cssi/SciSciGPT-SciSciNet huggingface dataset:
Pyrrolizidine Alkaloids Crosslink DNA with Actin

Pyrrolizidine alkaloids (PAs) are toxic constituents of hundreds of plant species, some of which people are exposed to in herbal products and traditional remedies. The bioactivity of PAs are related, at least in part, to their ability to form DNA-protein complexes (DPC). Previous studies from our laboratory indicated a possible role for actin in PA-induced DPCs. Nuclei prepared from Madin-Darby bovine kidney (MDBK) and human breast carcinoma (MCF-7) cells were treated with the pyrrolic PAs dehydrosenecionine (DHSN) and dehydromonocrotaline (DHMO). DPCs were purified and then analyzed by Western immunoblotting. Actin was found in DPCs induced by both DHSN and DHMO, but not in those from control nuclei. Actin was also present in DPCs induced by cisplatinum and mitomycin C, two bifunctional cross-linkers. In separate experiments, DHSN and DHMO were crosslinked to a mixture of HindIII digested lambda phage with varying amounts of glutathione (GSH), cysteine, or methionine to identify the stoichiometry of competition between DNA and alternate nucleophiles for crosslink formation with pyrroles. GSH and cysteine, but not methionine, competed with lambda phage for DNA crosslinking, indicating that reduced thiols may have a role in nucleophilic reactions with pyrroles in the cell. While actin involvement in cisplatinum-induced DPCs is documented, the discovery of actin crosslinking in PA or mitomycin C-treated cells or nuclei is, to our knowledge, novel. Pyrrole-induced DPC formation with actin, a protein with structural and/or regulatory importance proteins, may be a significant mechanism for PA toxicity and bioactivity.
Optimal Sensor Array Configuration in Remote Image Formation

Determination of optimal sensor configuration is an important issue in many remote imaging modalities, such as tomographic and interferometric imaging. In this paper, a statistical optimality criterion is defined and a search is performed over the space of candidate sensor locations to determine the configuration that optimizes the criterion over all candidates. To make the search process computationally feasible, a modified version of a previously proposed suboptimal backward greedy algorithm is used. A statistical framework is developed which allows for inclusion of several widely used image constraints. Computational complexity of the proposed algorithm is discussed and a fast implementation is described. Furthermore, upper bounds on the sum of the squared error of the proposed algorithm are derived. Connections of the method to the deterministic backward greedy algorithm for the subset selection problem are presented, and two application examples are described. Five compelling optimality criteria are considered, and their performance is investigated through numerical experiments for a tomographic imaging scenario. In all cases, it is verified that the configuration designed by the proposed algorithm performs better than wisely chosen alternatives.
Analysis of aerosol composition at Cheju Island, Korea, using a two-bin gas-aerosol equilibrium model

Aerosol chemical composition data measured at Cheju Island, Korea from March 1992 to December 1994 are analyzed with a gas-aerosol equilibrium model. The aerosol composition is divided into fine and coarse modes, with each mode assumed to be in equilibrium with the gas phase. The model represents the mean aerosol composition. The particulate ammonium is found to exist mostly in the fine mode to neutralize nss-sulfate, and the particulate nitrate and chloride are present mostly in the coarse mode and compete with each other to share sea salt and mineral cations. This means little formation of ammonium nitrate and chloride. Sensitivity analyses suggest that the aerosol in this region will be more deficit in chloride due to dechlorination and ammonium nitrate associated with the fine mode may become important.
Fibrin as a component of the tumor stroma: origins and biological significance

An association between cancer and the coagulation system was suggested by Trousseau more than a century ago and initial reports of fibrin deposition in the stroma of solid tumors date back some 25 years. However, the validity and generality of these observations have only quite recently been established, and their implications for an understanding of tumor biology, metastasis, and therapy are only now coming to be appreciated by investigators in the mainstream of cancer research. This article reviews the current status of fibrin's role in the biology of tumor growth, considering in turn: (1) the evidence that fibrin is present in tumors, the nature of such fibrin, and its relation to plasma fibronectin; (2) the mechanisms by which fibrin may come to be deposited in tumors; and (3) the potential biological and medical significance of tumorassociated fibrin deposition and degradation. Among the last are such important possiblities as a barrier function to the immune response and possible roles in angiogenesis, desmoplasia, and metastasis.
Polarization and losses of whispering-gallery waves along twisted trajectories

A geometrical optics treatment shows that whispering-gallery waves following twisted trajectories can be in eigenstates of polarization if σ = (radius of curvature × torsion) is a constant. The Jones vectors of these eigenpolarizations are calculated, along with their propagation constants and power attenuation constants. The curve representing the evolution of an arbitrary input polarization makes a constant angle with the circles passing through the points corresponding to the eigenpolarizations, on the Poincare sphere or in any one of the equivalent complex-plane representations. Experiments carried out with a cylindrical glass tube give results in good agreement with theoretical conclusions. The theory predicts that the smallest attenuation constant for three-dimensional trajectories in infrared and far-infrared guides should be about (1 + σ2) times larger than that for TE waves along two-dimensional trajectories of the same curvature, providing a practical criterion for the design of guides exhibiting twisted trajectories.
A statistical model for determining the error rate of the recording channel

A statistical model of the recording channel using a Monte Carlo computer simulation program has been developed. All the sources which contribute to the error rate can be simultaneously examined. System error rates and error rate trends due to parameter variations, sensitivities, and trade-offs can be studied with a good degree of confidence. Several examples of studies utilized in the development of the IBM 3330 Mod. II and 3340 drives are included.
Posterior packs and the nasopulmonary reflex.

Increased mortality and arterial hypoxemia have long been associated with posterior nasal packs placed for control of severe epistaxis. Several authors have postulated a nasopulmonary reflex to partially explain this clinically observed phenomenon. In ten young, healthy subjects, using a multiparameter pulmonary evaluation, posterior nasal packs were placed and no significant changes were observed in lung volumes, flow, and alveolar gas exchange, especially oxygenation. These findings suggest that aspiration, sedation, and degeneration of pulmonary function with age, not a nasopulmonary reflex, have not been adequately emphasized in previously performed studies.
Melding the public and private spheres: Taking commmensality seriously.

Abstract Tibor Scitovsky's The Joyless Economy distinguished the pleasure of moving from discomfort to comfort and the pleasure of replacing boredom with stimulation. I have argued that there are also pleasures distinctive to participating in public life. A third form of pleasure berlongs to both the private and the public domain: the common meal leads to individual satiation and, as a result of commensality, has important social and public effects. A good example is the banquet in ancient Greece, closely connected to the lottery—the basic mechanism of Athenian democracy. But the common meal can also lead to the degradation of human relations and political life.
Transistors to toys: teaching systems to freshmen

How should we introduce students to the art of system building, and when are students ready to start designing and building interesting systems? In this talk, I describe an experimental course at the University of Michigan that teaches systems to freshmen by having them conceive of, design, and build the hardware and software of a microprocessor-based educational toy. Students in this course build their own microprocessor on an FPGA using a hardware description language. They then write the complete software stack for their toy in assembly language, including device drivers for numerous I/O devices, a simple file system, a graphical user interface, digital audio processing, and application software. By building a substantial system involving hardware, system software, and application software, students gain an appreciation for the complexity and beauty of building computing systems.
Performance Assessment, Cognitive Abilities, and Technology: An Application

The increasing technological sophistication of organizations and the concomitant requirement for individuals to process large quantities of information has raised questions concerning the efficacy of traditional approaches to performance assessment within the personnel subsystem. Traditional approaches to aptitude testing have focused on relating psychometric profiles to subsequent job performance. These approaches are subject to criticism in that they use static measures (test scores) to predict the dynamic processes of learning and are heavily influenced by prior experience without reflecting the ability to acquire new information. An alternative to traditional psychometric approaches to personnel selection is the use of rate parameters (reflecting change in performance over time) derived from relatively complex cognitive tasks as predictors of training success. The use of microprocessor-administered tasks to assess cognitive skills and abilities is an integral part of this alternative approach. The use of computer-administered Complex Experimental Learning Tasks (CELTS) for the assessment of learning abilities illustrates the computerized, rate-based approach to performance assessment. The purpose of this paper is to describe an initial study to determine the predictability of learning rate measures for performance assessment and to suggest needed future developments in training as well as job performance research. Language: en
Toward a compact dual-wedge point-scanning confocal reflectance microscope

Confocal reflectance microscopy has been shown to provide optical sectioning and resolution sufficient to provide useful information about cellular structure in vivo . However, existing instruments are large and expensive, because of the need for fast, two-dimensional scanning in the pupil, and the associated relay optics. A more compact scanning system could lead to an affordable handheld instrument for in vivo imaging. Several approaches are being considered to minimize instrument size with different advantages and disadvantages. Here we report one approach that incorporates a dualwedge scanner within a point-scanning configuration. The dual-wedge scanner could reduce the cost and complexity of the confocal reflectance microscope while retaining the resolution and optical sectioning abilities of current pointscanning instruments. The scanner is implemented by replacing the scanning mirrors and the relay telescope between them with two optical prisms that are rotated about the optical axis. This scanning configuration produces a spiral scan if the prisms are rotated in the same direction, or a rosette scan if the prisms are rotated in opposite directions. Preliminary experimental results with the microscope show a lateral resolution on the order of 1 - 2 micrometers and onaxis optical sectioning on the order of 3 - 4 micrometers.
Studies on Blood Rheology in a Coronary Artery Using CFD Technique With an AE Sensor

There still exists a need for developing more accurate generalized models for multiscale biofluids systems that enable clearer understanding of normal microcirculation and complexities of disease hemorheology. Such work will yield enhanced computational and experimental techniques for a wider class of flows having fluid-solid interactions, complex moving boundaries, and involving red blood cell (RBC) aggregation under physiological conditions. The work reported here has involved the multiphase non-Newtonian fluid simulations of pulsatile flow in an idealized coronary artery model have been performed using numerical and experimental studies. The secondary flow affected a local RBC accumulation on the inside curvature and it changed the local flow characteristics as well. RBC viscosity and wall shear stress (WSS) were changed with a function of local hemotocrit. In practical work involving specialized velocity measurement and acoustic emission monitoring of flow characteristics, flow-induced vibration effects, as well as material and physiological aspects of arterial systems were conducted. Computations of arterial flows were made and experimental investigations using glass microtube simulations of arteries were carried out. This work contributes to an understanding of the mechanics of relationship between the progression of certain inherited diseases and the mechanical deformation characteristics of the arterial system and the RBC.Copyright © 2007 by ASME
Weddings on Contested Grounds: Slave Marriage in the Antebellum South

(1999). Weddings on Contested Grounds: Slave Marriage in the Antebellum South. The Historian: Vol. 62, No. 1, pp. 99-118.
Effect of Antrectomy on Acid Secretion from Pavlov Pouches in Cat

SummaryIn cats with Pavlov pouches antrectomy increased maximal acid secretion in response to histamine (40% increase) and to pentagastrin (30% increase). The mechanism of this effect is not known.
SARA-Regulated Vesicular Targeting Underlies Formation of the Light-Sensing Organelle in Mammalian Rods

The light-sensing organelle of the vertebrate rod photoreceptor, the outer segment (OS), is a modified cilium containing approximately 1,000 stacked disc membranes that are densely packed with visual pigment rhodopsin. The mammalian OS is renewed every ten days; new discs are assembled at the base of the OS by a poorly understood mechanism. Our results suggest that discs are formed and matured in a process that involves specific phospholipid-directed vesicular membrane targeting. Rhodopsin-laden vesicles in the OS axonemal cytoplasm fuse with nascent discs that are highly specialized with abundant phosphatidylinositol 3-phosphate (PI3P). This membrane coupling is regulated by the FYVE domain-containing protein, SARA, through its direct interaction with PI3P, rhodopsin, and SNARE protein syntaxin 3. Our model, in contrast to the previously proposed evagination model, suggests that the vesicular delivery of rhodopsin in the OS concentrates rhodopsin into discs, and this process directly participates in disc biogenesis.
Serum enzyme activities of glutamic oxalacetic transaminase, lactic dehydrogenase and isocitric dehydrogenase following embolization of the dog limb.

Abstract The effect of acute, severe ischemia of the dog limb upon the serum enzyme activities of glutamic oxalacetic transaminase, lactic dehydrogenase and isocitric dehydrogenase was determined by embolization of the femoral artery with lycopodium spores. All three enzyme activities became elevated soon after embolization and remained so during the entire postembolism observation period, lasting up to 144 hours. GOT showed the greatest rise, with a peak value at 24 to 48 hours. In contrast, “sham” operations produced no serum enzyme changes. By providing biochemical evidence of ischemic damage, serum enzyme studies should be a valuable adjunct to the routine clinical examination and circulation tests in the management of embolism of the limb.
Responses by corn snakes (Elaphe guttata) to chemicals from heterospecific snakes

Young corn snakes,Elaphe guttata, were tested for responses to chemicals from heterospecific snakes. Corn snakes exhibited more tongue-flicks to swabs freshly rubbed against the skin of an ophiophagous kingsnake,Lampropeltis getulus, than to blank swabs. Responses toL. getulus and a nonophiophagous western plains garter snake,Thamnophis radix haydeni, did not differ significantly. Corn snakes exhibited more tongue-flicks to swabs treated with chloroform extracts of the shed skins ofL. getulus; an ophiophagous eastern coachwhip,Masticophis flagellum; and a nonophiophagous gray ratsnake,Elaphe obsoleta, than to blank swabs, but they did not discriminate between ophiophagous and nonophiophagous species in every case. Corn snakes, when offered shelters containing bedding from the home cages of a nonophiophagous water snake,Nerodia erythrogaster, an occasionally ophiophagous water moccasin,Agkistrodon pisdvorus; orL. getulus and untreated bedding, failed to reside under snake-scented shelters at a rate significantly different from that expected by chance. The responses of corn snakes are compared with those reported for other snakes presented with heterospecific snake chemicals.
Structures of the Sgt2/SGTA Dimerization Domain with the Get5/UBL4A UBL Domain Reveal an Interaction that Forms a Conserved Dynamic Interface.

In the cytoplasm, the correct delivery of membrane proteins is an essential and highly regulated process. The posttranslational targeting of the important tail-anchor membrane (TA) proteins has recently been under intense investigation. A specialized pathway, called the guided entry of TA proteins (GET) pathway in yeast and the transmembrane domain recognition complex (TRC) pathway in vertebrates, recognizes endoplasmic-reticulum-targeted TA proteins and delivers them through a complex series of handoffs. An early step is the formation of a complex between Sgt2/SGTA, a cochaperone with a presumed ubiquitin-like-binding domain (UBD), and Get5/UBL4A, a ubiquitin-like domain (UBL)-containing protein. We structurally characterize this UBD/UBL interaction for both yeast and human proteins. This characterization is supported by biophysical studies that demonstrate that complex formation is mediated by electrostatics, generating an interface that has high-affinity with rapid kinetics. In total, this work provides a refined model of the interplay of Sgt2 homologs in TA targeting.
Comparison of the Thermoresponsive Deswelling Kinetics of Poly(2-(2-methoxyethoxy)ethyl methacrylate) Hydrogels Prepared by ATRP and FRP

Thermoresponsive hydrogels based on 2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA) were prepared by both atom transfer radical polymerization (ATRP) and conventional free radical polymerization (FRP). The lower critical solution temperature (LCST) transitions of the hydrogels prepared by the different polymerization mechanisms were compared at the macroscopic level and the molecular level. Gels prepared by ATRP swelled much more, but their macroscopic deswelling was retarded in comparison with gels prepared by FRP. This retardation was especially pronounced at higher temperatures and was attributed to the enhanced formation of skin layer in uniform gels prepared by ATRP. Variable-temperature time-lapse NMR spectroscopy showed that the rate of the dehydration of polymer chains at molecular level was much faster than macroscopic deswelling.
Theophylline Stimulates Fetal Breathing Movements during Hypoxia

ABSTRACT: The respiratory responses to theophylline during normoxia and hypoxia were determined in 13 unanesthetized fetal sheep. Theophylline (plasma levels ~ 111 μmol/L) increased the incidence of fetal breathing movements measured over 120 min from 37.7 ± 4.8% to 61.1 ± 5.7% (SEM) in normoxic fetuses. In isocapnic hypoxia (arterial O2 tension ~ 1.86 kPa), theophylline increased the incidence from 20.0 ± 6.3 to 52.0 ± 6.1%. Theophylline also resulted in an increase in the slope of inspiration during both normoxia and hypoxia. We conclude that adenosine modulates fetal respiratory drive during normoxia and hypoxia.
ELECTROMAGNETIC SCATTERING-BASED ARRAY PROCESSING METHODS FOR NEAR-FIELD OBJECT CHARACTERIZATION

We consider the use of high resolution array processing methods for detecting and localizing near-field extended targets for measurement geometries in which an array of electromagnetic receivers observes the fields scattered by the objects in response to a plane wave illumination. The algorithms presented here modify the conventional direction finding array processing techniques and use the spatial complexities of fields to determine both the range and the bearing of the targets in the region of interest. In contrast to previous source localization problems, we employ electromagnetic scattering models param- eterized explicitly in terms of the target positions and which account for all multiple scattering effects.These models play an integral role in allowing us to compute explicitly the analytical expressions for the Cramer-Rao bounds (CRB) for position estimates. The Cram6r-Rao bounds gives the lower bound for the estimates, and thus, specifies the lowest possible error variance that can be attained wit...
Practical thermometry with a thermographic camera-calibration, transmittance, and emittance measurements.

Methods of obtaining quantitative thermometric data with a thermographic camera are discussed. These include the assessment of errors associated with the camera itself and techniques for calibrating the particular camera. Difficulties arising from the nature of the object to be measured also are considered. These include determining the ’’penetration of depth’’ of infrared radiation emitted by the object (how ’’thick’’ is the surface?), measuring the transmittance of ’’windows’’ in front of th objects, and measuring the object’s emittance under somewhat adverse circumstances. Finally, an example of a temperature measurement is given. Practical considerations of theromometry are emphasized as opposed to radiometric measurements (such as spectral properties). Examples are drawn from measurements involving tissue‐equivalent electromagnetic phantom materials.
Chemical mapping of thaumasite formed in sulfate-attacked cement mortar using near-infrared Raman imaging microscopy

This work reports a new method for identifying and mapping the distributions of both thaumasite and ettringite in cement using near-infrared Raman imaging microscopy (NIRIM). This technique offers an important alternative to conventional X-ray diffraction (XRD) and scanning electron microscopy (SEM), which cannot easily distinguish preexisting ettringite from thaumasite formed as the result of sulfate attack. The NIRIM instrument used for these studies combines fiber-bundle image compression (FIC) hardware and multivariate signal processing software to identify and map chemical species in cement samples produced with and without extended exposure to sulfate. The NIRIM images clearly reveal thaumasite, ettringite, and gypsum microstructures. Cement paste formed in a carbon dioxide environment is found to contain both ettringite and gypsum species, while NIRIM images of cement exposed to sulfate reveals only thaumasite and gypsum. The NIRIM results are shown to correlate well with combined SEM/X-ray microanalysis of the same samples.
Patterns of interpreter use for hospitalized patients with limited English proficiency.

BACKGROUND Professional interpreter use improves the quality of care for patients with limited English proficiency (LEP), but little is known about interpreter use in the hospital.
Hormonal Regulation of Meiotic Maturation in the Hamster Oocyte Involves a Cytoskeleton-Mediated Process

Maturation of the mammalian oocyte involves hormone-induced meiotic cell cycle progression from prophase I to metaphase II and extrusion of the first polar body (PB). In this study, the effects of gonadotrophins on meiotic cell cycle progression in cultured hamster oocytes were analyzed with respect to changes in cumulus cell-oocyte interactions and the oocyte cytoskeleton. Cumulus-oocyte complexes were obtained from large antral follicles (> or = 700 microns in diameter) of eCG-primed animals and were cultured in the presence or absence of gonadotropins alone (FSH, hCG, LH) or in combination (FSH + hCG or FSH + LH). Oocytes were analyzed using conventional, digital, and confocal fluorescence microscopy to monitor chromatin, actin, and tubulin organization under different culture conditions. Most oocytes (83%) cultured with FSH alone progressed to and arrested at metaphase II and extruded the first PB; in contrast, meiotic progression and PB extrusion were impaired (45-85%) in all other groups. The presence of cumulus cells associated with the oocyte was found necessary for progression to metaphase I and for first PB emission. Completion of meiotic maturation in the presence of FSH alone was correlated with enhanced cortical actin polymerization in the oocyte and the retraction of actin-containing transzonal cumulus processes. The results demonstrate that gonadotropins exert specific effects on meiotic progression, PB emission, cumulus-oocyte interactions, and oocyte cytoskeletal organization during in vitro maturation of hamster oocytes, indicating that the hormonal control of meiosis involves cytoskeletal changes in both the somatic and germ cells.
Alphabet Soup: ERP, CT, and ACT for OCD

Abstract The present article comments on the case conference presented in this issue, namely, Himle and Franklin's (Himle & Franklin, 2009) exposure and response prevention (ERP); Chosak and colleagues' (Chosak, Marques, Fama, Renaud, & Wilhelm, 2009) cognitive therapy (CT); and (Twohig, 2009) Acceptance and Commitment Therapy (ACT). Two questions are addressed: (1) How different are these treatments? (2) What are the active vs. inert ingredients of each treatment? With regard to the first question, it is concluded that ERP and ACT appear more similar than dissimilar in terms of actual therapist/patient behaviors. CT shows more substantial differences from ERP and ACT, primarily in the therapist's direct efforts to target antecedent cognitions. With regard to the second question, examination of the likely active ingredients of each treatment suggests that interventions that encourage direct behavioral change (described as a characteristic feature of ERP and ACT and an incidental feature of CT) are most likely responsible for improvement in all three treatments, whereas evidence for the importance of altering antecedent cognitions (a characteristic feature of CT and an incidental feature of ERP) is less clear. Additional controlled research is recommended to identify which aspects of treatment are truly efficacious for OCD and other conditions.
Use of a dynamic programming model to estimate the value of clinical mastitis treatment and prevention options utilized by dairy producers

This study discusses and demonstrates the construction and application of a specially structured dynamic programming replacement and insemination optimization and simulation model of the dairy cow that includes detailed representation of repeated episodes of clinical mastitis (CM). The application determined optimal individual cow decisions, which were then compared with mastitis culling rules of thumb to determine the deviation of these rules from optimality. Calculation of break-even values of applying a preventive measure to reduce CM incidence or severity in the form of two fictitious mastitis vaccines were also carried out. Model input parameters were based on data from five large dairy herds in New York State (about 16,000 lactations), but these parameters can be easily changed for other types of dairy operations. To demonstrate the usefulness of this model to assist individual cow CM treatment options, the cost of the decision to cull a third lactation cow, six months after calving, with the first case of CM, was negative $3 USD for a low milk producing open or pregnant cow (i.e. cull), and positive $850 USD for a high milk producing and pregnant cow (i.e. treat even with extremely high treatment cost). Compared with the model recommended optimal policy, a rule of thumb decision to routinely treat all cows with a first case of CM resulted in an additional cost of $2 per cow per year, a very low deviation from optimality and suggests all cows should be given a second chance. A policy of replacing all CM cows after their second CM case after treatment of the first CM incident resulted in an additional cost of $27 per cow per year. If the decision was to replace all cows only after their third CM case this cost estimate was $8. The cost-benefit of applying two fictitious vaccinations showed that a vaccination reducing the milk loss caused by Gram-negative CM by 50% had a break-even cost of $14 per cow per year. A vaccination that would result in additional reduction of the risk of CM by 50% had a break-even cost of $37 per cow per year.
Extraction of Egg-Yolk Lecithin

In this research, the extraction of egg-yolk lecithin with ethanol was studied. Extraction was performed with deoiled and undeoiled yolks and with heated and unheated yolks. The yield of the extracted fraction relative to the initial material, phospholipid (PL) purity, and cholesterol content of both the PC-enriched fractions and the remaining PL fractions were determined. The yield and PL purity of the PC-enriched fractions obtained from the undeoiled yolks were 23.9 and 35.7%, and those obtained from deoiled yolks were 13.5 and 53.3%. The recovery of total PL in the two fractions was higher from the undeoiled (70%) than from the deoiled yolks (60%). However, heating had a negligible effect on PL extraction. Better enrichment of PC was observed by extraction from the undeoiled than from the deoiled yolks. The cholesterol content of the PC-enriched fraction obtained from the undeoiled yolks was much higher than that from the deoiled yolks.
Packaging of surface relief fiber Bragg gratings for harsh high temperature environments

The Surface Relief Fiber Bragg Grating (SR-FBG) is a viable alternative to the thermocouple for high temperature measurements in industry. To fabricate the SR-FBG we etch a grating into the flat surface of an elliptical-core D-fiber. At high temperature (1000 °C) the optical fiber becomes brittle. To overcome brittleness we thread the fiber through a preheated 0.020 inch diameter stainless steel tube. We insert the small tube into a larger one with a diameter of 0.125 inches. The smaller tube rests on ceramic inserts to prevent contact with the large tube. The end of the D-fiber is fitted with a standard fiber optic connecter. With this packaging scheme we conduct a series of test at high temperature. The sensor is robust with no power loss or Bragg wavelength shift, even after heating for 24 consecutive hours.
Forming the phosphate layer in reconstituted horse spleen ferritin and the role of phosphate in promoting core surface redox reactions.

Apo horse spleen ferritin (apo HoSF) was reconstituted to various core sizes (100−3500 Fe3+/HoSF) by depositing Fe(OH)3 within the hollow HoSF interior by air oxidation of Fe2+. Fe2+ and phosphate (Pi) were then added anaerobically at a 1:4 ratio, and both Fe2+ and Pi were incorporated into the HoSF cores. The resulting Pi layer consisted of Fe2+ and Pi at about a 1:3 ratio which is strongly attached to the reconstituted ferritin mineral core surface and is stable even after air oxidation of the bound Fe2+. The total amount of Fe2+ and Pi bound to the iron core surface increases as the core volume increases up to a maximum near 2500 iron atoms, above which the size of the Pi layer decreases with increasing core size. Mossbauer spectroscopic measurements of the Pi-reconstituted HoSF cores using 57Fe2+ show that 57Fe3+ is the major species present under anaerobic conditions. This result suggests that the incoming 57Fe2+ undergoes an internal redox reaction to form 57Fe3+ during the formation of the Pi layer...
Automatic recovery from software failure

n complex concurrent critical systems, such as autonomousrobots, unmanned air vehicles, and space systems, every component is a potential point of failure. This is true not only of embedded systems but also of purely software systems such as distributed and cyber applications. Typical attempts to make such systemsmore robust and secure are both brittle and incomplete due to reliance onmanual identification of and solutions to potential failures such as by usingexception mechanisms. That is, the security is easily broken, and there aremany possible failure modes that are not handled. Failures may be rare eventsso it is less easy to test for good coverage of fault scenarios. Techniques thatexpand to handling component-level failures are very expensive to apply, yetare still quite brittle and incomplete. This is not because engineers are lazy—the sheer size and complexity of modern information systems overwhelms theattempts of engineers, and myriad methodologies, to systematically investi-gate, identify, and specify a response to all possible failures of a system.
Prenatal exposure of guinea pigs to the organophosphorus pesticide chlorpyrifos disrupts the structural and functional integrity of the brain.

Abstract This study was designed to test the hypothesis that prenatal exposure of guinea pigs to the organophosphorus (OP) pesticide chlorpyrifos (CPF) disrupts the structural and functional integrity of the brain. Pregnant guinea pigs were injected with chlorpyrifos (25 mg/kg, s.c.) or vehicle (peanut oil) once per day for 10 consecutive days, starting approximately on the 50th day of gestation. Cognitive behavior of female offspring was examined starting at 40–45 post-natal days (PND) using the Morris water maze (MWM), and brain structural integrity was analyzed at PND 70 using magnetic resonance imaging (MRI) methods, including T 2 -weighted anatomical scans and diffusion kurtosis imaging (DKI). The offspring of exposed mothers had significantly decreased body weight and brain volume, particularly in the frontal regions of the brain including the striatum. Furthermore, the offspring demonstrated significant spatial learning deficits in MWM recall compared to the vehicle group. Diffusion measures revealed reduced white matter integrity within the striatum and amygdala that correlated with spatial learning performance. These findings reveal the lasting effect of prenatal exposure to CPF as well as the danger of mother to child transmission of CPF in the environment.
Detection of S-phase overreplication following chronic hypoxia using a monoclonal anti-BrdUrd

Abstract We have examined cytokinetic perturbations induced in Chinese hamster V-79 cells in vitro during and following exposure to chronic hypoxia employing simultaneous flow cytometric measurement of incorporated BrdUrd and DNA content. These data indicate hypoxia inhibited G1 progression into S-phase, but did not significantly delay G2M division and progression into G1. Also, upon reaeration after 20 hr in hypoxia, cells originally in G1 exhibited significant kinetic delay. BrdUrd pulse/chase and pulse/fix data indicated DNA replication was reduced, but not completely inhibited during hypoxia. Also, between 6 and 20 hr of chronic hypoxia and following reaeration, a subset of the original S-phase cells overreplicated their DNA, such that these cells had >2C DNA content. This subpopulation was estimated on the average to comprise approximately 20% of the total population (30% of the treated S-phase subpopulation) by 24 hr following reaeration after 20 hr hypoxia. These results are discussed in light of the similarities between overreplication and gene amplification observed under certain conditions with other agents, which like chronic hypoxia, are used to transiently disrupt DNA synthesis.
Optimal algorithm for detecting two-dimensional images

In this paper, we present a new two-dimensional (2D) edge detection algorithm. The algorithm detects edges in 2D images by a curve segment based edge detection functional that uses the zero crossing contours of the Laplacian of Gaussian (LOG) as initial conditions to approach the true edge locations. We prove that the proposed edge detection functional is optimal in terms of signal-to-noise ratio and edge localization accuracy for detecting general 2D edges. In addition, the detected edge candidates preserve the nice scaling behavior that is held uniquely by the LOG zero crossing contours in scale space. The algorithm also provides: (1) an edge regularization procedure that enhances the continuity and smoothness of the detected edges; (2) an adaptive edge thresholding procedure that is based on a robust global noise estimation approach and two physiologically originated criteria to help generate edge detection results similar to those perceived by human visual systems; and (3) a scale space combination procedure that reliably combines edge candidates detected from different scales.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Intraoral endoscopic enucleation of a central mandibular condylar lesion.

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Atriopeptin release from the isolated perfused rabbit heart

Mammalian atrial extracts have been shown to contain bioactive peptides which exert natruiretic, diuretic, and smooth muscle relaxant effects. These extracts include several low molecular weight (less than 5,000 Mr) atrial peptides (atriopeptins) which exhibit identical sequences over a central core region which are derived from the high molecular weight peptide (atriopeptigen) precursor which has been purified and sequenced. In the current study we found that extracts of rabbit atria possess both high and low molecular weight bioactive atrial peptides, however, the coronary venous effluent obtained from the isolated perfused rabbit heart only contained the low molecular weight peptide. This trypsin labile activity causes a dose-dependent relaxation of rabbit aorta and chicken rectum assay strips. Separation of the bioactivity with gel filtration chromatography and reversed phase HPLC indicates the heart releases a single substance similar to atriopeptin III. There was no evidence that atriopeptigen was released from the isolated perfused rabbit heart. We suggest that atriopeptigen is proteolytically processed in the atria to an atriopeptin which is subsequently the released form of the atrial peptide.
Long-term approaches to end homelessness.

Using an epidemiologic framework, this article discusses the reports of two national conferences and the literature to describe homelessness as a consequence of poverty, alcoholism, mental illness, and family turmoil; power-lessness; and an unsupportive, hostile environment, where the demand for affordable housing exceeds the supply. Nurses are urged to advocate for legislation to create more affordable housing as the first priority of public policy, and also address other long-term approaches to end homelessness.
Collaborative role of E2F transcriptional activity and G1 cyclindependent kinase activity in the induction of S phase

A considerable body of evidence points to a role for both cyclin E/cyclin-dependent kinase (cdk)2 activity and E2F transcription activity in the induction of S phase. We show that overexpression of cyclin E/cdk2 in quiescent cells induces S phase, that this coincides with an induction of E2F activity, and that coexpression of E2F enhances the cyclin E/cdk2-mediated induction of S phase. Likewise, E2F overexpression can induce S phase and does so in the apparent absence of cyclin E/cdk2 activity. In addition, although the inhibition of cyclin E/cdk2 activity blocks the induction of S phase after growth stimulation of normal mouse embryo fibroblasts, inhibition of cyclin E/cdk2 does not block S phase induction in Rb−/− cells where E2F activity is deregulated. These results point to the important roles for E2F and cyclin E/cdk2 in the induction of S phase. Moreover, the nature of the E2F targets and the suspected targets for cyclin E/cdk2 suggests a potential molecular mechanism for the collaborative action of cyclin E/cdk2 and E2F in the induction of S phase.
Frame of reference effects on the performance of hollow fiber membranes

Fick's first law is generally accepted for describing the transfer of gas mixtures through pore-free dense polymeric membranes. Typically, the permeation flux is made up of two parts, namely, that resulting from the bulk motion and that resulting from diffusion. For simplicity most hollow fiber permeator models consider only the diffusion part; however, neglecting the frame of reference contribution can be erroneous in the case of mutlicomponent mixtures when the permeation flux of one of the permeants is much higher than the others. A comparative theoretical study is performed on the influence of two transport models on gas separation hollow-fiber modules: the diffusion and the frame of reference models. Simulations are performed for CO2/CH4 separation in 6FDA-TADPO polypyrrolone membranes. The comparison is made in terms of CH4 recovery and membrane selectivity under common design and operating conditions. It is shown that the differences in performance can be as high as 25% for membrane selectivity an...
Behavior of piezoelectric friction dampers under dynamic loading

Piezoelectric materials are stressed when exposed to electric field and subjected to a restraint in their motion due to the electromechanical coupling effect. Use can be made of this property to control the motion of civil engineering structures. This paper is focused on the conceptual design of a piezoelectric friction damper and the analytical study on its behavior under harmonic loads. The friction damper takes advantage of the slip mode at the friction surface to endure the large deformation in structures and uses the piezoelectric actuators to regulate the clamped force on the damper. A new algorithm is introduced to determine the friction force for increased energy dissipation capacity. It combines the hysteretic and viscous damping mechanisms. Analytical results have shown, the superiority of the proposed algorithm over others in terms of energy dissipation. The damper is then used to mitigate the dynamic responses of a single-story frame structure subjected to harmonic loads. The structural responses controlled with a friction damper are determined numerically. However, it is found that the structure with the damper can be approximately analyzed with an equivalent linear system. This approximation greatly simplifies the design of friction dampers for practical applications.
Engaging Kenyan secondary students in an Oral History Project: Education as emancipation

Abstract This article uses a case study approach to explore the viability and impact of learner-centered, emancipatory pedagogies. The research focuses on the implementation of an Oral History Project with students at a Kenyan secondary school. Findings reveal that the project had a significant impact on participants’ beliefs about teaching and learning, strengthened students’ sense of self-efficacy, and enhanced participants’ perceptions of community knowledge. The study suggests that while learner-centered, emancipatory pedagogies are viable and can have a transformative impact on students and teachers, systematic and sustained instructional support and professional development are needed to ensure long-term success.
Shedding and infection dynamics of porcine circovirus type 2 (PCV2) after experimental infection.

The objective of this study was to determine the amount and infectivity of porcine circovirus type 2 (PCV2) shed in nasal, oral and fecal secretions following experimental infection. Fecal, oral and nasal swabs and blood were collected at regular intervals until 69 days post-inoculation (DPI) from five PCV2-experimentally inoculated pigs (Trial 1). To assess the infectivity of the PCV2 present in excretions, secretions, and on a hypodermic needle, 26 PCV2-naive pigs (Trial 2) were inoculated with various samples obtained from Trial 1 pigs. In Trial 1, PCV2 DNA was detected in all sample types by 69 DPI. There were no differences in the amount of PCV2 DNA present in different sample types over time. In Trial 2, intraperitoneal inoculation with contaminated fecal, nasal and oral samples; intranasal inoculation of nasal secretions; and feces fed to naive animals resulted in viremia and seroconversion. Viremia and microscopic lesions were noted in one animal injected using a contaminated needle. In conclusion, experimental PCV2 exposure results in a long term infection. PCV2 is shed in similar amounts by nasal, oral and fecal routes and is infectious to naive pigs confirming that multiple routes of transmission are likely important in spread of PCV2 between pigs.
Heat wave mortality in nursing homes

Patterns of mortality in 11 air-conditioned and 9 un-air-conditioned nursing homes in New York City have been investigated to determine the impacts of heat waves on nursing home occupants and the efficacy of air conditioning in reducing these impacts. During each of four heat waves in 1972 and 1973, the number of deaths in un-air-conditioned nursing homes was significantly greater than the number of deaths expected on the basis of mortality during cooler control periods. In contrast, deaths in air-conditioned nursing homes were not significantly different from expected. The age- and sex-adjusted ratio of relative death rates was 2.29 (95% confidence interval = 1.75-2.98). Approximately 94 excess deaths occurred in the un-air-conditioned nursing homes. On the basis of this research, it is recommended that nursing homes and other institutions for the elderly located in climates like that of New York City be required to provide air conditioning.