cssi/SciSciGPT-SciSciNet huggingface dataset:
Spontaneous activity in the thalamic reticular nucleus during the sleep/wake cycle of the freely-moving rat

Neurons of the somatosensory thalamic reticular nucleus (TRN) were studied by extracellular recordings through the sleep/wake cycle in the unanesthetized, freely-moving rat. All electrophysiologically-identified TRN neurons expressed rhythmic patterns of discharge that altered with shifts in sleep/wake state. During slow wave (SW) sleep, neurons displayed spike-burst discharges in long trains followed by pauses. high-frequency oscillations in auto-correlograms in the spindle-frequency range (approximately 10 Hz) reflected the rhythm of interburst intervals within the trains whereas low-frequency oscillations (0.3-0.2 Hz) displayed the rhythm of intertrain intervals. During rapid eye movement (REM) sleep, a more continuous pattern of spike-burst discharges was prominent, resulting in absence of a detectable, low-frequency rhythm but persistence of spindle-frequency firing. At the transitions between SW and REM sleep, cell discharge was more tonic than during either sleep state and lacked a dominant rhythm. During the wake (AW) state, neurons fired in a single-spike mode that also lacked rhythmicity. Unlike their pattern of discharge, TRN neurons' mean rate of discharge did not distinguish sleep/wake state. The mean discharge rates were: SW, 18.4 +/- 1.3; REM, 17.4 +/- 1.2; AW, 22.3 +/- 2.1 (Hz +/- S.E.M.). Mean discharge rate during transitions from SW to REM sleep (28.6 +/- 2.1) was significantly higher, however, than during any sleep/wake state. Compelling evidence was lacking for segregation of TRN neurons into discrete populations according to absolute discharge rate. Neurons recorded simultaneously from the same electrode discharged synchronous trains of spike-bursts and pauses during SW sleep. This phenomenon may be related to generation of EEG slow waves.(ABSTRACT TRUNCATED AT 250 WORDS)
LABORATORY EVALUATION OF REAL-TIME DYNAMIC TRAFFIC ASSIGNMENT SYSTEMS

The success of Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS) depends on the availability and dissemination of timely and accurate estimates of prevailing and emerging traffic conditions, as well as the provision of faithful and coherent pretrip and en-route travel information and advisory to travelers. Real-time Dynamic Traffic Assignment (DTA) systems, envisioned as an ATMS support system that resides in transportation management centers, are being developed to supply these estimates and information. To ensure the deployment potential of such DTA systems in the field, extensive laboratory evaluations are required throughout the development process. This article discusses a software environment that economically supports the development and evaluation of DTA systems. A major simulation component developed under this environment is called a DTA evaluation system (DES). The DES is a virtual representation of a transportation system in which ATMS and ATIS technologies are deployed. It simulates the trip-making and vehicle-driving behaviors of travelers in response to real-time information and advisories from ATIS and ATMS. This article presents (1) major DES modeling capabilities required for developing and evaluating DTA systems, (2) a modular and extensible modeling framework for the DES, and (3) a top-level, object-oriented, and distributed DES design.
Critical factors in leadership succession

Abstract The topic of leadership succession (the planned or unplanned change of the formal leader of a group or organization) has received relatively little attention in the literature compared with other aspects of leadership phenomena. The dynamics of the succession process and their indirect implications for leadership and group effectiveness are not fully understood. This paper reviews relevant literature and then attempts to specify a model of leadership succession, based on prior research, group process literature, and logical analysis.
Molecular basis of localized responses during chemotaxis in amoebae and leukocytes

Free-living amoebae as well as mammalian leukocytes sense chemoattractants with seven helix receptors linked to G-proteins. The cells respond by extending pseudopods and moving in the direction of the highest concentration. Recent studies using GFP-tagged proteins in Dictyostelium have shown that the directional response becomes sharply localized downstream of the receptors and G-proteins but upstream of the actin cytoskeleton. These studies together with the isolation novel genes by insertional mutagenesis in Dictyostelium are leading to a new understanding of chemotaxis in eucaryotic cells.
The Second Closet: A Qualitative Study of HIV Stigma Among Seropositive Gay Men in a Southern U.S. City

ABSTRACTObjectives: Stigma connected with HIV/AIDS has decreased considerably since the early epidemic yet affects those living with HIV in many ways. Little research, particularly qualitative research, concerning HIV stigma from the perspective of gay men has emerged. The present qualitative study aimed to fill this evidence gap by examining how HIV stigma is perceived and experienced by gay men who have become HIV-infected and how they respond to this stigma. Methods: Thematic analysis of 19 gay men's narratives identified six main themes. Results: Encountering HIV stigmatization was common and was linked to the physical stigmata identifying respondents as HIV-positive. Overwhelmingly, they found stigmatization to be most intensely felt within gay communities. One profound theme was internalized HIV stigma, referring to respondents’ internalized negative feelings about their HIV status. A related theme was the closeted nature of HIV. Lastly, regarding how the men dealt with the HIV diagnosis and experie...
The Modified Blalock-Taussig Shunt Versus the Right Ventricle-to-Pulmonary Artery Conduit for the Norwood Procedure

The initial Norwood procedure remains the highest risk operation for the staged repair of univentricular congenital malformations with associated systemic outflow obstruction. The modified Blalock–Taussig shunt (MBTS) has been implicated as a major cause of not only the operative mortality, but also associated morbidity and interstage attrition. The etiology of these events has often been attributed to the diastolic runoff and “coronary steal” associated with the MBTS, in addition to the delicate balance between systemic and pulmonary blood flow that characterizes all systemic-to-pulmonary artery shunts. Recently, there has been renewed interest in the right ventricle-to-pulmonary artery conduit as a source of pulmonary blood flow for the Norwood procedure as a potential method for minimizing the negative aspects of the MBTS. The current literature is contradictory, retrospective, and predominantly historically controlled. The Trial of Right Ventricular vs Modified Blalock–Taussig Shunt in Infants with Single Ventricle Defect Undergoing Staged Reconstruction, a randomized controlled clinical trial comparing the two techniques, is ongoing and may provide answers to this controversy.
Influence of pH on Release of Phenytoin Sodium from Slow-Release Dosage Forms

Physicochemical factors influencing the release of phenytoin sodium from slow-release dosage forms were studied. Some of these factors were solubility and intrinsic dissolution rate as functions of pH, type of dosage form, pH of dissolution medium used, and conversion of the sodium salt to free acid (phenytoin). The innovator's product, Extended Phenytoin Sodium Capsule (Dilantin Kapseal, 100 mg, Parke-Davis), and two experimental formulations (one nondisintegrating tablet containing polymeric materials and the other a solid dispersion in an erodible matrix) served as the slow-release dosage forms. The sodium salt converts to practically insoluble phenytoin in the gastrointestinal pH range of 1 to 8. Due to such a conversion inside or at the surface of slow-release dosage forms, the release of drug in this pH range was incomplete. The extent of drug release also varied with the type of formulation used. In contrast, complete dissolution could be obtained in water because the pH of the medium gradually rose from approximately 6 to approximately 9.2 where the drug solubility was higher. Although several phenytoin sodium products might have similar dissolution rates in water, the extents of drug release under gastrointestinal pH conditions (pH 1-8) could differ greatly, thus supporting the Food and Drug Administration recognition that the similarity in dissolution profiles in water does not assure that the products are bioequivalent. The reported lower steady-state level of phenytoin in human plasma following oral administration of a slow-release dosage form may be related to incomplete drug release.
Tracing offensive values from exceptions

In debugging, techniques for tracing back offending values are extremely useful. In [1] Raphael Finkel presents us with an easily implemented and fairly useful technique. As was pointed out in [1] there has been other work in this area. In this note I would like to present a short taxonomy of the various techniques, and attempt to place Finkel's technique in its place in the hierarchy.
A Convenient Method for Constructing Oxazolidine and Thiazolidine Rings in C20-Diterpenoid Alkaloid Derivatives

Abstract Recently we isolated and elucidated1 the structures of two new C20-diterpenoid alkaloids, lindheimerine (1) and ovatine (2), from Garrya ovata var. lindheimeri. To correlate lindheimerine with ovatine and to prepare some new oxazolidine and thiazolidine ring-containing analogs from the imine-containing derivatives for biological testing and spectral studies, we required a simple, high-yield method for constructing these rings. The earlier method reported2 for constructing the oxazolidine ring from the imine derivative requires the use of a quaternization reaction involving ethylene chlorohydrine in dimethylformamide at 80°C.
Scanning mutagenesis of regions in the Gα protein Gpa1 that are predicted to interact with yeast mating pheromone receptors

The mechanism by which receptors activate heterotrimeric G proteins was examined by scanning mutagenesis of the Saccharomyces cerevisiae pheromone-responsive Gα protein (Gpa1). The juxtaposition of high-resolution structures for rhodopsin and its cognate G protein transducin predicted that at least six regions of Gα are in close proximity to the receptor. Mutagenesis was targeted to residues in these domains in Gpa1, which included four loop regions (β2–β3, α2–β4, α3–β5, and α4–β6) as well as the N and C termini. The mutants displayed a range of phenotypes from nonsignaling to constitutive activation of the pheromone pathway. The constitutive activity of some mutants could be explained by decreased production of Gpa1, which permits unregulated signaling by Gβγ. However, the constitutive activity caused by the F344C and E335C mutations in the α2–β4 loop and F378C in the α3–β5 loop was not due to decreased protein levels, and was apparently due to defects in sequestering Gβγ. The strongest loss of the function mutant, which was not detectably induced by a pheromone, was caused by a K314C substitution in the β2–β3 loop. Several other mutations caused weak signaling phenotypes. Altogether, these results suggest that residues in different interface regions of Gα contribute to activation of signaling.
Networking is IPC: a guiding principle to a better internet

This position paper outlines a new network architecture that is based on the fundamental principle that networking is interprocess communication (IPC). In this model, application processes (APes) communicate via an IPC facility. The IPC processes that make up this facility provide a protocol that implements an IPC mechanism, and a protocol for managing distributed IPC (routing, security and other management tasks). Our architecture is recursive in that the IPC processes can themselves be APes requesting services from lower IPC facilities. We present the repeating patterns and structures in our architecture, and show how the proposed model would cope with the challenges faced by today's Internet (and that of the future).
El arte de lo oculto: prácticas mágico-esotéricas en Rinconete y Cortadillo

One of the most frequently studied motifs in Rinconete y Cortadillo has been its relation to the picaresque as well as the new elements that it brings to this genre. It has also been asserted that, since chronologically it is one of the first novellas included in the collection of Novelas ejemplares , it eschews the structures of romance, which are prevalent in later novellas. This study foregrounds a series of elements of romance which can be found in Rinconete y Cortadillo and that reveal a series of hidden mysteries in the novella. The essay analyzes, among others, the motif of descent and the infernal geography of the novella; the presence of Mercury as a guide to the infernal regions; the final ascent promised by Rinconete and the onomastic secrets hidden in his name; the significance of perfect friendship; the desire for freedom and its implications; and the meaning of joy as found among the rogues and the followers of the barbarous Monipodio.
A fluorescent in situ hybridization analysis of X chromosome pairing in early human female meiosis

Fluorescent in situ hybridization (FISH) utilizing an X chromosome whole library probe was used directly to assess the rate of aneuploidy and pairing behavior of the X chromosome in human female meiosis. Over 3000 meiotic cells obtained from fetal ovaries (gestational age 13–22 weeks) were scored for meiotic stage and evaluated for pairing abnormalities. No pairing anomalies were observed in 832 pachytenes. Twenty-two percent (88/398) of cells in zygotene were partially paired, but nonhomologous pairings could not be identified. One aneuploid preleptotene oocyte, presumably from mitotic nondisjunction was detected. To our knowledge, this is the first report of the use of FISH utilizing whole chromosome probes to evaluate the pairing behavior of chromosomes in human female meiosis. The application of this technique to study the relationship between nondisjunction and chromosome pairing behavior in maternal-age-related aneuploidy is discussed.
A ‘blue’ copper oxidase from Nitrosomonas europaea

Abstract A soluble copper-containing protein with p -phenylenediamine oxidase activity was purified from Nitrosomonas europaea by flat-bed isoelectric focusing and chromatography on Sephacryl S-300. The native and subunit molecular weights were 127 500 and 40 100, respectively; the isoelectric point was pH 4.63. The protein had an absorption maximum at 607 nm in the oxidized form with an extinction coefficient of 6.0 cm −1 · mM −1 at pH 7.5. On reduction with dithionite, the absorbance was abolished. The electron paramagnetic resonance spectrum of the protein showed evidence for both Type 1 and Type 2 copper in a 1:1 ratio. The protein catalyzed the aerobic oxidation of p -phenylenediamine, cytochrome c -554, and hydroxylamine oxidoreductase. The enzyme catalyzed the reduction of nitrite with cytochrome c -552 as electron donor. In contrast, p -phenylenediamine, reduced cytochrome c -554, and hydroxylamine oxidoreductase were not active as electron donors for nitrite reduction.
An Inkjet-Printed Microfluidic RFID-Enabled Platform for Wireless Lab-on-Chip Applications

This paper introduces the first-of-its-kind wireless passive sensing platform combining radio frequency identification (RFID), microfluidics, and inkjet printing technology that enables remote fluid analysis and requires as little as 3 μL of fluid. The demonstrated variable microfluidic capacitors, resonators, and RFID tags are fabricated using a novel rapid, low-cost, and low-temperature additive inkjet process, making them disposable. However, even with their disposable nature, the RF microfluidic devices exhibit repeatability and long-term reusability for accurately detecting water, various alcohols, and % content of water/alcohol mixtures down to 1% water in ethanol. While the main discussion is on fluid sensing, the demonstrated components can also be used in fluid-tunable RF applications.
A Simple Algorithm for Integer Programs Using Group Constraints

This paper gives an algorithm for the solution of linear integer programs which is identical in spirit to Gomory's classic cutting plane procedure but uses the abelian group formulation, also pioneered by Gomory, instead. The underlying simplicity of recent algorithmic advances and their parallel with the cutting plane method are demonstrated.
Isotopic evidence for reduction of anthropogenic hexavalent chromium in Los Alamos National Laboratory groundwater

Abstract Reduction of toxic Cr(VI) to less toxic Cr(III) is an important process for attenuating Cr(VI) transport in groundwater. This process results in immobilization of chromium as Cr(III) and effectively decreases the overall mobility of the chromium inventory. During both abiotic and biotic reduction of Cr(VI) to Cr(III), a kinetic isotope effect occurs in which the lighter isotope, 52Cr, reacts preferentially, leaving the remaining dissolved Cr(VI) enriched in the heavier isotope, 53Cr. Cr isotopes have proven to be a useful tool for estimating the magnitude of Cr(VI) reduction and for determining where in a hydrologic system reduction is occurring. In this paper, we discuss patterns of reduction in perched-intermediate and regional aquifer systems contaminated with Cr(VI) related to historical use of potassium dichromate as an anticorrosion agent in cooling towers at a power plant at the Los Alamos National Laboratory in northern New Mexico. We utilize Cr isotopes to assess the relative effects of mixing and reduction on measured δ53Cr in groundwater, with an emphasis on where in the system reduction occurs. Chromium isotope measurements provide strong evidence for reduction of Cr(VI) in vadose zone basalts.
Tack in urethane elastomers

Abstract The phenomenon of tack has been studied in urethan—urea elastomers prepared from polyether or polyester prepolymers and 4,4′-methylenebis(2-chloroaniline). It is shown that tack at zero elongation is attained only in polymers in which the flexible chains, i.e., polyesters or polyethers, contain 50 chain links or more. This coincides with the requirements for the Gaussian vector function in elastomers. The results suggest that, in the absence of flexible chain ends in these polymers, tack is solely contributed by the flexible segments along the polymer chains, while the rigid blocks in the chains do not participate in the formation of tack.
Finite element methods for an acoustic well‐logging problem associated with a porous medium saturated by a two‐phase immiscible fluid

A mathematical model is presented concerning wave propagation in a domain that arises in geophysical well-logging problems. The domain consists of a borehole Ωf surrounded by a porous medium Ωp. Ωf is filled with a compressible inviscid fluid, and Ωp is saturated by a two-phase immiscible fluid. Absorbing boundary conditions for artificial boundaries and boundary conditions on the interface between Ωf and Ωp are used. The existence and uniqueness theorems are stated for the resulting initial-boundary value problem. Stability and convergence estimates for a finite element method are also studied. © 1993 John Wiley & Sons, Inc.
The preparation of perfluoroalkenyl allenes (trienes) and pentafluorophenyl allenes

Trifluorovinyl- and (Z)-pentafluoropropenylcopper reagents readily react with propargylic halides or tosylates. With primary propargylic substrates, the major product is the alkyne. With secondary propargylic substrates, mixtures of alkyne/allene are obtained; the allene product is the major product. With tertiary propargylic substrates, the allene is regiospecifically and stereospecifically formed in good isolated yields. With pentafluorophenyl copper and primary propargylic substrates, the major product is pentafluorobenzene. With secondary and tertiary propargylic substrates, the allene is regiospecifically formed in good isolated yields.
Technical communique: Perfect regulation of linear discrete-time systems: A low-gain-based design approach

This paper is concerned with the design of state feedback controllers in order to achieve an objective called perfect regulation (p.r.). Necessary and sufficient conditions for the existence of state feedback controllers that achieve p.r. are derived for general linear multivariable time-invariant discrete-time systems. More importantly, an explicit eigenstructure assignment procedure by state feedback that achieves p.r. is developed.
A versatile experimental system for coincidence measurements involving nuclear reactions

Abstract A reaction chamber and associated experimental system are described which are intended for coincidence and correlation studies involving charged-particle-induced nuclear reactions.
Comparative study on the flammability of polyethylene modified with commercial fire retardants and a zinc aluminum oleate layered double hydroxide

Abstract Polyethylene (PE) was modified by the addition of a layered double hydroxide of zinc aluminum oleate (ZnAl) and/or commercial fire retardants. Commercial additives included: melamine polyphosphate (MPP), ammonium polyphosphate (APP), triphenol phosphate (TPP), resorcinol diphosphate (RDP), decabromophenyl oxide (DECA) and antimony oxide (AO). The thermal stability and the combustion behaviors of the new composite polymeric materials are evaluated in TGA experiments and cone calorimetry. At 20% total additive loading, APP and LDH enhance the thermal stability of the PE composites and favor char formation. ZnAl leads to the best reduction in the peak of heat release rate (PHRR), 72%, while the combinations of PE with other additives give reductions in the range 20–40%. The combination of DECA and AO effectively increases the time to ignition and time to PHRR while LDH lowers these two parameters. APP and MPP on the other hand, do not affect the time to ignition, but they effectively increase the time to PHRR relative to the pristine polymer.
Identification and characterization of 1,25D3-membrane-associated rapid response, steroid (1,25D3-MARRS)-binding protein in rat IEC-6 cells.

Abstract We report the presence of a mammalian equivalent of the avian M embrane- A ssociated R apid R esponse, S teroid (1,25D 3 -MARRS)-binding protein specific for 1,25(OH) 2 D 3 in a rat small intestinal cell line, IEC-6, that demonstrates rapid responses to the steroid hormone. Identification of transcript and protein was achieved using RT-PCR with several specific primer sets, Western blot analysis with two separate antibodies recognizing distinct regions of the protein, ribozyme knockdown and immunohistochemistry. Promoter analysis of the 1000-bp upstream region of the 1,25D 3 -MARRS gene in several species revealed the presence of a conserved smad-3 element in the 5′ proximal promoter region, but no classical vitamin D response element (VDRE). Treatment of IEC-6 cells with transforming growth factor β1 (TGFβ1) increased steady-state levels of 1,25D 3 -MARRS (mRNA and protein) approximately two-fold over a 24-h period. In contrast, treatment with 1,25(OH) 2 D 3 failed to significantly change 1,25D 3 -MARRS protein or mRNA levels. Localization studies showed rapid nuclear translocation of a pool of 1,25D 3 -MARRS protein after 1,25(OH) 2 D 3 treatment, suggesting that the protein is subject to membrane-initiated signal pathway activation. Together these data point to complex interactions between the two important 1,25(OH) 2 D 3 sensitive response systems in intestinal cells, 1,25D 3 -MARRS protein and the well-studied nVDR, that together work to fine tune intestinal Ca 2+ absorption in a variety of avian and mammalian species.
Electrical suppression of tinnitus with high-rate pulse trains.

HypothesisApplication of high-rate pulse trains (e.g., 4800 pps) to the cochlea may represent an effective treatment of tinnitus.BackgroundTinnitus is a widespread clinical problem with multiple treatments but no cure. A cure for tinnitus would restore the perception of silence. One plausible hypoth
Information Asymmetry and the Franchise Decision

Abstract A key explanation for the existence of franchising as a marketing channel has its underpinnings in the information asymmetry between the firm and individual outlets. Franchising is the preferred option for outlets where information asymmetry leads to prohibitive monitoring costs within a vertically integrated system. While modern information technology has the potential to reduce monitoring costs at geographically isolated locations, several factors are likely to limit its effectiveness. Thus, the incentive to franchise these outlets should continue to exist. The paper also discusses the possible implications of the increased use of information technology in the franchised channel.
Idea 2004 Another Round in the Reauthorization Process

The Individuals with Disabilities Education Act (IDEA) was recently reauthorized as the Individuals with Disabilities Education Improvement Act of 2004. Several significant changes were made in the most recent reauthorization. These included requirements for “highly qualified” special education teachers; a track that will result in full funding; changes in the composition of Individualized Education Programs (IEPs) and committee involvement in the IEP process; transition from school to postschool; identification procedures for students with learning disabilities (LD); due process hearings; expulsion and suspension of students with disabilities; and a host of other, less significant changes. Although on the surface some of these changes appear to be major, the primary purpose of IDEA—providing a free, appropriate public education for children with disabilities—remains intact.
Erg margin of the Permian White Rim Sandstone, SE Utah

The Permian White Rim Sandstone of the Canyonlands National Park, Utah, contains a wide variety of sedimentary structures and features that largely result from stages in erg migration and marine influence on an erg margin. Three spatially distinct lithological and depositional facies are recognized and can be distinguished as informal units within the formation. The aeolian dune facies is composed predominantly of fine-grained cross-stratified sandstone of the White Rim erg. This facies is the most widespread and comprises the bulk of the formation. Within the aeolian dune facies are small subfacies that represent interdune deposits. A sheet sand facies, composed of parallel-bedded sandstone, makes up a significant part of the lowest part of the White Rim Formation. This facies appears to have been the precursor or leading (progradational) edge to the main erg system. The final facies is a reworked or veneer facies of rippled to disturbed sandstone that is localized in its extent. It is restricted to the upper few metres of the formation and is transitional in some places to the Triassic Moenkopi Formation. This veneer facies contains many structures which indicate marine reworking as well as periods of desiccation or subaerial exposure. Some previous interpretations of the White Rim Sandstone have tended to classify the whole formation as one depositional setting. It is clear that at the margin of a sand sea, as shown in the White Rim Sandstone, there are transitional facies due to the interactions with other environments. Additionally, variation in the stratigraphic relationships of facies can be related to stages of erg migration. Erg margin deposits preceded central erg development. Erg initiation occurred during a probable relative sea level low. Sea level influence is recorded at the top of the formation because erg termination accompanied a relative sea level high with cut-off of sand supply. Transgression of the Permian Kaibab Sea over the White Rim erg was probably the main process in preservation of original dune topographic relief. Sea level fluctuations also may have affected distribution of facies and the complexities of structures at the erg margin. Subsequent fluvial reworking of the veneer facies may have obliterated Late Permian features during lowest Triassic Moenkopi deposition.
Human LDL core cholesterol ester packing: three-dimensional image reconstruction and SAXS simulation studies

Human LDL undergoes a reversible thermal order-disorder phase transition associated with the cholesterol ester packing in the lipid core. Structural changes associated with this phase transition have been shown to affect the resistance of LDL to oxidation in vitro studies. Previous electron cryo-microscopy studies have provided image evidence that the cholesterol ester is packed in three flat layers in the core at temperatures below the phase transition. To study changes in lipid packing, overall structure and particle morphology in three dimensions (3D) subsequent to the phase transition, we cryo-preserved human LDL at a temperature above phase transition (53°C) and examined the sample by electron microscopy and image reconstruction. The LDL frozen from 53°C adopted a different morphology. The central density layer was disrupted and the outer two layers formed a “disrupted shell”-shaped density, located concentrically underneath the surface density of the LDL particle. Simulation of the small angle X-ray scattering curves and comparison with published data suggested that this disrupted shell organization represents an intermediate state in the transition from isotropic to layered packing of the lipid. Thus, the results revealed, with 3D images, the lipid packing in the dynamic process of the LDL lipid-core phase transition.
Edge Loading Has a Paradoxical Effect on Wear in Metal-on-Polyethylene Total Hip Arthroplasties

Background Edge wear is an adverse factor that can negatively impact certain THAs. In some metal-on-metal THAs, it can lead to adverse tissue reactions including aseptic lymphocytic vasculitis-associated lesions and even to pseudotumor formation. In some ceramic-on-ceramic THAs, it can lead to squeaking and/or stripe wear. Edge wear in metal-on-metal and ceramic-on-ceramic THAs can also be associated with accelerated wear across the articulation of these joints.
High-resolution correlation in apparently monotonous rocks: upper Ordovician Kope Formation, Cincinnati Arch.

Abstract Short stratigraphic sections in apparently monotonous strata pose several challenges to high-resolution (<1 m) correlation. A lack of distinctive marker horizons can prevent obvious visual correlations between the sections. The stratigraphic shortness of the outcrops further reduces the likelihood of any given section having a recognizable marker horizon. The Upper Ordovician Kope Formation of the Cincinnati, Ohio, area exhibits both of these problems and correlation within the Kope has not been accomplished easily, to date. However, cross-correlation of meter-scale cycles in the Kope can be used to identify potential correlations of small outcrops to larger, well-described outcrops. If multiple correlations are equally plausible, large-scale faunal transitions among facies fossils can then be used to select the best correlation. In this pilot study, two sections separated by 9 km are correlated successfully using these methodologies, which show promise for the correlation of numerous outcrops in...
Deleterious Cognitive and Motoric Effects of Haloperidol in an Adolescent With Cerebral Palsy: A Case Report

This case report describes a 15-year-old male patient with spastic diplegic cerebral palsy, Gross Motor Function Classification System Level III, who developed severe new cognitive and motoric impairments after the administration of haloperidol. He received this dopamine antagonist and typical antipsychotic medication for an acute postoperative episode of agitation. He improved when he received the dopamine agonists amantadine and carbidopa/levodopa. This case suggests that dopamine blockade may be deleterious for individuals with cerebral palsy. Potential explanations for the events observed in this case are also presented.
Marital Relationships of Alcoholic, Conflicted, and Nonconflicted Couples.

Twenty-six couples with alcoholic husbands, and 26 maritally conflicted and 26 nonconflicted couples without alcohol problems were compared. As predicted, the alcoholic and maritally conflicted couples did not differ, and both groups of problem couples showed greater relationship distress than nonconflicted couples on measures of marital stability, change desired, and positive communication behaviors. Contrary to predictions, alcoholic couples were not unique with respect to struggles for control, a pattern of wife dominance, a responsibility-avoiding style of communication by the alcoholic husband, or impaired perceptual accuracy. Unexpectedly, alcoholic husbands reported less marital unhappiness than both their wives and maritally conflicted husbands on most of the self-report marital satisfaction measures.
Mechanical relaxation in polypropylene as a function of polymorphism and degree of lamella orientation

Mechanical relaxation data as a function of temperature (ca. 1 Hz) have been obtained for several samples of isotactic polypropylene crystallized from the melt, which exhibit both α and β forms as well as varying degrees of lamella orientation. The samples ranged in morphology from an unoriented sample showing only the α form to one highly oriented having approximately 90 per cent the β form. Results for the logarithmic decrement Δ and loss modulus G″ are that the low temperature (ca. −75°C) and glass temperature (ca. 0°C) relaxations show little or no sensitivity to orientation in the α form, but that the intensity of the two processes is different in the α form than in the β form for samples of nearly equal overall per cent crystallinity. In both Δ and G″, the low-temperature peak decreased and the glass temperature peak increased in intensity as the fraction of β form crystallinity present increased. Data for the high-temperature relaxation (ca. 80°C) indicate a dependence upon orientation and/or crystal form in addition to a dependence upon per cent crystallinity.
Frictional convergence, atmospheric convection, and causality

Frictional convergence in an atmospheric boundary layer topped by a stable free troposphere is considered. In agreement with extensive previous work, we find that atmospheric stability reduces the vertical scale of the free tropospheric secondary circulation associated with frictional convergence. Associated with this reduction in vertical scale is a proportional reduction in the time scale for the frictional spindown of an atmospheric circulation. This reduction in time scale alters the balance between terms in the component of the momentum equation along the isobars. In particular, for disturbance scales less than a few hundred kilometers in typical tropical conditions, the momentum tendency term comes into approximate balance with the friction term, with the Coriolis term becoming less important. This reduces the magnitude of the cross-isobaric flow and the strength of the ascent in regions where this flow converges. If some other mechanism such as moist convection produces enough boundary layer convergence to nullify the spindown of the disturbance in question, then the magnitude of the convergence equals that predicted by the steady-state frictional convergence formulation. However, in this case the arrow of causality is reversed from that assumed in a naive treatment of frictional convergence. Frictional convergence is not “causing” the convection; the convection is actually causing the convergence, and the mechanism forcing the convection must be sought elsewhere. This distinction is crucial in understanding what drives deep convection. The present analysis is linearized and the picture may change when nonlinear effects become important. It is also limited to situations in which the boundary layer winds are relatively weak. Tropical cyclones, with their strong winds and nonlinear behavior, thus deserve an independent analysis.
High temperature pulses decrease indirect chilling injury and elevate ATP levels in the flesh fly, Sarcophaga crassipalpis.

Abstract Indirect chilling injury commonly occurs during long-term exposure to low temperature in many organisms including insects. A previous study revealed increased rates of survival and reduced cold injury in flesh flies, Sarcophaga crassipalpis, that experienced an intermittent pulse of high temperature during a low-temperature regiment. We extended these studies by determining survival rates and ATP levels for flies that had undergone continuous long-term exposure at 0 °C versus those experiencing a 24-h warming pulse of either 15 or 20 °C. Survival among flies that had undergone a warming pulse was significantly greater than for flies that were maintained continuously at 0 °C. Furthermore, ATP levels of flies that had experienced a warming pulse were significantly higher than those of flies maintained at 0 °C. These data suggest that brief warming pulses during long-term cold storage allow regeneration of energy reserves that promote survival and reduce indirect chilling injury.
Recursive functions with implicit termination: a new approach illustrated by software-engineering examples

The author describes how the extended non-first-normal-form (ENFNF) data model in combination with a recursion mechanism based on functions with implicit termination is a promising vehicle for the database part of software engineering systems. Functions have been used primarily as a tool for implementing recursive queries. It is shown how dependencies between software objects can be modeled by objects of the ENFNF data model in a convenient and natural way. Moreover, arbitrary dependencies can be queried by functionally recursive queries in a natural way. Nevertheless, the method is not limited to software engineering systems. Implementation techniques are presented. >
Good Vibrations: Tactile Feedback in Support of Attention Allocation and Human-Automation Coordination in Event-Driven Domains

Observed breakdowns in human-machine communication can be explained, in part, by the nature of current automation feedback, which relies heavily on focal visual attention. Such feedback is not well suited for capturing attention in case of unexpected changes and events or for supporting the parallel processing of large amounts of data in complex domains. As suggested by multiple-resource theory, one possible solution to this problem is to distribute information across various sensory modalities. A simulator study was conducted to compare the effectiveness of visual, tactile, and redundant visual and tactile cues for indicating unexpected changes in the status of an automated cockpit system. Both tactile conditions resulted in higher detection rates for, and faster response times to, uncommanded mode transitions. Tactile feedback did not interfere with, nor was its effectiveness affected by, the performance of concurrent visual tasks. The observed improvement in task-sharing performance indicates that the introduction of tactile feedback is a promising avenue toward better supporting human-machine communication in event-driven, information-rich domains.
Complete controllability region of a dynamic N-bus power system model with bounded controls

In this paper the complete controllability of an N-bus power system model is analyzed. The controls in this model are bounded, which is consistent with the limited capacities of actual control devices. The complete controllability region refers to a subset of the power system state space in which any pair of states is mutually reachable using available controls. The result shows that the complete controllability region exists and contains an open set of the state space. The computational task is nontrivial for high dimensional systems. In actual power systems, the proposed controllability region provides a tool to identify a set of states where the power system is completely controllable given the control limits.
Feasibility of noninvasive analysis of lead in the human tibia by soft x-ray fluorescence.

A postmortem study was conducted to assess the feasibility of measuring bone lead concentrations noninvasively in vivo. Characteristic L x rays were induced with an external source of /sup 125/I in the superficial tibial cortex of the intact legs of six adults who had no history of occupational exposure to lead. Tibial lead concentrations in the same bones subsequently determined by flameless atomic absorption spectroscopy varied from 15 to 35 ..mu..g Pb/g wet weight. The upper limit for the modern normal range of lead in the bone is about 25 mg Pb/g wet tissue. The linear correlation coefficient (r) between the measurements made with x-ray fluorescence and lead concentration by absorption spectroscopy was 0.90. Radiation doses of 10 mGy (1 rad) to 1 cm/sup 2/ of skin, with associated doses to the marrow of adjacent bone of about 0.6 mGy (60 mrad), yielded net lead fluorescence signals ranging from one to seven times the standard deviation of background.
Preservation of femoral bone mass after total hip replacements with a lateral flare stem

Uncemented, porous-coated femoral stems rely on bone in-growth to achieve stable, long-lasting fixation. The loss of proximal femoral bone mass around hip stems has been traditionally termed “stress shielding” and has been linked to the transfer of loads to the diaphysis and the relative unloading of the proximal femur. A total of 10 total hip arthroplasties with a proximally coated lateral flare device designed to engage both cortices at the metaphyseal level were evaluated with dual-energy X-ray (DEXA) absorptiometry and qualitative radiographic changes 3 weeks after surgery and at 12, 24 and 52 weeks thereafter. All hips were radiologically stable. The DEXA measurements revealed an overall increase in the bone mineral density (BMD) at 52 weeks of 3%. Greater gains were observed at or below the lateral flare of the stem in the metaphyseal femur.
Limited Contribution of Humoral Immunity to the Clearance of Measles Viremia in Rhesus Monkeys

The development of an improved vaccine for controlling measles virus (MV) infections in the developing world will require an understanding of the immune mechanisms responsible for the clearance of this virus. To evaluate the role of humoral immunity in the containment of MV, rhesus monkeys were treated at the time of MV challenge with either anti-CD20 monoclonal antibody (MAb) infusion, to deplete B lymphocytes, or both anti-CD20 and anti-CD8 MAb, to deplete both B lymphocytes and CD8+ effector T lymphocytes. Although the MV-specific antibody response in CD20+ lymphocyte-depleted monkeys was delayed by >1 week, the kinetics of MV clearance did not differ from those for monkeys that received control MAb. Furthermore, unusual clinical sequelae of MV infection were not observed in these monkeys. In contrast, MV-infected rhesus monkeys depleted of both CD20+ and CD8+ lymphocytes had a prolonged duration of viremia and developed a desquamating skin rash. These findings indicate that humoral immunity plays a limited role in the control of MV replication in an MV-naive individual and suggest that new measles vaccination strategies should focus on the elicitation of cell-mediated immune responses, in addition to neutralizing antibodies, to facilitate rapid elimination of locally replicating virus.
Use of Proteases to Reduce Steep Time and SO2 Requirements in a Corn Wet-Milling Process

ABSTRACT To eliminate the diffusion barriers associated with enzyme addition during conventional steeping, we have developed a two-stage milling procedure to evaluate the effects of enzyme addition on corn wet milling. The current study compares the effects of the addition of commercially available enzyme preparations during conventional steeping to their comparable addition in the two-stage procedure. Results are presented in terms of yields of fiber, starch, germ, and gluten. The results demonstrate that the application of enzymes to the normal steeping step of wet milling is not an effective means of decreasing the steeping time or sulfur dioxide usage. Only when specific enzymes are added to the hydrated ground corn, using the modified two-stage procedure, are enzymes effective in decreasing the steeping time and sulfur dioxide requirements. The overall steeping time with the two-stage modified procedure ranges from 6 to 8 hr, representing a 67–83% reduction over the conventional process. The modified...
The effects of computer animation on the particulate mental models of college chemistry students

Modern chemistry concepts have the particulate nature of matter at their core. Chemists explain most phenomena in terms of atomic and molecular models. The lack of understanding of chemistry concepts may be linked to the students' inability to build complete mental models that visualize particulate behavior. With computer animation technology, dynamic and three-dimensional presentations are possible. This study explores the effect of computer animations depicting the particulate nature of matter on college students' mental models of the chemical phenomena. A Particulate Nature of Matter Evaluation Test (PNMET) instrument was used to determine the nature of the students' visualizations and, therefore, their comprehension of the chemical concept studied. Animations were used in two treatment situations: (a) as a supplement in large-group lectures, and (b) as both the lecture supplement and an assigned individual activity in a computer laboratory. These two experimental treatments were compared to a control group. Both treatment groups received significantly higher conceptual understanding scores on the PNMET than did the control group. This increased understanding may be due to the superiority of the formation of more expertlike, dynamic mental models of particle behavior in these chemical processes.
Design, Analysis, and Development of a Large Ka-Band Slot Array for Digital Beam-Forming Application

This paper discusses the design, analysis, and development of a large Ka-band slot array for digital beam-forming application. The array consists of 160 times 160 elements in 16 subarrays for producing 16 digital beams in the receive mode. Infinite array mutual coupling model has been employed in the design and analysis models. Challenges posed in meeting the pattern and return loss specifications because of manufacturing tolerances are discussed. Measured return loss and pattern characteristics of 10 times 40 slot array modules as well as results on a 1 m times 1 m demonstration array are presented.
Flexible servers in tandem lines with setup costs

We study the dynamic assignment of flexible servers to stations in the presence of setup costs that are incurred when servers move between stations. The goal is to maximize the long-run average profit. We provide a general problem formulation and some structural results, and then concentrate on tandem lines with two stations, two servers, and a finite buffer between the stations. We investigate how the optimal server assignment policy for such systems depends on the magnitude of the setup costs, as well as on the homogeneity of servers and tasks. More specifically, for systems with either homogeneous servers or homogeneous tasks, small buffer sizes, and constant setup cost, we prove the optimality of "multiple threshold" policies (where servers' movement between stations depends on both the number of jobs in the system and the locations of the servers) and determine the values of the thresholds. For systems with heterogeneous servers and tasks, small buffers, and constant setup cost, we provide results that partially characterize the optimal server assignment policy. Finally, for systems with larger buffer sizes and various service rate and setup cost configurations, we present structural results for the optimal policy and provide numerical results that strongly support the optimality of multiple threshold policies.