cssi/SciSciGPT-SciSciNet huggingface dataset:
Uplink Resource Allocation in IEEE 802.11ax

One of the notable features of the upcoming Wireless Fidelity (Wi-Fi) standard&#x2014;namely, IEEE 802.11ax&#x2014;is the use of Multi-User Orthogonal Frequency Division Multiple Access (MU-OFDMA). MU-OFDMA facilitates multiple users to transmit simultaneously in smaller sub-channels (a.k.a. resource units (RUs)), thereby improving the 802.11ax MAC efficiency. The 802.11ax MAC enables MU-OFDMA transmissions in the uplink (UL) by using two types of RUs: i) Random Access (RA) RUs, and ii) Scheduled Access (SA) RUs. In this paper, we investigate the impact of different distributions of RA RU and SA RU on the MAC layer performance. We leverage our analysis in devising a practical UL RU allocation scheme that maximizes the overall 802.11ax network throughput. We implement the 802.11ax MAC in network simulator-3 (NS-3) and perform extensive simulations to validate the efficacy of our proposed scheme.
Coiled-Coil Domains for Self-Assembly and Sensitivity Enhancement of Protein–Polymer Conjugate Biosensors

While protein self-assembly has been used to improve the performance of biosensors and biocatalysts, few general techniques have been demonstrated to achieve well-ordered protein arrays under the h...
Chapter 142 – Island Biogeography

Publisher Summary This chapter discusses island biogeography. Studies of insects have played a major role in the general understanding of the biota of islands, touching on all areas of biogeography, ecology, evolution, and conservation. Larger islands contain more species. MacArthur and Wilson formalized this idea in the 1960s with the development of the Equilibrium Theory of Island Biogeography (ETIB). The premise of the theory is that the rate of immigration decreases with increasing distance from the source, whereas the rate of extinction decreases with increasing island size. The balance of these processes results in an equilibrium number of species on any one island. As the number of resident species on an island increases, the chance of an unrepresented species arriving on that island decreases and the likelihood of extinction of any one resident species increases. The ETIB assumes that islands are within the geographic distance that a species is likely to disperse, thus maintaining genetic populations between source and island populations. On islands that are beyond the range within which populations can maintain genetic contact with source populations, one might predict that few species should be present. The biota of islands is often unique — for example, the islands of the Pacific have been designated a biodiversity hotspot. Assessing this diversity, particularly for arthropods, is problematic. The major impediment is a lack of taxonomic understanding of arthropods on many islands, particularly those that are more remote.
Racial disparities in peripartum cardiomyopathy: eighteen years of observations

Background: Black women have greater than a three-fold risk of pregnancy-associated death compared to White women; cardiomyopathy is a leading cause of maternal mortality.Objectives: This study exa...
Undernutrition and Hypoleptinemia Modulate Alloimmunity and CMV-specific Viral Immunity in Transplantation.

BACKGROUND Immunological mechanisms linking undernutrition to infection and the alloimmune response are poorly understood in transplantation. We aimed to determine how undernutrition and hypoleptinemia impact T-cell allospecific and cytomegalovirus (CMV) viral-specific immunity in a murine model. METHODS Fed, fasted for 48 h (model of undernutrition), and fasted with leptin injections (leptin rescue), C57BL/6 mice received skin grafts from either C57BL/6 (syngeneic) or BALB/c (allogeneic) mice donors. Allograft rejection and survival were monitored. Fed, fasted, and leptin rescue C57BL/6 mice were inoculated with murine cytomegalovirus (mCMV). Mouse spleens were retrieved for T-cell flow cytometry analysis, mCMV DNA extraction, and quantitative polymerase chain reaction. Serum leptin levels were measured with ELISA. RESULTS Fasted mice had prolonged rejection-free and graft survival compared with fed mice (P = 0.0002 and P = 0.043). Leptin administration did not alter rejection-free survival or allograft failure. CD8+ central memory T cell and CD8+ effector T cell proportions were significantly lower in fasted mice receiving allogeneic skin transplants compared with fed mice (P = 0.0009 and P = 0.0015). Fasted mice had higher viral loads (P = 0.0028) and impaired mCMV-specific interferon-gamma-producing CD8+ T cells (P = 0.0007), which improved with leptin rescue (P = 0.032). CONCLUSIONS Undernutrition and its associated hypoleptinemia correlated with impaired allospecific and viral-specific immunities. Leptin administration decreased mCMV viral burden and increased mCMV-specific T-cell immunity, however, it did not increase rejection or worsen graft survival in complete major histocompatibility complex-mismatched skin allografts. Leptin may be a potential adjunctive therapy for CMV viremia in undernourished transplant recipients.
Racial-ethnic disparities in pain intensity and interference among middle-aged and older U.S. adults.

Background This study aims to better understand differing pain experiences across U.S. racial/ethnic subgroups by estimating racial-ethnic disparities in both pain intensity and domain-specific pain-related interference. To address this issue, we use a nationally-representative sample of non-Hispanic White, non-Hispanic Black, and Hispanic adults ages 50+ who report recently experiencing pain. Methods Using data from the 2010 wave of the Health and Retirement Study (HRS; N=684), we conducted a series of multivariate analyses to assess possible racial/ethnic disparities in pain intensity and seven domains of pain interference, controlling for relevant sociodemographic variables and other health problems. Results Black and Hispanic participants reported higher pain intensity than White participants after controlling for socioeconomic status (SES) and other health conditions. Both Black and Hispanic individuals reported more domain-specific pain interference in bivariate analyses. In multivariate analyses, Black (vs. White) participants reported significantly higher levels of pain interference with family-home responsibilities, occupation, sexual behavior, and daily self-care. We did not find significant Hispanic-White differences in the seven pain interference domains, nor did we find Black-White differences in three domains (recreation, social activities, and essential activities). Conclusions Our findings highlight the need for using multi-dimensional measures of pain when assessing for possible pain disparities with respect to race/ethnicity. Future studies on pain interventions should consider contextualizing the pain experience across different racial subgroups to help pain patients with diverse needs, with the ultimate goal of reducing racial/ethnic disparities in pain.
Biosensors for single-cell metabolomic characterization

Abstract Single-cell analysis is an emerging area to reveal the heterogeneity of individual cells among all populations. Understanding the cell-to-cell variation can greatly promote the development of drug discovery, disease diagnostics, and prognostics. Metabolites, the end products of cellular metabolism, directly reflect the phenotype, status, and microenvironment of cells. Single-cell metabolomics is the study of complete metabolites’ profiles in individual cells under certain conditions, illustrating the biological heterogeneity among different cells. Numerous studies of single-cell metabolomics have been achieved, and the pioneering work is benefited from technology development in this field. The analytical techniques utilized for single-cell metabolomics primarily include fluorescence, electrochemical analysis, and mass spectrometry, whereas the integration of different analytical tools can provide additional molecular information of single cells. Here, we briefly summarized the recent developments of technologies with examples. We expect that more exciting studies will appear in this fascinating field with future development of new analytical techniques.
Dynamics of Unimolecular Reactions

The subject of unimolecular dynamics deals with the intermolecular and intramolecular microscopic details of unimolecular reactions. Theories of unimolecular dynamics are concerned with molecular motion over potential energy surfaces and the behavior of molecular coordinates as a function of time. Most studies of unimolecular reactions have involved measurements and predictions of the rate at which an energized molecule will undergo a uni-molecular reaction. The basic postulate of all unimolecular theories is the rapidity of intramolecular vibrational energy relaxation. Experimentalists were awarded a rare opportunity to test two conflicting assumptions regarding this postulate by the simultaneous advent of the Slater(1) and Rice-Ramsperger-Kassel-Marcus (RRKM)(2) theories in the 1950s. Slater’s theory, which is dynamical, pictures a molecule as an assembly of harmonic oscillators. Within this framework vibrational energy relaxation between the normal modes is forbidden, and reaction occurs only when some coordinate, the reaction coordinate, reaches a critical extension by superposition of the various normal modes. In contrast, the RRKM theory, which is an extension by R. A. Marcus of the statistical theory developed by O. K. Rice, H. C. Ramsperger, and L. S. Kassel, assumes rapid relaxation of vibrational energy. The experimental tests overwhelmingly endorsed the RRKM theory, and the controversy involving intramolecular vibrational energy relaxation was seemingly laid to rest. It also appeared as though dynamical treatments of unimolecular reactions were unnecessary.
Metastatic Cancer Involving the Eye

Ten years ago this 52-year-old woman had a stage II adenocarcinoma of the left breast (estrogen receptor/progesterone receptor — ER/PR — positive) managed by a modified mastectomy and 1 year of adjuvant chemotherapy. Her present complaint is decreasing vision in her left eye. Visual acuity is 20/400 and ultrasound shows a mass in the choroid which corresponds to an 8-disk diameter mass in the inferior temporal portion of the fundus.
Degradation of Dielectric Films by XeF Excimer Intermediates

Many excimer laser designs require optical component surfaces to be in contact with both optical radiation and reactive components of the gain medium. The resulting environmental degradation of coatings on mirrors or windows is analyzed by isolating intermediates from the XeF gain medium and measuring quantitatively corrosive interaction between these species and the dielectric surfaces. Particular attention will be given to SiO 2 films whose reaction with XeF 2 and NF 2 with and without additional stimulation by ions will be Surveyed 2 . Temperature effects of the film substrate as well as the importance of synergistic effects for the stability of the SiO 2 coatings will be discussed.
Predicting Drug–Target Interactions Using Probabilistic Matrix Factorization

Quantitative analysis of known drug–target interactions emerged in recent years as a useful approach for drug repurposing and assessing side effects. In the present study, we present a method that uses probabilistic matrix factorization (PMF) for this purpose, which is particularly useful for analyzing large interaction networks. DrugBank drugs clustered based on PMF latent variables show phenotypic similarity even in the absence of 3D shape similarity. Benchmarking computations show that the method outperforms those recently introduced provided that the input data set of known interactions is sufficiently large—which is the case for enzymes and ion channels, but not for G-protein coupled receptors (GPCRs) and nuclear receptors. Runs performed on DrugBank after hiding 70% of known interactions show that, on average, 88 of the top 100 predictions hit the hidden interactions. De novo predictions permit us to identify new potential interactions. Drug–target pairs implicated in neurobiological disorders are o...
Replication of bacteriophage M13: VI. Attachment of M13 DNA to a fast-sedimenting host cell component☆

Abstract During RF 3 replication both parental and pulse labeled M13 DNA are associated with a fast sedimenting host cell component, tentatively identified as membrane. RF molecules containing parental label have equal amounts of linear and circular parental strands. Most of the pulse label in RF molecules is contained in strands of unit length or shorter. The proportion of pulse-labeled M13 DNA associated with membrane decreases with increasing pulse lengths. The freely sedimenting M13 DNA components are identified as RFI and RFII. Pulse label is found in both strands of membrane bound RFII, but in only the viral strand of freely sedimenting RFII. M13 DNA pulse labeled during single-strand synthesis also appears to be membrane associated, the proportion decreasing with increasing pulse lengths. The pulse label is contained exclusively in the viral strand of the bound RF molecules.
Challenges in Commercial Biotechnology. Part II. Product, Process, and Market Development

Publisher Summary The development process begins after the complete discovery of the product. This is a very lengthy, expensive, and tightly regulated process. Pharmaceutical companies spend much of the product development conducting clinical trials required to pass the safety, efficacy, and quality requirements of the drug, followed by the FDA review and approval. Product development also includes pharmaceutical development of dosage forms and formulations. In parallel with product development, process development is carried out. In microbial process biotechnology, it may start at the time of product discovery, when a new microbial product is available and when an appreciable amount of product is needed for chemical characterization. The technical development is expanded when a compound is more advanced and enters more extensive biological and preclinical test. Further process improvements and scale-up are needed for clinical tests and as the production decision is near. In addition, market development begins with the cost/benefit analysis, grows with product innovation, and peaks with capturing a substantial share of market.
On the Origin of Helicity in Active Region Magnetic Fields

The magnetic helicity H of flux tubes can be separated into twist T and writhe W (Moffatt & Ricca 1992). If magnetic flux rises in Ω-shaped loops through the convection zone (Babcock 1961), it acquires writhe through the Coriolis force on internal longitudinal flows (Fan, Fisher, & DeLuca 1993). The tilt θ of active regions with respect to the equator is an observable manifestation of such writhe, at photospheric levels. If H is conserved, as we expect (Taylor 1974), rising flux should acquire equal and opposite values of T and W. We expect W > 0 (θ < 0) in the Northern hemisphere, since the leading polarity of active regions tends to be closer to the equator. Hence, we expect T < 0 there.
Membrane electrofusion: a paradigm for study of membrane fusion mechanisms.

Publisher Summary This chapter describes the status of the electrofusion paradigm as it applies to the study of membrane fusion mechanisms. It explains the requirements for obtaining electrofusion in erythrocyte membranes (and its applicability to other membrane systems). Electrofusion is an interdisciplinary method, which is simple in overall concept, has novel characteristics, and is used successfully in many laboratories for various purposes and applications. Electrofusion depends on the use of a specific electric field treatment as a fusogen. Electrofusion has characteristics, which offer unique experimental access to the fusion event for mechanistic studies. For practical applications, electrofusion provides much higher fusion yields than chemical fusogens. It allows fusion to occur at low yields when chemical fusogens completely fail or have other undesirable characteristics. The four features of electrofusion, which may confer unique and advantageous characteristics to a mechanistic-oriented experiment are (1) it is nonchemical, (2) the fusogenic membrane alteration can be applied simultaneously to all membranes, (3) fusions can be induced in high yields, and (4) electrofusion is broadly applicable to a wide variety of cell and membrane types, including vesicular membranes.
Morphogenesis of intestinal villi. II. Mechanism of formation of previllous ridges.

Villi lining the avian intestine originate from longitudinal folds (previllous ridges) running the length of the embryonic intestine. The morphogenetic events that occur in the epithelium during initial ridge formation in the chick embryo duodenum were examined by light and electron microscopy. The epithelium, in cross-section, undergoes three stages prior to the formation of ridges; termed the circle (4½–6 days), the ellipse (6–8½ days), and the triangle (8½–9 days). At about 9 days of development three ridges form with three more forming one day later. The mechanisms responsible for folding of the epithelium were examined. Microdissection followed by organ culture demonstrated that constriction by the surrounding circular smooth muscle cannot account for folding of the epithelium. Mitotic pressure within the epithelium also cannot account for folding since there is no difference in the number of epithelial cells per cross-section between the ellipse and the triangle stages and the epithelial tube is not restricted from expanding. Active constrictions in groups of epithelial cells, mediated by bands of microfilaments, are thought to cause folding. Bundles of microfilaments are localized in the apical region of all epithelial cells at all stages studied and are localized in the basal region of those cells occupying the crests of the forming ridges. Cytochalasin B-treatment prevented ridge formation and disrupted the bundles of microfilaments.
MO-G-16A-01: Student and Trainee Mock Interviews

Need to practice your interviewing skills? Want feedback on your performance? Then this session is for you! The purpose of this session is to allow students and trainees to practice their interviewing skills with interviewers from various backgrounds (academic, clinical, industry) leading the interview and providing each interviewee with an evaluation and critique.
Radical Prostatectomy Findings in Men on Active Surveillance: Variable Findings Dependent on Reason for Surgery and Entry Criteria

Purpose: We studied adverse radical prostatectomy findings in men on an active surveillance program with different entry and exit criteria.Materials and Methods: The study included 80 men with biopsy progression, 33 who opted out for personal reasons and 24 who initially did not meet entry criteria mainly due to increased prostate specific antigen density.Results: Of men who opted out 78.8% had a higher Gleason score of 6 than men who progressed on biopsy (46.2%, p = 0.002) and men with high prostate specific antigen density (45.8%, p = 0.02). Men with high prostate specific antigen density had less organ confined disease than the group that opted out (p <0.006) and a trend compared to the biopsy progression group (p = 0.07). Mean dominant tumor volume was lower in men who opted out than in those with biopsy progression (0.56 vs 1.1 cc, p = 0.03). The incidence of insignificant cancer was higher in men who opted out (48.4%) than in those with biopsy progression (28.4%, p = 0.05) and those with high prosta...
Symmetric suprathermal electron depletions on closed field lines in the solar wind

[1] Strong, order of magnitude, depletions in suprathermal electron distribution functions, centered on and roughly symmetric about 90° pitch angle, are relatively common on closed field lines threading coronal mass ejection, CME, material in the solar wind. Such depletions are observed within at least portions of most CME events identified in data obtained from the ACE spacecraft. The symmetry of the depletions about 90° pitch angle is independent of the width or depth of the depletions or the strengths and angular widths of the field-aligned, counterstreaming beams that characterize closed field lines in the solar wind. We suggest that these symmetric depletions may be largely a consequence of double magnetic connection to the Sun and a relative lack of electron scattering from the counterstreaming beams to large pitch angles.
STUDYING WHILE BLACK

How should we explore the relationship between race and educational opportunity? One approach to the Black-White achievement gap explores how race and class cause disparities in access and opportunity. In this paper, I consider how education contributes to the creation of race. Considering examples of classroom micropolitics, I argue that breakdowns of trust and trustworthiness between teachers and students can cause substantial disadvantages and, in the contemporary United States, this happens along racial lines. Some of the disadvantages are academic: high achievement is more difficult when one faces mistrust, ego depletion, effort pessimism, and insult. And within a knowledge economy, exclusion from knowledge work makes one vulnerable to injustice. But the problem goes deeper than achievement, for schools are contexts in which we develop self-understandings and identities that situate us as members of society. If students of color are systematically denied full participation in trusting conversations that create shared knowledge—especially, knowledge that holds power within the dominant culture—they are unjustly deprived resources to form flourishing selves that are suited to the positions of power and authority. The argument suggests that knowledge is not best understood simply as a commodity to be distributed, and opportunity is not just a matter of access. Moreover, even if access is granted, those who are motivated and talented can fail: they drain their willpower by coping with insults, or reasonably lose optimism about their efficacy. Over time, motivation may shift away from achievement, and under the circumstances this can be a rational response. The barriers to achievement are many, but true opportunity is impossible without trust and trustworthiness.
Candida fungemia diagnosed from peripheral blood smear.

Primary catheter sepsis is a serious consequence of the use of indwelling catheters.1Candidafungi have been the most frequent nonbacterial organisms causing sepsis under these conditions.1-3Primary catheter sepsisis defined as sepsis in which no other sources of infection can be documented; the fever resolves following catheter removal, and catheter tip culture results are identical to those of the peripheral blood.4We describe a case where diagnosis of catheter-relatedCandidafungemia was diagnosed almost immediately from the peripheral blood smear, compared with the most rapid culture system available, an isolator lysis centrifugation system, which has a mean time to detection of 2.95 days.5 A 72-year-old woman had a Hickman catheter placed for long-term total parenteral nutrition. Eight days later she became febrille (temperature to 40°C), with chills and rigor. She had a white blood cell count of 12 × 109/L, including 77%
Implication of a quasi fixed point with a heavy fourth generation: The emergence of a TeV-scale physical cutoff

Abstract It has been shown in a recent Letter that the Higgs quartic and Yukawa sectors of the Standard Model (SM) with a heavy fourth generation exhibit at a two-loop level a quasi fixed point structure instead of the one-loop Landau singularity and which could be located in the TeV region, a scale which is denoted by Λ FP in this Letter. This provides the possibility of the existence of a TeV-scale physical cutoff endowed with several implications. In the vicinity of this quasi fixed point bound states and Higgs-like condensates made up of the 4th generation quarks and leptons get formed. It implies the possibility of a dynamical electroweak symmetry breaking generated by 4th generation condensates. The quasi fixed points also hint at a possible restoration of scale symmetry at Λ FP and above and the emergence of a theory which could be deeper than the SM.
Reliability measures in managing GI bleeding

Background Multiple procedures and devices are used in a complex interplay to diagnose and treat GI bleeding. Objective To model how a large variety of diagnostic and therapeutic components interact in the successful management of GI bleeding. Design The analysis uses the concept of reliability block diagrams from probability theory to model management outcome. Separate components of the management process are arranged in a serial or parallel fashion. If the outcome depends on the function of each component individually, such components are modeled to be arranged in series. If components complement each other and can mutually compensate for each of their failures, such components are arranged in a parallel fashion. Setting General endoscopy practice. Patients Patients with GI bleeding of unknown etiology. Interventions All available endoscopic and radiographic means to diagnose and treat GI bleeding. Main Outcome Measurements Process reliability in achieving hemostasis. Results Serial arrangements tend to reduce process reliability, whereas parallel arrangements increase it. Whenever possible, serial components should be bridged and complemented by additional alternative (parallel) routes of operation. Parallel components with low individual reliability can still contribute to overall process reliability as long as they function independently of other pre-existing alternatives. Limitations Probability of success associated with individual components is partly unknown. Conclusions Modeling management of GI bleeding by a reliability block diagram provides a useful tool in assessing the impact of individual endoscopic techniques and administrative structures on the overall outcome.
Translational control of protein synthesis in stimulated WI-38 fibroblasts

A cell-free protein synthesis system employing ribosomes from WI-38 human diploid fibroblasts was developed and its optimum MgC12 and KC1 levels and pH value found. The rate at which ribosomes are able to incorporate radioactive leucine into proteins ([14C]leucine incorporation/10 min/100 mug rRNA) and the number of growing peptide chains [3H]puromycinpeptides formed/100 mug rRNA) was determined. When confluent monolayers of WI-38 cells were stimulated to proliferate by serum, a transient increase in the rate of peptide elongation by ribosomes was observed at 60 min after stimulation. This increase was not affected by the presence of actinomycin D (10 mug/ml) in the stimulating medium. A change in the relative amount of certain ribosome-associated proteins accompanied the increased elongation rate of peptide growth. The alteration in associated proteins could not be accounted for by an increased synthesis of protein. Finally, the early activation of ribosomes in stimulated WI-38 cells appears to result from the removal of an inhibitor(s) of ribosome function.
Abstract 5491: Interrogating the mechanism of Wnt pathway inhibition by niclosamide

The Wnt signaling pathway regulates genes critical for normal development and is dysregulated in many cancers. Indeed, more than 80% of all sporadic and hereditary colorectal cancers (CRCs) show hyperactivation of the Wnt/β-catenin pathway due to mutations in adenomatous polyposis coli (APC) or β-catenin genes. As a result, drugs that modulate the Wnt pathway are highly sought-after as the basis of a new generation of innovative therapeutic agents to treat CRC. Unfortunately, the ability to target this pathway with small molecule inhibitors has hampered drug discovery such that no approved drugs specifically targeting the pathway have been identified. To address this gap, we constructed a chemical genetics high-throughput screen that evaluated internalization of the Frizzled receptor in order to identify modulators of the Wnt/Frizzled/LRP5/6 signaling pathway. Using this assay we discovered the small molecule drug niclosamide, a FDA-approved anthelmintic agent, decreased β-catenin levels and inhibited Wnt/β-catenin signaling, findings since confirmed by others. To support efforts to evaluate niclosamide in clinical studies of colorectal cancer with aberrant Wnt signaling, we studied the translocation of Frizzled1-GFP induced by niclosamide and the kinetics of inhibition of Wnt signaling in cell culture. We found that niclosamide induces the co-localization of Frizzled1-GFP and lysosome markers indicating the translocation of Frizzled1-GFP to the lysosome. Kinetic studies indicated that β-catenin levels are reduced significantly within three hours and that both the levels of β-catenin and β-catenin gene transcription remained significant decreased 12 hours after the compound was removed. These data suggest a mechanistic hypothesis in which an extended duration of inhibition of Wnt signaling by niclosamide may result from the induced degradation of key proteins in the Wnt signaling pathway and that continuous exposure to niclosamide may not be necessary over the entire dosing period to maintain sufficient pathway inhibition. Overall, the findings support plans to investigate the use of niclosamide in clinical trials of CRC. Citation Format: Robert A. Mook, Shengli Zhao, Wei Chen. Interrogating the mechanism of Wnt pathway inhibition by niclosamide. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5491. doi:10.1158/1538-7445.AM2014-5491
Liver Diseases by Alcohol and Hepatitis C: Early Detection and New Insights in Pathogenesis Lead to Improved Treatment

Much progress has been made in the understanding of the pathogenesis of alcoholic liver disease, resulting in improvement of treatment. Therapy must include correction of nutritional deficiencies, while taking into account changes of nutritional requirements. Methionine is normally activated to S-adenosylmethionine (SAMe). However, in liver disease, the corresponding enzyme is depressed. The resulting deficiencies can be attenuated by the administration of SAMe but not by methionine. Similarly, phosphatidylethanolamine methyltransferase activity is depressed, but the lacking phosphatidylcholine (PC) can be administrated as polyenylphosphatidylcholine (PPC). Chronic ethanol consumption increases CYP2E1, resulting in increased generation of toxic acetaldehyde and free radicals, tolerance to ethanol and other drugs, and multiple ethanol-drug interactions. Experimentally, PPC opposes CYP2E1 induction and fibrosis. Alcoholism and hepatitis C infection commonly co-exist, with acceleration of fibrosis, cirrhosis, and hepatocellular carcinoma. PPC is being tested clinically as a corresponding antifibrotic agent. Available antiviral agents are contraindicated in the alcoholic. Anti-inflammatory agents, such as steroids, may be selectively useful. Finally, anticraving agents, such as naltrexone or acamprosate, should be part of therapy.
Identification of spatial-temporal switched ARX systems

We consider the problem of identifying a model for data generated by a mixture of dynamical models, both in space and in time. We assume that the measurements at a particular time instant depend on a spatial variable, and that the dynamics of the data in different spatial regions can be modeled with different hybrid systems. We also assume that both the spatial regions as well as the discrete states of the hybrid systems are unknown. Furthermore, we allow the number of models to vary as a function of time. We call such a dynamical model a spatial-temporal hybrid system, and develop a recursive identification algorithm for the class of spatial-temporal switched ARX models. We demonstrate the applicability of our method to the segmentation of videos of dynamic textures, such as segmenting a bird floating on water.
Factors Affecting the Rapid Equilibrium Method for Analysis of Total Oil in Soybean Cultivars

A one minute rapid equilibrium extraction for total oil in soybeans was developed and factors influencing the extraction were examined. Comparisons of the rapid equilibrium extraction with a Goldfisch extraction were made, using 100 mesh flour on ten cultivars over a three year period. The equilibrium extraction consists of slurrying 100 mesh flour in hexane until an equilibrium between oil content inside and outside of the soybean particle is achieved. One minute was required for equilibration of 98% of the oil in the soybean flour, and one hour was required for complete equilibration when compared with a five hour Goldfisch extraction. Accuracy and precision of the method were excellent when proper technique was followed. A comparison of the rapid equilibrium and the Goldfisch extractions showed similar changes in oil content due to changes in soybean flour moisture and in preheating the soybeans. The amounts of phospholipid extracted from fine flour were considerably less than usually extracted from flakes under commercial conditions. The correlation between the rapid equilibrium and Goldfisch extractions for ten cultivars was excellent (r=0.9956) when analyzing 100 mesh flour. Environmental conditions caused significant interactions between cultivars and years of production.
Lack of depression effect on platelet activation in patients with heart failure

P-selectin is a marker of platelet activation. Previous studies have reported elevated P-selectin in patients with congestive heart failure (CHF) and depression as separate disorders. We examined if comorbid depression had an effect on platelet activation in CHF patients. Soluble (s)P-selectin was measured in 108 CHF patients; 24 with comorbid depression. There were no significant differences in age, cardiac parameters or (s)P-selectin levels between CHF-only patients and patients with comorbid depression. Our data show no group differences in P-selectin values, which suggests that comorbid depression has no additive effect on platelet activation in CHF patient.
Palliative Care: A Promising Philosophical Framework for Gastroenterology

Since the 1970s, much has happened to establish palliative care asa health philosophy that will enrich the practice of gastroenterology;conversely, developments in gastroenterology have already improved palliative care. Several recent concepts from the field of gastroenterology such as "the second brain" and "intestinal failure" fit well within the conceptual framework of palliative care. This type of synergy will ultimately encourage the application of this philosophy to a much broader spectrum of patients than those deemed to be at "end of life." This broader spectrum of care can be described as palliative gastroenterology.
Application of Portfolio Theory to Farmer and Lender Behavior

Randomness of commodity output and prices in agriculture are well-known phenomena that have plagued both farmers and their lenders as they develop plans and financial programs for the coming year. The same phenomena have plagued researchers who attempt to model the farmer-lender relationships for improved explanations of farmer and lender behavior. Early decision models of resource allocation under risk sought to maximize expected returns. However, in the early 1700s, Bernoulli demonstrated the irrationality of this criterion in explaining gambling behavior. More recently, portfolio theory, as developed by Markowitz and Tobin with extensions by Sharpe and Lintner, has improved our ability to analyze farmer and lender behavior under risk by considering variance as well as the expected value of returns. This paper discusses developments in portfolio theory, reviews its application to farmer and lender behavior, considers its limitations, and suggests several extensions to account for asset liquidity, liquidity risk, and portfolio adjustments. We conclude with recommendations for future application of portfolio theory to farmer and lender behavior.
Water discharge, nitrate concentration and nitrate flux in the lower Mississippi river

Abstract Thirty-five years of monthly lower Mississippi River water discharge, nitrate concentration and nitrate flux have been analyzed. The potential predictability of these quantities has been evaluated. Results indicate a large amplitude, long-term cycle in the nitrate concentration that is not observed in the water discharge. A decrease in average nitrate concentration from a peak in 1983 to the present confirms that this variability is more cyclic than trend-like. River-water discharge variation was greatest in association with the annual cycle. The annual water discharge and nitrate concentration cycles were similar; high nitrate concentrations usually occurred near the vernal freshet, and low concentrations usually occurred along with autumnal low-flow conditions. Nitrate flux variations exhibited a low amplitude, long-term modulation of a dominant, annual cycle. A predictor-hindcast analysis indicates that truly skilled forecasts of all three fields are feasible.
Invariance of the local segmental relaxation dispersion in polycyclohexylmethacrylate/poly-α-methylstyrene blends

Dielectric spectroscopy was carried out on polycyclohexylmethacrylate (PCHMA) and its blend with poly-α-methylstyrene (PaMS) as a function of temperature and pressure. When measured at conditions whereby the local segmental relaxation time for the PCHMA was constant, the dispersion in the loss spectra had a fixed shape; that is, the relaxation time determines the breadth of the relaxation time distribution, independently of T and P. This result is known for neat materials and could be observed for the blend herein due to the nonpolar character of the PaMS and the degree of thermodynamic miscibility of the blend.
Contrasting thermal histories across the Flying Point fault, southwestern Maine: Evidence for Mesozoic displacement

40 Ar/ 39 Ar analysis of hornblende, muscovite, biotite, and K-feldspar across the Flying Point fault in southwestern Maine reveals important information on the timing of thermal events and subsequent cooling history of the region. The Flying Point fault is the most significant structure associated with the Norumbega fault zone in southwestern Maine. It forms the boundary between two different lithotectonic sequences, offsets metamorphic isograds, and marks a remarkable time-temperature discontinuity. Southeast of the Flying Point fault in the Casco Bay Group, early Carboniferous hornblende ages and late Carboniferous muscovite and biotite ages reflect slow cooling following Middle to late Devonian (Acadian) metamorphism and deformation. No significant (>300 °C) late Paleozoic thermal event affected these rocks. In contrast, rocks northwest of the Flying Point fault were affected by a significant (>500 °C) late Paleozoic (Alleghanian) thermal event as indicated by latest Carboniferous-Permian hornblende cooling ages. This represents the northernmost occurrence of Alleghanian high-grade metamorphism reported in the Appalachian orogen. Cooling below muscovite and biotite closure temperatures northwest of the Flying Point fault did not occur until the Early Triassic. The thermochronologic data indicate that the rocks currently juxtaposed across the Flying Point fault underwent drastically different thermal histories during Permian and Triassic time. Approximately 4 km of post-Paleozoic west-side-up displacement along the Flying Point fault can account for the presently observed time-temperature discontinuity.
The networks course: old problems, new solutions

New approaches and techniques for teaching the undergraduate level course in networks and data communications will be discussed. Many of these ideas were presented at the 1998 Workshop on Networking sponsored by NSF and Michigan State University's Department of Computer Science and Engineering.
Distribution of protein, lipid and administered bromide between serum and CSF in myxedema

Abstract An analysis of the blood and CSF protein concentration and lipid profiles in 14 patients with clinical myxedema has been presented. In addition, the serum and CSF bromide concentrations were measured following the oral administration of sodium bromide during the pre- and post-treatment period. While the serum lipids and protein concentrations were noted to be elevated prior to treatment, the CSF constituents were elevated to a greater degree when compared to normal values than serum constituents, and treatment caused a return in concentration towards normal. Both serum and CSF bromide concentrations were elevated in the myxedematous state and returned toward normal following treatment, though a disproportionately greater rise in CSF than serum concentration was noted irrespective of treatment. That the evidence may reflect a breakdown in the “blood-CSF barrier” in myxedema, which is partially corrected by treatment, is discussed as a likely explanation for these observations.
Walks, trials and polymers with loops

Lattice models interpolating between free and self-avoiding random walks are investigated. Generating functions are constructed for k-tolerant walks, various trail problems, etc. For trail problems the effective field theory describing the global behaviour is analysed in the vicinity of the upper critical dimension dc=4. Their asymptotic large-scale behaviours are the same as those of the self-avoiding walk. Arguments are presented to support the same conclusion for much more general classes of walks including k-tolerant walks. One of the models exhibits a new tricritical point of order epsilon 1/2 if the fugacity for crossing is increased.
Mathematical Modeling of the Impact of Hospital Occupancy: When Do Dwindling Hospital Beds Cause ED Gridlock?

Objectives. The time emergency department (ED) patients spend from presentation to admittance is known as their length of stay (LOS). This study aimed to quantify the inpatient occupancy rate (InptOcc)/ED LOS relationship and develop a methodology for identifying resource-allocation triggers using InptOcc-LOS association-curve inflection points. Methods. This study was conducted over 200 consecutive days at a 700-bed hospital with an annual ED census of approximately 50,000 using multivariate spline (piecewise) regression to model the InptOcc/LOS relationship while adjusting for confounding covariates. Nonlinear modeling was used to assess for InptOcc/LOS associations and determine the inflection point where InptOcc profoundly impacted LOS. Results. At lower InptOcc, there was no association. Once InptOcc reached ≥88%, there was a strong InptOcc/LOS association; each 1% InptOcc increase predicted a 16-minute (95% CI, 12–20 minutes) LOS prolongation, while the confounder-adjusted analysis showed each 1% InptOcc increase >89% precipitating a 13-minute (95% CI, 10–16 minutes) LOS prolongation. Conclusions. The study hospital’s InptOcc was a significant predictor of prolonged ED LOS beyond the identified inflection point. Spline regression analysis identified a clear inflection point in the InptOcc-LOS curve that potentially identified a point at which to optimize inpatient bed availability to prevent increased costs of prolonged LOS.
Inflammatory pseudotumor of lymph node and spleen: an entity biologically distinct from inflammatory myofibroblastic tumor.

Inflammatory pseudotumors (IPTs) of the lymph node and spleen are an uncommon, benign cause of lymphadenopathy and/or splenomegaly that often bear striking clinicopathologic similarities to the inflammatory myofibroblastic tumors (IMTs) found in soft tissues. These tumors have classically been grouped together under the umbrella category of "inflammatory pseudotumor." Recent evidence shows that IMTs are in fact neoplastic processes that often harbor balanced chromosomal translocations involving the ALK kinase gene. These translocations result in expression of ALK kinase in IMTs as assessed by immunohistochemical studies. However, the relationship between IMT and IPT of the lymph node and spleen is uncertain. To determine if ALK tyrosine kinase expression is also present in IPT, 13 cases of IPT (9 involving lymph nodes, 4 splenic lesions) were examined for the presence of ALK tyrosine kinase by immunohistochemical staining on paraffin-embedded tissue. In addition, in situ hybridization studies for Epstein-Barr virus--encoded RNAs (EBER) and immunoperoxidase studies for human herpesvirus-8 (HHV8)--specific proteins were performed. All cases had clinical, morphologic, and immunophenotypic findings typical of IPT and had varying proportions of fibroblastic and inflammatory components. Age ranged from 11 to 75 (median, 40) years; 8 subjects were male, and 5 were female. None of the cases (0 of 13) had positive staining for ALK kinase or HHV8, and in 1 a lymph node (1 of 13) was focally positive for EBV (EBER) by in situ hybridization. The absence of ALK kinase as detected by immunohistochemical studies in IPT of the lymph node and spleen suggests that this entity is biologically distinct from the histologically similar IMT.
When Gold Is Not Noble: Nanoscale Gold Catalysts

While inert as bulk material, nanoscale gold particles dispersed on oxide supports exhibit a remarkable catalytic activity. Temperature-programmed reaction studies of the catalyzed combustion of CO on size-selected small monodispersed Aun (n ≤ 20) gold clusters supported on magnesia, and first-principle simulations, reveal the microscopic origins of the observed unusual catalytic activity, with Au8 found to be the smallest catalytically active size. Partial electron transfer from the surface to the gold cluster and oxygen-vacancy F-center defects are shown to play an essential role in the activation of nanosize gold clusters as catalysts for the combustion reaction.
Diphenylmethane diisocyanate (MDI)‐induced asthma: evaluation of the immunologic responses and application of an animal model of isocyanate sensitivity

A worker developed two episodes of severe asthma 90 min after cutting a polyurethane plate made of diphenylmethane diisocyanate (MDI) using a rapidly turning carbide blade. Intradermal skin testing with MDI-human serum albumin (MDI-HSA) and p-tolyl isocyanate-HSA (p-TMI-HSA) were positive at 0.002 mg/ml. Control subjects showed no reaction at 2 mg/ml. Bronchial provocations of the worker with MDI-HSA and p-TMI-HSA, made 1 year after the occupational asthmatic episode, were negative at 10 mg/ml. Bronchial reactivity to methacholine decreased toward normal during a 2-year follow-up. RAST using MDI-HSA or p-TMI-HSA were strongly positive when compared with binding by sera from atopic controls which contained the same amount of total IgE. RAST titres decreased during a 1-year follow-up. In the MDI-HSA RAST, inhibition studies indicated specificity of antibodies for MDI-HSA. In the p-TMI-HSA RAST, p-TMI-HSA was a very effective inhibitor whereas MDI-HSA was not. These results indicated the formation of at least two distinct groups of IgE antibodies: those reactive with MDI, and those reactive with p-TMI determinants. Guinea pigs immunized with MDI formed antibodies with specificities similar to those of the patient. We conclude that the worker had occupational asthma accompanied by the formation of specific IgE antibodies of the specificities. The causal relationship of the antibodies to the occupational asthma remains uncertain.
STEREOSELECTIVE SYNTHESES OF THE RHIZOXIN C(1)-C(9) AND C(12)-C(26) SUBUNITS

Abstract Stereoselective syntheses of the C(1)C(9) and C(12)C(26) subunits of the macrolide antitumor agent rhizoxin are described. Chelation-controlled Ireland-Claisen rearrangement, stereoselective Horner-Wadsworth-Emmons reactions and a thermodynamically-controlled diastereotopic group differentiation are featured.