cssi/SciSciGPT-SciSciNet huggingface dataset:
From Pathobiology to the Targeting of Pericytes for the Treatment of Diabetic Retinopathy

Pericytes, the mural cells that constitute the capillaries along with endothelial cells, have been associated with the pathobiology of diabetic retinopathy; however, therapeutic implications of this association remain largely unexplored. Pericytes appear to be highly susceptible to the metabolic challenges associated with a diabetic environment, and there is substantial evidence that their loss may contribute to microvascular instability leading to the formation of microaneurysms, microhemorrhages, acellular capillaries, and capillary nonperfusion. Since pericytes are strategically located at the interface between the vascular and neural components of the retina, they offer extraordinary opportunities for therapeutic interventions in diabetic retinopathy. Moreover, the availability of novel imaging methodologies now allows for the in vivo visualization of pericytes, enabling a new generation of clinical trials that use pericyte tracking as clinical endpoints. The recognition of multiple signaling mechanisms involved in pericyte development and survival should allow for a renewed interest in pericytes as a therapeutic target for diabetic retinopathy.
Judgments of Men's and Women's Feelings during Hypothetical Social Interactions.

We studied college students' perceptions of how good/bad and how powerful/powerless men and women feel during hypothetical social interactions. Stimuli were constructed by combining each of 16 behaviors that fell into four categories (negative, low power, sexual, and help) with each of four dyads (male-male, male-female, female-male, female-female). Subjects made judgments about the likelihood of each behavior occurring, and about how actors and recipients felt when engaging in each of 16 behaviors. Three themes pervaded the results. First, subjects perceived men to feel more powerful than women whether behaving as actors or recipients—especially during interactions with women. Second, subjects perceived behaviors to be more likely, and actors and recipients to feel better and more powerful when the interaction pattern was consistent with gender role norms. Third, subjects perceived recipients' affective responses as being more polarized in opposite-sex than in same-sex dyads. Results from this research show that subjects' perceptions about feelings are largely consistent with the literature on social interaction and sex role stereotypes, and are similar for male and female subjects. In addition, our results provide a rich set of hypotheses concerning whether perceptions of feelings reflect actual feelings and are related to interaction participants' actual behavior.
Pretransplant severe hepatic encephalopathy, peritransplant sodium and post‐liver transplantation morbidity and mortality

Background Hepatic encephalopathy (HE) does not enhance the prediction of model of end-stage liver disease (MELD) wait-list mortality, but its influence on post-liver transplantation (LT) morbidity and mortality is largely unknown. Aims To examine the association between severe pre-LT HE and peri-LT serum sodium levels as well as post-LT length of stay (LOS) and survival. Methods A retrospective cohort of 393 adult patients undergoing first LT for end-stage liver disease and followed for a median of 4 years post-LT was performed to evaluate the association between severe HE within the 30 days prior to LT and selected in-hospital post-LT outcomes. Results Thirty-nine (10%) of the cohort had severe HE pre-LT. Patients with severe HE more frequently had Na changes of ≥15 mmol/L in the peri-LT period (P = 0.002). LOS was significantly longer for severe HE than non-severe HE patients (16 vs. 8 days, P < 0.0001) and this association was independent of MELD, presence of hepatocellular carcinoma, pre-LT nadir serum sodium and pre- to post-LT change in serum sodium. The 1-year mortality was 15% in the severe HE vs. 7% in the non-severe HE groups (HR = 2.19, P = 0.08), and this difference was attenuated by adjusting for pre-LT severe hypernatremia, but increased by adjusting for donor risk index. Conclusion Severe HE mainly affects LOS, and this association is independent of MELD. Whether the large changes in peri-LT serum Na, more frequently seen in the severe HE group, contribute to post-LT morbidity requires further study.
Selection Versus Censorship in Libraries

The terrorist attacks of September 11 pose a potential threat to intellectual freedom inside and outside of libraries, particularly regarding information deemed to be useful to terrorists. After a brief look at this threat I proceed to discuss the liberal position on intellectual freedom in the light of Lester Asheim's distinction between censorship and selection. I then entertain a criticism of the liberal/Asheim position. The criticism suggests that the liberal position requires at least some public and academic libraries to carry potentially dangerous materials like bomb-making manuals. I defend the liberal position against this objection, concluding that such materials do have a place in some libraries, terrorist threats notwithstanding.
Use of region II of the a/q stability diagram for fast scanning of a linear quadrupole mass spectrometer

For evaluation as a detector for high-speed gas chromatography, a linear quadrupole mass spectrometer was operated in rf only mode by using Region II (a = 0; 7.514 < q < 7.580) of the Mathieu a/q stability diagram. The available power supply and the diameter of the quadrupole rods of the mass spectrometer placed an upper mass limit of ∼ m/z 93. Scan rates of 1000 scans/s were obtained with mass spectral peaks resolved over an 80-u range The m/z 91 and 92 ions produced from the electron ionization of toluene are resolved with an R1/2 of 135. A potential difference between the source and the quadruple mass filter of up to 1000 V was used to accelerate ions into the quadrupole. Broadening of mass-to-charge ratio peaks results from the time constant of the signal amplification rather than the small number of rf cycles the ions experience. The expected loss of sensitivity relative to Region I is observed, and the problem of mass aliasing is discussed.
Anatomical relationships of serotoninergic and noradrenalinergic projections with the GnRH system in septum and hypothalamus.

Immunahistochemical double staining for gonadotropin releasing hormone (GnRH) and serotonin or dopamine-β-hydroxylase reveals close appositions of fibers which contain serotonin or norepinephrine to GnRH producing neurons in the septo-preoptic region. In the organum vasculosum of the lamina terminalis and in the median eminence extensive anatomical overlap exists in the distribution of GnRH and serotoninergic fibers but little of GnRH and noradrenalinergic fibers. It is proposed that serotonin plays a major role in the regulation of GnRH secretion via contacts in all of the regions studied and that the influence of norepinephrine on GnRH-secretion in the median eminence is exerted mainly via involvement of dopaminergic tuberoinfundibular neurons.
Dynamic role of postsynaptic caspase-3 and BIRC4 in zebra finch song-response habituation.

Summary Activation of the protease caspase-3 is commonly thought to cause apoptotic cell death. Here, we show that caspase-3 activity is regulated at postsynaptic sites in brain following stimuli associated with memory (neural activation and subsequent response habituation) instead of cell death. In the zebra finch auditory forebrain, the concentration of caspase-3 active sites increases briefly within minutes after exposure to tape-recorded birdsong. With confocal and immunoelectron microscopy, we localize the activated enzyme to dendritic spines. The activated caspase-3 protein is present even in unstimulated brain but bound to an endogenous inhibitor, BIRC4 (xIAP), suggesting a mechanism for rapid release and sequestering at specific synaptic sites. Caspase-3 activity is necessary to consolidate a persistent physiological trace of the song stimulus, as demonstrated using pharmacological interference and the zenk gene habituation assay. Thus, the brain appears to have adapted a core component of cell death machinery to serve a unique role in learning and memory.
Comparative structural aspects of cation binding to phosphatidylserine bilayers.

Abstract X-ray diffraction data recorded for monovalent and divalent cation complexes of a series of phosphatidylserines (PS) varying in chain length reveal a simple structural pattern. Only two bilayer structural types differing in hydrocarbon chain tilt but with similar polar group conformations are observed for (i) anhydrous acidic PS, (ii) anhydrous K + -PS, and (iii) Li + , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , and Pr 3+ complexes of “hydrated” PS. The X-ray diffraction data suggest that PS becomes dehydrated on complexing with Li + , Mg 2+ , Ca 2+ , and other divalent cations and adopts either the chain untilted (form I) or tilted (form II) bilayer structure.
Cyclic-AlO2 revisited

Abstract In this report, we present the results of ab initio electronic structure calculations of the structures, harmonic vibrational frequencies and the dissociation energy of cyclic AlO2. At the highest level of theory employed [CCSD(T)/6-311++G(3df)] the 2A2 state is lower than the 2A1 state by roughly 7 kcal mol−1. The molecular structure for the 2A2 state is predicted to have r e (AlO) = 1.940 A and r e (OO) = 1.354 A . The AlO2 dissociation energy is computed to be 65 kcal mol−1 using full counterpoise corrections. The ω2 mode (AlO symmetric stretch) of 529 cm−1 calculated at the CCSD(T) level is about 6% higher than the experimental value of 496 cm−1.
Enhancing teaching effectiveness and vitality in the ambulatory setting

Ambulatory care faculty are taking on a role of unprecedented importance. Development of methods to assist them in this important role is essential. I have not attempted to include all possible approaches to improve faculty effectiveness and enthusiasm in this paper. Nevertheless, I hope that the framework used in this article will provide a basis for thinking about the roles of ambulatory care faculty and the support system they need to remain effective and enthusiastic. These teachers are important to the changing field of medicine and medical education. They now deserve our attention.
The New Public Service? Applying the Public Service Motivation Model to Nonprofit Employees:

Research in the for-profit and public sectors has long sought to understand the factors affecting employee motivation but little is known concerning motivation of the nonprofit workforce. It has been suggested that nonprofit employees are an integral part of the new public service and are in many ways motivated to serve similar to public employees. To test this notion, this research presents an adapted version of Perry’s Public Service Motivation (PSM) Scale to examine motivation of nonprofit sector employees and empirically measures the level of service motivation of the nonprofit employees surveyed. The findings suggest that the modified version of Perry’s PSM Scale provides a good empirical model of nonprofit service motivation (NPSM). This provides support for the idea that nonprofit employees are largely attracted to their jobs because of the intrinsic rewards involved. In addition, the level of NPSM was found to be affected by attraction to mission, race, depth of involvement in the nonprofit sector...
Regulation of proopiomelanocortin messenger ribonucleic acid levels in the ovine fetal anterior pituitary in vitro.

Abstract Parturition in sheep is dependent upon maturation of the fetal hypothalamo-pituitary-adrenocortical (HPA) axis. Anterior pituitary expression of the ACTH precursor, proopiomelanocortin (POMC), increases during the final days of gestation in spite of exponentially increasing fetal plasma cortisol levels. Lesion of the hypothalamic paraventricular nucleus prevents the late gestation increase in POMC mRNA. The purpose of this study was to examine glucocorticoid, corticotropin releasing factor (CRF) and arginine vasopressin (AVP) regulation of POMC mRNA levels in fetal anterior pituitary corticotropes in vitro and to address potential interactions between glucocorticoids and neuropeptides in regulating POMC. Anterior pituitaries from fetal sheep at two gestational ages (dGA; 118–125 dGA, n =9; 140–144 dGA, n =7) were enzymatically dispersed. POMC mRNA levels were determined at 24, 48 and 72 h post-dispersion. CRF, AVP and dexamethasone (DEX) regulation of POMC mRNA were determined at 24 and 72 h post-dispersion. The capacity of CRF and AVP to modulate DEX suppression of POMC mRNA levels was also examined. POMC mRNA was elevated at 24 h ( P P P P
DUALITY CONSTRAINTS IN INCLUSIVE REACTIONS.

Abstract A possible implementation of the Harari-Freund conjecture on a dual model is shown to lead to the vanishing of the pomeron-pomeron-reggeon coupling and a unique criterion for the absence of nonscaling (secondary) terms in inclusive reactions.
Ecology: much to be done in the North

The Boreal Ecosystem. By James A. Larsen. Pp.500. ISBN 0-12-436880-8. (Academic: 1981.) $45, £29.80.
A Parametric Study of Acetabular Cup Design Variables Using Finite Element Analysis and Statistical Design of Experiments

To isolate the primary variables influencing acetabular cup and interface stresses, we performed an evaluation of cup loading and cup support variables, using a Statistical Design of Experiments (SDOE) approach. We developed three-dimensional finite element (FEM) models of the pelvis and adjacent bone. Cup support variables included fixation mechanism (cemented or noncemented), amount of bone support, and presence of metal backing. Cup loading variables included head size and cup thickness, cup/head friction, and conformity between the cup and head. Interaction between and among variables was determined using SDOE techniques. Of the variables tested, conformity, head size, and backing emerged as significant influences on stresses. Since initially nonconforming surfaces would be expected to wear into conforming surfaces, conformity is not expected to be a clinically significant variable. This indicates that head size should be tightly toleranced during manufacturing, and that small changes in head size can have a disproportionate influence on the stress environment. In addition, attention should be paid to the use of nonmetal backed cups, in limiting cup/bone interface stresses. No combination of secondary variables could compensate for, or override the effect of, the primary variables. Based on the results using the SDOE approach, adaptive FEM models simulating the wear process may be able to limit their parameters to head size and cup backing.
Ecological Cues and Experience Modify Interspecific Aggression By the Damselfish, Stegastes Fasciolatus

Stegastas fasciolatus ist ein allesfressender "Damselfish", der aber in erster Linie von Tiefwasseralgen lebt. Er verteidigt seinen Lebensraum und greift manchmal die anderen Pflanzenfresser an. Wenn eingefangene Fische dem Cichliden Sarotherodon mossambica (Tilapia) ausgesetzt sind, zeigen sie wenig Angriffslust gegen diese Raubfischart, die sie nie vorher kennengelernt hatten. Die Theorie, dass die S. fasciolatus ihre Konkurrenzarten an ihren Fressgewohnheiten erkennen, haben wir bereits untersucht. Damselfische wurden Tilapia ausgesetzt, die trainiert waren, wie Pflanzenfresser oder Planktonfresser zu leben. Das Mas der Angriffslust gegen diese Tilapia und 2 Arten "Surgeonfische" wurde beobachtet. Die Erfahrungen mit planktonfressenden Tilapia ergaben wenig Unterschiercle, bis auf den Ruckgang der Angriffslust gegen andere Tilapia. Erfahrungen mit pflanzenfresscnden Tilapia haben zweierlei Arten von Veranderungen hervorgerufen. Erstens zeigte die Angriffslust gegen Tilapia eine allgemeine Ansteigerung. Zweitens anderte sich die raummassige Verteilung und der Effekt von Reizmitteln, besonders des futterns, qualitativ den Surgeonfischen gegenuber. Das Endresultat hat bewiesen, dass lebenswirtschaftliche Veranderungen einen merklichen Wechsel und eine neue Art von Konkurrenz erzeugcn konnen. Die Art der Veranderung zeigt sich in der Beobachtung der Bewegungen wahrend des Fressens, sei es mit oder ohne Konkurrenz. Weitere Beobachtungen ergaben vorlaufige Ergebnisse in Betracht auf Zusammenhang zwischen der Qualitat des Territoriums und der interspecifischen Angriffslust.
Relative incomes and rates of return for U.S. physicians.

Since 1967 the supply of physicians in the U.S. has been growing by more than 3 percent per annum. This, coupled with public insurer fee discounts, might have been expected to depress both the relative and absolute incomes of physicians in spite of growing insurance coverage and new technologies. Real incomes of physicians did decline at a 0.2 percent annual rate between 1967 and 1980, but this was apparently due to economy-wide events since the income trends for lawyers, dentists, and college graduates were virtually identical. Internal rates of return to undergraduate medical training remained high--between 14 and 17 percent in 1980. Specialty training became more profitable for internists, general surgeons, and obstetricians/gynecologists (all with 10-15 percent rates of return), while pediatricians continued to suffer a financial loss. While Medicare and Medicaid fee discounts have been criticized as inequitable, the programs are also shown to provide a 'hidden subsidy' to physicians during residency training, materially adding to rates of returns.
GaN epilayers grown on 100 mm diameter Si(111) substrates

Abstract We have grown GaN epilayers, with a thickness of 1.3–1.5 μm, on 100 mm diameter Si(111) substrates. The GaN films were grown by using buffer layers consisting of 3C–SiC and 2H–AlN. The buffer layers had flat surfaces without showing any grain microstructure. The GaN films were also flat and smooth without noticeable micro-cracks but had slip lines. X-ray diffraction and electron diffraction analyses showed that each of the buffer layers and the GaN film were single-crystals. The room temperature PL showed that the FWHM was as low as 35.5 meV, the narrowest for all reported GaN/Si films grown by blanket MOCVD. Voids on the top of a Si substrate were generated during the conversion of the Si surface to 3C–SiC. The voids may facilitate the Si top surface to act as a compliant layer to alleviate the film stresses resulting from mismatches in lattice parameters and thermal expansion coefficients between the films and substrate. This may be the mechanism that prevented films from cracking.
Leishmania donovani Infection Induces Anemia in Hamsters by Differentially Altering Erythropoiesis in Bone Marrow and Spleen

Leishmania donovani is a parasite that causes visceral leishmaniasis by infecting and replicating in macrophages of the bone marrow, spleen, and liver. Severe anemia and leucopenia is associated with the disease. Although immune defense mechanisms against the parasite have been studied, we have a limited understanding of how L. donovani alters hematopoiesis. In this study, we used Syrian golden hamsters to investigate effects of L. donovani infection on erythropoiesis. Infection resulted in severe anemia and leucopenia by 8 weeks post-infection. Anemia was associated with increased levels of serum erythropoietin, which indicates the hamsters respond to the anemia by producing erythropoietin. We found that infection also increased numbers of BFU-E and CFU-E progenitor populations in the spleen and bone marrow and differentially altered erythroid gene expression in these organs. In the bone marrow, the mRNA expression of erythroid differentiation genes (α-globin, β-globin, ALAS2) were inhibited by 50%, but mRNA levels of erythroid receptor (c-kit, EpoR) and transcription factors (GATA1, GATA2, FOG1) were not affected by the infection. This suggests that infection has a negative effect on differentiation of erythroblasts. In the spleen, erythroid gene expression was enhanced by infection, indicating that the anemia activates a stress erythropoiesis response in the spleen. Analysis of cytokine mRNA levels in spleen and bone marrow found that IFN-γ mRNA is highly increased by L. donovani infection. Expression of the IFN-γ inducible cytokine, TNF-related apoptosis-inducing ligand (TRAIL), was also up-regulated. Since TRAIL induces erythroblasts apoptosis, apoptosis of bone marrow erythroblasts from infected hamsters was examined by flow cytometry. Percentage of erythroblasts that were apoptotic was significantly increased by L. donovani infection. Together, our results suggest that L. donovani infection inhibits erythropoiesis in the bone marrow by cytokine-mediated apoptosis of erythroblasts.
Frustration and dynamics

Dynamical models incorporating frustration are discussed in general. In particular, it is shown how self-screening of Yang-Mills fields may lead to models of a generalized Ma-Rudnick genre for the spin-glass.
Reverse transcription complex: the key player of the early phase of HIV replication.

The early events of retroviral replication following virus–cell fusion and preceding integration of the viral genome into cellular chromatin occur within a context of a large multimolecular complex termed reverse transcription or preintegration complex. While some of the functions of these complexes (e.g., reverse transcription) are well described, most other events involved in assembly and processing of reverse transcription complexes, such as viral uncoating and nuclear transport, are poorly understood, and available data are very controversial. This article reviews the current literature on structure and function of reverse transcription complexes, focusing on the least known and most controversial steps.
Multiple Isolations of Eastern Equine Encephalitis and Highlands J Viruses from Mosquitoes (Diptera: Culicidae) During a 1996 Epizootic in Southeastern Connecticut

Thirty-six isolations of eastern equine encephalitis virus were obtained from 8 species of mosquitoes collected from 5 September through 18 October 1996 during an epizootic in southeastern Connecticut. These included Culiseta melanura (Coquillett) (19 isolates), Culex pipiens L. (8), Culiseta morsitans (Theobald) (3), Aedes sollicitans (Walker) (2), Aedes cantator (Coquillett) (1), Aedes trivittatus (Coquillett) (1), Aedes vexans (Meigen) (1), and Coquillettidia perturbans (Walker) (1). Isolations from Ae. cantator and Ae. trivittaus are new to North American records, and those from Ae. cantator and Ae. sollicitans represent the first infections of human-biting, salt-marsh mosquitoes with eastern equine encephalitis virus in Connecticut. With one exception, eastern equine encephalitis-infected Cs. melanura were found at all sites where eastern equine encephalitis virus was isolated. The large number of eastern equine encephalitis isolations from Cs. melanura and the collection of infected mosquitoes in residential woodlots and coastal salt marshes away from traditional red maple or white cedar swamp habitats, reaffirm the importance of local populations of this mosquito for viral amplification and dispersal from swamp foci. Highlands J virus was more widespread geographically, but fewer isolations of this virus were made from fewer species of mosquitoes. These included Cs. melanura (8 isolates), Cx. pipiens (5), Ae. vexans (3), Aedes canadensis (Theobald) (1), Ae. cantator (1) and Cs. morsitans (1). No human or horse cases of eastern equine encephalitis were reported, although this represents the largest number of isolations for eastern equine encephalitis ever recovered from field-collected mosquitoes in Connecticut.
The distribution of individual inbreeding coefficients and pairwise relatedness in a population of mimulus guttatus

In order to infer population structure at the individual level, we estimated individual inbreeding coefficients and examined the relationship between geographical distance and genetic relatedness from polymorphic microsatellite data for a population of Mimulus guttatus that has an intermediate selfing rate. Expected heterozygosities for five microsatellites ranged from 0.79 to 0.93. The population inbreeding coefficient was calculated to be 0.19 (SE=0.023). A method-of-moments estimator developed by Ritland (1996b) was used to estimate the distribution of inbreeding among and relatedness between individuals of a natural population. The mean individual inbreeding coefficient (F=0.16) did not differ significantly from the population-level estimate. Most of the individuals appeared to be outbred, and there were very few plants that had estimated inbreeding coefficients greater than one-half. Individuals sampled from one transect showed significantly more inbreeding than individuals sampled along the other (P=0.005). There was no apparent relationship between interplant distance (range: 0–14 m) and mean genetic relatedness between individuals. These results represent the first application of polymorphic microsatellites to estimate fine-scale genetic population structure.
Consistency relations for double-step strain experiments

Consistency relations for double-step strain deformations are formulated and applied in the evaluation of three constitutive models for nonlinear viscoelastic behavior: the Doi-Edwards model without the independent alignment approximation, an integral viscoanelastic model, and a strain-coupling model. The shear stress data were in reasonable accord with the consistency relation for the strain-coupling constitutive equation
On boundary misorientation distribution functions and how to incorporate them into three-dimensional models of microstructural evolution

The fundamental difficulties of incorporating experimentally obtained boundary misorientation distributions (BMDs) into three-dimensional microstructural models are discussed. An algorithm is described which overcomes these difficulties. The boundary misorientations are treated as a statistical ensemble which is evolved toward the desired BMD using a Monte Carlo method. The application of this algorithm to a number of complex arbitrary BMDs shows that the approach is effective for both conserved and non-conserved textures. The algorithm is successfully used to create the BMDs observed in deformation microstructures containing both incidental dislocation boundaries (IDBs) and geometrically necessary boundaries (GNBs). The application of an algorithm to grain boundary engineering is discussed.
Line integration of Ricci curvature and conjugate points in Lorentzian and Riemannian manifolds

Generalizing results of Cohn-Vossen and Gromoll, Meyer for Riemannian manifolds and Hawking and Penrose for Lorentzian manifolds, we use Morse index theory techniques to show that if the integral of the Ricci curvature of the tangent vector field of a complete geodesic in a Riemannian manifold or of a complete nonspacelike geodesic in a Lorentzian manifold is positive, then the geodesic contains a pair of conjugate points. Applications are given to geodesic incompleteness theorems for Lorentzian manifolds, the end structure of complete noncompact Riemannian manifolds, and the geodesic flow of compact Riemannian manifolds.
The status of sea turtles under International environmental law and International environmental agreements

(2002). The status of sea turtles under International environmental law and International environmental agreements. Journal of International Wildlife Law & Policy: Vol. 5, International Instruments and Marine Turtle Conservation, pp. 11-48.
Large-scale purification of synthetic oligonucleotides and carcinogen-modified oligodeoxynucleotides on a reverse-phase polystyrene (PRP-1) column.

Abstract A procedure is described for the large-scale purification of synthetic oligonucleotides using a polystyrene (PRP-1, Hamilton Co.) high-performance liquid chromatography (HPLC) column with a phosphate/methanol/acetonitrile solvent system. Pure oligonucleotides are obtained with a three-step procedure that involves only one column purification step. The dimethoxytrityl group is left on the oligomer for the HPLC purification. The use of the PRP-1 polystyrene column with a phosphate/methanol/acetonitrile solvent system provides excellent separation of the desired dimethoxytrityl-bearing oligonucleotide from failure sequences. The dimethoxytrityl group is removed by treatment with acetic acid and the oligonucleotide is desalted on a C-18 Sep-Pak cartridge. The oligodeoxynucleotides obtained are shown to be essentially pure by HPLC, polyacrylamide gel electrophoresis, and 500-MHz NMR spectroscopy. This procedure is especially useful for the largescale purification of oligonucleotides required for NMR studies. The PRP-1 column and the phosphate/methanol/acetonitrile solvent system is useful for purifying modified oligonucleotides containing lipophilic groups such as the carcinogen 2-(acetylamino)fluorene.
Intimal Thickening in Normochoiesterolemic Rhesus Monkeys Fed Low Supplements of Dietary Cholesterol

Rhesus monkeys were fed a high-fat diet containing either 0, 43, or 129 µg/kcal of cholesterol for 18 months. In the monkeys on the cholesterol-supplemented diets, changes in plasma cholesterol remained within the range found in monkeys fed the cholesterol-free diet. Monkeys on the cholesterol-supplemented diets were compared with monkeys given no dietary cholesterol with range-matched plasma cholesterol; intimal thickness of the aorta and branch arteries, distribution of lipoprotein cholesterol, and tissue content of cholesterol in aorta and liver were considered. The monkeys on the cholesterol-supplemented diets showed intimal thickening with more sudanophilia and increased aortic cholesterol, a decrease in plasma high-density lipoprotein cholesterol, and an increase in low-density lipoprotein cholesterol, and the monkeys fed the higher amount of dietary cholesterol showed an increase in hepatic cholesterol. No null point for the effect of dietary cholesterol on arterial intima was found even at an intake level far below that conventionally used for the induction of experimental atherosclerosis in the nonhuman primate. The intimal changes found in response to very low cholesterol intake imply that subtle qualitative alterations in lipoproteins are of critical importance to our understanding of lesion induction.
Seasonal variations in light scattering in the New York region and their relation to sources

Abstract Light scattering data collected during two periods of intensive sampling in New York City (one during summer months and one during winter months) are discussed and analyzed for diurnal patterns, their relationship to pollutant emission sources, meteorological parameters, and the size distribution and chemical composition of the ambient aerosol. The lack of a diurnal pattern for light scattering in summer in combination with a strong positive association with ozone and wind direction dependency suggests that in summer the transport of an aged aerosol in photochemically rich air masses rather than local emissions of primary pollutants is largely responsible for the observed levels of light scattering in New York City. Winter levels of light scattering observed in New York City, while approx. 50% lower than summer levels, were much less dependant on wind direction and closely related to pollutant emissions from local sources. This suggests that locally generated aerosol dominates light scattering in the winter. Particles 0.1–1.3 μm in diameter were strongly correlated with light scattering in New York City during both summer and winter periods. However, a given volume of aerosol between 0.1 and 1.3 μm scattered more light in summer than in winter, indicating the fresher nature of the winter aerosol. Variance in dry particulate light scattering was found to principally account for light extinction variance (calculated from airport visibility observations) in summer and winter. Sulfate aerosol was strongly correlated with light scattering during both summer and winter periods.
Randomized trial of a health IT tool to support between-visit-based laboratory monitoring for chronic disease medication prescriptions.

Background Lack of timely medication intensification and inadequate medication safety monitoring are two prevalent and potentially modifiable barriers to effective and safe chronic care. Innovative applications of health information technology tools may help support chronic disease management.
Separation and characterization of red blood cells with different membrane deformability using steric field-flow fractionation

Human red blood cells were treated in different ways to alter their membrane deformability, and the hydrodynamic behavior of these altered cells was studied using the steric field-flow fractionation (FFF) technique. The relationships between cell retention in the FFF channel, flow-rate of the carrier fluid and the applied field strength were studied for normal and glutaraldehyde-fixed human red cells, and separation conditions were optimized. The effect of flow-induced hydrodynamic lift forces on red cell retention in the steric FFF channel was studied, and the results suggest that the membrane deformability of the red cell is an important factor contributing to the lift force, besides other previously described effects due to density and flow velocity. Using steric FFF, a mixture of normal and glutaraldehyde-fixed human red cells was completely separated with a resolution twice that found in published data from gel permeation, another hydrodynamic separation technique. Partial loss of membrane deformability, induced by different degrees of glutaraldehyde-fixation, by diamide, or by a thermal treatment, has also been studied. Steric FFF is thus shown to have potential for rapid separation and differentiation of red cells with different density and membrane deformability, conditions known to be associated with, e.g., cell senescence and certain hematological diseases.
An interface-based Ada programming support environment

Programming Support Environments (PSEs) have recently been the focus of much research directed at producing new methods for developing software more efficiently and reliably. The traditional approach to developing PSEs has been to create a number of novel tools, and then integrate the tools together by adding a common database and modifying the interfaces between the tools until they can work together. Recently, however, it has been recognized that the interfaces between the tools and the rest of the environment are critical, and perhaps more important, than the tools themselves. To be useful in solving the larger problems currently associated with software, a PSE must be able to adapt and provide new capabilities, and be available to a relatively large number of users on a variety of machines.The goal of this research was to determine whether PSEs based on abstract interfaces provide enhanced portability and extensibility over traditionally designed environments. To accomplish this goal, a prototype interface-based PSE was developed and then compared against traditional environments to determine which had better portability and extensibility. First, an interface model was developed to define exactly what types of interface assumptions must be specified to define an appropriate abstract interface. Next, a prototype APSE based on that interface model was designed, specified, and implemented. Finally, this prototype APSE was measured against traditionally designed environments using original environment portability and extensibility metrics.
Towards a patient-specific modeling II: biomechanics of a growing aneurysm

Recent advances in medical imaging, computational methods, and biomechanics hold great promise for engineering-based decision making in clinical practice. Towards patient-specific modeling, however, we need to synthesize better the separate advances in computational biofluid mechanics and arterial wall mechanics. In this paper, we propose a mathematical model of growing fusiform aneurysms that is able to test multiple competing hypotheses with regard to the production, removal, and organization of intramural collagen, and thus to predict their consequences in enlargement and changes in material properties of the lesion. To apply this model to realistic cases, including fluid-solid interactions, we also need to develop a method to exploit current advances in computational biofluid mechanics. Thus, we describe a method to represent highly nonlinear and anisotropic material behaviors within a linearized constitutive equation commonly employed in fluid-structure simulations of blood flow in deformable arteries.
Components of cancer metabolism and therapeutic interventions

All forms of life share a common indispensible need of energy. The requirement of energy is necessary for an organism not only to survive but also to thrive. The metabolic activities in normal cells rely predominately on mitochondrial oxidative phophorylation for energy generation in the form of ATP. On the contrary, cancer cells predominately rely on glycolysis rather than oxidative phosphorylation. It is long believed that an impairment of mitochondrial oxidative phosphorylation is the cause of this glycolytic phenotype observed in cancers. However, studies in cancer metabolism have revealed that mitochondrial function in many cancers is intact. It has also been observed that cancers utilize various forms of metabolism. The various metabolic phenotypes that are employed by cancer cells have a common purpose, to balance macromolecular biosynthesis and sufficient ATP production in order to support the rapid proliferation rate characteristic of these aberrant cells. These metabolic pathways are attractive targets for possible therapeutic interventions and currently research is underway to meet this end. More importantly, normal cells have essentially the same metabolic requirements as cancer cells so finding an approach to target these metabolic pathways without incurring detrimental effects on normal tissues remains the challenge.
Study of spin-polarized transport properties for spin-FET design optimization

A Monte Carlo method developed previously for spin dynamics is applied to study spin-polarized transport properties of two-dimensional electron gas in semiconductor spin-FET structure. The specific symmetry of spin-orbit terms (Rashba and Dresselhaus) leads to strong anisotropy of spin dynamics in the low field regime. Coherent spin evolution and spin dephasing are investigated for different orientations of the device channel related to the crystallographic axes. Efforts have been made to suppress spin dephasing while conserving coherent oscillation of spin polarization required for spin-FET design. Results derived from this study provide useful information to assist in optimization of the spin-FET performance.
Characteristic Biological Effects of Anionic Polymers

Polyanions are polyelectrolytes with negative charges that reside on pendant groups attached to the backbone of the polymer chain. Both natural polyanions such as heparin and heparinoids and synthetic polyanions such as polyacrylic acid and pyran produce a variety of biological activities which have been discussed in detail [1,2]. These biological effects include induction of interferon and antiviral activity including inhibition of Maloney sarcoma, Rauscher leukemia, Friend leukemia, polyoma, vesicular stomatitis virus, Mengo, encephalomyocarditis, and foot-and-mouth disease.
Fundamentals of energy-constrained sensor network systems

This article is an overview of energy-constrained sensor networks, focusing on energy-conserving communications and signal processing strategies. We assume battery-driven nodes, employing robust communications, with little or no fixed infrastructure. Our discussion includes architectures, communications connectivity, capacity and scalability, mobility, network localization and synchronization, distributed signal processing, and cross-layer issues. Because energy is a precious system resource, all aspects of the network must be designed with energy savings in mind. In particular, transmissions and idle listening must be minimized, which implies the use of duty cycling to the maximum extent possible. When external assets are available, for tasks such as network synchronization and node geolocation, these can greatly relieve the energy burden and significantly enhance network lifetime.
AfPIF: Growing Africa's Internet Infrastructure

Africa Peering and Interconnection Forum (AfPIF) conferences have provided opportunities for discussing and addressing technical challenges and opportunities for Internet development in Africa, particularly around the establishment of Internet exchange points (IXPs). They've also provided a unique opportunity for participants to build personal relationships for sharing problems, solutions, and successes.
Service disciplines for guaranteed performance service in packet-switching networks

While today's computer networks support only best-effort service, future packet-switching integrated-services networks will have to support real-time communication services that allow clients to transport information with performance guarantees expressed in terms of delay, delay jitter, throughput, and loss rate. An important issue in providing guaranteed performance service is the choice of the packet service discipline at switching nodes. In this paper, we survey several service disciplines that are proposed in the literature to provide per-connection end-to-end performance guarantees in packet-switching networks. We describe their mechanisms, their similarities and differences and the performance guarantees they can provide. Various issues and tradeoffs in designing service disciplines for guaranteed performance service are discussed, and a general framework for studying and comparing these disciplines are presented. >
Epstein-Barr Virus DNA Loads in Adult Human Immunodeficiency Virus Type 1-Infected Patients Receiving Highly Active Antiretroviral Therapy

Patients with human immunodeficiency virus type 1 (HIV-1) infection are at high risk of developing Epstein-Barr virus (EBV)-associated lymphoma. However, little is known of the EBV DNA loads in patients receiving highly active antiretroviral therapy (HAART). Using a real-time quantitative polymerase chain reaction assay, we demonstrated that significantly more HIV-1-infected patients receiving HAART than HIV-1-uninfected volunteers had detectable EBV DNA in blood (57 [81%] of 70 vs. 11 [16%] of 68 patients; P=.001) and saliva (55 [79%] of 68 vs. 37 [54%] of 68 patients; P=.002). The mean EBV loads in blood and saliva samples were also higher in HIV-1-infected patients than in HIV-1-uninfected volunteers (P=.001). The frequency of EBV detection in blood was associated with lower CD4+ cell counts (P=.03) among HIV-1-infected individuals, although no differences were observed in the EBV DNA loads in blood or saliva samples in the HIV-1-infected group. Additional studies are needed to determine whether EBV-specific CD4+ and CD8+ cells play a role in the pathogenesis of EBV in HIV-1-infected patients receiving HAART.
A template-propagation method for segmentation of filamentous structures in electron tomograms

We report a method for semi-automated segmentation of extended features such as filamentous structures in electron tomograms. We present an application of this method for the automatic propagation of segmented neuro-filaments present along the axis of an axonal section of fixed, plastic-embedded mouse brain tissue imaged by three-dimensional electron microscopy. The algorithm uses the manually segmented features in a given slice to progressively extend the segmentation to successive slices based on knowledge of the centroids, shapes, and intensities of filaments in the previous slice. An iterative procedure allows for refinement of the most probable locations of the filaments in each slice. Evaluation of the performance of the propagation algorithm by visual inspection suggests that this approach can be used successfully for the rapid quantitative and statistical analysis of filamentous structures in cellular tomograms.
An Improved Split-Row Threshold Decoding Algorithm for LDPC Codes

We present an improved thresholding LDPC decoding algorithm which outperforms the Split-Row and original Split-Row Threshold decoders with a small increase in hard-ware. Simulation results show that the algorithm provides 0.27- 0.50 dB coding gain over Split-Row, 0.10-0.20 dB over Split-Row Threshold, and is within 0.08-0.13 dB of SPA. Compared with the original Threshold algorithm the check node processor's gate count is increased by 3% while total chip area is kept the same.
Optimal quadratic regulation for discrete-time switched linear systems: A numerical approach

This paper studies the discrete-time linear quadratic regulation problem for switched linear systems (DLQRS) based on dynamic programming approach. The unique contribution of this paper is the analytical characterizations of both the value function and the optimal control strategies for the DLQRS problem. Based on the particular structures of these analytical expressions, an efficient algorithm suitable for solving an arbitrary DLQRS problem is proposed. The algorithm is also tested through simulations on a number of second-order DLQRS problems. Simulation results indicate that the proposed algorithm can solve the second-order DLQRS problems with very low computational complexity. The theoretical analysis in this paper dramatically simplifies the computation, making an NP hard problem numerically tractable.
3D Electrothermal Simulation of Heterostructure Thin Film Micro-Coolers

A 3D electrothermal model is used to simulate and optimize Si/SiGe superlattice heterostructure micro-coolers. The model considers thermoelectric/thermionic cooling, heat conduction and Joule heating. It also includes non-ideal effects, such as contact resistance between metal and semiconductor, substrate/heatsink thermal resistance, the side contact resistance. The simulated results match very well with the experimental cooling curves for various device sizes ranging from 60×60μm2 up to 150×150μm2 . It is found that the key factor limiting maximum cooling is metal semiconductor contact resistance. The maximum cooling could be doubled if we remove the metal-semiconductor contact resistance. The thin film Si/SiGe superlattice micro-coolers can provide cooling power density over 500 W/cm2 as compared with a few W/cm2 of bulk Bi2 Te3 themoelectric coolers. This micro-cooler experimentally demonstrated a maximum cooling of 4.5°C at room temperature and 7°C of cooling at 100°C ambient temperature. It is a promising candidate for microprocessor spot cooling.Copyright © 2003 by ASME
Attenuation and speed of antiplane shear wave in fiber-reinforced composites with random interfacial cracks

Abstract Effects of fiber–matrix interfacial debonding on the attenuation and speed of antiplane shear wave propagating in fiber-reinforced composites are investigated. A probabilistic approach is proposed based on the scattering analysis of a single representative fiber from randomly distributed fibers with random interfacial cracks. The average total cross-section of the representative fiber is obtained using assumed probability distributions, and then the causal differential method is applied to calculate the effective wave speed and coherent attenuation. For a composite with low fiber volume fraction, the results are compared with those from other theories. When the mean crack size exceeds a certain subtending angle, the interfacial debonding affects significantly dynamic behaviors of the composite. The attenuation changes mainly in low frequency region quite sensitively to the variance of the crack length, whereas the variation of wave speed takes place in the whole frequency range considered.
The effects of metadata corruption on nfs

Distributed file systems need to be robust in the face of failures. In this work, we study the failure handling and recovery mechanisms of a widely used distributed file system, Linux NFS. We study the behavior of NFS under corruption of important metadata through fault injection. We find that the NFS protocol behaves in unexpected ways in the presence of these corruptions. On some occasions, incorrect errors are communicated to the client application; inothers, the system hangs applications or crashes outright; in a few cases, success is falsely reported when an operation has failed. We use the results of our study to draw lessons for future designs and implementations of the NFS protocol.