeologists and palaeoecologists have, untilrecently, viewed human-induced impacts on islandecosystems largely as consequences of forest clearingand ﬁre. Focusing on such direct human activities,these researchers have been reluctant to attributemajor impacts to the direct or indirect effects of rats.For us this contrast came into focus when StephenAthens (Athens et al. 2002; see Athens 2008)reported ﬁndings from his integrated palaeoecologi-cal and archaeological research on the Ewa Plain ofOahu, Hawaiian Islands. Athens, an archaeologist,showed with a detailed palaeoenvironmental andarchaeological record that rats (R. exulans) intro-duced by Polynesians to the Hawaiian Islands some1,000 years ago likely had a catastrophic impact on
Distressed binge eaters as a distinct subgroup among obese individuals

This study was conducted to examine the degree to which binge eating and psychological distress among obese adults are associated with a variety of behavioral patterns and competencies that could substantially affect weight control. Subjects were 167 obese people who sought help in a long-term cognitive behavioral treatment program. Subjects were divided into three groups depending on their level of psychological distress and severity of binge eating. Subjects were also assessed on coping style, subjective distress, weight history, and exercising and eating patterns. Results demonstrated substantial differences between those reporting relatively few problems with binge eating or psychological distress as opposed to those with noteworthy problems in both. The presence of either severe binge eating or psychological distress was associated with problems in regulating food-related behavior and, more generally, to problematic coping styles. These findings support the importance of in-depth assessment when treating obesity, more intensive treatment for some subgroupings, and long-term studies that incorporate comprehensive pretreatment process measure of eating style and psychological distress.
Shape discrimination using invariant Fourier representation and a neural network classifier

A neural network approach for classification of images represented by translation, scale, and rotation invariant features is presented. The invariant features are the Fourier descriptors (FDs) derived from the boundary (shape) of the object. The network is a multilayer perceptron (MLP) classifier with one hidden layer and back propagation training (MLP-BP). Performance of the MLP algorithm is compared to optimal curve matching (OCM) for the recognition of mechanical tools. The test data were 14 objects with eight images per object, each image having significant differences in scaling, translation, and rotation. Only 10 harmonics of the 1024 FD coefficients were used as the input vector. The neural network approach proved to be more stable and faster than the optimal curve matching algorithm in classifying the objects after the training phase. The simple calculations needed for the Fourier descriptors and the small number of coefficients needed to represent the boundary result in an efficient system, excluding training, which can be done off-line. Results are shown comparing the classification accuracy of the OCM method with the MLP-BP algorithm using different size training sets. The method can be extended to any patterns that can be discriminated by shape information.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nocturnal Nasal Intermittent Positive Pressure Ventilation with Bi-level Positive Airway Pressure (BiPAP) in Respiratory Failure

The purpose of this study was to assess the efficacy of bi-level positive airway pressure (BiPAP) ventilation through a nasal mask in the treatment of eight patients with hypoventilatory respiratory failure and nocturnal CO 2 retention. Nocturnal CO 2 retention was significantly reduced in all patients with the application of BiPAP during sleep (p 1 or FVC after three months of BiPAP. Daytime PaCO 2 improved slightly or remained stable in all patients after three months of home BiPAP. BiPAP nasal ventilation is effective in reducing nocturnal CO 2 retention short term in hypoventilatory respiratory failure due to obesity hypoventilation syndrome, chest wall restriction, or neuromuscular disease. Further studies in patients with COPD may be warranted.
Visually perceived eye level and perceived elevation of objects: linearly additive influences from visual field pitch and from gravity.

Observing a pitched visual field (i.e. tilted around a horizontal axis in the observer's frontal plane) results in large changes in the elevation visually perceived to correspond to eye level (VPEL) and in the perceived elevation and size of stationary objects viewed against the field. With topforward pitch (top toward observer) VPEL lies above true eye level and objects appear smaller and lower; with topbackward pitch VPEL lies below true eye level and objects appear larger and higher. Oscillation of the pitched field induces synchronous perceived oscillation of elevation of a stationary target viewed against the field. Typical VPEL settings deviated from true eye level by 20 degrees with the field pitched at 40 degrees, although some individuals mislocalized by as much as 40 degrees. VPEL varied linearly with visual field pitch with individual slopes for the relation between VPEL and visual field pitch ranging from +0.42 to +0.78 (avg = +0.56). The linear correlation (r) between VPEL in darkness and against an erect visual field was +0.91. The two relations--VPEL vs visual field pitch, VPEL in darkness vs VPEL in the erect illuminated visual field (slope approximately equal to 0.5)--are both accurately predicted by the linear model: VPEL = kvV + kbB; in which V is the influence of visual field structure and B is the influence of the body-referenced mechanism which combines information regarding the orientation of the head relative to gravity, the position of the eye in the orbit, and the vertical location of the image on the retina; kv and kb are the relative weights of V and B with kv + kb = 1. In an illuminated field kv = kb approximately equal to 0.5; in the dark kv = 0, kb = 1.
Combinatorial Treatment of Bone Marrow Stem Cells and Stromal Cell-Derived Factor 1 Improves Glycemia and Insulin Production in Diabetic Mice

Transdifferentiation of stem cells into insulin-producing cells for the treatment of diabetes have shown promising but inconsistent results. We examined the potential for attracting bone marrow stem cells (BMSCs) to the pancreas using a chemokine, stromal cell-derived factor 1 (SDF-1). SDF-1 treatment markedly increased the number of GFP labeled BMSCs in the pancreas, but surprisingly, the majority was observed in liver. The liver cells had typical pancreatic endocrine cell gene expression including insulin I, insulin II, PDX-1, somatostatin, and glucagon. Combined treatment with SDF-1 and BMSC transplant reduced hyperglycemia and prolonged the long-term survival of diabetic mice, and a sub group had complete normoglycemia (<150 mg/dl), restored blood insulin levels, and normal glucose tolerance. Our results suggest that SDF-1 could potentially be used to improve the homing of stem cells and β-cell regeneration. The mechanism appears to involve an increase in insulin producing cells mainly in the liver.
GPS Interferometric Attitude and Heading Determination: Initial Flight Test Results

Methods and results for realtime pitch, roll, and heading determination of a dynamic flexible platform are presented. Consideration is given to a GPS attitude and heading determination system installed in Ohio University's Douglas DC-3 research aircraft. Signals from four antennas are processed by an Ashtech 3DF 24-channel GPS receiver. Data from the receiver are sent to a microcomputer for storage and further computations. Attitude and heading data are sent to a second computer for display on a software generated artificial horizon. Demonstration of this technique proves its candidacy for augmentation of aircraft state estimation for flight control and navigation as well as for numerous other applications, such as reliable aircraft state estimation, measurement of structural flexing of large space structures, synthetic aperture radar, aerial photogrammetry, pointing systems, spacecraft attitude control, rendezvous and docking, and road mapping.
Full-Color Imaging On Amplitude-Quantized Color Mosaic Displays

We discuss halftoning techniques appropriate for matrix-addressed electronic displays, such as thin-film-transistor (TFT) liquid crystal displays, which use color mosaics to implement multi-color operation via space-division-multiplexing. The error propagation method of halftoning is briefly reviewed and extended into the present context. Temporally dynamic techniques are described for rapidly refreshed displays, as is their implementation in digital hardware. Artifact suppression and the use of auxiliary passive light-optical image enhancement techniques are also addressed.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
New Additions to Nonconjugated Conductive Polymers; Nonlinear Optical Effects

Recently, new additions to nonconjugated conductive polymers have been made that include: poly(β-pinene), poly(ethylenepyrrolediyl) derivative and polynorbornene. These polymers have different double-bond number fractions per repeat compared to previously reported nonconjugated conductive polymers. Upon doping with electron acceptor (e.g. iodine) the conductivities increase more than ten orders of magnitude to levels consistent with their double-bond number fractions. Radical cations that are formed upon doping have dimensions less than a nanometer leading to unexpectedly large nonlinear optical effects. The measured Kerr coefficient of doped polyisoprene is ∼1.6 × 10-10 m/V2 at 633 nm. For doped poly(β-pinene) the Kerr coefficient is ∼1.2 × 10-10 m/V2 and for poly(ethylenepyrrolediyl) derivative it is ∼1.2 × 10-9m/V2. Exceptionally large two-photon absorption coefficient (∼2.6 cm/MW at 810 nm) has been measured for doped poly(β-pinene). The mechanism of the nonlinear optical effect has been explained usi...
Is toxicity really necessary? III. Theoretical aspects

The choice of a dosage level for use in clinical trials designed to test the antitumor activity of chemotherapeutic agents is discussed from a theoretic viewpoint, with the question of the necessity of toxicity being the central topic. Three senses of “necessary” are discussed and the verbal discussion is paralleled by a formal argument in a mathematical language. The mathematical model developed focuses on different possibilities that are inherent in different experimental situations. Though it does not clarify the situation with regard to the present data, it clearly defines the quesions which should be answered by subsequent studies.
Calculating the free energy of nearly jammed hard-particle packings using molecular dynamics

We present a new event-driven molecular dynamics (MD) algorithm for measuring the free energy of nearly jammed packings of spherical and non-spherical hard particles. This Bounding Cell Molecular Dynamics (BCMD) algorithm exactly calculates the free-energy of a single-occupancy cell (SOC) model in which each particle is restricted to a neighborhood of its initial position using a hard-wall bounding cell. Our MD algorithm generalizes previous ones in the literature by enabling us to study non-spherical particles as well as to measure the free-energy change during continuous irreversible transformations. Moreover, we make connections to the well-studied problem of computing the volume of convex bodies in high dimensions using random walks. We test and verify the numerical accuracy of the method by comparing against rigorous asymptotic results for the free energy of jammed and isostatic disordered packings of both hard spheres and ellipsoids, for which the free energy can be calculated directly as the volume of a high-dimensional simplex. We also compare our results to previously published Monte Carlo results for hard-sphere crystals near melting and jamming and find excellent agreement. We have successfully used the BCMD algorithm to determine the configurational and free-volume contributions to the free energy of glassy states of binary hard disks [A. Donev, F.H. Stillinger, S. Torquato, Do binary hard disks exhibit an ideal glass transition? Phys. Rev. Lett. 96 (22) (2006) 225502]. The algorithm can also be used to determine phases with locally- or globally-minimal free energy, to calculate the free-energy cost of point and extended crystal defects, or to calculate the elastic moduli of glassy or crystalline solids, among other potential applications.
Orthotropic Creep and Complex Moduli of a Viscoelastic Composite Reinforced with Aligned Elliptic Fibers

A general micromechanical viscoelastic theory is developed to study the effective creep behavior and nine complex parameters of an orthotropic composite consisting of a viscoelastic matrix and aligned elliptic cylinders. With such a microgeometry it is first shown that two Maxwell or two Voigt constituents generally do not make a Maxwell or a Voigt composite, but under the conditions that the ratios of the shear modulus to the shear viscosity are equal for both constituents and that both Poisson's ratios remain unchanged in the course of deformation, a Maxwell and a Voigt composite can be constructed. The orthotropic creep compliances then are examined as the cross-sectional aspect ratio α (the thickness-to-width ratio) of the elastic elliptical cylinders changes from circular one (α = 1) to lamellar one (α→ 0) under six loading directions. It is found that under the three tensile loadings the composite with the lamellar structures gives rise to the strongest creep resistance. As the aspect ratio increase...
Microneedle array for transdermal biological fluid extraction and in situ analysis

Abstract This paper presents the design, fabrication and testing of a hollow microneedle array with integrated, fluidic microchannels. The microneedles are machined from single crystal silicon to a shank height of 250–350 μm with 300 μm center-to-center spacing. The needle size, density and shape are controlled by independent processing steps. Piercing of the protective stratum corenum layer of the skin by the microneedles, providing access to the living epithelial layers underneath, is successfully demonstrated. Filling of the integrated microchannels by capillary action with both non-biological fluids (glycerol, ethanol, surrogate interstitial fluid (ISF) and water) as well as biological fluids (ISF and whole blood) is demonstrated. The ability to extract interstitial fluid from human skin is successfully achieved and verified by the in situ measurement of glucose concentration. The microchip presented here represents the first step towards the realization of a transdermal, ISF extraction and analysis microsystem.
Techniques for avoiding conditional execute in APL2

Execute ( ) is unique among the APL2 primitive functions in that it is the only one which does not necessarily produce an explicit result. This makes it convenient for executing an APL expression conditionally. Execute is also unique in that it is the only symbolic primitive which permits only a character argument. This tends to produce awkward programming.This paper will look at ways to avoid the use of conditional execute by suggesting alternate methods and ways of thinking which are unique to APL. These methods have been used to great advantage in production code.Most examples of code used in this paper have been taken from an actual APL2 application. Although most of the examples are in APL2, many will work in other APL dialects. Some minor modifications have been made to the code in the interests of security and clarity. Most of these involved changing the names of some functions or variables.
Surface Initiated Polymerization from Nanoparticle Surfaces

Abstract The synthesis, characterization, and development of new nanoparticle materials have both scientific and technological significance. Surface initiated polymerization (SIP) from nanoparticle surfaces involves the growth of end‐tethered polymer brushes where the length or thickness can be more than twice the radius of gyration (Rg) compared to a free polymer in solution. Different mechanisms are possible on a variety of initiators, reaction conditions, monomers, and nanoparticles. Important differences to solution and bulk polymerization can be observed where the nanoparticles with grafted initiators behave as macroinitiators. In turn, the development of these materials will allow the preparation of thermodynamically and kinetically stable nanocomposites and colloids. Through the careful use of surface sensitive spectroscopic and microscopic techniques, much has been gained from the direct and in‐situ analysis of grafted polymers on the nanoparticles with regards to the kinetics and mechanism of the...
Control of formation and dissociation of the high-affinity complex between cytochrome c and cytochrome c peroxidase by ionic strength and the low-affinity binding site

A new ruthenium photoreduction technique was used to measure the formation and dissociation rate constants kf and kd of the high-affinity complex between yeast iso-1-cytochrome c (yCc) and cytochrome c peroxidase compound I (CMPI) over a wide range of ionic strength. These studies utilized Ru-39-Cc, which contains trisbipyridylruthenium attached to the cysteine residue in the H39C, C102T variant of yCc, and has the same reactivity with CMPI as native yCc. kd and kf were measured by photoreducing a small concentration of Ru-39-Cc in the presence of the oxidized yCcIII: CMPI complex, which must dissociate before Ru-39-CcII can bind to CMPI and reduce the radical action. The value of kd for the 1:1 high-affinity complex is very small at low ionic strength, 3 x 10(9) M-1 s-1 at low ionic strength to 1.3 x 10(9) M-1 s-1 at 150 mM ionic strength. These studies indicate that the rate-limiting step in enzyme turnover is product dissociation below 150 mM ionic strength and intracomplex electron transfer to the oxyferryl heme at higher ionic strength. The interaction between yCc and CcP is optimized at physiological ionic strength to provide the largest possible complex formation rate constant kf without allowing product dissociation to be rate-limiting. The effects of surface mutations on the kinetics provided evidence that the high-affinity binding site used for the reaction in solution is similar to the one identified in the yCc:CcP crystal structure.
Reversible hydrogen transfer reactions of cysteine thiyl radicals in peptides: the conversion of cysteine into dehydroalanine and alanine, and of alanine into dehydroalanine

The photodissociation of disulfide bonds in model peptides containing Ala and Ala-d3 generates a series of photoproducts following the generation of a CysS• thiyl radical pair. These photoproducts include transformations of Cys to dehydroalanine (Dha) and Ala, as well as Ala to Dha. Intramolecular Michael addition of an intact Cys with a photolytically generated Dha results in the formation of cyclic thioethers. The conversion of Cys into Dha likely involves a 1,3-H-shift from the Cys αC–H bond to the thiyl radical, followed by elimination of HS•. The conversion of Dha into Ala most likely involves hydrated electrons, which are generated through the photolysis of Cys, the photoproduct of disulfide photolysis. Prior to stable product formation, CysS• radicals engage in reversible hydrogen transfer reactions with αC–H and βC–H bonds of the surrounding amino acids. Especially for the βC–H bonds of Ala, such hydrogen transfer reactions are unexpected on the basis of thermodynamic grounds; however, the replace...
Postpartum Follow‐up Goals and Assessment

The bridge between hospital and home in the puerperal period needs to be assessed for effective intervention, anticipatory guidance, and support in parenting careers. Through the development of specific goals, assessment criteria and cultural implications, the nurse practitioner can hopefully minimize the developmental crisis for the postpartal family unit.
Further evidence that lipoxygenase activity is required for arachidonic acid-elicited hypersensitivity in potato callus cultures

Two tuber callus lines of Solanum tubersum L., one lacking detectable lipoxygenase (LOX) activity (LOX-null) and the other possessing activity (LOX-active), were treated with arachidonic acid (AA), an elicitor of the hypertensitive response (HR) and LOX substrate. LOX-active calli exhibited HR cell death and browning within 1 h of treatment, with maximum cell death occuring by 24 h. In contrast, tissue browning was not evident in LOX-null calli and cell viability did not change until 24 h after treatment, when only 10–15% of the cells appeared dead. LOX activity was undetectable in the LOX-null line regardless of treatment or sampling time. LOX-active calli exhibited a nearly linear loss of LOX activity, decreasing to 20% of the control levels by 96 h after arachidonic acid (AA) treatment. Polyphenol oxidase (PPO) activities showed large initial increases in calli from both lines, after which the activities declined to levels near that of the controls. Peroxidase (PER) activity in LOX-ative calli increased to over twice that of control levels within 6 h of treatment, but rapidly declined to 50% of the control values after 24 h. PER activity initially declined slightly in the LOX-null calli but increased to levels near those of the controls by 96 h. These results suggest that LOX, which catalyzes the peroxidation of AA, plays roles in the rapid hypersensitive cell death elicited by AA, while other tissue responses to AA function independently of LOX-activity.
HIV-1 envelope protein evokes intracellular calcium oscillations in rat hippocampal neurons

Abstract Treatment of single rat hippocampal neurons with 200 pM recombinant HIV-1 envelope glycoprotein, gp 120, resulted in large increases in the intracellular free calcium concentration ([Ca 2+ ] i ) as measured with indo-1-based microfluorimetry. Three patterns of [Ca 2+ ] i increases were observed: in one pattern the [Ca 2+ ] i rose rapidly and transiently as a single peak, in a second pattern gp120 induced [Ca 2+ ] i oscillations that subsided when the protein was removed, and in a third pattern the oscillations continued long after washout of gp120. Both single peak and oscillatory [Ca 2+ ] i increases were completely blocked by the Ca 2+ channel blocker nitrendipine (1 μM). The sustained oscillatory responses were also blocked completely and reversibly by the N- methyl- d -aspartate (NMDA) receptor antagonist CGS19755 (10 μM) and the Na + channel blocker tetrodotoxin (1 μM). Complete block by antagonists of Ca 2+ , Na + , and NMDA-gated ion channels suggests that at least two cells are required to maintain the [Ca 2+ ] i oscillations. We hypothesize that gp120 acts as an excitotoxin by increasing synaptic activity in the network of neurons established in primary culture.
Effects of Exposure to Stereotype Cues on Contamination Aversion and Avoidance in African Americans

Although heightened contamination aversion has been observed among African Americans, much remains unknown about the origins of this aversion. The present study examined the effects of exposure to stereotype cues on contamination aversion and avoidance in African Americans. African Americans and Caucasians were primed with either sad images or images depicting Jim Crow laws. Participants were then escorted into a public restroom where they completed a behavioral avoidance task (BAT) and provided anxiety and disgust ratings during the BAT. African Americans in the Jim Crow condition demonstrated more avoidance and aversion in the public restroom than African Americans and Caucasians in the other priming conditions. Furthermore, those in the other priming conditions did not differ from each other. Subsequent analysis revealed that the heightened avoidance and aversion in the public restroom among African Americans was not accounted for by heightened arousal and negative affect in response to the Jim Crow im...
Perfluoropolyalkylether Oil Degradation: Inference of FeF3 Formation on Steel Surfaces under Boundary Conditions

The formation of iron fluoride (FeF3) through the interaction of perfluoropolyalkylether (PEPE) oil with steel surfaces was investigated under boundary lubrication conditions. Ball-bearing rolling action was simulated by a specially designed wear-test apparatus that incorporated noncoaxial wear members to give a skid/roll ratio of ∼0.16. The contact stress was 8.3 × 108 N·m−2 (∼120 000 psi), and the speed was 1750 rpm. Under these conditions, FeF3 formation on the wear surfaces was inferred using x-ray photoelectron spectroscopic (XPS), Auger electron spectroscopic (AES), and secondary ion mass spectrometric (SIMS) surface analysis techniques. These findings support the hypothesis that, under the low oxygen environment of spacecraft earth orbit, formation of FeF3 and subsequent FeF3 catalyzed degradation of PEPE can constitute an important PFPE degradation pathway under boundary lubrication conditions. Presented at the 40th Annual Metting in Las Vegas, May 6–9, 1985
A possible alarm substance in the forced swimming test

Rats were tested in a forced swimming paradigm under a number of conditions which showed that time of day of testing did not significantly affect duration of immobility and a shorter ten-minute test period was as effective as the traditional longer protocol which tests animals 24 hours after initial immersion. Prior foot shock and noise decreased the immobility response. In addition, swimming in a cylinder in which another rat had been swimming also decreased the immobility response. The latter was not due to fecal or urinary contamination but appeared to be due to an alarm substance released during immersion in the water. Animals were affected by this proposed substance whether they released it themselves or it was released by a stranger. The proposed substance was released after a 3.5-minute or longer swimming period.
The variation of secondary emission with heat treatment

Abstract The ratio of the number of electrons striking a surface to the number leaving it was determined under various conditions for a number of metals contaminated by the condensation of grease vapors on them.The curves showing the variation of secondary emission with incident electron energy (evidently characteristic of the contamination rather than of the metals) are similar for all the targets and resemble the results obtained by Gehrts. Reducing the amount of the contamination by heating the metals at first reduces the secondary emission until it falls below that expected from a clean metal. The emission then increases with further heating and the characteristics of the metal appear. The variation of the work function during the “outgassing” process is indicated by this increase of the secondary emission followed by a decrease of the secondary emission as the process continues.
Fingertip reconstruction with flaps and nail bed grafts

We retrospectively reviewed the cases of 14 fingertips reconstructed with a combination of local or regional flaps and nail bed grafts, some of which were placed wholly or partially over a de-epithelialized flap. Most of the fingertips sustained a crushing injury and were reconstructed at the time of the injury. Soft tissue coverage was provided by palmar V-Y flaps in 6 cases, thenar flaps in 4, lateral V-Y flaps in 2, a Moberg flap in 1, and a cross-finger flap in 1. Split toenail bed grafts were used in 6 cases, full-thickness nail bed grafts from the amputated part in 6, and split nail bed grafts from the injured digit in 2. There was 1 partial graft loss and 1 partial flap loss. The remaining cases had completely successful grafts and good soft tissue healing. Subsequent nail growth and adherence were good in all but the 1 digit requiring secondary composite grafting.
A 12th century paradox of the infinite

Adam of Balsham (Parvipontanus) writing his Ars Disserendi in 1132 A.D. reaches the notion of a set A equinumerous with a set B containing A as a proper sub-set. References by page and line are to [Minio-Paluello]. It can be asked, says Adam (92,13) whether this one is something, and whether that one is something, and these are two askables (interrogabilia), and again whether a third is something, and similarly of anything whatever. He thinks, then, of the totality of 'objects' (92,12) as numbered. But this question can be put not only about those which are not askables; of any askable too it can be asked whether it is something. Whether the questions be actually put or not, makes no difference; even when they are not put, the points remain askable. Thus the totality of askables is seen to be equinumerous with the totality of objects, which last comprises both the objects which are not askables and those which are. And so the same set is more numerous than itself. Conscious that this paradoxical situation may be ascribed to his novel terminology and methods, Adam points out that a similar puzzle arises over things enunciated. Even if you do not want to term them 'enunciables,' still they are generally said to be true or false. Take the true ones, and compare them as to number with the totality of objects of which enunciations can be made. There he leaves this second version, but it is easy to see how the same result as before can be reached. The argument lightly paraphrased in the last paragraph but one concludes with the words 'which is impossible' (92,21). Instead, however, of rejecting some of his premisses, Adam lets everything stand, and breaks off the discussion on the ground that his purpose is to expound a finite process of achievement (artis viam finitam) rather than what infinitely exceeds our capability to construct or perhaps, the infinitely extending realm of possibility (possibilitatis excessum infinitum, 93,3-5). So he evidently did not mean 'self-contradictory' when he said 'which is impossible,' and he sees that his paradox has something to do with the infinity of the totality of objects considered. This infinity was not mentioned in the body of the argument, but its presence is clear from the fact that each of the (numbered) objects which is an askable, generates a further such. Here is the actual text of the main argument and the concluding passage, with spelling modernised: interrogari enim potest 'an hoc sit aliquid' et item 'an illud sit aliquid,' et haec duo interrogabilia sunt; item 'an tertium sit liquidd' et sic
Growth hormone-releasing factor increases somatostatin release and mRNA levels in the rat periventricular nucleus via nitric oxide by activation of guanylate cyclase.

Abstract Previous work has shown that growth hormone-releasing factor (GRF) stimulates cGMP production and somatostatin [somatotropin (growth hormone)-release-inhibiting factor, SRIF] release without altering cAMP accumulation by fragments of median eminence incubated in vitro. Therefore, this study was undertaken to evaluate the effect of GRF and cGMP on SRIF mRNA and SRIF release in the periventricular nuclei of male rats in vitro. SRIF mRNA levels were determined in explants of periventricular nuclei incubated for 6 hr in Waymouth's medium in the presence of various substances. Steady-state levels of SRIF mRNA were measured by an S1 nuclease protection assay using a 32P-labeled rat SRIF RNA probe. SRIF release and cGMP formation were measured at 30 min and 6 hr by RIA. SRIF mRNA levels and SRIF release were significantly (P < 0.025) increased (approximately 2-fold) by 1 microM dibutyryl cGMP, whereas sodium butyrate had no effect. This augmentation was not influenced by cycloheximide, an inhibitor of protein synthesis. Sodium nitroprusside (10 microM), an activator of the guanylate cyclase pathway via its release of nitric oxide, augmented (P < 0.001) SRIF mRNA levels and significantly increased (P < 0.05) SRIF release. GRF (1 nM) increased SRIF mRNA (P < 0.001) and stimulated the release of SRIF at 30 min (P < 0.05) and 6 hr (P < 0.01). This stimulation was abolished by 10 microM NG-monomethyl-L-arginine (L-NMMA), a specific inhibitor of nitric oxide synthase, but not by NG-monomethyl-D-arginine (D-NMMA, the inactive isomer). GRF also increased cGMP formation. This effect was completely blocked by incubation with L-NMMA but not D-NMMA. These results indicate that GRF releases nitric oxide. The nitric oxide diffuses to the adjacent SRIF neurons, where it activates guanylate cyclase, leading to increased formation of cGMP. This cGMP increases SRIF mRNA and SRIF release in the periventricular nuclei of male rats.
Minireview: Mechanisms of Growth Hormone-Mediated Gene Regulation

GH exerts a diverse array of physiological actions that include prominent roles in growth and metabolism, with a major contribution via stimulating IGF-1 synthesis. GH achieves its effects by influencing gene expression profiles, and Igf1 is a key transcriptional target of GH signaling in liver and other tissues. This review examines the mechanisms of GH-mediated gene regulation that begin with signal transduction pathways activated downstream of the GH receptor and continue with chromatin events at target genes and additionally encompasses the topics of negative regulation and cross talk with other cellular inputs. The transcription factor, signal transducer and activator of transcription 5b, is regarded as the major signaling pathway by which GH achieves its physiological effects, including in stimulating Igf1 gene transcription in liver. Recent studies exploring the mechanisms of how activated signal transducer and activator of transcription 5b accomplishes this are highlighted, which begin to characterize epigenetic features at regulatory domains of the Igf1 locus. Further research in this field offers promise to better understand the GH-IGF-1 axis in normal physiology and disease and to identify strategies to manipulate the axis to improve human health.