cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic mechanical properties of elastomeric nanoparticle composites

The blends of two crosslinked polystyrene-b-polyisoprene (PS-b-PI) copolymers with homopolystyrene were investigated for their dynamic mechanical properties. Elastomeric block copolymer nanofibers utilized as filler were prepared by employing the phase separation property of a polystyrene-b-polyisoprene copolymer, which was then exposed to a crosslinking agent (S2Cl2) for cold vulcanization. The crosslinking density and morphology of nanofillers resulted in three elastomeric block copolymer nanofillers: fully cross-linked nanofiber (FCF), fully crosslinked multi-junctioned nanofiber (FCM), and partially crosslinked multi-junctioned sample (PCM). Uncrosslinked PS-PI block copolymer (UBC) was also studied as a comparison. Crosslinking density was calculated by measuring the change in intensity of the double bond peaks using FTIR spectroscopy. Thermo-mechanical properties and morphology of the blends were characterized by dynamic mechanical analysis (DMA) and scanning electron microscope (SEM). DMA results show that modulus increases with increasing filler loading in the terminal region for both PS/FCM and PS/FCF systems and the increasing rate is related to crosslinking density. Open image in new window
A 6 V embedded 90 nm silicon nanocrystal nonvolatile memory

The first functional 6 V, 4 Mb silicon nanocrystal based nonvolatile memory arrays using conventional 90 nm and 0.25 /spl mu/m process technologies have been produced. The technology can be programmed and erased using conventional techniques in floating gate memories and can substantially reduce the cost of embedded flash at the 90 nm node and beyond.
Heinrich von Ofterdingen

Durch die Arbeit an der Europa-Rede kam Hardenberg in Kontakt mit Quellenstudien zum Mittelalter. Wahrend eines Aufenthalts in der Saline Artern sties er bereits im Juni 1799 in der Bibliothek seines Freundes Karl Wilhelm Ferdinand von Funk (1761–1828), der 1792 eine Biographie des Stauferkaisers Friedrich II. verfasst hatte, auf Chroniken uber den sagenhaften Heinrich von Ofterdingen. Nach dem Urteil von Kritikern wie Gottsched, Bodmer, Lessing und August Wilhelm Schlegel soll dieser Minnesanger wirklich gelebt und sich 1206 oder 1207 am Sangerkrieg auf der Wartburg gegen Konkurrenten wie Walther von der Vogelweide und Wolfram von Eschenbach beteiligt haben (vgl. Kasperowski 1997, S. 272–275). So hatte Hardenberg fur seinen zweiten Romanversuch ein Thema gefunden, das ihm einerseits die Moglichkeit bot, »eine tiefsinnige und romantische Zeit« darzustellen, die nach den Worten des Erzahlers »unter schlichtem Kleide eine hohere Gestalt verbirgt« (I, 204), aber andererseits als poetisiertes ›Mittelalter‹ vor allem die Verwandlung der eigenen prosaischen Gegenwart zum Thema hatte. Symptomatisch in dieser Hinsicht ist, dass der Vater des jungen Ofterdingens — ein tuchtiger und nuchterner Kunsthandwerker in Eisenach — dem Traum seines Sohnes jegliche hohere Bedeutung abspricht: »In dem Alter der Welt, wo wir leben, findet der unmittelbare Verkehr mit dem Himmel nicht mehr Statt« (I, 198).
Effectiveness of anti-oxidant polyethylene: What early retrievals can tell us.

The optimum UHMWPE orthopedic implant bearing surface must balance wear, oxidation, and fatigue resistance. Antioxidant polyethylene addresses free radicals, resulting from irradiation used in cross-linking, that could oxidize and potentially lead to fatigue damage under cycles of in vivo use. This study evaluates what short-term antioxidant UHMWPE retrievals can reveal about: (1) oxidation-resistance and (2) fatigue-resistance of these new materials. Retrievals of three different antioxidant polyethylene materials (n = 25) were analyzed by FTIR and uniaxial tensile tests and compared to conventional (n = 20) and remelted highly cross-linked (n = 30) polyethylene retrievals of similar in vivo duration. Maximum oxidation values differed significantly across material types (p = 0.018). No antioxidant retrieval exhibited a subsurface oxidation peak, in contrast to conventional gamma-sterilized (55%) and highly cross-linked (37%) retrievals that exhibited subsurface oxidation peaks over the same in vivo time. Trans-vinylene index (TVI) correlated positively with nominal irradiation dose (p < 0.001). Tensile toughness correlated negatively with increasing TVI (p < 0.001). The antioxidant materials in this study prevented in vivo oxidation more effectively than remelted HXL polyethylene at least over the in vivo period represented. The comparison of antioxidant retrieval tensile properties can be used as a guide for clinicians in choosing appropriate materials for the applications represented by their patients. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 353-359, 2018.
Old and new treatments for primary biliary cholangitis

Primary biliary cholangitis (formerly primary biliary cirrhosis) is a rare progressive cholestatic liver disease, whose hallmark features include a persistently elevated alkaline phosphatase level, presence of anti-mitochondrial antibodies and characteristic histology. Since 1998, ursodeoxycholic acid (UDCA), a bile acid, has been the only available therapeutic agent. Primary biliary cholangitis is associated with the development of end-stage liver disease, increased morbidity and mortality. UDCA has been shown to improve serum biochemistries, histology and delay the need for liver transplantation. The clinical issue is that approximately 25%-40% of patients do not respond to this standard therapy. In recent years, many trials have investigated alternative and adjunctive treatments, leading to the recent approval of obeticholic acid, an analogue of chenodeoxycholic acid, which has shown significant and sustained reductions in alkaline phosphatase levels in combination with UDCA. Obeticholic acid has rapidly been embraced as a new agent to improve the biochemical profile in refractory patients, in addition to being approved for use as monotherapy in patients who cannot tolerate UDCA. There are several other studies and targets which are being investigated. This review is intended to highlight the benefits of UDCA, educate the reader on the newly available obeticholic acid, and to summarize the many ongoing trials and therapeutic targets being investigated in attempts to control and cure primary biliary cholangitis.
Tracking mobility in the housing choice voucher program: a household level examination in Florida, USA

Previous research on the housing choice voucher (HCV) program has focused on neighbourhoods where voucher holders reside at one point of time. Little is known about mobility of voucher households d...
Assessing Culture-Bound Syndromes Among Asian-Americans

This chapter is focused on the assessment of culture-bound syndromes among Asian-Americans. First, we provide a rationale for the need to better understand Asian culture-bound syndromes. Next, we discuss the history and evolution of the diagnoses of these syndromes and provide specific examples of different types of syndromes. In addition, we provide some suggestions for the assessment of Asian culture-bound syndromes. We emphasize the importance of incorporating cultural values and a non-biased approach to working with clients who present with such concerns. Finally, we offer some directions for future efforts in research and practice as they relate to Asian culture-bound syndromes.
A hybrid optimization-agent-based model of REDD+ payments to households on an old deforestation frontier in the Brazilian Amazon

Abstract REDD+ was initially conceived of as a multi-level carbon-based payment for environmental services (PES). It is still often assumed to be a cost-effective climate change mitigation strategy, but this assumption is mostly based on theoretical studies and static opportunity cost calculations. We used spatial and socioeconomic datasets from an Amazonian deforestation frontier in Brazil to construct a simulation model of REDD + payments to households that can be used to assess REDD + interventions. Our SimREDD + model consists of dynamic optimization and land-use/cover change allocation submodels built into an agent-based model platform. The model assumes that households maximize profit under perfect market conditions and calculates the optimal household land-use/cover configuration at equilibrium under a given REDD + PES scenario. These scenarios include PES based on (1) forest area and (2) carbon stocks. Insights gained from simulations under different conditions can assist in the design of more effective, efficient, and equitable REDD + programs.
Using “Rapid Revisit” CYGNSS Wind Speed Measurements to Detect Convective Activity

The Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne GNSS-reflectometry mission, which was launched on December 15, 2016 for ocean surface wind speed measurement. CYGNSS includes eight small satellites in the same low earth orbit, so that the mission provides wind speed products having unprecedented coverage both in time and space to study multitemporal behaviors of oceanic winds. The nature of CYGNSS coverage results in some locations on earth experiencing multiple wind speed measurements within a short period of time (a “clump” of observations in time) resulting in a “rapid revisit” series of measurements. Such observations seemingly can provide indications of regions experiencing rapid changes in wind speeds, and therefore serve as an indicator of convective activity. An initial investigation of this concept using simulated and on-orbit CYGNSS measurements is provided in this paper. The temporally “clumped” properties of CYGNSS measurements are examined, and the results show that clump durations and spacing vary with latitude. For example, the duration of a clump can extend as long as a few hours at higher latitudes, with gaps between clumps ranging from 6 to as high as 12 h depending on latitude. Initial examples are provided to indicate the potential of changes within a clump to detect convective activity through a comparison with convective activity indicators derived from model datasets. The results at present are limited by the ongoing calibration of CYGNSS wind speed retrievals, so that future work will be required to obtain a more complete assessment, but nevertheless clearly indicate the potential utility of the method for studies of atmospheric convection.
Behavioral Modulation of Cardiovascular and Somatomotor-Cardiovascular Interactions in the Non-Human Primate

It is well-known that one can totally denervate the hearts of mammals, including man, and that these hearts are still capable of maintaining the circulation under a wide variety of conditions such as exercise, hypoxia, hypertension or hypotension. Furthermore, a number of primitive, vertebrate species exist in which there is virtually no innervation to the circulation. Thus, it is clear that myogenic and humoral mechanisms can regulate cardiovascular function relatively well. Since this is so, one needs to ask what role the nervous system performs in the regulation and control of the circulation.
Preservation of sweet cherry by isochoric (constant volume) freezing

Abstract Due to the perishable nature of fruits and the importance of reducing food waste, an effective preservation technique is required to prolong the shelf life and maintain the physical and nutritional properties of seasonal fruits. In this study, we evaluated isochoric freezing for preserving the quality of sweet cherries. We examined the physical characteristics and nutritional values of thawed cherries frozen to −4 °C or −7 °C in an isochoric system and compared them with those of fresh cherries, thawed cherries that were individually quick frozen and thawed cherries frozen to −4 °C or −7 °C in an isobaric system. We found that isochoric freezing decreased the drip loss and better preserved the color, texture, structure, ascorbic acid, phenolic and antioxidant content of frozen cherries, thereby proving their potential in frozen fruit applications.
Spermatogenesis, reproductive maturation, and spawning seasonality of male winter flounder, Pseudopleuronectes americanus: Comparisons among fishery stocks

Abstract Winter flounder, Pseudopleuronectes americanus, were collected from three fishery stocks in the United States (U.S.) during 2009–2013 to describe spermatogenesis. Spermatogenesis included rapid, synchronous transitions during autumn from mitotic spermatogonia to meiotic spermatocytes, then to haploid spermatids, and the release of spermatozoa into lobule lumen. As these transitions occurred several months prior to the spring spawning season, maturity of the testes are a poor indicator of spawning season, however, individuals can be readily evaluated prior to the spawning season for evidence of skipped spawning. Throughout this process, the gonad weight increased dramatically, with spawning-season maxima from 11 to 17% relative to individual somatic weight, suggesting considerable reproductive investment relative to other flatfishes. Fish condition also cycled seasonally, which indicated that males follow a capital breeding pattern that has been reported for female winter flounder. The timing of spermiogenesis was very similar in the fish among each U.S. stock (Southern New England [SNE], Georges Bank [GB], and the Gulf of Maine [GOM]) and published data from coastal Newfoundland, even though U.S. winter flounder spawned earlier in spring than fish in the Canadian stock. Male maturity varied in relation to both size and age, and over time, in patterns similar to those reported for female winter flounder, but at smaller and younger sizes than females. These intra-specific variations in reproductive seasonality, maturation, and skipped spawning suggest that winter flounder have the potential to adaptively respond to a dynamic environment in a region where ocean warming is occurring rapidly.
Off-label Medication Prescribing Patterns in Pediatrics: An Update

OBJECTIVES: To describe the frequency of off-label drug use in 2014 as defined by the Food and Drug Administration (FDA)–approved age ranges in patients ≤18 years of age, to determine the rate of off-label drug use in 2014 by drug classification, and to compare current off-label medication usage rates with historical rates. METHODS: This is a retrospective cohort study of an administrative database containing inpatient resource use data from January 1, 2014, to December 31, 2014. Patients ≤18 years of age receiving 1 of 76 selected commonly prescribed medications are included. Off-label drug use is defined as use in a patient younger than the lower limit of the FDA-approved age range for any indication or dosage form of that drug. RESULTS: At least 1 drug was prescribed off label in 779 270 of 2 773 770 (28.1%) patient visits during the study period. Younger age, longer hospital stays, and mortality were associated with higher rates of off-label medication prescription. Off-label usage of certain medications differed between care settings. Rates of off-label medication use were higher in observational (45.5%), inpatient (53.9%), and ambulatory (54.2%) settings. CONCLUSIONS: Although off-label drug use at major US pediatric hospitals is declining, 1 out of every 4 medications is not in accordance with FDA label indications for patient age. There exists substantial variation in off-label drug use among drug categories and encounter types. Although many commonly prescribed medications are FDA-approved for use in subpopulations of pediatric patients, studies of their safety, efficacy, pharmacokinetics, and optimal dosing are ongoing.
Semiparametric approaches for matched case–control studies with error-in-covariates

The matched case–control study is a popular design in public health, biomedical, and epidemiological research for human, animal, and other subjects for clustered binary outcomes. Often covariates in such studies are measured with error. Not accounting for this error can lead to incorrect inference for all covariates in the model. The methods for assessing and characterizing error-in-covariates in matched case–control studies are quite limited. In this article we propose several approaches for handling error-in-covariates that detect both parametric and nonparametric relationships between the covariates and the binary outcome. We propose a Bayesian approach and two approximate-Bayesian approaches for addressing error-in-covariates that is additive and Gaussian, where the variable measured with error has an unknown, nonlinear relationship with the response. The Bayesian approaches use an approximate latent variable probit model. All methods are developed using the nonparametric method of low-rank thin-plate splines. We assess the performance of each method in terms of mean squared error and mean bias in both simulations and a perturbed example of 1–4 matched case-crossover study.
Silane-Promoted Cycloisomerization of Functionalized 1,6-Dienes Catalyzed by a Cationic (π-Allyl)palladium Complex

A 1:1 mixture of the (π-allyl)palladium complex (η3-C3H5)Pd(Cl)PCy3 and NaB[3,5-C6H3(CF3)2]4 in the presence of HSiEt3 catalyzed the cycloisomerization of functionalized 1,6-dienes to form 1,2-disubstituted cyclopentenes in good yield with high selectivity (typically >94%). The protocol tolerated a range of functional groups and substitution at one of the allylic carbon atoms.
Challenging borders: The case for open borders with Joseph Carens and Jean-Luc Nancy:

Joseph Carens develops one of the most prominent cases for open borders in the academic literature on the basis of freedom and equality. Yet the implementation of his social membership theory would...
A chemical and engineering approach towards "smart" synthetic bone grafts.

The design of synthetic bone grafts that possess structural and biochemical microenvironment emulating the extracellular matrix of bone and exhibit good surgical handling characteristics is of significant importance to orthopedic applications. Using a combination of chemical and engineering tools, our lab has developed a number of osteogenic composite bone grafts that possess elastomeric or self-deployable shape memory properties facilitating the repair and regeneration of segmental bony defects. The first type of grafts are composites of poly(2-hydroxyethyl methacrylate) (pHEMA) and hydroxyapatite/tricalcium phosphate (HA/TCP) possessing osteoconductive mineral content approximating that of human bone. The grafts are fabricated by cross-linking pHEMA hydrogel in the presence of different types of HA/TCP powder using viscous ethylene glycol as a solvent. Despite the high HA/TCP contents, these composites exhibit elastomeric property and unusually high fracture resistance under physiological compressive loading. We demonstrate that tailored microstructural properties and compressive behavior of the composites can be achieved by the selective use of HA/TCP powder of varied sizes and aggregation. When subcutaneously implanted in rats, the mineral component dissolved slowly and osteoblastic differentiation of the bone marrow stromal cells pre-seeded on the substrates was observed. In vitro cell culture studies show that these composites are able to retain and locally release exogenous growth factors and cytokines regulating graft healing in a sustained manner. These grafts in facilitating the repair of critical-sized bony defects are being investigated using a rat femoral segmental defect model. The second type of composite grafts consist cross-linked poly(ester-urethane) that is strengthened by Si-based nanoparticles. Using ring-opening polymerization, biodegradable polylactide of varying lengths is first grafted to Si nanoparticles to generate star-shaped macromers. Using a solvent casting technique, these macromers are then crosslinked to generate composite grafts with tailored bonelike flexural moduli, tunable biodegradation rates consistent with the time frame of normal bone fracture healing, and physiologically relevant glass transition temperatures. These grafts possess unique shape memory properties that enable the grafts to efficiently recover (within seconds) from a temporary shape facilitating surgical insertion to a pre-programmed "permanent" shape matching the defect size upon mild thermal activation. The potential of these composites as deployable bone grafts for assisting the repair and regeneration of musculoskeletal defects are being explored.
How does the brain navigate knowledge of social relations? Overlapping but distinct mechanisms for attentional shifts in space and social knowledge

How does the human brain support reasoning about social relations (e.g., social status, friendships)? Converging theories suggest that navigating knowledge of social relations may co-opt neural circuitry with evolutionarily older functions (e.g., shifting attention in space). Here, we analyzed multivoxel response patterns of fMRI data to examine the neural mechanisms for shifting attention in knowledge of a social hierarchy. The "directions" in which participants mentally navigated social knowledge were encoded in multivoxel patterns in superior parietal cortex, which also encoded the direction of attentional shifts in space. Exploratory analyses implicated additional regions of posterior parietal and occipital cortex in encoding analogous mental operations in space and social knowledge. However, cross-domain analyses suggested that attentional shifts in space and social knowledge are encoded in functionally independent response patterns. These results elucidate the neural basis for navigating abstract knowledge of social relations, and its connection to more basic mental operations.
Prevalence of hyperdontia, hypodontia, and concomitant hypo-hyperdontia

Abstract Background/purpose Anomalies in human dentition are some of the most common occurrences of congenital abnormalities. Present study aimed to determine the prevalence of hypodontia, hyperdontia and concomitant hypo-hyperdontia (CHH) among patients attending the University of Nevada, Las Vegas (UNLV) School of Dental Medicine clinics. Materials and methods Retrospective search was conducted on patients’ clinical notes in AxiUm™. Search included using keywords such as “hypodontia”, “hyperdontia”, “supernumerary teeth” and “congenitally missing”. Panoramic radiographs were used to confirm the hyperdontia, hypodontia or CHH for patients attending the UNLV SDM clinics from 2010 to 2018. Collected data were analyzed using the chi-square test. Results 1101 patients were populated using the keywords. From these populated patients, 186 had hyperdontia, 23 hypodontia, and 3 presented with CHH. The distribution of males and females was 54.7% and 45.3% respectively. Hispanics, African Americans, Asians, Caucasians and ethnically unspecified patients represented 43.39%, 14.25%, 3.30%, 8.02%, and 31.13%, respectively, of those patients with a dental anomaly. Hyperdontia was most common amongst Hispanic patients with 39.24%, followed by the unspecified patients at 32.8% as well as amongst males at 56.45% (P value of 0.03). Unidentifiable supplemental teeth were overall the greatest in number with the lower right premolars, tooth 44, being the most common. This was demonstrated in the Hispanic patients whereas within the African American patients a 4th molar was in excess. Conclusion Hispanic patient population has a significant link to dental anomalies, specifically hyperdontia while the presence of the fourth molar was prominent among African American patients.
Risk of Infectious Endophthalmitis From a Resident-Performed Intravitreal Injection.

Purpose:This work assesses the safety of resident-performed intravitreal injections by comparing the incidence of postinjection endophthalmitis associated with residents vs surgical retina attendin...
AfterwordEntangled politics: borderscapes and sexuality

The volatility of the present moment requires scholars to direct nuanced intellectual attention to the intertwined space of borders and sexuality. While these subjects have historically come into v...
A Network Approach to Understanding Narcissistic Grandiosity via the Narcissistic Admiration and Rivalry Questionnaire and the Narcissistic Personality Inventory

The narcissistic admiration and rivalry concept (NARC) model of grandiose narcissism posits that striving for uniqueness, grandiose fantasies, and charmingness define narcissistic admiration, where...
AWS IoT and the Interconnected World – Aging in Place

This project is considered the startup component of a framework for sensor data fusion, data mining, and analytics in real-time. The long-term goal is to build a dynamic, efficient, scalable, and secure runtime of parsing and handling multi-sensor data. The outcomes of the project are meant to design a multi-sensors data fusion model. During this research, some concepts are used and studied for future use, such as data imperfections and inconsistencies, misled data association, data fusion portability, machine independence, security vulnerabilities, etc. We will build the sensor network, acquire data from multiple sensors, and use AWS IoT SDK (Software Development Kit) to handle the data fusion for basic algorithms. The core of the multiple sensor network will be a Raspberry Pi 4 to decrease system cost and increase portability. The outcomes of this project will help build a comprehensive, real-time data monitoring, and support system for assistive living and care providers.
Temporary Regulatory Deviations and the Coronavirus Disease 2019 (COVID-19) PCR Labeling Update Study Indicate What Laboratory-Developed Test Regulation by the US Food and Drug Administration (FDA) Could Look Like.

The coronavirus disease 2019 (COVID-19) response necessitated innovations and a series of regulatory deviations that also affected laboratory-developed tests (LDTs). To examine real-world consequences and specify regulatory paradigm shifts, legislative proposals were aligned on a common timeline with Emergency Use Authorization (EUA) of LDTs and the US Food and Drug Administration (FDA)-orchestrated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) labeling update study. The initial EUA adoption by LDT developers shows that the FDA can have oversight over LDTs. We used efficiency-corrected microcosting of our EUA PCR assay to estimate the national cost of the labeling update study to $0.3 to $1.4 million US dollars. Labeling update study performance data showed lower average detection limits in commercial in vitro diagnostic (IVD) assays versus LDTs (32,000 ± 75,000 versus 71,000 ± 147,000 nucleic acid amplification tests/mL; P = 0.04); however, comparison also shows that FDA review of IVD assays and LDTs did not prevent differences between initial and labeling update performance (IVD assay, P
Facticity and Transcendence Across the Disciplines: Phenomenology and the Promise

This paper begins from one of the most commonly found questions in phenomenology, “What is Phenomenlogy?”, to argue that phenomenology is a trans-disciplinary approach to engaging with the products of human culture. This approach is characterized by paying particular attention to the distinction between facticity and transcendence within “lived experience” so as to help us better articulate and evaluate the promises that animate every human institution. Such a task necessarily requires inter-disciplinary input and helps us engage in our lives—in our shared cultural life—differently.
Cognition of Complex Events: Visual Scenes and Music

Publisher Summary The ecological approach has become well-established in the domain traditionally known as "perception." Opposition to memory as a theoretical construct implies no judgment that the problems o f memory are unimportant or impossible to address. People do show the phenomena of remembering and forgetting, and there is no denying the necessity of understanding just how and why such phenomena occur. The issues raised by ecologically-oriented writers concern the concepts one use to understand the phenomena of memory—the challenge posed by the ecological approach is to conceptualize these phenomena without reliance on the notion of memory "stores" containing countless numbers of "engrams," "images," "traces," etc. The ecological approach to memory phenomena might be made comparable with the concept of schemata. The empirical phenomena of coherence and fusion led to conclude that "events can be primary units of analysis," and that these "events are natural wholes that are, so-to-speak, perceived through the slides (of a picture sequence), rather than built up from the slides."
Parallel Computation of Trajectories Using Graphics Processing Units and Interpolated Gravity Models

Seeking improvements in speed and accuracy in multiobject trajectory simulations, a solution methodology is presented that takes advantage of 1) new high-fidelity geopotential and third-body perturbation models that efficiently trade memory for speed, and 2) a graphics processing unit based integrator to achieve parallelism across multiple objects. The two methods combined lead to multiplicative speedups, making the tool three orders of magnitude faster, in some cases, compared to the same simulation performed in serial on a single central processing unit. The tool is capable of Monte Carlo simulations of a single object or of propagating the mean and covariance of all the objects in a space catalog. The tool performance is demonstrated for 1) a five-day Monte Carlo simulation of the state uncertainty point cloud modeled with over one million objects, and 2) a seven-day simulation of position and velocity states of a full space catalog with over 250,000 objects. The simulations required approximately 1 an...
Activity and specificity of Escherichia coli ClpAP protease in cleaving model peptide substrates.

Escherichia coli ClpAP protease is an ATP-dependent protease composed of the proteolytic component ClpP and a regulatory ATPase, ClpA. ClpAP protease degraded a variety of peptide bonds in protein and peptide substrates at a slow rate (kcat or = 800 min-1) for a synthetic peptide composed of the first 19 amino acids of ClpP, MSYSGERDNFAPHMALVPV, referred to as the propeptide. The propeptide was not degraded by ClpP alone, but was degraded in the presence of ClpA and ClpP. Degradation was activated by nonhydrolyzable analogs of ATP, indicating that nucleotide-promoted interaction between ClpA and ClpP is sufficient to activate ClpP for propeptide cleavage. The propeptide, as well as truncated forms lacking either the first 9 or the last 3 amino acids, was cleaved at the same Met-Ala bond at which autoprocessing occurs in vivo. No hydrolysis of FAPHMALVPV derivatives was observed when Met was replaced by Glu, Lys, Ser, Tyr, Ile, and D-Met, but cleavage at the same position did occur with Leu or Trp substitutions. A peptide composed of a tandem repeat of FAPHMALVPV was cleaved between both Met-Ala bonds (Kcat values > or = 39 min-1). Propeptides inhibited degradation of alpha-casein by competition for a binding site on ClpA, and they stimulated the basal ATPase activity of ClpA in the absence of ClpP. Peptides and protein substrates interact at an allosteric site on ClpA, which appears to be the site at which specific substrates are recognized by the Clp protease.
Enterprise modeling and enterprise transformation

The epitome of the modern enterprise is a large scale, geographically dispersed, complex entity. It interacts with other enterprises, perhaps large numbers of them, in many different locations, often with great frequency. It serves highly competitive markets, which may shift in a matter of days or weeks. Designing, planning, managing, and controlling the modern enterprise requires a supporting infrastructure that is capable, adaptable, understandable, and usable. While not all enterprises share all these characteristics, almost all enterprises are affected by the associated business processes and technologies. Over the past decade, Enterprise Modeling, or EM, has emerged as a response to the needs of those charged with designing and maintaining the enterprise infrastructure, and EM could well become the platform for developing not only enterprise infrastructure, but all enterprise decision support. As a result, EM may be a powerful enabler (or inhibitor) of enterprise transformation. This paper provides an introduction to EM, a brief history of its evolution, and an assessment of EM from an enterprise transformation perspective.
Resolution of longstanding protein-losing enteropathy in a patient with intestinal lymphangiectasia after treatment for malignant lymphoma

Abstract In 1956 we evaluated a patient who had a debilitating disease of a 2 yr duration, characterized by recurrent vomiting, diarrhea, cachexia, massive edema, hypoproteinemia, and dilated intestinal lymphatics. During our initial evaluation of this patient, we observed that 42% of her circulating protein pool was lost into her gastrointestinal tract daily, whereas normal gastrointestinal loss of protein does not exceed 1.6%. Her disease appeared to represent a classic example of intestinal lymphangiectasia. She was treated symptomatically for 13 yr with essentially no change. In 1969 the patient developed a stage IV diffuse, undifferentiated (non-Burkitt's) malignant lymphoma. Using immunoperoxidase staining, the neoplastic cells were found to contain cytoplasmic IgMκ, suggesting that the lymphoma had a monoclonal B-cell origin. She was successfully treated with cyclophosphamide, vincristine, and prednisone. Shortly after the initiation of this systemic combination chemotherapy, her serum protein concentration returned to normal, her edema resolved, and she was cured of gastrointestinal symptoms. Moreover, repeat studies revealed that her protein loss had fallen to only 2%. The simultaneous cure of both the intestinal lymphangiectasia and lymphoma with combination chemotherapy suggests new relationships between these conditions as well as new possibilities for the treatment of acquired forms of intestinal lymphangiectasia associated with overwhelming gastrointestinal protein loss.
Insulin Stimulation of Amino Acid Uptake in Rat Diaphragm RELATIONSHIP TO PROTEIN SYNTHESIS

Abstract 1. Puromycin dihydrochloride inhibited uptake of α-aminoisobutyric acid (AIB), 1-aminocyclopentane-1-carboxylic acid, and α,γ-diaminobutyric acid by intact diaphragm muscle from male rats weighing 60 to 90 g when the antibiotic was added to the system in vitro 120 and 180 min before the addition of the substrate. 2. In the absence of insulin, this inhibitory response was also produced by cycloheximide, but not by the aminonucleoside of puromycin or actinomycin D. In the presence of insulin, AIB uptake was inhibited by actinomycin D and the aminonucleoside of puromycin as well as by puromycin dihydrochloride and cycloheximide, the degree of inhibition paralleling inhibition of l-lysine incorporation into protein. 3. The antibiotics shown to inhibit amino acid transport did not change tissue water spaces, oxygen consumption, the concentration of α-amino nitrogen in the incubation medium, or the diffusion constant for AIB (Kd). 4. In diaphragm muscle from rats weighing 60 to 90 g, incubation with puromycin for 180 min reduced subsequent stimulation of AIB transport by insulin. In muscle from animals weighing 220 to 250 g, stimulation by insulin was completely abolished by puromycin. 5. These studies show that puromycin inhibits the synthesis of a rapidly turning over protein or proteins involved in the transport of AIB. The results suggest that insulin stimulates amino acid transport in two distinct ways: by increasing the affinity of the carrier mechanism for amino acids; and by initiating the synthesis of a specific protein or proteins which enhances transport.
Effects of Ca2+ on the kinetics of phosphate release in skeletal muscle.

Abstract The process of phosphate dissociation during the muscle cross-bridge cycle has been investigated by photoliberation of inorganic phosphate (Pi) within skinned fibers of rabbit psoas muscle. This permitted a test of the idea that Ca2+ controls muscle contraction by regulating the Pi release step of the cycle. Photoliberation of Pi from structurally distinct "caged" Pi precursors initiated a rapid tension decline of up to 12% of active tension, and this was followed by a slower tension decline. The apparent rate constant of the fast phase, kPi, depended on both [Pi] and [Ca2+], whereas the slow phase generally occurred at 2-4 s-1. At maximal Ca2+, kPi increased in a nonlinear manner from 43 +/- 2 s-1 to 118 +/- 7 s-1, as Pi was raised from 0.9 to 12 mM. This was analyzed in terms of a three-state kinetic model in which a force-generating transition is coupled to Pi dissociation from the cross-bridge. As Ca(2+)-activated tension was reduced from maximal (Pmax) to 0.1 Pmax, (i) kPi decreased by up to 2.5-fold, (ii) the relative amplitude of the rapid phase increased 2-fold, and (iii) the relative amplitude of the slow phase increased about 6-fold. Changes in the rapid phase are compatible with Ca2+ influencing an apparent equilibrium constant for the force-generating transition. By comparison, kPi was faster than the rate constant of tension redevelopment, ktr, and was influenced less by Ca2+. Ca2+ effects on the caged Pi transient cannot account for the large effects of Ca2+ on actomyosin ATPase rates or cross-bridge cycling kinetics but may be a manifestation of reciprocal interactions between the thin filament and force-generating cross-bridges, and may represent Ca2+ regulation of the distribution of cross-bridges between non-force-and force-generating states.
Twitter financial community sentiment and its predictive relationship to stock market movement

Twitter, one of the several major social media platforms, has been identified as an influential factor for financial markets by multiple academic and professional publications in recent years. The motivation of this study hinges on the growing popularity of the use of Twitter and the increasing prevalence of its influence among the financial investment community. This paper presents empirical evidence of the existence of a financial community on Twitter in which users’ interests align with financial market-related topics. We establish a methodology to identify relevant Twitter users who form the financial community, and we also present the empirical findings of network characteristics of the financial community. We observe that this financial community behaves similarly to a small-world network, and we further identify groups of critical nodes and analyse their influence within the financial community based on several network centrality measures. Using a novel sentiment analysis algorithm, we construct a weighted sentiment measure using tweet messages from these critical nodes, and we discover that it is significantly correlated with the returns of the major financial market indices. By forming a financial community within the Twitter universe, we argue that the influential Twitter users within the financial community provide a proxy for the relationship between social sentiment and financial market movement. Hence, we conclude that the weighted sentiment constructed from these critical nodes within the financial community provides a more robust predictor of financial markets than the general social sentiment.
Genetic and Physical Variability at the Mating Type Locus of the Oomycete, Phytophthora infestans

Mating type in the oomyceteous fungus, Phytophthora infestans, is determined by a single locus. In a previous study of a few isolates, the locus segregated in a manner genetically consistent with its linkage to a system of balanced lethal loci. To determine the prevalence of this phenomenon within P. infestans, genetic analyses were performed using isolates representative of the diversity within the species that had been selected by DNA fingerprinting using probes linked to mating type. Non-Mendelian segregation of the mating type locus was observed in crosses performed with each isolate. An unusual group of isolates was identified in which the mating type determinants had been rearranged within the genome; these strains also produced an aberrantly large number of self-fertile progeny. Curiously, in all isolates, markers linked to the mating type locus appeared prone to duplication, transposition, deletion, or other rearrangement. This was not observed for loci unlinked to mating type. Data from the crosses and analyses of marker variation were used to erect models to explain the bases of mating type determination and of the unusual segregation of the chromosomal region containing the mating type locus.
Prebreakdown imaging in DC stressed n-hexane

Sequential image recording obtained with the use of a high-sped framing camera was used to study the consequences of the DC stressing of n-hexane. It is observed that partial discharges, or conduction current pulses, produced by DC stressing are intimately related to the generation of prebreakdown streamers. The DC-induced events have characteristics that are similar to those produced by impulse voltages. In contrast to the impulse case, the absence of a displacement current for DC conditions allows the conduction current activity to be examined in detail. A demarcation is shown between streamer growth during the current wavefront and decay in the wavetail. The stepped nature of the current wavefront appears not to be related to the event profile, although it may be associated with the underlying discharge process. >
Optimal theoretical design of 2-D microscale viscous pumps for maximum mass flow rate and minimum power consumption

Abstract The present paper addresses the effect of geometric parameters such as channel height and rotor eccentricity on the mass flow rate and power consumption of a two-dimensional microscale viscous pumps. The objective is to maximize the mass flow rate and at the same time minimize shaft power consumption when an external pressure load is applied along the channel that houses the rotor. Three different viscous micropump configurations were considered, a straight housed pump (I-shaped housing) and two curved housed pumps (L- and U-shaped housings). Because the performance of a microviscous pumps are based on the asymmetric placement of the rotor within the surrounding housing, the numerical results show that the rotor eccentricity and the channel height have a major effect on the mass flow rate generated by the rotor and on the shaft power demanded by the rotor. Preliminary simulations showed that mass flow rate is maximized when the eccentricity is small. The results also show that micropumps with curved housing (i.e., L- and U-shaped configurations) not only provide higher mass flow rates when compared with straight housed pumps, but also demand less shaft power to operate. Optimized geometric dimensions of all three configurations are presented for several values of the Reynolds number and pressure load.
Influence of 3,4-benzo(a)pyrene on warfarin hypoprothrombinemia and disposition in the rat

Female Sprague-Dawley rats pretreated with 3,4-benzo(a)pyrene (BP) (20 mg/kg ip) in corn oil once daily for 4 days exhibited a shortened duration of hypoprothrombinemia and a shorter warfarin plasma half-life in comparison with rats pretreated with corn oil (1 ml/kg ip). Sodium warfarin (1 mg/kg ip) in normal saline was administered 36 hr after the final pretreatment injection. Prothrombin complex activity for BP rats was 94 ± 3% (mean ± SE) 60 hr after warfarin treatment; activity for controls was 48 ± 7% (p < 0.001). The plasma half-life of warfarin was 15 hr for the BP group and 23 hr for control rats. In vitro formation of hydroxylated warfarin metabolites was twofold higher for BP-treated animals. BP pretreatment marginally increased the plasma disappearance rate of indocyanine green but biliary secretion of warfarin and the hepatic uptake of warfarin were unchanged by BP pretreatment. These results suggest that 3,4-BP pretreatment alters the observed pharmacologic activity of warfarin in female rats by increasing the rate of warfarin elimination. The change in warfarin disposition in BP-pretreated animals appears to be due to increased hepatic metabolism with BP pretreatment exerting no effect on the hepatic uptake or biliary secretion of warfarin.
Using an integrated approach to link biomarker responses and physiological stress to growth impairment of cadmium-exposed larval topsmelt

In this study, we used an integrated approach to determine whether key biochemical, cellular, and physiological responses were related to growth impairment of cadmium (Cd)-exposed larval topsmelt (Atherinops affinis). Food intake (Artemia franciscana nauplii), oxygen consumption rates, apoptotic DNA fragmentation (TUNEL assay), and metallothionein (MT)-like protein levels, were separately measured in relation to growth of larval topsmelt aqueously exposed to sublethal doses of Cd for 14 days. Cadmium accumulation and concentrations of abundant metals were also evaluated in a subset of fish. Fish in the highest Cd treatments (50 and 100 ppb Cd) were smaller in final mean weight and length, and consumed fewer A. franciscana nauplii than control fish. Food intake was positively correlated with final weight of larval topsmelt in Cd and control treatments; food intake increased as final weight of the fish increased. Oxygen consumption rates were positively correlated with Cd concentration and mean oxygen consumption rates were inversely correlated with final mean weight of topsmelt; the smallest fish were found in the highest Cd treatment and were respiring at higher rates than control fish. Apoptotic DNA fragmentation was concentration-dependent and was associated with diminished growth. Apoptotic DNA fragmentation was elevated in the gill of fish exposed to 50 ppb Cd, and in the gut, gill, and liver of fish exposed to 100 ppb Cd. Metallothionein (MT)-like protein levels in fish from 100 ppb Cd treatments were significantly higher than those in other treatments. Oxygen consumption rates may have increased as a compensatory response to Cd exposure. However, it is likely that the energy produced was allocated to an increased metabolic demand due to apoptosis, MT synthesis, and changes in ion regulation. This diversion of energy expenditures could contribute to growth impairment of Cd-exposed fish.
THE EFFECTS OF PYRIDINE AND COKE POISONING ON BENZOTHIOPHENE HYDRODESULFURIZATION OVER CoMo/AI2O3 CATALYST†

Abstract The kinetics of benzothiophene hydrodesulphurizaiion (HDS) and hexene hydrogenation over a sulfided CoMo/Al2O3 catalyst were studied in a stirred flow microbalance reactor at atmospheric pressure. The effects of pyridine poisoning and coking on catalyst deactivation and kinetics were also determined. Benzothiophene HDS kinetics on the lined-out catalyst were best correlated with a Langmuir-Hinshel-wood equation of the form where r is the rate, kT the rate constant, p are partial pressures, K's are adsorption constants, and subscripts T, H and S stand for benzothiophene. H2 and H2S, respectively. This rate equation was the same for pyridine poisoned or coked catalyst, KT being lower, but KT and Ks being the same within experimental error. The rate of hexene hydrogenation was first order in hexene and hydrogen, and inhibited by hexene and hydrogen; but an explicit best equation could not be obtained. Pyridine deactivation of HDS was more selective than coke. At least two HDS sites exist, one being ...
Growth of C60 films on silicon surfaces

Abstract The growth of crystalline C 60 films on Si(111) and Si (100) surfaces has been studied using scanning tunneling microscopy and atomic force microscopy. It is found that the films on these two silicon substrates, which consist of both partially ordered monolayer and crystalline islands, differ in their morphologies. The results are explained in terms of the relative strength of interaction of the first monolayer of C 60 molecules with the silicon substrate and the C 60 islands above it. Annealing the samples to elevated temperatures causes the C 60 islands to evaporate, leaving a full layer of C 60 molecules capped on the substrate.