cssi/SciSciGPT-SciSciNet huggingface dataset:
Semiconducting organic–inorganic nanocomposites by intimately tethering conjugated polymers to inorganic tetrapods

Semiconducting organic-inorganic nanocomposites were judiciously crafted by placing conjugated polymers in intimate contact with inorganic tetrapods via click reaction. CdSe tetrapods were first synthesized by inducing elongated arms from CdSe zincblende seeds through seed-mediated growth. The subsequent effective inorganic ligand treatment, followed by reacting with short bifunctional ligands, yielded azide-functionalized CdSe tetrapods (i.e., CdSe-N3). Finally, the ethynyl-terminated conjugated polymer poly(3-hexylthiophene) (i.e., P3HT-[triple bond, length as m-dash]) was tethered to CdSe-N3 tetrapods via a catalyst-free alkyne-azide cycloaddition, forming intimate semiconducting P3HT-CdSe tetrapod nanocomposites. Intriguingly, the intimate contact between P3HT and CdSe tetrapod was found to not only render the effective dispersion of CdSe tetrapods in the P3HT matrix, but also facilitate the efficient electronic interaction between these two semiconducting constituents. The successful anchoring of P3HT chains onto CdSe tetrapods was substantiated through Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy measurements. Moreover, the absorption and photoluminescence studies further corroborated the intimate tethering between P3HT and CdSe tetrapods. The effect of the type of bifunctional ligands (i.e., aryl vs. aliphatic ligands) and the size of tetrapods on the device performance of hybrid organic-inorganic solar cells was also scrutinized. Interestingly, P3HT-CdSe tetrapod nanocomposites produced via the use of an aryl bifunctional ligand (i.e., 4-azidobenzoic acid) exhibited an improved photovoltaic performance compared to that synthesized with their aliphatic ligand counterpart (i.e., 5-bromovaleric acid). Clearly, the optimal size of CdSe tetrapods ensuring the effective charge transport in conjunction with the good dispersion of CdSe tetrapods rendered an improved device performance. We envision that the click-reaction strategy enabled by capitalizing on two consecutive effective ligand exchanges (i.e., inorganic ligand treatment and subsequent bifunctional ligand exchange) to yield intimately connected organic-inorganic nanocomposites provides a unique platform for developing functional optoelectronic devices.
Love and Rayleigh waves in nonhorizontally layered media

A new finite element technique has been developed to study the propagation of Love and Rayleigh waves across two-dimensional nonhorizontally layered media. This new technique gives a complete analysis of the medium and the amplitudes and phases of all of the reflected and transmitted Love or Rayleigh modes. It accounts exactly for all of the incident energy. It has led to two principal new results, true for both Love- and Rayleigh-wave propagation. First, the energy propagated in the transmitted fundamental Love or Rayleigh mode through a two-dimensional nonhorizontally layered medium is exactly the same both for a direction of incidence of the wave motion on one end of the medium and on the opposite end. The amplitude of the transmitted Love or Rayleigh mode is, in general, not the same for both directions of incidence. Second, the phase velocity of the fundamental Love or Rayleigh mode through a two-dimensional nonhorizontally layered medium is exactly the same for a direction of incidence of the wave motion on one end of the medium as it is on the opposite end. Apparently different observed phase velocities arise through body-wave interference. Two models are analyzed for Rayleigh-wave motion. One is of a half-space with a step elevation and the second is of a surface layer with an inclined base overlying a half-space.
Acquired Platelet Function Defects

Familiarity with disorders of platelet function is imperative because these defects are common causes both of clinical hemorrhage and unexplained bruising and constitute the most common nontechnical cause of surgical bleeding. This article summarizes the acquired and drug-induced platelet function defects with which clinicians and laboratory scientists should be familiar.
Control of lower esophageal sphincter pressure by two sites in dorsal motor nucleus of the vagus.

Our purpose was to determine the central vagal sites for regulating changes in lower esophageal sphincter (LES) pressure in the cat. Injection of the retrograde tracer, horseradish peroxidase, into...
Drug therapy. Combined beta-adrenergic and calcium-entry blockade in angina pectoris.

THE combination of beta-adrenergic-blocking and calcium-entry–blocking drugs has achieved widespread popularity in the care of patients with angina pectoris. Combined therapy is frequently used to ...
Tunable blocker-tolerant RF front-end filter with dual adaptive notches for reconfigurable receivers

This paper presents a novel design of a highly tunable active bandpass filter with adjustable notches close to the passband. The filter is based on two-path signal cancellation and consists of a tunable bandpass filter in parallel with a tunable bandstop filter. This combination ensures the correct amplitude and phase relationship across a wide tuning range to create adjustable transmission notches without sacrificing the gain of the passband. The proposed filter is implemented with high-Q N-path filter/resonator blocks in a 65-nm CMOS process. The passband of the filter is tunable from 0.2GHz to 1.2 GHz with a 3-dB bandwidth of 5.8–6.2 dB, a gain of 18.5–21 dB, a noise figure of 4.5–6.2 dB, and a total power consumption of 33–70mW. Transmission notches are created on both sides of the passband with a minimal offset of 20MHz and are tunable across a 20MHz range with up to 46 dB rejection. The blocker 1-dB compression point is 8dBm and the out-of-band IIP3 is 18 dBm. The reported filter provides a promising solution to multi-standard, multi-frequency software-defined radio applications.
Autonomous OA Removal in Real-Time from Single Channel EEG Data on a Wearable Device Using a Hybrid Algebraic-Wavelet Algorithm

Electroencephalography (EEG) is a non-invasive technique to record brain activities in natural settings. Ocular Artifacts (OA) usually contaminates EEG signals, removal of which is critical for accurate feature extraction and classification. With the increasing adoption of wearable technologies, single-channel real-time EEG systems that often require real-time signal processing for immediate real-time feedback are becoming more prevalent. However, traditional OA removal algorithms usually require multiple channels of EEG data, are computationally expensive, and do not perform well in real-time. In this article, a new hybrid algorithm is proposed that autonomously detects OA and subsequently removes OA from a single-channel steaming EEG data in real-time. The proposed single EEG channel algorithm also does not require additional reference electrooculography (EOG) channel. The algorithm has also been implemented on an embedded hardware platform of single channel wearable EEG system (NeuroMonitor). The algorithm first detects the OA zones using an Algebraic approach and then removes these artifacts from the detected OA zones using the Discrete Wavelet Transform (DWT) decomposition method. The de-noising technique is applied only to the OA zone, which minimizes loss of neural information outside the OA zone. A qualitative and quantitative performance evaluation was carried out with a 0.5s epoch in overlapping sliding window technique using time-frequency analysis, mean square coherence, and correlation coefficient statistics. The hybrid OA removal algorithm demonstrated real-time operation with 3s latency on the PSoC-3-microcontroller-based EEG system. Successful implementation of OA removal from single-channel real-time EEG data using the proposed algorithm shows promise for real-time feedback applications of wearable EEG devices.
Abstract 464: Progesterone Signaling in Endothelial Cells Results in Increased Vascular Permeability and Platelet Adhesion

Epidemiological studies have indicated the rather significant, yet unclear, impact of sex hormones on cardiovascular physiology and disease. Both observational studies and clinical trials have produced conflicting evidence as to the benefits of female sex hormones, particularly with regards to progesterone. Prolonged exposure to progesterone leads to break-through bleeding, vessel fragility and venous thromboembolisms. Currently, little is known on the molecular and cellular effects of progesterone on the cardiovascular system, or its cell specific functions. In fact, the vascular effects attributed to progesterone have been viewed, for the most part, as secondary consequences of its multiple systemic activities. Using a PRLacZ reporter mouse we have determined that progesterone receptor (PR) expression in the vasculature is restricted to endothelial cells of veins and lymphatics of the reproductive tract. Conditional deletion of PR from endothelial cells using VE-cadherin Cre leads to decreased vascular permeability in the uterus and ovary following treatment with progesterone. Transgenic misexpression of PR in the lung results in pathological vascular leakage and intravascular platelet adhesion in response to progesterone. Additionally, activation of PR within endothelial cells leads to the development of stress fibers, formation of inter-cellular gaps, increased permeability and changes in expression of cell-cell junctional proteins. These results reveal a previously unknown and direct role for PR on endothelial cell function with consequences for physiological permeability, blood vessel integrity and homeostasis.
Peginterferon Beta-1a Shows Antitumor Activity as a Single Agent and Enhances Efficacy of Standard of Care Cancer Therapeutics in Human Melanoma, Breast, Renal, and Colon Xenograft Models.

Because of its tumor-suppressive effect, interferon-based therapy has been used for the treatment of melanoma. However, limited data are available regarding the antitumor effects of pegylated interferons, either alone or in combination with approved anticancer drugs. We report that treatment of human WM-266-4 melanoma cells with peginterferon beta-1a induced apoptotic markers. Additionally, peginterferon beta-1a significantly inhibited the growth of human SK-MEL-1, A-375, and WM-266-4 melanoma xenografts established in immunocompromised mice. Peginterferon beta-1a regressed large, established WM-266-4 xenografts in nude mice. Treatment of SK-MEL-1 tumor-bearing mice with a combination of peginterferon beta-1a and the MEK inhibitor PD325901 ((R)-N-(2,3-dihydroxypropoxy)-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide) significantly improved tumor growth inhibition compared with either agent alone. Examination of the antitumor activity of peginterferon beta-1a in combination with approved anticancer dr...
Local muscle cooling does not impact expression of mitochondrial-related genes.

Abstract Recovery that takes place in a cold environment after endurance exercise elevates PGC-1α mRNA whereas ERRα and NRF2 mRNA expression are inhibited. However, the effect of local skeletal muscle cooling on mitochondrial-related gene expression is unknown. Purpose To determine the impact of local skeletal muscle cooling during recovery from an acute bout of exercise on mitochondrial-related gene expression. Methods Recreationally-trained male cyclists (n=8, age 25±3 y, height 181±6 cm, weight 79±8 kg, 12.8±3.6% body fat, VO 2peak 4.52±0.88 L·min −1 protocol) completed a 90-min variable intensity cycling protocol followed by 4 h of recovery. During recovery, ice was applied intermittently to one leg (ICE) while the other leg served as a control (CON). Intramuscular temperature was recorded continuously. Muscle biopsies were taken from each vastus lateralis at 4 h post-exercise for the analysis of mitochondrial-related gene expression. Results Intramuscular temperature was colder in ICE (26.7±1.1 °C) than CON (35.5±0.1 °C) throughout the 4 h recovery period (p Conclusion Local muscle cooling after exercise does not impact the expression of mitochondrial biogenesis-related genes compared to recovery from exercise in control conditions. When these data are considered with previous research, the stimuli for cold-induced gene expression alterations may be related to factors other than local muscle temperature. Additionally, different intramuscular temperatures should be examined to determine dose-response of mitochondrial-related gene expression.
Nonspecific electrostatic binding of substrates and inhibitors to porcine pepsin.

Porcine pepsin has long been recognized to have primary and secondary specificity for hydrophobic amino acids, and the binding of low molecular weight inhibitors (e.g., aliphatic alcohols) is also dominated by hydrophobic interactions1. However, the long standing ‘hydrophobic dogma’ in pepsin catalysis was seriously challenged when Pohl and Dunn2 described a series of polycationic oligopeptides that are among the most reactive synthetic substrates known. These highly hydrophilic molecules should not be well accommodated in a hydrophobic active site. Moreover, the steady state kinetic parameters were remarkably sensitive to the acidity of the medium. As the pH was increased from pH 3 to 6, the specificity number kcat/Km increased by three to four orders of magnitude and approached values close to the diffusion limit. The catalytic turnover number kcat was much less affected by the increase in pH, and the Michaelis constant Km decreased accordingly, by three to four orders of magnitude. A typical pH profile of steady state kinetic parameters, for the substrate Lys-Lys-Ala-Lys-Phe-Phe(NO2)-Arg-Leu, is shown in Figure 1.
Population Dynamics Modeling

Until now, we have dealt with deductive modeling exclusively, i.e., all our models were created on the basis of a physical understanding of the processes that we wished to capture. Therefore, this type of modeling is also frequently referred to as physical modeling. As we proceed to more and more complex systems, less and less meta-knowledge is available that would support physical modeling. Furthermore, the larger uncertainties inherent in most physical parameters of such systems make physical models less and less accurate. Consequently, researchers in fields such as biology or economics often prefer an entirely different approach to modeling. They make observations about the system under study and then try to fit a model to the observed data. This modeling approach is called inductive modeling. The structural and parametric assumptions behind inductive models are not based on physical intuition, but on factual observation. This chapter illustrates some of the virtues and vices associated with inductive modeling and lists the conditions under which either of the two approaches to modeling is more adequate than the other. This chapter documents how population dynamics models are created, discusses the difference between structural and behavior complexity of models in general, introduces the concept of chaotic motion, and addresses a rather difficult issue, namely, the question of self-organization within systems.
Customer Loyalty in Electronically Mediated Environments

For brands that are consumed in electronically mediated environments (EMEs), customer loyalty is a strategic imperative. We report results from a qualitative study where consumer descriptions of their brand experiences were used to develop key loyalty themes for six brands in three categories. Consumer loyalty can be characterized along seven consumption bases, though different brands and categories are positioned differently along these bases. Importantly, we posit a process model showing that loyalty “builds” over time as consumption proceeds through the stages of adoption, conversion, and (dis)adoption. A key factor in converting new adopters to be loyal is the extent of efficiency and effectiveness perceived along these loyalty bases. The process of customer loyalty emerges as complex and multi-faceted being punctuated by chance events.
History of Preclinical Models of Intracerebral Hemorrhage

In order to understand a disease process, effective modeling is required that can assist scientists in understanding the pathophysiological processes that take place. Intracerebral hemorrhage (ICH), a devastating disease representing 15% of all stroke cases, is just one example of how scientists have developed models that can effectively mimic human clinical scenarios. Currently there are three models of hematoma injections that are being used to induce an ICH in subjects. They include the microballoon model introduced in 1987 by Dr. David Mendelow, the bacterial collagenase injection model introduced in 1990 by Dr. Gary Rosenberg, and the autologous blood injection model introduced by Dr. Guo-Yuan Yang in 1994. These models have been applied on various animal models beginning in 1963 with canines, followed by rats and rabbits in 1982, pigs in 1996, and mice just recently in 2003. In this review, we will explore in detail the various injection models and animal subjects that have been used to study the ICH process while comparing and analyzing the benefits and disadvantages of each.
Physical Activity and Health-Related Quality of Life in Children and Adolescents: A Systematic Review and Meta-Analysis

OBJECTIVE The purpose of this study was to quantify the effect of physical activity (in both descriptive and intervention studies) on health-related quality of life (HRQOL) in children and adolescents from both healthy and chronic illness populations. METHOD A systematic review of PubMed, PsycINFO, and ProQuest identified 33 studies of physical activity and HRQOL in youth, including descriptive and prepost intervention designs. RESULTS In descriptive studies (N = 14), there was a small, positive association between physical activity and HRQOL based on child-reports (Hedges' g = .302, p < .001, 95% confidence interval, CI [.178, .426]) and a negligible association based on parent-proxy reports (Hedges' g = .115, p = .101, 95% CI [-.023, .253]). Intervention studies (N = 19) yielded a small, positive effect of physical activity intervention on HRQOL based on child-reports (Hedges' g = .279, p = .014, 95% CI [.057, .500]) and a medium, positive effect based on parent-proxy reports (Hedges' g = .522, p = .012, 95% CI [.117, .928]). Intervention effects were attenuated by removal of a single study. Hypothesized and exploratory moderators did not moderate the relationship between physical activity and HRQOL. CONCLUSIONS Findings supported the primary hypothesis that physical activity was related to better HRQOL in youth, although the magnitude of these effects did not represent a minimal clinically important difference (MCID) in most studies. Future studies are needed to assess HRQOL in youth before and after exercise interventions to quantify the type, frequency, duration, and intensity of physical activity needed to change HRQOL. (PsycINFO Database Record
The Portable Archives of the Westphalian Negotiations: From Archival Arsenals to Archival Absolutism (France, Portugal, and Spain)

This article analyzes the formation of scholar-jurists’ archives during Late Renaissance conflicts and their use by individuals and state powers. Departing from the case of the French scholar, Theodore Godefroy (1580-1649), and his role in the Peace of Westphalia (1643-1648), this article shows how scholars’ portable archives were used as archival arsenals during diplomatic negotiations, eventually leading to the adoption of a system of “archival absolutism” in France. This archival absolutism was a reaction to the fragmentation of archives that had previously fostered trans-imperial exchanges among scholars. This article also demonstrates, through the case of Godefroy’s portable archive and correspondence, how the search for political legitimacy by a “restored” monarchy—like Portugal—during a period of conflict between the chief hegemonic powers in western Europe—Spain and France—contributed to the distinct development of those states’ uses of legal experts and their archives over the course of the seventeenth century.
Value Analysis of the Costliest Elective Lifesaving Procedures at an Academic Medical Center

Introduction: When evaluating the cost of a lifesaving operation, one must consider the economic value, which can be defined as the relative cost per additional year of life lived. This evaluation might provide useful information for the application of costly procedures. The objective of this study was to determine the cost per year of life saved for the costliest operations performed at an urban academic medical center. Methods: Total hospital expenditures were categorized by diagnosis related group (DRG) between January 1, 2015 and December 31, 2016. Average cost and patient age for each procedure were calculated. Average lifespan following successful outcome was determined based upon published benchmarks. Cost per year of life saved was calculated for each procedure. Only those elective procedures necessary to prolong life and enhance health were analyzed. Results: 114,448 hospital admissions were reviewed. The 12 costliest procedures were identified and ranked according to cost per year of life saved: Coronary bypass ($1,345.45), portacaval shunt procedure ($2,261.70), cardiac valve/other major cardiothoracic procedure ($2,733.78), major bladder procedure ($2,733.78), cardiac defibrillator implant ($5,047.65), bone marrow transplant ($5,181.80), intracranial vascular procedures ($8,572.05), kidney transplant ($9,024.87), liver transplant ($11,112.73), endovascular cardiac valve replacement ($12,842.25), simultaneous pancreas/kidney transplant ($14,087.50), and heart transplant ($20,472.11). Conclusion: Among the costliest procedures, coronary bypass was the most economic, having the lowest cost per year of life saved ($1,345.45) and longest post-procedure life expectancy (17.6 years). These findings combined with further analysis of the identified procedures may allow us to better determine their relative value.
PRINCIPLES OF FOOD MICROBIOLOGY

A discussion of some of the fundamental principles that are involved in food microbiology. Particular stress is placed on the factors that contribute to initial and inplant contamination and to tho...
Epidemiological Impact of Expedited Partner Therapy for Men Who Have Sex With Men: A Modeling Study.

Background Expedited partner therapy (EPT) is an intervention for patients with gonorrhea or chlamydia, providing index patients with prescriptions or medication to give to their partners. Expedited partner therapy is recommended for heterosexuals but not for men who have sex with men (MSM), partially due to concerns about overtreatment of uninfected partners and missed opportunities for human immunodeficiency virus (HIV) diagnosis. Methods We extended our stochastic network-based mathematical model of HIV, gonorrhea, and chlamydia among MSM to include EPT. The EPT implementation was simulated for 10 years. Counterfactual scenarios varied EPT coverage, provision, uptake, and partnership window duration. We estimated sexually transmitted infection (STI) incidence, proportion of infections averted, and process outcomes under each scenario. Results Delivery of EPT to 20% of eligible MSM index patients (coverage) reduced cumulative STI incidence by 27% (interquartile range, 13%-39%) over 10 years compared with current estimated STI screening levels. A 20% increase in providing medication to non-index partners (provision) averted 32% (interquartile range, 20%-41%) of STI infections compared with estimated STI screening levels. When targeted by partnership type, EPT solely to casual partners maximized the population-level infections averted. The proportion of partners given medication who had no current STI varied from 52% to 63%, depending on coverage level. The proportion of partners given medication with undiagnosed HIV infection was 4% across scenarios. Conclusions Expedited partner therapy could reduce bacterial STI incidence for MSM. However, this intervention could result in missed opportunities for HIV/STI prevention and a substantial increase in use of antimicrobials by STI-uninfected MSM, raising concerns about cost and antimicrobial resistance.
CEO Reputation and Corporate Risk Taking

This paper investigates the relationship between CEO reputation and corporate risk-taking. The empirical results show that reputable CEOs tend to take more risk, especially idiosyncratic risk and unlevered risk. A one-standard-deviation shock in CEO reputation results in a 16.16% rise in total risk. We further investigate the channels of risk taking activities and find that reputable CEOs seek more R&D investments, but not higher financing risk. Finally, we examine the impact of CEO reputation on credit ratings and find that firms where the CEO enjoys a strong reputation experience lower credit ratings. Our results highlight the importance of CEO reputation on a crucial corporate outcome - the extent of corporate risk-taking.
Nitrogen fertilization of high biomass sorghum affects macro- and micronutrient accumulation and tissue concentrations

Abstract High biomass sorghum (HBS) (Sorghum bicolor (L.) Moench) is an emerging biofuel feedstock that can produce high yields in the Midwestern U.S. and is known for high nitrogen (N) use efficiency at low N fertilizer input. This two-year study examined the effect of five N fertilization treatments (0, 56, 112, 168, 224 kg N ha−1) on the uptake of 11 macro- and micronutrients by photoperiod sensitive HBS. Leaf, stem, and shoot nutrient concentrations and contents were determined and nutrient relationships examined. Few consistent relationships existed across all nutrients, but concentrations were generally greater in the drier and shorter growing season with less dry matter (DM) accumulation, and, when present, N treatment response often resulted in decreased concentrations with increasing N. Inversely, the amount of nutrients present in the shoot generally were associated with greater DM production in the wetter year with longer growing season. Content of nutrients in the shoot did not increase beyond the 56 kg N ha−1 treatment in the wetter year, but there was a nutrient uptake response to higher N rates in the drier crop year. This suggests more so than other nutrients that N was more of a limitation that year. Even though shoot mineral nutrient removal is often similar at higher N treatments, applying a minimal N fertilizer rate results in minimized tissue mineral concentrations, thereby creating an optimal crop management balance of targeting high crop yield, low concentrations to optimize conversion efficiency, and sustainable agronomic management.
Evidence for positive allosteric modulation of cognitive-enhancing effects of nicotine by low-dose galantamine in rats.

Abstract Cognitive-enhancing effects of nicotinic acetylcholine receptor (nAChR) agonists may be of therapeutic potential in disease states characterized by nAChR hypofunction; however, effects tend to be of small magnitude and unlikely clinical significance. The co-administration of a nAChR positive allosteric modulator (PAM) may enable larger effects by potentiating nAChR responses to an agonist. The acetylcholinesterase (AChE) inhibitor galantamine is a nAChR PAM at a low dose range. A recent clinical study testing effects of a single small dose of galantamine found evidence for synergistic effects with nicotine on one of several cognitive measures. In that study, residual AChE inhibition may have obscured interactions on other measures. The present study aimed at examining small galantamine doses devoid of AChE inhibitory activity in a rodent model of attention. The effects of galantamine (0.03–0.25 mg/kg s.c.) were tested in the presence and absence of nicotine (0.1 mg/kg s.c.) in rats performing the 5-Choice Serial Reaction Time Task, employing a within-subject factorial design. There were no effects on response accuracy of either nicotine or galantamine alone. However, the combination of nicotine and 0.06 mg/kg of galantamine significantly enhanced accuracy. AChE activity assays confirmed that, at this dose, galantamine was devoid of AChE inhibitory activity in the brain. The results suggest that cognitive-enhancing effects of nicotine may be potentiated or uncovered by an extremely small dose of galantamine, well below its typical therapeutic range in humans. Furthermore, these findings provide a general proof-of-principle for a nAChR agonist and PAM combination strategy for cognitive enhancement.
Therapeutic Latinx Story-Sharing or Chismorreo

Through the lens of de Cervantes’s classic Spanish novel, Don Quijote de la Mancha, we discuss the nature of language and reality and the idea of therapeutic story-sharing or chismorreo (gossiping). Within the Latinx community, the oral practice of chismear or chismorrear is a common communicational practice that involves imagination, fascination, and novelty (Tanaka, Fermentum. Revista Venezolana de Sociologia y Antropologia 17:646–672, 2007). In this chapter, we explore how Spanish-speaking marriage and family therapy (MFT) supervisors and therapists, at Our Lady of the Lake University, San Antonio, embrace their novelistic imagination to explore clients’ resourceful identities, peripheral stories, and undefined journeys.
Simplex-Tree Based Kinematics of Foldable Objects as Multi-body Systems Involving Loops

Many practical multi-body systems involve loops. Studying the kinematics of such systems has been challenging, partly because of the requirement of maintaining loop closure constraints, which have conventionally been formulated as highly nonlinear equations in joint parameters. Recently, novel parameters defined by trees of triangles have been introduced for a broad class of linkage systems involving loops (e.g., spatial loops with spherical joints and planar loops with revolute joints); these parameters greatly simplify kinematics related computations and endow system configuration spaces with highly tractable piecewise convex geometries. In this paper, we describe a more general approach for multi-body systems, with loops, that allow construction trees of simplices. We illustrate the applicability and efficiency of our simplex-tree based approach to kinematics by a study of foldable objects. We present two sets of new parameters for single-vertex rigid fold kinematics; like the parameters in the triangle-tree prototype, each has a geometrically meaningful and computationally tractable constraint formulation, and each endows the configuration space with a nice geometry.
Expression of p53 protein in pancreatic adenocarcinoma. Relationship to cigaret smoking.

We studied the expression of p53 gene product in pancreatic adenocarcinomas of the usual ductal type to determine its relationship to cigaret smoking and its usefulness as an independent prognostic indicator. Twenty-six resection speciments of pancreatic adenocarcinoma were examined by immunohistochemistry using an antigen retrieval solution and monoclonal PAb 1801 and polyclonal CM1 antibodies on paraffin-embedded material. Specific nuclear p53 expression for both PAb1801 and CM1 was identified in seven cases (27%). In all cases immunoreaction was confined to neoplastic cells. Three of four (75%) tumors from patients who had never smoked showed immunoreaction, whereas only three of 14 (21%) tumors from smokers showed positive staining. Cases with positive staining had shorter mean survival (6.3 mo) than cases that failed to stain (9.8 mo), but the difference was not statistically significant in this small study. There was no statistically significant association between p53 immunoreactivity and other clinicopathologic parameters. Our findings indicate that abnormalities of p53 gene in pancreatic adenocarcinomas may not be directly related to cigaret smoking. Those patients who survived the longest tended to have tumors negative for p53 immunostaining. p53 immunoreaction may be a useful feature in distinguishing adenocarcinoma from chronic pancreatitis in small biopsies.
Phospholipase Cβ2 Binds to and Inhibits Phospholipase Cδ1

Phospholipase Cβ (PLCβ) isoforms, which are under the control of Gαq and Gβγ subunits, generate Ca2+ signals induced by a broad array of extracellular agonists, whereas PLCδ isoforms depend on a rise in cytosolic Ca2+ for their activation. Here we find that PLCβ2 binds strongly to PLCδ1 and inhibits its catalytic activity in vitro and in living cells. In vitro, this PLC complex can be disrupted by increasing concentrations of free Gβγ subunits. Such competition has consequences for signaling, because in HEK293 cells PLCβ2 suppresses elevated basal [Ca2+] and inositol phosphates levels and the sustained agonist-induced elevation of Ca2+ levels caused by PLCδ1. Also, expression of both PLCs results in a synergistic release of [Ca2+] upon stimulation in A10 cells. These results support a model in which PLCβ2 suppresses the basal catalytic activity of PLCδ1, which is relieved by binding of Gβγ subunits to PLCβ2 allowing for amplified calcium signals.
The denatured state (the other half of the folding equation) and its role in protein stability.

Experimental studies of the physical interactions that stabilize protein structure are complicated by the fact that proteins do not unfold to a simple reference state. When their folded structure breaks down, protein chains do not become random coils. Instead, they enter a poorly understood ensemble of partially folded states known collectively as the denatured state. Although it has long been held that agents that promote protein unfolding act specifically on the denatured state, the idea that mutations can exert their destabilizing (or in some cases, stabilizing) effects directly on this state is not widely accepted. A large body of thermodynamic data on mutant proteins plus a limited amount of structural information describing mutational effects on denatured states indicate that 1) the denatured state plays a central role in all aspects of protein stability, including mutant effects, and 2) a quantitative understanding of how amino acid sequence encodes protein structure will probably depend on a more ...
The Halo of the Milky Way

We show that the star counts in the spheroid of the Milky Way are not symmetric about the l=0, l=180 deg. plane. The minimum counts are found towards l=155 deg. The Galactic longitude of maximum star counts depends on the magnitude and color selection of the halo stars. We interpret this as evidence that the spheroid population is triaxial with a major axis oriented 65 deg from the line of sight from the Sun to the Galactic center, and approximately perpendicular to the Galactic bar. Large local star concentrations from tidal debris and possible tidal debris are also observed. A full understanding of the Galactic spheroid population awaits position information and three dimensional space velocities for a representative set of stars in every substructure. Tangential velocities for many stars will be provided by current and planned astrometry missions, but no planned mission will measure stars faint enough to unravel the more distant parts of the spheroid, which contain the majority of the spatial substructure. This paper uses data from the Sloan Digital Sky Survey (SDSS) public data release DR3.
Origin of β-Aminoisobutyric Acid in Iris

ASEN et al. 1 have recently added β-aminoisobutyric acid (BAIB) to the growing list of amino-acids found in higher plants by isolating this compound from the roots of Iris tingitana var. Wedgewood. Fink et al. 2,3 have shown that BAIB can arise metabolically from thymine via dihydrothymine and β-ureidoisobutyric acid in the rat. This discovery, taken in conjunction with our recent observation4 that the higher plant Brassica napus (rape) forms radioactive dihydrothymine, β-ureidoisobutyric acid and carbon dioxide from 2-14C-thymine, strongly suggested to us that, in iris, thymine might well be the source of BAIB. This possibility was tested by supplying totally tritiated thymine to tissue sections of Iris tingitana var. Wedgewood.
Design, control, and simulation of marsupial systems for extending operational lifetime

The development of large scale marsupial robotic teams has been prohibitive for a number of reasons. The complexity of such systems has been hard to simulate, especially in the case of a “Many-to-One” relationship between a marsupial robot and the robots it can deploy. Additionally, the construction of physical systems can be expensive to implement and maintain. However, there are a number of scenarios in which large scale distributed teams are advantageous such as urban search and rescue, biological or chemical release monitoring, or distributed surveillance and reconnaissance. Distributed robotic teams that make use of marsupial systems are able to leverage the power, computational, and locomotive capabilities of a larger system to transport, coordinate, and control smaller robots which may carry more specialized sensing capabilities into areas that are spatially restrictive. As a result, it is necessary to pursue research into this area in order to improve robotic response capabilities. This work looks at the development of a simulation environment capable of modeling multiple “Many-to-One” marsupial systems and the relationship between this simulation environment and a prototype marsupial system presently under construction. Simulated experiments will be used to illustrate the capabilities of the proposed system to enable extended duration missions that would not have previously been possible.
Ether Transfer Methodology: Application to the Synthesis of Polyketide Natural Products

This chapter comprises two major components that sequentially describe existing methods pertinent to the stereoselective formation of 1,3-syn-diol functionality and the development of a new approach to 1,3-syn-diol monoethers and diethers through electrophilic activation of homoallylic alkoxymethyl ethers. The ability to quench a key chloromethyl ether intermediate with various nucleophiles highlights the versatility of the ether transfer method. The process provides selective access to either diol-monoethers or diethers, and it describes an opportunity to convert acyclic stereochemically rich fragments into highly functionalized pyran systems. This fundamentally new method was successfully applied to the synthesis of several complex polyketides including the synthesis of isotactic polyethers, the C7–C17 fragment of swinholide A, the C3–C17 fragment of phorboxazole A, and the neopeltolide macrolactone. Keywords: ether transfer; synthesis; polyketide; natural product; CO bond formation; stereoselective; regioselective; diether; electrophilic activation; chloromethyl ether; Ferrier rearrangement; methoxy transfer; benzyloxy transfer; monoether; 1 ;3-diol ether; iodoetherification
14C-Glucose Oxidation in Whole Blood: a Clinical Assay for Phagocyte Dysfunction

A screening test for chronic granulomatous disease is described; it is based on abnormal oxidation of glucose-1-14C to 14CO2 during phagocytosis by leukocytes in whole blood.
Localization of the promoter for the ptl genes of Bordetella pertussis, which encode proteins essential for secretion of pertussis toxin

The ptl locus of Bordetella pertussis, which encodes proteins necessary for the secretion of pertussis toxin into the extracellular medium, is located directly downstream from the ptx locus, which encodes the structural subunits of the toxin. We have found that the ptx promoter is essential for expression of the ptl genes. A strain of B. pertussis which lacked only the ptx promotor region but which retained all other portions of the ptx-ptl region did not produce PtlF. Moreover, insertion of a functional ptx promoter from B. pertussis at the 5' end of the ptx region of Bordetella bronchiseptica resulted in the production of PtlF in B. bronchiseptica, a species which normally does not produce PtlF. These results suggest that the ptx operon is larger than originally proposed and contains both the ptx and ptl genes.
Sensing lead failure in implantable defibrillators: a comparison of two commonly used leads.

Endocardial Sensing Lead Failure. Introduction: Despite major technological advances, structural problems in implantable cardioverter defibrillator (ICD) endocardial sensing leads remain a significant problem. There are two types of ICD sensing leads: (1) dedicated bipolar leads and (2) integrated lead systems that include defibrillation coils. The long-term performance of these two lead systems has not been directly compared. Methods and Results: We prospectively examined the incidence of lead failure manifested by inappropriate arrhythmia detection in 247 consecutive patients undergoing abdominal ICD implant at a single center between 1991 and 1995. A total of 107 patients received BT-10 (dedicated bipolar) leads and 140 patients received Endotak (integrated bipolar) leads. Over a mean follow-up of 860 ± 442 days, there were 19 (17.8%) lead failures with the BT-10 lead (261 to 1,505 days postimplant) compared with only 6 (4.3%; P < 0.01) with the Endotak lead (410 to 1,211 days postimplant). Lead failure was due to an insulation defect in all cases, with the problem occurring in the proximal lead (within the pulse generator pocket) in all but one case. Lead survival was significantly better with the Endotak lead (P = 0.015, risk ratio = 3.0, 95% confidence intervals 1.2 to 7.6). Conclusion: Late lead failure due to insulation defects in BT-10 sensing leads (causing inappropriate ICD activation) is a relatively common and progressive phenomenon, with difficulties becoming apparent as long as 4 years after implant. This problem is a likely cause of inappropriate shocks in patients with BT-10 leads. Implantation of a new sensing lead should be considered at the time of elective pulse generator replacement, even in the absence of demonstrable oversensing.
Element Analysis of Biological Samples. Principles and Practice.

Element Analysis of Biological Samples. Principles and Practice. G. Venkatesh Iyengar, K.S. Subramanian, and Joost R.W. Woittiez. Boca Raton, FL: CRC Press, 1998, 255 pp., $99.95. ISBN 0-8493-5424-2. This well-documented monograph is recommended for laboratory analysts performing trace element analysis on biological specimens as well as for those who may be …
The role of the opioid receptor-like (ORL1) receptor in motor stimulatory and rewarding actions of buprenorphine and morphine

We have previously shown that the ability of buprenorphine to activate the opioid receptor-like (ORL1) receptor compromises its antinociceptive effect. Furthermore, morphine has been shown to alter the level of orphanin FQ/nociceptin (OFQ/N), the endogenous ligand of the ORL1 receptor, raising the possibility that the endogenous OFQ/N/ORL1 receptor system may be involved in the actions of these opioids. Thus, using mice lacking the ORL1 receptor and their wild-type littermates, the present study assessed the role of the ORL1 receptor in psychomotor stimulant and rewarding actions of buprenorphine and morphine. Morphine (5, 10 mg/kg) dose-dependently increased motor activity and induced conditioned place preference. However, the magnitude of each response was comparable for the mutant mice and their wild-type littermates. In contrast, buprenorphine (1 mg/kg) induced greater motor stimulation in ORL1 receptor knockout mice as compared with their wild-type littermates. Further, single conditioning with buprenorphine (3 mg/kg) induced place preference in mutant mice but not in their wild-type littermates. The results of binding assay showed that buprenorphine concentration-dependently (0-1000 nM) displaced specific binding of [(3)H]-OFQ/N in brain membrane of wild-type mice. Together, the present results suggest that the ability of buprenorphine to interact with the ORL1 receptor modulates its acute motor stimulatory and rewarding effects.
Effect of Ultra-High-Temperature Steam Injection Upon Constituents of Skim Milk

Abstract Raw skim milk was heated to 143±1 C by direct steam injection, held for 8 to 10 s, and vacuum cooled. Analyses of different chemical characteristics of ultra-high-temperature processed skim milk showed a decrease in pH, titratable acidity, and ionized calcium as compared to the control; sialic acid and active sulfhydryls increased. Increases in sialic acid and sulfhydryls might be due to unfolding of protein moieties thus exposing: 1) glycoproteins containing sialic acid and 2) buried sulfhydryls and/or reduction of disulfide bridges in milk proteins. Alteration of the native protein was determined by two techniques: 1) isolation procedures for specific proteins and 2) electrophoretic and densitometric techniques. Casein micelles were most resistant to alteration of their structure while whey proteins, especially β -lactoglobulins, were very susceptible to structural changes. These structural changes may be related to sedimentation and flavor problems associated with ultra-high-temperature milks.
Polykaryocytes resembling warthin-finkeldey giant cells in reactive and neoplastic lymphoid disorders

Abstract Heretofore undescribed polykaryocytes resembling Warthin-Finkeldey giant cells were discovered in lymph nodes and extranodal tissues of 39 patients with reactive (8/39) as well as neoplatic (31/39) lymphoid disorders. These cells measured 25 to 150 microns in diameter and were characterized by four to 60 nuclei arranged in grapelike clusters. They were present in both neoplastic and non-neoplastic areas of involved tissue. The most common lymphoid malignant tumors associated with this type of giant cell were Hodgkin's disease (lymphocyte predominance type), nodular lymphoma (poorly differentiated lymphocytic type), and diffuse lymphoma (well differentiated lymphocytic type), all of which represent lymphomas of low grade malignancy. Their histogenesis and significance are not known at this time, although they appear to be non-neoplastic, and ultrastructural findings suggest their origin from lymphoid cells rather than histiocytes. Electron microscopy performed in three cases failed to reveal any virus particles. There were no clinical differences between patients with these giant cells and those without.
FAST-NEUTRON BOMBARDMENT OF n-TYPE Ge

The effect of fast-neutron bombardment on the electrical properties of $n$-type Ge has been extensively studied by a variety of experiments. The initial rate of carrier removal, the shape of the bombardment curve, and the temperature dependence of electron concentration in bombarded specimens all indicate the production of two vacant states, one located below the middle of the forbidden energy band and the other located \ensuremath{\sim}0.2 ev below the conduction band. These two vacant states are consistent with predictions of the model of James and Lark-Horovitz. Studies of mobility reveal that the additional scattering associated with bombardment-induced lattice disorder is more complex than charged impurity scattering in that it exhibits a much greater temperature dependence and is markedly dependent on electron concentration. Low-temperature exposure and subsequent warming experiments indicate that appreciable photoconductivity associated with minority-carrier trapping results from fast-neutron bombardment. The important minority-carrier traps appear to anneal during warming below room temperature.